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         spin_lock_irqsave(&ec->curr_lock, tmp);
 263         ec->curr = NULL;
 264         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 265         return ret;
 266 }
 267
 268 static int ec_check_ibf0(struct acpi_ec *ec)
 269 {
 270         u8 status = acpi_ec_read_status(ec);
 271         return (status & ACPI_EC_FLAG_IBF) == 0;
 272 }
 273
 274 static int ec_wait_ibf0(struct acpi_ec *ec)
 275 {
 276         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 277         /* interrupt wait manually if GPE mode is not active */
 278         while (time_before(jiffies, delay))
 279                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
 280                                         msecs_to_jiffies(1)))
 281                         return 0;
 282         return -ETIME;
 283 }
 284
 285 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 286 {
 287         int status;
 288         u32 glk;
 289         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 290                 return -EINVAL;
 291         if (t->rdata)
 292                 memset(t->rdata, 0, t->rlen);
 293         mutex_lock(&ec->lock);
 294         if (ec->global_lock) {
 295                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 296                 if (ACPI_FAILURE(status)) {
 297                         status = -ENODEV;
 298                         goto unlock;
 299                 }
 300         }
 301         if (ec_wait_ibf0(ec)) {
 302                 pr_err(PREFIX "input buffer is not empty, "
 303                                 "aborting transaction\n");
 304                 status = -ETIME;
 305                 goto end;
 306         }
 307         pr_debug(PREFIX "transaction start\n");
 308         /* disable GPE during transaction if storm is detected */
 309         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 310                 acpi_disable_gpe(NULL, ec->gpe);
 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                 /* 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         pr_debug(PREFIX "transaction end\n");
 327 end:
 328         if (ec->global_lock)
 329                 acpi_release_global_lock(glk);
 330 unlock:
 331         mutex_unlock(&ec->lock);
 332         return status;
 333 }
 334
 335 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 336 {
 337         u8 d;
 338         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 339                                 .wdata = NULL, .rdata = &d,
 340                                 .wlen = 0, .rlen = 1};
 341
 342         return acpi_ec_transaction(ec, &t);
 343 }
 344
 345 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 346 {
 347         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 348                                 .wdata = NULL, .rdata = NULL,
 349                                 .wlen = 0, .rlen = 0};
 350
 351         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 352                                 acpi_ec_transaction(ec, &t) : 0;
 353 }
 354
 355 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 356 {
 357         int result;
 358         u8 d;
 359         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 360                                 .wdata = &address, .rdata = &d,
 361                                 .wlen = 1, .rlen = 1};
 362
 363         result = acpi_ec_transaction(ec, &t);
 364         *data = d;
 365         return result;
 366 }
 367
 368 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 369 {
 370         u8 wdata[2] = { address, data };
 371         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 372                                 .wdata = wdata, .rdata = NULL,
 373                                 .wlen = 2, .rlen = 0};
 374
 375         return acpi_ec_transaction(ec, &t);
 376 }
 377
 378 /*
 379  * Externally callable EC access functions. For now, assume 1 EC only
 380  */
 381 int ec_burst_enable(void)
 382 {
 383         if (!first_ec)
 384                 return -ENODEV;
 385         return acpi_ec_burst_enable(first_ec);
 386 }
 387
 388 EXPORT_SYMBOL(ec_burst_enable);
 389
 390 int ec_burst_disable(void)
 391 {
 392         if (!first_ec)
 393                 return -ENODEV;
 394         return acpi_ec_burst_disable(first_ec);
 395 }
 396
 397 EXPORT_SYMBOL(ec_burst_disable);
 398
 399 int ec_read(u8 addr, u8 * val)
 400 {
 401         int err;
 402         u8 temp_data;
 403
 404         if (!first_ec)
 405                 return -ENODEV;
 406
 407         err = acpi_ec_read(first_ec, addr, &temp_data);
 408
 409         if (!err) {
 410                 *val = temp_data;
 411                 return 0;
 412         } else
 413                 return err;
 414 }
 415
 416 EXPORT_SYMBOL(ec_read);
 417
 418 int ec_write(u8 addr, u8 val)
 419 {
 420         int err;
 421
 422         if (!first_ec)
 423                 return -ENODEV;
 424
 425         err = acpi_ec_write(first_ec, addr, val);
 426
 427         return err;
 428 }
 429
 430 EXPORT_SYMBOL(ec_write);
 431
 432 int ec_transaction(u8 command,
 433                    const u8 * wdata, unsigned wdata_len,
 434                    u8 * rdata, unsigned rdata_len,
 435                    int force_poll)
 436 {
 437         struct transaction t = {.command = command,
 438                                 .wdata = wdata, .rdata = rdata,
 439                                 .wlen = wdata_len, .rlen = rdata_len};
 440         if (!first_ec)
 441                 return -ENODEV;
 442
 443         return acpi_ec_transaction(first_ec, &t);
 444 }
 445
 446 EXPORT_SYMBOL(ec_transaction);
 447
 448 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 449 {
 450         int result;
 451         u8 d;
 452         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 453                                 .wdata = NULL, .rdata = &d,
 454                                 .wlen = 0, .rlen = 1};
 455         if (!ec || !data)
 456                 return -EINVAL;
 457         /*
 458          * Query the EC to find out which _Qxx method we need to evaluate.
