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