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_COMMAND_STORM,         /* GPE storms occurred to the
 116                                          * current command processing */
 117 };
 118
 119 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
 120 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
 121
 122 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 123 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 124 module_param(ec_delay, uint, 0644);
 125 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
 126
 127 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
 128 module_param(ec_max_queries, uint, 0644);
 129 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
 130
 131 static bool ec_busy_polling __read_mostly;
 132 module_param(ec_busy_polling, bool, 0644);
 133 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
 134
 135 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
 136 module_param(ec_polling_guard, uint, 0644);
 137 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
 138
 139 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
 140
 141 /*
 142  * If the number of false interrupts per one transaction exceeds
 143  * this threshold, will think there is a GPE storm happened and
 144  * will disable the GPE for normal transaction.
 145  */
 146 static unsigned int ec_storm_threshold  __read_mostly = 8;
 147 module_param(ec_storm_threshold, uint, 0644);
 148 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 149
 150 static bool ec_freeze_events __read_mostly = false;
 151 module_param(ec_freeze_events, bool, 0644);
 152 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
 153
 154 static bool ec_no_wakeup __read_mostly;
 155 module_param(ec_no_wakeup, bool, 0644);
 156 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
 157
 158 struct acpi_ec_query_handler {
 159         struct list_head node;
 160         acpi_ec_query_func func;
 161         acpi_handle handle;
 162         void *data;
 163         u8 query_bit;
 164         struct kref kref;
 165 };
 166
 167 struct transaction {
 168         const u8 *wdata;
 169         u8 *rdata;
 170         unsigned short irq_count;
 171         u8 command;
 172         u8 wi;
 173         u8 ri;
 174         u8 wlen;
 175         u8 rlen;
 176         u8 flags;
 177 };
 178
 179 struct acpi_ec_query {
 180         struct transaction transaction;
 181         struct work_struct work;
 182         struct acpi_ec_query_handler *handler;
 183 };
 184
 185 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
 186 static void advance_transaction(struct acpi_ec *ec);
 187 static void acpi_ec_event_handler(struct work_struct *work);
 188 static void acpi_ec_event_processor(struct work_struct *work);
 189
 190 struct acpi_ec *boot_ec, *first_ec;
 191 EXPORT_SYMBOL(first_ec);
 192 static bool boot_ec_is_ecdt = false;
 193 static struct workqueue_struct *ec_query_wq;
 194
 195 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
 196 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
 197 static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
 198
 199 /* --------------------------------------------------------------------------
 200  *                           Logging/Debugging
 201  * -------------------------------------------------------------------------- */
 202
 203 /*
 204  * Splitters used by the developers to track the boundary of the EC
 205  * handling processes.
 206  */
 207 #ifdef DEBUG
 208 #define EC_DBG_SEP      " "
 209 #define EC_DBG_DRV      "+++++"
 210 #define EC_DBG_STM      "====="
 211 #define EC_DBG_REQ      "*****"
 212 #define EC_DBG_EVT      "#####"
 213 #else
 214 #define EC_DBG_SEP      ""
 215 #define EC_DBG_DRV
 216 #define EC_DBG_STM
 217 #define EC_DBG_REQ
 218 #define EC_DBG_EVT
 219 #endif
 220
 221 #define ec_log_raw(fmt, ...) \
 222         pr_info(fmt "\n", ##__VA_ARGS__)
 223 #define ec_dbg_raw(fmt, ...) \
 224         pr_debug(fmt "\n", ##__VA_ARGS__)
 225 #define ec_log(filter, fmt, ...) \
 226         ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 227 #define ec_dbg(filter, fmt, ...) \
 228         ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 229
 230 #define ec_log_drv(fmt, ...) \
 231         ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 232 #define ec_dbg_drv(fmt, ...) \
 233         ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 234 #define ec_dbg_stm(fmt, ...) \
 235         ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
 236 #define ec_dbg_req(fmt, ...) \
 237         ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
 238 #define ec_dbg_evt(fmt, ...) \
 239         ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
 240 #define ec_dbg_ref(ec, fmt, ...) \
 241         ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
 242
 243 /* --------------------------------------------------------------------------
 244  *                           Device Flags
 245  * -------------------------------------------------------------------------- */
 246
 247 static bool acpi_ec_started(struct acpi_ec *ec)
 248 {
 249         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
 250                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
 251 }
 252
 253 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
 254 {
 255         /*
 256          * There is an OSPM early stage logic. During the early stages
 257          * (boot/resume), OSPMs shouldn't enable the event handling, only
 258          * the EC transactions are allowed to be performed.
 259          */
 260         if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 261                 return false;
 262         /*
 263          * However, disabling the event handling is experimental for late
 264          * stage (suspend), and is controlled by the boot parameter of
 265          * "ec_freeze_events":
 266          * 1. true:  The EC event handling is disabled before entering
 267          *           the noirq stage.
 268          * 2. false: The EC event handling is automatically disabled as
 269          *           soon as the EC driver is stopped.
 270          */
 271         if (ec_freeze_events)
 272                 return acpi_ec_started(ec);
 273         else
 274                 return test_bit(EC_FLAGS_STARTED, &ec->flags);
 275 }
 276
 277 static bool acpi_ec_flushed(struct acpi_ec *ec)
 278 {
 279         return ec->reference_count == 1;
 280 }
 281
 282 /* --------------------------------------------------------------------------
 283  *                           EC Registers
 284  * -------------------------------------------------------------------------- */
 285
 286 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 287 {
 288         u8 x = inb(ec->command_addr);
 289
 290         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
 291                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
 292                    x,
 293                    !!(x & ACPI_EC_FLAG_SCI),
 294                    !!(x & ACPI_EC_FLAG_BURST),
 295                    !!(x & ACPI_EC_FLAG_CMD),
 296                    !!(x & ACPI_EC_FLAG_IBF),
 297                    !!(x & ACPI_EC_FLAG_OBF));
 298         return x;
 299 }
 300
 301 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 302 {
 303         u8 x = inb(ec->data_addr);
 304
 305         ec->timestamp = jiffies;
 306         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
 307         return x;
 308 }
 309
 310 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 311 {
 312         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
 313         outb(command, ec->command_addr);
 314         ec->timestamp = jiffies;
 315 }
 316
 317 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 318 {
 319         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
 320         outb(data, ec->data_addr);
 321         ec->timestamp = jiffies;
 322 }
 323
 324 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
 325 static const char *acpi_ec_cmd_string(u8 cmd)
 326 {
 327         switch (cmd) {
 328         case 0x80:
 329                 return "RD_EC";
 330         case 0x81:
 331                 return "WR_EC";
 332         case 0x82:
 333                 return "BE_EC";
 334         case 0x83:
 335                 return "BD_EC";
 336         case 0x84:
 337                 return "QR_EC";
 338         }
 339         return "UNKNOWN";
 340 }
 341 #else
 342 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 343 #endif
 344
 345 /* --------------------------------------------------------------------------
 346  *                           GPE Registers
 347  * -------------------------------------------------------------------------- */
 348
 349 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
 350 {
 351         acpi_event_status gpe_status = 0;
 352
 353         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
 354         return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
 355 }
 356
 357 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
 358 {
 359         if (open)
 360                 acpi_enable_gpe(NULL, ec->gpe);
 361         else {
 362                 BUG_ON(ec->reference_count < 1);
 363                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 364         }
 365         if (acpi_ec_is_gpe_raised(ec)) {
 366                 /*
 367                  * On some platforms, EN=1 writes cannot trigger GPE. So
 368                  * software need to manually trigger a pseudo GPE event on
 369                  * EN=1 writes.
