drivers/acpi/ec.c

   1 /*
   2  *  acpi_ec.c - ACPI Embedded Controller Driver ($Revision: 38 $)
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *
   7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or (at
  12  *  your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful, but
  15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *  General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License along
  20  *  with this program; if not, write to the Free Software Foundation, Inc.,
  21  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  22  *
  23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/module.h>
  28 #include <linux/init.h>
  29 #include <linux/types.h>
  30 #include <linux/delay.h>
  31 #include <linux/proc_fs.h>
  32 #include <asm/io.h>
  33 #include <acpi/acpi_bus.h>
  34 #include <acpi/acpi_drivers.h>
  35 #include <acpi/actypes.h>
  36
  37 #define _COMPONENT              ACPI_EC_COMPONENT
  38 ACPI_MODULE_NAME                ("acpi_ec")
  39
  40 #define ACPI_EC_COMPONENT               0x00100000
  41 #define ACPI_EC_CLASS                   "embedded_controller"
  42 #define ACPI_EC_HID                     "PNP0C09"
  43 #define ACPI_EC_DRIVER_NAME             "ACPI Embedded Controller Driver"
  44 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  45 #define ACPI_EC_FILE_INFO               "info"
  46
  47
  48 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  49 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  50 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  51
  52 #define ACPI_EC_EVENT_OBF       0x01    /* Output buffer full */
  53 #define ACPI_EC_EVENT_IBE       0x02    /* Input buffer empty */
  54
  55 #define ACPI_EC_UDELAY          100     /* Poll @ 100us increments */
  56 #define ACPI_EC_UDELAY_COUNT    1000    /* Wait 10ms max. during EC ops */
  57 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  58
  59 #define ACPI_EC_COMMAND_READ    0x80
  60 #define ACPI_EC_COMMAND_WRITE   0x81
  61 #define ACPI_EC_COMMAND_QUERY   0x84
  62
  63 static int acpi_ec_add (struct acpi_device *device);
  64 static int acpi_ec_remove (struct acpi_device *device, int type);
  65 static int acpi_ec_start (struct acpi_device *device);
  66 static int acpi_ec_stop (struct acpi_device *device, int type);
  67
  68 static struct acpi_driver acpi_ec_driver = {
  69         .name =         ACPI_EC_DRIVER_NAME,
  70         .class =        ACPI_EC_CLASS,
  71         .ids =          ACPI_EC_HID,
  72         .ops =          {
  73                                 .add =          acpi_ec_add,
  74                                 .remove =       acpi_ec_remove,
  75                                 .start =        acpi_ec_start,
  76                                 .stop =         acpi_ec_stop,
  77                         },
  78 };
  79
  80 struct acpi_ec {
  81         acpi_handle                     handle;
  82         unsigned long                   uid;
  83         unsigned long                   gpe_bit;
  84         struct acpi_generic_address     status_addr;
  85         struct acpi_generic_address     command_addr;
  86         struct acpi_generic_address     data_addr;
  87         unsigned long                   global_lock;
  88         spinlock_t                      lock;
  89 };
  90
  91 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  92 static struct acpi_ec   *ec_ecdt;
  93
  94 /* External interfaces use first EC only, so remember */
  95 static struct acpi_device *first_ec;
  96
  97 /* --------------------------------------------------------------------------
  98                              Transaction Management
  99    -------------------------------------------------------------------------- */
 100
 101 static int
 102 acpi_ec_wait (
 103         struct acpi_ec          *ec,
 104         u8                      event)
 105 {
 106         u32                     acpi_ec_status = 0;
 107         u32                     i = ACPI_EC_UDELAY_COUNT;
 108
 109         if (!ec)
 110                 return -EINVAL;
 111
 112         /* Poll the EC status register waiting for the event to occur. */
 113         switch (event) {
 114         case ACPI_EC_EVENT_OBF:
 115                 do {
 116                         acpi_hw_low_level_read(8, &acpi_ec_status, &ec->status_addr);
 117                         if (acpi_ec_status & ACPI_EC_FLAG_OBF)
 118                                 return 0;
 119                         udelay(ACPI_EC_UDELAY);
 120                 } while (--i>0);
 121                 break;
 122         case ACPI_EC_EVENT_IBE:
 123                 do {
 124                         acpi_hw_low_level_read(8, &acpi_ec_status, &ec->status_addr);
 125                         if (!(acpi_ec_status & ACPI_EC_FLAG_IBF))
 126                                 return 0;
 127                         udelay(ACPI_EC_UDELAY);
 128                 } while (--i>0);
 129                 break;
 130         default:
 131                 return -EINVAL;
 132         }
 133
 134         return -ETIME;
 135 }
 136
 137
 138 static int
 139 acpi_ec_read (
