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_wq;
 183 static struct workqueue_struct *ec_query_wq;
 184
 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                 queue_work(ec_wq, &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 void __acpi_ec_flush_work(void)
 537 {
 538         drain_workqueue(ec_wq); /* flush ec->work */
 539         flush_workqueue(ec_query_wq); /* flush queries */
 540 }
 541
 542 static void acpi_ec_disable_event(struct acpi_ec *ec)
 543 {
 544         unsigned long flags;
 545
 546         spin_lock_irqsave(&ec->lock, flags);
 547         __acpi_ec_disable_event(ec);
 548         spin_unlock_irqrestore(&ec->lock, flags);
 549
 550         /*
 551          * When ec_freeze_events is true, we need to flush events in
 552          * the proper position before entering the noirq stage.
 553          */
 554         __acpi_ec_flush_work();
 555 }
 556
 557 void acpi_ec_flush_work(void)
 558 {
 559         /* Without ec_wq there is nothing to flush. */
 560         if (!ec_wq)
 561                 return;
 562
 563         __acpi_ec_flush_work();
 564 }
 565 #endif /* CONFIG_PM_SLEEP */
 566
 567 static bool acpi_ec_guard_event(struct acpi_ec *ec)
 568 {
 569         bool guarded = true;
 570         unsigned long flags;
 571
 572         spin_lock_irqsave(&ec->lock, flags);
 573         /*
 574          * If firmware SCI_EVT clearing timing is "event", we actually
 575          * don't know when the SCI_EVT will be cleared by firmware after
 576          * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
 577          * acceptable period.
 578          *
 579          * The guarding period begins when EC_FLAGS_QUERY_PENDING is
 580          * flagged, which means SCI_EVT check has just been performed.
 581          * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
 582          * guarding should have already been performed (via
 583          * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
 584          * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
 585          * ACPI_EC_COMMAND_POLL state immediately.
 586          */
 587         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
 588             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
 589             !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
 590             (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
 591                 guarded = false;
 592         spin_unlock_irqrestore(&ec->lock, flags);
 593         return guarded;
 594 }
 595
 596 static int ec_transaction_polled(struct acpi_ec *ec)
 597 {
 598         unsigned long flags;
 599         int ret = 0;
 600
 601         spin_lock_irqsave(&ec->lock, flags);
 602         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
 603                 ret = 1;
 604         spin_unlock_irqrestore(&ec->lock, flags);
 605         return ret;
 606 }
 607
 608 static int ec_transaction_completed(struct acpi_ec *ec)
 609 {
 610         unsigned long flags;
 611         int ret = 0;
 612
 613         spin_lock_irqsave(&ec->lock, flags);
 614         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 615                 ret = 1;
 616         spin_unlock_irqrestore(&ec->lock, flags);
 617         return ret;
 618 }
 619
 620 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
 621 {
 622         ec->curr->flags |= flag;
 623         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 624                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
 625                     flag == ACPI_EC_COMMAND_POLL)
 626                         acpi_ec_complete_query(ec);
 627                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
 628                     flag == ACPI_EC_COMMAND_COMPLETE)
 629                         acpi_ec_complete_query(ec);
 630                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 631                     flag == ACPI_EC_COMMAND_COMPLETE)
 632                         set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 633         }
 634 }
 635
 636 static void advance_transaction(struct acpi_ec *ec)
 637 {
 638         struct transaction *t;
 639         u8 status;
 640         bool wakeup = false;
 641
 642         ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
 643                    smp_processor_id());
 644         /*
 645          * By always clearing STS before handling all indications, we can
 646          * ensure a hardware STS 0->1 change after this clearing can always
 647          * trigger a GPE interrupt.
 648          */
 649         if (ec->gpe >= 0)
 650                 acpi_ec_clear_gpe(ec);
 651
 652         status = acpi_ec_read_status(ec);
 653         t = ec->curr;
 654         /*
 655          * Another IRQ or a guarded polling mode advancement is detected,
 656          * the next QR_EC submission is then allowed.
 657          */
 658         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
 659                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 660                     (!ec->nr_pending_queries ||
 661                      test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
 662                         clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 663                         acpi_ec_complete_query(ec);
 664                 }
 665         }
 666         if (!t)
 667                 goto err;
 668         if (t->flags & ACPI_EC_COMMAND_POLL) {
 669                 if (t->wlen > t->wi) {
 670                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 671                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 672                         else
 673                                 goto err;
 674                 } else if (t->rlen > t->ri) {
 675                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 676                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 677                                 if (t->rlen == t->ri) {
 678                                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 679                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 680                                                 ec_dbg_evt("Command(%s) completed by hardware",
 681                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 682                                         wakeup = true;
 683                                 }
 684                         } else
 685                                 goto err;
 686                 } else if (t->wlen == t->wi &&
 687                            (status & ACPI_EC_FLAG_IBF) == 0) {
 688                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 689                         wakeup = true;
 690                 }
 691                 goto out;
 692         } else if (!(status & ACPI_EC_FLAG_IBF)) {
 693                 acpi_ec_write_cmd(ec, t->command);
 694                 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 695                 goto out;
 696         }
 697 err:
 698         /*
 699          * If SCI bit is set, then don't think it's a false IRQ
 700          * otherwise will take a not handled IRQ as a false one.
 701          */
 702         if (!(status & ACPI_EC_FLAG_SCI)) {
 703                 if (in_interrupt() && t) {
 704                         if (t->irq_count < ec_storm_threshold)
 705                                 ++t->irq_count;
 706                         /* Allow triggering on 0 threshold */
 707                         if (t->irq_count == ec_storm_threshold)
 708                                 acpi_ec_mask_events(ec);
 709                 }
 710         }
 711 out:
 712         if (status & ACPI_EC_FLAG_SCI)
 713                 acpi_ec_submit_query(ec);
 714         if (wakeup && in_interrupt())
 715                 wake_up(&ec->wait);
 716 }
 717
 718 static void start_transaction(struct acpi_ec *ec)
 719 {
 720         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 721         ec->curr->flags = 0;
 722 }
 723
 724 static int ec_guard(struct acpi_ec *ec)
 725 {
 726         unsigned long guard = usecs_to_jiffies(ec->polling_guard);
 727         unsigned long timeout = ec->timestamp + guard;
 728
 729         /* Ensure guarding period before polling EC status */
 730         do {
 731                 if (ec->busy_polling) {
 732                         /* Perform busy polling */
 733                         if (ec_transaction_completed(ec))
 734                                 return 0;
 735                         udelay(jiffies_to_usecs(guard));
 736                 } else {
 737                         /*
 738                          * Perform wait polling
 739                          * 1. Wait the transaction to be completed by the
 740                          *    GPE handler after the transaction enters
 741                          *    ACPI_EC_COMMAND_POLL state.
