drivers/acpi/ec.c

   1 /*
   2  *  acpi_ec.c - ACPI Embedded Controller Driver ($Revision: 38 $)
   3  *
   4  *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
   5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   7  *
   8  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or (at
  13  *  your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful, but
  16  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  *  General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License along
  21  *  with this program; if not, write to the Free Software Foundation, Inc.,
  22  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  23  *
  24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25  */
  26
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/init.h>
  30 #include <linux/types.h>
  31 #include <linux/delay.h>
  32 #include <linux/proc_fs.h>
  33 #include <linux/seq_file.h>
  34 #include <linux/interrupt.h>
  35 #include <asm/io.h>
  36 #include <acpi/acpi_bus.h>
  37 #include <acpi/acpi_drivers.h>
  38 #include <acpi/actypes.h>
  39
  40 #define _COMPONENT              ACPI_EC_COMPONENT
  41 ACPI_MODULE_NAME("acpi_ec")
  42 #define ACPI_EC_COMPONENT               0x00100000
  43 #define ACPI_EC_CLASS                   "embedded_controller"
  44 #define ACPI_EC_HID                     "PNP0C09"
  45 #define ACPI_EC_DRIVER_NAME             "ACPI Embedded Controller Driver"
  46 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  47 #define ACPI_EC_FILE_INFO               "info"
  48 #undef PREFIX
  49 #define PREFIX                          "ACPI: EC: "
  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 /* EC commands */
  56 enum ec_command {
  57         ACPI_EC_COMMAND_READ = 0x80,
  58         ACPI_EC_COMMAND_WRITE = 0x81,
  59         ACPI_EC_BURST_ENABLE = 0x82,
  60         ACPI_EC_BURST_DISABLE = 0x83,
  61         ACPI_EC_COMMAND_QUERY = 0x84,
  62 };
  63 /* EC events */
  64 enum ec_event {
  65         ACPI_EC_EVENT_OBF_1 = 1,        /* Output buffer full */
  66         ACPI_EC_EVENT_IBF_0,    /* Input buffer empty */
  67 };
  68
  69 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  70 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  71
  72 static enum ec_mode {
  73         EC_INTR = 1,            /* Output buffer full */
  74         EC_POLL,                /* Input buffer empty */
  75 } acpi_ec_mode = EC_INTR;
  76
  77 static int acpi_ec_remove(struct acpi_device *device, int type);
  78 static int acpi_ec_start(struct acpi_device *device);
  79 static int acpi_ec_stop(struct acpi_device *device, int type);
  80 static int acpi_ec_add(struct acpi_device *device);
  81
  82 static struct acpi_driver acpi_ec_driver = {
  83         .name = ACPI_EC_DRIVER_NAME,
  84         .class = ACPI_EC_CLASS,
  85         .ids = ACPI_EC_HID,
  86         .ops = {
  87                 .add = acpi_ec_add,
  88                 .remove = acpi_ec_remove,
  89                 .start = acpi_ec_start,
  90                 .stop = acpi_ec_stop,
  91                 },
  92 };
  93
  94 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  95 static struct acpi_ec {
  96         acpi_handle handle;
  97         unsigned long uid;
  98         unsigned long gpe;
  99         unsigned long command_addr;
 100         unsigned long data_addr;
 101         unsigned long global_lock;
 102         struct mutex lock;
 103         atomic_t query_pending;
 104         atomic_t leaving_burst; /* 0 : No, 1 : Yes, 2: abort */
 105         wait_queue_head_t wait;
 106 } *ec_ecdt;
 107
 108 /* External interfaces use first EC only, so remember */
 109 static struct acpi_device *first_ec;
 110
 111 /* --------------------------------------------------------------------------
 112                              Transaction Management
 113    -------------------------------------------------------------------------- */
 114
 115 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 116 {
 117         return inb(ec->command_addr);
 118 }
 119
 120 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 121 {
 122         return inb(ec->data_addr);
 123 }
 124
 125 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 126 {
 127         outb(command, ec->command_addr);
 128 }
 129
 130 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 131 {
 132         outb(data, ec->data_addr);
 133 }
 134
 135 static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
 136 {
 137         u8 status = acpi_ec_read_status(ec);
 138
 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 {
 152         if (acpi_ec_mode == EC_POLL) {
 153                 unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 154                 while (time_before(jiffies, delay)) {
 155                         if (acpi_ec_check_status(ec, event))
 156                                 return 0;
 157                 }
 158         } else {
 159                 if (wait_event_timeout(ec->wait,
 160                                        acpi_ec_check_status(ec, event),
 161                                        msecs_to_jiffies(ACPI_EC_DELAY)) ||
 162                     acpi_ec_check_status(ec, event)) {
 163                         return 0;
 164                 } else {
 165                         printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
 166                                " status = %d, expect_event = %d\n",
 167                                acpi_ec_read_status(ec), event);
 168                 }
 169         }
 170
 171         return -ETIME;
 172 }
 173
 174 #ifdef ACPI_FUTURE_USAGE
 175 /*
 176  * Note: samsung nv5000 doesn't work with ec burst mode.
