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
  38 /* EC status register */
  39 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  40 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  41 #define ACPI_EC_FLAG_CMD        0x08    /* Input buffer contains a command */
  42 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  43 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  44
  45 /*
  46  * The SCI_EVT clearing timing is not defined by the ACPI specification.
  47  * This leads to lots of practical timing issues for the host EC driver.
  48  * The following variations are defined (from the target EC firmware's
  49  * perspective):
  50  * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
  51  *         target can clear SCI_EVT at any time so long as the host can see
  52  *         the indication by reading the status register (EC_SC). So the
  53  *         host should re-check SCI_EVT after the first time the SCI_EVT
  54  *         indication is seen, which is the same time the query request
  55  *         (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
  56  *         at any later time could indicate another event. Normally such
  57  *         kind of EC firmware has implemented an event queue and will
  58  *         return 0x00 to indicate "no outstanding event".
  59  * QUERY: After seeing the query request (QR_EC) written to the command
  60  *        register (EC_CMD) by the host and having prepared the responding
  61  *        event value in the data register (EC_DATA), the target can safely
  62  *        clear SCI_EVT because the target can confirm that the current
  63  *        event is being handled by the host. The host then should check
  64  *        SCI_EVT right after reading the event response from the data
  65  *        register (EC_DATA).
  66  * EVENT: After seeing the event response read from the data register
  67  *        (EC_DATA) by the host, the target can clear SCI_EVT. As the
  68  *        target requires time to notice the change in the data register
  69  *        (EC_DATA), the host may be required to wait additional guarding
  70  *        time before checking the SCI_EVT again. Such guarding may not be
  71  *        necessary if the host is notified via another IRQ.
  72  */
  73 #define ACPI_EC_EVT_TIMING_STATUS       0x00
  74 #define ACPI_EC_EVT_TIMING_QUERY        0x01
  75 #define ACPI_EC_EVT_TIMING_EVENT        0x02
  76
  77 /* EC commands */
  78 enum ec_command {
  79         ACPI_EC_COMMAND_READ = 0x80,
  80         ACPI_EC_COMMAND_WRITE = 0x81,
  81         ACPI_EC_BURST_ENABLE = 0x82,
  82         ACPI_EC_BURST_DISABLE = 0x83,
  83         ACPI_EC_COMMAND_QUERY = 0x84,
  84 };
  85
  86 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  87 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  88 #define ACPI_EC_UDELAY_POLL     550     /* Wait 1ms for EC transaction polling */
  89 #define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
  90                                          * when trying to clear the EC */
  91 #define ACPI_EC_MAX_QUERIES     16      /* Maximum number of parallel queries */
  92
  93 enum {
  94         EC_FLAGS_QUERY_ENABLED,         /* Query is enabled */
  95         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  96         EC_FLAGS_QUERY_GUARDING,        /* Guard for SCI_EVT check */
  97         EC_FLAGS_EVENT_HANDLER_INSTALLED,       /* Event handler installed */
  98         EC_FLAGS_EC_HANDLER_INSTALLED,  /* OpReg handler installed */
  99         EC_FLAGS_QUERY_METHODS_INSTALLED, /* _Qxx handlers installed */
 100         EC_FLAGS_STARTED,               /* Driver is started */
 101         EC_FLAGS_STOPPED,               /* Driver is stopped */
 102         EC_FLAGS_EVENTS_MASKED,         /* Events masked */
 103 };
 104
 105 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
 106 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
 107
 108 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 109 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 110 module_param(ec_delay, uint, 0644);
 111 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
 112
 113 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
 114 module_param(ec_max_queries, uint, 0644);
 115 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
 116
 117 static bool ec_busy_polling __read_mostly;
 118 module_param(ec_busy_polling, bool, 0644);
 119 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
 120
 121 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
 122 module_param(ec_polling_guard, uint, 0644);
 123 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
 124
 125 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
 126
 127 /*
 128  * If the number of false interrupts per one transaction exceeds
 129  * this threshold, will think there is a GPE storm happened and
 130  * will disable the GPE for normal transaction.
 131  */
 132 static unsigned int ec_storm_threshold  __read_mostly = 8;
 133 module_param(ec_storm_threshold, uint, 0644);
 134 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 135
 136 static bool ec_freeze_events __read_mostly = false;
 137 module_param(ec_freeze_events, bool, 0644);
 138 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
 139
 140 static bool ec_no_wakeup __read_mostly;
 141 module_param(ec_no_wakeup, bool, 0644);
 142 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
 143
 144 struct acpi_ec_query_handler {
 145         struct list_head node;
 146         acpi_ec_query_func func;
 147         acpi_handle handle;
 148         void *data;
 149         u8 query_bit;
 150         struct kref kref;
 151 };
 152
 153 struct transaction {
 154         const u8 *wdata;
 155         u8 *rdata;
 156         unsigned short irq_count;
 157         u8 command;
 158         u8 wi;
 159         u8 ri;
 160         u8 wlen;
 161         u8 rlen;
 162         u8 flags;
 163 };
 164
 165 struct acpi_ec_query {
 166         struct transaction transaction;
 167         struct work_struct work;
 168         struct acpi_ec_query_handler *handler;
 169         struct acpi_ec *ec;
 170 };
 171
 172 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
 173 static void advance_transaction(struct acpi_ec *ec, bool interrupt);
 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_TRUST_DSDT_GPE; /* Needs DSDT GPE as correction setting */
 188 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 189
 190 /* --------------------------------------------------------------------------
 191  *                           Logging/Debugging
 192  * -------------------------------------------------------------------------- */
 193
 194 /*
 195  * Splitters used by the developers to track the boundary of the EC
 196  * handling processes.
 197  */
 198 #ifdef DEBUG
 199 #define EC_DBG_SEP      " "
 200 #define EC_DBG_DRV      "+++++"
 201 #define EC_DBG_STM      "====="
 202 #define EC_DBG_REQ      "*****"
 203 #define EC_DBG_EVT      "#####"
 204 #else
 205 #define EC_DBG_SEP      ""
 206 #define EC_DBG_DRV
 207 #define EC_DBG_STM
 208 #define EC_DBG_REQ
 209 #define EC_DBG_EVT
 210 #endif
 211
 212 #define ec_log_raw(fmt, ...) \
 213         pr_info(fmt "\n", ##__VA_ARGS__)
 214 #define ec_dbg_raw(fmt, ...) \
 215         pr_debug(fmt "\n", ##__VA_ARGS__)
 216 #define ec_log(filter, fmt, ...) \
 217         ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 218 #define ec_dbg(filter, fmt, ...) \
 219         ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 220
 221 #define ec_log_drv(fmt, ...) \
 222         ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 223 #define ec_dbg_drv(fmt, ...) \
 224         ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 225 #define ec_dbg_stm(fmt, ...) \
 226         ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
 227 #define ec_dbg_req(fmt, ...) \
 228         ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
 229 #define ec_dbg_evt(fmt, ...) \
 230         ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
 231 #define ec_dbg_ref(ec, fmt, ...) \
 232         ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
 233
 234 /* --------------------------------------------------------------------------
 235  *                           Device Flags
 236  * -------------------------------------------------------------------------- */
 237
 238 static bool acpi_ec_started(struct acpi_ec *ec)
 239 {
 240         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
 241                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
 242 }
 243
 244 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
 245 {
 246         /*
 247          * There is an OSPM early stage logic. During the early stages
 248          * (boot/resume), OSPMs shouldn't enable the event handling, only
 249          * the EC transactions are allowed to be performed.
 250          */
 251         if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 252                 return false;
 253         /*
 254          * However, disabling the event handling is experimental for late
 255          * stage (suspend), and is controlled by the boot parameter of
 256          * "ec_freeze_events":
 257          * 1. true:  The EC event handling is disabled before entering
 258          *           the noirq stage.
 259          * 2. false: The EC event handling is automatically disabled as
 260          *           soon as the EC driver is stopped.