 742                          * 2. A special guarding logic is also required
 743                          *    for event clearing mode "event" before the
 744                          *    transaction enters ACPI_EC_COMMAND_POLL
 745                          *    state.
 746                          */
 747                         if (!ec_transaction_polled(ec) &&
 748                             !acpi_ec_guard_event(ec))
 749                                 break;
 750                         if (wait_event_timeout(ec->wait,
 751                                                ec_transaction_completed(ec),
 752                                                guard))
 753                                 return 0;
 754                 }
 755         } while (time_before(jiffies, timeout));
 756         return -ETIME;
 757 }
 758
 759 static int ec_poll(struct acpi_ec *ec)
 760 {
 761         unsigned long flags;
 762         int repeat = 5; /* number of command restarts */
 763
 764         while (repeat--) {
 765                 unsigned long delay = jiffies +
 766                         msecs_to_jiffies(ec_delay);
 767                 do {
 768                         if (!ec_guard(ec))
 769                                 return 0;
 770                         spin_lock_irqsave(&ec->lock, flags);
 771                         advance_transaction(ec);
 772                         spin_unlock_irqrestore(&ec->lock, flags);
 773                 } while (time_before(jiffies, delay));
 774                 pr_debug("controller reset, restart transaction\n");
 775                 spin_lock_irqsave(&ec->lock, flags);
 776                 start_transaction(ec);
 777                 spin_unlock_irqrestore(&ec->lock, flags);
 778         }
 779         return -ETIME;
 780 }
 781
 782 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 783                                         struct transaction *t)
 784 {
 785         unsigned long tmp;
 786         int ret = 0;
 787
 788         /* start transaction */
 789         spin_lock_irqsave(&ec->lock, tmp);
 790         /* Enable GPE for command processing (IBF=0/OBF=1) */
 791         if (!acpi_ec_submit_flushable_request(ec)) {
 792                 ret = -EINVAL;
 793                 goto unlock;
 794         }
 795         ec_dbg_ref(ec, "Increase command");
 796         /* following two actions should be kept atomic */
 797         ec->curr = t;
 798         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 799         start_transaction(ec);
 800         spin_unlock_irqrestore(&ec->lock, tmp);
 801
 802         ret = ec_poll(ec);
 803
 804         spin_lock_irqsave(&ec->lock, tmp);
 805         if (t->irq_count == ec_storm_threshold)
 806                 acpi_ec_unmask_events(ec);
 807         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 808         ec->curr = NULL;
 809         /* Disable GPE for command processing (IBF=0/OBF=1) */
 810         acpi_ec_complete_request(ec);
 811         ec_dbg_ref(ec, "Decrease command");
 812 unlock:
 813         spin_unlock_irqrestore(&ec->lock, tmp);
 814         return ret;
 815 }
 816
 817 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 818 {
 819         int status;
 820         u32 glk;
 821
 822         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 823                 return -EINVAL;
 824         if (t->rdata)
 825                 memset(t->rdata, 0, t->rlen);
 826
 827         mutex_lock(&ec->mutex);
 828         if (ec->global_lock) {
 829                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 830                 if (ACPI_FAILURE(status)) {
 831                         status = -ENODEV;
 832                         goto unlock;
 833                 }
 834         }
 835
 836         status = acpi_ec_transaction_unlocked(ec, t);
 837
 838         if (ec->global_lock)
 839                 acpi_release_global_lock(glk);
 840 unlock:
 841         mutex_unlock(&ec->mutex);
 842         return status;
 843 }
 844
 845 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 846 {
 847         u8 d;
 848         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 849                                 .wdata = NULL, .rdata = &d,
 850                                 .wlen = 0, .rlen = 1};
 851
 852         return acpi_ec_transaction(ec, &t);
 853 }
 854
 855 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 856 {
 857         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 858                                 .wdata = NULL, .rdata = NULL,
 859                                 .wlen = 0, .rlen = 0};
 860
 861         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 862                                 acpi_ec_transaction(ec, &t) : 0;
 863 }
 864
 865 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 866 {
 867         int result;
 868         u8 d;
 869         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 870                                 .wdata = &address, .rdata = &d,
 871                                 .wlen = 1, .rlen = 1};
 872
 873         result = acpi_ec_transaction(ec, &t);
 874         *data = d;
 875         return result;
 876 }
 877
 878 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 879 {
 880         u8 wdata[2] = { address, data };
 881         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 882                                 .wdata = wdata, .rdata = NULL,
 883                                 .wlen = 2, .rlen = 0};
 884
 885         return acpi_ec_transaction(ec, &t);
 886 }
 887
 888 int ec_read(u8 addr, u8 *val)
 889 {
 890         int err;
 891         u8 temp_data;
 892
 893         if (!first_ec)
 894                 return -ENODEV;
 895
 896         err = acpi_ec_read(first_ec, addr, &temp_data);
 897
 898         if (!err) {
 899                 *val = temp_data;
 900                 return 0;
 901         }
 902         return err;
 903 }
 904 EXPORT_SYMBOL(ec_read);
 905
 906 int ec_write(u8 addr, u8 val)
 907 {
 908         int err;
 909
 910         if (!first_ec)
 911                 return -ENODEV;
 912
 913         err = acpi_ec_write(first_ec, addr, val);
 914
 915         return err;
 916 }
 917 EXPORT_SYMBOL(ec_write);
 918
 919 int ec_transaction(u8 command,
 920                    const u8 *wdata, unsigned wdata_len,
 921                    u8 *rdata, unsigned rdata_len)
 922 {
 923         struct transaction t = {.command = command,
 924                                 .wdata = wdata, .rdata = rdata,
 925                                 .wlen = wdata_len, .rlen = rdata_len};
 926
 927         if (!first_ec)
 928                 return -ENODEV;
 929
 930         return acpi_ec_transaction(first_ec, &t);
 931 }
 932 EXPORT_SYMBOL(ec_transaction);
 933
 934 /* Get the handle to the EC device */
 935 acpi_handle ec_get_handle(void)
 936 {
 937         if (!first_ec)
 938                 return NULL;
 939         return first_ec->handle;
 940 }
 941 EXPORT_SYMBOL(ec_get_handle);
 942
 943 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 944 {
 945         unsigned long flags;
 946
 947         spin_lock_irqsave(&ec->lock, flags);
 948         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 949                 ec_dbg_drv("Starting EC");
 950                 /* Enable GPE for event processing (SCI_EVT=1) */
 951                 if (!resuming) {
 952                         acpi_ec_submit_request(ec);
 953                         ec_dbg_ref(ec, "Increase driver");
 954                 }
 955                 ec_log_drv("EC started");
 956         }
