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 /*
  63  * The SCI_EVT clearing timing is not defined by the ACPI specification.
  64  * This leads to lots of practical timing issues for the host EC driver.
  65  * The following variations are defined (from the target EC firmware's
  66  * perspective):
  67  * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
  68  *         target can clear SCI_EVT at any time so long as the host can see
  69  *         the indication by reading the status register (EC_SC). So the
  70  *         host should re-check SCI_EVT after the first time the SCI_EVT
  71  *         indication is seen, which is the same time the query request
  72  *         (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
  73  *         at any later time could indicate another event. Normally such
  74  *         kind of EC firmware has implemented an event queue and will
  75  *         return 0x00 to indicate "no outstanding event".
  76  * QUERY: After seeing the query request (QR_EC) written to the command
  77  *        register (EC_CMD) by the host and having prepared the responding
  78  *        event value in the data register (EC_DATA), the target can safely
  79  *        clear SCI_EVT because the target can confirm that the current
  80  *        event is being handled by the host. The host then should check
  81  *        SCI_EVT right after reading the event response from the data
  82  *        register (EC_DATA).
  83  * EVENT: After seeing the event response read from the data register
  84  *        (EC_DATA) by the host, the target can clear SCI_EVT. As the
  85  *        target requires time to notice the change in the data register
  86  *        (EC_DATA), the host may be required to wait additional guarding
  87  *        time before checking the SCI_EVT again. Such guarding may not be
  88  *        necessary if the host is notified via another IRQ.
  89  */
  90 #define ACPI_EC_EVT_TIMING_STATUS       0x00
  91 #define ACPI_EC_EVT_TIMING_QUERY        0x01
  92 #define ACPI_EC_EVT_TIMING_EVENT        0x02
  93
  94 /* EC commands */
  95 enum ec_command {
  96         ACPI_EC_COMMAND_READ = 0x80,
  97         ACPI_EC_COMMAND_WRITE = 0x81,
  98         ACPI_EC_BURST_ENABLE = 0x82,
  99         ACPI_EC_BURST_DISABLE = 0x83,
 100         ACPI_EC_COMMAND_QUERY = 0x84,
 101 };
 102
 103 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
 104 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
 105 #define ACPI_EC_UDELAY_POLL     550     /* Wait 1ms for EC transaction polling */
 106 #define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
 107                                          * when trying to clear the EC */
 108
 109 enum {
 110         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
 111         EC_FLAGS_QUERY_GUARDING,        /* Guard for SCI_EVT check */
 112         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
 113                                          * OpReg are installed */
 114         EC_FLAGS_STARTED,               /* Driver is started */
 115         EC_FLAGS_STOPPED,               /* Driver is stopped */
 116         EC_FLAGS_COMMAND_STORM,         /* GPE storms occurred to the
 117                                          * current command processing */
 118 };
 119
 120 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
 121 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
 122
 123 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 124 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 125 module_param(ec_delay, uint, 0644);
 126 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
 127
 128 static bool ec_busy_polling __read_mostly;
 129 module_param(ec_busy_polling, bool, 0644);
 130 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
 131
 132 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
 133 module_param(ec_polling_guard, uint, 0644);
 134 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
 135
 136 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
 137
 138 /*
 139  * If the number of false interrupts per one transaction exceeds
 140  * this threshold, will think there is a GPE storm happened and
 141  * will disable the GPE for normal transaction.
 142  */
 143 static unsigned int ec_storm_threshold  __read_mostly = 8;
 144 module_param(ec_storm_threshold, uint, 0644);
 145 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 146
 147 struct acpi_ec_query_handler {
 148         struct list_head node;
 149         acpi_ec_query_func func;
 150         acpi_handle handle;
 151         void *data;
 152         u8 query_bit;
 153         struct kref kref;
 154 };
 155
 156 struct transaction {
 157         const u8 *wdata;
 158         u8 *rdata;
 159         unsigned short irq_count;
 160         u8 command;
 161         u8 wi;
 162         u8 ri;
 163         u8 wlen;
 164         u8 rlen;
 165         u8 flags;
 166 };
 167
 168 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
 169 static void advance_transaction(struct acpi_ec *ec);
 170
 171 struct acpi_ec *boot_ec, *first_ec;
 172 EXPORT_SYMBOL(first_ec);
 173
 174 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 175 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 176 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 177 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
 178
 179 /* --------------------------------------------------------------------------
 180  *                           Logging/Debugging
 181  * -------------------------------------------------------------------------- */
 182
 183 /*
 184  * Splitters used by the developers to track the boundary of the EC
 185  * handling processes.
