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_by_value(struct acpi_ec *ec, u8 value)
1057 {
1058         struct acpi_ec_query_handler *handler;
1059
1060         mutex_lock(&ec->mutex);
1061         list_for_each_entry(handler, &ec->list, node) {
1062                 if (value == handler->query_bit) {
1063                         kref_get(&handler->kref);
1064                         mutex_unlock(&ec->mutex);
1065                         return handler;
1066                 }
1067         }
1068         mutex_unlock(&ec->mutex);
1069         return NULL;
1070 }
1071
1072 static void acpi_ec_query_handler_release(struct kref *kref)
1073 {
1074         struct acpi_ec_query_handler *handler =
1075                 container_of(kref, struct acpi_ec_query_handler, kref);
1076
1077         kfree(handler);
1078 }
1079
1080 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1081 {
1082         kref_put(&handler->kref, acpi_ec_query_handler_release);
1083 }
1084
1085 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1086                               acpi_handle handle, acpi_ec_query_func func,
1087                               void *data)
1088 {
1089         struct acpi_ec_query_handler *handler =
1090             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1091
1092         if (!handler)
1093                 return -ENOMEM;
1094
1095         handler->query_bit = query_bit;
1096         handler->handle = handle;
1097         handler->func = func;
1098         handler->data = data;
1099         mutex_lock(&ec->mutex);
1100         kref_init(&handler->kref);
1101         list_add(&handler->node, &ec->list);
1102         mutex_unlock(&ec->mutex);
1103         return 0;
1104 }
1105 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1106
1107 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1108                                           bool remove_all, u8 query_bit)
1109 {
1110         struct acpi_ec_query_handler *handler, *tmp;
1111         LIST_HEAD(free_list);
1112
1113         mutex_lock(&ec->mutex);
1114         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1115                 if (remove_all || query_bit == handler->query_bit) {
1116                         list_del_init(&handler->node);
1117                         list_add(&handler->node, &free_list);
1118                 }
1119         }
1120         mutex_unlock(&ec->mutex);
1121         list_for_each_entry_safe(handler, tmp, &free_list, node)
1122                 acpi_ec_put_query_handler(handler);
1123 }
1124
1125 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1126 {
1127         acpi_ec_remove_query_handlers(ec, false, query_bit);
1128 }
1129 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1130
1131 static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
1132 {
1133         struct acpi_ec_query *q;
1134         struct transaction *t;
1135
1136         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1137         if (!q)
1138                 return NULL;
1139         INIT_WORK(&q->work, acpi_ec_event_processor);
1140         t = &q->transaction;
1141         t->command = ACPI_EC_COMMAND_QUERY;
1142         t->rdata = pval;
1143         t->rlen = 1;
1144         return q;
1145 }
1146
1147 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1148 {
1149         if (q) {
1150                 if (q->handler)
1151                         acpi_ec_put_query_handler(q->handler);
1152                 kfree(q);
1153         }
1154 }
1155
1156 static void acpi_ec_event_processor(struct work_struct *work)
1157 {
1158         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1159         struct acpi_ec_query_handler *handler = q->handler;
1160
1161         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1162         if (handler->func)
1163                 handler->func(handler->data);
1164         else if (handler->handle)
1165                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1166         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1167         acpi_ec_delete_query(q);
1168 }
1169
1170 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1171 {
1172         u8 value = 0;
1173         int result;
1174         struct acpi_ec_query *q;
1175
1176         q = acpi_ec_create_query(&value);
1177         if (!q)
1178                 return -ENOMEM;
1179
1180         /*
1181          * Query the EC to find out which _Qxx method we need to evaluate.
1182          * Note that successful completion of the query causes the ACPI_EC_SCI
1183          * bit to be cleared (and thus clearing the interrupt source).
1184          */
1185         result = acpi_ec_transaction(ec, &q->transaction);
1186         if (!value)
1187                 result = -ENODATA;
1188         if (result)
1189                 goto err_exit;
1190
1191         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1192         if (!q->handler) {
1193                 result = -ENODATA;
1194                 goto err_exit;
1195         }
1196
1197         /*
1198          * It is reported that _Qxx are evaluated in a parallel way on
1199          * Windows:
1200          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1201          *
1202          * Put this log entry before schedule_work() in order to make
1203          * it appearing before any other log entries occurred during the
1204          * work queue execution.
