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         atomic_t irq_count;
 133         u8 handlers_installed;
 134 } *boot_ec, *first_ec;
 135
 136 /* --------------------------------------------------------------------------
 137                              Transaction Management
 138    -------------------------------------------------------------------------- */
 139
 140 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 141 {
 142         u8 x = inb(ec->command_addr);
 143         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
 144         return x;
 145 }
 146
 147 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 148 {
 149         u8 x = inb(ec->data_addr);
 150         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
 151         return inb(ec->data_addr);
 152 }
 153
 154 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 155 {
 156         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
 157         outb(command, ec->command_addr);
 158 }
 159
 160 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 161 {
 162         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
 163         outb(data, ec->data_addr);
 164 }
 165
 166 static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
 167 {
 168         if (test_bit(EC_FLAGS_WAIT_GPE, &ec->flags))
 169                 return 0;
 170         if (event == ACPI_EC_EVENT_OBF_1) {
 171                 if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_OBF)
 172                         return 1;
 173         } else if (event == ACPI_EC_EVENT_IBF_0) {
 174                 if (!(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
 175                         return 1;
 176         }
 177
 178         return 0;
 179 }
 180
 181 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 182 {
 183         int ret = 0;
 184
 185         atomic_set(&ec->irq_count, 0);
 186
 187         if (unlikely(event == ACPI_EC_EVENT_OBF_1 &&
 188                      test_bit(EC_FLAGS_NO_OBF1_GPE, &ec->flags)))
 189                 force_poll = 1;
 190         if (unlikely(test_bit(EC_FLAGS_ADDRESS, &ec->flags) &&
 191                      test_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags)))
 192                 force_poll = 1;
 193         if (unlikely(test_bit(EC_FLAGS_WDATA, &ec->flags) &&
 194                      test_bit(EC_FLAGS_NO_WDATA_GPE, &ec->flags)))
 195                 force_poll = 1;
 196         if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&
 197             likely(!force_poll)) {
 198                 if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),
 199                                        msecs_to_jiffies(ACPI_EC_DELAY)))
 200                         goto end;
 201                 clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 202                 if (acpi_ec_check_status(ec, event)) {
 203                         if (event == ACPI_EC_EVENT_OBF_1) {
 204                                 /* miss OBF_1 GPE, don't expect it */
 205                                 pr_info(PREFIX "missing OBF confirmation, "
 206                                         "don't expect it any longer.\n");
 207                                 set_bit(EC_FLAGS_NO_OBF1_GPE, &ec->flags);
 208                         } else if (test_bit(EC_FLAGS_ADDRESS, &ec->flags)) {
 209                                 /* miss address GPE, don't expect it anymore */
 210                                 pr_info(PREFIX "missing address confirmation, "
 211                                         "don't expect it any longer.\n");
 212                                 set_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags);
 213                         } else if (test_bit(EC_FLAGS_WDATA, &ec->flags)) {
 214                                 /* miss write data GPE, don't expect it */
 215                                 pr_info(PREFIX "missing write data confirmation, "
 216                                         "don't expect it any longer.\n");
 217                                 set_bit(EC_FLAGS_NO_WDATA_GPE, &ec->flags);
 218                         } else {
 219                                 /* missing GPEs, switch back to poll mode */
 220                                 if (printk_ratelimit())
 221                                         pr_info(PREFIX "missing confirmations, "
 222                                                 "switch off interrupt mode.\n");
 223                                 clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 224                         }
 225                         goto end;
 226                 }
 227         } else {
