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   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_HID                     "PNP0C09"
  45 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  46 #define ACPI_EC_FILE_INFO               "info"
  47
  48 #undef PREFIX
  49 #define PREFIX                          "ACPI: EC: "
  50
  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
  57 /* EC commands */
  58 enum ec_command {
  59         ACPI_EC_COMMAND_READ = 0x80,
  60         ACPI_EC_COMMAND_WRITE = 0x81,
  61         ACPI_EC_BURST_ENABLE = 0x82,
  62         ACPI_EC_BURST_DISABLE = 0x83,
  63         ACPI_EC_COMMAND_QUERY = 0x84,
  64 };
  65
  66 /* EC events */
  67 enum ec_event {
  68         ACPI_EC_EVENT_OBF_1 = 1,        /* Output buffer full */
  69         ACPI_EC_EVENT_IBF_0,    /* Input buffer empty */
  70 };
  71
  72 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  73 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  74
  75 static enum ec_mode {
  76         EC_INTR = 1,            /* Output buffer full */
  77         EC_POLL,                /* Input buffer empty */
  78 } acpi_ec_mode = EC_INTR;
  79
  80 static int acpi_ec_remove(struct acpi_device *device, int type);
  81 static int acpi_ec_start(struct acpi_device *device);
  82 static int acpi_ec_stop(struct acpi_device *device, int type);
  83 static int acpi_ec_add(struct acpi_device *device);
  84
  85 static struct acpi_driver acpi_ec_driver = {
  86         .name = "ec",
  87         .class = ACPI_EC_CLASS,
  88         .ids = ACPI_EC_HID,
  89         .ops = {
  90                 .add = acpi_ec_add,
  91                 .remove = acpi_ec_remove,
  92                 .start = acpi_ec_start,
  93                 .stop = acpi_ec_stop,
  94                 },
  95 };
  96
  97 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  98 /* External interfaces use first EC only, so remember */
  99 typedef int (*acpi_ec_query_func) (void *data);
 100
 101 struct acpi_ec_query_handler {
 102         struct list_head node;
 103         acpi_ec_query_func func;
 104         acpi_handle handle;
 105         void *data;
 106         u8 query_bit;
 107 };
 108
 109 static struct acpi_ec {
 110         acpi_handle handle;
 111         unsigned long gpe;
 112         unsigned long command_addr;
 113         unsigned long data_addr;
 114         unsigned long global_lock;
 115         struct mutex lock;
 116         atomic_t query_pending;
 117         atomic_t event_count;
 118         wait_queue_head_t wait;
 119         struct list_head list;
 120 } *boot_ec, *first_ec;
 121
 122 /* --------------------------------------------------------------------------
 123                              Transaction Management
 124    -------------------------------------------------------------------------- */
 125
 126 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 127 {
 128         return inb(ec->command_addr);
 129 }
 130
 131 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 132 {
 133         return inb(ec->data_addr);
 134 }
 135
 136 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 137 {
 138         outb(command, ec->command_addr);
 139 }
 140
 141 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 142 {
 143         outb(data, ec->data_addr);
 144 }
 145
 146 static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event,
 147                                        unsigned old_count)
 148 {
 149         u8 status = acpi_ec_read_status(ec);
 150         if (old_count == atomic_read(&ec->event_count))
 151                 return 0;
 152         if (event == ACPI_EC_EVENT_OBF_1) {
 153                 if (status & ACPI_EC_FLAG_OBF)
 154                         return 1;
 155         } else if (event == ACPI_EC_EVENT_IBF_0) {
 156                 if (!(status & ACPI_EC_FLAG_IBF))
 157                         return 1;
 158         }
 159
 160         return 0;
 161 }
 162
 163 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event,
 164                         unsigned count, int force_poll)
 165 {
 166         if (unlikely(force_poll) || acpi_ec_mode == EC_POLL) {
 167                 unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 168                 while (time_before(jiffies, delay)) {
 169                         if (acpi_ec_check_status(ec, event, 0))
 170                                 return 0;
 171                 }
 172         } else {
