drivers/acpi/ec.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  ec.c - ACPI Embedded Controller Driver (v3)
   4  *
   5  *  Copyright (C) 2001-2015 Intel Corporation
   6  *    Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>
   7  *            2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
   8  *            2006       Denis Sadykov <denis.m.sadykov@intel.com>
   9  *            2004       Luming Yu <luming.yu@intel.com>
  10  *            2001, 2002 Andy Grover <andrew.grover@intel.com>
  11  *            2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
  12  *  Copyright (C) 2008      Alexey Starikovskiy <astarikovskiy@suse.de>
  13  */
  14
  15 /* Uncomment next line to get verbose printout */
  16 /* #define DEBUG */
  17 #define pr_fmt(fmt) "ACPI: EC: " fmt
  18
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/init.h>
  22 #include <linux/types.h>
  23 #include <linux/delay.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/list.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/slab.h>
  28 #include <linux/suspend.h>
  29 #include <linux/acpi.h>
  30 #include <linux/dmi.h>
  31 #include <asm/io.h>
  32
  33 #include "internal.h"
  34
  35 #define ACPI_EC_CLASS                   "embedded_controller"
  36 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  37 #define ACPI_EC_FILE_INFO               "info"
  38
  39 /* EC status register */
  40 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  41 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  42 #define ACPI_EC_FLAG_CMD        0x08    /* Input buffer contains a command */
  43 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  44 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  45
  46 /*
  47  * The SCI_EVT clearing timing is not defined by the ACPI specification.
  48  * This leads to lots of practical timing issues for the host EC driver.
  49  * The following variations are defined (from the target EC firmware's
  50  * perspective):
  51  * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
  52  *         target can clear SCI_EVT at any time so long as the host can see
  53  *         the indication by reading the status register (EC_SC). So the
  54  *         host should re-check SCI_EVT after the first time the SCI_EVT
  55  *         indication is seen, which is the same time the query request
  56  *         (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
  57  *         at any later time could indicate another event. Normally such
  58  *         kind of EC firmware has implemented an event queue and will
  59  *         return 0x00 to indicate "no outstanding event".
  60  * QUERY: After seeing the query request (QR_EC) written to the command
  61  *        register (EC_CMD) by the host and having prepared the responding
  62  *        event value in the data register (EC_DATA), the target can safely
  63  *        clear SCI_EVT because the target can confirm that the current
  64  *        event is being handled by the host. The host then should check
  65  *        SCI_EVT right after reading the event response from the data
  66  *        register (EC_DATA).
  67  * EVENT: After seeing the event response read from the data register
  68  *        (EC_DATA) by the host, the target can clear SCI_EVT. As the
  69  *        target requires time to notice the change in the data register
  70  *        (EC_DATA), the host may be required to wait additional guarding
  71  *        time before checking the SCI_EVT again. Such guarding may not be
  72  *        necessary if the host is notified via another IRQ.
  73  */
  74 #define ACPI_EC_EVT_TIMING_STATUS       0x00
  75 #define ACPI_EC_EVT_TIMING_QUERY        0x01
  76 #define ACPI_EC_EVT_TIMING_EVENT        0x02
  77
  78 /* EC commands */
  79 enum ec_command {
  80         ACPI_EC_COMMAND_READ = 0x80,
  81         ACPI_EC_COMMAND_WRITE = 0x81,
  82         ACPI_EC_BURST_ENABLE = 0x82,
  83         ACPI_EC_BURST_DISABLE = 0x83,
  84         ACPI_EC_COMMAND_QUERY = 0x84,
  85 };
  86
  87 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  88 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  89 #define ACPI_EC_UDELAY_POLL     550     /* Wait 1ms for EC transaction polling */
  90 #define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
  91                                          * when trying to clear the EC */
  92 #define ACPI_EC_MAX_QUERIES     16      /* Maximum number of parallel queries */
  93
  94 enum {
  95         EC_FLAGS_QUERY_ENABLED,         /* Query is enabled */
  96         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  97         EC_FLAGS_QUERY_GUARDING,        /* Guard for SCI_EVT check */
  98         EC_FLAGS_EVENT_HANDLER_INSTALLED,       /* Event handler installed */
  99         EC_FLAGS_EC_HANDLER_INSTALLED,  /* OpReg handler installed */
 100         EC_FLAGS_QUERY_METHODS_INSTALLED, /* _Qxx handlers installed */
 101         EC_FLAGS_STARTED,               /* Driver is started */
 102         EC_FLAGS_STOPPED,               /* Driver is stopped */
 103         EC_FLAGS_EVENTS_MASKED,         /* Events masked */
 104 };
 105
 106 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
 107 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
 108
 109 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 110 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 111 module_param(ec_delay, uint, 0644);
 112 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
 113
 114 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
 115 module_param(ec_max_queries, uint, 0644);
 116 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
 117
 118 static bool ec_busy_polling __read_mostly;
 119 module_param(ec_busy_polling, bool, 0644);
 120 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
 121
 122 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
 123 module_param(ec_polling_guard, uint, 0644);
 124 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
 125
 126 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
 127
 128 /*
 129  * If the number of false interrupts per one transaction exceeds
 130  * this threshold, will think there is a GPE storm happened and
 131  * will disable the GPE for normal transaction.
 132  */
 133 static unsigned int ec_storm_threshold  __read_mostly = 8;
 134 module_param(ec_storm_threshold, uint, 0644);
 135 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 136
 137 static bool ec_freeze_events __read_mostly = false;
 138 module_param(ec_freeze_events, bool, 0644);
 139 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
 140
 141 static bool ec_no_wakeup __read_mostly;
 142 module_param(ec_no_wakeup, bool, 0644);
 143 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
 144
 145 struct acpi_ec_query_handler {
 146         struct list_head node;
 147         acpi_ec_query_func func;
 148         acpi_handle handle;
 149         void *data;
 150         u8 query_bit;
 151         struct kref kref;
 152 };
 153
 154 struct transaction {
 155         const u8 *wdata;
 156         u8 *rdata;
 157         unsigned short irq_count;
 158         u8 command;
 159         u8 wi;
 160         u8 ri;
 161         u8 wlen;
 162         u8 rlen;
 163         u8 flags;
 164 };
 165
 166 struct acpi_ec_query {
 167         struct transaction transaction;
 168         struct work_struct work;
 169         struct acpi_ec_query_handler *handler;
 170 };
 171
 172 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
 173 static void advance_transaction(struct acpi_ec *ec);
 174 static void acpi_ec_event_handler(struct work_struct *work);
 175 static void acpi_ec_event_processor(struct work_struct *work);
 176
 177 struct acpi_ec *first_ec;
 178 EXPORT_SYMBOL(first_ec);
 179
 180 static struct acpi_ec *boot_ec;
 181 static bool boot_ec_is_ecdt = false;
 182 static struct workqueue_struct *ec_query_wq;
 183
 184 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
 185 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
 186 static int EC_FLAGS_IGNORE_DSDT_GPE; /* Needs ECDT GPE as correction setting */
 187 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 188
 189 /* --------------------------------------------------------------------------
 190  *                           Logging/Debugging
 191  * -------------------------------------------------------------------------- */
 192
 193 /*
 194  * Splitters used by the developers to track the boundary of the EC
 195  * handling processes.
 196  */
 197 #ifdef DEBUG
 198 #define EC_DBG_SEP      " "
 199 #define EC_DBG_DRV      "+++++"
 200 #define EC_DBG_STM      "====="
 201 #define EC_DBG_REQ      "*****"
 202 #define EC_DBG_EVT      "#####"
 203 #else
 204 #define EC_DBG_SEP      ""
 205 #define EC_DBG_DRV
 206 #define EC_DBG_STM
 207 #define EC_DBG_REQ
 208 #define EC_DBG_EVT
 209 #endif
 210
 211 #define ec_log_raw(fmt, ...) \
 212         pr_info(fmt "\n", ##__VA_ARGS__)
 213 #define ec_dbg_raw(fmt, ...) \
 214         pr_debug(fmt "\n", ##__VA_ARGS__)
 215 #define ec_log(filter, fmt, ...) \
 216         ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 217 #define ec_dbg(filter, fmt, ...) \
 218         ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 219
 220 #define ec_log_drv(fmt, ...) \
 221         ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 222 #define ec_dbg_drv(fmt, ...) \
 223         ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 224 #define ec_dbg_stm(fmt, ...) \
 225         ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
 226 #define ec_dbg_req(fmt, ...) \
 227         ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
 228 #define ec_dbg_evt(fmt, ...) \
 229         ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
 230 #define ec_dbg_ref(ec, fmt, ...) \
 231         ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
 232
 233 /* --------------------------------------------------------------------------
 234  *                           Device Flags
 235  * -------------------------------------------------------------------------- */
 236
 237 static bool acpi_ec_started(struct acpi_ec *ec)
 238 {
 239         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
 240                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
 241 }
 242
 243 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
 244 {
 245         /*
 246          * There is an OSPM early stage logic. During the early stages
 247          * (boot/resume), OSPMs shouldn't enable the event handling, only
 248          * the EC transactions are allowed to be performed.
