err.no Git - linux-2.6/blob - drivers/acpi/ec.c

   1 /*
   2  *  ec.c - ACPI Embedded Controller Driver (v2.0)
   3  *
   4  *  Copyright (C) 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
   5  *  Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
   6  *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
   7  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   8  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   9  *
  10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or (at
  15  *  your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful, but
  18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  *  General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License along
  23  *  with this program; if not, write to the Free Software Foundation, Inc.,
  24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  25  *
  26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  27  */
  28
  29 /* Uncomment next line to get verbose print outs*/
  30 /* #define DEBUG */
  31
  32 #include <linux/kernel.h>
  33 #include <linux/module.h>
  34 #include <linux/init.h>
  35 #include <linux/types.h>
  36 #include <linux/delay.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/seq_file.h>
  39 #include <linux/interrupt.h>
  40 #include <linux/list.h>
  41 #include <asm/io.h>
  42 #include <acpi/acpi_bus.h>
  43 #include <acpi/acpi_drivers.h>
  44 #include <acpi/actypes.h>
  45
  46 #define ACPI_EC_CLASS                   "embedded_controller"
  47 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  48 #define ACPI_EC_FILE_INFO               "info"
  49
  50 #undef PREFIX
  51 #define PREFIX                          "ACPI: EC: "
  52
  53 /* EC status register */
  54 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  55 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  56 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  57 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  58
  59 /* EC commands */
  60 enum ec_command {
  61         ACPI_EC_COMMAND_READ = 0x80,
  62         ACPI_EC_COMMAND_WRITE = 0x81,
  63         ACPI_EC_BURST_ENABLE = 0x82,
  64         ACPI_EC_BURST_DISABLE = 0x83,
  65         ACPI_EC_COMMAND_QUERY = 0x84,
  66 };
  67
  68 /* EC events */
  69 enum ec_event {
  70         ACPI_EC_EVENT_OBF_1 = 1,        /* Output buffer full */
  71         ACPI_EC_EVENT_IBF_0,            /* Input buffer empty */
  72 };
  73
  74 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  75 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  76
  77 enum {
  78         EC_FLAGS_WAIT_GPE = 0,          /* Don't check status until GPE arrives */
  79         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  80         EC_FLAGS_GPE_MODE,              /* Expect GPE to be sent for status change */
  81         EC_FLAGS_NO_ADDRESS_GPE,        /* Expect GPE only for non-address event */
  82         EC_FLAGS_ADDRESS,               /* Address is being written */
  83         EC_FLAGS_NO_WDATA_GPE,          /* Don't expect WDATA GPE event */
  84         EC_FLAGS_WDATA,                 /* Data is being written */
  85         EC_FLAGS_NO_OBF1_GPE,           /* Don't expect GPE before read */
  86 };
  87
  88 static int acpi_ec_remove(struct acpi_device *device, int type);
  89 static int acpi_ec_start(struct acpi_device *device);
  90 static int acpi_ec_stop(struct acpi_device *device, int type);
  91 static int acpi_ec_add(struct acpi_device *device);
  92
  93 static const struct acpi_device_id ec_device_ids[] = {
  94         {"PNP0C09", 0},
  95         {"", 0},
  96 };
  97
  98 static struct acpi_driver acpi_ec_driver = {
  99         .name = "ec",
 100         .class = ACPI_EC_CLASS,
 101         .ids = ec_device_ids,
 102         .ops = {
 103                 .add = acpi_ec_add,
 104                 .remove = acpi_ec_remove,
 105                 .start = acpi_ec_start,
 106                 .stop = acpi_ec_stop,
 107                 },
 108 };
 109
 110 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
 111 /* External interfaces use first EC only, so remember */
 112 typedef int (*acpi_ec_query_func) (void *data);
 113
 114 struct acpi_ec_query_handler {
 115         struct list_head node;
 116         acpi_ec_query_func func;
 117         acpi_handle handle;
 118         void *data;
 119         u8 query_bit;
 120 };
 121
 122 static struct acpi_ec {
 123         acpi_handle handle;
 124         unsigned long gpe;
 125         unsigned long command_addr;
 126         unsigned long data_addr;
 127         unsigned long global_lock;
 128         unsigned long flags;
 129         struct mutex lock;