 173                 if (wait_event_timeout(ec->wait,
 174                                        acpi_ec_check_status(ec, event, count),
 175                                        msecs_to_jiffies(ACPI_EC_DELAY)) ||
 176                     acpi_ec_check_status(ec, event, 0)) {
 177                         return 0;
 178                 } else {
 179                         printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
 180                                " status = %d, expect_event = %d\n",
 181                                acpi_ec_read_status(ec), event);
 182                 }
 183         }
 184
 185         return -ETIME;
 186 }
 187
 188 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
 189                                         const u8 * wdata, unsigned wdata_len,
 190                                         u8 * rdata, unsigned rdata_len,
 191                                         int force_poll)
 192 {
 193         int result = 0;
 194         unsigned count = atomic_read(&ec->event_count);
 195         acpi_ec_write_cmd(ec, command);
 196
 197         for (; wdata_len > 0; --wdata_len) {
 198                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count, force_poll);
 199                 if (result) {
 200                         printk(KERN_ERR PREFIX
 201                                "write_cmd timeout, command = %d\n", command);
 202                         goto end;
 203                 }
 204                 count = atomic_read(&ec->event_count);
 205                 acpi_ec_write_data(ec, *(wdata++));
 206         }
 207
 208         if (!rdata_len) {
 209                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count, force_poll);
 210                 if (result) {
 211                         printk(KERN_ERR PREFIX
 212                                "finish-write timeout, command = %d\n", command);
 213                         goto end;
 214                 }
 215         } else if (command == ACPI_EC_COMMAND_QUERY) {
 216                 atomic_set(&ec->query_pending, 0);
 217         }
 218
 219         for (; rdata_len > 0; --rdata_len) {
 220                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, count, force_poll);
 221                 if (result) {
 222                         printk(KERN_ERR PREFIX "read timeout, command = %d\n",
 223                                command);
 224                         goto end;
 225                 }
 226                 count = atomic_read(&ec->event_count);
 227                 *(rdata++) = acpi_ec_read_data(ec);
 228         }
 229       end:
 230         return result;
 231 }
 232
 233 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
 234                                const u8 * wdata, unsigned wdata_len,
 235                                u8 * rdata, unsigned rdata_len,
 236                                int force_poll)
 237 {
 238         int status;
 239         u32 glk;
 240
 241         if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
 242                 return -EINVAL;
 243
 244         if (rdata)
 245                 memset(rdata, 0, rdata_len);
 246
 247         mutex_lock(&ec->lock);
 248         if (ec->global_lock) {
 249                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 250                 if (ACPI_FAILURE(status)) {
 251                         mutex_unlock(&ec->lock);
 252                         return -ENODEV;
 253                 }
 254         }
 255
 256         /* Make sure GPE is enabled before doing transaction */
 257         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 258
 259         status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0, 0);
 260         if (status) {
 261                 printk(KERN_ERR PREFIX
 262                        "input buffer is not empty, aborting transaction\n");
 263                 goto end;
 264         }
 265
 266         status = acpi_ec_transaction_unlocked(ec, command,
 267                                               wdata, wdata_len,
 268                                               rdata, rdata_len,
 269                                               force_poll);
 270
 271       end:
 272
 273         if (ec->global_lock)
 274                 acpi_release_global_lock(glk);
 275         mutex_unlock(&ec->lock);
 276
 277         return status;
 278 }
 279
 280 /*
 281  * Note: samsung nv5000 doesn't work with ec burst mode.
