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 semaphore sem;
 107         atomic_t leaving_burst; /* 0 : No, 1 : Yes, 2: abort */
 108         wait_queue_head_t wait;
 109 } *ec_ecdt;
 110
 111 /* External interfaces use first EC only, so remember */
 112 static struct acpi_device *first_ec;
 113 static int acpi_ec_mode = EC_INTR;
 114
 115 /* --------------------------------------------------------------------------
 116                              Transaction Management
 117    -------------------------------------------------------------------------- */
 118
 119 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 120 {
 121         return inb(ec->command_addr);
 122 }
 123
 124 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 125 {
 126         return inb(ec->data_addr);
 127 }
 128
 129 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 130 {
 131         outb(command, ec->command_addr);
 132 }
 133
 134 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 135 {
 136         outb(data, ec->data_addr);
 137 }
 138
 139 static int acpi_ec_check_status(struct acpi_ec *ec, u8 event)
 140 {
 141         u8 status = acpi_ec_read_status(ec);
 142         switch (event) {
 143         case ACPI_EC_EVENT_OBF_1:
 144                 if (status & ACPI_EC_FLAG_OBF)
 145                         return 1;
 146                 break;
 147         case ACPI_EC_EVENT_IBF_0:
 148                 if (!(status & ACPI_EC_FLAG_IBF))
 149                         return 1;
 150                 break;
 151         default:
 152                 break;
 153         }
 154
 155         return 0;
 156 }
 157
 158 static int acpi_ec_wait(struct acpi_ec *ec, u8 event)
 159 {
 160         if (acpi_ec_mode == EC_POLL) {
 161                 int i;
 162                 for (i = 0; i < ACPI_EC_UDELAY_COUNT; ++i) {
 163                         if (acpi_ec_check_status(ec, event))
 164                                 return 0;
 165                         udelay(ACPI_EC_UDELAY);
 166                 }
 167         } else {
 168                 if (wait_event_timeout(ec->wait,
 169                                        acpi_ec_check_status(ec, event),
 170                                        msecs_to_jiffies(ACPI_EC_DELAY)) ||
 171                     acpi_ec_check_status(ec, event)) {
 172                         return 0;
 173                 } else {
 174                         printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
 175                                " status = %d, expect_event = %d\n",
 176                              acpi_ec_read_status(ec), event);
 177                 }
 178         }
 179
 180         return -ETIME;
 181 }
 182
 183 #ifdef ACPI_FUTURE_USAGE
 184 /*
 185  * Note: samsung nv5000 doesn't work with ec burst mode.
 186  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 187  */
 188 int acpi_ec_enter_burst_mode(struct acpi_ec *ec)
 189 {
 190         u8 tmp = 0;
 191         u8 status = 0;
 192
 193
 194         status = acpi_ec_read_status(ec);
 195         if (status != -EINVAL && !(status & ACPI_EC_FLAG_BURST)) {
 196                 status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 197                 if (status)
 198                         goto end;
 199                 acpi_ec_write_cmd(ec, ACPI_EC_BURST_ENABLE);
 200                 status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1);
 201                 tmp = acpi_ec_read_data(ec);
 202                 if (tmp != 0x90) {      /* Burst ACK byte */
 203                         return -EINVAL;
 204                 }
 205         }
 206
 207         atomic_set(&ec->leaving_burst, 0);
 208         return 0;
 209   end:
 210         ACPI_EXCEPTION((AE_INFO, status, "EC wait, burst mode"));
 211         return -1;
 212 }
 213
 214 int acpi_ec_leave_burst_mode(struct acpi_ec *ec)
 215 {
 216         u8 status = 0;
 217
 218
 219         status = acpi_ec_read_status(ec);
 220         if (status != -EINVAL && (status & ACPI_EC_FLAG_BURST)){
 221                 status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 222                 if(status)
 223                         goto end;
 224                 acpi_ec_write_cmd(ec, ACPI_EC_BURST_DISABLE);
 225                 acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 226         }
 227         atomic_set(&ec->leaving_burst, 1);
 228         return 0;
 229   end:
 230         ACPI_EXCEPTION((AE_INFO, status, "EC leave burst mode"));
 231         return -1;
 232 }
 233 #endif /* ACPI_FUTURE_USAGE */
 234
 235 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
 236                                         const u8 *wdata, unsigned wdata_len,
 237                                         u8 *rdata, unsigned rdata_len)
 238 {
 239         int result = 0;
 240
 241         acpi_ec_write_cmd(ec, command);
 242
 243         for (; wdata_len > 0; wdata_len --) {