 130         wait_queue_head_t wait;
 131         struct list_head list;
 132         u8 handlers_installed;
 133 } *boot_ec, *first_ec;
 134
 135 /* --------------------------------------------------------------------------
 136                              Transaction Management
 137    -------------------------------------------------------------------------- */
 138
 139 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 140 {
 141         u8 x = inb(ec->command_addr);
 142         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
 143         return x;
 144 }
 145
 146 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 147 {
 148         u8 x = inb(ec->data_addr);
 149         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
 150         return inb(ec->data_addr);
 151 }
 152
 153 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 154 {
 155         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
 156         outb(command, ec->command_addr);
 157 }
 158
 159 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 160 {
 161         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
 162         outb(data, ec->data_addr);
 163 }
 164
 165 static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
 166 {
 167         if (test_bit(EC_FLAGS_WAIT_GPE, &ec->flags))
 168                 return 0;
 169         if (event == ACPI_EC_EVENT_OBF_1) {
 170                 if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_OBF)
 171                         return 1;
 172         } else if (event == ACPI_EC_EVENT_IBF_0) {
 173                 if (!(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
 174                         return 1;
 175         }
 176
 177         return 0;
 178 }
 179
 180 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 181 {
 182         int ret = 0;
 183
 184         if (unlikely(event == ACPI_EC_EVENT_OBF_1 &&
 185                      test_bit(EC_FLAGS_NO_OBF1_GPE, &ec->flags)))
 186                 force_poll = 1;
 187         if (unlikely(test_bit(EC_FLAGS_ADDRESS, &ec->flags) &&
 188                      test_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags)))
 189                 force_poll = 1;
 190         if (unlikely(test_bit(EC_FLAGS_WDATA, &ec->flags) &&
 191                      test_bit(EC_FLAGS_NO_WDATA_GPE, &ec->flags)))
 192                 force_poll = 1;
 193         if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&
 194             likely(!force_poll)) {
 195                 if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),
 196                                        msecs_to_jiffies(ACPI_EC_DELAY)))
 197                         goto end;
 198                 clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 199                 if (acpi_ec_check_status(ec, event)) {
 200                         if (event == ACPI_EC_EVENT_OBF_1) {
 201                                 /* miss OBF_1 GPE, don't expect it */
 202                                 pr_info(PREFIX "missing OBF confirmation, "
 203                                         "don't expect it any longer.\n");
 204                                 set_bit(EC_FLAGS_NO_OBF1_GPE, &ec->flags);
 205                         } else if (test_bit(EC_FLAGS_ADDRESS, &ec->flags)) {
 206                                 /* miss address GPE, don't expect it anymore */
 207                                 pr_info(PREFIX "missing address confirmation, "
 208                                         "don't expect it any longer.\n");
 209                                 set_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags);
 210                         } else if (test_bit(EC_FLAGS_WDATA, &ec->flags)) {
 211                                 /* miss write data GPE, don't expect it */
 212                                 pr_info(PREFIX "missing write data confirmation, "
 213                                         "don't expect it any longer.\n");
 214                                 set_bit(EC_FLAGS_NO_WDATA_GPE, &ec->flags);
 215                         } else {
 216                                 /* missing GPEs, switch back to poll mode */
 217                                 if (printk_ratelimit())
 218                                         pr_info(PREFIX "missing confirmations, "
 219                                                 "switch off interrupt mode.\n");
 220                                 clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 221                         }
 222                         goto end;
 223                 }
 224         } else {