 370                  */
 371                 ec_dbg_raw("Polling quirk");
 372                 advance_transaction(ec);
 373         }
 374 }
 375
 376 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
 377 {
 378         if (close)
 379                 acpi_disable_gpe(NULL, ec->gpe);
 380         else {
 381                 BUG_ON(ec->reference_count < 1);
 382                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 383         }
 384 }
 385
 386 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
 387 {
 388         /*
 389          * GPE STS is a W1C register, which means:
 390          * 1. Software can clear it without worrying about clearing other
 391          *    GPEs' STS bits when the hardware sets them in parallel.
 392          * 2. As long as software can ensure only clearing it when it is
 393          *    set, hardware won't set it in parallel.
 394          * So software can clear GPE in any contexts.
 395          * Warning: do not move the check into advance_transaction() as the
 396          * EC commands will be sent without GPE raised.
 397          */
 398         if (!acpi_ec_is_gpe_raised(ec))
 399                 return;
 400         acpi_clear_gpe(NULL, ec->gpe);
 401 }
 402
 403 /* --------------------------------------------------------------------------
 404  *                           Transaction Management
 405  * -------------------------------------------------------------------------- */
 406
 407 static void acpi_ec_submit_request(struct acpi_ec *ec)
 408 {
 409         ec->reference_count++;
 410         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
 411             ec->reference_count == 1)
 412                 acpi_ec_enable_gpe(ec, true);
 413 }
 414
 415 static void acpi_ec_complete_request(struct acpi_ec *ec)
 416 {
 417         bool flushed = false;
 418
 419         ec->reference_count--;
 420         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags) &&
 421             ec->reference_count == 0)
 422                 acpi_ec_disable_gpe(ec, true);
 423         flushed = acpi_ec_flushed(ec);
 424         if (flushed)
 425                 wake_up(&ec->wait);
 426 }
 427
 428 static void acpi_ec_set_storm(struct acpi_ec *ec, u8 flag)
 429 {
 430         if (!test_bit(flag, &ec->flags)) {
 431                 acpi_ec_disable_gpe(ec, false);
 432                 ec_dbg_drv("Polling enabled");
 433                 set_bit(flag, &ec->flags);
 434         }
 435 }
 436
 437 static void acpi_ec_clear_storm(struct acpi_ec *ec, u8 flag)
 438 {
 439         if (test_bit(flag, &ec->flags)) {
 440                 clear_bit(flag, &ec->flags);
 441                 acpi_ec_enable_gpe(ec, false);
 442                 ec_dbg_drv("Polling disabled");
 443         }
 444 }
 445
 446 /*
 447  * acpi_ec_submit_flushable_request() - Increase the reference count unless
 448  *                                      the flush operation is not in
 449  *                                      progress
 450  * @ec: the EC device
 451  *
 452  * This function must be used before taking a new action that should hold
 453  * the reference count.  If this function returns false, then the action
 454  * must be discarded or it will prevent the flush operation from being
 455  * completed.
 456  */
 457 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
 458 {
 459         if (!acpi_ec_started(ec))
 460                 return false;
 461         acpi_ec_submit_request(ec);
 462         return true;
 463 }
 464
 465 static void acpi_ec_submit_query(struct acpi_ec *ec)
 466 {
 467         acpi_ec_set_storm(ec, EC_FLAGS_COMMAND_STORM);
 468         if (!acpi_ec_event_enabled(ec))
 469                 return;
 470         if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 471                 ec_dbg_evt("Command(%s) submitted/blocked",
 472                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 473                 ec->nr_pending_queries++;
 474                 schedule_work(&ec->work);
 475         }
 476 }
 477
 478 static void acpi_ec_complete_query(struct acpi_ec *ec)
 479 {
 480         if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 481                 ec_dbg_evt("Command(%s) unblocked",
 482                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 483         acpi_ec_clear_storm(ec, EC_FLAGS_COMMAND_STORM);
 484 }
 485
 486 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
 487 {
 488         if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 489                 ec_log_drv("event unblocked");
 490         if (!test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 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 static void acpi_ec_enable_event(struct acpi_ec *ec)
 501 {
 502         unsigned long flags;
 503
 504         spin_lock_irqsave(&ec->lock, flags);
 505         if (acpi_ec_started(ec))
 506                 __acpi_ec_enable_event(ec);
 507         spin_unlock_irqrestore(&ec->lock, flags);
 508 }
 509
 510 #ifdef CONFIG_PM_SLEEP
 511 static bool acpi_ec_query_flushed(struct acpi_ec *ec)
 512 {
 513         bool flushed;
 514         unsigned long flags;
 515
 516         spin_lock_irqsave(&ec->lock, flags);
 517         flushed = !ec->nr_pending_queries;
 518         spin_unlock_irqrestore(&ec->lock, flags);
 519         return flushed;
 520 }
 521
 522 static void __acpi_ec_flush_event(struct acpi_ec *ec)
 523 {
 524         /*
 525          * When ec_freeze_events is true, we need to flush events in
 526          * the proper position before entering the noirq stage.
 527          */
 528         wait_event(ec->wait, acpi_ec_query_flushed(ec));
 529         if (ec_query_wq)
 530                 flush_workqueue(ec_query_wq);
 531 }
 532
 533 static void acpi_ec_disable_event(struct acpi_ec *ec)
 534 {
 535         unsigned long flags;
 536
 537         spin_lock_irqsave(&ec->lock, flags);
 538         __acpi_ec_disable_event(ec);
 539         spin_unlock_irqrestore(&ec->lock, flags);
 540         __acpi_ec_flush_event(ec);
 541 }
 542 #endif /* CONFIG_PM_SLEEP */
 543
 544 static bool acpi_ec_guard_event(struct acpi_ec *ec)
 545 {
 546         bool guarded = true;
 547         unsigned long flags;
 548
 549         spin_lock_irqsave(&ec->lock, flags);
 550         /*
 551          * If firmware SCI_EVT clearing timing is "event", we actually
 552          * don't know when the SCI_EVT will be cleared by firmware after
 553          * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
 554          * acceptable period.
 555          *
 556          * The guarding period begins when EC_FLAGS_QUERY_PENDING is
 557          * flagged, which means SCI_EVT check has just been performed.
 558          * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
 559          * guarding should have already been performed (via
 560          * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
 561          * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
 562          * ACPI_EC_COMMAND_POLL state immediately.