 140         struct acpi_ec          *ec,
 141         u8                      address,
 142         u32                     *data)
 143 {
 144         acpi_status             status = AE_OK;
 145         int                     result = 0;
 146         unsigned long           flags = 0;
 147         u32                     glk = 0;
 148
 149         ACPI_FUNCTION_TRACE("acpi_ec_read");
 150
 151         if (!ec || !data)
 152                 return_VALUE(-EINVAL);
 153
 154         *data = 0;
 155
 156         if (ec->global_lock) {
 157                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 158                 if (ACPI_FAILURE(status))
 159                         return_VALUE(-ENODEV);
 160         }
 161
 162         spin_lock_irqsave(&ec->lock, flags);
 163
 164         acpi_hw_low_level_write(8, ACPI_EC_COMMAND_READ, &ec->command_addr);
 165         result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
 166         if (result)
 167                 goto end;
 168
 169         acpi_hw_low_level_write(8, address, &ec->data_addr);
 170         result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
 171         if (result)
 172                 goto end;
 173
 174
 175         acpi_hw_low_level_read(8, data, &ec->data_addr);
 176
 177         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Read [%02x] from address [%02x]\n",
 178                 *data, address));
 179
 180 end:
 181         spin_unlock_irqrestore(&ec->lock, flags);
 182
 183         if (ec->global_lock)
 184                 acpi_release_global_lock(glk);
 185
 186         return_VALUE(result);
 187 }
 188
 189
 190 static int
 191 acpi_ec_write (
 192         struct acpi_ec          *ec,
 193         u8                      address,
 194         u8                      data)
 195 {
 196         int                     result = 0;
 197         acpi_status             status = AE_OK;
 198         unsigned long           flags = 0;
 199         u32                     glk = 0;
 200
 201         ACPI_FUNCTION_TRACE("acpi_ec_write");
 202
 203         if (!ec)
 204                 return_VALUE(-EINVAL);
 205
 206         if (ec->global_lock) {
 207                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 208                 if (ACPI_FAILURE(status))
 209                         return_VALUE(-ENODEV);
 210         }
 211
 212         spin_lock_irqsave(&ec->lock, flags);
 213
 214         acpi_hw_low_level_write(8, ACPI_EC_COMMAND_WRITE, &ec->command_addr);
 215         result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
 216         if (result)
 217                 goto end;
 218
 219         acpi_hw_low_level_write(8, address, &ec->data_addr);
 220         result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
 221         if (result)
 222                 goto end;
 223
 224         acpi_hw_low_level_write(8, data, &ec->data_addr);
 225         result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
 226         if (result)
 227                 goto end;
 228
 229         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Wrote [%02x] to address [%02x]\n",
 230                 data, address));
 231
 232 end:
 233         spin_unlock_irqrestore(&ec->lock, flags);
 234
 235         if (ec->global_lock)
 236                 acpi_release_global_lock(glk);
 237
 238         return_VALUE(result);
 239 }
 240
 241 /*
 242  * Externally callable EC access functions. For now, assume 1 EC only
 243  */
 244 int
 245 ec_read(u8 addr, u8 *val)
 246 {
 247         struct acpi_ec *ec;
 248         int err;
 249         u32 temp_data;
 250
 251         if (!first_ec)
 252                 return -ENODEV;
 253
 254         ec = acpi_driver_data(first_ec);
 255
 256         err = acpi_ec_read(ec, addr, &temp_data);
 257
 258         if (!err) {
 259                 *val = temp_data;
 260                 return 0;
 261         }
 262         else
 263                 return err;
 264 }
 265
 266 int
 267 ec_write(u8 addr, u8 val)
 268 {
 269         struct acpi_ec *ec;
 270         int err;
 271
 272         if (!first_ec)
 273                 return -ENODEV;
 274
 275         ec = acpi_driver_data(first_ec);
 276
 277         err = acpi_ec_write(ec, addr, val);
 278
 279         return err;
 280 }
 281
 282
 283 static int
 284 acpi_ec_query (
 285         struct acpi_ec          *ec,
 286         u32                     *data)
 287 {
 288         int                     result = 0;
 289         acpi_status             status = AE_OK;
 290         unsigned long           flags = 0;
 291         u32                     glk = 0;
 292
 293         ACPI_FUNCTION_TRACE("acpi_ec_query");
 294
 295         if (!ec || !data)
 296                 return_VALUE(-EINVAL);
 297
 298         *data = 0;
 299
 300         if (ec->global_lock) {
 301                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 302                 if (ACPI_FAILURE(status))
 303                         return_VALUE(-ENODEV);
 304         }
 305
 306         /*
 307          * Query the EC to find out which _Qxx method we need to evaluate.
