drivers/acpi/ec.c

   1 /*
   2  *  ec.c - ACPI Embedded Controller Driver (v2.0)
   3  *
   4  *  Copyright (C) 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
   5  *  Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
   6  *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
   7  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   8  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   9  *
  10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or (at
  15  *  your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful, but
  18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  *  General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License along
  23  *  with this program; if not, write to the Free Software Foundation, Inc.,
  24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  25  *
  26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  27  */
  28
  29 #include <linux/kernel.h>
  30 #include <linux/module.h>
  31 #include <linux/init.h>
  32 #include <linux/types.h>
  33 #include <linux/delay.h>
  34 #include <linux/proc_fs.h>
  35 #include <linux/seq_file.h>
  36 #include <linux/interrupt.h>
  37 #include <asm/io.h>
  38 #include <acpi/acpi_bus.h>
  39 #include <acpi/acpi_drivers.h>
  40 #include <acpi/actypes.h>
  41
  42 #define ACPI_EC_CLASS                   "embedded_controller"
  43 #define ACPI_EC_HID                     "PNP0C09"
  44 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  45 #define ACPI_EC_FILE_INFO               "info"
  46 #undef PREFIX
  47 #define PREFIX                          "ACPI: EC: "
  48
  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
  55 /* EC commands */
  56 enum ec_command {
  57         ACPI_EC_COMMAND_READ = 0x80,
  58         ACPI_EC_COMMAND_WRITE = 0x81,
  59         ACPI_EC_BURST_ENABLE = 0x82,
  60         ACPI_EC_BURST_DISABLE = 0x83,
  61         ACPI_EC_COMMAND_QUERY = 0x84,
  62 };
  63 /* EC events */
  64 enum ec_event {
  65         ACPI_EC_EVENT_OBF_1 = 1,        /* Output buffer full */
  66         ACPI_EC_EVENT_IBF_0,    /* Input buffer empty */
  67 };
  68
  69 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  70 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  71
  72 static enum ec_mode {
  73         EC_INTR = 1,            /* Output buffer full */
  74         EC_POLL,                /* Input buffer empty */
  75 } acpi_ec_mode = EC_INTR;
  76
  77 static int acpi_ec_remove(struct acpi_device *device, int type);
  78 static int acpi_ec_start(struct acpi_device *device);
  79 static int acpi_ec_stop(struct acpi_device *device, int type);
  80 static int acpi_ec_add(struct acpi_device *device);
  81
  82 static struct acpi_driver acpi_ec_driver = {
  83         .name = "ec",
  84         .class = ACPI_EC_CLASS,
  85         .ids = ACPI_EC_HID,
  86         .ops = {
  87                 .add = acpi_ec_add,
  88                 .remove = acpi_ec_remove,
  89                 .start = acpi_ec_start,
  90                 .stop = acpi_ec_stop,
  91                 },
  92 };
  93
  94 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  95 /* External interfaces use first EC only, so remember */
  96 static struct acpi_ec {
  97         acpi_handle handle;
  98         unsigned long gpe;
  99         unsigned long command_addr;
 100         unsigned long data_addr;
 101         unsigned long global_lock;
 102         struct mutex lock;
 103         atomic_t query_pending;
 104         atomic_t event_count;
 105         wait_queue_head_t wait;
 106 } *boot_ec, *first_ec;
 107
 108 /* --------------------------------------------------------------------------
 109                              Transaction Management
 110    -------------------------------------------------------------------------- */
 111
 112 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 113 {
 114         return inb(ec->command_addr);
 115 }
 116
 117 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 118 {
 119         return inb(ec->data_addr);
 120 }
 121
 122 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 123 {
 124         outb(command, ec->command_addr);
 125 }
 126
 127 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 128 {
 129         outb(data, ec->data_addr);
 130 }
 131
 132 static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event,
 133                                        unsigned old_count)
 134 {
 135         u8 status = acpi_ec_read_status(ec);
 136         if (old_count == atomic_read(&ec->event_count))
 137                 return 0;
 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                         unsigned count, int force_poll)
 151 {
 152         if (unlikely(force_poll) || acpi_ec_mode == EC_POLL) {
