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 <linux/slab.h>
  43 #include <asm/io.h>
  44 #include <acpi/acpi_bus.h>
  45 #include <acpi/acpi_drivers.h>
  46 #include <linux/dmi.h>
  47
  48 #define ACPI_EC_CLASS                   "embedded_controller"
  49 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  50 #define ACPI_EC_FILE_INFO               "info"
  51
  52 #define PREFIX                          "ACPI: EC: "
  53
  54 /* EC status register */
  55 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  56 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  57 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  58 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  59
  60 /* EC commands */
  61 enum ec_command {
  62         ACPI_EC_COMMAND_READ = 0x80,
  63         ACPI_EC_COMMAND_WRITE = 0x81,
  64         ACPI_EC_BURST_ENABLE = 0x82,
  65         ACPI_EC_BURST_DISABLE = 0x83,
  66         ACPI_EC_COMMAND_QUERY = 0x84,
  67 };
  68
  69 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  70 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  71 #define ACPI_EC_CDELAY          10      /* Wait 10us before polling EC */
  72 #define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
  73
  74 #define ACPI_EC_STORM_THRESHOLD 8       /* number of false interrupts
  75                                            per one transaction */
  76
  77 enum {
  78         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  79         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  80         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
  81                                          * OpReg are installed */
  82         EC_FLAGS_FROZEN,                /* Transactions are suspended */
  83 };
  84
  85 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  86 /* External interfaces use first EC only, so remember */
  87 typedef int (*acpi_ec_query_func) (void *data);
  88
  89 struct acpi_ec_query_handler {
  90         struct list_head node;
  91         acpi_ec_query_func func;
  92         acpi_handle handle;
  93         void *data;
  94         u8 query_bit;
  95 };
  96
  97 struct transaction {
  98         const u8 *wdata;
  99         u8 *rdata;
 100         unsigned short irq_count;
 101         u8 command;
 102         u8 wi;
 103         u8 ri;
 104         u8 wlen;
 105         u8 rlen;
 106         bool done;
 107 };
 108
 109 static struct acpi_ec {
 110         acpi_handle handle;
 111         unsigned long gpe;
 112         unsigned long command_addr;
 113         unsigned long data_addr;
 114         unsigned long global_lock;
 115         unsigned long flags;
 116         struct mutex lock;
 117         wait_queue_head_t wait;
 118         struct list_head list;
 119         struct transaction *curr;
 120         spinlock_t curr_lock;
 121 } *boot_ec, *first_ec;
 122
 123 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 124 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 125 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 126
 127 /* --------------------------------------------------------------------------
 128                              Transaction Management
 129    -------------------------------------------------------------------------- */
 130
 131 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 132 {
 133         u8 x = inb(ec->command_addr);
 134         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
 135         return x;
 136 }
 137
 138 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 139 {
 140         u8 x = inb(ec->data_addr);
 141         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
 142         return x;
 143 }
 144
 145 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 146 {
 147         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
 148         outb(command, ec->command_addr);
 149 }
 150
 151 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 152 {
 153         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
 154         outb(data, ec->data_addr);
 155 }
 156
 157 static int ec_transaction_done(struct acpi_ec *ec)
 158 {
 159         unsigned long flags;
 160         int ret = 0;
 161         spin_lock_irqsave(&ec->curr_lock, flags);
 162         if (!ec->curr || ec->curr->done)
 163                 ret = 1;
 164         spin_unlock_irqrestore(&ec->curr_lock, flags);
 165         return ret;
 166 }
 167
 168 static void start_transaction(struct acpi_ec *ec)
 169 {
 170         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 171         ec->curr->done = false;
 172         acpi_ec_write_cmd(ec, ec->curr->command);
 173 }
 174
 175 static void advance_transaction(struct acpi_ec *ec, u8 status)
 176 {
 177         unsigned long flags;
 178         spin_lock_irqsave(&ec->curr_lock, flags);
 179         if (!ec->curr)
 180                 goto unlock;
 181         if (ec->curr->wlen > ec->curr->wi) {
 182                 if ((status & ACPI_EC_FLAG_IBF) == 0)
 183                         acpi_ec_write_data(ec,
 184                                 ec->curr->wdata[ec->curr->wi++]);
 185                 else
 186                         goto err;
 187         } else if (ec->curr->rlen > ec->curr->ri) {
 188                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
 189                         ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
