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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 #include <acpi/actypes.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_UDELAY          100     /* Wait 100us before polling EC again */
  72
  73 #define ACPI_EC_STORM_THRESHOLD 20      /* 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 wlen;
 104         u8 rlen;
 105 };
 106
 107 static struct acpi_ec {
 108         acpi_handle handle;
 109         unsigned long gpe;
 110         unsigned long command_addr;
 111         unsigned long data_addr;
 112         unsigned long global_lock;
 113         unsigned long flags;
 114         struct mutex lock;
 115         wait_queue_head_t wait;
 116         struct list_head list;
 117         struct transaction *curr;
 118         spinlock_t curr_lock;
 119 } *boot_ec, *first_ec;
 120
 121 /*
 122  * Some Asus system have exchanged ECDT data/command IO addresses.
 123  */
 124 static int print_ecdt_error(const struct dmi_system_id *id)
 125 {
 126         printk(KERN_NOTICE PREFIX "%s detected - "
 127                 "ECDT has exchanged control/data I/O address\n",
 128                 id->ident);
 129         return 0;
 130 }
 131
 132 static struct dmi_system_id __cpuinitdata ec_dmi_table[] = {
 133         {
 134         print_ecdt_error, "Asus L4R", {
 135         DMI_MATCH(DMI_BIOS_VERSION, "1008.006"),
 136         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),
 137         DMI_MATCH(DMI_BOARD_NAME, "L4R") }, NULL},
 138         {
 139         print_ecdt_error, "Asus M6R", {
 140         DMI_MATCH(DMI_BIOS_VERSION, "0207"),
 141         DMI_MATCH(DMI_PRODUCT_NAME, "M6R"),
 142         DMI_MATCH(DMI_BOARD_NAME, "M6R") }, NULL},
 143         {},
 144 };
 145
 146 /* --------------------------------------------------------------------------
 147                              Transaction Management
 148    -------------------------------------------------------------------------- */
 149
 150 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 151 {
 152         u8 x = inb(ec->command_addr);
 153         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
 154         return x;
 155 }
 156
 157 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 158 {
 159         u8 x = inb(ec->data_addr);
 160         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
 161         return x;
 162 }
 163
 164 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 165 {
 166         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
 167         outb(command, ec->command_addr);
 168 }
 169
 170 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 171 {
 172         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
 173         outb(data, ec->data_addr);
 174 }
 175
 176 static int ec_transaction_done(struct acpi_ec *ec)
 177 {
 178         unsigned long flags;
 179         int ret = 0;
 180         spin_lock_irqsave(&ec->curr_lock, flags);
 181         if (!ec->curr || (!ec->curr->wlen && !ec->curr->rlen))
 182                 ret = 1;
 183         spin_unlock_irqrestore(&ec->curr_lock, flags);
 184         return ret;
 185 }
 186
 187 static void gpe_transaction(struct acpi_ec *ec, u8 status)
 188 {
 189         unsigned long flags;
 190         spin_lock_irqsave(&ec->curr_lock, flags);
 191         if (!ec->curr)
 192                 goto unlock;
 193         if (ec->curr->wlen > 0) {
 194                 if ((status & ACPI_EC_FLAG_IBF) == 0) {
 195                         acpi_ec_write_data(ec, *(ec->curr->wdata++));
 196                         --ec->curr->wlen;
 197                 } else
 198                         /* false interrupt, state didn't change */
 199                         ++ec->curr->irq_count;
 200
 201         } else if (ec->curr->rlen > 0) {
 202                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
 203                         *(ec->curr->rdata++) = acpi_ec_read_data(ec);
 204                         --ec->curr->rlen;
 205                 } else
 206                         /* false interrupt, state didn't change */
 207                         ++ec->curr->irq_count;
 208         }
 209 unlock:
 210         spin_unlock_irqrestore(&ec->curr_lock, flags);
 211 }
 212
 213 static int acpi_ec_wait(struct acpi_ec *ec)
 214 {
 215         if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
 216                                msecs_to_jiffies(ACPI_EC_DELAY)))
 217                 return 0;
 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         msleep(1);
 243         while (time_before(jiffies, delay)) {
 244                 gpe_transaction(ec, acpi_ec_read_status(ec));
 245                 msleep(1);
 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, ACPI_NOT_ISR);
 263         }
 264         /* start transaction */
 265         spin_lock_irqsave(&ec->curr_lock, tmp);
 266         /* following two actions should be kept atomic */
 267         t->irq_count = 0;
 268         ec->curr = t;
 269         acpi_ec_write_cmd(ec, ec->curr->command);
 270         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 271                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 272         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 273         /* if we selected poll mode or failed in GPE-mode do a poll loop */
 274         if (force_poll ||
 275             !test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ||
 276             acpi_ec_wait(ec))
 277                 ret = ec_poll(ec);
 278         pr_debug(PREFIX "transaction end\n");
 279         spin_lock_irqsave(&ec->curr_lock, tmp);
 280         ec->curr = NULL;
 281         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 282         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 283                 /* check if we received SCI during transaction */
 284                 ec_check_sci(ec, acpi_ec_read_status(ec));
 285                 /* it is safe to enable GPE outside of transaction */
 286                 acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 287         } else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 288                    t->irq_count > ACPI_EC_STORM_THRESHOLD) {
 289                 pr_debug(PREFIX "GPE storm detected\n");
 290                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 291         }
 292         return ret;
 293 }
 294
 295 static int ec_check_ibf0(struct acpi_ec *ec)
 296 {
 297         u8 status = acpi_ec_read_status(ec);
 298         return (status & ACPI_EC_FLAG_IBF) == 0;
 299 }
 300
 301 static int ec_wait_ibf0(struct acpi_ec *ec)
 302 {
 303         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 304         /* interrupt wait manually if GPE mode is not active */
 305         unsigned long timeout = test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ?
 306                 msecs_to_jiffies(ACPI_EC_DELAY) : msecs_to_jiffies(1);
 307         while (time_before(jiffies, delay))
 308                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec), timeout))
 309                         return 0;
 310         return -ETIME;
 311 }
 312
 313 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t,
 314                                int force_poll)
 315 {
 316         int status;
 317         u32 glk;
 318         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 319                 return -EINVAL;
 320         if (t->rdata)
 321                 memset(t->rdata, 0, t->rlen);
 322         mutex_lock(&ec->lock);
 323         if (ec->global_lock) {
 324                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 325                 if (ACPI_FAILURE(status)) {
 326                         status = -ENODEV;
 327                         goto unlock;
 328                 }
 329         }
 330         if (ec_wait_ibf0(ec)) {
 331                 pr_err(PREFIX "input buffer is not empty, "
 332                                 "aborting transaction\n");
 333                 status = -ETIME;
 334                 goto end;
 335         }
 336         status = acpi_ec_transaction_unlocked(ec, t, force_poll);
 337 end:
 338         if (ec->global_lock)
 339                 acpi_release_global_lock(glk);
 340 unlock:
 341         mutex_unlock(&ec->lock);
 342         return status;
 343 }
 344
 345 /*
 346  * Note: samsung nv5000 doesn't work with ec burst mode.