 308          * Note that successful completion of the query causes the ACPI_EC_SCI
 309          * bit to be cleared (and thus clearing the interrupt source).
 310          */
 311         spin_lock_irqsave(&ec->lock, flags);
 312
 313         acpi_hw_low_level_write(8, ACPI_EC_COMMAND_QUERY, &ec->command_addr);
 314         result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
 315         if (result)
 316                 goto end;
 317
 318         acpi_hw_low_level_read(8, data, &ec->data_addr);
 319         if (!*data)
 320                 result = -ENODATA;
 321
 322 end:
 323         spin_unlock_irqrestore(&ec->lock, flags);
 324
 325         if (ec->global_lock)
 326                 acpi_release_global_lock(glk);
 327
 328         return_VALUE(result);
 329 }
 330
 331
 332 /* --------------------------------------------------------------------------
 333                                 Event Management
 334    -------------------------------------------------------------------------- */
 335
 336 struct acpi_ec_query_data {
 337         acpi_handle             handle;
 338         u8                      data;
 339 };
 340
 341 static void
 342 acpi_ec_gpe_query (
 343         void                    *ec_cxt)
 344 {
 345         struct acpi_ec          *ec = (struct acpi_ec *) ec_cxt;
 346         u32                     value = 0;
 347         unsigned long           flags = 0;
 348         static char             object_name[5] = {'_','Q','0','0','\0'};
 349         const char              hex[] = {'0','1','2','3','4','5','6','7',
 350                                          '8','9','A','B','C','D','E','F'};
 351
 352         ACPI_FUNCTION_TRACE("acpi_ec_gpe_query");
 353
 354         if (!ec_cxt)
 355                 goto end;
 356
 357         spin_lock_irqsave(&ec->lock, flags);
 358         acpi_hw_low_level_read(8, &value, &ec->command_addr);
 359         spin_unlock_irqrestore(&ec->lock, flags);
 360
 361         /* TBD: Implement asynch events!
 362          * NOTE: All we care about are EC-SCI's.  Other EC events are
 363          * handled via polling (yuck!).  This is because some systems
 364          * treat EC-SCIs as level (versus EDGE!) triggered, preventing
 365          *  a purely interrupt-driven approach (grumble, grumble).
 366          */
 367         if (!(value & ACPI_EC_FLAG_SCI))
 368                 goto end;
 369
 370         if (acpi_ec_query(ec, &value))
 371                 goto end;
 372
 373         object_name[2] = hex[((value >> 4) & 0x0F)];
 374         object_name[3] = hex[(value & 0x0F)];
 375
 376         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluating %s\n", object_name));
 377
 378         acpi_evaluate_object(ec->handle, object_name, NULL, NULL);
 379
 380 end:
 381         acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
 382 }
 383
 384 static u32
 385 acpi_ec_gpe_handler (
 386         void                    *data)
 387 {
 388         acpi_status             status = AE_OK;
 389         struct acpi_ec          *ec = (struct acpi_ec *) data;
 390
 391         if (!ec)
 392                 return ACPI_INTERRUPT_NOT_HANDLED;
 393
 394         acpi_disable_gpe(NULL, ec->gpe_bit, ACPI_ISR);
 395
 396         status = acpi_os_queue_for_execution(OSD_PRIORITY_GPE,
 397                 acpi_ec_gpe_query, ec);
 398
 399         if (status == AE_OK)
 400                 return ACPI_INTERRUPT_HANDLED;
 401         else
 402                 return ACPI_INTERRUPT_NOT_HANDLED;
 403 }
 404
 405 /* --------------------------------------------------------------------------
 406                              Address Space Management
 407    -------------------------------------------------------------------------- */
 408
 409 static acpi_status
 410 acpi_ec_space_setup (
 411         acpi_handle             region_handle,
 412         u32                     function,
 413         void                    *handler_context,
 414         void                    **return_context)
 415 {
 416         /*
 417          * The EC object is in the handler context and is needed
 418          * when calling the acpi_ec_space_handler.
