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 #undef PREFIX
  52 #define PREFIX                          "ACPI: EC: "
  53
  54 /* EC status register */
  55 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  56 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  57 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  58 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  59
  60 /* EC commands */
  61 enum ec_command {
  62         ACPI_EC_COMMAND_READ = 0x80,
  63         ACPI_EC_COMMAND_WRITE = 0x81,
  64         ACPI_EC_BURST_ENABLE = 0x82,
  65         ACPI_EC_BURST_DISABLE = 0x83,
  66         ACPI_EC_COMMAND_QUERY = 0x84,
  67 };
  68
  69 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  70 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  71 #define ACPI_EC_CDELAY          10      /* Wait 10us before polling EC */
  72
  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_MODE,              /* Expect GPE to be sent
  79                                          * for status change */
  80         EC_FLAGS_NO_GPE,                /* Don't use GPE mode */
  81         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  82         EC_FLAGS_HANDLERS_INSTALLED     /* Handlers for GPE and
  83                                          * OpReg are installed */
  84 };
  85
  86 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  87 /* External interfaces use first EC only, so remember */
  88 typedef int (*acpi_ec_query_func) (void *data);
  89
  90 struct acpi_ec_query_handler {
  91         struct list_head node;
  92         acpi_ec_query_func func;
  93         acpi_handle handle;
  94         void *data;
  95         u8 query_bit;
  96 };
  97
  98 struct transaction {
  99         const u8 *wdata;
 100         u8 *rdata;
 101         unsigned short irq_count;
 102         u8 command;
 103         u8 wi;
 104         u8 ri;
 105         u8 wlen;
 106         u8 rlen;
 107         bool done;
 108 };
 109
 110 static struct acpi_ec {
 111         acpi_handle handle;
 112         unsigned long gpe;
 113         unsigned long command_addr;
 114         unsigned long data_addr;
 115         unsigned long global_lock;
 116         unsigned long flags;
 117         struct mutex lock;
 118         wait_queue_head_t wait;
 119         struct list_head list;
 120         struct transaction *curr;
 121         spinlock_t curr_lock;
 122 } *boot_ec, *first_ec;
 123
 124 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 125
 126 /* --------------------------------------------------------------------------
 127                              Transaction Management
 128    -------------------------------------------------------------------------- */
 129
 130 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 131 {
 132         u8 x = inb(ec->command_addr);
 133         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
 134         return x;
 135 }
 136
 137 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 138 {
 139         u8 x = inb(ec->data_addr);
 140         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
 141         return x;
 142 }
 143
 144 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 145 {
 146         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
 147         outb(command, ec->command_addr);
 148 }
 149
 150 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 151 {
 152         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
 153         outb(data, ec->data_addr);
 154 }
 155
 156 static int ec_transaction_done(struct acpi_ec *ec)
 157 {
 158         unsigned long flags;
 159         int ret = 0;
 160         spin_lock_irqsave(&ec->curr_lock, flags);
 161         if (!ec->curr || ec->curr->done)
 162                 ret = 1;
 163         spin_unlock_irqrestore(&ec->curr_lock, flags);
 164         return ret;
 165 }
 166
 167 static void start_transaction(struct acpi_ec *ec)
 168 {
 169         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 170         ec->curr->done = false;
 171         acpi_ec_write_cmd(ec, ec->curr->command);
 172 }
 173
 174 static void gpe_transaction(struct acpi_ec *ec, u8 status)
 175 {
 176         unsigned long flags;
 177         spin_lock_irqsave(&ec->curr_lock, flags);
 178         if (!ec->curr)
 179                 goto unlock;
 180         if (ec->curr->wlen > ec->curr->wi) {
 181                 if ((status & ACPI_EC_FLAG_IBF) == 0)
 182                         acpi_ec_write_data(ec,
 183                                 ec->curr->wdata[ec->curr->wi++]);
 184                 else
 185                         goto err;
 186         } else if (ec->curr->rlen > ec->curr->ri) {
 187                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
 188                         ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
 189                         if (ec->curr->rlen == ec->curr->ri)
 190                                 ec->curr->done = true;
 191                 } else
 192                         goto err;
 193         } else if (ec->curr->wlen == ec->curr->wi &&
 194                    (status & ACPI_EC_FLAG_IBF) == 0)
 195                 ec->curr->done = true;
 196         goto unlock;
 197 err:
 198         /* false interrupt, state didn't change */
 199         if (in_interrupt())
 200                 ++ec->curr->irq_count;
 201 unlock:
 202         spin_unlock_irqrestore(&ec->curr_lock, flags);
 203 }
 204
 205 static int acpi_ec_wait(struct acpi_ec *ec)
 206 {
 207         if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
 208                                msecs_to_jiffies(ACPI_EC_DELAY)))
 209                 return 0;
 210         /* try restart command if we get any false interrupts */
 211         if (ec->curr->irq_count &&
 212             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 213                 pr_debug(PREFIX "controller reset, restart transaction\n");
 214                 start_transaction(ec);
 215                 if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
 216                                         msecs_to_jiffies(ACPI_EC_DELAY)))
 217                         return 0;
 218         }
 219         /* missing GPEs, switch back to poll mode */
 220         if (printk_ratelimit())
 221                 pr_info(PREFIX "missing confirmations, "
 222                                 "switch off interrupt mode.\n");
 223         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
 224         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 225         return 1;
 226 }
 227
 228 static void acpi_ec_gpe_query(void *ec_cxt);
 229
 230 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 231 {
 232         if (state & ACPI_EC_FLAG_SCI) {
 233                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 234                         return acpi_os_execute(OSL_EC_BURST_HANDLER,
 235                                 acpi_ec_gpe_query, ec);
 236         }
 237         return 0;
 238 }
 239
 240 static void ec_delay(void)
 241 {
 242         /* EC in MSI notebooks don't tolerate delays other than 550 usec */
 243         if (EC_FLAGS_MSI)
 244                 udelay(ACPI_EC_DELAY);
 245         else
 246                 /* Use shortest sleep available */
 247                 msleep(1);
 248 }
 249
 250 static int ec_poll(struct acpi_ec *ec)
 251 {
 252         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 253         udelay(ACPI_EC_CDELAY);
 254         while (time_before(jiffies, delay)) {
 255                 gpe_transaction(ec, acpi_ec_read_status(ec));
 256                 ec_delay();
 257                 if (ec_transaction_done(ec))
 258                         return 0;
 259         }
 260         return -ETIME;
 261 }
 262
 263 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 264                                         struct transaction *t,
 265                                         int force_poll)
 266 {
 267         unsigned long tmp;
 268         int ret = 0;
 269         pr_debug(PREFIX "transaction start\n");
 270         /* disable GPE during transaction if storm is detected */
 271         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 272                 clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 273                 acpi_disable_gpe(NULL, ec->gpe);
 274         }
 275         if (EC_FLAGS_MSI)
 276                 udelay(ACPI_EC_DELAY);
 277         /* start transaction */
 278         spin_lock_irqsave(&ec->curr_lock, tmp);
 279         /* following two actions should be kept atomic */
 280         ec->curr = t;
 281         start_transaction(ec);
 282         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 283                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 284         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 285         /* if we selected poll mode or failed in GPE-mode do a poll loop */
 286         if (force_poll ||
 287             !test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ||
 288             acpi_ec_wait(ec))
 289                 ret = ec_poll(ec);
 290         pr_debug(PREFIX "transaction end\n");
 291         spin_lock_irqsave(&ec->curr_lock, tmp);
 292         ec->curr = NULL;
 293         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 294         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 295                 /* check if we received SCI during transaction */
 296                 ec_check_sci(ec, acpi_ec_read_status(ec));
 297                 /* it is safe to enable GPE outside of transaction */
 298                 acpi_enable_gpe(NULL, ec->gpe);
 299         } else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 300                    t->irq_count > ACPI_EC_STORM_THRESHOLD) {
 301                 pr_info(PREFIX "GPE storm detected, "
 302                         "transactions will use polling mode\n");
 303                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 304         }
 305         return ret;
 306 }
 307
 308 static int ec_check_ibf0(struct acpi_ec *ec)
 309 {
 310         u8 status = acpi_ec_read_status(ec);
 311         return (status & ACPI_EC_FLAG_IBF) == 0;
 312 }
 313
 314 static int ec_wait_ibf0(struct acpi_ec *ec)
 315 {
 316         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 317         /* interrupt wait manually if GPE mode is not active */
 318         unsigned long timeout = test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ?