 459          * Note that successful completion of the query causes the ACPI_EC_SCI
 460          * bit to be cleared (and thus clearing the interrupt source).
 461          */
 462         result = acpi_ec_transaction_unlocked(ec, &t);
 463         if (result)
 464                 return result;
 465         if (!d)
 466                 return -ENODATA;
 467         *data = d;
 468         return 0;
 469 }
 470
 471 /* --------------------------------------------------------------------------
 472                                 Event Management
 473    -------------------------------------------------------------------------- */
 474 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 475                               acpi_handle handle, acpi_ec_query_func func,
 476                               void *data)
 477 {
 478         struct acpi_ec_query_handler *handler =
 479             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 480         if (!handler)
 481                 return -ENOMEM;
 482
 483         handler->query_bit = query_bit;
 484         handler->handle = handle;
 485         handler->func = func;
 486         handler->data = data;
 487         mutex_lock(&ec->lock);
 488         list_add(&handler->node, &ec->list);
 489         mutex_unlock(&ec->lock);
 490         return 0;
 491 }
 492
 493 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 494
 495 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 496 {
 497         struct acpi_ec_query_handler *handler, *tmp;
 498         mutex_lock(&ec->lock);
 499         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 500                 if (query_bit == handler->query_bit) {
 501                         list_del(&handler->node);
 502                         kfree(handler);
 503                 }
 504         }
 505         mutex_unlock(&ec->lock);
 506 }
 507
 508 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 509
 510 static void acpi_ec_run(void *cxt)
 511 {
 512         struct acpi_ec_query_handler *handler = cxt;
 513         if (!handler)
 514                 return;
 515         pr_debug(PREFIX "start query execution\n");
 516         if (handler->func)
 517                 handler->func(handler->data);
 518         else if (handler->handle)
 519                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 520         pr_debug(PREFIX "stop query execution\n");
 521         kfree(handler);
 522 }
 523
 524 static int acpi_ec_sync_query(struct acpi_ec *ec)
 525 {
 526         u8 value = 0;
 527         int status;
 528         struct acpi_ec_query_handler *handler, *copy;
 529         if ((status = acpi_ec_query_unlocked(ec, &value)))
 530                 return status;
 531         list_for_each_entry(handler, &ec->list, node) {
 532                 if (value == handler->query_bit) {
 533                         /* have custom handler for this bit */
 534                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 535                         if (!copy)
 536                                 return -ENOMEM;
 537                         memcpy(copy, handler, sizeof(*copy));
 538                         pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
 539                         return acpi_os_execute((copy->func) ?