 153                 unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 154                 while (time_before(jiffies, delay)) {
 155                         if (acpi_ec_check_status(ec, event, 0))
 156                                 return 0;
 157                 }
 158         } else {
 159                 if (wait_event_timeout(ec->wait,
 160                                        acpi_ec_check_status(ec, event, count),
 161                                        msecs_to_jiffies(ACPI_EC_DELAY)) ||
 162                     acpi_ec_check_status(ec, event, 0)) {
 163                         return 0;
 164                 } else {
 165                         printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
 166                                " status = %d, expect_event = %d\n",
 167                                acpi_ec_read_status(ec), event);
 168                 }
 169         }
 170
 171         return -ETIME;
 172 }
 173
 174 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
 175                                         const u8 * wdata, unsigned wdata_len,
 176                                         u8 * rdata, unsigned rdata_len,
 177                                         int force_poll)
 178 {
 179         int result = 0;
 180         unsigned count = atomic_read(&ec->event_count);
 181         acpi_ec_write_cmd(ec, command);
 182
 183         for (; wdata_len > 0; --wdata_len) {
 184                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count, force_poll);
 185                 if (result) {
 186                         printk(KERN_ERR PREFIX
 187                                "write_cmd timeout, command = %d\n", command);
 188                         goto end;
 189                 }
 190                 count = atomic_read(&ec->event_count);
 191                 acpi_ec_write_data(ec, *(wdata++));
 192         }
 193
 194         if (!rdata_len) {
 195                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count, force_poll);
 196                 if (result) {
 197                         printk(KERN_ERR PREFIX
 198                                "finish-write timeout, command = %d\n", command);
 199                         goto end;
 200                 }
 201         } else if (command == ACPI_EC_COMMAND_QUERY) {
 202                 atomic_set(&ec->query_pending, 0);
 203         }
 204
 205         for (; rdata_len > 0; --rdata_len) {
 206                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, count, force_poll);
 207                 if (result) {
 208                         printk(KERN_ERR PREFIX "read timeout, command = %d\n",
 209                                command);
 210                         goto end;
 211                 }
 212                 count = atomic_read(&ec->event_count);
 213                 *(rdata++) = acpi_ec_read_data(ec);
 214         }
 215       end:
 216         return result;
 217 }
 218
 219 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
 220                                const u8 * wdata, unsigned wdata_len,
 221                                u8 * rdata, unsigned rdata_len,
 222                                int force_poll)
 223 {
 224         int status;
 225         u32 glk;
 226
 227         if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
 228                 return -EINVAL;
 229
 230         if (rdata)
 231                 memset(rdata, 0, rdata_len);
 232
 233         mutex_lock(&ec->lock);
 234         if (ec->global_lock) {
 235                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 236                 if (ACPI_FAILURE(status)) {
 237                         mutex_unlock(&ec->lock);
 238                         return -ENODEV;
 239                 }
 240         }
 241
 242         /* Make sure GPE is enabled before doing transaction */
 243         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 244
 245         status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0, 0);
 246         if (status) {
 247                 printk(KERN_ERR PREFIX
 248                        "input buffer is not empty, aborting transaction\n");
 249                 goto end;
 250         }
 251
 252         status = acpi_ec_transaction_unlocked(ec, command,
 253                                               wdata, wdata_len,
 254                                               rdata, rdata_len,
 255                                               force_poll);
 256
 257       end:
 258
 259         if (ec->global_lock)
 260                 acpi_release_global_lock(glk);
 261         mutex_unlock(&ec->lock);
 262
 263         return status;
 264 }
 265
 266 /*
 267  * Note: samsung nv5000 doesn't work with ec burst mode.