 249          */
 250         if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 251                 return false;
 252         /*
 253          * However, disabling the event handling is experimental for late
 254          * stage (suspend), and is controlled by the boot parameter of
 255          * "ec_freeze_events":
 256          * 1. true:  The EC event handling is disabled before entering
 257          *           the noirq stage.
 258          * 2. false: The EC event handling is automatically disabled as
 259          *           soon as the EC driver is stopped.
 260          */
 261         if (ec_freeze_events)
 262                 return acpi_ec_started(ec);
 263         else
 264                 return test_bit(EC_FLAGS_STARTED, &ec->flags);
 265 }
 266
 267 static bool acpi_ec_flushed(struct acpi_ec *ec)
 268 {
 269         return ec->reference_count == 1;
 270 }
 271
 272 /* --------------------------------------------------------------------------
 273  *                           EC Registers
 274  * -------------------------------------------------------------------------- */
 275
 276 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 277 {
 278         u8 x = inb(ec->command_addr);
 279
 280         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
 281                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
 282                    x,
 283                    !!(x & ACPI_EC_FLAG_SCI),
 284                    !!(x & ACPI_EC_FLAG_BURST),
 285                    !!(x & ACPI_EC_FLAG_CMD),
 286                    !!(x & ACPI_EC_FLAG_IBF),
 287                    !!(x & ACPI_EC_FLAG_OBF));
 288         return x;
 289 }
 290
 291 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 292 {
 293         u8 x = inb(ec->data_addr);
 294
 295         ec->timestamp = jiffies;
 296         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
 297         return x;
 298 }
 299
 300 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 301 {
 302         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
 303         outb(command, ec->command_addr);
 304         ec->timestamp = jiffies;
 305 }
 306
 307 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 308 {
 309         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
 310         outb(data, ec->data_addr);
 311         ec->timestamp = jiffies;
 312 }
 313
 314 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
 315 static const char *acpi_ec_cmd_string(u8 cmd)
 316 {
 317         switch (cmd) {
 318         case 0x80:
 319                 return "RD_EC";
 320         case 0x81:
 321                 return "WR_EC";
 322         case 0x82:
 323                 return "BE_EC";
 324         case 0x83:
 325                 return "BD_EC";
 326         case 0x84:
 327                 return "QR_EC";
 328         }
 329         return "UNKNOWN";
 330 }
 331 #else
 332 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 333 #endif
 334
 335 /* --------------------------------------------------------------------------
 336  *                           GPE Registers
 337  * -------------------------------------------------------------------------- */
 338
 339 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
 340 {
 341         acpi_event_status gpe_status = 0;
 342
 343         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
 344         return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
 345 }
 346
 347 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
 348 {
 349         if (open)
 350                 acpi_enable_gpe(NULL, ec->gpe);
 351         else {
 352                 BUG_ON(ec->reference_count < 1);
 353                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 354         }
 355         if (acpi_ec_is_gpe_raised(ec)) {
 356                 /*
 357                  * On some platforms, EN=1 writes cannot trigger GPE. So
 358                  * software need to manually trigger a pseudo GPE event on
 359                  * EN=1 writes.
 360                  */
 361                 ec_dbg_raw("Polling quirk");
 362                 advance_transaction(ec);
 363         }
 364 }
 365
 366 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
 367 {
 368         if (close)
 369                 acpi_disable_gpe(NULL, ec->gpe);
 370         else {
 371                 BUG_ON(ec->reference_count < 1);
 372                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 373         }
 374 }
 375
 376 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
 377 {
 378         /*
 379          * GPE STS is a W1C register, which means:
 380          * 1. Software can clear it without worrying about clearing other
 381          *    GPEs' STS bits when the hardware sets them in parallel.
 382          * 2. As long as software can ensure only clearing it when it is
 383          *    set, hardware won't set it in parallel.
 384          * So software can clear GPE in any contexts.
 385          * Warning: do not move the check into advance_transaction() as the
 386          * EC commands will be sent without GPE raised.
 387          */
 388         if (!acpi_ec_is_gpe_raised(ec))
 389                 return;
 390         acpi_clear_gpe(NULL, ec->gpe);
 391 }
 392
 393 /* --------------------------------------------------------------------------
 394  *                           Transaction Management
 395  * -------------------------------------------------------------------------- */
 396
 397 static void acpi_ec_submit_request(struct acpi_ec *ec)
 398 {
 399         ec->reference_count++;
 400         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
 401             ec->gpe >= 0 && ec->reference_count == 1)
 402                 acpi_ec_enable_gpe(ec, true);
 403 }
 404
 405 static void acpi_ec_complete_request(struct acpi_ec *ec)
 406 {
 407         bool flushed = false;
 408
 409         ec->reference_count--;
 410         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
 411             ec->gpe >= 0 && ec->reference_count == 0)
 412                 acpi_ec_disable_gpe(ec, true);
 413         flushed = acpi_ec_flushed(ec);
 414         if (flushed)
 415                 wake_up(&ec->wait);
 416 }
 417
 418 static void acpi_ec_mask_events(struct acpi_ec *ec)
 419 {
 420         if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
 421                 if (ec->gpe >= 0)
 422                         acpi_ec_disable_gpe(ec, false);
 423                 else
 424                         disable_irq_nosync(ec->irq);
 425
 426                 ec_dbg_drv("Polling enabled");
 427                 set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
 428         }
 429 }
 430
 431 static void acpi_ec_unmask_events(struct acpi_ec *ec)
 432 {
 433         if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
 434                 clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
 435                 if (ec->gpe >= 0)
 436                         acpi_ec_enable_gpe(ec, false);
 437                 else
 438                         enable_irq(ec->irq);
 439
 440                 ec_dbg_drv("Polling disabled");
 441         }
 442 }
 443
 444 /*
 445  * acpi_ec_submit_flushable_request() - Increase the reference count unless
 446  *                                      the flush operation is not in
 447  *                                      progress
 448  * @ec: the EC device
 449  *
 450  * This function must be used before taking a new action that should hold
 451  * the reference count.  If this function returns false, then the action
 452  * must be discarded or it will prevent the flush operation from being
 453  * completed.
 454  */
 455 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
 456 {
 457         if (!acpi_ec_started(ec))
 458                 return false;
 459         acpi_ec_submit_request(ec);
 460         return true;
 461 }
 462
 463 static void acpi_ec_submit_query(struct acpi_ec *ec)
 464 {
 465         acpi_ec_mask_events(ec);
 466         if (!acpi_ec_event_enabled(ec))
 467                 return;
 468         if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 469                 ec_dbg_evt("Command(%s) submitted/blocked",
 470                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 471                 ec->nr_pending_queries++;
 472                 schedule_work(&ec->work);
 473         }
 474 }
 475
 476 static void acpi_ec_complete_query(struct acpi_ec *ec)
 477 {
 478         if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 479                 ec_dbg_evt("Command(%s) unblocked",
 480                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 481         acpi_ec_unmask_events(ec);
 482 }
 483
 484 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
 485 {
 486         if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 487                 ec_log_drv("event unblocked");
 488         /*
 489          * Unconditionally invoke this once after enabling the event
 490          * handling mechanism to detect the pending events.
 491          */
 492         advance_transaction(ec);
 493 }
 494
 495 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
 496 {
 497         if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 498                 ec_log_drv("event blocked");
 499 }
 500
 501 /*
 502  * Process _Q events that might have accumulated in the EC.
 503  * Run with locked ec mutex.
