git.oblomov.eu Git - linux-2.6/blob - drivers/acpi/ec.c

   1 /*
   2  *  ec.c - ACPI Embedded Controller Driver (v2.1)
   3  *
   4  *  Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@suse.de>
   5  *  Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
   6  *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
   7  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   8  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   9  *
  10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or (at
  15  *  your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful, but
  18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  *  General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License along
  23  *  with this program; if not, write to the Free Software Foundation, Inc.,
  24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  25  *
  26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  27  */
  28
  29 /* Uncomment next line to get verbose printout */
  30 /* #define DEBUG */
  31
  32 #include <linux/kernel.h>
  33 #include <linux/module.h>
  34 #include <linux/init.h>
  35 #include <linux/types.h>
  36 #include <linux/delay.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/seq_file.h>
  39 #include <linux/interrupt.h>
  40 #include <linux/list.h>
  41 #include <linux/spinlock.h>
  42 #include <asm/io.h>
  43 #include <acpi/acpi_bus.h>
  44 #include <acpi/acpi_drivers.h>
  45
  46 #define ACPI_EC_CLASS                   "embedded_controller"
  47 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  48 #define ACPI_EC_FILE_INFO               "info"
  49
  50 #undef PREFIX
  51 #define PREFIX                          "ACPI: EC: "
  52
  53 /* EC status register */
  54 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  55 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  56 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  57 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  58
  59 /* EC commands */
  60 enum ec_command {
  61         ACPI_EC_COMMAND_READ = 0x80,
  62         ACPI_EC_COMMAND_WRITE = 0x81,
  63         ACPI_EC_BURST_ENABLE = 0x82,
  64         ACPI_EC_BURST_DISABLE = 0x83,
  65         ACPI_EC_COMMAND_QUERY = 0x84,
  66 };
  67
  68 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  69 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  70 #define ACPI_EC_UDELAY          100     /* Wait 100us before polling EC again */
  71
  72 #define ACPI_EC_STORM_THRESHOLD 8       /* number of false interrupts
  73                                            per one transaction */
  74
  75 enum {
  76         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  77         EC_FLAGS_GPE_MODE,              /* Expect GPE to be sent
  78                                          * for status change */
  79         EC_FLAGS_NO_GPE,                /* Don't use GPE mode */
  80         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  81         EC_FLAGS_HANDLERS_INSTALLED     /* Handlers for GPE and
  82                                          * OpReg are installed */
  83 };
  84
  85 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  86 /* External interfaces use first EC only, so remember */
  87 typedef int (*acpi_ec_query_func) (void *data);
  88
  89 struct acpi_ec_query_handler {
  90         struct list_head node;
  91         acpi_ec_query_func func;
  92         acpi_handle handle;
  93         void *data;
  94         u8 query_bit;
  95 };
  96
  97 struct transaction {
  98         const u8 *wdata;
  99         u8 *rdata;
 100         unsigned short irq_count;
 101         u8 command;
 102         u8 wi;
 103         u8 ri;
 104         u8 wlen;
 105         u8 rlen;
 106         bool done;
 107 };
 108
 109 static struct acpi_ec {
 110         acpi_handle handle;
 111         unsigned long gpe;
 112         unsigned long command_addr;
 113         unsigned long data_addr;
 114         unsigned long global_lock;
 115         unsigned long flags;
 116         struct mutex lock;
 117         wait_queue_head_t wait;
 118         struct list_head list;
 119         struct transaction *curr;
 120         spinlock_t curr_lock;
 121 } *boot_ec, *first_ec;
 122
 123 /* --------------------------------------------------------------------------
 124                              Transaction Management
 125    -------------------------------------------------------------------------- */
 126
 127 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 128 {
 129         u8 x = inb(ec->command_addr);
 130         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
 131         return x;
 132 }
 133
 134 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 135 {
 136         u8 x = inb(ec->data_addr);
 137         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
 138         return x;
 139 }
 140
 141 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 142 {
 143         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
 144         outb(command, ec->command_addr);
 145 }
 146
 147 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 148 {
 149         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
 150         outb(data, ec->data_addr);
 151 }
 152
 153 static int ec_transaction_done(struct acpi_ec *ec)
 154 {
 155         unsigned long flags;
 156         int ret = 0;
 157         spin_lock_irqsave(&ec->curr_lock, flags);
 158         if (!ec->curr || ec->curr->done)
 159                 ret = 1;
 160         spin_unlock_irqrestore(&ec->curr_lock, flags);
 161         return ret;
 162 }
 163
 164 static void start_transaction(struct acpi_ec *ec)
 165 {
 166         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 167         ec->curr->done = false;
 168         acpi_ec_write_cmd(ec, ec->curr->command);
 169 }
 170
 171 static void gpe_transaction(struct acpi_ec *ec, u8 status)
 172 {
 173         unsigned long flags;
