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 <linux/list.h>
  38 #include <asm/io.h>
  39 #include <acpi/acpi_bus.h>
  40 #include <acpi/acpi_drivers.h>
  41 #include <acpi/actypes.h>
  42
  43 #define ACPI_EC_CLASS                   "embedded_controller"
  44 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  45 #define ACPI_EC_FILE_INFO               "info"
  46
  47 #undef PREFIX
  48 #define PREFIX                          "ACPI: EC: "
  49
  50 /* EC status register */
  51 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  52 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  53 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  54 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  55
  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
  65 /* EC events */
  66 enum ec_event {
  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_FLAGS_WAIT_GPE = 0,          /* Don't check status until GPE arrives */
  76         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  77         EC_FLAGS_GPE_MODE,              /* Expect GPE to be sent for status change */
  78         EC_FLAGS_ONLY_IBF_GPE,          /* Expect GPE only for IBF = 0 event */
  79 };
  80
  81 static int acpi_ec_remove(struct acpi_device *device, int type);
  82 static int acpi_ec_start(struct acpi_device *device);
  83 static int acpi_ec_stop(struct acpi_device *device, int type);
  84 static int acpi_ec_add(struct acpi_device *device);
  85
  86 static const struct acpi_device_id ec_device_ids[] = {
  87         {"PNP0C09", 0},
  88         {"", 0},
  89 };
  90
  91 static struct acpi_driver acpi_ec_driver = {
  92         .name = "ec",
  93         .class = ACPI_EC_CLASS,
  94         .ids = ec_device_ids,
  95         .ops = {
  96                 .add = acpi_ec_add,
  97                 .remove = acpi_ec_remove,
  98                 .start = acpi_ec_start,
  99                 .stop = acpi_ec_stop,
 100                 },
 101 };
 102
 103 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
 104 /* External interfaces use first EC only, so remember */
 105 typedef int (*acpi_ec_query_func) (void *data);
 106
 107 struct acpi_ec_query_handler {
 108         struct list_head node;
 109         acpi_ec_query_func func;
 110         acpi_handle handle;
 111         void *data;
 112         u8 query_bit;
 113 };
 114
 115 static struct acpi_ec {
 116         acpi_handle handle;
 117         unsigned long gpe;
 118         unsigned long command_addr;
 119         unsigned long data_addr;
 120         unsigned long global_lock;
 121         unsigned long flags;
 122         struct mutex lock;
 123         wait_queue_head_t wait;
 124         struct list_head list;
 125         u8 handlers_installed;
 126 } *boot_ec, *first_ec;
 127
 128 /* --------------------------------------------------------------------------
 129                              Transaction Management
 130    -------------------------------------------------------------------------- */
 131
 132 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 133 {
 134         return inb(ec->command_addr);
 135 }
 136
 137 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 138 {
 139         return inb(ec->data_addr);
 140 }
 141
 142 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 143 {
 144         outb(command, ec->command_addr);
 145 }
 146
 147 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 148 {
 149         outb(data, ec->data_addr);
 150 }
 151
 152 static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
 153 {
 154         if (test_bit(EC_FLAGS_WAIT_GPE, &ec->flags))
 155                 return 0;
 156         if (event == ACPI_EC_EVENT_OBF_1) {
 157                 if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_OBF)
 158                         return 1;
 159         } else if (event == ACPI_EC_EVENT_IBF_0) {
 160                 if (!(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
 161                         return 1;
 162         }
 163
 164         return 0;
 165 }
 166
 167 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 168 {
 169         if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&
 170             likely(!force_poll)) {
 171                 if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),
 172                                        msecs_to_jiffies(ACPI_EC_DELAY)))
 173                         return 0;
 174                 clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 175                 if (acpi_ec_check_status(ec, event)) {
 176                         if (event == ACPI_EC_EVENT_OBF_1) {
 177                                 /* miss OBF = 1 GPE, don't expect it anymore */
 178                                 printk(KERN_INFO PREFIX "missing OBF_1 confirmation,"
 179                                         "switching to degraded mode.\n");
 180                                 set_bit(EC_FLAGS_ONLY_IBF_GPE, &ec->flags);
