drivers/acpi/ec.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  ec.c - ACPI Embedded Controller Driver (v3)
   4  *
   5  *  Copyright (C) 2001-2015 Intel Corporation
   6  *    Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>
   7  *            2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
   8  *            2006       Denis Sadykov <denis.m.sadykov@intel.com>
   9  *            2004       Luming Yu <luming.yu@intel.com>
  10  *            2001, 2002 Andy Grover <andrew.grover@intel.com>
  11  *            2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
  12  *  Copyright (C) 2008      Alexey Starikovskiy <astarikovskiy@suse.de>
  13  */
  14
  15 /* Uncomment next line to get verbose printout */
  16 /* #define DEBUG */
  17 #define pr_fmt(fmt) "ACPI: EC: " fmt
  18
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/init.h>
  22 #include <linux/types.h>
  23 #include <linux/delay.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/list.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/slab.h>
  28 #include <linux/suspend.h>
  29 #include <linux/acpi.h>
  30 #include <linux/dmi.h>
  31 #include <asm/io.h>
  32
  33 #include "internal.h"
  34
  35 #define ACPI_EC_CLASS                   "embedded_controller"
  36 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  37
  38 /* EC status register */
  39 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  40 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  41 #define ACPI_EC_FLAG_CMD        0x08    /* Input buffer contains a command */
  42 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  43 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  44
  45 /*
  46  * The SCI_EVT clearing timing is not defined by the ACPI specification.
  47  * This leads to lots of practical timing issues for the host EC driver.
  48  * The following variations are defined (from the target EC firmware's
  49  * perspective):
  50  * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
  51  *         target can clear SCI_EVT at any time so long as the host can see
  52  *         the indication by reading the status register (EC_SC). So the
  53  *         host should re-check SCI_EVT after the first time the SCI_EVT
  54  *         indication is seen, which is the same time the query request
  55  *         (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
  56  *         at any later time could indicate another event. Normally such
  57  *         kind of EC firmware has implemented an event queue and will
  58  *         return 0x00 to indicate "no outstanding event".
  59  * QUERY: After seeing the query request (QR_EC) written to the command
  60  *        register (EC_CMD) by the host and having prepared the responding
  61  *        event value in the data register (EC_DATA), the target can safely
  62  *        clear SCI_EVT because the target can confirm that the current
  63  *        event is being handled by the host. The host then should check
  64  *        SCI_EVT right after reading the event response from the data
  65  *        register (EC_DATA).
  66  * EVENT: After seeing the event response read from the data register
  67  *        (EC_DATA) by the host, the target can clear SCI_EVT. As the
  68  *        target requires time to notice the change in the data register
  69  *        (EC_DATA), the host may be required to wait additional guarding
  70  *        time before checking the SCI_EVT again. Such guarding may not be
  71  *        necessary if the host is notified via another IRQ.
  72  */
  73 #define ACPI_EC_EVT_TIMING_STATUS       0x00
  74 #define ACPI_EC_EVT_TIMING_QUERY        0x01
  75 #define ACPI_EC_EVT_TIMING_EVENT        0x02
  76
  77 /* EC commands */
  78 enum ec_command {
  79         ACPI_EC_COMMAND_READ = 0x80,
  80         ACPI_EC_COMMAND_WRITE = 0x81,
  81         ACPI_EC_BURST_ENABLE = 0x82,
  82         ACPI_EC_BURST_DISABLE = 0x83,
  83         ACPI_EC_COMMAND_QUERY = 0x84,
  84 };
  85
  86 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  87 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  88 #define ACPI_EC_UDELAY_POLL     550     /* Wait 1ms for EC transaction polling */
  89 #define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
  90                                          * when trying to clear the EC */
  91 #define ACPI_EC_MAX_QUERIES     16      /* Maximum number of parallel queries */
  92
  93 enum {
  94         EC_FLAGS_QUERY_ENABLED,         /* Query is enabled */
  95         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  96         EC_FLAGS_QUERY_GUARDING,        /* Guard for SCI_EVT check */
  97         EC_FLAGS_EVENT_HANDLER_INSTALLED,       /* Event handler installed */
  98         EC_FLAGS_EC_HANDLER_INSTALLED,  /* OpReg handler installed */
  99         EC_FLAGS_QUERY_METHODS_INSTALLED, /* _Qxx handlers installed */
 100         EC_FLAGS_STARTED,               /* Driver is started */
 101         EC_FLAGS_STOPPED,               /* Driver is stopped */
 102         EC_FLAGS_EVENTS_MASKED,         /* Events masked */
 103 };
 104
 105 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
 106 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
 107
 108 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 109 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 110 module_param(ec_delay, uint, 0644);
 111 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
 112
 113 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
 114 module_param(ec_max_queries, uint, 0644);
 115 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
 116
 117 static bool ec_busy_polling __read_mostly;
 118 module_param(ec_busy_polling, bool, 0644);
 119 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
 120
 121 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
 122 module_param(ec_polling_guard, uint, 0644);
 123 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
 124
 125 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
 126
 127 /*
 128  * If the number of false interrupts per one transaction exceeds
 129  * this threshold, will think there is a GPE storm happened and
 130  * will disable the GPE for normal transaction.
 131  */
 132 static unsigned int ec_storm_threshold  __read_mostly = 8;
 133 module_param(ec_storm_threshold, uint, 0644);
 134 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 135
 136 static bool ec_freeze_events __read_mostly = false;
 137 module_param(ec_freeze_events, bool, 0644);
 138 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
 139
 140 static bool ec_no_wakeup __read_mostly;
 141 module_param(ec_no_wakeup, bool, 0644);
 142 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
 143
 144 struct acpi_ec_query_handler {
 145         struct list_head node;
 146         acpi_ec_query_func func;
 147         acpi_handle handle;
 148         void *data;
 149         u8 query_bit;
 150         struct kref kref;
 151 };
 152
 153 struct transaction {
 154         const u8 *wdata;
 155         u8 *rdata;
 156         unsigned short irq_count;
 157         u8 command;
 158         u8 wi;
 159         u8 ri;
 160         u8 wlen;
 161         u8 rlen;
 162         u8 flags;
 163 };
 164
 165 struct acpi_ec_query {
 166         struct transaction transaction;
 167         struct work_struct work;
 168         struct acpi_ec_query_handler *handler;
 169 };
 170
 171 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
 172 static void advance_transaction(struct acpi_ec *ec);
 173 static void acpi_ec_event_handler(struct work_struct *work);
 174 static void acpi_ec_event_processor(struct work_struct *work);
 175
 176 struct acpi_ec *first_ec;
 177 EXPORT_SYMBOL(first_ec);
 178
 179 static struct acpi_ec *boot_ec;
 180 static bool boot_ec_is_ecdt = false;
 181 static struct workqueue_struct *ec_wq;
 182 static struct workqueue_struct *ec_query_wq;
 183
 184 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
 185 static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
 186 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 187
 188 /* --------------------------------------------------------------------------
 189  *                           Logging/Debugging
 190  * -------------------------------------------------------------------------- */
 191
 192 /*
 193  * Splitters used by the developers to track the boundary of the EC
 194  * handling processes.
 195  */
 196 #ifdef DEBUG
 197 #define EC_DBG_SEP      " "
 198 #define EC_DBG_DRV      "+++++"
 199 #define EC_DBG_STM      "====="
 200 #define EC_DBG_REQ      "*****"
 201 #define EC_DBG_EVT      "#####"
 202 #else
 203 #define EC_DBG_SEP      ""
 204 #define EC_DBG_DRV
 205 #define EC_DBG_STM
 206 #define EC_DBG_REQ
 207 #define EC_DBG_EVT
 208 #endif
 209
 210 #define ec_log_raw(fmt, ...) \
 211         pr_info(fmt "\n", ##__VA_ARGS__)
 212 #define ec_dbg_raw(fmt, ...) \
 213         pr_debug(fmt "\n", ##__VA_ARGS__)
 214 #define ec_log(filter, fmt, ...) \
 215         ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 216 #define ec_dbg(filter, fmt, ...) \
 217         ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 218
 219 #define ec_log_drv(fmt, ...) \
 220         ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 221 #define ec_dbg_drv(fmt, ...) \
 222         ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 223 #define ec_dbg_stm(fmt, ...) \
 224         ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
 225 #define ec_dbg_req(fmt, ...) \
 226         ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
 227 #define ec_dbg_evt(fmt, ...) \
 228         ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
 229 #define ec_dbg_ref(ec, fmt, ...) \
 230         ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
 231
 232 /* --------------------------------------------------------------------------
 233  *                           Device Flags
 234  * -------------------------------------------------------------------------- */
 235
 236 static bool acpi_ec_started(struct acpi_ec *ec)
 237 {
 238         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
 239                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
 240 }
 241
 242 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
 243 {
 244         /*
 245          * There is an OSPM early stage logic. During the early stages
 246          * (boot/resume), OSPMs shouldn't enable the event handling, only
 247          * the EC transactions are allowed to be performed.
