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 _COMPONENT              ACPI_EC_COMPONENT
  43 ACPI_MODULE_NAME("ec");
  44 #define ACPI_EC_COMPONENT               0x00100000
  45 #define ACPI_EC_CLASS                   "embedded_controller"
  46 #define ACPI_EC_HID                     "PNP0C09"
  47 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  48 #define ACPI_EC_FILE_INFO               "info"
  49 #undef PREFIX
  50 #define PREFIX                          "ACPI: EC: "
  51 /* EC status register */
  52 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  53 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  54 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  55 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  56 /* EC commands */
  57 enum ec_command {
  58         ACPI_EC_COMMAND_READ = 0x80,
  59         ACPI_EC_COMMAND_WRITE = 0x81,
  60         ACPI_EC_BURST_ENABLE = 0x82,
  61         ACPI_EC_BURST_DISABLE = 0x83,
  62         ACPI_EC_COMMAND_QUERY = 0x84,
  63 };
  64 /* EC events */
  65 enum ec_event {
  66         ACPI_EC_EVENT_OBF_1 = 1,        /* Output buffer full */
  67         ACPI_EC_EVENT_IBF_0,    /* Input buffer empty */
  68 };
  69
  70 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  71 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  72
  73 static enum ec_mode {
  74         EC_INTR = 1,            /* Output buffer full */
  75         EC_POLL,                /* Input buffer empty */
  76 } acpi_ec_mode = EC_INTR;
  77
  78 static int acpi_ec_remove(struct acpi_device *device, int type);
  79 static int acpi_ec_start(struct acpi_device *device);
  80 static int acpi_ec_stop(struct acpi_device *device, int type);
  81 static int acpi_ec_add(struct acpi_device *device);
  82
  83 static struct acpi_driver acpi_ec_driver = {
  84         .name = "ec",
  85         .class = ACPI_EC_CLASS,
  86         .ids = ACPI_EC_HID,
  87         .ops = {
  88                 .add = acpi_ec_add,
  89                 .remove = acpi_ec_remove,
  90                 .start = acpi_ec_start,
  91                 .stop = acpi_ec_stop,
  92                 },
  93 };
  94
  95 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  96 /* External interfaces use first EC only, so remember */
  97 static struct acpi_ec {
  98         acpi_handle handle;
  99         unsigned long gpe;
 100         unsigned long command_addr;
 101         unsigned long data_addr;
 102         unsigned long global_lock;
 103         struct mutex lock;
 104         atomic_t query_pending;
 105         atomic_t event_count;
 106         wait_queue_head_t wait;
 107 } *boot_ec, *first_ec;
 108
 109 /* --------------------------------------------------------------------------
 110                              Transaction Management
 111    -------------------------------------------------------------------------- */
 112
 113 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 114 {
 115         return inb(ec->command_addr);
 116 }
 117
 118 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 119 {
 120         return inb(ec->data_addr);
 121 }
 122
 123 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 124 {
 125         outb(command, ec->command_addr);
 126 }
 127
 128 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 129 {
 130         outb(data, ec->data_addr);
 131 }
 132
 133 static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event,
 134                                        unsigned old_count)
 135 {
 136         u8 status = acpi_ec_read_status(ec);
 137         if (old_count == atomic_read(&ec->event_count))
 138                 return 0;
 139         if (event == ACPI_EC_EVENT_OBF_1) {
 140                 if (status & ACPI_EC_FLAG_OBF)
 141                         return 1;
 142         } else if (event == ACPI_EC_EVENT_IBF_0) {
 143                 if (!(status & ACPI_EC_FLAG_IBF))
 144                         return 1;
 145         }
 146
 147         return 0;
 148 }
 149
 150 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event,
 151                         unsigned count, int force_poll)
 152 {
 153         if (unlikely(force_poll) || acpi_ec_mode == EC_POLL) {
 154                 unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 155                 while (time_before(jiffies, delay)) {
 156                         if (acpi_ec_check_status(ec, event, 0))
 157                                 return 0;
 158                 }
