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                         mutex_unlock(&ec->lock);
 284                         return -ENODEV;
 285                 }
 286         }
 287
 288         /* Make sure GPE is enabled before doing transaction */
 289         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 290
 291         status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 292         if (status) {
 293                 printk(KERN_DEBUG PREFIX
 294                        "input buffer is not empty, aborting transaction\n");
 295                 goto end;
 296         }
 297
 298         status = acpi_ec_transaction_unlocked(ec, command,
 299                                               wdata, wdata_len,
 300                                               rdata, rdata_len);
 301
 302       end:
 303
 304         if (ec->global_lock)
 305                 acpi_release_global_lock(glk);
 306         mutex_unlock(&ec->lock);
 307
 308         return status;
 309 }
 310
 311 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 312 {
 313         int result;
 314         u8 d;
 315
 316         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
 317                                      &address, 1, &d, 1);
 318         *data = d;
 319         return result;
 320 }
 321
 322 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 323 {
 324         u8 wdata[2] = { address, data };
 325         return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
 326                                    wdata, 2, NULL, 0);
 327 }
 328
 329 /*
 330  * Externally callable EC access functions. For now, assume 1 EC only
 331  */
 332 int ec_read(u8 addr, u8 * val)
 333 {
 334         struct acpi_ec *ec;
 335         int err;
 336         u8 temp_data;
 337
 338         if (!first_ec)
 339                 return -ENODEV;
 340
 341         ec = acpi_driver_data(first_ec);
 342
 343         err = acpi_ec_read(ec, addr, &temp_data);
 344
 345         if (!err) {
 346                 *val = temp_data;
 347                 return 0;
 348         } else
 349                 return err;
 350 }
 351
 352 EXPORT_SYMBOL(ec_read);
 353
 354 int ec_write(u8 addr, u8 val)
 355 {
 356         struct acpi_ec *ec;
 357         int err;
 358
 359         if (!first_ec)
 360                 return -ENODEV;
 361
 362         ec = acpi_driver_data(first_ec);
 363
 364         err = acpi_ec_write(ec, addr, val);
 365
 366         return err;
 367 }
 368
 369 EXPORT_SYMBOL(ec_write);
 370
 371 int ec_transaction(u8 command,
 372                           const u8 * wdata, unsigned wdata_len,
 373                           u8 * rdata, unsigned rdata_len)
 374 {
 375         struct acpi_ec *ec;
 376
 377         if (!first_ec)
 378                 return -ENODEV;
 379
 380         ec = acpi_driver_data(first_ec);
 381
 382         return acpi_ec_transaction(ec, command, wdata,
 383                                    wdata_len, rdata, rdata_len);
 384 }
 385
 386 EXPORT_SYMBOL(ec_transaction);
 387
 388 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 389 {
 390         int result;
 391         u8 d;
 392
 393         if (!ec || !data)
 394                 return -EINVAL;
 395
 396         /*
 397          * Query the EC to find out which _Qxx method we need to evaluate.
 398          * Note that successful completion of the query causes the ACPI_EC_SCI
 399          * bit to be cleared (and thus clearing the interrupt source).
 400          */
 401
 402         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1);
 403         if (result)
 404                 return result;
 405
 406         if (!d)
 407                 return -ENODATA;
 408
 409         *data = d;
 410         return 0;
 411 }
 412
 413 /* --------------------------------------------------------------------------
 414                                 Event Management
 415    -------------------------------------------------------------------------- */
 416
 417 static void acpi_ec_gpe_query(void *ec_cxt)
 418 {
 419         struct acpi_ec *ec = (struct acpi_ec *)ec_cxt;
 420         u8 value = 0;
 421         char object_name[8];
 422
 423         if (!ec || acpi_ec_query(ec, &value))
 424                 return;
 425
 426         snprintf(object_name, 8, "_Q%2.2X", value);
 427
 428         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluating %s", object_name));
 429
 430         acpi_evaluate_object(ec->handle, object_name, NULL, NULL);
 431 }
 432
 433 static u32 acpi_ec_gpe_handler(void *data)
 434 {
 435         acpi_status status = AE_OK;
 436         u8 value;
 437         struct acpi_ec *ec = (struct acpi_ec *)data;
 438
 439         if (acpi_ec_mode == EC_INTR) {
 440                 wake_up(&ec->wait);
 441         }
 442
 443         value = acpi_ec_read_status(ec);
 444         if ((value & ACPI_EC_FLAG_SCI) && !atomic_read(&ec->query_pending)) {
 445                 atomic_set(&ec->query_pending, 1);
 446                 status =
 447                     acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query,
 448                                     ec);
 449         }
 450
 451         return status == AE_OK ?