 248          */
 249         if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 250                 return false;
 251         /*
 252          * However, disabling the event handling is experimental for late
 253          * stage (suspend), and is controlled by the boot parameter of
 254          * "ec_freeze_events":
 255          * 1. true:  The EC event handling is disabled before entering
 256          *           the noirq stage.
 257          * 2. false: The EC event handling is automatically disabled as
 258          *           soon as the EC driver is stopped.
 259          */
 260         if (ec_freeze_events)
 261                 return acpi_ec_started(ec);
 262         else
 263                 return test_bit(EC_FLAGS_STARTED, &ec->flags);
 264 }
 265
 266 static bool acpi_ec_flushed(struct acpi_ec *ec)
 267 {
 268         return ec->reference_count == 1;
 269 }
 270
 271 /* --------------------------------------------------------------------------
 272  *                           EC Registers
 273  * -------------------------------------------------------------------------- */
 274
 275 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 276 {
 277         u8 x = inb(ec->command_addr);
 278
 279         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
 280                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
 281                    x,
 282                    !!(x & ACPI_EC_FLAG_SCI),
 283                    !!(x & ACPI_EC_FLAG_BURST),
 284                    !!(x & ACPI_EC_FLAG_CMD),
 285                    !!(x & ACPI_EC_FLAG_IBF),
 286                    !!(x & ACPI_EC_FLAG_OBF));
 287         return x;
 288 }
 289
 290 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 291 {
 292         u8 x = inb(ec->data_addr);
 293
 294         ec->timestamp = jiffies;
 295         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
 296         return x;
 297 }
 298
 299 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 300 {
 301         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
 302         outb(command, ec->command_addr);
 303         ec->timestamp = jiffies;
 304 }
 305
 306 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 307 {
 308         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
 309         outb(data, ec->data_addr);
 310         ec->timestamp = jiffies;
 311 }
 312
 313 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
 314 static const char *acpi_ec_cmd_string(u8 cmd)
 315 {
 316         switch (cmd) {
 317         case 0x80:
 318                 return "RD_EC";
 319         case 0x81:
 320                 return "WR_EC";
 321         case 0x82:
 322                 return "BE_EC";
 323         case 0x83:
 324                 return "BD_EC";
 325         case 0x84:
 326                 return "QR_EC";
 327         }
 328         return "UNKNOWN";
 329 }
 330 #else
 331 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 332 #endif
 333
 334 /* --------------------------------------------------------------------------
 335  *                           GPE Registers
 336  * -------------------------------------------------------------------------- */
 337
 338 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
 339 {
 340         acpi_event_status gpe_status = 0;
 341
 342         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
 343         return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
 344 }
 345
 346 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
 347 {
 348         if (open)
 349                 acpi_enable_gpe(NULL, ec->gpe);
 350         else {
 351                 BUG_ON(ec->reference_count < 1);
 352                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 353         }
 354         if (acpi_ec_is_gpe_raised(ec)) {
 355                 /*
 356                  * On some platforms, EN=1 writes cannot trigger GPE. So
 357                  * software need to manually trigger a pseudo GPE event on
 358                  * EN=1 writes.
 359                  */
 360                 ec_dbg_raw("Polling quirk");
 361                 advance_transaction(ec);
 362         }
 363 }
 364
 365 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
 366 {
 367         if (close)
 368                 acpi_disable_gpe(NULL, ec->gpe);
 369         else {
 370                 BUG_ON(ec->reference_count < 1);
 371                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 372         }
 373 }
 374
 375 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
 376 {
 377         /*
 378          * GPE STS is a W1C register, which means:
 379          * 1. Software can clear it without worrying about clearing other
 380          *    GPEs' STS bits when the hardware sets them in parallel.
 381          * 2. As long as software can ensure only clearing it when it is
 382          *    set, hardware won't set it in parallel.
 383          * So software can clear GPE in any contexts.
 384          * Warning: do not move the check into advance_transaction() as the
 385          * EC commands will be sent without GPE raised.
 386          */
 387         if (!acpi_ec_is_gpe_raised(ec))
 388                 return;
 389         acpi_clear_gpe(NULL, ec->gpe);
 390 }
 391
 392 /* --------------------------------------------------------------------------
 393  *                           Transaction Management
 394  * -------------------------------------------------------------------------- */
 395
 396 static void acpi_ec_submit_request(struct acpi_ec *ec)
 397 {
 398         ec->reference_count++;
 399         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
 400             ec->gpe >= 0 && ec->reference_count == 1)
 401                 acpi_ec_enable_gpe(ec, true);
 402 }
 403
 404 static void acpi_ec_complete_request(struct acpi_ec *ec)
 405 {
 406         bool flushed = false;
 407
 408         ec->reference_count--;
 409         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
 410             ec->gpe >= 0 && ec->reference_count == 0)
 411                 acpi_ec_disable_gpe(ec, true);
 412         flushed = acpi_ec_flushed(ec);
 413         if (flushed)
 414                 wake_up(&ec->wait);
 415 }
 416
 417 static void acpi_ec_mask_events(struct acpi_ec *ec)
 418 {
 419         if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
 420                 if (ec->gpe >= 0)
 421                         acpi_ec_disable_gpe(ec, false);
 422                 else
 423                         disable_irq_nosync(ec->irq);
 424
 425                 ec_dbg_drv("Polling enabled");
 426                 set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
 427         }
 428 }
 429
 430 static void acpi_ec_unmask_events(struct acpi_ec *ec)
 431 {
 432         if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
 433                 clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
 434                 if (ec->gpe >= 0)
 435                         acpi_ec_enable_gpe(ec, false);
 436                 else
 437                         enable_irq(ec->irq);
 438
 439                 ec_dbg_drv("Polling disabled");
 440         }
 441 }
 442
 443 /*
 444  * acpi_ec_submit_flushable_request() - Increase the reference count unless
 445  *                                      the flush operation is not in
 446  *                                      progress
 447  * @ec: the EC device
 448  *
 449  * This function must be used before taking a new action that should hold
 450  * the reference count.  If this function returns false, then the action
 451  * must be discarded or it will prevent the flush operation from being
 452  * completed.
 453  */
 454 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
 455 {
 456         if (!acpi_ec_started(ec))
 457                 return false;
 458         acpi_ec_submit_request(ec);
 459         return true;
 460 }
 461
 462 static void acpi_ec_submit_query(struct acpi_ec *ec)
 463 {
 464         acpi_ec_mask_events(ec);
 465         if (!acpi_ec_event_enabled(ec))
 466                 return;
 467         if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 468                 ec_dbg_evt("Command(%s) submitted/blocked",
 469                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 470                 ec->nr_pending_queries++;
 471                 queue_work(ec_wq, &ec->work);
 472         }
 473 }
 474
 475 static void acpi_ec_complete_query(struct acpi_ec *ec)
 476 {
 477         if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 478                 ec_dbg_evt("Command(%s) unblocked",
 479                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 480         acpi_ec_unmask_events(ec);
 481 }
 482
 483 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
 484 {
 485         if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 486                 ec_log_drv("event unblocked");
 487         /*
 488          * Unconditionally invoke this once after enabling the event
 489          * handling mechanism to detect the pending events.
 490          */
 491         advance_transaction(ec);
 492 }
 493
 494 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
 495 {
 496         if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 497                 ec_log_drv("event blocked");
 498 }
 499
 500 /*
 501  * Process _Q events that might have accumulated in the EC.
 502  * Run with locked ec mutex.
