drivers/acpi/ec.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  ec.c - ACPI Embedded Controller Driver (v3)
   4  *
   5  *  Copyright (C) 2001-2015 Intel Corporation
   6  *    Author: 2014, 2015 Lv Zheng <[email protected]>
   7  *            2006, 2007 Alexey Starikovskiy <[email protected]>
   8  *            2006       Denis Sadykov <[email protected]>
   9  *            2004       Luming Yu <[email protected]>
  10  *            2001, 2002 Andy Grover <[email protected]>
  11  *            2001, 2002 Paul Diefenbaugh <[email protected]>
  12  *  Copyright (C) 2008      Alexey Starikovskiy <[email protected]>
  13  */
  14
  15 /* Uncomment next line to get verbose printout */
  16 /* #define DEBUG */
  17 #define pr_fmt(fmt) "ACPI: EC: " fmt
  18
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/init.h>
  22 #include <linux/types.h>
  23 #include <linux/delay.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/list.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/slab.h>
  28 #include <linux/suspend.h>
  29 #include <linux/acpi.h>
  30 #include <linux/dmi.h>
  31 #include <asm/io.h>
  32
  33 #include "internal.h"
  34
  35 #define ACPI_EC_CLASS                   "embedded_controller"
  36 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  37
  38 /* EC status register */
  39 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  40 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  41 #define ACPI_EC_FLAG_CMD        0x08    /* Input buffer contains a command */
  42 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  43 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  44
  45 /*
  46  * The SCI_EVT clearing timing is not defined by the ACPI specification.
  47  * This leads to lots of practical timing issues for the host EC driver.
  48  * The following variations are defined (from the target EC firmware's
  49  * perspective):
  50  * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
  51  *         target can clear SCI_EVT at any time so long as the host can see
  52  *         the indication by reading the status register (EC_SC). So the
  53  *         host should re-check SCI_EVT after the first time the SCI_EVT
  54  *         indication is seen, which is the same time the query request
  55  *         (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
  56  *         at any later time could indicate another event. Normally such
  57  *         kind of EC firmware has implemented an event queue and will
  58  *         return 0x00 to indicate "no outstanding event".
  59  * QUERY: After seeing the query request (QR_EC) written to the command
  60  *        register (EC_CMD) by the host and having prepared the responding
  61  *        event value in the data register (EC_DATA), the target can safely
  62  *        clear SCI_EVT because the target can confirm that the current
  63  *        event is being handled by the host. The host then should check
  64  *        SCI_EVT right after reading the event response from the data
  65  *        register (EC_DATA).
  66  * EVENT: After seeing the event response read from the data register
  67  *        (EC_DATA) by the host, the target can clear SCI_EVT. As the
  68  *        target requires time to notice the change in the data register
  69  *        (EC_DATA), the host may be required to wait additional guarding
  70  *        time before checking the SCI_EVT again. Such guarding may not be
  71  *        necessary if the host is notified via another IRQ.
  72  */
  73 #define ACPI_EC_EVT_TIMING_STATUS       0x00
  74 #define ACPI_EC_EVT_TIMING_QUERY        0x01
  75 #define ACPI_EC_EVT_TIMING_EVENT        0x02
  76
  77 /* EC commands */
  78 enum ec_command {
  79         ACPI_EC_COMMAND_READ = 0x80,
  80         ACPI_EC_COMMAND_WRITE = 0x81,
  81         ACPI_EC_BURST_ENABLE = 0x82,
  82         ACPI_EC_BURST_DISABLE = 0x83,
  83         ACPI_EC_COMMAND_QUERY = 0x84,
  84 };
  85
  86 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  87 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  88 #define ACPI_EC_UDELAY_POLL     550     /* Wait 1ms for EC transaction polling */
  89 #define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
  90                                          * when trying to clear the EC */
  91 #define ACPI_EC_MAX_QUERIES     16      /* Maximum number of parallel queries */
  92
  93 enum {
  94         EC_FLAGS_QUERY_ENABLED,         /* Query is enabled */
  95         EC_FLAGS_EVENT_HANDLER_INSTALLED,       /* Event handler installed */
  96         EC_FLAGS_EC_HANDLER_INSTALLED,  /* OpReg handler installed */
  97         EC_FLAGS_QUERY_METHODS_INSTALLED, /* _Qxx handlers installed */
  98         EC_FLAGS_STARTED,               /* Driver is started */
  99         EC_FLAGS_STOPPED,               /* Driver is stopped */
 100         EC_FLAGS_EVENTS_MASKED,         /* Events masked */
 101 };
 102
 103 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
 104 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
 105
 106 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 107 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 108 module_param(ec_delay, uint, 0644);
 109 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
 110
 111 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
 112 module_param(ec_max_queries, uint, 0644);
 113 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
 114
 115 static bool ec_busy_polling __read_mostly;
 116 module_param(ec_busy_polling, bool, 0644);
 117 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
 118
 119 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
 120 module_param(ec_polling_guard, uint, 0644);
 121 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
 122
 123 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
 124
 125 /*
 126  * If the number of false interrupts per one transaction exceeds
 127  * this threshold, will think there is a GPE storm happened and
 128  * will disable the GPE for normal transaction.
 129  */
 130 static unsigned int ec_storm_threshold  __read_mostly = 8;
 131 module_param(ec_storm_threshold, uint, 0644);
 132 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 133
 134 static bool ec_freeze_events __read_mostly;
 135 module_param(ec_freeze_events, bool, 0644);
 136 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
 137
 138 static bool ec_no_wakeup __read_mostly;
 139 module_param(ec_no_wakeup, bool, 0644);
 140 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
 141
 142 struct acpi_ec_query_handler {
 143         struct list_head node;
 144         acpi_ec_query_func func;
 145         acpi_handle handle;
 146         void *data;
 147         u8 query_bit;
 148         struct kref kref;
 149 };
 150
 151 struct transaction {
 152         const u8 *wdata;
 153         u8 *rdata;
 154         unsigned short irq_count;
 155         u8 command;
 156         u8 wi;
 157         u8 ri;
 158         u8 wlen;
 159         u8 rlen;
 160         u8 flags;
 161 };
 162
 163 struct acpi_ec_query {
 164         struct transaction transaction;
 165         struct work_struct work;
 166         struct acpi_ec_query_handler *handler;
 167         struct acpi_ec *ec;
 168 };
 169
 170 static int acpi_ec_submit_query(struct acpi_ec *ec);
 171 static bool advance_transaction(struct acpi_ec *ec, bool interrupt);
 172 static void acpi_ec_event_handler(struct work_struct *work);
 173
 174 struct acpi_ec *first_ec;
 175 EXPORT_SYMBOL(first_ec);
 176
 177 static struct acpi_ec *boot_ec;
 178 static bool boot_ec_is_ecdt;
 179 static struct workqueue_struct *ec_wq;
 180 static struct workqueue_struct *ec_query_wq;
 181
 182 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
 183 static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
 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 bool acpi_ec_submit_event(struct acpi_ec *ec)
 445 {
 446         acpi_ec_mask_events(ec);
 447         if (!acpi_ec_event_enabled(ec))
 448                 return false;
 449
 450         if (ec->event_state == EC_EVENT_READY) {
 451                 ec_dbg_evt("Command(%s) submitted/blocked",
 452                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 453
 454                 ec->event_state = EC_EVENT_IN_PROGRESS;
 455                 /*
 456                  * If events_to_process is greqter than 0 at this point, the
 457                  * while () loop in acpi_ec_event_handler() is still running
 458                  * and incrementing events_to_process will cause it to invoke
 459                  * acpi_ec_submit_query() once more, so it is not necessary to
 460                  * queue up the event work to start the same loop again.
 461                  */
 462                 if (ec->events_to_process++ > 0)
 463                         return true;
 464
 465                 ec->events_in_progress++;
 466                 return queue_work(ec_wq, &ec->work);
 467         }
 468
 469         /*
 470          * The event handling work has not been completed yet, so it needs to be
 471          * flushed.