 452             ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 453 }
 454
 455 /* --------------------------------------------------------------------------
 456                              Address Space Management
 457    -------------------------------------------------------------------------- */
 458
 459 static acpi_status
 460 acpi_ec_space_setup(acpi_handle region_handle,
 461                     u32 function, void *handler_context, void **return_context)
 462 {
 463         /*
 464          * The EC object is in the handler context and is needed
 465          * when calling the acpi_ec_space_handler.
 466          */
 467         *return_context = (function != ACPI_REGION_DEACTIVATE) ?
 468             handler_context : NULL;
 469
 470         return AE_OK;
 471 }
 472
 473 static acpi_status
 474 acpi_ec_space_handler(u32 function,
 475                       acpi_physical_address address,
 476                       u32 bit_width,
 477                       acpi_integer * value,
 478                       void *handler_context, void *region_context)
 479 {
 480         int result = 0;
 481         struct acpi_ec *ec = NULL;
 482         u64 temp = *value;
 483         acpi_integer f_v = 0;
 484         int i = 0;
 485
 486         if ((address > 0xFF) || !value || !handler_context)
 487                 return AE_BAD_PARAMETER;
 488
 489         if (bit_width != 8 && acpi_strict) {
 490                 return AE_BAD_PARAMETER;
 491         }
 492
 493         ec = (struct acpi_ec *)handler_context;
 494
 495       next_byte:
 496         switch (function) {
 497         case ACPI_READ:
 498                 temp = 0;
 499                 result = acpi_ec_read(ec, (u8) address, (u8 *) & temp);
 500                 break;
 501         case ACPI_WRITE:
 502                 result = acpi_ec_write(ec, (u8) address, (u8) temp);
 503                 break;
 504         default:
 505                 result = -EINVAL;
 506                 goto out;
 507                 break;
 508         }
 509
 510         bit_width -= 8;
 511         if (bit_width) {
 512                 if (function == ACPI_READ)
 513                         f_v |= temp << 8 * i;
 514                 if (function == ACPI_WRITE)
 515                         temp >>= 8;
 516                 i++;
 517                 address++;
 518                 goto next_byte;
 519         }
 520
 521         if (function == ACPI_READ) {
 522                 f_v |= temp << 8 * i;
 523                 *value = f_v;
 524         }
 525
 526       out:
 527         switch (result) {
 528         case -EINVAL:
 529                 return AE_BAD_PARAMETER;
 530                 break;
 531         case -ENODEV:
 532                 return AE_NOT_FOUND;
 533                 break;
 534         case -ETIME:
 535                 return AE_TIME;
 536                 break;
 537         default:
 538                 return AE_OK;
 539         }
 540 }
 541
 542 /* --------------------------------------------------------------------------
 543                               FS Interface (/proc)
 544    -------------------------------------------------------------------------- */
 545
 546 static struct proc_dir_entry *acpi_ec_dir;
 547
 548 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 549 {
 550         struct acpi_ec *ec = (struct acpi_ec *)seq->private;
 551
 552         if (!ec)
 553                 goto end;
 554
 555         seq_printf(seq, "gpe:                 0x%02x\n", (u32) ec->gpe);
 556         seq_printf(seq, "ports:                   0x%02x, 0x%02x\n",
 557                    (u32) ec->command_addr, (u32) ec->data_addr);
 558         seq_printf(seq, "use global lock:         %s\n",
 559                    ec->global_lock ? "yes" : "no");
 560         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 561
 562       end:
 563         return 0;
 564 }
 565
 566 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 567 {
 568         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 569 }
 570
 571 static struct file_operations acpi_ec_info_ops = {
 572         .open = acpi_ec_info_open_fs,
 573         .read = seq_read,
 574         .llseek = seq_lseek,
 575         .release = single_release,
 576         .owner = THIS_MODULE,
 577 };
 578
 579 static int acpi_ec_add_fs(struct acpi_device *device)
 580 {
 581         struct proc_dir_entry *entry = NULL;
 582
 583         if (!acpi_device_dir(device)) {
 584                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 585                                                      acpi_ec_dir);
