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("ec");
  42 #define ACPI_EC_COMPONENT               0x00100000
  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 #undef PREFIX
  48 #define PREFIX                          "ACPI: EC: "
  49 /* EC status register */
  50 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  51 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  52 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  53 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  54 /* EC commands */
  55 enum ec_command {
  56         ACPI_EC_COMMAND_READ = 0x80,
  57         ACPI_EC_COMMAND_WRITE = 0x81,
  58         ACPI_EC_BURST_ENABLE = 0x82,
  59         ACPI_EC_BURST_DISABLE = 0x83,
  60         ACPI_EC_COMMAND_QUERY = 0x84,
  61 };
  62 /* EC events */
  63 enum ec_event {
  64         ACPI_EC_EVENT_OBF_1 = 1,        /* Output buffer full */
  65         ACPI_EC_EVENT_IBF_0,    /* Input buffer empty */
  66 };
  67
  68 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  69 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  70
  71 static enum ec_mode {
  72         EC_INTR = 1,            /* Output buffer full */
  73         EC_POLL,                /* Input buffer empty */
  74 } acpi_ec_mode = EC_INTR;
  75
  76 static int acpi_ec_remove(struct acpi_device *device, int type);
  77 static int acpi_ec_start(struct acpi_device *device);
  78 static int acpi_ec_stop(struct acpi_device *device, int type);
  79 static int acpi_ec_add(struct acpi_device *device);
  80
  81 static struct acpi_driver acpi_ec_driver = {
  82         .name = "ec",
  83         .class = ACPI_EC_CLASS,
  84         .ids = ACPI_EC_HID,
  85         .ops = {
  86                 .add = acpi_ec_add,
  87                 .remove = acpi_ec_remove,
  88                 .start = acpi_ec_start,
  89                 .stop = acpi_ec_stop,
  90                 },
  91 };
  92
  93 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  94 static struct acpi_ec {
  95         acpi_handle handle;
  96         unsigned long uid;
  97         unsigned long gpe;
  98         unsigned long command_addr;
  99         unsigned long data_addr;
 100         unsigned long global_lock;
 101         struct mutex lock;
 102         atomic_t query_pending;
 103         atomic_t event_count;
 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                                        unsigned old_count)
 137 {
 138         u8 status = acpi_ec_read_status(ec);
 139         if (old_count == atomic_read(&ec->event_count))
 140                 return 0;
 141         if (event == ACPI_EC_EVENT_OBF_1) {
 142                 if (status & ACPI_EC_FLAG_OBF)
 143                         return 1;
 144         } else if (event == ACPI_EC_EVENT_IBF_0) {
 145                 if (!(status & ACPI_EC_FLAG_IBF))
 146                         return 1;
 147         }
 148
 149         return 0;
 150 }
 151
 152 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, unsigned count)
 153 {
 154         if (acpi_ec_mode == EC_POLL) {
 155                 unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 156                 while (time_before(jiffies, delay)) {
 157                         if (acpi_ec_check_status(ec, event, 0))
 158                                 return 0;
 159                 }
 160         } else {
 161                 if (wait_event_timeout(ec->wait,
 162                                        acpi_ec_check_status(ec, event, count),
 163                                        msecs_to_jiffies(ACPI_EC_DELAY)) ||
 164                     acpi_ec_check_status(ec, event, 0)) {
 165                         return 0;
 166                 } else {
 167                         printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
 168                                " status = %d, expect_event = %d\n",
 169                                acpi_ec_read_status(ec), event);
 170                 }
 171         }
 172
 173         return -ETIME;
 174 }
 175
 176 #ifdef ACPI_FUTURE_USAGE
 177 /*
 178  * Note: samsung nv5000 doesn't work with ec burst mode.
