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 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
 124
 125 struct acpi_ec *boot_ec, *first_ec;
 126 EXPORT_SYMBOL(first_ec);
 127
 128 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 129 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 130 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 131 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 132 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
 133
 134 /* --------------------------------------------------------------------------
 135  *                           Transaction Management
 136  * -------------------------------------------------------------------------- */
 137
 138 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 139 {
 140         u8 x = inb(ec->command_addr);
 141
 142         pr_debug("EC_SC(R) = 0x%2.2x "
 143                  "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d\n",
 144                  x,
 145                  !!(x & ACPI_EC_FLAG_SCI),
 146                  !!(x & ACPI_EC_FLAG_BURST),
 147                  !!(x & ACPI_EC_FLAG_CMD),
 148                  !!(x & ACPI_EC_FLAG_IBF),
 149                  !!(x & ACPI_EC_FLAG_OBF));
 150         return x;
 151 }
 152
 153 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 154 {
 155         u8 x = inb(ec->data_addr);
 156
 157         pr_debug("EC_DATA(R) = 0x%2.2x\n", x);
 158         return x;
 159 }
 160
 161 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 162 {
 163         pr_debug("EC_SC(W) = 0x%2.2x\n", command);
 164         outb(command, ec->command_addr);
 165 }
 166
 167 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 168 {
 169         pr_debug("EC_DATA(W) = 0x%2.2x\n", data);
 170         outb(data, ec->data_addr);
 171 }
 172
 173 #ifdef DEBUG
 174 static const char *acpi_ec_cmd_string(u8 cmd)
 175 {
 176         switch (cmd) {
 177         case 0x80:
 178                 return "RD_EC";
 179         case 0x81:
 180                 return "WR_EC";
 181         case 0x82:
 182                 return "BE_EC";
 183         case 0x83:
 184                 return "BD_EC";
 185         case 0x84:
 186                 return "QR_EC";
 187         }
 188         return "UNKNOWN";
 189 }
 190 #else
 191 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 192 #endif
 193
 194 static void acpi_ec_submit_query(struct acpi_ec *ec)
 195 {
 196         if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 197                 pr_debug("***** Event started *****\n");
 198                 schedule_work(&ec->work);
 199         }
 200 }
 201
 202 static void acpi_ec_complete_query(struct acpi_ec *ec)
 203 {
 204         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 205                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 206                 pr_debug("***** Event stopped *****\n");
 207         }
 208 }
 209
 210 static int ec_transaction_completed(struct acpi_ec *ec)
 211 {
 212         unsigned long flags;
 213         int ret = 0;
 214
 215         spin_lock_irqsave(&ec->lock, flags);
 216         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 217                 ret = 1;
 218         spin_unlock_irqrestore(&ec->lock, flags);
 219         return ret;
 220 }
 221
 222 static void advance_transaction(struct acpi_ec *ec)
 223 {
 224         struct transaction *t;
 225         u8 status;
 226         bool wakeup = false;
 227
 228         pr_debug("===== %s (%d) =====\n",
 229                  in_interrupt() ? "IRQ" : "TASK", smp_processor_id());
 230         status = acpi_ec_read_status(ec);
 231         t = ec->curr;
 232         if (!t)
 233                 goto err;
 234         if (t->flags & ACPI_EC_COMMAND_POLL) {
 235                 if (t->wlen > t->wi) {
 236                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 237                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 238                         else
 239                                 goto err;
 240                 } else if (t->rlen > t->ri) {
 241                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 242                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 243                                 if (t->rlen == t->ri) {
 244                                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 245                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 246                                                 pr_debug("***** Command(%s) hardware completion *****\n",
 247                                                          acpi_ec_cmd_string(t->command));
 248                                         wakeup = true;
 249                                 }
 250                         } else
 251                                 goto err;
 252                 } else if (t->wlen == t->wi &&
 253                            (status & ACPI_EC_FLAG_IBF) == 0) {
 254                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 255                         wakeup = true;
 256                 }
 257                 goto out;
 258         } else {
 259                 if (EC_FLAGS_QUERY_HANDSHAKE &&
 260                     !(status & ACPI_EC_FLAG_SCI) &&
 261                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 262                         t->flags |= ACPI_EC_COMMAND_POLL;
 263                         acpi_ec_complete_query(ec);
 264                         t->rdata[t->ri++] = 0x00;
 265                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 266                         pr_debug("***** Command(%s) software completion *****\n",
 267                                  acpi_ec_cmd_string(t->command));
 268                         wakeup = true;
 269                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 270                         acpi_ec_write_cmd(ec, t->command);
 271                         t->flags |= ACPI_EC_COMMAND_POLL;
 272                         acpi_ec_complete_query(ec);
 273                 } else
 274                         goto err;
 275                 goto out;
 276         }
 277 err:
 278         /*
 279          * If SCI bit is set, then don't think it's a false IRQ
 280          * otherwise will take a not handled IRQ as a false one.