 177  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 178  */
 179 int acpi_ec_enter_burst_mode(struct acpi_ec *ec)
 180 {
 181         u8 tmp = 0;
 182         u8 status = 0;
 183
 184         status = acpi_ec_read_status(ec);
 185         if (status != -EINVAL && !(status & ACPI_EC_FLAG_BURST)) {
 186                 status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 187                 if (status)
 188                         goto end;
 189                 acpi_ec_write_cmd(ec, ACPI_EC_BURST_ENABLE);
 190                 status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1);
 191                 tmp = acpi_ec_read_data(ec);
 192                 if (tmp != 0x90) {      /* Burst ACK byte */
 193                         return -EINVAL;
 194                 }
 195         }
 196
 197         atomic_set(&ec->leaving_burst, 0);
 198         return 0;
 199       end:
 200         ACPI_EXCEPTION((AE_INFO, status, "EC wait, burst mode"));
 201         return -1;
 202 }
 203
 204 int acpi_ec_leave_burst_mode(struct acpi_ec *ec)
 205 {
 206         u8 status = 0;
 207
 208         status = acpi_ec_read_status(ec);
 209         if (status != -EINVAL && (status & ACPI_EC_FLAG_BURST)) {
 210                 status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 211                 if (status)
 212                         goto end;
 213                 acpi_ec_write_cmd(ec, ACPI_EC_BURST_DISABLE);
 214                 acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 215         }
 216         atomic_set(&ec->leaving_burst, 1);
 217         return 0;
 218       end:
 219         ACPI_EXCEPTION((AE_INFO, status, "EC leave burst mode"));
 220         return -1;
 221 }
 222 #endif                          /* ACPI_FUTURE_USAGE */
 223
 224 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
 225                                         const u8 * wdata, unsigned wdata_len,
 226                                         u8 * rdata, unsigned rdata_len)
 227 {
 228         int result = 0;
 229
 230         acpi_ec_write_cmd(ec, command);
 231
 232         for (; wdata_len > 0; --wdata_len) {
 233                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 234                 if (result) {
 235                         printk(KERN_ERR PREFIX
 236                                "write_cmd timeout, command = %d\n", command);
 237                         goto end;
 238                 }
 239                 acpi_ec_write_data(ec, *(wdata++));
 240         }
 241
 242         if (!rdata_len) {
 243                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 244                 if (result) {
 245                         printk(KERN_ERR PREFIX
 246                                "finish-write timeout, command = %d\n", command);
 247                         goto end;
 248                 }
 249         } else if (command == ACPI_EC_COMMAND_QUERY) {
 250                 atomic_set(&ec->query_pending, 0);
 251         }
 252
 253         for (; rdata_len > 0; --rdata_len) {
 254                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1);
 255                 if (result) {
 256                         printk(KERN_ERR PREFIX "read timeout, command = %d\n",
 257                                command);
 258                         goto end;
 259                 }
 260
 261                 *(rdata++) = acpi_ec_read_data(ec);
 262         }
 263       end:
 264         return result;
 265 }
 266
 267 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
 268                                const u8 * wdata, unsigned wdata_len,
 269                                u8 * rdata, unsigned rdata_len)
 270 {
 271         int status;
 272         u32 glk;
 273
 274         if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
 275                 return -EINVAL;
 276
 277         if (rdata)
 278                 memset(rdata, 0, rdata_len);
 279
 280         mutex_lock(&ec->lock);
 281         if (ec->global_lock) {
 282                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 283                 if (ACPI_FAILURE(status))
 284                         return -ENODEV;
 285         }
 286
 287         /* Make sure GPE is enabled before doing transaction */
