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(OSL_GPE_HANDLER,
 539                                 acpi_ec_run, copy);
 540                 }
 541         }
 542         return 0;
 543 }
 544
 545 static void acpi_ec_gpe_query(void *ec_cxt)
 546 {
 547         struct acpi_ec *ec = ec_cxt;
 548         if (!ec)
 549                 return;
 550         mutex_lock(&ec->lock);
 551         acpi_ec_sync_query(ec);
 552         mutex_unlock(&ec->lock);
 553 }
 554
 555 static void acpi_ec_gpe_query(void *ec_cxt);
 556
 557 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 558 {
 559         if (state & ACPI_EC_FLAG_SCI) {
 560                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 561                         pr_debug(PREFIX "push gpe query to the queue\n");
 562                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 563                                 acpi_ec_gpe_query, ec);
 564                 }
 565         }
 566         return 0;
 567 }
 568
 569 static u32 acpi_ec_gpe_handler(void *data)
 570 {
 571         struct acpi_ec *ec = data;
 572
 573         pr_debug(PREFIX "~~~> interrupt\n");
 574
 575         advance_transaction(ec, acpi_ec_read_status(ec));
 576         if (ec_transaction_done(ec) &&
 577             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 578                 wake_up(&ec->wait);
 579                 ec_check_sci(ec, acpi_ec_read_status(ec));
 580         }
 581         return ACPI_INTERRUPT_HANDLED;
 582 }
 583
 584 /* --------------------------------------------------------------------------
 585                              Address Space Management
 586    -------------------------------------------------------------------------- */
 587
 588 static acpi_status
 589 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 590                       u32 bits, acpi_integer *value,
 591                       void *handler_context, void *region_context)
 592 {
 593         struct acpi_ec *ec = handler_context;
 594         int result = 0, i;
 595         u8 temp = 0;
 596
 597         if ((address > 0xFF) || !value || !handler_context)
 598                 return AE_BAD_PARAMETER;
 599
 600         if (function != ACPI_READ && function != ACPI_WRITE)
 601                 return AE_BAD_PARAMETER;
 602
 603         if (bits != 8 && acpi_strict)
 604                 return AE_BAD_PARAMETER;
 605
 606         if (EC_FLAGS_MSI)
 607                 acpi_ec_burst_enable(ec);
 608
 609         if (function == ACPI_READ) {
 610                 result = acpi_ec_read(ec, address, &temp);
 611                 *value = temp;
 612         } else {
 613                 temp = 0xff & (*value);
 614                 result = acpi_ec_write(ec, address, temp);
 615         }
 616
 617         for (i = 8; unlikely(bits - i > 0); i += 8) {
 618                 ++address;
 619                 if (function == ACPI_READ) {
 620                         result = acpi_ec_read(ec, address, &temp);
 621                         (*value) |= ((acpi_integer)temp) << i;
 622                 } else {
 623                         temp = 0xff & ((*value) >> i);
 624                         result = acpi_ec_write(ec, address, temp);
 625                 }
 626         }
 627
 628         if (EC_FLAGS_MSI)
 629                 acpi_ec_burst_disable(ec);
 630
 631         switch (result) {
 632         case -EINVAL:
 633                 return AE_BAD_PARAMETER;
 634                 break;
 635         case -ENODEV:
 636                 return AE_NOT_FOUND;
 637                 break;
 638         case -ETIME:
 639                 return AE_TIME;
 640                 break;
 641         default:
 642                 return AE_OK;
 643         }
 644 }
 645
 646 /* --------------------------------------------------------------------------
 647                               FS Interface (/proc)
 648    -------------------------------------------------------------------------- */
 649
 650 static struct proc_dir_entry *acpi_ec_dir;
 651
 652 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 653 {
 654         struct acpi_ec *ec = seq->private;
 655
 656         if (!ec)
 657                 goto end;
 658
 659         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 660         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 661                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 662         seq_printf(seq, "use global lock:\t%s\n",
 663                    ec->global_lock ? "yes" : "no");
 664       end:
 665         return 0;
 666 }
 667
 668 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 669 {
 670         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 671 }
 672
 673 static const struct file_operations acpi_ec_info_ops = {
 674         .open = acpi_ec_info_open_fs,
 675         .read = seq_read,
 676         .llseek = seq_lseek,
