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
  46 #define ACPI_EC_CLASS                   "embedded_controller"
  47 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  48 #define ACPI_EC_FILE_INFO               "info"
  49
  50 #undef PREFIX
  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_UDELAY          100     /* Wait 100us before polling EC again */
  71
  72 #define ACPI_EC_STORM_THRESHOLD 8       /* number of false interrupts
  73                                            per one transaction */
  74
  75 enum {
  76         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  77         EC_FLAGS_GPE_MODE,              /* Expect GPE to be sent
  78                                          * for status change */
  79         EC_FLAGS_NO_GPE,                /* Don't use GPE mode */
  80         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  81         EC_FLAGS_HANDLERS_INSTALLED     /* Handlers for GPE and
  82                                          * OpReg are installed */
  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
 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 gpe_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_wait(struct acpi_ec *ec)
 205 {
 206         if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
 207                                msecs_to_jiffies(ACPI_EC_DELAY)))
 208                 return 0;
 209         /* try restart command if we get any false interrupts */
 210         if (ec->curr->irq_count &&
 211             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 212                 pr_debug(PREFIX "controller reset, restart transaction\n");
 213                 start_transaction(ec);
 214                 if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
 215                                         msecs_to_jiffies(ACPI_EC_DELAY)))
 216                         return 0;
 217         }
 218         /* missing GPEs, switch back to poll mode */
 219         if (printk_ratelimit())
 220                 pr_info(PREFIX "missing confirmations, "
 221                                 "switch off interrupt mode.\n");
 222         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
 223         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 224         return 1;
 225 }
 226
 227 static void acpi_ec_gpe_query(void *ec_cxt);
 228
 229 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 230 {
 231         if (state & ACPI_EC_FLAG_SCI) {
 232                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 233                         return acpi_os_execute(OSL_EC_BURST_HANDLER,
 234                                 acpi_ec_gpe_query, ec);
 235         }
 236         return 0;
 237 }
 238
 239 static int ec_poll(struct acpi_ec *ec)
 240 {
 241         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 242         udelay(ACPI_EC_UDELAY);
 243         while (time_before(jiffies, delay)) {
 244                 gpe_transaction(ec, acpi_ec_read_status(ec));
 245                 udelay(ACPI_EC_UDELAY);
 246                 if (ec_transaction_done(ec))
 247                         return 0;
 248         }
 249         return -ETIME;
 250 }
 251
 252 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 253                                         struct transaction *t,
 254                                         int force_poll)
 255 {
 256         unsigned long tmp;
 257         int ret = 0;
 258         pr_debug(PREFIX "transaction start\n");
 259         /* disable GPE during transaction if storm is detected */
 260         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 261                 clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 262                 acpi_disable_gpe(NULL, ec->gpe);
 263         }
 264         if (EC_FLAGS_MSI)
 265                 udelay(ACPI_EC_DELAY);
 266         /* start transaction */
 267         spin_lock_irqsave(&ec->curr_lock, tmp);
 268         /* following two actions should be kept atomic */
 269         ec->curr = t;
 270         start_transaction(ec);
 271         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 272                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 273         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 274         /* if we selected poll mode or failed in GPE-mode do a poll loop */
 275         if (force_poll ||
 276             !test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ||
 277             acpi_ec_wait(ec))
 278                 ret = ec_poll(ec);
 279         pr_debug(PREFIX "transaction end\n");
 280         spin_lock_irqsave(&ec->curr_lock, tmp);
 281         ec->curr = NULL;
 282         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 283         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 284                 /* check if we received SCI during transaction */
 285                 ec_check_sci(ec, acpi_ec_read_status(ec));
 286                 /* it is safe to enable GPE outside of transaction */
 287                 acpi_enable_gpe(NULL, ec->gpe);
 288         } else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 289                    t->irq_count > ACPI_EC_STORM_THRESHOLD) {
 290                 pr_info(PREFIX "GPE storm detected, "
 291                         "transactions will use polling mode\n");
 292                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 293         }
 294         return ret;
 295 }
 296
 297 static int ec_check_ibf0(struct acpi_ec *ec)
 298 {
 299         u8 status = acpi_ec_read_status(ec);
 300         return (status & ACPI_EC_FLAG_IBF) == 0;
 301 }
 302
 303 static int ec_wait_ibf0(struct acpi_ec *ec)
 304 {
 305         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 306         /* interrupt wait manually if GPE mode is not active */
 307         unsigned long timeout = test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ?
