drivers/acpi/ec.c

   1 /*
   2  *  ec.c - ACPI Embedded Controller Driver (v2.2)
   3  *
   4  *  Copyright (C) 2001-2014 Intel Corporation
   5  *    Author: 2014       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_CLEAR_MAX       100     /* Maximum number of events to query
  75                                          * when trying to clear the EC */
  76
  77 enum {
  78         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  79         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  80         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
  81                                          * OpReg are installed */
  82         EC_FLAGS_BLOCKED,               /* Transactions are blocked */
  83 };
  84
  85 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
  86 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
  87
  88 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
  89 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
  90 module_param(ec_delay, uint, 0644);
  91 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
  92
  93 /*
  94  * If the number of false interrupts per one transaction exceeds
  95  * this threshold, will think there is a GPE storm happened and
  96  * will disable the GPE for normal transaction.
  97  */
  98 static unsigned int ec_storm_threshold  __read_mostly = 8;
  99 module_param(ec_storm_threshold, uint, 0644);
 100 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 101
 102 struct acpi_ec_query_handler {
 103         struct list_head node;
 104         acpi_ec_query_func func;
 105         acpi_handle handle;
 106         void *data;
 107         u8 query_bit;
 108         struct kref kref;
 109 };
 110
 111 struct transaction {
 112         const u8 *wdata;
 113         u8 *rdata;
 114         unsigned short irq_count;
 115         u8 command;
 116         u8 wi;
 117         u8 ri;
 118         u8 wlen;
 119         u8 rlen;
 120         u8 flags;
 121 };
 122
 123 struct acpi_ec *boot_ec, *first_ec;
 124 EXPORT_SYMBOL(first_ec);
 125
 126 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 127 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 128 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 129 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 130 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
 131
 132 /* --------------------------------------------------------------------------
 133  *                           Transaction Management
 134  * -------------------------------------------------------------------------- */
 135
 136 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 137 {
 138         u8 x = inb(ec->command_addr);
 139
 140         pr_debug("EC_SC(R) = 0x%2.2x "
 141                  "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d\n",
 142                  x,
 143                  !!(x & ACPI_EC_FLAG_SCI),
 144                  !!(x & ACPI_EC_FLAG_BURST),
 145                  !!(x & ACPI_EC_FLAG_CMD),
 146                  !!(x & ACPI_EC_FLAG_IBF),
 147                  !!(x & ACPI_EC_FLAG_OBF));
 148         return x;
 149 }
 150
 151 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 152 {
 153         u8 x = inb(ec->data_addr);
 154
 155         pr_debug("EC_DATA(R) = 0x%2.2x\n", x);
 156         return x;
 157 }
 158
 159 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 160 {
 161         pr_debug("EC_SC(W) = 0x%2.2x\n", command);
 162         outb(command, ec->command_addr);
 163 }
 164
 165 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 166 {
 167         pr_debug("EC_DATA(W) = 0x%2.2x\n", data);
 168         outb(data, ec->data_addr);
 169 }
 170
 171 #ifdef DEBUG
 172 static const char *acpi_ec_cmd_string(u8 cmd)
 173 {
 174         switch (cmd) {
 175         case 0x80:
 176                 return "RD_EC";
 177         case 0x81:
 178                 return "WR_EC";
 179         case 0x82:
 180                 return "BE_EC";
 181         case 0x83:
 182                 return "BD_EC";
 183         case 0x84:
 184                 return "QR_EC";
 185         }
 186         return "UNKNOWN";
 187 }
 188 #else
 189 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 190 #endif
 191
 192 static int ec_transaction_completed(struct acpi_ec *ec)
 193 {
 194         unsigned long flags;
 195         int ret = 0;
 196
 197         spin_lock_irqsave(&ec->lock, flags);
 198         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 199                 ret = 1;
 200         spin_unlock_irqrestore(&ec->lock, flags);
 201         return ret;
 202 }
 203
 204 static void advance_transaction(struct acpi_ec *ec)
 205 {
 206         struct transaction *t;
 207         u8 status;
 208         bool wakeup = false;
 209
 210         pr_debug("===== %s (%d) =====\n",
 211                  in_interrupt() ? "IRQ" : "TASK", smp_processor_id());
 212         status = acpi_ec_read_status(ec);
 213         t = ec->curr;
 214         if (!t)
 215                 goto err;
 216         if (t->flags & ACPI_EC_COMMAND_POLL) {
 217                 if (t->wlen > t->wi) {
 218                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 219                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 220                         else
 221                                 goto err;
 222                 } else if (t->rlen > t->ri) {
 223                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 224                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 225                                 if (t->rlen == t->ri) {
 226                                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 227                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 228                                                 pr_debug("***** Command(%s) hardware completion *****\n",
 229                                                          acpi_ec_cmd_string(t->command));
 230                                         wakeup = true;
 231                                 }
 232                         } else
 233                                 goto err;
 234                 } else if (t->wlen == t->wi &&
 235                            (status & ACPI_EC_FLAG_IBF) == 0) {
 236                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 237                         wakeup = true;
 238                 }
 239                 goto out;
 240         } else {
 241                 if (EC_FLAGS_QUERY_HANDSHAKE &&
 242                     !(status & ACPI_EC_FLAG_SCI) &&
 243                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 244                         t->flags |= ACPI_EC_COMMAND_POLL;
 245                         t->rdata[t->ri++] = 0x00;
 246                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 247                         pr_debug("***** Command(%s) software completion *****\n",
 248                                  acpi_ec_cmd_string(t->command));
 249                         wakeup = true;
 250                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 251                         acpi_ec_write_cmd(ec, t->command);
 252                         t->flags |= ACPI_EC_COMMAND_POLL;
 253                 } else
 254                         goto err;
 255                 goto out;
 256         }
 257 err:
 258         /*
 259          * If SCI bit is set, then don't think it's a false IRQ
 260          * otherwise will take a not handled IRQ as a false one.