 281          */
 282         if (!(status & ACPI_EC_FLAG_SCI)) {
 283                 if (in_interrupt() && t)
 284                         ++t->irq_count;
 285         }
 286 out:
 287         if (status & ACPI_EC_FLAG_SCI)
 288                 acpi_ec_submit_query(ec);
 289         if (wakeup && in_interrupt())
 290                 wake_up(&ec->wait);
 291 }
 292
 293 static void start_transaction(struct acpi_ec *ec)
 294 {
 295         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 296         ec->curr->flags = 0;
 297         advance_transaction(ec);
 298 }
 299
 300 static int ec_poll(struct acpi_ec *ec)
 301 {
 302         unsigned long flags;
 303         int repeat = 5; /* number of command restarts */
 304
 305         while (repeat--) {
 306                 unsigned long delay = jiffies +
 307                         msecs_to_jiffies(ec_delay);
 308                 do {
 309                         /* don't sleep with disabled interrupts */
 310                         if (EC_FLAGS_MSI || irqs_disabled()) {
 311                                 udelay(ACPI_EC_MSI_UDELAY);
 312                                 if (ec_transaction_completed(ec))
 313                                         return 0;
 314                         } else {
 315                                 if (wait_event_timeout(ec->wait,
 316                                                 ec_transaction_completed(ec),
 317                                                 msecs_to_jiffies(1)))
 318                                         return 0;
 319                         }
 320                         spin_lock_irqsave(&ec->lock, flags);
 321                         advance_transaction(ec);
 322                         spin_unlock_irqrestore(&ec->lock, flags);
 323                 } while (time_before(jiffies, delay));
 324                 pr_debug("controller reset, restart transaction\n");
 325                 spin_lock_irqsave(&ec->lock, flags);
 326                 start_transaction(ec);
 327                 spin_unlock_irqrestore(&ec->lock, flags);
 328         }
 329         return -ETIME;
 330 }
 331
 332 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 333                                         struct transaction *t)
 334 {
 335         unsigned long tmp;
 336         int ret = 0;
 337
 338         if (EC_FLAGS_MSI)
 339                 udelay(ACPI_EC_MSI_UDELAY);
 340         /* start transaction */
 341         spin_lock_irqsave(&ec->lock, tmp);
 342         /* following two actions should be kept atomic */
 343         ec->curr = t;
 344         pr_debug("***** Command(%s) started *****\n",
 345                  acpi_ec_cmd_string(t->command));
 346         start_transaction(ec);
 347         spin_unlock_irqrestore(&ec->lock, tmp);
 348         ret = ec_poll(ec);
 349         spin_lock_irqsave(&ec->lock, tmp);
 350         pr_debug("***** Command(%s) stopped *****\n",
 351                  acpi_ec_cmd_string(t->command));
 352         ec->curr = NULL;
 353         spin_unlock_irqrestore(&ec->lock, tmp);
 354         return ret;
 355 }
 356
 357 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 358 {
 359         int status;
 360         u32 glk;
 361
 362         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 363                 return -EINVAL;
 364         if (t->rdata)
 365                 memset(t->rdata, 0, t->rlen);
 366         mutex_lock(&ec->mutex);
 367         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 368                 status = -EINVAL;
 369                 goto unlock;
 370         }
 371         if (ec->global_lock) {
 372                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 373                 if (ACPI_FAILURE(status)) {
 374                         status = -ENODEV;
 375                         goto unlock;
 376                 }
 377         }
 378         /* disable GPE during transaction if storm is detected */
 379         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 380                 /* It has to be disabled, so that it doesn't trigger. */
