drivers/acpi/ec.c

   1 /*
   2  *  ec.c - ACPI Embedded Controller Driver (v2.1)
   3  *
   4  *  Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@suse.de>
   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 printout */
  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 <linux/spinlock.h>
  42 #include <asm/io.h>
  43 #include <acpi/acpi_bus.h>
  44 #include <acpi/acpi_drivers.h>
  45 #include <linux/dmi.h>
  46
  47 #define ACPI_EC_CLASS                   "embedded_controller"
  48 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  49 #define ACPI_EC_FILE_INFO               "info"
  50
  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 #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 #define ACPI_EC_CDELAY          10      /* Wait 10us before polling EC */
  71 #define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
  72
  73 #define ACPI_EC_STORM_THRESHOLD 8       /* number of false interrupts
  74                                            per one transaction */
  75
  76 enum {
  77         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  78         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  79         EC_FLAGS_HANDLERS_INSTALLED     /* Handlers for GPE and
  80                                          * OpReg are installed */
  81 };
  82
  83 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  84 /* External interfaces use first EC only, so remember */
  85 typedef int (*acpi_ec_query_func) (void *data);
  86
  87 struct acpi_ec_query_handler {
  88         struct list_head node;
  89         acpi_ec_query_func func;
  90         acpi_handle handle;
  91         void *data;
  92         u8 query_bit;
  93 };
  94
  95 struct transaction {
  96         const u8 *wdata;
  97         u8 *rdata;
  98         unsigned short irq_count;
  99         u8 command;
 100         u8 wi;
 101         u8 ri;
 102         u8 wlen;
 103         u8 rlen;
 104         bool done;
 105 };
 106
 107 static struct acpi_ec {
 108         acpi_handle handle;
 109         unsigned long gpe;
 110         unsigned long command_addr;
 111         unsigned long data_addr;
 112         unsigned long global_lock;
 113         unsigned long flags;
 114         struct mutex lock;
 115         wait_queue_head_t wait;
 116         struct list_head list;
 117         struct transaction *curr;
 118         spinlock_t curr_lock;
 119 } *boot_ec, *first_ec;
 120
 121 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 122 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 123 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 124
 125 /* --------------------------------------------------------------------------
 126                              Transaction Management
 127    -------------------------------------------------------------------------- */
 128
 129 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 130 {
 131         u8 x = inb(ec->command_addr);
 132         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
 133         return x;
 134 }
 135
 136 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 137 {
 138         u8 x = inb(ec->data_addr);
 139         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
 140         return x;
 141 }
 142
 143 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 144 {
 145         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
 146         outb(command, ec->command_addr);
 147 }
 148
 149 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 150 {
 151         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
 152         outb(data, ec->data_addr);
 153 }
 154
 155 static int ec_transaction_done(struct acpi_ec *ec)
 156 {
 157         unsigned long flags;
 158         int ret = 0;
 159         spin_lock_irqsave(&ec->curr_lock, flags);
 160         if (!ec->curr || ec->curr->done)
 161                 ret = 1;
 162         spin_unlock_irqrestore(&ec->curr_lock, flags);
 163         return ret;
 164 }
 165
 166 static void start_transaction(struct acpi_ec *ec)
 167 {
 168         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 169         ec->curr->done = false;
 170         acpi_ec_write_cmd(ec, ec->curr->command);
 171 }
 172
 173 static void advance_transaction(struct acpi_ec *ec, u8 status)
 174 {
 175         unsigned long flags;
 176         spin_lock_irqsave(&ec->curr_lock, flags);
 177         if (!ec->curr)
 178                 goto unlock;
 179         if (ec->curr->wlen > ec->curr->wi) {
 180                 if ((status & ACPI_EC_FLAG_IBF) == 0)
 181                         acpi_ec_write_data(ec,
 182                                 ec->curr->wdata[ec->curr->wi++]);
 183                 else
 184                         goto err;
 185         } else if (ec->curr->rlen > ec->curr->ri) {
 186                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
 187                         ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