 503  */
 504 static void acpi_ec_clear(struct acpi_ec *ec)
 505 {
 506         int i, status;
 507         u8 value = 0;
 508
 509         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 510                 status = acpi_ec_query(ec, &value);
 511                 if (status || !value)
 512                         break;
 513         }
 514         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 515                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 516         else
 517                 pr_info("%d stale EC events cleared\n", i);
 518 }
 519
 520 static void acpi_ec_enable_event(struct acpi_ec *ec)
 521 {
 522         unsigned long flags;
 523
 524         spin_lock_irqsave(&ec->lock, flags);
 525         if (acpi_ec_started(ec))
 526                 __acpi_ec_enable_event(ec);
 527         spin_unlock_irqrestore(&ec->lock, flags);
 528
 529         /* Drain additional events if hardware requires that */
 530         if (EC_FLAGS_CLEAR_ON_RESUME)
 531                 acpi_ec_clear(ec);
 532 }
 533
 534 #ifdef CONFIG_PM_SLEEP
 535 static void __acpi_ec_flush_work(void)
 536 {
 537         drain_workqueue(ec_wq); /* flush ec->work */
 538         flush_workqueue(ec_query_wq); /* flush queries */
 539 }
 540
 541 static void acpi_ec_disable_event(struct acpi_ec *ec)
 542 {
 543         unsigned long flags;
 544
 545         spin_lock_irqsave(&ec->lock, flags);
 546         __acpi_ec_disable_event(ec);
 547         spin_unlock_irqrestore(&ec->lock, flags);
 548
 549         /*
 550          * When ec_freeze_events is true, we need to flush events in
 551          * the proper position before entering the noirq stage.
 552          */
 553         __acpi_ec_flush_work();
 554 }
 555
 556 void acpi_ec_flush_work(void)
 557 {
 558         /* Without ec_wq there is nothing to flush. */
 559         if (!ec_wq)
 560                 return;
 561
 562         __acpi_ec_flush_work();
 563 }
 564 #endif /* CONFIG_PM_SLEEP */
 565
 566 static bool acpi_ec_guard_event(struct acpi_ec *ec)
 567 {
 568         bool guarded = true;
 569         unsigned long flags;
 570
 571         spin_lock_irqsave(&ec->lock, flags);
 572         /*
 573          * If firmware SCI_EVT clearing timing is "event", we actually
 574          * don't know when the SCI_EVT will be cleared by firmware after
 575          * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
 576          * acceptable period.
 577          *
 578          * The guarding period begins when EC_FLAGS_QUERY_PENDING is
 579          * flagged, which means SCI_EVT check has just been performed.
 580          * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
 581          * guarding should have already been performed (via
 582          * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
 583          * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
 584          * ACPI_EC_COMMAND_POLL state immediately.
 585          */
 586         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
 587             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
 588             !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
 589             (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
 590                 guarded = false;
 591         spin_unlock_irqrestore(&ec->lock, flags);
 592         return guarded;
 593 }
 594
 595 static int ec_transaction_polled(struct acpi_ec *ec)
 596 {
 597         unsigned long flags;
 598         int ret = 0;
 599
 600         spin_lock_irqsave(&ec->lock, flags);
 601         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
 602                 ret = 1;
 603         spin_unlock_irqrestore(&ec->lock, flags);
 604         return ret;
 605 }
 606
 607 static int ec_transaction_completed(struct acpi_ec *ec)
 608 {
 609         unsigned long flags;
 610         int ret = 0;
 611
 612         spin_lock_irqsave(&ec->lock, flags);
 613         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 614                 ret = 1;
 615         spin_unlock_irqrestore(&ec->lock, flags);
 616         return ret;
 617 }
 618
 619 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
 620 {
 621         ec->curr->flags |= flag;
 622         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 623                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
 624                     flag == ACPI_EC_COMMAND_POLL)
 625                         acpi_ec_complete_query(ec);
 626                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
 627                     flag == ACPI_EC_COMMAND_COMPLETE)
 628                         acpi_ec_complete_query(ec);
 629                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 630                     flag == ACPI_EC_COMMAND_COMPLETE)
 631                         set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 632         }
 633 }
 634
 635 static void advance_transaction(struct acpi_ec *ec)
 636 {
 637         struct transaction *t;
 638         u8 status;
 639         bool wakeup = false;
 640
 641         ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
 642                    smp_processor_id());
 643         /*
 644          * By always clearing STS before handling all indications, we can
 645          * ensure a hardware STS 0->1 change after this clearing can always
 646          * trigger a GPE interrupt.
 647          */
 648         if (ec->gpe >= 0)
 649                 acpi_ec_clear_gpe(ec);
 650
 651         status = acpi_ec_read_status(ec);
 652         t = ec->curr;
 653         /*
 654          * Another IRQ or a guarded polling mode advancement is detected,
 655          * the next QR_EC submission is then allowed.
 656          */
 657         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
 658                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 659                     (!ec->nr_pending_queries ||
 660                      test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
 661                         clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 662                         acpi_ec_complete_query(ec);
 663                 }
 664         }
 665         if (!t)
 666                 goto err;
 667         if (t->flags & ACPI_EC_COMMAND_POLL) {
 668                 if (t->wlen > t->wi) {
 669                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 670                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 671                         else
 672                                 goto err;
 673                 } else if (t->rlen > t->ri) {
 674                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 675                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 676                                 if (t->rlen == t->ri) {
 677                                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 678                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 679                                                 ec_dbg_evt("Command(%s) completed by hardware",
 680                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 681                                         wakeup = true;
 682                                 }
 683                         } else
 684                                 goto err;
 685                 } else if (t->wlen == t->wi &&
 686                            (status & ACPI_EC_FLAG_IBF) == 0) {
 687                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 688                         wakeup = true;
 689                 }
 690                 goto out;
 691         } else if (!(status & ACPI_EC_FLAG_IBF)) {
 692                 acpi_ec_write_cmd(ec, t->command);
 693                 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 694                 goto out;
 695         }
 696 err:
 697         /*
 698          * If SCI bit is set, then don't think it's a false IRQ
 699          * otherwise will take a not handled IRQ as a false one.
 700          */
 701         if (!(status & ACPI_EC_FLAG_SCI)) {
 702                 if (in_interrupt() && t) {
 703                         if (t->irq_count < ec_storm_threshold)
 704                                 ++t->irq_count;
 705                         /* Allow triggering on 0 threshold */
 706                         if (t->irq_count == ec_storm_threshold)
 707                                 acpi_ec_mask_events(ec);
 708                 }
 709         }
 710 out:
 711         if (status & ACPI_EC_FLAG_SCI)
 712                 acpi_ec_submit_query(ec);
 713         if (wakeup && in_interrupt())
 714                 wake_up(&ec->wait);
 715 }
 716
 717 static void start_transaction(struct acpi_ec *ec)
 718 {
 719         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 720         ec->curr->flags = 0;
 721 }
 722
 723 static int ec_guard(struct acpi_ec *ec)
 724 {
 725         unsigned long guard = usecs_to_jiffies(ec->polling_guard);
 726         unsigned long timeout = ec->timestamp + guard;
 727
 728         /* Ensure guarding period before polling EC status */
 729         do {
 730                 if (ec->busy_polling) {
 731                         /* Perform busy polling */
 732                         if (ec_transaction_completed(ec))
 733                                 return 0;
 734                         udelay(jiffies_to_usecs(guard));
 735                 } else {
 736                         /*
 737                          * Perform wait polling
 738                          * 1. Wait the transaction to be completed by the
 739                          *    GPE handler after the transaction enters
 740                          *    ACPI_EC_COMMAND_POLL state.
 741                          * 2. A special guarding logic is also required
 742                          *    for event clearing mode "event" before the
 743                          *    transaction enters ACPI_EC_COMMAND_POLL
 744                          *    state.
