drivers/acpi/ec.c

   1 /*
   2  *  ec.c - ACPI Embedded Controller Driver (v3)
   3  *
   4  *  Copyright (C) 2001-2015 Intel Corporation
   5  *    Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>
   6  *            2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
   7  *            2006       Denis Sadykov <denis.m.sadykov@intel.com>
   8  *            2004       Luming Yu <luming.yu@intel.com>
   9  *            2001, 2002 Andy Grover <andrew.grover@intel.com>
  10  *            2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
  11  *  Copyright (C) 2008      Alexey Starikovskiy <astarikovskiy@suse.de>
  12  *
  13  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  14  *
  15  *  This program is free software; you can redistribute it and/or modify
  16  *  it under the terms of the GNU General Public License as published by
  17  *  the Free Software Foundation; either version 2 of the License, or (at
  18  *  your option) any later version.
  19  *
  20  *  This program is distributed in the hope that it will be useful, but
  21  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  23  *  General Public License for more details.
  24  *
  25  *  You should have received a copy of the GNU General Public License along
  26  *  with this program; if not, write to the Free Software Foundation, Inc.,
  27  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  28  *
  29  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  30  */
  31
  32 /* Uncomment next line to get verbose printout */
  33 /* #define DEBUG */
  34 #define pr_fmt(fmt) "ACPI : EC: " fmt
  35
  36 #include <linux/kernel.h>
  37 #include <linux/module.h>
  38 #include <linux/init.h>
  39 #include <linux/types.h>
  40 #include <linux/delay.h>
  41 #include <linux/interrupt.h>
  42 #include <linux/list.h>
  43 #include <linux/spinlock.h>
  44 #include <linux/slab.h>
  45 #include <linux/acpi.h>
  46 #include <linux/dmi.h>
  47 #include <asm/io.h>
  48
  49 #include "internal.h"
  50
  51 #define ACPI_EC_CLASS                   "embedded_controller"
  52 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  53 #define ACPI_EC_FILE_INFO               "info"
  54
  55 /* EC status register */
  56 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  57 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  58 #define ACPI_EC_FLAG_CMD        0x08    /* Input buffer contains a command */
  59 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  60 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  61
  62 /* EC commands */
  63 enum ec_command {
  64         ACPI_EC_COMMAND_READ = 0x80,
  65         ACPI_EC_COMMAND_WRITE = 0x81,
  66         ACPI_EC_BURST_ENABLE = 0x82,
  67         ACPI_EC_BURST_DISABLE = 0x83,
  68         ACPI_EC_COMMAND_QUERY = 0x84,
  69 };
  70
  71 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  72 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  73 #define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
  74 #define ACPI_EC_UDELAY_POLL     1000    /* Wait 1ms for EC transaction polling */
  75 #define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
  76                                          * when trying to clear the EC */
  77
  78 enum {
  79         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  80         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
  81                                          * OpReg are installed */
  82         EC_FLAGS_STARTED,               /* Driver is started */
  83         EC_FLAGS_STOPPED,               /* Driver is stopped */
  84         EC_FLAGS_COMMAND_STORM,         /* GPE storms occurred to the
  85                                          * current command processing */
  86 };
  87
  88 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
  89 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
  90
  91 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
  92 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
  93 module_param(ec_delay, uint, 0644);
  94 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
  95
  96 /*
  97  * If the number of false interrupts per one transaction exceeds
  98  * this threshold, will think there is a GPE storm happened and
  99  * will disable the GPE for normal transaction.
 100  */
 101 static unsigned int ec_storm_threshold  __read_mostly = 8;
 102 module_param(ec_storm_threshold, uint, 0644);
 103 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 104
 105 struct acpi_ec_query_handler {
 106         struct list_head node;
 107         acpi_ec_query_func func;
 108         acpi_handle handle;
 109         void *data;
 110         u8 query_bit;
 111         struct kref kref;
 112 };
 113
 114 struct transaction {
 115         const u8 *wdata;
 116         u8 *rdata;
 117         unsigned short irq_count;
 118         u8 command;
 119         u8 wi;
 120         u8 ri;
 121         u8 wlen;
 122         u8 rlen;
 123         u8 flags;
 124         unsigned long timestamp;
 125 };
 126
 127 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
 128 static void advance_transaction(struct acpi_ec *ec);
 129
 130 struct acpi_ec *boot_ec, *first_ec;
 131 EXPORT_SYMBOL(first_ec);
 132
 133 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 134 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 135 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 136 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 137 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
 138
 139 /* --------------------------------------------------------------------------
 140  *                           Logging/Debugging
 141  * -------------------------------------------------------------------------- */
 142
 143 /*
 144  * Splitters used by the developers to track the boundary of the EC
 145  * handling processes.