 586                 if (!acpi_device_dir(device))
 587                         return -ENODEV;
 588         }
 589
 590         entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
 591                                   acpi_device_dir(device));
 592         if (!entry)
 593                 return -ENODEV;
 594         else {
 595                 entry->proc_fops = &acpi_ec_info_ops;
 596                 entry->data = acpi_driver_data(device);
 597                 entry->owner = THIS_MODULE;
 598         }
 599
 600         return 0;
 601 }
 602
 603 static int acpi_ec_remove_fs(struct acpi_device *device)
 604 {
 605
 606         if (acpi_device_dir(device)) {
 607                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 608                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 609                 acpi_device_dir(device) = NULL;
 610         }
 611
 612         return 0;
 613 }
 614
 615 /* --------------------------------------------------------------------------
 616                                Driver Interface
 617    -------------------------------------------------------------------------- */
 618
 619 static int acpi_ec_add(struct acpi_device *device)
 620 {
 621         int result = 0;
 622         acpi_status status = AE_OK;
 623         struct acpi_ec *ec = NULL;
 624
 625         if (!device)
 626                 return -EINVAL;
 627
 628         ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 629         if (!ec)
 630                 return -ENOMEM;
 631
 632         ec->handle = device->handle;
 633         ec->uid = -1;
 634         mutex_init(&ec->lock);
 635         atomic_set(&ec->query_pending, 0);
 636         if (acpi_ec_mode == EC_INTR) {
 637                 atomic_set(&ec->leaving_burst, 1);
 638                 init_waitqueue_head(&ec->wait);
 639         }
 640         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 641         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 642         acpi_driver_data(device) = ec;
 643
 644         /* Use the global lock for all EC transactions? */
 645         acpi_evaluate_integer(ec->handle, "_GLK", NULL, &ec->global_lock);
 646
 647         /* XXX we don't test uids, because on some boxes ecdt uid = 0, see:
 648            http://bugzilla.kernel.org/show_bug.cgi?id=6111 */
 649         if (ec_ecdt) {
 650                 acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
 651                                                   ACPI_ADR_SPACE_EC,
 652                                                   &acpi_ec_space_handler);
 653
 654                 acpi_remove_gpe_handler(NULL, ec_ecdt->gpe,
 655                                         &acpi_ec_gpe_handler);
 656
 657                 kfree(ec_ecdt);
 658         }
 659
 660         /* Get GPE bit assignment (EC events). */
 661         /* TODO: Add support for _GPE returning a package */
 662         status = acpi_evaluate_integer(ec->handle, "_GPE", NULL, &ec->gpe);
 663         if (ACPI_FAILURE(status)) {
 664                 ACPI_EXCEPTION((AE_INFO, status,
 665                                 "Obtaining GPE bit assignment"));
 666                 result = -ENODEV;
 667                 goto end;
 668         }
 669
 670         result = acpi_ec_add_fs(device);
 671         if (result)
 672                 goto end;
 673
 674         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s [%s] (gpe %d) interrupt mode.",
 675                           acpi_device_name(device), acpi_device_bid(device),
 676                           (u32) ec->gpe));
 677
 678         if (!first_ec)
 679                 first_ec = device;
 680
 681       end:
 682         if (result)
 683                 kfree(ec);
 684
 685         return result;
 686 }
 687
 688 static int acpi_ec_remove(struct acpi_device *device, int type)
 689 {
 690         struct acpi_ec *ec = NULL;
 691
 692         if (!device)
 693                 return -EINVAL;
 694
 695         ec = acpi_driver_data(device);
 696
 697         acpi_ec_remove_fs(device);
 698
 699         kfree(ec);
 700
 701         return 0;
 702 }
 703
 704 static acpi_status
 705 acpi_ec_io_ports(struct acpi_resource *resource, void *context)
 706 {
 707         struct acpi_ec *ec = (struct acpi_ec *)context;
 708
 709         if (resource->type != ACPI_RESOURCE_TYPE_IO) {
 710                 return AE_OK;
 711         }
 712
 713         /*
 714          * The first address region returned is the data port, and
 715          * the second address region returned is the status/command
 716          * port.