 188                         if (ec->curr->rlen == ec->curr->ri)
 189                                 ec->curr->done = true;
 190                 } else
 191                         goto err;
 192         } else if (ec->curr->wlen == ec->curr->wi &&
 193                    (status & ACPI_EC_FLAG_IBF) == 0)
 194                 ec->curr->done = true;
 195         goto unlock;
 196 err:
 197         /* false interrupt, state didn't change */
 198         if (in_interrupt())
 199                 ++ec->curr->irq_count;
 200 unlock:
 201         spin_unlock_irqrestore(&ec->curr_lock, flags);
 202 }
 203
 204 static int acpi_ec_sync_query(struct acpi_ec *ec);
 205
 206 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 207 {
 208         if (state & ACPI_EC_FLAG_SCI) {
 209                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 210                         return acpi_ec_sync_query(ec);
 211         }
 212         return 0;
 213 }
 214
 215 static int ec_poll(struct acpi_ec *ec)
 216 {
 217         unsigned long flags;
 218         int repeat = 2; /* number of command restarts */
 219         while (repeat--) {
 220                 unsigned long delay = jiffies +
 221                         msecs_to_jiffies(ACPI_EC_DELAY);
 222                 do {
 223                         /* don't sleep with disabled interrupts */
 224                         if (EC_FLAGS_MSI || irqs_disabled()) {
 225                                 udelay(ACPI_EC_MSI_UDELAY);
 226                                 if (ec_transaction_done(ec))
 227                                         return 0;
 228                         } else {
 229                                 if (wait_event_timeout(ec->wait,
 230                                                 ec_transaction_done(ec),
 231                                                 msecs_to_jiffies(1)))
 232                                         return 0;
 233                         }
 234                         advance_transaction(ec, acpi_ec_read_status(ec));
 235                 } while (time_before(jiffies, delay));
 236                 if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
 237                         break;
 238                 pr_debug(PREFIX "controller reset, restart transaction\n");
 239                 spin_lock_irqsave(&ec->curr_lock, flags);
 240                 start_transaction(ec);
 241                 spin_unlock_irqrestore(&ec->curr_lock, flags);
 242         }
 243         return -ETIME;
 244 }
 245
 246 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 247                                         struct transaction *t)
 248 {
 249         unsigned long tmp;
 250         int ret = 0;
 251         if (EC_FLAGS_MSI)
 252                 udelay(ACPI_EC_MSI_UDELAY);
 253         /* start transaction */
 254         spin_lock_irqsave(&ec->curr_lock, tmp);
 255         /* following two actions should be kept atomic */
 256         ec->curr = t;
 257         start_transaction(ec);
 258         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 259                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 260         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 261         ret = ec_poll(ec);
 262         pr_debug(PREFIX "transaction end\n");
 263         spin_lock_irqsave(&ec->curr_lock, tmp);
 264         ec->curr = NULL;
 265         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 266         return ret;
 267 }
 268
 269 static int ec_check_ibf0(struct acpi_ec *ec)
 270 {
 271         u8 status = acpi_ec_read_status(ec);
 272         return (status & ACPI_EC_FLAG_IBF) == 0;
 273 }
 274
 275 static int ec_wait_ibf0(struct acpi_ec *ec)
 276 {
 277         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 278         /* interrupt wait manually if GPE mode is not active */
 279         while (time_before(jiffies, delay))
 280                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
 281                                         msecs_to_jiffies(1)))
 282                         return 0;
 283         return -ETIME;
 284 }
 285
 286 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 287 {
 288         int status;
 289         u32 glk;
 290         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 291                 return -EINVAL;
 292         if (t->rdata)
 293                 memset(t->rdata, 0, t->rlen);
 294         mutex_lock(&ec->lock);
 295         if (ec->global_lock) {
 296                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 297                 if (ACPI_FAILURE(status)) {
 298                         status = -ENODEV;
 299                         goto unlock;
 300                 }
 301         }
 302         if (ec_wait_ibf0(ec)) {
 303                 pr_err(PREFIX "input buffer is not empty, "
 304                                 "aborting transaction\n");