 308                 msecs_to_jiffies(ACPI_EC_DELAY) : msecs_to_jiffies(1);
 309         while (time_before(jiffies, delay))
 310                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec), timeout))
 311                         return 0;
 312         return -ETIME;
 313 }
 314
 315 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t,
 316                                int force_poll)
 317 {
 318         int status;
 319         u32 glk;
 320         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 321                 return -EINVAL;
 322         if (t->rdata)
 323                 memset(t->rdata, 0, t->rlen);
 324         mutex_lock(&ec->lock);
 325         if (ec->global_lock) {
 326                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 327                 if (ACPI_FAILURE(status)) {
 328                         status = -ENODEV;
 329                         goto unlock;
 330                 }
 331         }
 332         if (ec_wait_ibf0(ec)) {
 333                 pr_err(PREFIX "input buffer is not empty, "
 334                                 "aborting transaction\n");
 335                 status = -ETIME;
 336                 goto end;
 337         }
 338         status = acpi_ec_transaction_unlocked(ec, t, force_poll);
 339 end:
 340         if (ec->global_lock)
 341                 acpi_release_global_lock(glk);
 342 unlock:
 343         mutex_unlock(&ec->lock);
 344         return status;
 345 }
 346
 347 /*
 348  * Note: samsung nv5000 doesn't work with ec burst mode.
 349  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 350  */
 351 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 352 {
 353         u8 d;
 354         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 355                                 .wdata = NULL, .rdata = &d,
 356                                 .wlen = 0, .rlen = 1};
 357
 358         return acpi_ec_transaction(ec, &t, 0);
 359 }
 360
 361 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 362 {
 363         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 364                                 .wdata = NULL, .rdata = NULL,
 365                                 .wlen = 0, .rlen = 0};
 366
 367         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 368                                 acpi_ec_transaction(ec, &t, 0) : 0;
 369 }
 370
 371 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 372 {
 373         int result;
 374         u8 d;
 375         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 376                                 .wdata = &address, .rdata = &d,
 377                                 .wlen = 1, .rlen = 1};
 378
 379         result = acpi_ec_transaction(ec, &t, 0);
 380         *data = d;
 381         return result;
 382 }
 383
 384 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 385 {
 386         u8 wdata[2] = { address, data };
 387         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 388                                 .wdata = wdata, .rdata = NULL,
 389                                 .wlen = 2, .rlen = 0};
 390
 391         return acpi_ec_transaction(ec, &t, 0);
 392 }
 393
 394 /*
 395  * Externally callable EC access functions. For now, assume 1 EC only
 396  */
 397 int ec_burst_enable(void)
 398 {
 399         if (!first_ec)
 400                 return -ENODEV;
 401         return acpi_ec_burst_enable(first_ec);
 402 }
 403
 404 EXPORT_SYMBOL(ec_burst_enable);
 405
 406 int ec_burst_disable(void)
 407 {
 408         if (!first_ec)
 409                 return -ENODEV;
 410         return acpi_ec_burst_disable(first_ec);
 411 }
 412
 413 EXPORT_SYMBOL(ec_burst_disable);
 414
 415 int ec_read(u8 addr, u8 * val)
 416 {
 417         int err;
 418         u8 temp_data;
 419
 420         if (!first_ec)
 421                 return -ENODEV;
 422
 423         err = acpi_ec_read(first_ec, addr, &temp_data);
 424
 425         if (!err) {
 426                 *val = temp_data;
 427                 return 0;
 428         } else
 429                 return err;
 430 }
 431
 432 EXPORT_SYMBOL(ec_read);
 433
 434 int ec_write(u8 addr, u8 val)
 435 {
 436         int err;
 437
 438         if (!first_ec)
 439                 return -ENODEV;
 440
 441         err = acpi_ec_write(first_ec, addr, val);
 442
 443         return err;
 444 }
 445
 446 EXPORT_SYMBOL(ec_write);
 447
 448 int ec_transaction(u8 command,
 449                    const u8 * wdata, unsigned wdata_len,
 450                    u8 * rdata, unsigned rdata_len,
 451                    int force_poll)
 452 {
 453         struct transaction t = {.command = command,
 454                                 .wdata = wdata, .rdata = rdata,
 455                                 .wlen = wdata_len, .rlen = rdata_len};
 456         if (!first_ec)
 457                 return -ENODEV;
 458
 459         return acpi_ec_transaction(first_ec, &t, force_poll);
 460 }
 461
 462 EXPORT_SYMBOL(ec_transaction);
 463
 464 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 465 {
 466         int result;
 467         u8 d;
 468         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 469                                 .wdata = NULL, .rdata = &d,
 470                                 .wlen = 0, .rlen = 1};
 471         if (!ec || !data)
 472                 return -EINVAL;
 473
 474         /*
 475          * Query the EC to find out which _Qxx method we need to evaluate.
