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/interrupt.h>
  38 #include <linux/list.h>
  39 #include <linux/spinlock.h>
  40 #include <linux/slab.h>
  41 #include <asm/io.h>
  42 #include <acpi/acpi_bus.h>
  43 #include <acpi/acpi_drivers.h>
  44 #include <linux/dmi.h>
  45
  46 #include "internal.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 #undef PREFIX
  53 #define PREFIX                          "ACPI: EC: "
  54
  55 /* EC status register */
  56 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  57 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  58 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  59 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  60
  61 /* EC commands */
  62 enum ec_command {
  63         ACPI_EC_COMMAND_READ = 0x80,
  64         ACPI_EC_COMMAND_WRITE = 0x81,
  65         ACPI_EC_BURST_ENABLE = 0x82,
  66         ACPI_EC_BURST_DISABLE = 0x83,
  67         ACPI_EC_COMMAND_QUERY = 0x84,
  68 };
  69
  70 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  71 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  72 #define ACPI_EC_CDELAY          10      /* Wait 10us before polling EC */
  73 #define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
  74
  75 #define ACPI_EC_STORM_THRESHOLD 8       /* number of false interrupts
  76                                            per one transaction */
  77
  78 enum {
  79         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  80         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  81         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
  82                                          * OpReg are installed */
  83         EC_FLAGS_BLOCKED,               /* Transactions are blocked */
  84 };
  85
  86 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  87 /* External interfaces use first EC only, so remember */
  88 typedef int (*acpi_ec_query_func) (void *data);
  89
  90 struct acpi_ec_query_handler {
  91         struct list_head node;
  92         acpi_ec_query_func func;
  93         acpi_handle handle;
  94         void *data;
  95         u8 query_bit;
  96 };
  97
  98 struct transaction {
  99         const u8 *wdata;
 100         u8 *rdata;
 101         unsigned short irq_count;
 102         u8 command;
 103         u8 wi;
 104         u8 ri;
 105         u8 wlen;
 106         u8 rlen;
 107         bool done;
 108 };
 109
 110 struct acpi_ec *boot_ec, *first_ec;
 111 EXPORT_SYMBOL(first_ec);
 112
 113 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 114 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 115 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 116
 117 /* --------------------------------------------------------------------------
 118                              Transaction Management
 119    -------------------------------------------------------------------------- */
 120
 121 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 122 {
 123         u8 x = inb(ec->command_addr);
 124         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
 125         return x;
 126 }
 127
 128 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 129 {
 130         u8 x = inb(ec->data_addr);
 131         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
 132         return x;
 133 }
 134
 135 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 136 {
 137         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
 138         outb(command, ec->command_addr);
 139 }
 140
 141 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 142 {
 143         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
 144         outb(data, ec->data_addr);
 145 }
 146
 147 static int ec_transaction_done(struct acpi_ec *ec)
 148 {
 149         unsigned long flags;
 150         int ret = 0;
 151         spin_lock_irqsave(&ec->curr_lock, flags);
 152         if (!ec->curr || ec->curr->done)
 153                 ret = 1;
 154         spin_unlock_irqrestore(&ec->curr_lock, flags);
 155         return ret;
 156 }
 157
 158 static void start_transaction(struct acpi_ec *ec)
 159 {
 160         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 161         ec->curr->done = false;
 162         acpi_ec_write_cmd(ec, ec->curr->command);
 163 }
 164
 165 static void advance_transaction(struct acpi_ec *ec, u8 status)
 166 {
 167         unsigned long flags;
 168         spin_lock_irqsave(&ec->curr_lock, flags);
 169         if (!ec->curr)
 170                 goto unlock;
 171         if (ec->curr->wlen > ec->curr->wi) {
 172                 if ((status & ACPI_EC_FLAG_IBF) == 0)
 173                         acpi_ec_write_data(ec,
 174                                 ec->curr->wdata[ec->curr->wi++]);
 175                 else
 176                         goto err;
 177         } else if (ec->curr->rlen > ec->curr->ri) {
 178                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
 179                         ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
 180                         if (ec->curr->rlen == ec->curr->ri)
 181                                 ec->curr->done = true;
 182                 } else
 183                         goto err;
 184         } else if (ec->curr->wlen == ec->curr->wi &&
 185                    (status & ACPI_EC_FLAG_IBF) == 0)
 186                 ec->curr->done = true;
 187         goto unlock;
 188 err:
 189         /* false interrupt, state didn't change */
 190         if (in_interrupt())
 191                 ++ec->curr->irq_count;
 192 unlock:
