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   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 #define PREFIX                          "ACPI: EC: "
  51
  52 /* EC status register */
  53 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  54 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  55 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  56 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  57
  58 /* EC commands */
  59 enum ec_command {
  60         ACPI_EC_COMMAND_READ = 0x80,
  61         ACPI_EC_COMMAND_WRITE = 0x81,
  62         ACPI_EC_BURST_ENABLE = 0x82,
  63         ACPI_EC_BURST_DISABLE = 0x83,
  64         ACPI_EC_COMMAND_QUERY = 0x84,
  65 };
  66
  67 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  68 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  69 #define ACPI_EC_CDELAY          10      /* Wait 10us before polling EC */
  70
  71 #define ACPI_EC_STORM_THRESHOLD 8       /* number of false interrupts
  72                                            per one transaction */
  73
  74 enum {
  75         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  76         EC_FLAGS_GPE_MODE,              /* Expect GPE to be sent
  77                                          * for status change */
  78         EC_FLAGS_NO_GPE,                /* Don't use GPE mode */
  79         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  80         EC_FLAGS_HANDLERS_INSTALLED     /* Handlers for GPE and
  81                                          * OpReg are installed */
  82 };
  83
  84 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  85 /* External interfaces use first EC only, so remember */
  86 typedef int (*acpi_ec_query_func) (void *data);
  87
  88 struct acpi_ec_query_handler {
  89         struct list_head node;
  90         acpi_ec_query_func func;
  91         acpi_handle handle;
  92         void *data;
  93         u8 query_bit;
  94 };
  95
  96 struct transaction {
  97         const u8 *wdata;
  98         u8 *rdata;
  99         unsigned short irq_count;
 100         u8 command;
 101         u8 wi;
 102         u8 ri;
 103         u8 wlen;
 104         u8 rlen;
 105         bool done;
 106 };
 107
 108 static struct acpi_ec {
 109         acpi_handle handle;
 110         unsigned long gpe;
 111         unsigned long command_addr;
 112         unsigned long data_addr;
 113         unsigned long global_lock;
 114         unsigned long flags;
 115         struct mutex lock;
 116         wait_queue_head_t wait;
 117         struct list_head list;
 118         struct transaction *curr;
 119         spinlock_t curr_lock;
 120 } *boot_ec, *first_ec;
 121
 122 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 123
 124 /* --------------------------------------------------------------------------
 125                              Transaction Management
 126    -------------------------------------------------------------------------- */
 127
 128 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 129 {
 130         u8 x = inb(ec->command_addr);
 131         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
 132         return x;
 133 }
 134
 135 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 136 {
 137         u8 x = inb(ec->data_addr);
 138         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
 139         return x;
 140 }
 141
 142 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 143 {
 144         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
 145         outb(command, ec->command_addr);
 146 }
 147
 148 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 149 {
 150         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
 151         outb(data, ec->data_addr);
 152 }
 153
 154 static int ec_transaction_done(struct acpi_ec *ec)
 155 {
 156         unsigned long flags;
 157         int ret = 0;
 158         spin_lock_irqsave(&ec->curr_lock, flags);
 159         if (!ec->curr || ec->curr->done)
 160                 ret = 1;
 161         spin_unlock_irqrestore(&ec->curr_lock, flags);
 162         return ret;
 163 }
 164
 165 static void start_transaction(struct acpi_ec *ec)
 166 {
 167         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 168         ec->curr->done = false;
 169         acpi_ec_write_cmd(ec, ec->curr->command);
 170 }
 171
 172 static void gpe_transaction(struct acpi_ec *ec, u8 status)
 173 {
 174         unsigned long flags;
 175         spin_lock_irqsave(&ec->curr_lock, flags);
 176         if (!ec->curr)
 177                 goto unlock;
 178         if (ec->curr->wlen > ec->curr->wi) {
 179                 if ((status & ACPI_EC_FLAG_IBF) == 0)
 180                         acpi_ec_write_data(ec,
 181                                 ec->curr->wdata[ec->curr->wi++]);
 182                 else
 183                         goto err;
 184         } else if (ec->curr->rlen > ec->curr->ri) {
 185                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
 186                         ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
 187                         if (ec->curr->rlen == ec->curr->ri)
 188                                 ec->curr->done = true;
 189                 } else
 190                         goto err;
 191         } else if (ec->curr->wlen == ec->curr->wi &&
 192                    (status & ACPI_EC_FLAG_IBF) == 0)