1205          */
1206         ec_dbg_evt("Query(0x%02x) scheduled", value);
1207         if (!queue_work(ec_query_wq, &q->work)) {
1208                 ec_dbg_evt("Query(0x%02x) overlapped", value);
1209                 result = -EBUSY;
1210         }
1211
1212 err_exit:
1213         if (result)
1214                 acpi_ec_delete_query(q);
1215         if (data)
1216                 *data = value;
1217         return result;
1218 }
1219
1220 static void acpi_ec_check_event(struct acpi_ec *ec)
1221 {
1222         unsigned long flags;
1223
1224         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1225                 if (ec_guard(ec)) {
1226                         spin_lock_irqsave(&ec->lock, flags);
1227                         /*
1228                          * Take care of the SCI_EVT unless no one else is
1229                          * taking care of it.
1230                          */
1231                         if (!ec->curr)
1232                                 advance_transaction(ec);
1233                         spin_unlock_irqrestore(&ec->lock, flags);
1234                 }
1235         }
1236 }
1237
1238 static void acpi_ec_event_handler(struct work_struct *work)
1239 {
1240         unsigned long flags;
1241         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1242
1243         ec_dbg_evt("Event started");
1244
1245         spin_lock_irqsave(&ec->lock, flags);
1246         while (ec->nr_pending_queries) {
1247                 spin_unlock_irqrestore(&ec->lock, flags);
1248                 (void)acpi_ec_query(ec, NULL);
1249                 spin_lock_irqsave(&ec->lock, flags);
1250                 ec->nr_pending_queries--;
1251                 /*
1252                  * Before exit, make sure that this work item can be
1253                  * scheduled again. There might be QR_EC failures, leaving
1254                  * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1255                  * item from being scheduled again.
1256                  */
1257                 if (!ec->nr_pending_queries) {
1258                         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1259                             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1260                                 acpi_ec_complete_query(ec);
1261                 }
1262         }
1263         spin_unlock_irqrestore(&ec->lock, flags);
1264
1265         ec_dbg_evt("Event stopped");
1266
1267         acpi_ec_check_event(ec);
1268 }
1269
1270 static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1271 {
1272         unsigned long flags;
1273
1274         spin_lock_irqsave(&ec->lock, flags);
1275         advance_transaction(ec);
1276         spin_unlock_irqrestore(&ec->lock, flags);
1277 }
1278
1279 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1280                                u32 gpe_number, void *data)
1281 {
1282         acpi_ec_handle_interrupt(data);
1283         return ACPI_INTERRUPT_HANDLED;
1284 }
1285
1286 static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1287 {
1288         acpi_ec_handle_interrupt(data);
1289         return IRQ_HANDLED;
1290 }
1291
1292 /* --------------------------------------------------------------------------
1293  *                           Address Space Management
1294  * -------------------------------------------------------------------------- */
1295
1296 static acpi_status
1297 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1298                       u32 bits, u64 *value64,
1299                       void *handler_context, void *region_context)
1300 {
1301         struct acpi_ec *ec = handler_context;
1302         int result = 0, i, bytes = bits / 8;
1303         u8 *value = (u8 *)value64;
1304
1305         if ((address > 0xFF) || !value || !handler_context)
1306                 return AE_BAD_PARAMETER;
1307
1308         if (function != ACPI_READ && function != ACPI_WRITE)
1309                 return AE_BAD_PARAMETER;
1310
1311         if (ec->busy_polling || bits > 8)
1312                 acpi_ec_burst_enable(ec);
1313
1314         for (i = 0; i < bytes; ++i, ++address, ++value)
1315                 result = (function == ACPI_READ) ?