 228                 unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 229                 clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 230                 while (time_before(jiffies, delay)) {
 231                         if (acpi_ec_check_status(ec, event))
 232                                 goto end;
 233                         msleep(5);
 234                 }
 235         }
 236         pr_err(PREFIX "acpi_ec_wait timeout,"
 237                                " status = %d, expect_event = %d\n",
 238                                acpi_ec_read_status(ec), event);
 239         ret = -ETIME;
 240       end:
 241         clear_bit(EC_FLAGS_ADDRESS, &ec->flags);
 242         return ret;
 243 }
 244
 245 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
 246                                         const u8 * wdata, unsigned wdata_len,
 247                                         u8 * rdata, unsigned rdata_len,
 248                                         int force_poll)
 249 {
 250         int result = 0;
 251         set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 252         acpi_ec_write_cmd(ec, command);
 253         pr_debug(PREFIX "transaction start\n");
 254         for (; wdata_len > 0; --wdata_len) {
 255                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
 256                 if (result) {
 257                         pr_err(PREFIX
 258                                "write_cmd timeout, command = %d\n", command);
 259                         goto end;
 260                 }
 261                 /* mark the address byte written to EC */
 262                 if (rdata_len + wdata_len > 1)
 263                         set_bit(EC_FLAGS_ADDRESS, &ec->flags);
 264                 set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 265                 acpi_ec_write_data(ec, *(wdata++));
 266         }
 267
 268         if (!rdata_len) {
 269                 set_bit(EC_FLAGS_WDATA, &ec->flags);
 270                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
 271                 if (result) {
 272                         pr_err(PREFIX
 273                                "finish-write timeout, command = %d\n", command);
 274                         goto end;
 275                 }
 276         } else if (command == ACPI_EC_COMMAND_QUERY)
 277                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 278
 279         for (; rdata_len > 0; --rdata_len) {
 280                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, force_poll);
 281                 if (result) {
 282                         pr_err(PREFIX "read timeout, command = %d\n", command);
 283                         goto end;
 284                 }
 285                 /* Don't expect GPE after last read */
 286                 if (rdata_len > 1)
 287                         set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 288                 *(rdata++) = acpi_ec_read_data(ec);
 289         }
 290       end:
 291         pr_debug(PREFIX "transaction end\n");
 292         return result;
 293 }
 294
 295 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
 296                                const u8 * wdata, unsigned wdata_len,
 297                                u8 * rdata, unsigned rdata_len,
 298                                int force_poll)
 299 {
 300         int status;
 301         u32 glk;
 302
 303         if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
 304                 return -EINVAL;
 305
 306         if (rdata)
 307                 memset(rdata, 0, rdata_len);
 308
 309         mutex_lock(&ec->lock);
 310         if (ec->global_lock) {
 311                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 312                 if (ACPI_FAILURE(status)) {
 313                         mutex_unlock(&ec->lock);
 314                         return -ENODEV;
 315                 }
 316         }
 317
 318         status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
 319         if (status) {
 320                 pr_err(PREFIX "input buffer is not empty, "
 321                                 "aborting transaction\n");
 322                 goto end;
 323         }
 324
 325         status = acpi_ec_transaction_unlocked(ec, command,
 326                                               wdata, wdata_len,
 327                                               rdata, rdata_len,
 328                                               force_poll);
 329
 330       end:
 331
 332         if (ec->global_lock)
 333                 acpi_release_global_lock(glk);
 334         mutex_unlock(&ec->lock);
 335
 336         return status;
 337 }
 338
 339 /*
 340  * Note: samsung nv5000 doesn't work with ec burst mode.