 261          */
 262         if (!(status & ACPI_EC_FLAG_SCI)) {
 263                 if (in_interrupt() && t)
 264                         ++t->irq_count;
 265         }
 266 out:
 267         if (wakeup && in_interrupt())
 268                 wake_up(&ec->wait);
 269 }
 270
 271 static void start_transaction(struct acpi_ec *ec)
 272 {
 273         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 274         ec->curr->flags = 0;
 275         advance_transaction(ec);
 276 }
 277
 278 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
 279
 280 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 281 {
 282         if (state & ACPI_EC_FLAG_SCI) {
 283                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 284                         return acpi_ec_sync_query(ec, NULL);
 285         }
 286         return 0;
 287 }
 288
 289 static int ec_poll(struct acpi_ec *ec)
 290 {
 291         unsigned long flags;
 292         int repeat = 5; /* number of command restarts */
 293
 294         while (repeat--) {
 295                 unsigned long delay = jiffies +
 296                         msecs_to_jiffies(ec_delay);
 297                 do {
 298                         /* don't sleep with disabled interrupts */
 299                         if (EC_FLAGS_MSI || irqs_disabled()) {
 300                                 udelay(ACPI_EC_MSI_UDELAY);
 301                                 if (ec_transaction_completed(ec))
 302                                         return 0;
 303                         } else {
 304                                 if (wait_event_timeout(ec->wait,
 305                                                 ec_transaction_completed(ec),
 306                                                 msecs_to_jiffies(1)))
 307                                         return 0;
 308                         }
 309                         spin_lock_irqsave(&ec->lock, flags);
 310                         advance_transaction(ec);
 311                         spin_unlock_irqrestore(&ec->lock, flags);
 312                 } while (time_before(jiffies, delay));
 313                 pr_debug("controller reset, restart transaction\n");
 314                 spin_lock_irqsave(&ec->lock, flags);
 315                 start_transaction(ec);
 316                 spin_unlock_irqrestore(&ec->lock, flags);
 317         }
 318         return -ETIME;
 319 }
 320
 321 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 322                                         struct transaction *t)
 323 {
 324         unsigned long tmp;
 325         int ret = 0;
 326
 327         if (EC_FLAGS_MSI)
 328                 udelay(ACPI_EC_MSI_UDELAY);
 329         /* start transaction */
 330         spin_lock_irqsave(&ec->lock, tmp);
 331         /* following two actions should be kept atomic */
 332         ec->curr = t;
 333         pr_debug("***** Command(%s) started *****\n",
 334                  acpi_ec_cmd_string(t->command));
 335         start_transaction(ec);
 336         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 337                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 338                 pr_debug("***** Event stopped *****\n");
 339         }
 340         spin_unlock_irqrestore(&ec->lock, tmp);
 341         ret = ec_poll(ec);
 342         spin_lock_irqsave(&ec->lock, tmp);
 343         pr_debug("***** Command(%s) stopped *****\n",
 344                  acpi_ec_cmd_string(t->command));
 345         ec->curr = NULL;
 346         spin_unlock_irqrestore(&ec->lock, tmp);
 347         return ret;
 348 }
 349
 350 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 351 {
 352         int status;
 353         u32 glk;
 354
 355         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 356                 return -EINVAL;
 357         if (t->rdata)
 358                 memset(t->rdata, 0, t->rlen);
 359         mutex_lock(&ec->mutex);
 360         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 361                 status = -EINVAL;
 362                 goto unlock;
 363         }
 364         if (ec->global_lock) {
 365                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 366                 if (ACPI_FAILURE(status)) {
 367                         status = -ENODEV;
 368                         goto unlock;
 369                 }