 193                 ec->curr->done = true;
 194         goto unlock;
 195 err:
 196         /* false interrupt, state didn't change */
 197         if (in_interrupt())
 198                 ++ec->curr->irq_count;
 199 unlock:
 200         spin_unlock_irqrestore(&ec->curr_lock, flags);
 201 }
 202
 203 static int acpi_ec_wait(struct acpi_ec *ec)
 204 {
 205         if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
 206                                msecs_to_jiffies(ACPI_EC_DELAY)))
 207                 return 0;
 208         /* try restart command if we get any false interrupts */
 209         if (ec->curr->irq_count &&
 210             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 211                 pr_debug(PREFIX "controller reset, restart transaction\n");
 212                 start_transaction(ec);
 213                 if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
 214                                         msecs_to_jiffies(ACPI_EC_DELAY)))
 215                         return 0;
 216         }
 217         /* missing GPEs, switch back to poll mode */
 218         if (printk_ratelimit())
 219                 pr_info(PREFIX "missing confirmations, "
 220                                 "switch off interrupt mode.\n");
 221         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
 222         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 223         return 1;
 224 }
 225
 226 static void acpi_ec_gpe_query(void *ec_cxt);
 227
 228 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 229 {
 230         if (state & ACPI_EC_FLAG_SCI) {
 231                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 232                         return acpi_os_execute(OSL_EC_BURST_HANDLER,
 233                                 acpi_ec_gpe_query, ec);
 234         }
 235         return 0;
 236 }
 237
 238 static void ec_delay(void)
 239 {
 240         /* EC in MSI notebooks don't tolerate delays other than 550 usec */
 241         if (EC_FLAGS_MSI)
 242                 udelay(ACPI_EC_DELAY);
 243         else
 244                 /* Use shortest sleep available */
 245                 msleep(1);
 246 }
 247
 248 static int ec_poll(struct acpi_ec *ec)
 249 {
 250         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 251         udelay(ACPI_EC_CDELAY);
 252         while (time_before(jiffies, delay)) {
 253                 gpe_transaction(ec, acpi_ec_read_status(ec));
 254                 ec_delay();
 255                 if (ec_transaction_done(ec))
 256                         return 0;
 257         }
 258         return -ETIME;
 259 }
 260
 261 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 262                                         struct transaction *t,
 263                                         int force_poll)
 264 {
 265         unsigned long tmp;
 266         int ret = 0;
 267         pr_debug(PREFIX "transaction start\n");
 268         /* disable GPE during transaction if storm is detected */
 269         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 270                 clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 271                 acpi_disable_gpe(NULL, ec->gpe);
 272         }
 273         if (EC_FLAGS_MSI)
 274                 udelay(ACPI_EC_DELAY);
 275         /* start transaction */
 276         spin_lock_irqsave(&ec->curr_lock, tmp);
 277         /* following two actions should be kept atomic */
 278         ec->curr = t;
 279         start_transaction(ec);
 280         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 281                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 282         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 283         /* if we selected poll mode or failed in GPE-mode do a poll loop */
 284         if (force_poll ||
 285             !test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ||
 286             acpi_ec_wait(ec))
 287                 ret = ec_poll(ec);
 288         pr_debug(PREFIX "transaction end\n");
 289         spin_lock_irqsave(&ec->curr_lock, tmp);
 290         ec->curr = NULL;
 291         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 292         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 293                 /* check if we received SCI during transaction */
 294                 ec_check_sci(ec, acpi_ec_read_status(ec));
 295                 /* it is safe to enable GPE outside of transaction */
 296                 acpi_enable_gpe(NULL, ec->gpe);
 297         } else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 298                    t->irq_count > ACPI_EC_STORM_THRESHOLD) {
 299                 pr_info(PREFIX "GPE storm detected, "
 300                         "transactions will use polling mode\n");
 301                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 302         }
 303         return ret;
 304 }
 305
 306 static int ec_check_ibf0(struct acpi_ec *ec)
 307 {
 308         u8 status = acpi_ec_read_status(ec);
 309         return (status & ACPI_EC_FLAG_IBF) == 0;
 310 }
 311
 312 static int ec_wait_ibf0(struct acpi_ec *ec)
 313 {
 314         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 315         /* interrupt wait manually if GPE mode is not active */
 316         unsigned long timeout = test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ?