 146  */
 147 #ifdef DEBUG
 148 #define EC_DBG_SEP      " "
 149 #define EC_DBG_DRV      "+++++"
 150 #define EC_DBG_STM      "====="
 151 #define EC_DBG_REQ      "*****"
 152 #define EC_DBG_EVT      "#####"
 153 #else
 154 #define EC_DBG_SEP      ""
 155 #define EC_DBG_DRV
 156 #define EC_DBG_STM
 157 #define EC_DBG_REQ
 158 #define EC_DBG_EVT
 159 #endif
 160
 161 #define ec_log_raw(fmt, ...) \
 162         pr_info(fmt "\n", ##__VA_ARGS__)
 163 #define ec_dbg_raw(fmt, ...) \
 164         pr_debug(fmt "\n", ##__VA_ARGS__)
 165 #define ec_log(filter, fmt, ...) \
 166         ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 167 #define ec_dbg(filter, fmt, ...) \
 168         ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 169
 170 #define ec_log_drv(fmt, ...) \
 171         ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 172 #define ec_dbg_drv(fmt, ...) \
 173         ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 174 #define ec_dbg_stm(fmt, ...) \
 175         ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
 176 #define ec_dbg_req(fmt, ...) \
 177         ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
 178 #define ec_dbg_evt(fmt, ...) \
 179         ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
 180
 181 /* --------------------------------------------------------------------------
 182  *                           Device Flags
 183  * -------------------------------------------------------------------------- */
 184
 185 static bool acpi_ec_started(struct acpi_ec *ec)
 186 {
 187         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
 188                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
 189 }
 190
 191 static bool acpi_ec_flushed(struct acpi_ec *ec)
 192 {
 193         return ec->reference_count == 1;
 194 }
 195
 196 /* --------------------------------------------------------------------------
 197  *                           EC Registers
 198  * -------------------------------------------------------------------------- */
 199
 200 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 201 {
 202         u8 x = inb(ec->command_addr);
 203
 204         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
 205                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
 206                    x,
 207                    !!(x & ACPI_EC_FLAG_SCI),
 208                    !!(x & ACPI_EC_FLAG_BURST),
 209                    !!(x & ACPI_EC_FLAG_CMD),
 210                    !!(x & ACPI_EC_FLAG_IBF),
 211                    !!(x & ACPI_EC_FLAG_OBF));
 212         return x;
 213 }
 214
 215 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 216 {
 217         u8 x = inb(ec->data_addr);
 218
 219         ec->curr->timestamp = jiffies;
 220         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
 221         return x;
 222 }
 223
 224 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 225 {
 226         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
 227         outb(command, ec->command_addr);
 228         ec->curr->timestamp = jiffies;
 229 }
 230
 231 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 232 {
 233         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
 234         outb(data, ec->data_addr);
 235         ec->curr->timestamp = jiffies;
 236 }
 237
 238 #ifdef DEBUG
 239 static const char *acpi_ec_cmd_string(u8 cmd)
 240 {
 241         switch (cmd) {
 242         case 0x80:
 243                 return "RD_EC";
 244         case 0x81:
 245                 return "WR_EC";
 246         case 0x82:
 247                 return "BE_EC";
 248         case 0x83:
 249                 return "BD_EC";
 250         case 0x84:
 251                 return "QR_EC";
 252         }
 253         return "UNKNOWN";
 254 }
 255 #else
 256 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 257 #endif
 258
 259 /* --------------------------------------------------------------------------
 260  *                           GPE Registers
 261  * -------------------------------------------------------------------------- */
 262
 263 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
 264 {
 265         acpi_event_status gpe_status = 0;
 266
 267         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
 268         return (gpe_status & ACPI_EVENT_FLAG_SET) ? true : false;
 269 }
 270
 271 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
 272 {
 273         if (open)
 274                 acpi_enable_gpe(NULL, ec->gpe);
 275         else {
 276                 BUG_ON(ec->reference_count < 1);
 277                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 278         }
 279         if (acpi_ec_is_gpe_raised(ec)) {
 280                 /*
 281                  * On some platforms, EN=1 writes cannot trigger GPE. So
 282                  * software need to manually trigger a pseudo GPE event on
 283                  * EN=1 writes.
 284                  */
 285                 ec_dbg_raw("Polling quirk");
 286                 advance_transaction(ec);
 287         }
 288 }
 289
 290 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
 291 {
 292         if (close)
 293                 acpi_disable_gpe(NULL, ec->gpe);
 294         else {
 295                 BUG_ON(ec->reference_count < 1);
 296                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 297         }
 298 }
 299
 300 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
 301 {
 302         /*
 303          * GPE STS is a W1C register, which means:
 304          * 1. Software can clear it without worrying about clearing other
 305          *    GPEs' STS bits when the hardware sets them in parallel.
 306          * 2. As long as software can ensure only clearing it when it is
 307          *    set, hardware won't set it in parallel.
 308          * So software can clear GPE in any contexts.
 309          * Warning: do not move the check into advance_transaction() as the
 310          * EC commands will be sent without GPE raised.
 311          */
 312         if (!acpi_ec_is_gpe_raised(ec))
 313                 return;
 314         acpi_clear_gpe(NULL, ec->gpe);
 315 }
 316
 317 /* --------------------------------------------------------------------------
 318  *                           Transaction Management
 319  * -------------------------------------------------------------------------- */
 320
 321 static void acpi_ec_submit_request(struct acpi_ec *ec)
 322 {
 323         ec->reference_count++;
 324         if (ec->reference_count == 1)
 325                 acpi_ec_enable_gpe(ec, true);
 326 }
 327
 328 static void acpi_ec_complete_request(struct acpi_ec *ec)
 329 {
 330         bool flushed = false;
 331
 332         ec->reference_count--;
 333         if (ec->reference_count == 0)
 334                 acpi_ec_disable_gpe(ec, true);
 335         flushed = acpi_ec_flushed(ec);
 336         if (flushed)
 337                 wake_up(&ec->wait);
 338 }
 339
 340 static void acpi_ec_set_storm(struct acpi_ec *ec, u8 flag)
 341 {
 342         if (!test_bit(flag, &ec->flags)) {
 343                 acpi_ec_disable_gpe(ec, false);
 344                 ec_dbg_drv("Polling enabled");
 345                 set_bit(flag, &ec->flags);
 346         }
 347 }
 348
 349 static void acpi_ec_clear_storm(struct acpi_ec *ec, u8 flag)
 350 {
 351         if (test_bit(flag, &ec->flags)) {
 352                 clear_bit(flag, &ec->flags);
 353                 acpi_ec_enable_gpe(ec, false);
 354                 ec_dbg_drv("Polling disabled");
 355         }
 356 }
 357
 358 /*
 359  * acpi_ec_submit_flushable_request() - Increase the reference count unless
 360  *                                      the flush operation is not in
 361  *                                      progress
 362  * @ec: the EC device
 363  *
 364  * This function must be used before taking a new action that should hold
 365  * the reference count.  If this function returns false, then the action
 366  * must be discarded or it will prevent the flush operation from being
 367  * completed.