 419          */
 420         if(function == ACPI_REGION_DEACTIVATE)
 421                 *return_context = NULL;
 422         else
 423                 *return_context = handler_context;
 424
 425         return AE_OK;
 426 }
 427
 428
 429 static acpi_status
 430 acpi_ec_space_handler (
 431         u32                     function,
 432         acpi_physical_address   address,
 433         u32                     bit_width,
 434         acpi_integer            *value,
 435         void                    *handler_context,
 436         void                    *region_context)
 437 {
 438         int                     result = 0;
 439         struct acpi_ec          *ec = NULL;
 440         u32                     temp = 0;
 441
 442         ACPI_FUNCTION_TRACE("acpi_ec_space_handler");
 443
 444         if ((address > 0xFF) || (bit_width != 8) || !value || !handler_context)
 445                 return_VALUE(AE_BAD_PARAMETER);
 446
 447         ec = (struct acpi_ec *) handler_context;
 448
 449         switch (function) {
 450         case ACPI_READ:
 451                 result = acpi_ec_read(ec, (u8) address, &temp);
 452                 *value = (acpi_integer) temp;
 453                 break;
 454         case ACPI_WRITE:
 455                 result = acpi_ec_write(ec, (u8) address, (u8) *value);
 456                 break;
 457         default:
 458                 result = -EINVAL;
 459                 break;
 460         }
 461
 462         switch (result) {
 463         case -EINVAL:
 464                 return_VALUE(AE_BAD_PARAMETER);
 465                 break;
 466         case -ENODEV:
 467                 return_VALUE(AE_NOT_FOUND);
 468                 break;
 469         case -ETIME:
 470                 return_VALUE(AE_TIME);
 471                 break;
 472         default:
 473                 return_VALUE(AE_OK);
 474         }
 475
 476 }
 477
 478
 479 /* --------------------------------------------------------------------------
 480                               FS Interface (/proc)
 481    -------------------------------------------------------------------------- */
 482
 483 struct proc_dir_entry           *acpi_ec_dir;
 484
 485
 486 static int
 487 acpi_ec_read_info (
 488         char                    *page,
 489         char                    **start,
 490         off_t                   off,
 491         int                     count,
 492         int                     *eof,
 493         void                    *data)
 494 {
 495         struct acpi_ec          *ec = (struct acpi_ec *) data;
 496         char                    *p = page;
 497         int                     len = 0;
 498
 499         ACPI_FUNCTION_TRACE("acpi_ec_read_info");
 500
 501         if (!ec || (off != 0))
 502                 goto end;
 503
 504         p += sprintf(p, "gpe bit:                 0x%02x\n",
 505                 (u32) ec->gpe_bit);
 506         p += sprintf(p, "ports:                   0x%02x, 0x%02x\n",
 507                 (u32) ec->status_addr.address, (u32) ec->data_addr.address);
 508         p += sprintf(p, "use global lock:         %s\n",
 509                 ec->global_lock?"yes":"no");
 510
 511 end:
 512         len = (p - page);
 513         if (len <= off+count) *eof = 1;
 514         *start = page + off;
 515         len -= off;
 516         if (len>count) len = count;
 517         if (len<0) len = 0;
 518
 519         return_VALUE(len);
 520 }
 521
 522
 523 static int
 524 acpi_ec_add_fs (
 525         struct acpi_device      *device)
 526 {
 527         struct proc_dir_entry   *entry = NULL;
 528
 529         ACPI_FUNCTION_TRACE("acpi_ec_add_fs");
 530
 531         if (!acpi_device_dir(device)) {
 532                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 533                         acpi_ec_dir);
 534                 if (!acpi_device_dir(device))
 535                         return_VALUE(-ENODEV);
 536         }
 537
 538         entry = create_proc_read_entry(ACPI_EC_FILE_INFO, S_IRUGO,
 539                 acpi_device_dir(device), acpi_ec_read_info,
 540                 acpi_driver_data(device));
 541         if (!entry)
 542                 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 543                         "Unable to create '%s' fs entry\n",
 544                         ACPI_EC_FILE_INFO));
 545
 546         return_VALUE(0);
