drivers/acpi/ec.c

   1 /*
   2  *  ec.c - ACPI Embedded Controller Driver (v3)
   3  *
   4  *  Copyright (C) 2001-2015 Intel Corporation
   5  *    Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>
   6  *            2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
   7  *            2006       Denis Sadykov <denis.m.sadykov@intel.com>
   8  *            2004       Luming Yu <luming.yu@intel.com>
   9  *            2001, 2002 Andy Grover <andrew.grover@intel.com>
  10  *            2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
  11  *  Copyright (C) 2008      Alexey Starikovskiy <astarikovskiy@suse.de>
  12  *
  13  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  14  *
  15  *  This program is free software; you can redistribute it and/or modify
  16  *  it under the terms of the GNU General Public License as published by
  17  *  the Free Software Foundation; either version 2 of the License, or (at
  18  *  your option) any later version.
  19  *
  20  *  This program is distributed in the hope that it will be useful, but
  21  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  23  *  General Public License for more details.
  24  *
  25  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  26  */
  27
  28 /* Uncomment next line to get verbose printout */
  29 /* #define DEBUG */
  30 #define pr_fmt(fmt) "ACPI: EC: " fmt
  31
  32 #include <linux/kernel.h>
  33 #include <linux/module.h>
  34 #include <linux/init.h>
  35 #include <linux/types.h>
  36 #include <linux/delay.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/list.h>
  39 #include <linux/spinlock.h>
  40 #include <linux/slab.h>
  41 #include <linux/acpi.h>
  42 #include <linux/dmi.h>
  43 #include <asm/io.h>
  44
  45 #include "internal.h"
  46
  47 #define ACPI_EC_CLASS                   "embedded_controller"
  48 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  49 #define ACPI_EC_FILE_INFO               "info"
  50
  51 /* EC status register */
  52 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  53 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  54 #define ACPI_EC_FLAG_CMD        0x08    /* Input buffer contains a command */
  55 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  56 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  57
  58 /*
  59  * The SCI_EVT clearing timing is not defined by the ACPI specification.
  60  * This leads to lots of practical timing issues for the host EC driver.
  61  * The following variations are defined (from the target EC firmware's
  62  * perspective):
  63  * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
  64  *         target can clear SCI_EVT at any time so long as the host can see
  65  *         the indication by reading the status register (EC_SC). So the
  66  *         host should re-check SCI_EVT after the first time the SCI_EVT
  67  *         indication is seen, which is the same time the query request
  68  *         (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
  69  *         at any later time could indicate another event. Normally such
  70  *         kind of EC firmware has implemented an event queue and will
  71  *         return 0x00 to indicate "no outstanding event".
  72  * QUERY: After seeing the query request (QR_EC) written to the command
  73  *        register (EC_CMD) by the host and having prepared the responding
  74  *        event value in the data register (EC_DATA), the target can safely
  75  *        clear SCI_EVT because the target can confirm that the current
  76  *        event is being handled by the host. The host then should check
  77  *        SCI_EVT right after reading the event response from the data
  78  *        register (EC_DATA).
  79  * EVENT: After seeing the event response read from the data register
  80  *        (EC_DATA) by the host, the target can clear SCI_EVT. As the
  81  *        target requires time to notice the change in the data register
  82  *        (EC_DATA), the host may be required to wait additional guarding
  83  *        time before checking the SCI_EVT again. Such guarding may not be
  84  *        necessary if the host is notified via another IRQ.
  85  */
  86 #define ACPI_EC_EVT_TIMING_STATUS       0x00
  87 #define ACPI_EC_EVT_TIMING_QUERY        0x01
  88 #define ACPI_EC_EVT_TIMING_EVENT        0x02
  89
  90 /* EC commands */
  91 enum ec_command {
  92         ACPI_EC_COMMAND_READ = 0x80,
  93         ACPI_EC_COMMAND_WRITE = 0x81,
  94         ACPI_EC_BURST_ENABLE = 0x82,
  95         ACPI_EC_BURST_DISABLE = 0x83,
  96         ACPI_EC_COMMAND_QUERY = 0x84,
  97 };
  98
  99 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
 100 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
 101 #define ACPI_EC_UDELAY_POLL     550     /* Wait 1ms for EC transaction polling */
 102 #define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
 103                                          * when trying to clear the EC */
 104 #define ACPI_EC_MAX_QUERIES     16      /* Maximum number of parallel queries */
 105
 106 enum {
 107         EC_FLAGS_QUERY_ENABLED,         /* Query is enabled */
 108         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
 109         EC_FLAGS_QUERY_GUARDING,        /* Guard for SCI_EVT check */
 110         EC_FLAGS_GPE_HANDLER_INSTALLED, /* GPE handler installed */
 111         EC_FLAGS_EC_HANDLER_INSTALLED,  /* OpReg handler installed */
 112         EC_FLAGS_EVT_HANDLER_INSTALLED, /* _Qxx handlers installed */
 113         EC_FLAGS_STARTED,               /* Driver is started */
 114         EC_FLAGS_STOPPED,               /* Driver is stopped */
 115         EC_FLAGS_GPE_MASKED,            /* GPE masked */
 116 };
 117
 118 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
 119 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
 120
 121 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 122 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 123 module_param(ec_delay, uint, 0644);
 124 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
 125
 126 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
 127 module_param(ec_max_queries, uint, 0644);
 128 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
 129
 130 static bool ec_busy_polling __read_mostly;
 131 module_param(ec_busy_polling, bool, 0644);
 132 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
 133
 134 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
 135 module_param(ec_polling_guard, uint, 0644);
 136 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
 137
 138 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
 139
 140 /*
 141  * If the number of false interrupts per one transaction exceeds
 142  * this threshold, will think there is a GPE storm happened and
 143  * will disable the GPE for normal transaction.
 144  */
 145 static unsigned int ec_storm_threshold  __read_mostly = 8;
 146 module_param(ec_storm_threshold, uint, 0644);
 147 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 148
 149 static bool ec_freeze_events __read_mostly = false;
 150 module_param(ec_freeze_events, bool, 0644);
 151 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
 152
 153 static bool ec_no_wakeup __read_mostly;
 154 module_param(ec_no_wakeup, bool, 0644);
 155 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
 156
 157 struct acpi_ec_query_handler {
 158         struct list_head node;
 159         acpi_ec_query_func func;
 160         acpi_handle handle;
 161         void *data;
 162         u8 query_bit;
 163         struct kref kref;
 164 };
 165
 166 struct transaction {
 167         const u8 *wdata;
 168         u8 *rdata;
 169         unsigned short irq_count;
 170         u8 command;
 171         u8 wi;
 172         u8 ri;
 173         u8 wlen;
 174         u8 rlen;
 175         u8 flags;
 176 };
 177
 178 struct acpi_ec_query {
 179         struct transaction transaction;
 180         struct work_struct work;
 181         struct acpi_ec_query_handler *handler;
 182 };
 183
 184 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
 185 static void advance_transaction(struct acpi_ec *ec);
 186 static void acpi_ec_event_handler(struct work_struct *work);
 187 static void acpi_ec_event_processor(struct work_struct *work);
 188
 189 struct acpi_ec *first_ec;
 190 EXPORT_SYMBOL(first_ec);
 191
 192 static struct acpi_ec *boot_ec;
 193 static bool boot_ec_is_ecdt = false;
 194 static struct workqueue_struct *ec_query_wq;
 195
 196 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
 197 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
 198 static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
 199
 200 /* --------------------------------------------------------------------------
 201  *                           Logging/Debugging
 202  * -------------------------------------------------------------------------- */
 203
 204 /*
 205  * Splitters used by the developers to track the boundary of the EC
 206  * handling processes.