 677         .release = single_release,
 678         .owner = THIS_MODULE,
 679 };
 680
 681 static int acpi_ec_add_fs(struct acpi_device *device)
 682 {
 683         struct proc_dir_entry *entry = NULL;
 684
 685         if (!acpi_device_dir(device)) {
 686                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 687                                                      acpi_ec_dir);
 688                 if (!acpi_device_dir(device))
 689                         return -ENODEV;
 690         }
 691
 692         entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
 693                                  acpi_device_dir(device),
 694                                  &acpi_ec_info_ops, acpi_driver_data(device));
 695         if (!entry)
 696                 return -ENODEV;
 697         return 0;
 698 }
 699
 700 static int acpi_ec_remove_fs(struct acpi_device *device)
 701 {
 702
 703         if (acpi_device_dir(device)) {
 704                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 705                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 706                 acpi_device_dir(device) = NULL;
 707         }
 708
 709         return 0;
 710 }
 711
 712 /* --------------------------------------------------------------------------
 713                                Driver Interface
 714    -------------------------------------------------------------------------- */
 715 static acpi_status
 716 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 717
 718 static struct acpi_ec *make_acpi_ec(void)
 719 {
 720         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 721         if (!ec)
 722                 return NULL;
 723         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 724         mutex_init(&ec->lock);
 725         init_waitqueue_head(&ec->wait);
 726         INIT_LIST_HEAD(&ec->list);
 727         spin_lock_init(&ec->curr_lock);
 728         return ec;
 729 }
 730
 731 static acpi_status
 732 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 733                                void *context, void **return_value)
 734 {
 735         char node_name[5];
 736         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 737         struct acpi_ec *ec = context;
 738         int value = 0;
 739         acpi_status status;
 740
 741         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 742
 743         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 744                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 745         }
 746         return AE_OK;
 747 }
 748
 749 static acpi_status
 750 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 751 {
 752         acpi_status status;
 753         unsigned long long tmp = 0;
 754
 755         struct acpi_ec *ec = context;
 756
 757         /* clear addr values, ec_parse_io_ports depend on it */
 758         ec->command_addr = ec->data_addr = 0;
 759
 760         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 761                                      ec_parse_io_ports, ec);
 762         if (ACPI_FAILURE(status))
 763                 return status;
 764
 765         /* Get GPE bit assignment (EC events). */
 766         /* TODO: Add support for _GPE returning a package */
 767         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 768         if (ACPI_FAILURE(status))
 769                 return status;
 770         ec->gpe = tmp;
 771         /* Use the global lock for all EC transactions? */
 772         tmp = 0;
 773         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 774         ec->global_lock = tmp;
 775         ec->handle = handle;
 776         return AE_CTRL_TERMINATE;
 777 }
 778
 779 static int ec_install_handlers(struct acpi_ec *ec)
 780 {
 781         acpi_status status;
 782         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 783                 return 0;
 784         status = acpi_install_gpe_handler(NULL, ec->gpe,
 785                                   ACPI_GPE_EDGE_TRIGGERED,
 786                                   &acpi_ec_gpe_handler, ec);
 787         if (ACPI_FAILURE(status))
 788                 return -ENODEV;
 789         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 790         acpi_enable_gpe(NULL, ec->gpe);
 791         status = acpi_install_address_space_handler(ec->handle,
 792                                                     ACPI_ADR_SPACE_EC,
 793                                                     &acpi_ec_space_handler,
 794                                                     NULL, ec);
 795         if (ACPI_FAILURE(status)) {
 796                 if (status == AE_NOT_FOUND) {
 797                         /*
 798                          * Maybe OS fails in evaluating the _REG object.
 799                          * The AE_NOT_FOUND error will be ignored and OS
 800                          * continue to initialize EC.