 547 }
 548
 549
 550 static int
 551 acpi_ec_remove_fs (
 552         struct acpi_device      *device)
 553 {
 554         ACPI_FUNCTION_TRACE("acpi_ec_remove_fs");
 555
 556         if (acpi_device_dir(device)) {
 557                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 558                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 559                 acpi_device_dir(device) = NULL;
 560         }
 561
 562         return_VALUE(0);
 563 }
 564
 565
 566 /* --------------------------------------------------------------------------
 567                                Driver Interface
 568    -------------------------------------------------------------------------- */
 569
 570 static int
 571 acpi_ec_add (
 572         struct acpi_device      *device)
 573 {
 574         int                     result = 0;
 575         acpi_status             status = AE_OK;
 576         struct acpi_ec          *ec = NULL;
 577         unsigned long           uid;
 578
 579         ACPI_FUNCTION_TRACE("acpi_ec_add");
 580
 581         if (!device)
 582                 return_VALUE(-EINVAL);
 583
 584         ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 585         if (!ec)
 586                 return_VALUE(-ENOMEM);
 587         memset(ec, 0, sizeof(struct acpi_ec));
 588
 589         ec->handle = device->handle;
 590         ec->uid = -1;
 591         ec->lock = SPIN_LOCK_UNLOCKED;
 592         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 593         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 594         acpi_driver_data(device) = ec;
 595
 596         /* Use the global lock for all EC transactions? */
 597         acpi_evaluate_integer(ec->handle, "_GLK", NULL, &ec->global_lock);
 598
 599         /* If our UID matches the UID for the ECDT-enumerated EC,
 600            we now have the *real* EC info, so kill the makeshift one.*/
 601         acpi_evaluate_integer(ec->handle, "_UID", NULL, &uid);
 602         if (ec_ecdt && ec_ecdt->uid == uid) {
 603                 acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
 604                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler);
 605
 606                 acpi_remove_gpe_handler(NULL, ec_ecdt->gpe_bit, &acpi_ec_gpe_handler);
 607
 608                 kfree(ec_ecdt);
 609         }
 610
 611         /* Get GPE bit assignment (EC events). */
 612         /* TODO: Add support for _GPE returning a package */
 613         status = acpi_evaluate_integer(ec->handle, "_GPE", NULL, &ec->gpe_bit);
 614         if (ACPI_FAILURE(status)) {
 615                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 616                         "Error obtaining GPE bit assignment\n"));
 617                 result = -ENODEV;
 618                 goto end;
 619         }
 620
 621         result = acpi_ec_add_fs(device);
 622         if (result)
 623                 goto end;
 624
 625         printk(KERN_INFO PREFIX "%s [%s] (gpe %d)\n",
 626                 acpi_device_name(device), acpi_device_bid(device),
 627                 (u32) ec->gpe_bit);
 628
 629         if (!first_ec)
 630                 first_ec = device;
 631
 632 end:
 633         if (result)
 634                 kfree(ec);
 635
 636         return_VALUE(result);
 637 }
 638
 639
 640 static int
 641 acpi_ec_remove (
 642         struct acpi_device      *device,
 643         int                     type)
 644 {
 645         struct acpi_ec          *ec = NULL;
 646
 647         ACPI_FUNCTION_TRACE("acpi_ec_remove");
 648
 649         if (!device)
 650                 return_VALUE(-EINVAL);
 651
 652         ec = acpi_driver_data(device);
 653
 654         acpi_ec_remove_fs(device);
 655
 656         kfree(ec);
 657
 658         return_VALUE(0);
 659 }
 660
 661
 662 static acpi_status
 663 acpi_ec_io_ports (
 664         struct acpi_resource    *resource,
 665         void                    *context)
 666 {
 667         struct acpi_ec          *ec = (struct acpi_ec *) context;
 668         struct acpi_generic_address *addr;
 669
 670         if (resource->id != ACPI_RSTYPE_IO) {
 671                 return AE_OK;
 672         }
 673
 674         /*
 675          * The first address region returned is the data port, and
 676          * the second address region returned is the status/command
 677          * port.