 341  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 342  */
 343 int acpi_ec_burst_enable(struct acpi_ec *ec)
 344 {
 345         u8 d;
 346         return acpi_ec_transaction(ec, ACPI_EC_BURST_ENABLE, NULL, 0, &d, 1, 0);
 347 }
 348
 349 int acpi_ec_burst_disable(struct acpi_ec *ec)
 350 {
 351         return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0, 0);
 352 }
 353
 354 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 355 {
 356         int result;
 357         u8 d;
 358
 359         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
 360                                      &address, 1, &d, 1, 0);
 361         *data = d;
 362         return result;
 363 }
 364
 365 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 366 {
 367         u8 wdata[2] = { address, data };
 368         return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
 369                                    wdata, 2, NULL, 0, 0);
 370 }
 371
 372 /*
 373  * Externally callable EC access functions. For now, assume 1 EC only
 374  */
 375 int ec_burst_enable(void)
 376 {
 377         if (!first_ec)
 378                 return -ENODEV;
 379         return acpi_ec_burst_enable(first_ec);
 380 }
 381
 382 EXPORT_SYMBOL(ec_burst_enable);
 383
 384 int ec_burst_disable(void)
 385 {
 386         if (!first_ec)
 387                 return -ENODEV;
 388         return acpi_ec_burst_disable(first_ec);
 389 }
 390
 391 EXPORT_SYMBOL(ec_burst_disable);
 392
 393 int ec_read(u8 addr, u8 * val)
 394 {
 395         int err;
 396         u8 temp_data;
 397
 398         if (!first_ec)
 399                 return -ENODEV;
 400
 401         err = acpi_ec_read(first_ec, addr, &temp_data);
 402
 403         if (!err) {
 404                 *val = temp_data;
 405                 return 0;
 406         } else
 407                 return err;
 408 }
 409
 410 EXPORT_SYMBOL(ec_read);
 411
 412 int ec_write(u8 addr, u8 val)
 413 {
 414         int err;
 415
 416         if (!first_ec)
 417                 return -ENODEV;
 418
 419         err = acpi_ec_write(first_ec, addr, val);
 420
 421         return err;
 422 }
 423
 424 EXPORT_SYMBOL(ec_write);
 425
 426 int ec_transaction(u8 command,
 427                    const u8 * wdata, unsigned wdata_len,
 428                    u8 * rdata, unsigned rdata_len,
 429                    int force_poll)
 430 {
 431         if (!first_ec)
 432                 return -ENODEV;
 433
 434         return acpi_ec_transaction(first_ec, command, wdata,
 435                                    wdata_len, rdata, rdata_len,
 436                                    force_poll);
 437 }
 438
 439 EXPORT_SYMBOL(ec_transaction);
 440
 441 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 442 {
 443         int result;
 444         u8 d;
 445
 446         if (!ec || !data)
 447                 return -EINVAL;
 448
 449         /*
 450          * Query the EC to find out which _Qxx method we need to evaluate.
 451          * Note that successful completion of the query causes the ACPI_EC_SCI
 452          * bit to be cleared (and thus clearing the interrupt source).
 453          */
 454
 455         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
 456         if (result)
 457                 return result;
 458
 459         if (!d)
 460                 return -ENODATA;
 461
 462         *data = d;
 463         return 0;
 464 }
 465
 466 /* --------------------------------------------------------------------------
 467                                 Event Management
 468    -------------------------------------------------------------------------- */
 469 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 470                               acpi_handle handle, acpi_ec_query_func func,
 471                               void *data)
 472 {
 473         struct acpi_ec_query_handler *handler =
 474             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 475         if (!handler)
 476                 return -ENOMEM;
 477
 478         handler->query_bit = query_bit;
 479         handler->handle = handle;
 480         handler->func = func;
 481         handler->data = data;
 482         mutex_lock(&ec->lock);
 483         list_add(&handler->node, &ec->list);
 484         mutex_unlock(&ec->lock);
 485         return 0;
 486 }
 487
 488 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 489
 490 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 491 {
 492         struct acpi_ec_query_handler *handler, *tmp;
 493         mutex_lock(&ec->lock);
 494         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 495                 if (query_bit == handler->query_bit) {
 496                         list_del(&handler->node);
 497                         kfree(handler);
 498                 }
 499         }
 500         mutex_unlock(&ec->lock);