 504  */
 505 static void acpi_ec_clear(struct acpi_ec *ec)
 506 {
 507         int i, status;
 508         u8 value = 0;
 509
 510         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 511                 status = acpi_ec_query(ec, &value);
 512                 if (status || !value)
 513                         break;
 514         }
 515         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 516                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 517         else
 518                 pr_info("%d stale EC events cleared\n", i);
 519 }
 520
 521 static void acpi_ec_enable_event(struct acpi_ec *ec)
 522 {
 523         unsigned long flags;
 524
 525         spin_lock_irqsave(&ec->lock, flags);
 526         if (acpi_ec_started(ec))
 527                 __acpi_ec_enable_event(ec);
 528         spin_unlock_irqrestore(&ec->lock, flags);
 529
 530         /* Drain additional events if hardware requires that */
 531         if (EC_FLAGS_CLEAR_ON_RESUME)
 532                 acpi_ec_clear(ec);
 533 }
 534
 535 #ifdef CONFIG_PM_SLEEP
 536 static bool acpi_ec_query_flushed(struct acpi_ec *ec)
 537 {
 538         bool flushed;
 539         unsigned long flags;
 540
 541         spin_lock_irqsave(&ec->lock, flags);
 542         flushed = !ec->nr_pending_queries;
 543         spin_unlock_irqrestore(&ec->lock, flags);
 544         return flushed;
 545 }
 546
 547 static void __acpi_ec_flush_event(struct acpi_ec *ec)
 548 {
 549         /*
 550          * When ec_freeze_events is true, we need to flush events in
 551          * the proper position before entering the noirq stage.
 552          */
 553         wait_event(ec->wait, acpi_ec_query_flushed(ec));
 554         if (ec_query_wq)
 555                 flush_workqueue(ec_query_wq);
 556 }
 557
 558 static void acpi_ec_disable_event(struct acpi_ec *ec)
 559 {
 560         unsigned long flags;
 561
 562         spin_lock_irqsave(&ec->lock, flags);
 563         __acpi_ec_disable_event(ec);
 564         spin_unlock_irqrestore(&ec->lock, flags);
 565         __acpi_ec_flush_event(ec);
 566 }
 567
 568 void acpi_ec_flush_work(void)
 569 {
 570         if (first_ec)
 571                 __acpi_ec_flush_event(first_ec);
 572
 573         flush_scheduled_work();
 574 }
 575 #endif /* CONFIG_PM_SLEEP */
 576
 577 static bool acpi_ec_guard_event(struct acpi_ec *ec)
 578 {
 579         bool guarded = true;
 580         unsigned long flags;
 581
 582         spin_lock_irqsave(&ec->lock, flags);
 583         /*
 584          * If firmware SCI_EVT clearing timing is "event", we actually
 585          * don't know when the SCI_EVT will be cleared by firmware after
 586          * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
 587          * acceptable period.
 588          *
 589          * The guarding period begins when EC_FLAGS_QUERY_PENDING is
 590          * flagged, which means SCI_EVT check has just been performed.
 591          * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
 592          * guarding should have already been performed (via
 593          * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
 594          * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
 595          * ACPI_EC_COMMAND_POLL state immediately.
 596          */
 597         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
 598             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
 599             !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
 600             (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
 601                 guarded = false;
 602         spin_unlock_irqrestore(&ec->lock, flags);
 603         return guarded;
 604 }
 605
 606 static int ec_transaction_polled(struct acpi_ec *ec)
 607 {
 608         unsigned long flags;
 609         int ret = 0;
 610
 611         spin_lock_irqsave(&ec->lock, flags);
 612         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
 613                 ret = 1;
 614         spin_unlock_irqrestore(&ec->lock, flags);
 615         return ret;
 616 }
 617
 618 static int ec_transaction_completed(struct acpi_ec *ec)
 619 {
 620         unsigned long flags;
 621         int ret = 0;
 622
 623         spin_lock_irqsave(&ec->lock, flags);
 624         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 625                 ret = 1;
 626         spin_unlock_irqrestore(&ec->lock, flags);
 627         return ret;
 628 }
 629
 630 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
 631 {
 632         ec->curr->flags |= flag;
 633         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 634                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
 635                     flag == ACPI_EC_COMMAND_POLL)
 636                         acpi_ec_complete_query(ec);
 637                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
 638                     flag == ACPI_EC_COMMAND_COMPLETE)
 639                         acpi_ec_complete_query(ec);
 640                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 641                     flag == ACPI_EC_COMMAND_COMPLETE)
 642                         set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 643         }
 644 }
 645
 646 static void advance_transaction(struct acpi_ec *ec)
 647 {
 648         struct transaction *t;
 649         u8 status;
 650         bool wakeup = false;
 651
 652         ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
 653                    smp_processor_id());
 654         /*
 655          * By always clearing STS before handling all indications, we can
 656          * ensure a hardware STS 0->1 change after this clearing can always
 657          * trigger a GPE interrupt.
 658          */
 659         if (ec->gpe >= 0)
 660                 acpi_ec_clear_gpe(ec);
 661
 662         status = acpi_ec_read_status(ec);
 663         t = ec->curr;
 664         /*
 665          * Another IRQ or a guarded polling mode advancement is detected,
 666          * the next QR_EC submission is then allowed.
 667          */
 668         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
 669                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 670                     (!ec->nr_pending_queries ||
 671                      test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
 672                         clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 673                         acpi_ec_complete_query(ec);
 674                 }
 675         }
 676         if (!t)
 677                 goto err;
 678         if (t->flags & ACPI_EC_COMMAND_POLL) {
 679                 if (t->wlen > t->wi) {
 680                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 681                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 682                         else
 683                                 goto err;
 684                 } else if (t->rlen > t->ri) {
 685                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 686                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 687                                 if (t->rlen == t->ri) {
 688                                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 689                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 690                                                 ec_dbg_evt("Command(%s) completed by hardware",
 691                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 692                                         wakeup = true;
 693                                 }
 694                         } else
 695                                 goto err;
 696                 } else if (t->wlen == t->wi &&
 697                            (status & ACPI_EC_FLAG_IBF) == 0) {
 698                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 699                         wakeup = true;
 700                 }
 701                 goto out;
 702         } else {
 703                 if (EC_FLAGS_QUERY_HANDSHAKE &&
 704                     !(status & ACPI_EC_FLAG_SCI) &&
 705                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 706                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 707                         t->rdata[t->ri++] = 0x00;
 708                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 709                         ec_dbg_evt("Command(%s) completed by software",
 710                                    acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 711                         wakeup = true;
 712                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 713                         acpi_ec_write_cmd(ec, t->command);
 714                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 715                 } else
 716                         goto err;
 717                 goto out;
 718         }
 719 err:
 720         /*
 721          * If SCI bit is set, then don't think it's a false IRQ
 722          * otherwise will take a not handled IRQ as a false one.
 723          */
 724         if (!(status & ACPI_EC_FLAG_SCI)) {
 725                 if (in_interrupt() && t) {
 726                         if (t->irq_count < ec_storm_threshold)
 727                                 ++t->irq_count;
 728                         /* Allow triggering on 0 threshold */
 729                         if (t->irq_count == ec_storm_threshold)
 730                                 acpi_ec_mask_events(ec);
 731                 }
 732         }
 733 out:
 734         if (status & ACPI_EC_FLAG_SCI)
 735                 acpi_ec_submit_query(ec);
 736         if (wakeup && in_interrupt())
 737                 wake_up(&ec->wait);
 738 }
 739
 740 static void start_transaction(struct acpi_ec *ec)
 741 {
 742         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 743         ec->curr->flags = 0;
 744 }
 745
 746 static int ec_guard(struct acpi_ec *ec)
 747 {
 748         unsigned long guard = usecs_to_jiffies(ec->polling_guard);
 749         unsigned long timeout = ec->timestamp + guard;
 750
 751         /* Ensure guarding period before polling EC status */
 752         do {
 753                 if (ec->busy_polling) {
 754                         /* Perform busy polling */
 755                         if (ec_transaction_completed(ec))
 756                                 return 0;
 757                         udelay(jiffies_to_usecs(guard));
 758                 } else {
 759                         /*
 760                          * Perform wait polling
 761                          * 1. Wait the transaction to be completed by the
 762                          *    GPE handler after the transaction enters
 763                          *    ACPI_EC_COMMAND_POLL state.
 764                          * 2. A special guarding logic is also required
 765                          *    for event clearing mode "event" before the
 766                          *    transaction enters ACPI_EC_COMMAND_POLL
 767                          *    state.