 225                 unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 226                 clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 227                 while (time_before(jiffies, delay)) {
 228                         if (acpi_ec_check_status(ec, event))
 229                                 goto end;
 230                 }
 231         }
 232         pr_err(PREFIX "acpi_ec_wait timeout,"
 233                                " status = %d, expect_event = %d\n",
 234                                acpi_ec_read_status(ec), event);
 235         ret = -ETIME;
 236       end:
 237         clear_bit(EC_FLAGS_ADDRESS, &ec->flags);
 238         return ret;
 239 }
 240
 241 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
 242                                         const u8 * wdata, unsigned wdata_len,
 243                                         u8 * rdata, unsigned rdata_len,
 244                                         int force_poll)
 245 {
 246         int result = 0;
 247         set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 248         acpi_ec_write_cmd(ec, command);
 249         pr_debug(PREFIX "transaction start\n");
 250         for (; wdata_len > 0; --wdata_len) {
 251                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
 252                 if (result) {
 253                         pr_err(PREFIX
 254                                "write_cmd timeout, command = %d\n", command);
 255                         goto end;
 256                 }
 257                 /* mark the address byte written to EC */
 258                 if (rdata_len + wdata_len > 1)
 259                         set_bit(EC_FLAGS_ADDRESS, &ec->flags);
 260                 set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 261                 acpi_ec_write_data(ec, *(wdata++));
 262         }
 263
 264         if (!rdata_len) {
 265                 set_bit(EC_FLAGS_WDATA, &ec->flags);
 266                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
 267                 if (result) {
 268                         pr_err(PREFIX
 269                                "finish-write timeout, command = %d\n", command);
 270                         goto end;
 271                 }
 272         } else if (command == ACPI_EC_COMMAND_QUERY)
 273                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 274
 275         for (; rdata_len > 0; --rdata_len) {
 276                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, force_poll);
 277                 if (result) {
 278                         pr_err(PREFIX "read timeout, command = %d\n", command);
 279                         goto end;
 280                 }
 281                 /* Don't expect GPE after last read */
 282                 if (rdata_len > 1)
 283                         set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 284                 *(rdata++) = acpi_ec_read_data(ec);
 285         }
 286       end:
 287         pr_debug(PREFIX "transaction end\n");
 288         return result;
 289 }
 290
 291 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
 292                                const u8 * wdata, unsigned wdata_len,
 293                                u8 * rdata, unsigned rdata_len,
 294                                int force_poll)
 295 {
 296         int status;
 297         u32 glk;
 298
 299         if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
 300                 return -EINVAL;
 301
 302         if (rdata)
 303                 memset(rdata, 0, rdata_len);
 304
 305         mutex_lock(&ec->lock);
 306         if (ec->global_lock) {
 307                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 308                 if (ACPI_FAILURE(status)) {
 309                         mutex_unlock(&ec->lock);
 310                         return -ENODEV;
 311                 }
 312         }
 313
 314         status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
 315         if (status) {
 316                 pr_err(PREFIX "input buffer is not empty, "
 317                                 "aborting transaction\n");
 318                 goto end;
 319         }
 320
 321         status = acpi_ec_transaction_unlocked(ec, command,
 322                                               wdata, wdata_len,
 323                                               rdata, rdata_len,
 324                                               force_poll);
 325
 326       end:
 327
 328         if (ec->global_lock)
 329                 acpi_release_global_lock(glk);
 330         mutex_unlock(&ec->lock);
 331
 332         return status;
 333 }
 334
 335 /*
 336  * Note: samsung nv5000 doesn't work with ec burst mode.