 540                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 541                                 acpi_ec_run, copy);
 542                 }
 543         }
 544         return 0;
 545 }
 546
 547 static void acpi_ec_gpe_query(void *ec_cxt)
 548 {
 549         struct acpi_ec *ec = ec_cxt;
 550         if (!ec)
 551                 return;
 552         mutex_lock(&ec->lock);
 553         acpi_ec_sync_query(ec);
 554         mutex_unlock(&ec->lock);
 555 }
 556
 557 static void acpi_ec_gpe_query(void *ec_cxt);
 558
 559 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 560 {
 561         if (state & ACPI_EC_FLAG_SCI) {
 562                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 563                         pr_debug(PREFIX "push gpe query to the queue\n");
 564                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 565                                 acpi_ec_gpe_query, ec);
 566                 }
 567         }
 568         return 0;
 569 }
 570
 571 static u32 acpi_ec_gpe_handler(void *data)
 572 {
 573         struct acpi_ec *ec = data;
 574
 575         pr_debug(PREFIX "~~~> interrupt\n");
 576
 577         advance_transaction(ec, acpi_ec_read_status(ec));
 578         if (ec_transaction_done(ec) &&
 579             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 580                 wake_up(&ec->wait);
 581                 ec_check_sci(ec, acpi_ec_read_status(ec));
 582         }
 583         return ACPI_INTERRUPT_HANDLED;
 584 }
 585
 586 /* --------------------------------------------------------------------------
 587                              Address Space Management
 588    -------------------------------------------------------------------------- */
 589
 590 static acpi_status
 591 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 592                       u32 bits, acpi_integer *value,
 593                       void *handler_context, void *region_context)
 594 {
 595         struct acpi_ec *ec = handler_context;
 596         int result = 0, i;
 597         u8 temp = 0;
 598
 599         if ((address > 0xFF) || !value || !handler_context)
 600                 return AE_BAD_PARAMETER;
 601
 602         if (function != ACPI_READ && function != ACPI_WRITE)
 603                 return AE_BAD_PARAMETER;
 604
 605         if (bits != 8 && acpi_strict)
 606                 return AE_BAD_PARAMETER;
 607
 608         if (EC_FLAGS_MSI)
 609                 acpi_ec_burst_enable(ec);
 610
 611         if (function == ACPI_READ) {
 612                 result = acpi_ec_read(ec, address, &temp);
 613                 *value = temp;
 614         } else {
 615                 temp = 0xff & (*value);
 616                 result = acpi_ec_write(ec, address, temp);
 617         }
 618
 619         for (i = 8; unlikely(bits - i > 0); i += 8) {
 620                 ++address;
 621                 if (function == ACPI_READ) {
 622                         result = acpi_ec_read(ec, address, &temp);
 623                         (*value) |= ((acpi_integer)temp) << i;
 624                 } else {
 625                         temp = 0xff & ((*value) >> i);
 626                         result = acpi_ec_write(ec, address, temp);
 627                 }
 628         }
 629
 630         if (EC_FLAGS_MSI)
 631                 acpi_ec_burst_disable(ec);
 632
 633         switch (result) {
 634         case -EINVAL:
 635                 return AE_BAD_PARAMETER;
 636                 break;
 637         case -ENODEV:
 638                 return AE_NOT_FOUND;
 639                 break;
 640         case -ETIME:
 641                 return AE_TIME;
 642                 break;
 643         default:
 644                 return AE_OK;
 645         }
 646 }
 647
 648 /* --------------------------------------------------------------------------
 649                               FS Interface (/proc)
 650    -------------------------------------------------------------------------- */
 651
 652 static struct proc_dir_entry *acpi_ec_dir;
 653
 654 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 655 {
 656         struct acpi_ec *ec = seq->private;
 657
 658         if (!ec)
 659                 goto end;
 660
 661         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 662         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 663                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 664         seq_printf(seq, "use global lock:\t%s\n",
 665                    ec->global_lock ? "yes" : "no");
 666       end:
 667         return 0;
 668 }
 669
 670 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 671 {
 672         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 673 }
 674
 675 static const struct file_operations acpi_ec_info_ops = {
 676         .open = acpi_ec_info_open_fs,
 677         .read = seq_read,
 678         .llseek = seq_lseek,