 381                 acpi_disable_gpe(NULL, ec->gpe);
 382         }
 383
 384         status = acpi_ec_transaction_unlocked(ec, t);
 385
 386         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 387                 msleep(1);
 388                 /* It is safe to enable the GPE outside of the transaction. */
 389                 acpi_enable_gpe(NULL, ec->gpe);
 390         } else if (t->irq_count > ec_storm_threshold) {
 391                 pr_info("GPE storm detected(%d GPEs), "
 392                         "transactions will use polling mode\n",
 393                         t->irq_count);
 394                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 395         }
 396         if (ec->global_lock)
 397                 acpi_release_global_lock(glk);
 398 unlock:
 399         mutex_unlock(&ec->mutex);
 400         return status;
 401 }
 402
 403 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 404 {
 405         u8 d;
 406         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 407                                 .wdata = NULL, .rdata = &d,
 408                                 .wlen = 0, .rlen = 1};
 409
 410         return acpi_ec_transaction(ec, &t);
 411 }
 412
 413 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 414 {
 415         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 416                                 .wdata = NULL, .rdata = NULL,
 417                                 .wlen = 0, .rlen = 0};
 418
 419         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 420                                 acpi_ec_transaction(ec, &t) : 0;
 421 }
 422
 423 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 424 {
 425         int result;
 426         u8 d;
 427         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 428                                 .wdata = &address, .rdata = &d,
 429                                 .wlen = 1, .rlen = 1};
 430
 431         result = acpi_ec_transaction(ec, &t);
 432         *data = d;
 433         return result;
 434 }
 435
 436 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 437 {
 438         u8 wdata[2] = { address, data };
 439         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 440                                 .wdata = wdata, .rdata = NULL,
 441                                 .wlen = 2, .rlen = 0};
 442
 443         return acpi_ec_transaction(ec, &t);
 444 }
 445
 446 int ec_read(u8 addr, u8 *val)
 447 {
 448         int err;
 449         u8 temp_data;
 450
 451         if (!first_ec)
 452                 return -ENODEV;
 453
 454         err = acpi_ec_read(first_ec, addr, &temp_data);
 455
 456         if (!err) {
 457                 *val = temp_data;
 458                 return 0;
 459         }
 460         return err;
 461 }
 462 EXPORT_SYMBOL(ec_read);
 463
 464 int ec_write(u8 addr, u8 val)
 465 {
 466         int err;
 467
 468         if (!first_ec)
 469                 return -ENODEV;
 470
 471         err = acpi_ec_write(first_ec, addr, val);
 472
 473         return err;
 474 }
 475 EXPORT_SYMBOL(ec_write);
 476
 477 int ec_transaction(u8 command,
 478                    const u8 *wdata, unsigned wdata_len,
 479                    u8 *rdata, unsigned rdata_len)
 480 {
 481         struct transaction t = {.command = command,
 482                                 .wdata = wdata, .rdata = rdata,
 483                                 .wlen = wdata_len, .rlen = rdata_len};
 484
 485         if (!first_ec)
 486                 return -ENODEV;
 487
 488         return acpi_ec_transaction(first_ec, &t);
 489 }
 490 EXPORT_SYMBOL(ec_transaction);
 491
 492 /* Get the handle to the EC device */
 493 acpi_handle ec_get_handle(void)
 494 {
 495         if (!first_ec)
 496                 return NULL;
 497         return first_ec->handle;
 498 }
 499 EXPORT_SYMBOL(ec_get_handle);
 500
 501 /*
 502  * Process _Q events that might have accumulated in the EC.
 503  * Run with locked ec mutex.
