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_EVENT_HANDLER_INSTALLED,       /* Event handler installed */
  96         EC_FLAGS_EC_HANDLER_INSTALLED,  /* OpReg handler installed */
  97         EC_FLAGS_QUERY_METHODS_INSTALLED, /* _Qxx handlers installed */
  98         EC_FLAGS_STARTED,               /* Driver is started */
  99         EC_FLAGS_STOPPED,               /* Driver is stopped */
 100         EC_FLAGS_EVENTS_MASKED,         /* Events masked */
 101 };
 102
 103 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
 104 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
 105
 106 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 107 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 108 module_param(ec_delay, uint, 0644);
 109 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
 110
 111 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
 112 module_param(ec_max_queries, uint, 0644);
 113 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
 114
 115 static bool ec_busy_polling __read_mostly;
 116 module_param(ec_busy_polling, bool, 0644);
 117 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
 118
 119 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
 120 module_param(ec_polling_guard, uint, 0644);
 121 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
 122
 123 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
 124
 125 /*
 126  * If the number of false interrupts per one transaction exceeds
 127  * this threshold, will think there is a GPE storm happened and
 128  * will disable the GPE for normal transaction.
 129  */
 130 static unsigned int ec_storm_threshold  __read_mostly = 8;
 131 module_param(ec_storm_threshold, uint, 0644);
 132 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 133
 134 static bool ec_freeze_events __read_mostly;
 135 module_param(ec_freeze_events, bool, 0644);
 136 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
 137
 138 static bool ec_no_wakeup __read_mostly;
 139 module_param(ec_no_wakeup, bool, 0644);
 140 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
 141
 142 struct acpi_ec_query_handler {
 143         struct list_head node;
 144         acpi_ec_query_func func;
 145         acpi_handle handle;
 146         void *data;
 147         u8 query_bit;
 148         struct kref kref;
 149 };
 150
 151 struct transaction {
 152         const u8 *wdata;
 153         u8 *rdata;
 154         unsigned short irq_count;
 155         u8 command;
 156         u8 wi;
 157         u8 ri;
 158         u8 wlen;
 159         u8 rlen;
 160         u8 flags;
 161 };
 162
 163 struct acpi_ec_query {
 164         struct transaction transaction;
 165         struct work_struct work;
 166         struct acpi_ec_query_handler *handler;
 167         struct acpi_ec *ec;
 168 };
 169
 170 static int acpi_ec_submit_query(struct acpi_ec *ec);
 171 static void advance_transaction(struct acpi_ec *ec, bool interrupt);
 172 static void acpi_ec_event_handler(struct work_struct *work);
 173
 174 struct acpi_ec *first_ec;
 175 EXPORT_SYMBOL(first_ec);
 176
 177 static struct acpi_ec *boot_ec;
 178 static bool boot_ec_is_ecdt;
 179 static struct workqueue_struct *ec_wq;
 180 static struct workqueue_struct *ec_query_wq;
 181
 182 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
 183 static int EC_FLAGS_TRUST_DSDT_GPE; /* Needs DSDT GPE as correction setting */
 184 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 185
 186 /* --------------------------------------------------------------------------
 187  *                           Logging/Debugging
 188  * -------------------------------------------------------------------------- */
 189
 190 /*
 191  * Splitters used by the developers to track the boundary of the EC
 192  * handling processes.
 193  */
 194 #ifdef DEBUG
 195 #define EC_DBG_SEP      " "
 196 #define EC_DBG_DRV      "+++++"
 197 #define EC_DBG_STM      "====="
 198 #define EC_DBG_REQ      "*****"
 199 #define EC_DBG_EVT      "#####"
 200 #else
 201 #define EC_DBG_SEP      ""
 202 #define EC_DBG_DRV
 203 #define EC_DBG_STM
 204 #define EC_DBG_REQ
 205 #define EC_DBG_EVT
 206 #endif
 207
 208 #define ec_log_raw(fmt, ...) \
 209         pr_info(fmt "\n", ##__VA_ARGS__)
 210 #define ec_dbg_raw(fmt, ...) \
 211         pr_debug(fmt "\n", ##__VA_ARGS__)
 212 #define ec_log(filter, fmt, ...) \
 213         ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 214 #define ec_dbg(filter, fmt, ...) \
 215         ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 216
 217 #define ec_log_drv(fmt, ...) \
 218         ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 219 #define ec_dbg_drv(fmt, ...) \
 220         ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 221 #define ec_dbg_stm(fmt, ...) \
 222         ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
 223 #define ec_dbg_req(fmt, ...) \
 224         ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
 225 #define ec_dbg_evt(fmt, ...) \
 226         ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
 227 #define ec_dbg_ref(ec, fmt, ...) \
 228         ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
 229
 230 /* --------------------------------------------------------------------------
 231  *                           Device Flags
 232  * -------------------------------------------------------------------------- */
 233
 234 static bool acpi_ec_started(struct acpi_ec *ec)
 235 {
 236         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
 237                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
 238 }
 239
 240 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
 241 {
 242         /*
 243          * There is an OSPM early stage logic. During the early stages
 244          * (boot/resume), OSPMs shouldn't enable the event handling, only
 245          * the EC transactions are allowed to be performed.
 246          */
 247         if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 248                 return false;
 249         /*
 250          * However, disabling the event handling is experimental for late
 251          * stage (suspend), and is controlled by the boot parameter of
 252          * "ec_freeze_events":
 253          * 1. true:  The EC event handling is disabled before entering
 254          *           the noirq stage.
 255          * 2. false: The EC event handling is automatically disabled as
 256          *           soon as the EC driver is stopped.
 257          */
 258         if (ec_freeze_events)
 259                 return acpi_ec_started(ec);
 260         else
 261                 return test_bit(EC_FLAGS_STARTED, &ec->flags);
 262 }
 263
 264 static bool acpi_ec_flushed(struct acpi_ec *ec)
 265 {
 266         return ec->reference_count == 1;
 267 }
 268
 269 /* --------------------------------------------------------------------------
 270  *                           EC Registers
 271  * -------------------------------------------------------------------------- */
 272
 273 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 274 {
 275         u8 x = inb(ec->command_addr);
 276
 277         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
 278                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
 279                    x,
 280                    !!(x & ACPI_EC_FLAG_SCI),
 281                    !!(x & ACPI_EC_FLAG_BURST),
 282                    !!(x & ACPI_EC_FLAG_CMD),
 283                    !!(x & ACPI_EC_FLAG_IBF),
 284                    !!(x & ACPI_EC_FLAG_OBF));
 285         return x;
 286 }
 287
 288 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 289 {
 290         u8 x = inb(ec->data_addr);
 291
 292         ec->timestamp = jiffies;
 293         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
 294         return x;
 295 }
 296
 297 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 298 {
 299         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
 300         outb(command, ec->command_addr);
 301         ec->timestamp = jiffies;
 302 }
 303
 304 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 305 {
 306         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
 307         outb(data, ec->data_addr);
 308         ec->timestamp = jiffies;
 309 }
 310
 311 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
 312 static const char *acpi_ec_cmd_string(u8 cmd)
 313 {
 314         switch (cmd) {
 315         case 0x80:
 316                 return "RD_EC";
 317         case 0x81:
 318                 return "WR_EC";
 319         case 0x82:
 320                 return "BE_EC";
 321         case 0x83:
 322                 return "BD_EC";
 323         case 0x84:
 324                 return "QR_EC";
 325         }
 326         return "UNKNOWN";
 327 }
 328 #else
 329 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 330 #endif
 331
 332 /* --------------------------------------------------------------------------
 333  *                           GPE Registers
 334  * -------------------------------------------------------------------------- */
 335
 336 static inline bool acpi_ec_gpe_status_set(struct acpi_ec *ec)
 337 {
 338         acpi_event_status gpe_status = 0;
 339
 340         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
 341         return !!(gpe_status & ACPI_EVENT_FLAG_STATUS_SET);
 342 }
 343
 344 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
 345 {
 346         if (open)
 347                 acpi_enable_gpe(NULL, ec->gpe);
 348         else {
 349                 BUG_ON(ec->reference_count < 1);
 350                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 351         }
 352         if (acpi_ec_gpe_status_set(ec)) {
 353                 /*
 354                  * On some platforms, EN=1 writes cannot trigger GPE. So
 355                  * software need to manually trigger a pseudo GPE event on
 356                  * EN=1 writes.