 957         spin_unlock_irqrestore(&ec->lock, flags);
 958 }
 959
 960 static bool acpi_ec_stopped(struct acpi_ec *ec)
 961 {
 962         unsigned long flags;
 963         bool flushed;
 964
 965         spin_lock_irqsave(&ec->lock, flags);
 966         flushed = acpi_ec_flushed(ec);
 967         spin_unlock_irqrestore(&ec->lock, flags);
 968         return flushed;
 969 }
 970
 971 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 972 {
 973         unsigned long flags;
 974
 975         spin_lock_irqsave(&ec->lock, flags);
 976         if (acpi_ec_started(ec)) {
 977                 ec_dbg_drv("Stopping EC");
 978                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
 979                 spin_unlock_irqrestore(&ec->lock, flags);
 980                 wait_event(ec->wait, acpi_ec_stopped(ec));
 981                 spin_lock_irqsave(&ec->lock, flags);
 982                 /* Disable GPE for event processing (SCI_EVT=1) */
 983                 if (!suspending) {
 984                         acpi_ec_complete_request(ec);
 985                         ec_dbg_ref(ec, "Decrease driver");
 986                 } else if (!ec_freeze_events)
 987                         __acpi_ec_disable_event(ec);
 988                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
 989                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
 990                 ec_log_drv("EC stopped");
 991         }
 992         spin_unlock_irqrestore(&ec->lock, flags);
 993 }
 994
 995 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
 996 {
 997         unsigned long flags;
 998
 999         spin_lock_irqsave(&ec->lock, flags);
1000         ec->busy_polling = true;
1001         ec->polling_guard = 0;
1002         ec_log_drv("interrupt blocked");
1003         spin_unlock_irqrestore(&ec->lock, flags);
1004 }
1005
1006 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1007 {
1008         unsigned long flags;
1009
1010         spin_lock_irqsave(&ec->lock, flags);
1011         ec->busy_polling = ec_busy_polling;
1012         ec->polling_guard = ec_polling_guard;
1013         ec_log_drv("interrupt unblocked");
1014         spin_unlock_irqrestore(&ec->lock, flags);
1015 }
1016
1017 void acpi_ec_block_transactions(void)
1018 {
1019         struct acpi_ec *ec = first_ec;
1020
1021         if (!ec)
1022                 return;
1023
1024         mutex_lock(&ec->mutex);
1025         /* Prevent transactions from being carried out */
1026         acpi_ec_stop(ec, true);
1027         mutex_unlock(&ec->mutex);
1028 }
1029
1030 void acpi_ec_unblock_transactions(void)
1031 {
1032         /*
1033          * Allow transactions to happen again (this function is called from
1034          * atomic context during wakeup, so we don't need to acquire the mutex).
1035          */
1036         if (first_ec)
1037                 acpi_ec_start(first_ec, true);
1038 }
1039
1040 /* --------------------------------------------------------------------------
1041                                 Event Management
1042    -------------------------------------------------------------------------- */
1043 static struct acpi_ec_query_handler *
1044 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1045 {
1046         struct acpi_ec_query_handler *handler;
1047
1048         mutex_lock(&ec->mutex);
1049         list_for_each_entry(handler, &ec->list, node) {
1050                 if (value == handler->query_bit) {
1051                         kref_get(&handler->kref);
1052                         mutex_unlock(&ec->mutex);
1053                         return handler;
1054                 }
1055         }
1056         mutex_unlock(&ec->mutex);
1057         return NULL;
1058 }
1059
1060 static void acpi_ec_query_handler_release(struct kref *kref)
1061 {
1062         struct acpi_ec_query_handler *handler =
1063                 container_of(kref, struct acpi_ec_query_handler, kref);
1064
1065         kfree(handler);
1066 }
1067
1068 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1069 {
1070         kref_put(&handler->kref, acpi_ec_query_handler_release);
1071 }
1072
1073 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1074                               acpi_handle handle, acpi_ec_query_func func,
1075                               void *data)
1076 {
1077         struct acpi_ec_query_handler *handler =
1078             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1079
1080         if (!handler)
1081                 return -ENOMEM;
1082
1083         handler->query_bit = query_bit;
1084         handler->handle = handle;
1085         handler->func = func;
1086         handler->data = data;
1087         mutex_lock(&ec->mutex);
1088         kref_init(&handler->kref);
1089         list_add(&handler->node, &ec->list);
1090         mutex_unlock(&ec->mutex);
1091         return 0;
1092 }
1093 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1094
1095 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1096                                           bool remove_all, u8 query_bit)
1097 {
1098         struct acpi_ec_query_handler *handler, *tmp;
1099         LIST_HEAD(free_list);
1100
1101         mutex_lock(&ec->mutex);
1102         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1103                 if (remove_all || query_bit == handler->query_bit) {
1104                         list_del_init(&handler->node);
1105                         list_add(&handler->node, &free_list);
1106                 }
1107         }
1108         mutex_unlock(&ec->mutex);
1109         list_for_each_entry_safe(handler, tmp, &free_list, node)
1110                 acpi_ec_put_query_handler(handler);
1111 }
1112
1113 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1114 {
1115         acpi_ec_remove_query_handlers(ec, false, query_bit);
1116 }
1117 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1118
1119 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1120 {
1121         struct acpi_ec_query *q;
1122         struct transaction *t;
1123
1124         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1125         if (!q)
1126                 return NULL;
1127         INIT_WORK(&q->work, acpi_ec_event_processor);
1128         t = &q->transaction;
1129         t->command = ACPI_EC_COMMAND_QUERY;
1130         t->rdata = pval;
1131         t->rlen = 1;
1132         return q;
1133 }
1134
1135 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1136 {
1137         if (q) {
1138                 if (q->handler)
1139                         acpi_ec_put_query_handler(q->handler);
1140                 kfree(q);
1141         }
1142 }
1143
1144 static void acpi_ec_event_processor(struct work_struct *work)
1145 {
1146         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1147         struct acpi_ec_query_handler *handler = q->handler;
1148
1149         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1150         if (handler->func)
1151                 handler->func(handler->data);
1152         else if (handler->handle)
1153                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1154         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1155         acpi_ec_delete_query(q);
1156 }
1157
1158 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1159 {
1160         u8 value = 0;
1161         int result;
1162         struct acpi_ec_query *q;
1163
1164         q = acpi_ec_create_query(&value);
1165         if (!q)
1166                 return -ENOMEM;
1167
1168         /*
1169          * Query the EC to find out which _Qxx method we need to evaluate.