 207  */
 208 #ifdef DEBUG
 209 #define EC_DBG_SEP      " "
 210 #define EC_DBG_DRV      "+++++"
 211 #define EC_DBG_STM      "====="
 212 #define EC_DBG_REQ      "*****"
 213 #define EC_DBG_EVT      "#####"
 214 #else
 215 #define EC_DBG_SEP      ""
 216 #define EC_DBG_DRV
 217 #define EC_DBG_STM
 218 #define EC_DBG_REQ
 219 #define EC_DBG_EVT
 220 #endif
 221
 222 #define ec_log_raw(fmt, ...) \
 223         pr_info(fmt "\n", ##__VA_ARGS__)
 224 #define ec_dbg_raw(fmt, ...) \
 225         pr_debug(fmt "\n", ##__VA_ARGS__)
 226 #define ec_log(filter, fmt, ...) \
 227         ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 228 #define ec_dbg(filter, fmt, ...) \
 229         ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 230
 231 #define ec_log_drv(fmt, ...) \
 232         ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 233 #define ec_dbg_drv(fmt, ...) \
 234         ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 235 #define ec_dbg_stm(fmt, ...) \
 236         ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
 237 #define ec_dbg_req(fmt, ...) \
 238         ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
 239 #define ec_dbg_evt(fmt, ...) \
 240         ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
 241 #define ec_dbg_ref(ec, fmt, ...) \
 242         ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
 243
 244 /* --------------------------------------------------------------------------
 245  *                           Device Flags
 246  * -------------------------------------------------------------------------- */
 247
 248 static bool acpi_ec_started(struct acpi_ec *ec)
 249 {
 250         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
 251                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
 252 }
 253
 254 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
 255 {
 256         /*
 257          * There is an OSPM early stage logic. During the early stages
 258          * (boot/resume), OSPMs shouldn't enable the event handling, only
 259          * the EC transactions are allowed to be performed.
 260          */
 261         if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 262                 return false;
 263         /*
 264          * However, disabling the event handling is experimental for late
 265          * stage (suspend), and is controlled by the boot parameter of
 266          * "ec_freeze_events":
 267          * 1. true:  The EC event handling is disabled before entering
 268          *           the noirq stage.
 269          * 2. false: The EC event handling is automatically disabled as
 270          *           soon as the EC driver is stopped.
 271          */
 272         if (ec_freeze_events)
 273                 return acpi_ec_started(ec);
 274         else
 275                 return test_bit(EC_FLAGS_STARTED, &ec->flags);
 276 }
 277
 278 static bool acpi_ec_flushed(struct acpi_ec *ec)
 279 {
 280         return ec->reference_count == 1;
 281 }
 282
 283 /* --------------------------------------------------------------------------
 284  *                           EC Registers
 285  * -------------------------------------------------------------------------- */
 286
 287 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 288 {
 289         u8 x = inb(ec->command_addr);
 290
 291         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
 292                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
 293                    x,
 294                    !!(x & ACPI_EC_FLAG_SCI),
 295                    !!(x & ACPI_EC_FLAG_BURST),
 296                    !!(x & ACPI_EC_FLAG_CMD),
 297                    !!(x & ACPI_EC_FLAG_IBF),
 298                    !!(x & ACPI_EC_FLAG_OBF));
 299         return x;
 300 }
 301
 302 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 303 {
 304         u8 x = inb(ec->data_addr);
 305
 306         ec->timestamp = jiffies;
 307         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
 308         return x;
 309 }
 310
 311 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 312 {
 313         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
 314         outb(command, ec->command_addr);
 315         ec->timestamp = jiffies;
 316 }
 317
 318 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 319 {
 320         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
 321         outb(data, ec->data_addr);
 322         ec->timestamp = jiffies;
 323 }
 324
 325 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
 326 static const char *acpi_ec_cmd_string(u8 cmd)
 327 {
 328         switch (cmd) {
 329         case 0x80:
 330                 return "RD_EC";
 331         case 0x81:
 332                 return "WR_EC";
 333         case 0x82:
 334                 return "BE_EC";
 335         case 0x83:
 336                 return "BD_EC";
 337         case 0x84:
 338                 return "QR_EC";
 339         }
 340         return "UNKNOWN";
 341 }
 342 #else
 343 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 344 #endif
 345
 346 /* --------------------------------------------------------------------------
 347  *                           GPE Registers
 348  * -------------------------------------------------------------------------- */
 349
 350 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
 351 {
 352         acpi_event_status gpe_status = 0;
 353
 354         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
 355         return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
 356 }
 357
 358 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
 359 {
 360         if (open)
 361                 acpi_enable_gpe(NULL, ec->gpe);
 362         else {
 363                 BUG_ON(ec->reference_count < 1);
 364                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 365         }
 366         if (acpi_ec_is_gpe_raised(ec)) {
 367                 /*
 368                  * On some platforms, EN=1 writes cannot trigger GPE. So
 369                  * software need to manually trigger a pseudo GPE event on
 370                  * EN=1 writes.
 371                  */
 372                 ec_dbg_raw("Polling quirk");
 373                 advance_transaction(ec);
 374         }
 375 }
 376
 377 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
 378 {
 379         if (close)
 380                 acpi_disable_gpe(NULL, ec->gpe);
 381         else {
 382                 BUG_ON(ec->reference_count < 1);
 383                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 384         }
 385 }
 386
 387 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
 388 {
 389         /*
 390          * GPE STS is a W1C register, which means:
 391          * 1. Software can clear it without worrying about clearing other
 392          *    GPEs' STS bits when the hardware sets them in parallel.
 393          * 2. As long as software can ensure only clearing it when it is
 394          *    set, hardware won't set it in parallel.
 395          * So software can clear GPE in any contexts.
 396          * Warning: do not move the check into advance_transaction() as the
 397          * EC commands will be sent without GPE raised.