 288         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 289
 290         status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 291         if (status) {
 292                 printk(KERN_DEBUG PREFIX
 293                        "input buffer is not empty, aborting transaction\n");
 294                 goto end;
 295         }
 296
 297         status = acpi_ec_transaction_unlocked(ec, command,
 298                                               wdata, wdata_len,
 299                                               rdata, rdata_len);
 300
 301       end:
 302
 303         if (ec->global_lock)
 304                 acpi_release_global_lock(glk);
 305         mutex_unlock(&ec->lock);
 306
 307         return status;
 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);
 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);
 326 }
 327
 328 /*
 329  * Externally callable EC access functions. For now, assume 1 EC only
 330  */
 331 int ec_read(u8 addr, u8 * val)
 332 {
 333         struct acpi_ec *ec;
 334         int err;
 335         u8 temp_data;
 336
 337         if (!first_ec)
 338                 return -ENODEV;
 339
 340         ec = acpi_driver_data(first_ec);
 341
 342         err = acpi_ec_read(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         struct acpi_ec *ec;
 356         int err;
 357
 358         if (!first_ec)
 359                 return -ENODEV;
 360
 361         ec = acpi_driver_data(first_ec);
 362
 363         err = acpi_ec_write(ec, addr, val);
 364
 365         return err;
 366 }
 367
 368 EXPORT_SYMBOL(ec_write);
 369
 370 int ec_transaction(u8 command,
 371                           const u8 * wdata, unsigned wdata_len,
 372                           u8 * rdata, unsigned rdata_len)
 373 {
 374         struct acpi_ec *ec;
 375
 376         if (!first_ec)
 377                 return -ENODEV;
 378
 379         ec = acpi_driver_data(first_ec);
 380
 381         return acpi_ec_transaction(ec, command, wdata,
 382                                    wdata_len, rdata, rdata_len);
 383 }
 384
 385 EXPORT_SYMBOL(ec_transaction);
 386
 387 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 388 {
 389         int result;
 390         u8 d;
 391
 392         if (!ec || !data)
 393                 return -EINVAL;
 394
 395         /*
 396          * Query the EC to find out which _Qxx method we need to evaluate.
 397          * Note that successful completion of the query causes the ACPI_EC_SCI
 398          * bit to be cleared (and thus clearing the interrupt source).
 399          */
 400
 401         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1);
 402         if (result)
 403                 return result;
 404
 405         if (!d)
 406                 return -ENODATA;
 407
 408         *data = d;
 409         return 0;
 410 }
 411
 412 /* --------------------------------------------------------------------------
 413                                 Event Management
 414    -------------------------------------------------------------------------- */
 415
 416 static void acpi_ec_gpe_query(void *ec_cxt)
 417 {
 418         struct acpi_ec *ec = (struct acpi_ec *)ec_cxt;
 419         u8 value = 0;
 420         char object_name[8];
 421
 422         if (!ec || acpi_ec_query(ec, &value))
 423                 return;
 424
 425         snprintf(object_name, 8, "_Q%2.2X", value);
 426
 427         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluating %s", object_name));
 428
 429         acpi_evaluate_object(ec->handle, object_name, NULL, NULL);
 430 }
 431
 432 static u32 acpi_ec_gpe_handler(void *data)
 433 {
 434         acpi_status status = AE_OK;
 435         u8 value;
 436         struct acpi_ec *ec = (struct acpi_ec *)data;
 437
 438         if (acpi_ec_mode == EC_INTR) {
 439                 wake_up(&ec->wait);
 440         }
 441
 442         value = acpi_ec_read_status(ec);
 443         if ((value & ACPI_EC_FLAG_SCI) && !atomic_read(&ec->query_pending)) {
 444                 atomic_set(&ec->query_pending, 1);
 445                 status =
 446                     acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query,
 447                                     ec);
 448         }
 449
 450         return status == AE_OK ?