 347  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 348  */
 349 int acpi_ec_burst_enable(struct acpi_ec *ec)
 350 {
 351         u8 d;
 352         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 353                                 .wdata = NULL, .rdata = &d,
 354                                 .wlen = 0, .rlen = 1};
 355
 356         return acpi_ec_transaction(ec, &t, 0);
 357 }
 358
 359 int acpi_ec_burst_disable(struct acpi_ec *ec)
 360 {
 361         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 362                                 .wdata = NULL, .rdata = NULL,
 363                                 .wlen = 0, .rlen = 0};
 364
 365         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 366                                 acpi_ec_transaction(ec, &t, 0) : 0;
 367 }
 368
 369 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 370 {
 371         int result;
 372         u8 d;
 373         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 374                                 .wdata = &address, .rdata = &d,
 375                                 .wlen = 1, .rlen = 1};
 376
 377         result = acpi_ec_transaction(ec, &t, 0);
 378         *data = d;
 379         return result;
 380 }
 381
 382 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 383 {
 384         u8 wdata[2] = { address, data };
 385         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 386                                 .wdata = wdata, .rdata = NULL,
 387                                 .wlen = 2, .rlen = 0};
 388
 389         return acpi_ec_transaction(ec, &t, 0);
 390 }
 391
 392 /*
 393  * Externally callable EC access functions. For now, assume 1 EC only
 394  */
 395 int ec_burst_enable(void)
 396 {
 397         if (!first_ec)
 398                 return -ENODEV;
 399         return acpi_ec_burst_enable(first_ec);
 400 }
 401
 402 EXPORT_SYMBOL(ec_burst_enable);
 403
 404 int ec_burst_disable(void)
 405 {
 406         if (!first_ec)
 407                 return -ENODEV;
 408         return acpi_ec_burst_disable(first_ec);
 409 }
 410
 411 EXPORT_SYMBOL(ec_burst_disable);
 412
 413 int ec_read(u8 addr, u8 * val)
 414 {
 415         int err;
 416         u8 temp_data;
 417
 418         if (!first_ec)
 419                 return -ENODEV;
 420
 421         err = acpi_ec_read(first_ec, addr, &temp_data);
 422
 423         if (!err) {
 424                 *val = temp_data;
 425                 return 0;
 426         } else
 427                 return err;
 428 }
 429
 430 EXPORT_SYMBOL(ec_read);
 431
 432 int ec_write(u8 addr, u8 val)
 433 {
 434         int err;
 435
 436         if (!first_ec)
 437                 return -ENODEV;
 438
 439         err = acpi_ec_write(first_ec, addr, val);
 440
 441         return err;
 442 }
 443
 444 EXPORT_SYMBOL(ec_write);
 445
 446 int ec_transaction(u8 command,
 447                    const u8 * wdata, unsigned wdata_len,
 448                    u8 * rdata, unsigned rdata_len,
 449                    int force_poll)
 450 {
 451         struct transaction t = {.command = command,
 452                                 .wdata = wdata, .rdata = rdata,
 453                                 .wlen = wdata_len, .rlen = rdata_len};
 454         if (!first_ec)
 455                 return -ENODEV;
 456
 457         return acpi_ec_transaction(first_ec, &t, force_poll);
 458 }
 459
 460 EXPORT_SYMBOL(ec_transaction);
 461
 462 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 463 {
 464         int result;
 465         u8 d;
 466         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 467                                 .wdata = NULL, .rdata = &d,
 468                                 .wlen = 0, .rlen = 1};
 469         if (!ec || !data)
 470                 return -EINVAL;
 471
 472         /*
 473          * Query the EC to find out which _Qxx method we need to evaluate.
 474          * Note that successful completion of the query causes the ACPI_EC_SCI
 475          * bit to be cleared (and thus clearing the interrupt source).
 476          */
 477
 478         result = acpi_ec_transaction(ec, &t, 0);
 479         if (result)
 480                 return result;
 481
 482         if (!d)
 483                 return -ENODATA;
 484
 485         *data = d;
 486         return 0;
 487 }
 488
 489 /* --------------------------------------------------------------------------
 490                                 Event Management
 491    -------------------------------------------------------------------------- */
 492 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 493                               acpi_handle handle, acpi_ec_query_func func,
 494                               void *data)
 495 {
 496         struct acpi_ec_query_handler *handler =
 497             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 498         if (!handler)
 499                 return -ENOMEM;
 500
 501         handler->query_bit = query_bit;
 502         handler->handle = handle;
 503         handler->func = func;
 504         handler->data = data;
 505         mutex_lock(&ec->lock);
 506         list_add(&handler->node, &ec->list);
 507         mutex_unlock(&ec->lock);
 508         return 0;
 509 }
 510
 511 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 512
 513 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 514 {
 515         struct acpi_ec_query_handler *handler, *tmp;
 516         mutex_lock(&ec->lock);
 517         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 518                 if (query_bit == handler->query_bit) {
 519                         list_del(&handler->node);
 520                         kfree(handler);
 521                 }
 522         }
 523         mutex_unlock(&ec->lock);
 524 }
 525
 526 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 527
 528 static void acpi_ec_gpe_query(void *ec_cxt)
 529 {
 530         struct acpi_ec *ec = ec_cxt;