 768                          */
 769                         if (!ec_transaction_polled(ec) &&
 770                             !acpi_ec_guard_event(ec))
 771                                 break;
 772                         if (wait_event_timeout(ec->wait,
 773                                                ec_transaction_completed(ec),
 774                                                guard))
 775                                 return 0;
 776                 }
 777         } while (time_before(jiffies, timeout));
 778         return -ETIME;
 779 }
 780
 781 static int ec_poll(struct acpi_ec *ec)
 782 {
 783         unsigned long flags;
 784         int repeat = 5; /* number of command restarts */
 785
 786         while (repeat--) {
 787                 unsigned long delay = jiffies +
 788                         msecs_to_jiffies(ec_delay);
 789                 do {
 790                         if (!ec_guard(ec))
 791                                 return 0;
 792                         spin_lock_irqsave(&ec->lock, flags);
 793                         advance_transaction(ec);
 794                         spin_unlock_irqrestore(&ec->lock, flags);
 795                 } while (time_before(jiffies, delay));
 796                 pr_debug("controller reset, restart transaction\n");
 797                 spin_lock_irqsave(&ec->lock, flags);
 798                 start_transaction(ec);
 799                 spin_unlock_irqrestore(&ec->lock, flags);
 800         }
 801         return -ETIME;
 802 }
 803
 804 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 805                                         struct transaction *t)
 806 {
 807         unsigned long tmp;
 808         int ret = 0;
 809
 810         /* start transaction */
 811         spin_lock_irqsave(&ec->lock, tmp);
 812         /* Enable GPE for command processing (IBF=0/OBF=1) */
 813         if (!acpi_ec_submit_flushable_request(ec)) {
 814                 ret = -EINVAL;
 815                 goto unlock;
 816         }
 817         ec_dbg_ref(ec, "Increase command");
 818         /* following two actions should be kept atomic */
 819         ec->curr = t;
 820         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 821         start_transaction(ec);
 822         spin_unlock_irqrestore(&ec->lock, tmp);
 823
 824         ret = ec_poll(ec);
 825
 826         spin_lock_irqsave(&ec->lock, tmp);
 827         if (t->irq_count == ec_storm_threshold)
 828                 acpi_ec_unmask_events(ec);
 829         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 830         ec->curr = NULL;
 831         /* Disable GPE for command processing (IBF=0/OBF=1) */
 832         acpi_ec_complete_request(ec);
 833         ec_dbg_ref(ec, "Decrease command");
 834 unlock:
 835         spin_unlock_irqrestore(&ec->lock, tmp);
 836         return ret;
 837 }
 838
 839 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 840 {
 841         int status;
 842         u32 glk;
 843
 844         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 845                 return -EINVAL;
 846         if (t->rdata)
 847                 memset(t->rdata, 0, t->rlen);
 848
 849         mutex_lock(&ec->mutex);
 850         if (ec->global_lock) {
 851                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 852                 if (ACPI_FAILURE(status)) {
 853                         status = -ENODEV;
 854                         goto unlock;
 855                 }
 856         }
 857
 858         status = acpi_ec_transaction_unlocked(ec, t);
 859
 860         if (ec->global_lock)
 861                 acpi_release_global_lock(glk);
 862 unlock:
 863         mutex_unlock(&ec->mutex);
 864         return status;
 865 }
 866
 867 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 868 {
 869         u8 d;
 870         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 871                                 .wdata = NULL, .rdata = &d,
 872                                 .wlen = 0, .rlen = 1};
 873
 874         return acpi_ec_transaction(ec, &t);
 875 }
 876
 877 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 878 {
 879         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 880                                 .wdata = NULL, .rdata = NULL,
 881                                 .wlen = 0, .rlen = 0};
 882
 883         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 884                                 acpi_ec_transaction(ec, &t) : 0;
 885 }
 886
 887 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 888 {
 889         int result;
 890         u8 d;
 891         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 892                                 .wdata = &address, .rdata = &d,
 893                                 .wlen = 1, .rlen = 1};
 894
 895         result = acpi_ec_transaction(ec, &t);
 896         *data = d;
 897         return result;
 898 }
 899
 900 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 901 {
 902         u8 wdata[2] = { address, data };
 903         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 904                                 .wdata = wdata, .rdata = NULL,
 905                                 .wlen = 2, .rlen = 0};
 906
 907         return acpi_ec_transaction(ec, &t);
 908 }
 909
 910 int ec_read(u8 addr, u8 *val)
 911 {
 912         int err;
 913         u8 temp_data;
 914
 915         if (!first_ec)
 916                 return -ENODEV;
 917
 918         err = acpi_ec_read(first_ec, addr, &temp_data);
 919
 920         if (!err) {
 921                 *val = temp_data;
 922                 return 0;
 923         }
 924         return err;
 925 }
 926 EXPORT_SYMBOL(ec_read);
 927
 928 int ec_write(u8 addr, u8 val)
 929 {
 930         int err;
 931
 932         if (!first_ec)
 933                 return -ENODEV;
 934
 935         err = acpi_ec_write(first_ec, addr, val);
 936
 937         return err;
 938 }
 939 EXPORT_SYMBOL(ec_write);
 940
 941 int ec_transaction(u8 command,
 942                    const u8 *wdata, unsigned wdata_len,
 943                    u8 *rdata, unsigned rdata_len)
 944 {
 945         struct transaction t = {.command = command,
 946                                 .wdata = wdata, .rdata = rdata,
 947                                 .wlen = wdata_len, .rlen = rdata_len};
 948
 949         if (!first_ec)
 950                 return -ENODEV;
 951
 952         return acpi_ec_transaction(first_ec, &t);
 953 }
 954 EXPORT_SYMBOL(ec_transaction);
 955
 956 /* Get the handle to the EC device */
 957 acpi_handle ec_get_handle(void)
 958 {
 959         if (!first_ec)
 960                 return NULL;
 961         return first_ec->handle;
 962 }
 963 EXPORT_SYMBOL(ec_get_handle);
 964
 965 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 966 {
 967         unsigned long flags;
 968
 969         spin_lock_irqsave(&ec->lock, flags);
 970         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 971                 ec_dbg_drv("Starting EC");
 972                 /* Enable GPE for event processing (SCI_EVT=1) */
 973                 if (!resuming) {
 974                         acpi_ec_submit_request(ec);
 975                         ec_dbg_ref(ec, "Increase driver");
 976                 }
 977                 ec_log_drv("EC started");
 978         }
 979         spin_unlock_irqrestore(&ec->lock, flags);
 980 }
 981
 982 static bool acpi_ec_stopped(struct acpi_ec *ec)
 983 {
 984         unsigned long flags;
 985         bool flushed;
 986
 987         spin_lock_irqsave(&ec->lock, flags);
 988         flushed = acpi_ec_flushed(ec);
 989         spin_unlock_irqrestore(&ec->lock, flags);
 990         return flushed;
 991 }
 992
 993 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 994 {
 995         unsigned long flags;
 996
 997         spin_lock_irqsave(&ec->lock, flags);
 998         if (acpi_ec_started(ec)) {
 999                 ec_dbg_drv("Stopping EC");
1000                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
1001                 spin_unlock_irqrestore(&ec->lock, flags);
1002                 wait_event(ec->wait, acpi_ec_stopped(ec));
1003                 spin_lock_irqsave(&ec->lock, flags);
1004                 /* Disable GPE for event processing (SCI_EVT=1) */
1005                 if (!suspending) {
1006                         acpi_ec_complete_request(ec);
1007                         ec_dbg_ref(ec, "Decrease driver");
1008                 } else if (!ec_freeze_events)
1009                         __acpi_ec_disable_event(ec);
1010                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
1011                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
1012                 ec_log_drv("EC stopped");
1013         }
1014         spin_unlock_irqrestore(&ec->lock, flags);
1015 }
1016
1017 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
1018 {
1019         unsigned long flags;
1020
1021         spin_lock_irqsave(&ec->lock, flags);
1022         ec->busy_polling = true;
1023         ec->polling_guard = 0;
1024         ec_log_drv("interrupt blocked");
1025         spin_unlock_irqrestore(&ec->lock, flags);
1026 }
1027
1028 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1029 {
1030         unsigned long flags;
1031
1032         spin_lock_irqsave(&ec->lock, flags);
1033         ec->busy_polling = ec_busy_polling;
1034         ec->polling_guard = ec_polling_guard;
1035         ec_log_drv("interrupt unblocked");
1036         spin_unlock_irqrestore(&ec->lock, flags);
1037 }
1038
1039 void acpi_ec_block_transactions(void)
1040 {
1041         struct acpi_ec *ec = first_ec;
1042
1043         if (!ec)
1044                 return;
1045
1046         mutex_lock(&ec->mutex);
1047         /* Prevent transactions from being carried out */
1048         acpi_ec_stop(ec, true);
1049         mutex_unlock(&ec->mutex);
1050 }
1051
1052 void acpi_ec_unblock_transactions(void)
1053 {
1054         /*
1055          * Allow transactions to happen again (this function is called from
1056          * atomic context during wakeup, so we don't need to acquire the mutex).
