drivers/acpi/ec.c

   1 /*
   2  *  acpi_ec.c - ACPI Embedded Controller Driver ($Revision: 38 $)
   3  *
   4  *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
   5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   7  *
   8  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or (at
  13  *  your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful, but
  16  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  *  General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License along
  21  *  with this program; if not, write to the Free Software Foundation, Inc.,
  22  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  23  *
  24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25  */
  26
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/init.h>
  30 #include <linux/types.h>
  31 #include <linux/delay.h>
  32 #include <linux/proc_fs.h>
  33 #include <linux/seq_file.h>
  34 #include <linux/interrupt.h>
  35 #include <asm/io.h>
  36 #include <acpi/acpi_bus.h>
  37 #include <acpi/acpi_drivers.h>
  38 #include <acpi/actypes.h>
  39
  40 #define _COMPONENT              ACPI_EC_COMPONENT
  41 ACPI_MODULE_NAME("acpi_ec")
  42 #define ACPI_EC_COMPONENT               0x00100000
  43 #define ACPI_EC_CLASS                   "embedded_controller"
  44 #define ACPI_EC_HID                     "PNP0C09"
  45 #define ACPI_EC_DRIVER_NAME             "ACPI Embedded Controller Driver"
  46 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  47 #define ACPI_EC_FILE_INFO               "info"
  48
  49 /* EC status register */
  50 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  51 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  52 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  53 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  54
  55 /* EC commands */
  56 #define ACPI_EC_COMMAND_READ    0x80
  57 #define ACPI_EC_COMMAND_WRITE   0x81
  58 #define ACPI_EC_BURST_ENABLE    0x82
  59 #define ACPI_EC_BURST_DISABLE   0x83
  60 #define ACPI_EC_COMMAND_QUERY   0x84
  61
  62 /* EC events */
  63 enum {
  64         ACPI_EC_EVENT_OBF_1 = 1,        /* Output buffer full */
  65         ACPI_EC_EVENT_IBF_0,            /* Input buffer empty */
  66 };
  67
  68 #define ACPI_EC_DELAY           50      /* Wait 50ms max. during EC ops */
  69 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  70 #define ACPI_EC_UDELAY         100      /* Poll @ 100us increments */
  71 #define ACPI_EC_UDELAY_COUNT   1000     /* Wait 10ms max. during EC ops */
  72
  73 enum {
  74         EC_INTR = 1,    /* Output buffer full */
  75         EC_POLL,        /* Input buffer empty */
  76 };
  77
  78 static int acpi_ec_remove(struct acpi_device *device, int type);
  79 static int acpi_ec_start(struct acpi_device *device);
  80 static int acpi_ec_stop(struct acpi_device *device, int type);
  81 static int acpi_ec_add(struct acpi_device *device);
  82
  83 static struct acpi_driver acpi_ec_driver = {
  84         .name = ACPI_EC_DRIVER_NAME,
  85         .class = ACPI_EC_CLASS,
  86         .ids = ACPI_EC_HID,
  87         .ops = {
  88                 .add = acpi_ec_add,
  89                 .remove = acpi_ec_remove,
  90                 .start = acpi_ec_start,
  91                 .stop = acpi_ec_stop,
  92                 },
  93 };
  94
  95 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  96 struct acpi_ec {
  97         acpi_handle handle;
  98         unsigned long uid;
  99         unsigned long gpe_bit;
 100         unsigned long command_addr;
 101         unsigned long data_addr;
 102         unsigned long global_lock;
 103         struct semaphore sem;
 104         unsigned int expect_event;
 105         atomic_t leaving_burst; /* 0 : No, 1 : Yes, 2: abort */
 106         wait_queue_head_t wait;
 107 } *ec_ecdt;
 108
 109 /* External interfaces use first EC only, so remember */
 110 static struct acpi_device *first_ec;
 111 static int acpi_ec_mode = EC_INTR;
 112
 113 /* --------------------------------------------------------------------------
 114                              Transaction Management
 115    -------------------------------------------------------------------------- */
 116
 117 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 118 {
 119         return inb(ec->command_addr);
 120 }
 121
 122 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 123 {
 124         return inb(ec->data_addr);