 317                 msecs_to_jiffies(ACPI_EC_DELAY) : msecs_to_jiffies(1);
 318         while (time_before(jiffies, delay))
 319                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec), timeout))
 320                         return 0;
 321         return -ETIME;
 322 }
 323
 324 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t,
 325                                int force_poll)
 326 {
 327         int status;
 328         u32 glk;
 329         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 330                 return -EINVAL;
 331         if (t->rdata)
 332                 memset(t->rdata, 0, t->rlen);
 333         mutex_lock(&ec->lock);
 334         if (ec->global_lock) {
 335                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 336                 if (ACPI_FAILURE(status)) {
 337                         status = -ENODEV;
 338                         goto unlock;
 339                 }
 340         }
 341         if (ec_wait_ibf0(ec)) {
 342                 pr_err(PREFIX "input buffer is not empty, "
 343                                 "aborting transaction\n");
 344                 status = -ETIME;
 345                 goto end;
 346         }
 347         status = acpi_ec_transaction_unlocked(ec, t, force_poll);
 348 end:
 349         if (ec->global_lock)
 350                 acpi_release_global_lock(glk);
 351 unlock:
 352         mutex_unlock(&ec->lock);
 353         return status;
 354 }
 355
 356 /*
 357  * Note: samsung nv5000 doesn't work with ec burst mode.
 358  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 359  */
 360 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 361 {
 362         u8 d;
 363         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 364                                 .wdata = NULL, .rdata = &d,
 365                                 .wlen = 0, .rlen = 1};
 366
 367         return acpi_ec_transaction(ec, &t, 0);
 368 }
 369
 370 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 371 {
 372         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 373                                 .wdata = NULL, .rdata = NULL,
 374                                 .wlen = 0, .rlen = 0};
 375
 376         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 377                                 acpi_ec_transaction(ec, &t, 0) : 0;
 378 }
 379
 380 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 381 {
 382         int result;
 383         u8 d;
 384         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 385                                 .wdata = &address, .rdata = &d,
 386                                 .wlen = 1, .rlen = 1};
 387
 388         result = acpi_ec_transaction(ec, &t, 0);
 389         *data = d;
 390         return result;
 391 }
 392
 393 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 394 {
 395         u8 wdata[2] = { address, data };
 396         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 397                                 .wdata = wdata, .rdata = NULL,
 398                                 .wlen = 2, .rlen = 0};
 399
 400         return acpi_ec_transaction(ec, &t, 0);
 401 }
 402
 403 /*
 404  * Externally callable EC access functions. For now, assume 1 EC only
 405  */
 406 int ec_burst_enable(void)
 407 {
 408         if (!first_ec)
 409                 return -ENODEV;
 410         return acpi_ec_burst_enable(first_ec);
 411 }
 412
 413 EXPORT_SYMBOL(ec_burst_enable);
 414
 415 int ec_burst_disable(void)
 416 {
 417         if (!first_ec)
 418                 return -ENODEV;
 419         return acpi_ec_burst_disable(first_ec);
 420 }
 421
 422 EXPORT_SYMBOL(ec_burst_disable);
 423
 424 int ec_read(u8 addr, u8 * val)
 425 {
 426         int err;
 427         u8 temp_data;
 428
 429         if (!first_ec)
 430                 return -ENODEV;
 431
 432         err = acpi_ec_read(first_ec, addr, &temp_data);
 433
 434         if (!err) {
 435                 *val = temp_data;
 436                 return 0;
 437         } else
 438                 return err;
 439 }
 440
 441 EXPORT_SYMBOL(ec_read);
 442
 443 int ec_write(u8 addr, u8 val)
 444 {
 445         int err;
 446
 447         if (!first_ec)
 448                 return -ENODEV;
 449
 450         err = acpi_ec_write(first_ec, addr, val);
 451
 452         return err;
 453 }
 454
 455 EXPORT_SYMBOL(ec_write);
 456
 457 int ec_transaction(u8 command,
 458                    const u8 * wdata, unsigned wdata_len,
 459                    u8 * rdata, unsigned rdata_len,
 460                    int force_poll)
 461 {
 462         struct transaction t = {.command = command,
 463                                 .wdata = wdata, .rdata = rdata,
 464                                 .wlen = wdata_len, .rlen = rdata_len};
 465         if (!first_ec)
 466                 return -ENODEV;
 467
 468         return acpi_ec_transaction(first_ec, &t, force_poll);
 469 }
 470
 471 EXPORT_SYMBOL(ec_transaction);
 472
 473 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 474 {
 475         int result;
 476         u8 d;
 477         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 478                                 .wdata = NULL, .rdata = &d,
 479                                 .wlen = 0, .rlen = 1};
 480         if (!ec || !data)
 481                 return -EINVAL;
 482
 483         /*
 484          * Query the EC to find out which _Qxx method we need to evaluate.
