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 void
 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;
 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
 400 /* --------------------------------------------------------------------------
 401                              Address Space Management
 402    -------------------------------------------------------------------------- */
 403
 404 static acpi_status
 405 acpi_ec_space_setup (
 406         acpi_handle             region_handle,
 407         u32                     function,
 408         void                    *handler_context,
 409         void                    **return_context)
 410 {
 411         /*
 412          * The EC object is in the handler context and is needed
 413          * when calling the acpi_ec_space_handler.
 414          */
 415         if(function == ACPI_REGION_DEACTIVATE)
 416                 *return_context = NULL;
 417         else
 418                 *return_context = handler_context;
 419
 420         return AE_OK;
 421 }
 422
 423
 424 static acpi_status
 425 acpi_ec_space_handler (
 426         u32                     function,
 427         acpi_physical_address   address,
 428         u32                     bit_width,
 429         acpi_integer            *value,
 430         void                    *handler_context,
 431         void                    *region_context)
 432 {
 433         int                     result = 0;
 434         struct acpi_ec          *ec = NULL;
 435         u32                     temp = 0;
 436
 437         ACPI_FUNCTION_TRACE("acpi_ec_space_handler");
 438
 439         if ((address > 0xFF) || (bit_width != 8) || !value || !handler_context)
 440                 return_VALUE(AE_BAD_PARAMETER);
 441
 442         ec = (struct acpi_ec *) handler_context;
 443
 444         switch (function) {
 445         case ACPI_READ:
 446                 result = acpi_ec_read(ec, (u8) address, &temp);
 447                 *value = (acpi_integer) temp;
 448                 break;
 449         case ACPI_WRITE:
 450                 result = acpi_ec_write(ec, (u8) address, (u8) *value);
 451                 break;
 452         default:
 453                 result = -EINVAL;
 454                 break;
 455         }
 456
 457         switch (result) {
 458         case -EINVAL:
 459                 return_VALUE(AE_BAD_PARAMETER);
 460                 break;
 461         case -ENODEV:
 462                 return_VALUE(AE_NOT_FOUND);
 463                 break;
 464         case -ETIME:
 465                 return_VALUE(AE_TIME);
 466                 break;
 467         default:
 468                 return_VALUE(AE_OK);
 469         }
 470
 471 }
 472
 473
 474 /* --------------------------------------------------------------------------
 475                               FS Interface (/proc)
 476    -------------------------------------------------------------------------- */
 477
 478 struct proc_dir_entry           *acpi_ec_dir;
 479
 480
 481 static int
 482 acpi_ec_read_info (
 483         char                    *page,
 484         char                    **start,
 485         off_t                   off,
 486         int                     count,
 487         int                     *eof,
 488         void                    *data)
 489 {
 490         struct acpi_ec          *ec = (struct acpi_ec *) data;
 491         char                    *p = page;
 492         int                     len = 0;
 493
 494         ACPI_FUNCTION_TRACE("acpi_ec_read_info");
 495
 496         if (!ec || (off != 0))
 497                 goto end;
 498
 499         p += sprintf(p, "gpe bit:                 0x%02x\n",
 500                 (u32) ec->gpe_bit);
 501         p += sprintf(p, "ports:                   0x%02x, 0x%02x\n",
 502                 (u32) ec->status_addr.address, (u32) ec->data_addr.address);
 503         p += sprintf(p, "use global lock:         %s\n",
 504                 ec->global_lock?"yes":"no");
 505
 506 end:
 507         len = (p - page);
 508         if (len <= off+count) *eof = 1;
 509         *start = page + off;
 510         len -= off;
 511         if (len>count) len = count;
 512         if (len<0) len = 0;
 513
 514         return_VALUE(len);
 515 }
 516
 517
 518 static int
 519 acpi_ec_add_fs (
 520         struct acpi_device      *device)
 521 {
 522         struct proc_dir_entry   *entry = NULL;
 523
 524         ACPI_FUNCTION_TRACE("acpi_ec_add_fs");
 525
 526         if (!acpi_device_dir(device)) {
 527                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 528                         acpi_ec_dir);
 529                 if (!acpi_device_dir(device))
 530                         return_VALUE(-ENODEV);
 531         }
 532
