kernel/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 #define ec_dbg_ref(ec, fmt, ...) \
 181         ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
 182
 183 /* --------------------------------------------------------------------------
 184  *                           Device Flags
 185  * -------------------------------------------------------------------------- */
 186
 187 static bool acpi_ec_started(struct acpi_ec *ec)
 188 {
 189         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
 190                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
 191 }
 192
 193 static bool acpi_ec_flushed(struct acpi_ec *ec)
 194 {
 195         return ec->reference_count == 1;
 196 }
 197
 198 /* --------------------------------------------------------------------------
 199  *                           EC Registers
 200  * -------------------------------------------------------------------------- */
 201
 202 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 203 {
 204         u8 x = inb(ec->command_addr);
 205
 206         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
 207                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
 208                    x,
 209                    !!(x & ACPI_EC_FLAG_SCI),
 210                    !!(x & ACPI_EC_FLAG_BURST),
 211                    !!(x & ACPI_EC_FLAG_CMD),
 212                    !!(x & ACPI_EC_FLAG_IBF),
 213                    !!(x & ACPI_EC_FLAG_OBF));
 214         return x;
 215 }
 216
 217 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 218 {
 219         u8 x = inb(ec->data_addr);
 220
 221         ec->curr->timestamp = jiffies;
 222         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
 223         return x;
 224 }
 225
 226 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 227 {
 228         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
 229         outb(command, ec->command_addr);
 230         ec->curr->timestamp = jiffies;
 231 }
 232
 233 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 234 {
 235         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
 236         outb(data, ec->data_addr);
 237         ec->curr->timestamp = jiffies;
 238 }
 239
 240 #ifdef DEBUG
 241 static const char *acpi_ec_cmd_string(u8 cmd)
 242 {
 243         switch (cmd) {
 244         case 0x80:
 245                 return "RD_EC";
 246         case 0x81:
 247                 return "WR_EC";
 248         case 0x82:
 249                 return "BE_EC";
 250         case 0x83:
 251                 return "BD_EC";
 252         case 0x84:
 253                 return "QR_EC";
 254         }
 255         return "UNKNOWN";
 256 }
 257 #else
 258 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 259 #endif
 260
 261 /* --------------------------------------------------------------------------
 262  *                           GPE Registers
 263  * -------------------------------------------------------------------------- */
 264
 265 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
 266 {
 267         acpi_event_status gpe_status = 0;
 268
 269         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
 270         return (gpe_status & ACPI_EVENT_FLAG_SET) ? true : false;
 271 }
 272
 273 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
 274 {
 275         if (open)
 276                 acpi_enable_gpe(NULL, ec->gpe);
 277         else {
 278                 BUG_ON(ec->reference_count < 1);
 279                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 280         }
 281         if (acpi_ec_is_gpe_raised(ec)) {
 282                 /*
 283                  * On some platforms, EN=1 writes cannot trigger GPE. So
 284                  * software need to manually trigger a pseudo GPE event on
 285                  * EN=1 writes.
 286                  */
 287                 ec_dbg_raw("Polling quirk");
 288                 advance_transaction(ec);
 289         }
 290 }
 291
 292 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
 293 {
 294         if (close)
 295                 acpi_disable_gpe(NULL, ec->gpe);
 296         else {
 297                 BUG_ON(ec->reference_count < 1);
 298                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 299         }
 300 }
 301
 302 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
 303 {
 304         /*
 305          * GPE STS is a W1C register, which means:
 306          * 1. Software can clear it without worrying about clearing other
 307          *    GPEs' STS bits when the hardware sets them in parallel.
 308          * 2. As long as software can ensure only clearing it when it is
 309          *    set, hardware won't set it in parallel.
 310          * So software can clear GPE in any contexts.
 311          * Warning: do not move the check into advance_transaction() as the
 312          * EC commands will be sent without GPE raised.
 313          */
 314         if (!acpi_ec_is_gpe_raised(ec))
 315                 return;
 316         acpi_clear_gpe(NULL, ec->gpe);
 317 }
 318
 319 /* --------------------------------------------------------------------------
 320  *                           Transaction Management
 321  * -------------------------------------------------------------------------- */
 322
 323 static void acpi_ec_submit_request(struct acpi_ec *ec)
 324 {
 325         ec->reference_count++;
 326         if (ec->reference_count == 1)
 327                 acpi_ec_enable_gpe(ec, true);
 328 }
 329
 330 static void acpi_ec_complete_request(struct acpi_ec *ec)
 331 {
 332         bool flushed = false;
 333
 334         ec->reference_count--;
 335         if (ec->reference_count == 0)
 336                 acpi_ec_disable_gpe(ec, true);
 337         flushed = acpi_ec_flushed(ec);
 338         if (flushed)
 339                 wake_up(&ec->wait);
 340 }
 341
 342 static void acpi_ec_set_storm(struct acpi_ec *ec, u8 flag)
 343 {
 344         if (!test_bit(flag, &ec->flags)) {
 345                 acpi_ec_disable_gpe(ec, false);
 346                 ec_dbg_drv("Polling enabled");
 347                 set_bit(flag, &ec->flags);
 348         }
 349 }
 350
 351 static void acpi_ec_clear_storm(struct acpi_ec *ec, u8 flag)
 352 {
 353         if (test_bit(flag, &ec->flags)) {
 354                 clear_bit(flag, &ec->flags);
 355                 acpi_ec_enable_gpe(ec, false);
 356                 ec_dbg_drv("Polling disabled");
 357         }
 358 }
 359
 360 /*
 361  * acpi_ec_submit_flushable_request() - Increase the reference count unless
 362  *                                      the flush operation is not in
 363  *                                      progress
 364  * @ec: the EC device
 365  *
 366  * This function must be used before taking a new action that should hold
 367  * the reference count.  If this function returns false, then the action
 368  * must be discarded or it will prevent the flush operation from being
 369  * completed.