 305                 status = -ETIME;
 306                 goto end;
 307         }
 308         pr_debug(PREFIX "transaction start\n");
 309         /* disable GPE during transaction if storm is detected */
 310         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 311                 acpi_disable_gpe(NULL, ec->gpe);
 312         }
 313
 314         status = acpi_ec_transaction_unlocked(ec, t);
 315
 316         /* check if we received SCI during transaction */
 317         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 318         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 319                 /* it is safe to enable GPE outside of transaction */
 320                 acpi_enable_gpe(NULL, ec->gpe);
 321         } else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
 322                 pr_info(PREFIX "GPE storm detected, "
 323                         "transactions will use polling mode\n");
 324                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 325         }
 326 end:
 327         if (ec->global_lock)
 328                 acpi_release_global_lock(glk);
 329 unlock:
 330         mutex_unlock(&ec->lock);
 331         return status;
 332 }
 333
 334 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 335 {
 336         u8 d;
 337         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 338                                 .wdata = NULL, .rdata = &d,
 339                                 .wlen = 0, .rlen = 1};
 340
 341         return acpi_ec_transaction(ec, &t);
 342 }
 343
 344 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 345 {
 346         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 347                                 .wdata = NULL, .rdata = NULL,
 348                                 .wlen = 0, .rlen = 0};
 349
 350         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 351                                 acpi_ec_transaction(ec, &t) : 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         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 359                                 .wdata = &address, .rdata = &d,
 360                                 .wlen = 1, .rlen = 1};
 361
 362         result = acpi_ec_transaction(ec, &t);
 363         *data = d;
 364         return result;
 365 }
 366
 367 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 368 {
 369         u8 wdata[2] = { address, data };
 370         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 371                                 .wdata = wdata, .rdata = NULL,
 372                                 .wlen = 2, .rlen = 0};
 373
 374         return acpi_ec_transaction(ec, &t);
 375 }
 376
 377 /*
 378  * Externally callable EC access functions. For now, assume 1 EC only
 379  */
 380 int ec_burst_enable(void)
 381 {
 382         if (!first_ec)
 383                 return -ENODEV;
 384         return acpi_ec_burst_enable(first_ec);
 385 }
 386
 387 EXPORT_SYMBOL(ec_burst_enable);
 388
 389 int ec_burst_disable(void)
 390 {
 391         if (!first_ec)
 392                 return -ENODEV;
 393         return acpi_ec_burst_disable(first_ec);
 394 }
 395
 396 EXPORT_SYMBOL(ec_burst_disable);
 397
 398 int ec_read(u8 addr, u8 * val)
 399 {
 400         int err;
 401         u8 temp_data;
 402
 403         if (!first_ec)
 404                 return -ENODEV;
 405
 406         err = acpi_ec_read(first_ec, addr, &temp_data);
 407
 408         if (!err) {
 409                 *val = temp_data;
 410                 return 0;
 411         } else
 412                 return err;
 413 }
 414
 415 EXPORT_SYMBOL(ec_read);
 416
 417 int ec_write(u8 addr, u8 val)
 418 {
 419         int err;
 420
 421         if (!first_ec)
 422                 return -ENODEV;
 423
 424         err = acpi_ec_write(first_ec, addr, val);
 425
 426         return err;
 427 }
 428
 429 EXPORT_SYMBOL(ec_write);
 430
 431 int ec_transaction(u8 command,
 432                    const u8 * wdata, unsigned wdata_len,
 433                    u8 * rdata, unsigned rdata_len,
 434                    int force_poll)
 435 {
 436         struct transaction t = {.command = command,
 437                                 .wdata = wdata, .rdata = rdata,
 438                                 .wlen = wdata_len, .rlen = rdata_len};
 439         if (!first_ec)
 440                 return -ENODEV;
 441
 442         return acpi_ec_transaction(first_ec, &t);
 443 }
 444
 445 EXPORT_SYMBOL(ec_transaction);
 446
 447 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 448 {
 449         int result;
 450         u8 d;
 451         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 452                                 .wdata = NULL, .rdata = &d,
 453                                 .wlen = 0, .rlen = 1};
 454         if (!ec || !data)
 455                 return -EINVAL;
 456         /*
 457          * Query the EC to find out which _Qxx method we need to evaluate.