 190                         if (ec->curr->rlen == ec->curr->ri)
 191                                 ec->curr->done = true;
 192                 } else
 193                         goto err;
 194         } else if (ec->curr->wlen == ec->curr->wi &&
 195                    (status & ACPI_EC_FLAG_IBF) == 0)
 196                 ec->curr->done = true;
 197         goto unlock;
 198 err:
 199         /* false interrupt, state didn't change */
 200         if (in_interrupt())
 201                 ++ec->curr->irq_count;
 202 unlock:
 203         spin_unlock_irqrestore(&ec->curr_lock, flags);
 204 }
 205
 206 static int acpi_ec_sync_query(struct acpi_ec *ec);
 207
 208 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 209 {
 210         if (state & ACPI_EC_FLAG_SCI) {
 211                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 212                         return acpi_ec_sync_query(ec);
 213         }
 214         return 0;
 215 }
 216
 217 static int ec_poll(struct acpi_ec *ec)
 218 {
 219         unsigned long flags;
 220         int repeat = 2; /* number of command restarts */
 221         while (repeat--) {
 222                 unsigned long delay = jiffies +
 223                         msecs_to_jiffies(ACPI_EC_DELAY);
 224                 do {
 225                         /* don't sleep with disabled interrupts */
 226                         if (EC_FLAGS_MSI || irqs_disabled()) {
 227                                 udelay(ACPI_EC_MSI_UDELAY);
 228                                 if (ec_transaction_done(ec))
 229                                         return 0;
 230                         } else {
 231                                 if (wait_event_timeout(ec->wait,
 232                                                 ec_transaction_done(ec),
 233                                                 msecs_to_jiffies(1)))
 234                                         return 0;
 235                         }
 236                         advance_transaction(ec, acpi_ec_read_status(ec));
 237                 } while (time_before(jiffies, delay));
 238                 if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
 239                         break;
 240                 pr_debug(PREFIX "controller reset, restart transaction\n");
 241                 spin_lock_irqsave(&ec->curr_lock, flags);
 242                 start_transaction(ec);
 243                 spin_unlock_irqrestore(&ec->curr_lock, flags);
 244         }
 245         return -ETIME;
 246 }
 247
 248 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 249                                         struct transaction *t)
 250 {
 251         unsigned long tmp;
 252         int ret = 0;
 253         if (EC_FLAGS_MSI)
 254                 udelay(ACPI_EC_MSI_UDELAY);
 255         /* start transaction */
 256         spin_lock_irqsave(&ec->curr_lock, tmp);
 257         /* following two actions should be kept atomic */
 258         ec->curr = t;
 259         start_transaction(ec);
 260         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 261                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 262         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 263         ret = ec_poll(ec);
 264         spin_lock_irqsave(&ec->curr_lock, tmp);
 265         ec->curr = NULL;
 266         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 267         return ret;
 268 }
 269
 270 static int ec_check_ibf0(struct acpi_ec *ec)
 271 {
 272         u8 status = acpi_ec_read_status(ec);
 273         return (status & ACPI_EC_FLAG_IBF) == 0;
 274 }
 275
 276 static int ec_wait_ibf0(struct acpi_ec *ec)
 277 {
 278         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 279         /* interrupt wait manually if GPE mode is not active */
 280         while (time_before(jiffies, delay))
 281                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
 282                                         msecs_to_jiffies(1)))
 283                         return 0;
 284         return -ETIME;
 285 }
 286
 287 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 288 {
 289         int status;
 290         u32 glk;
 291         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 292                 return -EINVAL;
 293         if (t->rdata)
 294                 memset(t->rdata, 0, t->rlen);
 295         mutex_lock(&ec->lock);
 296         if (test_bit(EC_FLAGS_FROZEN, &ec->flags)) {
 297                 status = -EINVAL;
 298                 goto unlock;
 299         }
 300         if (ec->global_lock) {
 301                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 302                 if (ACPI_FAILURE(status)) {
 303                         status = -ENODEV;
 304                         goto unlock;
 305                 }
 306         }
 307         if (ec_wait_ibf0(ec)) {
 308                 pr_err(PREFIX "input buffer is not empty, "
 309                                 "aborting transaction\n");
 310                 status = -ETIME;
 311                 goto end;
 312         }
 313         pr_debug(PREFIX "transaction start\n");
 314         /* disable GPE during transaction if storm is detected */
 315         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 316                 /*
 317                  * It has to be disabled at the hardware level regardless of the
 318                  * GPE reference counting, so that it doesn't trigger.
