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