 504  */
 505 static void acpi_ec_clear(struct acpi_ec *ec)
 506 {
 507         int i, status;
 508         u8 value = 0;
 509
 510         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 511                 status = acpi_ec_sync_query(ec, &value);
 512                 if (status || !value)
 513                         break;
 514         }
 515
 516         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 517                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 518         else
 519                 pr_info("%d stale EC events cleared\n", i);
 520 }
 521
 522 void acpi_ec_block_transactions(void)
 523 {
 524         struct acpi_ec *ec = first_ec;
 525
 526         if (!ec)
 527                 return;
 528
 529         mutex_lock(&ec->mutex);
 530         /* Prevent transactions from being carried out */
 531         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 532         mutex_unlock(&ec->mutex);
 533 }
 534
 535 void acpi_ec_unblock_transactions(void)
 536 {
 537         struct acpi_ec *ec = first_ec;
 538
 539         if (!ec)
 540                 return;
 541
 542         mutex_lock(&ec->mutex);
 543         /* Allow transactions to be carried out again */
 544         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 545
 546         if (EC_FLAGS_CLEAR_ON_RESUME)
 547                 acpi_ec_clear(ec);
 548
 549         mutex_unlock(&ec->mutex);
 550 }
 551
 552 void acpi_ec_unblock_transactions_early(void)
 553 {
 554         /*
 555          * Allow transactions to happen again (this function is called from
 556          * atomic context during wakeup, so we don't need to acquire the mutex).
 557          */
 558         if (first_ec)
 559                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 560 }
 561
 562 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 *data)
 563 {
 564         int result;
 565         u8 d;
 566         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 567                                 .wdata = NULL, .rdata = &d,
 568                                 .wlen = 0, .rlen = 1};
 569
 570         if (!ec || !data)
 571                 return -EINVAL;
 572         /*
 573          * Query the EC to find out which _Qxx method we need to evaluate.
 574          * Note that successful completion of the query causes the ACPI_EC_SCI
 575          * bit to be cleared (and thus clearing the interrupt source).
 576          */
 577         result = acpi_ec_transaction_unlocked(ec, &t);
 578         if (result)
 579                 return result;
 580         if (!d)
 581                 return -ENODATA;
 582         *data = d;
 583         return 0;
 584 }
 585
 586 /* --------------------------------------------------------------------------
 587                                 Event Management
 588    -------------------------------------------------------------------------- */
 589 static struct acpi_ec_query_handler *
 590 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
 591 {
 592         if (handler)
 593                 kref_get(&handler->kref);
 594         return handler;
 595 }
 596
 597 static void acpi_ec_query_handler_release(struct kref *kref)
 598 {
 599         struct acpi_ec_query_handler *handler =
 600                 container_of(kref, struct acpi_ec_query_handler, kref);
 601
 602         kfree(handler);
 603 }
 604
 605 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
 606 {
 607         kref_put(&handler->kref, acpi_ec_query_handler_release);
 608 }
 609
 610 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 611                               acpi_handle handle, acpi_ec_query_func func,
 612                               void *data)
 613 {
 614         struct acpi_ec_query_handler *handler =
 615             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 616
 617         if (!handler)
 618                 return -ENOMEM;
 619
 620         handler->query_bit = query_bit;
 621         handler->handle = handle;
 622         handler->func = func;
 623         handler->data = data;
 624         mutex_lock(&ec->mutex);
 625         kref_init(&handler->kref);
 626         list_add(&handler->node, &ec->list);
 627         mutex_unlock(&ec->mutex);
 628         return 0;
 629 }
 630 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 631
 632 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 633 {
 634         struct acpi_ec_query_handler *handler, *tmp;
 635         LIST_HEAD(free_list);
 636
 637         mutex_lock(&ec->mutex);
 638         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 639                 if (query_bit == handler->query_bit) {
 640                         list_del_init(&handler->node);
 641                         list_add(&handler->node, &free_list);
 642                 }
 643         }
 644         mutex_unlock(&ec->mutex);
 645         list_for_each_entry(handler, &free_list, node)
 646                 acpi_ec_put_query_handler(handler);
 647 }
 648 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 649
 650 static void acpi_ec_run(void *cxt)
 651 {
 652         struct acpi_ec_query_handler *handler = cxt;
 653
 654         if (!handler)
 655                 return;
 656         pr_debug("##### Query(0x%02x) started #####\n", handler->query_bit);
 657         if (handler->func)
 658                 handler->func(handler->data);
 659         else if (handler->handle)
 660                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 661         pr_debug("##### Query(0x%02x) stopped #####\n", handler->query_bit);
 662         acpi_ec_put_query_handler(handler);
 663 }
 664
 665 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
 666 {
 667         u8 value = 0;
 668         int result;
 669         acpi_status status;
 670         struct acpi_ec_query_handler *handler;
 671
 672         result = acpi_ec_query_unlocked(ec, &value);
 673         if (data)
 674                 *data = value;
 675         if (result)
 676                 return result;
 677
 678         list_for_each_entry(handler, &ec->list, node) {
 679                 if (value == handler->query_bit) {
 680                         /* have custom handler for this bit */
 681                         handler = acpi_ec_get_query_handler(handler);
 682                         pr_debug("##### Query(0x%02x) scheduled #####\n",
 683                                  handler->query_bit);
 684                         status = acpi_os_execute((handler->func) ?