 485          * Note that successful completion of the query causes the ACPI_EC_SCI
 486          * bit to be cleared (and thus clearing the interrupt source).
 487          */
 488
 489         result = acpi_ec_transaction(ec, &t, 0);
 490         if (result)
 491                 return result;
 492
 493         if (!d)
 494                 return -ENODATA;
 495
 496         *data = d;
 497         return 0;
 498 }
 499
 500 /* --------------------------------------------------------------------------
 501                                 Event Management
 502    -------------------------------------------------------------------------- */
 503 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 504                               acpi_handle handle, acpi_ec_query_func func,
 505                               void *data)
 506 {
 507         struct acpi_ec_query_handler *handler =
 508             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 509         if (!handler)
 510                 return -ENOMEM;
 511
 512         handler->query_bit = query_bit;
 513         handler->handle = handle;
 514         handler->func = func;
 515         handler->data = data;
 516         mutex_lock(&ec->lock);
 517         list_add(&handler->node, &ec->list);
 518         mutex_unlock(&ec->lock);
 519         return 0;
 520 }
 521
 522 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 523
 524 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 525 {
 526         struct acpi_ec_query_handler *handler, *tmp;
 527         mutex_lock(&ec->lock);
 528         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 529                 if (query_bit == handler->query_bit) {
 530                         list_del(&handler->node);
 531                         kfree(handler);
 532                 }
 533         }
 534         mutex_unlock(&ec->lock);
 535 }
 536
 537 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 538
 539 static void acpi_ec_gpe_query(void *ec_cxt)
 540 {
 541         struct acpi_ec *ec = ec_cxt;
 542         u8 value = 0;
 543         struct acpi_ec_query_handler *handler, copy;
 544
 545         if (!ec || acpi_ec_query(ec, &value))
 546                 return;
 547         mutex_lock(&ec->lock);
 548         list_for_each_entry(handler, &ec->list, node) {
 549                 if (value == handler->query_bit) {
 550                         /* have custom handler for this bit */
 551                         memcpy(&copy, handler, sizeof(copy));
 552                         mutex_unlock(&ec->lock);
 553                         if (copy.func) {
 554                                 copy.func(copy.data);
 555                         } else if (copy.handle) {
 556                                 acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
 557                         }
 558                         return;
 559                 }
 560         }
 561         mutex_unlock(&ec->lock);
 562 }
 563
 564 static u32 acpi_ec_gpe_handler(void *data)
 565 {
 566         struct acpi_ec *ec = data;
 567         u8 status;
 568
 569         pr_debug(PREFIX "~~~> interrupt\n");
 570         status = acpi_ec_read_status(ec);
 571
 572         if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) {
 573                 gpe_transaction(ec, status);
 574                 if (ec_transaction_done(ec) &&
 575                     (status & ACPI_EC_FLAG_IBF) == 0)
 576                         wake_up(&ec->wait);
 577         }
 578
 579         ec_check_sci(ec, status);
 580         if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 581             !test_bit(EC_FLAGS_NO_GPE, &ec->flags)) {
 582                 /* this is non-query, must be confirmation */
 583                 if (!test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 584                         if (printk_ratelimit())
 585                                 pr_info(PREFIX "non-query interrupt received,"
 586                                         " switching to interrupt mode\n");
 587                 } else {
 588                         /* hush, STORM switches the mode every transaction */
 589                         pr_debug(PREFIX "non-query interrupt received,"
 590                                 " switching to interrupt mode\n");
 591                 }
 592                 set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 593         }
 594         return ACPI_INTERRUPT_HANDLED;
 595 }
 596
 597 /* --------------------------------------------------------------------------
 598                              Address Space Management
 599    -------------------------------------------------------------------------- */
 600
 601 static acpi_status
 602 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 603                       u32 bits, acpi_integer *value,
 604                       void *handler_context, void *region_context)
 605 {
 606         struct acpi_ec *ec = handler_context;