 125 }
 126
 127 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 128 {
 129         outb(command, ec->command_addr);
 130 }
 131
 132 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 133 {
 134         outb(data, ec->data_addr);
 135 }
 136
 137 static int acpi_ec_check_status(u8 status, u8 event)
 138 {
 139         switch (event) {
 140         case ACPI_EC_EVENT_OBF_1:
 141                 if (status & ACPI_EC_FLAG_OBF)
 142                         return 1;
 143                 break;
 144         case ACPI_EC_EVENT_IBF_0:
 145                 if (!(status & ACPI_EC_FLAG_IBF))
 146                         return 1;
 147                 break;
 148         default:
 149                 break;
 150         }
 151
 152         return 0;
 153 }
 154
 155 static int acpi_ec_wait(struct acpi_ec *ec, u8 event)
 156 {
 157         int i = (acpi_ec_mode == EC_POLL) ? ACPI_EC_UDELAY_COUNT : 0;
 158         long time_left;
 159
 160         ec->expect_event = event;
 161         if (acpi_ec_check_status(acpi_ec_read_status(ec), event)) {
 162                 ec->expect_event = 0;
 163                 return 0;
 164         }
 165
 166         do {
 167                 if (acpi_ec_mode == EC_POLL) {
 168                         udelay(ACPI_EC_UDELAY);
 169                 } else {
 170                         time_left = wait_event_timeout(ec->wait,
 171                                     !ec->expect_event,
 172                                     msecs_to_jiffies(ACPI_EC_DELAY));
 173                         if (time_left > 0) {
 174                                 ec->expect_event = 0;
 175                                 return 0;
 176                         }
 177                 }
 178                 if (acpi_ec_check_status(acpi_ec_read_status(ec), event)) {
 179                         ec->expect_event = 0;
 180                         return 0;
 181                 }
 182         } while (--i > 0);
 183
 184         ec->expect_event = 0;
 185
 186         return -ETIME;
 187 }
 188
 189 #ifdef ACPI_FUTURE_USAGE
 190 /*
 191  * Note: samsung nv5000 doesn't work with ec burst mode.
 192  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 193  */
 194 int acpi_ec_enter_burst_mode(struct acpi_ec *ec)
 195 {
 196         u8 tmp = 0;
 197         u8 status = 0;
 198
 199
 200         status = acpi_ec_read_status(ec);
 201         if (status != -EINVAL && !(status & ACPI_EC_FLAG_BURST)) {
 202                 status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 203                 if (status)
 204                         goto end;
 205                 acpi_ec_write_cmd(ec, ACPI_EC_BURST_ENABLE);
 206                 status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1);
 207                 tmp = acpi_ec_read_data(ec);
 208                 if (tmp != 0x90) {      /* Burst ACK byte */
 209                         return -EINVAL;
 210                 }
 211         }
 212
 213         atomic_set(&ec->leaving_burst, 0);
 214         return 0;
 215   end:
 216         ACPI_EXCEPTION((AE_INFO, status, "EC wait, burst mode"));
 217         return -1;
 218 }
 219
 220 int acpi_ec_leave_burst_mode(struct acpi_ec *ec)
 221 {
 222         u8 status = 0;
 223
 224
 225         status = acpi_ec_read_status(ec);
 226         if (status != -EINVAL && (status & ACPI_EC_FLAG_BURST)){
 227                 status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 228                 if(status)
 229                         goto end;
 230                 acpi_ec_write_cmd(ec, ACPI_EC_BURST_DISABLE);
 231                 acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 232         }
 233         atomic_set(&ec->leaving_burst, 1);
 234         return 0;
 235   end:
 236         ACPI_EXCEPTION((AE_INFO, status, "EC leave burst mode"));
 237         return -1;
 238 }
 239 #endif /* ACPI_FUTURE_USAGE */
 240
 241 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
 242                                         const u8 *wdata, unsigned wdata_len,
 243                                         u8 *rdata, unsigned rdata_len)
 244 {
 245         int result;
 246
 247         acpi_ec_write_cmd(ec, command);
 248
 249         for (; wdata_len > 0; wdata_len --) {
 250                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 251                 if (result)
 252                         return result;