 398          */
 399         if (!acpi_ec_is_gpe_raised(ec))
 400                 return;
 401         acpi_clear_gpe(NULL, ec->gpe);
 402 }
 403
 404 /* --------------------------------------------------------------------------
 405  *                           Transaction Management
 406  * -------------------------------------------------------------------------- */
 407
 408 static void acpi_ec_submit_request(struct acpi_ec *ec)
 409 {
 410         ec->reference_count++;
 411         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
 412             ec->reference_count == 1)
 413                 acpi_ec_enable_gpe(ec, true);
 414 }
 415
 416 static void acpi_ec_complete_request(struct acpi_ec *ec)
 417 {
 418         bool flushed = false;
 419
 420         ec->reference_count--;
 421         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
 422             ec->reference_count == 0)
 423                 acpi_ec_disable_gpe(ec, true);
 424         flushed = acpi_ec_flushed(ec);
 425         if (flushed)
 426                 wake_up(&ec->wait);
 427 }
 428
 429 static void acpi_ec_mask_gpe(struct acpi_ec *ec)
 430 {
 431         if (!test_bit(EC_FLAGS_GPE_MASKED, &ec->flags)) {
 432                 acpi_ec_disable_gpe(ec, false);
 433                 ec_dbg_drv("Polling enabled");
 434                 set_bit(EC_FLAGS_GPE_MASKED, &ec->flags);
 435         }
 436 }
 437
 438 static void acpi_ec_unmask_gpe(struct acpi_ec *ec)
 439 {
 440         if (test_bit(EC_FLAGS_GPE_MASKED, &ec->flags)) {
 441                 clear_bit(EC_FLAGS_GPE_MASKED, &ec->flags);
 442                 acpi_ec_enable_gpe(ec, false);
 443                 ec_dbg_drv("Polling disabled");
 444         }
 445 }
 446
 447 /*
 448  * acpi_ec_submit_flushable_request() - Increase the reference count unless
 449  *                                      the flush operation is not in
 450  *                                      progress
 451  * @ec: the EC device
 452  *
 453  * This function must be used before taking a new action that should hold
 454  * the reference count.  If this function returns false, then the action
 455  * must be discarded or it will prevent the flush operation from being
 456  * completed.
 457  */
 458 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
 459 {
 460         if (!acpi_ec_started(ec))
 461                 return false;
 462         acpi_ec_submit_request(ec);
 463         return true;
 464 }
 465
 466 static void acpi_ec_submit_query(struct acpi_ec *ec)
 467 {
 468         acpi_ec_mask_gpe(ec);
 469         if (!acpi_ec_event_enabled(ec))
 470                 return;
 471         if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 472                 ec_dbg_evt("Command(%s) submitted/blocked",
 473                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 474                 ec->nr_pending_queries++;
 475                 schedule_work(&ec->work);
 476         }
 477 }
 478
 479 static void acpi_ec_complete_query(struct acpi_ec *ec)
 480 {
 481         if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 482                 ec_dbg_evt("Command(%s) unblocked",
 483                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 484         acpi_ec_unmask_gpe(ec);
 485 }
 486
 487 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
 488 {
 489         if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 490                 ec_log_drv("event unblocked");
 491         /*
 492          * Unconditionally invoke this once after enabling the event
 493          * handling mechanism to detect the pending events.
 494          */
 495         advance_transaction(ec);
 496 }
 497
 498 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
 499 {
 500         if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 501                 ec_log_drv("event blocked");
 502 }
 503
 504 static void acpi_ec_enable_event(struct acpi_ec *ec)
 505 {
 506         unsigned long flags;
 507
 508         spin_lock_irqsave(&ec->lock, flags);
 509         if (acpi_ec_started(ec))
 510                 __acpi_ec_enable_event(ec);
 511         spin_unlock_irqrestore(&ec->lock, flags);
 512 }
 513
 514 #ifdef CONFIG_PM_SLEEP
 515 static bool acpi_ec_query_flushed(struct acpi_ec *ec)
 516 {
 517         bool flushed;
 518         unsigned long flags;
 519
 520         spin_lock_irqsave(&ec->lock, flags);
 521         flushed = !ec->nr_pending_queries;
 522         spin_unlock_irqrestore(&ec->lock, flags);
 523         return flushed;
 524 }
 525
 526 static void __acpi_ec_flush_event(struct acpi_ec *ec)
 527 {
 528         /*
 529          * When ec_freeze_events is true, we need to flush events in
 530          * the proper position before entering the noirq stage.
 531          */
 532         wait_event(ec->wait, acpi_ec_query_flushed(ec));
 533         if (ec_query_wq)
 534                 flush_workqueue(ec_query_wq);
 535 }
 536
 537 static void acpi_ec_disable_event(struct acpi_ec *ec)
 538 {
 539         unsigned long flags;
 540
 541         spin_lock_irqsave(&ec->lock, flags);
 542         __acpi_ec_disable_event(ec);
 543         spin_unlock_irqrestore(&ec->lock, flags);
 544         __acpi_ec_flush_event(ec);
 545 }
 546
 547 void acpi_ec_flush_work(void)
 548 {
 549         if (first_ec)
 550                 __acpi_ec_flush_event(first_ec);
 551
 552         flush_scheduled_work();
 553 }
 554 #endif /* CONFIG_PM_SLEEP */
 555
 556 static bool acpi_ec_guard_event(struct acpi_ec *ec)
 557 {
 558         bool guarded = true;
 559         unsigned long flags;
 560
 561         spin_lock_irqsave(&ec->lock, flags);
 562         /*
 563          * If firmware SCI_EVT clearing timing is "event", we actually
 564          * don't know when the SCI_EVT will be cleared by firmware after
 565          * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
 566          * acceptable period.
 567          *
 568          * The guarding period begins when EC_FLAGS_QUERY_PENDING is
 569          * flagged, which means SCI_EVT check has just been performed.
 570          * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
 571          * guarding should have already been performed (via
 572          * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
 573          * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
 574          * ACPI_EC_COMMAND_POLL state immediately.
 575          */
 576         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
 577             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
 578             !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
 579             (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
 580                 guarded = false;
 581         spin_unlock_irqrestore(&ec->lock, flags);
 582         return guarded;
 583 }
 584
 585 static int ec_transaction_polled(struct acpi_ec *ec)
 586 {
 587         unsigned long flags;
 588         int ret = 0;
 589
 590         spin_lock_irqsave(&ec->lock, flags);
 591         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
 592                 ret = 1;
 593         spin_unlock_irqrestore(&ec->lock, flags);
 594         return ret;
 595 }
 596
 597 static int ec_transaction_completed(struct acpi_ec *ec)
 598 {
 599         unsigned long flags;
 600         int ret = 0;
 601
 602         spin_lock_irqsave(&ec->lock, flags);
 603         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 604                 ret = 1;
 605         spin_unlock_irqrestore(&ec->lock, flags);
 606         return ret;
 607 }
 608
 609 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
 610 {
 611         ec->curr->flags |= flag;
 612         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 613                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
 614                     flag == ACPI_EC_COMMAND_POLL)
 615                         acpi_ec_complete_query(ec);
 616                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
 617                     flag == ACPI_EC_COMMAND_COMPLETE)
 618                         acpi_ec_complete_query(ec);
 619                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 620                     flag == ACPI_EC_COMMAND_COMPLETE)
 621                         set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 622         }
 623 }
 624
 625 static void advance_transaction(struct acpi_ec *ec)
 626 {
 627         struct transaction *t;
 628         u8 status;
 629         bool wakeup = false;
 630
 631         ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
 632                    smp_processor_id());
 633         /*
 634          * By always clearing STS before handling all indications, we can
 635          * ensure a hardware STS 0->1 change after this clearing can always
 636          * trigger a GPE interrupt.