 186  */
 187 #ifdef DEBUG
 188 #define EC_DBG_SEP      " "
 189 #define EC_DBG_DRV      "+++++"
 190 #define EC_DBG_STM      "====="
 191 #define EC_DBG_REQ      "*****"
 192 #define EC_DBG_EVT      "#####"
 193 #else
 194 #define EC_DBG_SEP      ""
 195 #define EC_DBG_DRV
 196 #define EC_DBG_STM
 197 #define EC_DBG_REQ
 198 #define EC_DBG_EVT
 199 #endif
 200
 201 #define ec_log_raw(fmt, ...) \
 202         pr_info(fmt "\n", ##__VA_ARGS__)
 203 #define ec_dbg_raw(fmt, ...) \
 204         pr_debug(fmt "\n", ##__VA_ARGS__)
 205 #define ec_log(filter, fmt, ...) \
 206         ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 207 #define ec_dbg(filter, fmt, ...) \
 208         ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
 209
 210 #define ec_log_drv(fmt, ...) \
 211         ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 212 #define ec_dbg_drv(fmt, ...) \
 213         ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
 214 #define ec_dbg_stm(fmt, ...) \
 215         ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
 216 #define ec_dbg_req(fmt, ...) \
 217         ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
 218 #define ec_dbg_evt(fmt, ...) \
 219         ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
 220 #define ec_dbg_ref(ec, fmt, ...) \
 221         ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
 222
 223 /* --------------------------------------------------------------------------
 224  *                           Device Flags
 225  * -------------------------------------------------------------------------- */
 226
 227 static bool acpi_ec_started(struct acpi_ec *ec)
 228 {
 229         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
 230                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
 231 }
 232
 233 static bool acpi_ec_flushed(struct acpi_ec *ec)
 234 {
 235         return ec->reference_count == 1;
 236 }
 237
 238 /* --------------------------------------------------------------------------
 239  *                           EC Registers
 240  * -------------------------------------------------------------------------- */
 241
 242 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 243 {
 244         u8 x = inb(ec->command_addr);
 245
 246         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
 247                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
 248                    x,
 249                    !!(x & ACPI_EC_FLAG_SCI),
 250                    !!(x & ACPI_EC_FLAG_BURST),
 251                    !!(x & ACPI_EC_FLAG_CMD),
 252                    !!(x & ACPI_EC_FLAG_IBF),
 253                    !!(x & ACPI_EC_FLAG_OBF));
 254         return x;
 255 }
 256
 257 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 258 {
 259         u8 x = inb(ec->data_addr);
 260
 261         ec->timestamp = jiffies;
 262         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
 263         return x;
 264 }
 265
 266 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 267 {
 268         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
 269         outb(command, ec->command_addr);
 270         ec->timestamp = jiffies;
 271 }
 272
 273 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 274 {
 275         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
 276         outb(data, ec->data_addr);
 277         ec->timestamp = jiffies;
 278 }
 279
 280 #ifdef DEBUG
 281 static const char *acpi_ec_cmd_string(u8 cmd)
 282 {
 283         switch (cmd) {
 284         case 0x80:
 285                 return "RD_EC";
 286         case 0x81:
 287                 return "WR_EC";
 288         case 0x82:
 289                 return "BE_EC";
 290         case 0x83:
 291                 return "BD_EC";
 292         case 0x84:
 293                 return "QR_EC";
 294         }
 295         return "UNKNOWN";
 296 }
 297 #else
 298 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 299 #endif
 300
 301 /* --------------------------------------------------------------------------
 302  *                           GPE Registers
 303  * -------------------------------------------------------------------------- */
 304
 305 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
 306 {
 307         acpi_event_status gpe_status = 0;
 308
 309         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
 310         return (gpe_status & ACPI_EVENT_FLAG_STATUS_SET) ? true : false;
 311 }
 312
 313 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
 314 {
 315         if (open)
 316                 acpi_enable_gpe(NULL, ec->gpe);
 317         else {
 318                 BUG_ON(ec->reference_count < 1);
 319                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 320         }
 321         if (acpi_ec_is_gpe_raised(ec)) {
 322                 /*
 323                  * On some platforms, EN=1 writes cannot trigger GPE. So
 324                  * software need to manually trigger a pseudo GPE event on
 325                  * EN=1 writes.
 326                  */
 327                 ec_dbg_raw("Polling quirk");
 328                 advance_transaction(ec);
 329         }
 330 }
 331
 332 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
 333 {
 334         if (close)
 335                 acpi_disable_gpe(NULL, ec->gpe);
 336         else {
 337                 BUG_ON(ec->reference_count < 1);
 338                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 339         }
 340 }
 341
 342 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
 343 {
 344         /*
 345          * GPE STS is a W1C register, which means:
 346          * 1. Software can clear it without worrying about clearing other
 347          *    GPEs' STS bits when the hardware sets them in parallel.
 348          * 2. As long as software can ensure only clearing it when it is
 349          *    set, hardware won't set it in parallel.
 350          * So software can clear GPE in any contexts.
 351          * Warning: do not move the check into advance_transaction() as the
 352          * EC commands will be sent without GPE raised.
 353          */
 354         if (!acpi_ec_is_gpe_raised(ec))
 355                 return;
 356         acpi_clear_gpe(NULL, ec->gpe);
 357 }
 358
 359 /* --------------------------------------------------------------------------
 360  *                           Transaction Management
 361  * -------------------------------------------------------------------------- */
 362
 363 static void acpi_ec_submit_request(struct acpi_ec *ec)
 364 {
 365         ec->reference_count++;
 366         if (ec->reference_count == 1)
 367                 acpi_ec_enable_gpe(ec, true);
 368 }
 369
 370 static void acpi_ec_complete_request(struct acpi_ec *ec)
 371 {
 372         bool flushed = false;
 373
 374         ec->reference_count--;
 375         if (ec->reference_count == 0)
 376                 acpi_ec_disable_gpe(ec, true);
 377         flushed = acpi_ec_flushed(ec);
 378         if (flushed)
 379                 wake_up(&ec->wait);
 380 }
 381
 382 static void acpi_ec_set_storm(struct acpi_ec *ec, u8 flag)
 383 {
 384         if (!test_bit(flag, &ec->flags)) {
 385                 acpi_ec_disable_gpe(ec, false);
 386                 ec_dbg_drv("Polling enabled");
 387                 set_bit(flag, &ec->flags);
 388         }
 389 }
 390
 391 static void acpi_ec_clear_storm(struct acpi_ec *ec, u8 flag)
 392 {
 393         if (test_bit(flag, &ec->flags)) {
 394                 clear_bit(flag, &ec->flags);
 395                 acpi_ec_enable_gpe(ec, false);
 396                 ec_dbg_drv("Polling disabled");
 397         }
 398 }
 399
 400 /*
 401  * acpi_ec_submit_flushable_request() - Increase the reference count unless
 402  *                                      the flush operation is not in
 403  *                                      progress
 404  * @ec: the EC device
 405  *
 406  * This function must be used before taking a new action that should hold
 407  * the reference count.  If this function returns false, then the action
 408  * must be discarded or it will prevent the flush operation from being
 409  * completed.
 410  */
 411 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
 412 {
 413         if (!acpi_ec_started(ec))
 414                 return false;
 415         acpi_ec_submit_request(ec);
 416         return true;
 417 }
 418
 419 static void acpi_ec_submit_query(struct acpi_ec *ec)
 420 {
 421         if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 422                 ec_dbg_evt("Command(%s) submitted/blocked",
 423                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 424                 ec->nr_pending_queries++;
 425                 schedule_work(&ec->work);
 426         }
 427 }
 428
 429 static void acpi_ec_complete_query(struct acpi_ec *ec)
 430 {
 431         if (test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 432                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 433                 ec_dbg_evt("Command(%s) unblocked",
 434                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 435         }
 436 }
 437
 438 static bool acpi_ec_guard_event(struct acpi_ec *ec)
 439 {
 440         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
 441             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
 442             !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
 443             (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
 444                 return false;
 445
 446         /*
 447          * Postpone the query submission to allow the firmware to proceed,
 448          * we shouldn't check SCI_EVT before the firmware reflagging it.