 253                 acpi_ec_write_data(ec, *(wdata++));
 254         }
 255
 256         if (command == ACPI_EC_COMMAND_WRITE) {
 257                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 258                 if (result)
 259                         return result;
 260         }
 261
 262         for (; rdata_len > 0; rdata_len --) {
 263                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1);
 264                 if (result)
 265                         return result;
 266
 267                 *(rdata++) = acpi_ec_read_data(ec);
 268         }
 269
 270         return 0;
 271 }
 272
 273 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
 274                                 const u8 *wdata, unsigned wdata_len,
 275                                 u8 *rdata, unsigned rdata_len)
 276 {
 277         int status;
 278         u32 glk;
 279
 280         if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
 281                 return -EINVAL;
 282
 283         if (rdata)
 284                 memset(rdata, 0, rdata_len);
 285
 286         if (ec->global_lock) {
 287                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 288                 if (ACPI_FAILURE(status))
 289                         return -ENODEV;
 290         }
 291         down(&ec->sem);
 292
 293         status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 294         if (status) {
 295                 printk(KERN_DEBUG PREFIX "read EC, IB not empty\n");
 296                 goto end;
 297         }
 298
 299         status = acpi_ec_transaction_unlocked(ec, command,
 300                                               wdata, wdata_len,
 301                                               rdata, rdata_len);
 302
 303 end:
 304         up(&ec->sem);
 305
 306         if (ec->global_lock)
 307                 acpi_release_global_lock(glk);
 308
 309         return status;
 310 }
 311
 312 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 313 {
 314         int result;
 315         u8 d;
 316
 317         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
 318                                      &address, 1, &d, 1);
 319         *data = d;
 320         return result;
 321 }
 322
 323 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 324 {
 325         u8 wdata[2] = { address, data };
 326         return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
 327                                    wdata, 2, NULL, 0);
 328 }
 329
 330 /*
 331  * Externally callable EC access functions. For now, assume 1 EC only
 332  */
 333 int ec_read(u8 addr, u8 *val)
 334 {
 335         struct acpi_ec *ec;
 336         int err;
 337         u8 temp_data;
 338
 339         if (!first_ec)
 340                 return -ENODEV;
 341
 342         ec = acpi_driver_data(first_ec);
 343
 344         err = acpi_ec_read(ec, addr, &temp_data);
 345
 346         if (!err) {
 347                 *val = temp_data;
 348                 return 0;
 349         } else
 350                 return err;
 351 }
 352
 353 EXPORT_SYMBOL(ec_read);
 354
 355 int ec_write(u8 addr, u8 val)
 356 {
 357         struct acpi_ec *ec;
 358         int err;
 359
 360         if (!first_ec)
 361                 return -ENODEV;
 362
 363         ec = acpi_driver_data(first_ec);
 364
 365         err = acpi_ec_write(ec, addr, val);
 366
 367         return err;
 368 }
 369
 370 EXPORT_SYMBOL(ec_write);
 371
 372 extern int ec_transaction(u8 command,
 373                           const u8 *wdata, unsigned wdata_len,
 374                           u8 *rdata, unsigned rdata_len)
 375 {
 376         struct acpi_ec *ec;
 377
 378         if (!first_ec)
 379                 return -ENODEV;
 380
 381         ec = acpi_driver_data(first_ec);
 382
 383         return acpi_ec_transaction(ec, command, wdata,
 384                                    wdata_len, rdata, rdata_len);
 385 }
 386
 387 EXPORT_SYMBOL(ec_transaction);
 388
 389 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
 390 {
 391         int result;
 392         u8 d;
 393
 394         if (!ec || !data)
 395                 return -EINVAL;
 396
 397         /*
 398          * Query the EC to find out which _Qxx method we need to evaluate.
 399          * Note that successful completion of the query causes the ACPI_EC_SCI
 400          * bit to be cleared (and thus clearing the interrupt source).