 531         u8 value = 0;
 532         struct acpi_ec_query_handler *handler, copy;
 533
 534         if (!ec || acpi_ec_query(ec, &value))
 535                 return;
 536         mutex_lock(&ec->lock);
 537         list_for_each_entry(handler, &ec->list, node) {
 538                 if (value == handler->query_bit) {
 539                         /* have custom handler for this bit */
 540                         memcpy(&copy, handler, sizeof(copy));
 541                         mutex_unlock(&ec->lock);
 542                         if (copy.func) {
 543                                 copy.func(copy.data);
 544                         } else if (copy.handle) {
 545                                 acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
 546                         }
 547                         return;
 548                 }
 549         }
 550         mutex_unlock(&ec->lock);
 551 }
 552
 553 static u32 acpi_ec_gpe_handler(void *data)
 554 {
 555         struct acpi_ec *ec = data;
 556         u8 status;
 557
 558         pr_debug(PREFIX "~~~> interrupt\n");
 559         status = acpi_ec_read_status(ec);
 560
 561         gpe_transaction(ec, status);
 562         if (ec_transaction_done(ec) && (status & ACPI_EC_FLAG_IBF) == 0)
 563                 wake_up(&ec->wait);
 564
 565         ec_check_sci(ec, status);
 566         if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 567             !test_bit(EC_FLAGS_NO_GPE, &ec->flags)) {
 568                 /* this is non-query, must be confirmation */
 569                 if (printk_ratelimit())
 570                         pr_info(PREFIX "non-query interrupt received,"
 571                                 " switching to interrupt mode\n");
 572                 set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 573         }
 574         return ACPI_INTERRUPT_HANDLED;
 575 }
 576
 577 /* --------------------------------------------------------------------------
 578                              Address Space Management
 579    -------------------------------------------------------------------------- */
 580
 581 static acpi_status
 582 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 583                       u32 bits, acpi_integer *value,
 584                       void *handler_context, void *region_context)
 585 {
 586         struct acpi_ec *ec = handler_context;
 587         int result = 0, i;
 588         u8 temp = 0;
 589
 590         if ((address > 0xFF) || !value || !handler_context)
 591                 return AE_BAD_PARAMETER;
 592
 593         if (function != ACPI_READ && function != ACPI_WRITE)
 594                 return AE_BAD_PARAMETER;
 595
 596         if (bits != 8 && acpi_strict)
 597                 return AE_BAD_PARAMETER;
 598
 599         acpi_ec_burst_enable(ec);
 600
 601         if (function == ACPI_READ) {
 602                 result = acpi_ec_read(ec, address, &temp);
 603                 *value = temp;
 604         } else {
 605                 temp = 0xff & (*value);
 606                 result = acpi_ec_write(ec, address, temp);
 607         }
 608
 609         for (i = 8; unlikely(bits - i > 0); i += 8) {
 610                 ++address;
 611                 if (function == ACPI_READ) {
 612                         result = acpi_ec_read(ec, address, &temp);
 613                         (*value) |= ((acpi_integer)temp) << i;
 614                 } else {
 615                         temp = 0xff & ((*value) >> i);
 616                         result = acpi_ec_write(ec, address, temp);
 617                 }
 618         }
 619
 620         acpi_ec_burst_disable(ec);
 621
 622         switch (result) {
 623         case -EINVAL:
 624                 return AE_BAD_PARAMETER;
 625                 break;
 626         case -ENODEV:
 627                 return AE_NOT_FOUND;
 628                 break;
 629         case -ETIME:
 630                 return AE_TIME;
 631                 break;
 632         default:
 633                 return AE_OK;
 634         }
 635 }
 636
 637 /* --------------------------------------------------------------------------
 638                               FS Interface (/proc)
 639    -------------------------------------------------------------------------- */
 640
 641 static struct proc_dir_entry *acpi_ec_dir;
 642
 643 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 644 {
 645         struct acpi_ec *ec = seq->private;
 646
 647         if (!ec)
 648                 goto end;
 649
 650         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 651         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 652                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 653         seq_printf(seq, "use global lock:\t%s\n",
 654                    ec->global_lock ? "yes" : "no");
 655       end:
 656         return 0;
 657 }
 658
 659 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 660 {
 661         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 662 }
 663
 664 static struct file_operations acpi_ec_info_ops = {
 665         .open = acpi_ec_info_open_fs,
 666         .read = seq_read,
 667         .llseek = seq_lseek,
 668         .release = single_release,
 669         .owner = THIS_MODULE,
 670 };
 671
 672 static int acpi_ec_add_fs(struct acpi_device *device)
 673 {
 674         struct proc_dir_entry *entry = NULL;
 675
 676         if (!acpi_device_dir(device)) {
 677                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 678                                                      acpi_ec_dir);
 679                 if (!acpi_device_dir(device))
 680                         return -ENODEV;
 681         }
 682
 683         entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
 684                                  acpi_device_dir(device),
 685                                  &acpi_ec_info_ops, acpi_driver_data(device));