 449          */
 450         return true;
 451 }
 452
 453 static int ec_transaction_polled(struct acpi_ec *ec)
 454 {
 455         unsigned long flags;
 456         int ret = 0;
 457
 458         spin_lock_irqsave(&ec->lock, flags);
 459         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
 460                 ret = 1;
 461         spin_unlock_irqrestore(&ec->lock, flags);
 462         return ret;
 463 }
 464
 465 static int ec_transaction_completed(struct acpi_ec *ec)
 466 {
 467         unsigned long flags;
 468         int ret = 0;
 469
 470         spin_lock_irqsave(&ec->lock, flags);
 471         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 472                 ret = 1;
 473         spin_unlock_irqrestore(&ec->lock, flags);
 474         return ret;
 475 }
 476
 477 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
 478 {
 479         ec->curr->flags |= flag;
 480         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 481                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
 482                     flag == ACPI_EC_COMMAND_POLL)
 483                         acpi_ec_complete_query(ec);
 484                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
 485                     flag == ACPI_EC_COMMAND_COMPLETE)
 486                         acpi_ec_complete_query(ec);
 487                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 488                     flag == ACPI_EC_COMMAND_COMPLETE)
 489                         set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 490         }
 491 }
 492
 493 static void advance_transaction(struct acpi_ec *ec)
 494 {
 495         struct transaction *t;
 496         u8 status;
 497         bool wakeup = false;
 498
 499         ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
 500                    smp_processor_id());
 501         /*
 502          * By always clearing STS before handling all indications, we can
 503          * ensure a hardware STS 0->1 change after this clearing can always
 504          * trigger a GPE interrupt.
 505          */
 506         acpi_ec_clear_gpe(ec);
 507         status = acpi_ec_read_status(ec);
 508         t = ec->curr;
 509         /*
 510          * Another IRQ or a guarded polling mode advancement is detected,
 511          * the next QR_EC submission is then allowed.
 512          */
 513         if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
 514                 if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
 515                     (!ec->nr_pending_queries ||
 516                      test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
 517                         clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
 518                         acpi_ec_complete_query(ec);
 519                 }
 520         }
 521         if (!t)
 522                 goto err;
 523         if (t->flags & ACPI_EC_COMMAND_POLL) {
 524                 if (t->wlen > t->wi) {
 525                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 526                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 527                         else
 528                                 goto err;
 529                 } else if (t->rlen > t->ri) {
 530                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 531                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 532                                 if (t->rlen == t->ri) {
 533                                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 534                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 535                                                 ec_dbg_evt("Command(%s) completed by hardware",
 536                                                            acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 537                                         wakeup = true;
 538                                 }
 539                         } else
 540                                 goto err;
 541                 } else if (t->wlen == t->wi &&
 542                            (status & ACPI_EC_FLAG_IBF) == 0) {
 543                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 544                         wakeup = true;
 545                 }
 546                 goto out;
 547         } else {
 548                 if (EC_FLAGS_QUERY_HANDSHAKE &&
 549                     !(status & ACPI_EC_FLAG_SCI) &&
 550                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 551                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 552                         t->rdata[t->ri++] = 0x00;
 553                         ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
 554                         ec_dbg_evt("Command(%s) completed by software",
 555                                    acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
 556                         wakeup = true;
 557                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 558                         acpi_ec_write_cmd(ec, t->command);
 559                         ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
 560                 } else
 561                         goto err;
 562                 goto out;
 563         }
 564 err:
 565         /*
 566          * If SCI bit is set, then don't think it's a false IRQ
 567          * otherwise will take a not handled IRQ as a false one.
 568          */
 569         if (!(status & ACPI_EC_FLAG_SCI)) {
 570                 if (in_interrupt() && t) {
 571                         if (t->irq_count < ec_storm_threshold)
 572                                 ++t->irq_count;
 573                         /* Allow triggering on 0 threshold */
 574                         if (t->irq_count == ec_storm_threshold)
 575                                 acpi_ec_set_storm(ec, EC_FLAGS_COMMAND_STORM);
 576                 }
 577         }
 578 out:
 579         if (status & ACPI_EC_FLAG_SCI)
 580                 acpi_ec_submit_query(ec);
 581         if (wakeup && in_interrupt())
 582                 wake_up(&ec->wait);
 583 }
 584
 585 static void start_transaction(struct acpi_ec *ec)
 586 {
 587         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 588         ec->curr->flags = 0;
 589 }
 590
 591 static int ec_guard(struct acpi_ec *ec)
 592 {
 593         unsigned long guard = usecs_to_jiffies(ec_polling_guard);
 594         unsigned long timeout = ec->timestamp + guard;
 595
 596         do {
 597                 if (ec_busy_polling) {
 598                         /* Perform busy polling */
 599                         if (ec_transaction_completed(ec))
 600                                 return 0;
 601                         udelay(jiffies_to_usecs(guard));
 602                 } else {
 603                         /*
 604                          * Perform wait polling
 605                          *
 606                          * For SCI_EVT clearing timing of "event",
 607                          * performing guarding before re-checking the
 608                          * SCI_EVT. Otherwise, such guarding is not needed
 609                          * due to the old practices.