 261          */
 262         if (ec_freeze_events)
 263                 return acpi_ec_started(ec);
 264         else
 265                 return test_bit(EC_FLAGS_STARTED, &ec->flags);
 266 }
 267
 268 static bool acpi_ec_flushed(struct acpi_ec *ec)
 269 {
 270         return ec->reference_count == 1;
 271 }
 272
 273 /* --------------------------------------------------------------------------
 274  *                           EC Registers
 275  * -------------------------------------------------------------------------- */
 276
 277 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 278 {
 279         u8 x = inb(ec->command_addr);
 280
 281         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
 282                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
 283                    x,
 284                    !!(x & ACPI_EC_FLAG_SCI),
 285                    !!(x & ACPI_EC_FLAG_BURST),
 286                    !!(x & ACPI_EC_FLAG_CMD),
 287                    !!(x & ACPI_EC_FLAG_IBF),
 288                    !!(x & ACPI_EC_FLAG_OBF));
 289         return x;
 290 }
 291
 292 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 293 {
 294         u8 x = inb(ec->data_addr);
 295
 296         ec->timestamp = jiffies;
 297         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
 298         return x;
 299 }
 300
 301 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 302 {
 303         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
 304         outb(command, ec->command_addr);
 305         ec->timestamp = jiffies;
 306 }
 307
 308 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 309 {
 310         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
 311         outb(data, ec->data_addr);
 312         ec->timestamp = jiffies;
 313 }
 314
 315 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
 316 static const char *acpi_ec_cmd_string(u8 cmd)
 317 {
 318         switch (cmd) {
 319         case 0x80:
 320                 return "RD_EC";
 321         case 0x81:
 322                 return "WR_EC";
 323         case 0x82:
 324                 return "BE_EC";
 325         case 0x83:
 326                 return "BD_EC";
 327         case 0x84:
 328                 return "QR_EC";
 329         }
 330         return "UNKNOWN";
 331 }
 332 #else
 333 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 334 #endif
 335
 336 /* --------------------------------------------------------------------------
 337  *                           GPE Registers
 338  * -------------------------------------------------------------------------- */
 339
 340 static inline bool acpi_ec_gpe_status_set(struct acpi_ec *ec)
 341 {
 342         acpi_event_status gpe_status = 0;
 343
 344         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
 345         return !!(gpe_status & ACPI_EVENT_FLAG_STATUS_SET);
 346 }
 347
 348 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
 349 {
 350         if (open)
 351                 acpi_enable_gpe(NULL, ec->gpe);
 352         else {
 353                 BUG_ON(ec->reference_count < 1);
 354                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 355         }
 356         if (acpi_ec_gpe_status_set(ec)) {
 357                 /*
 358                  * On some platforms, EN=1 writes cannot trigger GPE. So
 359                  * software need to manually trigger a pseudo GPE event on
 360                  * EN=1 writes.
 361                  */
 362                 ec_dbg_raw("Polling quirk");
 363                 advance_transaction(ec, false);
 364         }
 365 }
 366
 367 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
 368 {
 369         if (close)
 370                 acpi_disable_gpe(NULL, ec->gpe);
 371         else {
 372                 BUG_ON(ec->reference_count < 1);
 373                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 374         }
 375 }
 376
 377 /* --------------------------------------------------------------------------
 378  *                           Transaction Management
 379  * -------------------------------------------------------------------------- */
 380
 381 static void acpi_ec_submit_request(struct acpi_ec *ec)
 382 {
 383         ec->reference_count++;
 384         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
 385             ec->gpe >= 0 && ec->reference_count == 1)
 386                 acpi_ec_enable_gpe(ec, true);
 387 }
 388
 389 static void acpi_ec_complete_request(struct acpi_ec *ec)
 390 {
 391         bool flushed = false;
 392
 393         ec->reference_count--;
 394         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
 395             ec->gpe >= 0 && ec->reference_count == 0)
 396                 acpi_ec_disable_gpe(ec, true);
 397         flushed = acpi_ec_flushed(ec);
 398         if (flushed)
 399                 wake_up(&ec->wait);
 400 }
 401
 402 static void acpi_ec_mask_events(struct acpi_ec *ec)
 403 {
 404         if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
 405                 if (ec->gpe >= 0)
 406                         acpi_ec_disable_gpe(ec, false);
 407                 else
 408                         disable_irq_nosync(ec->irq);
 409
 410                 ec_dbg_drv("Polling enabled");
 411                 set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
 412         }
 413 }
 414
 415 static void acpi_ec_unmask_events(struct acpi_ec *ec)
 416 {
 417         if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
 418                 clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
 419                 if (ec->gpe >= 0)
 420                         acpi_ec_enable_gpe(ec, false);
 421                 else
 422                         enable_irq(ec->irq);
 423
 424                 ec_dbg_drv("Polling disabled");
 425         }
 426 }
 427
 428 /*
 429  * acpi_ec_submit_flushable_request() - Increase the reference count unless
 430  *                                      the flush operation is not in
 431  *                                      progress
 432  * @ec: the EC device
 433  *
 434  * This function must be used before taking a new action that should hold
 435  * the reference count.  If this function returns false, then the action
 436  * must be discarded or it will prevent the flush operation from being
 437  * completed.
 438  */
 439 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
 440 {
 441         if (!acpi_ec_started(ec))
 442                 return false;
 443         acpi_ec_submit_request(ec);
 444         return true;
 445 }
 446
 447 static void acpi_ec_submit_query(struct acpi_ec *ec)
 448 {
 449         acpi_ec_mask_events(ec);
 450         if (!acpi_ec_event_enabled(ec))
 451                 return;
 452         if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 453                 ec_dbg_evt("Command(%s) submitted/blocked",
 454                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 455                 ec->nr_pending_queries++;
 456                 ec->events_in_progress++;
 457                 queue_work(ec_wq, &ec->work);
 458         }
 459 }
 460
 461 static void acpi_ec_complete_query(struct acpi_ec *ec)
 462 {
 463         if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 464                 ec_dbg_evt("Command(%s) unblocked",
 465                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 466         acpi_ec_unmask_events(ec);
 467 }
 468
 469 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
 470 {
 471         if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 472                 ec_log_drv("event unblocked");
 473         /*
 474          * Unconditionally invoke this once after enabling the event
 475          * handling mechanism to detect the pending events.
 476          */
 477         advance_transaction(ec, false);
 478 }
 479
 480 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
 481 {
 482         if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 483                 ec_log_drv("event blocked");
 484 }
 485
 486 /*
 487  * Process _Q events that might have accumulated in the EC.
 488  * Run with locked ec mutex.
 489  */
 490 static void acpi_ec_clear(struct acpi_ec *ec)
 491 {
 492         int i, status;
 493         u8 value = 0;
 494
 495         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 496                 status = acpi_ec_query(ec, &value);
 497                 if (status || !value)
 498                         break;
 499         }
 500         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 501                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 502         else
 503                 pr_info("%d stale EC events cleared\n", i);
 504 }
 505
 506 static void acpi_ec_enable_event(struct acpi_ec *ec)
 507 {
 508         unsigned long flags;
 509
 510         spin_lock_irqsave(&ec->lock, flags);
 511         if (acpi_ec_started(ec))
 512                 __acpi_ec_enable_event(ec);
 513         spin_unlock_irqrestore(&ec->lock, flags);
 514
 515         /* Drain additional events if hardware requires that */
 516         if (EC_FLAGS_CLEAR_ON_RESUME)
 517                 acpi_ec_clear(ec);
 518 }
 519
 520 #ifdef CONFIG_PM_SLEEP
 521 static void __acpi_ec_flush_work(void)
 522 {
 523         flush_workqueue(ec_wq); /* flush ec->work */
 524         flush_workqueue(ec_query_wq); /* flush queries */
 525 }
 526
 527 static void acpi_ec_disable_event(struct acpi_ec *ec)
 528 {
 529         unsigned long flags;
 530
 531         spin_lock_irqsave(&ec->lock, flags);
 532         __acpi_ec_disable_event(ec);
 533         spin_unlock_irqrestore(&ec->lock, flags);
 534
 535         /*
 536          * When ec_freeze_events is true, we need to flush events in
 537          * the proper position before entering the noirq stage.
 538          */
 539         __acpi_ec_flush_work();
 540 }
 541
 542 void acpi_ec_flush_work(void)
 543 {
 544         /* Without ec_wq there is nothing to flush. */
 545         if (!ec_wq)
 546                 return;
 547
 548         __acpi_ec_flush_work();
 549 }
 550 #endif /* CONFIG_PM_SLEEP */
 551
 552 static bool acpi_ec_guard_event(struct acpi_ec *ec)
 553 {
 554         bool guarded = true;
 555         unsigned long flags;
 556
 557         spin_lock_irqsave(&ec->lock, flags);
 558         /*
 559          * If firmware SCI_EVT clearing timing is "event", we actually
 560          * don't know when the SCI_EVT will be cleared by firmware after
 561          * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
 562          * acceptable period.