 193         spin_unlock_irqrestore(&ec->curr_lock, flags);
 194 }
 195
 196 static int acpi_ec_sync_query(struct acpi_ec *ec);
 197
 198 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 199 {
 200         if (state & ACPI_EC_FLAG_SCI) {
 201                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 202                         return acpi_ec_sync_query(ec);
 203         }
 204         return 0;
 205 }
 206
 207 static int ec_poll(struct acpi_ec *ec)
 208 {
 209         unsigned long flags;
 210         int repeat = 2; /* number of command restarts */
 211         while (repeat--) {
 212                 unsigned long delay = jiffies +
 213                         msecs_to_jiffies(ACPI_EC_DELAY);
 214                 do {
 215                         /* don't sleep with disabled interrupts */
 216                         if (EC_FLAGS_MSI || irqs_disabled()) {
 217                                 udelay(ACPI_EC_MSI_UDELAY);
 218                                 if (ec_transaction_done(ec))
 219                                         return 0;
 220                         } else {
 221                                 if (wait_event_timeout(ec->wait,
 222                                                 ec_transaction_done(ec),
 223                                                 msecs_to_jiffies(1)))
 224                                         return 0;
 225                         }
 226                         advance_transaction(ec, acpi_ec_read_status(ec));
 227                 } while (time_before(jiffies, delay));
 228                 if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
 229                         break;
 230                 pr_debug(PREFIX "controller reset, restart transaction\n");
 231                 spin_lock_irqsave(&ec->curr_lock, flags);
 232                 start_transaction(ec);
 233                 spin_unlock_irqrestore(&ec->curr_lock, flags);
 234         }
 235         return -ETIME;
 236 }
 237
 238 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 239                                         struct transaction *t)
 240 {
 241         unsigned long tmp;
 242         int ret = 0;
 243         if (EC_FLAGS_MSI)
 244                 udelay(ACPI_EC_MSI_UDELAY);
 245         /* start transaction */
 246         spin_lock_irqsave(&ec->curr_lock, tmp);
 247         /* following two actions should be kept atomic */
 248         ec->curr = t;
 249         start_transaction(ec);
 250         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 251                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 252         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 253         ret = ec_poll(ec);
 254         spin_lock_irqsave(&ec->curr_lock, tmp);
 255         ec->curr = NULL;
 256         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 257         return ret;
 258 }
 259
 260 static int ec_check_ibf0(struct acpi_ec *ec)
 261 {
 262         u8 status = acpi_ec_read_status(ec);
 263         return (status & ACPI_EC_FLAG_IBF) == 0;
 264 }
 265
 266 static int ec_wait_ibf0(struct acpi_ec *ec)
 267 {
 268         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 269         /* interrupt wait manually if GPE mode is not active */
 270         while (time_before(jiffies, delay))
 271                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
 272                                         msecs_to_jiffies(1)))
 273                         return 0;
 274         return -ETIME;
 275 }
 276
 277 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 278 {
 279         int status;
 280         u32 glk;
 281         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 282                 return -EINVAL;
 283         if (t->rdata)
 284                 memset(t->rdata, 0, t->rlen);
 285         mutex_lock(&ec->lock);
 286         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 287                 status = -EINVAL;
 288                 goto unlock;
 289         }
 290         if (ec->global_lock) {
 291                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 292                 if (ACPI_FAILURE(status)) {
 293                         status = -ENODEV;
 294                         goto unlock;
 295                 }
 296         }
 297         if (ec_wait_ibf0(ec)) {
 298                 pr_err(PREFIX "input buffer is not empty, "
 299                                 "aborting transaction\n");
 300                 status = -ETIME;
 301                 goto end;
 302         }
 303         pr_debug(PREFIX "transaction start\n");
 304         /* disable GPE during transaction if storm is detected */
 305         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 306                 /*
 307                  * It has to be disabled at the hardware level regardless of the
 308                  * GPE reference counting, so that it doesn't trigger.
 309                  */
 310                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 311         }
 312
 313         status = acpi_ec_transaction_unlocked(ec, t);
 314
 315         /* check if we received SCI during transaction */
 316         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 317         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 318                 msleep(1);
 319                 /*
 320                  * It is safe to enable the GPE outside of the transaction.  Use
 321                  * acpi_set_gpe() for that, since we used it to disable the GPE
 322                  * above.
