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 void __acpi_ec_flush_work(void)
 537 {
 538         flush_scheduled_work(); /* 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_query_wq there is nothing to flush. */
 560         if (!ec_query_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 {
 693                 if (EC_FLAGS_QUERY_HANDSHAKE &&
 694                     !(status & ACPI_EC_FLAG_SCI) &&
 695                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 696                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 697                         t->rdata[t->ri++] = 0x00;
 698                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 699                         ec_dbg_evt("Command(%s) completed by software",
 700                                    acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 701                         wakeup = true;
 702                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 703                         acpi_ec_write_cmd(ec, t->command);
 704                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 705                 } else
 706                         goto err;
 707                 goto out;
 708         }
 709 err:
 710         /*
 711          * If SCI bit is set, then don't think it's a false IRQ
 712          * otherwise will take a not handled IRQ as a false one.
 713          */
 714         if (!(status & ACPI_EC_FLAG_SCI)) {
 715                 if (in_interrupt() && t) {
 716                         if (t->irq_count < ec_storm_threshold)
 717                                 ++t->irq_count;
 718                         /* Allow triggering on 0 threshold */
 719                         if (t->irq_count == ec_storm_threshold)
 720                                 acpi_ec_mask_events(ec);
 721                 }
 722         }
 723 out:
 724         if (status & ACPI_EC_FLAG_SCI)
 725                 acpi_ec_submit_query(ec);
 726         if (wakeup && in_interrupt())
 727                 wake_up(&ec->wait);
 728 }
 729
 730 static void start_transaction(struct acpi_ec *ec)
 731 {
 732         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 733         ec->curr->flags = 0;
 734 }
 735
 736 static int ec_guard(struct acpi_ec *ec)
 737 {
 738         unsigned long guard = usecs_to_jiffies(ec->polling_guard);
 739         unsigned long timeout = ec->timestamp + guard;
 740
 741         /* Ensure guarding period before polling EC status */
 742         do {
 743                 if (ec->busy_polling) {
 744                         /* Perform busy polling */
 745                         if (ec_transaction_completed(ec))
 746                                 return 0;
 747                         udelay(jiffies_to_usecs(guard));
 748                 } else {
 749                         /*
 750                          * Perform wait polling
 751                          * 1. Wait the transaction to be completed by the
 752                          *    GPE handler after the transaction enters
 753                          *    ACPI_EC_COMMAND_POLL state.
 754                          * 2. A special guarding logic is also required
 755                          *    for event clearing mode "event" before the
 756                          *    transaction enters ACPI_EC_COMMAND_POLL
 757                          *    state.
 758                          */
 759                         if (!ec_transaction_polled(ec) &&
 760                             !acpi_ec_guard_event(ec))
 761                                 break;
 762                         if (wait_event_timeout(ec->wait,
 763                                                ec_transaction_completed(ec),
 764                                                guard))
 765                                 return 0;
 766                 }
 767         } while (time_before(jiffies, timeout));
 768         return -ETIME;
 769 }
 770
 771 static int ec_poll(struct acpi_ec *ec)
 772 {
 773         unsigned long flags;
 774         int repeat = 5; /* number of command restarts */
 775
 776         while (repeat--) {
 777                 unsigned long delay = jiffies +
 778                         msecs_to_jiffies(ec_delay);
 779                 do {
 780                         if (!ec_guard(ec))
 781                                 return 0;
 782                         spin_lock_irqsave(&ec->lock, flags);
 783                         advance_transaction(ec);
 784                         spin_unlock_irqrestore(&ec->lock, flags);
 785                 } while (time_before(jiffies, delay));
 786                 pr_debug("controller reset, restart transaction\n");
 787                 spin_lock_irqsave(&ec->lock, flags);
 788                 start_transaction(ec);
 789                 spin_unlock_irqrestore(&ec->lock, flags);
 790         }
 791         return -ETIME;
 792 }
 793
 794 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 795                                         struct transaction *t)
 796 {
 797         unsigned long tmp;
 798         int ret = 0;
 799
 800         /* start transaction */
 801         spin_lock_irqsave(&ec->lock, tmp);
 802         /* Enable GPE for command processing (IBF=0/OBF=1) */
 803         if (!acpi_ec_submit_flushable_request(ec)) {
 804                 ret = -EINVAL;
 805                 goto unlock;
 806         }
 807         ec_dbg_ref(ec, "Increase command");
 808         /* following two actions should be kept atomic */
 809         ec->curr = t;
 810         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 811         start_transaction(ec);
 812         spin_unlock_irqrestore(&ec->lock, tmp);
 813
 814         ret = ec_poll(ec);
 815
 816         spin_lock_irqsave(&ec->lock, tmp);
 817         if (t->irq_count == ec_storm_threshold)
 818                 acpi_ec_unmask_events(ec);
 819         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 820         ec->curr = NULL;
 821         /* Disable GPE for command processing (IBF=0/OBF=1) */
 822         acpi_ec_complete_request(ec);
 823         ec_dbg_ref(ec, "Decrease command");
 824 unlock:
 825         spin_unlock_irqrestore(&ec->lock, tmp);
 826         return ret;
 827 }
 828
 829 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 830 {
 831         int status;
 832         u32 glk;
 833
 834         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 835                 return -EINVAL;
 836         if (t->rdata)
 837                 memset(t->rdata, 0, t->rlen);
 838
 839         mutex_lock(&ec->mutex);
 840         if (ec->global_lock) {
 841                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 842                 if (ACPI_FAILURE(status)) {