1057          */
1058         if (first_ec)
1059                 acpi_ec_start(first_ec, true);
1060 }
1061
1062 /* --------------------------------------------------------------------------
1063                                 Event Management
1064    -------------------------------------------------------------------------- */
1065 static struct acpi_ec_query_handler *
1066 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
1067 {
1068         if (handler)
1069                 kref_get(&handler->kref);
1070         return handler;
1071 }
1072
1073 static struct acpi_ec_query_handler *
1074 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1075 {
1076         struct acpi_ec_query_handler *handler;
1077         bool found = false;
1078
1079         mutex_lock(&ec->mutex);
1080         list_for_each_entry(handler, &ec->list, node) {
1081                 if (value == handler->query_bit) {
1082                         found = true;
1083                         break;
1084                 }
1085         }
1086         mutex_unlock(&ec->mutex);
1087         return found ? acpi_ec_get_query_handler(handler) : NULL;
1088 }
1089
1090 static void acpi_ec_query_handler_release(struct kref *kref)
1091 {
1092         struct acpi_ec_query_handler *handler =
1093                 container_of(kref, struct acpi_ec_query_handler, kref);
1094
1095         kfree(handler);
1096 }
1097
1098 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1099 {
1100         kref_put(&handler->kref, acpi_ec_query_handler_release);
1101 }
1102
1103 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1104                               acpi_handle handle, acpi_ec_query_func func,
1105                               void *data)
1106 {
1107         struct acpi_ec_query_handler *handler =
1108             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1109
1110         if (!handler)
1111                 return -ENOMEM;
1112
1113         handler->query_bit = query_bit;
1114         handler->handle = handle;
1115         handler->func = func;
1116         handler->data = data;
1117         mutex_lock(&ec->mutex);
1118         kref_init(&handler->kref);
1119         list_add(&handler->node, &ec->list);
1120         mutex_unlock(&ec->mutex);
1121         return 0;
1122 }
1123 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1124
1125 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1126                                           bool remove_all, u8 query_bit)
1127 {
1128         struct acpi_ec_query_handler *handler, *tmp;
1129         LIST_HEAD(free_list);
1130
1131         mutex_lock(&ec->mutex);
1132         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1133                 if (remove_all || query_bit == handler->query_bit) {
1134                         list_del_init(&handler->node);
1135                         list_add(&handler->node, &free_list);
1136                 }
1137         }
1138         mutex_unlock(&ec->mutex);
1139         list_for_each_entry_safe(handler, tmp, &free_list, node)
1140                 acpi_ec_put_query_handler(handler);
1141 }
1142
1143 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1144 {
1145         acpi_ec_remove_query_handlers(ec, false, query_bit);
1146 }
1147 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1148
1149 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1150 {
1151         struct acpi_ec_query *q;
1152         struct transaction *t;
1153
1154         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1155         if (!q)
1156                 return NULL;
1157         INIT_WORK(&q->work, acpi_ec_event_processor);
1158         t = &q->transaction;
1159         t->command = ACPI_EC_COMMAND_QUERY;
1160         t->rdata = pval;
1161         t->rlen = 1;
1162         return q;
1163 }
1164
1165 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1166 {
1167         if (q) {
1168                 if (q->handler)
1169                         acpi_ec_put_query_handler(q->handler);
1170                 kfree(q);
1171         }
1172 }
1173
1174 static void acpi_ec_event_processor(struct work_struct *work)
1175 {
1176         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1177         struct acpi_ec_query_handler *handler = q->handler;
1178
1179         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1180         if (handler->func)
1181                 handler->func(handler->data);
1182         else if (handler->handle)
1183                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1184         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1185         acpi_ec_delete_query(q);
1186 }
1187
1188 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1189 {
1190         u8 value = 0;
1191         int result;
1192         struct acpi_ec_query *q;
1193
1194         q = acpi_ec_create_query(&value);
1195         if (!q)
1196                 return -ENOMEM;
1197
1198         /*
1199          * Query the EC to find out which _Qxx method we need to evaluate.
1200          * Note that successful completion of the query causes the ACPI_EC_SCI
1201          * bit to be cleared (and thus clearing the interrupt source).
1202          */
1203         result = acpi_ec_transaction(ec, &q->transaction);
1204         if (!value)
1205                 result = -ENODATA;
1206         if (result)
1207                 goto err_exit;
1208
1209         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1210         if (!q->handler) {
1211                 result = -ENODATA;
1212                 goto err_exit;
1213         }
1214
1215         /*
1216          * It is reported that _Qxx are evaluated in a parallel way on
1217          * Windows:
1218          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1219          *
1220          * Put this log entry before schedule_work() in order to make
1221          * it appearing before any other log entries occurred during the
1222          * work queue execution.
1223          */
1224         ec_dbg_evt("Query(0x%02x) scheduled", value);
1225         if (!queue_work(ec_query_wq, &q->work)) {
1226                 ec_dbg_evt("Query(0x%02x) overlapped", value);
1227                 result = -EBUSY;
1228         }
1229
1230 err_exit:
1231         if (result)
1232                 acpi_ec_delete_query(q);
1233         if (data)
1234                 *data = value;
1235         return result;
1236 }
1237
1238 static void acpi_ec_check_event(struct acpi_ec *ec)
1239 {
1240         unsigned long flags;
1241
1242         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1243                 if (ec_guard(ec)) {
1244                         spin_lock_irqsave(&ec->lock, flags);
1245                         /*
1246                          * Take care of the SCI_EVT unless no one else is
1247                          * taking care of it.
1248                          */
1249                         if (!ec->curr)
1250                                 advance_transaction(ec);
1251                         spin_unlock_irqrestore(&ec->lock, flags);
1252                 }
1253         }
1254 }
1255
1256 static void acpi_ec_event_handler(struct work_struct *work)
1257 {
1258         unsigned long flags;
1259         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1260
1261         ec_dbg_evt("Event started");
1262
1263         spin_lock_irqsave(&ec->lock, flags);
1264         while (ec->nr_pending_queries) {
1265                 spin_unlock_irqrestore(&ec->lock, flags);
1266                 (void)acpi_ec_query(ec, NULL);
1267                 spin_lock_irqsave(&ec->lock, flags);
1268                 ec->nr_pending_queries--;
1269                 /*
1270                  * Before exit, make sure that this work item can be
1271                  * scheduled again. There might be QR_EC failures, leaving
1272                  * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1273                  * item from being scheduled again.
1274                  */
1275                 if (!ec->nr_pending_queries) {
1276                         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1277                             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1278                                 acpi_ec_complete_query(ec);
1279                 }
1280         }
1281         spin_unlock_irqrestore(&ec->lock, flags);
1282
1283         ec_dbg_evt("Event stopped");
1284
1285         acpi_ec_check_event(ec);
1286 }
1287
1288 static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1289 {
1290         unsigned long flags;
1291
1292         spin_lock_irqsave(&ec->lock, flags);
1293         advance_transaction(ec);
1294         spin_unlock_irqrestore(&ec->lock, flags);
1295 }
1296
1297 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1298                                u32 gpe_number, void *data)
1299 {
1300         acpi_ec_handle_interrupt(data);
1301         return ACPI_INTERRUPT_HANDLED;
1302 }
1303
1304 static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1305 {
1306         acpi_ec_handle_interrupt(data);
1307         return IRQ_HANDLED;
1308 }
1309
1310 /* --------------------------------------------------------------------------
1311  *                           Address Space Management
1312  * -------------------------------------------------------------------------- */
1313
1314 static acpi_status
1315 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1316                       u32 bits, u64 *value64,
1317                       void *handler_context, void *region_context)
1318 {
1319         struct acpi_ec *ec = handler_context;
1320         int result = 0, i, bytes = bits / 8;
1321         u8 *value = (u8 *)value64;
1322
1323         if ((address > 0xFF) || !value || !handler_context)
1324                 return AE_BAD_PARAMETER;
1325
1326         if (function != ACPI_READ && function != ACPI_WRITE)
1327                 return AE_BAD_PARAMETER;
1328
1329         if (ec->busy_polling || bits > 8)
1330                 acpi_ec_burst_enable(ec);
1331
1332         for (i = 0; i < bytes; ++i, ++address, ++value)
1333                 result = (function == ACPI_READ) ?