 501 }
 502
 503 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 504
 505 static void acpi_ec_gpe_query(void *ec_cxt)
 506 {
 507         struct acpi_ec *ec = ec_cxt;
 508         u8 value = 0;
 509         struct acpi_ec_query_handler *handler, copy;
 510
 511         if (!ec || acpi_ec_query(ec, &value))
 512                 return;
 513         mutex_lock(&ec->lock);
 514         list_for_each_entry(handler, &ec->list, node) {
 515                 if (value == handler->query_bit) {
 516                         /* have custom handler for this bit */
 517                         memcpy(&copy, handler, sizeof(copy));
 518                         mutex_unlock(&ec->lock);
 519                         if (copy.func) {
 520                                 copy.func(copy.data);
 521                         } else if (copy.handle) {
 522                                 acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
 523                         }
 524                         return;
 525                 }
 526         }
 527         mutex_unlock(&ec->lock);
 528 }
 529
 530 static u32 acpi_ec_gpe_handler(void *data)
 531 {
 532         acpi_status status = AE_OK;
 533         struct acpi_ec *ec = data;
 534
 535         pr_debug(PREFIX "~~~> interrupt\n");
 536         atomic_inc(&ec->irq_count);
 537         if (atomic_read(&ec->irq_count) > 5) {
 538                 pr_err(PREFIX "GPE storm detected, disabling EC GPE\n");
 539                 acpi_disable_gpe(NULL, ec->gpe, ACPI_ISR);
 540                 clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 541                 return ACPI_INTERRUPT_HANDLED;
 542         }
 543         clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 544         if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
 545                 wake_up(&ec->wait);
 546
 547         if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_SCI) {
 548                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 549                         status = acpi_os_execute(OSL_EC_BURST_HANDLER,
 550                                 acpi_ec_gpe_query, ec);
 551         } else if (unlikely(!test_bit(EC_FLAGS_GPE_MODE, &ec->flags))) {
 552                 /* this is non-query, must be confirmation */
 553                 if (printk_ratelimit())
 554                         pr_info(PREFIX "non-query interrupt received,"
 555                                 " switching to interrupt mode\n");
 556                 set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 557         }
 558
 559         return ACPI_SUCCESS(status) ?
 560             ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 561 }
 562
 563 /* --------------------------------------------------------------------------
 564                              Address Space Management
 565    -------------------------------------------------------------------------- */
 566
 567 static acpi_status
 568 acpi_ec_space_setup(acpi_handle region_handle,
 569                     u32 function, void *handler_context, void **return_context)
 570 {
 571         /*
 572          * The EC object is in the handler context and is needed
 573          * when calling the acpi_ec_space_handler.
 574          */
 575         *return_context = (function != ACPI_REGION_DEACTIVATE) ?
 576             handler_context : NULL;
 577
 578         return AE_OK;
 579 }
 580
 581 static acpi_status
 582 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 583                       u32 bits, acpi_integer *value,
 584                       void *handler_context, void *region_context)
 585 {
 586         struct acpi_ec *ec = handler_context;
 587         int result = 0, i;
 588         u8 temp = 0;
 589
 590         if ((address > 0xFF) || !value || !handler_context)
 591                 return AE_BAD_PARAMETER;
 592
 593         if (function != ACPI_READ && function != ACPI_WRITE)
 594                 return AE_BAD_PARAMETER;
 595
 596         if (bits != 8 && acpi_strict)
 597                 return AE_BAD_PARAMETER;
 598
 599         acpi_ec_burst_enable(ec);
 600
 601         if (function == ACPI_READ) {
 602                 result = acpi_ec_read(ec, address, &temp);
 603                 *value = temp;
 604         } else {
 605                 temp = 0xff & (*value);
 606                 result = acpi_ec_write(ec, address, temp);
 607         }
 608
 609         for (i = 8; unlikely(bits - i > 0); i += 8) {
 610                 ++address;
 611                 if (function == ACPI_READ) {
 612                         result = acpi_ec_read(ec, address, &temp);
 613                         (*value) |= ((acpi_integer)temp) << i;
 614                 } else {
 615                         temp = 0xff & ((*value) >> i);
 616                         result = acpi_ec_write(ec, address, temp);