 337  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 338  */
 339 int acpi_ec_burst_enable(struct acpi_ec *ec)
 340 {
 341         u8 d;
 342         return acpi_ec_transaction(ec, ACPI_EC_BURST_ENABLE, NULL, 0, &d, 1, 0);
 343 }
 344
 345 int acpi_ec_burst_disable(struct acpi_ec *ec)
 346 {
 347         return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0, 0);
 348 }
 349
 350 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 351 {
 352         int result;
 353         u8 d;
 354
 355         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
 356                                      &address, 1, &d, 1, 0);
 357         *data = d;
 358         return result;
 359 }
 360
 361 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 362 {
 363         u8 wdata[2] = { address, data };
 364         return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
 365                                    wdata, 2, NULL, 0, 0);
 366 }
 367
 368 /*
 369  * Externally callable EC access functions. For now, assume 1 EC only
 370  */
 371 int ec_burst_enable(void)
 372 {
 373         if (!first_ec)
 374                 return -ENODEV;
 375         return acpi_ec_burst_enable(first_ec);
 376 }
 377
 378 EXPORT_SYMBOL(ec_burst_enable);
 379
 380 int ec_burst_disable(void)
 381 {
 382         if (!first_ec)
 383                 return -ENODEV;
 384         return acpi_ec_burst_disable(first_ec);
 385 }
 386
 387 EXPORT_SYMBOL(ec_burst_disable);
 388
 389 int ec_read(u8 addr, u8 * val)
 390 {
 391         int err;
 392         u8 temp_data;
 393
 394         if (!first_ec)
 395                 return -ENODEV;
 396
 397         err = acpi_ec_read(first_ec, addr, &temp_data);
 398
 399         if (!err) {
 400                 *val = temp_data;
 401                 return 0;
 402         } else
 403                 return err;
 404 }
 405
 406 EXPORT_SYMBOL(ec_read);
 407
 408 int ec_write(u8 addr, u8 val)
 409 {
 410         int err;
 411
 412         if (!first_ec)
 413                 return -ENODEV;
 414
 415         err = acpi_ec_write(first_ec, addr, val);
 416
 417         return err;
 418 }
 419
 420 EXPORT_SYMBOL(ec_write);
 421
 422 int ec_transaction(u8 command,
 423                    const u8 * wdata, unsigned wdata_len,
 424                    u8 * rdata, unsigned rdata_len,
 425                    int force_poll)
 426 {
 427         if (!first_ec)
 428                 return -ENODEV;
 429
 430         return acpi_ec_transaction(first_ec, command, wdata,
 431                                    wdata_len, rdata, rdata_len,
 432                                    force_poll);
 433 }
 434
 435 EXPORT_SYMBOL(ec_transaction);
 436
 437 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 438 {
 439         int result;
 440         u8 d;
 441
 442         if (!ec || !data)
 443                 return -EINVAL;
 444
 445         /*
 446          * Query the EC to find out which _Qxx method we need to evaluate.
 447          * Note that successful completion of the query causes the ACPI_EC_SCI
 448          * bit to be cleared (and thus clearing the interrupt source).
 449          */
 450
 451         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
 452         if (result)
 453                 return result;
 454
 455         if (!d)
 456                 return -ENODATA;
 457
 458         *data = d;
 459         return 0;
 460 }
 461
 462 /* --------------------------------------------------------------------------
 463                                 Event Management
 464    -------------------------------------------------------------------------- */
 465 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 466                               acpi_handle handle, acpi_ec_query_func func,
 467                               void *data)
 468 {
 469         struct acpi_ec_query_handler *handler =
 470             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 471         if (!handler)
 472                 return -ENOMEM;
 473
 474         handler->query_bit = query_bit;
 475         handler->handle = handle;
 476         handler->func = func;
 477         handler->data = data;
 478         mutex_lock(&ec->lock);
 479         list_add(&handler->node, &ec->list);
 480         mutex_unlock(&ec->lock);
 481         return 0;
 482 }
 483
 484 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 485
 486 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 487 {
 488         struct acpi_ec_query_handler *handler, *tmp;
 489         mutex_lock(&ec->lock);
 490         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 491                 if (query_bit == handler->query_bit) {
 492                         list_del(&handler->node);