 319                  */
 320                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 321         }
 322
 323         status = acpi_ec_transaction_unlocked(ec, t);
 324
 325         /* check if we received SCI during transaction */
 326         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 327         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 328                 msleep(1);
 329                 /*
 330                  * It is safe to enable the GPE outside of the transaction.  Use
 331                  * acpi_set_gpe() for that, since we used it to disable the GPE
 332                  * above.
 333                  */
 334                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 335         } else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
 336                 pr_info(PREFIX "GPE storm detected, "
 337                         "transactions will use polling mode\n");
 338                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 339         }
 340         pr_debug(PREFIX "transaction end\n");
 341 end:
 342         if (ec->global_lock)
 343                 acpi_release_global_lock(glk);
 344 unlock:
 345         mutex_unlock(&ec->lock);
 346         return status;
 347 }
 348
 349 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 350 {
 351         u8 d;
 352         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 353                                 .wdata = NULL, .rdata = &d,
 354                                 .wlen = 0, .rlen = 1};
 355
 356         return acpi_ec_transaction(ec, &t);
 357 }
 358
 359 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 360 {
 361         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 362                                 .wdata = NULL, .rdata = NULL,
 363                                 .wlen = 0, .rlen = 0};
 364
 365         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 366                                 acpi_ec_transaction(ec, &t) : 0;
 367 }
 368
 369 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 370 {
 371         int result;
 372         u8 d;
 373         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 374                                 .wdata = &address, .rdata = &d,
 375                                 .wlen = 1, .rlen = 1};
 376
 377         result = acpi_ec_transaction(ec, &t);
 378         *data = d;
 379         return result;
 380 }
 381
 382 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 383 {
 384         u8 wdata[2] = { address, data };
 385         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 386                                 .wdata = wdata, .rdata = NULL,
 387                                 .wlen = 2, .rlen = 0};
 388
 389         return acpi_ec_transaction(ec, &t);
 390 }
 391
 392 /*
 393  * Externally callable EC access functions. For now, assume 1 EC only
 394  */
 395 int ec_burst_enable(void)
 396 {
 397         if (!first_ec)
 398                 return -ENODEV;
 399         return acpi_ec_burst_enable(first_ec);
 400 }
 401
 402 EXPORT_SYMBOL(ec_burst_enable);
 403
 404 int ec_burst_disable(void)
 405 {
 406         if (!first_ec)
 407                 return -ENODEV;
 408         return acpi_ec_burst_disable(first_ec);
 409 }
 410
 411 EXPORT_SYMBOL(ec_burst_disable);
 412
 413 int ec_read(u8 addr, u8 * val)
 414 {
 415         int err;
 416         u8 temp_data;
 417
 418         if (!first_ec)
 419                 return -ENODEV;
 420
 421         err = acpi_ec_read(first_ec, addr, &temp_data);
 422
 423         if (!err) {
 424                 *val = temp_data;
 425                 return 0;
 426         } else
 427                 return err;
 428 }
 429
 430 EXPORT_SYMBOL(ec_read);
 431
 432 int ec_write(u8 addr, u8 val)
 433 {
 434         int err;
 435
 436         if (!first_ec)
 437                 return -ENODEV;
 438
 439         err = acpi_ec_write(first_ec, addr, val);
 440
 441         return err;
 442 }
 443
 444 EXPORT_SYMBOL(ec_write);
 445
 446 int ec_transaction(u8 command,
 447                    const u8 * wdata, unsigned wdata_len,
 448                    u8 * rdata, unsigned rdata_len,
 449                    int force_poll)
 450 {
 451         struct transaction t = {.command = command,
 452                                 .wdata = wdata, .rdata = rdata,
 453                                 .wlen = wdata_len, .rlen = rdata_len};
 454         if (!first_ec)
 455                 return -ENODEV;
 456
 457         return acpi_ec_transaction(first_ec, &t);