 319                 msecs_to_jiffies(ACPI_EC_DELAY) : msecs_to_jiffies(1);
 320         while (time_before(jiffies, delay))
 321                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec), timeout))
 322                         return 0;
 323         return -ETIME;
 324 }
 325
 326 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t,
 327                                int force_poll)
 328 {
 329         int status;
 330         u32 glk;
 331         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 332                 return -EINVAL;
 333         if (t->rdata)
 334                 memset(t->rdata, 0, t->rlen);
 335         mutex_lock(&ec->lock);
 336         if (ec->global_lock) {
 337                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 338                 if (ACPI_FAILURE(status)) {
 339                         status = -ENODEV;
 340                         goto unlock;
 341                 }
 342         }
 343         if (ec_wait_ibf0(ec)) {
 344                 pr_err(PREFIX "input buffer is not empty, "
 345                                 "aborting transaction\n");
 346                 status = -ETIME;
 347                 goto end;
 348         }
 349         status = acpi_ec_transaction_unlocked(ec, t, force_poll);
 350 end:
 351         if (ec->global_lock)
 352                 acpi_release_global_lock(glk);
 353 unlock:
 354         mutex_unlock(&ec->lock);
 355         return status;
 356 }
 357
 358 /*
 359  * Note: samsung nv5000 doesn't work with ec burst mode.
 360  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 361  */
 362 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 363 {
 364         u8 d;
 365         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 366                                 .wdata = NULL, .rdata = &d,
 367                                 .wlen = 0, .rlen = 1};
 368
 369         return acpi_ec_transaction(ec, &t, 0);
 370 }
 371
 372 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 373 {
 374         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 375                                 .wdata = NULL, .rdata = NULL,
 376                                 .wlen = 0, .rlen = 0};
 377
 378         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 379                                 acpi_ec_transaction(ec, &t, 0) : 0;
 380 }
 381
 382 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 383 {
 384         int result;
 385         u8 d;
 386         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 387                                 .wdata = &address, .rdata = &d,
 388                                 .wlen = 1, .rlen = 1};
 389
 390         result = acpi_ec_transaction(ec, &t, 0);
 391         *data = d;
 392         return result;
 393 }
 394
 395 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 396 {
 397         u8 wdata[2] = { address, data };
 398         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 399                                 .wdata = wdata, .rdata = NULL,
 400                                 .wlen = 2, .rlen = 0};
 401
 402         return acpi_ec_transaction(ec, &t, 0);
 403 }
 404
 405 /*
 406  * Externally callable EC access functions. For now, assume 1 EC only
 407  */
 408 int ec_burst_enable(void)
 409 {
 410         if (!first_ec)
 411                 return -ENODEV;
 412         return acpi_ec_burst_enable(first_ec);
 413 }
 414
 415 EXPORT_SYMBOL(ec_burst_enable);
 416
 417 int ec_burst_disable(void)
 418 {
 419         if (!first_ec)
 420                 return -ENODEV;
 421         return acpi_ec_burst_disable(first_ec);
 422 }
 423
 424 EXPORT_SYMBOL(ec_burst_disable);
 425
 426 int ec_read(u8 addr, u8 * val)
 427 {
 428         int err;
 429         u8 temp_data;
 430
 431         if (!first_ec)
 432                 return -ENODEV;
 433
 434         err = acpi_ec_read(first_ec, addr, &temp_data);
 435
 436         if (!err) {
 437                 *val = temp_data;
 438                 return 0;
 439         } else
 440                 return err;
 441 }
 442
 443 EXPORT_SYMBOL(ec_read);
 444
 445 int ec_write(u8 addr, u8 val)
 446 {
 447         int err;
 448
 449         if (!first_ec)
 450                 return -ENODEV;
 451
 452         err = acpi_ec_write(first_ec, addr, val);
 453
 454         return err;
 455 }
 456
 457 EXPORT_SYMBOL(ec_write);
 458
 459 int ec_transaction(u8 command,
 460                    const u8 * wdata, unsigned wdata_len,
 461                    u8 * rdata, unsigned rdata_len,
 462                    int force_poll)
 463 {
 464         struct transaction t = {.command = command,
 465                                 .wdata = wdata, .rdata = rdata,
 466                                 .wlen = wdata_len, .rlen = rdata_len};
 467         if (!first_ec)
 468                 return -ENODEV;
 469
 470         return acpi_ec_transaction(first_ec, &t, force_poll);
 471 }
 472
 473 EXPORT_SYMBOL(ec_transaction);
 474
 475 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 476 {
 477         int result;
 478         u8 d;
 479         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 480                                 .wdata = NULL, .rdata = &d,
 481                                 .wlen = 0, .rlen = 1};
 482         if (!ec || !data)
 483                 return -EINVAL;
 484
 485         /*
 486          * Query the EC to find out which _Qxx method we need to evaluate.