 174         spin_lock_irqsave(&ec->curr_lock, flags);
 175         if (!ec->curr)
 176                 goto unlock;
 177         if (ec->curr->wlen > ec->curr->wi) {
 178                 if ((status & ACPI_EC_FLAG_IBF) == 0)
 179                         acpi_ec_write_data(ec,
 180                                 ec->curr->wdata[ec->curr->wi++]);
 181                 else
 182                         goto err;
 183         } else if (ec->curr->rlen > ec->curr->ri) {
 184                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
 185                         ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
 186                         if (ec->curr->rlen == ec->curr->ri)
 187                                 ec->curr->done = true;
 188                 } else
 189                         goto err;
 190         } else if (ec->curr->wlen == ec->curr->wi &&
 191                    (status & ACPI_EC_FLAG_IBF) == 0)
 192                 ec->curr->done = true;
 193         goto unlock;
 194 err:
 195         /* false interrupt, state didn't change */
 196         if (in_interrupt())
 197                 ++ec->curr->irq_count;
 198 unlock:
 199         spin_unlock_irqrestore(&ec->curr_lock, flags);
 200 }
 201
 202 static int acpi_ec_wait(struct acpi_ec *ec)
 203 {
 204         if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
 205                                msecs_to_jiffies(ACPI_EC_DELAY)))
 206                 return 0;
 207         /* try restart command if we get any false interrupts */
 208         if (ec->curr->irq_count &&
 209             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 210                 pr_debug(PREFIX "controller reset, restart transaction\n");
 211                 start_transaction(ec);
 212                 if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
 213                                         msecs_to_jiffies(ACPI_EC_DELAY)))
 214                         return 0;
 215         }
 216         /* missing GPEs, switch back to poll mode */
 217         if (printk_ratelimit())
 218                 pr_info(PREFIX "missing confirmations, "
 219                                 "switch off interrupt mode.\n");
 220         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
 221         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 222         return 1;
 223 }
 224
 225 static void acpi_ec_gpe_query(void *ec_cxt);
 226
 227 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 228 {
 229         if (state & ACPI_EC_FLAG_SCI) {
 230                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 231                         return acpi_os_execute(OSL_EC_BURST_HANDLER,
 232                                 acpi_ec_gpe_query, ec);
 233         }
 234         return 0;
 235 }
 236
 237 static int ec_poll(struct acpi_ec *ec)
 238 {
 239         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 240         udelay(ACPI_EC_UDELAY);
 241         while (time_before(jiffies, delay)) {
 242                 gpe_transaction(ec, acpi_ec_read_status(ec));
 243                 udelay(ACPI_EC_UDELAY);
 244                 if (ec_transaction_done(ec))
 245                         return 0;
 246         }
 247         return -ETIME;
 248 }
 249
 250 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 251                                         struct transaction *t,
 252                                         int force_poll)
 253 {
 254         unsigned long tmp;
 255         int ret = 0;
 256         pr_debug(PREFIX "transaction start\n");
 257         /* disable GPE during transaction if storm is detected */
 258         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 259                 clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 260                 acpi_disable_gpe(NULL, ec->gpe);
 261         }
 262         /* start transaction */
 263         spin_lock_irqsave(&ec->curr_lock, tmp);
 264         /* following two actions should be kept atomic */
 265         ec->curr = t;
 266         start_transaction(ec);
 267         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 268                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 269         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 270         /* if we selected poll mode or failed in GPE-mode do a poll loop */
 271         if (force_poll ||
 272             !test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ||
 273             acpi_ec_wait(ec))
 274                 ret = ec_poll(ec);
 275         pr_debug(PREFIX "transaction end\n");
 276         spin_lock_irqsave(&ec->curr_lock, tmp);
 277         ec->curr = NULL;
 278         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 279         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 280                 /* check if we received SCI during transaction */
 281                 ec_check_sci(ec, acpi_ec_read_status(ec));
 282                 /* it is safe to enable GPE outside of transaction */
 283                 acpi_enable_gpe(NULL, ec->gpe);
 284         } else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 285                    t->irq_count > ACPI_EC_STORM_THRESHOLD) {
 286                 pr_info(PREFIX "GPE storm detected, "
 287                         "transactions will use polling mode\n");
 288                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 289         }
 290         return ret;
 291 }
 292
 293 static int ec_check_ibf0(struct acpi_ec *ec)
 294 {
 295         u8 status = acpi_ec_read_status(ec);
 296         return (status & ACPI_EC_FLAG_IBF) == 0;
 297 }
 298
 299 static int ec_wait_ibf0(struct acpi_ec *ec)
 300 {
 301         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 302         /* interrupt wait manually if GPE mode is not active */
 303         unsigned long timeout = test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ?