 745                          */
 746                         if (!ec_transaction_polled(ec) &&
 747                             !acpi_ec_guard_event(ec))
 748                                 break;
 749                         if (wait_event_timeout(ec->wait,
 750                                                ec_transaction_completed(ec),
 751                                                guard))
 752                                 return 0;
 753                 }
 754         } while (time_before(jiffies, timeout));
 755         return -ETIME;
 756 }
 757
 758 static int ec_poll(struct acpi_ec *ec)
 759 {
 760         unsigned long flags;
 761         int repeat = 5; /* number of command restarts */
 762
 763         while (repeat--) {
 764                 unsigned long delay = jiffies +
 765                         msecs_to_jiffies(ec_delay);
 766                 do {
 767                         if (!ec_guard(ec))
 768                                 return 0;
 769                         spin_lock_irqsave(&ec->lock, flags);
 770                         advance_transaction(ec);
 771                         spin_unlock_irqrestore(&ec->lock, flags);
 772                 } while (time_before(jiffies, delay));
 773                 pr_debug("controller reset, restart transaction\n");
 774                 spin_lock_irqsave(&ec->lock, flags);
 775                 start_transaction(ec);
 776                 spin_unlock_irqrestore(&ec->lock, flags);
 777         }
 778         return -ETIME;
 779 }
 780
 781 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 782                                         struct transaction *t)
 783 {
 784         unsigned long tmp;
 785         int ret = 0;
 786
 787         /* start transaction */
 788         spin_lock_irqsave(&ec->lock, tmp);
 789         /* Enable GPE for command processing (IBF=0/OBF=1) */
 790         if (!acpi_ec_submit_flushable_request(ec)) {
 791                 ret = -EINVAL;
 792                 goto unlock;
 793         }
 794         ec_dbg_ref(ec, "Increase command");
 795         /* following two actions should be kept atomic */
 796         ec->curr = t;
 797         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 798         start_transaction(ec);
 799         spin_unlock_irqrestore(&ec->lock, tmp);
 800
 801         ret = ec_poll(ec);
 802
 803         spin_lock_irqsave(&ec->lock, tmp);
 804         if (t->irq_count == ec_storm_threshold)
 805                 acpi_ec_unmask_events(ec);
 806         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 807         ec->curr = NULL;
 808         /* Disable GPE for command processing (IBF=0/OBF=1) */
 809         acpi_ec_complete_request(ec);
 810         ec_dbg_ref(ec, "Decrease command");
 811 unlock:
 812         spin_unlock_irqrestore(&ec->lock, tmp);
 813         return ret;
 814 }
 815
 816 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 817 {
 818         int status;
 819         u32 glk;
 820
 821         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 822                 return -EINVAL;
 823         if (t->rdata)
 824                 memset(t->rdata, 0, t->rlen);
 825
 826         mutex_lock(&ec->mutex);
 827         if (ec->global_lock) {
 828                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 829                 if (ACPI_FAILURE(status)) {
 830                         status = -ENODEV;
 831                         goto unlock;
 832                 }
 833         }
 834
 835         status = acpi_ec_transaction_unlocked(ec, t);
 836
 837         if (ec->global_lock)
 838                 acpi_release_global_lock(glk);
 839 unlock:
 840         mutex_unlock(&ec->mutex);
 841         return status;
 842 }
 843
 844 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 845 {
 846         u8 d;
 847         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 848                                 .wdata = NULL, .rdata = &d,
 849                                 .wlen = 0, .rlen = 1};
 850
 851         return acpi_ec_transaction(ec, &t);
 852 }
 853
 854 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 855 {
 856         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 857                                 .wdata = NULL, .rdata = NULL,
 858                                 .wlen = 0, .rlen = 0};
 859
 860         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 861                                 acpi_ec_transaction(ec, &t) : 0;
 862 }
 863
 864 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 865 {
 866         int result;
 867         u8 d;
 868         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 869                                 .wdata = &address, .rdata = &d,
 870                                 .wlen = 1, .rlen = 1};
 871
 872         result = acpi_ec_transaction(ec, &t);
 873         *data = d;
 874         return result;
 875 }
 876
 877 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 878 {
 879         u8 wdata[2] = { address, data };
 880         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 881                                 .wdata = wdata, .rdata = NULL,
 882                                 .wlen = 2, .rlen = 0};
 883
 884         return acpi_ec_transaction(ec, &t);
 885 }
 886
 887 int ec_read(u8 addr, u8 *val)
 888 {
 889         int err;
 890         u8 temp_data;
 891
 892         if (!first_ec)
 893                 return -ENODEV;
 894
 895         err = acpi_ec_read(first_ec, addr, &temp_data);
 896
 897         if (!err) {
 898                 *val = temp_data;
 899                 return 0;
 900         }
 901         return err;
 902 }
 903 EXPORT_SYMBOL(ec_read);
 904
 905 int ec_write(u8 addr, u8 val)
 906 {
 907         int err;
 908
 909         if (!first_ec)
 910                 return -ENODEV;
 911
 912         err = acpi_ec_write(first_ec, addr, val);
 913
 914         return err;
 915 }
 916 EXPORT_SYMBOL(ec_write);
 917
 918 int ec_transaction(u8 command,
 919                    const u8 *wdata, unsigned wdata_len,
 920                    u8 *rdata, unsigned rdata_len)
 921 {
 922         struct transaction t = {.command = command,
 923                                 .wdata = wdata, .rdata = rdata,
 924                                 .wlen = wdata_len, .rlen = rdata_len};
 925
 926         if (!first_ec)
 927                 return -ENODEV;
 928
 929         return acpi_ec_transaction(first_ec, &t);
 930 }
 931 EXPORT_SYMBOL(ec_transaction);
 932
 933 /* Get the handle to the EC device */
 934 acpi_handle ec_get_handle(void)
 935 {
 936         if (!first_ec)
 937                 return NULL;
 938         return first_ec->handle;
 939 }
 940 EXPORT_SYMBOL(ec_get_handle);
 941
 942 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 943 {
 944         unsigned long flags;
 945
 946         spin_lock_irqsave(&ec->lock, flags);
 947         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 948                 ec_dbg_drv("Starting EC");
 949                 /* Enable GPE for event processing (SCI_EVT=1) */
 950                 if (!resuming) {
 951                         acpi_ec_submit_request(ec);
 952                         ec_dbg_ref(ec, "Increase driver");
 953                 }
 954                 ec_log_drv("EC started");
 955         }
 956         spin_unlock_irqrestore(&ec->lock, flags);
 957 }
 958
 959 static bool acpi_ec_stopped(struct acpi_ec *ec)
 960 {
 961         unsigned long flags;
 962         bool flushed;
 963
 964         spin_lock_irqsave(&ec->lock, flags);
 965         flushed = acpi_ec_flushed(ec);
 966         spin_unlock_irqrestore(&ec->lock, flags);
 967         return flushed;
 968 }
 969
 970 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 971 {
 972         unsigned long flags;
 973
 974         spin_lock_irqsave(&ec->lock, flags);
 975         if (acpi_ec_started(ec)) {
 976                 ec_dbg_drv("Stopping EC");
 977                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
 978                 spin_unlock_irqrestore(&ec->lock, flags);
 979                 wait_event(ec->wait, acpi_ec_stopped(ec));
 980                 spin_lock_irqsave(&ec->lock, flags);
 981                 /* Disable GPE for event processing (SCI_EVT=1) */
 982                 if (!suspending) {
 983                         acpi_ec_complete_request(ec);
 984                         ec_dbg_ref(ec, "Decrease driver");
 985                 } else if (!ec_freeze_events)
 986                         __acpi_ec_disable_event(ec);
 987                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
 988                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
 989                 ec_log_drv("EC stopped");
 990         }
 991         spin_unlock_irqrestore(&ec->lock, flags);
 992 }
 993
 994 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
 995 {
 996         unsigned long flags;
 997
 998         spin_lock_irqsave(&ec->lock, flags);
 999         ec->busy_polling = true;
1000         ec->polling_guard = 0;
1001         ec_log_drv("interrupt blocked");
1002         spin_unlock_irqrestore(&ec->lock, flags);
1003 }
1004
1005 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1006 {
1007         unsigned long flags;
1008
1009         spin_lock_irqsave(&ec->lock, flags);
1010         ec->busy_polling = ec_busy_polling;
1011         ec->polling_guard = ec_polling_guard;
1012         ec_log_drv("interrupt unblocked");
1013         spin_unlock_irqrestore(&ec->lock, flags);
1014 }
1015
1016 void acpi_ec_block_transactions(void)
1017 {
1018         struct acpi_ec *ec = first_ec;
1019
1020         if (!ec)
1021                 return;
1022
1023         mutex_lock(&ec->mutex);
1024         /* Prevent transactions from being carried out */
1025         acpi_ec_stop(ec, true);
1026         mutex_unlock(&ec->mutex);
1027 }
1028
1029 void acpi_ec_unblock_transactions(void)
1030 {
1031         /*
1032          * Allow transactions to happen again (this function is called from
1033          * atomic context during wakeup, so we don't need to acquire the mutex).