1334                         acpi_ec_read(ec, address, value) :
1335                         acpi_ec_write(ec, address, *value);
1336
1337         if (ec->busy_polling || bits > 8)
1338                 acpi_ec_burst_disable(ec);
1339
1340         switch (result) {
1341         case -EINVAL:
1342                 return AE_BAD_PARAMETER;
1343         case -ENODEV:
1344                 return AE_NOT_FOUND;
1345         case -ETIME:
1346                 return AE_TIME;
1347         default:
1348                 return AE_OK;
1349         }
1350 }
1351
1352 /* --------------------------------------------------------------------------
1353  *                             Driver Interface
1354  * -------------------------------------------------------------------------- */
1355
1356 static acpi_status
1357 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1358
1359 static void acpi_ec_free(struct acpi_ec *ec)
1360 {
1361         if (first_ec == ec)
1362                 first_ec = NULL;
1363         if (boot_ec == ec)
1364                 boot_ec = NULL;
1365         kfree(ec);
1366 }
1367
1368 static struct acpi_ec *acpi_ec_alloc(void)
1369 {
1370         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1371
1372         if (!ec)
1373                 return NULL;
1374         mutex_init(&ec->mutex);
1375         init_waitqueue_head(&ec->wait);
1376         INIT_LIST_HEAD(&ec->list);
1377         spin_lock_init(&ec->lock);
1378         INIT_WORK(&ec->work, acpi_ec_event_handler);
1379         ec->timestamp = jiffies;
1380         ec->busy_polling = true;
1381         ec->polling_guard = 0;
1382         ec->gpe = -1;
1383         ec->irq = -1;
1384         return ec;
1385 }
1386
1387 static acpi_status
1388 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1389                                void *context, void **return_value)
1390 {
1391         char node_name[5];
1392         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1393         struct acpi_ec *ec = context;
1394         int value = 0;
1395         acpi_status status;
1396
1397         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1398
1399         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1400                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1401         return AE_OK;
1402 }
1403
1404 static acpi_status
1405 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1406 {
1407         acpi_status status;
1408         unsigned long long tmp = 0;
1409         struct acpi_ec *ec = context;
1410
1411         /* clear addr values, ec_parse_io_ports depend on it */
1412         ec->command_addr = ec->data_addr = 0;
1413
1414         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1415                                      ec_parse_io_ports, ec);
1416         if (ACPI_FAILURE(status))
1417                 return status;
1418         if (ec->data_addr == 0 || ec->command_addr == 0)
1419                 return AE_OK;
1420
1421         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1422                 /*
1423                  * Always inherit the GPE number setting from the ECDT
1424                  * EC.
1425                  */
1426                 ec->gpe = boot_ec->gpe;
1427         } else {
1428                 /* Get GPE bit assignment (EC events). */
1429                 /* TODO: Add support for _GPE returning a package */
1430                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1431                 if (ACPI_SUCCESS(status))
1432                         ec->gpe = tmp;
1433
1434                 /*
1435                  * Errors are non-fatal, allowing for ACPI Reduced Hardware
1436                  * platforms which use GpioInt instead of GPE.
1437                  */
1438         }
1439         /* Use the global lock for all EC transactions? */
1440         tmp = 0;
1441         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1442         ec->global_lock = tmp;
1443         ec->handle = handle;
1444         return AE_CTRL_TERMINATE;
1445 }
1446
1447 static void install_gpe_event_handler(struct acpi_ec *ec)
1448 {
1449         acpi_status status =
1450                 acpi_install_gpe_raw_handler(NULL, ec->gpe,
1451                                              ACPI_GPE_EDGE_TRIGGERED,
1452                                              &acpi_ec_gpe_handler,
1453                                              ec);
1454         if (ACPI_SUCCESS(status)) {
1455                 /* This is not fatal as we can poll EC events */
1456                 set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1457                 acpi_ec_leave_noirq(ec);
1458                 if (test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1459                     ec->reference_count >= 1)
1460                         acpi_ec_enable_gpe(ec, true);
1461         }
1462 }
1463
1464 /* ACPI reduced hardware platforms use a GpioInt specified in _CRS. */
1465 static int install_gpio_irq_event_handler(struct acpi_ec *ec,
1466                                           struct acpi_device *device)
1467 {
1468         int irq = acpi_dev_gpio_irq_get(device, 0);
1469         int ret;
1470
1471         if (irq < 0)
1472                 return irq;
1473
1474         ret = request_irq(irq, acpi_ec_irq_handler, IRQF_SHARED,
1475                           "ACPI EC", ec);
1476
1477         /*
1478          * Unlike the GPE case, we treat errors here as fatal, we'll only
1479          * implement GPIO polling if we find a case that needs it.
1480          */
1481         if (ret < 0)
1482                 return ret;
1483
1484         ec->irq = irq;
1485         set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1486         acpi_ec_leave_noirq(ec);
1487
1488         return 0;
1489 }
1490
1491 /*
1492  * Note: This function returns an error code only when the address space
1493  *       handler is not installed, which means "not able to handle
1494  *       transactions".
1495  */
1496 static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device,
1497                                bool handle_events)
1498 {
1499         acpi_status status;
1500
1501         acpi_ec_start(ec, false);
1502
1503         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1504                 acpi_ec_enter_noirq(ec);
1505                 status = acpi_install_address_space_handler(ec->handle,
1506                                                             ACPI_ADR_SPACE_EC,
1507                                                             &acpi_ec_space_handler,
1508                                                             NULL, ec);
1509                 if (ACPI_FAILURE(status)) {
1510                         if (status == AE_NOT_FOUND) {
1511                                 /*
1512                                  * Maybe OS fails in evaluating the _REG
1513                                  * object. The AE_NOT_FOUND error will be
1514                                  * ignored and OS * continue to initialize
1515                                  * EC.
1516                                  */
1517                                 pr_err("Fail in evaluating the _REG object"
1518                                         " of EC device. Broken bios is suspected.\n");
1519                         } else {
1520                                 acpi_ec_stop(ec, false);
1521                                 return -ENODEV;
1522                         }
1523                 }
1524                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1525         }
1526
1527         if (!handle_events)
1528                 return 0;
1529
1530         if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1531                 /* Find and register all query methods */
1532                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1533                                     acpi_ec_register_query_methods,
1534                                     NULL, ec, NULL);
1535                 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1536         }
1537         if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1538                 if (ec->gpe >= 0) {
1539                         install_gpe_event_handler(ec);
1540                 } else if (device) {
1541                         int ret = install_gpio_irq_event_handler(ec, device);
1542
1543                         if (ret)
1544                                 return ret;
1545                 } else { /* No GPE and no GpioInt? */
1546                         return -ENODEV;
1547                 }
1548         }
1549         /* EC is fully operational, allow queries */
1550         acpi_ec_enable_event(ec);
1551
1552         return 0;
1553 }
1554
1555 static void ec_remove_handlers(struct acpi_ec *ec)
1556 {
1557         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1558                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1559                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1560                         pr_err("failed to remove space handler\n");
1561                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1562         }
1563
1564         /*
1565          * Stops handling the EC transactions after removing the operation
1566          * region handler. This is required because _REG(DISCONNECT)
1567          * invoked during the removal can result in new EC transactions.
1568          *
1569          * Flushes the EC requests and thus disables the GPE before
1570          * removing the GPE handler. This is required by the current ACPICA
1571          * GPE core. ACPICA GPE core will automatically disable a GPE when
1572          * it is indicated but there is no way to handle it. So the drivers
1573          * must disable the GPEs prior to removing the GPE handlers.
1574          */
1575         acpi_ec_stop(ec, false);
1576
1577         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1578                 if (ec->gpe >= 0 &&
1579                     ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1580                                  &acpi_ec_gpe_handler)))
1581                         pr_err("failed to remove gpe handler\n");
1582
1583                 if (ec->irq >= 0)
1584                         free_irq(ec->irq, ec);
1585
1586                 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1587         }
1588         if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1589                 acpi_ec_remove_query_handlers(ec, true, 0);
1590                 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1591         }
1592 }
1593
1594 static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device,
1595                          bool handle_events)
1596 {
1597         int ret;
1598
1599         ret = ec_install_handlers(ec, device, handle_events);
1600         if (ret)
1601                 return ret;
1602
1603         /* First EC capable of handling transactions */
1604         if (!first_ec) {
1605                 first_ec = ec;
1606                 acpi_handle_info(first_ec->handle, "Used as first EC\n");
1607         }
1608
1609         acpi_handle_info(ec->handle,
1610                          "GPE=0x%x, IRQ=%d, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n",
1611                          ec->gpe, ec->irq, ec->command_addr, ec->data_addr);
1612         return ret;
1613 }
1614
1615 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)
1616 {
1617         struct acpi_table_ecdt *ecdt_ptr;
1618         acpi_status status;
1619         acpi_handle handle;
1620
1621         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1622                                 (struct acpi_table_header **)&ecdt_ptr);
1623         if (ACPI_FAILURE(status))
1624                 return false;
1625
1626         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1627         if (ACPI_FAILURE(status))
1628                 return false;
1629
1630         *phandle = handle;
1631         return true;
1632 }
1633
1634 static int acpi_ec_add(struct acpi_device *device)
1635 {
1636         struct acpi_ec *ec = NULL;
1637         bool dep_update = true;
1638         acpi_status status;
1639         int ret;
1640
1641         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1642         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1643
1644         if (!strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) {
1645                 boot_ec_is_ecdt = true;
1646                 ec = boot_ec;
1647                 dep_update = false;
1648         } else {
1649                 ec = acpi_ec_alloc();
1650                 if (!ec)
1651                         return -ENOMEM;
1652
1653                 status = ec_parse_device(device->handle, 0, ec, NULL);
1654                 if (status != AE_CTRL_TERMINATE) {
1655                         ret = -EINVAL;
1656                         goto err_alloc;
1657                 }
1658
1659                 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1660                     ec->data_addr == boot_ec->data_addr) {
1661                         boot_ec_is_ecdt = false;
1662                         /*
1663                          * Trust PNP0C09 namespace location rather than
1664                          * ECDT ID. But trust ECDT GPE rather than _GPE
1665                          * because of ASUS quirks, so do not change
1666                          * boot_ec->gpe to ec->gpe.