 801                          */
 802                         printk(KERN_ERR "Fail in evaluating the _REG object"
 803                                 " of EC device. Broken bios is suspected.\n");
 804                 } else {
 805                         acpi_remove_gpe_handler(NULL, ec->gpe,
 806                                 &acpi_ec_gpe_handler);
 807                         return -ENODEV;
 808                 }
 809         }
 810
 811         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 812         return 0;
 813 }
 814
 815 static void ec_remove_handlers(struct acpi_ec *ec)
 816 {
 817         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 818                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 819                 pr_err(PREFIX "failed to remove space handler\n");
 820         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 821                                 &acpi_ec_gpe_handler)))
 822                 pr_err(PREFIX "failed to remove gpe handler\n");
 823         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 824 }
 825
 826 static int acpi_ec_add(struct acpi_device *device)
 827 {
 828         struct acpi_ec *ec = NULL;
 829         int ret;
 830
 831         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 832         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 833
 834         /* Check for boot EC */
 835         if (boot_ec &&
 836             (boot_ec->handle == device->handle ||
 837              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 838                 ec = boot_ec;
 839                 boot_ec = NULL;
 840         } else {
 841                 ec = make_acpi_ec();
 842                 if (!ec)
 843                         return -ENOMEM;
 844         }
 845         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 846                 AE_CTRL_TERMINATE) {
 847                         kfree(ec);
 848                         return -EINVAL;
 849         }
 850
 851         ec->handle = device->handle;
 852
 853         /* Find and register all query methods */
 854         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 855                             acpi_ec_register_query_methods, NULL, ec, NULL);
 856
 857         if (!first_ec)
 858                 first_ec = ec;
 859         device->driver_data = ec;
 860         acpi_ec_add_fs(device);
 861         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 862                           ec->gpe, ec->command_addr, ec->data_addr);
 863
 864         ret = ec_install_handlers(ec);
 865
 866         /* EC is fully operational, allow queries */
 867         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 868         return ret;
 869 }
 870
 871 static int acpi_ec_remove(struct acpi_device *device, int type)
 872 {
 873         struct acpi_ec *ec;
 874         struct acpi_ec_query_handler *handler, *tmp;
 875
 876         if (!device)
 877                 return -EINVAL;
 878
 879         ec = acpi_driver_data(device);
 880         ec_remove_handlers(ec);
 881         mutex_lock(&ec->lock);
 882         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 883                 list_del(&handler->node);
 884                 kfree(handler);
 885         }
 886         mutex_unlock(&ec->lock);
 887         acpi_ec_remove_fs(device);
 888         device->driver_data = NULL;
 889         if (ec == first_ec)
 890                 first_ec = NULL;
 891         kfree(ec);
 892         return 0;
 893 }
 894
 895 static acpi_status
 896 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 897 {
 898         struct acpi_ec *ec = context;
 899
 900         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 901                 return AE_OK;
 902
 903         /*
 904          * The first address region returned is the data port, and
 905          * the second address region returned is the status/command
 906          * port.
 907          */
 908         if (ec->data_addr == 0)
 909                 ec->data_addr = resource->data.io.minimum;
 910         else if (ec->command_addr == 0)
 911                 ec->command_addr = resource->data.io.minimum;
 912         else
 913                 return AE_CTRL_TERMINATE;
 914
 915         return AE_OK;
 916 }
 917
 918 int __init acpi_boot_ec_enable(void)
 919 {
 920         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 921                 return 0;
 922         if (!ec_install_handlers(boot_ec)) {
 923                 first_ec = boot_ec;
 924                 return 0;
 925         }
 926         return -EFAULT;
 927 }
 928
 929 static const struct acpi_device_id ec_device_ids[] = {
 930         {"PNP0C09", 0},
 931         {"", 0},
 932 };
 933
 934 /* Some BIOS do not survive early DSDT scan, skip it */
 935 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 936 {
 937         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 938         return 0;
 939 }
 940
 941 /* ASUStek often supplies us with broken ECDT, validate it */
 942 static int ec_validate_ecdt(const struct dmi_system_id *id)
 943 {
 944         EC_FLAGS_VALIDATE_ECDT = 1;
 945         return 0;
 946 }
 947
 948 /* MSI EC needs special treatment, enable it */
 949 static int ec_flag_msi(const struct dmi_system_id *id)
 950 {
 951         printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
 952         EC_FLAGS_MSI = 1;
 953         EC_FLAGS_VALIDATE_ECDT = 1;
 954         return 0;
 955 }
 956
 957 static struct dmi_system_id __initdata ec_dmi_table[] = {
 958         {
 959         ec_skip_dsdt_scan, "Compal JFL92", {
 960         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 961         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 962         {
 963         ec_flag_msi, "MSI hardware", {