 244                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 245                 if (result) {
 246                         printk(KERN_ERR PREFIX "write_cmd timeout, command = %d\n",
 247                              command);
 248                         goto end;
 249                 }
 250                 acpi_ec_write_data(ec, *(wdata++));
 251         }
 252
 253         if (!rdata_len) {
 254                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 255                 if (result) {
 256                         printk(KERN_ERR PREFIX "finish-write timeout, command = %d\n",
 257                              command);
 258                         goto end;
 259                 }
 260         }
 261
 262         for (; rdata_len > 0; rdata_len --) {
 263                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1);
 264                 if (result) {
 265                         printk(KERN_ERR PREFIX "read timeout, command = %d\n",
 266                              command);
 267                         goto end;
 268                 }
 269
 270                 *(rdata++) = acpi_ec_read_data(ec);
 271         }
 272       end:
 273         return result;
 274 }
 275
 276 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
 277                                 const u8 *wdata, unsigned wdata_len,
 278                                 u8 *rdata, unsigned rdata_len)
 279 {
 280         int status;
 281         u32 glk;
 282
 283         if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
 284                 return -EINVAL;
 285
 286         if (rdata)
 287                 memset(rdata, 0, rdata_len);
 288
 289         if (ec->global_lock) {
 290                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 291                 if (ACPI_FAILURE(status))
 292                         return -ENODEV;
 293         }
 294         down(&ec->sem);
 295
 296         /* Make sure GPE is enabled before doing transaction */
 297         acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
 298
 299         status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 300         if (status) {
 301                 printk(KERN_DEBUG PREFIX "read EC, IB not empty\n");
 302                 goto end;
 303         }
 304
 305         status = acpi_ec_transaction_unlocked(ec, command,
 306                                               wdata, wdata_len,
 307                                               rdata, rdata_len);
 308
 309 end:
 310         up(&ec->sem);
 311
 312         if (ec->global_lock)
 313                 acpi_release_global_lock(glk);
 314
 315         return status;
 316 }
 317
 318 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 319 {
 320         int result;
 321         u8 d;
 322
 323         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
 324                                      &address, 1, &d, 1);
 325         *data = d;
 326         return result;
 327 }
 328
 329 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 330 {
 331         u8 wdata[2] = { address, data };
 332         return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
 333                                    wdata, 2, NULL, 0);
 334 }
 335
 336 /*
 337  * Externally callable EC access functions. For now, assume 1 EC only
 338  */
 339 int ec_read(u8 addr, u8 *val)
 340 {
 341         struct acpi_ec *ec;
 342         int err;
 343         u8 temp_data;
 344
 345         if (!first_ec)
 346                 return -ENODEV;
 347
 348         ec = acpi_driver_data(first_ec);
 349
 350         err = acpi_ec_read(ec, addr, &temp_data);
 351
 352         if (!err) {
 353                 *val = temp_data;
 354                 return 0;
 355         } else
 356                 return err;
 357 }
 358
 359 EXPORT_SYMBOL(ec_read);
 360
 361 int ec_write(u8 addr, u8 val)
 362 {
 363         struct acpi_ec *ec;
 364         int err;
 365
 366         if (!first_ec)
 367                 return -ENODEV;
 368
 369         ec = acpi_driver_data(first_ec);
 370
 371         err = acpi_ec_write(ec, addr, val);
 372
 373         return err;
 374 }
 375
 376 EXPORT_SYMBOL(ec_write);
 377
 378 extern int ec_transaction(u8 command,
 379                           const u8 *wdata, unsigned wdata_len,
 380                           u8 *rdata, unsigned rdata_len)
 381 {
 382         struct acpi_ec *ec;
 383
 384         if (!first_ec)
 385                 return -ENODEV;
 386
 387         ec = acpi_driver_data(first_ec);
 388
 389         return acpi_ec_transaction(ec, command, wdata,
 390                                    wdata_len, rdata, rdata_len);
 391 }
 392
 393 EXPORT_SYMBOL(ec_transaction);
 394
 395 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
 396 {
 397         int result;
 398         u8 d;
 399
 400         if (!ec || !data)
 401                 return -EINVAL;
 402
 403         /*
 404          * Query the EC to find out which _Qxx method we need to evaluate.