 282  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 283  */
 284 int acpi_ec_burst_enable(struct acpi_ec *ec)
 285 {
 286         u8 d;
 287         return acpi_ec_transaction(ec, ACPI_EC_BURST_ENABLE, NULL, 0, &d, 1, 0);
 288 }
 289
 290 int acpi_ec_burst_disable(struct acpi_ec *ec)
 291 {
 292         return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0, 0);
 293 }
 294
 295 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 296 {
 297         int result;
 298         u8 d;
 299
 300         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
 301                                      &address, 1, &d, 1, 0);
 302         *data = d;
 303         return result;
 304 }
 305
 306 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 307 {
 308         u8 wdata[2] = { address, data };
 309         return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
 310                                    wdata, 2, NULL, 0, 0);
 311 }
 312
 313 /*
 314  * Externally callable EC access functions. For now, assume 1 EC only
 315  */
 316 int ec_burst_enable(void)
 317 {
 318         if (!first_ec)
 319                 return -ENODEV;
 320         return acpi_ec_burst_enable(first_ec);
 321 }
 322
 323 EXPORT_SYMBOL(ec_burst_enable);
 324
 325 int ec_burst_disable(void)
 326 {
 327         if (!first_ec)
 328                 return -ENODEV;
 329         return acpi_ec_burst_disable(first_ec);
 330 }
 331
 332 EXPORT_SYMBOL(ec_burst_disable);
 333
 334 int ec_read(u8 addr, u8 * val)
 335 {
 336         int err;
 337         u8 temp_data;
 338
 339         if (!first_ec)
 340                 return -ENODEV;
 341
 342         err = acpi_ec_read(first_ec, addr, &temp_data);
 343
 344         if (!err) {
 345                 *val = temp_data;
 346                 return 0;
 347         } else
 348                 return err;
 349 }
 350
 351 EXPORT_SYMBOL(ec_read);
 352
 353 int ec_write(u8 addr, u8 val)
 354 {
 355         int err;
 356
 357         if (!first_ec)
 358                 return -ENODEV;
 359
 360         err = acpi_ec_write(first_ec, addr, val);
 361
 362         return err;
 363 }
 364
 365 EXPORT_SYMBOL(ec_write);
 366
 367 int ec_transaction(u8 command,
 368                    const u8 * wdata, unsigned wdata_len,
 369                    u8 * rdata, unsigned rdata_len,
 370                    int force_poll)
 371 {
 372         if (!first_ec)
 373                 return -ENODEV;
 374
 375         return acpi_ec_transaction(first_ec, command, wdata,
 376                                    wdata_len, rdata, rdata_len,
 377                                    force_poll);
 378 }
 379
 380 EXPORT_SYMBOL(ec_transaction);
 381
 382 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 383 {
 384         int result;
 385         u8 d;
 386
 387         if (!ec || !data)
 388                 return -EINVAL;
 389
 390         /*
 391          * Query the EC to find out which _Qxx method we need to evaluate.
 392          * Note that successful completion of the query causes the ACPI_EC_SCI
 393          * bit to be cleared (and thus clearing the interrupt source).