 179  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 180  */
 181 int acpi_ec_enter_burst_mode(struct acpi_ec *ec)
 182 {
 183         u8 tmp = 0;
 184         u8 status = 0;
 185
 186         status = acpi_ec_read_status(ec);
 187         if (status != -EINVAL && !(status & ACPI_EC_FLAG_BURST)) {
 188                 status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 189                 if (status)
 190                         goto end;
 191                 acpi_ec_write_cmd(ec, ACPI_EC_BURST_ENABLE);
 192                 status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1);
 193                 tmp = acpi_ec_read_data(ec);
 194                 if (tmp != 0x90) {      /* Burst ACK byte */
 195                         return -EINVAL;
 196                 }
 197         }
 198
 199         atomic_set(&ec->leaving_burst, 0);
 200         return 0;
 201       end:
 202         ACPI_EXCEPTION((AE_INFO, status, "EC wait, burst mode"));
 203         return -1;
 204 }
 205
 206 int acpi_ec_leave_burst_mode(struct acpi_ec *ec)
 207 {
 208         u8 status = 0;
 209
 210         status = acpi_ec_read_status(ec);
 211         if (status != -EINVAL && (status & ACPI_EC_FLAG_BURST)) {
 212                 status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 213                 if (status)
 214                         goto end;
 215                 acpi_ec_write_cmd(ec, ACPI_EC_BURST_DISABLE);
 216                 acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0);
 217         }
 218         atomic_set(&ec->leaving_burst, 1);
 219         return 0;
 220       end:
 221         ACPI_EXCEPTION((AE_INFO, status, "EC leave burst mode"));
 222         return -1;
 223 }
 224 #endif                          /* ACPI_FUTURE_USAGE */
 225
 226 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
 227                                         const u8 * wdata, unsigned wdata_len,
 228                                         u8 * rdata, unsigned rdata_len)
 229 {
 230         int result = 0;
 231         unsigned count = atomic_read(&ec->event_count);
 232         acpi_ec_write_cmd(ec, command);
 233
 234         for (; wdata_len > 0; --wdata_len) {
 235                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count);
 236                 if (result) {
 237                         printk(KERN_ERR PREFIX
 238                                "write_cmd timeout, command = %d\n", command);
 239                         goto end;
 240                 }
 241                 count = atomic_read(&ec->event_count);
 242                 acpi_ec_write_data(ec, *(wdata++));
 243         }
 244
 245         if (!rdata_len) {
 246                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, count);
 247                 if (result) {
 248                         printk(KERN_ERR PREFIX
 249                                "finish-write timeout, command = %d\n", command);
 250                         goto end;
 251                 }
 252         } else if (command == ACPI_EC_COMMAND_QUERY) {
 253                 atomic_set(&ec->query_pending, 0);
 254         }
 255
 256         for (; rdata_len > 0; --rdata_len) {
 257                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, count);
 258                 if (result) {
 259                         printk(KERN_ERR PREFIX "read timeout, command = %d\n",
 260                                command);
 261                         goto end;
 262                 }
 263                 count = atomic_read(&ec->event_count);
 264                 *(rdata++) = acpi_ec_read_data(ec);
 265         }
 266       end:
 267         return result;
 268 }
 269
 270 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
 271                                const u8 * wdata, unsigned wdata_len,
 272                                u8 * rdata, unsigned rdata_len)
 273 {
 274         int status;
 275         u32 glk;
 276
 277         if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
 278                 return -EINVAL;
 279
 280         if (rdata)
 281                 memset(rdata, 0, rdata_len);
 282
 283         mutex_lock(&ec->lock);
 284         if (ec->global_lock) {
 285                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 286                 if (ACPI_FAILURE(status)) {
 287                         mutex_unlock(&ec->lock);
 288                         return -ENODEV;
 289                 }
 290         }
 291
 292         /* Make sure GPE is enabled before doing transaction */
 293         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 294
 295         status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
 296         if (status) {
 297                 printk(KERN_DEBUG PREFIX