 159         } else {
 160                 if (wait_event_timeout(ec->wait,
 161                                        acpi_ec_check_status(ec, event, count),
 162                                        msecs_to_jiffies(ACPI_EC_DELAY)) ||
 163                     acpi_ec_check_status(ec, event, 0)) {
 164                         return 0;
 165                 } else {
 166                         printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
 167                                " status = %d, expect_event = %d\n",
 168                                acpi_ec_read_status(ec), event);
 169                 }
 170         }
 171
 172         return -ETIME;
 173 }
 174
 175 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
 176                                         const u8 * wdata, unsigned wdata_len,
 177                                         u8 * rdata, unsigned rdata_len,
 178                                         int force_poll)
 179 {
 180         int result = 0;
 181         unsigned count = atomic_read(&ec->event_count);
 182         acpi_ec_write_cmd(ec, command);
 183
 184         for (; wdata_len > 0; --wdata_len) {
 185                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count, force_poll);
 186                 if (result) {
 187                         printk(KERN_ERR PREFIX
 188                                "write_cmd timeout, command = %d\n", command);
 189                         goto end;
 190                 }
 191                 count = atomic_read(&ec->event_count);
 192                 acpi_ec_write_data(ec, *(wdata++));
 193         }
 194
 195         if (!rdata_len) {
 196                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count, force_poll);
 197                 if (result) {
 198                         printk(KERN_ERR PREFIX
 199                                "finish-write timeout, command = %d\n", command);
 200                         goto end;
 201                 }
 202         } else if (command == ACPI_EC_COMMAND_QUERY) {
 203                 atomic_set(&ec->query_pending, 0);
 204         }
 205
 206         for (; rdata_len > 0; --rdata_len) {
 207                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, count, force_poll);
 208                 if (result) {
 209                         printk(KERN_ERR PREFIX "read timeout, command = %d\n",
 210                                command);
 211                         goto end;
 212                 }
 213                 count = atomic_read(&ec->event_count);
 214                 *(rdata++) = acpi_ec_read_data(ec);
 215         }
 216       end:
 217         return result;
 218 }
 219
 220 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
 221                                const u8 * wdata, unsigned wdata_len,
 222                                u8 * rdata, unsigned rdata_len,
 223                                int force_poll)
 224 {
 225         int status;
 226         u32 glk;
 227
 228         if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
 229                 return -EINVAL;
 230
 231         if (rdata)
 232                 memset(rdata, 0, rdata_len);
 233
 234         mutex_lock(&ec->lock);
 235         if (ec->global_lock) {
 236                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 237                 if (ACPI_FAILURE(status)) {
 238                         mutex_unlock(&ec->lock);
 239                         return -ENODEV;
 240                 }
 241         }
 242
 243         /* Make sure GPE is enabled before doing transaction */
 244         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 245
 246         status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0, 0);
 247         if (status) {
 248                 printk(KERN_DEBUG PREFIX
 249                        "input buffer is not empty, aborting transaction\n");
 250                 goto end;
 251         }
 252
 253         status = acpi_ec_transaction_unlocked(ec, command,
 254                                               wdata, wdata_len,
 255                                               rdata, rdata_len,
 256                                               force_poll);
 257
 258       end:
 259
 260         if (ec->global_lock)
 261                 acpi_release_global_lock(glk);
 262         mutex_unlock(&ec->lock);
 263
 264         return status;
 265 }
 266
 267 /*
 268  * Note: samsung nv5000 doesn't work with ec burst mode.