 685                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 686                                 acpi_ec_run, handler);
 687                         if (ACPI_FAILURE(status))
 688                                 result = -EBUSY;
 689                         break;
 690                 }
 691         }
 692         return result;
 693 }
 694
 695 static void acpi_ec_gpe_poller(struct work_struct *work)
 696 {
 697         acpi_status status;
 698         u32 glk;
 699         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
 700
 701         mutex_lock(&ec->mutex);
 702         if (ec->global_lock) {
 703                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 704                 if (ACPI_FAILURE(status))
 705                         goto unlock;
 706         }
 707         acpi_ec_sync_query(ec, NULL);
 708         if (ec->global_lock)
 709                 acpi_release_global_lock(glk);
 710 unlock:
 711         mutex_unlock(&ec->mutex);
 712 }
 713
 714 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 715         u32 gpe_number, void *data)
 716 {
 717         unsigned long flags;
 718         struct acpi_ec *ec = data;
 719
 720         spin_lock_irqsave(&ec->lock, flags);
 721         advance_transaction(ec);
 722         spin_unlock_irqrestore(&ec->lock, flags);
 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         INIT_WORK(&ec->work, acpi_ec_gpe_poller);
 787         return ec;
 788 }
 789
 790 static acpi_status
 791 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 792                                void *context, void **return_value)
 793 {
 794         char node_name[5];
 795         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 796         struct acpi_ec *ec = context;
 797         int value = 0;
 798         acpi_status status;
 799
 800         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 801
 802         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
 803                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 804         return AE_OK;
 805 }
 806
 807 static acpi_status
 808 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 809 {
 810         acpi_status status;
 811         unsigned long long tmp = 0;
 812         struct acpi_ec *ec = context;
 813
 814         /* clear addr values, ec_parse_io_ports depend on it */
 815         ec->command_addr = ec->data_addr = 0;
 816
 817         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 818                                      ec_parse_io_ports, ec);
 819         if (ACPI_FAILURE(status))
 820                 return status;
 821
 822         /* Get GPE bit assignment (EC events). */
 823         /* TODO: Add support for _GPE returning a package */
 824         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 825         if (ACPI_FAILURE(status))
 826                 return status;
 827         ec->gpe = tmp;
 828         /* Use the global lock for all EC transactions? */
 829         tmp = 0;
 830         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 831         ec->global_lock = tmp;
 832         ec->handle = handle;
 833         return AE_CTRL_TERMINATE;
 834 }
 835
 836 static int ec_install_handlers(struct acpi_ec *ec)
 837 {
 838         acpi_status status;
 839
 840         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 841                 return 0;
 842         status = acpi_install_gpe_handler(NULL, ec->gpe,
 843                                   ACPI_GPE_EDGE_TRIGGERED,
 844                                   &acpi_ec_gpe_handler, ec);
 845         if (ACPI_FAILURE(status))
 846                 return -ENODEV;
 847
 848         acpi_enable_gpe(NULL, ec->gpe);
 849         status = acpi_install_address_space_handler(ec->handle,
 850                                                     ACPI_ADR_SPACE_EC,
 851                                                     &acpi_ec_space_handler,
 852                                                     NULL, ec);
 853         if (ACPI_FAILURE(status)) {
 854                 if (status == AE_NOT_FOUND) {
 855                         /*
 856                          * Maybe OS fails in evaluating the _REG object.