 563          */
 564         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
 565             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
 566             !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
 567             (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
 568                 guarded = false;
 569         spin_unlock_irqrestore(&ec->lock, flags);
 570         return guarded;
 571 }
 572
 573 static int ec_transaction_polled(struct acpi_ec *ec)
 574 {
 575         unsigned long flags;
 576         int ret = 0;
 577
 578         spin_lock_irqsave(&ec->lock, flags);
 579         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
 580                 ret = 1;
 581         spin_unlock_irqrestore(&ec->lock, flags);
 582         return ret;
 583 }
 584
 585 static int ec_transaction_completed(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_COMPLETE))
 592                 ret = 1;
 593         spin_unlock_irqrestore(&ec->lock, flags);
 594         return ret;
 595 }
 596
 597 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
 598 {
 599         ec->curr->flags |= flag;
 600         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 601                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
 602                     flag == ACPI_EC_COMMAND_POLL)
 603                         acpi_ec_complete_query(ec);
 604                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
 605                     flag == ACPI_EC_COMMAND_COMPLETE)
 606                         acpi_ec_complete_query(ec);
 607                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 608                     flag == ACPI_EC_COMMAND_COMPLETE)
 609                         set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 610         }
 611 }
 612
 613 static void advance_transaction(struct acpi_ec *ec)
 614 {
 615         struct transaction *t;
 616         u8 status;
 617         bool wakeup = false;
 618
 619         ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
 620                    smp_processor_id());
 621         /*
 622          * By always clearing STS before handling all indications, we can
 623          * ensure a hardware STS 0->1 change after this clearing can always
 624          * trigger a GPE interrupt.
 625          */
 626         acpi_ec_clear_gpe(ec);
 627         status = acpi_ec_read_status(ec);
 628         t = ec->curr;
 629         /*
 630          * Another IRQ or a guarded polling mode advancement is detected,
 631          * the next QR_EC submission is then allowed.
 632          */
 633         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
 634                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 635                     (!ec->nr_pending_queries ||
 636                      test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
 637                         clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 638                         acpi_ec_complete_query(ec);
 639                 }
 640         }
 641         if (!t)
 642                 goto err;
 643         if (t->flags & ACPI_EC_COMMAND_POLL) {
 644                 if (t->wlen > t->wi) {
 645                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 646                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 647                         else
 648                                 goto err;
 649                 } else if (t->rlen > t->ri) {
 650                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 651                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 652                                 if (t->rlen == t->ri) {
 653                                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 654                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 655                                                 ec_dbg_evt("Command(%s) completed by hardware",
 656                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 657                                         wakeup = true;
 658                                 }
 659                         } else
 660                                 goto err;
 661                 } else if (t->wlen == t->wi &&
 662                            (status & ACPI_EC_FLAG_IBF) == 0) {
 663                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 664                         wakeup = true;
 665                 }
 666                 goto out;
 667         } else {
 668                 if (EC_FLAGS_QUERY_HANDSHAKE &&
 669                     !(status & ACPI_EC_FLAG_SCI) &&
 670                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 671                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 672                         t->rdata[t->ri++] = 0x00;
 673                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 674                         ec_dbg_evt("Command(%s) completed by software",
 675                                    acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 676                         wakeup = true;
 677                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 678                         acpi_ec_write_cmd(ec, t->command);
 679                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 680                 } else
 681                         goto err;
 682                 goto out;
 683         }
 684 err:
 685         /*
 686          * If SCI bit is set, then don't think it's a false IRQ
 687          * otherwise will take a not handled IRQ as a false one.
 688          */
 689         if (!(status & ACPI_EC_FLAG_SCI)) {
 690                 if (in_interrupt() && t) {
 691                         if (t->irq_count < ec_storm_threshold)
 692                                 ++t->irq_count;
 693                         /* Allow triggering on 0 threshold */
 694                         if (t->irq_count == ec_storm_threshold)
 695                                 acpi_ec_set_storm(ec, EC_FLAGS_COMMAND_STORM);
 696                 }
 697         }
 698 out:
 699         if (status & ACPI_EC_FLAG_SCI)
 700                 acpi_ec_submit_query(ec);
 701         if (wakeup && in_interrupt())
 702                 wake_up(&ec->wait);
 703 }
 704
 705 static void start_transaction(struct acpi_ec *ec)
 706 {
 707         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 708         ec->curr->flags = 0;
 709 }
 710
 711 static int ec_guard(struct acpi_ec *ec)
 712 {
 713         unsigned long guard = usecs_to_jiffies(ec->polling_guard);
 714         unsigned long timeout = ec->timestamp + guard;
 715
 716         /* Ensure guarding period before polling EC status */
 717         do {
 718                 if (ec->busy_polling) {
 719                         /* Perform busy polling */
 720                         if (ec_transaction_completed(ec))
 721                                 return 0;
 722                         udelay(jiffies_to_usecs(guard));
 723                 } else {
 724                         /*
 725                          * Perform wait polling
 726                          * 1. Wait the transaction to be completed by the
 727                          *    GPE handler after the transaction enters
 728                          *    ACPI_EC_COMMAND_POLL state.
 729                          * 2. A special guarding logic is also required
 730                          *    for event clearing mode "event" before the
 731                          *    transaction enters ACPI_EC_COMMAND_POLL
 732                          *    state.
 733                          */
 734                         if (!ec_transaction_polled(ec) &&
 735                             !acpi_ec_guard_event(ec))
 736                                 break;
 737                         if (wait_event_timeout(ec->wait,
 738                                                ec_transaction_completed(ec),
 739                                                guard))
 740                                 return 0;
 741                 }
 742         } while (time_before(jiffies, timeout));
 743         return -ETIME;
 744 }
 745
 746 static int ec_poll(struct acpi_ec *ec)
 747 {
 748         unsigned long flags;
 749         int repeat = 5; /* number of command restarts */
 750
 751         while (repeat--) {
 752                 unsigned long delay = jiffies +
 753                         msecs_to_jiffies(ec_delay);
 754                 do {
 755                         if (!ec_guard(ec))
 756                                 return 0;
 757                         spin_lock_irqsave(&ec->lock, flags);
 758                         advance_transaction(ec);
 759                         spin_unlock_irqrestore(&ec->lock, flags);
 760                 } while (time_before(jiffies, delay));