 357                  */
 358                 ec_dbg_raw("Polling quirk");
 359                 advance_transaction(ec, false);
 360         }
 361 }
 362
 363 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
 364 {
 365         if (close)
 366                 acpi_disable_gpe(NULL, ec->gpe);
 367         else {
 368                 BUG_ON(ec->reference_count < 1);
 369                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 370         }
 371 }
 372
 373 /* --------------------------------------------------------------------------
 374  *                           Transaction Management
 375  * -------------------------------------------------------------------------- */
 376
 377 static void acpi_ec_submit_request(struct acpi_ec *ec)
 378 {
 379         ec->reference_count++;
 380         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
 381             ec->gpe >= 0 && ec->reference_count == 1)
 382                 acpi_ec_enable_gpe(ec, true);
 383 }
 384
 385 static void acpi_ec_complete_request(struct acpi_ec *ec)
 386 {
 387         bool flushed = false;
 388
 389         ec->reference_count--;
 390         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
 391             ec->gpe >= 0 && ec->reference_count == 0)
 392                 acpi_ec_disable_gpe(ec, true);
 393         flushed = acpi_ec_flushed(ec);
 394         if (flushed)
 395                 wake_up(&ec->wait);
 396 }
 397
 398 static void acpi_ec_mask_events(struct acpi_ec *ec)
 399 {
 400         if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
 401                 if (ec->gpe >= 0)
 402                         acpi_ec_disable_gpe(ec, false);
 403                 else
 404                         disable_irq_nosync(ec->irq);
 405
 406                 ec_dbg_drv("Polling enabled");
 407                 set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
 408         }
 409 }
 410
 411 static void acpi_ec_unmask_events(struct acpi_ec *ec)
 412 {
 413         if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
 414                 clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
 415                 if (ec->gpe >= 0)
 416                         acpi_ec_enable_gpe(ec, false);
 417                 else
 418                         enable_irq(ec->irq);
 419
 420                 ec_dbg_drv("Polling disabled");
 421         }
 422 }
 423
 424 /*
 425  * acpi_ec_submit_flushable_request() - Increase the reference count unless
 426  *                                      the flush operation is not in
 427  *                                      progress
 428  * @ec: the EC device
 429  *
 430  * This function must be used before taking a new action that should hold
 431  * the reference count.  If this function returns false, then the action
 432  * must be discarded or it will prevent the flush operation from being
 433  * completed.
 434  */
 435 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
 436 {
 437         if (!acpi_ec_started(ec))
 438                 return false;
 439         acpi_ec_submit_request(ec);
 440         return true;
 441 }
 442
 443 static void acpi_ec_submit_event(struct acpi_ec *ec)
 444 {
 445         /*
 446          * It is safe to mask the events here, because acpi_ec_close_event()
 447          * will run at least once after this.
 448          */
 449         acpi_ec_mask_events(ec);
 450         if (!acpi_ec_event_enabled(ec))
 451                 return;
 452
 453         if (ec->event_state != EC_EVENT_READY)
 454                 return;
 455
 456         ec_dbg_evt("Command(%s) submitted/blocked",
 457                    acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 458
 459         ec->event_state = EC_EVENT_IN_PROGRESS;
 460         /*
 461          * If events_to_process is greater than 0 at this point, the while ()
 462          * loop in acpi_ec_event_handler() is still running and incrementing
 463          * events_to_process will cause it to invoke acpi_ec_submit_query() once
 464          * more, so it is not necessary to queue up the event work to start the
 465          * same loop again.
 466          */
 467         if (ec->events_to_process++ > 0)
 468                 return;
 469
 470         ec->events_in_progress++;
 471         queue_work(ec_wq, &ec->work);
 472 }
 473
 474 static void acpi_ec_complete_event(struct acpi_ec *ec)
 475 {
 476         if (ec->event_state == EC_EVENT_IN_PROGRESS)
 477                 ec->event_state = EC_EVENT_COMPLETE;
 478 }
 479
 480 static void acpi_ec_close_event(struct acpi_ec *ec)
 481 {
 482         if (ec->event_state != EC_EVENT_READY)
 483                 ec_dbg_evt("Command(%s) unblocked",
 484                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 485
 486         ec->event_state = EC_EVENT_READY;
 487         acpi_ec_unmask_events(ec);
 488 }
 489
 490 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
 491 {
 492         if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 493                 ec_log_drv("event unblocked");
 494         /*
 495          * Unconditionally invoke this once after enabling the event
 496          * handling mechanism to detect the pending events.
 497          */
 498         advance_transaction(ec, false);
 499 }
 500
 501 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
 502 {
 503         if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
 504                 ec_log_drv("event blocked");
 505 }
 506
 507 /*
 508  * Process _Q events that might have accumulated in the EC.
 509  * Run with locked ec mutex.
 510  */
 511 static void acpi_ec_clear(struct acpi_ec *ec)
 512 {
 513         int i;
 514
 515         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 516                 if (acpi_ec_submit_query(ec))
 517                         break;
 518         }
 519         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 520                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 521         else
 522                 pr_info("%d stale EC events cleared\n", i);
 523 }
 524
 525 static void acpi_ec_enable_event(struct acpi_ec *ec)
 526 {
 527         unsigned long flags;
 528
 529         spin_lock_irqsave(&ec->lock, flags);
 530         if (acpi_ec_started(ec))
 531                 __acpi_ec_enable_event(ec);
 532         spin_unlock_irqrestore(&ec->lock, flags);
 533
 534         /* Drain additional events if hardware requires that */
 535         if (EC_FLAGS_CLEAR_ON_RESUME)
 536                 acpi_ec_clear(ec);
 537 }
 538
 539 #ifdef CONFIG_PM_SLEEP
 540 static void __acpi_ec_flush_work(void)
 541 {
 542         flush_workqueue(ec_wq); /* flush ec->work */
 543         flush_workqueue(ec_query_wq); /* flush queries */
 544 }
 545
 546 static void acpi_ec_disable_event(struct acpi_ec *ec)
 547 {
 548         unsigned long flags;
 549
 550         spin_lock_irqsave(&ec->lock, flags);
 551         __acpi_ec_disable_event(ec);
 552         spin_unlock_irqrestore(&ec->lock, flags);
 553
 554         /*
 555          * When ec_freeze_events is true, we need to flush events in
 556          * the proper position before entering the noirq stage.