 857                          * The AE_NOT_FOUND error will be ignored and OS
 858                          * continue to initialize EC.
 859                          */
 860                         pr_err("Fail in evaluating the _REG object"
 861                                 " of EC device. Broken bios is suspected.\n");
 862                 } else {
 863                         acpi_disable_gpe(NULL, ec->gpe);
 864                         acpi_remove_gpe_handler(NULL, ec->gpe,
 865                                 &acpi_ec_gpe_handler);
 866                         return -ENODEV;
 867                 }
 868         }
 869
 870         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 871         return 0;
 872 }
 873
 874 static void ec_remove_handlers(struct acpi_ec *ec)
 875 {
 876         if (!test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 877                 return;
 878         acpi_disable_gpe(NULL, ec->gpe);
 879         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 880                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 881                 pr_err("failed to remove space handler\n");
 882         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 883                                 &acpi_ec_gpe_handler)))
 884                 pr_err("failed to remove gpe handler\n");
 885         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 886 }
 887
 888 static int acpi_ec_add(struct acpi_device *device)
 889 {
 890         struct acpi_ec *ec = NULL;
 891         int ret;
 892
 893         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 894         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 895
 896         /* Check for boot EC */
 897         if (boot_ec &&
 898             (boot_ec->handle == device->handle ||
 899              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 900                 ec = boot_ec;
 901                 boot_ec = NULL;
 902         } else {
 903                 ec = make_acpi_ec();
 904                 if (!ec)
 905                         return -ENOMEM;
 906         }
 907         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 908                 AE_CTRL_TERMINATE) {
 909                         kfree(ec);
 910                         return -EINVAL;
 911         }
 912
 913         /* Find and register all query methods */
 914         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 915                             acpi_ec_register_query_methods, NULL, ec, NULL);
 916
 917         if (!first_ec)
 918                 first_ec = ec;
 919         device->driver_data = ec;
 920
 921         ret = !!request_region(ec->data_addr, 1, "EC data");
 922         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
 923         ret = !!request_region(ec->command_addr, 1, "EC cmd");
 924         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
 925
 926         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 927                           ec->gpe, ec->command_addr, ec->data_addr);
 928
 929         ret = ec_install_handlers(ec);
 930
 931         /* EC is fully operational, allow queries */
 932         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 933
 934         /* Clear stale _Q events if hardware might require that */
 935         if (EC_FLAGS_CLEAR_ON_RESUME) {
 936                 mutex_lock(&ec->mutex);
 937                 acpi_ec_clear(ec);
 938                 mutex_unlock(&ec->mutex);
 939         }
 940         return ret;
 941 }
 942
 943 static int acpi_ec_remove(struct acpi_device *device)
 944 {
 945         struct acpi_ec *ec;
 946         struct acpi_ec_query_handler *handler, *tmp;
 947
 948         if (!device)
 949                 return -EINVAL;
 950
 951         ec = acpi_driver_data(device);
 952         ec_remove_handlers(ec);
 953         mutex_lock(&ec->mutex);
 954         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 955                 list_del(&handler->node);
 956                 kfree(handler);
 957         }
 958         mutex_unlock(&ec->mutex);
 959         release_region(ec->data_addr, 1);
 960         release_region(ec->command_addr, 1);
 961         device->driver_data = NULL;
 962         if (ec == first_ec)
 963                 first_ec = NULL;
 964         kfree(ec);
 965         return 0;
 966 }
 967
 968 static acpi_status
 969 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 970 {
 971         struct acpi_ec *ec = context;
 972
 973         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 974                 return AE_OK;
 975
 976         /*
 977          * The first address region returned is the data port, and
 978          * the second address region returned is the status/command
 979          * port.