 717          */
 718         if (ec->data_addr == 0) {
 719                 ec->data_addr = resource->data.io.minimum;
 720         } else if (ec->command_addr == 0) {
 721                 ec->command_addr = resource->data.io.minimum;
 722         } else {
 723                 return AE_CTRL_TERMINATE;
 724         }
 725
 726         return AE_OK;
 727 }
 728
 729 static int acpi_ec_start(struct acpi_device *device)
 730 {
 731         acpi_status status = AE_OK;
 732         struct acpi_ec *ec = NULL;
 733
 734         if (!device)
 735                 return -EINVAL;
 736
 737         ec = acpi_driver_data(device);
 738
 739         if (!ec)
 740                 return -EINVAL;
 741
 742         /*
 743          * Get I/O port addresses. Convert to GAS format.
 744          */
 745         status = acpi_walk_resources(ec->handle, METHOD_NAME__CRS,
 746                                      acpi_ec_io_ports, ec);
 747         if (ACPI_FAILURE(status) || ec->command_addr == 0) {
 748                 ACPI_EXCEPTION((AE_INFO, status,
 749                                 "Error getting I/O port addresses"));
 750                 return -ENODEV;
 751         }
 752
 753         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "gpe=0x%02lx, ports=0x%2lx,0x%2lx",
 754                           ec->gpe, ec->command_addr, ec->data_addr));
 755
 756         /*
 757          * Install GPE handler
 758          */
 759         status = acpi_install_gpe_handler(NULL, ec->gpe,
 760                                           ACPI_GPE_EDGE_TRIGGERED,
 761                                           &acpi_ec_gpe_handler, ec);
 762         if (ACPI_FAILURE(status)) {
 763                 return -ENODEV;
 764         }
 765         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 766         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 767
 768         status = acpi_install_address_space_handler(ec->handle,
 769                                                     ACPI_ADR_SPACE_EC,
 770                                                     &acpi_ec_space_handler,
 771                                                     &acpi_ec_space_setup, ec);
 772         if (ACPI_FAILURE(status)) {
 773                 acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 774                 return -ENODEV;
 775         }
 776
 777         return AE_OK;
 778 }
 779
 780 static int acpi_ec_stop(struct acpi_device *device, int type)
 781 {
 782         acpi_status status = AE_OK;
 783         struct acpi_ec *ec = NULL;
 784
 785         if (!device)
 786                 return -EINVAL;
 787
 788         ec = acpi_driver_data(device);
 789
 790         status = acpi_remove_address_space_handler(ec->handle,
 791                                                    ACPI_ADR_SPACE_EC,
 792                                                    &acpi_ec_space_handler);
 793         if (ACPI_FAILURE(status))
 794                 return -ENODEV;
 795
 796         status = acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 797         if (ACPI_FAILURE(status))
 798                 return -ENODEV;
 799
 800         return 0;
 801 }
 802
 803 static acpi_status __init
 804 acpi_fake_ecdt_callback(acpi_handle handle,
 805                         u32 Level, void *context, void **retval)
 806 {
 807         acpi_status status;
 808
 809         mutex_init(&ec_ecdt->lock);
 810         if (acpi_ec_mode == EC_INTR) {
 811                 init_waitqueue_head(&ec_ecdt->wait);
 812         }
 813         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 814                                      acpi_ec_io_ports, ec_ecdt);