1316                         acpi_ec_read(ec, address, value) :
1317                         acpi_ec_write(ec, address, *value);
1318
1319         if (ec->busy_polling || bits > 8)
1320                 acpi_ec_burst_disable(ec);
1321
1322         switch (result) {
1323         case -EINVAL:
1324                 return AE_BAD_PARAMETER;
1325         case -ENODEV:
1326                 return AE_NOT_FOUND;
1327         case -ETIME:
1328                 return AE_TIME;
1329         default:
1330                 return AE_OK;
1331         }
1332 }
1333
1334 /* --------------------------------------------------------------------------
1335  *                             Driver Interface
1336  * -------------------------------------------------------------------------- */
1337
1338 static acpi_status
1339 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1340
1341 static void acpi_ec_free(struct acpi_ec *ec)
1342 {
1343         if (first_ec == ec)
1344                 first_ec = NULL;
1345         if (boot_ec == ec)
1346                 boot_ec = NULL;
1347         kfree(ec);
1348 }
1349
1350 static struct acpi_ec *acpi_ec_alloc(void)
1351 {
1352         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1353
1354         if (!ec)
1355                 return NULL;
1356         mutex_init(&ec->mutex);
1357         init_waitqueue_head(&ec->wait);
1358         INIT_LIST_HEAD(&ec->list);
1359         spin_lock_init(&ec->lock);
1360         INIT_WORK(&ec->work, acpi_ec_event_handler);
1361         ec->timestamp = jiffies;
1362         ec->busy_polling = true;
1363         ec->polling_guard = 0;
1364         ec->gpe = -1;
1365         ec->irq = -1;
1366         return ec;
1367 }
1368
1369 static acpi_status
1370 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1371                                void *context, void **return_value)
1372 {
1373         char node_name[5];
1374         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1375         struct acpi_ec *ec = context;
1376         int value = 0;
1377         acpi_status status;
1378
1379         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1380
1381         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1382                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1383         return AE_OK;
1384 }
1385
1386 static acpi_status
1387 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1388 {
1389         acpi_status status;
1390         unsigned long long tmp = 0;
1391         struct acpi_ec *ec = context;
1392
1393         /* clear addr values, ec_parse_io_ports depend on it */
1394         ec->command_addr = ec->data_addr = 0;
1395
1396         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1397                                      ec_parse_io_ports, ec);
1398         if (ACPI_FAILURE(status))
1399                 return status;
1400         if (ec->data_addr == 0 || ec->command_addr == 0)
1401                 return AE_OK;
1402
1403         if (boot_ec && boot_ec_is_ecdt && EC_FLAGS_IGNORE_DSDT_GPE) {
1404                 /*
1405                  * Always inherit the GPE number setting from the ECDT
1406                  * EC.
1407                  */
1408                 ec->gpe = boot_ec->gpe;
1409         } else {
1410                 /* Get GPE bit assignment (EC events). */
1411                 /* TODO: Add support for _GPE returning a package */
1412                 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1413                 if (ACPI_SUCCESS(status))
1414                         ec->gpe = tmp;
1415
1416                 /*
1417                  * Errors are non-fatal, allowing for ACPI Reduced Hardware
1418                  * platforms which use GpioInt instead of GPE.
1419                  */
1420         }
1421         /* Use the global lock for all EC transactions? */
1422         tmp = 0;
1423         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1424         ec->global_lock = tmp;
1425         ec->handle = handle;
1426         return AE_CTRL_TERMINATE;
1427 }
1428
1429 static void install_gpe_event_handler(struct acpi_ec *ec)
1430 {
1431         acpi_status status =
1432                 acpi_install_gpe_raw_handler(NULL, ec->gpe,
1433                                              ACPI_GPE_EDGE_TRIGGERED,
1434                                              &acpi_ec_gpe_handler,
1435                                              ec);
1436         if (ACPI_SUCCESS(status)) {
1437                 /* This is not fatal as we can poll EC events */
1438                 set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1439                 acpi_ec_leave_noirq(ec);
1440                 if (test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1441                     ec->reference_count >= 1)
1442                         acpi_ec_enable_gpe(ec, true);
1443         }
1444 }
1445
1446 /* ACPI reduced hardware platforms use a GpioInt specified in _CRS. */
1447 static int install_gpio_irq_event_handler(struct acpi_ec *ec,
1448                                           struct acpi_device *device)
1449 {
1450         int irq = acpi_dev_gpio_irq_get(device, 0);
1451         int ret;
1452
1453         if (irq < 0)
1454                 return irq;
1455
1456         ret = request_irq(irq, acpi_ec_irq_handler, IRQF_SHARED,
1457                           "ACPI EC", ec);
1458
1459         /*
1460          * Unlike the GPE case, we treat errors here as fatal, we'll only
1461          * implement GPIO polling if we find a case that needs it.