 401          */
 402
 403         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1);
 404         if (result)
 405                 return result;
 406
 407         if (!d)
 408                 return -ENODATA;
 409
 410         *data = d;
 411         return 0;
 412 }
 413
 414 /* --------------------------------------------------------------------------
 415                                 Event Management
 416    -------------------------------------------------------------------------- */
 417
 418 struct acpi_ec_query_data {
 419         acpi_handle handle;
 420         u8 data;
 421 };
 422
 423 static void acpi_ec_gpe_query(void *ec_cxt)
 424 {
 425         struct acpi_ec *ec = (struct acpi_ec *)ec_cxt;
 426         u8 value = 0;
 427         static char object_name[8];
 428
 429         if (!ec)
 430                 goto end;
 431
 432         value = acpi_ec_read_status(ec);
 433
 434         if (!(value & ACPI_EC_FLAG_SCI))
 435                 goto end;
 436
 437         if (acpi_ec_query(ec, &value))
 438                 goto end;
 439
 440         snprintf(object_name, 8, "_Q%2.2X", value);
 441
 442         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluating %s", object_name));
 443
 444         acpi_evaluate_object(ec->handle, object_name, NULL, NULL);
 445
 446       end:
 447         acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
 448 }
 449
 450 static u32 acpi_ec_gpe_handler(void *data)
 451 {
 452         acpi_status status = AE_OK;
 453         u8 value;
 454         struct acpi_ec *ec = (struct acpi_ec *)data;
 455
 456         acpi_clear_gpe(NULL, ec->gpe_bit, ACPI_ISR);
 457         value = acpi_ec_read_status(ec);
 458
 459         if (acpi_ec_mode == EC_INTR) {
 460                 if (acpi_ec_check_status(value, ec->expect_event)) {
 461                         ec->expect_event = 0;
 462                         wake_up(&ec->wait);
 463                 }
 464         }
 465
 466         if (value & ACPI_EC_FLAG_SCI) {
 467                 status = acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query, ec);
 468                 return status == AE_OK ?
 469                     ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 470         }
 471         acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_ISR);
 472         return status == AE_OK ?
 473             ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 474 }
 475
 476 /* --------------------------------------------------------------------------
 477                              Address Space Management
 478    -------------------------------------------------------------------------- */
 479
 480 static acpi_status
 481 acpi_ec_space_setup(acpi_handle region_handle,
 482                     u32 function, void *handler_context, void **return_context)
 483 {
 484         /*
 485          * The EC object is in the handler context and is needed
 486          * when calling the acpi_ec_space_handler.
 487          */
 488         *return_context = (function != ACPI_REGION_DEACTIVATE) ?
 489             handler_context : NULL;
 490
 491         return AE_OK;
 492 }
 493
 494 static acpi_status
 495 acpi_ec_space_handler(u32 function,
 496                       acpi_physical_address address,
 497                       u32 bit_width,
 498                       acpi_integer * value,
 499                       void *handler_context, void *region_context)
 500 {
 501         int result = 0;
 502         struct acpi_ec *ec = NULL;
 503         u64 temp = *value;
 504         acpi_integer f_v = 0;
 505         int i = 0;
 506
 507
 508         if ((address > 0xFF) || !value || !handler_context)
 509                 return AE_BAD_PARAMETER;
 510
 511         if (bit_width != 8 && acpi_strict) {
 512                 return AE_BAD_PARAMETER;
 513         }
 514
 515         ec = (struct acpi_ec *)handler_context;
 516
 517       next_byte:
 518         switch (function) {
 519         case ACPI_READ:
 520                 temp = 0;
 521                 result = acpi_ec_read(ec, (u8) address, (u8 *) &temp);
 522                 break;
 523         case ACPI_WRITE:
 524                 result = acpi_ec_write(ec, (u8) address, (u8) temp);
 525                 break;
 526         default:
 527                 result = -EINVAL;
 528                 goto out;
 529                 break;
 530         }
 531
 532         bit_width -= 8;
 533         if (bit_width) {
 534                 if (function == ACPI_READ)
 535                         f_v |= temp << 8 * i;
 536                 if (function == ACPI_WRITE)
 537                         temp >>= 8;
 538                 i++;
 539                 address++;
 540                 goto next_byte;
 541         }
 542
 543         if (function == ACPI_READ) {
 544                 f_v |= temp << 8 * i;
 545                 *value = f_v;
 546         }
 547
 548       out:
 549         switch (result) {
 550         case -EINVAL:
 551                 return AE_BAD_PARAMETER;
 552                 break;
 553         case -ENODEV:
 554                 return AE_NOT_FOUND;
 555                 break;
 556         case -ETIME:
 557                 return AE_TIME;
 558                 break;
 559         default:
 560                 return AE_OK;
 561         }
 562 }
 563
 564 /* --------------------------------------------------------------------------
 565                               FS Interface (/proc)
 566    -------------------------------------------------------------------------- */
 567
 568 static struct proc_dir_entry *acpi_ec_dir;
 569
 570 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 571 {
 572         struct acpi_ec *ec = (struct acpi_ec *)seq->private;
 573
 574
 575         if (!ec)
 576                 goto end;
 577
 578         seq_printf(seq, "gpe bit:                 0x%02x\n",