 557          */
 558         __acpi_ec_flush_work();
 559 }
 560
 561 void acpi_ec_flush_work(void)
 562 {
 563         /* Without ec_wq there is nothing to flush. */
 564         if (!ec_wq)
 565                 return;
 566
 567         __acpi_ec_flush_work();
 568 }
 569 #endif /* CONFIG_PM_SLEEP */
 570
 571 static bool acpi_ec_guard_event(struct acpi_ec *ec)
 572 {
 573         unsigned long flags;
 574         bool guarded;
 575
 576         spin_lock_irqsave(&ec->lock, flags);
 577         /*
 578          * If firmware SCI_EVT clearing timing is "event", we actually
 579          * don't know when the SCI_EVT will be cleared by firmware after
 580          * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
 581          * acceptable period.
 582          *
 583          * The guarding period is applicable if the event state is not
 584          * EC_EVENT_READY, but otherwise if the current transaction is of the
 585          * ACPI_EC_COMMAND_QUERY type, the guarding should have elapsed already
 586          * and it should not be applied to let the transaction transition into
 587          * the ACPI_EC_COMMAND_POLL state immediately.
 588          */
 589         guarded = ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 590                 ec->event_state != EC_EVENT_READY &&
 591                 (!ec->curr || ec->curr->command != ACPI_EC_COMMAND_QUERY);
 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
 624         if (ec->curr->command != ACPI_EC_COMMAND_QUERY)
 625                 return;
 626
 627         switch (ec_event_clearing) {
 628         case ACPI_EC_EVT_TIMING_STATUS:
 629                 if (flag == ACPI_EC_COMMAND_POLL)
 630                         acpi_ec_close_event(ec);
 631
 632                 return;
 633
 634         case ACPI_EC_EVT_TIMING_QUERY:
 635                 if (flag == ACPI_EC_COMMAND_COMPLETE)
 636                         acpi_ec_close_event(ec);
 637
 638                 return;
 639
 640         case ACPI_EC_EVT_TIMING_EVENT:
 641                 if (flag == ACPI_EC_COMMAND_COMPLETE)
 642                         acpi_ec_complete_event(ec);
 643         }
 644 }
 645
 646 static void acpi_ec_spurious_interrupt(struct acpi_ec *ec, struct transaction *t)
 647 {
 648         if (t->irq_count < ec_storm_threshold)
 649                 ++t->irq_count;
 650
 651         /* Trigger if the threshold is 0 too. */
 652         if (t->irq_count == ec_storm_threshold)
 653                 acpi_ec_mask_events(ec);
 654 }
 655
 656 static void advance_transaction(struct acpi_ec *ec, bool interrupt)
 657 {
 658         struct transaction *t = ec->curr;
 659         bool wakeup = false;
 660         u8 status;
 661
 662         ec_dbg_stm("%s (%d)", interrupt ? "IRQ" : "TASK", smp_processor_id());
 663
 664         /*
 665          * Clear GPE_STS upfront to allow subsequent hardware GPE_STS 0->1
 666          * changes to always trigger a GPE interrupt.
 667          *
 668          * GPE STS is a W1C register, which means:
 669          *
 670          * 1. Software can clear it without worrying about clearing the other
 671          *    GPEs' STS bits when the hardware sets them in parallel.
 672          *
 673          * 2. As long as software can ensure only clearing it when it is set,
 674          *    hardware won't set it in parallel.
 675          */
 676         if (ec->gpe >= 0 && acpi_ec_gpe_status_set(ec))
 677                 acpi_clear_gpe(NULL, ec->gpe);
 678
 679         status = acpi_ec_read_status(ec);
 680
 681         /*
 682          * Another IRQ or a guarded polling mode advancement is detected,
 683          * the next QR_EC submission is then allowed.
 684          */
 685         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
 686                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 687                     ec->event_state == EC_EVENT_COMPLETE)
 688                         acpi_ec_close_event(ec);
 689
 690                 if (!t)
 691                         goto out;
 692         }
 693
 694         if (t->flags & ACPI_EC_COMMAND_POLL) {
 695                 if (t->wlen > t->wi) {
 696                         if (!(status & ACPI_EC_FLAG_IBF))
 697                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 698                         else if (interrupt && !(status & ACPI_EC_FLAG_SCI))
 699                                 acpi_ec_spurious_interrupt(ec, t);
 700                 } else if (t->rlen > t->ri) {
 701                         if (status & ACPI_EC_FLAG_OBF) {
 702                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 703                                 if (t->rlen == t->ri) {
 704                                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 705                                         wakeup = true;
 706                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 707                                                 ec_dbg_evt("Command(%s) completed by hardware",
 708                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 709                                 }
 710                         } else if (interrupt && !(status & ACPI_EC_FLAG_SCI)) {
 711                                 acpi_ec_spurious_interrupt(ec, t);
 712                         }
 713                 } else if (t->wlen == t->wi && !(status & ACPI_EC_FLAG_IBF)) {
 714                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 715                         wakeup = true;
 716                 }
 717         } else if (!(status & ACPI_EC_FLAG_IBF)) {
 718                 acpi_ec_write_cmd(ec, t->command);
 719                 ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 720         }
 721
 722 out:
 723         if (status & ACPI_EC_FLAG_SCI)
 724                 acpi_ec_submit_event(ec);
 725
 726         if (wakeup && 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, false);
 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         if (!first_ec)
 921                 return -ENODEV;
 922
 923         return acpi_ec_write(first_ec, addr, val);
 924 }
 925 EXPORT_SYMBOL(ec_write);
 926
 927 int ec_transaction(u8 command,
 928                    const u8 *wdata, unsigned wdata_len,
 929                    u8 *rdata, unsigned rdata_len)
 930 {
 931         struct transaction t = {.command = command,
 932                                 .wdata = wdata, .rdata = rdata,
 933                                 .wlen = wdata_len, .rlen = rdata_len};
 934
 935         if (!first_ec)
 936                 return -ENODEV;
 937
 938         return acpi_ec_transaction(first_ec, &t);
 939 }
 940 EXPORT_SYMBOL(ec_transaction);
 941
 942 /* Get the handle to the EC device */
 943 acpi_handle ec_get_handle(void)
 944 {
 945         if (!first_ec)
 946                 return NULL;
 947         return first_ec->handle;
 948 }
 949 EXPORT_SYMBOL(ec_get_handle);
 950
 951 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 952 {
 953         unsigned long flags;
 954
 955         spin_lock_irqsave(&ec->lock, flags);
 956         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 957                 ec_dbg_drv("Starting EC");
 958                 /* Enable GPE for event processing (SCI_EVT=1) */
 959                 if (!resuming) {
 960                         acpi_ec_submit_request(ec);
 961                         ec_dbg_ref(ec, "Increase driver");
 962                 }
 963                 ec_log_drv("EC started");
 964         }
 965         spin_unlock_irqrestore(&ec->lock, flags);
 966 }
 967
 968 static bool acpi_ec_stopped(struct acpi_ec *ec)
 969 {
 970         unsigned long flags;
 971         bool flushed;
 972
 973         spin_lock_irqsave(&ec->lock, flags);
 974         flushed = acpi_ec_flushed(ec);
 975         spin_unlock_irqrestore(&ec->lock, flags);
 976         return flushed;
 977 }
 978
 979 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 980 {
 981         unsigned long flags;
 982
 983         spin_lock_irqsave(&ec->lock, flags);
 984         if (acpi_ec_started(ec)) {
 985                 ec_dbg_drv("Stopping EC");
 986                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
 987                 spin_unlock_irqrestore(&ec->lock, flags);
 988                 wait_event(ec->wait, acpi_ec_stopped(ec));
 989                 spin_lock_irqsave(&ec->lock, flags);
 990                 /* Disable GPE for event processing (SCI_EVT=1) */
 991                 if (!suspending) {
 992                         acpi_ec_complete_request(ec);
 993                         ec_dbg_ref(ec, "Decrease driver");
 994                 } else if (!ec_freeze_events)
 995                         __acpi_ec_disable_event(ec);
 996                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
 997                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
 998                 ec_log_drv("EC stopped");
 999         }
1000         spin_unlock_irqrestore(&ec->lock, flags);
1001 }
1002
1003 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
1004 {
1005         unsigned long flags;
1006
1007         spin_lock_irqsave(&ec->lock, flags);
1008         ec->busy_polling = true;
1009         ec->polling_guard = 0;
1010         ec_log_drv("interrupt blocked");
1011         spin_unlock_irqrestore(&ec->lock, flags);
1012 }
1013
1014 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1015 {
1016         unsigned long flags;
1017
1018         spin_lock_irqsave(&ec->lock, flags);
1019         ec->busy_polling = ec_busy_polling;
1020         ec->polling_guard = ec_polling_guard;
1021         ec_log_drv("interrupt unblocked");
1022         spin_unlock_irqrestore(&ec->lock, flags);
1023 }
1024
1025 void acpi_ec_block_transactions(void)
1026 {
1027         struct acpi_ec *ec = first_ec;
1028
1029         if (!ec)
1030                 return;
1031
1032         mutex_lock(&ec->mutex);
1033         /* Prevent transactions from being carried out */
1034         acpi_ec_stop(ec, true);
1035         mutex_unlock(&ec->mutex);
1036 }
1037
1038 void acpi_ec_unblock_transactions(void)
1039 {
1040         /*
1041          * Allow transactions to happen again (this function is called from
1042          * atomic context during wakeup, so we don't need to acquire the mutex).