 637          */
 638         acpi_ec_clear_gpe(ec);
 639         status = acpi_ec_read_status(ec);
 640         t = ec->curr;
 641         /*
 642          * Another IRQ or a guarded polling mode advancement is detected,
 643          * the next QR_EC submission is then allowed.
 644          */
 645         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
 646                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 647                     (!ec->nr_pending_queries ||
 648                      test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
 649                         clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 650                         acpi_ec_complete_query(ec);
 651                 }
 652         }
 653         if (!t)
 654                 goto err;
 655         if (t->flags & ACPI_EC_COMMAND_POLL) {
 656                 if (t->wlen > t->wi) {
 657                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 658                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 659                         else
 660                                 goto err;
 661                 } else if (t->rlen > t->ri) {
 662                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 663                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 664                                 if (t->rlen == t->ri) {
 665                                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 666                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 667                                                 ec_dbg_evt("Command(%s) completed by hardware",
 668                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 669                                         wakeup = true;
 670                                 }
 671                         } else
 672                                 goto err;
 673                 } else if (t->wlen == t->wi &&
 674                            (status & ACPI_EC_FLAG_IBF) == 0) {
 675                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 676                         wakeup = true;
 677                 }
 678                 goto out;
 679         } else {
 680                 if (EC_FLAGS_QUERY_HANDSHAKE &&
 681                     !(status & ACPI_EC_FLAG_SCI) &&
 682                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 683                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 684                         t->rdata[t->ri++] = 0x00;
 685                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 686                         ec_dbg_evt("Command(%s) completed by software",
 687                                    acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 688                         wakeup = true;
 689                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 690                         acpi_ec_write_cmd(ec, t->command);
 691                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 692                 } else
 693                         goto err;
 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_gpe(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_gpe(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 void acpi_ec_mark_gpe_for_wake(void)
1040 {
1041         if (first_ec && !ec_no_wakeup)
1042                 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
1043 }
1044
1045 void acpi_ec_set_gpe_wake_mask(u8 action)
1046 {
1047         if (first_ec && !ec_no_wakeup)
1048                 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
1049 }
1050
1051 void acpi_ec_dispatch_gpe(void)
1052 {
1053         if (first_ec)
1054                 acpi_dispatch_gpe(NULL, first_ec->gpe);
1055 }
1056
1057 /* --------------------------------------------------------------------------
1058                                 Event Management
1059    -------------------------------------------------------------------------- */
1060 static struct acpi_ec_query_handler *
1061 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
1062 {
1063         if (handler)
1064                 kref_get(&handler->kref);
1065         return handler;
1066 }
1067
1068 static struct acpi_ec_query_handler *
1069 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1070 {
1071         struct acpi_ec_query_handler *handler;
1072         bool found = false;
1073
1074         mutex_lock(&ec->mutex);
1075         list_for_each_entry(handler, &ec->list, node) {
1076                 if (value == handler->query_bit) {
1077                         found = true;
1078                         break;
1079                 }
1080         }
1081         mutex_unlock(&ec->mutex);
1082         return found ? acpi_ec_get_query_handler(handler) : NULL;
1083 }
1084
1085 static void acpi_ec_query_handler_release(struct kref *kref)
1086 {
1087         struct acpi_ec_query_handler *handler =
1088                 container_of(kref, struct acpi_ec_query_handler, kref);
1089
1090         kfree(handler);
1091 }
1092
1093 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1094 {
1095         kref_put(&handler->kref, acpi_ec_query_handler_release);
1096 }
1097
1098 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1099                               acpi_handle handle, acpi_ec_query_func func,
1100                               void *data)
1101 {
1102         struct acpi_ec_query_handler *handler =
1103             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1104
1105         if (!handler)
1106                 return -ENOMEM;
1107
1108         handler->query_bit = query_bit;
1109         handler->handle = handle;
1110         handler->func = func;
1111         handler->data = data;
1112         mutex_lock(&ec->mutex);
1113         kref_init(&handler->kref);
1114         list_add(&handler->node, &ec->list);
1115         mutex_unlock(&ec->mutex);
1116         return 0;
1117 }
1118 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1119
1120 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1121                                           bool remove_all, u8 query_bit)
1122 {
1123         struct acpi_ec_query_handler *handler, *tmp;
1124         LIST_HEAD(free_list);
1125
1126         mutex_lock(&ec->mutex);
1127         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1128                 if (remove_all || query_bit == handler->query_bit) {
1129                         list_del_init(&handler->node);
1130                         list_add(&handler->node, &free_list);
1131                 }
1132         }
1133         mutex_unlock(&ec->mutex);
1134         list_for_each_entry_safe(handler, tmp, &free_list, node)
1135                 acpi_ec_put_query_handler(handler);
1136 }
1137
1138 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1139 {
1140         acpi_ec_remove_query_handlers(ec, false, query_bit);
1141 }
1142 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1143
1144 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1145 {
1146         struct acpi_ec_query *q;
1147         struct transaction *t;
1148
1149         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1150         if (!q)
1151                 return NULL;
1152         INIT_WORK(&q->work, acpi_ec_event_processor);
1153         t = &q->transaction;
1154         t->command = ACPI_EC_COMMAND_QUERY;
1155         t->rdata = pval;
1156         t->rlen = 1;
1157         return q;
1158 }
1159
1160 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1161 {
1162         if (q) {
1163                 if (q->handler)
1164                         acpi_ec_put_query_handler(q->handler);
1165                 kfree(q);
1166         }
1167 }
1168
1169 static void acpi_ec_event_processor(struct work_struct *work)
1170 {
1171         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1172         struct acpi_ec_query_handler *handler = q->handler;
1173
1174         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1175         if (handler->func)
1176                 handler->func(handler->data);
1177         else if (handler->handle)
1178                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1179         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1180         acpi_ec_delete_query(q);
1181 }
1182
1183 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1184 {
1185         u8 value = 0;
1186         int result;
1187         struct acpi_ec_query *q;
1188
1189         q = acpi_ec_create_query(&value);
1190         if (!q)
1191                 return -ENOMEM;
1192
1193         /*
1194          * Query the EC to find out which _Qxx method we need to evaluate.
1195          * Note that successful completion of the query causes the ACPI_EC_SCI
1196          * bit to be cleared (and thus clearing the interrupt source).