1170          * Note that successful completion of the query causes the ACPI_EC_SCI
1171          * bit to be cleared (and thus clearing the interrupt source).
1172          */
1173         result = acpi_ec_transaction(ec, &q->transaction);
1174         if (!value)
1175                 result = -ENODATA;
1176         if (result)
1177                 goto err_exit;
1178
1179         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1180         if (!q->handler) {
1181                 result = -ENODATA;
1182                 goto err_exit;
1183         }
1184
1185         /*
1186          * It is reported that _Qxx are evaluated in a parallel way on
1187          * Windows:
1188          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1189          *
1190          * Put this log entry before schedule_work() in order to make
1191          * it appearing before any other log entries occurred during the
1192          * work queue execution.
1193          */
1194         ec_dbg_evt("Query(0x%02x) scheduled", value);
1195         if (!queue_work(ec_query_wq, &q->work)) {
1196                 ec_dbg_evt("Query(0x%02x) overlapped", value);
1197                 result = -EBUSY;
1198         }
1199
1200 err_exit:
1201         if (result)
1202                 acpi_ec_delete_query(q);
1203         if (data)
1204                 *data = value;
1205         return result;
1206 }
1207
1208 static void acpi_ec_check_event(struct acpi_ec *ec)
1209 {
1210         unsigned long flags;
1211
1212         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1213                 if (ec_guard(ec)) {
1214                         spin_lock_irqsave(&ec->lock, flags);
1215                         /*
1216                          * Take care of the SCI_EVT unless no one else is
1217                          * taking care of it.
1218                          */
1219                         if (!ec->curr)
1220                                 advance_transaction(ec);
1221                         spin_unlock_irqrestore(&ec->lock, flags);
1222                 }
1223         }
1224 }
1225
1226 static void acpi_ec_event_handler(struct work_struct *work)
1227 {
1228         unsigned long flags;
1229         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1230
1231         ec_dbg_evt("Event started");
1232
1233         spin_lock_irqsave(&ec->lock, flags);
1234         while (ec->nr_pending_queries) {
1235                 spin_unlock_irqrestore(&ec->lock, flags);
1236                 (void)acpi_ec_query(ec, NULL);
1237                 spin_lock_irqsave(&ec->lock, flags);
1238                 ec->nr_pending_queries--;
1239                 /*
1240                  * Before exit, make sure that this work item can be
1241                  * scheduled again. There might be QR_EC failures, leaving
1242                  * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1243                  * item from being scheduled again.
1244                  */
1245                 if (!ec->nr_pending_queries) {
1246                         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1247                             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1248                                 acpi_ec_complete_query(ec);
1249                 }
1250         }
1251         spin_unlock_irqrestore(&ec->lock, flags);
1252
1253         ec_dbg_evt("Event stopped");
1254
1255         acpi_ec_check_event(ec);
1256 }
1257
1258 static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1259 {
1260         unsigned long flags;
1261
1262         spin_lock_irqsave(&ec->lock, flags);
1263         advance_transaction(ec);
1264         spin_unlock_irqrestore(&ec->lock, flags);
1265 }
1266
1267 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1268                                u32 gpe_number, void *data)
1269 {
1270         acpi_ec_handle_interrupt(data);
1271         return ACPI_INTERRUPT_HANDLED;
1272 }
1273
1274 static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1275 {
1276         acpi_ec_handle_interrupt(data);
1277         return IRQ_HANDLED;
1278 }
1279
1280 /* --------------------------------------------------------------------------
1281  *                           Address Space Management
1282  * -------------------------------------------------------------------------- */
1283
1284 static acpi_status
1285 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1286                       u32 bits, u64 *value64,
1287                       void *handler_context, void *region_context)
1288 {
1289         struct acpi_ec *ec = handler_context;
1290         int result = 0, i, bytes = bits / 8;
1291         u8 *value = (u8 *)value64;
1292
1293         if ((address > 0xFF) || !value || !handler_context)
1294                 return AE_BAD_PARAMETER;
1295
1296         if (function != ACPI_READ && function != ACPI_WRITE)
1297                 return AE_BAD_PARAMETER;
1298
1299         if (ec->busy_polling || bits > 8)
1300                 acpi_ec_burst_enable(ec);
1301
1302         for (i = 0; i < bytes; ++i, ++address, ++value)
1303                 result = (function == ACPI_READ) ?