 181                         } else {
 182                                 /* missing GPEs, switch back to poll mode */
 183                                 printk(KERN_INFO PREFIX "missing IBF_1 confirmations,"
 184                                         "switch off interrupt mode.\n");
 185                                 clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 186                         }
 187                         return 0;
 188                 }
 189         } else {
 190                 unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 191                 clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 192                 while (time_before(jiffies, delay)) {
 193                         if (acpi_ec_check_status(ec, event))
 194                                 return 0;
 195                 }
 196         }
 197         printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
 198                                " status = %d, expect_event = %d\n",
 199                                acpi_ec_read_status(ec), event);
 200         return -ETIME;
 201 }
 202
 203 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
 204                                         const u8 * wdata, unsigned wdata_len,
 205                                         u8 * rdata, unsigned rdata_len,
 206                                         int force_poll)
 207 {
 208         int result = 0;
 209         set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 210         acpi_ec_write_cmd(ec, command);
 211
 212         for (; wdata_len > 0; --wdata_len) {
 213                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
 214                 if (result) {
 215                         printk(KERN_ERR PREFIX
 216                                "write_cmd timeout, command = %d\n", command);
 217                         goto end;
 218                 }
 219                 set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 220                 acpi_ec_write_data(ec, *(wdata++));
 221         }
 222
 223         if (!rdata_len) {
 224                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
 225                 if (result) {
 226                         printk(KERN_ERR PREFIX
 227                                "finish-write timeout, command = %d\n", command);
 228                         goto end;
 229                 }
 230         } else if (command == ACPI_EC_COMMAND_QUERY)
 231                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 232
 233         for (; rdata_len > 0; --rdata_len) {
 234                 if (test_bit(EC_FLAGS_ONLY_IBF_GPE, &ec->flags))
 235                         force_poll = 1;
 236                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, force_poll);
 237                 if (result) {
 238                         printk(KERN_ERR PREFIX "read timeout, command = %d\n",
 239                                command);
 240                         goto end;
 241                 }
 242                 /* Don't expect GPE after last read */
 243                 if (rdata_len > 1)
 244                         set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 245                 *(rdata++) = acpi_ec_read_data(ec);
 246         }
 247       end:
 248         return result;
 249 }
 250
 251 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
 252                                const u8 * wdata, unsigned wdata_len,
 253                                u8 * rdata, unsigned rdata_len,
 254                                int force_poll)
 255 {
 256         int status;
 257         u32 glk;
 258
 259         if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
 260                 return -EINVAL;
 261
 262         if (rdata)
 263                 memset(rdata, 0, rdata_len);
 264
 265         mutex_lock(&ec->lock);
 266         if (ec->global_lock) {
 267                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 268                 if (ACPI_FAILURE(status)) {
 269                         mutex_unlock(&ec->lock);
 270                         return -ENODEV;
 271                 }
 272         }
 273
 274         status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
 275         if (status) {
 276                 printk(KERN_ERR PREFIX
 277                        "input buffer is not empty, aborting transaction\n");
 278                 goto end;
 279         }
 280
 281         status = acpi_ec_transaction_unlocked(ec, command,
 282                                               wdata, wdata_len,
 283                                               rdata, rdata_len,
 284                                               force_poll);
 285
 286       end:
 287
 288         if (ec->global_lock)
 289                 acpi_release_global_lock(glk);
 290         mutex_unlock(&ec->lock);
 291
 292         return status;
 293 }
 294
 295 /*
 296  * Note: samsung nv5000 doesn't work with ec burst mode.