1043          */
1044         if (first_ec)
1045                 acpi_ec_start(first_ec, true);
1046 }
1047
1048 /* --------------------------------------------------------------------------
1049                                 Event Management
1050    -------------------------------------------------------------------------- */
1051 static struct acpi_ec_query_handler *
1052 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1053 {
1054         struct acpi_ec_query_handler *handler;
1055
1056         mutex_lock(&ec->mutex);
1057         list_for_each_entry(handler, &ec->list, node) {
1058                 if (value == handler->query_bit) {
1059                         kref_get(&handler->kref);
1060                         mutex_unlock(&ec->mutex);
1061                         return handler;
1062                 }
1063         }
1064         mutex_unlock(&ec->mutex);
1065         return NULL;
1066 }
1067
1068 static void acpi_ec_query_handler_release(struct kref *kref)
1069 {
1070         struct acpi_ec_query_handler *handler =
1071                 container_of(kref, struct acpi_ec_query_handler, kref);
1072
1073         kfree(handler);
1074 }
1075
1076 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1077 {
1078         kref_put(&handler->kref, acpi_ec_query_handler_release);
1079 }
1080
1081 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1082                               acpi_handle handle, acpi_ec_query_func func,
1083                               void *data)
1084 {
1085         struct acpi_ec_query_handler *handler =
1086             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1087
1088         if (!handler)
1089                 return -ENOMEM;
1090
1091         handler->query_bit = query_bit;
1092         handler->handle = handle;
1093         handler->func = func;
1094         handler->data = data;
1095         mutex_lock(&ec->mutex);
1096         kref_init(&handler->kref);
1097         list_add(&handler->node, &ec->list);
1098         mutex_unlock(&ec->mutex);
1099         return 0;
1100 }
1101 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1102
1103 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1104                                           bool remove_all, u8 query_bit)
1105 {
1106         struct acpi_ec_query_handler *handler, *tmp;
1107         LIST_HEAD(free_list);
1108
1109         mutex_lock(&ec->mutex);
1110         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1111                 if (remove_all || query_bit == handler->query_bit) {
1112                         list_del_init(&handler->node);
1113                         list_add(&handler->node, &free_list);
1114                 }
1115         }
1116         mutex_unlock(&ec->mutex);
1117         list_for_each_entry_safe(handler, tmp, &free_list, node)
1118                 acpi_ec_put_query_handler(handler);
1119 }
1120
1121 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1122 {
1123         acpi_ec_remove_query_handlers(ec, false, query_bit);
1124 }
1125 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1126
1127 static void acpi_ec_event_processor(struct work_struct *work)
1128 {
1129         struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1130         struct acpi_ec_query_handler *handler = q->handler;
1131         struct acpi_ec *ec = q->ec;
1132
1133         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1134
1135         if (handler->func)
1136                 handler->func(handler->data);
1137         else if (handler->handle)
1138                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1139
1140         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1141
1142         spin_lock_irq(&ec->lock);
1143         ec->queries_in_progress--;
1144         spin_unlock_irq(&ec->lock);
1145
1146         acpi_ec_put_query_handler(handler);
1147         kfree(q);
1148 }
1149
1150 static struct acpi_ec_query *acpi_ec_create_query(struct acpi_ec *ec, u8 *pval)
1151 {
1152         struct acpi_ec_query *q;
1153         struct transaction *t;
1154
1155         q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1156         if (!q)
1157                 return NULL;
1158
1159         INIT_WORK(&q->work, acpi_ec_event_processor);
1160         t = &q->transaction;
1161         t->command = ACPI_EC_COMMAND_QUERY;
1162         t->rdata = pval;
1163         t->rlen = 1;
1164         q->ec = ec;
1165         return q;
1166 }
1167
1168 static int acpi_ec_submit_query(struct acpi_ec *ec)
1169 {
1170         struct acpi_ec_query *q;
1171         u8 value = 0;
1172         int result;
1173
1174         q = acpi_ec_create_query(ec, &value);
1175         if (!q)
1176                 return -ENOMEM;
1177
1178         /*
1179          * Query the EC to find out which _Qxx method we need to evaluate.
1180          * Note that successful completion of the query causes the ACPI_EC_SCI
1181          * bit to be cleared (and thus clearing the interrupt source).
1182          */
1183         result = acpi_ec_transaction(ec, &q->transaction);
1184         if (result)
1185                 goto err_exit;
1186
1187         if (!value) {
1188                 result = -ENODATA;
1189                 goto err_exit;
1190         }
1191
1192         q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1193         if (!q->handler) {
1194                 result = -ENODATA;
1195                 goto err_exit;
1196         }
1197
1198         /*
1199          * It is reported that _Qxx are evaluated in a parallel way on Windows:
1200          * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1201          *
1202          * Put this log entry before queue_work() to make it appear in the log
1203          * before any other messages emitted during workqueue handling.
1204          */
1205         ec_dbg_evt("Query(0x%02x) scheduled", value);
1206
1207         spin_lock_irq(&ec->lock);
1208
1209         ec->queries_in_progress++;
1210         queue_work(ec_query_wq, &q->work);
1211
1212         spin_unlock_irq(&ec->lock);
1213
1214         return 0;
1215
1216 err_exit:
1217         kfree(q);
1218
1219         return result;
1220 }
1221
1222 static void acpi_ec_event_handler(struct work_struct *work)
1223 {
1224         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1225
1226         ec_dbg_evt("Event started");
1227
1228         spin_lock_irq(&ec->lock);
1229
1230         while (ec->events_to_process) {
1231                 spin_unlock_irq(&ec->lock);
1232
1233                 acpi_ec_submit_query(ec);
1234
1235                 spin_lock_irq(&ec->lock);
1236
1237                 ec->events_to_process--;
1238         }
1239
1240         /*
1241          * Before exit, make sure that the it will be possible to queue up the
1242          * event handling work again regardless of whether or not the query
1243          * queued up above is processed successfully.