 607         int result = 0, i;
 608         u8 temp = 0;
 609
 610         if ((address > 0xFF) || !value || !handler_context)
 611                 return AE_BAD_PARAMETER;
 612
 613         if (function != ACPI_READ && function != ACPI_WRITE)
 614                 return AE_BAD_PARAMETER;
 615
 616         if (bits != 8 && acpi_strict)
 617                 return AE_BAD_PARAMETER;
 618
 619         acpi_ec_burst_enable(ec);
 620
 621         if (function == ACPI_READ) {
 622                 result = acpi_ec_read(ec, address, &temp);
 623                 *value = temp;
 624         } else {
 625                 temp = 0xff & (*value);
 626                 result = acpi_ec_write(ec, address, temp);
 627         }
 628
 629         for (i = 8; unlikely(bits - i > 0); i += 8) {
 630                 ++address;
 631                 if (function == ACPI_READ) {
 632                         result = acpi_ec_read(ec, address, &temp);
 633                         (*value) |= ((acpi_integer)temp) << i;
 634                 } else {
 635                         temp = 0xff & ((*value) >> i);
 636                         result = acpi_ec_write(ec, address, temp);
 637                 }
 638         }
 639
 640         acpi_ec_burst_disable(ec);
 641
 642         switch (result) {
 643         case -EINVAL:
 644                 return AE_BAD_PARAMETER;
 645                 break;
 646         case -ENODEV:
 647                 return AE_NOT_FOUND;
 648                 break;
 649         case -ETIME:
 650                 return AE_TIME;
 651                 break;
 652         default:
 653                 return AE_OK;
 654         }
 655 }
 656
 657 /* --------------------------------------------------------------------------
 658                               FS Interface (/proc)
 659    -------------------------------------------------------------------------- */
 660
 661 static struct proc_dir_entry *acpi_ec_dir;
 662
 663 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 664 {
 665         struct acpi_ec *ec = seq->private;
 666
 667         if (!ec)
 668                 goto end;
 669
 670         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 671         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 672                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 673         seq_printf(seq, "use global lock:\t%s\n",
 674                    ec->global_lock ? "yes" : "no");
 675       end:
 676         return 0;
 677 }
 678
 679 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 680 {
 681         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 682 }
 683
 684 static const struct file_operations acpi_ec_info_ops = {
 685         .open = acpi_ec_info_open_fs,
 686         .read = seq_read,
 687         .llseek = seq_lseek,
 688         .release = single_release,
 689         .owner = THIS_MODULE,
 690 };
 691
 692 static int acpi_ec_add_fs(struct acpi_device *device)
 693 {
 694         struct proc_dir_entry *entry = NULL;
 695
 696         if (!acpi_device_dir(device)) {
 697                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 698                                                      acpi_ec_dir);
 699                 if (!acpi_device_dir(device))
 700                         return -ENODEV;
 701         }
 702
 703         entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
 704                                  acpi_device_dir(device),
 705                                  &acpi_ec_info_ops, acpi_driver_data(device));
 706         if (!entry)
 707                 return -ENODEV;
 708         return 0;
 709 }
 710
 711 static int acpi_ec_remove_fs(struct acpi_device *device)
 712 {
 713
 714         if (acpi_device_dir(device)) {
 715                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 716                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 717                 acpi_device_dir(device) = NULL;
 718         }
 719
 720         return 0;
 721 }
 722
 723 /* --------------------------------------------------------------------------
 724                                Driver Interface
 725    -------------------------------------------------------------------------- */
 726 static acpi_status
 727 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 728
 729 static struct acpi_ec *make_acpi_ec(void)
 730 {
 731         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 732         if (!ec)
 733                 return NULL;
 734         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 735         mutex_init(&ec->lock);
 736         init_waitqueue_head(&ec->wait);
 737         INIT_LIST_HEAD(&ec->list);
 738         spin_lock_init(&ec->curr_lock);
 739         return ec;
 740 }
 741
 742 static acpi_status
 743 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 744                                void *context, void **return_value)