 487          * Note that successful completion of the query causes the ACPI_EC_SCI
 488          * bit to be cleared (and thus clearing the interrupt source).
 489          */
 490
 491         result = acpi_ec_transaction(ec, &t, 0);
 492         if (result)
 493                 return result;
 494
 495         if (!d)
 496                 return -ENODATA;
 497
 498         *data = d;
 499         return 0;
 500 }
 501
 502 /* --------------------------------------------------------------------------
 503                                 Event Management
 504    -------------------------------------------------------------------------- */
 505 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 506                               acpi_handle handle, acpi_ec_query_func func,
 507                               void *data)
 508 {
 509         struct acpi_ec_query_handler *handler =
 510             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 511         if (!handler)
 512                 return -ENOMEM;
 513
 514         handler->query_bit = query_bit;
 515         handler->handle = handle;
 516         handler->func = func;
 517         handler->data = data;
 518         mutex_lock(&ec->lock);
 519         list_add(&handler->node, &ec->list);
 520         mutex_unlock(&ec->lock);
 521         return 0;
 522 }
 523
 524 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 525
 526 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 527 {
 528         struct acpi_ec_query_handler *handler, *tmp;
 529         mutex_lock(&ec->lock);
 530         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 531                 if (query_bit == handler->query_bit) {
 532                         list_del(&handler->node);
 533                         kfree(handler);
 534                 }
 535         }
 536         mutex_unlock(&ec->lock);
 537 }
 538
 539 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 540
 541 static void acpi_ec_gpe_query(void *ec_cxt)
 542 {
 543         struct acpi_ec *ec = ec_cxt;
 544         u8 value = 0;
 545         struct acpi_ec_query_handler *handler, copy;
 546
 547         if (!ec || acpi_ec_query(ec, &value))
 548                 return;
 549         mutex_lock(&ec->lock);
 550         list_for_each_entry(handler, &ec->list, node) {
 551                 if (value == handler->query_bit) {
 552                         /* have custom handler for this bit */
 553                         memcpy(&copy, handler, sizeof(copy));
 554                         mutex_unlock(&ec->lock);
 555                         if (copy.func) {
 556                                 copy.func(copy.data);
 557                         } else if (copy.handle) {
 558                                 acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
 559                         }
 560                         return;
 561                 }
 562         }
 563         mutex_unlock(&ec->lock);
 564 }
 565
 566 static u32 acpi_ec_gpe_handler(void *data)
 567 {
 568         struct acpi_ec *ec = data;
 569         u8 status;
 570
 571         pr_debug(PREFIX "~~~> interrupt\n");
 572         status = acpi_ec_read_status(ec);
 573
 574         if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) {
 575                 gpe_transaction(ec, status);
 576                 if (ec_transaction_done(ec) &&
 577                     (status & ACPI_EC_FLAG_IBF) == 0)
 578                         wake_up(&ec->wait);
 579         }
 580
 581         ec_check_sci(ec, status);
 582         if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 583             !test_bit(EC_FLAGS_NO_GPE, &ec->flags)) {
 584                 /* this is non-query, must be confirmation */
 585                 if (!test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 586                         if (printk_ratelimit())
 587                                 pr_info(PREFIX "non-query interrupt received,"
 588                                         " switching to interrupt mode\n");
 589                 } else {
 590                         /* hush, STORM switches the mode every transaction */
 591                         pr_debug(PREFIX "non-query interrupt received,"
 592                                 " switching to interrupt mode\n");
 593                 }
 594                 set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 595         }
 596         return ACPI_INTERRUPT_HANDLED;
 597 }
 598
 599 /* --------------------------------------------------------------------------
 600                              Address Space Management
 601    -------------------------------------------------------------------------- */
 602
 603 static acpi_status
 604 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 605                       u32 bits, acpi_integer *value,
 606                       void *handler_context, void *region_context)
 607 {
 608         struct acpi_ec *ec = handler_context;