 458 }
 459
 460 EXPORT_SYMBOL(ec_transaction);
 461
 462 void acpi_ec_suspend_transactions(void)
 463 {
 464         struct acpi_ec *ec = first_ec;
 465
 466         if (!ec)
 467                 return;
 468
 469         mutex_lock(&ec->lock);
 470         /* Prevent transactions from being carried out */
 471         set_bit(EC_FLAGS_FROZEN, &ec->flags);
 472         mutex_unlock(&ec->lock);
 473 }
 474
 475 void acpi_ec_resume_transactions(void)
 476 {
 477         struct acpi_ec *ec = first_ec;
 478
 479         if (!ec)
 480                 return;
 481
 482         mutex_lock(&ec->lock);
 483         /* Allow transactions to be carried out again */
 484         clear_bit(EC_FLAGS_FROZEN, &ec->flags);
 485         mutex_unlock(&ec->lock);
 486 }
 487
 488 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 489 {
 490         int result;
 491         u8 d;
 492         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 493                                 .wdata = NULL, .rdata = &d,
 494                                 .wlen = 0, .rlen = 1};
 495         if (!ec || !data)
 496                 return -EINVAL;
 497         /*
 498          * Query the EC to find out which _Qxx method we need to evaluate.
 499          * Note that successful completion of the query causes the ACPI_EC_SCI
 500          * bit to be cleared (and thus clearing the interrupt source).
 501          */
 502         result = acpi_ec_transaction_unlocked(ec, &t);
 503         if (result)
 504                 return result;
 505         if (!d)
 506                 return -ENODATA;
 507         *data = d;
 508         return 0;
 509 }
 510
 511 /* --------------------------------------------------------------------------
 512                                 Event Management
 513    -------------------------------------------------------------------------- */
 514 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 515                               acpi_handle handle, acpi_ec_query_func func,
 516                               void *data)
 517 {
 518         struct acpi_ec_query_handler *handler =
 519             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 520         if (!handler)
 521                 return -ENOMEM;
 522
 523         handler->query_bit = query_bit;
 524         handler->handle = handle;
 525         handler->func = func;
 526         handler->data = data;
 527         mutex_lock(&ec->lock);
 528         list_add(&handler->node, &ec->list);
 529         mutex_unlock(&ec->lock);
 530         return 0;
 531 }
 532
 533 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 534
 535 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 536 {
 537         struct acpi_ec_query_handler *handler, *tmp;
 538         mutex_lock(&ec->lock);
 539         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 540                 if (query_bit == handler->query_bit) {
 541                         list_del(&handler->node);
 542                         kfree(handler);
 543                 }
 544         }
 545         mutex_unlock(&ec->lock);
 546 }
 547
 548 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 549
 550 static void acpi_ec_run(void *cxt)
 551 {
 552         struct acpi_ec_query_handler *handler = cxt;
 553         if (!handler)
 554                 return;
 555         pr_debug(PREFIX "start query execution\n");
 556         if (handler->func)
 557                 handler->func(handler->data);
 558         else if (handler->handle)
 559                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 560         pr_debug(PREFIX "stop query execution\n");
 561         kfree(handler);
 562 }
 563
 564 static int acpi_ec_sync_query(struct acpi_ec *ec)
 565 {
 566         u8 value = 0;
 567         int status;
 568         struct acpi_ec_query_handler *handler, *copy;
 569         if ((status = acpi_ec_query_unlocked(ec, &value)))
 570                 return status;
 571         list_for_each_entry(handler, &ec->list, node) {
 572                 if (value == handler->query_bit) {
 573                         /* have custom handler for this bit */
 574                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 575                         if (!copy)
 576                                 return -ENOMEM;
 577                         memcpy(copy, handler, sizeof(*copy));
 578                         pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
 579                         return acpi_os_execute((copy->func) ?