1304                         acpi_ec_read(ec, address, value) :
1305                         acpi_ec_write(ec, address, *value);
1306
1307         if (ec->busy_polling || bits > 8)
1308                 acpi_ec_burst_disable(ec);
1309
1310         switch (result) {
1311         case -EINVAL:
1312                 return AE_BAD_PARAMETER;
1313         case -ENODEV:
1314                 return AE_NOT_FOUND;
1315         case -ETIME:
1316                 return AE_TIME;
1317         default:
1318                 return AE_OK;
1319         }
1320 }
1321
1322 /* --------------------------------------------------------------------------
1323  *                             Driver Interface
1324  * -------------------------------------------------------------------------- */
1325
1326 static acpi_status
1327 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1328
1329 static void acpi_ec_free(struct acpi_ec *ec)
1330 {
1331         if (first_ec == ec)
1332                 first_ec = NULL;
1333         if (boot_ec == ec)
1334                 boot_ec = NULL;
1335         kfree(ec);
1336 }
1337
1338 static struct acpi_ec *acpi_ec_alloc(void)
1339 {
1340         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1341
1342         if (!ec)
1343                 return NULL;
1344         mutex_init(&ec->mutex);
1345         init_waitqueue_head(&ec->wait);
1346         INIT_LIST_HEAD(&ec->list);
1347         spin_lock_init(&ec->lock);
1348         INIT_WORK(&ec->work, acpi_ec_event_handler);
1349         ec->timestamp = jiffies;
1350         ec->busy_polling = true;
1351         ec->polling_guard = 0;
1352         ec->gpe = -1;
1353         ec->irq = -1;
1354         return ec;
1355 }
1356
1357 static acpi_status
1358 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1359                                void *context, void **return_value)
1360 {
1361         char node_name[5];
1362         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1363         struct acpi_ec *ec = context;
1364         int value = 0;
1365         acpi_status status;
1366
1367         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1368
1369         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1370                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1371         return AE_OK;
1372 }
1373
1374 static acpi_status
1375 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1376 {
1377         acpi_status status;
1378         unsigned long long tmp = 0;
1379         struct acpi_ec *ec = context;
1380
1381         /* clear addr values, ec_parse_io_ports depend on it */
1382         ec->command_addr = ec->data_addr = 0;
1383
1384         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1385                                      ec_parse_io_ports, ec);
1386         if (ACPI_FAILURE(status))
1387                 return status;
1388         if (ec->data_addr == 0 || ec->command_addr == 0)
1389                 return AE_OK;
1390
1391         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1392                 /*
1393                  * Always inherit the GPE number setting from the ECDT
1394                  * EC.
1395                  */
1396                 ec->gpe = boot_ec->gpe;
1397         } else {
1398                 /* Get GPE bit assignment (EC events). */
1399                 /* TODO: Add support for _GPE returning a package */
1400                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1401                 if (ACPI_SUCCESS(status))
1402                         ec->gpe = tmp;
1403
1404                 /*
1405                  * Errors are non-fatal, allowing for ACPI Reduced Hardware
1406                  * platforms which use GpioInt instead of GPE.
1407                  */
1408         }
1409         /* Use the global lock for all EC transactions? */
1410         tmp = 0;
1411         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1412         ec->global_lock = tmp;
1413         ec->handle = handle;
1414         return AE_CTRL_TERMINATE;
1415 }
1416
1417 static bool install_gpe_event_handler(struct acpi_ec *ec)
1418 {
1419         acpi_status status;
1420
1421         status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1422                                               ACPI_GPE_EDGE_TRIGGERED,
1423                                               &acpi_ec_gpe_handler, ec);
1424         if (ACPI_FAILURE(status))
1425                 return false;
1426
1427         if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1428                 acpi_ec_enable_gpe(ec, true);
1429
1430         return true;
1431 }
1432
1433 static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1434 {
1435         return request_irq(ec->irq, acpi_ec_irq_handler, IRQF_SHARED,
1436                            "ACPI EC", ec) >= 0;
1437 }
1438
1439 /**
1440  * ec_install_handlers - Install service callbacks and register query methods.
1441  * @ec: Target EC.
1442  * @device: ACPI device object corresponding to @ec.
1443  *
1444  * Install a handler for the EC address space type unless it has been installed
1445  * already.  If @device is not NULL, also look for EC query methods in the
1446  * namespace and register them, and install an event (either GPE or GPIO IRQ)
1447  * handler for the EC, if possible.
1448  *
1449  * Return:
1450  * -ENODEV if the address space handler cannot be installed, which means
1451  *  "unable to handle transactions",
1452  * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1453  * or 0 (success) otherwise.
1454  */
1455 static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device)
1456 {
1457         acpi_status status;
1458
1459         acpi_ec_start(ec, false);
1460
1461         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1462                 acpi_ec_enter_noirq(ec);
1463                 status = acpi_install_address_space_handler(ec->handle,
1464                                                             ACPI_ADR_SPACE_EC,
1465                                                             &acpi_ec_space_handler,
1466                                                             NULL, ec);
1467                 if (ACPI_FAILURE(status)) {
1468                         acpi_ec_stop(ec, false);
1469                         return -ENODEV;
1470                 }
1471                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1472         }
1473
1474         if (!device)
1475                 return 0;
1476
1477         if (ec->gpe < 0) {
1478                 /* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1479                 int irq = acpi_dev_gpio_irq_get(device, 0);
1480                 /*
1481                  * Bail out right away for deferred probing or complete the
1482                  * initialization regardless of any other errors.
1483                  */
1484                 if (irq == -EPROBE_DEFER)
1485                         return -EPROBE_DEFER;
1486                 else if (irq >= 0)
1487                         ec->irq = irq;
1488         }
1489
1490         if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1491                 /* Find and register all query methods */
1492                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1493                                     acpi_ec_register_query_methods,
1494                                     NULL, ec, NULL);
1495                 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1496         }
1497         if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1498                 bool ready = false;
1499
1500                 if (ec->gpe >= 0)
1501                         ready = install_gpe_event_handler(ec);
1502                 else if (ec->irq >= 0)
1503                         ready = install_gpio_irq_event_handler(ec);
1504
1505                 if (ready) {
1506                         set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1507                         acpi_ec_leave_noirq(ec);
1508                 }
1509                 /*
1510                  * Failures to install an event handler are not fatal, because
1511                  * the EC can be polled for events.