 980          */
 981         if (ec->data_addr == 0)
 982                 ec->data_addr = resource->data.io.minimum;
 983         else if (ec->command_addr == 0)
 984                 ec->command_addr = resource->data.io.minimum;
 985         else
 986                 return AE_CTRL_TERMINATE;
 987
 988         return AE_OK;
 989 }
 990
 991 int __init acpi_boot_ec_enable(void)
 992 {
 993         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 994                 return 0;
 995         if (!ec_install_handlers(boot_ec)) {
 996                 first_ec = boot_ec;
 997                 return 0;
 998         }
 999         return -EFAULT;
1000 }
1001
1002 static const struct acpi_device_id ec_device_ids[] = {
1003         {"PNP0C09", 0},
1004         {"", 0},
1005 };
1006
1007 /* Some BIOS do not survive early DSDT scan, skip it */
1008 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
1009 {
1010         EC_FLAGS_SKIP_DSDT_SCAN = 1;
1011         return 0;
1012 }
1013
1014 /* ASUStek often supplies us with broken ECDT, validate it */
1015 static int ec_validate_ecdt(const struct dmi_system_id *id)
1016 {
1017         EC_FLAGS_VALIDATE_ECDT = 1;
1018         return 0;
1019 }
1020
1021 /* MSI EC needs special treatment, enable it */
1022 static int ec_flag_msi(const struct dmi_system_id *id)
1023 {
1024         pr_debug("Detected MSI hardware, enabling workarounds.\n");
1025         EC_FLAGS_MSI = 1;
1026         EC_FLAGS_VALIDATE_ECDT = 1;
1027         return 0;
1028 }
1029
1030 /*
1031  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
1032  * the GPE storm threshold back to 20
1033  */
1034 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
1035 {
1036         pr_debug("Setting the EC GPE storm threshold to 20\n");
1037         ec_storm_threshold  = 20;
1038         return 0;
1039 }
1040
1041 /*
1042  * Acer EC firmware refuses to respond QR_EC when SCI_EVT is not set, for
1043  * which case, we complete the QR_EC without issuing it to the firmware.
1044  * https://bugzilla.kernel.org/show_bug.cgi?id=86211
1045  */
1046 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1047 {
1048         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1049         EC_FLAGS_QUERY_HANDSHAKE = 1;
1050         return 0;
1051 }
1052
1053 /*
1054  * On some hardware it is necessary to clear events accumulated by the EC during
1055  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1056  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1057  *
1058  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1059  *
1060  * Ideally, the EC should also be instructed NOT to accumulate events during
1061  * sleep (which Windows seems to do somehow), but the interface to control this
1062  * behaviour is not known at this time.
1063  *
1064  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1065  * however it is very likely that other Samsung models are affected.
1066  *
1067  * On systems which don't accumulate _Q events during sleep, this extra check
1068  * should be harmless.
1069  */
1070 static int ec_clear_on_resume(const struct dmi_system_id *id)
1071 {
1072         pr_debug("Detected system needing EC poll on resume.\n");
1073         EC_FLAGS_CLEAR_ON_RESUME = 1;
1074         return 0;
1075 }
1076
1077 static struct dmi_system_id ec_dmi_table[] __initdata = {
1078         {
1079         ec_skip_dsdt_scan, "Compal JFL92", {
1080         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1081         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1082         {
1083         ec_flag_msi, "MSI hardware", {
1084         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1085         {
1086         ec_flag_msi, "MSI hardware", {
1087         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1088         {
1089         ec_flag_msi, "MSI hardware", {
1090         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1091         {
1092         ec_flag_msi, "MSI hardware", {
1093         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1094         {
1095         ec_flag_msi, "Quanta hardware", {
1096         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1097         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1098         {
1099         ec_flag_msi, "Quanta hardware", {
1100         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1101         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1102         {
1103         ec_flag_msi, "Clevo W350etq", {
1104         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
1105         DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
1106         {
1107         ec_validate_ecdt, "ASUS hardware", {
1108         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1109         {
1110         ec_validate_ecdt, "ASUS hardware", {
1111         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1112         {
1113         ec_enlarge_storm_threshold, "CLEVO hardware", {
1114         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1115         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1116         {