 370         }
 371         /* disable GPE during transaction if storm is detected */
 372         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 373                 /* It has to be disabled, so that it doesn't trigger. */
 374                 acpi_disable_gpe(NULL, ec->gpe);
 375         }
 376
 377         status = acpi_ec_transaction_unlocked(ec, t);
 378
 379         /* check if we received SCI during transaction */
 380         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 381         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 382                 msleep(1);
 383                 /* It is safe to enable the GPE outside of the transaction. */
 384                 acpi_enable_gpe(NULL, ec->gpe);
 385         } else if (t->irq_count > ec_storm_threshold) {
 386                 pr_info("GPE storm detected(%d GPEs), "
 387                         "transactions will use polling mode\n",
 388                         t->irq_count);
 389                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 390         }
 391         if (ec->global_lock)
 392                 acpi_release_global_lock(glk);
 393 unlock:
 394         mutex_unlock(&ec->mutex);
 395         return status;
 396 }
 397
 398 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 399 {
 400         u8 d;
 401         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 402                                 .wdata = NULL, .rdata = &d,
 403                                 .wlen = 0, .rlen = 1};
 404
 405         return acpi_ec_transaction(ec, &t);
 406 }
 407
 408 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 409 {
 410         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 411                                 .wdata = NULL, .rdata = NULL,
 412                                 .wlen = 0, .rlen = 0};
 413
 414         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 415                                 acpi_ec_transaction(ec, &t) : 0;
 416 }
 417
 418 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 419 {
 420         int result;
 421         u8 d;
 422         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 423                                 .wdata = &address, .rdata = &d,
 424                                 .wlen = 1, .rlen = 1};
 425
 426         result = acpi_ec_transaction(ec, &t);
 427         *data = d;
 428         return result;
 429 }
 430
 431 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 432 {
 433         u8 wdata[2] = { address, data };
 434         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 435                                 .wdata = wdata, .rdata = NULL,
 436                                 .wlen = 2, .rlen = 0};
 437
 438         return acpi_ec_transaction(ec, &t);
 439 }
 440
 441 int ec_read(u8 addr, u8 *val)
 442 {
 443         int err;
 444         u8 temp_data;
 445
 446         if (!first_ec)
 447                 return -ENODEV;
 448
 449         err = acpi_ec_read(first_ec, addr, &temp_data);
 450
 451         if (!err) {
 452                 *val = temp_data;
 453                 return 0;
 454         }
 455         return err;
 456 }
 457 EXPORT_SYMBOL(ec_read);
 458
 459 int ec_write(u8 addr, u8 val)
 460 {
 461         int err;
 462
 463         if (!first_ec)
 464                 return -ENODEV;
 465
 466         err = acpi_ec_write(first_ec, addr, val);
 467
 468         return err;
 469 }
 470 EXPORT_SYMBOL(ec_write);
 471
 472 int ec_transaction(u8 command,
 473                    const u8 *wdata, unsigned wdata_len,
 474                    u8 *rdata, unsigned rdata_len)
 475 {
 476         struct transaction t = {.command = command,
 477                                 .wdata = wdata, .rdata = rdata,
 478                                 .wlen = wdata_len, .rlen = rdata_len};
 479
 480         if (!first_ec)
 481                 return -ENODEV;
 482
 483         return acpi_ec_transaction(first_ec, &t);
 484 }
 485 EXPORT_SYMBOL(ec_transaction);
 486
 487 /* Get the handle to the EC device */
 488 acpi_handle ec_get_handle(void)
 489 {
 490         if (!first_ec)
 491                 return NULL;
 492         return first_ec->handle;
 493 }
 494 EXPORT_SYMBOL(ec_get_handle);
 495
 496 /*
 497  * Process _Q events that might have accumulated in the EC.
 498  * Run with locked ec mutex.