1512                  */
1513         }
1514         /* EC is fully operational, allow queries */
1515         acpi_ec_enable_event(ec);
1516
1517         return 0;
1518 }
1519
1520 static void ec_remove_handlers(struct acpi_ec *ec)
1521 {
1522         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1523                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1524                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1525                         pr_err("failed to remove space handler\n");
1526                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1527         }
1528
1529         /*
1530          * Stops handling the EC transactions after removing the operation
1531          * region handler. This is required because _REG(DISCONNECT)
1532          * invoked during the removal can result in new EC transactions.
1533          *
1534          * Flushes the EC requests and thus disables the GPE before
1535          * removing the GPE handler. This is required by the current ACPICA
1536          * GPE core. ACPICA GPE core will automatically disable a GPE when
1537          * it is indicated but there is no way to handle it. So the drivers
1538          * must disable the GPEs prior to removing the GPE handlers.
1539          */
1540         acpi_ec_stop(ec, false);
1541
1542         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1543                 if (ec->gpe >= 0 &&
1544                     ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1545                                  &acpi_ec_gpe_handler)))
1546                         pr_err("failed to remove gpe handler\n");
1547
1548                 if (ec->irq >= 0)
1549                         free_irq(ec->irq, ec);
1550
1551                 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1552         }
1553         if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1554                 acpi_ec_remove_query_handlers(ec, true, 0);
1555                 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1556         }
1557 }
1558
1559 static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device)
1560 {
1561         int ret;
1562
1563         ret = ec_install_handlers(ec, device);
1564         if (ret)
1565                 return ret;
1566
1567         /* First EC capable of handling transactions */
1568         if (!first_ec)
1569                 first_ec = ec;
1570
1571         pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1572                 ec->data_addr);
1573
1574         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1575                 if (ec->gpe >= 0)
1576                         pr_info("GPE=0x%x\n", ec->gpe);
1577                 else
1578                         pr_info("IRQ=%d\n", ec->irq);
1579         }
1580
1581         return ret;
1582 }
1583
1584 static int acpi_ec_add(struct acpi_device *device)
1585 {
1586         struct acpi_ec *ec;
1587         int ret;
1588
1589         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1590         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1591
1592         if (boot_ec && (boot_ec->handle == device->handle ||
1593             !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
1594                 /* Fast path: this device corresponds to the boot EC. */
1595                 ec = boot_ec;
1596         } else {
1597                 acpi_status status;
1598
1599                 ec = acpi_ec_alloc();
1600                 if (!ec)
1601                         return -ENOMEM;
1602
1603                 status = ec_parse_device(device->handle, 0, ec, NULL);
1604                 if (status != AE_CTRL_TERMINATE) {
1605                         ret = -EINVAL;
1606                         goto err;
1607                 }
1608
1609                 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1610                     ec->data_addr == boot_ec->data_addr) {
1611                         /*
1612                          * Trust PNP0C09 namespace location rather than
1613                          * ECDT ID. But trust ECDT GPE rather than _GPE
1614                          * because of ASUS quirks, so do not change
1615                          * boot_ec->gpe to ec->gpe.
1616                          */
1617                         boot_ec->handle = ec->handle;
1618                         acpi_handle_debug(ec->handle, "duplicated.\n");
1619                         acpi_ec_free(ec);
1620                         ec = boot_ec;
1621                 }
1622         }
1623
1624         ret = acpi_ec_setup(ec, device);
1625         if (ret)
1626                 goto err;
1627
1628         if (ec == boot_ec)
1629                 acpi_handle_info(boot_ec->handle,
1630                                  "Boot %s EC initialization complete\n",
1631                                  boot_ec_is_ecdt ? "ECDT" : "DSDT");
1632
1633         acpi_handle_info(ec->handle,
1634                          "EC: Used to handle transactions and events\n");
1635
1636         device->driver_data = ec;
1637
1638         ret = !!request_region(ec->data_addr, 1, "EC data");
1639         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1640         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1641         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1642
1643         /* Reprobe devices depending on the EC */
1644         acpi_walk_dep_device_list(ec->handle);
1645
1646         acpi_handle_debug(ec->handle, "enumerated.\n");
1647         return 0;
1648
1649 err:
1650         if (ec != boot_ec)
1651                 acpi_ec_free(ec);
1652
1653         return ret;
1654 }
1655
1656 static int acpi_ec_remove(struct acpi_device *device)
1657 {
1658         struct acpi_ec *ec;
1659
1660         if (!device)
1661                 return -EINVAL;
1662
1663         ec = acpi_driver_data(device);
1664         release_region(ec->data_addr, 1);
1665         release_region(ec->command_addr, 1);
1666         device->driver_data = NULL;
1667         if (ec != boot_ec) {
1668                 ec_remove_handlers(ec);
1669                 acpi_ec_free(ec);
1670         }
1671         return 0;
1672 }
1673
1674 static acpi_status
1675 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1676 {
1677         struct acpi_ec *ec = context;
1678
1679         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1680                 return AE_OK;
1681
1682         /*
1683          * The first address region returned is the data port, and
1684          * the second address region returned is the status/command
1685          * port.
1686          */
1687         if (ec->data_addr == 0)
1688                 ec->data_addr = resource->data.io.minimum;
1689         else if (ec->command_addr == 0)
1690                 ec->command_addr = resource->data.io.minimum;
1691         else
1692                 return AE_CTRL_TERMINATE;
1693
1694         return AE_OK;
1695 }
1696
1697 static const struct acpi_device_id ec_device_ids[] = {
1698         {"PNP0C09", 0},
1699         {ACPI_ECDT_HID, 0},
1700         {"", 0},
1701 };
1702
1703 /*
1704  * This function is not Windows-compatible as Windows never enumerates the
1705  * namespace EC before the main ACPI device enumeration process. It is
1706  * retained for historical reason and will be deprecated in the future.
1707  */
1708 void __init acpi_ec_dsdt_probe(void)
1709 {
1710         struct acpi_ec *ec;
1711         acpi_status status;
1712         int ret;
1713
1714         /*
1715          * If a platform has ECDT, there is no need to proceed as the
1716          * following probe is not a part of the ACPI device enumeration,
1717          * executing _STA is not safe, and thus this probe may risk of
1718          * picking up an invalid EC device.