 686         if (!entry)
 687                 return -ENODEV;
 688         return 0;
 689 }
 690
 691 static int acpi_ec_remove_fs(struct acpi_device *device)
 692 {
 693
 694         if (acpi_device_dir(device)) {
 695                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 696                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 697                 acpi_device_dir(device) = NULL;
 698         }
 699
 700         return 0;
 701 }
 702
 703 /* --------------------------------------------------------------------------
 704                                Driver Interface
 705    -------------------------------------------------------------------------- */
 706 static acpi_status
 707 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 708
 709 static struct acpi_ec *make_acpi_ec(void)
 710 {
 711         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 712         if (!ec)
 713                 return NULL;
 714         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 715         mutex_init(&ec->lock);
 716         init_waitqueue_head(&ec->wait);
 717         INIT_LIST_HEAD(&ec->list);
 718         spin_lock_init(&ec->curr_lock);
 719         return ec;
 720 }
 721
 722 static acpi_status
 723 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 724                                void *context, void **return_value)
 725 {
 726         struct acpi_namespace_node *node = handle;
 727         struct acpi_ec *ec = context;
 728         int value = 0;
 729         if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
 730                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 731         }
 732         return AE_OK;
 733 }
 734
 735 static acpi_status
 736 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 737 {
 738         acpi_status status;
 739
 740         struct acpi_ec *ec = context;
 741         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 742                                      ec_parse_io_ports, ec);
 743         if (ACPI_FAILURE(status))
 744                 return status;
 745
 746         /* Get GPE bit assignment (EC events). */
 747         /* TODO: Add support for _GPE returning a package */
 748         status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
 749         if (ACPI_FAILURE(status))
 750                 return status;
 751         /* Use the global lock for all EC transactions? */
 752         acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
 753         ec->handle = handle;
 754         return AE_CTRL_TERMINATE;
 755 }
 756
 757 static void ec_remove_handlers(struct acpi_ec *ec)
 758 {
 759         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 760                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 761                 pr_err(PREFIX "failed to remove space handler\n");
 762         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 763                                 &acpi_ec_gpe_handler)))
 764                 pr_err(PREFIX "failed to remove gpe handler\n");
 765         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 766 }
 767
 768 static int acpi_ec_add(struct acpi_device *device)
 769 {
 770         struct acpi_ec *ec = NULL;
 771
 772         if (!device)
 773                 return -EINVAL;
 774         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 775         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 776
 777         /* Check for boot EC */
 778         if (boot_ec &&
 779             (boot_ec->handle == device->handle ||
 780              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 781                 ec = boot_ec;
 782                 boot_ec = NULL;
 783         } else {
 784                 ec = make_acpi_ec();
 785                 if (!ec)
 786                         return -ENOMEM;
 787                 if (ec_parse_device(device->handle, 0, ec, NULL) !=
 788                     AE_CTRL_TERMINATE) {
 789                         kfree(ec);
 790                         return -EINVAL;
 791                 }
 792         }
 793
 794         ec->handle = device->handle;
 795
 796         /* Find and register all query methods */
 797         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 798                             acpi_ec_register_query_methods, ec, NULL);
 799
 800         if (!first_ec)
 801                 first_ec = ec;
 802         device->driver_data = ec;
 803         acpi_ec_add_fs(device);
 804         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 805                           ec->gpe, ec->command_addr, ec->data_addr);
 806         pr_info(PREFIX "driver started in %s mode\n",
 807                 (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
 808         return 0;
 809 }
 810
 811 static int acpi_ec_remove(struct acpi_device *device, int type)
 812 {
 813         struct acpi_ec *ec;
 814         struct acpi_ec_query_handler *handler, *tmp;
 815
 816         if (!device)
 817                 return -EINVAL;
 818
 819         ec = acpi_driver_data(device);
 820         mutex_lock(&ec->lock);
 821         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 822                 list_del(&handler->node);
 823                 kfree(handler);
 824         }
 825         mutex_unlock(&ec->lock);
 826         acpi_ec_remove_fs(device);
 827         device->driver_data = NULL;
 828         if (ec == first_ec)
 829                 first_ec = NULL;
 830         kfree(ec);
 831         return 0;
 832 }
 833
 834 static acpi_status
 835 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 836 {
 837         struct acpi_ec *ec = context;
 838
 839         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 840                 return AE_OK;
 841
 842         /*
 843          * The first address region returned is the data port, and
 844          * the second address region returned is the status/command
 845          * port.