 499  */
 500 static void acpi_ec_clear(struct acpi_ec *ec)
 501 {
 502         int i, status;
 503         u8 value = 0;
 504
 505         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 506                 status = acpi_ec_sync_query(ec, &value);
 507                 if (status || !value)
 508                         break;
 509         }
 510
 511         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 512                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 513         else
 514                 pr_info("%d stale EC events cleared\n", i);
 515 }
 516
 517 void acpi_ec_block_transactions(void)
 518 {
 519         struct acpi_ec *ec = first_ec;
 520
 521         if (!ec)
 522                 return;
 523
 524         mutex_lock(&ec->mutex);
 525         /* Prevent transactions from being carried out */
 526         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 527         mutex_unlock(&ec->mutex);
 528 }
 529
 530 void acpi_ec_unblock_transactions(void)
 531 {
 532         struct acpi_ec *ec = first_ec;
 533
 534         if (!ec)
 535                 return;
 536
 537         mutex_lock(&ec->mutex);
 538         /* Allow transactions to be carried out again */
 539         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 540
 541         if (EC_FLAGS_CLEAR_ON_RESUME)
 542                 acpi_ec_clear(ec);
 543
 544         mutex_unlock(&ec->mutex);
 545 }
 546
 547 void acpi_ec_unblock_transactions_early(void)
 548 {
 549         /*
 550          * Allow transactions to happen again (this function is called from
 551          * atomic context during wakeup, so we don't need to acquire the mutex).
 552          */
 553         if (first_ec)
 554                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 555 }
 556
 557 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 *data)
 558 {
 559         int result;
 560         u8 d;
 561         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 562                                 .wdata = NULL, .rdata = &d,
 563                                 .wlen = 0, .rlen = 1};
 564
 565         if (!ec || !data)
 566                 return -EINVAL;
 567         /*
 568          * Query the EC to find out which _Qxx method we need to evaluate.
 569          * Note that successful completion of the query causes the ACPI_EC_SCI
 570          * bit to be cleared (and thus clearing the interrupt source).
 571          */
 572         result = acpi_ec_transaction_unlocked(ec, &t);
 573         if (result)
 574                 return result;
 575         if (!d)
 576                 return -ENODATA;
 577         *data = d;
 578         return 0;
 579 }
 580
 581 /* --------------------------------------------------------------------------
 582                                 Event Management
 583    -------------------------------------------------------------------------- */
 584 static struct acpi_ec_query_handler *
 585 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
 586 {
 587         if (handler)
 588                 kref_get(&handler->kref);
 589         return handler;
 590 }
 591
 592 static void acpi_ec_query_handler_release(struct kref *kref)
 593 {
 594         struct acpi_ec_query_handler *handler =
 595                 container_of(kref, struct acpi_ec_query_handler, kref);
 596
 597         kfree(handler);
 598 }
 599
 600 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
 601 {
 602         kref_put(&handler->kref, acpi_ec_query_handler_release);
 603 }
 604
 605 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 606                               acpi_handle handle, acpi_ec_query_func func,
 607                               void *data)
 608 {
 609         struct acpi_ec_query_handler *handler =
 610             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 611
 612         if (!handler)
 613                 return -ENOMEM;
 614
 615         handler->query_bit = query_bit;
 616         handler->handle = handle;
 617         handler->func = func;
 618         handler->data = data;
 619         mutex_lock(&ec->mutex);
 620         kref_init(&handler->kref);
 621         list_add(&handler->node, &ec->list);
 622         mutex_unlock(&ec->mutex);
 623         return 0;
 624 }
 625 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 626
 627 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 628 {
 629         struct acpi_ec_query_handler *handler, *tmp;
 630         LIST_HEAD(free_list);
 631
 632         mutex_lock(&ec->mutex);
 633         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 634                 if (query_bit == handler->query_bit) {
 635                         list_del_init(&handler->node);
 636                         list_add(&handler->node, &free_list);
 637                 }
 638         }
 639         mutex_unlock(&ec->mutex);
 640         list_for_each_entry(handler, &free_list, node)
 641                 acpi_ec_put_query_handler(handler);
 642 }
 643 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 644
 645 static void acpi_ec_run(void *cxt)
 646 {
 647         struct acpi_ec_query_handler *handler = cxt;
 648
 649         if (!handler)
 650                 return;
 651         pr_debug("##### Query(0x%02x) started #####\n", handler->query_bit);
 652         if (handler->func)
 653                 handler->func(handler->data);
 654         else if (handler->handle)
 655                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 656         pr_debug("##### Query(0x%02x) stopped #####\n", handler->query_bit);
 657         acpi_ec_put_query_handler(handler);
 658 }
 659
 660 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
 661 {
 662         u8 value = 0;
 663         int result;
 664         acpi_status status;
 665         struct acpi_ec_query_handler *handler;
 666
 667         result = acpi_ec_query_unlocked(ec, &value);
 668         if (data)
 669                 *data = value;
 670         if (result)
 671                 return result;
 672
 673         list_for_each_entry(handler, &ec->list, node) {
 674                 if (value == handler->query_bit) {
 675                         /* have custom handler for this bit */
 676                         handler = acpi_ec_get_query_handler(handler);
 677                         pr_debug("##### Query(0x%02x) scheduled #####\n",
 678                                  handler->query_bit);
 679                         status = acpi_os_execute((handler->func) ?