 533         entry = create_proc_read_entry(ACPI_EC_FILE_INFO, S_IRUGO,
 534                 acpi_device_dir(device), acpi_ec_read_info,
 535                 acpi_driver_data(device));
 536         if (!entry)
 537                 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 538                         "Unable to create '%s' fs entry\n",
 539                         ACPI_EC_FILE_INFO));
 540
 541         return_VALUE(0);
 542 }
 543
 544
 545 static int
 546 acpi_ec_remove_fs (
 547         struct acpi_device      *device)
 548 {
 549         ACPI_FUNCTION_TRACE("acpi_ec_remove_fs");
 550
 551         if (acpi_device_dir(device)) {
 552                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 553                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 554                 acpi_device_dir(device) = NULL;
 555         }
 556
 557         return_VALUE(0);
 558 }
 559
 560
 561 /* --------------------------------------------------------------------------
 562                                Driver Interface
 563    -------------------------------------------------------------------------- */
 564
 565 static int
 566 acpi_ec_add (
 567         struct acpi_device      *device)
 568 {
 569         int                     result = 0;
 570         acpi_status             status = AE_OK;
 571         struct acpi_ec          *ec = NULL;
 572         unsigned long           uid;
 573
 574         ACPI_FUNCTION_TRACE("acpi_ec_add");
 575
 576         if (!device)
 577                 return_VALUE(-EINVAL);
 578
 579         ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 580         if (!ec)
 581                 return_VALUE(-ENOMEM);
 582         memset(ec, 0, sizeof(struct acpi_ec));
 583
 584         ec->handle = device->handle;
 585         ec->uid = -1;
 586         ec->lock = SPIN_LOCK_UNLOCKED;
 587         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 588         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 589         acpi_driver_data(device) = ec;
 590
 591         /* Use the global lock for all EC transactions? */
 592         acpi_evaluate_integer(ec->handle, "_GLK", NULL, &ec->global_lock);
 593
 594         /* If our UID matches the UID for the ECDT-enumerated EC,
 595            we now have the *real* EC info, so kill the makeshift one.*/
 596         acpi_evaluate_integer(ec->handle, "_UID", NULL, &uid);
 597         if (ec_ecdt && ec_ecdt->uid == uid) {
 598                 acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
 599                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler);
 600
 601                 acpi_remove_gpe_handler(NULL, ec_ecdt->gpe_bit, &acpi_ec_gpe_handler);
 602
 603                 kfree(ec_ecdt);
 604         }
 605
 606         /* Get GPE bit assignment (EC events). */
 607         /* TODO: Add support for _GPE returning a package */
 608         status = acpi_evaluate_integer(ec->handle, "_GPE", NULL, &ec->gpe_bit);
 609         if (ACPI_FAILURE(status)) {
 610                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 611                         "Error obtaining GPE bit assignment\n"));
 612                 result = -ENODEV;
 613                 goto end;
 614         }
 615
 616         result = acpi_ec_add_fs(device);
 617         if (result)
 618                 goto end;
 619
 620         printk(KERN_INFO PREFIX "%s [%s] (gpe %d)\n",
 621                 acpi_device_name(device), acpi_device_bid(device),
 622                 (u32) ec->gpe_bit);
 623
 624         if (!first_ec)
 625                 first_ec = device;
 626
 627 end:
 628         if (result)
 629                 kfree(ec);
 630
 631         return_VALUE(result);
 632 }
 633
 634
 635 static int
 636 acpi_ec_remove (
 637         struct acpi_device      *device,
 638         int                     type)
 639 {
 640         struct acpi_ec          *ec = NULL;
 641
 642         ACPI_FUNCTION_TRACE("acpi_ec_remove");
 643
 644         if (!device)
 645                 return_VALUE(-EINVAL);
 646
 647         ec = acpi_driver_data(device);
 648
 649         acpi_ec_remove_fs(device);
 650
 651         kfree(ec);
 652
 653         return_VALUE(0);
 654 }
 655
 656
 657 static acpi_status
 658 acpi_ec_io_ports (
 659         struct acpi_resource    *resource,
 660         void                    *context)
 661 {
 662         struct acpi_ec          *ec = (struct acpi_ec *) context;
 663         struct acpi_generic_address *addr;
 664
 665         if (resource->id != ACPI_RSTYPE_IO) {
 666                 return AE_OK;
 667         }
 668
 669         /*
 670          * The first address region returned is the data port, and
 671          * the second address region returned is the status/command
 672          * port.