 472          */
 473         return true;
 474 }
 475
 476 static void acpi_ec_complete_event(struct acpi_ec *ec)
 477 {
 478         if (ec->event_state == EC_EVENT_IN_PROGRESS)
 479                 ec->event_state = EC_EVENT_COMPLETE;
 480 }
 481
 482 static void acpi_ec_close_event(struct acpi_ec *ec)
 483 {
 484         if (ec->event_state != EC_EVENT_READY)
 485                 ec_dbg_evt("Command(%s) unblocked",
 486                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 487
 488         ec->event_state = EC_EVENT_READY;
 489         acpi_ec_unmask_events(ec);
 490 }
 491
 492 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
 493 {
 494         if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 495                 ec_log_drv("event unblocked");
 496         /*
 497          * Unconditionally invoke this once after enabling the event
 498          * handling mechanism to detect the pending events.
 499          */
 500         advance_transaction(ec, false);
 501 }
 502
 503 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
 504 {
 505         if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 506                 ec_log_drv("event blocked");
 507 }
 508
 509 /*
 510  * Process _Q events that might have accumulated in the EC.
 511  * Run with locked ec mutex.
 512  */
 513 static void acpi_ec_clear(struct acpi_ec *ec)
 514 {
 515         int i;
 516
 517         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 518                 if (acpi_ec_submit_query(ec))
 519                         break;
 520         }
 521         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 522                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 523         else
 524                 pr_info("%d stale EC events cleared\n", i);
 525 }
 526
 527 static void acpi_ec_enable_event(struct acpi_ec *ec)
 528 {
 529         unsigned long flags;
 530
 531         spin_lock_irqsave(&ec->lock, flags);
 532         if (acpi_ec_started(ec))
 533                 __acpi_ec_enable_event(ec);
 534         spin_unlock_irqrestore(&ec->lock, flags);
 535
 536         /* Drain additional events if hardware requires that */
 537         if (EC_FLAGS_CLEAR_ON_RESUME)
 538                 acpi_ec_clear(ec);
 539 }
 540
 541 #ifdef CONFIG_PM_SLEEP
 542 static void __acpi_ec_flush_work(void)
 543 {
 544         flush_workqueue(ec_wq); /* flush ec->work */
 545         flush_workqueue(ec_query_wq); /* flush queries */
 546 }
 547
 548 static void acpi_ec_disable_event(struct acpi_ec *ec)
 549 {
 550         unsigned long flags;
 551
 552         spin_lock_irqsave(&ec->lock, flags);
 553         __acpi_ec_disable_event(ec);
 554         spin_unlock_irqrestore(&ec->lock, flags);
 555
 556         /*
 557          * When ec_freeze_events is true, we need to flush events in
 558          * the proper position before entering the noirq stage.
 559          */
 560         __acpi_ec_flush_work();
 561 }
 562
 563 void acpi_ec_flush_work(void)
 564 {
 565         /* Without ec_wq there is nothing to flush. */
 566         if (!ec_wq)
 567                 return;
 568
 569         __acpi_ec_flush_work();
 570 }
 571 #endif /* CONFIG_PM_SLEEP */
 572
 573 static bool acpi_ec_guard_event(struct acpi_ec *ec)
 574 {
 575         unsigned long flags;
 576         bool guarded;
 577
 578         spin_lock_irqsave(&ec->lock, flags);
 579         /*
 580          * If firmware SCI_EVT clearing timing is "event", we actually
 581          * don't know when the SCI_EVT will be cleared by firmware after
 582          * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
 583          * acceptable period.
 584          *
 585          * The guarding period is applicable if the event state is not
 586          * EC_EVENT_READY, but otherwise if the current transaction is of the
 587          * ACPI_EC_COMMAND_QUERY type, the guarding should have elapsed already
 588          * and it should not be applied to let the transaction transition into
 589          * the ACPI_EC_COMMAND_POLL state immediately.
 590          */
 591         guarded = ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 592                 ec->event_state != EC_EVENT_READY &&
 593                 (!ec->curr || ec->curr->command != ACPI_EC_COMMAND_QUERY);
 594         spin_unlock_irqrestore(&ec->lock, flags);
 595         return guarded;
 596 }
 597
 598 static int ec_transaction_polled(struct acpi_ec *ec)
 599 {
 600         unsigned long flags;
 601         int ret = 0;
 602
 603         spin_lock_irqsave(&ec->lock, flags);
 604         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
 605                 ret = 1;
 606         spin_unlock_irqrestore(&ec->lock, flags);
 607         return ret;
 608 }
 609
 610 static int ec_transaction_completed(struct acpi_ec *ec)
 611 {
 612         unsigned long flags;
 613         int ret = 0;
 614
 615         spin_lock_irqsave(&ec->lock, flags);
 616         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 617                 ret = 1;
 618         spin_unlock_irqrestore(&ec->lock, flags);
 619         return ret;
 620 }
 621
 622 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
 623 {
 624         ec->curr->flags |= flag;
 625
 626         if (ec->curr->command != ACPI_EC_COMMAND_QUERY)
 627                 return;
 628
 629         switch (ec_event_clearing) {
 630         case ACPI_EC_EVT_TIMING_STATUS:
 631                 if (flag == ACPI_EC_COMMAND_POLL)
 632                         acpi_ec_close_event(ec);
 633
 634                 return;
 635
 636         case ACPI_EC_EVT_TIMING_QUERY:
 637                 if (flag == ACPI_EC_COMMAND_COMPLETE)
 638                         acpi_ec_close_event(ec);
 639
 640                 return;
 641
 642         case ACPI_EC_EVT_TIMING_EVENT:
 643                 if (flag == ACPI_EC_COMMAND_COMPLETE)
 644                         acpi_ec_complete_event(ec);
 645         }
 646 }
 647
 648 static void acpi_ec_spurious_interrupt(struct acpi_ec *ec, struct transaction *t)
 649 {
 650         if (t->irq_count < ec_storm_threshold)
 651                 ++t->irq_count;
 652
 653         /* Trigger if the threshold is 0 too. */
 654         if (t->irq_count == ec_storm_threshold)
 655                 acpi_ec_mask_events(ec);
 656 }
 657
 658 static bool advance_transaction(struct acpi_ec *ec, bool interrupt)
 659 {
 660         struct transaction *t = ec->curr;
 661         bool wakeup = false;
 662         bool ret = false;
 663         u8 status;
 664
 665         ec_dbg_stm("%s (%d)", interrupt ? "IRQ" : "TASK", smp_processor_id());
 666
 667         /*
 668          * Clear GPE_STS upfront to allow subsequent hardware GPE_STS 0->1
 669          * changes to always trigger a GPE interrupt.
 670          *
 671          * GPE STS is a W1C register, which means:
 672          *
 673          * 1. Software can clear it without worrying about clearing the other
 674          *    GPEs' STS bits when the hardware sets them in parallel.
 675          *
 676          * 2. As long as software can ensure only clearing it when it is set,
 677          *    hardware won't set it in parallel.
 678          */
 679         if (ec->gpe >= 0 && acpi_ec_gpe_status_set(ec))
 680                 acpi_clear_gpe(NULL, ec->gpe);
 681
 682         status = acpi_ec_read_status(ec);
 683
 684         /*
 685          * Another IRQ or a guarded polling mode advancement is detected,
 686          * the next QR_EC submission is then allowed.