 815         if (ACPI_FAILURE(status))
 816                 return status;
 817
 818         ec_ecdt->uid = -1;
 819         acpi_evaluate_integer(handle, "_UID", NULL, &ec_ecdt->uid);
 820
 821         status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec_ecdt->gpe);
 822         if (ACPI_FAILURE(status))
 823                 return status;
 824         ec_ecdt->global_lock = TRUE;
 825         ec_ecdt->handle = handle;
 826
 827         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "GPE=0x%02lx, ports=0x%2lx, 0x%2lx",
 828                           ec_ecdt->gpe, ec_ecdt->command_addr,
 829                           ec_ecdt->data_addr));
 830
 831         return AE_CTRL_TERMINATE;
 832 }
 833
 834 /*
 835  * Some BIOS (such as some from Gateway laptops) access EC region very early
 836  * such as in BAT0._INI or EC._INI before an EC device is found and
 837  * do not provide an ECDT. According to ACPI spec, ECDT isn't mandatorily
 838  * required, but if EC regison is accessed early, it is required.
 839  * The routine tries to workaround the BIOS bug by pre-scan EC device
 840  * It assumes that _CRS, _HID, _GPE, _UID methods of EC don't touch any
 841  * op region (since _REG isn't invoked yet). The assumption is true for
 842  * all systems found.
 843  */
 844 static int __init acpi_ec_fake_ecdt(void)
 845 {
 846         acpi_status status;
 847         int ret = 0;
 848
 849         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Try to make an fake ECDT"));
 850
 851         ec_ecdt = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 852         if (!ec_ecdt) {
 853                 ret = -ENOMEM;
 854                 goto error;
 855         }
 856
 857         status = acpi_get_devices(ACPI_EC_HID,
 858                                   acpi_fake_ecdt_callback, NULL, NULL);
 859         if (ACPI_FAILURE(status)) {
 860                 kfree(ec_ecdt);
 861                 ec_ecdt = NULL;
 862                 ret = -ENODEV;
 863                 ACPI_EXCEPTION((AE_INFO, status, "Can't make an fake ECDT"));
 864                 goto error;
 865         }
 866         return 0;
 867       error:
 868         return ret;
 869 }
 870
 871 static int __init acpi_ec_get_real_ecdt(void)
 872 {
 873         acpi_status status;
 874         struct acpi_table_ecdt *ecdt_ptr;
 875
 876         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 877                                 (struct acpi_table_header **)&ecdt_ptr);
 878         if (ACPI_FAILURE(status))
 879                 return -ENODEV;
 880
 881         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found ECDT"));
 882
 883         /*
 884          * Generate a temporary ec context to use until the namespace is scanned
 885          */
 886         ec_ecdt = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 887         if (!ec_ecdt)
 888                 return -ENOMEM;
 889
 890         mutex_init(&ec_ecdt->lock);
 891         if (acpi_ec_mode == EC_INTR) {
 892                 init_waitqueue_head(&ec_ecdt->wait);
 893         }
 894         ec_ecdt->command_addr = ecdt_ptr->control.address;
 895         ec_ecdt->data_addr = ecdt_ptr->data.address;
 896         ec_ecdt->gpe = ecdt_ptr->gpe;
 897         /* use the GL just to be safe */
 898         ec_ecdt->global_lock = TRUE;
 899         ec_ecdt->uid = ecdt_ptr->uid;
 900
 901         status = acpi_get_handle(NULL, ecdt_ptr->id, &ec_ecdt->handle);
 902         if (ACPI_FAILURE(status)) {
 903                 goto error;
 904         }
 905
 906         return 0;
 907       error:
 908         ACPI_EXCEPTION((AE_INFO, status, "Could not use ECDT"));