 846          */
 847         if (ec->data_addr == 0)
 848                 ec->data_addr = resource->data.io.minimum;
 849         else if (ec->command_addr == 0)
 850                 ec->command_addr = resource->data.io.minimum;
 851         else
 852                 return AE_CTRL_TERMINATE;
 853
 854         return AE_OK;
 855 }
 856
 857 static int ec_install_handlers(struct acpi_ec *ec)
 858 {
 859         acpi_status status;
 860         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 861                 return 0;
 862         status = acpi_install_gpe_handler(NULL, ec->gpe,
 863                                   ACPI_GPE_EDGE_TRIGGERED,
 864                                   &acpi_ec_gpe_handler, ec);
 865         if (ACPI_FAILURE(status))
 866                 return -ENODEV;
 867         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 868         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 869         status = acpi_install_address_space_handler(ec->handle,
 870                                                     ACPI_ADR_SPACE_EC,
 871                                                     &acpi_ec_space_handler,
 872                                                     NULL, ec);
 873         if (ACPI_FAILURE(status)) {
 874                 if (status == AE_NOT_FOUND) {
 875                         /*
 876                          * Maybe OS fails in evaluating the _REG object.
 877                          * The AE_NOT_FOUND error will be ignored and OS
 878                          * continue to initialize EC.
 879                          */
 880                         printk(KERN_ERR "Fail in evaluating the _REG object"
 881                                 " of EC device. Broken bios is suspected.\n");
 882                 } else {
 883                         acpi_remove_gpe_handler(NULL, ec->gpe,
 884                                 &acpi_ec_gpe_handler);
 885                         return -ENODEV;
 886                 }
 887         }
 888
 889         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 890         return 0;
 891 }
 892
 893 static int acpi_ec_start(struct acpi_device *device)
 894 {
 895         struct acpi_ec *ec;
 896         int ret = 0;
 897
 898         if (!device)
 899                 return -EINVAL;
 900
 901         ec = acpi_driver_data(device);
 902
 903         if (!ec)
 904                 return -EINVAL;
 905
 906         ret = ec_install_handlers(ec);
 907
 908         /* EC is fully operational, allow queries */
 909         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 910         return ret;
 911 }
 912
 913 static int acpi_ec_stop(struct acpi_device *device, int type)
 914 {
 915         struct acpi_ec *ec;
 916         if (!device)
 917                 return -EINVAL;
 918         ec = acpi_driver_data(device);
 919         if (!ec)
 920                 return -EINVAL;
 921         ec_remove_handlers(ec);
 922
 923         return 0;
 924 }
 925
 926 int __init acpi_boot_ec_enable(void)
 927 {
 928         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 929                 return 0;
 930         if (!ec_install_handlers(boot_ec)) {
 931                 first_ec = boot_ec;
 932                 return 0;
 933         }
 934         return -EFAULT;
 935 }
 936
 937 static const struct acpi_device_id ec_device_ids[] = {
 938         {"PNP0C09", 0},
 939         {"", 0},
 940 };
 941
 942 int __init acpi_ec_ecdt_probe(void)
 943 {
 944         int ret;
 945         acpi_status status;
 946         struct acpi_table_ecdt *ecdt_ptr;
 947
 948         boot_ec = make_acpi_ec();
 949         if (!boot_ec)
 950                 return -ENOMEM;
 951         /*
 952          * Generate a boot ec context
 953          */
 954         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 955                                 (struct acpi_table_header **)&ecdt_ptr);
 956         if (ACPI_SUCCESS(status)) {
 957                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
 958                 boot_ec->command_addr = ecdt_ptr->control.address;
 959                 boot_ec->data_addr = ecdt_ptr->data.address;
 960                 if (dmi_check_system(ec_dmi_table)) {
 961                         /*
 962                          * If the board falls into ec_dmi_table, it means
 963                          * that ECDT table gives the incorrect command/status
 964                          * & data I/O address. Just fix it.