 476          * Note that successful completion of the query causes the ACPI_EC_SCI
 477          * bit to be cleared (and thus clearing the interrupt source).
 478          */
 479
 480         result = acpi_ec_transaction(ec, &t, 0);
 481         if (result)
 482                 return result;
 483
 484         if (!d)
 485                 return -ENODATA;
 486
 487         *data = d;
 488         return 0;
 489 }
 490
 491 /* --------------------------------------------------------------------------
 492                                 Event Management
 493    -------------------------------------------------------------------------- */
 494 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 495                               acpi_handle handle, acpi_ec_query_func func,
 496                               void *data)
 497 {
 498         struct acpi_ec_query_handler *handler =
 499             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 500         if (!handler)
 501                 return -ENOMEM;
 502
 503         handler->query_bit = query_bit;
 504         handler->handle = handle;
 505         handler->func = func;
 506         handler->data = data;
 507         mutex_lock(&ec->lock);
 508         list_add(&handler->node, &ec->list);
 509         mutex_unlock(&ec->lock);
 510         return 0;
 511 }
 512
 513 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 514
 515 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 516 {
 517         struct acpi_ec_query_handler *handler, *tmp;
 518         mutex_lock(&ec->lock);
 519         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 520                 if (query_bit == handler->query_bit) {
 521                         list_del(&handler->node);
 522                         kfree(handler);
 523                 }
 524         }
 525         mutex_unlock(&ec->lock);
 526 }
 527
 528 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 529
 530 static void acpi_ec_gpe_query(void *ec_cxt)
 531 {
 532         struct acpi_ec *ec = ec_cxt;
 533         u8 value = 0;
 534         struct acpi_ec_query_handler *handler, copy;
 535
 536         if (!ec || acpi_ec_query(ec, &value))
 537                 return;
 538         mutex_lock(&ec->lock);
 539         list_for_each_entry(handler, &ec->list, node) {
 540                 if (value == handler->query_bit) {
 541                         /* have custom handler for this bit */
 542                         memcpy(&copy, handler, sizeof(copy));
 543                         mutex_unlock(&ec->lock);
 544                         if (copy.func) {
 545                                 copy.func(copy.data);
 546                         } else if (copy.handle) {
 547                                 acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
 548                         }
 549                         return;
 550                 }
 551         }
 552         mutex_unlock(&ec->lock);
 553 }
 554
 555 static u32 acpi_ec_gpe_handler(void *data)
 556 {
 557         struct acpi_ec *ec = data;
 558         u8 status;
 559
 560         pr_debug(PREFIX "~~~> interrupt\n");
 561         status = acpi_ec_read_status(ec);
 562
 563         if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) {
 564                 gpe_transaction(ec, status);
 565                 if (ec_transaction_done(ec) &&
 566                     (status & ACPI_EC_FLAG_IBF) == 0)
 567                         wake_up(&ec->wait);
 568         }
 569
 570         ec_check_sci(ec, status);
 571         if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 572             !test_bit(EC_FLAGS_NO_GPE, &ec->flags)) {
 573                 /* this is non-query, must be confirmation */
 574                 if (!test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 575                         if (printk_ratelimit())
 576                                 pr_info(PREFIX "non-query interrupt received,"
 577                                         " switching to interrupt mode\n");
 578                 } else {
 579                         /* hush, STORM switches the mode every transaction */
 580                         pr_debug(PREFIX "non-query interrupt received,"
 581                                 " switching to interrupt mode\n");
 582                 }
 583                 set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 584         }
 585         return ACPI_INTERRUPT_HANDLED;
 586 }
 587
 588 /* --------------------------------------------------------------------------
 589                              Address Space Management
 590    -------------------------------------------------------------------------- */
 591
 592 static acpi_status
 593 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 594                       u32 bits, acpi_integer *value,
 595                       void *handler_context, void *region_context)
 596 {
 597         struct acpi_ec *ec = handler_context;
 598         int result = 0, i;
 599         u8 temp = 0;
 600
 601         if ((address > 0xFF) || !value || !handler_context)
 602                 return AE_BAD_PARAMETER;
 603
 604         if (function != ACPI_READ && function != ACPI_WRITE)