 297  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 298  */
 299 int acpi_ec_burst_enable(struct acpi_ec *ec)
 300 {
 301         u8 d;
 302         return acpi_ec_transaction(ec, ACPI_EC_BURST_ENABLE, NULL, 0, &d, 1, 0);
 303 }
 304
 305 int acpi_ec_burst_disable(struct acpi_ec *ec)
 306 {
 307         return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0, 0);
 308 }
 309
 310 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 311 {
 312         int result;
 313         u8 d;
 314
 315         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
 316                                      &address, 1, &d, 1, 0);
 317         *data = d;
 318         return result;
 319 }
 320
 321 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 322 {
 323         u8 wdata[2] = { address, data };
 324         return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
 325                                    wdata, 2, NULL, 0, 0);
 326 }
 327
 328 /*
 329  * Externally callable EC access functions. For now, assume 1 EC only
 330  */
 331 int ec_burst_enable(void)
 332 {
 333         if (!first_ec)
 334                 return -ENODEV;
 335         return acpi_ec_burst_enable(first_ec);
 336 }
 337
 338 EXPORT_SYMBOL(ec_burst_enable);
 339
 340 int ec_burst_disable(void)
 341 {
 342         if (!first_ec)
 343                 return -ENODEV;
 344         return acpi_ec_burst_disable(first_ec);
 345 }
 346
 347 EXPORT_SYMBOL(ec_burst_disable);
 348
 349 int ec_read(u8 addr, u8 * val)
 350 {
 351         int err;
 352         u8 temp_data;
 353
 354         if (!first_ec)
 355                 return -ENODEV;
 356
 357         err = acpi_ec_read(first_ec, addr, &temp_data);
 358
 359         if (!err) {
 360                 *val = temp_data;
 361                 return 0;
 362         } else
 363                 return err;
 364 }
 365
 366 EXPORT_SYMBOL(ec_read);
 367
 368 int ec_write(u8 addr, u8 val)
 369 {
 370         int err;
 371
 372         if (!first_ec)
 373                 return -ENODEV;
 374
 375         err = acpi_ec_write(first_ec, addr, val);
 376
 377         return err;
 378 }
 379
 380 EXPORT_SYMBOL(ec_write);
 381
 382 int ec_transaction(u8 command,
 383                    const u8 * wdata, unsigned wdata_len,
 384                    u8 * rdata, unsigned rdata_len,
 385                    int force_poll)
 386 {
 387         if (!first_ec)
 388                 return -ENODEV;
 389
 390         return acpi_ec_transaction(first_ec, command, wdata,
 391                                    wdata_len, rdata, rdata_len,
 392                                    force_poll);
 393 }
 394
 395 EXPORT_SYMBOL(ec_transaction);
 396
 397 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 398 {
 399         int result;
 400         u8 d;
 401
 402         if (!ec || !data)
 403                 return -EINVAL;
 404
 405         /*
 406          * Query the EC to find out which _Qxx method we need to evaluate.
 407          * Note that successful completion of the query causes the ACPI_EC_SCI
 408          * bit to be cleared (and thus clearing the interrupt source).
 409          */
 410
 411         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
 412         if (result)
 413                 return result;
 414
 415         if (!d)
 416                 return -ENODATA;
 417
 418         *data = d;
 419         return 0;
 420 }
 421
 422 /* --------------------------------------------------------------------------
 423                                 Event Management
 424    -------------------------------------------------------------------------- */
 425 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 426                               acpi_handle handle, acpi_ec_query_func func,
 427                               void *data)
 428 {
 429         struct acpi_ec_query_handler *handler =
 430             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 431         if (!handler)
 432                 return -ENOMEM;
 433
 434         handler->query_bit = query_bit;
 435         handler->handle = handle;
 436         handler->func = func;
 437         handler->data = data;
 438         mutex_lock(&ec->lock);
 439         list_add(&handler->node, &ec->list);
 440         mutex_unlock(&ec->lock);
 441         return 0;
 442 }
 443
 444 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 445
 446 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 447 {
 448         struct acpi_ec_query_handler *handler, *tmp;
 449         mutex_lock(&ec->lock);
 450         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 451                 if (query_bit == handler->query_bit) {
 452                         list_del(&handler->node);
 453                         kfree(handler);
 454                 }
 455         }
 456         mutex_unlock(&ec->lock);
 457 }
 458
 459 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 460
 461 static void acpi_ec_gpe_query(void *ec_cxt)
 462 {
 463         struct acpi_ec *ec = ec_cxt;
 464         u8 value = 0;
 465         struct acpi_ec_query_handler *handler, copy;
 466
 467         if (!ec || acpi_ec_query(ec, &value))
 468                 return;
 469         mutex_lock(&ec->lock);
 470         list_for_each_entry(handler, &ec->list, node) {
 471                 if (value == handler->query_bit) {
 472                         /* have custom handler for this bit */
 473                         memcpy(&copy, handler, sizeof(copy));
 474                         mutex_unlock(&ec->lock);
 475                         if (copy.func) {
 476                                 copy.func(copy.data);
 477                         } else if (copy.handle) {
 478                                 acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
 479                         }
 480                         return;
 481                 }
 482         }
 483         mutex_unlock(&ec->lock);
 484 }
 485
 486 static u32 acpi_ec_gpe_handler(void *data)
 487 {
 488         acpi_status status = AE_OK;
 489         struct acpi_ec *ec = data;
 490
 491         clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 492         if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
 493                 wake_up(&ec->wait);
 494
 495         if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_SCI) {
 496                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 497                         status = acpi_os_execute(OSL_EC_BURST_HANDLER,
 498                                 acpi_ec_gpe_query, ec);
 499         } else if (unlikely(!test_bit(EC_FLAGS_GPE_MODE, &ec->flags))) {
 500                 /* this is non-query, must be confirmation */
 501                 printk(KERN_INFO PREFIX "non-query interrupt received,"
 502                         " switching to interrupt mode\n");
 503                 set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 504         }
 505
 506         return ACPI_SUCCESS(status) ?