 298                        "input buffer is not empty, aborting transaction\n");
 299                 goto end;
 300         }
 301
 302         status = acpi_ec_transaction_unlocked(ec, command,
 303                                               wdata, wdata_len,
 304                                               rdata, rdata_len);
 305
 306       end:
 307
 308         if (ec->global_lock)
 309                 acpi_release_global_lock(glk);
 310         mutex_unlock(&ec->lock);
 311
 312         return status;
 313 }
 314
 315 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 316 {
 317         int result;
 318         u8 d;
 319
 320         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
 321                                      &address, 1, &d, 1);
 322         *data = d;
 323         return result;
 324 }
 325
 326 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 327 {
 328         u8 wdata[2] = { address, data };
 329         return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
 330                                    wdata, 2, NULL, 0);
 331 }
 332
 333 /*
 334  * Externally callable EC access functions. For now, assume 1 EC only
 335  */
 336 int ec_read(u8 addr, u8 * val)
 337 {
 338         struct acpi_ec *ec;
 339         int err;
 340         u8 temp_data;
 341
 342         if (!first_ec)
 343                 return -ENODEV;
 344
 345         ec = acpi_driver_data(first_ec);
 346
 347         err = acpi_ec_read(ec, addr, &temp_data);
 348
 349         if (!err) {
 350                 *val = temp_data;
 351                 return 0;
 352         } else
 353                 return err;
 354 }
 355
 356 EXPORT_SYMBOL(ec_read);
 357
 358 int ec_write(u8 addr, u8 val)
 359 {
 360         struct acpi_ec *ec;
 361         int err;
 362
 363         if (!first_ec)
 364                 return -ENODEV;
 365
 366         ec = acpi_driver_data(first_ec);
 367
 368         err = acpi_ec_write(ec, addr, val);
 369
 370         return err;
 371 }
 372
 373 EXPORT_SYMBOL(ec_write);
 374
 375 int ec_transaction(u8 command,
 376                    const u8 * wdata, unsigned wdata_len,
 377                    u8 * rdata, unsigned rdata_len)
 378 {
 379         struct acpi_ec *ec;
 380
 381         if (!first_ec)
 382                 return -ENODEV;
 383
 384         ec = acpi_driver_data(first_ec);
 385
 386         return acpi_ec_transaction(ec, command, wdata,
 387                                    wdata_len, rdata, rdata_len);
 388 }
 389
 390 EXPORT_SYMBOL(ec_transaction);
 391
 392 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 393 {
 394         int result;
 395         u8 d;
 396
 397         if (!ec || !data)
 398                 return -EINVAL;
 399
 400         /*
 401          * Query the EC to find out which _Qxx method we need to evaluate.
 402          * Note that successful completion of the query causes the ACPI_EC_SCI
 403          * bit to be cleared (and thus clearing the interrupt source).
 404          */
 405
 406         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1);
 407         if (result)
 408                 return result;
 409
 410         if (!d)
 411                 return -ENODATA;
 412
 413         *data = d;
 414         return 0;
 415 }
 416
 417 /* --------------------------------------------------------------------------
 418                                 Event Management
 419    -------------------------------------------------------------------------- */
 420
 421 static void acpi_ec_gpe_query(void *ec_cxt)
 422 {
 423         struct acpi_ec *ec = (struct acpi_ec *)ec_cxt;
 424         u8 value = 0;
 425         char object_name[8];
 426
 427         if (!ec || acpi_ec_query(ec, &value))
 428                 return;
 429
 430         snprintf(object_name, 8, "_Q%2.2X", value);
 431
 432         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluating %s", object_name));
 433
 434         acpi_evaluate_object(ec->handle, object_name, NULL, NULL);
 435 }
 436
 437 static u32 acpi_ec_gpe_handler(void *data)
 438 {
 439         acpi_status status = AE_OK;
 440         u8 value;
 441         struct acpi_ec *ec = (struct acpi_ec *)data;
 442         atomic_inc(&ec->event_count);
 443         if (acpi_ec_mode == EC_INTR) {
 444                 wake_up(&ec->wait);
 445         }
 446
 447         value = acpi_ec_read_status(ec);
 448         if ((value & ACPI_EC_FLAG_SCI) && !atomic_read(&ec->query_pending)) {
 449                 atomic_set(&ec->query_pending, 1);
 450                 status =
 451                     acpi_os_execute(OSL_EC_BURST_HANDLER, acpi_ec_gpe_query,
 452                                     ec);
 453         }
 454
 455         return status == AE_OK ?