 493                         kfree(handler);
 494                 }
 495         }
 496         mutex_unlock(&ec->lock);
 497 }
 498
 499 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 500
 501 static void acpi_ec_gpe_query(void *ec_cxt)
 502 {
 503         struct acpi_ec *ec = ec_cxt;
 504         u8 value = 0;
 505         struct acpi_ec_query_handler *handler, copy;
 506
 507         if (!ec || acpi_ec_query(ec, &value))
 508                 return;
 509         mutex_lock(&ec->lock);
 510         list_for_each_entry(handler, &ec->list, node) {
 511                 if (value == handler->query_bit) {
 512                         /* have custom handler for this bit */
 513                         memcpy(&copy, handler, sizeof(copy));
 514                         mutex_unlock(&ec->lock);
 515                         if (copy.func) {
 516                                 copy.func(copy.data);
 517                         } else if (copy.handle) {
 518                                 acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
 519                         }
 520                         return;
 521                 }
 522         }
 523         mutex_unlock(&ec->lock);
 524 }
 525
 526 static u32 acpi_ec_gpe_handler(void *data)
 527 {
 528         acpi_status status = AE_OK;
 529         struct acpi_ec *ec = data;
 530
 531         pr_debug(PREFIX "~~~> interrupt\n");
 532         clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 533         if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
 534                 wake_up(&ec->wait);
 535
 536         if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_SCI) {
 537                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 538                         status = acpi_os_execute(OSL_EC_BURST_HANDLER,
 539                                 acpi_ec_gpe_query, ec);
 540         } else if (unlikely(!test_bit(EC_FLAGS_GPE_MODE, &ec->flags))) {
 541                 /* this is non-query, must be confirmation */
 542                 if (printk_ratelimit())
 543                         pr_info(PREFIX "non-query interrupt received,"
 544                                 " switching to interrupt mode\n");
 545                 set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 546         }
 547
 548         return ACPI_SUCCESS(status) ?
 549             ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 550 }
 551
 552 /* --------------------------------------------------------------------------
 553                              Address Space Management
 554    -------------------------------------------------------------------------- */
 555
 556 static acpi_status
 557 acpi_ec_space_setup(acpi_handle region_handle,
 558                     u32 function, void *handler_context, void **return_context)
 559 {
 560         /*
 561          * The EC object is in the handler context and is needed
 562          * when calling the acpi_ec_space_handler.
 563          */
 564         *return_context = (function != ACPI_REGION_DEACTIVATE) ?
 565             handler_context : NULL;
 566
 567         return AE_OK;
 568 }
 569
 570 static acpi_status
 571 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 572                       u32 bits, acpi_integer *value,
 573                       void *handler_context, void *region_context)
 574 {
 575         struct acpi_ec *ec = handler_context;
 576         int result = 0, i;
 577         u8 temp = 0;
 578
 579         if ((address > 0xFF) || !value || !handler_context)
 580                 return AE_BAD_PARAMETER;
 581
 582         if (function != ACPI_READ && function != ACPI_WRITE)
 583                 return AE_BAD_PARAMETER;
 584
 585         if (bits != 8 && acpi_strict)
 586                 return AE_BAD_PARAMETER;
 587
 588         acpi_ec_burst_enable(ec);
 589
 590         if (function == ACPI_READ) {
 591                 result = acpi_ec_read(ec, address, &temp);
 592                 *value = temp;
 593         } else {
 594                 temp = 0xff & (*value);
 595                 result = acpi_ec_write(ec, address, temp);
 596         }
 597
 598         for (i = 8; unlikely(bits - i > 0); i += 8) {
 599                 ++address;
 600                 if (function == ACPI_READ) {
 601                         result = acpi_ec_read(ec, address, &temp);
 602                         (*value) |= ((acpi_integer)temp) << i;
 603                 } else {
 604                         temp = 0xff & ((*value) >> i);
 605                         result = acpi_ec_write(ec, address, temp);
 606                 }
 607         }
 608
 609         acpi_ec_burst_disable(ec);
 610
 611         switch (result) {
 612         case -EINVAL:
 613                 return AE_BAD_PARAMETER;
 614                 break;
 615         case -ENODEV:
 616                 return AE_NOT_FOUND;
 617                 break;
 618         case -ETIME:
 619                 return AE_TIME;
 620                 break;
 621         default:
 622                 return AE_OK;
 623         }
 624 }
 625
 626 /* --------------------------------------------------------------------------
 627                               FS Interface (/proc)
 628    -------------------------------------------------------------------------- */
 629
 630 static struct proc_dir_entry *acpi_ec_dir;
 631
 632 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 633 {
 634         struct acpi_ec *ec = seq->private;
 635
 636         if (!ec)
 637                 goto end;
 638
 639         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 640         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 641                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 642         seq_printf(seq, "use global lock:\t%s\n",
 643                    ec->global_lock ? "yes" : "no");
 644       end:
 645         return 0;
 646 }
 647
 648 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 649 {
 650         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 651 }
 652
 653 static struct file_operations acpi_ec_info_ops = {
 654         .open = acpi_ec_info_open_fs,
 655         .read = seq_read,
 656         .llseek = seq_lseek,
 657         .release = single_release,
 658         .owner = THIS_MODULE,
 659 };
 660
 661 static int acpi_ec_add_fs(struct acpi_device *device)
 662 {
 663         struct proc_dir_entry *entry = NULL;
 664
 665         if (!acpi_device_dir(device)) {
 666                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 667                                                      acpi_ec_dir);
 668                 if (!acpi_device_dir(device))
 669                         return -ENODEV;
 670         }
 671
 672         entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
 673                                  acpi_device_dir(device),
 674                                  &acpi_ec_info_ops, acpi_driver_data(device));
 675         if (!entry)
 676                 return -ENODEV;
 677         return 0;
 678 }
 679
 680 static int acpi_ec_remove_fs(struct acpi_device *device)
 681 {
 682
 683         if (acpi_device_dir(device)) {
 684                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 685                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 686                 acpi_device_dir(device) = NULL;
 687         }
 688
 689         return 0;
 690 }
 691
 692 /* --------------------------------------------------------------------------
 693                                Driver Interface
 694    -------------------------------------------------------------------------- */
 695 static acpi_status
 696 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 697
 698 static struct acpi_ec *make_acpi_ec(void)
 699 {
 700         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 701         if (!ec)
 702                 return NULL;
 703         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 704         mutex_init(&ec->lock);
 705         init_waitqueue_head(&ec->wait);
 706         INIT_LIST_HEAD(&ec->list);
 707         return ec;
 708 }
 709
 710 static acpi_status
 711 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 712                                void *context, void **return_value)
 713 {
 714         struct acpi_namespace_node *node = handle;
 715         struct acpi_ec *ec = context;
 716         int value = 0;
 717         if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
 718                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 719         }
 720         return AE_OK;
 721 }
 722
 723 static acpi_status
 724 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 725 {
 726         acpi_status status;
 727
 728         struct acpi_ec *ec = context;
 729         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 730                                      ec_parse_io_ports, ec);
 731         if (ACPI_FAILURE(status))
 732                 return status;
 733
 734         /* Get GPE bit assignment (EC events). */
 735         /* TODO: Add support for _GPE returning a package */
 736         status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
 737         if (ACPI_FAILURE(status))
 738                 return status;
 739         /* Find and register all query methods */
 740         acpi_walk_namespace(ACPI_TYPE_METHOD, handle, 1,
 741                             acpi_ec_register_query_methods, ec, NULL);