 563          *
 564          * The guarding period begins when EC_FLAGS_QUERY_PENDING is
 565          * flagged, which means SCI_EVT check has just been performed.
 566          * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
 567          * guarding should have already been performed (via
 568          * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
 569          * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
 570          * ACPI_EC_COMMAND_POLL state immediately.
 571          */
 572         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
 573             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
 574             !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
 575             (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
 576                 guarded = false;
 577         spin_unlock_irqrestore(&ec->lock, flags);
 578         return guarded;
 579 }
 580
 581 static int ec_transaction_polled(struct acpi_ec *ec)
 582 {
 583         unsigned long flags;
 584         int ret = 0;
 585
 586         spin_lock_irqsave(&ec->lock, flags);
 587         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
 588                 ret = 1;
 589         spin_unlock_irqrestore(&ec->lock, flags);
 590         return ret;
 591 }
 592
 593 static int ec_transaction_completed(struct acpi_ec *ec)
 594 {
 595         unsigned long flags;
 596         int ret = 0;
 597
 598         spin_lock_irqsave(&ec->lock, flags);
 599         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 600                 ret = 1;
 601         spin_unlock_irqrestore(&ec->lock, flags);
 602         return ret;
 603 }
 604
 605 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
 606 {
 607         ec->curr->flags |= flag;
 608         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 609                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
 610                     flag == ACPI_EC_COMMAND_POLL)
 611                         acpi_ec_complete_query(ec);
 612                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
 613                     flag == ACPI_EC_COMMAND_COMPLETE)
 614                         acpi_ec_complete_query(ec);
 615                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 616                     flag == ACPI_EC_COMMAND_COMPLETE)
 617                         set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 618         }
 619 }
 620
 621 static void acpi_ec_spurious_interrupt(struct acpi_ec *ec, struct transaction *t)
 622 {
 623         if (t->irq_count < ec_storm_threshold)
 624                 ++t->irq_count;
 625
 626         /* Trigger if the threshold is 0 too. */
 627         if (t->irq_count == ec_storm_threshold)
 628                 acpi_ec_mask_events(ec);
 629 }
 630
 631 static void advance_transaction(struct acpi_ec *ec, bool interrupt)
 632 {
 633         struct transaction *t = ec->curr;
 634         bool wakeup = false;
 635         u8 status;
 636
 637         ec_dbg_stm("%s (%d)", interrupt ? "IRQ" : "TASK", smp_processor_id());
 638
 639         /*
 640          * Clear GPE_STS upfront to allow subsequent hardware GPE_STS 0->1
 641          * changes to always trigger a GPE interrupt.
 642          *
 643          * GPE STS is a W1C register, which means:
 644          *
 645          * 1. Software can clear it without worrying about clearing the other
 646          *    GPEs' STS bits when the hardware sets them in parallel.
 647          *
 648          * 2. As long as software can ensure only clearing it when it is set,
 649          *    hardware won't set it in parallel.
 650          */
 651         if (ec->gpe >= 0 && acpi_ec_gpe_status_set(ec))
 652                 acpi_clear_gpe(NULL, ec->gpe);
 653
 654         status = acpi_ec_read_status(ec);
 655
 656         /*
 657          * Another IRQ or a guarded polling mode advancement is detected,
 658          * the next QR_EC submission is then allowed.
 659          */
 660         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
 661                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 662                     (!ec->nr_pending_queries ||
 663                      test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
 664                         clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 665                         acpi_ec_complete_query(ec);
 666                 }
 667                 if (!t)
 668                         goto out;
 669         }
 670
 671         if (t->flags & ACPI_EC_COMMAND_POLL) {
 672                 if (t->wlen > t->wi) {
 673                         if (!(status & ACPI_EC_FLAG_IBF))
 674                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 675                         else if (interrupt && !(status & ACPI_EC_FLAG_SCI))
 676                                 acpi_ec_spurious_interrupt(ec, t);
 677                 } else if (t->rlen > t->ri) {
 678                         if (status & ACPI_EC_FLAG_OBF) {
 679                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 680                                 if (t->rlen == t->ri) {
 681                                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 682                                         wakeup = true;
 683                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 684                                                 ec_dbg_evt("Command(%s) completed by hardware",
 685                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 686                                 }
 687                         } else if (interrupt && !(status & ACPI_EC_FLAG_SCI)) {
 688                                 acpi_ec_spurious_interrupt(ec, t);
 689                         }
 690                 } else if (t->wlen == t->wi && !(status & ACPI_EC_FLAG_IBF)) {
 691                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 692                         wakeup = true;
 693                 }
 694         } else if (!(status & ACPI_EC_FLAG_IBF)) {
 695                 acpi_ec_write_cmd(ec, t->command);
 696                 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 697         }
 698
 699 out:
 700         if (status & ACPI_EC_FLAG_SCI)
 701                 acpi_ec_submit_query(ec);
 702
 703         if (wakeup && interrupt)
 704                 wake_up(&ec->wait);
 705 }
 706
 707 static void start_transaction(struct acpi_ec *ec)
 708 {
 709         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 710         ec->curr->flags = 0;
 711 }
 712
 713 static int ec_guard(struct acpi_ec *ec)
 714 {
 715         unsigned long guard = usecs_to_jiffies(ec->polling_guard);
 716         unsigned long timeout = ec->timestamp + guard;
 717
 718         /* Ensure guarding period before polling EC status */
 719         do {
 720                 if (ec->busy_polling) {
 721                         /* Perform busy polling */
 722                         if (ec_transaction_completed(ec))
 723                                 return 0;
 724                         udelay(jiffies_to_usecs(guard));
 725                 } else {
 726                         /*
 727                          * Perform wait polling
 728                          * 1. Wait the transaction to be completed by the
 729                          *    GPE handler after the transaction enters
 730                          *    ACPI_EC_COMMAND_POLL state.
 731                          * 2. A special guarding logic is also required
 732                          *    for event clearing mode "event" before the
 733                          *    transaction enters ACPI_EC_COMMAND_POLL
 734                          *    state.