 679         .release = single_release,
 680         .owner = THIS_MODULE,
 681 };
 682
 683 static int acpi_ec_add_fs(struct acpi_device *device)
 684 {
 685         struct proc_dir_entry *entry = NULL;
 686
 687         if (!acpi_device_dir(device)) {
 688                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 689                                                      acpi_ec_dir);
 690                 if (!acpi_device_dir(device))
 691                         return -ENODEV;
 692         }
 693
 694         entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
 695                                  acpi_device_dir(device),
 696                                  &acpi_ec_info_ops, acpi_driver_data(device));
 697         if (!entry)
 698                 return -ENODEV;
 699         return 0;
 700 }
 701
 702 static int acpi_ec_remove_fs(struct acpi_device *device)
 703 {
 704
 705         if (acpi_device_dir(device)) {
 706                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 707                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 708                 acpi_device_dir(device) = NULL;
 709         }
 710
 711         return 0;
 712 }
 713
 714 /* --------------------------------------------------------------------------
 715                                Driver Interface
 716    -------------------------------------------------------------------------- */
 717 static acpi_status
 718 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 719
 720 static struct acpi_ec *make_acpi_ec(void)
 721 {
 722         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 723         if (!ec)
 724                 return NULL;
 725         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 726         mutex_init(&ec->lock);
 727         init_waitqueue_head(&ec->wait);
 728         INIT_LIST_HEAD(&ec->list);
 729         spin_lock_init(&ec->curr_lock);
 730         return ec;
 731 }
 732
 733 static acpi_status
 734 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 735                                void *context, void **return_value)
 736 {
 737         char node_name[5];
 738         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 739         struct acpi_ec *ec = context;
 740         int value = 0;
 741         acpi_status status;
 742
 743         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 744
 745         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 746                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 747         }
 748         return AE_OK;
 749 }
 750
 751 static acpi_status
 752 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 753 {
 754         acpi_status status;
 755         unsigned long long tmp = 0;
 756
 757         struct acpi_ec *ec = context;
 758
 759         /* clear addr values, ec_parse_io_ports depend on it */
 760         ec->command_addr = ec->data_addr = 0;
 761
 762         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 763                                      ec_parse_io_ports, ec);
 764         if (ACPI_FAILURE(status))
 765                 return status;
 766
 767         /* Get GPE bit assignment (EC events). */
 768         /* TODO: Add support for _GPE returning a package */
 769         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 770         if (ACPI_FAILURE(status))
 771                 return status;
 772         ec->gpe = tmp;
 773         /* Use the global lock for all EC transactions? */
 774         tmp = 0;
 775         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 776         ec->global_lock = tmp;
 777         ec->handle = handle;
 778         return AE_CTRL_TERMINATE;
 779 }
 780
 781 static int ec_install_handlers(struct acpi_ec *ec)
 782 {
 783         acpi_status status;
 784         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 785                 return 0;
 786         status = acpi_install_gpe_handler(NULL, ec->gpe,
 787                                   ACPI_GPE_EDGE_TRIGGERED,
 788                                   &acpi_ec_gpe_handler, ec);
 789         if (ACPI_FAILURE(status))
 790                 return -ENODEV;
 791         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 792         acpi_enable_gpe(NULL, ec->gpe);
 793         status = acpi_install_address_space_handler(ec->handle,
 794                                                     ACPI_ADR_SPACE_EC,
 795                                                     &acpi_ec_space_handler,
 796                                                     NULL, ec);
 797         if (ACPI_FAILURE(status)) {
 798                 if (status == AE_NOT_FOUND) {
 799                         /*
 800                          * Maybe OS fails in evaluating the _REG object.
 801                          * The AE_NOT_FOUND error will be ignored and OS
 802                          * continue to initialize EC.