 610                          */
 611                         if (!ec_transaction_polled(ec) &&
 612                             !acpi_ec_guard_event(ec))
 613                                 break;
 614                         if (wait_event_timeout(ec->wait,
 615                                                ec_transaction_completed(ec),
 616                                                guard))
 617                                 return 0;
 618                 }
 619                 /* Guard the register accesses for the polling modes */
 620         } while (time_before(jiffies, timeout));
 621         return -ETIME;
 622 }
 623
 624 static int ec_poll(struct acpi_ec *ec)
 625 {
 626         unsigned long flags;
 627         int repeat = 5; /* number of command restarts */
 628
 629         while (repeat--) {
 630                 unsigned long delay = jiffies +
 631                         msecs_to_jiffies(ec_delay);
 632                 do {
 633                         if (!ec_guard(ec))
 634                                 return 0;
 635                         spin_lock_irqsave(&ec->lock, flags);
 636                         advance_transaction(ec);
 637                         spin_unlock_irqrestore(&ec->lock, flags);
 638                 } while (time_before(jiffies, delay));
 639                 pr_debug("controller reset, restart transaction\n");
 640                 spin_lock_irqsave(&ec->lock, flags);
 641                 start_transaction(ec);
 642                 spin_unlock_irqrestore(&ec->lock, flags);
 643         }
 644         return -ETIME;
 645 }
 646
 647 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 648                                         struct transaction *t)
 649 {
 650         unsigned long tmp;
 651         int ret = 0;
 652
 653         /* start transaction */
 654         spin_lock_irqsave(&ec->lock, tmp);
 655         /* Enable GPE for command processing (IBF=0/OBF=1) */
 656         if (!acpi_ec_submit_flushable_request(ec)) {
 657                 ret = -EINVAL;
 658                 goto unlock;
 659         }
 660         ec_dbg_ref(ec, "Increase command");
 661         /* following two actions should be kept atomic */
 662         ec->curr = t;
 663         ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
 664         start_transaction(ec);
 665         spin_unlock_irqrestore(&ec->lock, tmp);
 666
 667         ret = ec_poll(ec);
 668
 669         spin_lock_irqsave(&ec->lock, tmp);
 670         if (t->irq_count == ec_storm_threshold)
 671                 acpi_ec_clear_storm(ec, EC_FLAGS_COMMAND_STORM);
 672         ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
 673         ec->curr = NULL;
 674         /* Disable GPE for command processing (IBF=0/OBF=1) */
 675         acpi_ec_complete_request(ec);
 676         ec_dbg_ref(ec, "Decrease command");
 677 unlock:
 678         spin_unlock_irqrestore(&ec->lock, tmp);
 679         return ret;
 680 }
 681
 682 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 683 {
 684         int status;
 685         u32 glk;
 686
 687         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 688                 return -EINVAL;
 689         if (t->rdata)
 690                 memset(t->rdata, 0, t->rlen);
 691
 692         mutex_lock(&ec->mutex);
 693         if (ec->global_lock) {
 694                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 695                 if (ACPI_FAILURE(status)) {
 696                         status = -ENODEV;
 697                         goto unlock;
 698                 }
 699         }
 700
 701         status = acpi_ec_transaction_unlocked(ec, t);
 702
 703         if (ec->global_lock)
 704                 acpi_release_global_lock(glk);
 705 unlock:
 706         mutex_unlock(&ec->mutex);
 707         return status;
 708 }
 709
 710 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 711 {
 712         u8 d;
 713         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 714                                 .wdata = NULL, .rdata = &d,
 715                                 .wlen = 0, .rlen = 1};
 716
 717         return acpi_ec_transaction(ec, &t);
 718 }
 719
 720 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 721 {
 722         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 723                                 .wdata = NULL, .rdata = NULL,
 724                                 .wlen = 0, .rlen = 0};
 725
 726         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 727                                 acpi_ec_transaction(ec, &t) : 0;
 728 }
 729
 730 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 731 {
 732         int result;
 733         u8 d;
 734         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 735                                 .wdata = &address, .rdata = &d,
 736                                 .wlen = 1, .rlen = 1};
 737
 738         result = acpi_ec_transaction(ec, &t);
 739         *data = d;
 740         return result;
 741 }
 742
 743 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 744 {
 745         u8 wdata[2] = { address, data };
 746         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 747                                 .wdata = wdata, .rdata = NULL,
 748                                 .wlen = 2, .rlen = 0};
 749
 750         return acpi_ec_transaction(ec, &t);
 751 }
 752
 753 int ec_read(u8 addr, u8 *val)
 754 {
 755         int err;
 756         u8 temp_data;
 757
 758         if (!first_ec)
 759                 return -ENODEV;
 760
 761         err = acpi_ec_read(first_ec, addr, &temp_data);
 762
 763         if (!err) {
 764                 *val = temp_data;
 765                 return 0;
 766         }
 767         return err;
 768 }
 769 EXPORT_SYMBOL(ec_read);
 770
 771 int ec_write(u8 addr, u8 val)
 772 {
 773         int err;
 774
 775         if (!first_ec)
 776                 return -ENODEV;
 777
 778         err = acpi_ec_write(first_ec, addr, val);
 779
 780         return err;
 781 }
 782 EXPORT_SYMBOL(ec_write);
 783
 784 int ec_transaction(u8 command,
 785                    const u8 *wdata, unsigned wdata_len,
 786                    u8 *rdata, unsigned rdata_len)
 787 {
 788         struct transaction t = {.command = command,
 789                                 .wdata = wdata, .rdata = rdata,
 790                                 .wlen = wdata_len, .rlen = rdata_len};
 791
 792         if (!first_ec)
 793                 return -ENODEV;
 794
 795         return acpi_ec_transaction(first_ec, &t);
 796 }
 797 EXPORT_SYMBOL(ec_transaction);
 798
 799 /* Get the handle to the EC device */
 800 acpi_handle ec_get_handle(void)
 801 {
 802         if (!first_ec)
 803                 return NULL;
 804         return first_ec->handle;
 805 }
 806 EXPORT_SYMBOL(ec_get_handle);
 807
 808 /*
 809  * Process _Q events that might have accumulated in the EC.
 810  * Run with locked ec mutex.