 268  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 269  */
 270 int acpi_ec_burst_enable(struct acpi_ec *ec)
 271 {
 272         u8 d;
 273         return acpi_ec_transaction(ec, ACPI_EC_BURST_ENABLE, NULL, 0, &d, 1, 0);
 274 }
 275
 276 int acpi_ec_burst_disable(struct acpi_ec *ec)
 277 {
 278         return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0, 0);
 279 }
 280
 281 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 282 {
 283         int result;
 284         u8 d;
 285
 286         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
 287                                      &address, 1, &d, 1, 0);
 288         *data = d;
 289         return result;
 290 }
 291
 292 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 293 {
 294         u8 wdata[2] = { address, data };
 295         return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
 296                                    wdata, 2, NULL, 0, 0);
 297 }
 298
 299 /*
 300  * Externally callable EC access functions. For now, assume 1 EC only
 301  */
 302 int ec_burst_enable(void)
 303 {
 304         if (!first_ec)
 305                 return -ENODEV;
 306         return acpi_ec_burst_enable(first_ec);
 307 }
 308
 309 EXPORT_SYMBOL(ec_burst_enable);
 310
 311 int ec_burst_disable(void)
 312 {
 313         if (!first_ec)
 314                 return -ENODEV;
 315         return acpi_ec_burst_disable(first_ec);
 316 }
 317
 318 EXPORT_SYMBOL(ec_burst_disable);
 319
 320 int ec_read(u8 addr, u8 * val)
 321 {
 322         int err;
 323         u8 temp_data;
 324
 325         if (!first_ec)
 326                 return -ENODEV;
 327
 328         err = acpi_ec_read(first_ec, addr, &temp_data);
 329
 330         if (!err) {
 331                 *val = temp_data;
 332                 return 0;
 333         } else
 334                 return err;
 335 }
 336
 337 EXPORT_SYMBOL(ec_read);
 338
 339 int ec_write(u8 addr, u8 val)
 340 {
 341         int err;
 342
 343         if (!first_ec)
 344                 return -ENODEV;
 345
 346         err = acpi_ec_write(first_ec, addr, val);
 347
 348         return err;
 349 }
 350
 351 EXPORT_SYMBOL(ec_write);
 352
 353 int ec_transaction(u8 command,
 354                    const u8 * wdata, unsigned wdata_len,
 355                    u8 * rdata, unsigned rdata_len,
 356                    int force_poll)
 357 {
 358         if (!first_ec)
 359                 return -ENODEV;
 360
 361         return acpi_ec_transaction(first_ec, command, wdata,
 362                                    wdata_len, rdata, rdata_len,
 363                                    force_poll);
 364 }
 365
 366 EXPORT_SYMBOL(ec_transaction);
 367
 368 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 369 {
 370         int result;
 371         u8 d;
 372
 373         if (!ec || !data)
 374                 return -EINVAL;
 375
 376         /*
 377          * Query the EC to find out which _Qxx method we need to evaluate.
 378          * Note that successful completion of the query causes the ACPI_EC_SCI
 379          * bit to be cleared (and thus clearing the interrupt source).
 380          */
 381
 382         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
 383         if (result)
 384                 return result;
 385
 386         if (!d)
 387                 return -ENODATA;
 388
 389         *data = d;
 390         return 0;
 391 }
 392
 393 /* --------------------------------------------------------------------------
 394                                 Event Management
 395    -------------------------------------------------------------------------- */
 396
 397 static void acpi_ec_gpe_query(void *ec_cxt)
 398 {
 399         struct acpi_ec *ec = ec_cxt;
 400         u8 value = 0;
 401         char object_name[8];
 402
 403         if (!ec || acpi_ec_query(ec, &value))
 404                 return;
 405
 406         snprintf(object_name, 8, "_Q%2.2X", value);
 407
 408         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluating %s", object_name));
 409
 410         acpi_evaluate_object(ec->handle, object_name, NULL, NULL);
 411 }
 412
 413 static u32 acpi_ec_gpe_handler(void *data)
 414 {
 415         acpi_status status = AE_OK;
 416         u8 value;
 417         struct acpi_ec *ec = data;
 418
 419         atomic_inc(&ec->event_count);
 420
 421         if (acpi_ec_mode == EC_INTR) {
 422                 wake_up(&ec->wait);
 423         }
 424
 425         value = acpi_ec_read_status(ec);
 426         if ((value & ACPI_EC_FLAG_SCI) && !atomic_read(&ec->query_pending)) {
 427                 atomic_set(&ec->query_pending, 1);
 428                 status =
 429                     acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query,
 430                                     ec);
 431         }
 432
 433         return status == AE_OK ?