1462          */
1463         if (ret < 0)
1464                 return ret;
1465
1466         ec->irq = irq;
1467         set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1468         acpi_ec_leave_noirq(ec);
1469
1470         return 0;
1471 }
1472
1473 /*
1474  * Note: This function returns an error code only when the address space
1475  *       handler is not installed, which means "not able to handle
1476  *       transactions".
1477  */
1478 static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device,
1479                                bool handle_events)
1480 {
1481         acpi_status status;
1482
1483         acpi_ec_start(ec, false);
1484
1485         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1486                 acpi_ec_enter_noirq(ec);
1487                 status = acpi_install_address_space_handler(ec->handle,
1488                                                             ACPI_ADR_SPACE_EC,
1489                                                             &acpi_ec_space_handler,
1490                                                             NULL, ec);
1491                 if (ACPI_FAILURE(status)) {
1492                         if (status == AE_NOT_FOUND) {
1493                                 /*
1494                                  * Maybe OS fails in evaluating the _REG
1495                                  * object. The AE_NOT_FOUND error will be
1496                                  * ignored and OS * continue to initialize
1497                                  * EC.
1498                                  */
1499                                 pr_err("Fail in evaluating the _REG object"
1500                                         " of EC device. Broken bios is suspected.\n");
1501                         } else {
1502                                 acpi_ec_stop(ec, false);
1503                                 return -ENODEV;
1504                         }
1505                 }
1506                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1507         }
1508
1509         if (!handle_events)
1510                 return 0;
1511
1512         if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1513                 /* Find and register all query methods */
1514                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1515                                     acpi_ec_register_query_methods,
1516                                     NULL, ec, NULL);
1517                 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1518         }
1519         if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1520                 if (ec->gpe >= 0) {
1521                         install_gpe_event_handler(ec);
1522                 } else if (device) {
1523                         int ret = install_gpio_irq_event_handler(ec, device);
1524
1525                         if (ret)
1526                                 return ret;
1527                 } else { /* No GPE and no GpioInt? */
1528                         return -ENODEV;
1529                 }
1530         }
1531         /* EC is fully operational, allow queries */
1532         acpi_ec_enable_event(ec);
1533
1534         return 0;
1535 }
1536
1537 static void ec_remove_handlers(struct acpi_ec *ec)
1538 {
1539         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1540                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1541                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1542                         pr_err("failed to remove space handler\n");
1543                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1544         }
1545
1546         /*
1547          * Stops handling the EC transactions after removing the operation
1548          * region handler. This is required because _REG(DISCONNECT)
1549          * invoked during the removal can result in new EC transactions.
1550          *
1551          * Flushes the EC requests and thus disables the GPE before
1552          * removing the GPE handler. This is required by the current ACPICA
1553          * GPE core. ACPICA GPE core will automatically disable a GPE when
1554          * it is indicated but there is no way to handle it. So the drivers
1555          * must disable the GPEs prior to removing the GPE handlers.