 803                          */
 804                         printk(KERN_ERR "Fail in evaluating the _REG object"
 805                                 " of EC device. Broken bios is suspected.\n");
 806                 } else {
 807                         acpi_remove_gpe_handler(NULL, ec->gpe,
 808                                 &acpi_ec_gpe_handler);
 809                         return -ENODEV;
 810                 }
 811         }
 812
 813         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 814         return 0;
 815 }
 816
 817 static void ec_remove_handlers(struct acpi_ec *ec)
 818 {
 819         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 820                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 821                 pr_err(PREFIX "failed to remove space handler\n");
 822         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 823                                 &acpi_ec_gpe_handler)))
 824                 pr_err(PREFIX "failed to remove gpe handler\n");
 825         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 826 }
 827
 828 static int acpi_ec_add(struct acpi_device *device)
 829 {
 830         struct acpi_ec *ec = NULL;
 831         int ret;
 832
 833         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 834         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 835
 836         /* Check for boot EC */
 837         if (boot_ec &&
 838             (boot_ec->handle == device->handle ||
 839              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 840                 ec = boot_ec;
 841                 boot_ec = NULL;
 842         } else {
 843                 ec = make_acpi_ec();
 844                 if (!ec)
 845                         return -ENOMEM;
 846         }
 847         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 848                 AE_CTRL_TERMINATE) {
 849                         kfree(ec);
 850                         return -EINVAL;
 851         }
 852
 853         ec->handle = device->handle;
 854
 855         /* Find and register all query methods */
 856         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 857                             acpi_ec_register_query_methods, NULL, ec, NULL);
 858
 859         if (!first_ec)
 860                 first_ec = ec;
 861         device->driver_data = ec;
 862         acpi_ec_add_fs(device);
 863         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 864                           ec->gpe, ec->command_addr, ec->data_addr);
 865
 866         ret = ec_install_handlers(ec);
 867
 868         /* EC is fully operational, allow queries */
 869         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 870         return ret;
 871 }
 872
 873 static int acpi_ec_remove(struct acpi_device *device, int type)
 874 {
 875         struct acpi_ec *ec;
 876         struct acpi_ec_query_handler *handler, *tmp;
 877
 878         if (!device)
 879                 return -EINVAL;
 880
 881         ec = acpi_driver_data(device);
 882         ec_remove_handlers(ec);
 883         mutex_lock(&ec->lock);
 884         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 885                 list_del(&handler->node);
 886                 kfree(handler);
 887         }
 888         mutex_unlock(&ec->lock);
 889         acpi_ec_remove_fs(device);
 890         device->driver_data = NULL;
 891         if (ec == first_ec)
 892                 first_ec = NULL;
 893         kfree(ec);
 894         return 0;
 895 }
 896
 897 static acpi_status
 898 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 899 {
 900         struct acpi_ec *ec = context;
 901
 902         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 903                 return AE_OK;
 904
 905         /*
 906          * The first address region returned is the data port, and
 907          * the second address region returned is the status/command
 908          * port.
 909          */
 910         if (ec->data_addr == 0)
 911                 ec->data_addr = resource->data.io.minimum;
 912         else if (ec->command_addr == 0)
 913                 ec->command_addr = resource->data.io.minimum;
 914         else
 915                 return AE_CTRL_TERMINATE;
 916
 917         return AE_OK;
 918 }
 919
 920 int __init acpi_boot_ec_enable(void)
 921 {
 922         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 923                 return 0;
 924         if (!ec_install_handlers(boot_ec)) {
 925                 first_ec = boot_ec;
 926                 return 0;
 927         }
 928         return -EFAULT;
 929 }
 930
 931 static const struct acpi_device_id ec_device_ids[] = {
 932         {"PNP0C09", 0},
 933         {"", 0},
 934 };
 935
 936 /* Some BIOS do not survive early DSDT scan, skip it */
 937 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 938 {
 939         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 940         return 0;
 941 }
 942
 943 /* ASUStek often supplies us with broken ECDT, validate it */
 944 static int ec_validate_ecdt(const struct dmi_system_id *id)
 945 {
 946         EC_FLAGS_VALIDATE_ECDT = 1;
 947         return 0;
 948 }
 949
 950 /* MSI EC needs special treatment, enable it */
 951 static int ec_flag_msi(const struct dmi_system_id *id)
 952 {
 953         printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
 954         EC_FLAGS_MSI = 1;
 955         EC_FLAGS_VALIDATE_ECDT = 1;
 956         return 0;
 957 }
 958
 959 static struct dmi_system_id __initdata ec_dmi_table[] = {
 960         {
 961         ec_skip_dsdt_scan, "Compal JFL92", {
 962         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 963         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 964         {
 965         ec_flag_msi, "MSI hardware", {