 745 {
 746         char node_name[5];
 747         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 748         struct acpi_ec *ec = context;
 749         int value = 0;
 750         acpi_status status;
 751
 752         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 753
 754         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 755                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 756         }
 757         return AE_OK;
 758 }
 759
 760 static acpi_status
 761 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 762 {
 763         acpi_status status;
 764         unsigned long long tmp = 0;
 765
 766         struct acpi_ec *ec = context;
 767
 768         /* clear addr values, ec_parse_io_ports depend on it */
 769         ec->command_addr = ec->data_addr = 0;
 770
 771         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 772                                      ec_parse_io_ports, ec);
 773         if (ACPI_FAILURE(status))
 774                 return status;
 775
 776         /* Get GPE bit assignment (EC events). */
 777         /* TODO: Add support for _GPE returning a package */
 778         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 779         if (ACPI_FAILURE(status))
 780                 return status;
 781         ec->gpe = tmp;
 782         /* Use the global lock for all EC transactions? */
 783         tmp = 0;
 784         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 785         ec->global_lock = tmp;
 786         ec->handle = handle;
 787         return AE_CTRL_TERMINATE;
 788 }
 789
 790 static void ec_remove_handlers(struct acpi_ec *ec)
 791 {
 792         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 793                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 794                 pr_err(PREFIX "failed to remove space handler\n");
 795         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 796                                 &acpi_ec_gpe_handler)))
 797                 pr_err(PREFIX "failed to remove gpe handler\n");
 798         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 799 }
 800
 801 static int acpi_ec_add(struct acpi_device *device)
 802 {
 803         struct acpi_ec *ec = NULL;
 804
 805         if (!device)
 806                 return -EINVAL;
 807         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 808         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 809
 810         /* Check for boot EC */
 811         if (boot_ec &&
 812             (boot_ec->handle == device->handle ||
 813              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 814                 ec = boot_ec;
 815                 boot_ec = NULL;
 816         } else {
 817                 ec = make_acpi_ec();
 818                 if (!ec)
 819                         return -ENOMEM;
 820         }
 821         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 822                 AE_CTRL_TERMINATE) {
 823                         kfree(ec);
 824                         return -EINVAL;
 825         }
 826
 827         ec->handle = device->handle;
 828
 829         /* Find and register all query methods */
 830         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 831                             acpi_ec_register_query_methods, ec, NULL);
 832
 833         if (!first_ec)
 834                 first_ec = ec;
 835         device->driver_data = ec;
 836         acpi_ec_add_fs(device);
 837         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 838                           ec->gpe, ec->command_addr, ec->data_addr);
 839         pr_info(PREFIX "driver started in %s mode\n",
 840                 (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
 841         return 0;
 842 }
 843
 844 static int acpi_ec_remove(struct acpi_device *device, int type)
 845 {
 846         struct acpi_ec *ec;
 847         struct acpi_ec_query_handler *handler, *tmp;
 848
 849         if (!device)
 850                 return -EINVAL;
 851
 852         ec = acpi_driver_data(device);
 853         mutex_lock(&ec->lock);
 854         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 855                 list_del(&handler->node);
 856                 kfree(handler);
 857         }
 858         mutex_unlock(&ec->lock);
 859         acpi_ec_remove_fs(device);
 860         device->driver_data = NULL;
 861         if (ec == first_ec)
 862                 first_ec = NULL;
 863         kfree(ec);
 864         return 0;
 865 }
 866
 867 static acpi_status
 868 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 869 {
 870         struct acpi_ec *ec = context;
 871
 872         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 873                 return AE_OK;
 874
 875         /*
 876          * The first address region returned is the data port, and
 877          * the second address region returned is the status/command
 878          * port.