 579                    (u32) ec->gpe_bit);
 580         seq_printf(seq, "ports:                   0x%02x, 0x%02x\n",
 581                    (u32) ec->command_addr,
 582                    (u32) ec->data_addr);
 583         seq_printf(seq, "use global lock:         %s\n",
 584                    ec->global_lock ? "yes" : "no");
 585         acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
 586
 587       end:
 588         return 0;
 589 }
 590
 591 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 592 {
 593         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 594 }
 595
 596 static struct file_operations acpi_ec_info_ops = {
 597         .open = acpi_ec_info_open_fs,
 598         .read = seq_read,
 599         .llseek = seq_lseek,
 600         .release = single_release,
 601         .owner = THIS_MODULE,
 602 };
 603
 604 static int acpi_ec_add_fs(struct acpi_device *device)
 605 {
 606         struct proc_dir_entry *entry = NULL;
 607
 608
 609         if (!acpi_device_dir(device)) {
 610                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 611                                                      acpi_ec_dir);
 612                 if (!acpi_device_dir(device))
 613                         return -ENODEV;
 614         }
 615
 616         entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
 617                                   acpi_device_dir(device));
 618         if (!entry)
 619                 return -ENODEV;
 620         else {
 621                 entry->proc_fops = &acpi_ec_info_ops;
 622                 entry->data = acpi_driver_data(device);
 623                 entry->owner = THIS_MODULE;
 624         }
 625
 626         return 0;
 627 }
 628
 629 static int acpi_ec_remove_fs(struct acpi_device *device)
 630 {
 631
 632         if (acpi_device_dir(device)) {
 633                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 634                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 635                 acpi_device_dir(device) = NULL;
 636         }
 637
 638         return 0;
 639 }
 640
 641 /* --------------------------------------------------------------------------
 642                                Driver Interface
 643    -------------------------------------------------------------------------- */
 644
 645 static int acpi_ec_add(struct acpi_device *device)
 646 {
 647         int result = 0;
 648         acpi_status status = AE_OK;
 649         struct acpi_ec *ec = NULL;
 650
 651
 652         if (!device)
 653                 return -EINVAL;
 654
 655         ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 656         if (!ec)
 657                 return -ENOMEM;
 658         memset(ec, 0, sizeof(struct acpi_ec));
 659
 660         ec->handle = device->handle;
 661         ec->uid = -1;
 662         init_MUTEX(&ec->sem);
 663         if (acpi_ec_mode == EC_INTR) {
 664                 atomic_set(&ec->leaving_burst, 1);
 665                 init_waitqueue_head(&ec->wait);
 666         }
 667         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 668         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 669         acpi_driver_data(device) = ec;
 670
 671         /* Use the global lock for all EC transactions? */
 672         acpi_evaluate_integer(ec->handle, "_GLK", NULL,
 673                               &ec->global_lock);
 674
 675         /* XXX we don't test uids, because on some boxes ecdt uid = 0, see:
 676            http://bugzilla.kernel.org/show_bug.cgi?id=6111 */
 677         if (ec_ecdt) {
 678                 acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
 679                                                   ACPI_ADR_SPACE_EC,
 680                                                   &acpi_ec_space_handler);
 681
 682                 acpi_remove_gpe_handler(NULL, ec_ecdt->gpe_bit,
 683                                         &acpi_ec_gpe_handler);
 684
 685                 kfree(ec_ecdt);
 686         }
 687
 688         /* Get GPE bit assignment (EC events). */
 689         /* TODO: Add support for _GPE returning a package */
 690         status =
 691             acpi_evaluate_integer(ec->handle, "_GPE", NULL,
 692                                   &ec->gpe_bit);
 693         if (ACPI_FAILURE(status)) {
 694                 ACPI_EXCEPTION((AE_INFO, status, "Obtaining GPE bit assignment"));
 695                 result = -ENODEV;
 696                 goto end;
 697         }
 698
 699         result = acpi_ec_add_fs(device);
 700         if (result)
 701                 goto end;
 702
 703         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s [%s] (gpe %d) interrupt mode.",
 704                acpi_device_name(device), acpi_device_bid(device),
 705                (u32) ec->gpe_bit));
 706
 707         if (!first_ec)
 708                 first_ec = device;
 709
 710   end:
 711         if (result)
 712                 kfree(ec);
 713
 714         return result;
 715 }
 716
 717 static int acpi_ec_remove(struct acpi_device *device, int type)
 718 {
 719         struct acpi_ec *ec = NULL;
 720
 721
 722         if (!device)
 723                 return -EINVAL;
 724
 725         ec = acpi_driver_data(device);
 726
 727         acpi_ec_remove_fs(device);
 728
 729         kfree(ec);
 730
 731         return 0;
 732 }
 733
 734 static acpi_status
 735 acpi_ec_io_ports(struct acpi_resource *resource, void *context)
 736 {
 737         struct acpi_ec *ec = (struct acpi_ec *)context;
 738
 739         if (resource->type != ACPI_RESOURCE_TYPE_IO) {
 740                 return AE_OK;
 741         }
 742
 743         /*
 744          * The first address region returned is the data port, and
 745          * the second address region returned is the status/command
 746          * port.