 456             ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 457 }
 458
 459 /* --------------------------------------------------------------------------
 460                              Address Space Management
 461    -------------------------------------------------------------------------- */
 462
 463 static acpi_status
 464 acpi_ec_space_setup(acpi_handle region_handle,
 465                     u32 function, void *handler_context, void **return_context)
 466 {
 467         /*
 468          * The EC object is in the handler context and is needed
 469          * when calling the acpi_ec_space_handler.
 470          */
 471         *return_context = (function != ACPI_REGION_DEACTIVATE) ?
 472             handler_context : NULL;
 473
 474         return AE_OK;
 475 }
 476
 477 static acpi_status
 478 acpi_ec_space_handler(u32 function,
 479                       acpi_physical_address address,
 480                       u32 bit_width,
 481                       acpi_integer * value,
 482                       void *handler_context, void *region_context)
 483 {
 484         int result = 0;
 485         struct acpi_ec *ec = NULL;
 486         u64 temp = *value;
 487         acpi_integer f_v = 0;
 488         int i = 0;
 489
 490         if ((address > 0xFF) || !value || !handler_context)
 491                 return AE_BAD_PARAMETER;
 492
 493         if (bit_width != 8 && acpi_strict) {
 494                 return AE_BAD_PARAMETER;
 495         }
 496
 497         ec = (struct acpi_ec *)handler_context;
 498
 499       next_byte:
 500         switch (function) {
 501         case ACPI_READ:
 502                 temp = 0;
 503                 result = acpi_ec_read(ec, (u8) address, (u8 *) & temp);
 504                 break;
 505         case ACPI_WRITE:
 506                 result = acpi_ec_write(ec, (u8) address, (u8) temp);
 507                 break;
 508         default:
 509                 result = -EINVAL;
 510                 goto out;
 511                 break;
 512         }
 513
 514         bit_width -= 8;
 515         if (bit_width) {
 516                 if (function == ACPI_READ)
 517                         f_v |= temp << 8 * i;
 518                 if (function == ACPI_WRITE)
 519                         temp >>= 8;
 520                 i++;
 521                 address++;
 522                 goto next_byte;
 523         }
 524
 525         if (function == ACPI_READ) {
 526                 f_v |= temp << 8 * i;
 527                 *value = f_v;
 528         }
 529
 530       out:
 531         switch (result) {
 532         case -EINVAL:
 533                 return AE_BAD_PARAMETER;
 534                 break;
 535         case -ENODEV:
 536                 return AE_NOT_FOUND;
 537                 break;
 538         case -ETIME:
 539                 return AE_TIME;
 540                 break;
 541         default:
 542                 return AE_OK;
 543         }
 544 }
 545
 546 /* --------------------------------------------------------------------------
 547                               FS Interface (/proc)
 548    -------------------------------------------------------------------------- */
 549
 550 static struct proc_dir_entry *acpi_ec_dir;
 551
 552 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 553 {
 554         struct acpi_ec *ec = (struct acpi_ec *)seq->private;
 555
 556         if (!ec)
 557                 goto end;
 558
 559         seq_printf(seq, "gpe:                 0x%02x\n", (u32) ec->gpe);
 560         seq_printf(seq, "ports:                   0x%02x, 0x%02x\n",
 561                    (u32) ec->command_addr, (u32) ec->data_addr);
 562         seq_printf(seq, "use global lock:         %s\n",
 563                    ec->global_lock ? "yes" : "no");
 564         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 565
 566       end:
 567         return 0;
 568 }
 569
 570 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 571 {
 572         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 573 }
 574
 575 static struct file_operations acpi_ec_info_ops = {
 576         .open = acpi_ec_info_open_fs,
 577         .read = seq_read,
 578         .llseek = seq_lseek,
 579         .release = single_release,
 580         .owner = THIS_MODULE,
 581 };
 582
 583 static int acpi_ec_add_fs(struct acpi_device *device)
 584 {
 585         struct proc_dir_entry *entry = NULL;
 586
 587         if (!acpi_device_dir(device)) {
 588                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 589                                                      acpi_ec_dir);