 843                         status = -ENODEV;
 844                         goto unlock;
 845                 }
 846         }
 847
 848         status = acpi_ec_transaction_unlocked(ec, t);
 849
 850         if (ec->global_lock)
 851                 acpi_release_global_lock(glk);
 852 unlock:
 853         mutex_unlock(&ec->mutex);
 854         return status;
 855 }
 856
 857 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 858 {
 859         u8 d;
 860         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 861                                 .wdata = NULL, .rdata = &d,
 862                                 .wlen = 0, .rlen = 1};
 863
 864         return acpi_ec_transaction(ec, &t);
 865 }
 866
 867 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 868 {
 869         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 870                                 .wdata = NULL, .rdata = NULL,
 871                                 .wlen = 0, .rlen = 0};
 872
 873         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 874                                 acpi_ec_transaction(ec, &t) : 0;
 875 }
 876
 877 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 878 {
 879         int result;
 880         u8 d;
 881         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 882                                 .wdata = &address, .rdata = &d,
 883                                 .wlen = 1, .rlen = 1};
 884
 885         result = acpi_ec_transaction(ec, &t);
 886         *data = d;
 887         return result;
 888 }
 889
 890 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 891 {
 892         u8 wdata[2] = { address, data };
 893         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 894                                 .wdata = wdata, .rdata = NULL,
 895                                 .wlen = 2, .rlen = 0};
 896
 897         return acpi_ec_transaction(ec, &t);
 898 }
 899
 900 int ec_read(u8 addr, u8 *val)
 901 {
 902         int err;
 903         u8 temp_data;
 904
 905         if (!first_ec)
 906                 return -ENODEV;
 907
 908         err = acpi_ec_read(first_ec, addr, &temp_data);
 909
 910         if (!err) {
 911                 *val = temp_data;
 912                 return 0;
 913         }
 914         return err;
 915 }
 916 EXPORT_SYMBOL(ec_read);
 917
 918 int ec_write(u8 addr, u8 val)
 919 {
 920         int err;
 921
 922         if (!first_ec)
 923                 return -ENODEV;
 924
 925         err = acpi_ec_write(first_ec, addr, val);
 926
 927         return err;
 928 }
 929 EXPORT_SYMBOL(ec_write);
 930
 931 int ec_transaction(u8 command,
 932                    const u8 *wdata, unsigned wdata_len,
 933                    u8 *rdata, unsigned rdata_len)
 934 {
 935         struct transaction t = {.command = command,
 936                                 .wdata = wdata, .rdata = rdata,
 937                                 .wlen = wdata_len, .rlen = rdata_len};
 938
 939         if (!first_ec)
 940                 return -ENODEV;
 941
 942         return acpi_ec_transaction(first_ec, &t);
 943 }
 944 EXPORT_SYMBOL(ec_transaction);
 945
 946 /* Get the handle to the EC device */
 947 acpi_handle ec_get_handle(void)
 948 {
 949         if (!first_ec)
 950                 return NULL;
 951         return first_ec->handle;
 952 }
 953 EXPORT_SYMBOL(ec_get_handle);
 954
 955 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 956 {
 957         unsigned long flags;
 958
 959         spin_lock_irqsave(&ec->lock, flags);
 960         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 961                 ec_dbg_drv("Starting EC");
 962                 /* Enable GPE for event processing (SCI_EVT=1) */
 963                 if (!resuming) {
 964                         acpi_ec_submit_request(ec);
 965                         ec_dbg_ref(ec, "Increase driver");
 966                 }
 967                 ec_log_drv("EC started");
 968         }
 969         spin_unlock_irqrestore(&ec->lock, flags);
 970 }
 971
 972 static bool acpi_ec_stopped(struct acpi_ec *ec)
 973 {
 974         unsigned long flags;
 975         bool flushed;
 976
 977         spin_lock_irqsave(&ec->lock, flags);
 978         flushed = acpi_ec_flushed(ec);
 979         spin_unlock_irqrestore(&ec->lock, flags);
 980         return flushed;
 981 }
 982
 983 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 984 {
 985         unsigned long flags;
 986
 987         spin_lock_irqsave(&ec->lock, flags);
 988         if (acpi_ec_started(ec)) {
 989                 ec_dbg_drv("Stopping EC");
 990                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
 991                 spin_unlock_irqrestore(&ec->lock, flags);
 992                 wait_event(ec->wait, acpi_ec_stopped(ec));
 993                 spin_lock_irqsave(&ec->lock, flags);
 994                 /* Disable GPE for event processing (SCI_EVT=1) */
 995                 if (!suspending) {
 996                         acpi_ec_complete_request(ec);
 997                         ec_dbg_ref(ec, "Decrease driver");
 998                 } else if (!ec_freeze_events)
 999                         __acpi_ec_disable_event(ec);
1000                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
1001                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
1002                 ec_log_drv("EC stopped");
1003         }
1004         spin_unlock_irqrestore(&ec->lock, flags);
1005 }
1006
1007 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
1008 {
1009         unsigned long flags;
1010
1011         spin_lock_irqsave(&ec->lock, flags);
1012         ec->busy_polling = true;
1013         ec->polling_guard = 0;
1014         ec_log_drv("interrupt blocked");
1015         spin_unlock_irqrestore(&ec->lock, flags);
1016 }
1017
1018 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1019 {
1020         unsigned long flags;
1021
1022         spin_lock_irqsave(&ec->lock, flags);
1023         ec->busy_polling = ec_busy_polling;
1024         ec->polling_guard = ec_polling_guard;
1025         ec_log_drv("interrupt unblocked");
1026         spin_unlock_irqrestore(&ec->lock, flags);
1027 }
1028
1029 void acpi_ec_block_transactions(void)
1030 {
1031         struct acpi_ec *ec = first_ec;
1032
1033         if (!ec)
1034                 return;
1035
1036         mutex_lock(&ec->mutex);
1037         /* Prevent transactions from being carried out */
1038         acpi_ec_stop(ec, true);
1039         mutex_unlock(&ec->mutex);
1040 }
1041
1042 void acpi_ec_unblock_transactions(void)
1043 {
1044         /*
1045          * Allow transactions to happen again (this function is called from
1046          * atomic context during wakeup, so we don't need to acquire the mutex).