 405          * Note that successful completion of the query causes the ACPI_EC_SCI
 406          * bit to be cleared (and thus clearing the interrupt source).
 407          */
 408
 409         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1);
 410         if (result)
 411                 return result;
 412
 413         if (!d)
 414                 return -ENODATA;
 415
 416         *data = d;
 417         return 0;
 418 }
 419
 420 /* --------------------------------------------------------------------------
 421                                 Event Management
 422    -------------------------------------------------------------------------- */
 423
 424 static void acpi_ec_gpe_query(void *ec_cxt)
 425 {
 426         struct acpi_ec *ec = (struct acpi_ec *)ec_cxt;
 427         u8 value = 0;
 428         static char object_name[8];
 429
 430         if (!ec)
 431                 return;
 432
 433         value = acpi_ec_read_status(ec);
 434
 435         if (!(value & ACPI_EC_FLAG_SCI))
 436                 return;
 437
 438         if (acpi_ec_query(ec, &value))
 439                 return;
 440
 441         snprintf(object_name, 8, "_Q%2.2X", value);
 442
 443         printk(KERN_INFO PREFIX "evaluating %s\n", object_name);
 444
 445         acpi_evaluate_object(ec->handle, object_name, NULL, NULL);
 446 }
 447
 448 static u32 acpi_ec_gpe_handler(void *data)
 449 {
 450         acpi_status status = AE_OK;
 451         u8 value;
 452         struct acpi_ec *ec = (struct acpi_ec *)data;
 453
 454
 455         if (acpi_ec_mode == EC_INTR) {
 456                 wake_up(&ec->wait);
 457         }
 458
 459         value = acpi_ec_read_status(ec);
 460         if (value & ACPI_EC_FLAG_SCI) {
 461                 status = acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query, ec);
 462         }
 463
 464         return status == AE_OK ?
 465             ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 466 }
 467
 468 /* --------------------------------------------------------------------------
 469                              Address Space Management
 470    -------------------------------------------------------------------------- */
 471
 472 static acpi_status
 473 acpi_ec_space_setup(acpi_handle region_handle,
 474                     u32 function, void *handler_context, void **return_context)
 475 {
 476         /*
 477          * The EC object is in the handler context and is needed
 478          * when calling the acpi_ec_space_handler.
 479          */
 480         *return_context = (function != ACPI_REGION_DEACTIVATE) ?
 481             handler_context : NULL;
 482
 483         return AE_OK;
 484 }
 485
 486 static acpi_status
 487 acpi_ec_space_handler(u32 function,
 488                       acpi_physical_address address,
 489                       u32 bit_width,
 490                       acpi_integer * value,
 491                       void *handler_context, void *region_context)
 492 {
 493         int result = 0;
 494         struct acpi_ec *ec = NULL;
 495         u64 temp = *value;
 496         acpi_integer f_v = 0;
 497         int i = 0;
 498
 499
 500         if ((address > 0xFF) || !value || !handler_context)
 501                 return AE_BAD_PARAMETER;
 502
 503         if (bit_width != 8 && acpi_strict) {
 504                 return AE_BAD_PARAMETER;
 505         }
 506
 507         ec = (struct acpi_ec *)handler_context;
 508
 509       next_byte:
 510         switch (function) {
 511         case ACPI_READ:
 512                 temp = 0;
 513                 result = acpi_ec_read(ec, (u8) address, (u8 *) &temp);
 514                 break;
 515         case ACPI_WRITE:
 516                 result = acpi_ec_write(ec, (u8) address, (u8) temp);
 517                 break;
 518         default:
 519                 result = -EINVAL;
 520                 goto out;
 521                 break;
 522         }
 523
 524         bit_width -= 8;
 525         if (bit_width) {
 526                 if (function == ACPI_READ)
 527                         f_v |= temp << 8 * i;
 528                 if (function == ACPI_WRITE)
 529                         temp >>= 8;
 530                 i++;
 531                 address++;
 532                 goto next_byte;
 533         }
 534
 535         if (function == ACPI_READ) {
 536                 f_v |= temp << 8 * i;
 537                 *value = f_v;
 538         }
 539
 540       out:
 541         switch (result) {
 542         case -EINVAL:
 543                 return AE_BAD_PARAMETER;
 544                 break;
 545         case -ENODEV:
 546                 return AE_NOT_FOUND;
 547                 break;
 548         case -ETIME:
 549                 return AE_TIME;
 550                 break;
 551         default:
 552                 return AE_OK;
 553         }
 554 }
 555
 556 /* --------------------------------------------------------------------------
 557                               FS Interface (/proc)
 558    -------------------------------------------------------------------------- */
 559
 560 static struct proc_dir_entry *acpi_ec_dir;
 561
 562 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 563 {
 564         struct acpi_ec *ec = (struct acpi_ec *)seq->private;
 565
 566
 567         if (!ec)
 568                 goto end;
 569
 570         seq_printf(seq, "gpe bit:                 0x%02x\n",
 571                    (u32) ec->gpe_bit);
 572         seq_printf(seq, "ports:                   0x%02x, 0x%02x\n",
 573                    (u32) ec->command_addr,
 574                    (u32) ec->data_addr);
 575         seq_printf(seq, "use global lock:         %s\n",
 576                    ec->global_lock ? "yes" : "no");
 577         acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
 578
 579       end:
 580         return 0;
 581 }
 582
 583 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 584 {
 585         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 586 }
 587
 588 static struct file_operations acpi_ec_info_ops = {
 589         .open = acpi_ec_info_open_fs,
 590         .read = seq_read,
 591         .llseek = seq_lseek,
 592         .release = single_release,
 593         .owner = THIS_MODULE,
 594 };
 595
 596 static int acpi_ec_add_fs(struct acpi_device *device)
 597 {
 598         struct proc_dir_entry *entry = NULL;
 599
 600
 601         if (!acpi_device_dir(device)) {
 602                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 603                                                      acpi_ec_dir);
 604                 if (!acpi_device_dir(device))
 605                         return -ENODEV;
 606         }
 607
 608         entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
 609                                   acpi_device_dir(device));
 610         if (!entry)
 611                 return -ENODEV;
 612         else {
 613                 entry->proc_fops = &acpi_ec_info_ops;
 614                 entry->data = acpi_driver_data(device);
 615                 entry->owner = THIS_MODULE;
 616         }
 617
 618         return 0;
 619 }
 620
 621 static int acpi_ec_remove_fs(struct acpi_device *device)
 622 {
 623
 624         if (acpi_device_dir(device)) {
 625                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 626                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 627                 acpi_device_dir(device) = NULL;
 628         }
 629
 630         return 0;
 631 }
 632
 633 /* --------------------------------------------------------------------------
 634                                Driver Interface
 635    -------------------------------------------------------------------------- */
 636
 637 static int acpi_ec_add(struct acpi_device *device)
 638 {
 639         int result = 0;
 640         acpi_status status = AE_OK;
 641         struct acpi_ec *ec = NULL;
 642
 643
 644         if (!device)
 645                 return -EINVAL;
 646
 647         ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 648         if (!ec)
 649                 return -ENOMEM;
 650         memset(ec, 0, sizeof(struct acpi_ec));
 651
 652         ec->handle = device->handle;
 653         ec->uid = -1;
 654         init_MUTEX(&ec->sem);
 655         if (acpi_ec_mode == EC_INTR) {
 656                 atomic_set(&ec->leaving_burst, 1);
 657                 init_waitqueue_head(&ec->wait);
 658         }
 659         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 660         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 661         acpi_driver_data(device) = ec;
 662
 663         /* Use the global lock for all EC transactions? */
 664         acpi_evaluate_integer(ec->handle, "_GLK", NULL,
 665                               &ec->global_lock);
 666
 667         /* XXX we don't test uids, because on some boxes ecdt uid = 0, see:
 668            http://bugzilla.kernel.org/show_bug.cgi?id=6111 */
 669         if (ec_ecdt) {
 670                 acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