1719          */
1720         if (boot_ec)
1721                 return;
1722
1723         ec = acpi_ec_alloc();
1724         if (!ec)
1725                 return;
1726
1727         /*
1728          * At this point, the namespace is initialized, so start to find
1729          * the namespace objects.
1730          */
1731         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1732         if (ACPI_FAILURE(status) || !ec->handle) {
1733                 acpi_ec_free(ec);
1734                 return;
1735         }
1736
1737         /*
1738          * When the DSDT EC is available, always re-configure boot EC to
1739          * have _REG evaluated. _REG can only be evaluated after the
1740          * namespace initialization.
1741          * At this point, the GPE is not fully initialized, so do not to
1742          * handle the events.
1743          */
1744         ret = acpi_ec_setup(ec, NULL);
1745         if (ret) {
1746                 acpi_ec_free(ec);
1747                 return;
1748         }
1749
1750         boot_ec = ec;
1751
1752         acpi_handle_info(ec->handle,
1753                          "Boot DSDT EC used to handle transactions\n");
1754 }
1755
1756 /*
1757  * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization.
1758  *
1759  * First, look for an ACPI handle for the boot ECDT EC if acpi_ec_add() has not
1760  * found a matching object in the namespace.
1761  *
1762  * Next, in case the DSDT EC is not functioning, it is still necessary to
1763  * provide a functional ECDT EC to handle events, so add an extra device object
1764  * to represent it (see https://bugzilla.kernel.org/show_bug.cgi?id=115021).
1765  *
1766  * This is useful on platforms with valid ECDT and invalid DSDT EC settings,
1767  * like ASUS X550ZE (see https://bugzilla.kernel.org/show_bug.cgi?id=196847).
1768  */
1769 static void __init acpi_ec_ecdt_start(void)
1770 {
1771         struct acpi_table_ecdt *ecdt_ptr;
1772         acpi_handle handle;
1773         acpi_status status;
1774
1775         /* Bail out if a matching EC has been found in the namespace. */
1776         if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT)
1777                 return;
1778
1779         /* Look up the object pointed to from the ECDT in the namespace. */
1780         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1781                                 (struct acpi_table_header **)&ecdt_ptr);
1782         if (ACPI_FAILURE(status))
1783                 return;
1784
1785         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1786         if (ACPI_FAILURE(status))
1787                 return;
1788
1789         boot_ec->handle = handle;
1790
1791         /* Add a special ACPI device object to represent the boot EC. */
1792         acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1793 }
1794
1795 /*
1796  * On some hardware it is necessary to clear events accumulated by the EC during
1797  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1798  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1799  *
1800  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1801  *
1802  * Ideally, the EC should also be instructed NOT to accumulate events during
1803  * sleep (which Windows seems to do somehow), but the interface to control this
1804  * behaviour is not known at this time.
1805  *
1806  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1807  * however it is very likely that other Samsung models are affected.
1808  *
1809  * On systems which don't accumulate _Q events during sleep, this extra check
1810  * should be harmless.
1811  */
1812 static int ec_clear_on_resume(const struct dmi_system_id *id)
1813 {
1814         pr_debug("Detected system needing EC poll on resume.\n");
1815         EC_FLAGS_CLEAR_ON_RESUME = 1;
1816         ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1817         return 0;
1818 }
1819
1820 /*
1821  * Some ECDTs contain wrong register addresses.
1822  * MSI MS-171F
1823  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1824  */
1825 static int ec_correct_ecdt(const struct dmi_system_id *id)
1826 {
1827         pr_debug("Detected system needing ECDT address correction.\n");
1828         EC_FLAGS_CORRECT_ECDT = 1;
1829         return 0;
1830 }
1831
1832 /*
1833  * Some DSDTs contain wrong GPE setting.
1834  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1835  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1836  */
1837 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1838 {
1839         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1840         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1841         return 0;
1842 }
1843
1844 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1845         {
1846         ec_correct_ecdt, "MSI MS-171F", {
1847         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1848         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1849         {
1850         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1851         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1852         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1853         {
1854         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1855         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1856         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1857         {
1858         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1859         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1860         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1861         {
1862         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1863         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1864         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1865         {
1866         ec_honor_ecdt_gpe, "ASUS X580VD", {
1867         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1868         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1869         {
1870         ec_clear_on_resume, "Samsung hardware", {
1871         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1872         {},
1873 };
1874
1875 void __init acpi_ec_ecdt_probe(void)
1876 {
1877         struct acpi_table_ecdt *ecdt_ptr;
1878         struct acpi_ec *ec;
1879         acpi_status status;
1880         int ret;
1881
1882         /* Generate a boot ec context. */
1883         dmi_check_system(ec_dmi_table);
1884         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1885                                 (struct acpi_table_header **)&ecdt_ptr);
1886         if (ACPI_FAILURE(status))
1887                 return;
1888
1889         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1890                 /*
1891                  * Asus X50GL:
1892                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1893                  */
1894                 return;
1895         }
1896
1897         ec = acpi_ec_alloc();
1898         if (!ec)
1899                 return;
1900
1901         if (EC_FLAGS_CORRECT_ECDT) {
1902                 ec->command_addr = ecdt_ptr->data.address;
1903                 ec->data_addr = ecdt_ptr->control.address;
1904         } else {
1905                 ec->command_addr = ecdt_ptr->control.address;
1906                 ec->data_addr = ecdt_ptr->data.address;
1907         }
1908
1909         /*
1910          * Ignore the GPE value on Reduced Hardware platforms.
1911          * Some products have this set to an erroneous value.
1912          */
1913         if (!acpi_gbl_reduced_hardware)
1914                 ec->gpe = ecdt_ptr->gpe;
1915
1916         ec->handle = ACPI_ROOT_OBJECT;
1917
1918         /*
1919          * At this point, the namespace is not initialized, so do not find
1920          * the namespace objects, or handle the events.