1034          */
1035         if (first_ec)
1036                 acpi_ec_start(first_ec, true);
1037 }
1038
1039 /* --------------------------------------------------------------------------
1040                                 Event Management
1041    -------------------------------------------------------------------------- */
1042 static struct acpi_ec_query_handler *
1043 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1044 {
1045         struct acpi_ec_query_handler *handler;
1046
1047         mutex_lock(&ec->mutex);
1048         list_for_each_entry(handler, &ec->list, node) {
1049                 if (value == handler->query_bit) {
1050                         kref_get(&handler->kref);
1051                         mutex_unlock(&ec->mutex);
1052                         return handler;
1053                 }
1054         }
1055         mutex_unlock(&ec->mutex);
1056         return NULL;
1057 }
1058
1059 static void acpi_ec_query_handler_release(struct kref *kref)
1060 {
1061         struct acpi_ec_query_handler *handler =
1062                 container_of(kref, struct acpi_ec_query_handler, kref);
1063
1064         kfree(handler);
1065 }
1066
1067 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1068 {
1069         kref_put(&handler->kref, acpi_ec_query_handler_release);
1070 }
1071
1072 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1073                               acpi_handle handle, acpi_ec_query_func func,
1074                               void *data)
1075 {
1076         struct acpi_ec_query_handler *handler =
1077             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1078
1079         if (!handler)
1080                 return -ENOMEM;
1081
1082         handler->query_bit = query_bit;
1083         handler->handle = handle;
1084         handler->func = func;
1085         handler->data = data;
1086         mutex_lock(&ec->mutex);
1087         kref_init(&handler->kref);
1088         list_add(&handler->node, &ec->list);
1089         mutex_unlock(&ec->mutex);
1090         return 0;
1091 }
1092 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1093
1094 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1095                                           bool remove_all, u8 query_bit)
1096 {
1097         struct acpi_ec_query_handler *handler, *tmp;
1098         LIST_HEAD(free_list);
1099
1100         mutex_lock(&ec->mutex);
1101         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1102                 if (remove_all || query_bit == handler->query_bit) {
1103                         list_del_init(&handler->node);
1104                         list_add(&handler->node, &free_list);
1105                 }
1106         }
1107         mutex_unlock(&ec->mutex);
1108         list_for_each_entry_safe(handler, tmp, &free_list, node)
1109                 acpi_ec_put_query_handler(handler);
1110 }
1111
1112 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1113 {
1114         acpi_ec_remove_query_handlers(ec, false, query_bit);
1115 }
1116 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1117
1118 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1119 {
1120         struct acpi_ec_query *q;
1121         struct transaction *t;
1122
1123         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1124         if (!q)
1125                 return NULL;
1126         INIT_WORK(&q->work, acpi_ec_event_processor);
1127         t = &q->transaction;
1128         t->command = ACPI_EC_COMMAND_QUERY;
1129         t->rdata = pval;
1130         t->rlen = 1;
1131         return q;
1132 }
1133
1134 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1135 {
1136         if (q) {
1137                 if (q->handler)
1138                         acpi_ec_put_query_handler(q->handler);
1139                 kfree(q);
1140         }
1141 }
1142
1143 static void acpi_ec_event_processor(struct work_struct *work)
1144 {
1145         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1146         struct acpi_ec_query_handler *handler = q->handler;
1147
1148         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1149         if (handler->func)
1150                 handler->func(handler->data);
1151         else if (handler->handle)
1152                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1153         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1154         acpi_ec_delete_query(q);
1155 }
1156
1157 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1158 {
1159         u8 value = 0;
1160         int result;
1161         struct acpi_ec_query *q;
1162
1163         q = acpi_ec_create_query(&value);
1164         if (!q)
1165                 return -ENOMEM;
1166
1167         /*
1168          * Query the EC to find out which _Qxx method we need to evaluate.
1169          * Note that successful completion of the query causes the ACPI_EC_SCI
1170          * bit to be cleared (and thus clearing the interrupt source).
1171          */
1172         result = acpi_ec_transaction(ec, &q->transaction);
1173         if (!value)
1174                 result = -ENODATA;
1175         if (result)
1176                 goto err_exit;
1177
1178         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1179         if (!q->handler) {
1180                 result = -ENODATA;
1181                 goto err_exit;
1182         }
1183
1184         /*
1185          * It is reported that _Qxx are evaluated in a parallel way on
1186          * Windows:
1187          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1188          *
1189          * Put this log entry before schedule_work() in order to make
1190          * it appearing before any other log entries occurred during the
1191          * work queue execution.
1192          */
1193         ec_dbg_evt("Query(0x%02x) scheduled", value);
1194         if (!queue_work(ec_query_wq, &q->work)) {
1195                 ec_dbg_evt("Query(0x%02x) overlapped", value);
1196                 result = -EBUSY;
1197         }
1198
1199 err_exit:
1200         if (result)
1201                 acpi_ec_delete_query(q);
1202         if (data)
1203                 *data = value;
1204         return result;
1205 }
1206
1207 static void acpi_ec_check_event(struct acpi_ec *ec)
1208 {
1209         unsigned long flags;
1210
1211         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1212                 if (ec_guard(ec)) {
1213                         spin_lock_irqsave(&ec->lock, flags);
1214                         /*
1215                          * Take care of the SCI_EVT unless no one else is
1216                          * taking care of it.
1217                          */
1218                         if (!ec->curr)
1219                                 advance_transaction(ec);
1220                         spin_unlock_irqrestore(&ec->lock, flags);
1221                 }
1222         }
1223 }
1224
1225 static void acpi_ec_event_handler(struct work_struct *work)
1226 {
1227         unsigned long flags;
1228         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1229
1230         ec_dbg_evt("Event started");
1231
1232         spin_lock_irqsave(&ec->lock, flags);
1233         while (ec->nr_pending_queries) {
1234                 spin_unlock_irqrestore(&ec->lock, flags);
1235                 (void)acpi_ec_query(ec, NULL);
1236                 spin_lock_irqsave(&ec->lock, flags);
1237                 ec->nr_pending_queries--;
1238                 /*
1239                  * Before exit, make sure that this work item can be
1240                  * scheduled again. There might be QR_EC failures, leaving
1241                  * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1242                  * item from being scheduled again.
1243                  */
1244                 if (!ec->nr_pending_queries) {
1245                         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1246                             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1247                                 acpi_ec_complete_query(ec);
1248                 }
1249         }
1250         spin_unlock_irqrestore(&ec->lock, flags);
1251
1252         ec_dbg_evt("Event stopped");
1253
1254         acpi_ec_check_event(ec);
1255 }
1256
1257 static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1258 {
1259         unsigned long flags;
1260
1261         spin_lock_irqsave(&ec->lock, flags);
1262         advance_transaction(ec);
1263         spin_unlock_irqrestore(&ec->lock, flags);
1264 }
1265
1266 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1267                                u32 gpe_number, void *data)
1268 {
1269         acpi_ec_handle_interrupt(data);
1270         return ACPI_INTERRUPT_HANDLED;
1271 }
1272
1273 static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1274 {
1275         acpi_ec_handle_interrupt(data);
1276         return IRQ_HANDLED;
1277 }
1278
1279 /* --------------------------------------------------------------------------
1280  *                           Address Space Management
1281  * -------------------------------------------------------------------------- */
1282
1283 static acpi_status
1284 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1285                       u32 bits, u64 *value64,
1286                       void *handler_context, void *region_context)
1287 {
1288         struct acpi_ec *ec = handler_context;
1289         int result = 0, i, bytes = bits / 8;
1290         u8 *value = (u8 *)value64;
1291
1292         if ((address > 0xFF) || !value || !handler_context)
1293                 return AE_BAD_PARAMETER;
1294
1295         if (function != ACPI_READ && function != ACPI_WRITE)
1296                 return AE_BAD_PARAMETER;
1297
1298         if (ec->busy_polling || bits > 8)
1299                 acpi_ec_burst_enable(ec);
1300
1301         for (i = 0; i < bytes; ++i, ++address, ++value)
1302                 result = (function == ACPI_READ) ?