 590                 if (!acpi_device_dir(device))
 591                         return -ENODEV;
 592         }
 593
 594         entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
 595                                   acpi_device_dir(device));
 596         if (!entry)
 597                 return -ENODEV;
 598         else {
 599                 entry->proc_fops = &acpi_ec_info_ops;
 600                 entry->data = acpi_driver_data(device);
 601                 entry->owner = THIS_MODULE;
 602         }
 603
 604         return 0;
 605 }
 606
 607 static int acpi_ec_remove_fs(struct acpi_device *device)
 608 {
 609
 610         if (acpi_device_dir(device)) {
 611                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 612                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 613                 acpi_device_dir(device) = NULL;
 614         }
 615
 616         return 0;
 617 }
 618
 619 /* --------------------------------------------------------------------------
 620                                Driver Interface
 621    -------------------------------------------------------------------------- */
 622
 623 static int acpi_ec_add(struct acpi_device *device)
 624 {
 625         int result = 0;
 626         acpi_status status = AE_OK;
 627         struct acpi_ec *ec = NULL;
 628
 629         if (!device)
 630                 return -EINVAL;
 631
 632         ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 633         if (!ec)
 634                 return -ENOMEM;
 635
 636         ec->handle = device->handle;
 637         ec->uid = -1;
 638         mutex_init(&ec->lock);
 639         atomic_set(&ec->query_pending, 0);
 640         atomic_set(&ec->event_count, 1);
 641         if (acpi_ec_mode == EC_INTR) {
 642                 atomic_set(&ec->leaving_burst, 1);
 643                 init_waitqueue_head(&ec->wait);
 644         }
 645         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 646         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 647         acpi_driver_data(device) = ec;
 648
 649         /* Use the global lock for all EC transactions? */
 650         acpi_evaluate_integer(ec->handle, "_GLK", NULL, &ec->global_lock);
 651
 652         /* XXX we don't test uids, because on some boxes ecdt uid = 0, see:
 653            http://bugzilla.kernel.org/show_bug.cgi?id=6111 */
 654         if (ec_ecdt) {
 655                 acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
 656                                                   ACPI_ADR_SPACE_EC,
 657                                                   &acpi_ec_space_handler);
 658
 659                 acpi_remove_gpe_handler(NULL, ec_ecdt->gpe,
 660                                         &acpi_ec_gpe_handler);
 661
 662                 kfree(ec_ecdt);
 663         }
 664
 665         /* Get GPE bit assignment (EC events). */
 666         /* TODO: Add support for _GPE returning a package */
 667         status = acpi_evaluate_integer(ec->handle, "_GPE", NULL, &ec->gpe);
 668         if (ACPI_FAILURE(status)) {
 669                 ACPI_EXCEPTION((AE_INFO, status,
 670                                 "Obtaining GPE bit assignment"));
 671                 result = -ENODEV;
 672                 goto end;
 673         }
 674
 675         result = acpi_ec_add_fs(device);
 676         if (result)
 677                 goto end;
 678
 679         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s [%s] (gpe %d) interrupt mode.",
 680                           acpi_device_name(device), acpi_device_bid(device),
 681                           (u32) ec->gpe));
 682
 683         if (!first_ec)
 684                 first_ec = device;
 685
 686       end:
 687         if (result)
 688                 kfree(ec);
 689
 690         return result;
 691 }
 692
 693 static int acpi_ec_remove(struct acpi_device *device, int type)
 694 {
 695         struct acpi_ec *ec = NULL;
 696
 697         if (!device)
 698                 return -EINVAL;
 699
 700         ec = acpi_driver_data(device);
 701
 702         acpi_ec_remove_fs(device);
 703
 704         kfree(ec);
 705
 706         return 0;
 707 }
 708
 709 static acpi_status
 710 acpi_ec_io_ports(struct acpi_resource *resource, void *context)
 711 {
 712         struct acpi_ec *ec = (struct acpi_ec *)context;
 713
 714         if (resource->type != ACPI_RESOURCE_TYPE_IO) {
 715                 return AE_OK;
 716         }
 717
 718         /*
 719          * The first address region returned is the data port, and
 720          * the second address region returned is the status/command
 721          * port.