1667                          */
1668                         boot_ec->handle = ec->handle;
1669                         acpi_handle_debug(ec->handle, "duplicated.\n");
1670                         acpi_ec_free(ec);
1671                         ec = boot_ec;
1672                 }
1673         }
1674
1675         ret = acpi_ec_setup(ec, device, true);
1676         if (ret)
1677                 goto err_query;
1678
1679         if (ec == boot_ec)
1680                 acpi_handle_info(boot_ec->handle,
1681                                  "Boot %s EC used to handle transactions and events\n",
1682                                  boot_ec_is_ecdt ? "ECDT" : "DSDT");
1683
1684         device->driver_data = ec;
1685
1686         ret = !!request_region(ec->data_addr, 1, "EC data");
1687         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1688         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1689         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1690
1691         if (dep_update) {
1692                 /* Reprobe devices depending on the EC */
1693                 acpi_walk_dep_device_list(ec->handle);
1694         }
1695         acpi_handle_debug(ec->handle, "enumerated.\n");
1696         return 0;
1697
1698 err_query:
1699         if (ec != boot_ec)
1700                 acpi_ec_remove_query_handlers(ec, true, 0);
1701 err_alloc:
1702         if (ec != boot_ec)
1703                 acpi_ec_free(ec);
1704         return ret;
1705 }
1706
1707 static int acpi_ec_remove(struct acpi_device *device)
1708 {
1709         struct acpi_ec *ec;
1710
1711         if (!device)
1712                 return -EINVAL;
1713
1714         ec = acpi_driver_data(device);
1715         release_region(ec->data_addr, 1);
1716         release_region(ec->command_addr, 1);
1717         device->driver_data = NULL;
1718         if (ec != boot_ec) {
1719                 ec_remove_handlers(ec);
1720                 acpi_ec_free(ec);
1721         }
1722         return 0;
1723 }
1724
1725 static acpi_status
1726 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1727 {
1728         struct acpi_ec *ec = context;
1729
1730         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1731                 return AE_OK;
1732
1733         /*
1734          * The first address region returned is the data port, and
1735          * the second address region returned is the status/command
1736          * port.
1737          */
1738         if (ec->data_addr == 0)
1739                 ec->data_addr = resource->data.io.minimum;
1740         else if (ec->command_addr == 0)
1741                 ec->command_addr = resource->data.io.minimum;
1742         else
1743                 return AE_CTRL_TERMINATE;
1744
1745         return AE_OK;
1746 }
1747
1748 static const struct acpi_device_id ec_device_ids[] = {
1749         {"PNP0C09", 0},
1750         {ACPI_ECDT_HID, 0},
1751         {"", 0},
1752 };
1753
1754 /*
1755  * This function is not Windows-compatible as Windows never enumerates the
1756  * namespace EC before the main ACPI device enumeration process. It is
1757  * retained for historical reason and will be deprecated in the future.
1758  */
1759 void __init acpi_ec_dsdt_probe(void)
1760 {
1761         struct acpi_ec *ec;
1762         acpi_status status;
1763         int ret;
1764
1765         /*
1766          * If a platform has ECDT, there is no need to proceed as the
1767          * following probe is not a part of the ACPI device enumeration,
1768          * executing _STA is not safe, and thus this probe may risk of
1769          * picking up an invalid EC device.
1770          */
1771         if (boot_ec)
1772                 return;
1773
1774         ec = acpi_ec_alloc();
1775         if (!ec)
1776                 return;
1777
1778         /*
1779          * At this point, the namespace is initialized, so start to find
1780          * the namespace objects.
1781          */
1782         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1783         if (ACPI_FAILURE(status) || !ec->handle) {
1784                 acpi_ec_free(ec);
1785                 return;
1786         }
1787
1788         /*
1789          * When the DSDT EC is available, always re-configure boot EC to
1790          * have _REG evaluated. _REG can only be evaluated after the
1791          * namespace initialization.
1792          * At this point, the GPE is not fully initialized, so do not to
1793          * handle the events.
1794          */
1795         ret = acpi_ec_setup(ec, NULL, false);
1796         if (ret) {
1797                 acpi_ec_free(ec);
1798                 return;
1799         }
1800
1801         boot_ec = ec;
1802
1803         acpi_handle_info(ec->handle,
1804                          "Boot DSDT EC used to handle transactions\n");
1805 }
1806
1807 /*
1808  * If the DSDT EC is not functioning, we still need to prepare a fully
1809  * functioning ECDT EC first in order to handle the events.
1810  * https://bugzilla.kernel.org/show_bug.cgi?id=115021
1811  */
1812 static int __init acpi_ec_ecdt_start(void)
1813 {
1814         acpi_handle handle;
1815
1816         if (!boot_ec)
1817                 return -ENODEV;
1818         /* In case acpi_ec_ecdt_start() is called after acpi_ec_add() */
1819         if (!boot_ec_is_ecdt)
1820                 return -ENODEV;
1821
1822         /*
1823          * At this point, the namespace and the GPE is initialized, so
1824          * start to find the namespace objects and handle the events.
1825          *
1826          * Note: ec->handle can be valid if this function is called after
1827          * acpi_ec_add(), hence the fast path.
1828          */
1829         if (boot_ec->handle == ACPI_ROOT_OBJECT) {
1830                 if (!acpi_ec_ecdt_get_handle(&handle))
1831                         return -ENODEV;
1832                 boot_ec->handle = handle;
1833         }
1834
1835         /* Register to ACPI bus with PM ops attached */
1836         return acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1837 }
1838
1839 #if 0
1840 /*
1841  * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1842  * set, for which case, we complete the QR_EC without issuing it to the
1843  * firmware.
1844  * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1845  * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1846  */
1847 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1848 {
1849         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1850         EC_FLAGS_QUERY_HANDSHAKE = 1;
1851         return 0;
1852 }
1853 #endif
1854
1855 /*
1856  * On some hardware it is necessary to clear events accumulated by the EC during
1857  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1858  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1859  *
1860  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1861  *
1862  * Ideally, the EC should also be instructed NOT to accumulate events during
1863  * sleep (which Windows seems to do somehow), but the interface to control this
1864  * behaviour is not known at this time.
1865  *
1866  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1867  * however it is very likely that other Samsung models are affected.
1868  *
1869  * On systems which don't accumulate _Q events during sleep, this extra check
1870  * should be harmless.
1871  */
1872 static int ec_clear_on_resume(const struct dmi_system_id *id)
1873 {
1874         pr_debug("Detected system needing EC poll on resume.\n");
1875         EC_FLAGS_CLEAR_ON_RESUME = 1;
1876         ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1877         return 0;
1878 }
1879
1880 /*
1881  * Some ECDTs contain wrong register addresses.
1882  * MSI MS-171F
1883  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1884  */
1885 static int ec_correct_ecdt(const struct dmi_system_id *id)
1886 {
1887         pr_debug("Detected system needing ECDT address correction.\n");
1888         EC_FLAGS_CORRECT_ECDT = 1;
1889         return 0;
1890 }
1891
1892 /*
1893  * Some DSDTs contain wrong GPE setting.