 678          */
 679         if (ec->data_addr.register_bit_width == 0) {
 680                 addr = &ec->data_addr;
 681         } else if (ec->command_addr.register_bit_width == 0) {
 682                 addr = &ec->command_addr;
 683         } else {
 684                 return AE_CTRL_TERMINATE;
 685         }
 686
 687         addr->address_space_id = ACPI_ADR_SPACE_SYSTEM_IO;
 688         addr->register_bit_width = 8;
 689         addr->register_bit_offset = 0;
 690         addr->address = resource->data.io.min_base_address;
 691
 692         return AE_OK;
 693 }
 694
 695
 696 static int
 697 acpi_ec_start (
 698         struct acpi_device      *device)
 699 {
 700         acpi_status             status = AE_OK;
 701         struct acpi_ec          *ec = NULL;
 702
 703         ACPI_FUNCTION_TRACE("acpi_ec_start");
 704
 705         if (!device)
 706                 return_VALUE(-EINVAL);
 707
 708         ec = acpi_driver_data(device);
 709
 710         if (!ec)
 711                 return_VALUE(-EINVAL);
 712
 713         /*
 714          * Get I/O port addresses. Convert to GAS format.
 715          */
 716         status = acpi_walk_resources(ec->handle, METHOD_NAME__CRS,
 717                 acpi_ec_io_ports, ec);
 718         if (ACPI_FAILURE(status) || ec->command_addr.register_bit_width == 0) {
 719                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error getting I/O port addresses"));
 720                 return_VALUE(-ENODEV);
 721         }
 722
 723         ec->status_addr = ec->command_addr;
 724
 725         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "gpe=0x%02x, ports=0x%2x,0x%2x\n",
 726                 (u32) ec->gpe_bit, (u32) ec->command_addr.address,
 727                 (u32) ec->data_addr.address));
 728
 729         /*
 730          * Install GPE handler
 731          */
 732         status = acpi_install_gpe_handler(NULL, ec->gpe_bit,
 733                 ACPI_GPE_EDGE_TRIGGERED, &acpi_ec_gpe_handler, ec);
 734         if (ACPI_FAILURE(status)) {
 735                 return_VALUE(-ENODEV);
 736         }
 737         acpi_set_gpe_type (NULL, ec->gpe_bit, ACPI_GPE_TYPE_RUNTIME);
 738         acpi_enable_gpe (NULL, ec->gpe_bit, ACPI_NOT_ISR);
 739
 740         status = acpi_install_address_space_handler (ec->handle,
 741                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler,
 742                         &acpi_ec_space_setup, ec);
 743         if (ACPI_FAILURE(status)) {
 744                 acpi_remove_gpe_handler(NULL, ec->gpe_bit, &acpi_ec_gpe_handler);
 745                 return_VALUE(-ENODEV);
 746         }
 747
 748         return_VALUE(AE_OK);
 749 }
 750
 751
 752 static int
 753 acpi_ec_stop (
 754         struct acpi_device      *device,
 755         int                     type)
 756 {
 757         acpi_status             status = AE_OK;
 758         struct acpi_ec          *ec = NULL;
 759
 760         ACPI_FUNCTION_TRACE("acpi_ec_stop");
 761
 762         if (!device)
 763                 return_VALUE(-EINVAL);
 764
 765         ec = acpi_driver_data(device);
 766
 767         status = acpi_remove_address_space_handler(ec->handle,
 768                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler);
 769         if (ACPI_FAILURE(status))
 770                 return_VALUE(-ENODEV);
 771
 772         status = acpi_remove_gpe_handler(NULL, ec->gpe_bit, &acpi_ec_gpe_handler);
 773         if (ACPI_FAILURE(status))
 774                 return_VALUE(-ENODEV);
 775
 776         return_VALUE(0);
 777 }
 778
 779