 747          */
 748         if (ec->data_addr == 0) {
 749                 ec->data_addr = resource->data.io.minimum;
 750         } else if (ec->command_addr == 0) {
 751                 ec->command_addr = resource->data.io.minimum;
 752         } else {
 753                 return AE_CTRL_TERMINATE;
 754         }
 755
 756         return AE_OK;
 757 }
 758
 759 static int acpi_ec_start(struct acpi_device *device)
 760 {
 761         acpi_status status = AE_OK;
 762         struct acpi_ec *ec = NULL;
 763
 764
 765         if (!device)
 766                 return -EINVAL;
 767
 768         ec = acpi_driver_data(device);
 769
 770         if (!ec)
 771                 return -EINVAL;
 772
 773         /*
 774          * Get I/O port addresses. Convert to GAS format.
 775          */
 776         status = acpi_walk_resources(ec->handle, METHOD_NAME__CRS,
 777                                      acpi_ec_io_ports, ec);
 778         if (ACPI_FAILURE(status) || ec->command_addr == 0) {
 779                 ACPI_EXCEPTION((AE_INFO, status,
 780                                 "Error getting I/O port addresses"));
 781                 return -ENODEV;
 782         }
 783
 784         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "gpe=0x%02lx, ports=0x%2lx,0x%2lx",
 785                           ec->gpe_bit, ec->command_addr, ec->data_addr));
 786
 787         /*
 788          * Install GPE handler
 789          */
 790         status = acpi_install_gpe_handler(NULL, ec->gpe_bit,
 791                                           ACPI_GPE_EDGE_TRIGGERED,
 792                                           &acpi_ec_gpe_handler, ec);
 793         if (ACPI_FAILURE(status)) {
 794                 return -ENODEV;
 795         }
 796         acpi_set_gpe_type(NULL, ec->gpe_bit, ACPI_GPE_TYPE_RUNTIME);
 797         acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
 798
 799         status = acpi_install_address_space_handler(ec->handle,
 800                                                     ACPI_ADR_SPACE_EC,
 801                                                     &acpi_ec_space_handler,
 802                                                     &acpi_ec_space_setup, ec);
 803         if (ACPI_FAILURE(status)) {
 804                 acpi_remove_gpe_handler(NULL, ec->gpe_bit,
 805                                         &acpi_ec_gpe_handler);
 806                 return -ENODEV;
 807         }
 808
 809         return AE_OK;
 810 }
 811
 812 static int acpi_ec_stop(struct acpi_device *device, int type)
 813 {
 814         acpi_status status = AE_OK;
 815         struct acpi_ec *ec = NULL;
 816
 817
 818         if (!device)
 819                 return -EINVAL;
 820
 821         ec = acpi_driver_data(device);
 822
 823         status = acpi_remove_address_space_handler(ec->handle,
 824                                                    ACPI_ADR_SPACE_EC,
 825                                                    &acpi_ec_space_handler);
 826         if (ACPI_FAILURE(status))
 827                 return -ENODEV;
 828
 829         status =
 830             acpi_remove_gpe_handler(NULL, ec->gpe_bit,
 831                                     &acpi_ec_gpe_handler);
 832         if (ACPI_FAILURE(status))
 833                 return -ENODEV;
 834
 835         return 0;
 836 }
 837
 838 static acpi_status __init
 839 acpi_fake_ecdt_callback(acpi_handle handle,
 840                         u32 Level, void *context, void **retval)
 841 {
 842         acpi_status status;
 843
 844         init_MUTEX(&ec_ecdt->sem);
 845         if (acpi_ec_mode == EC_INTR) {
 846                 init_waitqueue_head(&ec_ecdt->wait);
 847         }
 848         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 849                                      acpi_ec_io_ports, ec_ecdt);