 507             ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 508 }
 509
 510 /* --------------------------------------------------------------------------
 511                              Address Space Management
 512    -------------------------------------------------------------------------- */
 513
 514 static acpi_status
 515 acpi_ec_space_setup(acpi_handle region_handle,
 516                     u32 function, void *handler_context, void **return_context)
 517 {
 518         /*
 519          * The EC object is in the handler context and is needed
 520          * when calling the acpi_ec_space_handler.
 521          */
 522         *return_context = (function != ACPI_REGION_DEACTIVATE) ?
 523             handler_context : NULL;
 524
 525         return AE_OK;
 526 }
 527
 528 static acpi_status
 529 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 530                       u32 bits, acpi_integer *value,
 531                       void *handler_context, void *region_context)
 532 {
 533         struct acpi_ec *ec = handler_context;
 534         int result = 0, i = 0;
 535         u8 temp = 0;
 536
 537         if ((address > 0xFF) || !value || !handler_context)
 538                 return AE_BAD_PARAMETER;
 539
 540         if (function != ACPI_READ && function != ACPI_WRITE)
 541                 return AE_BAD_PARAMETER;
 542
 543         if (bits != 8 && acpi_strict)
 544                 return AE_BAD_PARAMETER;
 545
 546         while (bits - i > 0) {
 547                 if (function == ACPI_READ) {
 548                         result = acpi_ec_read(ec, address, &temp);
 549                         (*value) |= ((acpi_integer)temp) << i;
 550                 } else {
 551                         temp = 0xff & ((*value) >> i);
 552                         result = acpi_ec_write(ec, address, temp);
 553                 }
 554                 i += 8;
 555                 ++address;
 556         }
 557
 558         switch (result) {
 559         case -EINVAL:
 560                 return AE_BAD_PARAMETER;
 561                 break;
 562         case -ENODEV:
 563                 return AE_NOT_FOUND;
 564                 break;
 565         case -ETIME:
 566                 return AE_TIME;
 567                 break;
 568         default:
 569                 return AE_OK;
 570         }
 571 }
 572
 573 /* --------------------------------------------------------------------------
 574                               FS Interface (/proc)
 575    -------------------------------------------------------------------------- */
 576
 577 static struct proc_dir_entry *acpi_ec_dir;
 578
 579 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 580 {
 581         struct acpi_ec *ec = seq->private;
 582
 583         if (!ec)
 584                 goto end;
 585
 586         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 587         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 588                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 589         seq_printf(seq, "use global lock:\t%s\n",
 590                    ec->global_lock ? "yes" : "no");
 591       end:
 592         return 0;
 593 }
 594
 595 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 596 {
 597         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 598 }
 599
 600 static struct file_operations acpi_ec_info_ops = {
 601         .open = acpi_ec_info_open_fs,
 602         .read = seq_read,
 603         .llseek = seq_lseek,
 604         .release = single_release,
 605         .owner = THIS_MODULE,
 606 };
 607
 608 static int acpi_ec_add_fs(struct acpi_device *device)
 609 {
 610         struct proc_dir_entry *entry = NULL;
 611
 612         if (!acpi_device_dir(device)) {
 613                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 614                                                      acpi_ec_dir);
 615                 if (!acpi_device_dir(device))
 616                         return -ENODEV;
 617         }
 618
 619         entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
 620                                   acpi_device_dir(device));
 621         if (!entry)
 622                 return -ENODEV;
 623         else {
 624                 entry->proc_fops = &acpi_ec_info_ops;
 625                 entry->data = acpi_driver_data(device);
 626                 entry->owner = THIS_MODULE;
 627         }
 628
 629         return 0;
 630 }
 631
 632 static int acpi_ec_remove_fs(struct acpi_device *device)
 633 {
 634
 635         if (acpi_device_dir(device)) {
 636                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 637                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 638                 acpi_device_dir(device) = NULL;
 639         }
 640
 641         return 0;
 642 }
 643
 644 /* --------------------------------------------------------------------------
 645                                Driver Interface
 646    -------------------------------------------------------------------------- */
 647 static acpi_status
 648 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 649
 650 static struct acpi_ec *make_acpi_ec(void)
 651 {
 652         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 653         if (!ec)
 654                 return NULL;