 761                 pr_debug("controller reset, restart transaction\n");
 762                 spin_lock_irqsave(&ec->lock, flags);
 763                 start_transaction(ec);
 764                 spin_unlock_irqrestore(&ec->lock, flags);
 765         }
 766         return -ETIME;
 767 }
 768
 769 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 770                                         struct transaction *t)
 771 {
 772         unsigned long tmp;
 773         int ret = 0;
 774
 775         /* start transaction */
 776         spin_lock_irqsave(&ec->lock, tmp);
 777         /* Enable GPE for command processing (IBF=0/OBF=1) */
 778         if (!acpi_ec_submit_flushable_request(ec)) {
 779                 ret = -EINVAL;
 780                 goto unlock;
 781         }
 782         ec_dbg_ref(ec, "Increase command");
 783         /* following two actions should be kept atomic */
 784         ec->curr = t;
 785         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 786         start_transaction(ec);
 787         spin_unlock_irqrestore(&ec->lock, tmp);
 788
 789         ret = ec_poll(ec);
 790
 791         spin_lock_irqsave(&ec->lock, tmp);
 792         if (t->irq_count == ec_storm_threshold)
 793                 acpi_ec_clear_storm(ec, EC_FLAGS_COMMAND_STORM);
 794         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 795         ec->curr = NULL;
 796         /* Disable GPE for command processing (IBF=0/OBF=1) */
 797         acpi_ec_complete_request(ec);
 798         ec_dbg_ref(ec, "Decrease command");
 799 unlock:
 800         spin_unlock_irqrestore(&ec->lock, tmp);
 801         return ret;
 802 }
 803
 804 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 805 {
 806         int status;
 807         u32 glk;
 808
 809         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 810                 return -EINVAL;
 811         if (t->rdata)
 812                 memset(t->rdata, 0, t->rlen);
 813
 814         mutex_lock(&ec->mutex);
 815         if (ec->global_lock) {
 816                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 817                 if (ACPI_FAILURE(status)) {
 818                         status = -ENODEV;
 819                         goto unlock;
 820                 }
 821         }
 822
 823         status = acpi_ec_transaction_unlocked(ec, t);
 824
 825         if (ec->global_lock)
 826                 acpi_release_global_lock(glk);
 827 unlock:
 828         mutex_unlock(&ec->mutex);
 829         return status;
 830 }
 831
 832 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 833 {
 834         u8 d;
 835         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 836                                 .wdata = NULL, .rdata = &d,
 837                                 .wlen = 0, .rlen = 1};
 838
 839         return acpi_ec_transaction(ec, &t);
 840 }
 841
 842 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 843 {
 844         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 845                                 .wdata = NULL, .rdata = NULL,
 846                                 .wlen = 0, .rlen = 0};
 847
 848         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 849                                 acpi_ec_transaction(ec, &t) : 0;
 850 }
 851
 852 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 853 {
 854         int result;
 855         u8 d;
 856         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 857                                 .wdata = &address, .rdata = &d,
 858                                 .wlen = 1, .rlen = 1};
 859
 860         result = acpi_ec_transaction(ec, &t);
 861         *data = d;
 862         return result;
 863 }
 864
 865 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 866 {
 867         u8 wdata[2] = { address, data };
 868         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 869                                 .wdata = wdata, .rdata = NULL,
 870                                 .wlen = 2, .rlen = 0};
 871
 872         return acpi_ec_transaction(ec, &t);
 873 }
 874
 875 int ec_read(u8 addr, u8 *val)
 876 {
 877         int err;
 878         u8 temp_data;
 879
 880         if (!first_ec)
 881                 return -ENODEV;
 882
 883         err = acpi_ec_read(first_ec, addr, &temp_data);
 884
 885         if (!err) {
 886                 *val = temp_data;
 887                 return 0;
 888         }
 889         return err;
 890 }
 891 EXPORT_SYMBOL(ec_read);
 892
 893 int ec_write(u8 addr, u8 val)
 894 {
 895         int err;
 896
 897         if (!first_ec)
 898                 return -ENODEV;
 899
 900         err = acpi_ec_write(first_ec, addr, val);
 901
 902         return err;
 903 }
 904 EXPORT_SYMBOL(ec_write);
 905
 906 int ec_transaction(u8 command,
 907                    const u8 *wdata, unsigned wdata_len,
 908                    u8 *rdata, unsigned rdata_len)
 909 {
 910         struct transaction t = {.command = command,
 911                                 .wdata = wdata, .rdata = rdata,
 912                                 .wlen = wdata_len, .rlen = rdata_len};
 913
 914         if (!first_ec)
 915                 return -ENODEV;
 916
 917         return acpi_ec_transaction(first_ec, &t);
 918 }
 919 EXPORT_SYMBOL(ec_transaction);
 920
 921 /* Get the handle to the EC device */
 922 acpi_handle ec_get_handle(void)
 923 {
 924         if (!first_ec)
 925                 return NULL;
 926         return first_ec->handle;
 927 }
 928 EXPORT_SYMBOL(ec_get_handle);
 929
 930 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 931 {
 932         unsigned long flags;
 933
 934         spin_lock_irqsave(&ec->lock, flags);
 935         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 936                 ec_dbg_drv("Starting EC");
 937                 /* Enable GPE for event processing (SCI_EVT=1) */
 938                 if (!resuming) {
 939                         acpi_ec_submit_request(ec);
 940                         ec_dbg_ref(ec, "Increase driver");
 941                 }
 942                 ec_log_drv("EC started");
 943         }
 944         spin_unlock_irqrestore(&ec->lock, flags);
 945 }
 946
 947 static bool acpi_ec_stopped(struct acpi_ec *ec)
 948 {
 949         unsigned long flags;
 950         bool flushed;
 951
 952         spin_lock_irqsave(&ec->lock, flags);
 953         flushed = acpi_ec_flushed(ec);
 954         spin_unlock_irqrestore(&ec->lock, flags);
 955         return flushed;
 956 }
 957
 958 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 959 {
 960         unsigned long flags;
 961
 962         spin_lock_irqsave(&ec->lock, flags);
 963         if (acpi_ec_started(ec)) {
 964                 ec_dbg_drv("Stopping EC");
 965                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
 966                 spin_unlock_irqrestore(&ec->lock, flags);
 967                 wait_event(ec->wait, acpi_ec_stopped(ec));
 968                 spin_lock_irqsave(&ec->lock, flags);
 969                 /* Disable GPE for event processing (SCI_EVT=1) */
 970                 if (!suspending) {
 971                         acpi_ec_complete_request(ec);
 972                         ec_dbg_ref(ec, "Decrease driver");
 973                 } else if (!ec_freeze_events)
 974                         __acpi_ec_disable_event(ec);
 975                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
 976                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
 977                 ec_log_drv("EC stopped");
 978         }
 979         spin_unlock_irqrestore(&ec->lock, flags);
 980 }
 981
 982 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
 983 {
 984         unsigned long flags;
 985
 986         spin_lock_irqsave(&ec->lock, flags);
 987         ec->busy_polling = true;
 988         ec->polling_guard = 0;
 989         ec_log_drv("interrupt blocked");
 990         spin_unlock_irqrestore(&ec->lock, flags);
 991 }
 992
 993 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
 994 {
 995         unsigned long flags;
 996
 997         spin_lock_irqsave(&ec->lock, flags);
 998         ec->busy_polling = ec_busy_polling;
 999         ec->polling_guard = ec_polling_guard;
1000         ec_log_drv("interrupt unblocked");
1001         spin_unlock_irqrestore(&ec->lock, flags);
1002 }
1003
1004 void acpi_ec_block_transactions(void)
1005 {
1006         struct acpi_ec *ec = first_ec;
1007
1008         if (!ec)
1009                 return;
1010
1011         mutex_lock(&ec->mutex);
1012         /* Prevent transactions from being carried out */
1013         acpi_ec_stop(ec, true);
1014         mutex_unlock(&ec->mutex);
1015 }
1016
1017 void acpi_ec_unblock_transactions(void)
1018 {
1019         /*
1020          * Allow transactions to happen again (this function is called from
1021          * atomic context during wakeup, so we don't need to acquire the mutex).