 368  */
 369 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
 370 {
 371         if (!acpi_ec_started(ec))
 372                 return false;
 373         acpi_ec_submit_request(ec);
 374         return true;
 375 }
 376
 377 static void acpi_ec_submit_query(struct acpi_ec *ec)
 378 {
 379         if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 380                 ec_dbg_req("Event started");
 381                 schedule_work(&ec->work);
 382         }
 383 }
 384
 385 static void acpi_ec_complete_query(struct acpi_ec *ec)
 386 {
 387         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 388                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 389                 ec_dbg_req("Event stopped");
 390         }
 391 }
 392
 393 static int ec_transaction_completed(struct acpi_ec *ec)
 394 {
 395         unsigned long flags;
 396         int ret = 0;
 397
 398         spin_lock_irqsave(&ec->lock, flags);
 399         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 400                 ret = 1;
 401         spin_unlock_irqrestore(&ec->lock, flags);
 402         return ret;
 403 }
 404
 405 static void advance_transaction(struct acpi_ec *ec)
 406 {
 407         struct transaction *t;
 408         u8 status;
 409         bool wakeup = false;
 410
 411         ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
 412                    smp_processor_id());
 413         /*
 414          * By always clearing STS before handling all indications, we can
 415          * ensure a hardware STS 0->1 change after this clearing can always
 416          * trigger a GPE interrupt.
 417          */
 418         acpi_ec_clear_gpe(ec);
 419         status = acpi_ec_read_status(ec);
 420         t = ec->curr;
 421         if (!t)
 422                 goto err;
 423         if (t->flags & ACPI_EC_COMMAND_POLL) {
 424                 if (t->wlen > t->wi) {
 425                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 426                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 427                         else
 428                                 goto err;
 429                 } else if (t->rlen > t->ri) {
 430                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 431                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 432                                 if (t->rlen == t->ri) {
 433                                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 434                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 435                                                 ec_dbg_req("Command(%s) hardware completion",
 436                                                            acpi_ec_cmd_string(t->command));
 437                                         wakeup = true;
 438                                 }
 439                         } else
 440                                 goto err;
 441                 } else if (t->wlen == t->wi &&
 442                            (status & ACPI_EC_FLAG_IBF) == 0) {
 443                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 444                         wakeup = true;
 445                 }
 446                 goto out;
 447         } else {
 448                 if (EC_FLAGS_QUERY_HANDSHAKE &&
 449                     !(status & ACPI_EC_FLAG_SCI) &&
 450                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 451                         t->flags |= ACPI_EC_COMMAND_POLL;
 452                         acpi_ec_complete_query(ec);
 453                         t->rdata[t->ri++] = 0x00;
 454                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 455                         ec_dbg_req("Command(%s) software completion",
 456                                    acpi_ec_cmd_string(t->command));
 457                         wakeup = true;
 458                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 459                         acpi_ec_write_cmd(ec, t->command);
 460                         t->flags |= ACPI_EC_COMMAND_POLL;
 461                         acpi_ec_complete_query(ec);
 462                 } else
 463                         goto err;
 464                 goto out;
 465         }
 466 err:
 467         /*
 468          * If SCI bit is set, then don't think it's a false IRQ
 469          * otherwise will take a not handled IRQ as a false one.
 470          */
 471         if (!(status & ACPI_EC_FLAG_SCI)) {
 472                 if (in_interrupt() && t) {
 473                         if (t->irq_count < ec_storm_threshold)
 474                                 ++t->irq_count;
 475                         /* Allow triggering on 0 threshold */
 476                         if (t->irq_count == ec_storm_threshold)
 477                                 acpi_ec_set_storm(ec, EC_FLAGS_COMMAND_STORM);
 478                 }
 479         }
 480 out:
 481         if (status & ACPI_EC_FLAG_SCI)
 482                 acpi_ec_submit_query(ec);
 483         if (wakeup && in_interrupt())
 484                 wake_up(&ec->wait);
 485 }
 486
 487 static void start_transaction(struct acpi_ec *ec)
 488 {
 489         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 490         ec->curr->flags = 0;
 491         ec->curr->timestamp = jiffies;
 492         advance_transaction(ec);
 493 }
 494
 495 static int ec_poll(struct acpi_ec *ec)
 496 {
 497         unsigned long flags;
 498         int repeat = 5; /* number of command restarts */
 499
 500         while (repeat--) {
 501                 unsigned long delay = jiffies +
 502                         msecs_to_jiffies(ec_delay);
 503                 unsigned long usecs = ACPI_EC_UDELAY_POLL;
 504                 do {
 505                         /* don't sleep with disabled interrupts */
 506                         if (EC_FLAGS_MSI || irqs_disabled()) {
 507                                 usecs = ACPI_EC_MSI_UDELAY;
 508                                 udelay(usecs);
 509                                 if (ec_transaction_completed(ec))
 510                                         return 0;
 511                         } else {
 512                                 if (wait_event_timeout(ec->wait,
 513                                                 ec_transaction_completed(ec),