 269  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 270  */
 271 int acpi_ec_burst_enable(struct acpi_ec *ec)
 272 {
 273         u8 d;
 274         return acpi_ec_transaction(ec, ACPI_EC_BURST_ENABLE, NULL, 0, &d, 1, 0);
 275 }
 276
 277 int acpi_ec_burst_disable(struct acpi_ec *ec)
 278 {
 279         return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0, 0);
 280 }
 281
 282 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 283 {
 284         int result;
 285         u8 d;
 286
 287         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
 288                                      &address, 1, &d, 1, 0);
 289         *data = d;
 290         return result;
 291 }
 292
 293 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 294 {
 295         u8 wdata[2] = { address, data };
 296         return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
 297                                    wdata, 2, NULL, 0, 0);
 298 }
 299
 300 /*
 301  * Externally callable EC access functions. For now, assume 1 EC only
 302  */
 303 int ec_burst_enable(void)
 304 {
 305         if (!first_ec)
 306                 return -ENODEV;
 307         return acpi_ec_burst_enable(first_ec);
 308 }
 309
 310 EXPORT_SYMBOL(ec_burst_enable);
 311
 312 int ec_burst_disable(void)
 313 {
 314         if (!first_ec)
 315                 return -ENODEV;
 316         return acpi_ec_burst_disable(first_ec);
 317 }
 318
 319 EXPORT_SYMBOL(ec_burst_disable);
 320
 321 int ec_read(u8 addr, u8 * val)
 322 {
 323         int err;
 324         u8 temp_data;
 325
 326         if (!first_ec)
 327                 return -ENODEV;
 328
 329         err = acpi_ec_read(first_ec, addr, &temp_data);
 330
 331         if (!err) {
 332                 *val = temp_data;
 333                 return 0;
 334         } else
 335                 return err;
 336 }
 337
 338 EXPORT_SYMBOL(ec_read);
 339
 340 int ec_write(u8 addr, u8 val)
 341 {
 342         int err;
 343
 344         if (!first_ec)
 345                 return -ENODEV;
 346
 347         err = acpi_ec_write(first_ec, addr, val);
 348
 349         return err;
 350 }
 351
 352 EXPORT_SYMBOL(ec_write);
 353
 354 int ec_transaction(u8 command,
 355                    const u8 * wdata, unsigned wdata_len,
 356                    u8 * rdata, unsigned rdata_len,
 357                    int force_poll)
 358 {
 359         if (!first_ec)
 360                 return -ENODEV;
 361
 362         return acpi_ec_transaction(first_ec, command, wdata,
 363                                    wdata_len, rdata, rdata_len,
 364                                    force_poll);
 365 }
 366
 367 EXPORT_SYMBOL(ec_transaction);
 368
 369 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 370 {
 371         int result;
 372         u8 d;
 373
 374         if (!ec || !data)
 375                 return -EINVAL;
 376
 377         /*
 378          * Query the EC to find out which _Qxx method we need to evaluate.
 379          * Note that successful completion of the query causes the ACPI_EC_SCI
 380          * bit to be cleared (and thus clearing the interrupt source).
 381          */
 382
 383         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
 384         if (result)
 385                 return result;
 386
 387         if (!d)
 388                 return -ENODATA;
 389
 390         *data = d;
 391         return 0;
 392 }
 393
 394 /* --------------------------------------------------------------------------
 395                                 Event Management
 396    -------------------------------------------------------------------------- */
 397
 398 static void acpi_ec_gpe_query(void *ec_cxt)
 399 {
 400         struct acpi_ec *ec = ec_cxt;
 401         u8 value = 0;
 402         char object_name[8];
 403
 404         if (!ec || acpi_ec_query(ec, &value))
 405                 return;
 406
 407         snprintf(object_name, 8, "_Q%2.2X", value);
 408
 409         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluating %s", object_name));
 410
 411         acpi_evaluate_object(ec->handle, object_name, NULL, NULL);
 412 }
 413
 414 static u32 acpi_ec_gpe_handler(void *data)
 415 {
 416         acpi_status status = AE_OK;
 417         u8 value;
 418         struct acpi_ec *ec = data;
 419
 420         atomic_inc(&ec->event_count);
 421
 422         if (acpi_ec_mode == EC_INTR) {
 423                 wake_up(&ec->wait);
 424         }
 425
 426         value = acpi_ec_read_status(ec);
 427         if ((value & ACPI_EC_FLAG_SCI) && !atomic_read(&ec->query_pending)) {
 428                 atomic_set(&ec->query_pending, 1);
 429                 status =
 430                     acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query,
 431                                     ec);
 432         }
 433
 434         return status == AE_OK ?
 435             ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 436 }
 437
 438 /* --------------------------------------------------------------------------
 439                              Address Space Management
 440    -------------------------------------------------------------------------- */
 441
 442 static acpi_status
 443 acpi_ec_space_setup(acpi_handle region_handle,
 444                     u32 function, void *handler_context, void **return_context)
 445 {
 446         /*
 447          * The EC object is in the handler context and is needed
 448          * when calling the acpi_ec_space_handler.
 449          */
 450         *return_context = (function != ACPI_REGION_DEACTIVATE) ?