1197          */
1198         result = acpi_ec_transaction(ec, &q->transaction);
1199         if (!value)
1200                 result = -ENODATA;
1201         if (result)
1202                 goto err_exit;
1203
1204         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1205         if (!q->handler) {
1206                 result = -ENODATA;
1207                 goto err_exit;
1208         }
1209
1210         /*
1211          * It is reported that _Qxx are evaluated in a parallel way on
1212          * Windows:
1213          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1214          *
1215          * Put this log entry before schedule_work() in order to make
1216          * it appearing before any other log entries occurred during the
1217          * work queue execution.
1218          */
1219         ec_dbg_evt("Query(0x%02x) scheduled", value);
1220         if (!queue_work(ec_query_wq, &q->work)) {
1221                 ec_dbg_evt("Query(0x%02x) overlapped", value);
1222                 result = -EBUSY;
1223         }
1224
1225 err_exit:
1226         if (result)
1227                 acpi_ec_delete_query(q);
1228         if (data)
1229                 *data = value;
1230         return result;
1231 }
1232
1233 static void acpi_ec_check_event(struct acpi_ec *ec)
1234 {
1235         unsigned long flags;
1236
1237         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1238                 if (ec_guard(ec)) {
1239                         spin_lock_irqsave(&ec->lock, flags);
1240                         /*
1241                          * Take care of the SCI_EVT unless no one else is
1242                          * taking care of it.
1243                          */
1244                         if (!ec->curr)
1245                                 advance_transaction(ec);
1246                         spin_unlock_irqrestore(&ec->lock, flags);
1247                 }
1248         }
1249 }
1250
1251 static void acpi_ec_event_handler(struct work_struct *work)
1252 {
1253         unsigned long flags;
1254         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1255
1256         ec_dbg_evt("Event started");
1257
1258         spin_lock_irqsave(&ec->lock, flags);
1259         while (ec->nr_pending_queries) {
1260                 spin_unlock_irqrestore(&ec->lock, flags);
1261                 (void)acpi_ec_query(ec, NULL);
1262                 spin_lock_irqsave(&ec->lock, flags);
1263                 ec->nr_pending_queries--;
1264                 /*
1265                  * Before exit, make sure that this work item can be
1266                  * scheduled again. There might be QR_EC failures, leaving
1267                  * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1268                  * item from being scheduled again.
1269                  */
1270                 if (!ec->nr_pending_queries) {
1271                         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1272                             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1273                                 acpi_ec_complete_query(ec);
1274                 }
1275         }
1276         spin_unlock_irqrestore(&ec->lock, flags);
1277
1278         ec_dbg_evt("Event stopped");
1279
1280         acpi_ec_check_event(ec);
1281 }
1282
1283 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1284         u32 gpe_number, void *data)
1285 {
1286         unsigned long flags;
1287         struct acpi_ec *ec = data;
1288
1289         spin_lock_irqsave(&ec->lock, flags);
1290         advance_transaction(ec);
1291         spin_unlock_irqrestore(&ec->lock, flags);
1292         return ACPI_INTERRUPT_HANDLED;
1293 }
1294
1295 /* --------------------------------------------------------------------------
1296  *                           Address Space Management
1297  * -------------------------------------------------------------------------- */
1298
1299 static acpi_status
1300 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1301                       u32 bits, u64 *value64,
1302                       void *handler_context, void *region_context)
1303 {
1304         struct acpi_ec *ec = handler_context;
1305         int result = 0, i, bytes = bits / 8;
1306         u8 *value = (u8 *)value64;
1307
1308         if ((address > 0xFF) || !value || !handler_context)
1309                 return AE_BAD_PARAMETER;
1310
1311         if (function != ACPI_READ && function != ACPI_WRITE)
1312                 return AE_BAD_PARAMETER;
1313
1314         if (ec->busy_polling || bits > 8)
1315                 acpi_ec_burst_enable(ec);
1316
1317         for (i = 0; i < bytes; ++i, ++address, ++value)
1318                 result = (function == ACPI_READ) ?
1319                         acpi_ec_read(ec, address, value) :
1320                         acpi_ec_write(ec, address, *value);
1321
1322         if (ec->busy_polling || bits > 8)
1323                 acpi_ec_burst_disable(ec);
1324
1325         switch (result) {
1326         case -EINVAL:
1327                 return AE_BAD_PARAMETER;
1328         case -ENODEV:
1329                 return AE_NOT_FOUND;
1330         case -ETIME:
1331                 return AE_TIME;
1332         default:
1333                 return AE_OK;
1334         }
1335 }
1336
1337 /* --------------------------------------------------------------------------
1338  *                             Driver Interface
1339  * -------------------------------------------------------------------------- */
1340
1341 static acpi_status
1342 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1343
1344 static void acpi_ec_free(struct acpi_ec *ec)
1345 {
1346         if (first_ec == ec)
1347                 first_ec = NULL;
1348         if (boot_ec == ec)
1349                 boot_ec = NULL;
1350         kfree(ec);
1351 }
1352
1353 static struct acpi_ec *acpi_ec_alloc(void)
1354 {
1355         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1356
1357         if (!ec)
1358                 return NULL;
1359         mutex_init(&ec->mutex);
1360         init_waitqueue_head(&ec->wait);
1361         INIT_LIST_HEAD(&ec->list);
1362         spin_lock_init(&ec->lock);
1363         INIT_WORK(&ec->work, acpi_ec_event_handler);
1364         ec->timestamp = jiffies;
1365         ec->busy_polling = true;
1366         ec->polling_guard = 0;
1367         return ec;
1368 }
1369
1370 static acpi_status
1371 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1372                                void *context, void **return_value)
1373 {
1374         char node_name[5];
1375         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1376         struct acpi_ec *ec = context;
1377         int value = 0;
1378         acpi_status status;
1379
1380         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1381
1382         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1383                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1384         return AE_OK;
1385 }
1386
1387 static acpi_status
1388 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1389 {
1390         acpi_status status;
1391         unsigned long long tmp = 0;
1392         struct acpi_ec *ec = context;
1393
1394         /* clear addr values, ec_parse_io_ports depend on it */
1395         ec->command_addr = ec->data_addr = 0;
1396
1397         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1398                                      ec_parse_io_ports, ec);
1399         if (ACPI_FAILURE(status))
1400                 return status;
1401         if (ec->data_addr == 0 || ec->command_addr == 0)
1402                 return AE_OK;
1403
1404         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1405                 /*
1406                  * Always inherit the GPE number setting from the ECDT
1407                  * EC.
1408                  */
1409                 ec->gpe = boot_ec->gpe;
1410         } else {
1411                 /* Get GPE bit assignment (EC events). */
1412                 /* TODO: Add support for _GPE returning a package */
1413                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1414                 if (ACPI_FAILURE(status))
1415                         return status;
1416                 ec->gpe = tmp;
1417         }
1418         /* Use the global lock for all EC transactions? */
1419         tmp = 0;
1420         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1421         ec->global_lock = tmp;
1422         ec->handle = handle;
1423         return AE_CTRL_TERMINATE;
1424 }
1425
1426 /*
1427  * Note: This function returns an error code only when the address space
1428  *       handler is not installed, which means "not able to handle
1429  *       transactions".