 964         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
 965         {
 966         ec_flag_msi, "MSI hardware", {
 967         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
 968         {
 969         ec_flag_msi, "MSI hardware", {
 970         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
 971         {
 972         ec_validate_ecdt, "ASUS hardware", {
 973         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
 974         {},
 975 };
 976
 977
 978 int __init acpi_ec_ecdt_probe(void)
 979 {
 980         acpi_status status;
 981         struct acpi_ec *saved_ec = NULL;
 982         struct acpi_table_ecdt *ecdt_ptr;
 983
 984         boot_ec = make_acpi_ec();
 985         if (!boot_ec)
 986                 return -ENOMEM;
 987         /*
 988          * Generate a boot ec context
 989          */
 990         dmi_check_system(ec_dmi_table);
 991         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 992                                 (struct acpi_table_header **)&ecdt_ptr);
 993         if (ACPI_SUCCESS(status)) {
 994                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
 995                 boot_ec->command_addr = ecdt_ptr->control.address;
 996                 boot_ec->data_addr = ecdt_ptr->data.address;
 997                 boot_ec->gpe = ecdt_ptr->gpe;
 998                 boot_ec->handle = ACPI_ROOT_OBJECT;
 999                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1000                 /* Don't trust ECDT, which comes from ASUSTek */
1001                 if (!EC_FLAGS_VALIDATE_ECDT)
1002                         goto install;
1003                 saved_ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1004                 if (!saved_ec)
1005                         return -ENOMEM;
1006                 memcpy(saved_ec, boot_ec, sizeof(struct acpi_ec));
1007         /* fall through */
1008         }
1009
1010         if (EC_FLAGS_SKIP_DSDT_SCAN)
1011                 return -ENODEV;
1012
1013         /* This workaround is needed only on some broken machines,
1014          * which require early EC, but fail to provide ECDT */
1015         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1016         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1017                                         boot_ec, NULL);
1018         /* Check that acpi_get_devices actually find something */
1019         if (ACPI_FAILURE(status) || !boot_ec->handle)
1020                 goto error;
1021         if (saved_ec) {
1022                 /* try to find good ECDT from ASUSTek */
1023                 if (saved_ec->command_addr != boot_ec->command_addr ||
1024                     saved_ec->data_addr != boot_ec->data_addr ||
1025                     saved_ec->gpe != boot_ec->gpe ||
1026                     saved_ec->handle != boot_ec->handle)
1027                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1028                         "ECDT tables, which are very hard to workaround. "
1029                         "Trying to use DSDT EC info instead. Please send "
1030                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1031                 kfree(saved_ec);
1032                 saved_ec = NULL;
1033         } else {
1034                 /* We really need to limit this workaround, the only ASUS,
1035                 * which needs it, has fake EC._INI method, so use it as flag.
1036                 * Keep boot_ec struct as it will be needed soon.
1037                 */
1038                 acpi_handle dummy;
1039                 if (!dmi_name_in_vendors("ASUS") ||
1040                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1041                                                         &dummy)))
1042                         return -ENODEV;
1043         }
1044 install:
1045         if (!ec_install_handlers(boot_ec)) {
1046                 first_ec = boot_ec;
1047                 return 0;
1048         }
1049 error:
1050         kfree(boot_ec);
1051         boot_ec = NULL;
1052         return -ENODEV;
1053 }
1054
1055 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1056 {
1057         struct acpi_ec *ec = acpi_driver_data(device);
1058         /* Stop using GPE */
1059         acpi_disable_gpe(NULL, ec->gpe);
1060         return 0;
1061 }
1062
1063 static int acpi_ec_resume(struct acpi_device *device)
1064 {
1065         struct acpi_ec *ec = acpi_driver_data(device);
1066         /* Enable use of GPE back */
1067         acpi_enable_gpe(NULL, ec->gpe);
1068         return 0;
1069 }
1070
1071 static struct acpi_driver acpi_ec_driver = {
1072         .name = "ec",
1073         .class = ACPI_EC_CLASS,
1074         .ids = ec_device_ids,
1075         .ops = {
1076                 .add = acpi_ec_add,
1077                 .remove = acpi_ec_remove,
1078                 .suspend = acpi_ec_suspend,
1079                 .resume = acpi_ec_resume,
1080                 },
1081 };
1082
1083 int __init acpi_ec_init(void)
1084 {
1085         int result = 0;
1086
1087         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1088         if (!acpi_ec_dir)
1089                 return -ENODEV;
1090
1091         /* Now register the driver for the EC */
1092         result = acpi_bus_register_driver(&acpi_ec_driver);
1093         if (result < 0) {
1094                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1095                 return -ENODEV;
1096         }
1097
1098         return result;
1099 }
1100
1101 /* EC driver currently not unloadable */
1102 #if 0
1103 static void __exit acpi_ec_exit(void)
1104 {
1105
1106         acpi_bus_unregister_driver(&acpi_ec_driver);
1107
1108         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1109
1110         return;
1111 }
1112 #endif  /* 0 */