 304                 msecs_to_jiffies(ACPI_EC_DELAY) : msecs_to_jiffies(1);
 305         while (time_before(jiffies, delay))
 306                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec), timeout))
 307                         return 0;
 308         return -ETIME;
 309 }
 310
 311 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t,
 312                                int force_poll)
 313 {
 314         int status;
 315         u32 glk;
 316         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 317                 return -EINVAL;
 318         if (t->rdata)
 319                 memset(t->rdata, 0, t->rlen);
 320         mutex_lock(&ec->lock);
 321         if (ec->global_lock) {
 322                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 323                 if (ACPI_FAILURE(status)) {
 324                         status = -ENODEV;
 325                         goto unlock;
 326                 }
 327         }
 328         if (ec_wait_ibf0(ec)) {
 329                 pr_err(PREFIX "input buffer is not empty, "
 330                                 "aborting transaction\n");
 331                 status = -ETIME;
 332                 goto end;
 333         }
 334         status = acpi_ec_transaction_unlocked(ec, t, force_poll);
 335 end:
 336         if (ec->global_lock)
 337                 acpi_release_global_lock(glk);
 338 unlock:
 339         mutex_unlock(&ec->lock);
 340         return status;
 341 }
 342
 343 /*
 344  * Note: samsung nv5000 doesn't work with ec burst mode.
 345  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 346  */
 347 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 348 {
 349         u8 d;
 350         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 351                                 .wdata = NULL, .rdata = &d,
 352                                 .wlen = 0, .rlen = 1};
 353
 354         return acpi_ec_transaction(ec, &t, 0);
 355 }
 356
 357 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 358 {
 359         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 360                                 .wdata = NULL, .rdata = NULL,
 361                                 .wlen = 0, .rlen = 0};
 362
 363         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 364                                 acpi_ec_transaction(ec, &t, 0) : 0;
 365 }
 366
 367 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 368 {
 369         int result;
 370         u8 d;
 371         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 372                                 .wdata = &address, .rdata = &d,
 373                                 .wlen = 1, .rlen = 1};
 374
 375         result = acpi_ec_transaction(ec, &t, 0);
 376         *data = d;
 377         return result;
 378 }
 379
 380 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 381 {
 382         u8 wdata[2] = { address, data };
 383         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 384                                 .wdata = wdata, .rdata = NULL,
 385                                 .wlen = 2, .rlen = 0};
 386
 387         return acpi_ec_transaction(ec, &t, 0);
 388 }
 389
 390 /*
 391  * Externally callable EC access functions. For now, assume 1 EC only
 392  */
 393 int ec_burst_enable(void)
 394 {
 395         if (!first_ec)
 396                 return -ENODEV;
 397         return acpi_ec_burst_enable(first_ec);
 398 }
 399
 400 EXPORT_SYMBOL(ec_burst_enable);
 401
 402 int ec_burst_disable(void)
 403 {
 404         if (!first_ec)
 405                 return -ENODEV;
 406         return acpi_ec_burst_disable(first_ec);
 407 }
 408
 409 EXPORT_SYMBOL(ec_burst_disable);
 410
 411 int ec_read(u8 addr, u8 * val)
 412 {
 413         int err;
 414         u8 temp_data;
 415
 416         if (!first_ec)
 417                 return -ENODEV;
 418
 419         err = acpi_ec_read(first_ec, addr, &temp_data);
 420
 421         if (!err) {
 422                 *val = temp_data;
 423                 return 0;
 424         } else
 425                 return err;
 426 }
 427
 428 EXPORT_SYMBOL(ec_read);
 429
 430 int ec_write(u8 addr, u8 val)
 431 {
 432         int err;
 433
 434         if (!first_ec)
 435                 return -ENODEV;
 436
 437         err = acpi_ec_write(first_ec, addr, val);
 438
 439         return err;
 440 }
 441
 442 EXPORT_SYMBOL(ec_write);
 443
 444 int ec_transaction(u8 command,
 445                    const u8 * wdata, unsigned wdata_len,
 446                    u8 * rdata, unsigned rdata_len,
 447                    int force_poll)
 448 {
 449         struct transaction t = {.command = command,
 450                                 .wdata = wdata, .rdata = rdata,
 451                                 .wlen = wdata_len, .rlen = rdata_len};
 452         if (!first_ec)
 453                 return -ENODEV;
 454
 455         return acpi_ec_transaction(first_ec, &t, force_poll);
 456 }