 451             ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 452 }
 453
 454 /* --------------------------------------------------------------------------
 455                              Address Space Management
 456    -------------------------------------------------------------------------- */
 457
 458 static acpi_status
 459 acpi_ec_space_setup(acpi_handle region_handle,
 460                     u32 function, void *handler_context, void **return_context)
 461 {
 462         /*
 463          * The EC object is in the handler context and is needed
 464          * when calling the acpi_ec_space_handler.
 465          */
 466         *return_context = (function != ACPI_REGION_DEACTIVATE) ?
 467             handler_context : NULL;
 468
 469         return AE_OK;
 470 }
 471
 472 static acpi_status
 473 acpi_ec_space_handler(u32 function,
 474                       acpi_physical_address address,
 475                       u32 bit_width,
 476                       acpi_integer * value,
 477                       void *handler_context, void *region_context)
 478 {
 479         int result = 0;
 480         struct acpi_ec *ec = NULL;
 481         u64 temp = *value;
 482         acpi_integer f_v = 0;
 483         int i = 0;
 484
 485         if ((address > 0xFF) || !value || !handler_context)
 486                 return AE_BAD_PARAMETER;
 487
 488         if (bit_width != 8 && acpi_strict) {
 489                 return AE_BAD_PARAMETER;
 490         }
 491
 492         ec = (struct acpi_ec *)handler_context;
 493
 494       next_byte:
 495         switch (function) {
 496         case ACPI_READ:
 497                 temp = 0;
 498                 result = acpi_ec_read(ec, (u8) address, (u8 *) & temp);
 499                 break;
 500         case ACPI_WRITE:
 501                 result = acpi_ec_write(ec, (u8) address, (u8) temp);
 502                 break;
 503         default:
 504                 result = -EINVAL;
 505                 goto out;
 506                 break;
 507         }
 508
 509         bit_width -= 8;
 510         if (bit_width) {
 511                 if (function == ACPI_READ)
 512                         f_v |= temp << 8 * i;
 513                 if (function == ACPI_WRITE)
 514                         temp >>= 8;
 515                 i++;
 516                 address++;
 517                 goto next_byte;
 518         }
 519
 520         if (function == ACPI_READ) {
 521                 f_v |= temp << 8 * i;
 522                 *value = f_v;
 523         }
 524
 525       out:
 526         switch (result) {
 527         case -EINVAL:
 528                 return AE_BAD_PARAMETER;
 529                 break;
 530         case -ENODEV:
 531                 return AE_NOT_FOUND;
 532                 break;
 533         case -ETIME:
 534                 return AE_TIME;
 535                 break;
 536         default:
 537                 return AE_OK;
 538         }
 539 }
 540
 541 /* --------------------------------------------------------------------------
 542                               FS Interface (/proc)
 543    -------------------------------------------------------------------------- */
 544
 545 static struct proc_dir_entry *acpi_ec_dir;
 546
 547 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 548 {
 549         struct acpi_ec *ec = (struct acpi_ec *)seq->private;
 550
 551         if (!ec)
 552                 goto end;
 553
 554         seq_printf(seq, "gpe:                 0x%02x\n", (u32) ec->gpe);
 555         seq_printf(seq, "ports:                   0x%02x, 0x%02x\n",
 556                    (u32) ec->command_addr, (u32) ec->data_addr);
 557         seq_printf(seq, "use global lock:         %s\n",
 558                    ec->global_lock ? "yes" : "no");
 559         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 560
 561       end:
 562         return 0;
 563 }
 564
 565 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 566 {
 567         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 568 }
 569
 570 static struct file_operations acpi_ec_info_ops = {
 571         .open = acpi_ec_info_open_fs,
 572         .read = seq_read,
 573         .llseek = seq_lseek,
 574         .release = single_release,
 575         .owner = THIS_MODULE,
 576 };
 577
 578 static int acpi_ec_add_fs(struct acpi_device *device)
 579 {
 580         struct proc_dir_entry *entry = NULL;
 581
 582         if (!acpi_device_dir(device)) {
 583                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 584                                                      acpi_ec_dir);