 655         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 656         mutex_init(&ec->lock);
 657         init_waitqueue_head(&ec->wait);
 658         INIT_LIST_HEAD(&ec->list);
 659         return ec;
 660 }
 661
 662 static acpi_status
 663 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 664                                void *context, void **return_value)
 665 {
 666         struct acpi_namespace_node *node = handle;
 667         struct acpi_ec *ec = context;
 668         int value = 0;
 669         if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
 670                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 671         }
 672         return AE_OK;
 673 }
 674
 675 static acpi_status
 676 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 677 {
 678         acpi_status status;
 679
 680         struct acpi_ec *ec = context;
 681         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 682                                      ec_parse_io_ports, ec);
 683         if (ACPI_FAILURE(status))
 684                 return status;
 685
 686         /* Get GPE bit assignment (EC events). */
 687         /* TODO: Add support for _GPE returning a package */
 688         status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
 689         if (ACPI_FAILURE(status))
 690                 return status;
 691         /* Find and register all query methods */
 692         acpi_walk_namespace(ACPI_TYPE_METHOD, handle, 1,
 693                             acpi_ec_register_query_methods, ec, NULL);
 694         /* Use the global lock for all EC transactions? */
 695         acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
 696         ec->handle = handle;
 697         return AE_CTRL_TERMINATE;
 698 }
 699
 700 static void ec_remove_handlers(struct acpi_ec *ec)
 701 {
 702         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 703                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 704                 printk(KERN_ERR PREFIX "failed to remove space handler\n");
 705         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 706                                 &acpi_ec_gpe_handler)))
 707                 printk(KERN_ERR PREFIX "failed to remove gpe handler\n");
 708         ec->handlers_installed = 0;
 709 }
 710
 711 static int acpi_ec_add(struct acpi_device *device)
 712 {
 713         struct acpi_ec *ec = NULL;
 714
 715         if (!device)
 716                 return -EINVAL;
 717         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 718         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 719
 720         /* Check for boot EC */
 721         if (boot_ec) {
 722                 if (boot_ec->handle == device->handle) {
 723                         /* Pre-loaded EC from DSDT, just move pointer */
 724                         ec = boot_ec;
 725                         boot_ec = NULL;
 726                         goto end;
 727                 } else if (boot_ec->handle == ACPI_ROOT_OBJECT) {
 728                         /* ECDT-based EC, time to shut it down */
 729                         ec_remove_handlers(boot_ec);
 730                         kfree(boot_ec);
 731                         first_ec = boot_ec = NULL;
 732                 }
 733         }
 734
 735         ec = make_acpi_ec();
 736         if (!ec)
 737                 return -ENOMEM;
 738
 739         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 740             AE_CTRL_TERMINATE) {
 741                 kfree(ec);
 742                 return -EINVAL;
 743         }
 744         ec->handle = device->handle;
 745       end:
 746         if (!first_ec)
 747                 first_ec = ec;
 748         acpi_driver_data(device) = ec;
 749         acpi_ec_add_fs(device);
 750         printk(KERN_INFO PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 751                           ec->gpe, ec->command_addr, ec->data_addr);
 752         printk(KERN_INFO PREFIX "driver started in %s mode\n",
 753                 (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
 754         return 0;
 755 }
 756
 757 static int acpi_ec_remove(struct acpi_device *device, int type)
 758 {
 759         struct acpi_ec *ec;
 760         struct acpi_ec_query_handler *handler, *tmp;
 761
 762         if (!device)
 763                 return -EINVAL;
 764
 765         ec = acpi_driver_data(device);
 766         mutex_lock(&ec->lock);
 767         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 768                 list_del(&handler->node);
 769                 kfree(handler);
 770         }
 771         mutex_unlock(&ec->lock);
 772         acpi_ec_remove_fs(device);
 773         acpi_driver_data(device) = NULL;
 774         if (ec == first_ec)
 775                 first_ec = NULL;
 776         kfree(ec);
 777         return 0;
 778 }
 779
 780 static acpi_status
 781 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 782 {
 783         struct acpi_ec *ec = context;
 784
 785         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 786                 return AE_OK;
 787
 788         /*
 789          * The first address region returned is the data port, and
 790          * the second address region returned is the status/command
 791          * port.