1117         ec_skip_dsdt_scan, "HP Folio 13", {
1118         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1119         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1120         {
1121         ec_validate_ecdt, "ASUS hardware", {
1122         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1123         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1124         {
1125         ec_clear_on_resume, "Samsung hardware", {
1126         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1127         {
1128         ec_flag_query_handshake, "Acer hardware", {
1129         DMI_MATCH(DMI_SYS_VENDOR, "Acer"), }, NULL},
1130         {},
1131 };
1132
1133 int __init acpi_ec_ecdt_probe(void)
1134 {
1135         acpi_status status;
1136         struct acpi_ec *saved_ec = NULL;
1137         struct acpi_table_ecdt *ecdt_ptr;
1138
1139         boot_ec = make_acpi_ec();
1140         if (!boot_ec)
1141                 return -ENOMEM;
1142         /*
1143          * Generate a boot ec context
1144          */
1145         dmi_check_system(ec_dmi_table);
1146         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1147                                 (struct acpi_table_header **)&ecdt_ptr);
1148         if (ACPI_SUCCESS(status)) {
1149                 pr_info("EC description table is found, configuring boot EC\n");
1150                 boot_ec->command_addr = ecdt_ptr->control.address;
1151                 boot_ec->data_addr = ecdt_ptr->data.address;
1152                 boot_ec->gpe = ecdt_ptr->gpe;
1153                 boot_ec->handle = ACPI_ROOT_OBJECT;
1154                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id,
1155                                 &boot_ec->handle);
1156                 /* Don't trust ECDT, which comes from ASUSTek */
1157                 if (!EC_FLAGS_VALIDATE_ECDT)
1158                         goto install;
1159                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1160                 if (!saved_ec)
1161                         return -ENOMEM;
1162         /* fall through */
1163         }
1164
1165         if (EC_FLAGS_SKIP_DSDT_SCAN) {
1166                 kfree(saved_ec);
1167                 return -ENODEV;
1168         }
1169
1170         /* This workaround is needed only on some broken machines,
1171          * which require early EC, but fail to provide ECDT */
1172         pr_debug("Look up EC in DSDT\n");
1173         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1174                                         boot_ec, NULL);
1175         /* Check that acpi_get_devices actually find something */
1176         if (ACPI_FAILURE(status) || !boot_ec->handle)
1177                 goto error;
1178         if (saved_ec) {
1179                 /* try to find good ECDT from ASUSTek */
1180                 if (saved_ec->command_addr != boot_ec->command_addr ||
1181                     saved_ec->data_addr != boot_ec->data_addr ||
1182                     saved_ec->gpe != boot_ec->gpe ||
1183                     saved_ec->handle != boot_ec->handle)
1184                         pr_info("ASUSTek keeps feeding us with broken "
1185                         "ECDT tables, which are very hard to workaround. "
1186                         "Trying to use DSDT EC info instead. Please send "
1187                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1188                 kfree(saved_ec);
1189                 saved_ec = NULL;
1190         } else {
1191                 /* We really need to limit this workaround, the only ASUS,
1192                 * which needs it, has fake EC._INI method, so use it as flag.
1193                 * Keep boot_ec struct as it will be needed soon.
1194                 */
1195                 if (!dmi_name_in_vendors("ASUS") ||
1196                     !acpi_has_method(boot_ec->handle, "_INI"))
1197                         return -ENODEV;
1198         }
1199 install:
1200         if (!ec_install_handlers(boot_ec)) {
1201                 first_ec = boot_ec;
1202                 return 0;
1203         }
1204 error:
1205         kfree(boot_ec);
1206         kfree(saved_ec);
1207         boot_ec = NULL;
1208         return -ENODEV;
1209 }
1210
1211 static struct acpi_driver acpi_ec_driver = {
1212         .name = "ec",
1213         .class = ACPI_EC_CLASS,
1214         .ids = ec_device_ids,
1215         .ops = {
1216                 .add = acpi_ec_add,
1217                 .remove = acpi_ec_remove,
1218                 },
1219 };
1220
1221 int __init acpi_ec_init(void)
1222 {
1223         int result = 0;
1224
1225         /* Now register the driver for the EC */
1226         result = acpi_bus_register_driver(&acpi_ec_driver);
1227         if (result < 0)
1228                 return -ENODEV;
1229
1230         return result;
1231 }
1232
1233 /* EC driver currently not unloadable */
1234 #if 0
1235 static void __exit acpi_ec_exit(void)
1236 {
1237
1238         acpi_bus_unregister_driver(&acpi_ec_driver);
1239 }
1240 #endif  /* 0 */