 879          */
 880         if (ec->data_addr == 0)
 881                 ec->data_addr = resource->data.io.minimum;
 882         else if (ec->command_addr == 0)
 883                 ec->command_addr = resource->data.io.minimum;
 884         else
 885                 return AE_CTRL_TERMINATE;
 886
 887         return AE_OK;
 888 }
 889
 890 static int ec_install_handlers(struct acpi_ec *ec)
 891 {
 892         acpi_status status;
 893         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 894                 return 0;
 895         status = acpi_install_gpe_handler(NULL, ec->gpe,
 896                                   ACPI_GPE_EDGE_TRIGGERED,
 897                                   &acpi_ec_gpe_handler, ec);
 898         if (ACPI_FAILURE(status))
 899                 return -ENODEV;
 900         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 901         acpi_enable_gpe(NULL, ec->gpe);
 902         status = acpi_install_address_space_handler(ec->handle,
 903                                                     ACPI_ADR_SPACE_EC,
 904                                                     &acpi_ec_space_handler,
 905                                                     NULL, ec);
 906         if (ACPI_FAILURE(status)) {
 907                 if (status == AE_NOT_FOUND) {
 908                         /*
 909                          * Maybe OS fails in evaluating the _REG object.
 910                          * The AE_NOT_FOUND error will be ignored and OS
 911                          * continue to initialize EC.
 912                          */
 913                         printk(KERN_ERR "Fail in evaluating the _REG object"
 914                                 " of EC device. Broken bios is suspected.\n");
 915                 } else {
 916                         acpi_remove_gpe_handler(NULL, ec->gpe,
 917                                 &acpi_ec_gpe_handler);
 918                         return -ENODEV;
 919                 }
 920         }
 921
 922         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 923         return 0;
 924 }
 925
 926 static int acpi_ec_start(struct acpi_device *device)
 927 {
 928         struct acpi_ec *ec;
 929         int ret = 0;
 930
 931         if (!device)
 932                 return -EINVAL;
 933
 934         ec = acpi_driver_data(device);
 935
 936         if (!ec)
 937                 return -EINVAL;
 938
 939         ret = ec_install_handlers(ec);
 940
 941         /* EC is fully operational, allow queries */
 942         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 943         return ret;
 944 }
 945
 946 static int acpi_ec_stop(struct acpi_device *device, int type)
 947 {
 948         struct acpi_ec *ec;
 949         if (!device)
 950                 return -EINVAL;
 951         ec = acpi_driver_data(device);
 952         if (!ec)
 953                 return -EINVAL;
 954         ec_remove_handlers(ec);
 955
 956         return 0;
 957 }
 958
 959 int __init acpi_boot_ec_enable(void)
 960 {
 961         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 962                 return 0;
 963         if (!ec_install_handlers(boot_ec)) {
 964                 first_ec = boot_ec;
 965                 return 0;
 966         }
 967         return -EFAULT;
 968 }
 969
 970 static const struct acpi_device_id ec_device_ids[] = {
 971         {"PNP0C09", 0},
 972         {"", 0},
 973 };
 974
 975 int __init acpi_ec_ecdt_probe(void)
 976 {
 977         acpi_status status;
 978         struct acpi_ec *saved_ec = NULL;
 979         struct acpi_table_ecdt *ecdt_ptr;
 980
 981         boot_ec = make_acpi_ec();
 982         if (!boot_ec)
 983                 return -ENOMEM;
 984         /*
 985          * Generate a boot ec context
 986          */
 987         if (dmi_name_in_vendors("Micro-Star") ||
 988             dmi_name_in_vendors("Notebook")) {
 989                 pr_info(PREFIX "Enabling special treatment for EC from MSI.\n");
 990                 EC_FLAGS_MSI = 1;
 991         }
 992         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 993                                 (struct acpi_table_header **)&ecdt_ptr);
 994         if (ACPI_SUCCESS(status)) {
 995                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
 996                 boot_ec->command_addr = ecdt_ptr->control.address;
 997                 boot_ec->data_addr = ecdt_ptr->data.address;
 998                 boot_ec->gpe = ecdt_ptr->gpe;
 999                 boot_ec->handle = ACPI_ROOT_OBJECT;
1000                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1001                 /* Don't trust ECDT, which comes from ASUSTek */