 735                          */
 736                         if (!ec_transaction_polled(ec) &&
 737                             !acpi_ec_guard_event(ec))
 738                                 break;
 739                         if (wait_event_timeout(ec->wait,
 740                                                ec_transaction_completed(ec),
 741                                                guard))
 742                                 return 0;
 743                 }
 744         } while (time_before(jiffies, timeout));
 745         return -ETIME;
 746 }
 747
 748 static int ec_poll(struct acpi_ec *ec)
 749 {
 750         unsigned long flags;
 751         int repeat = 5; /* number of command restarts */
 752
 753         while (repeat--) {
 754                 unsigned long delay = jiffies +
 755                         msecs_to_jiffies(ec_delay);
 756                 do {
 757                         if (!ec_guard(ec))
 758                                 return 0;
 759                         spin_lock_irqsave(&ec->lock, flags);
 760                         advance_transaction(ec, false);
 761                         spin_unlock_irqrestore(&ec->lock, flags);
 762                 } while (time_before(jiffies, delay));
 763                 pr_debug("controller reset, restart transaction\n");
 764                 spin_lock_irqsave(&ec->lock, flags);
 765                 start_transaction(ec);
 766                 spin_unlock_irqrestore(&ec->lock, flags);
 767         }
 768         return -ETIME;
 769 }
 770
 771 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 772                                         struct transaction *t)
 773 {
 774         unsigned long tmp;
 775         int ret = 0;
 776
 777         /* start transaction */
 778         spin_lock_irqsave(&ec->lock, tmp);
 779         /* Enable GPE for command processing (IBF=0/OBF=1) */
 780         if (!acpi_ec_submit_flushable_request(ec)) {
 781                 ret = -EINVAL;
 782                 goto unlock;
 783         }
 784         ec_dbg_ref(ec, "Increase command");
 785         /* following two actions should be kept atomic */
 786         ec->curr = t;
 787         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 788         start_transaction(ec);
 789         spin_unlock_irqrestore(&ec->lock, tmp);
 790
 791         ret = ec_poll(ec);
 792
 793         spin_lock_irqsave(&ec->lock, tmp);
 794         if (t->irq_count == ec_storm_threshold)
 795                 acpi_ec_unmask_events(ec);
 796         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 797         ec->curr = NULL;
 798         /* Disable GPE for command processing (IBF=0/OBF=1) */
 799         acpi_ec_complete_request(ec);
 800         ec_dbg_ref(ec, "Decrease command");
 801 unlock:
 802         spin_unlock_irqrestore(&ec->lock, tmp);
 803         return ret;
 804 }
 805
 806 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 807 {
 808         int status;
 809         u32 glk;
 810
 811         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 812                 return -EINVAL;
 813         if (t->rdata)
 814                 memset(t->rdata, 0, t->rlen);
 815
 816         mutex_lock(&ec->mutex);
 817         if (ec->global_lock) {
 818                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 819                 if (ACPI_FAILURE(status)) {
 820                         status = -ENODEV;
 821                         goto unlock;
 822                 }
 823         }
 824
 825         status = acpi_ec_transaction_unlocked(ec, t);
 826
 827         if (ec->global_lock)
 828                 acpi_release_global_lock(glk);
 829 unlock:
 830         mutex_unlock(&ec->mutex);
 831         return status;
 832 }
 833
 834 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 835 {
 836         u8 d;
 837         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 838                                 .wdata = NULL, .rdata = &d,
 839                                 .wlen = 0, .rlen = 1};
 840
 841         return acpi_ec_transaction(ec, &t);
 842 }
 843
 844 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 845 {
 846         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 847                                 .wdata = NULL, .rdata = NULL,
 848                                 .wlen = 0, .rlen = 0};
 849
 850         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 851                                 acpi_ec_transaction(ec, &t) : 0;
 852 }
 853
 854 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 855 {
 856         int result;
 857         u8 d;
 858         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 859                                 .wdata = &address, .rdata = &d,
 860                                 .wlen = 1, .rlen = 1};
 861
 862         result = acpi_ec_transaction(ec, &t);
 863         *data = d;
 864         return result;
 865 }
 866
 867 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 868 {
 869         u8 wdata[2] = { address, data };
 870         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 871                                 .wdata = wdata, .rdata = NULL,
 872                                 .wlen = 2, .rlen = 0};
 873
 874         return acpi_ec_transaction(ec, &t);
 875 }
 876
 877 int ec_read(u8 addr, u8 *val)
 878 {
 879         int err;
 880         u8 temp_data;
 881
 882         if (!first_ec)
 883                 return -ENODEV;
 884
 885         err = acpi_ec_read(first_ec, addr, &temp_data);
 886
 887         if (!err) {
 888                 *val = temp_data;
 889                 return 0;
 890         }
 891         return err;
 892 }
 893 EXPORT_SYMBOL(ec_read);
 894
 895 int ec_write(u8 addr, u8 val)
 896 {
 897         int err;
 898
 899         if (!first_ec)
 900                 return -ENODEV;
 901
 902         err = acpi_ec_write(first_ec, addr, val);
 903
 904         return err;
 905 }
 906 EXPORT_SYMBOL(ec_write);
 907
 908 int ec_transaction(u8 command,
 909                    const u8 *wdata, unsigned wdata_len,
 910                    u8 *rdata, unsigned rdata_len)
 911 {
 912         struct transaction t = {.command = command,
 913                                 .wdata = wdata, .rdata = rdata,
 914                                 .wlen = wdata_len, .rlen = rdata_len};
 915
 916         if (!first_ec)
 917                 return -ENODEV;
 918
 919         return acpi_ec_transaction(first_ec, &t);
 920 }
 921 EXPORT_SYMBOL(ec_transaction);
 922
 923 /* Get the handle to the EC device */
 924 acpi_handle ec_get_handle(void)
 925 {
 926         if (!first_ec)
 927                 return NULL;
 928         return first_ec->handle;
 929 }
 930 EXPORT_SYMBOL(ec_get_handle);
 931
 932 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 933 {
 934         unsigned long flags;
 935
 936         spin_lock_irqsave(&ec->lock, flags);
 937         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 938                 ec_dbg_drv("Starting EC");
 939                 /* Enable GPE for event processing (SCI_EVT=1) */
 940                 if (!resuming) {
 941                         acpi_ec_submit_request(ec);
 942                         ec_dbg_ref(ec, "Increase driver");
 943                 }
 944                 ec_log_drv("EC started");
 945         }
 946         spin_unlock_irqrestore(&ec->lock, flags);
 947 }
 948
 949 static bool acpi_ec_stopped(struct acpi_ec *ec)
 950 {
 951         unsigned long flags;
 952         bool flushed;
 953
 954         spin_lock_irqsave(&ec->lock, flags);
 955         flushed = acpi_ec_flushed(ec);
 956         spin_unlock_irqrestore(&ec->lock, flags);
 957         return flushed;
 958 }
 959
 960 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 961 {
 962         unsigned long flags;
 963
 964         spin_lock_irqsave(&ec->lock, flags);
 965         if (acpi_ec_started(ec)) {
 966                 ec_dbg_drv("Stopping EC");
 967                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
 968                 spin_unlock_irqrestore(&ec->lock, flags);
 969                 wait_event(ec->wait, acpi_ec_stopped(ec));
 970                 spin_lock_irqsave(&ec->lock, flags);
 971                 /* Disable GPE for event processing (SCI_EVT=1) */
 972                 if (!suspending) {
 973                         acpi_ec_complete_request(ec);
 974                         ec_dbg_ref(ec, "Decrease driver");
 975                 } else if (!ec_freeze_events)
 976                         __acpi_ec_disable_event(ec);
 977                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
 978                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
 979                 ec_log_drv("EC stopped");
 980         }
 981         spin_unlock_irqrestore(&ec->lock, flags);
 982 }
 983
 984 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
 985 {
 986         unsigned long flags;
 987
 988         spin_lock_irqsave(&ec->lock, flags);
 989         ec->busy_polling = true;
 990         ec->polling_guard = 0;
 991         ec_log_drv("interrupt blocked");
 992         spin_unlock_irqrestore(&ec->lock, flags);
 993 }
 994
 995 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
 996 {
 997         unsigned long flags;
 998
 999         spin_lock_irqsave(&ec->lock, flags);
1000         ec->busy_polling = ec_busy_polling;
1001         ec->polling_guard = ec_polling_guard;
1002         ec_log_drv("interrupt unblocked");
1003         spin_unlock_irqrestore(&ec->lock, flags);
1004 }
1005
1006 void acpi_ec_block_transactions(void)
1007 {
1008         struct acpi_ec *ec = first_ec;
1009
1010         if (!ec)
1011                 return;
1012
1013         mutex_lock(&ec->mutex);
1014         /* Prevent transactions from being carried out */
1015         acpi_ec_stop(ec, true);
1016         mutex_unlock(&ec->mutex);
1017 }
1018
1019 void acpi_ec_unblock_transactions(void)
1020 {
1021         /*
1022          * Allow transactions to happen again (this function is called from
1023          * atomic context during wakeup, so we don't need to acquire the mutex).