 966         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
 967         {
 968         ec_flag_msi, "MSI hardware", {
 969         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
 970         {
 971         ec_flag_msi, "MSI hardware", {
 972         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
 973         {
 974         ec_validate_ecdt, "ASUS hardware", {
 975         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
 976         {},
 977 };
 978
 979
 980 int __init acpi_ec_ecdt_probe(void)
 981 {
 982         acpi_status status;
 983         struct acpi_ec *saved_ec = NULL;
 984         struct acpi_table_ecdt *ecdt_ptr;
 985
 986         boot_ec = make_acpi_ec();
 987         if (!boot_ec)
 988                 return -ENOMEM;
 989         /*
 990          * Generate a boot ec context
 991          */
 992         dmi_check_system(ec_dmi_table);
 993         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 994                                 (struct acpi_table_header **)&ecdt_ptr);
 995         if (ACPI_SUCCESS(status)) {
 996                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
 997                 boot_ec->command_addr = ecdt_ptr->control.address;
 998                 boot_ec->data_addr = ecdt_ptr->data.address;
 999                 boot_ec->gpe = ecdt_ptr->gpe;
1000                 boot_ec->handle = ACPI_ROOT_OBJECT;
1001                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1002                 /* Don't trust ECDT, which comes from ASUSTek */
1003                 if (!EC_FLAGS_VALIDATE_ECDT)
1004                         goto install;
1005                 saved_ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1006                 if (!saved_ec)
1007                         return -ENOMEM;
1008                 memcpy(saved_ec, boot_ec, sizeof(struct acpi_ec));
1009         /* fall through */
1010         }
1011
1012         if (EC_FLAGS_SKIP_DSDT_SCAN)
1013                 return -ENODEV;
1014
1015         /* This workaround is needed only on some broken machines,
1016          * which require early EC, but fail to provide ECDT */
1017         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1018         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1019                                         boot_ec, NULL);
1020         /* Check that acpi_get_devices actually find something */
1021         if (ACPI_FAILURE(status) || !boot_ec->handle)
1022                 goto error;
1023         if (saved_ec) {
1024                 /* try to find good ECDT from ASUSTek */
1025                 if (saved_ec->command_addr != boot_ec->command_addr ||
1026                     saved_ec->data_addr != boot_ec->data_addr ||
1027                     saved_ec->gpe != boot_ec->gpe ||
1028                     saved_ec->handle != boot_ec->handle)
1029                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1030                         "ECDT tables, which are very hard to workaround. "
1031                         "Trying to use DSDT EC info instead. Please send "
1032                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1033                 kfree(saved_ec);
1034                 saved_ec = NULL;
1035         } else {
1036                 /* We really need to limit this workaround, the only ASUS,
1037                 * which needs it, has fake EC._INI method, so use it as flag.
1038                 * Keep boot_ec struct as it will be needed soon.
1039                 */
1040                 acpi_handle dummy;
1041                 if (!dmi_name_in_vendors("ASUS") ||
1042                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1043                                                         &dummy)))
1044                         return -ENODEV;
1045         }
1046 install:
1047         if (!ec_install_handlers(boot_ec)) {
1048                 first_ec = boot_ec;
1049                 return 0;
1050         }
1051 error:
1052         kfree(boot_ec);
1053         boot_ec = NULL;
1054         return -ENODEV;
1055 }
1056
1057 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1058 {
1059         struct acpi_ec *ec = acpi_driver_data(device);
1060         /* Stop using GPE */
1061         acpi_disable_gpe(NULL, ec->gpe);
1062         return 0;
1063 }
1064
1065 static int acpi_ec_resume(struct acpi_device *device)
1066 {
1067         struct acpi_ec *ec = acpi_driver_data(device);
1068         /* Enable use of GPE back */
1069         acpi_enable_gpe(NULL, ec->gpe);
1070         return 0;
1071 }
1072
1073 static struct acpi_driver acpi_ec_driver = {
1074         .name = "ec",
1075         .class = ACPI_EC_CLASS,
1076         .ids = ec_device_ids,
1077         .ops = {
1078                 .add = acpi_ec_add,
1079                 .remove = acpi_ec_remove,
1080                 .suspend = acpi_ec_suspend,
1081                 .resume = acpi_ec_resume,
1082                 },
1083 };
1084
1085 int __init acpi_ec_init(void)
1086 {
1087         int result = 0;
1088
1089         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1090         if (!acpi_ec_dir)
1091                 return -ENODEV;
1092
1093         /* Now register the driver for the EC */
1094         result = acpi_bus_register_driver(&acpi_ec_driver);
1095         if (result < 0) {
1096                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1097                 return -ENODEV;
1098         }
1099
1100         return result;
1101 }
1102
1103 /* EC driver currently not unloadable */
1104 #if 0
1105 static void __exit acpi_ec_exit(void)
1106 {
1107
1108         acpi_bus_unregister_driver(&acpi_ec_driver);
1109
1110         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1111
1112         return;
1113 }
1114 #endif  /* 0 */