1303                         acpi_ec_read(ec, address, value) :
1304                         acpi_ec_write(ec, address, *value);
1305
1306         if (ec->busy_polling || bits > 8)
1307                 acpi_ec_burst_disable(ec);
1308
1309         switch (result) {
1310         case -EINVAL:
1311                 return AE_BAD_PARAMETER;
1312         case -ENODEV:
1313                 return AE_NOT_FOUND;
1314         case -ETIME:
1315                 return AE_TIME;
1316         default:
1317                 return AE_OK;
1318         }
1319 }
1320
1321 /* --------------------------------------------------------------------------
1322  *                             Driver Interface
1323  * -------------------------------------------------------------------------- */
1324
1325 static acpi_status
1326 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1327
1328 static void acpi_ec_free(struct acpi_ec *ec)
1329 {
1330         if (first_ec == ec)
1331                 first_ec = NULL;
1332         if (boot_ec == ec)
1333                 boot_ec = NULL;
1334         kfree(ec);
1335 }
1336
1337 static struct acpi_ec *acpi_ec_alloc(void)
1338 {
1339         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1340
1341         if (!ec)
1342                 return NULL;
1343         mutex_init(&ec->mutex);
1344         init_waitqueue_head(&ec->wait);
1345         INIT_LIST_HEAD(&ec->list);
1346         spin_lock_init(&ec->lock);
1347         INIT_WORK(&ec->work, acpi_ec_event_handler);
1348         ec->timestamp = jiffies;
1349         ec->busy_polling = true;
1350         ec->polling_guard = 0;
1351         ec->gpe = -1;
1352         ec->irq = -1;
1353         return ec;
1354 }
1355
1356 static acpi_status
1357 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1358                                void *context, void **return_value)
1359 {
1360         char node_name[5];
1361         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1362         struct acpi_ec *ec = context;
1363         int value = 0;
1364         acpi_status status;
1365
1366         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1367
1368         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1369                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1370         return AE_OK;
1371 }
1372
1373 static acpi_status
1374 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1375 {
1376         acpi_status status;
1377         unsigned long long tmp = 0;
1378         struct acpi_ec *ec = context;
1379
1380         /* clear addr values, ec_parse_io_ports depend on it */
1381         ec->command_addr = ec->data_addr = 0;
1382
1383         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1384                                      ec_parse_io_ports, ec);
1385         if (ACPI_FAILURE(status))
1386                 return status;
1387         if (ec->data_addr == 0 || ec->command_addr == 0)
1388                 return AE_OK;
1389
1390         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1391                 /*
1392                  * Always inherit the GPE number setting from the ECDT
1393                  * EC.
1394                  */
1395                 ec->gpe = boot_ec->gpe;
1396         } else {
1397                 /* Get GPE bit assignment (EC events). */
1398                 /* TODO: Add support for _GPE returning a package */
1399                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1400                 if (ACPI_SUCCESS(status))
1401                         ec->gpe = tmp;
1402
1403                 /*
1404                  * Errors are non-fatal, allowing for ACPI Reduced Hardware
1405                  * platforms which use GpioInt instead of GPE.
1406                  */
1407         }
1408         /* Use the global lock for all EC transactions? */
1409         tmp = 0;
1410         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1411         ec->global_lock = tmp;
1412         ec->handle = handle;
1413         return AE_CTRL_TERMINATE;
1414 }
1415
1416 static bool install_gpe_event_handler(struct acpi_ec *ec)
1417 {
1418         acpi_status status;
1419
1420         status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1421                                               ACPI_GPE_EDGE_TRIGGERED,
1422                                               &acpi_ec_gpe_handler, ec);
1423         if (ACPI_FAILURE(status))
1424                 return false;
1425
1426         if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1427                 acpi_ec_enable_gpe(ec, true);
1428
1429         return true;
1430 }
1431
1432 static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1433 {
1434         return request_irq(ec->irq, acpi_ec_irq_handler, IRQF_SHARED,
1435                            "ACPI EC", ec) >= 0;
1436 }
1437
1438 /**
1439  * ec_install_handlers - Install service callbacks and register query methods.
1440  * @ec: Target EC.
1441  * @device: ACPI device object corresponding to @ec.
1442  *
1443  * Install a handler for the EC address space type unless it has been installed
1444  * already.  If @device is not NULL, also look for EC query methods in the
1445  * namespace and register them, and install an event (either GPE or GPIO IRQ)
1446  * handler for the EC, if possible.
1447  *
1448  * Return:
1449  * -ENODEV if the address space handler cannot be installed, which means
1450  *  "unable to handle transactions",
1451  * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1452  * or 0 (success) otherwise.
1453  */
1454 static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device)
1455 {
1456         acpi_status status;
1457
1458         acpi_ec_start(ec, false);
1459
1460         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1461                 acpi_ec_enter_noirq(ec);
1462                 status = acpi_install_address_space_handler(ec->handle,
1463                                                             ACPI_ADR_SPACE_EC,
1464                                                             &acpi_ec_space_handler,
1465                                                             NULL, ec);
1466                 if (ACPI_FAILURE(status)) {
1467                         acpi_ec_stop(ec, false);
1468                         return -ENODEV;
1469                 }
1470                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1471         }
1472
1473         if (!device)
1474                 return 0;
1475
1476         if (ec->gpe < 0) {
1477                 /* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1478                 int irq = acpi_dev_gpio_irq_get(device, 0);
1479                 /*
1480                  * Bail out right away for deferred probing or complete the
1481                  * initialization regardless of any other errors.
1482                  */
1483                 if (irq == -EPROBE_DEFER)
1484                         return -EPROBE_DEFER;
1485                 else if (irq >= 0)
1486                         ec->irq = irq;
1487         }
1488
1489         if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1490                 /* Find and register all query methods */
1491                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1492                                     acpi_ec_register_query_methods,
1493                                     NULL, ec, NULL);
1494                 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1495         }
1496         if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1497                 bool ready = false;
1498
1499                 if (ec->gpe >= 0)
1500                         ready = install_gpe_event_handler(ec);
1501                 else if (ec->irq >= 0)
1502                         ready = install_gpio_irq_event_handler(ec);
1503
1504                 if (ready) {
1505                         set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1506                         acpi_ec_leave_noirq(ec);
1507                 }
1508                 /*
1509                  * Failures to install an event handler are not fatal, because
1510                  * the EC can be polled for events.
1511                  */
1512         }
1513         /* EC is fully operational, allow queries */
1514         acpi_ec_enable_event(ec);
1515
1516         return 0;
1517 }
1518
1519 static void ec_remove_handlers(struct acpi_ec *ec)
1520 {
1521         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1522                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1523                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1524                         pr_err("failed to remove space handler\n");
1525                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1526         }
1527
1528         /*
1529          * Stops handling the EC transactions after removing the operation
1530          * region handler. This is required because _REG(DISCONNECT)
1531          * invoked during the removal can result in new EC transactions.
1532          *
1533          * Flushes the EC requests and thus disables the GPE before
1534          * removing the GPE handler. This is required by the current ACPICA
1535          * GPE core. ACPICA GPE core will automatically disable a GPE when
1536          * it is indicated but there is no way to handle it. So the drivers
1537          * must disable the GPEs prior to removing the GPE handlers.
1538          */
1539         acpi_ec_stop(ec, false);
1540
1541         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1542                 if (ec->gpe >= 0 &&
1543                     ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1544                                  &acpi_ec_gpe_handler)))
1545                         pr_err("failed to remove gpe handler\n");
1546
1547                 if (ec->irq >= 0)
1548                         free_irq(ec->irq, ec);
1549
1550                 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1551         }
1552         if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1553                 acpi_ec_remove_query_handlers(ec, true, 0);
1554                 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1555         }
1556 }
1557
1558 static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device)
1559 {
1560         int ret;
1561
1562         ret = ec_install_handlers(ec, device);
1563         if (ret)
1564                 return ret;
1565
1566         /* First EC capable of handling transactions */
1567         if (!first_ec)
1568                 first_ec = ec;
1569
1570         pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1571                 ec->data_addr);
1572
1573         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1574                 if (ec->gpe >= 0)
1575                         pr_info("GPE=0x%x\n", ec->gpe);
1576                 else
1577                         pr_info("IRQ=%d\n", ec->irq);
1578         }
1579
1580         return ret;
1581 }
1582
1583 static int acpi_ec_add(struct acpi_device *device)
1584 {
1585         struct acpi_ec *ec;
1586         int ret;
1587
1588         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1589         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1590
1591         if (boot_ec && (boot_ec->handle == device->handle ||
1592             !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
1593                 /* Fast path: this device corresponds to the boot EC. */
1594                 ec = boot_ec;
1595         } else {
1596                 acpi_status status;
1597
1598                 ec = acpi_ec_alloc();
1599                 if (!ec)
1600                         return -ENOMEM;
1601
1602                 status = ec_parse_device(device->handle, 0, ec, NULL);
1603                 if (status != AE_CTRL_TERMINATE) {
1604                         ret = -EINVAL;
1605                         goto err;
1606                 }
1607
1608                 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1609                     ec->data_addr == boot_ec->data_addr) {
1610                         /*
1611                          * Trust PNP0C09 namespace location rather than
1612                          * ECDT ID. But trust ECDT GPE rather than _GPE
1613                          * because of ASUS quirks, so do not change
1614                          * boot_ec->gpe to ec->gpe.