 370  */
 371 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
 372 {
 373         if (!acpi_ec_started(ec))
 374                 return false;
 375         acpi_ec_submit_request(ec);
 376         return true;
 377 }
 378
 379 static void acpi_ec_submit_query(struct acpi_ec *ec)
 380 {
 381         if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 382                 ec_dbg_req("Event started");
 383                 schedule_work(&ec->work);
 384         }
 385 }
 386
 387 static void acpi_ec_complete_query(struct acpi_ec *ec)
 388 {
 389         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 390                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 391                 ec_dbg_req("Event stopped");
 392         }
 393 }
 394
 395 static int ec_transaction_completed(struct acpi_ec *ec)
 396 {
 397         unsigned long flags;
 398         int ret = 0;
 399
 400         spin_lock_irqsave(&ec->lock, flags);
 401         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 402                 ret = 1;
 403         spin_unlock_irqrestore(&ec->lock, flags);
 404         return ret;
 405 }
 406
 407 static void advance_transaction(struct acpi_ec *ec)
 408 {
 409         struct transaction *t;
 410         u8 status;
 411         bool wakeup = false;
 412
 413         ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
 414                    smp_processor_id());
 415         /*
 416          * By always clearing STS before handling all indications, we can
 417          * ensure a hardware STS 0->1 change after this clearing can always
 418          * trigger a GPE interrupt.
 419          */
 420         acpi_ec_clear_gpe(ec);
 421         status = acpi_ec_read_status(ec);
 422         t = ec->curr;
 423         if (!t)
 424                 goto err;
 425         if (t->flags & ACPI_EC_COMMAND_POLL) {
 426                 if (t->wlen > t->wi) {
 427                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 428                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 429                         else
 430                                 goto err;
 431                 } else if (t->rlen > t->ri) {
 432                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 433                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 434                                 if (t->rlen == t->ri) {
 435                                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 436                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 437                                                 ec_dbg_req("Command(%s) hardware completion",
 438                                                            acpi_ec_cmd_string(t->command));
 439                                         wakeup = true;
 440                                 }
 441                         } else
 442                                 goto err;
 443                 } else if (t->wlen == t->wi &&
 444                            (status & ACPI_EC_FLAG_IBF) == 0) {
 445                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 446                         wakeup = true;
 447                 }
 448                 goto out;
 449         } else {
 450                 if (EC_FLAGS_QUERY_HANDSHAKE &&
 451                     !(status & ACPI_EC_FLAG_SCI) &&
 452                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 453                         t->flags |= ACPI_EC_COMMAND_POLL;
 454                         acpi_ec_complete_query(ec);
 455                         t->rdata[t->ri++] = 0x00;
 456                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 457                         ec_dbg_req("Command(%s) software completion",
 458                                    acpi_ec_cmd_string(t->command));
 459                         wakeup = true;
 460                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 461                         acpi_ec_write_cmd(ec, t->command);
 462                         t->flags |= ACPI_EC_COMMAND_POLL;
 463                         acpi_ec_complete_query(ec);
 464                 } else
 465                         goto err;
 466                 goto out;
 467         }
 468 err:
 469         /*
 470          * If SCI bit is set, then don't think it's a false IRQ
 471          * otherwise will take a not handled IRQ as a false one.