1894  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1895  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1896  */
1897 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1898 {
1899         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1900         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1901         return 0;
1902 }
1903
1904 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1905         {
1906         ec_correct_ecdt, "MSI MS-171F", {
1907         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1908         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1909         {
1910         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1911         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1912         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1913         {
1914         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1915         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1916         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1917         {
1918         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1919         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1920         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1921         {
1922         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1923         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1924         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1925         {
1926         ec_honor_ecdt_gpe, "ASUS X580VD", {
1927         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1928         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1929         {
1930         ec_clear_on_resume, "Samsung hardware", {
1931         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1932         {},
1933 };
1934
1935 void __init acpi_ec_ecdt_probe(void)
1936 {
1937         struct acpi_table_ecdt *ecdt_ptr;
1938         struct acpi_ec *ec;
1939         acpi_status status;
1940         int ret;
1941
1942         /* Generate a boot ec context. */
1943         dmi_check_system(ec_dmi_table);
1944         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1945                                 (struct acpi_table_header **)&ecdt_ptr);
1946         if (ACPI_FAILURE(status))
1947                 return;
1948
1949         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1950                 /*
1951                  * Asus X50GL:
1952                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1953                  */
1954                 return;
1955         }
1956
1957         ec = acpi_ec_alloc();
1958         if (!ec)
1959                 return;
1960
1961         if (EC_FLAGS_CORRECT_ECDT) {
1962                 ec->command_addr = ecdt_ptr->data.address;
1963                 ec->data_addr = ecdt_ptr->control.address;
1964         } else {
1965                 ec->command_addr = ecdt_ptr->control.address;
1966                 ec->data_addr = ecdt_ptr->data.address;
1967         }
1968
1969         /*
1970          * Ignore the GPE value on Reduced Hardware platforms.
1971          * Some products have this set to an erroneous value.
1972          */
1973         if (!acpi_gbl_reduced_hardware)
1974                 ec->gpe = ecdt_ptr->gpe;
1975
1976         ec->handle = ACPI_ROOT_OBJECT;
1977
1978         /*
1979          * At this point, the namespace is not initialized, so do not find
1980          * the namespace objects, or handle the events.
1981          */
1982         ret = acpi_ec_setup(ec, NULL, false);
1983         if (ret) {
1984                 acpi_ec_free(ec);
1985                 return;
1986         }
1987
1988         boot_ec = ec;
1989         boot_ec_is_ecdt = true;
1990
1991         pr_info("Boot ECDT EC used to handle transactions\n");
1992 }
1993
1994 #ifdef CONFIG_PM_SLEEP
1995 static int acpi_ec_suspend(struct device *dev)
1996 {
1997         struct acpi_ec *ec =
1998                 acpi_driver_data(to_acpi_device(dev));
1999
2000         if (!pm_suspend_no_platform() && ec_freeze_events)
2001                 acpi_ec_disable_event(ec);
2002         return 0;
2003 }
2004
2005 static int acpi_ec_suspend_noirq(struct device *dev)
2006 {
2007         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2008
2009         /*
2010          * The SCI handler doesn't run at this point, so the GPE can be
2011          * masked at the low level without side effects.
2012          */
2013         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2014             ec->gpe >= 0 && ec->reference_count >= 1)
2015                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
2016
2017         acpi_ec_enter_noirq(ec);
2018
2019         return 0;
2020 }
2021
2022 static int acpi_ec_resume_noirq(struct device *dev)
2023 {
2024         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2025
2026         acpi_ec_leave_noirq(ec);
2027
2028         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2029             ec->gpe >= 0 && ec->reference_count >= 1)
2030                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
2031
2032         return 0;
2033 }
2034
2035 static int acpi_ec_resume(struct device *dev)
2036 {
2037         struct acpi_ec *ec =
2038                 acpi_driver_data(to_acpi_device(dev));
2039
2040         acpi_ec_enable_event(ec);
2041         return 0;
2042 }
2043
2044 void acpi_ec_mark_gpe_for_wake(void)
2045 {
2046         if (first_ec && !ec_no_wakeup)
2047                 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
2048 }
2049 EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
2050
2051 void acpi_ec_set_gpe_wake_mask(u8 action)
2052 {
2053         if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
2054                 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
2055 }
2056
2057 bool acpi_ec_dispatch_gpe(void)
2058 {
2059         u32 ret;
2060
2061         if (!first_ec)
2062                 return false;
2063
2064         ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
2065         if (ret == ACPI_INTERRUPT_HANDLED) {
2066                 pm_pr_dbg("EC GPE dispatched\n");
2067                 return true;
2068         }
2069         return false;
2070 }
2071 #endif /* CONFIG_PM_SLEEP */
2072
2073 static const struct dev_pm_ops acpi_ec_pm = {
2074         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2075         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2076 };
2077
2078 static int param_set_event_clearing(const char *val,
2079                                     const struct kernel_param *kp)
2080 {
2081         int result = 0;
2082
2083         if (!strncmp(val, "status", sizeof("status") - 1)) {
2084                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2085                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2086         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2087                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2088                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2089         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2090                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2091                 pr_info("Assuming SCI_EVT clearing on event reads\n");
2092         } else
2093                 result = -EINVAL;
2094         return result;
2095 }
2096
2097 static int param_get_event_clearing(char *buffer,
2098                                     const struct kernel_param *kp)
2099 {
2100         switch (ec_event_clearing) {
2101         case ACPI_EC_EVT_TIMING_STATUS:
2102                 return sprintf(buffer, "status");
2103         case ACPI_EC_EVT_TIMING_QUERY:
2104                 return sprintf(buffer, "query");
2105         case ACPI_EC_EVT_TIMING_EVENT:
2106                 return sprintf(buffer, "event");
2107         default:
2108                 return sprintf(buffer, "invalid");
2109         }
2110         return 0;
2111 }
2112
2113 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2114                   NULL, 0644);
2115 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2116
2117 static struct acpi_driver acpi_ec_driver = {
2118         .name = "ec",
2119         .class = ACPI_EC_CLASS,
2120         .ids = ec_device_ids,
2121         .ops = {
2122                 .add = acpi_ec_add,
2123                 .remove = acpi_ec_remove,
2124                 },
2125         .drv.pm = &acpi_ec_pm,
2126 };
2127
2128 static inline int acpi_ec_query_init(void)
2129 {
2130         if (!ec_query_wq) {
2131                 ec_query_wq = alloc_workqueue("kec_query", 0,
2132                                               ec_max_queries);
2133                 if (!ec_query_wq)
2134                         return -ENODEV;
2135         }
2136         return 0;
2137 }
2138
2139 static inline void acpi_ec_query_exit(void)
2140 {
2141         if (ec_query_wq) {
2142                 destroy_workqueue(ec_query_wq);
2143                 ec_query_wq = NULL;
2144         }
2145 }
2146
2147 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2148         {
2149                 .ident = "Thinkpad X1 Carbon 6th",
2150                 .matches = {
2151                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2152                         DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2153                 },
2154         },
2155         {
2156                 .ident = "ThinkPad X1 Carbon 6th",
2157                 .matches = {
2158                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2159                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2160                 },
2161         },
2162         {
2163                 .ident = "ThinkPad X1 Yoga 3rd",
2164                 .matches = {
2165                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2166                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2167                 },
2168         },
2169         { },
2170 };
2171
2172 int __init acpi_ec_init(void)
2173 {
2174         int result;
2175         int ecdt_fail, dsdt_fail;
2176
2177         /* register workqueue for _Qxx evaluations */
2178         result = acpi_ec_query_init();
2179         if (result)
2180                 return result;
2181
2182         /*
2183          * Disable EC wakeup on following systems to prevent periodic
2184          * wakeup from EC GPE.
2185          */
2186         if (dmi_check_system(acpi_ec_no_wakeup)) {
2187                 ec_no_wakeup = true;
2188                 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2189         }
2190
2191         /* Drivers must be started after acpi_ec_query_init() */
2192         dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver);
2193         /*
2194          * Register ECDT to ACPI bus only when PNP0C09 probe fails. This is
2195          * useful for platforms (confirmed on ASUS X550ZE) with valid ECDT
2196          * settings but invalid DSDT settings.
2197          * https://bugzilla.kernel.org/show_bug.cgi?id=196847
2198          */
2199         ecdt_fail = acpi_ec_ecdt_start();
2200         return ecdt_fail && dsdt_fail ? -ENODEV : 0;
2201 }
2202
2203 /* EC driver currently not unloadable */
2204 #if 0
2205 static void __exit acpi_ec_exit(void)
2206 {
2207
2208         acpi_bus_unregister_driver(&acpi_ec_driver);
2209         acpi_ec_query_exit();
2210 }
2211 #endif  /* 0 */