 671                                                   ACPI_ADR_SPACE_EC,
 672                                                   &acpi_ec_space_handler);
 673
 674                 acpi_remove_gpe_handler(NULL, ec_ecdt->gpe_bit,
 675                                         &acpi_ec_gpe_handler);
 676
 677                 kfree(ec_ecdt);
 678         }
 679
 680         /* Get GPE bit assignment (EC events). */
 681         /* TODO: Add support for _GPE returning a package */
 682         status =
 683             acpi_evaluate_integer(ec->handle, "_GPE", NULL,
 684                                   &ec->gpe_bit);
 685         if (ACPI_FAILURE(status)) {
 686                 ACPI_EXCEPTION((AE_INFO, status, "Obtaining GPE bit assignment"));
 687                 result = -ENODEV;
 688                 goto end;
 689         }
 690
 691         result = acpi_ec_add_fs(device);
 692         if (result)
 693                 goto end;
 694
 695         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s [%s] (gpe %d) interrupt mode.",
 696                acpi_device_name(device), acpi_device_bid(device),
 697                (u32) ec->gpe_bit));
 698
 699         if (!first_ec)
 700                 first_ec = device;
 701
 702   end:
 703         if (result)
 704                 kfree(ec);
 705
 706         return result;
 707 }
 708
 709 static int acpi_ec_remove(struct acpi_device *device, int type)
 710 {
 711         struct acpi_ec *ec = NULL;
 712
 713
 714         if (!device)
 715                 return -EINVAL;
 716
 717         ec = acpi_driver_data(device);
 718
 719         acpi_ec_remove_fs(device);
 720
 721         kfree(ec);
 722
 723         return 0;
 724 }
 725
 726 static acpi_status
 727 acpi_ec_io_ports(struct acpi_resource *resource, void *context)
 728 {
 729         struct acpi_ec *ec = (struct acpi_ec *)context;
 730
 731         if (resource->type != ACPI_RESOURCE_TYPE_IO) {
 732                 return AE_OK;
 733         }
 734
 735         /*
 736          * The first address region returned is the data port, and
 737          * the second address region returned is the status/command
 738          * port.
 739          */
 740         if (ec->data_addr == 0) {
 741                 ec->data_addr = resource->data.io.minimum;
 742         } else if (ec->command_addr == 0) {
 743                 ec->command_addr = resource->data.io.minimum;
 744         } else {
 745                 return AE_CTRL_TERMINATE;
 746         }
 747
 748         return AE_OK;
 749 }
 750
 751 static int acpi_ec_start(struct acpi_device *device)
 752 {
 753         acpi_status status = AE_OK;
 754         struct acpi_ec *ec = NULL;
 755
 756
 757         if (!device)
 758                 return -EINVAL;
 759
 760         ec = acpi_driver_data(device);
 761
 762         if (!ec)
 763                 return -EINVAL;
 764
 765         /*
 766          * Get I/O port addresses. Convert to GAS format.
 767          */
 768         status = acpi_walk_resources(ec->handle, METHOD_NAME__CRS,
 769                                      acpi_ec_io_ports, ec);
 770         if (ACPI_FAILURE(status) || ec->command_addr == 0) {
 771                 ACPI_EXCEPTION((AE_INFO, status,
 772                                 "Error getting I/O port addresses"));
 773                 return -ENODEV;
 774         }
 775
 776         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "gpe=0x%02lx, ports=0x%2lx,0x%2lx",
 777                           ec->gpe_bit, ec->command_addr, ec->data_addr));
 778
 779         /*
 780          * Install GPE handler
 781          */
 782         status = acpi_install_gpe_handler(NULL, ec->gpe_bit,
 783                                           ACPI_GPE_EDGE_TRIGGERED,
 784                                           &acpi_ec_gpe_handler, ec);
 785         if (ACPI_FAILURE(status)) {
 786                 return -ENODEV;
 787         }
 788         acpi_set_gpe_type(NULL, ec->gpe_bit, ACPI_GPE_TYPE_RUNTIME);
 789         acpi_enable_gpe(NULL, ec->gpe_bit, ACPI_NOT_ISR);
 790
 791         status = acpi_install_address_space_handler(ec->handle,
 792                                                     ACPI_ADR_SPACE_EC,
 793                                                     &acpi_ec_space_handler,
 794                                                     &acpi_ec_space_setup, ec);
 795         if (ACPI_FAILURE(status)) {
 796                 acpi_remove_gpe_handler(NULL, ec->gpe_bit,