 451             handler_context : NULL;
 452
 453         return AE_OK;
 454 }
 455
 456 static acpi_status
 457 acpi_ec_space_handler(u32 function,
 458                       acpi_physical_address address,
 459                       u32 bit_width,
 460                       acpi_integer * value,
 461                       void *handler_context, void *region_context)
 462 {
 463         int result = 0;
 464         struct acpi_ec *ec = handler_context;
 465         u64 temp = *value;
 466         acpi_integer f_v = 0;
 467         int i = 0;
 468
 469         if ((address > 0xFF) || !value || !handler_context)
 470                 return AE_BAD_PARAMETER;
 471
 472         if (bit_width != 8 && acpi_strict) {
 473                 return AE_BAD_PARAMETER;
 474         }
 475
 476       next_byte:
 477         switch (function) {
 478         case ACPI_READ:
 479                 temp = 0;
 480                 result = acpi_ec_read(ec, (u8) address, (u8 *) & temp);
 481                 break;
 482         case ACPI_WRITE:
 483                 result = acpi_ec_write(ec, (u8) address, (u8) temp);
 484                 break;
 485         default:
 486                 result = -EINVAL;
 487                 goto out;
 488                 break;
 489         }
 490
 491         bit_width -= 8;
 492         if (bit_width) {
 493                 if (function == ACPI_READ)
 494                         f_v |= temp << 8 * i;
 495                 if (function == ACPI_WRITE)
 496                         temp >>= 8;
 497                 i++;
 498                 address++;
 499                 goto next_byte;
 500         }
 501
 502         if (function == ACPI_READ) {
 503                 f_v |= temp << 8 * i;
 504                 *value = f_v;
 505         }
 506
 507       out:
 508         switch (result) {
 509         case -EINVAL:
 510                 return AE_BAD_PARAMETER;
 511                 break;
 512         case -ENODEV:
 513                 return AE_NOT_FOUND;
 514                 break;
 515         case -ETIME:
 516                 return AE_TIME;
 517                 break;
 518         default:
 519                 return AE_OK;
 520         }
 521 }
 522
 523 /* --------------------------------------------------------------------------
 524                               FS Interface (/proc)
 525    -------------------------------------------------------------------------- */
 526
 527 static struct proc_dir_entry *acpi_ec_dir;
 528
 529 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 530 {
 531         struct acpi_ec *ec = seq->private;
 532
 533         if (!ec)
 534                 goto end;
 535
 536         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 537         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 538                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 539         seq_printf(seq, "use global lock:\t%s\n",
 540                    ec->global_lock ? "yes" : "no");
 541       end:
 542         return 0;
 543 }
 544
 545 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 546 {
 547         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 548 }
 549
 550 static struct file_operations acpi_ec_info_ops = {
 551         .open = acpi_ec_info_open_fs,
 552         .read = seq_read,
 553         .llseek = seq_lseek,
 554         .release = single_release,
 555         .owner = THIS_MODULE,
 556 };
 557
 558 static int acpi_ec_add_fs(struct acpi_device *device)
 559 {
 560         struct proc_dir_entry *entry = NULL;
 561
 562         if (!acpi_device_dir(device)) {
 563                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 564                                                      acpi_ec_dir);
 565                 if (!acpi_device_dir(device))
 566                         return -ENODEV;
 567         }
 568
 569         entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
 570                                   acpi_device_dir(device));
 571         if (!entry)
 572                 return -ENODEV;
 573         else {
 574                 entry->proc_fops = &acpi_ec_info_ops;
 575                 entry->data = acpi_driver_data(device);
 576                 entry->owner = THIS_MODULE;
 577         }
 578
 579         return 0;
 580 }
 581
 582 static int acpi_ec_remove_fs(struct acpi_device *device)
 583 {
 584
 585         if (acpi_device_dir(device)) {
 586                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 587                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 588                 acpi_device_dir(device) = NULL;
 589         }
 590
 591         return 0;
 592 }
 593
 594 /* --------------------------------------------------------------------------
 595                                Driver Interface
 596    -------------------------------------------------------------------------- */