 394          */
 395
 396         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
 397         if (result)
 398                 return result;
 399
 400         if (!d)
 401                 return -ENODATA;
 402
 403         *data = d;
 404         return 0;
 405 }
 406
 407 /* --------------------------------------------------------------------------
 408                                 Event Management
 409    -------------------------------------------------------------------------- */
 410 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 411                               acpi_handle handle, acpi_ec_query_func func,
 412                               void *data)
 413 {
 414         struct acpi_ec_query_handler *handler =
 415             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 416         if (!handler)
 417                 return -ENOMEM;
 418
 419         handler->query_bit = query_bit;
 420         handler->handle = handle;
 421         handler->func = func;
 422         handler->data = data;
 423         mutex_lock(&ec->lock);
 424         list_add_tail(&handler->node, &ec->list);
 425         mutex_unlock(&ec->lock);
 426         return 0;
 427 }
 428
 429 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 430
 431 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 432 {
 433         struct acpi_ec_query_handler *handler;
 434         mutex_lock(&ec->lock);
 435         list_for_each_entry(handler, &ec->list, node) {
 436                 if (query_bit == handler->query_bit) {
 437                         list_del(&handler->node);
 438                         kfree(handler);
 439                         break;
 440                 }
 441         }
 442         mutex_unlock(&ec->lock);
 443 }
 444
 445 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 446
 447 static void acpi_ec_gpe_query(void *ec_cxt)
 448 {
 449         struct acpi_ec *ec = ec_cxt;
 450         u8 value = 0;
 451         struct acpi_ec_query_handler *handler, copy;
 452
 453         if (!ec || acpi_ec_query(ec, &value))
 454                 return;
 455         mutex_lock(&ec->lock);
 456         list_for_each_entry(handler, &ec->list, node) {
 457                 if (value == handler->query_bit) {
 458                         /* have custom handler for this bit */
 459                         memcpy(&copy, handler, sizeof(copy));
 460                         mutex_unlock(&ec->lock);
 461                         if (copy.func) {
 462                                 copy.func(copy.data);
 463                         } else if (copy.handle) {
 464                                 acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
 465                         }
 466                         return;
 467                 }
 468         }
 469         mutex_unlock(&ec->lock);
 470         printk(KERN_ERR PREFIX "Handler for query 0x%x is not found!\n", value);
 471 }
 472
 473 static u32 acpi_ec_gpe_handler(void *data)
 474 {
 475         acpi_status status = AE_OK;
 476         u8 value;
 477         struct acpi_ec *ec = data;
 478
 479         atomic_inc(&ec->event_count);
 480
 481         if (acpi_ec_mode == EC_INTR) {
 482                 wake_up(&ec->wait);
 483         }
 484
 485         value = acpi_ec_read_status(ec);
 486         if ((value & ACPI_EC_FLAG_SCI) && !atomic_read(&ec->query_pending)) {
 487                 atomic_set(&ec->query_pending, 1);
 488                 status =
 489                     acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query, ec);
 490         }
 491
 492         return status == AE_OK ?
 493             ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 494 }
 495
 496 /* --------------------------------------------------------------------------
 497                              Address Space Management
 498    -------------------------------------------------------------------------- */
 499
 500 static acpi_status
 501 acpi_ec_space_setup(acpi_handle region_handle,
 502                     u32 function, void *handler_context, void **return_context)
 503 {
 504         /*
 505          * The EC object is in the handler context and is needed
 506          * when calling the acpi_ec_space_handler.
 507          */
 508         *return_context = (function != ACPI_REGION_DEACTIVATE) ?
 509             handler_context : NULL;
 510
 511         return AE_OK;
 512 }
 513
 514 static acpi_status
 515 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 516                       u32 bits, acpi_integer *value,
 517                       void *handler_context, void *region_context)
 518 {
 519         struct acpi_ec *ec = handler_context;
 520         int result = 0, i = 0;