 742         /* Use the global lock for all EC transactions? */
 743         acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
 744         ec->handle = handle;
 745         return AE_CTRL_TERMINATE;
 746 }
 747
 748 static void ec_remove_handlers(struct acpi_ec *ec)
 749 {
 750         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 751                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 752                 pr_err(PREFIX "failed to remove space handler\n");
 753         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 754                                 &acpi_ec_gpe_handler)))
 755                 pr_err(PREFIX "failed to remove gpe handler\n");
 756         ec->handlers_installed = 0;
 757 }
 758
 759 static int acpi_ec_add(struct acpi_device *device)
 760 {
 761         struct acpi_ec *ec = NULL;
 762
 763         if (!device)
 764                 return -EINVAL;
 765         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 766         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 767
 768         /* Check for boot EC */
 769         if (boot_ec) {
 770                 if (boot_ec->handle == device->handle) {
 771                         /* Pre-loaded EC from DSDT, just move pointer */
 772                         ec = boot_ec;
 773                         boot_ec = NULL;
 774                         goto end;
 775                 } else if (boot_ec->handle == ACPI_ROOT_OBJECT) {
 776                         /* ECDT-based EC, time to shut it down */
 777                         ec_remove_handlers(boot_ec);
 778                         kfree(boot_ec);
 779                         first_ec = boot_ec = NULL;
 780                 }
 781         }
 782
 783         ec = make_acpi_ec();
 784         if (!ec)
 785                 return -ENOMEM;
 786
 787         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 788             AE_CTRL_TERMINATE) {
 789                 kfree(ec);
 790                 return -EINVAL;
 791         }
 792         ec->handle = device->handle;
 793       end:
 794         if (!first_ec)
 795                 first_ec = ec;
 796         acpi_driver_data(device) = ec;
 797         acpi_ec_add_fs(device);
 798         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 799                           ec->gpe, ec->command_addr, ec->data_addr);
 800         pr_info(PREFIX "driver started in %s mode\n",
 801                 (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
 802         return 0;
 803 }
 804
 805 static int acpi_ec_remove(struct acpi_device *device, int type)
 806 {
 807         struct acpi_ec *ec;
 808         struct acpi_ec_query_handler *handler, *tmp;
 809
 810         if (!device)
 811                 return -EINVAL;
 812
 813         ec = acpi_driver_data(device);
 814         mutex_lock(&ec->lock);
 815         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 816                 list_del(&handler->node);
 817                 kfree(handler);
 818         }
 819         mutex_unlock(&ec->lock);
 820         acpi_ec_remove_fs(device);
 821         acpi_driver_data(device) = NULL;
 822         if (ec == first_ec)
 823                 first_ec = NULL;
 824         kfree(ec);
 825         return 0;
 826 }
 827
 828 static acpi_status
 829 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 830 {
 831         struct acpi_ec *ec = context;
 832
 833         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 834                 return AE_OK;
 835
 836         /*
 837          * The first address region returned is the data port, and
 838          * the second address region returned is the status/command
 839          * port.
 840          */
 841         if (ec->data_addr == 0)
 842                 ec->data_addr = resource->data.io.minimum;
 843         else if (ec->command_addr == 0)
 844                 ec->command_addr = resource->data.io.minimum;
 845         else
 846                 return AE_CTRL_TERMINATE;
 847
 848         return AE_OK;
 849 }
 850
 851 static int ec_install_handlers(struct acpi_ec *ec)
 852 {
 853         acpi_status status;
 854         if (ec->handlers_installed)
 855                 return 0;
 856         status = acpi_install_gpe_handler(NULL, ec->gpe,
 857                                           ACPI_GPE_EDGE_TRIGGERED,
 858                                           &acpi_ec_gpe_handler, ec);
 859         if (ACPI_FAILURE(status))
 860                 return -ENODEV;
 861
 862         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 863         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 864
 865         status = acpi_install_address_space_handler(ec->handle,
 866                                                     ACPI_ADR_SPACE_EC,