 457
 458 EXPORT_SYMBOL(ec_transaction);
 459
 460 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 461 {
 462         int result;
 463         u8 d;
 464         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 465                                 .wdata = NULL, .rdata = &d,
 466                                 .wlen = 0, .rlen = 1};
 467         if (!ec || !data)
 468                 return -EINVAL;
 469
 470         /*
 471          * Query the EC to find out which _Qxx method we need to evaluate.
 472          * Note that successful completion of the query causes the ACPI_EC_SCI
 473          * bit to be cleared (and thus clearing the interrupt source).
 474          */
 475
 476         result = acpi_ec_transaction(ec, &t, 0);
 477         if (result)
 478                 return result;
 479
 480         if (!d)
 481                 return -ENODATA;
 482
 483         *data = d;
 484         return 0;
 485 }
 486
 487 /* --------------------------------------------------------------------------
 488                                 Event Management
 489    -------------------------------------------------------------------------- */
 490 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 491                               acpi_handle handle, acpi_ec_query_func func,
 492                               void *data)
 493 {
 494         struct acpi_ec_query_handler *handler =
 495             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 496         if (!handler)
 497                 return -ENOMEM;
 498
 499         handler->query_bit = query_bit;
 500         handler->handle = handle;
 501         handler->func = func;
 502         handler->data = data;
 503         mutex_lock(&ec->lock);
 504         list_add(&handler->node, &ec->list);
 505         mutex_unlock(&ec->lock);
 506         return 0;
 507 }
 508
 509 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 510
 511 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 512 {
 513         struct acpi_ec_query_handler *handler, *tmp;
 514         mutex_lock(&ec->lock);
 515         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 516                 if (query_bit == handler->query_bit) {
 517                         list_del(&handler->node);
 518                         kfree(handler);
 519                 }
 520         }
 521         mutex_unlock(&ec->lock);
 522 }
 523
 524 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 525
 526 static void acpi_ec_gpe_query(void *ec_cxt)
 527 {
 528         struct acpi_ec *ec = ec_cxt;
 529         u8 value = 0;
 530         struct acpi_ec_query_handler *handler, copy;
 531
 532         if (!ec || acpi_ec_query(ec, &value))
 533                 return;
 534         mutex_lock(&ec->lock);
 535         list_for_each_entry(handler, &ec->list, node) {
 536                 if (value == handler->query_bit) {
 537                         /* have custom handler for this bit */
 538                         memcpy(&copy, handler, sizeof(copy));
 539                         mutex_unlock(&ec->lock);
 540                         if (copy.func) {
 541                                 copy.func(copy.data);
 542                         } else if (copy.handle) {
 543                                 acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
 544                         }
 545                         return;
 546                 }
 547         }
 548         mutex_unlock(&ec->lock);
 549 }
 550
 551 static u32 acpi_ec_gpe_handler(void *data)
 552 {
 553         struct acpi_ec *ec = data;
 554         u8 status;
 555
 556         pr_debug(PREFIX "~~~> interrupt\n");
 557         status = acpi_ec_read_status(ec);
 558
 559         if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) {
 560                 gpe_transaction(ec, status);
 561                 if (ec_transaction_done(ec) &&
 562                     (status & ACPI_EC_FLAG_IBF) == 0)
 563                         wake_up(&ec->wait);
 564         }
 565
 566         ec_check_sci(ec, status);
 567         if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 568             !test_bit(EC_FLAGS_NO_GPE, &ec->flags)) {
 569                 /* this is non-query, must be confirmation */
 570                 if (!test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 571                         if (printk_ratelimit())
 572                                 pr_info(PREFIX "non-query interrupt received,"
 573                                         " switching to interrupt mode\n");
 574                 } else {
 575                         /* hush, STORM switches the mode every transaction */
 576                         pr_debug(PREFIX "non-query interrupt received,"
 577                                 " switching to interrupt mode\n");
 578                 }
 579                 set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 580         }