 605                 return AE_BAD_PARAMETER;
 606
 607         if (bits != 8 && acpi_strict)
 608                 return AE_BAD_PARAMETER;
 609
 610         acpi_ec_burst_enable(ec);
 611
 612         if (function == ACPI_READ) {
 613                 result = acpi_ec_read(ec, address, &temp);
 614                 *value = temp;
 615         } else {
 616                 temp = 0xff & (*value);
 617                 result = acpi_ec_write(ec, address, temp);
 618         }
 619
 620         for (i = 8; unlikely(bits - i > 0); i += 8) {
 621                 ++address;
 622                 if (function == ACPI_READ) {
 623                         result = acpi_ec_read(ec, address, &temp);
 624                         (*value) |= ((acpi_integer)temp) << i;
 625                 } else {
 626                         temp = 0xff & ((*value) >> i);
 627                         result = acpi_ec_write(ec, address, temp);
 628                 }
 629         }
 630
 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 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         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 759                                      ec_parse_io_ports, ec);
 760         if (ACPI_FAILURE(status))
 761                 return status;
 762
 763         /* Get GPE bit assignment (EC events). */
 764         /* TODO: Add support for _GPE returning a package */
 765         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 766         if (ACPI_FAILURE(status))
 767                 return status;
 768         ec->gpe = tmp;
 769         /* Use the global lock for all EC transactions? */
 770         tmp = 0;
 771         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 772         ec->global_lock = tmp;
 773         ec->handle = handle;
 774         return AE_CTRL_TERMINATE;
 775 }
 776
 777 static void ec_remove_handlers(struct acpi_ec *ec)
 778 {
 779         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 780                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 781                 pr_err(PREFIX "failed to remove space handler\n");
 782         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 783                                 &acpi_ec_gpe_handler)))
 784                 pr_err(PREFIX "failed to remove gpe handler\n");
 785         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 786 }
 787
 788 static int acpi_ec_add(struct acpi_device *device)
 789 {
 790         struct acpi_ec *ec = NULL;
 791
 792         if (!device)
 793                 return -EINVAL;
 794         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 795         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 796
 797         /* Check for boot EC */
 798         if (boot_ec &&
 799             (boot_ec->handle == device->handle ||
 800              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 801                 ec = boot_ec;
 802                 boot_ec = NULL;
 803         } else {
 804                 ec = make_acpi_ec();
 805                 if (!ec)
 806                         return -ENOMEM;
 807                 if (ec_parse_device(device->handle, 0, ec, NULL) !=
 808                     AE_CTRL_TERMINATE) {
 809                         kfree(ec);
 810                         return -EINVAL;
 811                 }
 812         }
 813
 814         ec->handle = device->handle;
 815
 816         /* Find and register all query methods */
 817         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 818                             acpi_ec_register_query_methods, ec, NULL);
 819
 820         if (!first_ec)
 821                 first_ec = ec;
 822         device->driver_data = ec;
 823         acpi_ec_add_fs(device);
 824         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 825                           ec->gpe, ec->command_addr, ec->data_addr);
 826         pr_info(PREFIX "driver started in %s mode\n",
 827                 (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
 828         return 0;
 829 }
 830
 831 static int acpi_ec_remove(struct acpi_device *device, int type)
 832 {
 833         struct acpi_ec *ec;
 834         struct acpi_ec_query_handler *handler, *tmp;
 835
 836         if (!device)
 837                 return -EINVAL;
 838
 839         ec = acpi_driver_data(device);
 840         mutex_lock(&ec->lock);
 841         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 842                 list_del(&handler->node);
 843                 kfree(handler);
 844         }
 845         mutex_unlock(&ec->lock);
 846         acpi_ec_remove_fs(device);
 847         device->driver_data = NULL;
 848         if (ec == first_ec)
 849                 first_ec = NULL;
 850         kfree(ec);
 851         return 0;
 852 }
 853
 854 static acpi_status
 855 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 856 {
 857         struct acpi_ec *ec = context;
 858
 859         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 860                 return AE_OK;
 861
 862         /*
 863          * The first address region returned is the data port, and
 864          * the second address region returned is the status/command
 865          * port.