 472          */
 473         if (!(status & ACPI_EC_FLAG_SCI)) {
 474                 if (in_interrupt() && t) {
 475                         if (t->irq_count < ec_storm_threshold)
 476                                 ++t->irq_count;
 477                         /* Allow triggering on 0 threshold */
 478                         if (t->irq_count == ec_storm_threshold)
 479                                 acpi_ec_set_storm(ec, EC_FLAGS_COMMAND_STORM);
 480                 }
 481         }
 482 out:
 483         if (status & ACPI_EC_FLAG_SCI)
 484                 acpi_ec_submit_query(ec);
 485         if (wakeup && in_interrupt())
 486                 wake_up(&ec->wait);
 487 }
 488
 489 static void start_transaction(struct acpi_ec *ec)
 490 {
 491         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 492         ec->curr->flags = 0;
 493         ec->curr->timestamp = jiffies;
 494         advance_transaction(ec);
 495 }
 496
 497 static int ec_poll(struct acpi_ec *ec)
 498 {
 499         unsigned long flags;
 500         int repeat = 5; /* number of command restarts */
 501
 502         while (repeat--) {
 503                 unsigned long delay = jiffies +
 504                         msecs_to_jiffies(ec_delay);
 505                 unsigned long usecs = ACPI_EC_UDELAY_POLL;
 506                 do {
 507                         /* don't sleep with disabled interrupts */
 508                         if (EC_FLAGS_MSI || irqs_disabled()) {
 509                                 usecs = ACPI_EC_MSI_UDELAY;
 510                                 udelay(usecs);
 511                                 if (ec_transaction_completed(ec))
 512                                         return 0;
 513                         } else {
 514                                 if (wait_event_timeout(ec->wait,
 515                                                 ec_transaction_completed(ec),
 516                                                 usecs_to_jiffies(usecs)))
 517                                         return 0;
 518                         }
 519                         spin_lock_irqsave(&ec->lock, flags);
 520                         if (time_after(jiffies,
 521                                         ec->curr->timestamp +
 522                                         usecs_to_jiffies(usecs)))
 523                                 advance_transaction(ec);
 524                         spin_unlock_irqrestore(&ec->lock, flags);
 525                 } while (time_before(jiffies, delay));
 526                 pr_debug("controller reset, restart transaction\n");
 527                 spin_lock_irqsave(&ec->lock, flags);
 528                 start_transaction(ec);
 529                 spin_unlock_irqrestore(&ec->lock, flags);
 530         }
 531         return -ETIME;
 532 }
 533
 534 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 535                                         struct transaction *t)
 536 {
 537         unsigned long tmp;
 538         int ret = 0;
 539
 540         if (EC_FLAGS_MSI)
 541                 udelay(ACPI_EC_MSI_UDELAY);
 542         /* start transaction */
 543         spin_lock_irqsave(&ec->lock, tmp);
 544         /* Enable GPE for command processing (IBF=0/OBF=1) */
 545         if (!acpi_ec_submit_flushable_request(ec)) {
 546                 ret = -EINVAL;
 547                 goto unlock;
 548         }
 549         ec_dbg_ref(ec, "Increase command");
 550         /* following two actions should be kept atomic */
 551         ec->curr = t;
 552         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 553         start_transaction(ec);
 554         spin_unlock_irqrestore(&ec->lock, tmp);
 555         ret = ec_poll(ec);
 556         spin_lock_irqsave(&ec->lock, tmp);
 557         if (t->irq_count == ec_storm_threshold)
 558                 acpi_ec_clear_storm(ec, EC_FLAGS_COMMAND_STORM);
 559         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 560         ec->curr = NULL;
 561         /* Disable GPE for command processing (IBF=0/OBF=1) */
 562         acpi_ec_complete_request(ec);
 563         ec_dbg_ref(ec, "Decrease command");
 564 unlock:
 565         spin_unlock_irqrestore(&ec->lock, tmp);
 566         return ret;
 567 }
 568
 569 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 570 {
 571         int status;
 572         u32 glk;
 573
 574         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 575                 return -EINVAL;
 576         if (t->rdata)
 577                 memset(t->rdata, 0, t->rlen);
 578         mutex_lock(&ec->mutex);
 579         if (ec->global_lock) {
 580                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 581                 if (ACPI_FAILURE(status)) {
 582                         status = -ENODEV;
 583                         goto unlock;
 584                 }
 585         }
 586
 587         status = acpi_ec_transaction_unlocked(ec, t);
 588
 589         if (test_bit(EC_FLAGS_COMMAND_STORM, &ec->flags))
 590                 msleep(1);
 591         if (ec->global_lock)
 592                 acpi_release_global_lock(glk);
 593 unlock:
 594         mutex_unlock(&ec->mutex);
 595         return status;
 596 }
 597
 598 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 599 {
 600         u8 d;
 601         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 602                                 .wdata = NULL, .rdata = &d,
 603                                 .wlen = 0, .rlen = 1};
 604
 605         return acpi_ec_transaction(ec, &t);
 606 }
 607
 608 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 609 {
 610         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 611                                 .wdata = NULL, .rdata = NULL,
 612                                 .wlen = 0, .rlen = 0};
 613
 614         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 615                                 acpi_ec_transaction(ec, &t) : 0;
 616 }
 617
 618 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 619 {
 620         int result;
 621         u8 d;
 622         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 623                                 .wdata = &address, .rdata = &d,
 624                                 .wlen = 1, .rlen = 1};
 625
 626         result = acpi_ec_transaction(ec, &t);
 627         *data = d;
 628         return result;
 629 }
 630
 631 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 632 {
 633         u8 wdata[2] = { address, data };
 634         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 635                                 .wdata = wdata, .rdata = NULL,
 636                                 .wlen = 2, .rlen = 0};
 637
 638         return acpi_ec_transaction(ec, &t);
 639 }
 640
 641 int ec_read(u8 addr, u8 *val)
 642 {
 643         int err;
 644         u8 temp_data;
 645
 646         if (!first_ec)
 647                 return -ENODEV;
 648
 649         err = acpi_ec_read(first_ec, addr, &temp_data);
 650
 651         if (!err) {
 652                 *val = temp_data;
 653                 return 0;
 654         }
 655         return err;
 656 }
 657 EXPORT_SYMBOL(ec_read);
 658
 659 int ec_write(u8 addr, u8 val)
 660 {
 661         int err;
 662
 663         if (!first_ec)
 664                 return -ENODEV;
 665
 666         err = acpi_ec_write(first_ec, addr, val);
 667
 668         return err;
 669 }
 670 EXPORT_SYMBOL(ec_write);
 671
 672 int ec_transaction(u8 command,
 673                    const u8 *wdata, unsigned wdata_len,
 674                    u8 *rdata, unsigned rdata_len)
 675 {
 676         struct transaction t = {.command = command,
 677                                 .wdata = wdata, .rdata = rdata,
 678                                 .wlen = wdata_len, .rlen = rdata_len};
 679
 680         if (!first_ec)
 681                 return -ENODEV;
 682
 683         return acpi_ec_transaction(first_ec, &t);
 684 }
 685 EXPORT_SYMBOL(ec_transaction);
 686
 687 /* Get the handle to the EC device */
 688 acpi_handle ec_get_handle(void)
 689 {
 690         if (!first_ec)
 691                 return NULL;
 692         return first_ec->handle;
 693 }
 694 EXPORT_SYMBOL(ec_get_handle);
 695
 696 /*
 697  * Process _Q events that might have accumulated in the EC.