 792          */
 793         if (ec->data_addr == 0)
 794                 ec->data_addr = resource->data.io.minimum;
 795         else if (ec->command_addr == 0)
 796                 ec->command_addr = resource->data.io.minimum;
 797         else
 798                 return AE_CTRL_TERMINATE;
 799
 800         return AE_OK;
 801 }
 802
 803 static int ec_install_handlers(struct acpi_ec *ec)
 804 {
 805         acpi_status status;
 806         if (ec->handlers_installed)
 807                 return 0;
 808         status = acpi_install_gpe_handler(NULL, ec->gpe,
 809                                           ACPI_GPE_EDGE_TRIGGERED,
 810                                           &acpi_ec_gpe_handler, ec);
 811         if (ACPI_FAILURE(status))
 812                 return -ENODEV;
 813
 814         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 815         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 816
 817         status = acpi_install_address_space_handler(ec->handle,
 818                                                     ACPI_ADR_SPACE_EC,
 819                                                     &acpi_ec_space_handler,
 820                                                     &acpi_ec_space_setup, ec);
 821         if (ACPI_FAILURE(status)) {
 822                 acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 823                 return -ENODEV;
 824         }
 825
 826         ec->handlers_installed = 1;
 827         return 0;
 828 }
 829
 830 static int acpi_ec_start(struct acpi_device *device)
 831 {
 832         struct acpi_ec *ec;
 833         int ret = 0;
 834
 835         if (!device)
 836                 return -EINVAL;
 837
 838         ec = acpi_driver_data(device);
 839
 840         if (!ec)
 841                 return -EINVAL;
 842
 843         ret = ec_install_handlers(ec);
 844
 845         /* EC is fully operational, allow queries */
 846         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 847         return ret;
 848 }
 849
 850 static int acpi_ec_stop(struct acpi_device *device, int type)
 851 {
 852         struct acpi_ec *ec;
 853         if (!device)
 854                 return -EINVAL;
 855         ec = acpi_driver_data(device);
 856         if (!ec)
 857                 return -EINVAL;
 858         ec_remove_handlers(ec);
 859
 860         return 0;
 861 }
 862
 863 int __init acpi_ec_ecdt_probe(void)
 864 {
 865         int ret;
 866         acpi_status status;
 867         struct acpi_table_ecdt *ecdt_ptr;
 868
 869         boot_ec = make_acpi_ec();
 870         if (!boot_ec)
 871                 return -ENOMEM;
 872         /*
 873          * Generate a boot ec context
 874          */
 875         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 876                                 (struct acpi_table_header **)&ecdt_ptr);
 877         if (ACPI_SUCCESS(status)) {
 878                 printk(KERN_INFO PREFIX "EC description table is found, configuring boot EC\n");
 879                 boot_ec->command_addr = ecdt_ptr->control.address;
 880                 boot_ec->data_addr = ecdt_ptr->data.address;
 881                 boot_ec->gpe = ecdt_ptr->gpe;
 882                 boot_ec->handle = ACPI_ROOT_OBJECT;
 883         } else {
 884                 printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
 885                 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
 886                                                 boot_ec, NULL);
 887                 /* Check that acpi_get_devices actually find something */
 888                 if (ACPI_FAILURE(status) || !boot_ec->handle)
 889                         goto error;
 890         }
 891
 892         ret = ec_install_handlers(boot_ec);
 893         if (!ret) {
 894                 first_ec = boot_ec;
 895                 return 0;
 896         }
 897       error:
 898         kfree(boot_ec);
 899         boot_ec = NULL;
 900         return -ENODEV;
 901 }
 902
 903 static int __init acpi_ec_init(void)
 904 {
 905         int result = 0;
 906
 907         if (acpi_disabled)
 908                 return 0;
 909
 910         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
 911         if (!acpi_ec_dir)
 912                 return -ENODEV;
 913
 914         /* Now register the driver for the EC */
 915         result = acpi_bus_register_driver(&acpi_ec_driver);
 916         if (result < 0) {
 917                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 918                 return -ENODEV;
 919         }
 920
 921         return result;
 922 }
 923
 924 subsys_initcall(acpi_ec_init);
 925
 926 /* EC driver currently not unloadable */
 927 #if 0
 928 static void __exit acpi_ec_exit(void)
 929 {
 930
 931         acpi_bus_unregister_driver(&acpi_ec_driver);
 932
 933         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 934
 935         return;
 936 }
 937 #endif  /* 0 */