 609         int result = 0, i;
 610         u8 temp = 0;
 611
 612         if ((address > 0xFF) || !value || !handler_context)
 613                 return AE_BAD_PARAMETER;
 614
 615         if (function != ACPI_READ && function != ACPI_WRITE)
 616                 return AE_BAD_PARAMETER;
 617
 618         if (bits != 8 && acpi_strict)
 619                 return AE_BAD_PARAMETER;
 620
 621         acpi_ec_burst_enable(ec);
 622
 623         if (function == ACPI_READ) {
 624                 result = acpi_ec_read(ec, address, &temp);
 625                 *value = temp;
 626         } else {
 627                 temp = 0xff & (*value);
 628                 result = acpi_ec_write(ec, address, temp);
 629         }
 630
 631         for (i = 8; unlikely(bits - i > 0); i += 8) {
 632                 ++address;
 633                 if (function == ACPI_READ) {
 634                         result = acpi_ec_read(ec, address, &temp);
 635                         (*value) |= ((acpi_integer)temp) << i;
 636                 } else {
 637                         temp = 0xff & ((*value) >> i);
 638                         result = acpi_ec_write(ec, address, temp);
 639                 }
 640         }
 641
 642         acpi_ec_burst_disable(ec);
 643
 644         switch (result) {
 645         case -EINVAL:
 646                 return AE_BAD_PARAMETER;
 647                 break;
 648         case -ENODEV:
 649                 return AE_NOT_FOUND;
 650                 break;
 651         case -ETIME:
 652                 return AE_TIME;
 653                 break;
 654         default:
 655                 return AE_OK;
 656         }
 657 }
 658
 659 /* --------------------------------------------------------------------------
 660                               FS Interface (/proc)
 661    -------------------------------------------------------------------------- */
 662
 663 static struct proc_dir_entry *acpi_ec_dir;
 664
 665 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 666 {
 667         struct acpi_ec *ec = seq->private;
 668
 669         if (!ec)
 670                 goto end;
 671
 672         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 673         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 674                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 675         seq_printf(seq, "use global lock:\t%s\n",
 676                    ec->global_lock ? "yes" : "no");
 677       end:
 678         return 0;
 679 }
 680
 681 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 682 {
 683         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 684 }
 685
 686 static const struct file_operations acpi_ec_info_ops = {
 687         .open = acpi_ec_info_open_fs,
 688         .read = seq_read,
 689         .llseek = seq_lseek,
 690         .release = single_release,
 691         .owner = THIS_MODULE,
 692 };
 693
 694 static int acpi_ec_add_fs(struct acpi_device *device)
 695 {
 696         struct proc_dir_entry *entry = NULL;
 697
 698         if (!acpi_device_dir(device)) {
 699                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 700                                                      acpi_ec_dir);
 701                 if (!acpi_device_dir(device))
 702                         return -ENODEV;
 703         }
 704
 705         entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
 706                                  acpi_device_dir(device),
 707                                  &acpi_ec_info_ops, acpi_driver_data(device));
 708         if (!entry)
 709                 return -ENODEV;
 710         return 0;
 711 }
 712
 713 static int acpi_ec_remove_fs(struct acpi_device *device)
 714 {
 715
 716         if (acpi_device_dir(device)) {
 717                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 718                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 719                 acpi_device_dir(device) = NULL;
 720         }
 721
 722         return 0;
 723 }
 724
 725 /* --------------------------------------------------------------------------
 726                                Driver Interface
 727    -------------------------------------------------------------------------- */
 728 static acpi_status
 729 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 730
 731 static struct acpi_ec *make_acpi_ec(void)
 732 {
 733         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 734         if (!ec)
 735                 return NULL;
 736         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 737         mutex_init(&ec->lock);
 738         init_waitqueue_head(&ec->wait);
 739         INIT_LIST_HEAD(&ec->list);
 740         spin_lock_init(&ec->curr_lock);
 741         return ec;
 742 }
 743
 744 static acpi_status
 745 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 746                                void *context, void **return_value)