 698  * Run with locked ec mutex.
 699  */
 700 static void acpi_ec_clear(struct acpi_ec *ec)
 701 {
 702         int i, status;
 703         u8 value = 0;
 704
 705         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 706                 status = acpi_ec_query(ec, &value);
 707                 if (status || !value)
 708                         break;
 709         }
 710
 711         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 712                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 713         else
 714                 pr_info("%d stale EC events cleared\n", i);
 715 }
 716
 717 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 718 {
 719         unsigned long flags;
 720
 721         spin_lock_irqsave(&ec->lock, flags);
 722         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 723                 ec_dbg_drv("Starting EC");
 724                 /* Enable GPE for event processing (SCI_EVT=1) */
 725                 if (!resuming) {
 726                         acpi_ec_submit_request(ec);
 727                         ec_dbg_ref(ec, "Increase driver");
 728                 }
 729                 ec_log_drv("EC started");
 730         }
 731         spin_unlock_irqrestore(&ec->lock, flags);
 732 }
 733
 734 static bool acpi_ec_stopped(struct acpi_ec *ec)
 735 {
 736         unsigned long flags;
 737         bool flushed;
 738
 739         spin_lock_irqsave(&ec->lock, flags);
 740         flushed = acpi_ec_flushed(ec);
 741         spin_unlock_irqrestore(&ec->lock, flags);
 742         return flushed;
 743 }
 744
 745 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 746 {
 747         unsigned long flags;
 748
 749         spin_lock_irqsave(&ec->lock, flags);
 750         if (acpi_ec_started(ec)) {
 751                 ec_dbg_drv("Stopping EC");
 752                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
 753                 spin_unlock_irqrestore(&ec->lock, flags);
 754                 wait_event(ec->wait, acpi_ec_stopped(ec));
 755                 spin_lock_irqsave(&ec->lock, flags);
 756                 /* Disable GPE for event processing (SCI_EVT=1) */
 757                 if (!suspending) {
 758                         acpi_ec_complete_request(ec);
 759                         ec_dbg_ref(ec, "Decrease driver");
 760                 }
 761                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
 762                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
 763                 ec_log_drv("EC stopped");
 764         }
 765         spin_unlock_irqrestore(&ec->lock, flags);
 766 }
 767
 768 void acpi_ec_block_transactions(void)
 769 {
 770         struct acpi_ec *ec = first_ec;
 771
 772         if (!ec)
 773                 return;
 774
 775         mutex_lock(&ec->mutex);
 776         /* Prevent transactions from being carried out */
 777         acpi_ec_stop(ec, true);
 778         mutex_unlock(&ec->mutex);
 779 }
 780
 781 void acpi_ec_unblock_transactions(void)
 782 {
 783         struct acpi_ec *ec = first_ec;
 784
 785         if (!ec)
 786                 return;
 787
 788         /* Allow transactions to be carried out again */
 789         acpi_ec_start(ec, true);
 790
 791         if (EC_FLAGS_CLEAR_ON_RESUME)
 792                 acpi_ec_clear(ec);
 793 }
 794
 795 void acpi_ec_unblock_transactions_early(void)
 796 {
 797         /*
 798          * Allow transactions to happen again (this function is called from
 799          * atomic context during wakeup, so we don't need to acquire the mutex).