 585                 if (!acpi_device_dir(device))
 586                         return -ENODEV;
 587         }
 588
 589         entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
 590                                   acpi_device_dir(device));
 591         if (!entry)
 592                 return -ENODEV;
 593         else {
 594                 entry->proc_fops = &acpi_ec_info_ops;
 595                 entry->data = acpi_driver_data(device);
 596                 entry->owner = THIS_MODULE;
 597         }
 598
 599         return 0;
 600 }
 601
 602 static int acpi_ec_remove_fs(struct acpi_device *device)
 603 {
 604
 605         if (acpi_device_dir(device)) {
 606                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 607                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 608                 acpi_device_dir(device) = NULL;
 609         }
 610
 611         return 0;
 612 }
 613
 614 /* --------------------------------------------------------------------------
 615                                Driver Interface
 616    -------------------------------------------------------------------------- */
 617
 618 static int acpi_ec_add(struct acpi_device *device)
 619 {
 620         int result = 0;
 621         acpi_status status = AE_OK;
 622         struct acpi_ec *ec = NULL;
 623
 624         if (!device)
 625                 return -EINVAL;
 626
 627         ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 628         if (!ec)
 629                 return -ENOMEM;
 630
 631         ec->handle = device->handle;
 632         ec->uid = -1;
 633         mutex_init(&ec->lock);
 634         atomic_set(&ec->query_pending, 0);
 635         if (acpi_ec_mode == EC_INTR) {
 636                 atomic_set(&ec->leaving_burst, 1);
 637                 init_waitqueue_head(&ec->wait);
 638         }
 639         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 640         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 641         acpi_driver_data(device) = ec;
 642
 643         /* Use the global lock for all EC transactions? */
 644         acpi_evaluate_integer(ec->handle, "_GLK", NULL, &ec->global_lock);
 645
 646         /* XXX we don't test uids, because on some boxes ecdt uid = 0, see:
 647            http://bugzilla.kernel.org/show_bug.cgi?id=6111 */
 648         if (ec_ecdt) {
 649                 acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
 650                                                   ACPI_ADR_SPACE_EC,
 651                                                   &acpi_ec_space_handler);
 652
 653                 acpi_remove_gpe_handler(NULL, ec_ecdt->gpe,
 654                                         &acpi_ec_gpe_handler);
 655
 656                 kfree(ec_ecdt);
 657         }
 658
 659         /* Get GPE bit assignment (EC events). */
 660         /* TODO: Add support for _GPE returning a package */
 661         status = acpi_evaluate_integer(ec->handle, "_GPE", NULL, &ec->gpe);
 662         if (ACPI_FAILURE(status)) {
 663                 ACPI_EXCEPTION((AE_INFO, status,
 664                                 "Obtaining GPE bit assignment"));
 665                 result = -ENODEV;
 666                 goto end;
 667         }
 668
 669         result = acpi_ec_add_fs(device);
 670         if (result)
 671                 goto end;
 672
 673         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s [%s] (gpe %d) interrupt mode.",
 674                           acpi_device_name(device), acpi_device_bid(device),
 675                           (u32) ec->gpe));
 676
 677         if (!first_ec)
 678                 first_ec = device;
 679
 680       end:
 681         if (result)
 682                 kfree(ec);
 683
 684         return result;
 685 }
 686
 687 static int acpi_ec_remove(struct acpi_device *device, int type)
 688 {
 689         struct acpi_ec *ec = NULL;
 690
 691         if (!device)
 692                 return -EINVAL;
 693
 694         ec = acpi_driver_data(device);
 695
 696         acpi_ec_remove_fs(device);
 697
 698         kfree(ec);
 699
 700         return 0;
 701 }
 702
 703 static acpi_status
 704 acpi_ec_io_ports(struct acpi_resource *resource, void *context)
 705 {
 706         struct acpi_ec *ec = (struct acpi_ec *)context;
 707
 708         if (resource->type != ACPI_RESOURCE_TYPE_IO) {
 709                 return AE_OK;
 710         }
 711
 712         /*
 713          * The first address region returned is the data port, and
 714          * the second address region returned is the status/command
 715          * port.