 965                          */
 966                         boot_ec->data_addr = ecdt_ptr->control.address;
 967                         boot_ec->command_addr = ecdt_ptr->data.address;
 968                 }
 969                 boot_ec->gpe = ecdt_ptr->gpe;
 970                 boot_ec->handle = ACPI_ROOT_OBJECT;
 971                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
 972         } else {
 973                 /* This workaround is needed only on some broken machines,
 974                  * which require early EC, but fail to provide ECDT */
 975                 acpi_handle x;
 976                 printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
 977                 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
 978                                                 boot_ec, NULL);
 979                 /* Check that acpi_get_devices actually find something */
 980                 if (ACPI_FAILURE(status) || !boot_ec->handle)
 981                         goto error;
 982                 /* We really need to limit this workaround, the only ASUS,
 983                  * which needs it, has fake EC._INI method, so use it as flag.
 984                  * Keep boot_ec struct as it will be needed soon.
 985                  */
 986                 if (ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI", &x)))
 987                         return -ENODEV;
 988         }
 989
 990         ret = ec_install_handlers(boot_ec);
 991         if (!ret) {
 992                 first_ec = boot_ec;
 993                 return 0;
 994         }
 995       error:
 996         kfree(boot_ec);
 997         boot_ec = NULL;
 998         return -ENODEV;
 999 }
1000
1001 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1002 {
1003         struct acpi_ec *ec = acpi_driver_data(device);
1004         /* Stop using GPE */
1005         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
1006         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
1007         acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
1008         return 0;
1009 }
1010
1011 static int acpi_ec_resume(struct acpi_device *device)
1012 {
1013         struct acpi_ec *ec = acpi_driver_data(device);
1014         /* Enable use of GPE back */
1015         clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
1016         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
1017         return 0;
1018 }
1019
1020 static struct acpi_driver acpi_ec_driver = {
1021         .name = "ec",
1022         .class = ACPI_EC_CLASS,
1023         .ids = ec_device_ids,
1024         .ops = {
1025                 .add = acpi_ec_add,
1026                 .remove = acpi_ec_remove,
1027                 .start = acpi_ec_start,
1028                 .stop = acpi_ec_stop,
1029                 .suspend = acpi_ec_suspend,
1030                 .resume = acpi_ec_resume,
1031                 },
1032 };
1033
1034 static int __init acpi_ec_init(void)
1035 {
1036         int result = 0;
1037
1038         if (acpi_disabled)
1039                 return 0;
1040
1041         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1042         if (!acpi_ec_dir)
1043                 return -ENODEV;
1044
1045         /* Now register the driver for the EC */
1046         result = acpi_bus_register_driver(&acpi_ec_driver);
1047         if (result < 0) {
1048                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1049                 return -ENODEV;
1050         }
1051
1052         return result;
1053 }
1054
1055 subsys_initcall(acpi_ec_init);
1056
1057 /* EC driver currently not unloadable */
1058 #if 0
1059 static void __exit acpi_ec_exit(void)
1060 {
1061
1062         acpi_bus_unregister_driver(&acpi_ec_driver);
1063
1064         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1065
1066         return;
1067 }
1068 #endif  /* 0 */