 458          * Note that successful completion of the query causes the ACPI_EC_SCI
 459          * bit to be cleared (and thus clearing the interrupt source).
 460          */
 461         result = acpi_ec_transaction_unlocked(ec, &t);
 462         if (result)
 463                 return result;
 464         if (!d)
 465                 return -ENODATA;
 466         *data = d;
 467         return 0;
 468 }
 469
 470 /* --------------------------------------------------------------------------
 471                                 Event Management
 472    -------------------------------------------------------------------------- */
 473 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 474                               acpi_handle handle, acpi_ec_query_func func,
 475                               void *data)
 476 {
 477         struct acpi_ec_query_handler *handler =
 478             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 479         if (!handler)
 480                 return -ENOMEM;
 481
 482         handler->query_bit = query_bit;
 483         handler->handle = handle;
 484         handler->func = func;
 485         handler->data = data;
 486         mutex_lock(&ec->lock);
 487         list_add(&handler->node, &ec->list);
 488         mutex_unlock(&ec->lock);
 489         return 0;
 490 }
 491
 492 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 493
 494 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 495 {
 496         struct acpi_ec_query_handler *handler, *tmp;
 497         mutex_lock(&ec->lock);
 498         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 499                 if (query_bit == handler->query_bit) {
 500                         list_del(&handler->node);
 501                         kfree(handler);
 502                 }
 503         }
 504         mutex_unlock(&ec->lock);
 505 }
 506
 507 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 508
 509 static void acpi_ec_run(void *cxt)
 510 {
 511         struct acpi_ec_query_handler *handler = cxt;
 512         if (!handler)
 513                 return;
 514         pr_debug(PREFIX "start query execution\n");
 515         if (handler->func)
 516                 handler->func(handler->data);
 517         else if (handler->handle)
 518                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 519         pr_debug(PREFIX "stop query execution\n");
 520         kfree(handler);
 521 }
 522
 523 static int acpi_ec_sync_query(struct acpi_ec *ec)
 524 {
 525         u8 value = 0;
 526         int status;
 527         struct acpi_ec_query_handler *handler, *copy;
 528         if ((status = acpi_ec_query_unlocked(ec, &value)))
 529                 return status;
 530         list_for_each_entry(handler, &ec->list, node) {
 531                 if (value == handler->query_bit) {
 532                         /* have custom handler for this bit */
 533                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 534                         if (!copy)
 535                                 return -ENOMEM;
 536                         memcpy(copy, handler, sizeof(*copy));
 537                         pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
 538                         return acpi_os_execute((copy->func) ?
 539                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 540                                 acpi_ec_run, copy);
 541                 }
 542         }
 543         return 0;
 544 }
 545
 546 static void acpi_ec_gpe_query(void *ec_cxt)
 547 {
 548         struct acpi_ec *ec = ec_cxt;
 549         if (!ec)
 550                 return;
 551         mutex_lock(&ec->lock);
 552         acpi_ec_sync_query(ec);
 553         mutex_unlock(&ec->lock);
 554 }
 555
 556 static void acpi_ec_gpe_query(void *ec_cxt);
 557
 558 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 559 {
 560         if (state & ACPI_EC_FLAG_SCI) {
 561                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 562                         pr_debug(PREFIX "push gpe query to the queue\n");
 563                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 564                                 acpi_ec_gpe_query, ec);
 565                 }
 566         }
 567         return 0;
 568 }
 569
 570 static u32 acpi_ec_gpe_handler(void *data)
 571 {
 572         struct acpi_ec *ec = data;
 573
 574         pr_debug(PREFIX "~~~> interrupt\n");
 575
 576         advance_transaction(ec, acpi_ec_read_status(ec));
 577         if (ec_transaction_done(ec) &&
 578             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 579                 wake_up(&ec->wait);
 580                 ec_check_sci(ec, acpi_ec_read_status(ec));
 581         }
 582         return ACPI_INTERRUPT_HANDLED;
 583 }
 584
 585 /* --------------------------------------------------------------------------
 586                              Address Space Management