 514                                                 usecs_to_jiffies(usecs)))
 515                                         return 0;
 516                         }
 517                         spin_lock_irqsave(&ec->lock, flags);
 518                         if (time_after(jiffies,
 519                                         ec->curr->timestamp +
 520                                         usecs_to_jiffies(usecs)))
 521                                 advance_transaction(ec);
 522                         spin_unlock_irqrestore(&ec->lock, flags);
 523                 } while (time_before(jiffies, delay));
 524                 pr_debug("controller reset, restart transaction\n");
 525                 spin_lock_irqsave(&ec->lock, flags);
 526                 start_transaction(ec);
 527                 spin_unlock_irqrestore(&ec->lock, flags);
 528         }
 529         return -ETIME;
 530 }
 531
 532 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 533                                         struct transaction *t)
 534 {
 535         unsigned long tmp;
 536         int ret = 0;
 537
 538         if (EC_FLAGS_MSI)
 539                 udelay(ACPI_EC_MSI_UDELAY);
 540         /* start transaction */
 541         spin_lock_irqsave(&ec->lock, tmp);
 542         /* Enable GPE for command processing (IBF=0/OBF=1) */
 543         if (!acpi_ec_submit_flushable_request(ec)) {
 544                 ret = -EINVAL;
 545                 goto unlock;
 546         }
 547         /* following two actions should be kept atomic */
 548         ec->curr = t;
 549         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 550         start_transaction(ec);
 551         spin_unlock_irqrestore(&ec->lock, tmp);
 552         ret = ec_poll(ec);
 553         spin_lock_irqsave(&ec->lock, tmp);
 554         if (t->irq_count == ec_storm_threshold)
 555                 acpi_ec_clear_storm(ec, EC_FLAGS_COMMAND_STORM);
 556         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 557         ec->curr = NULL;
 558         /* Disable GPE for command processing (IBF=0/OBF=1) */
 559         acpi_ec_complete_request(ec);
 560 unlock:
 561         spin_unlock_irqrestore(&ec->lock, tmp);
 562         return ret;
 563 }
 564
 565 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 566 {
 567         int status;
 568         u32 glk;
 569
 570         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 571                 return -EINVAL;
 572         if (t->rdata)
 573                 memset(t->rdata, 0, t->rlen);
 574         mutex_lock(&ec->mutex);
 575         if (ec->global_lock) {
 576                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 577                 if (ACPI_FAILURE(status)) {
 578                         status = -ENODEV;
 579                         goto unlock;
 580                 }
 581         }
 582
 583         status = acpi_ec_transaction_unlocked(ec, t);
 584
 585         if (test_bit(EC_FLAGS_COMMAND_STORM, &ec->flags))
 586                 msleep(1);
 587         if (ec->global_lock)
 588                 acpi_release_global_lock(glk);
 589 unlock:
 590         mutex_unlock(&ec->mutex);
 591         return status;
 592 }
 593
 594 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 595 {
 596         u8 d;
 597         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 598                                 .wdata = NULL, .rdata = &d,
 599                                 .wlen = 0, .rlen = 1};
 600
 601         return acpi_ec_transaction(ec, &t);
 602 }
 603
 604 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 605 {
 606         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 607                                 .wdata = NULL, .rdata = NULL,
 608                                 .wlen = 0, .rlen = 0};
 609
 610         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 611                                 acpi_ec_transaction(ec, &t) : 0;
 612 }
 613
 614 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 615 {
 616         int result;
 617         u8 d;
 618         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 619                                 .wdata = &address, .rdata = &d,
 620                                 .wlen = 1, .rlen = 1};
 621
 622         result = acpi_ec_transaction(ec, &t);
 623         *data = d;
 624         return result;
 625 }
 626
 627 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 628 {
 629         u8 wdata[2] = { address, data };
 630         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 631                                 .wdata = wdata, .rdata = NULL,
 632                                 .wlen = 2, .rlen = 0};
 633
 634         return acpi_ec_transaction(ec, &t);
 635 }
 636
 637 int ec_read(u8 addr, u8 *val)
 638 {
 639         int err;
 640         u8 temp_data;
 641
 642         if (!first_ec)
 643                 return -ENODEV;
 644
 645         err = acpi_ec_read(first_ec, addr, &temp_data);
 646
 647         if (!err) {
 648                 *val = temp_data;
 649                 return 0;
 650         }
 651         return err;
 652 }
 653 EXPORT_SYMBOL(ec_read);
 654
 655 int ec_write(u8 addr, u8 val)
 656 {
 657         int err;
 658
 659         if (!first_ec)
 660                 return -ENODEV;
 661
 662         err = acpi_ec_write(first_ec, addr, val);
 663
 664         return err;
 665 }
 666 EXPORT_SYMBOL(ec_write);
 667
 668 int ec_transaction(u8 command,
 669                    const u8 *wdata, unsigned wdata_len,
 670                    u8 *rdata, unsigned rdata_len)
 671 {
 672         struct transaction t = {.command = command,
 673                                 .wdata = wdata, .rdata = rdata,
 674                                 .wlen = wdata_len, .rlen = rdata_len};
 675
 676         if (!first_ec)
 677                 return -ENODEV;
 678
 679         return acpi_ec_transaction(first_ec, &t);
 680 }
 681 EXPORT_SYMBOL(ec_transaction);
 682
 683 /* Get the handle to the EC device */
 684 acpi_handle ec_get_handle(void)
 685 {
 686         if (!first_ec)
 687                 return NULL;
 688         return first_ec->handle;
 689 }
 690 EXPORT_SYMBOL(ec_get_handle);
 691
 692 /*
 693  * Process _Q events that might have accumulated in the EC.
 694  * Run with locked ec mutex.