 716          */
 717         if (ec->data_addr == 0) {
 718                 ec->data_addr = resource->data.io.minimum;
 719         } else if (ec->command_addr == 0) {
 720                 ec->command_addr = resource->data.io.minimum;
 721         } else {
 722                 return AE_CTRL_TERMINATE;
 723         }
 724
 725         return AE_OK;
 726 }
 727
 728 static int acpi_ec_start(struct acpi_device *device)
 729 {
 730         acpi_status status = AE_OK;
 731         struct acpi_ec *ec = NULL;
 732
 733         if (!device)
 734                 return -EINVAL;
 735
 736         ec = acpi_driver_data(device);
 737
 738         if (!ec)
 739                 return -EINVAL;
 740
 741         /*
 742          * Get I/O port addresses. Convert to GAS format.
 743          */
 744         status = acpi_walk_resources(ec->handle, METHOD_NAME__CRS,
 745                                      acpi_ec_io_ports, ec);
 746         if (ACPI_FAILURE(status) || ec->command_addr == 0) {
 747                 ACPI_EXCEPTION((AE_INFO, status,
 748                                 "Error getting I/O port addresses"));
 749                 return -ENODEV;
 750         }
 751
 752         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "gpe=0x%02lx, ports=0x%2lx,0x%2lx",
 753                           ec->gpe, ec->command_addr, ec->data_addr));
 754
 755         /*
 756          * Install GPE handler
 757          */
 758         status = acpi_install_gpe_handler(NULL, ec->gpe,
 759                                           ACPI_GPE_EDGE_TRIGGERED,
 760                                           &acpi_ec_gpe_handler, ec);
 761         if (ACPI_FAILURE(status)) {
 762                 return -ENODEV;
 763         }
 764         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 765         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 766
 767         status = acpi_install_address_space_handler(ec->handle,
 768                                                     ACPI_ADR_SPACE_EC,
 769                                                     &acpi_ec_space_handler,
 770                                                     &acpi_ec_space_setup, ec);
 771         if (ACPI_FAILURE(status)) {
 772                 acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 773                 return -ENODEV;
 774         }
 775
 776         return AE_OK;
 777 }
 778
 779 static int acpi_ec_stop(struct acpi_device *device, int type)
 780 {
 781         acpi_status status = AE_OK;
 782         struct acpi_ec *ec = NULL;
 783
 784         if (!device)
 785                 return -EINVAL;
 786
 787         ec = acpi_driver_data(device);
 788
 789         status = acpi_remove_address_space_handler(ec->handle,
 790                                                    ACPI_ADR_SPACE_EC,
 791                                                    &acpi_ec_space_handler);
 792         if (ACPI_FAILURE(status))
 793                 return -ENODEV;
 794
 795         status = acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 796         if (ACPI_FAILURE(status))
 797                 return -ENODEV;
 798
 799         return 0;
 800 }
 801
 802 static acpi_status __init
 803 acpi_fake_ecdt_callback(acpi_handle handle,
 804                         u32 Level, void *context, void **retval)
 805 {
 806         acpi_status status;
 807
 808         mutex_init(&ec_ecdt->lock);
 809         if (acpi_ec_mode == EC_INTR) {
 810                 init_waitqueue_head(&ec_ecdt->wait);
 811         }
 812         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 813                                      acpi_ec_io_ports, ec_ecdt);