1022          */
1023         if (first_ec)
1024                 acpi_ec_start(first_ec, true);
1025 }
1026
1027 /* --------------------------------------------------------------------------
1028                                 Event Management
1029    -------------------------------------------------------------------------- */
1030 static struct acpi_ec_query_handler *
1031 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
1032 {
1033         if (handler)
1034                 kref_get(&handler->kref);
1035         return handler;
1036 }
1037
1038 static struct acpi_ec_query_handler *
1039 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1040 {
1041         struct acpi_ec_query_handler *handler;
1042         bool found = false;
1043
1044         mutex_lock(&ec->mutex);
1045         list_for_each_entry(handler, &ec->list, node) {
1046                 if (value == handler->query_bit) {
1047                         found = true;
1048                         break;
1049                 }
1050         }
1051         mutex_unlock(&ec->mutex);
1052         return found ? acpi_ec_get_query_handler(handler) : NULL;
1053 }
1054
1055 static void acpi_ec_query_handler_release(struct kref *kref)
1056 {
1057         struct acpi_ec_query_handler *handler =
1058                 container_of(kref, struct acpi_ec_query_handler, kref);
1059
1060         kfree(handler);
1061 }
1062
1063 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1064 {
1065         kref_put(&handler->kref, acpi_ec_query_handler_release);
1066 }
1067
1068 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1069                               acpi_handle handle, acpi_ec_query_func func,
1070                               void *data)
1071 {
1072         struct acpi_ec_query_handler *handler =
1073             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1074
1075         if (!handler)
1076                 return -ENOMEM;
1077
1078         handler->query_bit = query_bit;
1079         handler->handle = handle;
1080         handler->func = func;
1081         handler->data = data;
1082         mutex_lock(&ec->mutex);
1083         kref_init(&handler->kref);
1084         list_add(&handler->node, &ec->list);
1085         mutex_unlock(&ec->mutex);
1086         return 0;
1087 }
1088 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1089
1090 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1091                                           bool remove_all, u8 query_bit)
1092 {
1093         struct acpi_ec_query_handler *handler, *tmp;
1094         LIST_HEAD(free_list);
1095
1096         mutex_lock(&ec->mutex);
1097         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1098                 if (remove_all || query_bit == handler->query_bit) {
1099                         list_del_init(&handler->node);
1100                         list_add(&handler->node, &free_list);
1101                 }
1102         }
1103         mutex_unlock(&ec->mutex);
1104         list_for_each_entry_safe(handler, tmp, &free_list, node)
1105                 acpi_ec_put_query_handler(handler);
1106 }
1107
1108 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1109 {
1110         acpi_ec_remove_query_handlers(ec, false, query_bit);
1111 }
1112 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1113
1114 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1115 {
1116         struct acpi_ec_query *q;
1117         struct transaction *t;
1118
1119         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1120         if (!q)
1121                 return NULL;
1122         INIT_WORK(&q->work, acpi_ec_event_processor);
1123         t = &q->transaction;
1124         t->command = ACPI_EC_COMMAND_QUERY;
1125         t->rdata = pval;
1126         t->rlen = 1;
1127         return q;
1128 }
1129
1130 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1131 {
1132         if (q) {
1133                 if (q->handler)
1134                         acpi_ec_put_query_handler(q->handler);
1135                 kfree(q);
1136         }
1137 }
1138
1139 static void acpi_ec_event_processor(struct work_struct *work)
1140 {
1141         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1142         struct acpi_ec_query_handler *handler = q->handler;
1143
1144         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1145         if (handler->func)
1146                 handler->func(handler->data);
1147         else if (handler->handle)
1148                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1149         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1150         acpi_ec_delete_query(q);
1151 }
1152
1153 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1154 {
1155         u8 value = 0;
1156         int result;
1157         struct acpi_ec_query *q;
1158
1159         q = acpi_ec_create_query(&value);
1160         if (!q)
1161                 return -ENOMEM;
1162
1163         /*
1164          * Query the EC to find out which _Qxx method we need to evaluate.
1165          * Note that successful completion of the query causes the ACPI_EC_SCI
1166          * bit to be cleared (and thus clearing the interrupt source).
1167          */
1168         result = acpi_ec_transaction(ec, &q->transaction);
1169         if (!value)
1170                 result = -ENODATA;
1171         if (result)
1172                 goto err_exit;
1173
1174         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1175         if (!q->handler) {
1176                 result = -ENODATA;
1177                 goto err_exit;
1178         }
1179
1180         /*
1181          * It is reported that _Qxx are evaluated in a parallel way on
1182          * Windows:
1183          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1184          *
1185          * Put this log entry before schedule_work() in order to make
1186          * it appearing before any other log entries occurred during the
1187          * work queue execution.
1188          */
1189         ec_dbg_evt("Query(0x%02x) scheduled", value);
1190         if (!queue_work(ec_query_wq, &q->work)) {
1191                 ec_dbg_evt("Query(0x%02x) overlapped", value);
1192                 result = -EBUSY;
1193         }
1194
1195 err_exit:
1196         if (result)
1197                 acpi_ec_delete_query(q);
1198         if (data)
1199                 *data = value;
1200         return result;
1201 }
1202
1203 static void acpi_ec_check_event(struct acpi_ec *ec)
1204 {
1205         unsigned long flags;
1206
1207         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1208                 if (ec_guard(ec)) {
1209                         spin_lock_irqsave(&ec->lock, flags);
1210                         /*
1211                          * Take care of the SCI_EVT unless no one else is
1212                          * taking care of it.
1213                          */
1214                         if (!ec->curr)
1215                                 advance_transaction(ec);
1216                         spin_unlock_irqrestore(&ec->lock, flags);
1217                 }
1218         }
1219 }
1220
1221 static void acpi_ec_event_handler(struct work_struct *work)
1222 {
1223         unsigned long flags;
1224         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1225
1226         ec_dbg_evt("Event started");
1227
1228         spin_lock_irqsave(&ec->lock, flags);
1229         while (ec->nr_pending_queries) {
1230                 spin_unlock_irqrestore(&ec->lock, flags);
1231                 (void)acpi_ec_query(ec, NULL);
1232                 spin_lock_irqsave(&ec->lock, flags);
1233                 ec->nr_pending_queries--;
1234                 /*
1235                  * Before exit, make sure that this work item can be
1236                  * scheduled again. There might be QR_EC failures, leaving
1237                  * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1238                  * item from being scheduled again.
1239                  */
1240                 if (!ec->nr_pending_queries) {
1241                         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1242                             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1243                                 acpi_ec_complete_query(ec);
1244                 }
1245         }
1246         spin_unlock_irqrestore(&ec->lock, flags);
1247
1248         ec_dbg_evt("Event stopped");
1249
1250         acpi_ec_check_event(ec);
1251 }
1252
1253 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1254         u32 gpe_number, void *data)
1255 {
1256         unsigned long flags;
1257         struct acpi_ec *ec = data;
1258
1259         spin_lock_irqsave(&ec->lock, flags);
1260         advance_transaction(ec);
1261         spin_unlock_irqrestore(&ec->lock, flags);
1262         return ACPI_INTERRUPT_HANDLED;
1263 }
1264
1265 /* --------------------------------------------------------------------------
1266  *                           Address Space Management
1267  * -------------------------------------------------------------------------- */
1268
1269 static acpi_status
1270 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1271                       u32 bits, u64 *value64,
1272                       void *handler_context, void *region_context)
1273 {
1274         struct acpi_ec *ec = handler_context;
1275         int result = 0, i, bytes = bits / 8;
1276         u8 *value = (u8 *)value64;
1277
1278         if ((address > 0xFF) || !value || !handler_context)
1279                 return AE_BAD_PARAMETER;
1280
1281         if (function != ACPI_READ && function != ACPI_WRITE)
1282                 return AE_BAD_PARAMETER;
1283
1284         if (ec->busy_polling || bits > 8)
1285                 acpi_ec_burst_enable(ec);
1286
1287         for (i = 0; i < bytes; ++i, ++address, ++value)
1288                 result = (function == ACPI_READ) ?