 680                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 681                                 acpi_ec_run, handler);
 682                         if (ACPI_FAILURE(status))
 683                                 result = -EBUSY;
 684                         break;
 685                 }
 686         }
 687         return result;
 688 }
 689
 690 static void acpi_ec_gpe_query(void *ec_cxt)
 691 {
 692         struct acpi_ec *ec = ec_cxt;
 693
 694         if (!ec)
 695                 return;
 696         mutex_lock(&ec->mutex);
 697         acpi_ec_sync_query(ec, NULL);
 698         mutex_unlock(&ec->mutex);
 699 }
 700
 701 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 702 {
 703         if (state & ACPI_EC_FLAG_SCI) {
 704                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 705                         pr_debug("***** Event started *****\n");
 706                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 707                                 acpi_ec_gpe_query, ec);
 708                 }
 709         }
 710         return 0;
 711 }
 712
 713 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 714         u32 gpe_number, void *data)
 715 {
 716         unsigned long flags;
 717         struct acpi_ec *ec = data;
 718
 719         spin_lock_irqsave(&ec->lock, flags);
 720         advance_transaction(ec);
 721         spin_unlock_irqrestore(&ec->lock, flags);
 722         ec_check_sci(ec, acpi_ec_read_status(ec));
 723         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 724 }
 725
 726 /* --------------------------------------------------------------------------
 727  *                           Address Space Management
 728  * -------------------------------------------------------------------------- */
 729
 730 static acpi_status
 731 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 732                       u32 bits, u64 *value64,
 733                       void *handler_context, void *region_context)
 734 {
 735         struct acpi_ec *ec = handler_context;
 736         int result = 0, i, bytes = bits / 8;
 737         u8 *value = (u8 *)value64;
 738
 739         if ((address > 0xFF) || !value || !handler_context)
 740                 return AE_BAD_PARAMETER;
 741
 742         if (function != ACPI_READ && function != ACPI_WRITE)
 743                 return AE_BAD_PARAMETER;
 744
 745         if (EC_FLAGS_MSI || bits > 8)
 746                 acpi_ec_burst_enable(ec);
 747
 748         for (i = 0; i < bytes; ++i, ++address, ++value)
 749                 result = (function == ACPI_READ) ?
 750                         acpi_ec_read(ec, address, value) :
 751                         acpi_ec_write(ec, address, *value);
 752
 753         if (EC_FLAGS_MSI || bits > 8)
 754                 acpi_ec_burst_disable(ec);
 755
 756         switch (result) {
 757         case -EINVAL:
 758                 return AE_BAD_PARAMETER;
 759         case -ENODEV:
 760                 return AE_NOT_FOUND;
 761         case -ETIME:
 762                 return AE_TIME;
 763         default:
 764                 return AE_OK;
 765         }
 766 }
 767
 768 /* --------------------------------------------------------------------------
 769  *                             Driver Interface
 770  * -------------------------------------------------------------------------- */
 771
 772 static acpi_status
 773 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 774
 775 static struct acpi_ec *make_acpi_ec(void)
 776 {
 777         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 778
 779         if (!ec)
 780                 return NULL;
 781         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 782         mutex_init(&ec->mutex);
 783         init_waitqueue_head(&ec->wait);
 784         INIT_LIST_HEAD(&ec->list);
 785         spin_lock_init(&ec->lock);
 786         return ec;
 787 }
 788
 789 static acpi_status
 790 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 791                                void *context, void **return_value)
 792 {
 793         char node_name[5];
 794         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 795         struct acpi_ec *ec = context;
 796         int value = 0;
 797         acpi_status status;
 798
 799         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 800
 801         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
 802                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 803         return AE_OK;
 804 }
 805
 806 static acpi_status
 807 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 808 {
 809         acpi_status status;
 810         unsigned long long tmp = 0;
 811         struct acpi_ec *ec = context;
 812
 813         /* clear addr values, ec_parse_io_ports depend on it */
 814         ec->command_addr = ec->data_addr = 0;
 815
 816         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 817                                      ec_parse_io_ports, ec);
 818         if (ACPI_FAILURE(status))
 819                 return status;
 820
 821         /* Get GPE bit assignment (EC events). */
 822         /* TODO: Add support for _GPE returning a package */
 823         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 824         if (ACPI_FAILURE(status))
 825                 return status;
 826         ec->gpe = tmp;
 827         /* Use the global lock for all EC transactions? */
 828         tmp = 0;
 829         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 830         ec->global_lock = tmp;
 831         ec->handle = handle;
 832         return AE_CTRL_TERMINATE;
 833 }
 834
 835 static int ec_install_handlers(struct acpi_ec *ec)
 836 {
 837         acpi_status status;
 838
 839         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 840                 return 0;
 841         status = acpi_install_gpe_handler(NULL, ec->gpe,
 842                                   ACPI_GPE_EDGE_TRIGGERED,
 843                                   &acpi_ec_gpe_handler, ec);
 844         if (ACPI_FAILURE(status))
 845                 return -ENODEV;
 846
 847         acpi_enable_gpe(NULL, ec->gpe);
 848         status = acpi_install_address_space_handler(ec->handle,
 849                                                     ACPI_ADR_SPACE_EC,
 850                                                     &acpi_ec_space_handler,
 851                                                     NULL, ec);
 852         if (ACPI_FAILURE(status)) {
 853                 if (status == AE_NOT_FOUND) {
 854                         /*
 855                          * Maybe OS fails in evaluating the _REG object.