 814         if (ACPI_FAILURE(status))
 815                 return status;
 816
 817         ec_ecdt->uid = -1;
 818         acpi_evaluate_integer(handle, "_UID", NULL, &ec_ecdt->uid);
 819
 820         status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec_ecdt->gpe);
 821         if (ACPI_FAILURE(status))
 822                 return status;
 823         ec_ecdt->global_lock = TRUE;
 824         ec_ecdt->handle = handle;
 825
 826         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "GPE=0x%02lx, ports=0x%2lx, 0x%2lx",
 827                           ec_ecdt->gpe, ec_ecdt->command_addr,
 828                           ec_ecdt->data_addr));
 829
 830         return AE_CTRL_TERMINATE;
 831 }
 832
 833 /*
 834  * Some BIOS (such as some from Gateway laptops) access EC region very early
 835  * such as in BAT0._INI or EC._INI before an EC device is found and
 836  * do not provide an ECDT. According to ACPI spec, ECDT isn't mandatorily
 837  * required, but if EC regison is accessed early, it is required.
 838  * The routine tries to workaround the BIOS bug by pre-scan EC device
 839  * It assumes that _CRS, _HID, _GPE, _UID methods of EC don't touch any
 840  * op region (since _REG isn't invoked yet). The assumption is true for
 841  * all systems found.
 842  */
 843 static int __init acpi_ec_fake_ecdt(void)
 844 {
 845         acpi_status status;
 846         int ret = 0;
 847
 848         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Try to make an fake ECDT"));
 849
 850         ec_ecdt = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 851         if (!ec_ecdt) {
 852                 ret = -ENOMEM;
 853                 goto error;
 854         }
 855
 856         status = acpi_get_devices(ACPI_EC_HID,
 857                                   acpi_fake_ecdt_callback, NULL, NULL);
 858         if (ACPI_FAILURE(status)) {
 859                 kfree(ec_ecdt);
 860                 ec_ecdt = NULL;
 861                 ret = -ENODEV;
 862                 ACPI_EXCEPTION((AE_INFO, status, "Can't make an fake ECDT"));
 863                 goto error;
 864         }
 865         return 0;
 866       error:
 867         return ret;
 868 }
 869
 870 static int __init acpi_ec_get_real_ecdt(void)
 871 {
 872         acpi_status status;
 873         struct acpi_table_ecdt *ecdt_ptr;
 874
 875         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 876                                 (struct acpi_table_header **)&ecdt_ptr);
 877         if (ACPI_FAILURE(status))
 878                 return -ENODEV;
 879
 880         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found ECDT"));
 881
 882         /*
 883          * Generate a temporary ec context to use until the namespace is scanned
 884          */
 885         ec_ecdt = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 886         if (!ec_ecdt)
 887                 return -ENOMEM;
 888
 889         mutex_init(&ec_ecdt->lock);
 890         if (acpi_ec_mode == EC_INTR) {
 891                 init_waitqueue_head(&ec_ecdt->wait);
 892         }
 893         ec_ecdt->command_addr = ecdt_ptr->control.address;
 894         ec_ecdt->data_addr = ecdt_ptr->data.address;
 895         ec_ecdt->gpe = ecdt_ptr->gpe;
 896         /* use the GL just to be safe */
 897         ec_ecdt->global_lock = TRUE;
 898         ec_ecdt->uid = ecdt_ptr->uid;
 899
 900         status = acpi_get_handle(NULL, ecdt_ptr->id, &ec_ecdt->handle);
 901         if (ACPI_FAILURE(status)) {
 902                 goto error;
 903         }
 904
 905         return 0;
 906       error:
 907         ACPI_EXCEPTION((AE_INFO, status, "Could not use ECDT"));