 323                  */
 324                 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
 325         } else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
 326                 pr_info(PREFIX "GPE storm detected, "
 327                         "transactions will use polling mode\n");
 328                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 329         }
 330         pr_debug(PREFIX "transaction end\n");
 331 end:
 332         if (ec->global_lock)
 333                 acpi_release_global_lock(glk);
 334 unlock:
 335         mutex_unlock(&ec->lock);
 336         return status;
 337 }
 338
 339 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 340 {
 341         u8 d;
 342         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 343                                 .wdata = NULL, .rdata = &d,
 344                                 .wlen = 0, .rlen = 1};
 345
 346         return acpi_ec_transaction(ec, &t);
 347 }
 348
 349 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 350 {
 351         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 352                                 .wdata = NULL, .rdata = NULL,
 353                                 .wlen = 0, .rlen = 0};
 354
 355         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 356                                 acpi_ec_transaction(ec, &t) : 0;
 357 }
 358
 359 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 360 {
 361         int result;
 362         u8 d;
 363         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 364                                 .wdata = &address, .rdata = &d,
 365                                 .wlen = 1, .rlen = 1};
 366
 367         result = acpi_ec_transaction(ec, &t);
 368         *data = d;
 369         return result;
 370 }
 371
 372 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 373 {
 374         u8 wdata[2] = { address, data };
 375         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 376                                 .wdata = wdata, .rdata = NULL,
 377                                 .wlen = 2, .rlen = 0};
 378
 379         return acpi_ec_transaction(ec, &t);
 380 }
 381
 382 /*
 383  * Externally callable EC access functions. For now, assume 1 EC only
 384  */
 385 int ec_burst_enable(void)
 386 {
 387         if (!first_ec)
 388                 return -ENODEV;
 389         return acpi_ec_burst_enable(first_ec);
 390 }
 391
 392 EXPORT_SYMBOL(ec_burst_enable);
 393
 394 int ec_burst_disable(void)
 395 {
 396         if (!first_ec)
 397                 return -ENODEV;
 398         return acpi_ec_burst_disable(first_ec);
 399 }
 400
 401 EXPORT_SYMBOL(ec_burst_disable);
 402
 403 int ec_read(u8 addr, u8 * val)
 404 {
 405         int err;
 406         u8 temp_data;
 407
 408         if (!first_ec)
 409                 return -ENODEV;
 410
 411         err = acpi_ec_read(first_ec, addr, &temp_data);
 412
 413         if (!err) {
 414                 *val = temp_data;
 415                 return 0;
 416         } else
 417                 return err;
 418 }
 419
 420 EXPORT_SYMBOL(ec_read);
 421
 422 int ec_write(u8 addr, u8 val)
 423 {
 424         int err;
 425
 426         if (!first_ec)
 427                 return -ENODEV;
 428
 429         err = acpi_ec_write(first_ec, addr, val);
 430
 431         return err;
 432 }
 433
 434 EXPORT_SYMBOL(ec_write);
 435
 436 int ec_transaction(u8 command,
 437                    const u8 * wdata, unsigned wdata_len,
 438                    u8 * rdata, unsigned rdata_len,
 439                    int force_poll)
 440 {
 441         struct transaction t = {.command = command,
 442                                 .wdata = wdata, .rdata = rdata,
 443                                 .wlen = wdata_len, .rlen = rdata_len};
 444         if (!first_ec)
 445                 return -ENODEV;
 446
 447         return acpi_ec_transaction(first_ec, &t);
 448 }
 449
 450 EXPORT_SYMBOL(ec_transaction);
 451
 452 void acpi_ec_block_transactions(void)
 453 {
 454         struct acpi_ec *ec = first_ec;
 455
 456         if (!ec)
 457                 return;
 458
 459         mutex_lock(&ec->lock);
 460         /* Prevent transactions from being carried out */
 461         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 462         mutex_unlock(&ec->lock);
 463 }
 464
 465 void acpi_ec_unblock_transactions(void)
 466 {
 467         struct acpi_ec *ec = first_ec;
 468
 469         if (!ec)
 470                 return;
 471
 472         mutex_lock(&ec->lock);
 473         /* Allow transactions to be carried out again */
 474         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 475         mutex_unlock(&ec->lock);
 476 }
 477
 478 void acpi_ec_unblock_transactions_early(void)
 479 {
 480         /*
 481          * Allow transactions to happen again (this function is called from
 482          * atomic context during wakeup, so we don't need to acquire the mutex).