1002                 if (!dmi_name_in_vendors("ASUS") && EC_FLAGS_MSI == 0)
1003                         goto install;
1004                 saved_ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1005                 if (!saved_ec)
1006                         return -ENOMEM;
1007                 memcpy(saved_ec, boot_ec, sizeof(struct acpi_ec));
1008         /* fall through */
1009         }
1010         /* This workaround is needed only on some broken machines,
1011          * which require early EC, but fail to provide ECDT */
1012         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1013         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1014                                         boot_ec, NULL);
1015         /* Check that acpi_get_devices actually find something */
1016         if (ACPI_FAILURE(status) || !boot_ec->handle)
1017                 goto error;
1018         if (saved_ec) {
1019                 /* try to find good ECDT from ASUSTek */
1020                 if (saved_ec->command_addr != boot_ec->command_addr ||
1021                     saved_ec->data_addr != boot_ec->data_addr ||
1022                     saved_ec->gpe != boot_ec->gpe ||
1023                     saved_ec->handle != boot_ec->handle)
1024                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1025                         "ECDT tables, which are very hard to workaround. "
1026                         "Trying to use DSDT EC info instead. Please send "
1027                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1028                 kfree(saved_ec);
1029                 saved_ec = NULL;
1030         } else {
1031                 /* We really need to limit this workaround, the only ASUS,
1032                 * which needs it, has fake EC._INI method, so use it as flag.
1033                 * Keep boot_ec struct as it will be needed soon.
1034                 */
1035                 acpi_handle dummy;
1036                 if (!dmi_name_in_vendors("ASUS") ||
1037                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1038                                                         &dummy)))
1039                         return -ENODEV;
1040         }
1041 install:
1042         if (!ec_install_handlers(boot_ec)) {
1043                 first_ec = boot_ec;
1044                 return 0;
1045         }
1046 error:
1047         kfree(boot_ec);
1048         boot_ec = NULL;
1049         return -ENODEV;
1050 }
1051
1052 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1053 {
1054         struct acpi_ec *ec = acpi_driver_data(device);
1055         /* Stop using GPE */
1056         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
1057         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
1058         acpi_disable_gpe(NULL, ec->gpe);
1059         return 0;
1060 }
1061
1062 static int acpi_ec_resume(struct acpi_device *device)
1063 {
1064         struct acpi_ec *ec = acpi_driver_data(device);
1065         /* Enable use of GPE back */
1066         clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
1067         set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
1068         acpi_enable_gpe(NULL, ec->gpe);
1069         return 0;
1070 }
1071
1072 static struct acpi_driver acpi_ec_driver = {
1073         .name = "ec",
1074         .class = ACPI_EC_CLASS,
1075         .ids = ec_device_ids,
1076         .ops = {
1077                 .add = acpi_ec_add,
1078                 .remove = acpi_ec_remove,
1079                 .start = acpi_ec_start,
1080                 .stop = acpi_ec_stop,
1081                 .suspend = acpi_ec_suspend,
1082                 .resume = acpi_ec_resume,
1083                 },
1084 };
1085
1086 int __init acpi_ec_init(void)
1087 {
1088         int result = 0;
1089
1090         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1091         if (!acpi_ec_dir)
1092                 return -ENODEV;
1093
1094         /* Now register the driver for the EC */
1095         result = acpi_bus_register_driver(&acpi_ec_driver);
1096         if (result < 0) {
1097                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1098                 return -ENODEV;
1099         }
1100
1101         return result;
1102 }
1103
1104 /* EC driver currently not unloadable */
1105 #if 0
1106 static void __exit acpi_ec_exit(void)
1107 {
1108
1109         acpi_bus_unregister_driver(&acpi_ec_driver);
1110
1111         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1112
1113         return;
1114 }
1115 #endif  /* 0 */