1430  */
1431 static int ec_install_handlers(struct acpi_ec *ec, bool handle_events)
1432 {
1433         acpi_status status;
1434
1435         acpi_ec_start(ec, false);
1436
1437         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1438                 acpi_ec_enter_noirq(ec);
1439                 status = acpi_install_address_space_handler(ec->handle,
1440                                                             ACPI_ADR_SPACE_EC,
1441                                                             &acpi_ec_space_handler,
1442                                                             NULL, ec);
1443                 if (ACPI_FAILURE(status)) {
1444                         if (status == AE_NOT_FOUND) {
1445                                 /*
1446                                  * Maybe OS fails in evaluating the _REG
1447                                  * object. The AE_NOT_FOUND error will be
1448                                  * ignored and OS * continue to initialize
1449                                  * EC.
1450                                  */
1451                                 pr_err("Fail in evaluating the _REG object"
1452                                         " of EC device. Broken bios is suspected.\n");
1453                         } else {
1454                                 acpi_ec_stop(ec, false);
1455                                 return -ENODEV;
1456                         }
1457                 }
1458                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1459         }
1460
1461         if (!handle_events)
1462                 return 0;
1463
1464         if (!test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1465                 /* Find and register all query methods */
1466                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1467                                     acpi_ec_register_query_methods,
1468                                     NULL, ec, NULL);
1469                 set_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1470         }
1471         if (!test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1472                 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1473                                           ACPI_GPE_EDGE_TRIGGERED,
1474                                           &acpi_ec_gpe_handler, ec);
1475                 /* This is not fatal as we can poll EC events */
1476                 if (ACPI_SUCCESS(status)) {
1477                         set_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1478                         acpi_ec_leave_noirq(ec);
1479                         if (test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1480                             ec->reference_count >= 1)
1481                                 acpi_ec_enable_gpe(ec, true);
1482                 }
1483         }
1484         /* EC is fully operational, allow queries */
1485         acpi_ec_enable_event(ec);
1486
1487         return 0;
1488 }
1489
1490 static void ec_remove_handlers(struct acpi_ec *ec)
1491 {
1492         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1493                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1494                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1495                         pr_err("failed to remove space handler\n");
1496                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1497         }
1498
1499         /*
1500          * Stops handling the EC transactions after removing the operation
1501          * region handler. This is required because _REG(DISCONNECT)
1502          * invoked during the removal can result in new EC transactions.
1503          *
1504          * Flushes the EC requests and thus disables the GPE before
1505          * removing the GPE handler. This is required by the current ACPICA
1506          * GPE core. ACPICA GPE core will automatically disable a GPE when
1507          * it is indicated but there is no way to handle it. So the drivers
1508          * must disable the GPEs prior to removing the GPE handlers.
1509          */
1510         acpi_ec_stop(ec, false);
1511
1512         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1513                 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1514                                         &acpi_ec_gpe_handler)))
1515                         pr_err("failed to remove gpe handler\n");
1516                 clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1517         }
1518         if (test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1519                 acpi_ec_remove_query_handlers(ec, true, 0);
1520                 clear_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1521         }
1522 }
1523
1524 static int acpi_ec_setup(struct acpi_ec *ec, bool handle_events)
1525 {
1526         int ret;
1527
1528         ret = ec_install_handlers(ec, handle_events);
1529         if (ret)
1530                 return ret;
1531
1532         /* First EC capable of handling transactions */
1533         if (!first_ec) {
1534                 first_ec = ec;
1535                 acpi_handle_info(first_ec->handle, "Used as first EC\n");
1536         }
1537
1538         acpi_handle_info(ec->handle,
1539                          "GPE=0x%x, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n",
1540                          ec->gpe, ec->command_addr, ec->data_addr);
1541         return ret;
1542 }
1543
1544 static int acpi_config_boot_ec(struct acpi_ec *ec, acpi_handle handle,
1545                                bool handle_events, bool is_ecdt)
1546 {
1547         int ret;
1548
1549         /*
1550          * Changing the ACPI handle results in a re-configuration of the
1551          * boot EC. And if it happens after the namespace initialization,
1552          * it causes _REG evaluations.
1553          */
1554         if (boot_ec && boot_ec->handle != handle)
1555                 ec_remove_handlers(boot_ec);
1556
1557         /* Unset old boot EC */
1558         if (boot_ec != ec)
1559                 acpi_ec_free(boot_ec);
1560
1561         /*
1562          * ECDT device creation is split into acpi_ec_ecdt_probe() and
1563          * acpi_ec_ecdt_start(). This function takes care of completing the
1564          * ECDT parsing logic as the handle update should be performed
1565          * between the installation/uninstallation of the handlers.
1566          */
1567         if (ec->handle != handle)
1568                 ec->handle = handle;
1569
1570         ret = acpi_ec_setup(ec, handle_events);
1571         if (ret)
1572                 return ret;
1573
1574         /* Set new boot EC */
1575         if (!boot_ec) {
1576                 boot_ec = ec;
1577                 boot_ec_is_ecdt = is_ecdt;
1578         }
1579
1580         acpi_handle_info(boot_ec->handle,
1581                          "Used as boot %s EC to handle transactions%s\n",
1582                          is_ecdt ? "ECDT" : "DSDT",
1583                          handle_events ? " and events" : "");
1584         return ret;
1585 }
1586
1587 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)
1588 {
1589         struct acpi_table_ecdt *ecdt_ptr;
1590         acpi_status status;
1591         acpi_handle handle;
1592
1593         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1594                                 (struct acpi_table_header **)&ecdt_ptr);
1595         if (ACPI_FAILURE(status))
1596                 return false;
1597
1598         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1599         if (ACPI_FAILURE(status))
1600                 return false;
1601
1602         *phandle = handle;
1603         return true;
1604 }
1605
1606 static bool acpi_is_boot_ec(struct acpi_ec *ec)
1607 {
1608         if (!boot_ec)
1609                 return false;
1610         if (ec->command_addr == boot_ec->command_addr &&
1611             ec->data_addr == boot_ec->data_addr)
1612                 return true;
1613         return false;
1614 }
1615
1616 static int acpi_ec_add(struct acpi_device *device)
1617 {
1618         struct acpi_ec *ec = NULL;
1619         int ret;
1620         bool is_ecdt = false;
1621         acpi_status status;
1622
1623         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1624         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1625
1626         if (!strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) {
1627                 is_ecdt = true;
1628                 ec = boot_ec;
1629         } else {
1630                 ec = acpi_ec_alloc();
1631                 if (!ec)
1632                         return -ENOMEM;
1633                 status = ec_parse_device(device->handle, 0, ec, NULL);
1634                 if (status != AE_CTRL_TERMINATE) {
1635                         ret = -EINVAL;
1636                         goto err_alloc;
1637                 }
1638         }
1639
1640         if (acpi_is_boot_ec(ec)) {
1641                 boot_ec_is_ecdt = is_ecdt;
1642                 if (!is_ecdt) {
1643                         /*
1644                          * Trust PNP0C09 namespace location rather than
1645                          * ECDT ID. But trust ECDT GPE rather than _GPE
1646                          * because of ASUS quirks, so do not change
1647                          * boot_ec->gpe to ec->gpe.