 800          */
 801         if (first_ec)
 802                 acpi_ec_start(first_ec, true);
 803 }
 804
 805 /* --------------------------------------------------------------------------
 806                                 Event Management
 807    -------------------------------------------------------------------------- */
 808 static struct acpi_ec_query_handler *
 809 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
 810 {
 811         if (handler)
 812                 kref_get(&handler->kref);
 813         return handler;
 814 }
 815
 816 static void acpi_ec_query_handler_release(struct kref *kref)
 817 {
 818         struct acpi_ec_query_handler *handler =
 819                 container_of(kref, struct acpi_ec_query_handler, kref);
 820
 821         kfree(handler);
 822 }
 823
 824 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
 825 {
 826         kref_put(&handler->kref, acpi_ec_query_handler_release);
 827 }
 828
 829 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 830                               acpi_handle handle, acpi_ec_query_func func,
 831                               void *data)
 832 {
 833         struct acpi_ec_query_handler *handler =
 834             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 835
 836         if (!handler)
 837                 return -ENOMEM;
 838
 839         handler->query_bit = query_bit;
 840         handler->handle = handle;
 841         handler->func = func;
 842         handler->data = data;
 843         mutex_lock(&ec->mutex);
 844         kref_init(&handler->kref);
 845         list_add(&handler->node, &ec->list);
 846         mutex_unlock(&ec->mutex);
 847         return 0;
 848 }
 849 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 850
 851 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 852 {
 853         struct acpi_ec_query_handler *handler, *tmp;
 854         LIST_HEAD(free_list);
 855
 856         mutex_lock(&ec->mutex);
 857         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 858                 if (query_bit == handler->query_bit) {
 859                         list_del_init(&handler->node);
 860                         list_add(&handler->node, &free_list);
 861                 }
 862         }
 863         mutex_unlock(&ec->mutex);
 864         list_for_each_entry_safe(handler, tmp, &free_list, node)
 865                 acpi_ec_put_query_handler(handler);
 866 }
 867 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 868
 869 static void acpi_ec_run(void *cxt)
 870 {
 871         struct acpi_ec_query_handler *handler = cxt;
 872
 873         if (!handler)
 874                 return;
 875         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
 876         if (handler->func)
 877                 handler->func(handler->data);
 878         else if (handler->handle)
 879                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 880         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
 881         acpi_ec_put_query_handler(handler);
 882 }
 883
 884 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
 885 {
 886         u8 value = 0;
 887         int result;
 888         acpi_status status;
 889         struct acpi_ec_query_handler *handler;
 890         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 891                                 .wdata = NULL, .rdata = &value,
 892                                 .wlen = 0, .rlen = 1};
 893
 894         /*
 895          * Query the EC to find out which _Qxx method we need to evaluate.
 896          * Note that successful completion of the query causes the ACPI_EC_SCI
 897          * bit to be cleared (and thus clearing the interrupt source).
 898          */
 899         result = acpi_ec_transaction(ec, &t);
 900         if (result)
 901                 return result;
 902         if (data)
 903                 *data = value;
 904         if (!value)
 905                 return -ENODATA;
 906
 907         mutex_lock(&ec->mutex);
 908         list_for_each_entry(handler, &ec->list, node) {
 909                 if (value == handler->query_bit) {
 910                         /* have custom handler for this bit */
 911                         handler = acpi_ec_get_query_handler(handler);
 912                         ec_dbg_evt("Query(0x%02x) scheduled",
 913                                    handler->query_bit);
 914                         status = acpi_os_execute((handler->func) ?
 915                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 916                                 acpi_ec_run, handler);
 917                         if (ACPI_FAILURE(status))
 918                                 result = -EBUSY;
 919                         break;
 920                 }
 921         }
 922         mutex_unlock(&ec->mutex);
 923         return result;
 924 }
 925
 926 static void acpi_ec_gpe_poller(struct work_struct *work)
 927 {
 928         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
 929
 930         acpi_ec_query(ec, NULL);
 931 }
 932
 933 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 934         u32 gpe_number, void *data)
 935 {
 936         unsigned long flags;
 937         struct acpi_ec *ec = data;
 938
 939         spin_lock_irqsave(&ec->lock, flags);
 940         advance_transaction(ec);
 941         spin_unlock_irqrestore(&ec->lock, flags);
 942         return ACPI_INTERRUPT_HANDLED;
 943 }
 944
 945 /* --------------------------------------------------------------------------
 946  *                           Address Space Management
 947  * -------------------------------------------------------------------------- */
 948
 949 static acpi_status
 950 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 951                       u32 bits, u64 *value64,
 952                       void *handler_context, void *region_context)
 953 {
 954         struct acpi_ec *ec = handler_context;
 955         int result = 0, i, bytes = bits / 8;
 956         u8 *value = (u8 *)value64;
 957
 958         if ((address > 0xFF) || !value || !handler_context)
 959                 return AE_BAD_PARAMETER;
 960
 961         if (function != ACPI_READ && function != ACPI_WRITE)
 962                 return AE_BAD_PARAMETER;
 963
 964         if (EC_FLAGS_MSI || bits > 8)
 965                 acpi_ec_burst_enable(ec);
 966
 967         for (i = 0; i < bytes; ++i, ++address, ++value)
 968                 result = (function == ACPI_READ) ?