 673          */
 674         if (ec->data_addr.register_bit_width == 0) {
 675                 addr = &ec->data_addr;
 676         } else if (ec->command_addr.register_bit_width == 0) {
 677                 addr = &ec->command_addr;
 678         } else {
 679                 return AE_CTRL_TERMINATE;
 680         }
 681
 682         addr->address_space_id = ACPI_ADR_SPACE_SYSTEM_IO;
 683         addr->register_bit_width = 8;
 684         addr->register_bit_offset = 0;
 685         addr->address = resource->data.io.min_base_address;
 686
 687         return AE_OK;
 688 }
 689
 690
 691 static int
 692 acpi_ec_start (
 693         struct acpi_device      *device)
 694 {
 695         acpi_status             status = AE_OK;
 696         struct acpi_ec          *ec = NULL;
 697
 698         ACPI_FUNCTION_TRACE("acpi_ec_start");
 699
 700         if (!device)
 701                 return_VALUE(-EINVAL);
 702
 703         ec = acpi_driver_data(device);
 704
 705         if (!ec)
 706                 return_VALUE(-EINVAL);
 707
 708         /*
 709          * Get I/O port addresses. Convert to GAS format.
 710          */
 711         status = acpi_walk_resources(ec->handle, METHOD_NAME__CRS,
 712                 acpi_ec_io_ports, ec);
 713         if (ACPI_FAILURE(status) || ec->command_addr.register_bit_width == 0) {
 714                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error getting I/O port addresses"));
 715                 return_VALUE(-ENODEV);
 716         }
 717
 718         ec->status_addr = ec->command_addr;
 719
 720         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "gpe=0x%02x, ports=0x%2x,0x%2x\n",
 721                 (u32) ec->gpe_bit, (u32) ec->command_addr.address,
 722                 (u32) ec->data_addr.address));
 723
 724         /*
 725          * Install GPE handler
 726          */
 727         status = acpi_install_gpe_handler(NULL, ec->gpe_bit,
 728                 ACPI_GPE_EDGE_TRIGGERED, &acpi_ec_gpe_handler, ec);
 729         if (ACPI_FAILURE(status)) {
 730                 return_VALUE(-ENODEV);
 731         }
 732
 733         status = acpi_install_address_space_handler (ec->handle,
 734                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler,
 735                         &acpi_ec_space_setup, ec);
 736         if (ACPI_FAILURE(status)) {
 737                 acpi_remove_gpe_handler(NULL, ec->gpe_bit, &acpi_ec_gpe_handler);
 738                 return_VALUE(-ENODEV);
 739         }
 740
 741         return_VALUE(AE_OK);
 742 }
 743
 744
 745 static int
 746 acpi_ec_stop (
 747         struct acpi_device      *device,
 748         int                     type)
 749 {
 750         acpi_status             status = AE_OK;
 751         struct acpi_ec          *ec = NULL;
 752
 753         ACPI_FUNCTION_TRACE("acpi_ec_stop");
 754
 755         if (!device)
 756                 return_VALUE(-EINVAL);
 757
 758         ec = acpi_driver_data(device);
 759
 760         status = acpi_remove_address_space_handler(ec->handle,
 761                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler);
 762         if (ACPI_FAILURE(status))
 763                 return_VALUE(-ENODEV);
 764
 765         status = acpi_remove_gpe_handler(NULL, ec->gpe_bit, &acpi_ec_gpe_handler);
 766         if (ACPI_FAILURE(status))
 767                 return_VALUE(-ENODEV);
 768
 769         return_VALUE(0);
 770 }
 771