1648                          */
1649                         boot_ec->handle = ec->handle;
1650                         acpi_handle_debug(ec->handle, "duplicated.\n");
1651                         acpi_ec_free(ec);
1652                         ec = boot_ec;
1653                 }
1654                 ret = acpi_config_boot_ec(ec, ec->handle, true, is_ecdt);
1655         } else
1656                 ret = acpi_ec_setup(ec, true);
1657         if (ret)
1658                 goto err_query;
1659
1660         device->driver_data = ec;
1661
1662         ret = !!request_region(ec->data_addr, 1, "EC data");
1663         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1664         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1665         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1666
1667         if (!is_ecdt) {
1668                 /* Reprobe devices depending on the EC */
1669                 acpi_walk_dep_device_list(ec->handle);
1670         }
1671         acpi_handle_debug(ec->handle, "enumerated.\n");
1672         return 0;
1673
1674 err_query:
1675         if (ec != boot_ec)
1676                 acpi_ec_remove_query_handlers(ec, true, 0);
1677 err_alloc:
1678         if (ec != boot_ec)
1679                 acpi_ec_free(ec);
1680         return ret;
1681 }
1682
1683 static int acpi_ec_remove(struct acpi_device *device)
1684 {
1685         struct acpi_ec *ec;
1686
1687         if (!device)
1688                 return -EINVAL;
1689
1690         ec = acpi_driver_data(device);
1691         release_region(ec->data_addr, 1);
1692         release_region(ec->command_addr, 1);
1693         device->driver_data = NULL;
1694         if (ec != boot_ec) {
1695                 ec_remove_handlers(ec);
1696                 acpi_ec_free(ec);
1697         }
1698         return 0;
1699 }
1700
1701 static acpi_status
1702 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1703 {
1704         struct acpi_ec *ec = context;
1705
1706         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1707                 return AE_OK;
1708
1709         /*
1710          * The first address region returned is the data port, and
1711          * the second address region returned is the status/command
1712          * port.
1713          */
1714         if (ec->data_addr == 0)
1715                 ec->data_addr = resource->data.io.minimum;
1716         else if (ec->command_addr == 0)
1717                 ec->command_addr = resource->data.io.minimum;
1718         else
1719                 return AE_CTRL_TERMINATE;
1720
1721         return AE_OK;
1722 }
1723
1724 static const struct acpi_device_id ec_device_ids[] = {
1725         {"PNP0C09", 0},
1726         {ACPI_ECDT_HID, 0},
1727         {"", 0},
1728 };
1729
1730 /*
1731  * This function is not Windows-compatible as Windows never enumerates the
1732  * namespace EC before the main ACPI device enumeration process. It is
1733  * retained for historical reason and will be deprecated in the future.
1734  */
1735 void __init acpi_ec_dsdt_probe(void)
1736 {
1737         struct acpi_ec *ec;
1738         acpi_status status;
1739         int ret;
1740
1741         /*
1742          * If a platform has ECDT, there is no need to proceed as the
1743          * following probe is not a part of the ACPI device enumeration,
1744          * executing _STA is not safe, and thus this probe may risk of
1745          * picking up an invalid EC device.
1746          */
1747         if (boot_ec)
1748                 return;
1749
1750         ec = acpi_ec_alloc();
1751         if (!ec)
1752                 return;
1753
1754         /*
1755          * At this point, the namespace is initialized, so start to find
1756          * the namespace objects.
1757          */
1758         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1759         if (ACPI_FAILURE(status) || !ec->handle) {
1760                 acpi_ec_free(ec);
1761                 return;
1762         }
1763
1764         /*
1765          * When the DSDT EC is available, always re-configure boot EC to
1766          * have _REG evaluated. _REG can only be evaluated after the
1767          * namespace initialization.
1768          * At this point, the GPE is not fully initialized, so do not to
1769          * handle the events.
1770          */
1771         ret = acpi_config_boot_ec(ec, ec->handle, false, false);
1772         if (ret)
1773                 acpi_ec_free(ec);
1774 }
1775
1776 /*
1777  * If the DSDT EC is not functioning, we still need to prepare a fully
1778  * functioning ECDT EC first in order to handle the events.
1779  * https://bugzilla.kernel.org/show_bug.cgi?id=115021
1780  */
1781 static int __init acpi_ec_ecdt_start(void)
1782 {
1783         acpi_handle handle;
1784
1785         if (!boot_ec)
1786                 return -ENODEV;
1787         /* In case acpi_ec_ecdt_start() is called after acpi_ec_add() */
1788         if (!boot_ec_is_ecdt)
1789                 return -ENODEV;
1790
1791         /*
1792          * At this point, the namespace and the GPE is initialized, so
1793          * start to find the namespace objects and handle the events.
1794          *
1795          * Note: ec->handle can be valid if this function is called after
1796          * acpi_ec_add(), hence the fast path.
1797          */
1798         if (boot_ec->handle == ACPI_ROOT_OBJECT) {
1799                 if (!acpi_ec_ecdt_get_handle(&handle))
1800                         return -ENODEV;
1801                 boot_ec->handle = handle;
1802         }
1803
1804         /* Register to ACPI bus with PM ops attached */
1805         return acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1806 }
1807
1808 #if 0
1809 /*
1810  * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1811  * set, for which case, we complete the QR_EC without issuing it to the
1812  * firmware.
1813  * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1814  * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1815  */
1816 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1817 {
1818         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1819         EC_FLAGS_QUERY_HANDSHAKE = 1;
1820         return 0;
1821 }
1822 #endif
1823
1824 /*
1825  * Some ECDTs contain wrong register addresses.
1826  * MSI MS-171F
1827  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1828  */
1829 static int ec_correct_ecdt(const struct dmi_system_id *id)
1830 {
1831         pr_debug("Detected system needing ECDT address correction.\n");
1832         EC_FLAGS_CORRECT_ECDT = 1;
1833         return 0;
1834 }
1835
1836 /*
1837  * Some DSDTs contain wrong GPE setting.