 581         return ACPI_INTERRUPT_HANDLED;
 582 }
 583
 584 /* --------------------------------------------------------------------------
 585                              Address Space Management
 586    -------------------------------------------------------------------------- */
 587
 588 static acpi_status
 589 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 590                       u32 bits, acpi_integer *value,
 591                       void *handler_context, void *region_context)
 592 {
 593         struct acpi_ec *ec = handler_context;
 594         int result = 0, i;
 595         u8 temp = 0;
 596
 597         if ((address > 0xFF) || !value || !handler_context)
 598                 return AE_BAD_PARAMETER;
 599
 600         if (function != ACPI_READ && function != ACPI_WRITE)
 601                 return AE_BAD_PARAMETER;
 602
 603         if (bits != 8 && acpi_strict)
 604                 return AE_BAD_PARAMETER;
 605
 606         acpi_ec_burst_enable(ec);
 607
 608         if (function == ACPI_READ) {
 609                 result = acpi_ec_read(ec, address, &temp);
 610                 *value = temp;
 611         } else {
 612                 temp = 0xff & (*value);
 613                 result = acpi_ec_write(ec, address, temp);
 614         }
 615
 616         for (i = 8; unlikely(bits - i > 0); i += 8) {
 617                 ++address;
 618                 if (function == ACPI_READ) {
 619                         result = acpi_ec_read(ec, address, &temp);
 620                         (*value) |= ((acpi_integer)temp) << i;
 621                 } else {
 622                         temp = 0xff & ((*value) >> i);
 623                         result = acpi_ec_write(ec, address, temp);
 624                 }
 625         }
 626
 627         acpi_ec_burst_disable(ec);
 628
 629         switch (result) {
 630         case -EINVAL:
 631                 return AE_BAD_PARAMETER;
 632                 break;
 633         case -ENODEV:
 634                 return AE_NOT_FOUND;
 635                 break;
 636         case -ETIME:
 637                 return AE_TIME;
 638                 break;
 639         default:
 640                 return AE_OK;
 641         }
 642 }
 643
 644 /* --------------------------------------------------------------------------
 645                               FS Interface (/proc)
 646    -------------------------------------------------------------------------- */
 647
 648 static struct proc_dir_entry *acpi_ec_dir;
 649
 650 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 651 {
 652         struct acpi_ec *ec = seq->private;
 653
 654         if (!ec)
 655                 goto end;
 656
 657         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 658         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 659                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 660         seq_printf(seq, "use global lock:\t%s\n",
 661                    ec->global_lock ? "yes" : "no");
 662       end:
 663         return 0;
 664 }
 665
 666 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 667 {
 668         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 669 }
 670
 671 static struct file_operations acpi_ec_info_ops = {
 672         .open = acpi_ec_info_open_fs,
 673         .read = seq_read,
 674         .llseek = seq_lseek,
 675         .release = single_release,
 676         .owner = THIS_MODULE,
 677 };
 678
 679 static int acpi_ec_add_fs(struct acpi_device *device)
 680 {
 681         struct proc_dir_entry *entry = NULL;
 682
 683         if (!acpi_device_dir(device)) {
 684                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 685                                                      acpi_ec_dir);
 686                 if (!acpi_device_dir(device))
 687                         return -ENODEV;
 688         }
 689
 690         entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
 691                                  acpi_device_dir(device),
 692                                  &acpi_ec_info_ops, acpi_driver_data(device));
 693         if (!entry)
 694                 return -ENODEV;
 695         return 0;
 696 }
 697
 698 static int acpi_ec_remove_fs(struct acpi_device *device)
 699 {
 700
 701         if (acpi_device_dir(device)) {
 702                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 703                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 704                 acpi_device_dir(device) = NULL;
 705         }
 706
 707         return 0;
 708 }
 709
 710 /* --------------------------------------------------------------------------
 711                                Driver Interface
 712    -------------------------------------------------------------------------- */
 713 static acpi_status
 714 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 715
 716 static struct acpi_ec *make_acpi_ec(void)
 717 {