 866          */
 867         if (ec->data_addr == 0)
 868                 ec->data_addr = resource->data.io.minimum;
 869         else if (ec->command_addr == 0)
 870                 ec->command_addr = resource->data.io.minimum;
 871         else
 872                 return AE_CTRL_TERMINATE;
 873
 874         return AE_OK;
 875 }
 876
 877 static int ec_install_handlers(struct acpi_ec *ec)
 878 {
 879         acpi_status status;
 880         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 881                 return 0;
 882         status = acpi_install_gpe_handler(NULL, ec->gpe,
 883                                   ACPI_GPE_EDGE_TRIGGERED,
 884                                   &acpi_ec_gpe_handler, ec);
 885         if (ACPI_FAILURE(status))
 886                 return -ENODEV;
 887         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 888         acpi_enable_gpe(NULL, ec->gpe);
 889         status = acpi_install_address_space_handler(ec->handle,
 890                                                     ACPI_ADR_SPACE_EC,
 891                                                     &acpi_ec_space_handler,
 892                                                     NULL, ec);
 893         if (ACPI_FAILURE(status)) {
 894                 if (status == AE_NOT_FOUND) {
 895                         /*
 896                          * Maybe OS fails in evaluating the _REG object.
 897                          * The AE_NOT_FOUND error will be ignored and OS
 898                          * continue to initialize EC.
 899                          */
 900                         printk(KERN_ERR "Fail in evaluating the _REG object"
 901                                 " of EC device. Broken bios is suspected.\n");
 902                 } else {
 903                         acpi_remove_gpe_handler(NULL, ec->gpe,
 904                                 &acpi_ec_gpe_handler);
 905                         return -ENODEV;
 906                 }
 907         }
 908
 909         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 910         return 0;
 911 }
 912
 913 static int acpi_ec_start(struct acpi_device *device)
 914 {
 915         struct acpi_ec *ec;
 916         int ret = 0;
 917
 918         if (!device)
 919                 return -EINVAL;
 920
 921         ec = acpi_driver_data(device);
 922
 923         if (!ec)
 924                 return -EINVAL;
 925
 926         ret = ec_install_handlers(ec);
 927
 928         /* EC is fully operational, allow queries */
 929         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 930         return ret;
 931 }
 932
 933 static int acpi_ec_stop(struct acpi_device *device, int type)
 934 {
 935         struct acpi_ec *ec;
 936         if (!device)
 937                 return -EINVAL;
 938         ec = acpi_driver_data(device);
 939         if (!ec)
 940                 return -EINVAL;
 941         ec_remove_handlers(ec);
 942
 943         return 0;
 944 }
 945
 946 int __init acpi_boot_ec_enable(void)
 947 {
 948         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 949                 return 0;
 950         if (!ec_install_handlers(boot_ec)) {
 951                 first_ec = boot_ec;
 952                 return 0;
 953         }
 954         return -EFAULT;
 955 }
 956
 957 static const struct acpi_device_id ec_device_ids[] = {
 958         {"PNP0C09", 0},
 959         {"", 0},
 960 };
 961
 962 int __init acpi_ec_ecdt_probe(void)
 963 {
 964         acpi_status status;
 965         struct acpi_ec *saved_ec = NULL;
 966         struct acpi_table_ecdt *ecdt_ptr;
 967
 968         boot_ec = make_acpi_ec();
 969         if (!boot_ec)
 970                 return -ENOMEM;
 971         /*
 972          * Generate a boot ec context
 973          */
 974         if (dmi_name_in_vendors("Micro-Star") ||
 975             dmi_name_in_vendors("Notebook")) {
 976                 pr_info(PREFIX "Enabling special treatment for EC from MSI.\n");
 977                 EC_FLAGS_MSI = 1;
 978         }
 979         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 980                                 (struct acpi_table_header **)&ecdt_ptr);
 981         if (ACPI_SUCCESS(status)) {
 982                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
 983                 boot_ec->command_addr = ecdt_ptr->control.address;
 984                 boot_ec->data_addr = ecdt_ptr->data.address;
 985                 boot_ec->gpe = ecdt_ptr->gpe;
 986                 boot_ec->handle = ACPI_ROOT_OBJECT;
 987                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