 747 {
 748         char node_name[5];
 749         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 750         struct acpi_ec *ec = context;
 751         int value = 0;
 752         acpi_status status;
 753
 754         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 755
 756         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 757                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 758         }
 759         return AE_OK;
 760 }
 761
 762 static acpi_status
 763 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 764 {
 765         acpi_status status;
 766         unsigned long long tmp = 0;
 767
 768         struct acpi_ec *ec = context;
 769
 770         /* clear addr values, ec_parse_io_ports depend on it */
 771         ec->command_addr = ec->data_addr = 0;
 772
 773         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 774                                      ec_parse_io_ports, ec);
 775         if (ACPI_FAILURE(status))
 776                 return status;
 777
 778         /* Get GPE bit assignment (EC events). */
 779         /* TODO: Add support for _GPE returning a package */
 780         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 781         if (ACPI_FAILURE(status))
 782                 return status;
 783         ec->gpe = tmp;
 784         /* Use the global lock for all EC transactions? */
 785         tmp = 0;
 786         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 787         ec->global_lock = tmp;
 788         ec->handle = handle;
 789         return AE_CTRL_TERMINATE;
 790 }
 791
 792 static void ec_remove_handlers(struct acpi_ec *ec)
 793 {
 794         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 795                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 796                 pr_err(PREFIX "failed to remove space handler\n");
 797         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 798                                 &acpi_ec_gpe_handler)))
 799                 pr_err(PREFIX "failed to remove gpe handler\n");
 800         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 801 }
 802
 803 static int acpi_ec_add(struct acpi_device *device)
 804 {
 805         struct acpi_ec *ec = NULL;
 806
 807         if (!device)
 808                 return -EINVAL;
 809         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 810         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 811
 812         /* Check for boot EC */
 813         if (boot_ec &&
 814             (boot_ec->handle == device->handle ||
 815              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 816                 ec = boot_ec;
 817                 boot_ec = NULL;
 818         } else {
 819                 ec = make_acpi_ec();
 820                 if (!ec)
 821                         return -ENOMEM;
 822         }
 823         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 824                 AE_CTRL_TERMINATE) {
 825                         kfree(ec);
 826                         return -EINVAL;
 827         }
 828
 829         ec->handle = device->handle;
 830
 831         /* Find and register all query methods */
 832         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 833                             acpi_ec_register_query_methods, ec, NULL);
 834
 835         if (!first_ec)
 836                 first_ec = ec;
 837         device->driver_data = ec;
 838         acpi_ec_add_fs(device);
 839         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 840                           ec->gpe, ec->command_addr, ec->data_addr);
 841         pr_info(PREFIX "driver started in %s mode\n",
 842                 (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
 843         return 0;
 844 }
 845
 846 static int acpi_ec_remove(struct acpi_device *device, int type)
 847 {
 848         struct acpi_ec *ec;
 849         struct acpi_ec_query_handler *handler, *tmp;
 850
 851         if (!device)
 852                 return -EINVAL;
 853
 854         ec = acpi_driver_data(device);
 855         mutex_lock(&ec->lock);
 856         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 857                 list_del(&handler->node);
 858                 kfree(handler);
 859         }
 860         mutex_unlock(&ec->lock);
 861         acpi_ec_remove_fs(device);
 862         device->driver_data = NULL;
 863         if (ec == first_ec)
 864                 first_ec = NULL;
 865         kfree(ec);
 866         return 0;
 867 }
 868
 869 static acpi_status
 870 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 871 {
 872         struct acpi_ec *ec = context;
 873
 874         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 875                 return AE_OK;
 876
 877         /*
 878          * The first address region returned is the data port, and
 879          * the second address region returned is the status/command
 880          * port.