 617                 }
 618         }
 619
 620         acpi_ec_burst_disable(ec);
 621
 622         switch (result) {
 623         case -EINVAL:
 624                 return AE_BAD_PARAMETER;
 625                 break;
 626         case -ENODEV:
 627                 return AE_NOT_FOUND;
 628                 break;
 629         case -ETIME:
 630                 return AE_TIME;
 631                 break;
 632         default:
 633                 return AE_OK;
 634         }
 635 }
 636
 637 /* --------------------------------------------------------------------------
 638                               FS Interface (/proc)
 639    -------------------------------------------------------------------------- */
 640
 641 static struct proc_dir_entry *acpi_ec_dir;
 642
 643 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 644 {
 645         struct acpi_ec *ec = seq->private;
 646
 647         if (!ec)
 648                 goto end;
 649
 650         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 651         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 652                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 653         seq_printf(seq, "use global lock:\t%s\n",
 654                    ec->global_lock ? "yes" : "no");
 655       end:
 656         return 0;
 657 }
 658
 659 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 660 {
 661         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 662 }
 663
 664 static struct file_operations acpi_ec_info_ops = {
 665         .open = acpi_ec_info_open_fs,
 666         .read = seq_read,
 667         .llseek = seq_lseek,
 668         .release = single_release,
 669         .owner = THIS_MODULE,
 670 };
 671
 672 static int acpi_ec_add_fs(struct acpi_device *device)
 673 {
 674         struct proc_dir_entry *entry = NULL;
 675
 676         if (!acpi_device_dir(device)) {
 677                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 678                                                      acpi_ec_dir);
 679                 if (!acpi_device_dir(device))
 680                         return -ENODEV;
 681         }
 682
 683         entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
 684                                   acpi_device_dir(device));
 685         if (!entry)
 686                 return -ENODEV;
 687         else {
 688                 entry->proc_fops = &acpi_ec_info_ops;
 689                 entry->data = acpi_driver_data(device);
 690                 entry->owner = THIS_MODULE;
 691         }
 692
 693         return 0;
 694 }
 695
 696 static int acpi_ec_remove_fs(struct acpi_device *device)
 697 {
 698
 699         if (acpi_device_dir(device)) {
 700                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 701                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 702                 acpi_device_dir(device) = NULL;
 703         }
 704
 705         return 0;
 706 }
 707
 708 /* --------------------------------------------------------------------------
 709                                Driver Interface
 710    -------------------------------------------------------------------------- */
 711 static acpi_status
 712 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 713
 714 static struct acpi_ec *make_acpi_ec(void)
 715 {
 716         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 717         if (!ec)
 718                 return NULL;
 719         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 720         mutex_init(&ec->lock);
 721         init_waitqueue_head(&ec->wait);
 722         INIT_LIST_HEAD(&ec->list);
 723         return ec;
 724 }
 725
 726 static acpi_status
 727 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 728                                void *context, void **return_value)
 729 {
 730         struct acpi_namespace_node *node = handle;
 731         struct acpi_ec *ec = context;
 732         int value = 0;
 733         if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
 734                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 735         }
 736         return AE_OK;
 737 }
 738
 739 static acpi_status
 740 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 741 {
 742         acpi_status status;
 743
 744         struct acpi_ec *ec = context;
 745         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 746                                      ec_parse_io_ports, ec);
 747         if (ACPI_FAILURE(status))
 748                 return status;
 749
 750         /* Get GPE bit assignment (EC events). */
 751         /* TODO: Add support for _GPE returning a package */
 752         status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
 753         if (ACPI_FAILURE(status))
 754                 return status;