 850         if (ACPI_FAILURE(status))
 851                 return status;
 852
 853         ec_ecdt->uid = -1;
 854         acpi_evaluate_integer(handle, "_UID", NULL, &ec_ecdt->uid);
 855
 856         status =
 857             acpi_evaluate_integer(handle, "_GPE", NULL,
 858                                   &ec_ecdt->gpe_bit);
 859         if (ACPI_FAILURE(status))
 860                 return status;
 861         ec_ecdt->global_lock = TRUE;
 862         ec_ecdt->handle = handle;
 863
 864         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "GPE=0x%02lx, ports=0x%2lx, 0x%2lx",
 865                ec_ecdt->gpe_bit, ec_ecdt->command_addr, ec_ecdt->data_addr));
 866
 867         return AE_CTRL_TERMINATE;
 868 }
 869
 870 /*
 871  * Some BIOS (such as some from Gateway laptops) access EC region very early
 872  * such as in BAT0._INI or EC._INI before an EC device is found and
 873  * do not provide an ECDT. According to ACPI spec, ECDT isn't mandatorily
 874  * required, but if EC regison is accessed early, it is required.
 875  * The routine tries to workaround the BIOS bug by pre-scan EC device
 876  * It assumes that _CRS, _HID, _GPE, _UID methods of EC don't touch any
 877  * op region (since _REG isn't invoked yet). The assumption is true for
 878  * all systems found.
 879  */
 880 static int __init acpi_ec_fake_ecdt(void)
 881 {
 882         acpi_status status;
 883         int ret = 0;
 884
 885         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Try to make an fake ECDT"));
 886
 887         ec_ecdt = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 888         if (!ec_ecdt) {
 889                 ret = -ENOMEM;
 890                 goto error;
 891         }
 892         memset(ec_ecdt, 0, sizeof(struct acpi_ec));
 893
 894         status = acpi_get_devices(ACPI_EC_HID,
 895                                   acpi_fake_ecdt_callback, NULL, NULL);
 896         if (ACPI_FAILURE(status)) {
 897                 kfree(ec_ecdt);
 898                 ec_ecdt = NULL;
 899                 ret = -ENODEV;
 900                 ACPI_EXCEPTION((AE_INFO, status, "Can't make an fake ECDT"));
 901                 goto error;
 902         }
 903         return 0;
 904   error:
 905         return ret;
 906 }
 907
 908 static int __init acpi_ec_get_real_ecdt(void)
 909 {
 910         acpi_status status;
 911         struct acpi_table_ecdt *ecdt_ptr;
 912
 913         status = acpi_get_firmware_table("ECDT", 1, ACPI_LOGICAL_ADDRESSING,
 914                                          (struct acpi_table_header **)
 915                                          &ecdt_ptr);
 916         if (ACPI_FAILURE(status))
 917                 return -ENODEV;
 918
 919         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found ECDT"));
 920
 921         /*
 922          * Generate a temporary ec context to use until the namespace is scanned
 923          */
 924         ec_ecdt = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 925         if (!ec_ecdt)
 926                 return -ENOMEM;
 927         memset(ec_ecdt, 0, sizeof(struct acpi_ec));
 928
 929         init_MUTEX(&ec_ecdt->sem);
 930         if (acpi_ec_mode == EC_INTR) {
 931                 init_waitqueue_head(&ec_ecdt->wait);
 932         }
 933         ec_ecdt->command_addr = ecdt_ptr->ec_control.address;
 934         ec_ecdt->data_addr = ecdt_ptr->ec_data.address;
 935         ec_ecdt->gpe_bit = ecdt_ptr->gpe_bit;
 936         /* use the GL just to be safe */
 937         ec_ecdt->global_lock = TRUE;
 938         ec_ecdt->uid = ecdt_ptr->uid;
 939
 940         status =
 941             acpi_get_handle(NULL, ecdt_ptr->ec_id, &ec_ecdt->handle);
 942         if (ACPI_FAILURE(status)) {
 943                 goto error;