 687          */
 688         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
 689                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 690                     ec->event_state == EC_EVENT_COMPLETE)
 691                         acpi_ec_close_event(ec);
 692
 693                 if (!t)
 694                         goto out;
 695         }
 696
 697         if (t->flags & ACPI_EC_COMMAND_POLL) {
 698                 if (t->wlen > t->wi) {
 699                         if (!(status & ACPI_EC_FLAG_IBF))
 700                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 701                         else if (interrupt && !(status & ACPI_EC_FLAG_SCI))
 702                                 acpi_ec_spurious_interrupt(ec, t);
 703                 } else if (t->rlen > t->ri) {
 704                         if (status & ACPI_EC_FLAG_OBF) {
 705                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 706                                 if (t->rlen == t->ri) {
 707                                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 708                                         wakeup = true;
 709                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 710                                                 ec_dbg_evt("Command(%s) completed by hardware",
 711                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 712                                 }
 713                         } else if (interrupt && !(status & ACPI_EC_FLAG_SCI)) {
 714                                 acpi_ec_spurious_interrupt(ec, t);
 715                         }
 716                 } else if (t->wlen == t->wi && !(status & ACPI_EC_FLAG_IBF)) {
 717                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 718                         wakeup = true;
 719                 }
 720         } else if (!(status & ACPI_EC_FLAG_IBF)) {
 721                 acpi_ec_write_cmd(ec, t->command);
 722                 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 723         }
 724
 725 out:
 726         if (status & ACPI_EC_FLAG_SCI)
 727                 ret = acpi_ec_submit_event(ec);
 728
 729         if (wakeup && interrupt)
 730                 wake_up(&ec->wait);
 731
 732         return ret;
 733 }
 734
 735 static void start_transaction(struct acpi_ec *ec)
 736 {
 737         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 738         ec->curr->flags = 0;
 739 }
 740
 741 static int ec_guard(struct acpi_ec *ec)
 742 {
 743         unsigned long guard = usecs_to_jiffies(ec->polling_guard);
 744         unsigned long timeout = ec->timestamp + guard;
 745
 746         /* Ensure guarding period before polling EC status */
 747         do {
 748                 if (ec->busy_polling) {
 749                         /* Perform busy polling */
 750                         if (ec_transaction_completed(ec))
 751                                 return 0;
 752                         udelay(jiffies_to_usecs(guard));
 753                 } else {
 754                         /*
 755                          * Perform wait polling
 756                          * 1. Wait the transaction to be completed by the
 757                          *    GPE handler after the transaction enters
 758                          *    ACPI_EC_COMMAND_POLL state.
 759                          * 2. A special guarding logic is also required
 760                          *    for event clearing mode "event" before the
 761                          *    transaction enters ACPI_EC_COMMAND_POLL
 762                          *    state.
 763                          */
 764                         if (!ec_transaction_polled(ec) &&
 765                             !acpi_ec_guard_event(ec))
 766                                 break;
 767                         if (wait_event_timeout(ec->wait,
 768                                                ec_transaction_completed(ec),
 769                                                guard))
 770                                 return 0;
 771                 }
 772         } while (time_before(jiffies, timeout));
 773         return -ETIME;
 774 }
 775
 776 static int ec_poll(struct acpi_ec *ec)
 777 {
 778         unsigned long flags;
 779         int repeat = 5; /* number of command restarts */
 780
 781         while (repeat--) {
 782                 unsigned long delay = jiffies +
 783                         msecs_to_jiffies(ec_delay);
 784                 do {
 785                         if (!ec_guard(ec))
 786                                 return 0;
 787                         spin_lock_irqsave(&ec->lock, flags);
 788                         advance_transaction(ec, false);
 789                         spin_unlock_irqrestore(&ec->lock, flags);
 790                 } while (time_before(jiffies, delay));
 791                 pr_debug("controller reset, restart transaction\n");
 792                 spin_lock_irqsave(&ec->lock, flags);
 793                 start_transaction(ec);
 794                 spin_unlock_irqrestore(&ec->lock, flags);
 795         }
 796         return -ETIME;
 797 }
 798
 799 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 800                                         struct transaction *t)
 801 {
 802         unsigned long tmp;
 803         int ret = 0;
 804
 805         /* start transaction */
 806         spin_lock_irqsave(&ec->lock, tmp);
 807         /* Enable GPE for command processing (IBF=0/OBF=1) */
 808         if (!acpi_ec_submit_flushable_request(ec)) {
 809                 ret = -EINVAL;
 810                 goto unlock;
 811         }
 812         ec_dbg_ref(ec, "Increase command");
 813         /* following two actions should be kept atomic */
 814         ec->curr = t;
 815         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 816         start_transaction(ec);
 817         spin_unlock_irqrestore(&ec->lock, tmp);
 818
 819         ret = ec_poll(ec);
 820
 821         spin_lock_irqsave(&ec->lock, tmp);
 822         if (t->irq_count == ec_storm_threshold)
 823                 acpi_ec_unmask_events(ec);
 824         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 825         ec->curr = NULL;
 826         /* Disable GPE for command processing (IBF=0/OBF=1) */
 827         acpi_ec_complete_request(ec);
 828         ec_dbg_ref(ec, "Decrease command");
 829 unlock:
 830         spin_unlock_irqrestore(&ec->lock, tmp);
 831         return ret;
 832 }
 833
 834 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 835 {
 836         int status;
 837         u32 glk;
 838
 839         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 840                 return -EINVAL;
 841         if (t->rdata)
 842                 memset(t->rdata, 0, t->rlen);
 843
 844         mutex_lock(&ec->mutex);
 845         if (ec->global_lock) {
 846                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 847                 if (ACPI_FAILURE(status)) {
 848                         status = -ENODEV;
 849                         goto unlock;
 850                 }
 851         }
 852
 853         status = acpi_ec_transaction_unlocked(ec, t);
 854
 855         if (ec->global_lock)
 856                 acpi_release_global_lock(glk);
 857 unlock:
 858         mutex_unlock(&ec->mutex);
 859         return status;
 860 }
 861
 862 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 863 {
 864         u8 d;
 865         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 866                                 .wdata = NULL, .rdata = &d,
 867                                 .wlen = 0, .rlen = 1};
 868
 869         return acpi_ec_transaction(ec, &t);
 870 }
 871
 872 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 873 {
 874         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 875                                 .wdata = NULL, .rdata = NULL,
 876                                 .wlen = 0, .rlen = 0};
 877
 878         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 879                                 acpi_ec_transaction(ec, &t) : 0;
 880 }
 881
 882 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 883 {
 884         int result;
 885         u8 d;
 886         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 887                                 .wdata = &address, .rdata = &d,
 888                                 .wlen = 1, .rlen = 1};
 889
 890         result = acpi_ec_transaction(ec, &t);
 891         *data = d;
 892         return result;
 893 }
 894
 895 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 896 {
 897         u8 wdata[2] = { address, data };
 898         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 899                                 .wdata = wdata, .rdata = NULL,
 900                                 .wlen = 2, .rlen = 0};
 901
 902         return acpi_ec_transaction(ec, &t);
 903 }
 904
 905 int ec_read(u8 addr, u8 *val)
 906 {
 907         int err;
 908         u8 temp_data;
 909
 910         if (!first_ec)
 911                 return -ENODEV;
 912
 913         err = acpi_ec_read(first_ec, addr, &temp_data);
 914
 915         if (!err) {
 916                 *val = temp_data;
 917                 return 0;
 918         }
 919         return err;
 920 }
 921 EXPORT_SYMBOL(ec_read);
 922
 923 int ec_write(u8 addr, u8 val)