 811  */
 812 static void acpi_ec_clear(struct acpi_ec *ec)
 813 {
 814         int i, status;
 815         u8 value = 0;
 816
 817         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 818                 status = acpi_ec_query(ec, &value);
 819                 if (status || !value)
 820                         break;
 821         }
 822
 823         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 824                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 825         else
 826                 pr_info("%d stale EC events cleared\n", i);
 827 }
 828
 829 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
 830 {
 831         unsigned long flags;
 832
 833         spin_lock_irqsave(&ec->lock, flags);
 834         if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
 835                 ec_dbg_drv("Starting EC");
 836                 /* Enable GPE for event processing (SCI_EVT=1) */
 837                 if (!resuming) {
 838                         acpi_ec_submit_request(ec);
 839                         ec_dbg_ref(ec, "Increase driver");
 840                 }
 841                 ec_log_drv("EC started");
 842         }
 843         spin_unlock_irqrestore(&ec->lock, flags);
 844 }
 845
 846 static bool acpi_ec_stopped(struct acpi_ec *ec)
 847 {
 848         unsigned long flags;
 849         bool flushed;
 850
 851         spin_lock_irqsave(&ec->lock, flags);
 852         flushed = acpi_ec_flushed(ec);
 853         spin_unlock_irqrestore(&ec->lock, flags);
 854         return flushed;
 855 }
 856
 857 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
 858 {
 859         unsigned long flags;
 860
 861         spin_lock_irqsave(&ec->lock, flags);
 862         if (acpi_ec_started(ec)) {
 863                 ec_dbg_drv("Stopping EC");
 864                 set_bit(EC_FLAGS_STOPPED, &ec->flags);
 865                 spin_unlock_irqrestore(&ec->lock, flags);
 866                 wait_event(ec->wait, acpi_ec_stopped(ec));
 867                 spin_lock_irqsave(&ec->lock, flags);
 868                 /* Disable GPE for event processing (SCI_EVT=1) */
 869                 if (!suspending) {
 870                         acpi_ec_complete_request(ec);
 871                         ec_dbg_ref(ec, "Decrease driver");
 872                 }
 873                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
 874                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
 875                 ec_log_drv("EC stopped");
 876         }
 877         spin_unlock_irqrestore(&ec->lock, flags);
 878 }
 879
 880 void acpi_ec_block_transactions(void)
 881 {
 882         struct acpi_ec *ec = first_ec;
 883
 884         if (!ec)
 885                 return;
 886
 887         mutex_lock(&ec->mutex);
 888         /* Prevent transactions from being carried out */
 889         acpi_ec_stop(ec, true);
 890         mutex_unlock(&ec->mutex);
 891 }
 892
 893 void acpi_ec_unblock_transactions(void)
 894 {
 895         struct acpi_ec *ec = first_ec;
 896
 897         if (!ec)
 898                 return;
 899
 900         /* Allow transactions to be carried out again */
 901         acpi_ec_start(ec, true);
 902
 903         if (EC_FLAGS_CLEAR_ON_RESUME)
 904                 acpi_ec_clear(ec);
 905 }
 906
 907 void acpi_ec_unblock_transactions_early(void)
 908 {
 909         /*
 910          * Allow transactions to happen again (this function is called from
 911          * atomic context during wakeup, so we don't need to acquire the mutex).
 912          */
 913         if (first_ec)
 914                 acpi_ec_start(first_ec, true);
 915 }
 916
 917 /* --------------------------------------------------------------------------
 918                                 Event Management
 919    -------------------------------------------------------------------------- */
 920 static struct acpi_ec_query_handler *
 921 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
 922 {
 923         if (handler)
 924                 kref_get(&handler->kref);
 925         return handler;
 926 }
 927
 928 static void acpi_ec_query_handler_release(struct kref *kref)
 929 {
 930         struct acpi_ec_query_handler *handler =
 931                 container_of(kref, struct acpi_ec_query_handler, kref);
 932
 933         kfree(handler);
 934 }
 935
 936 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
 937 {
 938         kref_put(&handler->kref, acpi_ec_query_handler_release);
 939 }
 940
 941 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 942                               acpi_handle handle, acpi_ec_query_func func,
 943                               void *data)
 944 {
 945         struct acpi_ec_query_handler *handler =
 946             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 947
 948         if (!handler)
 949                 return -ENOMEM;
 950
 951         handler->query_bit = query_bit;
 952         handler->handle = handle;
 953         handler->func = func;
 954         handler->data = data;
 955         mutex_lock(&ec->mutex);
 956         kref_init(&handler->kref);
 957         list_add(&handler->node, &ec->list);
 958         mutex_unlock(&ec->mutex);
 959         return 0;
 960 }
 961 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 962
 963 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 964 {
 965         struct acpi_ec_query_handler *handler, *tmp;
 966         LIST_HEAD(free_list);
 967
 968         mutex_lock(&ec->mutex);
 969         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 970                 if (query_bit == handler->query_bit) {
 971                         list_del_init(&handler->node);
 972                         list_add(&handler->node, &free_list);
 973                 }
 974         }
 975         mutex_unlock(&ec->mutex);
 976         list_for_each_entry_safe(handler, tmp, &free_list, node)
 977                 acpi_ec_put_query_handler(handler);
 978 }
 979 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 980
 981 static void acpi_ec_run(void *cxt)
 982 {
 983         struct acpi_ec_query_handler *handler = cxt;
 984
 985         if (!handler)
 986                 return;
 987         ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
 988         if (handler->func)
 989                 handler->func(handler->data);
 990         else if (handler->handle)
 991                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 992         ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
 993         acpi_ec_put_query_handler(handler);
 994 }
 995
 996 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
 997 {
 998         u8 value = 0;
 999         int result;
1000         acpi_status status;
1001         struct acpi_ec_query_handler *handler;
1002         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
1003                                 .wdata = NULL, .rdata = &value,
1004                                 .wlen = 0, .rlen = 1};
1005
1006         /*
1007          * Query the EC to find out which _Qxx method we need to evaluate.
1008          * Note that successful completion of the query causes the ACPI_EC_SCI
1009          * bit to be cleared (and thus clearing the interrupt source).
1010          */
1011         result = acpi_ec_transaction(ec, &t);
1012         if (result)
1013                 return result;
1014         if (data)
1015                 *data = value;
1016         if (!value)
1017                 return -ENODATA;
1018
1019         mutex_lock(&ec->mutex);
1020         list_for_each_entry(handler, &ec->list, node) {
1021                 if (value == handler->query_bit) {
1022                         /* have custom handler for this bit */
1023                         handler = acpi_ec_get_query_handler(handler);
1024                         ec_dbg_evt("Query(0x%02x) scheduled",
1025                                    handler->query_bit);
1026                         status = acpi_os_execute((handler->func) ?
1027                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
1028                                 acpi_ec_run, handler);
1029                         if (ACPI_FAILURE(status))
1030                                 result = -EBUSY;
1031                         break;
1032                 }
1033         }
1034         mutex_unlock(&ec->mutex);
1035         return result;
1036 }
1037
1038 static void acpi_ec_check_event(struct acpi_ec *ec)
1039 {
1040         unsigned long flags;
1041
1042         if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1043                 if (ec_guard(ec)) {
1044                         spin_lock_irqsave(&ec->lock, flags);
1045                         /*
1046                          * Take care of the SCI_EVT unless no one else is
1047                          * taking care of it.