 521         u8 temp = 0;
 522
 523         if ((address > 0xFF) || !value || !handler_context)
 524                 return AE_BAD_PARAMETER;
 525
 526         if (function != ACPI_READ && function != ACPI_WRITE)
 527                 return AE_BAD_PARAMETER;
 528
 529         if (bits != 8 && acpi_strict)
 530                 return AE_BAD_PARAMETER;
 531
 532         while (bits - i > 0) {
 533                 if (function == ACPI_READ) {
 534                         result = acpi_ec_read(ec, address, &temp);
 535                         (*value) |= ((acpi_integer)temp) << i;
 536                 } else {
 537                         temp = 0xff & ((*value) >> i);
 538                         result = acpi_ec_write(ec, address, temp);
 539                 }
 540                 i += 8;
 541                 ++address;
 542         }
 543
 544         switch (result) {
 545         case -EINVAL:
 546                 return AE_BAD_PARAMETER;
 547                 break;
 548         case -ENODEV:
 549                 return AE_NOT_FOUND;
 550                 break;
 551         case -ETIME:
 552                 return AE_TIME;
 553                 break;
 554         default:
 555                 return AE_OK;
 556         }
 557 }
 558
 559 /* --------------------------------------------------------------------------
 560                               FS Interface (/proc)
 561    -------------------------------------------------------------------------- */
 562
 563 static struct proc_dir_entry *acpi_ec_dir;
 564
 565 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 566 {
 567         struct acpi_ec *ec = seq->private;
 568
 569         if (!ec)
 570                 goto end;
 571
 572         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 573         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 574                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 575         seq_printf(seq, "use global lock:\t%s\n",
 576                    ec->global_lock ? "yes" : "no");
 577       end:
 578         return 0;
 579 }
 580
 581 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 582 {
 583         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 584 }
 585
 586 static struct file_operations acpi_ec_info_ops = {
 587         .open = acpi_ec_info_open_fs,
 588         .read = seq_read,
 589         .llseek = seq_lseek,
 590         .release = single_release,
 591         .owner = THIS_MODULE,
 592 };
 593
 594 static int acpi_ec_add_fs(struct acpi_device *device)
 595 {
 596         struct proc_dir_entry *entry = NULL;
 597
 598         if (!acpi_device_dir(device)) {
 599                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 600                                                      acpi_ec_dir);
 601                 if (!acpi_device_dir(device))
 602                         return -ENODEV;
 603         }
 604
 605         entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
 606                                   acpi_device_dir(device));
 607         if (!entry)
 608                 return -ENODEV;
 609         else {
 610                 entry->proc_fops = &acpi_ec_info_ops;
 611                 entry->data = acpi_driver_data(device);
 612                 entry->owner = THIS_MODULE;
 613         }
 614
 615         return 0;
 616 }
 617
 618 static int acpi_ec_remove_fs(struct acpi_device *device)
 619 {
 620
 621         if (acpi_device_dir(device)) {
 622                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 623                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 624                 acpi_device_dir(device) = NULL;
 625         }
 626
 627         return 0;
 628 }
 629
 630 /* --------------------------------------------------------------------------
 631                                Driver Interface
 632    -------------------------------------------------------------------------- */
 633 static acpi_status
 634 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 635
 636 static struct acpi_ec *make_acpi_ec(void)
 637 {
 638         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 639         if (!ec)
 640                 return NULL;
 641
 642         atomic_set(&ec->query_pending, 1);
 643         atomic_set(&ec->event_count, 1);
 644         mutex_init(&ec->lock);
 645         init_waitqueue_head(&ec->wait);
 646         INIT_LIST_HEAD(&ec->list);
 647
 648         return ec;
 649 }
 650
 651 static acpi_status
 652 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 653                                void *context, void **return_value)
 654 {
 655         struct acpi_namespace_node *node = handle;
 656         struct acpi_ec *ec = context;