1244          */
1245         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1246                 bool guard_timeout;
1247
1248                 acpi_ec_complete_event(ec);
1249
1250                 ec_dbg_evt("Event stopped");
1251
1252                 spin_unlock_irq(&ec->lock);
1253
1254                 guard_timeout = !!ec_guard(ec);
1255
1256                 spin_lock_irq(&ec->lock);
1257
1258                 /* Take care of SCI_EVT unless someone else is doing that. */
1259                 if (guard_timeout && !ec->curr)
1260                         advance_transaction(ec, false);
1261         } else {
1262                 acpi_ec_close_event(ec);
1263
1264                 ec_dbg_evt("Event stopped");
1265         }
1266
1267         ec->events_in_progress--;
1268
1269         spin_unlock_irq(&ec->lock);
1270 }
1271
1272 static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1273 {
1274         unsigned long flags;
1275
1276         spin_lock_irqsave(&ec->lock, flags);
1277         advance_transaction(ec, true);
1278         spin_unlock_irqrestore(&ec->lock, flags);
1279 }
1280
1281 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1282                                u32 gpe_number, void *data)
1283 {
1284         acpi_ec_handle_interrupt(data);
1285         return ACPI_INTERRUPT_HANDLED;
1286 }
1287
1288 static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1289 {
1290         acpi_ec_handle_interrupt(data);
1291         return IRQ_HANDLED;
1292 }
1293
1294 /* --------------------------------------------------------------------------
1295  *                           Address Space Management
1296  * -------------------------------------------------------------------------- */
1297
1298 static acpi_status
1299 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1300                       u32 bits, u64 *value64,
1301                       void *handler_context, void *region_context)
1302 {
1303         struct acpi_ec *ec = handler_context;
1304         int result = 0, i, bytes = bits / 8;
1305         u8 *value = (u8 *)value64;
1306
1307         if ((address > 0xFF) || !value || !handler_context)
1308                 return AE_BAD_PARAMETER;
1309
1310         if (function != ACPI_READ && function != ACPI_WRITE)
1311                 return AE_BAD_PARAMETER;
1312
1313         if (ec->busy_polling || bits > 8)
1314                 acpi_ec_burst_enable(ec);
1315
1316         for (i = 0; i < bytes; ++i, ++address, ++value)
1317                 result = (function == ACPI_READ) ?
1318                         acpi_ec_read(ec, address, value) :
1319                         acpi_ec_write(ec, address, *value);
1320
1321         if (ec->busy_polling || bits > 8)
1322                 acpi_ec_burst_disable(ec);
1323
1324         switch (result) {
1325         case -EINVAL:
1326                 return AE_BAD_PARAMETER;
1327         case -ENODEV:
1328                 return AE_NOT_FOUND;
1329         case -ETIME:
1330                 return AE_TIME;
1331         default:
1332                 return AE_OK;
1333         }
1334 }
1335
1336 /* --------------------------------------------------------------------------
1337  *                             Driver Interface
1338  * -------------------------------------------------------------------------- */
1339
1340 static acpi_status
1341 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1342
1343 static void acpi_ec_free(struct acpi_ec *ec)
1344 {
1345         if (first_ec == ec)
1346                 first_ec = NULL;
1347         if (boot_ec == ec)
1348                 boot_ec = NULL;
1349         kfree(ec);
1350 }
1351
1352 static struct acpi_ec *acpi_ec_alloc(void)
1353 {
1354         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1355
1356         if (!ec)
1357                 return NULL;
1358         mutex_init(&ec->mutex);
1359         init_waitqueue_head(&ec->wait);
1360         INIT_LIST_HEAD(&ec->list);
1361         spin_lock_init(&ec->lock);
1362         INIT_WORK(&ec->work, acpi_ec_event_handler);
1363         ec->timestamp = jiffies;
1364         ec->busy_polling = true;
1365         ec->polling_guard = 0;
1366         ec->gpe = -1;
1367         ec->irq = -1;
1368         return ec;
1369 }
1370
1371 static acpi_status
1372 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1373                                void *context, void **return_value)
1374 {
1375         char node_name[5];
1376         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1377         struct acpi_ec *ec = context;
1378         int value = 0;
1379         acpi_status status;
1380
1381         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1382
1383         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1384                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1385         return AE_OK;
1386 }
1387
1388 static acpi_status
1389 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1390 {
1391         acpi_status status;
1392         unsigned long long tmp = 0;
1393         struct acpi_ec *ec = context;
1394
1395         /* clear addr values, ec_parse_io_ports depend on it */
1396         ec->command_addr = ec->data_addr = 0;
1397
1398         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1399                                      ec_parse_io_ports, ec);
1400         if (ACPI_FAILURE(status))
1401                 return status;
1402         if (ec->data_addr == 0 || ec->command_addr == 0)
1403                 return AE_OK;
1404
1405         /* Get GPE bit assignment (EC events). */
1406         /* TODO: Add support for _GPE returning a package */
1407         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1408         if (ACPI_SUCCESS(status))
1409                 ec->gpe = tmp;
1410         /*
1411          * Errors are non-fatal, allowing for ACPI Reduced Hardware
1412          * platforms which use GpioInt instead of GPE.
1413          */
1414
1415         /* Use the global lock for all EC transactions? */
1416         tmp = 0;
1417         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1418         ec->global_lock = tmp;
1419         ec->handle = handle;
1420         return AE_CTRL_TERMINATE;
1421 }
1422
1423 static bool install_gpe_event_handler(struct acpi_ec *ec)
1424 {
1425         acpi_status status;
1426
1427         status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1428                                               ACPI_GPE_EDGE_TRIGGERED,
1429                                               &acpi_ec_gpe_handler, ec);
1430         if (ACPI_FAILURE(status))
1431                 return false;
1432
1433         if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1434                 acpi_ec_enable_gpe(ec, true);
1435
1436         return true;
1437 }
1438
1439 static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1440 {
1441         return request_irq(ec->irq, acpi_ec_irq_handler, IRQF_SHARED,
1442                            "ACPI EC", ec) >= 0;
1443 }
1444
1445 /**
1446  * ec_install_handlers - Install service callbacks and register query methods.
1447  * @ec: Target EC.
1448  * @device: ACPI device object corresponding to @ec.
1449  *
1450  * Install a handler for the EC address space type unless it has been installed
1451  * already.  If @device is not NULL, also look for EC query methods in the
1452  * namespace and register them, and install an event (either GPE or GPIO IRQ)
1453  * handler for the EC, if possible.
1454  *
1455  * Return:
1456  * -ENODEV if the address space handler cannot be installed, which means
1457  *  "unable to handle transactions",
1458  * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1459  * or 0 (success) otherwise.
1460  */
1461 static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device)
1462 {
1463         acpi_status status;
1464
1465         acpi_ec_start(ec, false);
1466
1467         if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1468                 acpi_ec_enter_noirq(ec);
1469                 status = acpi_install_address_space_handler(ec->handle,
1470                                                             ACPI_ADR_SPACE_EC,
1471                                                             &acpi_ec_space_handler,
1472                                                             NULL, ec);
1473                 if (ACPI_FAILURE(status)) {
1474                         acpi_ec_stop(ec, false);
1475                         return -ENODEV;
1476                 }
1477                 set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1478         }
1479
1480         if (!device)
1481                 return 0;
1482
1483         if (ec->gpe < 0) {
1484                 /* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1485                 int irq = acpi_dev_gpio_irq_get(device, 0);
1486                 /*
1487                  * Bail out right away for deferred probing or complete the
1488                  * initialization regardless of any other errors.