 580                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 581                                 acpi_ec_run, copy);
 582                 }
 583         }
 584         return 0;
 585 }
 586
 587 static void acpi_ec_gpe_query(void *ec_cxt)
 588 {
 589         struct acpi_ec *ec = ec_cxt;
 590         if (!ec)
 591                 return;
 592         mutex_lock(&ec->lock);
 593         acpi_ec_sync_query(ec);
 594         mutex_unlock(&ec->lock);
 595 }
 596
 597 static void acpi_ec_gpe_query(void *ec_cxt);
 598
 599 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 600 {
 601         if (state & ACPI_EC_FLAG_SCI) {
 602                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 603                         pr_debug(PREFIX "push gpe query to the queue\n");
 604                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 605                                 acpi_ec_gpe_query, ec);
 606                 }
 607         }
 608         return 0;
 609 }
 610
 611 static u32 acpi_ec_gpe_handler(void *data)
 612 {
 613         struct acpi_ec *ec = data;
 614
 615         pr_debug(PREFIX "~~~> interrupt\n");
 616
 617         advance_transaction(ec, acpi_ec_read_status(ec));
 618         if (ec_transaction_done(ec) &&
 619             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 620                 wake_up(&ec->wait);
 621                 ec_check_sci(ec, acpi_ec_read_status(ec));
 622         }
 623         return ACPI_INTERRUPT_HANDLED;
 624 }
 625
 626 /* --------------------------------------------------------------------------
 627                              Address Space Management
 628    -------------------------------------------------------------------------- */
 629
 630 static acpi_status
 631 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 632                       u32 bits, u64 *value64,
 633                       void *handler_context, void *region_context)
 634 {
 635         struct acpi_ec *ec = handler_context;
 636         int result = 0, i, bytes = bits / 8;
 637         u8 *value = (u8 *)value64;
 638
 639         if ((address > 0xFF) || !value || !handler_context)
 640                 return AE_BAD_PARAMETER;
 641
 642         if (function != ACPI_READ && function != ACPI_WRITE)
 643                 return AE_BAD_PARAMETER;
 644
 645         if (EC_FLAGS_MSI || bits > 8)
 646                 acpi_ec_burst_enable(ec);
 647
 648         for (i = 0; i < bytes; ++i, ++address, ++value)
 649                 result = (function == ACPI_READ) ?
 650                         acpi_ec_read(ec, address, value) :
 651                         acpi_ec_write(ec, address, *value);
 652
 653         if (EC_FLAGS_MSI || bits > 8)
 654                 acpi_ec_burst_disable(ec);
 655
 656         switch (result) {
 657         case -EINVAL:
 658                 return AE_BAD_PARAMETER;
 659                 break;
 660         case -ENODEV:
 661                 return AE_NOT_FOUND;
 662                 break;
 663         case -ETIME:
 664                 return AE_TIME;
 665                 break;
 666         default:
 667                 return AE_OK;
 668         }
 669 }
 670
 671 /* --------------------------------------------------------------------------
 672                               FS Interface (/proc)
 673    -------------------------------------------------------------------------- */
 674
 675 static struct proc_dir_entry *acpi_ec_dir;
 676
 677 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 678 {
 679         struct acpi_ec *ec = seq->private;
 680
 681         if (!ec)
 682                 goto end;
 683
 684         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 685         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 686                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 687         seq_printf(seq, "use global lock:\t%s\n",
 688                    ec->global_lock ? "yes" : "no");
 689       end:
 690         return 0;
 691 }
 692
 693 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 694 {
 695         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 696 }
 697
 698 static const struct file_operations acpi_ec_info_ops = {
 699         .open = acpi_ec_info_open_fs,
 700         .read = seq_read,
 701         .llseek = seq_lseek,
 702         .release = single_release,
 703         .owner = THIS_MODULE,
 704 };
 705
 706 static int acpi_ec_add_fs(struct acpi_device *device)
 707 {
 708         struct proc_dir_entry *entry = NULL;
 709
 710         if (!acpi_device_dir(device)) {
 711                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 712                                                      acpi_ec_dir);
 713                 if (!acpi_device_dir(device))
 714                         return -ENODEV;
 715         }
 716
 717         entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
 718                                  acpi_device_dir(device),
 719                                  &acpi_ec_info_ops, acpi_driver_data(device));
 720         if (!entry)
 721                 return -ENODEV;
 722         return 0;
 723 }
 724
 725 static int acpi_ec_remove_fs(struct acpi_device *device)
 726 {
 727
 728         if (acpi_device_dir(device)) {