1024          */
1025         if (first_ec)
1026                 acpi_ec_start(first_ec, true);
1027 }
1028
1029 /* --------------------------------------------------------------------------
1030                                 Event Management
1031    -------------------------------------------------------------------------- */
1032 static struct acpi_ec_query_handler *
1033 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1034 {
1035         struct acpi_ec_query_handler *handler;
1036
1037         mutex_lock(&ec->mutex);
1038         list_for_each_entry(handler, &ec->list, node) {
1039                 if (value == handler->query_bit) {
1040                         kref_get(&handler->kref);
1041                         mutex_unlock(&ec->mutex);
1042                         return handler;
1043                 }
1044         }
1045         mutex_unlock(&ec->mutex);
1046         return NULL;
1047 }
1048
1049 static void acpi_ec_query_handler_release(struct kref *kref)
1050 {
1051         struct acpi_ec_query_handler *handler =
1052                 container_of(kref, struct acpi_ec_query_handler, kref);
1053
1054         kfree(handler);
1055 }
1056
1057 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1058 {
1059         kref_put(&handler->kref, acpi_ec_query_handler_release);
1060 }
1061
1062 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1063                               acpi_handle handle, acpi_ec_query_func func,
1064                               void *data)
1065 {
1066         struct acpi_ec_query_handler *handler =
1067             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1068
1069         if (!handler)
1070                 return -ENOMEM;
1071
1072         handler->query_bit = query_bit;
1073         handler->handle = handle;
1074         handler->func = func;
1075         handler->data = data;
1076         mutex_lock(&ec->mutex);
1077         kref_init(&handler->kref);
1078         list_add(&handler->node, &ec->list);
1079         mutex_unlock(&ec->mutex);
1080         return 0;
1081 }
1082 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1083
1084 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1085                                           bool remove_all, u8 query_bit)
1086 {
1087         struct acpi_ec_query_handler *handler, *tmp;
1088         LIST_HEAD(free_list);
1089
1090         mutex_lock(&ec->mutex);
1091         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1092                 if (remove_all || query_bit == handler->query_bit) {
1093                         list_del_init(&handler->node);
1094                         list_add(&handler->node, &free_list);
1095                 }
1096         }
1097         mutex_unlock(&ec->mutex);
1098         list_for_each_entry_safe(handler, tmp, &free_list, node)
1099                 acpi_ec_put_query_handler(handler);
1100 }
1101
1102 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1103 {
1104         acpi_ec_remove_query_handlers(ec, false, query_bit);
1105 }
1106 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1107
1108 static struct acpi_ec_query *acpi_ec_create_query(struct acpi_ec *ec, u8 *pval)
1109 {
1110         struct acpi_ec_query *q;
1111         struct transaction *t;
1112
1113         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1114         if (!q)
1115                 return NULL;
1116
1117         INIT_WORK(&q->work, acpi_ec_event_processor);
1118         t = &q->transaction;
1119         t->command = ACPI_EC_COMMAND_QUERY;
1120         t->rdata = pval;
1121         t->rlen = 1;
1122         q->ec = ec;
1123         return q;
1124 }
1125
1126 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1127 {
1128         if (q) {
1129                 if (q->handler)
1130                         acpi_ec_put_query_handler(q->handler);
1131                 kfree(q);
1132         }
1133 }
1134
1135 static void acpi_ec_event_processor(struct work_struct *work)
1136 {
1137         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1138         struct acpi_ec_query_handler *handler = q->handler;
1139         struct acpi_ec *ec = q->ec;
1140
1141         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1142
1143         if (handler->func)
1144                 handler->func(handler->data);
1145         else if (handler->handle)
1146                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1147
1148         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1149
1150         spin_lock_irq(&ec->lock);
1151         ec->queries_in_progress--;
1152         spin_unlock_irq(&ec->lock);
1153
1154         acpi_ec_delete_query(q);
1155 }
1156
1157 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1158 {
1159         u8 value = 0;
1160         int result;
1161         struct acpi_ec_query *q;
1162
1163         q = acpi_ec_create_query(ec, &value);
1164         if (!q)
1165                 return -ENOMEM;
1166
1167         /*
1168          * Query the EC to find out which _Qxx method we need to evaluate.
1169          * Note that successful completion of the query causes the ACPI_EC_SCI
1170          * bit to be cleared (and thus clearing the interrupt source).
1171          */
1172         result = acpi_ec_transaction(ec, &q->transaction);
1173         if (!value)
1174                 result = -ENODATA;
1175         if (result)
1176                 goto err_exit;
1177
1178         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1179         if (!q->handler) {
1180                 result = -ENODATA;
1181                 goto err_exit;
1182         }
1183
1184         /*
1185          * It is reported that _Qxx are evaluated in a parallel way on Windows:
1186          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1187          *
1188          * Put this log entry before queue_work() to make it appear in the log
1189          * before any other messages emitted during workqueue handling.
1190          */
1191         ec_dbg_evt("Query(0x%02x) scheduled", value);
1192
1193         spin_lock_irq(&ec->lock);
1194
1195         ec->queries_in_progress++;
1196         queue_work(ec_query_wq, &q->work);
1197
1198         spin_unlock_irq(&ec->lock);
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, false);
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         spin_lock_irqsave(&ec->lock, flags);
1258         ec->events_in_progress--;
1259         spin_unlock_irqrestore(&ec->lock, flags);
1260 }
1261
1262 static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1263 {
1264         unsigned long flags;
1265
1266         spin_lock_irqsave(&ec->lock, flags);
1267         advance_transaction(ec, true);
1268         spin_unlock_irqrestore(&ec->lock, flags);
1269 }
1270
1271 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1272                                u32 gpe_number, void *data)
1273 {
1274         acpi_ec_handle_interrupt(data);
1275         return ACPI_INTERRUPT_HANDLED;
1276 }
1277
1278 static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1279 {
1280         acpi_ec_handle_interrupt(data);
1281         return IRQ_HANDLED;
1282 }
1283
1284 /* --------------------------------------------------------------------------
1285  *                           Address Space Management
1286  * -------------------------------------------------------------------------- */
1287
1288 static acpi_status
1289 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1290                       u32 bits, u64 *value64,
1291                       void *handler_context, void *region_context)
1292 {
1293         struct acpi_ec *ec = handler_context;
1294         int result = 0, i, bytes = bits / 8;
1295         u8 *value = (u8 *)value64;
1296
1297         if ((address > 0xFF) || !value || !handler_context)
1298                 return AE_BAD_PARAMETER;
1299
1300         if (function != ACPI_READ && function != ACPI_WRITE)
1301                 return AE_BAD_PARAMETER;
1302
1303         if (ec->busy_polling || bits > 8)
1304                 acpi_ec_burst_enable(ec);
1305
1306         for (i = 0; i < bytes; ++i, ++address, ++value)
1307                 result = (function == ACPI_READ) ?
1308                         acpi_ec_read(ec, address, value) :
1309                         acpi_ec_write(ec, address, *value);
1310
1311         if (ec->busy_polling || bits > 8)
1312                 acpi_ec_burst_disable(ec);
1313
1314         switch (result) {
1315         case -EINVAL:
1316                 return AE_BAD_PARAMETER;
1317         case -ENODEV:
1318                 return AE_NOT_FOUND;
1319         case -ETIME:
1320                 return AE_TIME;
1321         default:
1322                 return AE_OK;
1323         }
1324 }
1325
1326 /* --------------------------------------------------------------------------
1327  *                             Driver Interface
1328  * -------------------------------------------------------------------------- */
1329
1330 static acpi_status
1331 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1332
1333 static void acpi_ec_free(struct acpi_ec *ec)
1334 {
1335         if (first_ec == ec)
1336                 first_ec = NULL;
1337         if (boot_ec == ec)
1338                 boot_ec = NULL;
1339         kfree(ec);
1340 }
1341
1342 static struct acpi_ec *acpi_ec_alloc(void)
1343 {
1344         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1345
1346         if (!ec)
1347                 return NULL;
1348         mutex_init(&ec->mutex);
1349         init_waitqueue_head(&ec->wait);
1350         INIT_LIST_HEAD(&ec->list);
1351         spin_lock_init(&ec->lock);
1352         INIT_WORK(&ec->work, acpi_ec_event_handler);
1353         ec->timestamp = jiffies;
1354         ec->busy_polling = true;
1355         ec->polling_guard = 0;
1356         ec->gpe = -1;
1357         ec->irq = -1;
1358         return ec;
1359 }
1360
1361 static acpi_status
1362 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1363                                void *context, void **return_value)
1364 {
1365         char node_name[5];
1366         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1367         struct acpi_ec *ec = context;
1368         int value = 0;
1369         acpi_status status;
1370
1371         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1372
1373         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1374                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1375         return AE_OK;
1376 }
1377
1378 static acpi_status
1379 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1380 {
1381         acpi_status status;
1382         unsigned long long tmp = 0;
1383         struct acpi_ec *ec = context;
1384
1385         /* clear addr values, ec_parse_io_ports depend on it */
1386         ec->command_addr = ec->data_addr = 0;
1387
1388         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1389                                      ec_parse_io_ports, ec);
1390         if (ACPI_FAILURE(status))
1391                 return status;
1392         if (ec->data_addr == 0 || ec->command_addr == 0)
1393                 return AE_OK;
1394
1395         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1396                 /*
1397                  * Always inherit the GPE number setting from the ECDT
1398                  * EC.