 587    -------------------------------------------------------------------------- */
 588
 589 static acpi_status
 590 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 591                       u32 bits, acpi_integer *value,
 592                       void *handler_context, void *region_context)
 593 {
 594         struct acpi_ec *ec = handler_context;
 595         int result = 0, i;
 596         u8 temp = 0;
 597
 598         if ((address > 0xFF) || !value || !handler_context)
 599                 return AE_BAD_PARAMETER;
 600
 601         if (function != ACPI_READ && function != ACPI_WRITE)
 602                 return AE_BAD_PARAMETER;
 603
 604         if (bits != 8 && acpi_strict)
 605                 return AE_BAD_PARAMETER;
 606
 607         if (EC_FLAGS_MSI)
 608                 acpi_ec_burst_enable(ec);
 609
 610         if (function == ACPI_READ) {
 611                 result = acpi_ec_read(ec, address, &temp);
 612                 *value = temp;
 613         } else {
 614                 temp = 0xff & (*value);
 615                 result = acpi_ec_write(ec, address, temp);
 616         }
 617
 618         for (i = 8; unlikely(bits - i > 0); i += 8) {
 619                 ++address;
 620                 if (function == ACPI_READ) {
 621                         result = acpi_ec_read(ec, address, &temp);
 622                         (*value) |= ((acpi_integer)temp) << i;
 623                 } else {
 624                         temp = 0xff & ((*value) >> i);
 625                         result = acpi_ec_write(ec, address, temp);
 626                 }
 627         }
 628
 629         if (EC_FLAGS_MSI)
 630                 acpi_ec_burst_disable(ec);
 631
 632         switch (result) {
 633         case -EINVAL:
 634                 return AE_BAD_PARAMETER;
 635                 break;
 636         case -ENODEV:
 637                 return AE_NOT_FOUND;
 638                 break;
 639         case -ETIME:
 640                 return AE_TIME;
 641                 break;
 642         default:
 643                 return AE_OK;
 644         }
 645 }
 646
 647 /* --------------------------------------------------------------------------
 648                               FS Interface (/proc)
 649    -------------------------------------------------------------------------- */
 650
 651 static struct proc_dir_entry *acpi_ec_dir;
 652
 653 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 654 {
 655         struct acpi_ec *ec = seq->private;
 656
 657         if (!ec)
 658                 goto end;
 659
 660         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 661         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 662                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 663         seq_printf(seq, "use global lock:\t%s\n",
 664                    ec->global_lock ? "yes" : "no");
 665       end:
 666         return 0;
 667 }
 668
 669 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 670 {
 671         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 672 }
 673
 674 static const struct file_operations acpi_ec_info_ops = {
 675         .open = acpi_ec_info_open_fs,
 676         .read = seq_read,
 677         .llseek = seq_lseek,
 678         .release = single_release,
 679         .owner = THIS_MODULE,
 680 };
 681
 682 static int acpi_ec_add_fs(struct acpi_device *device)
 683 {
 684         struct proc_dir_entry *entry = NULL;
 685
 686         if (!acpi_device_dir(device)) {
 687                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 688                                                      acpi_ec_dir);
 689                 if (!acpi_device_dir(device))
 690                         return -ENODEV;
 691         }
 692
 693         entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
 694                                  acpi_device_dir(device),
 695                                  &acpi_ec_info_ops, acpi_driver_data(device));
 696         if (!entry)
 697                 return -ENODEV;
 698         return 0;
 699 }
 700
 701 static int acpi_ec_remove_fs(struct acpi_device *device)
 702 {
 703
 704         if (acpi_device_dir(device)) {
 705                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 706                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 707                 acpi_device_dir(device) = NULL;
 708         }
 709
 710         return 0;
 711 }
 712
 713 /* --------------------------------------------------------------------------
 714                                Driver Interface
 715    -------------------------------------------------------------------------- */
 716 static acpi_status
 717 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 718
 719 static struct acpi_ec *make_acpi_ec(void)
 720 {
 721         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 722         if (!ec)
 723                 return NULL;