 856                          * The AE_NOT_FOUND error will be ignored and OS
 857                          * continue to initialize EC.
 858                          */
 859                         pr_err("Fail in evaluating the _REG object"
 860                                 " of EC device. Broken bios is suspected.\n");
 861                 } else {
 862                         acpi_disable_gpe(NULL, ec->gpe);
 863                         acpi_remove_gpe_handler(NULL, ec->gpe,
 864                                 &acpi_ec_gpe_handler);
 865                         return -ENODEV;
 866                 }
 867         }
 868
 869         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 870         return 0;
 871 }
 872
 873 static void ec_remove_handlers(struct acpi_ec *ec)
 874 {
 875         if (!test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 876                 return;
 877         acpi_disable_gpe(NULL, ec->gpe);
 878         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 879                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 880                 pr_err("failed to remove space handler\n");
 881         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 882                                 &acpi_ec_gpe_handler)))
 883                 pr_err("failed to remove gpe handler\n");
 884         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 885 }
 886
 887 static int acpi_ec_add(struct acpi_device *device)
 888 {
 889         struct acpi_ec *ec = NULL;
 890         int ret;
 891
 892         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 893         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 894
 895         /* Check for boot EC */
 896         if (boot_ec &&
 897             (boot_ec->handle == device->handle ||
 898              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 899                 ec = boot_ec;
 900                 boot_ec = NULL;
 901         } else {
 902                 ec = make_acpi_ec();
 903                 if (!ec)
 904                         return -ENOMEM;
 905         }
 906         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 907                 AE_CTRL_TERMINATE) {
 908                         kfree(ec);
 909                         return -EINVAL;
 910         }
 911
 912         /* Find and register all query methods */
 913         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 914                             acpi_ec_register_query_methods, NULL, ec, NULL);
 915
 916         if (!first_ec)
 917                 first_ec = ec;
 918         device->driver_data = ec;
 919
 920         ret = !!request_region(ec->data_addr, 1, "EC data");
 921         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
 922         ret = !!request_region(ec->command_addr, 1, "EC cmd");
 923         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
 924
 925         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 926                           ec->gpe, ec->command_addr, ec->data_addr);
 927
 928         ret = ec_install_handlers(ec);
 929
 930         /* EC is fully operational, allow queries */
 931         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 932
 933         /* Clear stale _Q events if hardware might require that */
 934         if (EC_FLAGS_CLEAR_ON_RESUME) {
 935                 mutex_lock(&ec->mutex);
 936                 acpi_ec_clear(ec);
 937                 mutex_unlock(&ec->mutex);
 938         }
 939         return ret;
 940 }
 941
 942 static int acpi_ec_remove(struct acpi_device *device)
 943 {
 944         struct acpi_ec *ec;
 945         struct acpi_ec_query_handler *handler, *tmp;
 946
 947         if (!device)
 948                 return -EINVAL;
 949
 950         ec = acpi_driver_data(device);
 951         ec_remove_handlers(ec);
 952         mutex_lock(&ec->mutex);
 953         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 954                 list_del(&handler->node);
 955                 kfree(handler);
 956         }
 957         mutex_unlock(&ec->mutex);
 958         release_region(ec->data_addr, 1);
 959         release_region(ec->command_addr, 1);
 960         device->driver_data = NULL;
 961         if (ec == first_ec)
 962                 first_ec = NULL;
 963         kfree(ec);
 964         return 0;
 965 }
 966
 967 static acpi_status
 968 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 969 {
 970         struct acpi_ec *ec = context;
 971
 972         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 973                 return AE_OK;
 974
 975         /*
 976          * The first address region returned is the data port, and
 977          * the second address region returned is the status/command
 978          * port.