1047          */
1048         if (first_ec)
1049                 acpi_ec_start(first_ec, true);
1050 }
1051
1052 /* --------------------------------------------------------------------------
1053                                 Event Management
1054    -------------------------------------------------------------------------- */
1055 static struct acpi_ec_query_handler *
1056 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
1057 {
1058         if (handler)
1059                 kref_get(&handler->kref);
1060         return handler;
1061 }
1062
1063 static struct acpi_ec_query_handler *
1064 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1065 {
1066         struct acpi_ec_query_handler *handler;
1067         bool found = false;
1068
1069         mutex_lock(&ec->mutex);
1070         list_for_each_entry(handler, &ec->list, node) {
1071                 if (value == handler->query_bit) {
1072                         found = true;
1073                         break;
1074                 }
1075         }
1076         mutex_unlock(&ec->mutex);
1077         return found ? acpi_ec_get_query_handler(handler) : NULL;
1078 }
1079
1080 static void acpi_ec_query_handler_release(struct kref *kref)
1081 {
1082         struct acpi_ec_query_handler *handler =
1083                 container_of(kref, struct acpi_ec_query_handler, kref);
1084
1085         kfree(handler);
1086 }
1087
1088 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1089 {
1090         kref_put(&handler->kref, acpi_ec_query_handler_release);
1091 }
1092
1093 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1094                               acpi_handle handle, acpi_ec_query_func func,
1095                               void *data)
1096 {
1097         struct acpi_ec_query_handler *handler =
1098             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1099
1100         if (!handler)
1101                 return -ENOMEM;
1102
1103         handler->query_bit = query_bit;
1104         handler->handle = handle;
1105         handler->func = func;
1106         handler->data = data;
1107         mutex_lock(&ec->mutex);
1108         kref_init(&handler->kref);
1109         list_add(&handler->node, &ec->list);
1110         mutex_unlock(&ec->mutex);
1111         return 0;
1112 }
1113 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1114
1115 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1116                                           bool remove_all, u8 query_bit)
1117 {
1118         struct acpi_ec_query_handler *handler, *tmp;
1119         LIST_HEAD(free_list);
1120
1121         mutex_lock(&ec->mutex);
1122         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1123                 if (remove_all || query_bit == handler->query_bit) {
1124                         list_del_init(&handler->node);
1125                         list_add(&handler->node, &free_list);
1126                 }
1127         }
1128         mutex_unlock(&ec->mutex);
1129         list_for_each_entry_safe(handler, tmp, &free_list, node)
1130                 acpi_ec_put_query_handler(handler);
1131 }
1132
1133 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1134 {
1135         acpi_ec_remove_query_handlers(ec, false, query_bit);
1136 }
1137 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1138
1139 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1140 {
1141         struct acpi_ec_query *q;
1142         struct transaction *t;
1143
1144         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1145         if (!q)
1146                 return NULL;
1147         INIT_WORK(&q->work, acpi_ec_event_processor);
1148         t = &q->transaction;
1149         t->command = ACPI_EC_COMMAND_QUERY;
1150         t->rdata = pval;
1151         t->rlen = 1;
1152         return q;
1153 }
1154
1155 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1156 {
1157         if (q) {
1158                 if (q->handler)
1159                         acpi_ec_put_query_handler(q->handler);
1160                 kfree(q);
1161         }
1162 }
1163
1164 static void acpi_ec_event_processor(struct work_struct *work)
1165 {
1166         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1167         struct acpi_ec_query_handler *handler = q->handler;
1168
1169         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1170         if (handler->func)
1171                 handler->func(handler->data);
1172         else if (handler->handle)
1173                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1174         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1175         acpi_ec_delete_query(q);
1176 }
1177
1178 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1179 {
1180         u8 value = 0;
1181         int result;
1182         struct acpi_ec_query *q;
1183
1184         q = acpi_ec_create_query(&value);
1185         if (!q)
1186                 return -ENOMEM;
1187
1188         /*
1189          * Query the EC to find out which _Qxx method we need to evaluate.
1190          * Note that successful completion of the query causes the ACPI_EC_SCI
1191          * bit to be cleared (and thus clearing the interrupt source).
1192          */
1193         result = acpi_ec_transaction(ec, &q->transaction);
1194         if (!value)
1195                 result = -ENODATA;
1196         if (result)
1197                 goto err_exit;
1198
1199         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1200         if (!q->handler) {
1201                 result = -ENODATA;
1202                 goto err_exit;
1203         }
1204
1205         /*
1206          * It is reported that _Qxx are evaluated in a parallel way on
1207          * Windows:
1208          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1209          *
1210          * Put this log entry before schedule_work() in order to make
1211          * it appearing before any other log entries occurred during the
1212          * work queue execution.
1213          */
1214         ec_dbg_evt("Query(0x%02x) scheduled", value);
1215         if (!queue_work(ec_query_wq, &q->work)) {
1216                 ec_dbg_evt("Query(0x%02x) overlapped", value);
1217                 result = -EBUSY;
1218         }
1219
1220 err_exit:
1221         if (result)
1222                 acpi_ec_delete_query(q);
1223         if (data)
1224                 *data = value;
1225         return result;
1226 }
1227
1228 static void acpi_ec_check_event(struct acpi_ec *ec)
1229 {
1230         unsigned long flags;
1231
1232         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1233                 if (ec_guard(ec)) {
1234                         spin_lock_irqsave(&ec->lock, flags);
1235                         /*
1236                          * Take care of the SCI_EVT unless no one else is
1237                          * taking care of it.