1556          */
1557         acpi_ec_stop(ec, false);
1558
1559         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1560                 if (ec->gpe >= 0 &&
1561                     ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1562                                  &acpi_ec_gpe_handler)))
1563                         pr_err("failed to remove gpe handler\n");
1564
1565                 if (ec->irq >= 0)
1566                         free_irq(ec->irq, ec);
1567
1568                 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1569         }
1570         if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1571                 acpi_ec_remove_query_handlers(ec, true, 0);
1572                 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1573         }
1574 }
1575
1576 static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device,
1577                          bool handle_events)
1578 {
1579         int ret;
1580
1581         ret = ec_install_handlers(ec, device, handle_events);
1582         if (ret)
1583                 return ret;
1584
1585         /* First EC capable of handling transactions */
1586         if (!first_ec) {
1587                 first_ec = ec;
1588                 acpi_handle_info(first_ec->handle, "Used as first EC\n");
1589         }
1590
1591         acpi_handle_info(ec->handle,
1592                          "GPE=0x%x, IRQ=%d, EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n",
1593                          ec->gpe, ec->irq, ec->command_addr, ec->data_addr);
1594         return ret;
1595 }
1596
1597 static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)
1598 {
1599         struct acpi_table_ecdt *ecdt_ptr;
1600         acpi_status status;
1601         acpi_handle handle;
1602
1603         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1604                                 (struct acpi_table_header **)&ecdt_ptr);
1605         if (ACPI_FAILURE(status))
1606                 return false;
1607
1608         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1609         if (ACPI_FAILURE(status))
1610                 return false;
1611
1612         *phandle = handle;
1613         return true;
1614 }
1615
1616 static int acpi_ec_add(struct acpi_device *device)
1617 {
1618         struct acpi_ec *ec = NULL;
1619         bool dep_update = true;
1620         acpi_status status;
1621         int ret;
1622
1623         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1624         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1625
1626         if (!strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) {
1627                 boot_ec_is_ecdt = true;
1628                 ec = boot_ec;
1629                 dep_update = false;
1630         } else {
1631                 ec = acpi_ec_alloc();
1632                 if (!ec)
1633                         return -ENOMEM;
1634
1635                 status = ec_parse_device(device->handle, 0, ec, NULL);
1636                 if (status != AE_CTRL_TERMINATE) {
1637                         ret = -EINVAL;
1638                         goto err_alloc;
1639                 }
1640
1641                 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1642                     ec->data_addr == boot_ec->data_addr) {
1643                         boot_ec_is_ecdt = false;
1644                         /*
1645                          * Trust PNP0C09 namespace location rather than
1646                          * ECDT ID. But trust ECDT GPE rather than _GPE
1647                          * because of ASUS quirks, so do not change
1648                          * boot_ec->gpe to ec->gpe.
1649                          */
1650                         boot_ec->handle = ec->handle;
1651                         acpi_handle_debug(ec->handle, "duplicated.\n");
1652                         acpi_ec_free(ec);
1653                         ec = boot_ec;
1654                 }
1655         }
1656
1657         ret = acpi_ec_setup(ec, device, true);
1658         if (ret)
1659                 goto err_query;
1660
1661         if (ec == boot_ec)
1662                 acpi_handle_info(boot_ec->handle,
1663                                  "Boot %s EC used to handle transactions and events\n",
1664                                  boot_ec_is_ecdt ? "ECDT" : "DSDT");
1665
1666         device->driver_data = ec;
1667
1668         ret = !!request_region(ec->data_addr, 1, "EC data");
1669         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1670         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1671         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1672
1673         if (dep_update) {
1674                 /* Reprobe devices depending on the EC */
1675                 acpi_walk_dep_device_list(ec->handle);
1676         }
1677         acpi_handle_debug(ec->handle, "enumerated.\n");
1678         return 0;
1679
1680 err_query:
1681         if (ec != boot_ec)
1682                 acpi_ec_remove_query_handlers(ec, true, 0);
1683 err_alloc:
1684         if (ec != boot_ec)
1685                 acpi_ec_free(ec);
1686         return ret;
1687 }
1688
1689 static int acpi_ec_remove(struct acpi_device *device)
1690 {
1691         struct acpi_ec *ec;
1692
1693         if (!device)
1694                 return -EINVAL;
1695
1696         ec = acpi_driver_data(device);
1697         release_region(ec->data_addr, 1);
1698         release_region(ec->command_addr, 1);
1699         device->driver_data = NULL;
1700         if (ec != boot_ec) {
1701                 ec_remove_handlers(ec);
1702                 acpi_ec_free(ec);
1703         }
1704         return 0;
1705 }
1706
1707 static acpi_status
1708 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1709 {
1710         struct acpi_ec *ec = context;
1711
1712         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1713                 return AE_OK;
1714
1715         /*
1716          * The first address region returned is the data port, and
1717          * the second address region returned is the status/command
1718          * port.
1719          */
1720         if (ec->data_addr == 0)
1721                 ec->data_addr = resource->data.io.minimum;
1722         else if (ec->command_addr == 0)
1723                 ec->command_addr = resource->data.io.minimum;
1724         else
1725                 return AE_CTRL_TERMINATE;
1726
1727         return AE_OK;
1728 }
1729
1730 static const struct acpi_device_id ec_device_ids[] = {
1731         {"PNP0C09", 0},
1732         {ACPI_ECDT_HID, 0},
1733         {"", 0},
1734 };
1735
1736 /*
1737  * This function is not Windows-compatible as Windows never enumerates the
1738  * namespace EC before the main ACPI device enumeration process. It is
1739  * retained for historical reason and will be deprecated in the future.