 979          */
 980         if (ec->data_addr == 0)
 981                 ec->data_addr = resource->data.io.minimum;
 982         else if (ec->command_addr == 0)
 983                 ec->command_addr = resource->data.io.minimum;
 984         else
 985                 return AE_CTRL_TERMINATE;
 986
 987         return AE_OK;
 988 }
 989
 990 int __init acpi_boot_ec_enable(void)
 991 {
 992         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 993                 return 0;
 994         if (!ec_install_handlers(boot_ec)) {
 995                 first_ec = boot_ec;
 996                 return 0;
 997         }
 998         return -EFAULT;
 999 }
1000
1001 static const struct acpi_device_id ec_device_ids[] = {
1002         {"PNP0C09", 0},
1003         {"", 0},
1004 };
1005
1006 /* Some BIOS do not survive early DSDT scan, skip it */
1007 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
1008 {
1009         EC_FLAGS_SKIP_DSDT_SCAN = 1;
1010         return 0;
1011 }
1012
1013 /* ASUStek often supplies us with broken ECDT, validate it */
1014 static int ec_validate_ecdt(const struct dmi_system_id *id)
1015 {
1016         EC_FLAGS_VALIDATE_ECDT = 1;
1017         return 0;
1018 }
1019
1020 /* MSI EC needs special treatment, enable it */
1021 static int ec_flag_msi(const struct dmi_system_id *id)
1022 {
1023         pr_debug("Detected MSI hardware, enabling workarounds.\n");
1024         EC_FLAGS_MSI = 1;
1025         EC_FLAGS_VALIDATE_ECDT = 1;
1026         return 0;
1027 }
1028
1029 /*
1030  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
1031  * the GPE storm threshold back to 20
1032  */
1033 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
1034 {
1035         pr_debug("Setting the EC GPE storm threshold to 20\n");
1036         ec_storm_threshold  = 20;
1037         return 0;
1038 }
1039
1040 /*
1041  * Acer EC firmware refuses to respond QR_EC when SCI_EVT is not set, for
1042  * which case, we complete the QR_EC without issuing it to the firmware.
1043  * https://bugzilla.kernel.org/show_bug.cgi?id=86211
1044  */
1045 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1046 {
1047         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1048         EC_FLAGS_QUERY_HANDSHAKE = 1;
1049         return 0;
1050 }
1051
1052 /*
1053  * On some hardware it is necessary to clear events accumulated by the EC during
1054  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1055  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1056  *
1057  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1058  *
1059  * Ideally, the EC should also be instructed NOT to accumulate events during
1060  * sleep (which Windows seems to do somehow), but the interface to control this
1061  * behaviour is not known at this time.
1062  *
1063  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1064  * however it is very likely that other Samsung models are affected.
1065  *
1066  * On systems which don't accumulate _Q events during sleep, this extra check
1067  * should be harmless.