 657         int value = 0;
 658         if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
 659                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 660         }
 661         return AE_OK;
 662 }
 663
 664 static int ec_parse_device(struct acpi_ec *ec, acpi_handle handle)
 665 {
 666         if (ACPI_FAILURE(acpi_walk_resources(handle, METHOD_NAME__CRS,
 667                                      ec_parse_io_ports, ec)))
 668                 return -EINVAL;
 669
 670         /* Get GPE bit assignment (EC events). */
 671         /* TODO: Add support for _GPE returning a package */
 672         if (ACPI_FAILURE(acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe)))
 673                 return -EINVAL;
 674
 675         /* Use the global lock for all EC transactions? */
 676         acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
 677
 678         /* Find and register all query methods */
 679         acpi_walk_namespace(ACPI_TYPE_METHOD, handle, 1,
 680                             acpi_ec_register_query_methods, ec, NULL);
 681
 682         ec->handle = handle;
 683
 684         printk(KERN_INFO PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx",
 685                           ec->gpe, ec->command_addr, ec->data_addr);
 686
 687         return 0;
 688 }
 689
 690 static int acpi_ec_add(struct acpi_device *device)
 691 {
 692         struct acpi_ec *ec = NULL;
 693
 694         if (!device)
 695                 return -EINVAL;
 696
 697         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 698         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 699
 700         ec = make_acpi_ec();
 701         if (!ec)
 702                 return -ENOMEM;
 703
 704         if (ec_parse_device(ec, device->handle)) {
 705                 kfree(ec);
 706                 return -EINVAL;
 707         }
 708
 709         /* Check if we found the boot EC */
 710         if (boot_ec) {
 711                 if (boot_ec->gpe == ec->gpe) {
 712                         /* We might have incorrect info for GL at boot time */
 713                         mutex_lock(&boot_ec->lock);
 714                         boot_ec->global_lock = ec->global_lock;
 715                         /* Copy handlers from new ec into boot ec */
 716                         list_splice(&ec->list, &boot_ec->list);
 717                         mutex_unlock(&boot_ec->lock);
 718                         kfree(ec);
 719                         ec = boot_ec;
 720                 }
 721         } else
 722                 first_ec = ec;
 723         ec->handle = device->handle;
 724         acpi_driver_data(device) = ec;
 725
 726         acpi_ec_add_fs(device);
 727         return 0;
 728 }
 729
 730 static int acpi_ec_remove(struct acpi_device *device, int type)
 731 {
 732         struct acpi_ec *ec;
 733         struct acpi_ec_query_handler *handler;
 734
 735         if (!device)
 736                 return -EINVAL;
 737
 738         ec = acpi_driver_data(device);
 739         mutex_lock(&ec->lock);
 740         list_for_each_entry(handler, &ec->list, node) {
 741                 list_del(&handler->node);
 742                 kfree(handler);
 743         }
 744         mutex_unlock(&ec->lock);
 745         acpi_ec_remove_fs(device);
 746         acpi_driver_data(device) = NULL;
 747         if (ec == first_ec)
 748                 first_ec = NULL;
 749
 750         /* Don't touch boot EC */
 751         if (boot_ec != ec)
 752                 kfree(ec);
 753         return 0;
 754 }
 755
 756 static acpi_status
 757 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 758 {
 759         struct acpi_ec *ec = context;
 760
 761         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 762                 return AE_OK;
 763
 764         /*
 765          * The first address region returned is the data port, and
 766          * the second address region returned is the status/command
 767          * port.
 768          */
 769         if (ec->data_addr == 0)
 770                 ec->data_addr = resource->data.io.minimum;
 771         else if (ec->command_addr == 0)
 772                 ec->command_addr = resource->data.io.minimum;
 773         else
 774                 return AE_CTRL_TERMINATE;
 775
 776         return AE_OK;
 777 }
 778
 779 static int ec_install_handlers(struct acpi_ec *ec)
 780 {
 781         acpi_status status;
 782         status = acpi_install_gpe_handler(NULL, ec->gpe,
 783                                           ACPI_GPE_EDGE_TRIGGERED,
 784                                           &acpi_ec_gpe_handler, ec);
 785         if (ACPI_FAILURE(status))
 786                 return -ENODEV;
 787