1740  */
1741 void __init acpi_ec_dsdt_probe(void)
1742 {
1743         struct acpi_ec *ec;
1744         acpi_status status;
1745         int ret;
1746
1747         /*
1748          * If a platform has ECDT, there is no need to proceed as the
1749          * following probe is not a part of the ACPI device enumeration,
1750          * executing _STA is not safe, and thus this probe may risk of
1751          * picking up an invalid EC device.
1752          */
1753         if (boot_ec)
1754                 return;
1755
1756         ec = acpi_ec_alloc();
1757         if (!ec)
1758                 return;
1759
1760         /*
1761          * At this point, the namespace is initialized, so start to find
1762          * the namespace objects.
1763          */
1764         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1765         if (ACPI_FAILURE(status) || !ec->handle) {
1766                 acpi_ec_free(ec);
1767                 return;
1768         }
1769
1770         /*
1771          * When the DSDT EC is available, always re-configure boot EC to
1772          * have _REG evaluated. _REG can only be evaluated after the
1773          * namespace initialization.
1774          * At this point, the GPE is not fully initialized, so do not to
1775          * handle the events.
1776          */
1777         ret = acpi_ec_setup(ec, NULL, false);
1778         if (ret) {
1779                 acpi_ec_free(ec);
1780                 return;
1781         }
1782
1783         boot_ec = ec;
1784
1785         acpi_handle_info(ec->handle,
1786                          "Boot DSDT EC used to handle transactions\n");
1787 }
1788
1789 /*
1790  * If the DSDT EC is not functioning, we still need to prepare a fully
1791  * functioning ECDT EC first in order to handle the events.
1792  * https://bugzilla.kernel.org/show_bug.cgi?id=115021
1793  */
1794 static int __init acpi_ec_ecdt_start(void)
1795 {
1796         acpi_handle handle;
1797
1798         if (!boot_ec)
1799                 return -ENODEV;
1800         /* In case acpi_ec_ecdt_start() is called after acpi_ec_add() */
1801         if (!boot_ec_is_ecdt)
1802                 return -ENODEV;
1803
1804         /*
1805          * At this point, the namespace and the GPE is initialized, so
1806          * start to find the namespace objects and handle the events.
1807          *
1808          * Note: ec->handle can be valid if this function is called after
1809          * acpi_ec_add(), hence the fast path.
1810          */
1811         if (boot_ec->handle == ACPI_ROOT_OBJECT) {
1812                 if (!acpi_ec_ecdt_get_handle(&handle))
1813                         return -ENODEV;
1814                 boot_ec->handle = handle;
1815         }
1816
1817         /* Register to ACPI bus with PM ops attached */
1818         return acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1819 }
1820
1821 #if 0
1822 /*
1823  * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1824  * set, for which case, we complete the QR_EC without issuing it to the
1825  * firmware.
1826  * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1827  * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1828  */
1829 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1830 {
1831         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1832         EC_FLAGS_QUERY_HANDSHAKE = 1;
1833         return 0;
1834 }
1835 #endif
1836
1837 /*
1838  * On some hardware it is necessary to clear events accumulated by the EC during
1839  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1840  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1841  *
1842  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1843  *
1844  * Ideally, the EC should also be instructed NOT to accumulate events during
1845  * sleep (which Windows seems to do somehow), but the interface to control this
1846  * behaviour is not known at this time.
1847  *
1848  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1849  * however it is very likely that other Samsung models are affected.
1850  *
1851  * On systems which don't accumulate _Q events during sleep, this extra check
1852  * should be harmless.
1853  */
1854 static int ec_clear_on_resume(const struct dmi_system_id *id)
1855 {
1856         pr_debug("Detected system needing EC poll on resume.\n");
1857         EC_FLAGS_CLEAR_ON_RESUME = 1;
1858         ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1859         return 0;
1860 }
1861
1862 /*
1863  * Some ECDTs contain wrong register addresses.