1289                         acpi_ec_read(ec, address, value) :
1290                         acpi_ec_write(ec, address, *value);
1291
1292         if (ec->busy_polling || bits > 8)
1293                 acpi_ec_burst_disable(ec);
1294
1295         switch (result) {
1296         case -EINVAL:
1297                 return AE_BAD_PARAMETER;
1298         case -ENODEV:
1299                 return AE_NOT_FOUND;
1300         case -ETIME:
1301                 return AE_TIME;
1302         default:
1303                 return AE_OK;
1304         }
1305 }
1306
1307 /* --------------------------------------------------------------------------
1308  *                             Driver Interface
1309  * -------------------------------------------------------------------------- */
1310
1311 static acpi_status
1312 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1313
1314 static void acpi_ec_free(struct acpi_ec *ec)
1315 {
1316         if (first_ec == ec)
1317                 first_ec = NULL;
1318         if (boot_ec == ec)
1319                 boot_ec = NULL;
1320         kfree(ec);
1321 }
1322
1323 static struct acpi_ec *acpi_ec_alloc(void)
1324 {
1325         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1326
1327         if (!ec)
1328                 return NULL;
1329         mutex_init(&ec->mutex);
1330         init_waitqueue_head(&ec->wait);
1331         INIT_LIST_HEAD(&ec->list);
1332         spin_lock_init(&ec->lock);
1333         INIT_WORK(&ec->work, acpi_ec_event_handler);
1334         ec->timestamp = jiffies;
1335         ec->busy_polling = true;
1336         ec->polling_guard = 0;
1337         return ec;
1338 }
1339
1340 static acpi_status
1341 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1342                                void *context, void **return_value)
1343 {
1344         char node_name[5];
1345         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1346         struct acpi_ec *ec = context;
1347         int value = 0;
1348         acpi_status status;
1349
1350         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1351
1352         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1353                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1354         return AE_OK;
1355 }
1356
1357 static acpi_status
1358 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1359 {
1360         acpi_status status;
1361         unsigned long long tmp = 0;
1362         struct acpi_ec *ec = context;
1363
1364         /* clear addr values, ec_parse_io_ports depend on it */
1365         ec->command_addr = ec->data_addr = 0;
1366
1367         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1368                                      ec_parse_io_ports, ec);
1369         if (ACPI_FAILURE(status))
1370                 return status;
1371         if (ec->data_addr == 0 || ec->command_addr == 0)
1372                 return AE_OK;
1373
1374         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1375                 /*
1376                  * Always inherit the GPE number setting from the ECDT
1377                  * EC.
1378                  */
1379                 ec->gpe = boot_ec->gpe;
1380         } else {
1381                 /* Get GPE bit assignment (EC events). */
1382                 /* TODO: Add support for _GPE returning a package */
1383                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1384                 if (ACPI_FAILURE(status))
1385                         return status;
1386                 ec->gpe = tmp;
1387         }
1388         /* Use the global lock for all EC transactions? */
1389         tmp = 0;
1390         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1391         ec->global_lock = tmp;
1392         ec->handle = handle;
1393         return AE_CTRL_TERMINATE;
1394 }
1395
1396 /*
1397  * Note: This function returns an error code only when the address space
1398  *       handler is not installed, which means "not able to handle
1399  *       transactions".
1400  */
1401 static int ec_install_handlers(struct acpi_ec *ec, bool handle_events)
1402 {
1403         acpi_status status;
1404
1405         acpi_ec_start(ec, false);
1406
1407         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1408                 acpi_ec_enter_noirq(ec);
1409                 status = acpi_install_address_space_handler(ec->handle,
1410                                                             ACPI_ADR_SPACE_EC,
1411                                                             &acpi_ec_space_handler,
1412                                                             NULL, ec);
1413                 if (ACPI_FAILURE(status)) {
1414                         if (status == AE_NOT_FOUND) {
1415                                 /*
1416                                  * Maybe OS fails in evaluating the _REG
1417                                  * object. The AE_NOT_FOUND error will be
1418                                  * ignored and OS * continue to initialize
1419                                  * EC.
1420                                  */
1421                                 pr_err("Fail in evaluating the _REG object"
1422                                         " of EC device. Broken bios is suspected.\n");
1423                         } else {
1424                                 acpi_ec_stop(ec, false);
1425                                 return -ENODEV;
1426                         }
1427                 }
1428                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1429         }
1430
1431         if (!handle_events)
1432                 return 0;
1433
1434         if (!test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1435                 /* Find and register all query methods */
1436                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1437                                     acpi_ec_register_query_methods,
1438                                     NULL, ec, NULL);
1439                 set_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1440         }
1441         if (!test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1442                 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1443                                           ACPI_GPE_EDGE_TRIGGERED,
1444                                           &acpi_ec_gpe_handler, ec);
1445                 /* This is not fatal as we can poll EC events */
1446                 if (ACPI_SUCCESS(status)) {
1447                         set_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1448                         acpi_ec_leave_noirq(ec);
1449                         if (test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1450                             ec->reference_count >= 1)
1451                                 acpi_ec_enable_gpe(ec, true);
1452
1453                         /* EC is fully operational, allow queries */
1454                         acpi_ec_enable_event(ec);
1455                 }
1456         }
1457
1458         return 0;
1459 }
1460
1461 static void ec_remove_handlers(struct acpi_ec *ec)
1462 {
1463         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1464                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1465                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1466                         pr_err("failed to remove space handler\n");
1467                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1468         }
1469
1470         /*
1471          * Stops handling the EC transactions after removing the operation
1472          * region handler. This is required because _REG(DISCONNECT)
1473          * invoked during the removal can result in new EC transactions.
1474          *
1475          * Flushes the EC requests and thus disables the GPE before
1476          * removing the GPE handler. This is required by the current ACPICA
1477          * GPE core. ACPICA GPE core will automatically disable a GPE when
1478          * it is indicated but there is no way to handle it. So the drivers
1479          * must disable the GPEs prior to removing the GPE handlers.
1480          */
1481         acpi_ec_stop(ec, false);
1482
1483         if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
1484                 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1485                                         &acpi_ec_gpe_handler)))
1486                         pr_err("failed to remove gpe handler\n");
1487                 clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
1488         }
1489         if (test_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags)) {
1490                 acpi_ec_remove_query_handlers(ec, true, 0);
1491                 clear_bit(EC_FLAGS_EVT_HANDLER_INSTALLED, &ec->flags);
1492         }
1493 }
1494
1495 static int acpi_ec_setup(struct acpi_ec *ec, bool handle_events)
1496 {
1497         int ret;
1498
1499         ret = ec_install_handlers(ec, handle_events);
1500         if (ret)
1501                 return ret;
1502
1503         /* First EC capable of handling transactions */
1504         if (!first_ec) {
1505                 first_ec = ec;
1506                 acpi_handle_info(first_ec->handle, "Used as first EC\n");
1507         }
1508
1509         acpi_handle_info(ec->handle,
1510                          "GPE=0x%lx, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n",
1511                          ec->gpe, ec->command_addr, ec->data_addr);
1512         return ret;
1513 }
1514
1515 static int acpi_config_boot_ec(struct acpi_ec *ec, acpi_handle handle,
1516                                bool handle_events, bool is_ecdt)
1517 {
1518         int ret;
1519
1520         /*
1521          * Changing the ACPI handle results in a re-configuration of the
1522          * boot EC. And if it happens after the namespace initialization,
1523          * it causes _REG evaluations.