1399                  */
1400                 ec->gpe = boot_ec->gpe;
1401         } else {
1402                 /* Get GPE bit assignment (EC events). */
1403                 /* TODO: Add support for _GPE returning a package */
1404                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1405                 if (ACPI_SUCCESS(status))
1406                         ec->gpe = tmp;
1407
1408                 /*
1409                  * Errors are non-fatal, allowing for ACPI Reduced Hardware
1410                  * platforms which use GpioInt instead of GPE.
1411                  */
1412         }
1413         /* Use the global lock for all EC transactions? */
1414         tmp = 0;
1415         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1416         ec->global_lock = tmp;
1417         ec->handle = handle;
1418         return AE_CTRL_TERMINATE;
1419 }
1420
1421 static bool install_gpe_event_handler(struct acpi_ec *ec)
1422 {
1423         acpi_status status;
1424
1425         status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1426                                               ACPI_GPE_EDGE_TRIGGERED,
1427                                               &acpi_ec_gpe_handler, ec);
1428         if (ACPI_FAILURE(status))
1429                 return false;
1430
1431         if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1432                 acpi_ec_enable_gpe(ec, true);
1433
1434         return true;
1435 }
1436
1437 static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1438 {
1439         return request_irq(ec->irq, acpi_ec_irq_handler, IRQF_SHARED,
1440                            "ACPI EC", ec) >= 0;
1441 }
1442
1443 /**
1444  * ec_install_handlers - Install service callbacks and register query methods.
1445  * @ec: Target EC.
1446  * @device: ACPI device object corresponding to @ec.
1447  *
1448  * Install a handler for the EC address space type unless it has been installed
1449  * already.  If @device is not NULL, also look for EC query methods in the
1450  * namespace and register them, and install an event (either GPE or GPIO IRQ)
1451  * handler for the EC, if possible.
1452  *
1453  * Return:
1454  * -ENODEV if the address space handler cannot be installed, which means
1455  *  "unable to handle transactions",
1456  * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1457  * or 0 (success) otherwise.
1458  */
1459 static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device)
1460 {
1461         acpi_status status;
1462
1463         acpi_ec_start(ec, false);
1464
1465         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1466                 acpi_ec_enter_noirq(ec);
1467                 status = acpi_install_address_space_handler(ec->handle,
1468                                                             ACPI_ADR_SPACE_EC,
1469                                                             &acpi_ec_space_handler,
1470                                                             NULL, ec);
1471                 if (ACPI_FAILURE(status)) {
1472                         acpi_ec_stop(ec, false);
1473                         return -ENODEV;
1474                 }
1475                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1476         }
1477
1478         if (!device)
1479                 return 0;
1480
1481         if (ec->gpe < 0) {
1482                 /* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1483                 int irq = acpi_dev_gpio_irq_get(device, 0);
1484                 /*
1485                  * Bail out right away for deferred probing or complete the
1486                  * initialization regardless of any other errors.
1487                  */
1488                 if (irq == -EPROBE_DEFER)
1489                         return -EPROBE_DEFER;
1490                 else if (irq >= 0)
1491                         ec->irq = irq;
1492         }
1493
1494         if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1495                 /* Find and register all query methods */
1496                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1497                                     acpi_ec_register_query_methods,
1498                                     NULL, ec, NULL);
1499                 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1500         }
1501         if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1502                 bool ready = false;
1503
1504                 if (ec->gpe >= 0)
1505                         ready = install_gpe_event_handler(ec);
1506                 else if (ec->irq >= 0)
1507                         ready = install_gpio_irq_event_handler(ec);
1508
1509                 if (ready) {
1510                         set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1511                         acpi_ec_leave_noirq(ec);
1512                 }
1513                 /*
1514                  * Failures to install an event handler are not fatal, because
1515                  * the EC can be polled for events.
1516                  */
1517         }
1518         /* EC is fully operational, allow queries */
1519         acpi_ec_enable_event(ec);
1520
1521         return 0;
1522 }
1523
1524 static void ec_remove_handlers(struct acpi_ec *ec)
1525 {
1526         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1527                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1528                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1529                         pr_err("failed to remove space handler\n");
1530                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1531         }
1532
1533         /*
1534          * Stops handling the EC transactions after removing the operation
1535          * region handler. This is required because _REG(DISCONNECT)
1536          * invoked during the removal can result in new EC transactions.
1537          *
1538          * Flushes the EC requests and thus disables the GPE before
1539          * removing the GPE handler. This is required by the current ACPICA
1540          * GPE core. ACPICA GPE core will automatically disable a GPE when
1541          * it is indicated but there is no way to handle it. So the drivers
1542          * must disable the GPEs prior to removing the GPE handlers.
1543          */
1544         acpi_ec_stop(ec, false);
1545
1546         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1547                 if (ec->gpe >= 0 &&
1548                     ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1549                                  &acpi_ec_gpe_handler)))
1550                         pr_err("failed to remove gpe handler\n");
1551
1552                 if (ec->irq >= 0)
1553                         free_irq(ec->irq, ec);
1554
1555                 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1556         }
1557         if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1558                 acpi_ec_remove_query_handlers(ec, true, 0);
1559                 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1560         }
1561 }
1562
1563 static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device)
1564 {
1565         int ret;
1566
1567         ret = ec_install_handlers(ec, device);
1568         if (ret)
1569                 return ret;
1570
1571         /* First EC capable of handling transactions */
1572         if (!first_ec)
1573                 first_ec = ec;
1574
1575         pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1576                 ec->data_addr);
1577
1578         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1579                 if (ec->gpe >= 0)
1580                         pr_info("GPE=0x%x\n", ec->gpe);
1581                 else
1582                         pr_info("IRQ=%d\n", ec->irq);
1583         }
1584
1585         return ret;
1586 }
1587
1588 static int acpi_ec_add(struct acpi_device *device)
1589 {
1590         struct acpi_ec *ec;
1591         int ret;
1592
1593         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1594         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1595
1596         if (boot_ec && (boot_ec->handle == device->handle ||
1597             !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
1598                 /* Fast path: this device corresponds to the boot EC. */
1599                 ec = boot_ec;
1600         } else {
1601                 acpi_status status;
1602
1603                 ec = acpi_ec_alloc();
1604                 if (!ec)
1605                         return -ENOMEM;
1606
1607                 status = ec_parse_device(device->handle, 0, ec, NULL);
1608                 if (status != AE_CTRL_TERMINATE) {
1609                         ret = -EINVAL;
1610                         goto err;
1611                 }
1612
1613                 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1614                     ec->data_addr == boot_ec->data_addr &&
1615                     !EC_FLAGS_TRUST_DSDT_GPE) {
1616                         /*
1617                          * Trust PNP0C09 namespace location rather than
1618                          * ECDT ID. But trust ECDT GPE rather than _GPE
1619                          * because of ASUS quirks, so do not change
1620                          * boot_ec->gpe to ec->gpe.
1621                          */
1622                         boot_ec->handle = ec->handle;
1623                         acpi_handle_debug(ec->handle, "duplicated.\n");
1624                         acpi_ec_free(ec);
1625                         ec = boot_ec;
1626                 }
1627         }
1628
1629         ret = acpi_ec_setup(ec, device);
1630         if (ret)
1631                 goto err;
1632
1633         if (ec == boot_ec)
1634                 acpi_handle_info(boot_ec->handle,
1635                                  "Boot %s EC initialization complete\n",
1636                                  boot_ec_is_ecdt ? "ECDT" : "DSDT");
1637
1638         acpi_handle_info(ec->handle,
1639                          "EC: Used to handle transactions and events\n");
1640
1641         device->driver_data = ec;
1642
1643         ret = !!request_region(ec->data_addr, 1, "EC data");
1644         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1645         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1646         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1647
1648         /* Reprobe devices depending on the EC */
1649         acpi_dev_clear_dependencies(device);
1650
1651         acpi_handle_debug(ec->handle, "enumerated.\n");
1652         return 0;
1653
1654 err:
1655         if (ec != boot_ec)
1656                 acpi_ec_free(ec);
1657
1658         return ret;
1659 }
1660
1661 static int acpi_ec_remove(struct acpi_device *device)
1662 {
1663         struct acpi_ec *ec;
1664
1665         if (!device)
1666                 return -EINVAL;
1667
1668         ec = acpi_driver_data(device);
1669         release_region(ec->data_addr, 1);
1670         release_region(ec->command_addr, 1);
1671         device->driver_data = NULL;
1672         if (ec != boot_ec) {
1673                 ec_remove_handlers(ec);
1674                 acpi_ec_free(ec);
1675         }
1676         return 0;
1677 }
1678
1679 static acpi_status
1680 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1681 {
1682         struct acpi_ec *ec = context;
1683
1684         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1685                 return AE_OK;
1686
1687         /*
1688          * The first address region returned is the data port, and
1689          * the second address region returned is the status/command
1690          * port.