 729                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 730                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 731                 acpi_device_dir(device) = NULL;
 732         }
 733
 734         return 0;
 735 }
 736
 737 /* --------------------------------------------------------------------------
 738                                Driver Interface
 739    -------------------------------------------------------------------------- */
 740 static acpi_status
 741 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 742
 743 static struct acpi_ec *make_acpi_ec(void)
 744 {
 745         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 746         if (!ec)
 747                 return NULL;
 748         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 749         mutex_init(&ec->lock);
 750         init_waitqueue_head(&ec->wait);
 751         INIT_LIST_HEAD(&ec->list);
 752         spin_lock_init(&ec->curr_lock);
 753         return ec;
 754 }
 755
 756 static acpi_status
 757 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 758                                void *context, void **return_value)
 759 {
 760         char node_name[5];
 761         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 762         struct acpi_ec *ec = context;
 763         int value = 0;
 764         acpi_status status;
 765
 766         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 767
 768         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 769                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 770         }
 771         return AE_OK;
 772 }
 773
 774 static acpi_status
 775 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 776 {
 777         acpi_status status;
 778         unsigned long long tmp = 0;
 779
 780         struct acpi_ec *ec = context;
 781
 782         /* clear addr values, ec_parse_io_ports depend on it */
 783         ec->command_addr = ec->data_addr = 0;
 784
 785         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 786                                      ec_parse_io_ports, ec);
 787         if (ACPI_FAILURE(status))
 788                 return status;
 789
 790         /* Get GPE bit assignment (EC events). */
 791         /* TODO: Add support for _GPE returning a package */
 792         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 793         if (ACPI_FAILURE(status))
 794                 return status;
 795         ec->gpe = tmp;
 796         /* Use the global lock for all EC transactions? */
 797         tmp = 0;
 798         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 799         ec->global_lock = tmp;
 800         ec->handle = handle;
 801         return AE_CTRL_TERMINATE;
 802 }
 803
 804 static int ec_install_handlers(struct acpi_ec *ec)
 805 {
 806         acpi_status status;
 807         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 808                 return 0;
 809         status = acpi_install_gpe_handler(NULL, ec->gpe,
 810                                   ACPI_GPE_EDGE_TRIGGERED,
 811                                   &acpi_ec_gpe_handler, ec);
 812         if (ACPI_FAILURE(status))
 813                 return -ENODEV;
 814
 815         acpi_enable_gpe(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 816         status = acpi_install_address_space_handler(ec->handle,
 817                                                     ACPI_ADR_SPACE_EC,
 818                                                     &acpi_ec_space_handler,
 819                                                     NULL, ec);
 820         if (ACPI_FAILURE(status)) {
 821                 if (status == AE_NOT_FOUND) {
 822                         /*
 823                          * Maybe OS fails in evaluating the _REG object.
 824                          * The AE_NOT_FOUND error will be ignored and OS
 825                          * continue to initialize EC.
 826                          */
 827                         printk(KERN_ERR "Fail in evaluating the _REG object"
 828                                 " of EC device. Broken bios is suspected.\n");
 829                 } else {
 830                         acpi_remove_gpe_handler(NULL, ec->gpe,
 831                                 &acpi_ec_gpe_handler);
 832                         acpi_disable_gpe(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 833                         return -ENODEV;
 834                 }
 835         }
 836
 837         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 838         return 0;
 839 }
 840
 841 static void ec_remove_handlers(struct acpi_ec *ec)
 842 {
 843         acpi_disable_gpe(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 844         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 845                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 846                 pr_err(PREFIX "failed to remove space handler\n");
 847         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 848                                 &acpi_ec_gpe_handler)))
 849                 pr_err(PREFIX "failed to remove gpe handler\n");
 850         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 851 }
 852
 853 static int acpi_ec_add(struct acpi_device *device)