 695  */
 696 static void acpi_ec_clear(struct acpi_ec *ec)
 697 {
 698         int i, status;
 699         u8 value = 0;
 700
 701         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 702                 status = acpi_ec_query(ec, &value);
 703                 if (status || !value)
 704                         break;
 705         }
 706
 707         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 708                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 709         else
 710                 pr_info("%d stale EC events cleared\n", i);
 711 }
 712
 713 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 714 {
 715         unsigned long flags;
 716
 717         spin_lock_irqsave(&ec->lock, flags);
 718         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 719                 ec_dbg_drv("Starting EC");
 720                 /* Enable GPE for event processing (SCI_EVT=1) */
 721                 if (!resuming)
 722                         acpi_ec_submit_request(ec);
 723                 ec_log_drv("EC started");
 724         }
 725         spin_unlock_irqrestore(&ec->lock, flags);
 726 }
 727
 728 static bool acpi_ec_stopped(struct acpi_ec *ec)
 729 {
 730         unsigned long flags;
 731         bool flushed;
 732
 733         spin_lock_irqsave(&ec->lock, flags);
 734         flushed = acpi_ec_flushed(ec);
 735         spin_unlock_irqrestore(&ec->lock, flags);
 736         return flushed;
 737 }
 738
 739 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 740 {
 741         unsigned long flags;
 742
 743         spin_lock_irqsave(&ec->lock, flags);
 744         if (acpi_ec_started(ec)) {
 745                 ec_dbg_drv("Stopping EC");
 746                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
 747                 spin_unlock_irqrestore(&ec->lock, flags);
 748                 wait_event(ec->wait, acpi_ec_stopped(ec));
 749                 spin_lock_irqsave(&ec->lock, flags);
 750                 /* Disable GPE for event processing (SCI_EVT=1) */
 751                 if (!suspending)
 752                         acpi_ec_complete_request(ec);
 753                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
 754                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
 755                 ec_log_drv("EC stopped");
 756         }
 757         spin_unlock_irqrestore(&ec->lock, flags);
 758 }
 759
 760 void acpi_ec_block_transactions(void)
 761 {
 762         struct acpi_ec *ec = first_ec;
 763
 764         if (!ec)
 765                 return;
 766
 767         mutex_lock(&ec->mutex);
 768         /* Prevent transactions from being carried out */
 769         acpi_ec_stop(ec, true);
 770         mutex_unlock(&ec->mutex);
 771 }
 772
 773 void acpi_ec_unblock_transactions(void)
 774 {
 775         struct acpi_ec *ec = first_ec;
 776
 777         if (!ec)
 778                 return;
 779
 780         /* Allow transactions to be carried out again */
 781         acpi_ec_start(ec, true);
 782
 783         if (EC_FLAGS_CLEAR_ON_RESUME)
 784                 acpi_ec_clear(ec);
 785 }
 786
 787 void acpi_ec_unblock_transactions_early(void)
 788 {
 789         /*
 790          * Allow transactions to happen again (this function is called from
 791          * atomic context during wakeup, so we don't need to acquire the mutex).
 792          */
 793         if (first_ec)
 794                 acpi_ec_start(first_ec, true);
 795 }
 796
 797 /* --------------------------------------------------------------------------
 798                                 Event Management
 799    -------------------------------------------------------------------------- */
 800 static struct acpi_ec_query_handler *
 801 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
 802 {
 803         if (handler)
 804                 kref_get(&handler->kref);
 805         return handler;
 806 }
 807
 808 static void acpi_ec_query_handler_release(struct kref *kref)
 809 {
 810         struct acpi_ec_query_handler *handler =
 811                 container_of(kref, struct acpi_ec_query_handler, kref);
 812
 813         kfree(handler);
 814 }
 815
 816 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
 817 {
 818         kref_put(&handler->kref, acpi_ec_query_handler_release);
 819 }
 820
 821 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 822                               acpi_handle handle, acpi_ec_query_func func,
 823                               void *data)
 824 {
 825         struct acpi_ec_query_handler *handler =
 826             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 827
 828         if (!handler)
 829                 return -ENOMEM;
 830
 831         handler->query_bit = query_bit;
 832         handler->handle = handle;
 833         handler->func = func;
 834         handler->data = data;
 835         mutex_lock(&ec->mutex);
 836         kref_init(&handler->kref);
 837         list_add(&handler->node, &ec->list);
 838         mutex_unlock(&ec->mutex);
 839         return 0;
 840 }
 841 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 842
 843 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 844 {
 845         struct acpi_ec_query_handler *handler, *tmp;
 846         LIST_HEAD(free_list);
 847
 848         mutex_lock(&ec->mutex);
 849         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 850                 if (query_bit == handler->query_bit) {
 851                         list_del_init(&handler->node);
 852                         list_add(&handler->node, &free_list);
 853                 }
 854         }
 855         mutex_unlock(&ec->mutex);
 856         list_for_each_entry(handler, &free_list, node)
 857                 acpi_ec_put_query_handler(handler);
 858 }
 859 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 860
 861 static void acpi_ec_run(void *cxt)
 862 {
 863         struct acpi_ec_query_handler *handler = cxt;
 864
 865         if (!handler)
 866                 return;
 867         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
 868         if (handler->func)
 869                 handler->func(handler->data);
 870         else if (handler->handle)
 871                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 872         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
 873         acpi_ec_put_query_handler(handler);
 874 }
 875
 876 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
 877 {
 878         u8 value = 0;
 879         int result;
 880         acpi_status status;
 881         struct acpi_ec_query_handler *handler;
 882         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 883                                 .wdata = NULL, .rdata = &value,
 884                                 .wlen = 0, .rlen = 1};
 885
 886         /*
 887          * Query the EC to find out which _Qxx method we need to evaluate.
 888          * Note that successful completion of the query causes the ACPI_EC_SCI
 889          * bit to be cleared (and thus clearing the interrupt source).
 890          */
 891         result = acpi_ec_transaction(ec, &t);
 892         if (result)
 893                 return result;
 894         if (data)
 895                 *data = value;
 896         if (!value)
 897                 return -ENODATA;
 898
 899         mutex_lock(&ec->mutex);
 900         list_for_each_entry(handler, &ec->list, node) {
 901                 if (value == handler->query_bit) {
 902                         /* have custom handler for this bit */
 903                         handler = acpi_ec_get_query_handler(handler);
 904                         ec_dbg_evt("Query(0x%02x) scheduled",
 905                                    handler->query_bit);
 906                         status = acpi_os_execute((handler->func) ?