1238                          */
1239                         if (!ec->curr)
1240                                 advance_transaction(ec);
1241                         spin_unlock_irqrestore(&ec->lock, flags);
1242                 }
1243         }
1244 }
1245
1246 static void acpi_ec_event_handler(struct work_struct *work)
1247 {
1248         unsigned long flags;
1249         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1250
1251         ec_dbg_evt("Event started");
1252
1253         spin_lock_irqsave(&ec->lock, flags);
1254         while (ec->nr_pending_queries) {
1255                 spin_unlock_irqrestore(&ec->lock, flags);
1256                 (void)acpi_ec_query(ec, NULL);
1257                 spin_lock_irqsave(&ec->lock, flags);
1258                 ec->nr_pending_queries--;
1259                 /*
1260                  * Before exit, make sure that this work item can be
1261                  * scheduled again. There might be QR_EC failures, leaving
1262                  * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1263                  * item from being scheduled again.
1264                  */
1265                 if (!ec->nr_pending_queries) {
1266                         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1267                             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1268                                 acpi_ec_complete_query(ec);
1269                 }
1270         }
1271         spin_unlock_irqrestore(&ec->lock, flags);
1272
1273         ec_dbg_evt("Event stopped");
1274
1275         acpi_ec_check_event(ec);
1276 }
1277
1278 static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1279 {
1280         unsigned long flags;
1281
1282         spin_lock_irqsave(&ec->lock, flags);
1283         advance_transaction(ec);
1284         spin_unlock_irqrestore(&ec->lock, flags);
1285 }
1286
1287 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1288                                u32 gpe_number, void *data)
1289 {
1290         acpi_ec_handle_interrupt(data);
1291         return ACPI_INTERRUPT_HANDLED;
1292 }
1293
1294 static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1295 {
1296         acpi_ec_handle_interrupt(data);
1297         return IRQ_HANDLED;
1298 }
1299
1300 /* --------------------------------------------------------------------------
1301  *                           Address Space Management
1302  * -------------------------------------------------------------------------- */
1303
1304 static acpi_status
1305 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1306                       u32 bits, u64 *value64,
1307                       void *handler_context, void *region_context)
1308 {
1309         struct acpi_ec *ec = handler_context;
1310         int result = 0, i, bytes = bits / 8;
1311         u8 *value = (u8 *)value64;
1312
1313         if ((address > 0xFF) || !value || !handler_context)
1314                 return AE_BAD_PARAMETER;
1315
1316         if (function != ACPI_READ && function != ACPI_WRITE)
1317                 return AE_BAD_PARAMETER;
1318
1319         if (ec->busy_polling || bits > 8)
1320                 acpi_ec_burst_enable(ec);
1321
1322         for (i = 0; i < bytes; ++i, ++address, ++value)
1323                 result = (function == ACPI_READ) ?
1324                         acpi_ec_read(ec, address, value) :
1325                         acpi_ec_write(ec, address, *value);
1326
1327         if (ec->busy_polling || bits > 8)
1328                 acpi_ec_burst_disable(ec);
1329
1330         switch (result) {
1331         case -EINVAL:
1332                 return AE_BAD_PARAMETER;
1333         case -ENODEV:
1334                 return AE_NOT_FOUND;
1335         case -ETIME:
1336                 return AE_TIME;
1337         default:
1338                 return AE_OK;
1339         }
1340 }
1341
1342 /* --------------------------------------------------------------------------
1343  *                             Driver Interface
1344  * -------------------------------------------------------------------------- */
1345
1346 static acpi_status
1347 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1348
1349 static void acpi_ec_free(struct acpi_ec *ec)
1350 {
1351         if (first_ec == ec)
1352                 first_ec = NULL;
1353         if (boot_ec == ec)
1354                 boot_ec = NULL;
1355         kfree(ec);
1356 }
1357
1358 static struct acpi_ec *acpi_ec_alloc(void)
1359 {
1360         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1361
1362         if (!ec)
1363                 return NULL;
1364         mutex_init(&ec->mutex);
1365         init_waitqueue_head(&ec->wait);
1366         INIT_LIST_HEAD(&ec->list);
1367         spin_lock_init(&ec->lock);
1368         INIT_WORK(&ec->work, acpi_ec_event_handler);
1369         ec->timestamp = jiffies;
1370         ec->busy_polling = true;
1371         ec->polling_guard = 0;
1372         ec->gpe = -1;
1373         ec->irq = -1;
1374         return ec;
1375 }
1376
1377 static acpi_status
1378 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1379                                void *context, void **return_value)
1380 {
1381         char node_name[5];
1382         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1383         struct acpi_ec *ec = context;
1384         int value = 0;
1385         acpi_status status;
1386
1387         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1388
1389         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1390                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1391         return AE_OK;
1392 }
1393
1394 static acpi_status
1395 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1396 {
1397         acpi_status status;
1398         unsigned long long tmp = 0;
1399         struct acpi_ec *ec = context;
1400
1401         /* clear addr values, ec_parse_io_ports depend on it */
1402         ec->command_addr = ec->data_addr = 0;
1403
1404         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1405                                      ec_parse_io_ports, ec);
1406         if (ACPI_FAILURE(status))
1407                 return status;
1408         if (ec->data_addr == 0 || ec->command_addr == 0)
1409                 return AE_OK;
1410
1411         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1412                 /*
1413                  * Always inherit the GPE number setting from the ECDT
1414                  * EC.
1415                  */
1416                 ec->gpe = boot_ec->gpe;
1417         } else {
1418                 /* Get GPE bit assignment (EC events). */
1419                 /* TODO: Add support for _GPE returning a package */
1420                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1421                 if (ACPI_SUCCESS(status))
1422                         ec->gpe = tmp;
1423
1424                 /*
1425                  * Errors are non-fatal, allowing for ACPI Reduced Hardware
1426                  * platforms which use GpioInt instead of GPE.