 724         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 725         mutex_init(&ec->lock);
 726         init_waitqueue_head(&ec->wait);
 727         INIT_LIST_HEAD(&ec->list);
 728         spin_lock_init(&ec->curr_lock);
 729         return ec;
 730 }
 731
 732 static acpi_status
 733 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 734                                void *context, void **return_value)
 735 {
 736         char node_name[5];
 737         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 738         struct acpi_ec *ec = context;
 739         int value = 0;
 740         acpi_status status;
 741
 742         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 743
 744         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 745                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 746         }
 747         return AE_OK;
 748 }
 749
 750 static acpi_status
 751 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 752 {
 753         acpi_status status;
 754         unsigned long long tmp = 0;
 755
 756         struct acpi_ec *ec = context;
 757
 758         /* clear addr values, ec_parse_io_ports depend on it */
 759         ec->command_addr = ec->data_addr = 0;
 760
 761         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 762                                      ec_parse_io_ports, ec);
 763         if (ACPI_FAILURE(status))
 764                 return status;
 765
 766         /* Get GPE bit assignment (EC events). */
 767         /* TODO: Add support for _GPE returning a package */
 768         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 769         if (ACPI_FAILURE(status))
 770                 return status;
 771         ec->gpe = tmp;
 772         /* Use the global lock for all EC transactions? */
 773         tmp = 0;
 774         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 775         ec->global_lock = tmp;
 776         ec->handle = handle;
 777         return AE_CTRL_TERMINATE;
 778 }
 779
 780 static int ec_install_handlers(struct acpi_ec *ec)
 781 {
 782         acpi_status status;
 783         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 784                 return 0;
 785         status = acpi_install_gpe_handler(NULL, ec->gpe,
 786                                   ACPI_GPE_EDGE_TRIGGERED,
 787                                   &acpi_ec_gpe_handler, ec);
 788         if (ACPI_FAILURE(status))
 789                 return -ENODEV;
 790         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 791         acpi_enable_gpe(NULL, ec->gpe);
 792         status = acpi_install_address_space_handler(ec->handle,
 793                                                     ACPI_ADR_SPACE_EC,
 794                                                     &acpi_ec_space_handler,
 795                                                     NULL, ec);
 796         if (ACPI_FAILURE(status)) {
 797                 if (status == AE_NOT_FOUND) {
 798                         /*
 799                          * Maybe OS fails in evaluating the _REG object.
 800                          * The AE_NOT_FOUND error will be ignored and OS
 801                          * continue to initialize EC.
 802                          */
 803                         printk(KERN_ERR "Fail in evaluating the _REG object"
 804                                 " of EC device. Broken bios is suspected.\n");
 805                 } else {
 806                         acpi_remove_gpe_handler(NULL, ec->gpe,
 807                                 &acpi_ec_gpe_handler);
 808                         return -ENODEV;
 809                 }
 810         }
 811
 812         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 813         return 0;
 814 }
 815
 816 static void ec_remove_handlers(struct acpi_ec *ec)
 817 {
 818         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 819                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 820                 pr_err(PREFIX "failed to remove space handler\n");
 821         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 822                                 &acpi_ec_gpe_handler)))
 823                 pr_err(PREFIX "failed to remove gpe handler\n");
 824         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 825 }
 826
 827 static int acpi_ec_add(struct acpi_device *device)
 828 {
 829         struct acpi_ec *ec = NULL;
 830         int ret;
 831
 832         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 833         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 834
 835         /* Check for boot EC */
 836         if (boot_ec &&
 837             (boot_ec->handle == device->handle ||
 838              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 839                 ec = boot_ec;
 840                 boot_ec = NULL;
 841         } else {
 842                 ec = make_acpi_ec();
 843                 if (!ec)