1048                          */
1049                         if (!ec->curr)
1050                                 advance_transaction(ec);
1051                         spin_unlock_irqrestore(&ec->lock, flags);
1052                 }
1053         }
1054 }
1055
1056 static void acpi_ec_event_handler(struct work_struct *work)
1057 {
1058         unsigned long flags;
1059         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1060
1061         ec_dbg_evt("Event started");
1062
1063         spin_lock_irqsave(&ec->lock, flags);
1064         while (ec->nr_pending_queries) {
1065                 spin_unlock_irqrestore(&ec->lock, flags);
1066                 (void)acpi_ec_query(ec, NULL);
1067                 spin_lock_irqsave(&ec->lock, flags);
1068                 ec->nr_pending_queries--;
1069                 /*
1070                  * Before exit, make sure that this work item can be
1071                  * scheduled again. There might be QR_EC failures, leaving
1072                  * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1073                  * item from being scheduled again.
1074                  */
1075                 if (!ec->nr_pending_queries) {
1076                         if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1077                             ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1078                                 acpi_ec_complete_query(ec);
1079                 }
1080         }
1081         spin_unlock_irqrestore(&ec->lock, flags);
1082
1083         ec_dbg_evt("Event stopped");
1084
1085         acpi_ec_check_event(ec);
1086 }
1087
1088 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1089         u32 gpe_number, void *data)
1090 {
1091         unsigned long flags;
1092         struct acpi_ec *ec = data;
1093
1094         spin_lock_irqsave(&ec->lock, flags);
1095         advance_transaction(ec);
1096         spin_unlock_irqrestore(&ec->lock, flags);
1097         return ACPI_INTERRUPT_HANDLED;
1098 }
1099
1100 /* --------------------------------------------------------------------------
1101  *                           Address Space Management
1102  * -------------------------------------------------------------------------- */
1103
1104 static acpi_status
1105 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1106                       u32 bits, u64 *value64,
1107                       void *handler_context, void *region_context)
1108 {
1109         struct acpi_ec *ec = handler_context;
1110         int result = 0, i, bytes = bits / 8;
1111         u8 *value = (u8 *)value64;
1112
1113         if ((address > 0xFF) || !value || !handler_context)
1114                 return AE_BAD_PARAMETER;
1115
1116         if (function != ACPI_READ && function != ACPI_WRITE)
1117                 return AE_BAD_PARAMETER;
1118
1119         if (ec_busy_polling || bits > 8)
1120                 acpi_ec_burst_enable(ec);
1121
1122         for (i = 0; i < bytes; ++i, ++address, ++value)
1123                 result = (function == ACPI_READ) ?
1124                         acpi_ec_read(ec, address, value) :
1125                         acpi_ec_write(ec, address, *value);
1126
1127         if (ec_busy_polling || bits > 8)
1128                 acpi_ec_burst_disable(ec);
1129
1130         switch (result) {
1131         case -EINVAL:
1132                 return AE_BAD_PARAMETER;
1133         case -ENODEV:
1134                 return AE_NOT_FOUND;
1135         case -ETIME:
1136                 return AE_TIME;
1137         default:
1138                 return AE_OK;
1139         }
1140 }
1141
1142 /* --------------------------------------------------------------------------
1143  *                             Driver Interface
1144  * -------------------------------------------------------------------------- */
1145
1146 static acpi_status
1147 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1148
1149 static struct acpi_ec *make_acpi_ec(void)
1150 {
1151         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1152
1153         if (!ec)
1154                 return NULL;
1155         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
1156         mutex_init(&ec->mutex);
1157         init_waitqueue_head(&ec->wait);
1158         INIT_LIST_HEAD(&ec->list);
1159         spin_lock_init(&ec->lock);
1160         INIT_WORK(&ec->work, acpi_ec_event_handler);
1161         ec->timestamp = jiffies;
1162         return ec;
1163 }
1164
1165 static acpi_status
1166 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1167                                void *context, void **return_value)
1168 {
1169         char node_name[5];
1170         struct acpi_buffer buffer = { sizeof(node_name), node_name };
1171         struct acpi_ec *ec = context;
1172         int value = 0;
1173         acpi_status status;
1174
1175         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1176
1177         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1178                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1179         return AE_OK;
1180 }
1181
1182 static acpi_status
1183 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1184 {
1185         acpi_status status;
1186         unsigned long long tmp = 0;
1187         struct acpi_ec *ec = context;
1188
1189         /* clear addr values, ec_parse_io_ports depend on it */
1190         ec->command_addr = ec->data_addr = 0;
1191
1192         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1193                                      ec_parse_io_ports, ec);
1194         if (ACPI_FAILURE(status))
1195                 return status;
1196
1197         /* Get GPE bit assignment (EC events). */
1198         /* TODO: Add support for _GPE returning a package */
1199         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1200         if (ACPI_FAILURE(status))
1201                 return status;
1202         ec->gpe = tmp;
1203         /* Use the global lock for all EC transactions? */
1204         tmp = 0;
1205         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1206         ec->global_lock = tmp;
1207         ec->handle = handle;
1208         return AE_CTRL_TERMINATE;
1209 }
1210
1211 static int ec_install_handlers(struct acpi_ec *ec)
1212 {
1213         acpi_status status;
1214
1215         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
1216                 return 0;
1217         status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1218                                   ACPI_GPE_EDGE_TRIGGERED,
1219                                   &acpi_ec_gpe_handler, ec);
1220         if (ACPI_FAILURE(status))
1221                 return -ENODEV;
1222
1223         acpi_ec_start(ec, false);
1224         status = acpi_install_address_space_handler(ec->handle,
1225                                                     ACPI_ADR_SPACE_EC,
1226                                                     &acpi_ec_space_handler,
1227                                                     NULL, ec);
1228         if (ACPI_FAILURE(status)) {
1229                 if (status == AE_NOT_FOUND) {
1230                         /*
1231                          * Maybe OS fails in evaluating the _REG object.