 907                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 908                                 acpi_ec_run, handler);
 909                         if (ACPI_FAILURE(status))
 910                                 result = -EBUSY;
 911                         break;
 912                 }
 913         }
 914         mutex_unlock(&ec->mutex);
 915         return result;
 916 }
 917
 918 static void acpi_ec_gpe_poller(struct work_struct *work)
 919 {
 920         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
 921
 922         acpi_ec_query(ec, NULL);
 923 }
 924
 925 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 926         u32 gpe_number, void *data)
 927 {
 928         unsigned long flags;
 929         struct acpi_ec *ec = data;
 930
 931         spin_lock_irqsave(&ec->lock, flags);
 932         advance_transaction(ec);
 933         spin_unlock_irqrestore(&ec->lock, flags);
 934         return ACPI_INTERRUPT_HANDLED;
 935 }
 936
 937 /* --------------------------------------------------------------------------
 938  *                           Address Space Management
 939  * -------------------------------------------------------------------------- */
 940
 941 static acpi_status
 942 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 943                       u32 bits, u64 *value64,
 944                       void *handler_context, void *region_context)
 945 {
 946         struct acpi_ec *ec = handler_context;
 947         int result = 0, i, bytes = bits / 8;
 948         u8 *value = (u8 *)value64;
 949
 950         if ((address > 0xFF) || !value || !handler_context)
 951                 return AE_BAD_PARAMETER;
 952
 953         if (function != ACPI_READ && function != ACPI_WRITE)
 954                 return AE_BAD_PARAMETER;
 955
 956         if (EC_FLAGS_MSI || bits > 8)
 957                 acpi_ec_burst_enable(ec);
 958
 959         for (i = 0; i < bytes; ++i, ++address, ++value)
 960                 result = (function == ACPI_READ) ?
 961                         acpi_ec_read(ec, address, value) :
 962                         acpi_ec_write(ec, address, *value);
 963
 964         if (EC_FLAGS_MSI || bits > 8)
 965                 acpi_ec_burst_disable(ec);
 966
 967         switch (result) {
 968         case -EINVAL:
 969                 return AE_BAD_PARAMETER;
 970         case -ENODEV:
 971                 return AE_NOT_FOUND;
 972         case -ETIME:
 973                 return AE_TIME;
 974         default:
 975                 return AE_OK;
 976         }
 977 }
 978
 979 /* --------------------------------------------------------------------------
 980  *                             Driver Interface
 981  * -------------------------------------------------------------------------- */
 982
 983 static acpi_status
 984 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 985
 986 static struct acpi_ec *make_acpi_ec(void)
 987 {
 988         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 989
 990         if (!ec)
 991                 return NULL;
 992         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 993         mutex_init(&ec->mutex);
 994         init_waitqueue_head(&ec->wait);
 995         INIT_LIST_HEAD(&ec->list);
 996         spin_lock_init(&ec->lock);
 997         INIT_WORK(&ec->work, acpi_ec_gpe_poller);
 998         return ec;
 999 }
1000
1001 static acpi_status
1002 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1003                                void *context, void **return_value)
1004 {
1005         char node_name[5];
1006         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1007         struct acpi_ec *ec = context;
1008         int value = 0;
1009         acpi_status status;
1010
1011         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1012
1013         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1014                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1015         return AE_OK;
1016 }
1017
1018 static acpi_status
1019 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1020 {
1021         acpi_status status;
1022         unsigned long long tmp = 0;
1023         struct acpi_ec *ec = context;
1024
1025         /* clear addr values, ec_parse_io_ports depend on it */
1026         ec->command_addr = ec->data_addr = 0;
1027
1028         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1029                                      ec_parse_io_ports, ec);
1030         if (ACPI_FAILURE(status))
1031                 return status;
1032
1033         /* Get GPE bit assignment (EC events). */
1034         /* TODO: Add support for _GPE returning a package */
1035         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1036         if (ACPI_FAILURE(status))
1037                 return status;
1038         ec->gpe = tmp;
1039         /* Use the global lock for all EC transactions? */
1040         tmp = 0;
1041         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1042         ec->global_lock = tmp;
1043         ec->handle = handle;
1044         return AE_CTRL_TERMINATE;
1045 }
1046
1047 static int ec_install_handlers(struct acpi_ec *ec)
1048 {
1049         acpi_status status;
1050
1051         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
1052                 return 0;
1053         status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1054                                   ACPI_GPE_EDGE_TRIGGERED,
1055                                   &acpi_ec_gpe_handler, ec);
1056         if (ACPI_FAILURE(status))
1057                 return -ENODEV;
1058
1059         acpi_ec_start(ec, false);
1060         status = acpi_install_address_space_handler(ec->handle,
1061                                                     ACPI_ADR_SPACE_EC,
1062                                                     &acpi_ec_space_handler,
1063                                                     NULL, ec);
1064         if (ACPI_FAILURE(status)) {
1065                 if (status == AE_NOT_FOUND) {
1066                         /*
1067                          * Maybe OS fails in evaluating the _REG object.
1068                          * The AE_NOT_FOUND error will be ignored and OS
1069                          * continue to initialize EC.