1427                  */
1428         }
1429         /* Use the global lock for all EC transactions? */
1430         tmp = 0;
1431         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1432         ec->global_lock = tmp;
1433         ec->handle = handle;
1434         return AE_CTRL_TERMINATE;
1435 }
1436
1437 static void install_gpe_event_handler(struct acpi_ec *ec)
1438 {
1439         acpi_status status =
1440                 acpi_install_gpe_raw_handler(NULL, ec->gpe,
1441                                              ACPI_GPE_EDGE_TRIGGERED,
1442                                              &acpi_ec_gpe_handler,
1443                                              ec);
1444         if (ACPI_SUCCESS(status)) {
1445                 /* This is not fatal as we can poll EC events */
1446                 set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1447                 acpi_ec_leave_noirq(ec);
1448                 if (test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1449                     ec->reference_count >= 1)
1450                         acpi_ec_enable_gpe(ec, true);
1451         }
1452 }
1453
1454 /* ACPI reduced hardware platforms use a GpioInt specified in _CRS. */
1455 static int install_gpio_irq_event_handler(struct acpi_ec *ec,
1456                                           struct acpi_device *device)
1457 {
1458         int irq = acpi_dev_gpio_irq_get(device, 0);
1459         int ret;
1460
1461         if (irq < 0)
1462                 return irq;
1463
1464         ret = request_irq(irq, acpi_ec_irq_handler, IRQF_SHARED,
1465                           "ACPI EC", ec);
1466
1467         /*
1468          * Unlike the GPE case, we treat errors here as fatal, we'll only
1469          * implement GPIO polling if we find a case that needs it.
1470          */
1471         if (ret < 0)
1472                 return ret;
1473
1474         ec->irq = irq;
1475         set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1476         acpi_ec_leave_noirq(ec);
1477
1478         return 0;
1479 }
1480
1481 /*
1482  * Note: This function returns an error code only when the address space
1483  *       handler is not installed, which means "not able to handle
1484  *       transactions".
1485  */
1486 static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device,
1487                                bool handle_events)
1488 {
1489         acpi_status status;
1490
1491         acpi_ec_start(ec, false);
1492
1493         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1494                 acpi_ec_enter_noirq(ec);
1495                 status = acpi_install_address_space_handler(ec->handle,
1496                                                             ACPI_ADR_SPACE_EC,
1497                                                             &acpi_ec_space_handler,
1498                                                             NULL, ec);
1499                 if (ACPI_FAILURE(status)) {
1500                         if (status == AE_NOT_FOUND) {
1501                                 /*
1502                                  * Maybe OS fails in evaluating the _REG
1503                                  * object. The AE_NOT_FOUND error will be
1504                                  * ignored and OS * continue to initialize
1505                                  * EC.
1506                                  */
1507                                 pr_err("Fail in evaluating the _REG object"
1508                                         " of EC device. Broken bios is suspected.\n");
1509                         } else {
1510                                 acpi_ec_stop(ec, false);
1511                                 return -ENODEV;
1512                         }
1513                 }
1514                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1515         }
1516
1517         if (!handle_events)
1518                 return 0;
1519
1520         if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1521                 /* Find and register all query methods */
1522                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1523                                     acpi_ec_register_query_methods,
1524                                     NULL, ec, NULL);
1525                 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1526         }
1527         if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1528                 if (ec->gpe >= 0) {
1529                         install_gpe_event_handler(ec);
1530                 } else if (device) {
1531                         int ret = install_gpio_irq_event_handler(ec, device);
1532
1533                         if (ret)
1534                                 return ret;
1535                 } else { /* No GPE and no GpioInt? */
1536                         return -ENODEV;
1537                 }
1538         }
1539         /* EC is fully operational, allow queries */
1540         acpi_ec_enable_event(ec);
1541
1542         return 0;
1543 }
1544
1545 static void ec_remove_handlers(struct acpi_ec *ec)
1546 {
1547         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1548                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1549                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1550                         pr_err("failed to remove space handler\n");
1551                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1552         }
1553
1554         /*
1555          * Stops handling the EC transactions after removing the operation
1556          * region handler. This is required because _REG(DISCONNECT)
1557          * invoked during the removal can result in new EC transactions.
1558          *
1559          * Flushes the EC requests and thus disables the GPE before
1560          * removing the GPE handler. This is required by the current ACPICA
1561          * GPE core. ACPICA GPE core will automatically disable a GPE when
1562          * it is indicated but there is no way to handle it. So the drivers
1563          * must disable the GPEs prior to removing the GPE handlers.