 722          */
 723         if (ec->data_addr == 0) {
 724                 ec->data_addr = resource->data.io.minimum;
 725         } else if (ec->command_addr == 0) {
 726                 ec->command_addr = resource->data.io.minimum;
 727         } else {
 728                 return AE_CTRL_TERMINATE;
 729         }
 730
 731         return AE_OK;
 732 }
 733
 734 static int acpi_ec_start(struct acpi_device *device)
 735 {
 736         acpi_status status = AE_OK;
 737         struct acpi_ec *ec = NULL;
 738
 739         if (!device)
 740                 return -EINVAL;
 741
 742         ec = acpi_driver_data(device);
 743
 744         if (!ec)
 745                 return -EINVAL;
 746
 747         /*
 748          * Get I/O port addresses. Convert to GAS format.
 749          */
 750         status = acpi_walk_resources(ec->handle, METHOD_NAME__CRS,
 751                                      acpi_ec_io_ports, ec);
 752         if (ACPI_FAILURE(status) || ec->command_addr == 0) {
 753                 ACPI_EXCEPTION((AE_INFO, status,
 754                                 "Error getting I/O port addresses"));
 755                 return -ENODEV;
 756         }
 757
 758         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "gpe=0x%02lx, ports=0x%2lx,0x%2lx",
 759                           ec->gpe, ec->command_addr, ec->data_addr));
 760
 761         /*
 762          * Install GPE handler
 763          */
 764         status = acpi_install_gpe_handler(NULL, ec->gpe,
 765                                           ACPI_GPE_EDGE_TRIGGERED,
 766                                           &acpi_ec_gpe_handler, ec);
 767         if (ACPI_FAILURE(status)) {
 768                 return -ENODEV;
 769         }
 770         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 771         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 772
 773         status = acpi_install_address_space_handler(ec->handle,
 774                                                     ACPI_ADR_SPACE_EC,
 775                                                     &acpi_ec_space_handler,
 776                                                     &acpi_ec_space_setup, ec);
 777         if (ACPI_FAILURE(status)) {
 778                 acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 779                 return -ENODEV;
 780         }
 781
 782         return AE_OK;
 783 }
 784
 785 static int acpi_ec_stop(struct acpi_device *device, int type)
 786 {
 787         acpi_status status = AE_OK;
 788         struct acpi_ec *ec = NULL;
 789
 790         if (!device)
 791                 return -EINVAL;
 792
 793         ec = acpi_driver_data(device);
 794
 795         status = acpi_remove_address_space_handler(ec->handle,
 796                                                    ACPI_ADR_SPACE_EC,
 797                                                    &acpi_ec_space_handler);
 798         if (ACPI_FAILURE(status))
 799                 return -ENODEV;
 800
 801         status = acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 802         if (ACPI_FAILURE(status))
 803                 return -ENODEV;
 804
 805         return 0;
 806 }
 807
 808 static acpi_status __init
 809 acpi_fake_ecdt_callback(acpi_handle handle,
 810                         u32 Level, void *context, void **retval)
 811 {
 812         acpi_status status;
 813
 814         mutex_init(&ec_ecdt->lock);
 815         atomic_set(&ec_ecdt->event_count, 1);
 816         if (acpi_ec_mode == EC_INTR) {
 817                 init_waitqueue_head(&ec_ecdt->wait);
 818         }
 819         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 820                                      acpi_ec_io_ports, ec_ecdt);