1524          */
1525         if (boot_ec && boot_ec->handle != handle)
1526                 ec_remove_handlers(boot_ec);
1527
1528         /* Unset old boot EC */
1529         if (boot_ec != ec)
1530                 acpi_ec_free(boot_ec);
1531
1532         /*
1533          * ECDT device creation is split into acpi_ec_ecdt_probe() and
1534          * acpi_ec_ecdt_start(). This function takes care of completing the
1535          * ECDT parsing logic as the handle update should be performed
1536          * between the installation/uninstallation of the handlers.
1537          */
1538         if (ec->handle != handle)
1539                 ec->handle = handle;
1540
1541         ret = acpi_ec_setup(ec, handle_events);
1542         if (ret)
1543                 return ret;
1544
1545         /* Set new boot EC */
1546         if (!boot_ec) {
1547                 boot_ec = ec;
1548                 boot_ec_is_ecdt = is_ecdt;
1549         }
1550
1551         acpi_handle_info(boot_ec->handle,
1552                          "Used as boot %s EC to handle transactions%s\n",
1553                          is_ecdt ? "ECDT" : "DSDT",
1554                          handle_events ? " and events" : "");
1555         return ret;
1556 }
1557
1558 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)
1559 {
1560         struct acpi_table_ecdt *ecdt_ptr;
1561         acpi_status status;
1562         acpi_handle handle;
1563
1564         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1565                                 (struct acpi_table_header **)&ecdt_ptr);
1566         if (ACPI_FAILURE(status))
1567                 return false;
1568
1569         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1570         if (ACPI_FAILURE(status))
1571                 return false;
1572
1573         *phandle = handle;
1574         return true;
1575 }
1576
1577 static bool acpi_is_boot_ec(struct acpi_ec *ec)
1578 {
1579         if (!boot_ec)
1580                 return false;
1581         if (ec->handle == boot_ec->handle &&
1582             ec->gpe == boot_ec->gpe &&
1583             ec->command_addr == boot_ec->command_addr &&
1584             ec->data_addr == boot_ec->data_addr)
1585                 return true;
1586         return false;
1587 }
1588
1589 static int acpi_ec_add(struct acpi_device *device)
1590 {
1591         struct acpi_ec *ec = NULL;
1592         int ret;
1593
1594         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1595         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1596
1597         ec = acpi_ec_alloc();
1598         if (!ec)
1599                 return -ENOMEM;
1600         if (ec_parse_device(device->handle, 0, ec, NULL) !=
1601                 AE_CTRL_TERMINATE) {
1602                         ret = -EINVAL;
1603                         goto err_alloc;
1604         }
1605
1606         if (acpi_is_boot_ec(ec)) {
1607                 boot_ec_is_ecdt = false;
1608                 acpi_handle_debug(ec->handle, "duplicated.\n");
1609                 acpi_ec_free(ec);
1610                 ec = boot_ec;
1611                 ret = acpi_config_boot_ec(ec, ec->handle, true, false);
1612         } else
1613                 ret = acpi_ec_setup(ec, true);
1614         if (ret)
1615                 goto err_query;
1616
1617         device->driver_data = ec;
1618
1619         ret = !!request_region(ec->data_addr, 1, "EC data");
1620         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1621         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1622         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1623
1624         /* Reprobe devices depending on the EC */
1625         acpi_walk_dep_device_list(ec->handle);
1626         acpi_handle_debug(ec->handle, "enumerated.\n");
1627         return 0;
1628
1629 err_query:
1630         if (ec != boot_ec)
1631                 acpi_ec_remove_query_handlers(ec, true, 0);
1632 err_alloc:
1633         if (ec != boot_ec)
1634                 acpi_ec_free(ec);
1635         return ret;
1636 }
1637
1638 static int acpi_ec_remove(struct acpi_device *device)
1639 {
1640         struct acpi_ec *ec;
1641
1642         if (!device)
1643                 return -EINVAL;
1644
1645         ec = acpi_driver_data(device);
1646         release_region(ec->data_addr, 1);
1647         release_region(ec->command_addr, 1);
1648         device->driver_data = NULL;
1649         if (ec != boot_ec) {
1650                 ec_remove_handlers(ec);
1651                 acpi_ec_free(ec);
1652         }
1653         return 0;
1654 }
1655
1656 static acpi_status
1657 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1658 {
1659         struct acpi_ec *ec = context;
1660
1661         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1662                 return AE_OK;
1663
1664         /*
1665          * The first address region returned is the data port, and
1666          * the second address region returned is the status/command
1667          * port.
1668          */
1669         if (ec->data_addr == 0)
1670                 ec->data_addr = resource->data.io.minimum;
1671         else if (ec->command_addr == 0)
1672                 ec->command_addr = resource->data.io.minimum;
1673         else
1674                 return AE_CTRL_TERMINATE;
1675
1676         return AE_OK;
1677 }
1678
1679 static const struct acpi_device_id ec_device_ids[] = {
1680         {"PNP0C09", 0},
1681         {"", 0},
1682 };
1683
1684 /*
1685  * This function is not Windows-compatible as Windows never enumerates the
1686  * namespace EC before the main ACPI device enumeration process. It is
1687  * retained for historical reason and will be deprecated in the future.
1688  */
1689 int __init acpi_ec_dsdt_probe(void)
1690 {
1691         acpi_status status;
1692         struct acpi_ec *ec;
1693         int ret;
1694
1695         /*
1696          * If a platform has ECDT, there is no need to proceed as the
1697          * following probe is not a part of the ACPI device enumeration,
1698          * executing _STA is not safe, and thus this probe may risk of
1699          * picking up an invalid EC device.
1700          */
1701         if (boot_ec)
1702                 return -ENODEV;
1703
1704         ec = acpi_ec_alloc();
1705         if (!ec)
1706                 return -ENOMEM;
1707         /*
1708          * At this point, the namespace is initialized, so start to find
1709          * the namespace objects.
1710          */
1711         status = acpi_get_devices(ec_device_ids[0].id,
1712                                   ec_parse_device, ec, NULL);
1713         if (ACPI_FAILURE(status) || !ec->handle) {
1714                 ret = -ENODEV;
1715                 goto error;
1716         }
1717         /*
1718          * When the DSDT EC is available, always re-configure boot EC to
1719          * have _REG evaluated. _REG can only be evaluated after the
1720          * namespace initialization.
1721          * At this point, the GPE is not fully initialized, so do not to
1722          * handle the events.
1723          */
1724         ret = acpi_config_boot_ec(ec, ec->handle, false, false);
1725 error:
1726         if (ret)
1727                 acpi_ec_free(ec);
1728         return ret;
1729 }
1730
1731 /*
1732  * If the DSDT EC is not functioning, we still need to prepare a fully
1733  * functioning ECDT EC first in order to handle the events.
1734  * https://bugzilla.kernel.org/show_bug.cgi?id=115021
1735  */
1736 int __init acpi_ec_ecdt_start(void)
1737 {
1738         acpi_handle handle;
1739
1740         if (!boot_ec)
1741                 return -ENODEV;
1742         /*
1743          * The DSDT EC should have already been started in
1744          * acpi_ec_add().
1745          */
1746         if (!boot_ec_is_ecdt)
1747                 return -ENODEV;
1748
1749         /*
1750          * At this point, the namespace and the GPE is initialized, so
1751          * start to find the namespace objects and handle the events.