1564          */
1565         acpi_ec_stop(ec, false);
1566
1567         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1568                 if (ec->gpe >= 0 &&
1569                     ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1570                                  &acpi_ec_gpe_handler)))
1571                         pr_err("failed to remove gpe handler\n");
1572
1573                 if (ec->irq >= 0)
1574                         free_irq(ec->irq, ec);
1575
1576                 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1577         }
1578         if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1579                 acpi_ec_remove_query_handlers(ec, true, 0);
1580                 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1581         }
1582 }
1583
1584 static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device,
1585                          bool handle_events)
1586 {
1587         int ret;
1588
1589         ret = ec_install_handlers(ec, device, handle_events);
1590         if (ret)
1591                 return ret;
1592
1593         /* First EC capable of handling transactions */
1594         if (!first_ec) {
1595                 first_ec = ec;
1596                 acpi_handle_info(first_ec->handle, "Used as first EC\n");
1597         }
1598
1599         acpi_handle_info(ec->handle,
1600                          "GPE=0x%x, IRQ=%d, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n",
1601                          ec->gpe, ec->irq, ec->command_addr, ec->data_addr);
1602         return ret;
1603 }
1604
1605 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)
1606 {
1607         struct acpi_table_ecdt *ecdt_ptr;
1608         acpi_status status;
1609         acpi_handle handle;
1610
1611         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1612                                 (struct acpi_table_header **)&ecdt_ptr);
1613         if (ACPI_FAILURE(status))
1614                 return false;
1615
1616         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1617         if (ACPI_FAILURE(status))
1618                 return false;
1619
1620         *phandle = handle;
1621         return true;
1622 }
1623
1624 static int acpi_ec_add(struct acpi_device *device)
1625 {
1626         struct acpi_ec *ec = NULL;
1627         bool dep_update = true;
1628         acpi_status status;
1629         int ret;
1630
1631         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1632         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1633
1634         if (!strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) {
1635                 boot_ec_is_ecdt = true;
1636                 ec = boot_ec;
1637                 dep_update = false;
1638         } else {
1639                 ec = acpi_ec_alloc();
1640                 if (!ec)
1641                         return -ENOMEM;
1642
1643                 status = ec_parse_device(device->handle, 0, ec, NULL);
1644                 if (status != AE_CTRL_TERMINATE) {
1645                         ret = -EINVAL;
1646                         goto err_alloc;
1647                 }
1648
1649                 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1650                     ec->data_addr == boot_ec->data_addr) {
1651                         boot_ec_is_ecdt = false;
1652                         /*
1653                          * Trust PNP0C09 namespace location rather than
1654                          * ECDT ID. But trust ECDT GPE rather than _GPE
1655                          * because of ASUS quirks, so do not change
1656                          * boot_ec->gpe to ec->gpe.
1657                          */
1658                         boot_ec->handle = ec->handle;
1659                         acpi_handle_debug(ec->handle, "duplicated.\n");
1660                         acpi_ec_free(ec);
1661                         ec = boot_ec;
1662                 }
1663         }
1664
1665         ret = acpi_ec_setup(ec, device, true);
1666         if (ret)
1667                 goto err_query;
1668
1669         if (ec == boot_ec)
1670                 acpi_handle_info(boot_ec->handle,
1671                                  "Boot %s EC used to handle transactions and events\n",
1672                                  boot_ec_is_ecdt ? "ECDT" : "DSDT");
1673
1674         device->driver_data = ec;
1675
1676         ret = !!request_region(ec->data_addr, 1, "EC data");
1677         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1678         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1679         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1680
1681         if (dep_update) {
1682                 /* Reprobe devices depending on the EC */
1683                 acpi_walk_dep_device_list(ec->handle);
1684         }
1685         acpi_handle_debug(ec->handle, "enumerated.\n");
1686         return 0;
1687
1688 err_query:
1689         if (ec != boot_ec)
1690                 acpi_ec_remove_query_handlers(ec, true, 0);
1691 err_alloc:
1692         if (ec != boot_ec)
1693                 acpi_ec_free(ec);
1694         return ret;
1695 }
1696
1697 static int acpi_ec_remove(struct acpi_device *device)
1698 {
1699         struct acpi_ec *ec;
1700
1701         if (!device)
1702                 return -EINVAL;
1703
1704         ec = acpi_driver_data(device);
1705         release_region(ec->data_addr, 1);
1706         release_region(ec->command_addr, 1);
1707         device->driver_data = NULL;
1708         if (ec != boot_ec) {
1709                 ec_remove_handlers(ec);
1710                 acpi_ec_free(ec);
1711         }
1712         return 0;
1713 }
1714
1715 static acpi_status
1716 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1717 {
1718         struct acpi_ec *ec = context;
1719
1720         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1721                 return AE_OK;
1722
1723         /*
1724          * The first address region returned is the data port, and
1725          * the second address region returned is the status/command
1726          * port.
1727          */
1728         if (ec->data_addr == 0)
1729                 ec->data_addr = resource->data.io.minimum;
1730         else if (ec->command_addr == 0)
1731                 ec->command_addr = resource->data.io.minimum;
1732         else
1733                 return AE_CTRL_TERMINATE;
1734
1735         return AE_OK;
1736 }
1737
1738 static const struct acpi_device_id ec_device_ids[] = {
1739         {"PNP0C09", 0},
1740         {ACPI_ECDT_HID, 0},
1741         {"", 0},
1742 };
1743
1744 /*
1745  * This function is not Windows-compatible as Windows never enumerates the
1746  * namespace EC before the main ACPI device enumeration process. It is
1747  * retained for historical reason and will be deprecated in the future.
1748  */
1749 void __init acpi_ec_dsdt_probe(void)
1750 {
1751         struct acpi_ec *ec;
1752         acpi_status status;
1753         int ret;
1754
1755         /*
1756          * If a platform has ECDT, there is no need to proceed as the
1757          * following probe is not a part of the ACPI device enumeration,
1758          * executing _STA is not safe, and thus this probe may risk of
1759          * picking up an invalid EC device.
1760          */
1761         if (boot_ec)
1762                 return;
1763
1764         ec = acpi_ec_alloc();
1765         if (!ec)
1766                 return;
1767
1768         /*
1769          * At this point, the namespace is initialized, so start to find
1770          * the namespace objects.
1771          */
1772         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1773         if (ACPI_FAILURE(status) || !ec->handle) {
1774                 acpi_ec_free(ec);
1775                 return;
1776         }
1777
1778         /*
1779          * When the DSDT EC is available, always re-configure boot EC to
1780          * have _REG evaluated. _REG can only be evaluated after the
1781          * namespace initialization.
1782          * At this point, the GPE is not fully initialized, so do not to
1783          * handle the events.
1784          */
1785         ret = acpi_ec_setup(ec, NULL, false);
1786         if (ret) {
1787                 acpi_ec_free(ec);
1788                 return;
1789         }
1790
1791         boot_ec = ec;
1792
1793         acpi_handle_info(ec->handle,
1794                          "Boot DSDT EC used to handle transactions\n");
1795 }
1796
1797 /*
1798  * If the DSDT EC is not functioning, we still need to prepare a fully
1799  * functioning ECDT EC first in order to handle the events.