1489                  */
1490                 if (irq == -EPROBE_DEFER)
1491                         return -EPROBE_DEFER;
1492                 else if (irq >= 0)
1493                         ec->irq = irq;
1494         }
1495
1496         if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1497                 /* Find and register all query methods */
1498                 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1499                                     acpi_ec_register_query_methods,
1500                                     NULL, ec, NULL);
1501                 set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1502         }
1503         if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1504                 bool ready = false;
1505
1506                 if (ec->gpe >= 0)
1507                         ready = install_gpe_event_handler(ec);
1508                 else if (ec->irq >= 0)
1509                         ready = install_gpio_irq_event_handler(ec);
1510
1511                 if (ready) {
1512                         set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1513                         acpi_ec_leave_noirq(ec);
1514                 }
1515                 /*
1516                  * Failures to install an event handler are not fatal, because
1517                  * the EC can be polled for events.
1518                  */
1519         }
1520         /* EC is fully operational, allow queries */
1521         acpi_ec_enable_event(ec);
1522
1523         return 0;
1524 }
1525
1526 static void ec_remove_handlers(struct acpi_ec *ec)
1527 {
1528         if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1529                 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1530                                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1531                         pr_err("failed to remove space handler\n");
1532                 clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1533         }
1534
1535         /*
1536          * Stops handling the EC transactions after removing the operation
1537          * region handler. This is required because _REG(DISCONNECT)
1538          * invoked during the removal can result in new EC transactions.
1539          *
1540          * Flushes the EC requests and thus disables the GPE before
1541          * removing the GPE handler. This is required by the current ACPICA
1542          * GPE core. ACPICA GPE core will automatically disable a GPE when
1543          * it is indicated but there is no way to handle it. So the drivers
1544          * must disable the GPEs prior to removing the GPE handlers.
1545          */
1546         acpi_ec_stop(ec, false);
1547
1548         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1549                 if (ec->gpe >= 0 &&
1550                     ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1551                                  &acpi_ec_gpe_handler)))
1552                         pr_err("failed to remove gpe handler\n");
1553
1554                 if (ec->irq >= 0)
1555                         free_irq(ec->irq, ec);
1556
1557                 clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1558         }
1559         if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1560                 acpi_ec_remove_query_handlers(ec, true, 0);
1561                 clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1562         }
1563 }
1564
1565 static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device)
1566 {
1567         int ret;
1568
1569         ret = ec_install_handlers(ec, device);
1570         if (ret)
1571                 return ret;
1572
1573         /* First EC capable of handling transactions */
1574         if (!first_ec)
1575                 first_ec = ec;
1576
1577         pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1578                 ec->data_addr);
1579
1580         if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1581                 if (ec->gpe >= 0)
1582                         pr_info("GPE=0x%x\n", ec->gpe);
1583                 else
1584                         pr_info("IRQ=%d\n", ec->irq);
1585         }
1586
1587         return ret;
1588 }
1589
1590 static int acpi_ec_add(struct acpi_device *device)
1591 {
1592         struct acpi_ec *ec;
1593         int ret;
1594
1595         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1596         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1597
1598         if (boot_ec && (boot_ec->handle == device->handle ||
1599             !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
1600                 /* Fast path: this device corresponds to the boot EC. */
1601                 ec = boot_ec;
1602         } else {
1603                 acpi_status status;
1604
1605                 ec = acpi_ec_alloc();
1606                 if (!ec)
1607                         return -ENOMEM;
1608
1609                 status = ec_parse_device(device->handle, 0, ec, NULL);
1610                 if (status != AE_CTRL_TERMINATE) {
1611                         ret = -EINVAL;
1612                         goto err;
1613                 }
1614
1615                 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1616                     ec->data_addr == boot_ec->data_addr) {
1617                         /*
1618                          * Trust PNP0C09 namespace location rather than ECDT ID.
1619                          * But trust ECDT GPE rather than _GPE because of ASUS
1620                          * quirks. So do not change boot_ec->gpe to ec->gpe,
1621                          * except when the TRUST_DSDT_GPE quirk is set.
1622                          */
1623                         boot_ec->handle = ec->handle;
1624
1625                         if (EC_FLAGS_TRUST_DSDT_GPE)
1626                                 boot_ec->gpe = ec->gpe;
1627
1628                         acpi_handle_debug(ec->handle, "duplicated.\n");
1629                         acpi_ec_free(ec);
1630                         ec = boot_ec;
1631                 }
1632         }
1633
1634         ret = acpi_ec_setup(ec, device);
1635         if (ret)
1636                 goto err;
1637
1638         if (ec == boot_ec)
1639                 acpi_handle_info(boot_ec->handle,
1640                                  "Boot %s EC initialization complete\n",
1641                                  boot_ec_is_ecdt ? "ECDT" : "DSDT");
1642
1643         acpi_handle_info(ec->handle,
1644                          "EC: Used to handle transactions and events\n");
1645
1646         device->driver_data = ec;
1647
1648         ret = !!request_region(ec->data_addr, 1, "EC data");
1649         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1650         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1651         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1652
1653         /* Reprobe devices depending on the EC */
1654         acpi_dev_clear_dependencies(device);
1655
1656         acpi_handle_debug(ec->handle, "enumerated.\n");
1657         return 0;
1658
1659 err:
1660         if (ec != boot_ec)
1661                 acpi_ec_free(ec);
1662
1663         return ret;
1664 }
1665
1666 static int acpi_ec_remove(struct acpi_device *device)
1667 {
1668         struct acpi_ec *ec;
1669
1670         if (!device)
1671                 return -EINVAL;
1672
1673         ec = acpi_driver_data(device);
1674         release_region(ec->data_addr, 1);
1675         release_region(ec->command_addr, 1);
1676         device->driver_data = NULL;
1677         if (ec != boot_ec) {
1678                 ec_remove_handlers(ec);
1679                 acpi_ec_free(ec);
1680         }
1681         return 0;
1682 }
1683
1684 static acpi_status
1685 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1686 {
1687         struct acpi_ec *ec = context;
1688
1689         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1690                 return AE_OK;
1691
1692         /*
1693          * The first address region returned is the data port, and
1694          * the second address region returned is the status/command
1695          * port.
1696          */
1697         if (ec->data_addr == 0)
1698                 ec->data_addr = resource->data.io.minimum;
1699         else if (ec->command_addr == 0)
1700                 ec->command_addr = resource->data.io.minimum;
1701         else
1702                 return AE_CTRL_TERMINATE;
1703
1704         return AE_OK;
1705 }
1706
1707 static const struct acpi_device_id ec_device_ids[] = {
1708         {"PNP0C09", 0},
1709         {ACPI_ECDT_HID, 0},
1710         {"", 0},
1711 };
1712
1713 /*
1714  * This function is not Windows-compatible as Windows never enumerates the
1715  * namespace EC before the main ACPI device enumeration process. It is
1716  * retained for historical reason and will be deprecated in the future.
1717  */
1718 void __init acpi_ec_dsdt_probe(void)
1719 {
1720         struct acpi_ec *ec;
1721         acpi_status status;
1722         int ret;
1723
1724         /*
1725          * If a platform has ECDT, there is no need to proceed as the
1726          * following probe is not a part of the ACPI device enumeration,
1727          * executing _STA is not safe, and thus this probe may risk of
1728          * picking up an invalid EC device.