1232                          * The AE_NOT_FOUND error will be ignored and OS
1233                          * continue to initialize EC.
1234                          */
1235                         pr_err("Fail in evaluating the _REG object"
1236                                 " of EC device. Broken bios is suspected.\n");
1237                 } else {
1238                         acpi_ec_stop(ec, false);
1239                         acpi_remove_gpe_handler(NULL, ec->gpe,
1240                                 &acpi_ec_gpe_handler);
1241                         return -ENODEV;
1242                 }
1243         }
1244
1245         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
1246         return 0;
1247 }
1248
1249 static void ec_remove_handlers(struct acpi_ec *ec)
1250 {
1251         if (!test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
1252                 return;
1253         acpi_ec_stop(ec, false);
1254         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1255                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1256                 pr_err("failed to remove space handler\n");
1257         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1258                                 &acpi_ec_gpe_handler)))
1259                 pr_err("failed to remove gpe handler\n");
1260         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
1261 }
1262
1263 static int acpi_ec_add(struct acpi_device *device)
1264 {
1265         struct acpi_ec *ec = NULL;
1266         int ret;
1267
1268         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1269         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1270
1271         /* Check for boot EC */
1272         if (boot_ec &&
1273             (boot_ec->handle == device->handle ||
1274              boot_ec->handle == ACPI_ROOT_OBJECT)) {
1275                 ec = boot_ec;
1276                 boot_ec = NULL;
1277         } else {
1278                 ec = make_acpi_ec();
1279                 if (!ec)
1280                         return -ENOMEM;
1281         }
1282         if (ec_parse_device(device->handle, 0, ec, NULL) !=
1283                 AE_CTRL_TERMINATE) {
1284                         kfree(ec);
1285                         return -EINVAL;
1286         }
1287
1288         /* Find and register all query methods */
1289         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1290                             acpi_ec_register_query_methods, NULL, ec, NULL);
1291
1292         if (!first_ec)
1293                 first_ec = ec;
1294         device->driver_data = ec;
1295
1296         ret = !!request_region(ec->data_addr, 1, "EC data");
1297         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1298         ret = !!request_region(ec->command_addr, 1, "EC cmd");
1299         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1300
1301         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
1302                           ec->gpe, ec->command_addr, ec->data_addr);
1303
1304         ret = ec_install_handlers(ec);
1305
1306         /* Reprobe devices depending on the EC */
1307         acpi_walk_dep_device_list(ec->handle);
1308
1309         /* EC is fully operational, allow queries */
1310         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
1311
1312         /* Clear stale _Q events if hardware might require that */
1313         if (EC_FLAGS_CLEAR_ON_RESUME)
1314                 acpi_ec_clear(ec);
1315         return ret;
1316 }
1317
1318 static int acpi_ec_remove(struct acpi_device *device)
1319 {
1320         struct acpi_ec *ec;
1321         struct acpi_ec_query_handler *handler, *tmp;
1322
1323         if (!device)
1324                 return -EINVAL;
1325
1326         ec = acpi_driver_data(device);
1327         ec_remove_handlers(ec);
1328         mutex_lock(&ec->mutex);
1329         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1330                 list_del(&handler->node);
1331                 kfree(handler);
1332         }
1333         mutex_unlock(&ec->mutex);
1334         release_region(ec->data_addr, 1);
1335         release_region(ec->command_addr, 1);
1336         device->driver_data = NULL;
1337         if (ec == first_ec)
1338                 first_ec = NULL;
1339         kfree(ec);
1340         return 0;
1341 }
1342
1343 static acpi_status
1344 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1345 {
1346         struct acpi_ec *ec = context;
1347
1348         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1349                 return AE_OK;
1350
1351         /*
1352          * The first address region returned is the data port, and
1353          * the second address region returned is the status/command
1354          * port.
1355          */
1356         if (ec->data_addr == 0)
1357                 ec->data_addr = resource->data.io.minimum;
1358         else if (ec->command_addr == 0)
1359                 ec->command_addr = resource->data.io.minimum;
1360         else
1361                 return AE_CTRL_TERMINATE;
1362
1363         return AE_OK;
1364 }
1365
1366 int __init acpi_boot_ec_enable(void)
1367 {
1368         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
1369                 return 0;
1370         if (!ec_install_handlers(boot_ec)) {
1371                 first_ec = boot_ec;
1372                 return 0;
1373         }
1374         return -EFAULT;
1375 }
1376
1377 static const struct acpi_device_id ec_device_ids[] = {
1378         {"PNP0C09", 0},
1379         {"", 0},
1380 };
1381
1382 /* Some BIOS do not survive early DSDT scan, skip it */
1383 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
1384 {
1385         EC_FLAGS_SKIP_DSDT_SCAN = 1;
1386         return 0;
1387 }
1388
1389 /* ASUStek often supplies us with broken ECDT, validate it */
1390 static int ec_validate_ecdt(const struct dmi_system_id *id)
1391 {
1392         EC_FLAGS_VALIDATE_ECDT = 1;
1393         return 0;
1394 }
1395
1396 #if 0
1397 /*
1398  * Some EC firmware variations refuses to respond QR_EC when SCI_EVT is not
1399  * set, for which case, we complete the QR_EC without issuing it to the
1400  * firmware.
1401  * https://bugzilla.kernel.org/show_bug.cgi?id=82611
1402  * https://bugzilla.kernel.org/show_bug.cgi?id=97381
1403  */
1404 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1405 {
1406         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1407         EC_FLAGS_QUERY_HANDSHAKE = 1;
1408         return 0;
1409 }
1410 #endif
1411
1412 /*
1413  * On some hardware it is necessary to clear events accumulated by the EC during
1414  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1415  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1416  *
1417  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1418  *
1419  * Ideally, the EC should also be instructed NOT to accumulate events during
1420  * sleep (which Windows seems to do somehow), but the interface to control this
1421  * behaviour is not known at this time.
1422  *
1423  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1424  * however it is very likely that other Samsung models are affected.
1425  *
1426  * On systems which don't accumulate _Q events during sleep, this extra check
1427  * should be harmless.