 483          */
 484         if (first_ec)
 485                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 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                                Driver Interface
 673    -------------------------------------------------------------------------- */
 674 static acpi_status
 675 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 676
 677 static struct acpi_ec *make_acpi_ec(void)
 678 {
 679         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 680         if (!ec)
 681                 return NULL;
 682         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 683         mutex_init(&ec->lock);
 684         init_waitqueue_head(&ec->wait);
 685         INIT_LIST_HEAD(&ec->list);
 686         spin_lock_init(&ec->curr_lock);
 687         return ec;
 688 }
 689
 690 static acpi_status
 691 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 692                                void *context, void **return_value)
 693 {
 694         char node_name[5];
 695         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 696         struct acpi_ec *ec = context;
 697         int value = 0;
 698         acpi_status status;
 699
 700         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 701
 702         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 703                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 704         }
 705         return AE_OK;
 706 }
 707
 708 static acpi_status
 709 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 710 {
 711         acpi_status status;
 712         unsigned long long tmp = 0;
 713
 714         struct acpi_ec *ec = context;
 715
 716         /* clear addr values, ec_parse_io_ports depend on it */
 717         ec->command_addr = ec->data_addr = 0;
 718
 719         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 720                                      ec_parse_io_ports, ec);
 721         if (ACPI_FAILURE(status))
 722                 return status;
 723
 724         /* Get GPE bit assignment (EC events). */
 725         /* TODO: Add support for _GPE returning a package */
 726         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 727         if (ACPI_FAILURE(status))
 728                 return status;
 729         ec->gpe = tmp;
 730         /* Use the global lock for all EC transactions? */
 731         tmp = 0;
 732         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 733         ec->global_lock = tmp;
 734         ec->handle = handle;
 735         return AE_CTRL_TERMINATE;
 736 }
 737
 738 static int ec_install_handlers(struct acpi_ec *ec)
 739 {
 740         acpi_status status;
 741         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 742                 return 0;
 743         status = acpi_install_gpe_handler(NULL, ec->gpe,
 744                                   ACPI_GPE_EDGE_TRIGGERED,
 745                                   &acpi_ec_gpe_handler, ec);
 746         if (ACPI_FAILURE(status))
 747                 return -ENODEV;
 748
 749         acpi_enable_gpe(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 750         status = acpi_install_address_space_handler(ec->handle,
 751                                                     ACPI_ADR_SPACE_EC,
 752                                                     &acpi_ec_space_handler,
 753                                                     NULL, ec);
 754         if (ACPI_FAILURE(status)) {
 755                 if (status == AE_NOT_FOUND) {
 756                         /*
 757                          * Maybe OS fails in evaluating the _REG object.
 758                          * The AE_NOT_FOUND error will be ignored and OS
 759                          * continue to initialize EC.