1729          */
1730         if (boot_ec)
1731                 return;
1732
1733         ec = acpi_ec_alloc();
1734         if (!ec)
1735                 return;
1736
1737         /*
1738          * At this point, the namespace is initialized, so start to find
1739          * the namespace objects.
1740          */
1741         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1742         if (ACPI_FAILURE(status) || !ec->handle) {
1743                 acpi_ec_free(ec);
1744                 return;
1745         }
1746
1747         /*
1748          * When the DSDT EC is available, always re-configure boot EC to
1749          * have _REG evaluated. _REG can only be evaluated after the
1750          * namespace initialization.
1751          * At this point, the GPE is not fully initialized, so do not to
1752          * handle the events.
1753          */
1754         ret = acpi_ec_setup(ec, NULL);
1755         if (ret) {
1756                 acpi_ec_free(ec);
1757                 return;
1758         }
1759
1760         boot_ec = ec;
1761
1762         acpi_handle_info(ec->handle,
1763                          "Boot DSDT EC used to handle transactions\n");
1764 }
1765
1766 /*
1767  * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization.
1768  *
1769  * First, look for an ACPI handle for the boot ECDT EC if acpi_ec_add() has not
1770  * found a matching object in the namespace.
1771  *
1772  * Next, in case the DSDT EC is not functioning, it is still necessary to
1773  * provide a functional ECDT EC to handle events, so add an extra device object
1774  * to represent it (see https://bugzilla.kernel.org/show_bug.cgi?id=115021).
1775  *
1776  * This is useful on platforms with valid ECDT and invalid DSDT EC settings,
1777  * like ASUS X550ZE (see https://bugzilla.kernel.org/show_bug.cgi?id=196847).
1778  */
1779 static void __init acpi_ec_ecdt_start(void)
1780 {
1781         struct acpi_table_ecdt *ecdt_ptr;
1782         acpi_handle handle;
1783         acpi_status status;
1784
1785         /* Bail out if a matching EC has been found in the namespace. */
1786         if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT)
1787                 return;
1788
1789         /* Look up the object pointed to from the ECDT in the namespace. */
1790         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1791                                 (struct acpi_table_header **)&ecdt_ptr);
1792         if (ACPI_FAILURE(status))
1793                 return;
1794
1795         status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1796         if (ACPI_SUCCESS(status)) {
1797                 boot_ec->handle = handle;
1798
1799                 /* Add a special ACPI device object to represent the boot EC. */
1800                 acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1801         }
1802
1803         acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1804 }
1805
1806 /*
1807  * On some hardware it is necessary to clear events accumulated by the EC during
1808  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1809  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1810  *
1811  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1812  *
1813  * Ideally, the EC should also be instructed NOT to accumulate events during
1814  * sleep (which Windows seems to do somehow), but the interface to control this
1815  * behaviour is not known at this time.
1816  *
1817  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1818  * however it is very likely that other Samsung models are affected.
1819  *
1820  * On systems which don't accumulate _Q events during sleep, this extra check
1821  * should be harmless.
1822  */
1823 static int ec_clear_on_resume(const struct dmi_system_id *id)
1824 {
1825         pr_debug("Detected system needing EC poll on resume.\n");
1826         EC_FLAGS_CLEAR_ON_RESUME = 1;
1827         ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1828         return 0;
1829 }
1830
1831 /*
1832  * Some ECDTs contain wrong register addresses.
1833  * MSI MS-171F
1834  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1835  */
1836 static int ec_correct_ecdt(const struct dmi_system_id *id)
1837 {
1838         pr_debug("Detected system needing ECDT address correction.\n");
1839         EC_FLAGS_CORRECT_ECDT = 1;
1840         return 0;
1841 }
1842
1843 /*
1844  * Some ECDTs contain wrong GPE setting, but they share the same port addresses
1845  * with DSDT EC, don't duplicate the DSDT EC with ECDT EC in this case.
1846  * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1847  */
1848 static int ec_honor_dsdt_gpe(const struct dmi_system_id *id)
1849 {
1850         pr_debug("Detected system needing DSDT GPE setting.\n");
1851         EC_FLAGS_TRUST_DSDT_GPE = 1;
1852         return 0;
1853 }
1854
1855 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1856         {
1857                 /*
1858                  * MSI MS-171F
1859                  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1860                  */
1861                 .callback = ec_correct_ecdt,
1862                 .matches = {
1863                         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1864                         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),
1865                 },
1866         },
1867         {
1868                 /*
1869                  * HP Pavilion Gaming Laptop 15-cx0xxx
1870                  * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1871                  */
1872                 .callback = ec_honor_dsdt_gpe,
1873                 .matches = {
1874                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1875                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-cx0xxx"),
1876                 },
1877         },
1878         {
1879                 /*
1880                  * Samsung hardware
1881                  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1882                  */
1883                 .callback = ec_clear_on_resume,
1884                 .matches = {
1885                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
1886                 },
1887         },
1888         {}
1889 };
1890
1891 void __init acpi_ec_ecdt_probe(void)
1892 {
1893         struct acpi_table_ecdt *ecdt_ptr;
1894         struct acpi_ec *ec;
1895         acpi_status status;
1896         int ret;
1897
1898         /* Generate a boot ec context. */
1899         dmi_check_system(ec_dmi_table);
1900         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1901                                 (struct acpi_table_header **)&ecdt_ptr);
1902         if (ACPI_FAILURE(status))
1903                 return;
1904
1905         if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1906                 /*
1907                  * Asus X50GL:
1908                  * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1909                  */
1910                 goto out;
1911         }
1912
1913         ec = acpi_ec_alloc();
1914         if (!ec)
1915                 goto out;
1916
1917         if (EC_FLAGS_CORRECT_ECDT) {
1918                 ec->command_addr = ecdt_ptr->data.address;
1919                 ec->data_addr = ecdt_ptr->control.address;
1920         } else {
1921                 ec->command_addr = ecdt_ptr->control.address;
1922                 ec->data_addr = ecdt_ptr->data.address;
1923         }
1924
1925         /*
1926          * Ignore the GPE value on Reduced Hardware platforms.
1927          * Some products have this set to an erroneous value.
1928          */
1929         if (!acpi_gbl_reduced_hardware)
1930                 ec->gpe = ecdt_ptr->gpe;
1931
1932         ec->handle = ACPI_ROOT_OBJECT;
1933
1934         /*
1935          * At this point, the namespace is not initialized, so do not find
1936          * the namespace objects, or handle the events.
1937          */
1938         ret = acpi_ec_setup(ec, NULL);
1939         if (ret) {
1940                 acpi_ec_free(ec);
1941                 goto out;
1942         }
1943
1944         boot_ec = ec;
1945         boot_ec_is_ecdt = true;
1946
1947         pr_info("Boot ECDT EC used to handle transactions\n");
1948
1949 out:
1950         acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1951 }
1952
1953 #ifdef CONFIG_PM_SLEEP
1954 static int acpi_ec_suspend(struct device *dev)
1955 {
1956         struct acpi_ec *ec =
1957                 acpi_driver_data(to_acpi_device(dev));
1958
1959         if (!pm_suspend_no_platform() && ec_freeze_events)
1960                 acpi_ec_disable_event(ec);
1961         return 0;
1962 }
1963
1964 static int acpi_ec_suspend_noirq(struct device *dev)
1965 {
1966         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1967
1968         /*
1969          * The SCI handler doesn't run at this point, so the GPE can be
1970          * masked at the low level without side effects.