 909         kfree(ec_ecdt);
 910         ec_ecdt = NULL;
 911
 912         return -ENODEV;
 913 }
 914
 915 static int __initdata acpi_fake_ecdt_enabled;
 916 int __init acpi_ec_ecdt_probe(void)
 917 {
 918         acpi_status status;
 919         int ret;
 920
 921         ret = acpi_ec_get_real_ecdt();
 922         /* Try to make a fake ECDT */
 923         if (ret && acpi_fake_ecdt_enabled) {
 924                 ret = acpi_ec_fake_ecdt();
 925         }
 926
 927         if (ret)
 928                 return 0;
 929
 930         /*
 931          * Install GPE handler
 932          */
 933         status = acpi_install_gpe_handler(NULL, ec_ecdt->gpe,
 934                                           ACPI_GPE_EDGE_TRIGGERED,
 935                                           &acpi_ec_gpe_handler, ec_ecdt);
 936         if (ACPI_FAILURE(status)) {
 937                 goto error;
 938         }
 939         acpi_set_gpe_type(NULL, ec_ecdt->gpe, ACPI_GPE_TYPE_RUNTIME);
 940         acpi_enable_gpe(NULL, ec_ecdt->gpe, ACPI_NOT_ISR);
 941
 942         status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
 943                                                     ACPI_ADR_SPACE_EC,
 944                                                     &acpi_ec_space_handler,
 945                                                     &acpi_ec_space_setup,
 946                                                     ec_ecdt);
 947         if (ACPI_FAILURE(status)) {
 948                 acpi_remove_gpe_handler(NULL, ec_ecdt->gpe,
 949                                         &acpi_ec_gpe_handler);
 950                 goto error;
 951         }
 952
 953         return 0;
 954
 955       error:
 956         ACPI_EXCEPTION((AE_INFO, status, "Could not use ECDT"));
 957         kfree(ec_ecdt);
 958         ec_ecdt = NULL;
 959
 960         return -ENODEV;
 961 }
 962
 963 static int __init acpi_ec_init(void)
 964 {
 965         int result = 0;
 966
 967         if (acpi_disabled)
 968                 return 0;
 969
 970         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
 971         if (!acpi_ec_dir)
 972                 return -ENODEV;
 973
 974         /* Now register the driver for the EC */
 975         result = acpi_bus_register_driver(&acpi_ec_driver);
 976         if (result < 0) {
 977                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 978                 return -ENODEV;
 979         }
 980
 981         return result;
 982 }
 983
 984 subsys_initcall(acpi_ec_init);
 985
 986 /* EC driver currently not unloadable */
 987 #if 0
 988 static void __exit acpi_ec_exit(void)
 989 {
 990
 991         acpi_bus_unregister_driver(&acpi_ec_driver);
 992
 993         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 994
 995         return;
 996 }
 997 #endif                          /* 0 */
 998
 999 static int __init acpi_fake_ecdt_setup(char *str)
1000 {
1001         acpi_fake_ecdt_enabled = 1;
1002         return 1;
1003 }
1004
1005 __setup("acpi_fake_ecdt", acpi_fake_ecdt_setup);
1006 static int __init acpi_ec_set_intr_mode(char *str)
1007 {
1008         int intr;
1009
1010         if (!get_option(&str, &intr))
1011                 return 0;
1012
1013         if (intr) {
1014                 acpi_ec_mode = EC_INTR;
1015         } else {
1016                 acpi_ec_mode = EC_POLL;
1017         }
1018         acpi_ec_driver.ops.add = acpi_ec_add;
1019         printk(KERN_NOTICE PREFIX "%s mode.\n",
1020                           intr ? "interrupt" : "polling");
1021
1022         return 1;
1023 }
1024
1025 __setup("ec_intr=", acpi_ec_set_intr_mode);