 760                          */
 761                         printk(KERN_ERR "Fail in evaluating the _REG object"
 762                                 " of EC device. Broken bios is suspected.\n");
 763                 } else {
 764                         acpi_remove_gpe_handler(NULL, ec->gpe,
 765                                 &acpi_ec_gpe_handler);
 766                         acpi_disable_gpe(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 767                         return -ENODEV;
 768                 }
 769         }
 770
 771         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 772         return 0;
 773 }
 774
 775 static void ec_remove_handlers(struct acpi_ec *ec)
 776 {
 777         acpi_disable_gpe(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 778         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 779                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 780                 pr_err(PREFIX "failed to remove space handler\n");
 781         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 782                                 &acpi_ec_gpe_handler)))
 783                 pr_err(PREFIX "failed to remove gpe handler\n");
 784         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 785 }
 786
 787 static int acpi_ec_add(struct acpi_device *device)
 788 {
 789         struct acpi_ec *ec = NULL;
 790         int ret;
 791
 792         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 793         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 794
 795         /* Check for boot EC */
 796         if (boot_ec &&
 797             (boot_ec->handle == device->handle ||
 798              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 799                 ec = boot_ec;
 800                 boot_ec = NULL;
 801         } else {
 802                 ec = make_acpi_ec();
 803                 if (!ec)
 804                         return -ENOMEM;
 805         }
 806         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 807                 AE_CTRL_TERMINATE) {
 808                         kfree(ec);
 809                         return -EINVAL;
 810         }
 811
 812         ec->handle = device->handle;
 813
 814         /* Find and register all query methods */
 815         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 816                             acpi_ec_register_query_methods, NULL, ec, NULL);
 817
 818         if (!first_ec)
 819                 first_ec = ec;
 820         device->driver_data = ec;
 821
 822         WARN(!request_region(ec->data_addr, 1, "EC data"),
 823              "Could not request EC data io port 0x%lx", ec->data_addr);
 824         WARN(!request_region(ec->command_addr, 1, "EC cmd"),
 825              "Could not request EC cmd io port 0x%lx", ec->command_addr);
 826
 827         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 828                           ec->gpe, ec->command_addr, ec->data_addr);
 829
 830         ret = ec_install_handlers(ec);
 831
 832         /* EC is fully operational, allow queries */
 833         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 834         return ret;
 835 }
 836
 837 static int acpi_ec_remove(struct acpi_device *device, int type)
 838 {
 839         struct acpi_ec *ec;
 840         struct acpi_ec_query_handler *handler, *tmp;
 841
 842         if (!device)
 843                 return -EINVAL;
 844
 845         ec = acpi_driver_data(device);
 846         ec_remove_handlers(ec);
 847         mutex_lock(&ec->lock);
 848         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 849                 list_del(&handler->node);
 850                 kfree(handler);
 851         }
 852         mutex_unlock(&ec->lock);
 853         release_region(ec->data_addr, 1);
 854         release_region(ec->command_addr, 1);
 855         device->driver_data = NULL;
 856         if (ec == first_ec)
 857                 first_ec = NULL;
 858         kfree(ec);
 859         return 0;
 860 }
 861
 862 static acpi_status
 863 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 864 {
 865         struct acpi_ec *ec = context;
 866
 867         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 868                 return AE_OK;
 869
 870         /*
 871          * The first address region returned is the data port, and
 872          * the second address region returned is the status/command
 873          * port.
 874          */
 875         if (ec->data_addr == 0)
 876                 ec->data_addr = resource->data.io.minimum;
 877         else if (ec->command_addr == 0)
 878                 ec->command_addr = resource->data.io.minimum;
 879         else
 880                 return AE_CTRL_TERMINATE;
 881
 882         return AE_OK;
 883 }
 884
 885 int __init acpi_boot_ec_enable(void)
 886 {
 887         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 888                 return 0;
 889         if (!ec_install_handlers(boot_ec)) {
 890                 first_ec = boot_ec;
 891                 return 0;
 892         }
 893         return -EFAULT;
 894 }
 895
 896 static const struct acpi_device_id ec_device_ids[] = {
 897         {"PNP0C09", 0},
 898         {"", 0},
 899 };
 900
 901 /* Some BIOS do not survive early DSDT scan, skip it */
 902 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 903 {
 904         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 905         return 0;
 906 }
 907
 908 /* ASUStek often supplies us with broken ECDT, validate it */
 909 static int ec_validate_ecdt(const struct dmi_system_id *id)
 910 {
 911         EC_FLAGS_VALIDATE_ECDT = 1;
 912         return 0;
 913 }
 914
 915 /* MSI EC needs special treatment, enable it */
 916 static int ec_flag_msi(const struct dmi_system_id *id)
 917 {
 918         printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
 919         EC_FLAGS_MSI = 1;
 920         EC_FLAGS_VALIDATE_ECDT = 1;