 772
 773 int __init
 774 acpi_ec_ecdt_probe (void)
 775 {
 776         acpi_status             status;
 777         struct acpi_table_ecdt  *ecdt_ptr;
 778
 779         status = acpi_get_firmware_table("ECDT", 1, ACPI_LOGICAL_ADDRESSING,
 780                 (struct acpi_table_header **) &ecdt_ptr);
 781         if (ACPI_FAILURE(status))
 782                 return 0;
 783
 784         printk(KERN_INFO PREFIX "Found ECDT\n");
 785
 786          /*
 787          * Generate a temporary ec context to use until the namespace is scanned
 788          */
 789         ec_ecdt = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 790         if (!ec_ecdt)
 791                 return -ENOMEM;
 792         memset(ec_ecdt, 0, sizeof(struct acpi_ec));
 793
 794         ec_ecdt->command_addr = ecdt_ptr->ec_control;
 795         ec_ecdt->status_addr = ecdt_ptr->ec_control;
 796         ec_ecdt->data_addr = ecdt_ptr->ec_data;
 797         ec_ecdt->gpe_bit = ecdt_ptr->gpe_bit;
 798         ec_ecdt->lock = SPIN_LOCK_UNLOCKED;
 799         /* use the GL just to be safe */
 800         ec_ecdt->global_lock = TRUE;
 801         ec_ecdt->uid = ecdt_ptr->uid;
 802
 803         status = acpi_get_handle(NULL, ecdt_ptr->ec_id, &ec_ecdt->handle);
 804         if (ACPI_FAILURE(status)) {
 805                 goto error;
 806         }
 807
 808         /*
 809          * Install GPE handler
 810          */
 811         status = acpi_install_gpe_handler(NULL, ec_ecdt->gpe_bit,
 812                 ACPI_GPE_EDGE_TRIGGERED, &acpi_ec_gpe_handler,
 813                 ec_ecdt);
 814         if (ACPI_FAILURE(status)) {
 815                 goto error;
 816         }
 817
 818         status = acpi_install_address_space_handler (ACPI_ROOT_OBJECT,
 819                         ACPI_ADR_SPACE_EC, &acpi_ec_space_handler,
 820                         &acpi_ec_space_setup, ec_ecdt);
 821         if (ACPI_FAILURE(status)) {
 822                 acpi_remove_gpe_handler(NULL, ec_ecdt->gpe_bit,
 823                         &acpi_ec_gpe_handler);
 824                 goto error;
 825         }
 826
 827         return 0;
 828
 829 error:
 830         printk(KERN_ERR PREFIX "Could not use ECDT\n");
 831         kfree(ec_ecdt);
 832         ec_ecdt = NULL;
 833
 834         return -ENODEV;
 835 }
 836
 837
 838 static int __init acpi_ec_init (void)
 839 {
 840         int                     result = 0;
 841
 842         ACPI_FUNCTION_TRACE("acpi_ec_init");
 843
 844         if (acpi_disabled)
 845                 return_VALUE(0);
 846
 847         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
 848         if (!acpi_ec_dir)
 849                 return_VALUE(-ENODEV);
 850
 851         /* Now register the driver for the EC */
 852         result = acpi_bus_register_driver(&acpi_ec_driver);
 853         if (result < 0) {
 854                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 855                 return_VALUE(-ENODEV);
 856         }
 857
 858         return_VALUE(result);
 859 }
 860
 861 subsys_initcall(acpi_ec_init);
 862
 863 /* EC driver currently not unloadable */
 864 #if 0
 865 static void __exit
 866 acpi_ec_exit (void)
 867 {
 868         ACPI_FUNCTION_TRACE("acpi_ec_exit");
 869
 870         acpi_bus_unregister_driver(&acpi_ec_driver);
 871
 872         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 873
 874         return_VOID;
 875 }
 876 #endif /* 0 */
 877