 597 static acpi_status
 598 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 599
 600 static acpi_status
 601 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval);
 602
 603 static struct acpi_ec *make_acpi_ec(void)
 604 {
 605         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 606         if (!ec)
 607                 return NULL;
 608
 609         atomic_set(&ec->query_pending, 1);
 610         atomic_set(&ec->event_count, 1);
 611         mutex_init(&ec->lock);
 612         init_waitqueue_head(&ec->wait);
 613
 614         return ec;
 615 }
 616
 617 static int acpi_ec_add(struct acpi_device *device)
 618 {
 619         acpi_status status = AE_OK;
 620         struct acpi_ec *ec = NULL;
 621
 622         if (!device)
 623                 return -EINVAL;
 624
 625         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 626         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 627
 628         ec = make_acpi_ec();
 629         if (!ec)
 630                 return -ENOMEM;
 631
 632         status = ec_parse_device(device->handle, 0, ec, NULL);
 633         if (status != AE_CTRL_TERMINATE) {
 634                 kfree(ec);
 635                 return -EINVAL;
 636         }
 637
 638         /* Check if we found the boot EC */
 639         if (boot_ec) {
 640                 if (boot_ec->gpe == ec->gpe) {
 641                         /* We might have incorrect info for GL at boot time */
 642                         mutex_lock(&boot_ec->lock);
 643                         boot_ec->global_lock = ec->global_lock;
 644                         mutex_unlock(&boot_ec->lock);
 645                         kfree(ec);
 646                         ec = boot_ec;
 647                 }
 648         } else
 649                 first_ec = ec;
 650         ec->handle = device->handle;
 651         acpi_driver_data(device) = ec;
 652
 653         acpi_ec_add_fs(device);
 654
 655         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s [%s] (gpe %d) interrupt mode.",
 656                           acpi_device_name(device), acpi_device_bid(device),
 657                           (u32) ec->gpe));
 658
 659         return 0;
 660 }
 661
 662 static int acpi_ec_remove(struct acpi_device *device, int type)
 663 {
 664         struct acpi_ec *ec;
 665
 666         if (!device)
 667                 return -EINVAL;
 668
 669         ec = acpi_driver_data(device);
 670         acpi_ec_remove_fs(device);
 671         acpi_driver_data(device) = NULL;
 672         if (ec == first_ec)
 673                 first_ec = NULL;
 674
 675         /* Don't touch boot EC */
 676         if (boot_ec != ec)
 677                 kfree(ec);
 678         return 0;
 679 }
 680
 681 static acpi_status
 682 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 683 {
 684         struct acpi_ec *ec = context;
 685
 686         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 687                 return AE_OK;
 688
 689         /*
 690          * The first address region returned is the data port, and
 691          * the second address region returned is the status/command
 692          * port.
 693          */
 694         if (ec->data_addr == 0)
 695                 ec->data_addr = resource->data.io.minimum;
 696         else if (ec->command_addr == 0)
 697                 ec->command_addr = resource->data.io.minimum;
 698         else
 699                 return AE_CTRL_TERMINATE;
 700
 701         return AE_OK;
 702 }
 703
 704 static int ec_install_handlers(struct acpi_ec *ec)
 705 {
 706         acpi_status status;
 707         status = acpi_install_gpe_handler(NULL, ec->gpe,
 708                                           ACPI_GPE_EDGE_TRIGGERED,
 709                                           &acpi_ec_gpe_handler, ec);
 710         if (ACPI_FAILURE(status))
 711                 return -ENODEV;
 712
 713         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 714         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 715
 716         status = acpi_install_address_space_handler(ec->handle,
 717                                                     ACPI_ADR_SPACE_EC,
 718                                                     &acpi_ec_space_handler,
 719                                                     &acpi_ec_space_setup, ec);
 720         if (ACPI_FAILURE(status)) {
 721                 acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 722                 return -ENODEV;
 723         }
 724
 725         /* EC is fully operational, allow queries */
 726         atomic_set(&ec->query_pending, 0);
 727
 728         return 0;
 729 }
 730
 731 static int acpi_ec_start(struct acpi_device *device)
 732 {
 733         struct acpi_ec *ec;
 734
 735         if (!device)
 736                 return -EINVAL;
 737
 738         ec = acpi_driver_data(device);
 739
 740         if (!ec)
 741                 return -EINVAL;