 821         if (ACPI_FAILURE(status))
 822                 return status;
 823
 824         ec_ecdt->uid = -1;
 825         acpi_evaluate_integer(handle, "_UID", NULL, &ec_ecdt->uid);
 826
 827         status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec_ecdt->gpe);
 828         if (ACPI_FAILURE(status))
 829                 return status;
 830         ec_ecdt->global_lock = TRUE;
 831         ec_ecdt->handle = handle;
 832
 833         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "GPE=0x%02lx, ports=0x%2lx, 0x%2lx",
 834                           ec_ecdt->gpe, ec_ecdt->command_addr,
 835                           ec_ecdt->data_addr));
 836
 837         return AE_CTRL_TERMINATE;
 838 }
 839
 840 /*
 841  * Some BIOS (such as some from Gateway laptops) access EC region very early
 842  * such as in BAT0._INI or EC._INI before an EC device is found and
 843  * do not provide an ECDT. According to ACPI spec, ECDT isn't mandatorily
 844  * required, but if EC regison is accessed early, it is required.
 845  * The routine tries to workaround the BIOS bug by pre-scan EC device
 846  * It assumes that _CRS, _HID, _GPE, _UID methods of EC don't touch any
 847  * op region (since _REG isn't invoked yet). The assumption is true for
 848  * all systems found.
 849  */
 850 static int __init acpi_ec_fake_ecdt(void)
 851 {
 852         acpi_status status;
 853         int ret = 0;
 854
 855         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Try to make an fake ECDT"));
 856
 857         ec_ecdt = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 858         if (!ec_ecdt) {
 859                 ret = -ENOMEM;
 860                 goto error;
 861         }
 862
 863         status = acpi_get_devices(ACPI_EC_HID,
 864                                   acpi_fake_ecdt_callback, NULL, NULL);
 865         if (ACPI_FAILURE(status)) {
 866                 kfree(ec_ecdt);
 867                 ec_ecdt = NULL;
 868                 ret = -ENODEV;
 869                 ACPI_EXCEPTION((AE_INFO, status, "Can't make an fake ECDT"));
 870                 goto error;
 871         }
 872         return 0;
 873       error:
 874         return ret;
 875 }
 876
 877 static int __init acpi_ec_get_real_ecdt(void)
 878 {
 879         acpi_status status;
 880         struct acpi_table_ecdt *ecdt_ptr;
 881
 882         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 883                                 (struct acpi_table_header **)&ecdt_ptr);
 884         if (ACPI_FAILURE(status))
 885                 return -ENODEV;
 886
 887         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found ECDT"));
 888
 889         /*
 890          * Generate a temporary ec context to use until the namespace is scanned
 891          */
 892         ec_ecdt = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 893         if (!ec_ecdt)
 894                 return -ENOMEM;
 895
 896         mutex_init(&ec_ecdt->lock);
 897         atomic_set(&ec_ecdt->event_count, 1);
 898         if (acpi_ec_mode == EC_INTR) {
 899                 init_waitqueue_head(&ec_ecdt->wait);
 900         }
 901         ec_ecdt->command_addr = ecdt_ptr->control.address;
 902         ec_ecdt->data_addr = ecdt_ptr->data.address;
 903         ec_ecdt->gpe = ecdt_ptr->gpe;
 904         /* use the GL just to be safe */
 905         ec_ecdt->global_lock = TRUE;
 906         ec_ecdt->uid = ecdt_ptr->uid;
 907
 908         status = acpi_get_handle(NULL, ecdt_ptr->id, &ec_ecdt->handle);
 909         if (ACPI_FAILURE(status)) {
 910                 goto error;
 911         }
 912
 913         return 0;