1615                          */
1616                         boot_ec->handle = ec->handle;
1617                         acpi_handle_debug(ec->handle, "duplicated.\n");
1618                         acpi_ec_free(ec);
1619                         ec = boot_ec;
1620                 }
1621         }
1622
1623         ret = acpi_ec_setup(ec, device);
1624         if (ret)
1625                 goto err;
1626
1627         if (ec == boot_ec)
1628                 acpi_handle_info(boot_ec->handle,
1629                                  "Boot %s EC initialization complete\n",
1630                                  boot_ec_is_ecdt ? "ECDT" : "DSDT");
1631
1632         acpi_handle_info(ec->handle,
1633                          "EC: Used to handle transactions and events\n");
1634
1635         device->driver_data = ec;
1636
1637         ret = !!request_region(ec->data_addr, 1, "EC data");
1638         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1639         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1640         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1641
1642         /* Reprobe devices depending on the EC */
1643         acpi_walk_dep_device_list(ec->handle);
1644
1645         acpi_handle_debug(ec->handle, "enumerated.\n");
1646         return 0;
1647
1648 err:
1649         if (ec != boot_ec)
1650                 acpi_ec_free(ec);
1651
1652         return ret;
1653 }
1654
1655 static int acpi_ec_remove(struct acpi_device *device)
1656 {
1657         struct acpi_ec *ec;
1658
1659         if (!device)
1660                 return -EINVAL;
1661
1662         ec = acpi_driver_data(device);
1663         release_region(ec->data_addr, 1);
1664         release_region(ec->command_addr, 1);
1665         device->driver_data = NULL;
1666         if (ec != boot_ec) {
1667                 ec_remove_handlers(ec);
1668                 acpi_ec_free(ec);
1669         }
1670         return 0;
1671 }
1672
1673 static acpi_status
1674 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1675 {
1676         struct acpi_ec *ec = context;
1677
1678         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1679                 return AE_OK;
1680
1681         /*
1682          * The first address region returned is the data port, and
1683          * the second address region returned is the status/command
1684          * port.
1685          */
1686         if (ec->data_addr == 0)
1687                 ec->data_addr = resource->data.io.minimum;
1688         else if (ec->command_addr == 0)
1689                 ec->command_addr = resource->data.io.minimum;
1690         else
1691                 return AE_CTRL_TERMINATE;
1692
1693         return AE_OK;
1694 }
1695
1696 static const struct acpi_device_id ec_device_ids[] = {
1697         {"PNP0C09", 0},
1698         {ACPI_ECDT_HID, 0},
1699         {"", 0},
1700 };
1701
1702 /*
1703  * This function is not Windows-compatible as Windows never enumerates the
1704  * namespace EC before the main ACPI device enumeration process. It is
1705  * retained for historical reason and will be deprecated in the future.
1706  */
1707 void __init acpi_ec_dsdt_probe(void)
1708 {
1709         struct acpi_ec *ec;
1710         acpi_status status;
1711         int ret;
1712
1713         /*
1714          * If a platform has ECDT, there is no need to proceed as the
1715          * following probe is not a part of the ACPI device enumeration,
1716          * executing _STA is not safe, and thus this probe may risk of
1717          * picking up an invalid EC device.
1718          */
1719         if (boot_ec)
1720                 return;
1721
1722         ec = acpi_ec_alloc();
1723         if (!ec)
1724                 return;
1725
1726         /*
1727          * At this point, the namespace is initialized, so start to find
1728          * the namespace objects.
1729          */
1730         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1731         if (ACPI_FAILURE(status) || !ec->handle) {
1732                 acpi_ec_free(ec);
1733                 return;
1734         }
1735
1736         /*
1737          * When the DSDT EC is available, always re-configure boot EC to
1738          * have _REG evaluated. _REG can only be evaluated after the
1739          * namespace initialization.
1740          * At this point, the GPE is not fully initialized, so do not to
1741          * handle the events.
1742          */
1743         ret = acpi_ec_setup(ec, NULL);
1744         if (ret) {
1745                 acpi_ec_free(ec);
1746                 return;
1747         }
1748
1749         boot_ec = ec;
1750
1751         acpi_handle_info(ec->handle,
1752                          "Boot DSDT EC used to handle transactions\n");
1753 }
1754
1755 /*
1756  * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization.
1757  *
1758  * First, look for an ACPI handle for the boot ECDT EC if acpi_ec_add() has not
1759  * found a matching object in the namespace.
1760  *
1761  * Next, in case the DSDT EC is not functioning, it is still necessary to
1762  * provide a functional ECDT EC to handle events, so add an extra device object
1763  * to represent it (see https://bugzilla.kernel.org/show_bug.cgi?id=115021).
1764  *
1765  * This is useful on platforms with valid ECDT and invalid DSDT EC settings,
1766  * like ASUS X550ZE (see https://bugzilla.kernel.org/show_bug.cgi?id=196847).
1767  */
1768 static void __init acpi_ec_ecdt_start(void)
1769 {
1770         struct acpi_table_ecdt *ecdt_ptr;
1771         acpi_handle handle;
1772         acpi_status status;
1773
1774         /* Bail out if a matching EC has been found in the namespace. */
1775         if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT)
1776                 return;
1777
1778         /* Look up the object pointed to from the ECDT in the namespace. */
1779         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1780                                 (struct acpi_table_header **)&ecdt_ptr);
1781         if (ACPI_FAILURE(status))
1782                 return;
1783
1784         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1785         if (ACPI_SUCCESS(status)) {
1786                 boot_ec->handle = handle;
1787
1788                 /* Add a special ACPI device object to represent the boot EC. */
1789                 acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1790         }
1791
1792         acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1793 }
1794
1795 /*
1796  * On some hardware it is necessary to clear events accumulated by the EC during
1797  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1798  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1799  *
1800  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1801  *
1802  * Ideally, the EC should also be instructed NOT to accumulate events during
1803  * sleep (which Windows seems to do somehow), but the interface to control this
1804  * behaviour is not known at this time.
1805  *
1806  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1807  * however it is very likely that other Samsung models are affected.
1808  *
1809  * On systems which don't accumulate _Q events during sleep, this extra check
1810  * should be harmless.
1811  */
1812 static int ec_clear_on_resume(const struct dmi_system_id *id)
1813 {
1814         pr_debug("Detected system needing EC poll on resume.\n");
1815         EC_FLAGS_CLEAR_ON_RESUME = 1;
1816         ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1817         return 0;
1818 }
1819
1820 /*
1821  * Some ECDTs contain wrong register addresses.
1822  * MSI MS-171F
1823  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1824  */
1825 static int ec_correct_ecdt(const struct dmi_system_id *id)
1826 {
1827         pr_debug("Detected system needing ECDT address correction.\n");
1828         EC_FLAGS_CORRECT_ECDT = 1;
1829         return 0;
1830 }
1831
1832 /*
1833  * Some DSDTs contain wrong GPE setting.