 924 {
 925         int err;
 926
 927         if (!first_ec)
 928                 return -ENODEV;
 929
 930         err = acpi_ec_write(first_ec, addr, val);
 931
 932         return err;
 933 }
 934 EXPORT_SYMBOL(ec_write);
 935
 936 int ec_transaction(u8 command,
 937                    const u8 *wdata, unsigned wdata_len,
 938                    u8 *rdata, unsigned rdata_len)
 939 {
 940         struct transaction t = {.command = command,
 941                                 .wdata = wdata, .rdata = rdata,
 942                                 .wlen = wdata_len, .rlen = rdata_len};
 943
 944         if (!first_ec)
 945                 return -ENODEV;
 946
 947         return acpi_ec_transaction(first_ec, &t);
 948 }
 949 EXPORT_SYMBOL(ec_transaction);
 950
 951 /* Get the handle to the EC device */
 952 acpi_handle ec_get_handle(void)
 953 {
 954         if (!first_ec)
 955                 return NULL;
 956         return first_ec->handle;
 957 }
 958 EXPORT_SYMBOL(ec_get_handle);
 959
 960 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 961 {
 962         unsigned long flags;
 963
 964         spin_lock_irqsave(&ec->lock, flags);
 965         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 966                 ec_dbg_drv("Starting EC");
 967                 /* Enable GPE for event processing (SCI_EVT=1) */
 968                 if (!resuming) {
 969                         acpi_ec_submit_request(ec);
 970                         ec_dbg_ref(ec, "Increase driver");
 971                 }
 972                 ec_log_drv("EC started");
 973         }
 974         spin_unlock_irqrestore(&ec->lock, flags);
 975 }
 976
 977 static bool acpi_ec_stopped(struct acpi_ec *ec)
 978 {
 979         unsigned long flags;
 980         bool flushed;
 981
 982         spin_lock_irqsave(&ec->lock, flags);
 983         flushed = acpi_ec_flushed(ec);
 984         spin_unlock_irqrestore(&ec->lock, flags);
 985         return flushed;
 986 }
 987
 988 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 989 {
 990         unsigned long flags;
 991
 992         spin_lock_irqsave(&ec->lock, flags);
 993         if (acpi_ec_started(ec)) {
 994                 ec_dbg_drv("Stopping EC");
 995                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
 996                 spin_unlock_irqrestore(&ec->lock, flags);
 997                 wait_event(ec->wait, acpi_ec_stopped(ec));
 998                 spin_lock_irqsave(&ec->lock, flags);
 999                 /* Disable GPE for event processing (SCI_EVT=1) */
1000                 if (!suspending) {
1001                         acpi_ec_complete_request(ec);
1002                         ec_dbg_ref(ec, "Decrease driver");
1003                 } else if (!ec_freeze_events)
1004                         __acpi_ec_disable_event(ec);
1005                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
1006                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
1007                 ec_log_drv("EC stopped");
1008         }
1009         spin_unlock_irqrestore(&ec->lock, flags);
1010 }
1011
1012 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
1013 {
1014         unsigned long flags;
1015
1016         spin_lock_irqsave(&ec->lock, flags);
1017         ec->busy_polling = true;
1018         ec->polling_guard = 0;
1019         ec_log_drv("interrupt blocked");
1020         spin_unlock_irqrestore(&ec->lock, flags);
1021 }
1022
1023 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1024 {
1025         unsigned long flags;
1026
1027         spin_lock_irqsave(&ec->lock, flags);
1028         ec->busy_polling = ec_busy_polling;
1029         ec->polling_guard = ec_polling_guard;
1030         ec_log_drv("interrupt unblocked");
1031         spin_unlock_irqrestore(&ec->lock, flags);
1032 }
1033
1034 void acpi_ec_block_transactions(void)
1035 {
1036         struct acpi_ec *ec = first_ec;
1037
1038         if (!ec)
1039                 return;
1040
1041         mutex_lock(&ec->mutex);
1042         /* Prevent transactions from being carried out */
1043         acpi_ec_stop(ec, true);
1044         mutex_unlock(&ec->mutex);
1045 }
1046
1047 void acpi_ec_unblock_transactions(void)
1048 {
1049         /*
1050          * Allow transactions to happen again (this function is called from
1051          * atomic context during wakeup, so we don't need to acquire the mutex).
1052          */
1053         if (first_ec)
1054                 acpi_ec_start(first_ec, true);
1055 }
1056
1057 /* --------------------------------------------------------------------------
1058                                 Event Management
1059    -------------------------------------------------------------------------- */
1060 static struct acpi_ec_query_handler *
1061 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1062 {
1063         struct acpi_ec_query_handler *handler;
1064
1065         mutex_lock(&ec->mutex);
1066         list_for_each_entry(handler, &ec->list, node) {
1067                 if (value == handler->query_bit) {
1068                         kref_get(&handler->kref);
1069                         mutex_unlock(&ec->mutex);
1070                         return handler;
1071                 }
1072         }
1073         mutex_unlock(&ec->mutex);
1074         return NULL;
1075 }
1076
1077 static void acpi_ec_query_handler_release(struct kref *kref)
1078 {
1079         struct acpi_ec_query_handler *handler =
1080                 container_of(kref, struct acpi_ec_query_handler, kref);
1081
1082         kfree(handler);
1083 }
1084
1085 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1086 {
1087         kref_put(&handler->kref, acpi_ec_query_handler_release);
1088 }
1089
1090 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1091                               acpi_handle handle, acpi_ec_query_func func,
1092                               void *data)
1093 {
1094         struct acpi_ec_query_handler *handler =
1095             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1096
1097         if (!handler)
1098                 return -ENOMEM;
1099
1100         handler->query_bit = query_bit;
1101         handler->handle = handle;
1102         handler->func = func;
1103         handler->data = data;
1104         mutex_lock(&ec->mutex);
1105         kref_init(&handler->kref);
1106         list_add(&handler->node, &ec->list);
1107         mutex_unlock(&ec->mutex);
1108         return 0;
1109 }
1110 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1111
1112 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1113                                           bool remove_all, u8 query_bit)
1114 {
1115         struct acpi_ec_query_handler *handler, *tmp;
1116         LIST_HEAD(free_list);
1117
1118         mutex_lock(&ec->mutex);
1119         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1120                 if (remove_all || query_bit == handler->query_bit) {
1121                         list_del_init(&handler->node);
1122                         list_add(&handler->node, &free_list);
1123                 }
1124         }
1125         mutex_unlock(&ec->mutex);
1126         list_for_each_entry_safe(handler, tmp, &free_list, node)
1127                 acpi_ec_put_query_handler(handler);
1128 }
1129
1130 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1131 {
1132         acpi_ec_remove_query_handlers(ec, false, query_bit);
1133 }
1134 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1135
1136 static void acpi_ec_event_processor(struct work_struct *work)
1137 {
1138         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1139         struct acpi_ec_query_handler *handler = q->handler;
1140         struct acpi_ec *ec = q->ec;
1141
1142         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1143
1144         if (handler->func)
1145                 handler->func(handler->data);
1146         else if (handler->handle)
1147                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1148
1149         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1150
1151         spin_lock_irq(&ec->lock);
1152         ec->queries_in_progress--;
1153         spin_unlock_irq(&ec->lock);
1154
1155         acpi_ec_put_query_handler(handler);
1156         kfree(q);
1157 }
1158
1159 static struct acpi_ec_query *acpi_ec_create_query(struct acpi_ec *ec, u8 *pval)
1160 {
1161         struct acpi_ec_query *q;
1162         struct transaction *t;
1163
1164         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1165         if (!q)
1166                 return NULL;
1167
1168         INIT_WORK(&q->work, acpi_ec_event_processor);
1169         t = &q->transaction;
1170         t->command = ACPI_EC_COMMAND_QUERY;
1171         t->rdata = pval;
1172         t->rlen = 1;
1173         q->ec = ec;
1174         return q;
1175 }
1176
1177 static int acpi_ec_submit_query(struct acpi_ec *ec)
1178 {
1179         struct acpi_ec_query *q;
1180         u8 value = 0;
1181         int result;
1182
1183         q = acpi_ec_create_query(ec, &value);
1184         if (!q)
1185                 return -ENOMEM;
1186
1187         /*
1188          * Query the EC to find out which _Qxx method we need to evaluate.
1189          * Note that successful completion of the query causes the ACPI_EC_SCI
1190          * bit to be cleared (and thus clearing the interrupt source).