 921         return 0;
 922 }
 923
 924 static struct dmi_system_id __initdata ec_dmi_table[] = {
 925         {
 926         ec_skip_dsdt_scan, "Compal JFL92", {
 927         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 928         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 929         {
 930         ec_flag_msi, "MSI hardware", {
 931         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
 932         {
 933         ec_flag_msi, "MSI hardware", {
 934         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
 935         {
 936         ec_flag_msi, "MSI hardware", {
 937         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
 938         {
 939         ec_validate_ecdt, "ASUS hardware", {
 940         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
 941         {},
 942 };
 943
 944
 945 int __init acpi_ec_ecdt_probe(void)
 946 {
 947         acpi_status status;
 948         struct acpi_ec *saved_ec = NULL;
 949         struct acpi_table_ecdt *ecdt_ptr;
 950
 951         boot_ec = make_acpi_ec();
 952         if (!boot_ec)
 953                 return -ENOMEM;
 954         /*
 955          * Generate a boot ec context
 956          */
 957         dmi_check_system(ec_dmi_table);
 958         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 959                                 (struct acpi_table_header **)&ecdt_ptr);
 960         if (ACPI_SUCCESS(status)) {
 961                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
 962                 boot_ec->command_addr = ecdt_ptr->control.address;
 963                 boot_ec->data_addr = ecdt_ptr->data.address;
 964                 boot_ec->gpe = ecdt_ptr->gpe;
 965                 boot_ec->handle = ACPI_ROOT_OBJECT;
 966                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
 967                 /* Don't trust ECDT, which comes from ASUSTek */
 968                 if (!EC_FLAGS_VALIDATE_ECDT)
 969                         goto install;
 970                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
 971                 if (!saved_ec)
 972                         return -ENOMEM;
 973         /* fall through */
 974         }
 975
 976         if (EC_FLAGS_SKIP_DSDT_SCAN)
 977                 return -ENODEV;
 978
 979         /* This workaround is needed only on some broken machines,
 980          * which require early EC, but fail to provide ECDT */
 981         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
 982         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
 983                                         boot_ec, NULL);
 984         /* Check that acpi_get_devices actually find something */
 985         if (ACPI_FAILURE(status) || !boot_ec->handle)
 986                 goto error;
 987         if (saved_ec) {
 988                 /* try to find good ECDT from ASUSTek */
 989                 if (saved_ec->command_addr != boot_ec->command_addr ||
 990                     saved_ec->data_addr != boot_ec->data_addr ||
 991                     saved_ec->gpe != boot_ec->gpe ||
 992                     saved_ec->handle != boot_ec->handle)
 993                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
 994                         "ECDT tables, which are very hard to workaround. "
 995                         "Trying to use DSDT EC info instead. Please send "
 996                         "output of acpidump to linux-acpi@vger.kernel.org\n");
 997                 kfree(saved_ec);
 998                 saved_ec = NULL;
 999         } else {
1000                 /* We really need to limit this workaround, the only ASUS,
1001                 * which needs it, has fake EC._INI method, so use it as flag.
1002                 * Keep boot_ec struct as it will be needed soon.
1003                 */
1004                 acpi_handle dummy;
1005                 if (!dmi_name_in_vendors("ASUS") ||
1006                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1007                                                         &dummy)))
1008                         return -ENODEV;
1009         }
1010 install:
1011         if (!ec_install_handlers(boot_ec)) {
1012                 first_ec = boot_ec;
1013                 return 0;
1014         }
1015 error:
1016         kfree(boot_ec);
1017         boot_ec = NULL;
1018         return -ENODEV;
1019 }
1020
1021 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1022 {
1023         struct acpi_ec *ec = acpi_driver_data(device);
1024         /* Stop using the GPE, but keep it reference counted. */
1025         acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1026         return 0;
1027 }
1028
1029 static int acpi_ec_resume(struct acpi_device *device)
1030 {
1031         struct acpi_ec *ec = acpi_driver_data(device);
1032         /* Enable the GPE again, but don't reference count it once more. */
1033         acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1034         return 0;
1035 }
1036
1037 static struct acpi_driver acpi_ec_driver = {
1038         .name = "ec",
1039         .class = ACPI_EC_CLASS,
1040         .ids = ec_device_ids,
1041         .ops = {
1042                 .add = acpi_ec_add,
1043                 .remove = acpi_ec_remove,
1044                 .suspend = acpi_ec_suspend,
1045                 .resume = acpi_ec_resume,
1046                 },
1047 };
1048
1049 int __init acpi_ec_init(void)
1050 {
1051         int result = 0;
1052
1053         /* Now register the driver for the EC */
1054         result = acpi_bus_register_driver(&acpi_ec_driver);
1055         if (result < 0)
1056                 return -ENODEV;
1057
1058         return result;
1059 }
1060
1061 /* EC driver currently not unloadable */
1062 #if 0
1063 static void __exit acpi_ec_exit(void)
1064 {
1065
1066         acpi_bus_unregister_driver(&acpi_ec_driver);
1067         return;
1068 }
1069 #endif  /* 0 */