1800  * https://bugzilla.kernel.org/show_bug.cgi?id=115021
1801  */
1802 static int __init acpi_ec_ecdt_start(void)
1803 {
1804         acpi_handle handle;
1805
1806         if (!boot_ec)
1807                 return -ENODEV;
1808         /* In case acpi_ec_ecdt_start() is called after acpi_ec_add() */
1809         if (!boot_ec_is_ecdt)
1810                 return -ENODEV;
1811
1812         /*
1813          * At this point, the namespace and the GPE is initialized, so
1814          * start to find the namespace objects and handle the events.
1815          *
1816          * Note: ec->handle can be valid if this function is called after
1817          * acpi_ec_add(), hence the fast path.
1818          */
1819         if (boot_ec->handle == ACPI_ROOT_OBJECT) {
1820                 if (!acpi_ec_ecdt_get_handle(&handle))
1821                         return -ENODEV;
1822                 boot_ec->handle = handle;
1823         }
1824
1825         /* Register to ACPI bus with PM ops attached */
1826         return acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1827 }
1828
1829 #if 0
1830 /*
1831  * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1832  * set, for which case, we complete the QR_EC without issuing it to the
1833  * firmware.
1834  * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1835  * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1836  */
1837 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1838 {
1839         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1840         EC_FLAGS_QUERY_HANDSHAKE = 1;
1841         return 0;
1842 }
1843 #endif
1844
1845 /*
1846  * On some hardware it is necessary to clear events accumulated by the EC during
1847  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1848  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1849  *
1850  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1851  *
1852  * Ideally, the EC should also be instructed NOT to accumulate events during
1853  * sleep (which Windows seems to do somehow), but the interface to control this
1854  * behaviour is not known at this time.
1855  *
1856  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1857  * however it is very likely that other Samsung models are affected.
1858  *
1859  * On systems which don't accumulate _Q events during sleep, this extra check
1860  * should be harmless.
1861  */
1862 static int ec_clear_on_resume(const struct dmi_system_id *id)
1863 {
1864         pr_debug("Detected system needing EC poll on resume.\n");
1865         EC_FLAGS_CLEAR_ON_RESUME = 1;
1866         ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1867         return 0;
1868 }
1869
1870 /*
1871  * Some ECDTs contain wrong register addresses.
1872  * MSI MS-171F
1873  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1874  */
1875 static int ec_correct_ecdt(const struct dmi_system_id *id)
1876 {
1877         pr_debug("Detected system needing ECDT address correction.\n");
1878         EC_FLAGS_CORRECT_ECDT = 1;
1879         return 0;
1880 }
1881
1882 /*
1883  * Some DSDTs contain wrong GPE setting.
1884  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1885  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1886  */
1887 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1888 {
1889         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1890         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1891         return 0;
1892 }
1893
1894 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1895         {
1896         ec_correct_ecdt, "MSI MS-171F", {
1897         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1898         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1899         {
1900         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1901         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1902         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1903         {
1904         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1905         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1906         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1907         {
1908         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1909         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1910         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1911         {
1912         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1913         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1914         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1915         {
1916         ec_honor_ecdt_gpe, "ASUS X580VD", {
1917         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1918         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1919         {
1920         ec_clear_on_resume, "Samsung hardware", {
1921         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1922         {},
1923 };
1924
1925 void __init acpi_ec_ecdt_probe(void)
1926 {
1927         struct acpi_table_ecdt *ecdt_ptr;
1928         struct acpi_ec *ec;
1929         acpi_status status;
1930         int ret;
1931
1932         /* Generate a boot ec context. */
1933         dmi_check_system(ec_dmi_table);
1934         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1935                                 (struct acpi_table_header **)&ecdt_ptr);
1936         if (ACPI_FAILURE(status))
1937                 return;
1938
1939         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1940                 /*
1941                  * Asus X50GL:
1942                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1943                  */
1944                 return;
1945         }
1946
1947         ec = acpi_ec_alloc();
1948         if (!ec)
1949                 return;
1950
1951         if (EC_FLAGS_CORRECT_ECDT) {
1952                 ec->command_addr = ecdt_ptr->data.address;
1953                 ec->data_addr = ecdt_ptr->control.address;
1954         } else {
1955                 ec->command_addr = ecdt_ptr->control.address;
1956                 ec->data_addr = ecdt_ptr->data.address;
1957         }
1958
1959         /*
1960          * Ignore the GPE value on Reduced Hardware platforms.
1961          * Some products have this set to an erroneous value.
1962          */
1963         if (!acpi_gbl_reduced_hardware)
1964                 ec->gpe = ecdt_ptr->gpe;
1965
1966         ec->handle = ACPI_ROOT_OBJECT;
1967
1968         /*
1969          * At this point, the namespace is not initialized, so do not find
1970          * the namespace objects, or handle the events.
1971          */
1972         ret = acpi_ec_setup(ec, NULL, false);
1973         if (ret) {
1974                 acpi_ec_free(ec);
1975                 return;
1976         }
1977
1978         boot_ec = ec;
1979         boot_ec_is_ecdt = true;
1980
1981         pr_info("Boot ECDT EC used to handle transactions\n");
1982 }
1983
1984 #ifdef CONFIG_PM_SLEEP
1985 static int acpi_ec_suspend(struct device *dev)
1986 {
1987         struct acpi_ec *ec =
1988                 acpi_driver_data(to_acpi_device(dev));
1989
1990         if (!pm_suspend_no_platform() && ec_freeze_events)
1991                 acpi_ec_disable_event(ec);
1992         return 0;
1993 }
1994
1995 static int acpi_ec_suspend_noirq(struct device *dev)
1996 {
1997         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1998
1999         /*
2000          * The SCI handler doesn't run at this point, so the GPE can be
2001          * masked at the low level without side effects.