 755         /* Find and register all query methods */
 756         acpi_walk_namespace(ACPI_TYPE_METHOD, handle, 1,
 757                             acpi_ec_register_query_methods, ec, NULL);
 758         /* Use the global lock for all EC transactions? */
 759         acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
 760         ec->handle = handle;
 761         return AE_CTRL_TERMINATE;
 762 }
 763
 764 static void ec_remove_handlers(struct acpi_ec *ec)
 765 {
 766         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 767                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 768                 pr_err(PREFIX "failed to remove space handler\n");
 769         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 770                                 &acpi_ec_gpe_handler)))
 771                 pr_err(PREFIX "failed to remove gpe handler\n");
 772         ec->handlers_installed = 0;
 773 }
 774
 775 static int acpi_ec_add(struct acpi_device *device)
 776 {
 777         struct acpi_ec *ec = NULL;
 778
 779         if (!device)
 780                 return -EINVAL;
 781         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 782         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 783
 784         /* Check for boot EC */
 785         if (boot_ec) {
 786                 if (boot_ec->handle == device->handle) {
 787                         /* Pre-loaded EC from DSDT, just move pointer */
 788                         ec = boot_ec;
 789                         boot_ec = NULL;
 790                         goto end;
 791                 } else if (boot_ec->handle == ACPI_ROOT_OBJECT) {
 792                         /* ECDT-based EC, time to shut it down */
 793                         ec_remove_handlers(boot_ec);
 794                         kfree(boot_ec);
 795                         first_ec = boot_ec = NULL;
 796                 }
 797         }
 798
 799         ec = make_acpi_ec();
 800         if (!ec)
 801                 return -ENOMEM;
 802
 803         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 804             AE_CTRL_TERMINATE) {
 805                 kfree(ec);
 806                 return -EINVAL;
 807         }
 808         ec->handle = device->handle;
 809       end:
 810         if (!first_ec)
 811                 first_ec = ec;
 812         acpi_driver_data(device) = ec;
 813         acpi_ec_add_fs(device);
 814         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 815                           ec->gpe, ec->command_addr, ec->data_addr);
 816         pr_info(PREFIX "driver started in %s mode\n",
 817                 (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
 818         return 0;
 819 }
 820
 821 static int acpi_ec_remove(struct acpi_device *device, int type)
 822 {
 823         struct acpi_ec *ec;
 824         struct acpi_ec_query_handler *handler, *tmp;
 825
 826         if (!device)
 827                 return -EINVAL;
 828
 829         ec = acpi_driver_data(device);
 830         mutex_lock(&ec->lock);
 831         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 832                 list_del(&handler->node);
 833                 kfree(handler);
 834         }
 835         mutex_unlock(&ec->lock);
 836         acpi_ec_remove_fs(device);
 837         acpi_driver_data(device) = NULL;
 838         if (ec == first_ec)
 839                 first_ec = NULL;
 840         kfree(ec);
 841         return 0;
 842 }
 843
 844 static acpi_status
 845 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 846 {
 847         struct acpi_ec *ec = context;
 848
 849         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 850                 return AE_OK;
 851
 852         /*
 853          * The first address region returned is the data port, and
 854          * the second address region returned is the status/command
 855          * port.
 856          */
 857         if (ec->data_addr == 0)
 858                 ec->data_addr = resource->data.io.minimum;
 859         else if (ec->command_addr == 0)
 860                 ec->command_addr = resource->data.io.minimum;
 861         else
 862                 return AE_CTRL_TERMINATE;
 863
 864         return AE_OK;
 865 }
 866
 867 static int ec_install_handlers(struct acpi_ec *ec)
 868 {
 869         acpi_status status;
 870         if (ec->handlers_installed)
 871                 return 0;
 872         status = acpi_install_gpe_handler(NULL, ec->gpe,
 873                                           ACPI_GPE_EDGE_TRIGGERED,
 874                                           &acpi_ec_gpe_handler, ec);
 875         if (ACPI_FAILURE(status))
 876                 return -ENODEV;
 877
 878         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 879         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 880