 988                 /* Don't trust ECDT, which comes from ASUSTek */
 989                 if (!dmi_name_in_vendors("ASUS"))
 990                         goto install;
 991                 saved_ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 992                 if (!saved_ec)
 993                         return -ENOMEM;
 994                 memcpy(saved_ec, boot_ec, sizeof(*saved_ec));
 995         /* fall through */
 996         }
 997         /* This workaround is needed only on some broken machines,
 998          * which require early EC, but fail to provide ECDT */
 999         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1000         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1001                                         boot_ec, NULL);
1002         /* Check that acpi_get_devices actually find something */
1003         if (ACPI_FAILURE(status) || !boot_ec->handle)
1004                 goto error;
1005         if (saved_ec) {
1006                 /* try to find good ECDT from ASUSTek */
1007                 if (saved_ec->command_addr != boot_ec->command_addr ||
1008                     saved_ec->data_addr != boot_ec->data_addr ||
1009                     saved_ec->gpe != boot_ec->gpe ||
1010                     saved_ec->handle != boot_ec->handle)
1011                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1012                         "ECDT tables, which are very hard to workaround. "
1013                         "Trying to use DSDT EC info instead. Please send "
1014                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1015                 kfree(saved_ec);
1016                 saved_ec = NULL;
1017         } else {
1018                 /* We really need to limit this workaround, the only ASUS,
1019                 * which needs it, has fake EC._INI method, so use it as flag.
1020                 * Keep boot_ec struct as it will be needed soon.
1021                 */
1022                 acpi_handle dummy;
1023                 if (!dmi_name_in_vendors("ASUS") ||
1024                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1025                                                         &dummy)))
1026                         return -ENODEV;
1027         }
1028 install:
1029         if (!ec_install_handlers(boot_ec)) {
1030                 first_ec = boot_ec;
1031                 return 0;
1032         }
1033 error:
1034         kfree(boot_ec);
1035         boot_ec = NULL;
1036         return -ENODEV;
1037 }
1038
1039 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1040 {
1041         struct acpi_ec *ec = acpi_driver_data(device);
1042         /* Stop using GPE */
1043         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
1044         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
1045         acpi_disable_gpe(NULL, ec->gpe);
1046         return 0;
1047 }
1048
1049 static int acpi_ec_resume(struct acpi_device *device)
1050 {
1051         struct acpi_ec *ec = acpi_driver_data(device);
1052         /* Enable use of GPE back */
1053         clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
1054         acpi_enable_gpe(NULL, ec->gpe);
1055         return 0;
1056 }
1057
1058 static struct acpi_driver acpi_ec_driver = {
1059         .name = "ec",
1060         .class = ACPI_EC_CLASS,
1061         .ids = ec_device_ids,
1062         .ops = {
1063                 .add = acpi_ec_add,
1064                 .remove = acpi_ec_remove,
1065                 .start = acpi_ec_start,
1066                 .stop = acpi_ec_stop,
1067                 .suspend = acpi_ec_suspend,
1068                 .resume = acpi_ec_resume,
1069                 },
1070 };
1071
1072 static int __init acpi_ec_init(void)
1073 {
1074         int result = 0;
1075
1076         if (acpi_disabled)
1077                 return 0;
1078
1079         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1080         if (!acpi_ec_dir)
1081                 return -ENODEV;
1082
1083         /* Now register the driver for the EC */
1084         result = acpi_bus_register_driver(&acpi_ec_driver);
1085         if (result < 0) {
1086                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1087                 return -ENODEV;
1088         }
1089
1090         return result;
1091 }
1092
1093 subsys_initcall(acpi_ec_init);
1094
1095 /* EC driver currently not unloadable */
1096 #if 0
1097 static void __exit acpi_ec_exit(void)
1098 {
1099
1100         acpi_bus_unregister_driver(&acpi_ec_driver);
1101
1102         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1103
1104         return;
1105 }
1106 #endif  /* 0 */