 854 {
 855         struct acpi_ec *ec = NULL;
 856         int ret;
 857
 858         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 859         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 860
 861         /* Check for boot EC */
 862         if (boot_ec &&
 863             (boot_ec->handle == device->handle ||
 864              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 865                 ec = boot_ec;
 866                 boot_ec = NULL;
 867         } else {
 868                 ec = make_acpi_ec();
 869                 if (!ec)
 870                         return -ENOMEM;
 871         }
 872         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 873                 AE_CTRL_TERMINATE) {
 874                         kfree(ec);
 875                         return -EINVAL;
 876         }
 877
 878         ec->handle = device->handle;
 879
 880         /* Find and register all query methods */
 881         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 882                             acpi_ec_register_query_methods, NULL, ec, NULL);
 883
 884         if (!first_ec)
 885                 first_ec = ec;
 886         device->driver_data = ec;
 887         acpi_ec_add_fs(device);
 888         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 889                           ec->gpe, ec->command_addr, ec->data_addr);
 890
 891         ret = ec_install_handlers(ec);
 892
 893         /* EC is fully operational, allow queries */
 894         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 895         return ret;
 896 }
 897
 898 static int acpi_ec_remove(struct acpi_device *device, int type)
 899 {
 900         struct acpi_ec *ec;
 901         struct acpi_ec_query_handler *handler, *tmp;
 902
 903         if (!device)
 904                 return -EINVAL;
 905
 906         ec = acpi_driver_data(device);
 907         ec_remove_handlers(ec);
 908         mutex_lock(&ec->lock);
 909         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 910                 list_del(&handler->node);
 911                 kfree(handler);
 912         }
 913         mutex_unlock(&ec->lock);
 914         acpi_ec_remove_fs(device);
 915         device->driver_data = NULL;
 916         if (ec == first_ec)
 917                 first_ec = NULL;
 918         kfree(ec);
 919         return 0;
 920 }
 921
 922 static acpi_status
 923 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 924 {
 925         struct acpi_ec *ec = context;
 926
 927         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 928                 return AE_OK;
 929
 930         /*
 931          * The first address region returned is the data port, and
 932          * the second address region returned is the status/command
 933          * port.
 934          */
 935         if (ec->data_addr == 0)
 936                 ec->data_addr = resource->data.io.minimum;
 937         else if (ec->command_addr == 0)
 938                 ec->command_addr = resource->data.io.minimum;
 939         else
 940                 return AE_CTRL_TERMINATE;
 941
 942         return AE_OK;
 943 }
 944
 945 int __init acpi_boot_ec_enable(void)
 946 {
 947         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 948                 return 0;
 949         if (!ec_install_handlers(boot_ec)) {
 950                 first_ec = boot_ec;
 951                 return 0;
 952         }
 953         return -EFAULT;
 954 }
 955
 956 static const struct acpi_device_id ec_device_ids[] = {
 957         {"PNP0C09", 0},
 958         {"", 0},
 959 };
 960
 961 /* Some BIOS do not survive early DSDT scan, skip it */
 962 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 963 {
 964         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 965         return 0;
 966 }
 967
 968 /* ASUStek often supplies us with broken ECDT, validate it */
 969 static int ec_validate_ecdt(const struct dmi_system_id *id)
 970 {
 971         EC_FLAGS_VALIDATE_ECDT = 1;
 972         return 0;
 973 }
 974
 975 /* MSI EC needs special treatment, enable it */
 976 static int ec_flag_msi(const struct dmi_system_id *id)
 977 {
 978         printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
 979         EC_FLAGS_MSI = 1;
 980         EC_FLAGS_VALIDATE_ECDT = 1;
 981         return 0;
 982 }
 983
 984 static struct dmi_system_id __initdata ec_dmi_table[] = {
 985         {
 986         ec_skip_dsdt_scan, "Compal JFL92", {
 987         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 988         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 989         {
 990         ec_flag_msi, "MSI hardware", {
 991         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
 992         {
 993         ec_flag_msi, "MSI hardware", {
 994         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
 995         {
 996         ec_flag_msi, "MSI hardware", {
 997         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
 998         {
 999         ec_validate_ecdt, "ASUS hardware", {
1000         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1001         {},
1002 };
1003
1004
1005 int __init acpi_ec_ecdt_probe(void)
1006 {
1007         acpi_status status;
1008         struct acpi_ec *saved_ec = NULL;
1009         struct acpi_table_ecdt *ecdt_ptr;