1191          */
1192         result = acpi_ec_transaction(ec, &q->transaction);
1193         if (result)
1194                 goto err_exit;
1195
1196         if (!value) {
1197                 result = -ENODATA;
1198                 goto err_exit;
1199         }
1200
1201         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1202         if (!q->handler) {
1203                 result = -ENODATA;
1204                 goto err_exit;
1205         }
1206
1207         /*
1208          * It is reported that _Qxx are evaluated in a parallel way on Windows:
1209          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1210          *
1211          * Put this log entry before queue_work() to make it appear in the log
1212          * before any other messages emitted during workqueue handling.
1213          */
1214         ec_dbg_evt("Query(0x%02x) scheduled", value);
1215
1216         spin_lock_irq(&ec->lock);
1217
1218         ec->queries_in_progress++;
1219         queue_work(ec_query_wq, &q->work);
1220
1221         spin_unlock_irq(&ec->lock);
1222
1223         return 0;
1224
1225 err_exit:
1226         kfree(q);
1227
1228         return result;
1229 }
1230
1231 static void acpi_ec_event_handler(struct work_struct *work)
1232 {
1233         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1234
1235         ec_dbg_evt("Event started");
1236
1237         spin_lock_irq(&ec->lock);
1238
1239         while (ec->events_to_process) {
1240                 spin_unlock_irq(&ec->lock);
1241
1242                 acpi_ec_submit_query(ec);
1243
1244                 spin_lock_irq(&ec->lock);
1245                 ec->events_to_process--;
1246         }
1247
1248         /*
1249          * Before exit, make sure that the it will be possible to queue up the
1250          * event handling work again regardless of whether or not the query
1251          * queued up above is processed successfully.
1252          */
1253         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT)
1254                 acpi_ec_complete_event(ec);
1255         else
1256                 acpi_ec_close_event(ec);
1257
1258         spin_unlock_irq(&ec->lock);
1259
1260         ec_dbg_evt("Event stopped");
1261
1262         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT && ec_guard(ec)) {
1263                 spin_lock_irq(&ec->lock);
1264
1265                 /* Take care of SCI_EVT unless someone else is doing that. */
1266                 if (!ec->curr)
1267                         advance_transaction(ec, false);
1268
1269                 spin_unlock_irq(&ec->lock);
1270         }
1271
1272         spin_lock_irq(&ec->lock);
1273         ec->events_in_progress--;
1274         spin_unlock_irq(&ec->lock);
1275 }
1276
1277 static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1278 {
1279         unsigned long flags;
1280
1281         spin_lock_irqsave(&ec->lock, flags);
1282         advance_transaction(ec, true);
1283         spin_unlock_irqrestore(&ec->lock, flags);
1284 }
1285
1286 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1287                                u32 gpe_number, void *data)
1288 {
1289         acpi_ec_handle_interrupt(data);
1290         return ACPI_INTERRUPT_HANDLED;
1291 }
1292
1293 static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1294 {
1295         acpi_ec_handle_interrupt(data);
1296         return IRQ_HANDLED;
1297 }
1298
1299 /* --------------------------------------------------------------------------
1300  *                           Address Space Management
1301  * -------------------------------------------------------------------------- */
1302
1303 static acpi_status
1304 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1305                       u32 bits, u64 *value64,
1306                       void *handler_context, void *region_context)
1307 {
1308         struct acpi_ec *ec = handler_context;
1309         int result = 0, i, bytes = bits / 8;
1310         u8 *value = (u8 *)value64;
1311
1312         if ((address > 0xFF) || !value || !handler_context)
1313                 return AE_BAD_PARAMETER;
1314
1315         if (function != ACPI_READ && function != ACPI_WRITE)
1316                 return AE_BAD_PARAMETER;
1317
1318         if (ec->busy_polling || bits > 8)
1319                 acpi_ec_burst_enable(ec);
1320
1321         for (i = 0; i < bytes; ++i, ++address, ++value)
1322                 result = (function == ACPI_READ) ?
1323                         acpi_ec_read(ec, address, value) :
1324                         acpi_ec_write(ec, address, *value);
1325
1326         if (ec->busy_polling || bits > 8)
1327                 acpi_ec_burst_disable(ec);
1328
1329         switch (result) {
1330         case -EINVAL:
1331                 return AE_BAD_PARAMETER;
1332         case -ENODEV:
1333                 return AE_NOT_FOUND;
1334         case -ETIME:
1335                 return AE_TIME;
1336         default:
1337                 return AE_OK;
1338         }
1339 }
1340
1341 /* --------------------------------------------------------------------------
1342  *                             Driver Interface
1343  * -------------------------------------------------------------------------- */
1344
1345 static acpi_status
1346 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1347
1348 static void acpi_ec_free(struct acpi_ec *ec)
1349 {
1350         if (first_ec == ec)
1351                 first_ec = NULL;
1352         if (boot_ec == ec)
1353                 boot_ec = NULL;
1354         kfree(ec);
1355 }
1356
1357 static struct acpi_ec *acpi_ec_alloc(void)
1358 {
1359         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1360
1361         if (!ec)
1362                 return NULL;
1363         mutex_init(&ec->mutex);
1364         init_waitqueue_head(&ec->wait);
1365         INIT_LIST_HEAD(&ec->list);
1366         spin_lock_init(&ec->lock);
1367         INIT_WORK(&ec->work, acpi_ec_event_handler);
1368         ec->timestamp = jiffies;
1369         ec->busy_polling = true;
1370         ec->polling_guard = 0;
1371         ec->gpe = -1;
1372         ec->irq = -1;
1373         return ec;
1374 }
1375
1376 static acpi_status
1377 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1378                                void *context, void **return_value)
1379 {
1380         char node_name[5];
1381         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1382         struct acpi_ec *ec = context;
1383         int value = 0;
1384         acpi_status status;
1385
1386         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1387
1388         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1389                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1390         return AE_OK;
1391 }
1392
1393 static acpi_status
1394 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1395 {
1396         acpi_status status;
1397         unsigned long long tmp = 0;
1398         struct acpi_ec *ec = context;
1399
1400         /* clear addr values, ec_parse_io_ports depend on it */
1401         ec->command_addr = ec->data_addr = 0;
1402
1403         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1404                                      ec_parse_io_ports, ec);
1405         if (ACPI_FAILURE(status))
1406                 return status;
1407         if (ec->data_addr == 0 || ec->command_addr == 0)
1408                 return AE_OK;
1409
1410         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1411                 /*
1412                  * Always inherit the GPE number setting from the ECDT
1413                  * EC.
1414                  */
1415                 ec->gpe = boot_ec->gpe;
1416         } else {
1417                 /* Get GPE bit assignment (EC events). */
1418                 /* TODO: Add support for _GPE returning a package */
1419                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1420                 if (ACPI_SUCCESS(status))
1421                         ec->gpe = tmp;
1422
1423                 /*
1424                  * Errors are non-fatal, allowing for ACPI Reduced Hardware
1425                  * platforms which use GpioInt instead of GPE.
1426                  */
1427         }
1428         /* Use the global lock for all EC transactions? */
1429         tmp = 0;
1430         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1431         ec->global_lock = tmp;
1432         ec->handle = handle;
1433         return AE_CTRL_TERMINATE;
1434 }
1435
1436 static bool install_gpe_event_handler(struct acpi_ec *ec)
1437 {
1438         acpi_status status;
1439
1440         status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1441                                               ACPI_GPE_EDGE_TRIGGERED,
1442                                               &acpi_ec_gpe_handler, ec);
1443         if (ACPI_FAILURE(status))
1444                 return false;
1445
1446         if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1447                 acpi_ec_enable_gpe(ec, true);
1448
1449         return true;
1450 }
1451
1452 static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1453 {
1454         return request_irq(ec->irq, acpi_ec_irq_handler, IRQF_SHARED,
1455                            "ACPI EC", ec) >= 0;
1456 }
1457
1458 /**
1459  * ec_install_handlers - Install service callbacks and register query methods.
1460  * @ec: Target EC.