 788         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 789         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 790
 791         status = acpi_install_address_space_handler(ec->handle,
 792                                                     ACPI_ADR_SPACE_EC,
 793                                                     &acpi_ec_space_handler,
 794                                                     &acpi_ec_space_setup, ec);
 795         if (ACPI_FAILURE(status)) {
 796                 acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 797                 return -ENODEV;
 798         }
 799
 800         return 0;
 801 }
 802
 803 static int acpi_ec_start(struct acpi_device *device)
 804 {
 805         struct acpi_ec *ec;
 806         int ret = 0;
 807
 808         if (!device)
 809                 return -EINVAL;
 810
 811         ec = acpi_driver_data(device);
 812
 813         if (!ec)
 814                 return -EINVAL;
 815
 816         /* Boot EC is already working */
 817         if (ec != boot_ec)
 818                 ret = ec_install_handlers(ec);
 819
 820         /* EC is fully operational, allow queries */
 821         atomic_set(&ec->query_pending, 0);
 822
 823         return ret;
 824 }
 825
 826 static int acpi_ec_stop(struct acpi_device *device, int type)
 827 {
 828         acpi_status status;
 829         struct acpi_ec *ec;
 830
 831         if (!device)
 832                 return -EINVAL;
 833
 834         ec = acpi_driver_data(device);
 835         if (!ec)
 836                 return -EINVAL;
 837
 838         /* Don't touch boot EC */
 839         if (ec == boot_ec)
 840                 return 0;
 841
 842         status = acpi_remove_address_space_handler(ec->handle,
 843                                                    ACPI_ADR_SPACE_EC,
 844                                                    &acpi_ec_space_handler);
 845         if (ACPI_FAILURE(status))
 846                 return -ENODEV;
 847
 848         status = acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 849         if (ACPI_FAILURE(status))
 850                 return -ENODEV;
 851
 852         return 0;
 853 }
 854
 855 int __init acpi_ec_ecdt_probe(void)
 856 {
 857         int ret;
 858         acpi_status status;
 859         struct acpi_table_ecdt *ecdt_ptr;
 860
 861         boot_ec = make_acpi_ec();
 862         if (!boot_ec)
 863                 return -ENOMEM;
 864         /*
 865          * Generate a boot ec context
 866          */
 867
 868         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 869                                 (struct acpi_table_header **)&ecdt_ptr);
 870         if (ACPI_FAILURE(status))
 871                 goto error;
 872
 873         printk(KERN_INFO PREFIX "EC description table is found, configuring boot EC\n");
 874
 875         boot_ec->command_addr = ecdt_ptr->control.address;
 876         boot_ec->data_addr = ecdt_ptr->data.address;
 877         boot_ec->gpe = ecdt_ptr->gpe;
 878         boot_ec->handle = ACPI_ROOT_OBJECT;
 879
 880         ret = ec_install_handlers(boot_ec);
 881         if (!ret) {
 882                 first_ec = boot_ec;
 883                 return 0;
 884         }
 885       error:
 886         kfree(boot_ec);
 887         boot_ec = NULL;
 888
 889         return -ENODEV;
 890 }
 891
 892 static int __init acpi_ec_init(void)
 893 {
 894         int result = 0;
 895
 896         if (acpi_disabled)
 897                 return 0;
 898
 899         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
 900         if (!acpi_ec_dir)
 901                 return -ENODEV;
 902
 903         /* Now register the driver for the EC */
 904         result = acpi_bus_register_driver(&acpi_ec_driver);
 905         if (result < 0) {
 906                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 907                 return -ENODEV;
 908         }
 909
 910         return result;
 911 }
 912
 913 subsys_initcall(acpi_ec_init);
 914
 915 /* EC driver currently not unloadable */
 916 #if 0
 917 static void __exit acpi_ec_exit(void)
 918 {
 919
 920         acpi_bus_unregister_driver(&acpi_ec_driver);
 921
 922         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 923
 924         return;
 925 }
 926 #endif                          /* 0 */
 927
 928 static int __init acpi_ec_set_intr_mode(char *str)
 929 {
 930         int intr;
 931
 932         if (!get_option(&str, &intr))
 933                 return 0;
 934
 935         acpi_ec_mode = (intr) ? EC_INTR : EC_POLL;
 936
 937         printk(KERN_NOTICE PREFIX "%s mode.\n", intr ? "interrupt" : "polling");
 938
 939         return 1;
 940 }
 941
 942 __setup("ec_intr=", acpi_ec_set_intr_mode);