1070                          */
1071                         pr_err("Fail in evaluating the _REG object"
1072                                 " of EC device. Broken bios is suspected.\n");
1073                 } else {
1074                         acpi_ec_stop(ec, false);
1075                         acpi_remove_gpe_handler(NULL, ec->gpe,
1076                                 &acpi_ec_gpe_handler);
1077                         return -ENODEV;
1078                 }
1079         }
1080
1081         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
1082         return 0;
1083 }
1084
1085 static void ec_remove_handlers(struct acpi_ec *ec)
1086 {
1087         if (!test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
1088                 return;
1089         acpi_ec_stop(ec, false);
1090         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1091                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1092                 pr_err("failed to remove space handler\n");
1093         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1094                                 &acpi_ec_gpe_handler)))
1095                 pr_err("failed to remove gpe handler\n");
1096         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
1097 }
1098
1099 static int acpi_ec_add(struct acpi_device *device)
1100 {
1101         struct acpi_ec *ec = NULL;
1102         int ret;
1103
1104         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1105         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1106
1107         /* Check for boot EC */
1108         if (boot_ec &&
1109             (boot_ec->handle == device->handle ||
1110              boot_ec->handle == ACPI_ROOT_OBJECT)) {
1111                 ec = boot_ec;
1112                 boot_ec = NULL;
1113         } else {
1114                 ec = make_acpi_ec();
1115                 if (!ec)
1116                         return -ENOMEM;
1117         }
1118         if (ec_parse_device(device->handle, 0, ec, NULL) !=
1119                 AE_CTRL_TERMINATE) {
1120                         kfree(ec);
1121                         return -EINVAL;
1122         }
1123
1124         /* Find and register all query methods */
1125         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1126                             acpi_ec_register_query_methods, NULL, ec, NULL);
1127
1128         if (!first_ec)
1129                 first_ec = ec;
1130         device->driver_data = ec;
1131
1132         ret = !!request_region(ec->data_addr, 1, "EC data");
1133         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1134         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1135         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1136
1137         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
1138                           ec->gpe, ec->command_addr, ec->data_addr);
1139
1140         ret = ec_install_handlers(ec);
1141
1142         /* EC is fully operational, allow queries */
1143         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
1144
1145         /* Clear stale _Q events if hardware might require that */
1146         if (EC_FLAGS_CLEAR_ON_RESUME)
1147                 acpi_ec_clear(ec);
1148         return ret;
1149 }
1150
1151 static int acpi_ec_remove(struct acpi_device *device)
1152 {
1153         struct acpi_ec *ec;
1154         struct acpi_ec_query_handler *handler, *tmp;
1155
1156         if (!device)
1157                 return -EINVAL;
1158
1159         ec = acpi_driver_data(device);
1160         ec_remove_handlers(ec);
1161         mutex_lock(&ec->mutex);
1162         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1163                 list_del(&handler->node);
1164                 kfree(handler);
1165         }
1166         mutex_unlock(&ec->mutex);
1167         release_region(ec->data_addr, 1);
1168         release_region(ec->command_addr, 1);
1169         device->driver_data = NULL;
1170         if (ec == first_ec)
1171                 first_ec = NULL;
1172         kfree(ec);
1173         return 0;
1174 }
1175
1176 static acpi_status
1177 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1178 {
1179         struct acpi_ec *ec = context;
1180
1181         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1182                 return AE_OK;
1183
1184         /*
1185          * The first address region returned is the data port, and
1186          * the second address region returned is the status/command
1187          * port.
1188          */
1189         if (ec->data_addr == 0)
1190                 ec->data_addr = resource->data.io.minimum;
1191         else if (ec->command_addr == 0)
1192                 ec->command_addr = resource->data.io.minimum;
1193         else
1194                 return AE_CTRL_TERMINATE;
1195
1196         return AE_OK;
1197 }
1198
1199 int __init acpi_boot_ec_enable(void)
1200 {
1201         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
1202                 return 0;
1203         if (!ec_install_handlers(boot_ec)) {
1204                 first_ec = boot_ec;
1205                 return 0;
1206         }
1207         return -EFAULT;
1208 }
1209
1210 static const struct acpi_device_id ec_device_ids[] = {
1211         {"PNP0C09", 0},
1212         {"", 0},
1213 };
1214
1215 /* Some BIOS do not survive early DSDT scan, skip it */
1216 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
1217 {
1218         EC_FLAGS_SKIP_DSDT_SCAN = 1;
1219         return 0;
1220 }
1221
1222 /* ASUStek often supplies us with broken ECDT, validate it */
1223 static int ec_validate_ecdt(const struct dmi_system_id *id)
1224 {
1225         EC_FLAGS_VALIDATE_ECDT = 1;
1226         return 0;
1227 }
1228
1229 /* MSI EC needs special treatment, enable it */
1230 static int ec_flag_msi(const struct dmi_system_id *id)
1231 {
1232         pr_debug("Detected MSI hardware, enabling workarounds.\n");
1233         EC_FLAGS_MSI = 1;
1234         EC_FLAGS_VALIDATE_ECDT = 1;
1235         return 0;
1236 }
1237
1238 /*
1239  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
1240  * the GPE storm threshold back to 20
1241  */
1242 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
1243 {
1244         pr_debug("Setting the EC GPE storm threshold to 20\n");
1245         ec_storm_threshold  = 20;
1246         return 0;
1247 }
1248
1249 /*
1250  * Acer EC firmware refuses to respond QR_EC when SCI_EVT is not set, for
1251  * which case, we complete the QR_EC without issuing it to the firmware.
1252  * https://bugzilla.kernel.org/show_bug.cgi?id=86211
1253  */
1254 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1255 {
1256         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1257         EC_FLAGS_QUERY_HANDSHAKE = 1;
1258         return 0;
1259 }
1260
1261 /*
1262  * On some hardware it is necessary to clear events accumulated by the EC during
1263  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1264  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1265  *
1266  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1267  *
1268  * Ideally, the EC should also be instructed NOT to accumulate events during
1269  * sleep (which Windows seems to do somehow), but the interface to control this
1270  * behaviour is not known at this time.
1271  *
1272  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1273  * however it is very likely that other Samsung models are affected.
1274  *
1275  * On systems which don't accumulate _Q events during sleep, this extra check
1276  * should be harmless.