1461  * @device: ACPI device object corresponding to @ec.
1462  *
1463  * Install a handler for the EC address space type unless it has been installed
1464  * already.  If @device is not NULL, also look for EC query methods in the
1465  * namespace and register them, and install an event (either GPE or GPIO IRQ)
1466  * handler for the EC, if possible.
1467  *
1468  * Return:
1469  * -ENODEV if the address space handler cannot be installed, which means
1470  *  "unable to handle transactions",
1471  * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1472  * or 0 (success) otherwise.
1473  */
1474 static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device)
1475 {
1476         acpi_status status;
1477
1478         acpi_ec_start(ec, false);
1479
1480         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1481                 acpi_ec_enter_noirq(ec);
1482                 status = acpi_install_address_space_handler(ec->handle,
1483                                                             ACPI_ADR_SPACE_EC,
1484                                                             &acpi_ec_space_handler,
1485                                                             NULL, ec);
1486                 if (ACPI_FAILURE(status)) {
1487                         acpi_ec_stop(ec, false);
1488                         return -ENODEV;
1489                 }
1490                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1491         }
1492
1493         if (!device)
1494                 return 0;
1495
1496         if (ec->gpe < 0) {
1497                 /* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1498                 int irq = acpi_dev_gpio_irq_get(device, 0);
1499                 /*
1500                  * Bail out right away for deferred probing or complete the
1501                  * initialization regardless of any other errors.
1502                  */
1503                 if (irq == -EPROBE_DEFER)
1504                         return -EPROBE_DEFER;
1505                 else if (irq >= 0)
1506                         ec->irq = irq;
1507         }
1508
1509         if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1510                 /* Find and register all query methods */
1511                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1512                                     acpi_ec_register_query_methods,
1513                                     NULL, ec, NULL);
1514                 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1515         }
1516         if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1517                 bool ready = false;
1518
1519                 if (ec->gpe >= 0)
1520                         ready = install_gpe_event_handler(ec);
1521                 else if (ec->irq >= 0)
1522                         ready = install_gpio_irq_event_handler(ec);
1523
1524                 if (ready) {
1525                         set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1526                         acpi_ec_leave_noirq(ec);
1527                 }
1528                 /*
1529                  * Failures to install an event handler are not fatal, because
1530                  * the EC can be polled for events.
1531                  */
1532         }
1533         /* EC is fully operational, allow queries */
1534         acpi_ec_enable_event(ec);
1535
1536         return 0;
1537 }
1538
1539 static void ec_remove_handlers(struct acpi_ec *ec)
1540 {
1541         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1542                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1543                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1544                         pr_err("failed to remove space handler\n");
1545                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1546         }
1547
1548         /*
1549          * Stops handling the EC transactions after removing the operation
1550          * region handler. This is required because _REG(DISCONNECT)
1551          * invoked during the removal can result in new EC transactions.
1552          *
1553          * Flushes the EC requests and thus disables the GPE before
1554          * removing the GPE handler. This is required by the current ACPICA
1555          * GPE core. ACPICA GPE core will automatically disable a GPE when
1556          * it is indicated but there is no way to handle it. So the drivers
1557          * must disable the GPEs prior to removing the GPE handlers.
1558          */
1559         acpi_ec_stop(ec, false);
1560
1561         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1562                 if (ec->gpe >= 0 &&
1563                     ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1564                                  &acpi_ec_gpe_handler)))
1565                         pr_err("failed to remove gpe handler\n");
1566
1567                 if (ec->irq >= 0)
1568                         free_irq(ec->irq, ec);
1569
1570                 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1571         }
1572         if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1573                 acpi_ec_remove_query_handlers(ec, true, 0);
1574                 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1575         }
1576 }
1577
1578 static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device)
1579 {
1580         int ret;
1581
1582         ret = ec_install_handlers(ec, device);
1583         if (ret)
1584                 return ret;
1585
1586         /* First EC capable of handling transactions */
1587         if (!first_ec)
1588                 first_ec = ec;
1589
1590         pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1591                 ec->data_addr);
1592
1593         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1594                 if (ec->gpe >= 0)
1595                         pr_info("GPE=0x%x\n", ec->gpe);
1596                 else
1597                         pr_info("IRQ=%d\n", ec->irq);
1598         }
1599
1600         return ret;
1601 }
1602
1603 static int acpi_ec_add(struct acpi_device *device)
1604 {
1605         struct acpi_ec *ec;
1606         int ret;
1607
1608         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1609         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1610
1611         if (boot_ec && (boot_ec->handle == device->handle ||
1612             !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
1613                 /* Fast path: this device corresponds to the boot EC. */
1614                 ec = boot_ec;
1615         } else {
1616                 acpi_status status;
1617
1618                 ec = acpi_ec_alloc();
1619                 if (!ec)
1620                         return -ENOMEM;
1621
1622                 status = ec_parse_device(device->handle, 0, ec, NULL);
1623                 if (status != AE_CTRL_TERMINATE) {
1624                         ret = -EINVAL;
1625                         goto err;
1626                 }
1627
1628                 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1629                     ec->data_addr == boot_ec->data_addr &&
1630                     !EC_FLAGS_TRUST_DSDT_GPE) {
1631                         /*
1632                          * Trust PNP0C09 namespace location rather than
1633                          * ECDT ID. But trust ECDT GPE rather than _GPE
1634                          * because of ASUS quirks, so do not change
1635                          * boot_ec->gpe to ec->gpe.
1636                          */
1637                         boot_ec->handle = ec->handle;
1638                         acpi_handle_debug(ec->handle, "duplicated.\n");
1639                         acpi_ec_free(ec);
1640                         ec = boot_ec;
1641                 }
1642         }
1643
1644         ret = acpi_ec_setup(ec, device);
1645         if (ret)
1646                 goto err;
1647
1648         if (ec == boot_ec)
1649                 acpi_handle_info(boot_ec->handle,
1650                                  "Boot %s EC initialization complete\n",
1651                                  boot_ec_is_ecdt ? "ECDT" : "DSDT");
1652
1653         acpi_handle_info(ec->handle,
1654                          "EC: Used to handle transactions and events\n");
1655
1656         device->driver_data = ec;
1657
1658         ret = !!request_region(ec->data_addr, 1, "EC data");
1659         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1660         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1661         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1662
1663         /* Reprobe devices depending on the EC */
1664         acpi_dev_clear_dependencies(device);
1665
1666         acpi_handle_debug(ec->handle, "enumerated.\n");
1667         return 0;
1668
1669 err:
1670         if (ec != boot_ec)
1671                 acpi_ec_free(ec);
1672
1673         return ret;
1674 }
1675
1676 static int acpi_ec_remove(struct acpi_device *device)
1677 {
1678         struct acpi_ec *ec;
1679
1680         if (!device)
1681                 return -EINVAL;
1682
1683         ec = acpi_driver_data(device);
1684         release_region(ec->data_addr, 1);
1685         release_region(ec->command_addr, 1);
1686         device->driver_data = NULL;
1687         if (ec != boot_ec) {
1688                 ec_remove_handlers(ec);
1689                 acpi_ec_free(ec);
1690         }
1691         return 0;
1692 }
1693
1694 static acpi_status
1695 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1696 {
1697         struct acpi_ec *ec = context;
1698
1699         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1700                 return AE_OK;
1701
1702         /*
1703          * The first address region returned is the data port, and
1704          * the second address region returned is the status/command
1705          * port.
1706          */
1707         if (ec->data_addr == 0)
1708                 ec->data_addr = resource->data.io.minimum;
1709         else if (ec->command_addr == 0)
1710                 ec->command_addr = resource->data.io.minimum;
1711         else
1712                 return AE_CTRL_TERMINATE;
1713
1714         return AE_OK;
1715 }
1716
1717 static const struct acpi_device_id ec_device_ids[] = {
1718         {"PNP0C09", 0},
1719         {ACPI_ECDT_HID, 0},
1720         {"", 0},
1721 };
1722
1723 /*
1724  * This function is not Windows-compatible as Windows never enumerates the
1725  * namespace EC before the main ACPI device enumeration process. It is
1726  * retained for historical reason and will be deprecated in the future.