 944         }
 945
 946         return 0;
 947   error:
 948         ACPI_EXCEPTION((AE_INFO, status, "Could not use ECDT"));
 949         kfree(ec_ecdt);
 950         ec_ecdt = NULL;
 951
 952         return -ENODEV;
 953 }
 954
 955 static int __initdata acpi_fake_ecdt_enabled;
 956 int __init acpi_ec_ecdt_probe(void)
 957 {
 958         acpi_status status;
 959         int ret;
 960
 961         ret = acpi_ec_get_real_ecdt();
 962         /* Try to make a fake ECDT */
 963         if (ret && acpi_fake_ecdt_enabled) {
 964                 ret = acpi_ec_fake_ecdt();
 965         }
 966
 967         if (ret)
 968                 return 0;
 969
 970         /*
 971          * Install GPE handler
 972          */
 973         status = acpi_install_gpe_handler(NULL, ec_ecdt->gpe_bit,
 974                                           ACPI_GPE_EDGE_TRIGGERED,
 975                                           &acpi_ec_gpe_handler, ec_ecdt);
 976         if (ACPI_FAILURE(status)) {
 977                 goto error;
 978         }
 979         acpi_set_gpe_type(NULL, ec_ecdt->gpe_bit, ACPI_GPE_TYPE_RUNTIME);
 980         acpi_enable_gpe(NULL, ec_ecdt->gpe_bit, ACPI_NOT_ISR);
 981
 982         status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
 983                                                     ACPI_ADR_SPACE_EC,
 984                                                     &acpi_ec_space_handler,
 985                                                     &acpi_ec_space_setup,
 986                                                     ec_ecdt);
 987         if (ACPI_FAILURE(status)) {
 988                 acpi_remove_gpe_handler(NULL, ec_ecdt->gpe_bit,
 989                                         &acpi_ec_gpe_handler);
 990                 goto error;
 991         }
 992
 993         return 0;
 994
 995       error:
 996         ACPI_EXCEPTION((AE_INFO, status, "Could not use ECDT"));
 997         kfree(ec_ecdt);
 998         ec_ecdt = NULL;
 999
1000         return -ENODEV;
1001 }
1002
1003 static int __init acpi_ec_init(void)
1004 {
1005         int result = 0;
1006
1007
1008         if (acpi_disabled)
1009                 return 0;
1010
1011         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1012         if (!acpi_ec_dir)
1013                 return -ENODEV;
1014
1015         /* Now register the driver for the EC */
1016         result = acpi_bus_register_driver(&acpi_ec_driver);
1017         if (result < 0) {
1018                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1019                 return -ENODEV;
1020         }
1021
1022         return result;
1023 }
1024
1025 subsys_initcall(acpi_ec_init);
1026
1027 /* EC driver currently not unloadable */
1028 #if 0
1029 static void __exit acpi_ec_exit(void)
1030 {
1031
1032         acpi_bus_unregister_driver(&acpi_ec_driver);
1033
1034         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1035
1036         return;
1037 }
1038 #endif                          /* 0 */
1039
1040 static int __init acpi_fake_ecdt_setup(char *str)
1041 {
1042         acpi_fake_ecdt_enabled = 1;
1043         return 1;
1044 }
1045
1046 __setup("acpi_fake_ecdt", acpi_fake_ecdt_setup);
1047 static int __init acpi_ec_set_intr_mode(char *str)
1048 {
1049         int intr;
1050
1051         if (!get_option(&str, &intr))
1052                 return 0;
1053
1054         if (intr) {
1055                 acpi_ec_mode = EC_INTR;
1056         } else {
1057                 acpi_ec_mode = EC_POLL;
1058         }
1059         acpi_ec_driver.ops.add = acpi_ec_add;
1060         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "EC %s mode.\n", intr ? "interrupt" : "polling"));
1061
1062         return 1;
1063 }
1064
1065 __setup("ec_intr=", acpi_ec_set_intr_mode);