1691          */
1692         if (ec->data_addr == 0)
1693                 ec->data_addr = resource->data.io.minimum;
1694         else if (ec->command_addr == 0)
1695                 ec->command_addr = resource->data.io.minimum;
1696         else
1697                 return AE_CTRL_TERMINATE;
1698
1699         return AE_OK;
1700 }
1701
1702 static const struct acpi_device_id ec_device_ids[] = {
1703         {"PNP0C09", 0},
1704         {ACPI_ECDT_HID, 0},
1705         {"", 0},
1706 };
1707
1708 /*
1709  * This function is not Windows-compatible as Windows never enumerates the
1710  * namespace EC before the main ACPI device enumeration process. It is
1711  * retained for historical reason and will be deprecated in the future.
1712  */
1713 void __init acpi_ec_dsdt_probe(void)
1714 {
1715         struct acpi_ec *ec;
1716         acpi_status status;
1717         int ret;
1718
1719         /*
1720          * If a platform has ECDT, there is no need to proceed as the
1721          * following probe is not a part of the ACPI device enumeration,
1722          * executing _STA is not safe, and thus this probe may risk of
1723          * picking up an invalid EC device.
1724          */
1725         if (boot_ec)
1726                 return;
1727
1728         ec = acpi_ec_alloc();
1729         if (!ec)
1730                 return;
1731
1732         /*
1733          * At this point, the namespace is initialized, so start to find
1734          * the namespace objects.
1735          */
1736         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1737         if (ACPI_FAILURE(status) || !ec->handle) {
1738                 acpi_ec_free(ec);
1739                 return;
1740         }
1741
1742         /*
1743          * When the DSDT EC is available, always re-configure boot EC to
1744          * have _REG evaluated. _REG can only be evaluated after the
1745          * namespace initialization.
1746          * At this point, the GPE is not fully initialized, so do not to
1747          * handle the events.
1748          */
1749         ret = acpi_ec_setup(ec, NULL);
1750         if (ret) {
1751                 acpi_ec_free(ec);
1752                 return;
1753         }
1754
1755         boot_ec = ec;
1756
1757         acpi_handle_info(ec->handle,
1758                          "Boot DSDT EC used to handle transactions\n");
1759 }
1760
1761 /*
1762  * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization.
1763  *
1764  * First, look for an ACPI handle for the boot ECDT EC if acpi_ec_add() has not
1765  * found a matching object in the namespace.
1766  *
1767  * Next, in case the DSDT EC is not functioning, it is still necessary to
1768  * provide a functional ECDT EC to handle events, so add an extra device object
1769  * to represent it (see https://bugzilla.kernel.org/show_bug.cgi?id=115021).
1770  *
1771  * This is useful on platforms with valid ECDT and invalid DSDT EC settings,
1772  * like ASUS X550ZE (see https://bugzilla.kernel.org/show_bug.cgi?id=196847).
1773  */
1774 static void __init acpi_ec_ecdt_start(void)
1775 {
1776         struct acpi_table_ecdt *ecdt_ptr;
1777         acpi_handle handle;
1778         acpi_status status;
1779
1780         /* Bail out if a matching EC has been found in the namespace. */
1781         if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT)
1782                 return;
1783
1784         /* Look up the object pointed to from the ECDT in the namespace. */
1785         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1786                                 (struct acpi_table_header **)&ecdt_ptr);
1787         if (ACPI_FAILURE(status))
1788                 return;
1789
1790         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1791         if (ACPI_SUCCESS(status)) {
1792                 boot_ec->handle = handle;
1793
1794                 /* Add a special ACPI device object to represent the boot EC. */
1795                 acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1796         }
1797
1798         acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1799 }
1800
1801 /*
1802  * On some hardware it is necessary to clear events accumulated by the EC during
1803  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1804  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1805  *
1806  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1807  *
1808  * Ideally, the EC should also be instructed NOT to accumulate events during
1809  * sleep (which Windows seems to do somehow), but the interface to control this
1810  * behaviour is not known at this time.
1811  *
1812  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1813  * however it is very likely that other Samsung models are affected.
1814  *
1815  * On systems which don't accumulate _Q events during sleep, this extra check
1816  * should be harmless.
1817  */
1818 static int ec_clear_on_resume(const struct dmi_system_id *id)
1819 {
1820         pr_debug("Detected system needing EC poll on resume.\n");
1821         EC_FLAGS_CLEAR_ON_RESUME = 1;
1822         ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1823         return 0;
1824 }
1825
1826 /*
1827  * Some ECDTs contain wrong register addresses.
1828  * MSI MS-171F
1829  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1830  */
1831 static int ec_correct_ecdt(const struct dmi_system_id *id)
1832 {
1833         pr_debug("Detected system needing ECDT address correction.\n");
1834         EC_FLAGS_CORRECT_ECDT = 1;
1835         return 0;
1836 }
1837
1838 /*
1839  * Some ECDTs contain wrong GPE setting, but they share the same port addresses
1840  * with DSDT EC, don't duplicate the DSDT EC with ECDT EC in this case.
1841  * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1842  */
1843 static int ec_honor_dsdt_gpe(const struct dmi_system_id *id)
1844 {
1845         pr_debug("Detected system needing DSDT GPE setting.\n");
1846         EC_FLAGS_TRUST_DSDT_GPE = 1;
1847         return 0;
1848 }
1849
1850 /*
1851  * Some DSDTs contain wrong GPE setting.
1852  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1853  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1854  */
1855 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1856 {
1857         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1858         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1859         return 0;
1860 }
1861
1862 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1863         {
1864         ec_correct_ecdt, "MSI MS-171F", {
1865         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1866         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1867         {
1868         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1869         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1870         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1871         {
1872         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1873         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1874         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1875         {
1876         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1877         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1878         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1879         {
1880         ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X505BA", {
1881         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1882         DMI_MATCH(DMI_PRODUCT_NAME, "X505BA"),}, NULL},
1883         {
1884         ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X505BP", {
1885         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1886         DMI_MATCH(DMI_PRODUCT_NAME, "X505BP"),}, NULL},
1887         {
1888         ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X542BA", {
1889         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1890         DMI_MATCH(DMI_PRODUCT_NAME, "X542BA"),}, NULL},
1891         {
1892         ec_honor_ecdt_gpe, "ASUSTeK COMPUTER INC. X542BP", {
1893         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1894         DMI_MATCH(DMI_PRODUCT_NAME, "X542BP"),}, NULL},
1895         {
1896         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1897         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1898         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1899         {
1900         ec_honor_ecdt_gpe, "ASUS X580VD", {
1901         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1902         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1903         {
1904         /* https://bugzilla.kernel.org/show_bug.cgi?id=209989 */
1905         ec_honor_dsdt_gpe, "HP Pavilion Gaming Laptop 15-cx0xxx", {
1906         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1907         DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-cx0xxx"),}, NULL},
1908         {
1909         ec_clear_on_resume, "Samsung hardware", {
1910         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1911         {},
1912 };
1913
1914 void __init acpi_ec_ecdt_probe(void)
1915 {
1916         struct acpi_table_ecdt *ecdt_ptr;
1917         struct acpi_ec *ec;
1918         acpi_status status;
1919         int ret;
1920
1921         /* Generate a boot ec context. */
1922         dmi_check_system(ec_dmi_table);
1923         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1924                                 (struct acpi_table_header **)&ecdt_ptr);
1925         if (ACPI_FAILURE(status))
1926                 return;
1927
1928         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1929                 /*
1930                  * Asus X50GL:
1931                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1932                  */
1933                 goto out;
1934         }
1935
1936         ec = acpi_ec_alloc();
1937         if (!ec)
1938                 goto out;
1939
1940         if (EC_FLAGS_CORRECT_ECDT) {
1941                 ec->command_addr = ecdt_ptr->data.address;
1942                 ec->data_addr = ecdt_ptr->control.address;
1943         } else {
1944                 ec->command_addr = ecdt_ptr->control.address;
1945                 ec->data_addr = ecdt_ptr->data.address;
1946         }
1947
1948         /*
1949          * Ignore the GPE value on Reduced Hardware platforms.