1727  */
1728 void __init acpi_ec_dsdt_probe(void)
1729 {
1730         struct acpi_ec *ec;
1731         acpi_status status;
1732         int ret;
1733
1734         /*
1735          * If a platform has ECDT, there is no need to proceed as the
1736          * following probe is not a part of the ACPI device enumeration,
1737          * executing _STA is not safe, and thus this probe may risk of
1738          * picking up an invalid EC device.
1739          */
1740         if (boot_ec)
1741                 return;
1742
1743         ec = acpi_ec_alloc();
1744         if (!ec)
1745                 return;
1746
1747         /*
1748          * At this point, the namespace is initialized, so start to find
1749          * the namespace objects.
1750          */
1751         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1752         if (ACPI_FAILURE(status) || !ec->handle) {
1753                 acpi_ec_free(ec);
1754                 return;
1755         }
1756
1757         /*
1758          * When the DSDT EC is available, always re-configure boot EC to
1759          * have _REG evaluated. _REG can only be evaluated after the
1760          * namespace initialization.
1761          * At this point, the GPE is not fully initialized, so do not to
1762          * handle the events.
1763          */
1764         ret = acpi_ec_setup(ec, NULL);
1765         if (ret) {
1766                 acpi_ec_free(ec);
1767                 return;
1768         }
1769
1770         boot_ec = ec;
1771
1772         acpi_handle_info(ec->handle,
1773                          "Boot DSDT EC used to handle transactions\n");
1774 }
1775
1776 /*
1777  * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization.
1778  *
1779  * First, look for an ACPI handle for the boot ECDT EC if acpi_ec_add() has not
1780  * found a matching object in the namespace.
1781  *
1782  * Next, in case the DSDT EC is not functioning, it is still necessary to
1783  * provide a functional ECDT EC to handle events, so add an extra device object
1784  * to represent it (see https://bugzilla.kernel.org/show_bug.cgi?id=115021).
1785  *
1786  * This is useful on platforms with valid ECDT and invalid DSDT EC settings,
1787  * like ASUS X550ZE (see https://bugzilla.kernel.org/show_bug.cgi?id=196847).
1788  */
1789 static void __init acpi_ec_ecdt_start(void)
1790 {
1791         struct acpi_table_ecdt *ecdt_ptr;
1792         acpi_handle handle;
1793         acpi_status status;
1794
1795         /* Bail out if a matching EC has been found in the namespace. */
1796         if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT)
1797                 return;
1798
1799         /* Look up the object pointed to from the ECDT in the namespace. */
1800         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1801                                 (struct acpi_table_header **)&ecdt_ptr);
1802         if (ACPI_FAILURE(status))
1803                 return;
1804
1805         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1806         if (ACPI_SUCCESS(status)) {
1807                 boot_ec->handle = handle;
1808
1809                 /* Add a special ACPI device object to represent the boot EC. */
1810                 acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1811         }
1812
1813         acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1814 }
1815
1816 /*
1817  * On some hardware it is necessary to clear events accumulated by the EC during
1818  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1819  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1820  *
1821  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1822  *
1823  * Ideally, the EC should also be instructed NOT to accumulate events during
1824  * sleep (which Windows seems to do somehow), but the interface to control this
1825  * behaviour is not known at this time.
1826  *
1827  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1828  * however it is very likely that other Samsung models are affected.
1829  *
1830  * On systems which don't accumulate _Q events during sleep, this extra check
1831  * should be harmless.
1832  */
1833 static int ec_clear_on_resume(const struct dmi_system_id *id)
1834 {
1835         pr_debug("Detected system needing EC poll on resume.\n");
1836         EC_FLAGS_CLEAR_ON_RESUME = 1;
1837         ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1838         return 0;
1839 }
1840
1841 /*
1842  * Some ECDTs contain wrong register addresses.
1843  * MSI MS-171F
1844  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1845  */
1846 static int ec_correct_ecdt(const struct dmi_system_id *id)
1847 {
1848         pr_debug("Detected system needing ECDT address correction.\n");
1849         EC_FLAGS_CORRECT_ECDT = 1;
1850         return 0;
1851 }
1852
1853 /*
1854  * Some ECDTs contain wrong GPE setting, but they share the same port addresses
1855  * with DSDT EC, don't duplicate the DSDT EC with ECDT EC in this case.
1856  * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1857  */
1858 static int ec_honor_dsdt_gpe(const struct dmi_system_id *id)
1859 {
1860         pr_debug("Detected system needing DSDT GPE setting.\n");
1861         EC_FLAGS_TRUST_DSDT_GPE = 1;
1862         return 0;
1863 }
1864
1865 /*
1866  * Some DSDTs contain wrong GPE setting.
1867  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1868  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1869  */
1870 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1871 {
1872         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1873         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1874         return 0;
1875 }
1876
1877 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1878         {
1879         ec_correct_ecdt, "MSI MS-171F", {
1880         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1881         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1882         {
1883         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1884         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1885         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1886         {
1887         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1888         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1889         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1890         {
1891         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1892         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1893         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1894         {
1895         ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X505BA", {
1896         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1897         DMI_MATCH(DMI_PRODUCT_NAME, "X505BA"),}, NULL},
1898         {
1899         ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X505BP", {
1900         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1901         DMI_MATCH(DMI_PRODUCT_NAME, "X505BP"),}, NULL},
1902         {
1903         ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X542BA", {
1904         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1905         DMI_MATCH(DMI_PRODUCT_NAME, "X542BA"),}, NULL},
1906         {
1907         ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X542BP", {
1908         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1909         DMI_MATCH(DMI_PRODUCT_NAME, "X542BP"),}, NULL},
1910         {
1911         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1912         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1913         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1914         {
1915         ec_honor_ecdt_gpe, "ASUS X580VD", {
1916         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1917         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1918         {
1919         /* https://bugzilla.kernel.org/show_bug.cgi?id=209989 */
1920         ec_honor_dsdt_gpe, "HP Pavilion Gaming Laptop 15-cx0xxx", {
1921         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1922         DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-cx0xxx"),}, NULL},
1923         {
1924         ec_clear_on_resume, "Samsung hardware", {
1925         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1926         {},
1927 };
1928
1929 void __init acpi_ec_ecdt_probe(void)
1930 {
1931         struct acpi_table_ecdt *ecdt_ptr;
1932         struct acpi_ec *ec;
1933         acpi_status status;
1934         int ret;
1935
1936         /* Generate a boot ec context. */
1937         dmi_check_system(ec_dmi_table);
1938         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1939                                 (struct acpi_table_header **)&ecdt_ptr);
1940         if (ACPI_FAILURE(status))
1941                 return;
1942
1943         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1944                 /*
1945                  * Asus X50GL:
1946                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1947                  */
1948                 goto out;
1949         }
1950
1951         ec = acpi_ec_alloc();
1952         if (!ec)
1953                 goto out;
1954
1955         if (EC_FLAGS_CORRECT_ECDT) {
1956                 ec->command_addr = ecdt_ptr->data.address;
1957                 ec->data_addr = ecdt_ptr->control.address;
1958         } else {
1959                 ec->command_addr = ecdt_ptr->control.address;
1960                 ec->data_addr = ecdt_ptr->data.address;
1961         }
1962
1963         /*
1964          * Ignore the GPE value on Reduced Hardware platforms.
1965          * Some products have this set to an erroneous value.
1966          */
1967         if (!acpi_gbl_reduced_hardware)
1968                 ec->gpe = ecdt_ptr->gpe;
1969
1970         ec->handle = ACPI_ROOT_OBJECT;
1971
1972         /*
1973          * At this point, the namespace is not initialized, so do not find
1974          * the namespace objects, or handle the events.