1864  * MSI MS-171F
1865  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1866  */
1867 static int ec_correct_ecdt(const struct dmi_system_id *id)
1868 {
1869         pr_debug("Detected system needing ECDT address correction.\n");
1870         EC_FLAGS_CORRECT_ECDT = 1;
1871         return 0;
1872 }
1873
1874 /*
1875  * Some DSDTs contain wrong GPE setting.
1876  * Asus FX502VD/VE, GL702VMK, X550VXK, X580VD
1877  * https://bugzilla.kernel.org/show_bug.cgi?id=195651
1878  */
1879 static int ec_honor_ecdt_gpe(const struct dmi_system_id *id)
1880 {
1881         pr_debug("Detected system needing ignore DSDT GPE setting.\n");
1882         EC_FLAGS_IGNORE_DSDT_GPE = 1;
1883         return 0;
1884 }
1885
1886 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1887         {
1888         ec_correct_ecdt, "MSI MS-171F", {
1889         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1890         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1891         {
1892         ec_honor_ecdt_gpe, "ASUS FX502VD", {
1893         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1894         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VD"),}, NULL},
1895         {
1896         ec_honor_ecdt_gpe, "ASUS FX502VE", {
1897         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1898         DMI_MATCH(DMI_PRODUCT_NAME, "FX502VE"),}, NULL},
1899         {
1900         ec_honor_ecdt_gpe, "ASUS GL702VMK", {
1901         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1902         DMI_MATCH(DMI_PRODUCT_NAME, "GL702VMK"),}, NULL},
1903         {
1904         ec_honor_ecdt_gpe, "ASUS X550VXK", {
1905         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1906         DMI_MATCH(DMI_PRODUCT_NAME, "X550VXK"),}, NULL},
1907         {
1908         ec_honor_ecdt_gpe, "ASUS X580VD", {
1909         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
1910         DMI_MATCH(DMI_PRODUCT_NAME, "X580VD"),}, NULL},
1911         {
1912         ec_clear_on_resume, "Samsung hardware", {
1913         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1914         {},
1915 };
1916
1917 void __init acpi_ec_ecdt_probe(void)
1918 {
1919         struct acpi_table_ecdt *ecdt_ptr;
1920         struct acpi_ec *ec;
1921         acpi_status status;
1922         int ret;
1923
1924         /* Generate a boot ec context. */
1925         dmi_check_system(ec_dmi_table);
1926         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1927                                 (struct acpi_table_header **)&ecdt_ptr);
1928         if (ACPI_FAILURE(status))
1929                 return;
1930
1931         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1932                 /*
1933                  * Asus X50GL:
1934                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1935                  */
1936                 return;
1937         }
1938
1939         ec = acpi_ec_alloc();
1940         if (!ec)
1941                 return;
1942
1943         if (EC_FLAGS_CORRECT_ECDT) {
1944                 ec->command_addr = ecdt_ptr->data.address;
1945                 ec->data_addr = ecdt_ptr->control.address;
1946         } else {
1947                 ec->command_addr = ecdt_ptr->control.address;
1948                 ec->data_addr = ecdt_ptr->data.address;
1949         }
1950
1951         /*
1952          * Ignore the GPE value on Reduced Hardware platforms.
1953          * Some products have this set to an erroneous value.
1954          */
1955         if (!acpi_gbl_reduced_hardware)
1956                 ec->gpe = ecdt_ptr->gpe;
1957
1958         ec->handle = ACPI_ROOT_OBJECT;
1959
1960         /*
1961          * At this point, the namespace is not initialized, so do not find
1962          * the namespace objects, or handle the events.