 797                                         &acpi_ec_gpe_handler);
 798                 return -ENODEV;
 799         }
 800
 801         return AE_OK;
 802 }
 803
 804 static int acpi_ec_stop(struct acpi_device *device, int type)
 805 {
 806         acpi_status status = AE_OK;
 807         struct acpi_ec *ec = NULL;
 808
 809
 810         if (!device)
 811                 return -EINVAL;
 812
 813         ec = acpi_driver_data(device);
 814
 815         status = acpi_remove_address_space_handler(ec->handle,
 816                                                    ACPI_ADR_SPACE_EC,
 817                                                    &acpi_ec_space_handler);
 818         if (ACPI_FAILURE(status))
 819                 return -ENODEV;
 820
 821         status =
 822             acpi_remove_gpe_handler(NULL, ec->gpe_bit,
 823                                     &acpi_ec_gpe_handler);
 824         if (ACPI_FAILURE(status))
 825                 return -ENODEV;
 826
 827         return 0;
 828 }
 829
 830 static acpi_status __init
 831 acpi_fake_ecdt_callback(acpi_handle handle,
 832                         u32 Level, void *context, void **retval)
 833 {
 834         acpi_status status;
 835
 836         init_MUTEX(&ec_ecdt->sem);
 837         if (acpi_ec_mode == EC_INTR) {
 838                 init_waitqueue_head(&ec_ecdt->wait);
 839         }
 840         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 841                                      acpi_ec_io_ports, ec_ecdt);
 842         if (ACPI_FAILURE(status))
 843                 return status;
 844
 845         ec_ecdt->uid = -1;
 846         acpi_evaluate_integer(handle, "_UID", NULL, &ec_ecdt->uid);
 847
 848         status =
 849             acpi_evaluate_integer(handle, "_GPE", NULL,
 850                                   &ec_ecdt->gpe_bit);
 851         if (ACPI_FAILURE(status))
 852                 return status;
 853         ec_ecdt->global_lock = TRUE;
 854         ec_ecdt->handle = handle;
 855
 856         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "GPE=0x%02lx, ports=0x%2lx, 0x%2lx",
 857                ec_ecdt->gpe_bit, ec_ecdt->command_addr, ec_ecdt->data_addr));
 858
 859         return AE_CTRL_TERMINATE;
 860 }
 861
 862 /*
 863  * Some BIOS (such as some from Gateway laptops) access EC region very early
 864  * such as in BAT0._INI or EC._INI before an EC device is found and
 865  * do not provide an ECDT. According to ACPI spec, ECDT isn't mandatorily
 866  * required, but if EC regison is accessed early, it is required.
 867  * The routine tries to workaround the BIOS bug by pre-scan EC device
 868  * It assumes that _CRS, _HID, _GPE, _UID methods of EC don't touch any
 869  * op region (since _REG isn't invoked yet). The assumption is true for
 870  * all systems found.
 871  */
 872 static int __init acpi_ec_fake_ecdt(void)
 873 {
 874         acpi_status status;
 875         int ret = 0;
 876
 877         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Try to make an fake ECDT"));
 878
 879         ec_ecdt = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 880         if (!ec_ecdt) {
 881                 ret = -ENOMEM;
 882                 goto error;
 883         }
 884         memset(ec_ecdt, 0, sizeof(struct acpi_ec));
 885
 886         status = acpi_get_devices(ACPI_EC_HID,
 887                                   acpi_fake_ecdt_callback, NULL, NULL);
 888         if (ACPI_FAILURE(status)) {
 889                 kfree(ec_ecdt);
 890                 ec_ecdt = NULL;
 891                 ret = -ENODEV;
 892                 ACPI_EXCEPTION((AE_INFO, status, "Can't make an fake ECDT"));
 893                 goto error;
 894         }
 895         return 0;
 896   error:
 897         return ret;
 898 }
 899
 900 static int __init acpi_ec_get_real_ecdt(void)
 901 {
 902         acpi_status status;
 903         struct acpi_table_ecdt *ecdt_ptr;
 904
 905         status = acpi_get_firmware_table("ECDT", 1, ACPI_LOGICAL_ADDRESSING,
 906                                          (struct acpi_table_header **)
 907                                          &ecdt_ptr);
 908         if (ACPI_FAILURE(status))
 909                 return -ENODEV;
 910
 911         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found ECDT"));
 912
 913         /*
 914          * Generate a temporary ec context to use until the namespace is scanned
 915          */
 916         ec_ecdt = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 917         if (!ec_ecdt)