 881          */
 882         if (ec->data_addr == 0)
 883                 ec->data_addr = resource->data.io.minimum;
 884         else if (ec->command_addr == 0)
 885                 ec->command_addr = resource->data.io.minimum;
 886         else
 887                 return AE_CTRL_TERMINATE;
 888
 889         return AE_OK;
 890 }
 891
 892 static int ec_install_handlers(struct acpi_ec *ec)
 893 {
 894         acpi_status status;
 895         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 896                 return 0;
 897         status = acpi_install_gpe_handler(NULL, ec->gpe,
 898                                   ACPI_GPE_EDGE_TRIGGERED,
 899                                   &acpi_ec_gpe_handler, ec);
 900         if (ACPI_FAILURE(status))
 901                 return -ENODEV;
 902         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 903         acpi_enable_gpe(NULL, ec->gpe);
 904         status = acpi_install_address_space_handler(ec->handle,
 905                                                     ACPI_ADR_SPACE_EC,
 906                                                     &acpi_ec_space_handler,
 907                                                     NULL, ec);
 908         if (ACPI_FAILURE(status)) {
 909                 if (status == AE_NOT_FOUND) {
 910                         /*
 911                          * Maybe OS fails in evaluating the _REG object.
 912                          * The AE_NOT_FOUND error will be ignored and OS
 913                          * continue to initialize EC.
 914                          */
 915                         printk(KERN_ERR "Fail in evaluating the _REG object"
 916                                 " of EC device. Broken bios is suspected.\n");
 917                 } else {
 918                         acpi_remove_gpe_handler(NULL, ec->gpe,
 919                                 &acpi_ec_gpe_handler);
 920                         return -ENODEV;
 921                 }
 922         }
 923
 924         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 925         return 0;
 926 }
 927
 928 static int acpi_ec_start(struct acpi_device *device)
 929 {
 930         struct acpi_ec *ec;
 931         int ret = 0;
 932
 933         if (!device)
 934                 return -EINVAL;
 935
 936         ec = acpi_driver_data(device);
 937
 938         if (!ec)
 939                 return -EINVAL;
 940
 941         ret = ec_install_handlers(ec);
 942
 943         /* EC is fully operational, allow queries */
 944         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 945         return ret;
 946 }
 947
 948 static int acpi_ec_stop(struct acpi_device *device, int type)
 949 {
 950         struct acpi_ec *ec;
 951         if (!device)
 952                 return -EINVAL;
 953         ec = acpi_driver_data(device);
 954         if (!ec)
 955                 return -EINVAL;
 956         ec_remove_handlers(ec);
 957
 958         return 0;
 959 }
 960
 961 int __init acpi_boot_ec_enable(void)
 962 {
 963         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 964                 return 0;
 965         if (!ec_install_handlers(boot_ec)) {
 966                 first_ec = boot_ec;
 967                 return 0;
 968         }
 969         return -EFAULT;
 970 }
 971
 972 static const struct acpi_device_id ec_device_ids[] = {
 973         {"PNP0C09", 0},
 974         {"", 0},
 975 };
 976
 977 int __init acpi_ec_ecdt_probe(void)
 978 {
 979         acpi_status status;
 980         struct acpi_ec *saved_ec = NULL;
 981         struct acpi_table_ecdt *ecdt_ptr;
 982
 983         boot_ec = make_acpi_ec();
 984         if (!boot_ec)
 985                 return -ENOMEM;
 986         /*
 987          * Generate a boot ec context
 988          */
 989         if (dmi_name_in_vendors("Micro-Star") ||
 990             dmi_name_in_vendors("Notebook")) {
 991                 pr_info(PREFIX "Enabling special treatment for EC from MSI.\n");
 992                 EC_FLAGS_MSI = 1;
 993         }
 994         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 995                                 (struct acpi_table_header **)&ecdt_ptr);
 996         if (ACPI_SUCCESS(status)) {
 997                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
 998                 boot_ec->command_addr = ecdt_ptr->control.address;
 999                 boot_ec->data_addr = ecdt_ptr->data.address;
1000                 boot_ec->gpe = ecdt_ptr->gpe;
1001                 boot_ec->handle = ACPI_ROOT_OBJECT;
1002                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1003                 /* Don't trust ECDT, which comes from ASUSTek */