 844                         return -ENOMEM;
 845         }
 846         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 847                 AE_CTRL_TERMINATE) {
 848                         kfree(ec);
 849                         return -EINVAL;
 850         }
 851
 852         ec->handle = device->handle;
 853
 854         /* Find and register all query methods */
 855         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 856                             acpi_ec_register_query_methods, NULL, ec, NULL);
 857
 858         if (!first_ec)
 859                 first_ec = ec;
 860         device->driver_data = ec;
 861         acpi_ec_add_fs(device);
 862         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 863                           ec->gpe, ec->command_addr, ec->data_addr);
 864
 865         ret = ec_install_handlers(ec);
 866
 867         /* EC is fully operational, allow queries */
 868         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 869         return ret;
 870 }
 871
 872 static int acpi_ec_remove(struct acpi_device *device, int type)
 873 {
 874         struct acpi_ec *ec;
 875         struct acpi_ec_query_handler *handler, *tmp;
 876
 877         if (!device)
 878                 return -EINVAL;
 879
 880         ec = acpi_driver_data(device);
 881         ec_remove_handlers(ec);
 882         mutex_lock(&ec->lock);
 883         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 884                 list_del(&handler->node);
 885                 kfree(handler);
 886         }
 887         mutex_unlock(&ec->lock);
 888         acpi_ec_remove_fs(device);
 889         device->driver_data = NULL;
 890         if (ec == first_ec)
 891                 first_ec = NULL;
 892         kfree(ec);
 893         return 0;
 894 }
 895
 896 static acpi_status
 897 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 898 {
 899         struct acpi_ec *ec = context;
 900
 901         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 902                 return AE_OK;
 903
 904         /*
 905          * The first address region returned is the data port, and
 906          * the second address region returned is the status/command
 907          * port.
 908          */
 909         if (ec->data_addr == 0)
 910                 ec->data_addr = resource->data.io.minimum;
 911         else if (ec->command_addr == 0)
 912                 ec->command_addr = resource->data.io.minimum;
 913         else
 914                 return AE_CTRL_TERMINATE;
 915
 916         return AE_OK;
 917 }
 918
 919 int __init acpi_boot_ec_enable(void)
 920 {
 921         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 922                 return 0;
 923         if (!ec_install_handlers(boot_ec)) {
 924                 first_ec = boot_ec;
 925                 return 0;
 926         }
 927         return -EFAULT;
 928 }
 929
 930 static const struct acpi_device_id ec_device_ids[] = {
 931         {"PNP0C09", 0},
 932         {"", 0},
 933 };
 934
 935 /* Some BIOS do not survive early DSDT scan, skip it */
 936 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 937 {
 938         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 939         return 0;
 940 }
 941
 942 /* ASUStek often supplies us with broken ECDT, validate it */
 943 static int ec_validate_ecdt(const struct dmi_system_id *id)
 944 {
 945         EC_FLAGS_VALIDATE_ECDT = 1;
 946         return 0;
 947 }
 948
 949 /* MSI EC needs special treatment, enable it */
 950 static int ec_flag_msi(const struct dmi_system_id *id)
 951 {
 952         printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
 953         EC_FLAGS_MSI = 1;
 954         EC_FLAGS_VALIDATE_ECDT = 1;
 955         return 0;
 956 }
 957
 958 static struct dmi_system_id __initdata ec_dmi_table[] = {
 959         {
 960         ec_skip_dsdt_scan, "Compal JFL92", {
 961         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 962         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 963         {
 964         ec_flag_msi, "MSI hardware", {
 965         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
 966         {
 967         ec_flag_msi, "MSI hardware", {
 968         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
 969         {
 970         ec_flag_msi, "MSI hardware", {
 971         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
 972         {
 973         ec_validate_ecdt, "ASUS hardware", {
 974         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
 975         {},
 976 };
 977
 978
 979 int __init acpi_ec_ecdt_probe(void)
 980 {
 981         acpi_status status;
 982         struct acpi_ec *saved_ec = NULL;
 983         struct acpi_table_ecdt *ecdt_ptr;
 984
 985         boot_ec = make_acpi_ec();
 986         if (!boot_ec)
 987                 return -ENOMEM;
 988         /*
 989          * Generate a boot ec context
 990          */