 867                                                     &acpi_ec_space_handler,
 868                                                     &acpi_ec_space_setup, ec);
 869         if (ACPI_FAILURE(status)) {
 870                 acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 871                 return -ENODEV;
 872         }
 873
 874         ec->handlers_installed = 1;
 875         return 0;
 876 }
 877
 878 static int acpi_ec_start(struct acpi_device *device)
 879 {
 880         struct acpi_ec *ec;
 881         int ret = 0;
 882
 883         if (!device)
 884                 return -EINVAL;
 885
 886         ec = acpi_driver_data(device);
 887
 888         if (!ec)
 889                 return -EINVAL;
 890
 891         ret = ec_install_handlers(ec);
 892
 893         /* EC is fully operational, allow queries */
 894         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 895         return ret;
 896 }
 897
 898 static int acpi_ec_stop(struct acpi_device *device, int type)
 899 {
 900         struct acpi_ec *ec;
 901         if (!device)
 902                 return -EINVAL;
 903         ec = acpi_driver_data(device);
 904         if (!ec)
 905                 return -EINVAL;
 906         ec_remove_handlers(ec);
 907
 908         return 0;
 909 }
 910
 911 int __init acpi_boot_ec_enable(void)
 912 {
 913         if (!boot_ec || boot_ec->handlers_installed)
 914                 return 0;
 915         if (!ec_install_handlers(boot_ec)) {
 916                 first_ec = boot_ec;
 917                 return 0;
 918         }
 919         return -EFAULT;
 920 }
 921
 922 int __init acpi_ec_ecdt_probe(void)
 923 {
 924         int ret;
 925         acpi_status status;
 926         struct acpi_table_ecdt *ecdt_ptr;
 927
 928         boot_ec = make_acpi_ec();
 929         if (!boot_ec)
 930                 return -ENOMEM;
 931         /*
 932          * Generate a boot ec context
 933          */
 934         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 935                                 (struct acpi_table_header **)&ecdt_ptr);
 936         if (ACPI_SUCCESS(status)) {
 937                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
 938                 boot_ec->command_addr = ecdt_ptr->control.address;
 939                 boot_ec->data_addr = ecdt_ptr->data.address;
 940                 boot_ec->gpe = ecdt_ptr->gpe;
 941                 boot_ec->handle = ACPI_ROOT_OBJECT;
 942         } else {
 943                 /* This workaround is needed only on some broken machines,
 944                  * which require early EC, but fail to provide ECDT */
 945                 acpi_handle x;
 946                 printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
 947                 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
 948                                                 boot_ec, NULL);
 949                 /* Check that acpi_get_devices actually find something */
 950                 if (ACPI_FAILURE(status) || !boot_ec->handle)
 951                         goto error;
 952                 /* We really need to limit this workaround, the only ASUS,
 953                  * which needs it, has fake EC._INI method, so use it as flag.
 954                  * Keep boot_ec struct as it will be needed soon.
 955                  */
 956                 if (ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI", &x)))
 957                         return -ENODEV;
 958         }
 959
 960         ret = ec_install_handlers(boot_ec);
 961         if (!ret) {
 962                 first_ec = boot_ec;
 963                 return 0;
 964         }
 965       error:
 966         kfree(boot_ec);
 967         boot_ec = NULL;
 968         return -ENODEV;
 969 }
 970
 971 static int __init acpi_ec_init(void)
 972 {
 973         int result = 0;
 974
 975         if (acpi_disabled)
 976                 return 0;
 977
 978         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
 979         if (!acpi_ec_dir)
 980                 return -ENODEV;
 981
 982         /* Now register the driver for the EC */
 983         result = acpi_bus_register_driver(&acpi_ec_driver);
 984         if (result < 0) {
 985                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 986                 return -ENODEV;
 987         }
 988
 989         return result;
 990 }
 991
 992 subsys_initcall(acpi_ec_init);
 993
 994 /* EC driver currently not unloadable */
 995 #if 0
 996 static void __exit acpi_ec_exit(void)
 997 {
 998
 999         acpi_bus_unregister_driver(&acpi_ec_driver);
1000
1001         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1002
1003         return;
1004 }
1005 #endif  /* 0 */