 780 int __init
 781 acpi_ec_ecdt_probe (void)
 782 {
 783         acpi_status             status;
 784         struct acpi_table_ecdt  *ecdt_ptr;
 785
 786         status = acpi_get_firmware_table("ECDT", 1, ACPI_LOGICAL_ADDRESSING,
 787                 (struct acpi_table_header **) &ecdt_ptr);
 788         if (ACPI_FAILURE(status))
 789                 return 0;
 790
 791         printk(KERN_INFO PREFIX "Found ECDT\n");
 792
 793          /*
 794          * Generate a temporary ec context to use until the namespace is scanned
 795          */
 796         ec_ecdt = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 797         if (!ec_ecdt)
 798                 return -ENOMEM;
 799         memset(ec_ecdt, 0, sizeof(struct acpi_ec));
 800
 801         ec_ecdt->command_addr = ecdt_ptr->ec_control;
 802         ec_ecdt->status_addr = ecdt_ptr->ec_control;
 803         ec_ecdt->data_addr = ecdt_ptr->ec_data;
 804         ec_ecdt->gpe_bit = ecdt_ptr->gpe_bit;
 805         ec_ecdt->lock = SPIN_LOCK_UNLOCKED;
 806         /* use the GL just to be safe */
 807         ec_ecdt->global_lock = TRUE;
 808         ec_ecdt->uid = ecdt_ptr->uid;
 809
 810         status = acpi_get_handle(NULL, ecdt_ptr->ec_id, &ec_ecdt->handle);
 811         if (ACPI_FAILURE(status)) {
 812                 goto error;
 813         }
 814
 815         /*
 816          * Install GPE handler
 817          */
 818         status = acpi_install_gpe_handler(NULL, ec_ecdt->gpe_bit,
 819                 ACPI_GPE_EDGE_TRIGGERED, &acpi_ec_gpe_handler,
 820                 ec_ecdt);
 821         if (ACPI_FAILURE(status)) {
 822                 goto error;
 823         }
 824         acpi_set_gpe_type (NULL, ec_ecdt->gpe_bit, ACPI_GPE_TYPE_RUNTIME);
 825         acpi_enable_gpe (NULL, ec_ecdt->gpe_bit, ACPI_NOT_ISR);
 826
 827         status = acpi_install_address_space_handler (ACPI_ROOT_OBJECT,
 828                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler,
 829                         &acpi_ec_space_setup, ec_ecdt);
 830         if (ACPI_FAILURE(status)) {
 831                 acpi_remove_gpe_handler(NULL, ec_ecdt->gpe_bit,
 832                         &acpi_ec_gpe_handler);
 833                 goto error;
 834         }
 835
 836         return 0;
 837
 838 error:
 839         printk(KERN_ERR PREFIX "Could not use ECDT\n");
 840         kfree(ec_ecdt);
 841         ec_ecdt = NULL;
 842
 843         return -ENODEV;
 844 }
 845
 846
 847 static int __init acpi_ec_init (void)
 848 {
 849         int                     result = 0;
 850
 851         ACPI_FUNCTION_TRACE("acpi_ec_init");
 852
 853         if (acpi_disabled)
 854                 return_VALUE(0);
 855
 856         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
 857         if (!acpi_ec_dir)
 858                 return_VALUE(-ENODEV);
 859
 860         /* Now register the driver for the EC */
 861         result = acpi_bus_register_driver(&acpi_ec_driver);
 862         if (result < 0) {
 863                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 864                 return_VALUE(-ENODEV);
 865         }
 866
 867         return_VALUE(result);
 868 }
 869
 870 subsys_initcall(acpi_ec_init);
 871
 872 /* EC driver currently not unloadable */
 873 #if 0
 874 static void __exit
 875 acpi_ec_exit (void)
 876 {
 877         ACPI_FUNCTION_TRACE("acpi_ec_exit");
 878
 879         acpi_bus_unregister_driver(&acpi_ec_driver);
 880
 881         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 882
 883         return_VOID;
 884 }
 885 #endif /* 0 */
 886