 914       error:
 915         ACPI_EXCEPTION((AE_INFO, status, "Could not use ECDT"));
 916         kfree(ec_ecdt);
 917         ec_ecdt = NULL;
 918
 919         return -ENODEV;
 920 }
 921
 922 static int __initdata acpi_fake_ecdt_enabled;
 923 int __init acpi_ec_ecdt_probe(void)
 924 {
 925         acpi_status status;
 926         int ret;
 927
 928         ret = acpi_ec_get_real_ecdt();
 929         /* Try to make a fake ECDT */
 930         if (ret && acpi_fake_ecdt_enabled) {
 931                 ret = acpi_ec_fake_ecdt();
 932         }
 933
 934         if (ret)
 935                 return 0;
 936
 937         /*
 938          * Install GPE handler
 939          */
 940         status = acpi_install_gpe_handler(NULL, ec_ecdt->gpe,
 941                                           ACPI_GPE_EDGE_TRIGGERED,
 942                                           &acpi_ec_gpe_handler, ec_ecdt);
 943         if (ACPI_FAILURE(status)) {
 944                 goto error;
 945         }
 946         acpi_set_gpe_type(NULL, ec_ecdt->gpe, ACPI_GPE_TYPE_RUNTIME);
 947         acpi_enable_gpe(NULL, ec_ecdt->gpe, ACPI_NOT_ISR);
 948
 949         status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
 950                                                     ACPI_ADR_SPACE_EC,
 951                                                     &acpi_ec_space_handler,
 952                                                     &acpi_ec_space_setup,
 953                                                     ec_ecdt);
 954         if (ACPI_FAILURE(status)) {
 955                 acpi_remove_gpe_handler(NULL, ec_ecdt->gpe,
 956                                         &acpi_ec_gpe_handler);
 957                 goto error;
 958         }
 959
 960         return 0;
 961
 962       error:
 963         ACPI_EXCEPTION((AE_INFO, status, "Could not use ECDT"));
 964         kfree(ec_ecdt);
 965         ec_ecdt = NULL;
 966
 967         return -ENODEV;
 968 }
 969
 970 static int __init acpi_ec_init(void)
 971 {
 972         int result = 0;
 973
 974         if (acpi_disabled)
 975                 return 0;
 976
 977         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
 978         if (!acpi_ec_dir)
 979                 return -ENODEV;
 980
 981         /* Now register the driver for the EC */
 982         result = acpi_bus_register_driver(&acpi_ec_driver);
 983         if (result < 0) {
 984                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 985                 return -ENODEV;
 986         }
 987
 988         return result;
 989 }
 990
 991 subsys_initcall(acpi_ec_init);
 992
 993 /* EC driver currently not unloadable */
 994 #if 0
 995 static void __exit acpi_ec_exit(void)
 996 {
 997
 998         acpi_bus_unregister_driver(&acpi_ec_driver);
 999
1000         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1001
1002         return;
1003 }
1004 #endif                          /* 0 */
1005
1006 static int __init acpi_fake_ecdt_setup(char *str)
1007 {
1008         acpi_fake_ecdt_enabled = 1;
1009         return 1;
1010 }
1011
1012 __setup("acpi_fake_ecdt", acpi_fake_ecdt_setup);
1013 static int __init acpi_ec_set_intr_mode(char *str)
1014 {
1015         int intr;
1016
1017         if (!get_option(&str, &intr))
1018                 return 0;
1019
1020         if (intr) {
1021                 acpi_ec_mode = EC_INTR;
1022         } else {
1023                 acpi_ec_mode = EC_POLL;
1024         }
1025         acpi_ec_driver.ops.add = acpi_ec_add;
1026         printk(KERN_NOTICE PREFIX "%s mode.\n", intr ? "interrupt" : "polling");
1027
1028         return 1;
1029 }
1030
1031 __setup("ec_intr=", acpi_ec_set_intr_mode);