1963          */
1964         ret = acpi_ec_setup(ec, NULL, false);
1965         if (ret) {
1966                 acpi_ec_free(ec);
1967                 return;
1968         }
1969
1970         boot_ec = ec;
1971         boot_ec_is_ecdt = true;
1972
1973         pr_info("Boot ECDT EC used to handle transactions\n");
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         u32 ret;
2042
2043         if (!first_ec)
2044                 return false;
2045
2046         ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
2047         if (ret == ACPI_INTERRUPT_HANDLED) {
2048                 pm_pr_dbg("EC GPE dispatched\n");
2049                 return true;
2050         }
2051         return false;
2052 }
2053 #endif /* CONFIG_PM_SLEEP */
2054
2055 static const struct dev_pm_ops acpi_ec_pm = {
2056         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2057         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2058 };
2059
2060 static int param_set_event_clearing(const char *val,
2061                                     const struct kernel_param *kp)
2062 {
2063         int result = 0;
2064
2065         if (!strncmp(val, "status", sizeof("status") - 1)) {
2066                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2067                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2068         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2069                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2070                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2071         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2072                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2073                 pr_info("Assuming SCI_EVT clearing on event reads\n");
2074         } else
2075                 result = -EINVAL;
2076         return result;
2077 }
2078
2079 static int param_get_event_clearing(char *buffer,
2080                                     const struct kernel_param *kp)
2081 {
2082         switch (ec_event_clearing) {
2083         case ACPI_EC_EVT_TIMING_STATUS:
2084                 return sprintf(buffer, "status");
2085         case ACPI_EC_EVT_TIMING_QUERY:
2086                 return sprintf(buffer, "query");
2087         case ACPI_EC_EVT_TIMING_EVENT:
2088                 return sprintf(buffer, "event");
2089         default:
2090                 return sprintf(buffer, "invalid");
2091         }
2092         return 0;
2093 }
2094
2095 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2096                   NULL, 0644);
2097 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2098
2099 static struct acpi_driver acpi_ec_driver = {
2100         .name = "ec",
2101         .class = ACPI_EC_CLASS,
2102         .ids = ec_device_ids,
2103         .ops = {
2104                 .add = acpi_ec_add,
2105                 .remove = acpi_ec_remove,
2106                 },
2107         .drv.pm = &acpi_ec_pm,
2108 };
2109
2110 static inline int acpi_ec_query_init(void)
2111 {
2112         if (!ec_query_wq) {
2113                 ec_query_wq = alloc_workqueue("kec_query", 0,
2114                                               ec_max_queries);
2115                 if (!ec_query_wq)
2116                         return -ENODEV;
2117         }
2118         return 0;
2119 }
2120
2121 static inline void acpi_ec_query_exit(void)
2122 {
2123         if (ec_query_wq) {
2124                 destroy_workqueue(ec_query_wq);
2125                 ec_query_wq = NULL;
2126         }
2127 }
2128
2129 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2130         {
2131                 .ident = "Thinkpad X1 Carbon 6th",
2132                 .matches = {
2133                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2134                         DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2135                 },
2136         },
2137         {
2138                 .ident = "ThinkPad X1 Carbon 6th",
2139                 .matches = {
2140                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2141                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Carbon 6th"),
2142                 },
2143         },
2144         {
2145                 .ident = "ThinkPad X1 Yoga 3rd",
2146                 .matches = {
2147                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2148                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2149                 },
2150         },
2151         { },
2152 };
2153
2154 int __init acpi_ec_init(void)
2155 {
2156         int result;
2157         int ecdt_fail, dsdt_fail;
2158
2159         /* register workqueue for _Qxx evaluations */
2160         result = acpi_ec_query_init();
2161         if (result)
2162                 return result;
2163
2164         /*
2165          * Disable EC wakeup on following systems to prevent periodic
2166          * wakeup from EC GPE.
2167          */
2168         if (dmi_check_system(acpi_ec_no_wakeup)) {
2169                 ec_no_wakeup = true;
2170                 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2171         }
2172
2173         /* Drivers must be started after acpi_ec_query_init() */
2174         dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver);
2175         /*
2176          * Register ECDT to ACPI bus only when PNP0C09 probe fails. This is
2177          * useful for platforms (confirmed on ASUS X550ZE) with valid ECDT
2178          * settings but invalid DSDT settings.
2179          * https://bugzilla.kernel.org/show_bug.cgi?id=196847
2180          */
2181         ecdt_fail = acpi_ec_ecdt_start();
2182         return ecdt_fail && dsdt_fail ? -ENODEV : 0;
2183 }
2184
2185 /* EC driver currently not unloadable */
2186 #if 0
2187 static void __exit acpi_ec_exit(void)
2188 {
2189
2190         acpi_bus_unregister_driver(&acpi_ec_driver);
2191         acpi_ec_query_exit();
2192 }
2193 #endif  /* 0 */