 434             ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 435 }
 436
 437 /* --------------------------------------------------------------------------
 438                              Address Space Management
 439    -------------------------------------------------------------------------- */
 440
 441 static acpi_status
 442 acpi_ec_space_setup(acpi_handle region_handle,
 443                     u32 function, void *handler_context, void **return_context)
 444 {
 445         /*
 446          * The EC object is in the handler context and is needed
 447          * when calling the acpi_ec_space_handler.
 448          */
 449         *return_context = (function != ACPI_REGION_DEACTIVATE) ?
 450             handler_context : NULL;
 451
 452         return AE_OK;
 453 }
 454
 455 static acpi_status
 456 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 457                       u32 bits, acpi_integer *value,
 458                       void *handler_context, void *region_context)
 459 {
 460         struct acpi_ec *ec = handler_context;
 461         int result = 0, i = 0;
 462         u8 temp = 0;
 463
 464         if ((address > 0xFF) || !value || !handler_context)
 465                 return AE_BAD_PARAMETER;
 466
 467         if (function != ACPI_READ && function != ACPI_WRITE)
 468                 return AE_BAD_PARAMETER;
 469
 470         if (bits != 8 && acpi_strict)
 471                 return AE_BAD_PARAMETER;
 472
 473         while (bits - i > 0) {
 474                 if (function == ACPI_READ) {
 475                         result = acpi_ec_read(ec, address, &temp);
 476                         (*value) |= ((acpi_integer)temp) << i;
 477                 } else {
 478                         temp = 0xff & ((*value) >> i);
 479                         result = acpi_ec_write(ec, address, temp);
 480                 }
 481                 i += 8;
 482                 ++address;
 483         }
 484
 485         switch (result) {
 486         case -EINVAL:
 487                 return AE_BAD_PARAMETER;
 488                 break;
 489         case -ENODEV:
 490                 return AE_NOT_FOUND;
 491                 break;
 492         case -ETIME:
 493                 return AE_TIME;
 494                 break;
 495         default:
 496                 return AE_OK;
 497         }
 498 }
 499
 500 /* --------------------------------------------------------------------------
 501                               FS Interface (/proc)
 502    -------------------------------------------------------------------------- */
 503
 504 static struct proc_dir_entry *acpi_ec_dir;
 505
 506 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 507 {
 508         struct acpi_ec *ec = seq->private;
 509
 510         if (!ec)
 511                 goto end;
 512
 513         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 514         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 515                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 516         seq_printf(seq, "use global lock:\t%s\n",
 517                    ec->global_lock ? "yes" : "no");
 518       end:
 519         return 0;
 520 }
 521
 522 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 523 {
 524         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 525 }
 526
 527 static struct file_operations acpi_ec_info_ops = {
 528         .open = acpi_ec_info_open_fs,
 529         .read = seq_read,
 530         .llseek = seq_lseek,
 531         .release = single_release,
 532         .owner = THIS_MODULE,
 533 };
 534
 535 static int acpi_ec_add_fs(struct acpi_device *device)
 536 {
 537         struct proc_dir_entry *entry = NULL;
 538
 539         if (!acpi_device_dir(device)) {
 540                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 541                                                      acpi_ec_dir);
 542                 if (!acpi_device_dir(device))
 543                         return -ENODEV;
 544         }
 545
 546         entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
 547                                   acpi_device_dir(device));
 548         if (!entry)
 549                 return -ENODEV;
 550         else {
 551                 entry->proc_fops = &acpi_ec_info_ops;
 552                 entry->data = acpi_driver_data(device);
 553                 entry->owner = THIS_MODULE;
 554         }
 555
 556         return 0;
 557 }
 558
 559 static int acpi_ec_remove_fs(struct acpi_device *device)
 560 {
 561
 562         if (acpi_device_dir(device)) {
 563                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 564                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 565                 acpi_device_dir(device) = NULL;
 566         }
 567
 568         return 0;