1975          */
1976         ret = acpi_ec_setup(ec, NULL);
1977         if (ret) {
1978                 acpi_ec_free(ec);
1979                 goto out;
1980         }
1981
1982         boot_ec = ec;
1983         boot_ec_is_ecdt = true;
1984
1985         pr_info("Boot ECDT EC used to handle transactions\n");
1986
1987 out:
1988         acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1989 }
1990
1991 #ifdef CONFIG_PM_SLEEP
1992 static int acpi_ec_suspend(struct device *dev)
1993 {
1994         struct acpi_ec *ec =
1995                 acpi_driver_data(to_acpi_device(dev));
1996
1997         if (!pm_suspend_no_platform() && ec_freeze_events)
1998                 acpi_ec_disable_event(ec);
1999         return 0;
2000 }
2001
2002 static int acpi_ec_suspend_noirq(struct device *dev)
2003 {
2004         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2005
2006         /*
2007          * The SCI handler doesn't run at this point, so the GPE can be
2008          * masked at the low level without side effects.
2009          */
2010         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2011             ec->gpe >= 0 && ec->reference_count >= 1)
2012                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
2013
2014         acpi_ec_enter_noirq(ec);
2015
2016         return 0;
2017 }
2018
2019 static int acpi_ec_resume_noirq(struct device *dev)
2020 {
2021         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2022
2023         acpi_ec_leave_noirq(ec);
2024
2025         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2026             ec->gpe >= 0 && ec->reference_count >= 1)
2027                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
2028
2029         return 0;
2030 }
2031
2032 static int acpi_ec_resume(struct device *dev)
2033 {
2034         struct acpi_ec *ec =
2035                 acpi_driver_data(to_acpi_device(dev));
2036
2037         acpi_ec_enable_event(ec);
2038         return 0;
2039 }
2040
2041 void acpi_ec_mark_gpe_for_wake(void)
2042 {
2043         if (first_ec && !ec_no_wakeup)
2044                 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
2045 }
2046 EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
2047
2048 void acpi_ec_set_gpe_wake_mask(u8 action)
2049 {
2050         if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
2051                 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
2052 }
2053
2054 bool acpi_ec_dispatch_gpe(void)
2055 {
2056         bool work_in_progress = false;
2057
2058         if (!first_ec)
2059                 return acpi_any_gpe_status_set(U32_MAX);
2060
2061         /*
2062          * Report wakeup if the status bit is set for any enabled GPE other
2063          * than the EC one.
2064          */
2065         if (acpi_any_gpe_status_set(first_ec->gpe))
2066                 return true;
2067
2068         /*
2069          * Dispatch the EC GPE in-band, but do not report wakeup in any case
2070          * to allow the caller to process events properly after that.
2071          */
2072         spin_lock_irq(&first_ec->lock);
2073
2074         if (acpi_ec_gpe_status_set(first_ec))
2075                 work_in_progress = advance_transaction(first_ec, false);
2076
2077         spin_unlock_irq(&first_ec->lock);
2078
2079         if (!work_in_progress)
2080                 return false;
2081
2082         pm_pr_dbg("ACPI EC GPE dispatched\n");
2083
2084         /* Drain EC work. */
2085         do {
2086                 acpi_ec_flush_work();
2087
2088                 pm_pr_dbg("ACPI EC work flushed\n");
2089
2090                 spin_lock_irq(&first_ec->lock);
2091
2092                 work_in_progress = first_ec->events_in_progress +
2093                         first_ec->queries_in_progress > 0;
2094
2095                 spin_unlock_irq(&first_ec->lock);
2096         } while (work_in_progress && !pm_wakeup_pending());
2097
2098         return false;
2099 }
2100 #endif /* CONFIG_PM_SLEEP */
2101
2102 static const struct dev_pm_ops acpi_ec_pm = {
2103         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2104         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2105 };
2106
2107 static int param_set_event_clearing(const char *val,
2108                                     const struct kernel_param *kp)
2109 {
2110         int result = 0;
2111
2112         if (!strncmp(val, "status", sizeof("status") - 1)) {
2113                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2114                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2115         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2116                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2117                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2118         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2119                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2120                 pr_info("Assuming SCI_EVT clearing on event reads\n");
2121         } else
2122                 result = -EINVAL;
2123         return result;
2124 }
2125
2126 static int param_get_event_clearing(char *buffer,
2127                                     const struct kernel_param *kp)
2128 {
2129         switch (ec_event_clearing) {
2130         case ACPI_EC_EVT_TIMING_STATUS:
2131                 return sprintf(buffer, "status\n");
2132         case ACPI_EC_EVT_TIMING_QUERY:
2133                 return sprintf(buffer, "query\n");
2134         case ACPI_EC_EVT_TIMING_EVENT:
2135                 return sprintf(buffer, "event\n");
2136         default:
2137                 return sprintf(buffer, "invalid\n");
2138         }
2139         return 0;
2140 }
2141
2142 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2143                   NULL, 0644);
2144 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2145
2146 static struct acpi_driver acpi_ec_driver = {
2147         .name = "ec",
2148         .class = ACPI_EC_CLASS,
2149         .ids = ec_device_ids,
2150         .ops = {
2151                 .add = acpi_ec_add,
2152                 .remove = acpi_ec_remove,
2153                 },
2154         .drv.pm = &acpi_ec_pm,
2155 };
2156
2157 static void acpi_ec_destroy_workqueues(void)
2158 {
2159         if (ec_wq) {
2160                 destroy_workqueue(ec_wq);
2161                 ec_wq = NULL;
2162         }
2163         if (ec_query_wq) {
2164                 destroy_workqueue(ec_query_wq);
2165                 ec_query_wq = NULL;
2166         }
2167 }
2168
2169 static int acpi_ec_init_workqueues(void)
2170 {
2171         if (!ec_wq)
2172                 ec_wq = alloc_ordered_workqueue("kec", 0);
2173
2174         if (!ec_query_wq)
2175                 ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2176
2177         if (!ec_wq || !ec_query_wq) {
2178                 acpi_ec_destroy_workqueues();
2179                 return -ENODEV;
2180         }
2181         return 0;
2182 }
2183
2184 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2185         {
2186                 .ident = "Thinkpad X1 Carbon 6th",
2187                 .matches = {
2188                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2189                         DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2190                 },
2191         },
2192         {
2193                 .ident = "ThinkPad X1 Carbon 6th",
2194                 .matches = {
2195                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2196                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2197                 },
2198         },
2199         {
2200                 .ident = "ThinkPad X1 Yoga 3rd",
2201                 .matches = {
2202                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2203                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2204                 },
2205         },
2206         {
2207                 .ident = "HP ZHAN 66 Pro",
2208                 .matches = {
2209                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
2210                         DMI_MATCH(DMI_PRODUCT_FAMILY, "103C_5336AN HP ZHAN 66 Pro"),
2211                 },
2212         },
2213         { },
2214 };
2215
2216 void __init acpi_ec_init(void)
2217 {
2218         int result;
2219
2220         result = acpi_ec_init_workqueues();
2221         if (result)
2222                 return;
2223
2224         /*
2225          * Disable EC wakeup on following systems to prevent periodic
2226          * wakeup from EC GPE.
2227          */
2228         if (dmi_check_system(acpi_ec_no_wakeup)) {
2229                 ec_no_wakeup = true;
2230                 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2231         }
2232
2233         /* Driver must be registered after acpi_ec_init_workqueues(). */
2234         acpi_bus_register_driver(&acpi_ec_driver);
2235
2236         acpi_ec_ecdt_start();
2237 }
2238
2239 /* EC driver currently not unloadable */
2240 #if 0
2241 static void __exit acpi_ec_exit(void)
2242 {
2243
2244         acpi_bus_unregister_driver(&acpi_ec_driver);
2245         acpi_ec_destroy_workqueues();
2246 }
2247 #endif  /* 0 */