 742
 743         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "gpe=0x%02lx, ports=0x%2lx,0x%2lx",
 744                           ec->gpe, ec->command_addr, ec->data_addr));
 745
 746         /* Boot EC is already working */
 747         if (ec == boot_ec)
 748                 return 0;
 749
 750         return ec_install_handlers(ec);
 751 }
 752
 753 static int acpi_ec_stop(struct acpi_device *device, int type)
 754 {
 755         acpi_status status;
 756         struct acpi_ec *ec;
 757
 758         if (!device)
 759                 return -EINVAL;
 760
 761         ec = acpi_driver_data(device);
 762         if (!ec)
 763                 return -EINVAL;
 764
 765         /* Don't touch boot EC */
 766         if (ec == boot_ec)
 767                 return 0;
 768
 769         status = acpi_remove_address_space_handler(ec->handle,
 770                                                    ACPI_ADR_SPACE_EC,
 771                                                    &acpi_ec_space_handler);
 772         if (ACPI_FAILURE(status))
 773                 return -ENODEV;
 774
 775         status = acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 776         if (ACPI_FAILURE(status))
 777                 return -ENODEV;
 778
 779         return 0;
 780 }
 781
 782 static acpi_status
 783 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 784 {
 785         acpi_status status;
 786
 787         struct acpi_ec *ec = context;
 788         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 789                                      ec_parse_io_ports, ec);
 790         if (ACPI_FAILURE(status))
 791                 return status;
 792
 793         /* Get GPE bit assignment (EC events). */
 794         /* TODO: Add support for _GPE returning a package */
 795         status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
 796         if (ACPI_FAILURE(status))
 797                 return status;
 798
 799         /* Use the global lock for all EC transactions? */
 800         acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
 801
 802         ec->handle = handle;
 803
 804         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "GPE=0x%02lx, ports=0x%2lx, 0x%2lx",
 805                           ec->gpe, ec->command_addr, ec->data_addr));
 806
 807         return AE_CTRL_TERMINATE;
 808 }
 809
 810 int __init acpi_ec_ecdt_probe(void)
 811 {
 812         int ret;
 813         acpi_status status;
 814         struct acpi_table_ecdt *ecdt_ptr;
 815
 816         boot_ec = make_acpi_ec();
 817         if (!boot_ec)
 818                 return -ENOMEM;
 819         /*
 820          * Generate a boot ec context
 821          */
 822
 823         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 824                                 (struct acpi_table_header **)&ecdt_ptr);
 825         if (ACPI_FAILURE(status))
 826                 goto error;
 827
 828         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found ECDT"));
 829
 830         boot_ec->command_addr = ecdt_ptr->control.address;
 831         boot_ec->data_addr = ecdt_ptr->data.address;
 832         boot_ec->gpe = ecdt_ptr->gpe;
 833         boot_ec->handle = ACPI_ROOT_OBJECT;
 834
 835         ret = ec_install_handlers(boot_ec);
 836         if (!ret) {
 837                 first_ec = boot_ec;
 838                 return 0;
 839         }
 840       error:
 841         kfree(boot_ec);
 842         boot_ec = NULL;
 843
 844         return -ENODEV;
 845 }
 846
 847 static int __init acpi_ec_init(void)
 848 {
 849         int result = 0;
 850
 851         if (acpi_disabled)
 852                 return 0;
 853
 854         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
 855         if (!acpi_ec_dir)
 856                 return -ENODEV;
 857
 858         /* Now register the driver for the EC */
 859         result = acpi_bus_register_driver(&acpi_ec_driver);
 860         if (result < 0) {
 861                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 862                 return -ENODEV;
 863         }
 864
 865         return result;
 866 }
 867
 868 subsys_initcall(acpi_ec_init);
 869
 870 /* EC driver currently not unloadable */
 871 #if 0
 872 static void __exit acpi_ec_exit(void)
 873 {
 874
 875         acpi_bus_unregister_driver(&acpi_ec_driver);
 876
 877         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 878
 879         return;
 880 }
 881 #endif                          /* 0 */
 882
 883 static int __init acpi_ec_set_intr_mode(char *str)
 884 {
 885         int intr;
 886
 887         if (!get_option(&str, &intr))
 888                 return 0;
 889
 890         acpi_ec_mode = (intr) ? EC_INTR : EC_POLL;
 891
 892         printk(KERN_NOTICE PREFIX "%s mode.\n", intr ? "interrupt" : "polling");
 893
 894         return 1;
 895 }
 896
 897 __setup("ec_intr=", acpi_ec_set_intr_mode);