2002          */
2003         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2004             ec->gpe >= 0 && ec->reference_count >= 1)
2005                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
2006
2007         acpi_ec_enter_noirq(ec);
2008
2009         return 0;
2010 }
2011
2012 static int acpi_ec_resume_noirq(struct device *dev)
2013 {
2014         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2015
2016         acpi_ec_leave_noirq(ec);
2017
2018         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2019             ec->gpe >= 0 && ec->reference_count >= 1)
2020                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
2021
2022         return 0;
2023 }
2024
2025 static int acpi_ec_resume(struct device *dev)
2026 {
2027         struct acpi_ec *ec =
2028                 acpi_driver_data(to_acpi_device(dev));
2029
2030         acpi_ec_enable_event(ec);
2031         return 0;
2032 }
2033
2034 void acpi_ec_mark_gpe_for_wake(void)
2035 {
2036         if (first_ec && !ec_no_wakeup)
2037                 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
2038 }
2039 EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
2040
2041 void acpi_ec_set_gpe_wake_mask(u8 action)
2042 {
2043         if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
2044                 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
2045 }
2046
2047 bool acpi_ec_dispatch_gpe(void)
2048 {
2049         u32 ret;
2050
2051         if (!first_ec)
2052                 return false;
2053
2054         ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
2055         if (ret == ACPI_INTERRUPT_HANDLED) {
2056                 pm_pr_dbg("EC GPE dispatched\n");
2057                 return true;
2058         }
2059         return false;
2060 }
2061 #endif /* CONFIG_PM_SLEEP */
2062
2063 static const struct dev_pm_ops acpi_ec_pm = {
2064         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2065         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2066 };
2067
2068 static int param_set_event_clearing(const char *val,
2069                                     const struct kernel_param *kp)
2070 {
2071         int result = 0;
2072
2073         if (!strncmp(val, "status", sizeof("status") - 1)) {
2074                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2075                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2076         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2077                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2078                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2079         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2080                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2081                 pr_info("Assuming SCI_EVT clearing on event reads\n");
2082         } else
2083                 result = -EINVAL;
2084         return result;
2085 }
2086
2087 static int param_get_event_clearing(char *buffer,
2088                                     const struct kernel_param *kp)
2089 {
2090         switch (ec_event_clearing) {
2091         case ACPI_EC_EVT_TIMING_STATUS:
2092                 return sprintf(buffer, "status");
2093         case ACPI_EC_EVT_TIMING_QUERY:
2094                 return sprintf(buffer, "query");
2095         case ACPI_EC_EVT_TIMING_EVENT:
2096                 return sprintf(buffer, "event");
2097         default:
2098                 return sprintf(buffer, "invalid");
2099         }
2100         return 0;
2101 }
2102
2103 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2104                   NULL, 0644);
2105 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2106
2107 static struct acpi_driver acpi_ec_driver = {
2108         .name = "ec",
2109         .class = ACPI_EC_CLASS,
2110         .ids = ec_device_ids,
2111         .ops = {
2112                 .add = acpi_ec_add,
2113                 .remove = acpi_ec_remove,
2114                 },
2115         .drv.pm = &acpi_ec_pm,
2116 };
2117
2118 static inline int acpi_ec_query_init(void)
2119 {
2120         if (!ec_query_wq) {
2121                 ec_query_wq = alloc_workqueue("kec_query", 0,
2122                                               ec_max_queries);
2123                 if (!ec_query_wq)
2124                         return -ENODEV;
2125         }
2126         return 0;
2127 }
2128
2129 static inline void acpi_ec_query_exit(void)
2130 {
2131         if (ec_query_wq) {
2132                 destroy_workqueue(ec_query_wq);
2133                 ec_query_wq = NULL;
2134         }
2135 }
2136
2137 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2138         {
2139                 .ident = "Thinkpad X1 Carbon 6th",
2140                 .matches = {
2141                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2142                         DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2143                 },
2144         },
2145         {
2146                 .ident = "ThinkPad X1 Carbon 6th",
2147                 .matches = {
2148                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2149                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2150                 },
2151         },
2152         {
2153                 .ident = "ThinkPad X1 Yoga 3rd",
2154                 .matches = {
2155                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2156                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2157                 },
2158         },
2159         { },
2160 };
2161
2162 int __init acpi_ec_init(void)
2163 {
2164         int result;
2165         int ecdt_fail, dsdt_fail;
2166
2167         /* register workqueue for _Qxx evaluations */
2168         result = acpi_ec_query_init();
2169         if (result)
2170                 return result;
2171
2172         /*
2173          * Disable EC wakeup on following systems to prevent periodic
2174          * wakeup from EC GPE.
2175          */
2176         if (dmi_check_system(acpi_ec_no_wakeup)) {
2177                 ec_no_wakeup = true;
2178                 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2179         }
2180
2181         /* Drivers must be started after acpi_ec_query_init() */
2182         dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver);
2183         /*
2184          * Register ECDT to ACPI bus only when PNP0C09 probe fails. This is
2185          * useful for platforms (confirmed on ASUS X550ZE) with valid ECDT
2186          * settings but invalid DSDT settings.
2187          * https://bugzilla.kernel.org/show_bug.cgi?id=196847
2188          */
2189         ecdt_fail = acpi_ec_ecdt_start();
2190         return ecdt_fail && dsdt_fail ? -ENODEV : 0;
2191 }
2192
2193 /* EC driver currently not unloadable */
2194 #if 0
2195 static void __exit acpi_ec_exit(void)
2196 {
2197
2198         acpi_bus_unregister_driver(&acpi_ec_driver);
2199         acpi_ec_query_exit();
2200 }
2201 #endif  /* 0 */