 881         status = acpi_install_address_space_handler(ec->handle,
 882                                                     ACPI_ADR_SPACE_EC,
 883                                                     &acpi_ec_space_handler,
 884                                                     &acpi_ec_space_setup, ec);
 885         if (ACPI_FAILURE(status)) {
 886                 acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 887                 return -ENODEV;
 888         }
 889
 890         ec->handlers_installed = 1;
 891         return 0;
 892 }
 893
 894 static int acpi_ec_start(struct acpi_device *device)
 895 {
 896         struct acpi_ec *ec;
 897         int ret = 0;
 898
 899         if (!device)
 900                 return -EINVAL;
 901
 902         ec = acpi_driver_data(device);
 903
 904         if (!ec)
 905                 return -EINVAL;
 906
 907         ret = ec_install_handlers(ec);
 908
 909         /* EC is fully operational, allow queries */
 910         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 911         return ret;
 912 }
 913
 914 static int acpi_ec_stop(struct acpi_device *device, int type)
 915 {
 916         struct acpi_ec *ec;
 917         if (!device)
 918                 return -EINVAL;
 919         ec = acpi_driver_data(device);
 920         if (!ec)
 921                 return -EINVAL;
 922         ec_remove_handlers(ec);
 923
 924         return 0;
 925 }
 926
 927 int __init acpi_boot_ec_enable(void)
 928 {
 929         if (!boot_ec || boot_ec->handlers_installed)
 930                 return 0;
 931         if (!ec_install_handlers(boot_ec)) {
 932                 first_ec = boot_ec;
 933                 return 0;
 934         }
 935         return -EFAULT;
 936 }
 937
 938 int __init acpi_ec_ecdt_probe(void)
 939 {
 940         int ret;
 941         acpi_status status;
 942         struct acpi_table_ecdt *ecdt_ptr;
 943
 944         boot_ec = make_acpi_ec();
 945         if (!boot_ec)
 946                 return -ENOMEM;
 947         /*
 948          * Generate a boot ec context
 949          */
 950         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 951                                 (struct acpi_table_header **)&ecdt_ptr);
 952         if (ACPI_SUCCESS(status)) {
 953                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
 954                 boot_ec->command_addr = ecdt_ptr->control.address;
 955                 boot_ec->data_addr = ecdt_ptr->data.address;
 956                 boot_ec->gpe = ecdt_ptr->gpe;
 957                 boot_ec->handle = ACPI_ROOT_OBJECT;
 958         } else {
 959                 /* This workaround is needed only on some broken machines,
 960                  * which require early EC, but fail to provide ECDT */
 961                 acpi_handle x;
 962                 printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
 963                 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
 964                                                 boot_ec, NULL);
 965                 /* Check that acpi_get_devices actually find something */
 966                 if (ACPI_FAILURE(status) || !boot_ec->handle)
 967                         goto error;
 968                 /* We really need to limit this workaround, the only ASUS,
 969                  * which needs it, has fake EC._INI method, so use it as flag.
 970                  * Keep boot_ec struct as it will be needed soon.
 971                  */
 972                 if (ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI", &x)))
 973                         return -ENODEV;
 974         }
 975
 976         ret = ec_install_handlers(boot_ec);
 977         if (!ret) {
 978                 first_ec = boot_ec;
 979                 return 0;
 980         }
 981       error:
 982         kfree(boot_ec);
 983         boot_ec = NULL;
 984         return -ENODEV;
 985 }
 986
 987 static int __init acpi_ec_init(void)
 988 {
 989         int result = 0;
 990
 991         if (acpi_disabled)
 992                 return 0;
 993
 994         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
 995         if (!acpi_ec_dir)
 996                 return -ENODEV;
 997
 998         /* Now register the driver for the EC */
 999         result = acpi_bus_register_driver(&acpi_ec_driver);
1000         if (result < 0) {
1001                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1002                 return -ENODEV;
1003         }
1004
1005         return result;
1006 }
1007
1008 subsys_initcall(acpi_ec_init);
1009
1010 /* EC driver currently not unloadable */
1011 #if 0
1012 static void __exit acpi_ec_exit(void)
1013 {
1014
1015         acpi_bus_unregister_driver(&acpi_ec_driver);
1016
1017         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1018
1019         return;
1020 }
1021 #endif  /* 0 */