 991         dmi_check_system(ec_dmi_table);
 992         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 993                                 (struct acpi_table_header **)&ecdt_ptr);
 994         if (ACPI_SUCCESS(status)) {
 995                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
 996                 boot_ec->command_addr = ecdt_ptr->control.address;
 997                 boot_ec->data_addr = ecdt_ptr->data.address;
 998                 boot_ec->gpe = ecdt_ptr->gpe;
 999                 boot_ec->handle = ACPI_ROOT_OBJECT;
1000                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1001                 /* Don't trust ECDT, which comes from ASUSTek */
1002                 if (!EC_FLAGS_VALIDATE_ECDT)
1003                         goto install;
1004                 saved_ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1005                 if (!saved_ec)
1006                         return -ENOMEM;
1007                 memcpy(saved_ec, boot_ec, sizeof(struct acpi_ec));
1008         /* fall through */
1009         }
1010
1011         if (EC_FLAGS_SKIP_DSDT_SCAN)
1012                 return -ENODEV;
1013
1014         /* This workaround is needed only on some broken machines,
1015          * which require early EC, but fail to provide ECDT */
1016         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1017         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1018                                         boot_ec, NULL);
1019         /* Check that acpi_get_devices actually find something */
1020         if (ACPI_FAILURE(status) || !boot_ec->handle)
1021                 goto error;
1022         if (saved_ec) {
1023                 /* try to find good ECDT from ASUSTek */
1024                 if (saved_ec->command_addr != boot_ec->command_addr ||
1025                     saved_ec->data_addr != boot_ec->data_addr ||
1026                     saved_ec->gpe != boot_ec->gpe ||
1027                     saved_ec->handle != boot_ec->handle)
1028                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1029                         "ECDT tables, which are very hard to workaround. "
1030                         "Trying to use DSDT EC info instead. Please send "
1031                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1032                 kfree(saved_ec);
1033                 saved_ec = NULL;
1034         } else {
1035                 /* We really need to limit this workaround, the only ASUS,
1036                 * which needs it, has fake EC._INI method, so use it as flag.
1037                 * Keep boot_ec struct as it will be needed soon.
1038                 */
1039                 acpi_handle dummy;
1040                 if (!dmi_name_in_vendors("ASUS") ||
1041                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1042                                                         &dummy)))
1043                         return -ENODEV;
1044         }
1045 install:
1046         if (!ec_install_handlers(boot_ec)) {
1047                 first_ec = boot_ec;
1048                 return 0;
1049         }
1050 error:
1051         kfree(boot_ec);
1052         boot_ec = NULL;
1053         return -ENODEV;
1054 }
1055
1056 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1057 {
1058         struct acpi_ec *ec = acpi_driver_data(device);
1059         /* Stop using GPE */
1060         acpi_disable_gpe(NULL, ec->gpe);
1061         return 0;
1062 }
1063
1064 static int acpi_ec_resume(struct acpi_device *device)
1065 {
1066         struct acpi_ec *ec = acpi_driver_data(device);
1067         /* Enable use of GPE back */
1068         acpi_enable_gpe(NULL, ec->gpe);
1069         return 0;
1070 }
1071
1072 static struct acpi_driver acpi_ec_driver = {
1073         .name = "ec",
1074         .class = ACPI_EC_CLASS,
1075         .ids = ec_device_ids,
1076         .ops = {
1077                 .add = acpi_ec_add,
1078                 .remove = acpi_ec_remove,
1079                 .suspend = acpi_ec_suspend,
1080                 .resume = acpi_ec_resume,
1081                 },
1082 };
1083
1084 int __init acpi_ec_init(void)
1085 {
1086         int result = 0;
1087
1088         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1089         if (!acpi_ec_dir)
1090                 return -ENODEV;
1091
1092         /* Now register the driver for the EC */
1093         result = acpi_bus_register_driver(&acpi_ec_driver);
1094         if (result < 0) {
1095                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1096                 return -ENODEV;
1097         }
1098
1099         return result;
1100 }
1101
1102 /* EC driver currently not unloadable */
1103 #if 0
1104 static void __exit acpi_ec_exit(void)
1105 {
1106
1107         acpi_bus_unregister_driver(&acpi_ec_driver);
1108
1109         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1110
1111         return;
1112 }
1113 #endif  /* 0 */