1752          */
1753         if (!acpi_ec_ecdt_get_handle(&handle))
1754                 return -ENODEV;
1755         return acpi_config_boot_ec(boot_ec, handle, true, true);
1756 }
1757
1758 #if 0
1759 /*
1760  * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1761  * set, for which case, we complete the QR_EC without issuing it to the
1762  * firmware.
1763  * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1764  * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1765  */
1766 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1767 {
1768         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1769         EC_FLAGS_QUERY_HANDSHAKE = 1;
1770         return 0;
1771 }
1772 #endif
1773
1774 /*
1775  * Some ECDTs contain wrong register addresses.
1776  * MSI MS-171F
1777  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1778  */
1779 static int ec_correct_ecdt(const struct dmi_system_id *id)
1780 {
1781         pr_debug("Detected system needing ECDT address correction.\n");
1782         EC_FLAGS_CORRECT_ECDT = 1;
1783         return 0;
1784 }
1785
1786 /*
1787  * Some DSDTs contain wrong GPE setting.
1788  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1789  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1790  */
1791 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1792 {
1793         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1794         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1795         return 0;
1796 }
1797
1798 static struct dmi_system_id ec_dmi_table[] __initdata = {
1799         {
1800         ec_correct_ecdt, "MSI MS-171F", {
1801         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1802         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1803         {
1804         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1805         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1806         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1807         {
1808         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1809         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1810         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1811         {
1812         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1813         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1814         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1815         {
1816         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1817         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1818         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1819         {
1820         ec_honor_ecdt_gpe, "ASUS X580VD", {
1821         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1822         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1823         {},
1824 };
1825
1826 int __init acpi_ec_ecdt_probe(void)
1827 {
1828         int ret;
1829         acpi_status status;
1830         struct acpi_table_ecdt *ecdt_ptr;
1831         struct acpi_ec *ec;
1832
1833         ec = acpi_ec_alloc();
1834         if (!ec)
1835                 return -ENOMEM;
1836         /*
1837          * Generate a boot ec context
1838          */
1839         dmi_check_system(ec_dmi_table);
1840         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1841                                 (struct acpi_table_header **)&ecdt_ptr);
1842         if (ACPI_FAILURE(status)) {
1843                 ret = -ENODEV;
1844                 goto error;
1845         }
1846
1847         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1848                 /*
1849                  * Asus X50GL:
1850                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1851                  */
1852                 ret = -ENODEV;
1853                 goto error;
1854         }
1855
1856         if (EC_FLAGS_CORRECT_ECDT) {
1857                 ec->command_addr = ecdt_ptr->data.address;
1858                 ec->data_addr = ecdt_ptr->control.address;
1859         } else {
1860                 ec->command_addr = ecdt_ptr->control.address;
1861                 ec->data_addr = ecdt_ptr->data.address;
1862         }
1863         ec->gpe = ecdt_ptr->gpe;
1864
1865         /*
1866          * At this point, the namespace is not initialized, so do not find
1867          * the namespace objects, or handle the events.
1868          */
1869         ret = acpi_config_boot_ec(ec, ACPI_ROOT_OBJECT, false, true);
1870 error:
1871         if (ret)
1872                 acpi_ec_free(ec);
1873         return ret;
1874 }
1875
1876 #ifdef CONFIG_PM_SLEEP
1877 static int acpi_ec_suspend(struct device *dev)
1878 {
1879         struct acpi_ec *ec =
1880                 acpi_driver_data(to_acpi_device(dev));
1881
1882         if (acpi_sleep_no_ec_events() && ec_freeze_events)
1883                 acpi_ec_disable_event(ec);
1884         return 0;
1885 }
1886
1887 static int acpi_ec_suspend_noirq(struct device *dev)
1888 {
1889         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1890
1891         /*
1892          * The SCI handler doesn't run at this point, so the GPE can be
1893          * masked at the low level without side effects.
1894          */
1895         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1896             ec->reference_count >= 1)
1897                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1898
1899         return 0;
1900 }
1901
1902 static int acpi_ec_resume_noirq(struct device *dev)
1903 {
1904         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1905
1906         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1907             ec->reference_count >= 1)
1908                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1909
1910         return 0;
1911 }
1912
1913 static int acpi_ec_resume(struct device *dev)
1914 {
1915         struct acpi_ec *ec =
1916                 acpi_driver_data(to_acpi_device(dev));
1917
1918         acpi_ec_enable_event(ec);
1919         return 0;
1920 }
1921 #endif
1922
1923 static const struct dev_pm_ops acpi_ec_pm = {
1924         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
1925         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
1926 };
1927
1928 static int param_set_event_clearing(const char *val, struct kernel_param *kp)
1929 {
1930         int result = 0;
1931
1932         if (!strncmp(val, "status", sizeof("status") - 1)) {
1933                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1934                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
1935         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
1936                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
1937                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
1938         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
1939                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
1940                 pr_info("Assuming SCI_EVT clearing on event reads\n");
1941         } else
1942                 result = -EINVAL;
1943         return result;
1944 }
1945
1946 static int param_get_event_clearing(char *buffer, struct kernel_param *kp)
1947 {
1948         switch (ec_event_clearing) {
1949         case ACPI_EC_EVT_TIMING_STATUS:
1950                 return sprintf(buffer, "status");
1951         case ACPI_EC_EVT_TIMING_QUERY:
1952                 return sprintf(buffer, "query");
1953         case ACPI_EC_EVT_TIMING_EVENT:
1954                 return sprintf(buffer, "event");
1955         default:
1956                 return sprintf(buffer, "invalid");
1957         }
1958         return 0;
1959 }
1960
1961 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
1962                   NULL, 0644);
1963 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
1964
1965 static struct acpi_driver acpi_ec_driver = {
1966         .name = "ec",
1967         .class = ACPI_EC_CLASS,
1968         .ids = ec_device_ids,
1969         .ops = {
1970                 .add = acpi_ec_add,
1971                 .remove = acpi_ec_remove,
1972                 },
1973         .drv.pm = &acpi_ec_pm,
1974 };
1975
1976 static inline int acpi_ec_query_init(void)
1977 {
1978         if (!ec_query_wq) {
1979                 ec_query_wq = alloc_workqueue("kec_query", 0,
1980                                               ec_max_queries);
1981                 if (!ec_query_wq)
1982                         return -ENODEV;
1983         }
1984         return 0;
1985 }
1986
1987 static inline void acpi_ec_query_exit(void)
1988 {
1989         if (ec_query_wq) {
1990                 destroy_workqueue(ec_query_wq);
1991                 ec_query_wq = NULL;
1992         }
1993 }
1994
1995 int __init acpi_ec_init(void)
1996 {
1997         int result;
1998
1999         /* register workqueue for _Qxx evaluations */
2000         result = acpi_ec_query_init();
2001         if (result)
2002                 goto err_exit;
2003         /* Now register the driver for the EC */
2004         result = acpi_bus_register_driver(&acpi_ec_driver);
2005         if (result)
2006                 goto err_exit;
2007
2008 err_exit:
2009         if (result)
2010                 acpi_ec_query_exit();
2011         return result;
2012 }
2013
2014 /* EC driver currently not unloadable */
2015 #if 0
2016 static void __exit acpi_ec_exit(void)
2017 {
2018
2019         acpi_bus_unregister_driver(&acpi_ec_driver);
2020         acpi_ec_query_exit();
2021 }
2022 #endif  /* 0 */