1834  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1835  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1836  */
1837 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1838 {
1839         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1840         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1841         return 0;
1842 }
1843
1844 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1845         {
1846         ec_correct_ecdt, "MSI MS-171F", {
1847         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1848         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1849         {
1850         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1851         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1852         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1853         {
1854         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1855         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1856         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1857         {
1858         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1859         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1860         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1861         {
1862         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1863         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1864         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1865         {
1866         ec_honor_ecdt_gpe, "ASUS X580VD", {
1867         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1868         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1869         {
1870         ec_clear_on_resume, "Samsung hardware", {
1871         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1872         {},
1873 };
1874
1875 void __init acpi_ec_ecdt_probe(void)
1876 {
1877         struct acpi_table_ecdt *ecdt_ptr;
1878         struct acpi_ec *ec;
1879         acpi_status status;
1880         int ret;
1881
1882         /* Generate a boot ec context. */
1883         dmi_check_system(ec_dmi_table);
1884         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1885                                 (struct acpi_table_header **)&ecdt_ptr);
1886         if (ACPI_FAILURE(status))
1887                 return;
1888
1889         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1890                 /*
1891                  * Asus X50GL:
1892                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1893                  */
1894                 goto out;
1895         }
1896
1897         ec = acpi_ec_alloc();
1898         if (!ec)
1899                 goto out;
1900
1901         if (EC_FLAGS_CORRECT_ECDT) {
1902                 ec->command_addr = ecdt_ptr->data.address;
1903                 ec->data_addr = ecdt_ptr->control.address;
1904         } else {
1905                 ec->command_addr = ecdt_ptr->control.address;
1906                 ec->data_addr = ecdt_ptr->data.address;
1907         }
1908
1909         /*
1910          * Ignore the GPE value on Reduced Hardware platforms.
1911          * Some products have this set to an erroneous value.
1912          */
1913         if (!acpi_gbl_reduced_hardware)
1914                 ec->gpe = ecdt_ptr->gpe;
1915
1916         ec->handle = ACPI_ROOT_OBJECT;
1917
1918         /*
1919          * At this point, the namespace is not initialized, so do not find
1920          * the namespace objects, or handle the events.
1921          */
1922         ret = acpi_ec_setup(ec, NULL);
1923         if (ret) {
1924                 acpi_ec_free(ec);
1925                 goto out;
1926         }
1927
1928         boot_ec = ec;
1929         boot_ec_is_ecdt = true;
1930
1931         pr_info("Boot ECDT EC used to handle transactions\n");
1932
1933 out:
1934         acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1935 }
1936
1937 #ifdef CONFIG_PM_SLEEP
1938 static int acpi_ec_suspend(struct device *dev)
1939 {
1940         struct acpi_ec *ec =
1941                 acpi_driver_data(to_acpi_device(dev));
1942
1943         if (!pm_suspend_no_platform() && ec_freeze_events)
1944                 acpi_ec_disable_event(ec);
1945         return 0;
1946 }
1947
1948 static int acpi_ec_suspend_noirq(struct device *dev)
1949 {
1950         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1951
1952         /*
1953          * The SCI handler doesn't run at this point, so the GPE can be
1954          * masked at the low level without side effects.
1955          */
1956         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1957             ec->gpe >= 0 && ec->reference_count >= 1)
1958                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1959
1960         acpi_ec_enter_noirq(ec);
1961
1962         return 0;
1963 }
1964
1965 static int acpi_ec_resume_noirq(struct device *dev)
1966 {
1967         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1968
1969         acpi_ec_leave_noirq(ec);
1970
1971         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1972             ec->gpe >= 0 && ec->reference_count >= 1)
1973                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1974
1975         return 0;
1976 }
1977
1978 static int acpi_ec_resume(struct device *dev)
1979 {
1980         struct acpi_ec *ec =
1981                 acpi_driver_data(to_acpi_device(dev));
1982
1983         acpi_ec_enable_event(ec);
1984         return 0;
1985 }
1986
1987 void acpi_ec_mark_gpe_for_wake(void)
1988 {
1989         if (first_ec && !ec_no_wakeup)
1990                 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
1991 }
1992 EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
1993
1994 void acpi_ec_set_gpe_wake_mask(u8 action)
1995 {
1996         if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
1997                 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
1998 }
1999
2000 bool acpi_ec_dispatch_gpe(void)
2001 {
2002         u32 ret;
2003
2004         if (!first_ec)
2005                 return acpi_any_gpe_status_set(U32_MAX);
2006
2007         /*
2008          * Report wakeup if the status bit is set for any enabled GPE other
2009          * than the EC one.
2010          */
2011         if (acpi_any_gpe_status_set(first_ec->gpe))
2012                 return true;
2013
2014         /*
2015          * Dispatch the EC GPE in-band, but do not report wakeup in any case
2016          * to allow the caller to process events properly after that.
2017          */
2018         ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
2019         if (ret == ACPI_INTERRUPT_HANDLED)
2020                 pm_pr_dbg("ACPI EC GPE dispatched\n");
2021
2022         /* Flush the event and query workqueues. */
2023         acpi_ec_flush_work();
2024
2025         return false;
2026 }
2027 #endif /* CONFIG_PM_SLEEP */
2028
2029 static const struct dev_pm_ops acpi_ec_pm = {
2030         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2031         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2032 };
2033
2034 static int param_set_event_clearing(const char *val,
2035                                     const struct kernel_param *kp)
2036 {
2037         int result = 0;
2038
2039         if (!strncmp(val, "status", sizeof("status") - 1)) {
2040                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2041                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2042         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2043                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2044                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2045         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2046                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2047                 pr_info("Assuming SCI_EVT clearing on event reads\n");
2048         } else
2049                 result = -EINVAL;
2050         return result;
2051 }
2052
2053 static int param_get_event_clearing(char *buffer,
2054                                     const struct kernel_param *kp)
2055 {
2056         switch (ec_event_clearing) {
2057         case ACPI_EC_EVT_TIMING_STATUS:
2058                 return sprintf(buffer, "status\n");
2059         case ACPI_EC_EVT_TIMING_QUERY:
2060                 return sprintf(buffer, "query\n");
2061         case ACPI_EC_EVT_TIMING_EVENT:
2062                 return sprintf(buffer, "event\n");
2063         default:
2064                 return sprintf(buffer, "invalid\n");
2065         }
2066         return 0;
2067 }
2068
2069 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2070                   NULL, 0644);
2071 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2072
2073 static struct acpi_driver acpi_ec_driver = {
2074         .name = "ec",
2075         .class = ACPI_EC_CLASS,
2076         .ids = ec_device_ids,
2077         .ops = {
2078                 .add = acpi_ec_add,
2079                 .remove = acpi_ec_remove,
2080                 },
2081         .drv.pm = &acpi_ec_pm,
2082 };
2083
2084 static void acpi_ec_destroy_workqueues(void)
2085 {
2086         if (ec_wq) {
2087                 destroy_workqueue(ec_wq);
2088                 ec_wq = NULL;
2089         }
2090         if (ec_query_wq) {
2091                 destroy_workqueue(ec_query_wq);
2092                 ec_query_wq = NULL;
2093         }
2094 }
2095
2096 static int acpi_ec_init_workqueues(void)
2097 {
2098         if (!ec_wq)
2099                 ec_wq = alloc_ordered_workqueue("kec", 0);
2100
2101         if (!ec_query_wq)
2102                 ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2103
2104         if (!ec_wq || !ec_query_wq) {
2105                 acpi_ec_destroy_workqueues();
2106                 return -ENODEV;
2107         }
2108         return 0;
2109 }
2110
2111 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2112         {
2113                 .ident = "Thinkpad X1 Carbon 6th",
2114                 .matches = {
2115                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2116                         DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2117                 },
2118         },
2119         {
2120                 .ident = "ThinkPad X1 Carbon 6th",
2121                 .matches = {
2122                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2123                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2124                 },
2125         },
2126         {
2127                 .ident = "ThinkPad X1 Yoga 3rd",
2128                 .matches = {
2129                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2130                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2131                 },
2132         },
2133         { },
2134 };
2135
2136 void __init acpi_ec_init(void)
2137 {
2138         int result;
2139
2140         result = acpi_ec_init_workqueues();
2141         if (result)
2142                 return;
2143
2144         /*
2145          * Disable EC wakeup on following systems to prevent periodic
2146          * wakeup from EC GPE.
2147          */
2148         if (dmi_check_system(acpi_ec_no_wakeup)) {
2149                 ec_no_wakeup = true;
2150                 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2151         }
2152
2153         /* Driver must be registered after acpi_ec_init_workqueues(). */
2154         acpi_bus_register_driver(&acpi_ec_driver);
2155
2156         acpi_ec_ecdt_start();
2157 }
2158
2159 /* EC driver currently not unloadable */
2160 #if 0
2161 static void __exit acpi_ec_exit(void)
2162 {
2163
2164         acpi_bus_unregister_driver(&acpi_ec_driver);
2165         acpi_ec_destroy_workqueues();
2166 }
2167 #endif  /* 0 */