1068  */
1069 static int ec_clear_on_resume(const struct dmi_system_id *id)
1070 {
1071         pr_debug("Detected system needing EC poll on resume.\n");
1072         EC_FLAGS_CLEAR_ON_RESUME = 1;
1073         return 0;
1074 }
1075
1076 static struct dmi_system_id ec_dmi_table[] __initdata = {
1077         {
1078         ec_skip_dsdt_scan, "Compal JFL92", {
1079         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1080         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1081         {
1082         ec_flag_msi, "MSI hardware", {
1083         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1084         {
1085         ec_flag_msi, "MSI hardware", {
1086         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1087         {
1088         ec_flag_msi, "MSI hardware", {
1089         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1090         {
1091         ec_flag_msi, "MSI hardware", {
1092         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1093         {
1094         ec_flag_msi, "Quanta hardware", {
1095         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1096         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1097         {
1098         ec_flag_msi, "Quanta hardware", {
1099         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1100         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1101         {
1102         ec_flag_msi, "Clevo W350etq", {
1103         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
1104         DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
1105         {
1106         ec_validate_ecdt, "ASUS hardware", {
1107         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1108         {
1109         ec_validate_ecdt, "ASUS hardware", {
1110         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1111         {
1112         ec_enlarge_storm_threshold, "CLEVO hardware", {
1113         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1114         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1115         {
1116         ec_skip_dsdt_scan, "HP Folio 13", {
1117         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1118         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1119         {
1120         ec_validate_ecdt, "ASUS hardware", {
1121         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1122         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1123         {
1124         ec_clear_on_resume, "Samsung hardware", {
1125         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1126         {
1127         ec_flag_query_handshake, "Acer hardware", {
1128         DMI_MATCH(DMI_SYS_VENDOR, "Acer"), }, NULL},
1129         {},
1130 };
1131
1132 int __init acpi_ec_ecdt_probe(void)
1133 {
1134         acpi_status status;
1135         struct acpi_ec *saved_ec = NULL;
1136         struct acpi_table_ecdt *ecdt_ptr;
1137
1138         boot_ec = make_acpi_ec();
1139         if (!boot_ec)
1140                 return -ENOMEM;
1141         /*
1142          * Generate a boot ec context
1143          */
1144         dmi_check_system(ec_dmi_table);
1145         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1146                                 (struct acpi_table_header **)&ecdt_ptr);
1147         if (ACPI_SUCCESS(status)) {
1148                 pr_info("EC description table is found, configuring boot EC\n");
1149                 boot_ec->command_addr = ecdt_ptr->control.address;
1150                 boot_ec->data_addr = ecdt_ptr->data.address;
1151                 boot_ec->gpe = ecdt_ptr->gpe;
1152                 boot_ec->handle = ACPI_ROOT_OBJECT;
1153                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id,
1154                                 &boot_ec->handle);
1155                 /* Don't trust ECDT, which comes from ASUSTek */
1156                 if (!EC_FLAGS_VALIDATE_ECDT)
1157                         goto install;
1158                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1159                 if (!saved_ec)
1160                         return -ENOMEM;
1161         /* fall through */
1162         }
1163
1164         if (EC_FLAGS_SKIP_DSDT_SCAN) {
1165                 kfree(saved_ec);
1166                 return -ENODEV;
1167         }
1168
1169         /* This workaround is needed only on some broken machines,
1170          * which require early EC, but fail to provide ECDT */
1171         pr_debug("Look up EC in DSDT\n");
1172         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1173                                         boot_ec, NULL);
1174         /* Check that acpi_get_devices actually find something */
1175         if (ACPI_FAILURE(status) || !boot_ec->handle)
1176                 goto error;
1177         if (saved_ec) {
1178                 /* try to find good ECDT from ASUSTek */
1179                 if (saved_ec->command_addr != boot_ec->command_addr ||
1180                     saved_ec->data_addr != boot_ec->data_addr ||
1181                     saved_ec->gpe != boot_ec->gpe ||
1182                     saved_ec->handle != boot_ec->handle)
1183                         pr_info("ASUSTek keeps feeding us with broken "
1184                         "ECDT tables, which are very hard to workaround. "
1185                         "Trying to use DSDT EC info instead. Please send "
1186                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1187                 kfree(saved_ec);
1188                 saved_ec = NULL;
1189         } else {
1190                 /* We really need to limit this workaround, the only ASUS,
1191                 * which needs it, has fake EC._INI method, so use it as flag.
1192                 * Keep boot_ec struct as it will be needed soon.
1193                 */
1194                 if (!dmi_name_in_vendors("ASUS") ||
1195                     !acpi_has_method(boot_ec->handle, "_INI"))
1196                         return -ENODEV;
1197         }
1198 install:
1199         if (!ec_install_handlers(boot_ec)) {
1200                 first_ec = boot_ec;
1201                 return 0;
1202         }
1203 error:
1204         kfree(boot_ec);
1205         kfree(saved_ec);
1206         boot_ec = NULL;
1207         return -ENODEV;
1208 }
1209
1210 static struct acpi_driver acpi_ec_driver = {
1211         .name = "ec",
1212         .class = ACPI_EC_CLASS,
1213         .ids = ec_device_ids,
1214         .ops = {
1215                 .add = acpi_ec_add,
1216                 .remove = acpi_ec_remove,
1217                 },
1218 };
1219
1220 int __init acpi_ec_init(void)
1221 {
1222         int result = 0;
1223
1224         /* Now register the driver for the EC */
1225         result = acpi_bus_register_driver(&acpi_ec_driver);
1226         if (result < 0)
1227                 return -ENODEV;
1228
1229         return result;
1230 }
1231
1232 /* EC driver currently not unloadable */
1233 #if 0
1234 static void __exit acpi_ec_exit(void)
1235 {
1236
1237         acpi_bus_unregister_driver(&acpi_ec_driver);
1238 }
1239 #endif  /* 0 */