 918                 return -ENOMEM;
 919         memset(ec_ecdt, 0, sizeof(struct acpi_ec));
 920
 921         init_MUTEX(&ec_ecdt->sem);
 922         if (acpi_ec_mode == EC_INTR) {
 923                 init_waitqueue_head(&ec_ecdt->wait);
 924         }
 925         ec_ecdt->command_addr = ecdt_ptr->ec_control.address;
 926         ec_ecdt->data_addr = ecdt_ptr->ec_data.address;
 927         ec_ecdt->gpe_bit = ecdt_ptr->gpe_bit;
 928         /* use the GL just to be safe */
 929         ec_ecdt->global_lock = TRUE;
 930         ec_ecdt->uid = ecdt_ptr->uid;
 931
 932         status =
 933             acpi_get_handle(NULL, ecdt_ptr->ec_id, &ec_ecdt->handle);
 934         if (ACPI_FAILURE(status)) {
 935                 goto error;
 936         }
 937
 938         return 0;
 939   error:
 940         ACPI_EXCEPTION((AE_INFO, status, "Could not use ECDT"));
 941         kfree(ec_ecdt);
 942         ec_ecdt = NULL;
 943
 944         return -ENODEV;
 945 }
 946
 947 static int __initdata acpi_fake_ecdt_enabled;
 948 int __init acpi_ec_ecdt_probe(void)
 949 {
 950         acpi_status status;
 951         int ret;
 952
 953         ret = acpi_ec_get_real_ecdt();
 954         /* Try to make a fake ECDT */
 955         if (ret && acpi_fake_ecdt_enabled) {
 956                 ret = acpi_ec_fake_ecdt();
 957         }
 958
 959         if (ret)
 960                 return 0;
 961
 962         /*
 963          * Install GPE handler
 964          */
 965         status = acpi_install_gpe_handler(NULL, ec_ecdt->gpe_bit,
 966                                           ACPI_GPE_EDGE_TRIGGERED,
 967                                           &acpi_ec_gpe_handler, ec_ecdt);
 968         if (ACPI_FAILURE(status)) {
 969                 goto error;
 970         }
 971         acpi_set_gpe_type(NULL, ec_ecdt->gpe_bit, ACPI_GPE_TYPE_RUNTIME);
 972         acpi_enable_gpe(NULL, ec_ecdt->gpe_bit, ACPI_NOT_ISR);
 973
 974         status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
 975                                                     ACPI_ADR_SPACE_EC,
 976                                                     &acpi_ec_space_handler,
 977                                                     &acpi_ec_space_setup,
 978                                                     ec_ecdt);
 979         if (ACPI_FAILURE(status)) {
 980                 acpi_remove_gpe_handler(NULL, ec_ecdt->gpe_bit,
 981                                         &acpi_ec_gpe_handler);
 982                 goto error;
 983         }
 984
 985         return 0;
 986
 987       error:
 988         ACPI_EXCEPTION((AE_INFO, status, "Could not use ECDT"));
 989         kfree(ec_ecdt);
 990         ec_ecdt = NULL;
 991
 992         return -ENODEV;
 993 }
 994
 995 static int __init acpi_ec_init(void)
 996 {
 997         int result = 0;
 998
 999
1000         if (acpi_disabled)
1001                 return 0;
1002
1003         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1004         if (!acpi_ec_dir)
1005                 return -ENODEV;
1006
1007         /* Now register the driver for the EC */
1008         result = acpi_bus_register_driver(&acpi_ec_driver);
1009         if (result < 0) {
1010                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1011                 return -ENODEV;
1012         }
1013
1014         return result;
1015 }
1016
1017 subsys_initcall(acpi_ec_init);
1018
1019 /* EC driver currently not unloadable */
1020 #if 0
1021 static void __exit acpi_ec_exit(void)
1022 {
1023
1024         acpi_bus_unregister_driver(&acpi_ec_driver);
1025
1026         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1027
1028         return;
1029 }
1030 #endif                          /* 0 */
1031
1032 static int __init acpi_fake_ecdt_setup(char *str)
1033 {
1034         acpi_fake_ecdt_enabled = 1;
1035         return 1;
1036 }
1037
1038 __setup("acpi_fake_ecdt", acpi_fake_ecdt_setup);
1039 static int __init acpi_ec_set_intr_mode(char *str)
1040 {
1041         int intr;
1042
1043         if (!get_option(&str, &intr))
1044                 return 0;
1045
1046         if (intr) {
1047                 acpi_ec_mode = EC_INTR;
1048         } else {
1049                 acpi_ec_mode = EC_POLL;
1050         }
1051         acpi_ec_driver.ops.add = acpi_ec_add;
1052         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "EC %s mode.\n", intr ? "interrupt" : "polling"));
1053
1054         return 1;
1055 }
1056
1057 __setup("ec_intr=", acpi_ec_set_intr_mode);