1950          * Some products have this set to an erroneous value.
1951          */
1952         if (!acpi_gbl_reduced_hardware)
1953                 ec->gpe = ecdt_ptr->gpe;
1954
1955         ec->handle = ACPI_ROOT_OBJECT;
1956
1957         /*
1958          * At this point, the namespace is not initialized, so do not find
1959          * the namespace objects, or handle the events.
1960          */
1961         ret = acpi_ec_setup(ec, NULL);
1962         if (ret) {
1963                 acpi_ec_free(ec);
1964                 goto out;
1965         }
1966
1967         boot_ec = ec;
1968         boot_ec_is_ecdt = true;
1969
1970         pr_info("Boot ECDT EC used to handle transactions\n");
1971
1972 out:
1973         acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1974 }
1975
1976 #ifdef CONFIG_PM_SLEEP
1977 static int acpi_ec_suspend(struct device *dev)
1978 {
1979         struct acpi_ec *ec =
1980                 acpi_driver_data(to_acpi_device(dev));
1981
1982         if (!pm_suspend_no_platform() && ec_freeze_events)
1983                 acpi_ec_disable_event(ec);
1984         return 0;
1985 }
1986
1987 static int acpi_ec_suspend_noirq(struct device *dev)
1988 {
1989         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1990
1991         /*
1992          * The SCI handler doesn't run at this point, so the GPE can be
1993          * masked at the low level without side effects.
1994          */
1995         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1996             ec->gpe >= 0 && ec->reference_count >= 1)
1997                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1998
1999         acpi_ec_enter_noirq(ec);
2000
2001         return 0;
2002 }
2003
2004 static int acpi_ec_resume_noirq(struct device *dev)
2005 {
2006         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2007
2008         acpi_ec_leave_noirq(ec);
2009
2010         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2011             ec->gpe >= 0 && ec->reference_count >= 1)
2012                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
2013
2014         return 0;
2015 }
2016
2017 static int acpi_ec_resume(struct device *dev)
2018 {
2019         struct acpi_ec *ec =
2020                 acpi_driver_data(to_acpi_device(dev));
2021
2022         acpi_ec_enable_event(ec);
2023         return 0;
2024 }
2025
2026 void acpi_ec_mark_gpe_for_wake(void)
2027 {
2028         if (first_ec && !ec_no_wakeup)
2029                 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
2030 }
2031 EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
2032
2033 void acpi_ec_set_gpe_wake_mask(u8 action)
2034 {
2035         if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
2036                 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
2037 }
2038
2039 bool acpi_ec_dispatch_gpe(void)
2040 {
2041         bool work_in_progress;
2042         u32 ret;
2043
2044         if (!first_ec)
2045                 return acpi_any_gpe_status_set(U32_MAX);
2046
2047         /*
2048          * Report wakeup if the status bit is set for any enabled GPE other
2049          * than the EC one.
2050          */
2051         if (acpi_any_gpe_status_set(first_ec->gpe))
2052                 return true;
2053
2054         /*
2055          * Cancel the SCI wakeup and process all pending events in case there
2056          * are any wakeup ones in there.
2057          *
2058          * Note that if any non-EC GPEs are active at this point, the SCI will
2059          * retrigger after the rearming in acpi_s2idle_wake(), so no events
2060          * should be missed by canceling the wakeup here.
2061          */
2062         pm_system_cancel_wakeup();
2063
2064         /*
2065          * Dispatch the EC GPE in-band, but do not report wakeup in any case
2066          * to allow the caller to process events properly after that.
2067          */
2068         ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
2069         if (ret == ACPI_INTERRUPT_HANDLED)
2070                 pm_pr_dbg("ACPI EC GPE dispatched\n");
2071
2072         /* Drain EC work. */
2073         do {
2074                 acpi_ec_flush_work();
2075
2076                 pm_pr_dbg("ACPI EC work flushed\n");
2077
2078                 spin_lock_irq(&first_ec->lock);
2079
2080                 work_in_progress = first_ec->events_in_progress +
2081                         first_ec->queries_in_progress > 0;
2082
2083                 spin_unlock_irq(&first_ec->lock);
2084         } while (work_in_progress && !pm_wakeup_pending());
2085
2086         return false;
2087 }
2088 #endif /* CONFIG_PM_SLEEP */
2089
2090 static const struct dev_pm_ops acpi_ec_pm = {
2091         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2092         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2093 };
2094
2095 static int param_set_event_clearing(const char *val,
2096                                     const struct kernel_param *kp)
2097 {
2098         int result = 0;
2099
2100         if (!strncmp(val, "status", sizeof("status") - 1)) {
2101                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2102                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2103         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2104                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2105                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2106         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2107                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2108                 pr_info("Assuming SCI_EVT clearing on event reads\n");
2109         } else
2110                 result = -EINVAL;
2111         return result;
2112 }
2113
2114 static int param_get_event_clearing(char *buffer,
2115                                     const struct kernel_param *kp)
2116 {
2117         switch (ec_event_clearing) {
2118         case ACPI_EC_EVT_TIMING_STATUS:
2119                 return sprintf(buffer, "status\n");
2120         case ACPI_EC_EVT_TIMING_QUERY:
2121                 return sprintf(buffer, "query\n");
2122         case ACPI_EC_EVT_TIMING_EVENT:
2123                 return sprintf(buffer, "event\n");
2124         default:
2125                 return sprintf(buffer, "invalid\n");
2126         }
2127         return 0;
2128 }
2129
2130 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2131                   NULL, 0644);
2132 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2133
2134 static struct acpi_driver acpi_ec_driver = {
2135         .name = "ec",
2136         .class = ACPI_EC_CLASS,
2137         .ids = ec_device_ids,
2138         .ops = {
2139                 .add = acpi_ec_add,
2140                 .remove = acpi_ec_remove,
2141                 },
2142         .drv.pm = &acpi_ec_pm,
2143 };
2144
2145 static void acpi_ec_destroy_workqueues(void)
2146 {
2147         if (ec_wq) {
2148                 destroy_workqueue(ec_wq);
2149                 ec_wq = NULL;
2150         }
2151         if (ec_query_wq) {
2152                 destroy_workqueue(ec_query_wq);
2153                 ec_query_wq = NULL;
2154         }
2155 }
2156
2157 static int acpi_ec_init_workqueues(void)
2158 {
2159         if (!ec_wq)
2160                 ec_wq = alloc_ordered_workqueue("kec", 0);
2161
2162         if (!ec_query_wq)
2163                 ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2164
2165         if (!ec_wq || !ec_query_wq) {
2166                 acpi_ec_destroy_workqueues();
2167                 return -ENODEV;
2168         }
2169         return 0;
2170 }
2171
2172 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2173         {
2174                 .ident = "Thinkpad X1 Carbon 6th",
2175                 .matches = {
2176                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2177                         DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2178                 },
2179         },
2180         {
2181                 .ident = "ThinkPad X1 Carbon 6th",
2182                 .matches = {
2183                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2184                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2185                 },
2186         },
2187         {
2188                 .ident = "ThinkPad X1 Yoga 3rd",
2189                 .matches = {
2190                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2191                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2192                 },
2193         },
2194         { },
2195 };
2196
2197 void __init acpi_ec_init(void)
2198 {
2199         int result;
2200
2201         result = acpi_ec_init_workqueues();
2202         if (result)
2203                 return;
2204
2205         /*
2206          * Disable EC wakeup on following systems to prevent periodic
2207          * wakeup from EC GPE.
2208          */
2209         if (dmi_check_system(acpi_ec_no_wakeup)) {
2210                 ec_no_wakeup = true;
2211                 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2212         }
2213
2214         /* Driver must be registered after acpi_ec_init_workqueues(). */
2215         acpi_bus_register_driver(&acpi_ec_driver);
2216
2217         acpi_ec_ecdt_start();
2218 }
2219
2220 /* EC driver currently not unloadable */
2221 #if 0
2222 static void __exit acpi_ec_exit(void)
2223 {
2224
2225         acpi_bus_unregister_driver(&acpi_ec_driver);
2226         acpi_ec_destroy_workqueues();
2227 }
2228 #endif  /* 0 */