1428  */
1429 static int ec_clear_on_resume(const struct dmi_system_id *id)
1430 {
1431         pr_debug("Detected system needing EC poll on resume.\n");
1432         EC_FLAGS_CLEAR_ON_RESUME = 1;
1433         ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1434         return 0;
1435 }
1436
1437 static struct dmi_system_id ec_dmi_table[] __initdata = {
1438         {
1439         ec_skip_dsdt_scan, "Compal JFL92", {
1440         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1441         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1442         {
1443         ec_validate_ecdt, "MSI MS-171F", {
1444         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1445         DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1446         {
1447         ec_validate_ecdt, "ASUS hardware", {
1448         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1449         {
1450         ec_validate_ecdt, "ASUS hardware", {
1451         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1452         {
1453         ec_skip_dsdt_scan, "HP Folio 13", {
1454         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1455         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1456         {
1457         ec_validate_ecdt, "ASUS hardware", {
1458         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1459         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1460         {
1461         ec_clear_on_resume, "Samsung hardware", {
1462         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1463         {},
1464 };
1465
1466 int __init acpi_ec_ecdt_probe(void)
1467 {
1468         acpi_status status;
1469         struct acpi_ec *saved_ec = NULL;
1470         struct acpi_table_ecdt *ecdt_ptr;
1471
1472         boot_ec = make_acpi_ec();
1473         if (!boot_ec)
1474                 return -ENOMEM;
1475         /*
1476          * Generate a boot ec context
1477          */
1478         dmi_check_system(ec_dmi_table);
1479         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1480                                 (struct acpi_table_header **)&ecdt_ptr);
1481         if (ACPI_SUCCESS(status)) {
1482                 pr_info("EC description table is found, configuring boot EC\n");
1483                 boot_ec->command_addr = ecdt_ptr->control.address;
1484                 boot_ec->data_addr = ecdt_ptr->data.address;
1485                 boot_ec->gpe = ecdt_ptr->gpe;
1486                 boot_ec->handle = ACPI_ROOT_OBJECT;
1487                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id,
1488                                 &boot_ec->handle);
1489                 /* Don't trust ECDT, which comes from ASUSTek */
1490                 if (!EC_FLAGS_VALIDATE_ECDT)
1491                         goto install;
1492                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1493                 if (!saved_ec)
1494                         return -ENOMEM;
1495         /* fall through */
1496         }
1497
1498         if (EC_FLAGS_SKIP_DSDT_SCAN) {
1499                 kfree(saved_ec);
1500                 return -ENODEV;
1501         }
1502
1503         /* This workaround is needed only on some broken machines,
1504          * which require early EC, but fail to provide ECDT */
1505         pr_debug("Look up EC in DSDT\n");
1506         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1507                                         boot_ec, NULL);
1508         /* Check that acpi_get_devices actually find something */
1509         if (ACPI_FAILURE(status) || !boot_ec->handle)
1510                 goto error;
1511         if (saved_ec) {
1512                 /* try to find good ECDT from ASUSTek */
1513                 if (saved_ec->command_addr != boot_ec->command_addr ||
1514                     saved_ec->data_addr != boot_ec->data_addr ||
1515                     saved_ec->gpe != boot_ec->gpe ||
1516                     saved_ec->handle != boot_ec->handle)
1517                         pr_info("ASUSTek keeps feeding us with broken "
1518                         "ECDT tables, which are very hard to workaround. "
1519                         "Trying to use DSDT EC info instead. Please send "
1520                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1521                 kfree(saved_ec);
1522                 saved_ec = NULL;
1523         } else {
1524                 /* We really need to limit this workaround, the only ASUS,
1525                 * which needs it, has fake EC._INI method, so use it as flag.
1526                 * Keep boot_ec struct as it will be needed soon.
1527                 */
1528                 if (!dmi_name_in_vendors("ASUS") ||
1529                     !acpi_has_method(boot_ec->handle, "_INI"))
1530                         return -ENODEV;
1531         }
1532 install:
1533         if (!ec_install_handlers(boot_ec)) {
1534                 first_ec = boot_ec;
1535                 return 0;
1536         }
1537 error:
1538         kfree(boot_ec);
1539         kfree(saved_ec);
1540         boot_ec = NULL;
1541         return -ENODEV;
1542 }
1543
1544 static int param_set_event_clearing(const char *val, struct kernel_param *kp)
1545 {
1546         int result = 0;
1547
1548         if (!strncmp(val, "status", sizeof("status") - 1)) {
1549                 ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1550                 pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
1551         } else if (!strncmp(val, "query", sizeof("query") - 1)) {
1552                 ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
1553                 pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
1554         } else if (!strncmp(val, "event", sizeof("event") - 1)) {
1555                 ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
1556                 pr_info("Assuming SCI_EVT clearing on event reads\n");
1557         } else
1558                 result = -EINVAL;
1559         return result;
1560 }
1561
1562 static int param_get_event_clearing(char *buffer, struct kernel_param *kp)
1563 {
1564         switch (ec_event_clearing) {
1565         case ACPI_EC_EVT_TIMING_STATUS:
1566                 return sprintf(buffer, "status");
1567         case ACPI_EC_EVT_TIMING_QUERY:
1568                 return sprintf(buffer, "query");
1569         case ACPI_EC_EVT_TIMING_EVENT:
1570                 return sprintf(buffer, "event");
1571         default:
1572                 return sprintf(buffer, "invalid");
1573         }
1574         return 0;
1575 }
1576
1577 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
1578                   NULL, 0644);
1579 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
1580
1581 static struct acpi_driver acpi_ec_driver = {
1582         .name = "ec",
1583         .class = ACPI_EC_CLASS,
1584         .ids = ec_device_ids,
1585         .ops = {
1586                 .add = acpi_ec_add,
1587                 .remove = acpi_ec_remove,
1588                 },
1589 };
1590
1591 int __init acpi_ec_init(void)
1592 {
1593         int result = 0;
1594
1595         /* Now register the driver for the EC */
1596         result = acpi_bus_register_driver(&acpi_ec_driver);
1597         if (result < 0)
1598                 return -ENODEV;
1599
1600         return result;
1601 }
1602
1603 /* EC driver currently not unloadable */
1604 #if 0
1605 static void __exit acpi_ec_exit(void)
1606 {
1607
1608         acpi_bus_unregister_driver(&acpi_ec_driver);
1609 }
1610 #endif  /* 0 */