1971          */
1972         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1973             ec->gpe >= 0 && ec->reference_count >= 1)
1974                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1975
1976         acpi_ec_enter_noirq(ec);
1977
1978         return 0;
1979 }
1980
1981 static int acpi_ec_resume_noirq(struct device *dev)
1982 {
1983         struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1984
1985         acpi_ec_leave_noirq(ec);
1986
1987         if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1988             ec->gpe >= 0 && ec->reference_count >= 1)
1989                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1990
1991         return 0;
1992 }
1993
1994 static int acpi_ec_resume(struct device *dev)
1995 {
1996         struct acpi_ec *ec =
1997                 acpi_driver_data(to_acpi_device(dev));
1998
1999         acpi_ec_enable_event(ec);
2000         return 0;
2001 }
2002
2003 void acpi_ec_mark_gpe_for_wake(void)
2004 {
2005         if (first_ec && !ec_no_wakeup)
2006                 acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
2007 }
2008 EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
2009
2010 void acpi_ec_set_gpe_wake_mask(u8 action)
2011 {
2012         if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
2013                 acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
2014 }
2015
2016 static bool acpi_ec_work_in_progress(struct acpi_ec *ec)
2017 {
2018         return ec->events_in_progress + ec->queries_in_progress > 0;
2019 }
2020
2021 bool acpi_ec_dispatch_gpe(void)
2022 {
2023         bool work_in_progress = false;
2024
2025         if (!first_ec)
2026                 return acpi_any_gpe_status_set(U32_MAX);
2027
2028         /*
2029          * Report wakeup if the status bit is set for any enabled GPE other
2030          * than the EC one.
2031          */
2032         if (acpi_any_gpe_status_set(first_ec->gpe))
2033                 return true;
2034
2035         /*
2036          * Cancel the SCI wakeup and process all pending events in case there
2037          * are any wakeup ones in there.
2038          *
2039          * Note that if any non-EC GPEs are active at this point, the SCI will
2040          * retrigger after the rearming in acpi_s2idle_wake(), so no events
2041          * should be missed by canceling the wakeup here.
2042          */
2043         pm_system_cancel_wakeup();
2044
2045         /*
2046          * Dispatch the EC GPE in-band, but do not report wakeup in any case
2047          * to allow the caller to process events properly after that.
2048          */
2049         spin_lock_irq(&first_ec->lock);
2050
2051         if (acpi_ec_gpe_status_set(first_ec)) {
2052                 pm_pr_dbg("ACPI EC GPE status set\n");
2053
2054                 advance_transaction(first_ec, false);
2055                 work_in_progress = acpi_ec_work_in_progress(first_ec);
2056         }
2057
2058         spin_unlock_irq(&first_ec->lock);
2059
2060         if (!work_in_progress)
2061                 return false;
2062
2063         pm_pr_dbg("ACPI EC GPE dispatched\n");
2064
2065         /* Drain EC work. */
2066         do {
2067                 acpi_ec_flush_work();
2068
2069                 pm_pr_dbg("ACPI EC work flushed\n");
2070
2071                 spin_lock_irq(&first_ec->lock);
2072
2073                 work_in_progress = acpi_ec_work_in_progress(first_ec);
2074
2075                 spin_unlock_irq(&first_ec->lock);
2076         } while (work_in_progress && !pm_wakeup_pending());
2077
2078         return false;
2079 }
2080 #endif /* CONFIG_PM_SLEEP */
2081
2082 static const struct dev_pm_ops acpi_ec_pm = {
2083         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2084         SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2085 };
2086
2087 static int param_set_event_clearing(const char *val,
2088                                     const struct kernel_param *kp)
2089 {
2090         int result = 0;
2091
2092         if (!strncmp(val, "status", sizeof("status") - 1)) {
2093                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2094                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2095         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
2096                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2097                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2098         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
2099                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2100                 pr_info("Assuming SCI_EVT clearing on event reads\n");
2101         } else
2102                 result = -EINVAL;
2103         return result;
2104 }
2105
2106 static int param_get_event_clearing(char *buffer,
2107                                     const struct kernel_param *kp)
2108 {
2109         switch (ec_event_clearing) {
2110         case ACPI_EC_EVT_TIMING_STATUS:
2111                 return sprintf(buffer, "status\n");
2112         case ACPI_EC_EVT_TIMING_QUERY:
2113                 return sprintf(buffer, "query\n");
2114         case ACPI_EC_EVT_TIMING_EVENT:
2115                 return sprintf(buffer, "event\n");
2116         default:
2117                 return sprintf(buffer, "invalid\n");
2118         }
2119         return 0;
2120 }
2121
2122 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2123                   NULL, 0644);
2124 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2125
2126 static struct acpi_driver acpi_ec_driver = {
2127         .name = "ec",
2128         .class = ACPI_EC_CLASS,
2129         .ids = ec_device_ids,
2130         .ops = {
2131                 .add = acpi_ec_add,
2132                 .remove = acpi_ec_remove,
2133                 },
2134         .drv.pm = &acpi_ec_pm,
2135 };
2136
2137 static void acpi_ec_destroy_workqueues(void)
2138 {
2139         if (ec_wq) {
2140                 destroy_workqueue(ec_wq);
2141                 ec_wq = NULL;
2142         }
2143         if (ec_query_wq) {
2144                 destroy_workqueue(ec_query_wq);
2145                 ec_query_wq = NULL;
2146         }
2147 }
2148
2149 static int acpi_ec_init_workqueues(void)
2150 {
2151         if (!ec_wq)
2152                 ec_wq = alloc_ordered_workqueue("kec", 0);
2153
2154         if (!ec_query_wq)
2155                 ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2156
2157         if (!ec_wq || !ec_query_wq) {
2158                 acpi_ec_destroy_workqueues();
2159                 return -ENODEV;
2160         }
2161         return 0;
2162 }
2163
2164 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2165         {
2166                 .matches = {
2167                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2168                         DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2169                 },
2170         },
2171         {
2172                 .matches = {
2173                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2174                         DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2175                 },
2176         },
2177         {
2178                 .matches = {
2179                         DMI_MATCH(DMI_SYS_VENDOR, "HP"),
2180                         DMI_MATCH(DMI_PRODUCT_FAMILY, "103C_5336AN HP ZHAN 66 Pro"),
2181                 },
2182         },
2183         { },
2184 };
2185
2186 void __init acpi_ec_init(void)
2187 {
2188         int result;
2189
2190         result = acpi_ec_init_workqueues();
2191         if (result)
2192                 return;
2193
2194         /*
2195          * Disable EC wakeup on following systems to prevent periodic
2196          * wakeup from EC GPE.
2197          */
2198         if (dmi_check_system(acpi_ec_no_wakeup)) {
2199                 ec_no_wakeup = true;
2200                 pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2201         }
2202
2203         /* Driver must be registered after acpi_ec_init_workqueues(). */
2204         acpi_bus_register_driver(&acpi_ec_driver);
2205
2206         acpi_ec_ecdt_start();
2207 }
2208
2209 /* EC driver currently not unloadable */
2210 #if 0
2211 static void __exit acpi_ec_exit(void)
2212 {
2213
2214         acpi_bus_unregister_driver(&acpi_ec_driver);
2215         acpi_ec_destroy_workqueues();
2216 }
2217 #endif  /* 0 */