 569 }
 570
 571 /* --------------------------------------------------------------------------
 572                                Driver Interface
 573    -------------------------------------------------------------------------- */
 574 static acpi_status
 575 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 576
 577 static acpi_status
 578 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval);
 579
 580 static struct acpi_ec *make_acpi_ec(void)
 581 {
 582         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 583         if (!ec)
 584                 return NULL;
 585
 586         atomic_set(&ec->query_pending, 1);
 587         atomic_set(&ec->event_count, 1);
 588         mutex_init(&ec->lock);
 589         init_waitqueue_head(&ec->wait);
 590
 591         return ec;
 592 }
 593
 594 static int acpi_ec_add(struct acpi_device *device)
 595 {
 596         acpi_status status = AE_OK;
 597         struct acpi_ec *ec = NULL;
 598
 599         if (!device)
 600                 return -EINVAL;
 601
 602         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 603         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 604
 605         ec = make_acpi_ec();
 606         if (!ec)
 607                 return -ENOMEM;
 608
 609         status = ec_parse_device(device->handle, 0, ec, NULL);
 610         if (status != AE_CTRL_TERMINATE) {
 611                 kfree(ec);
 612                 return -EINVAL;
 613         }
 614
 615         /* Check if we found the boot EC */
 616         if (boot_ec) {
 617                 if (boot_ec->gpe == ec->gpe) {
 618                         /* We might have incorrect info for GL at boot time */
 619                         mutex_lock(&boot_ec->lock);
 620                         boot_ec->global_lock = ec->global_lock;
 621                         mutex_unlock(&boot_ec->lock);
 622                         kfree(ec);
 623                         ec = boot_ec;
 624                 }
 625         } else
 626                 first_ec = ec;
 627         ec->handle = device->handle;
 628         acpi_driver_data(device) = ec;
 629
 630         acpi_ec_add_fs(device);
 631
 632         return 0;
 633 }
 634
 635 static int acpi_ec_remove(struct acpi_device *device, int type)
 636 {
 637         struct acpi_ec *ec;
 638
 639         if (!device)
 640                 return -EINVAL;
 641
 642         ec = acpi_driver_data(device);
 643         acpi_ec_remove_fs(device);
 644         acpi_driver_data(device) = NULL;
 645         if (ec == first_ec)
 646                 first_ec = NULL;
 647
 648         /* Don't touch boot EC */
 649         if (boot_ec != ec)
 650                 kfree(ec);
 651         return 0;
 652 }
 653
 654 static acpi_status
 655 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 656 {
 657         struct acpi_ec *ec = context;
 658
 659         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 660                 return AE_OK;
 661
 662         /*
 663          * The first address region returned is the data port, and
 664          * the second address region returned is the status/command
 665          * port.
 666          */
 667         if (ec->data_addr == 0)
 668                 ec->data_addr = resource->data.io.minimum;
 669         else if (ec->command_addr == 0)
 670                 ec->command_addr = resource->data.io.minimum;
 671         else
 672                 return AE_CTRL_TERMINATE;
 673
 674         return AE_OK;
 675 }
 676
 677 static int ec_install_handlers(struct acpi_ec *ec)
 678 {
 679         acpi_status status;
 680         status = acpi_install_gpe_handler(NULL, ec->gpe,
 681                                           ACPI_GPE_EDGE_TRIGGERED,
 682                                           &acpi_ec_gpe_handler, ec);
 683         if (ACPI_FAILURE(status))
 684                 return -ENODEV;
 685
 686         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 687         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 688
 689         status = acpi_install_address_space_handler(ec->handle,
 690                                                     ACPI_ADR_SPACE_EC,
 691                                                     &acpi_ec_space_handler,
 692                                                     &acpi_ec_space_setup, ec);
 693         if (ACPI_FAILURE(status)) {
 694                 acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 695                 return -ENODEV;
 696         }
 697
 698         /* EC is fully operational, allow queries */
 699         atomic_set(&ec->query_pending, 0);
 700
 701         return 0;
 702 }
 703
 704 static int acpi_ec_start(struct acpi_device *device)
 705 {
 706         struct acpi_ec *ec;
 707
 708         if (!device)
 709                 return -EINVAL;