1010
1011         boot_ec = make_acpi_ec();
1012         if (!boot_ec)
1013                 return -ENOMEM;
1014         /*
1015          * Generate a boot ec context
1016          */
1017         dmi_check_system(ec_dmi_table);
1018         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1019                                 (struct acpi_table_header **)&ecdt_ptr);
1020         if (ACPI_SUCCESS(status)) {
1021                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
1022                 boot_ec->command_addr = ecdt_ptr->control.address;
1023                 boot_ec->data_addr = ecdt_ptr->data.address;
1024                 boot_ec->gpe = ecdt_ptr->gpe;
1025                 boot_ec->handle = ACPI_ROOT_OBJECT;
1026                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1027                 /* Don't trust ECDT, which comes from ASUSTek */
1028                 if (!EC_FLAGS_VALIDATE_ECDT)
1029                         goto install;
1030                 saved_ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1031                 if (!saved_ec)
1032                         return -ENOMEM;
1033                 memcpy(saved_ec, boot_ec, sizeof(struct acpi_ec));
1034         /* fall through */
1035         }
1036
1037         if (EC_FLAGS_SKIP_DSDT_SCAN)
1038                 return -ENODEV;
1039
1040         /* This workaround is needed only on some broken machines,
1041          * which require early EC, but fail to provide ECDT */
1042         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1043         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1044                                         boot_ec, NULL);
1045         /* Check that acpi_get_devices actually find something */
1046         if (ACPI_FAILURE(status) || !boot_ec->handle)
1047                 goto error;
1048         if (saved_ec) {
1049                 /* try to find good ECDT from ASUSTek */
1050                 if (saved_ec->command_addr != boot_ec->command_addr ||
1051                     saved_ec->data_addr != boot_ec->data_addr ||
1052                     saved_ec->gpe != boot_ec->gpe ||
1053                     saved_ec->handle != boot_ec->handle)
1054                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1055                         "ECDT tables, which are very hard to workaround. "
1056                         "Trying to use DSDT EC info instead. Please send "
1057                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1058                 kfree(saved_ec);
1059                 saved_ec = NULL;
1060         } else {
1061                 /* We really need to limit this workaround, the only ASUS,
1062                 * which needs it, has fake EC._INI method, so use it as flag.
1063                 * Keep boot_ec struct as it will be needed soon.
1064                 */
1065                 acpi_handle dummy;
1066                 if (!dmi_name_in_vendors("ASUS") ||
1067                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1068                                                         &dummy)))
1069                         return -ENODEV;
1070         }
1071 install:
1072         if (!ec_install_handlers(boot_ec)) {
1073                 first_ec = boot_ec;
1074                 return 0;
1075         }
1076 error:
1077         kfree(boot_ec);
1078         boot_ec = NULL;
1079         return -ENODEV;
1080 }
1081
1082 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1083 {
1084         struct acpi_ec *ec = acpi_driver_data(device);
1085         /* Stop using the GPE, but keep it reference counted. */
1086         acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1087         return 0;
1088 }
1089
1090 static int acpi_ec_resume(struct acpi_device *device)
1091 {
1092         struct acpi_ec *ec = acpi_driver_data(device);
1093         /* Enable the GPE again, but don't reference count it once more. */
1094         acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1095         return 0;
1096 }
1097
1098 static struct acpi_driver acpi_ec_driver = {
1099         .name = "ec",
1100         .class = ACPI_EC_CLASS,
1101         .ids = ec_device_ids,
1102         .ops = {
1103                 .add = acpi_ec_add,
1104                 .remove = acpi_ec_remove,
1105                 .suspend = acpi_ec_suspend,
1106                 .resume = acpi_ec_resume,
1107                 },
1108 };
1109
1110 int __init acpi_ec_init(void)
1111 {
1112         int result = 0;
1113
1114         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1115         if (!acpi_ec_dir)
1116                 return -ENODEV;
1117
1118         /* Now register the driver for the EC */
1119         result = acpi_bus_register_driver(&acpi_ec_driver);
1120         if (result < 0) {
1121                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1122                 return -ENODEV;
1123         }
1124
1125         return result;
1126 }
1127
1128 /* EC driver currently not unloadable */
1129 #if 0
1130 static void __exit acpi_ec_exit(void)
1131 {
1132
1133         acpi_bus_unregister_driver(&acpi_ec_driver);
1134
1135         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1136
1137         return;
1138 }
1139 #endif  /* 0 */