 969                         acpi_ec_read(ec, address, value) :
 970                         acpi_ec_write(ec, address, *value);
 971
 972         if (EC_FLAGS_MSI || bits > 8)
 973                 acpi_ec_burst_disable(ec);
 974
 975         switch (result) {
 976         case -EINVAL:
 977                 return AE_BAD_PARAMETER;
 978         case -ENODEV:
 979                 return AE_NOT_FOUND;
 980         case -ETIME:
 981                 return AE_TIME;
 982         default:
 983                 return AE_OK;
 984         }
 985 }
 986
 987 /* --------------------------------------------------------------------------
 988  *                             Driver Interface
 989  * -------------------------------------------------------------------------- */
 990
 991 static acpi_status
 992 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 993
 994 static struct acpi_ec *make_acpi_ec(void)
 995 {
 996         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 997
 998         if (!ec)
 999                 return NULL;
1000         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
1001         mutex_init(&ec->mutex);
1002         init_waitqueue_head(&ec->wait);
1003         INIT_LIST_HEAD(&ec->list);
1004         spin_lock_init(&ec->lock);
1005         INIT_WORK(&ec->work, acpi_ec_gpe_poller);
1006         return ec;
1007 }
1008
1009 static acpi_status
1010 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1011                                void *context, void **return_value)
1012 {
1013         char node_name[5];
1014         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1015         struct acpi_ec *ec = context;
1016         int value = 0;
1017         acpi_status status;
1018
1019         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1020
1021         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1022                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1023         return AE_OK;
1024 }
1025
1026 static acpi_status
1027 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1028 {
1029         acpi_status status;
1030         unsigned long long tmp = 0;
1031         struct acpi_ec *ec = context;
1032
1033         /* clear addr values, ec_parse_io_ports depend on it */
1034         ec->command_addr = ec->data_addr = 0;
1035
1036         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1037                                      ec_parse_io_ports, ec);
1038         if (ACPI_FAILURE(status))
1039                 return status;
1040
1041         /* Get GPE bit assignment (EC events). */
1042         /* TODO: Add support for _GPE returning a package */
1043         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1044         if (ACPI_FAILURE(status))
1045                 return status;
1046         ec->gpe = tmp;
1047         /* Use the global lock for all EC transactions? */
1048         tmp = 0;
1049         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1050         ec->global_lock = tmp;
1051         ec->handle = handle;
1052         return AE_CTRL_TERMINATE;
1053 }
1054
1055 static int ec_install_handlers(struct acpi_ec *ec)
1056 {
1057         acpi_status status;
1058
1059         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
1060                 return 0;
1061         status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1062                                   ACPI_GPE_EDGE_TRIGGERED,
1063                                   &acpi_ec_gpe_handler, ec);
1064         if (ACPI_FAILURE(status))
1065                 return -ENODEV;
1066
1067         acpi_ec_start(ec, false);
1068         status = acpi_install_address_space_handler(ec->handle,
1069                                                     ACPI_ADR_SPACE_EC,
1070                                                     &acpi_ec_space_handler,
1071                                                     NULL, ec);
1072         if (ACPI_FAILURE(status)) {
1073                 if (status == AE_NOT_FOUND) {
1074                         /*
1075                          * Maybe OS fails in evaluating the _REG object.
1076                          * The AE_NOT_FOUND error will be ignored and OS
1077                          * continue to initialize EC.
1078                          */
1079                         pr_err("Fail in evaluating the _REG object"
1080                                 " of EC device. Broken bios is suspected.\n");
1081                 } else {
1082                         acpi_ec_stop(ec, false);
1083                         acpi_remove_gpe_handler(NULL, ec->gpe,
1084                                 &acpi_ec_gpe_handler);
1085                         return -ENODEV;
1086                 }
1087         }
1088
1089         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
1090         return 0;
1091 }
1092
1093 static void ec_remove_handlers(struct acpi_ec *ec)
1094 {
1095         if (!test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
1096                 return;
1097         acpi_ec_stop(ec, false);
1098         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1099                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1100                 pr_err("failed to remove space handler\n");
1101         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1102                                 &acpi_ec_gpe_handler)))
1103                 pr_err("failed to remove gpe handler\n");
1104         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
1105 }
1106
1107 static int acpi_ec_add(struct acpi_device *device)
1108 {
1109         struct acpi_ec *ec = NULL;
1110         int ret;
1111
1112         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1113         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1114
1115         /* Check for boot EC */
1116         if (boot_ec &&
1117             (boot_ec->handle == device->handle ||
1118              boot_ec->handle == ACPI_ROOT_OBJECT)) {
1119                 ec = boot_ec;
1120                 boot_ec = NULL;
1121         } else {
1122                 ec = make_acpi_ec();
1123                 if (!ec)
1124                         return -ENOMEM;
1125         }
1126         if (ec_parse_device(device->handle, 0, ec, NULL) !=
1127                 AE_CTRL_TERMINATE) {
1128                         kfree(ec);
1129                         return -EINVAL;
1130         }
1131
1132         /* Find and register all query methods */
1133         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1134                             acpi_ec_register_query_methods, NULL, ec, NULL);
1135
1136         if (!first_ec)
1137                 first_ec = ec;
1138         device->driver_data = ec;
1139
1140         ret = !!request_region(ec->data_addr, 1, "EC data");
1141         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1142         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1143         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1144
1145         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
1146                           ec->gpe, ec->command_addr, ec->data_addr);
1147
1148         ret = ec_install_handlers(ec);
1149
1150         /* Reprobe devices depending on the EC */
1151         acpi_walk_dep_device_list(ec->handle);
1152
1153         /* EC is fully operational, allow queries */
1154         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
1155
1156         /* Clear stale _Q events if hardware might require that */
1157         if (EC_FLAGS_CLEAR_ON_RESUME)
1158                 acpi_ec_clear(ec);
1159         return ret;
1160 }
1161
1162 static int acpi_ec_remove(struct acpi_device *device)
1163 {
1164         struct acpi_ec *ec;
1165         struct acpi_ec_query_handler *handler, *tmp;
1166
1167         if (!device)
1168                 return -EINVAL;
1169
1170         ec = acpi_driver_data(device);
1171         ec_remove_handlers(ec);
1172         mutex_lock(&ec->mutex);
1173         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1174                 list_del(&handler->node);
1175                 kfree(handler);
1176         }
1177         mutex_unlock(&ec->mutex);
1178         release_region(ec->data_addr, 1);
1179         release_region(ec->command_addr, 1);
1180         device->driver_data = NULL;
1181         if (ec == first_ec)
1182                 first_ec = NULL;
1183         kfree(ec);
1184         return 0;
1185 }
1186
1187 static acpi_status
1188 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1189 {
1190         struct acpi_ec *ec = context;
1191
1192         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1193                 return AE_OK;
1194
1195         /*
1196          * The first address region returned is the data port, and
1197          * the second address region returned is the status/command
1198          * port.