 710
 711         ec = acpi_driver_data(device);
 712
 713         if (!ec)
 714                 return -EINVAL;
 715
 716         /* Boot EC is already working */
 717         if (ec == boot_ec)
 718                 return 0;
 719
 720         return ec_install_handlers(ec);
 721 }
 722
 723 static int acpi_ec_stop(struct acpi_device *device, int type)
 724 {
 725         acpi_status status;
 726         struct acpi_ec *ec;
 727
 728         if (!device)
 729                 return -EINVAL;
 730
 731         ec = acpi_driver_data(device);
 732         if (!ec)
 733                 return -EINVAL;
 734
 735         /* Don't touch boot EC */
 736         if (ec == boot_ec)
 737                 return 0;
 738
 739         status = acpi_remove_address_space_handler(ec->handle,
 740                                                    ACPI_ADR_SPACE_EC,
 741                                                    &acpi_ec_space_handler);
 742         if (ACPI_FAILURE(status))
 743                 return -ENODEV;
 744
 745         status = acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 746         if (ACPI_FAILURE(status))
 747                 return -ENODEV;
 748
 749         return 0;
 750 }
 751
 752 static acpi_status
 753 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 754 {
 755         acpi_status status;
 756
 757         struct acpi_ec *ec = context;
 758         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 759                                      ec_parse_io_ports, ec);
 760         if (ACPI_FAILURE(status))
 761                 return status;
 762
 763         /* Get GPE bit assignment (EC events). */
 764         /* TODO: Add support for _GPE returning a package */
 765         status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
 766         if (ACPI_FAILURE(status))
 767                 return status;
 768
 769         /* Use the global lock for all EC transactions? */
 770         acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
 771
 772         ec->handle = handle;
 773
 774         printk(KERN_INFO PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx",
 775                           ec->gpe, ec->command_addr, ec->data_addr);
 776
 777         return AE_CTRL_TERMINATE;
 778 }
 779
 780 int __init acpi_ec_ecdt_probe(void)
 781 {
 782         int ret;
 783         acpi_status status;
 784         struct acpi_table_ecdt *ecdt_ptr;
 785
 786         boot_ec = make_acpi_ec();
 787         if (!boot_ec)
 788                 return -ENOMEM;
 789         /*
 790          * Generate a boot ec context
 791          */
 792
 793         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 794                                 (struct acpi_table_header **)&ecdt_ptr);
 795         if (ACPI_FAILURE(status))
 796                 goto error;
 797
 798         printk(KERN_INFO PREFIX "EC description table is found, configuring boot EC\n");
 799
 800         boot_ec->command_addr = ecdt_ptr->control.address;
 801         boot_ec->data_addr = ecdt_ptr->data.address;
 802         boot_ec->gpe = ecdt_ptr->gpe;
 803         boot_ec->handle = ACPI_ROOT_OBJECT;
 804
 805         ret = ec_install_handlers(boot_ec);
 806         if (!ret) {
 807                 first_ec = boot_ec;
 808                 return 0;
 809         }
 810       error:
 811         kfree(boot_ec);
 812         boot_ec = NULL;
 813
 814         return -ENODEV;
 815 }
 816
 817 static int __init acpi_ec_init(void)
 818 {
 819         int result = 0;
 820
 821         if (acpi_disabled)
 822                 return 0;
 823
 824         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
 825         if (!acpi_ec_dir)
 826                 return -ENODEV;
 827
 828         /* Now register the driver for the EC */
 829         result = acpi_bus_register_driver(&acpi_ec_driver);
 830         if (result < 0) {
 831                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 832                 return -ENODEV;
 833         }
 834
 835         return result;
 836 }
 837
 838 subsys_initcall(acpi_ec_init);
 839
 840 /* EC driver currently not unloadable */
 841 #if 0
 842 static void __exit acpi_ec_exit(void)
 843 {
 844
 845         acpi_bus_unregister_driver(&acpi_ec_driver);
 846
 847         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 848
 849         return;
 850 }
 851 #endif                          /* 0 */
 852
 853 static int __init acpi_ec_set_intr_mode(char *str)
 854 {
 855         int intr;
 856
 857         if (!get_option(&str, &intr))
 858                 return 0;
 859
 860         acpi_ec_mode = (intr) ? EC_INTR : EC_POLL;
 861
 862         printk(KERN_NOTICE PREFIX "%s mode.\n", intr ? "interrupt" : "polling");
 863
 864         return 1;
 865 }
 866
 867 __setup("ec_intr=", acpi_ec_set_intr_mode);