1921          */
1922         ret = acpi_ec_setup(ec, NULL);
1923         if (ret) {
1924                 acpi_ec_free(ec);
1925                 return;
1926         }
1927
1928         boot_ec = ec;
1929         boot_ec_is_ecdt = true;
1930
1931         pr_info("Boot ECDT EC used to handle transactions\n");
1932 }
1933
1934 #ifdef CONFIG_PM_SLEEP
1935 static int acpi_ec_suspend(struct device *dev)
1936 {
1937         struct acpi_ec *ec =
1938                 acpi_driver_data(to_acpi_device(dev));
1939
1940         if (!pm_suspend_no_platform() && ec_freeze_events)
1941                 acpi_ec_disable_event(ec);
1942         return 0;
1943 }
1944
1945 static int acpi_ec_suspend_noirq(struct device *dev)
1946 {
1947         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1948
1949         /*
1950          * The SCI handler doesn't run at this point, so the GPE can be
1951          * masked at the low level without side effects.
1952          */
1953         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1954             ec->gpe >= 0 && ec->reference_count >= 1)
1955                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1956
1957         acpi_ec_enter_noirq(ec);
1958
1959         return 0;
1960 }
1961
1962 static int acpi_ec_resume_noirq(struct device *dev)
1963 {
1964         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1965
1966         acpi_ec_leave_noirq(ec);
1967
1968         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1969             ec->gpe >= 0 && ec->reference_count >= 1)
1970                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1971
1972         return 0;
1973 }
1974
1975 static int acpi_ec_resume(struct device *dev)
1976 {
1977         struct acpi_ec *ec =
1978                 acpi_driver_data(to_acpi_device(dev));
1979
1980         acpi_ec_enable_event(ec);
1981         return 0;
1982 }
1983
1984 void acpi_ec_mark_gpe_for_wake(void)
1985 {
1986         if (first_ec && !ec_no_wakeup)
1987                 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
1988 }
1989 EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
1990
1991 void acpi_ec_set_gpe_wake_mask(u8 action)
1992 {
1993         if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
1994                 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
1995 }
1996
1997 bool acpi_ec_other_gpes_active(void)
1998 {
1999         return acpi_any_gpe_status_set(first_ec ? first_ec->gpe : U32_MAX);
2000 }
2001
2002 bool acpi_ec_dispatch_gpe(void)
2003 {
2004         u32 ret;
2005
2006         if (!first_ec)
2007                 return false;
2008
2009         ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
2010         if (ret == ACPI_INTERRUPT_HANDLED) {
2011                 pm_pr_dbg("EC GPE dispatched\n");
2012                 return true;
2013         }
2014         return false;
2015 }
2016 #endif /* CONFIG_PM_SLEEP */
2017
2018 static const struct dev_pm_ops acpi_ec_pm = {
2019         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2020         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2021 };
2022
2023 static int param_set_event_clearing(const char *val,
2024                                     const struct kernel_param *kp)
2025 {
2026         int result = 0;
2027
2028         if (!strncmp(val, "status", sizeof("status") - 1)) {
2029                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2030                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2031         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2032                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2033                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2034         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2035                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2036                 pr_info("Assuming SCI_EVT clearing on event reads\n");
2037         } else
2038                 result = -EINVAL;
2039         return result;
2040 }
2041
2042 static int param_get_event_clearing(char *buffer,
2043                                     const struct kernel_param *kp)
2044 {
2045         switch (ec_event_clearing) {
2046         case ACPI_EC_EVT_TIMING_STATUS:
2047                 return sprintf(buffer, "status");
2048         case ACPI_EC_EVT_TIMING_QUERY:
2049                 return sprintf(buffer, "query");
2050         case ACPI_EC_EVT_TIMING_EVENT:
2051                 return sprintf(buffer, "event");
2052         default:
2053                 return sprintf(buffer, "invalid");
2054         }
2055         return 0;
2056 }
2057
2058 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2059                   NULL, 0644);
2060 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2061
2062 static struct acpi_driver acpi_ec_driver = {
2063         .name = "ec",
2064         .class = ACPI_EC_CLASS,
2065         .ids = ec_device_ids,
2066         .ops = {
2067                 .add = acpi_ec_add,
2068                 .remove = acpi_ec_remove,
2069                 },
2070         .drv.pm = &acpi_ec_pm,
2071 };
2072
2073 static void acpi_ec_destroy_workqueues(void)
2074 {
2075         if (ec_wq) {
2076                 destroy_workqueue(ec_wq);
2077                 ec_wq = NULL;
2078         }
2079         if (ec_query_wq) {
2080                 destroy_workqueue(ec_query_wq);
2081                 ec_query_wq = NULL;
2082         }
2083 }
2084
2085 static int acpi_ec_init_workqueues(void)
2086 {
2087         if (!ec_wq)
2088                 ec_wq = alloc_ordered_workqueue("kec", 0);
2089
2090         if (!ec_query_wq)
2091                 ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2092
2093         if (!ec_wq || !ec_query_wq) {
2094                 acpi_ec_destroy_workqueues();
2095                 return -ENODEV;
2096         }
2097         return 0;
2098 }
2099
2100 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2101         {
2102                 .ident = "Thinkpad X1 Carbon 6th",
2103                 .matches = {
2104                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2105                         DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2106                 },
2107         },
2108         {
2109                 .ident = "ThinkPad X1 Carbon 6th",
2110                 .matches = {
2111                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2112                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2113                 },
2114         },
2115         {
2116                 .ident = "ThinkPad X1 Yoga 3rd",
2117                 .matches = {
2118                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2119                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2120                 },
2121         },
2122         { },
2123 };
2124
2125 void __init acpi_ec_init(void)
2126 {
2127         int result;
2128
2129         result = acpi_ec_init_workqueues();
2130         if (result)
2131                 return;
2132
2133         /*
2134          * Disable EC wakeup on following systems to prevent periodic
2135          * wakeup from EC GPE.
2136          */
2137         if (dmi_check_system(acpi_ec_no_wakeup)) {
2138                 ec_no_wakeup = true;
2139                 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2140         }
2141
2142         /* Driver must be registered after acpi_ec_init_workqueues(). */
2143         acpi_bus_register_driver(&acpi_ec_driver);
2144
2145         acpi_ec_ecdt_start();
2146 }
2147
2148 /* EC driver currently not unloadable */
2149 #if 0
2150 static void __exit acpi_ec_exit(void)
2151 {
2152
2153         acpi_bus_unregister_driver(&acpi_ec_driver);
2154         acpi_ec_destroy_workqueues();
2155 }
2156 #endif  /* 0 */