1199          */
1200         if (ec->data_addr == 0)
1201                 ec->data_addr = resource->data.io.minimum;
1202         else if (ec->command_addr == 0)
1203                 ec->command_addr = resource->data.io.minimum;
1204         else
1205                 return AE_CTRL_TERMINATE;
1206
1207         return AE_OK;
1208 }
1209
1210 int __init acpi_boot_ec_enable(void)
1211 {
1212         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
1213                 return 0;
1214         if (!ec_install_handlers(boot_ec)) {
1215                 first_ec = boot_ec;
1216                 return 0;
1217         }
1218         return -EFAULT;
1219 }
1220
1221 static const struct acpi_device_id ec_device_ids[] = {
1222         {"PNP0C09", 0},
1223         {"", 0},
1224 };
1225
1226 /* Some BIOS do not survive early DSDT scan, skip it */
1227 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
1228 {
1229         EC_FLAGS_SKIP_DSDT_SCAN = 1;
1230         return 0;
1231 }
1232
1233 /* ASUStek often supplies us with broken ECDT, validate it */
1234 static int ec_validate_ecdt(const struct dmi_system_id *id)
1235 {
1236         EC_FLAGS_VALIDATE_ECDT = 1;
1237         return 0;
1238 }
1239
1240 /* MSI EC needs special treatment, enable it */
1241 static int ec_flag_msi(const struct dmi_system_id *id)
1242 {
1243         pr_debug("Detected MSI hardware, enabling workarounds.\n");
1244         EC_FLAGS_MSI = 1;
1245         EC_FLAGS_VALIDATE_ECDT = 1;
1246         return 0;
1247 }
1248
1249 /*
1250  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
1251  * the GPE storm threshold back to 20
1252  */
1253 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
1254 {
1255         pr_debug("Setting the EC GPE storm threshold to 20\n");
1256         ec_storm_threshold  = 20;
1257         return 0;
1258 }
1259
1260 /*
1261  * Acer EC firmware refuses to respond QR_EC when SCI_EVT is not set, for
1262  * which case, we complete the QR_EC without issuing it to the firmware.
1263  * https://bugzilla.kernel.org/show_bug.cgi?id=86211
1264  */
1265 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1266 {
1267         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1268         EC_FLAGS_QUERY_HANDSHAKE = 1;
1269         return 0;
1270 }
1271
1272 /*
1273  * On some hardware it is necessary to clear events accumulated by the EC during
1274  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1275  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1276  *
1277  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1278  *
1279  * Ideally, the EC should also be instructed NOT to accumulate events during
1280  * sleep (which Windows seems to do somehow), but the interface to control this
1281  * behaviour is not known at this time.
1282  *
1283  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1284  * however it is very likely that other Samsung models are affected.
1285  *
1286  * On systems which don't accumulate _Q events during sleep, this extra check
1287  * should be harmless.
