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