1277  */
1278 static int ec_clear_on_resume(const struct dmi_system_id *id)
1279 {
1280         pr_debug("Detected system needing EC poll on resume.\n");
1281         EC_FLAGS_CLEAR_ON_RESUME = 1;
1282         return 0;
1283 }
1284
1285 static struct dmi_system_id ec_dmi_table[] __initdata = {
1286         {
1287         ec_skip_dsdt_scan, "Compal JFL92", {
1288         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1289         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1290         {
1291         ec_flag_msi, "MSI hardware", {
1292         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1293         {
1294         ec_flag_msi, "MSI hardware", {
1295         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1296         {
1297         ec_flag_msi, "MSI hardware", {
1298         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1299         {
1300         ec_flag_msi, "MSI hardware", {
1301         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1302         {
1303         ec_flag_msi, "Quanta hardware", {
1304         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1305         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1306         {
1307         ec_flag_msi, "Quanta hardware", {
1308         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1309         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1310         {
1311         ec_flag_msi, "Clevo W350etq", {
1312         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
1313         DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
1314         {
1315         ec_validate_ecdt, "ASUS hardware", {
1316         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1317         {
1318         ec_validate_ecdt, "ASUS hardware", {
1319         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1320         {
1321         ec_enlarge_storm_threshold, "CLEVO hardware", {
1322         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1323         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1324         {
1325         ec_skip_dsdt_scan, "HP Folio 13", {
1326         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1327         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1328         {
1329         ec_validate_ecdt, "ASUS hardware", {
1330         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1331         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1332         {
1333         ec_clear_on_resume, "Samsung hardware", {
1334         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1335         {
1336         ec_flag_query_handshake, "Acer hardware", {
1337         DMI_MATCH(DMI_SYS_VENDOR, "Acer"), }, NULL},
1338         {},
1339 };
1340
1341 int __init acpi_ec_ecdt_probe(void)
1342 {
1343         acpi_status status;
1344         struct acpi_ec *saved_ec = NULL;
1345         struct acpi_table_ecdt *ecdt_ptr;
1346
1347         boot_ec = make_acpi_ec();
1348         if (!boot_ec)
1349                 return -ENOMEM;
1350         /*
1351          * Generate a boot ec context
1352          */
1353         dmi_check_system(ec_dmi_table);
1354         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1355                                 (struct acpi_table_header **)&ecdt_ptr);
1356         if (ACPI_SUCCESS(status)) {
1357                 pr_info("EC description table is found, configuring boot EC\n");
1358                 boot_ec->command_addr = ecdt_ptr->control.address;
1359                 boot_ec->data_addr = ecdt_ptr->data.address;
1360                 boot_ec->gpe = ecdt_ptr->gpe;
1361                 boot_ec->handle = ACPI_ROOT_OBJECT;
1362                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id,
1363                                 &boot_ec->handle);
1364                 /* Don't trust ECDT, which comes from ASUSTek */
1365                 if (!EC_FLAGS_VALIDATE_ECDT)
1366                         goto install;
1367                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1368                 if (!saved_ec)
1369                         return -ENOMEM;
1370         /* fall through */
1371         }
1372
1373         if (EC_FLAGS_SKIP_DSDT_SCAN) {
1374                 kfree(saved_ec);
1375                 return -ENODEV;
1376         }
1377
1378         /* This workaround is needed only on some broken machines,
1379          * which require early EC, but fail to provide ECDT */
1380         pr_debug("Look up EC in DSDT\n");
1381         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1382                                         boot_ec, NULL);
1383         /* Check that acpi_get_devices actually find something */
1384         if (ACPI_FAILURE(status) || !boot_ec->handle)
1385                 goto error;
1386         if (saved_ec) {
1387                 /* try to find good ECDT from ASUSTek */
1388                 if (saved_ec->command_addr != boot_ec->command_addr ||
1389                     saved_ec->data_addr != boot_ec->data_addr ||
1390                     saved_ec->gpe != boot_ec->gpe ||
1391                     saved_ec->handle != boot_ec->handle)
1392                         pr_info("ASUSTek keeps feeding us with broken "
1393                         "ECDT tables, which are very hard to workaround. "
1394                         "Trying to use DSDT EC info instead. Please send "
1395                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1396                 kfree(saved_ec);
1397                 saved_ec = NULL;
1398         } else {
1399                 /* We really need to limit this workaround, the only ASUS,
1400                 * which needs it, has fake EC._INI method, so use it as flag.
1401                 * Keep boot_ec struct as it will be needed soon.
1402                 */
1403                 if (!dmi_name_in_vendors("ASUS") ||
1404                     !acpi_has_method(boot_ec->handle, "_INI"))
1405                         return -ENODEV;
1406         }
1407 install:
1408         if (!ec_install_handlers(boot_ec)) {
1409                 first_ec = boot_ec;
1410                 return 0;
1411         }
1412 error:
1413         kfree(boot_ec);
1414         kfree(saved_ec);
1415         boot_ec = NULL;
1416         return -ENODEV;
1417 }
1418
1419 static struct acpi_driver acpi_ec_driver = {
1420         .name = "ec",
1421         .class = ACPI_EC_CLASS,
1422         .ids = ec_device_ids,
1423         .ops = {
1424                 .add = acpi_ec_add,
1425                 .remove = acpi_ec_remove,
1426                 },
1427 };
1428
1429 int __init acpi_ec_init(void)
1430 {
1431         int result = 0;
1432
1433         /* Now register the driver for the EC */
1434         result = acpi_bus_register_driver(&acpi_ec_driver);
1435         if (result < 0)
1436                 return -ENODEV;
1437
1438         return result;
1439 }
1440
1441 /* EC driver currently not unloadable */
1442 #if 0
1443 static void __exit acpi_ec_exit(void)
1444 {
1445
1446         acpi_bus_unregister_driver(&acpi_ec_driver);
1447 }
1448 #endif  /* 0 */