1288  */
1289 static int ec_clear_on_resume(const struct dmi_system_id *id)
1290 {
1291         pr_debug("Detected system needing EC poll on resume.\n");
1292         EC_FLAGS_CLEAR_ON_RESUME = 1;
1293         return 0;
1294 }
1295
1296 static struct dmi_system_id ec_dmi_table[] __initdata = {
1297         {
1298         ec_skip_dsdt_scan, "Compal JFL92", {
1299         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1300         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1301         {
1302         ec_flag_msi, "MSI hardware", {
1303         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1304         {
1305         ec_flag_msi, "MSI hardware", {
1306         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1307         {
1308         ec_flag_msi, "MSI hardware", {
1309         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1310         {
1311         ec_flag_msi, "MSI hardware", {
1312         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1313         {
1314         ec_flag_msi, "Quanta hardware", {
1315         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1316         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1317         {
1318         ec_flag_msi, "Quanta hardware", {
1319         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1320         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1321         {
1322         ec_flag_msi, "Clevo W350etq", {
1323         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
1324         DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
1325         {
1326         ec_validate_ecdt, "ASUS hardware", {
1327         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1328         {
1329         ec_validate_ecdt, "ASUS hardware", {
1330         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1331         {
1332         ec_enlarge_storm_threshold, "CLEVO hardware", {
1333         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1334         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1335         {
1336         ec_skip_dsdt_scan, "HP Folio 13", {
1337         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1338         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1339         {
1340         ec_validate_ecdt, "ASUS hardware", {
1341         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1342         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1343         {
1344         ec_clear_on_resume, "Samsung hardware", {
1345         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1346         {
1347         ec_flag_query_handshake, "Acer hardware", {
1348         DMI_MATCH(DMI_SYS_VENDOR, "Acer"), }, NULL},
1349         {},
1350 };
1351
1352 int __init acpi_ec_ecdt_probe(void)
1353 {
1354         acpi_status status;
1355         struct acpi_ec *saved_ec = NULL;
1356         struct acpi_table_ecdt *ecdt_ptr;
1357
1358         boot_ec = make_acpi_ec();
1359         if (!boot_ec)
1360                 return -ENOMEM;
1361         /*
1362          * Generate a boot ec context
1363          */
1364         dmi_check_system(ec_dmi_table);
1365         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1366                                 (struct acpi_table_header **)&ecdt_ptr);
1367         if (ACPI_SUCCESS(status)) {
1368                 pr_info("EC description table is found, configuring boot EC\n");
1369                 boot_ec->command_addr = ecdt_ptr->control.address;
1370                 boot_ec->data_addr = ecdt_ptr->data.address;
1371                 boot_ec->gpe = ecdt_ptr->gpe;
1372                 boot_ec->handle = ACPI_ROOT_OBJECT;
1373                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id,
1374                                 &boot_ec->handle);
1375                 /* Don't trust ECDT, which comes from ASUSTek */
1376                 if (!EC_FLAGS_VALIDATE_ECDT)
1377                         goto install;
1378                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1379                 if (!saved_ec)
1380                         return -ENOMEM;
1381         /* fall through */
1382         }
1383
1384         if (EC_FLAGS_SKIP_DSDT_SCAN) {
1385                 kfree(saved_ec);
1386                 return -ENODEV;
1387         }
1388
1389         /* This workaround is needed only on some broken machines,
1390          * which require early EC, but fail to provide ECDT */
1391         pr_debug("Look up EC in DSDT\n");
1392         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1393                                         boot_ec, NULL);
1394         /* Check that acpi_get_devices actually find something */
1395         if (ACPI_FAILURE(status) || !boot_ec->handle)
1396                 goto error;
1397         if (saved_ec) {
1398                 /* try to find good ECDT from ASUSTek */
1399                 if (saved_ec->command_addr != boot_ec->command_addr ||
1400                     saved_ec->data_addr != boot_ec->data_addr ||
1401                     saved_ec->gpe != boot_ec->gpe ||
1402                     saved_ec->handle != boot_ec->handle)
1403                         pr_info("ASUSTek keeps feeding us with broken "
1404                         "ECDT tables, which are very hard to workaround. "
1405                         "Trying to use DSDT EC info instead. Please send "
1406                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1407                 kfree(saved_ec);
1408                 saved_ec = NULL;
1409         } else {
1410                 /* We really need to limit this workaround, the only ASUS,
1411                 * which needs it, has fake EC._INI method, so use it as flag.
1412                 * Keep boot_ec struct as it will be needed soon.
1413                 */
1414                 if (!dmi_name_in_vendors("ASUS") ||
1415                     !acpi_has_method(boot_ec->handle, "_INI"))
1416                         return -ENODEV;
1417         }
1418 install:
1419         if (!ec_install_handlers(boot_ec)) {
1420                 first_ec = boot_ec;
1421                 return 0;
1422         }
1423 error:
1424         kfree(boot_ec);
1425         kfree(saved_ec);
1426         boot_ec = NULL;
1427         return -ENODEV;
1428 }
1429
1430 static struct acpi_driver acpi_ec_driver = {
1431         .name = "ec",
1432         .class = ACPI_EC_CLASS,
1433         .ids = ec_device_ids,
1434         .ops = {
1435                 .add = acpi_ec_add,
1436                 .remove = acpi_ec_remove,
1437                 },
1438 };
1439
1440 int __init acpi_ec_init(void)
1441 {
1442         int result = 0;
1443
1444         /* Now register the driver for the EC */
1445         result = acpi_bus_register_driver(&acpi_ec_driver);
1446         if (result < 0)
1447                 return -ENODEV;
1448
1449         return result;
1450 }
1451
1452 /* EC driver currently not unloadable */
1453 #if 0
1454 static void __exit acpi_ec_exit(void)
1455 {
1456
1457         acpi_bus_unregister_driver(&acpi_ec_driver);
1458 }
1459 #endif  /* 0 */