1004                 if (!dmi_name_in_vendors("ASUS") && EC_FLAGS_MSI == 0)
1005                         goto install;
1006                 saved_ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1007                 if (!saved_ec)
1008                         return -ENOMEM;
1009                 memcpy(saved_ec, boot_ec, sizeof(struct acpi_ec));
1010         /* fall through */
1011         }
1012         /* This workaround is needed only on some broken machines,
1013          * which require early EC, but fail to provide ECDT */
1014         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1015         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1016                                         boot_ec, NULL);
1017         /* Check that acpi_get_devices actually find something */
1018         if (ACPI_FAILURE(status) || !boot_ec->handle)
1019                 goto error;
1020         if (saved_ec) {
1021                 /* try to find good ECDT from ASUSTek */
1022                 if (saved_ec->command_addr != boot_ec->command_addr ||
1023                     saved_ec->data_addr != boot_ec->data_addr ||
1024                     saved_ec->gpe != boot_ec->gpe ||
1025                     saved_ec->handle != boot_ec->handle)
1026                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1027                         "ECDT tables, which are very hard to workaround. "
1028                         "Trying to use DSDT EC info instead. Please send "
1029                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1030                 kfree(saved_ec);
1031                 saved_ec = NULL;
1032         } else {
1033                 /* We really need to limit this workaround, the only ASUS,
1034                 * which needs it, has fake EC._INI method, so use it as flag.
1035                 * Keep boot_ec struct as it will be needed soon.
1036                 */
1037                 acpi_handle dummy;
1038                 if (!dmi_name_in_vendors("ASUS") ||
1039                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1040                                                         &dummy)))
1041                         return -ENODEV;
1042         }
1043 install:
1044         if (!ec_install_handlers(boot_ec)) {
1045                 first_ec = boot_ec;
1046                 return 0;
1047         }
1048 error:
1049         kfree(boot_ec);
1050         boot_ec = NULL;
1051         return -ENODEV;
1052 }
1053
1054 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1055 {
1056         struct acpi_ec *ec = acpi_driver_data(device);
1057         /* Stop using GPE */
1058         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
1059         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
1060         acpi_disable_gpe(NULL, ec->gpe);
1061         return 0;
1062 }
1063
1064 static int acpi_ec_resume(struct acpi_device *device)
1065 {
1066         struct acpi_ec *ec = acpi_driver_data(device);
1067         /* Enable use of GPE back */
1068         clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
1069         set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
1070         acpi_enable_gpe(NULL, ec->gpe);
1071         return 0;
1072 }
1073
1074 static struct acpi_driver acpi_ec_driver = {
1075         .name = "ec",
1076         .class = ACPI_EC_CLASS,
1077         .ids = ec_device_ids,
1078         .ops = {
1079                 .add = acpi_ec_add,
1080                 .remove = acpi_ec_remove,
1081                 .start = acpi_ec_start,
1082                 .stop = acpi_ec_stop,
1083                 .suspend = acpi_ec_suspend,
1084                 .resume = acpi_ec_resume,
1085                 },
1086 };
1087
1088 int __init acpi_ec_init(void)
1089 {
1090         int result = 0;
1091
1092         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1093         if (!acpi_ec_dir)
1094                 return -ENODEV;
1095
1096         /* Now register the driver for the EC */
1097         result = acpi_bus_register_driver(&acpi_ec_driver);
1098         if (result < 0) {
1099                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1100                 return -ENODEV;
1101         }
1102
1103         return result;
1104 }
1105
1106 /* EC driver currently not unloadable */
1107 #if 0
1108 static void __exit acpi_ec_exit(void)
1109 {
1110
1111         acpi_bus_unregister_driver(&acpi_ec_driver);
1112
1113         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1114
1115         return;
1116 }
1117 #endif  /* 0 */