 908         kfree(ec_ecdt);
 909         ec_ecdt = NULL;
 910
 911         return -ENODEV;
 912 }
 913
 914 static int __initdata acpi_fake_ecdt_enabled;
 915 int __init acpi_ec_ecdt_probe(void)
 916 {
 917         acpi_status status;
 918         int ret;
 919
 920         ret = acpi_ec_get_real_ecdt();
 921         /* Try to make a fake ECDT */
 922         if (ret && acpi_fake_ecdt_enabled) {
 923                 ret = acpi_ec_fake_ecdt();
 924         }
 925
 926         if (ret)
 927                 return 0;
 928
 929         /*
 930          * Install GPE handler
 931          */
 932         status = acpi_install_gpe_handler(NULL, ec_ecdt->gpe,
 933                                           ACPI_GPE_EDGE_TRIGGERED,
 934                                           &acpi_ec_gpe_handler, ec_ecdt);
 935         if (ACPI_FAILURE(status)) {
 936                 goto error;
 937         }
 938         acpi_set_gpe_type(NULL, ec_ecdt->gpe, ACPI_GPE_TYPE_RUNTIME);
 939         acpi_enable_gpe(NULL, ec_ecdt->gpe, ACPI_NOT_ISR);
 940
 941         status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
 942                                                     ACPI_ADR_SPACE_EC,
 943                                                     &acpi_ec_space_handler,
 944                                                     &acpi_ec_space_setup,
 945                                                     ec_ecdt);
 946         if (ACPI_FAILURE(status)) {
 947                 acpi_remove_gpe_handler(NULL, ec_ecdt->gpe,
 948                                         &acpi_ec_gpe_handler);
 949                 goto error;
 950         }
 951
 952         return 0;
 953
 954       error:
 955         ACPI_EXCEPTION((AE_INFO, status, "Could not use ECDT"));
 956         kfree(ec_ecdt);
 957         ec_ecdt = NULL;
 958
 959         return -ENODEV;
 960 }
 961
 962 static int __init acpi_ec_init(void)
 963 {
 964         int result = 0;
 965
 966         if (acpi_disabled)
 967                 return 0;
 968
 969         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
 970         if (!acpi_ec_dir)
 971                 return -ENODEV;
 972
 973         /* Now register the driver for the EC */
 974         result = acpi_bus_register_driver(&acpi_ec_driver);
 975         if (result < 0) {
 976                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 977                 return -ENODEV;
 978         }
 979
 980         return result;
 981 }
 982
 983 subsys_initcall(acpi_ec_init);
 984
 985 /* EC driver currently not unloadable */
 986 #if 0
 987 static void __exit acpi_ec_exit(void)
 988 {
 989
 990         acpi_bus_unregister_driver(&acpi_ec_driver);
 991
 992         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 993
 994         return;
 995 }
 996 #endif                          /* 0 */
 997
 998 static int __init acpi_fake_ecdt_setup(char *str)
 999 {
1000         acpi_fake_ecdt_enabled = 1;
1001         return 1;
1002 }
1003
1004 __setup("acpi_fake_ecdt", acpi_fake_ecdt_setup);
1005 static int __init acpi_ec_set_intr_mode(char *str)
1006 {
1007         int intr;
1008
1009         if (!get_option(&str, &intr))
1010                 return 0;
1011
1012         if (intr) {
1013                 acpi_ec_mode = EC_INTR;
1014         } else {
1015                 acpi_ec_mode = EC_POLL;
1016         }
1017         acpi_ec_driver.ops.add = acpi_ec_add;
1018         printk(KERN_NOTICE PREFIX "%s mode.\n",
1019                           intr ? "interrupt" : "polling");
1020
1021         return 1;
1022 }
1023
1024 __setup("ec_intr=", acpi_ec_set_intr_mode);