1838  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1839  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1840  */
1841 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1842 {
1843         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1844         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1845         return 0;
1846 }
1847
1848 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1849         {
1850         ec_correct_ecdt, "MSI MS-171F", {
1851         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1852         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1853         {
1854         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1855         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1856         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1857         {
1858         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1859         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1860         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1861         {
1862         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1863         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1864         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1865         {
1866         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1867         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1868         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1869         {
1870         ec_honor_ecdt_gpe, "ASUS X580VD", {
1871         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1872         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1873         {},
1874 };
1875
1876 void __init acpi_ec_ecdt_probe(void)
1877 {
1878         struct acpi_table_ecdt *ecdt_ptr;
1879         struct acpi_ec *ec;
1880         acpi_status status;
1881         int ret;
1882
1883         /* Generate a boot ec context. */
1884         dmi_check_system(ec_dmi_table);
1885         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1886                                 (struct acpi_table_header **)&ecdt_ptr);
1887         if (ACPI_FAILURE(status))
1888                 return;
1889
1890         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1891                 /*
1892                  * Asus X50GL:
1893                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1894                  */
1895                 return;
1896         }
1897
1898         ec = acpi_ec_alloc();
1899         if (!ec)
1900                 return;
1901
1902         if (EC_FLAGS_CORRECT_ECDT) {
1903                 ec->command_addr = ecdt_ptr->data.address;
1904                 ec->data_addr = ecdt_ptr->control.address;
1905         } else {
1906                 ec->command_addr = ecdt_ptr->control.address;
1907                 ec->data_addr = ecdt_ptr->data.address;
1908         }
1909         ec->gpe = ecdt_ptr->gpe;
1910
1911         /*
1912          * At this point, the namespace is not initialized, so do not find
1913          * the namespace objects, or handle the events.
1914          */
1915         ret = acpi_config_boot_ec(ec, ACPI_ROOT_OBJECT, false, true);
1916         if (ret)
1917                 acpi_ec_free(ec);
1918 }
1919
1920 #ifdef CONFIG_PM_SLEEP
1921 static int acpi_ec_suspend(struct device *dev)
1922 {
1923         struct acpi_ec *ec =
1924                 acpi_driver_data(to_acpi_device(dev));
1925
1926         if (acpi_sleep_no_ec_events() && ec_freeze_events)
1927                 acpi_ec_disable_event(ec);
1928         return 0;
1929 }
1930
1931 static int acpi_ec_suspend_noirq(struct device *dev)
1932 {
1933         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1934
1935         /*
1936          * The SCI handler doesn't run at this point, so the GPE can be
1937          * masked at the low level without side effects.
1938          */
1939         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1940             ec->reference_count >= 1)
1941                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1942
1943         if (acpi_sleep_no_ec_events())
1944                 acpi_ec_enter_noirq(ec);
1945
1946         return 0;
1947 }
1948
1949 static int acpi_ec_resume_noirq(struct device *dev)
1950 {
1951         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1952
1953         if (acpi_sleep_no_ec_events())
1954                 acpi_ec_leave_noirq(ec);
1955
1956         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1957             ec->reference_count >= 1)
1958                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1959
1960         return 0;
1961 }
1962
1963 static int acpi_ec_resume(struct device *dev)
1964 {
1965         struct acpi_ec *ec =
1966                 acpi_driver_data(to_acpi_device(dev));
1967
1968         acpi_ec_enable_event(ec);
1969         return 0;
1970 }
1971 #endif
1972
1973 static const struct dev_pm_ops acpi_ec_pm = {
1974         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
1975         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
1976 };
1977
1978 static int param_set_event_clearing(const char *val,
1979                                     const struct kernel_param *kp)
1980 {
1981         int result = 0;
1982
1983         if (!strncmp(val, "status", sizeof("status") - 1)) {
1984                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1985                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
1986         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
1987                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
1988                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
1989         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
1990                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
1991                 pr_info("Assuming SCI_EVT clearing on event reads\n");
1992         } else
1993                 result = -EINVAL;
1994         return result;
1995 }
1996
1997 static int param_get_event_clearing(char *buffer,
1998                                     const struct kernel_param *kp)
1999 {
2000         switch (ec_event_clearing) {
2001         case ACPI_EC_EVT_TIMING_STATUS:
2002                 return sprintf(buffer, "status");
2003         case ACPI_EC_EVT_TIMING_QUERY:
2004                 return sprintf(buffer, "query");
2005         case ACPI_EC_EVT_TIMING_EVENT:
2006                 return sprintf(buffer, "event");
2007         default:
2008                 return sprintf(buffer, "invalid");
2009         }
2010         return 0;
2011 }
2012
2013 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2014                   NULL, 0644);
2015 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2016
2017 static struct acpi_driver acpi_ec_driver = {
2018         .name = "ec",
2019         .class = ACPI_EC_CLASS,
2020         .ids = ec_device_ids,
2021         .ops = {
2022                 .add = acpi_ec_add,
2023                 .remove = acpi_ec_remove,
2024                 },
2025         .drv.pm = &acpi_ec_pm,
2026 };
2027
2028 static inline int acpi_ec_query_init(void)
2029 {
2030         if (!ec_query_wq) {
2031                 ec_query_wq = alloc_workqueue("kec_query", 0,
2032                                               ec_max_queries);
2033                 if (!ec_query_wq)
2034                         return -ENODEV;
2035         }
2036         return 0;
2037 }
2038
2039 static inline void acpi_ec_query_exit(void)
2040 {
2041         if (ec_query_wq) {
2042                 destroy_workqueue(ec_query_wq);
2043                 ec_query_wq = NULL;
2044         }
2045 }
2046
2047 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2048         {
2049                 .ident = "Thinkpad X1 Carbon 6th",
2050                 .matches = {
2051                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2052                         DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2053                 },
2054         },
2055         {
2056                 .ident = "ThinkPad X1 Carbon 6th",
2057                 .matches = {
2058                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2059                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2060                 },
2061         },
2062         {
2063                 .ident = "ThinkPad X1 Yoga 3rd",
2064                 .matches = {
2065                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2066                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2067                 },
2068         },
2069         { },
2070 };
2071
2072 int __init acpi_ec_init(void)
2073 {
2074         int result;
2075         int ecdt_fail, dsdt_fail;
2076
2077         /* register workqueue for _Qxx evaluations */
2078         result = acpi_ec_query_init();
2079         if (result)
2080                 return result;
2081
2082         /*
2083          * Disable EC wakeup on following systems to prevent periodic
2084          * wakeup from EC GPE.
2085          */
2086         if (dmi_check_system(acpi_ec_no_wakeup)) {
2087                 ec_no_wakeup = true;
2088                 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2089         }
2090
2091         /* Drivers must be started after acpi_ec_query_init() */
2092         dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver);
2093         /*
2094          * Register ECDT to ACPI bus only when PNP0C09 probe fails. This is
2095          * useful for platforms (confirmed on ASUS X550ZE) with valid ECDT
2096          * settings but invalid DSDT settings.
2097          * https://bugzilla.kernel.org/show_bug.cgi?id=196847
2098          */
2099         ecdt_fail = acpi_ec_ecdt_start();
2100         return ecdt_fail && dsdt_fail ? -ENODEV : 0;
2101 }
2102
2103 /* EC driver currently not unloadable */
2104 #if 0
2105 static void __exit acpi_ec_exit(void)
2106 {
2107
2108         acpi_bus_unregister_driver(&acpi_ec_driver);
2109         acpi_ec_query_exit();
2110 }
2111 #endif  /* 0 */