 718         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 719         if (!ec)
 720                 return NULL;
 721         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 722         mutex_init(&ec->lock);
 723         init_waitqueue_head(&ec->wait);
 724         INIT_LIST_HEAD(&ec->list);
 725         spin_lock_init(&ec->curr_lock);
 726         return ec;
 727 }
 728
 729 static acpi_status
 730 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 731                                void *context, void **return_value)
 732 {
 733         char node_name[5];
 734         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 735         struct acpi_ec *ec = context;
 736         int value = 0;
 737         acpi_status status;
 738
 739         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 740
 741         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 742                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 743         }
 744         return AE_OK;
 745 }
 746
 747 static acpi_status
 748 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 749 {
 750         acpi_status status;
 751         unsigned long long tmp = 0;
 752
 753         struct acpi_ec *ec = context;
 754         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 755                                      ec_parse_io_ports, ec);
 756         if (ACPI_FAILURE(status))
 757                 return status;
 758
 759         /* Get GPE bit assignment (EC events). */
 760         /* TODO: Add support for _GPE returning a package */
 761         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 762         if (ACPI_FAILURE(status))
 763                 return status;
 764         ec->gpe = tmp;
 765         /* Use the global lock for all EC transactions? */
 766         tmp = 0;
 767         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 768         ec->global_lock = tmp;
 769         ec->handle = handle;
 770         return AE_CTRL_TERMINATE;
 771 }
 772
 773 static void ec_remove_handlers(struct acpi_ec *ec)
 774 {
 775         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 776                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 777                 pr_err(PREFIX "failed to remove space handler\n");
 778         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 779                                 &acpi_ec_gpe_handler)))
 780                 pr_err(PREFIX "failed to remove gpe handler\n");
 781         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 782 }
 783
 784 static int acpi_ec_add(struct acpi_device *device)
 785 {
 786         struct acpi_ec *ec = NULL;
 787
 788         if (!device)
 789                 return -EINVAL;
 790         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 791         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 792
 793         /* Check for boot EC */
 794         if (boot_ec &&
 795             (boot_ec->handle == device->handle ||
 796              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 797                 ec = boot_ec;
 798                 boot_ec = NULL;
 799         } else {
 800                 ec = make_acpi_ec();
 801                 if (!ec)
 802                         return -ENOMEM;
 803                 if (ec_parse_device(device->handle, 0, ec, NULL) !=
 804                     AE_CTRL_TERMINATE) {
 805                         kfree(ec);
 806                         return -EINVAL;
 807                 }
 808         }
 809
 810         ec->handle = device->handle;
 811
 812         /* Find and register all query methods */
 813         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 814                             acpi_ec_register_query_methods, ec, NULL);
 815
 816         if (!first_ec)
 817                 first_ec = ec;
 818         device->driver_data = ec;
 819         acpi_ec_add_fs(device);
 820         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 821                           ec->gpe, ec->command_addr, ec->data_addr);
 822         pr_info(PREFIX "driver started in %s mode\n",
 823                 (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
 824         return 0;
 825 }
 826
 827 static int acpi_ec_remove(struct acpi_device *device, int type)
 828 {
 829         struct acpi_ec *ec;
 830         struct acpi_ec_query_handler *handler, *tmp;
 831
 832         if (!device)
 833                 return -EINVAL;
 834
 835         ec = acpi_driver_data(device);
 836         mutex_lock(&ec->lock);
 837         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 838                 list_del(&handler->node);
 839                 kfree(handler);
 840         }
 841         mutex_unlock(&ec->lock);
 842         acpi_ec_remove_fs(device);
 843         device->driver_data = NULL;
 844         if (ec == first_ec)
 845                 first_ec = NULL;
 846         kfree(ec);
 847         return 0;
 848 }
 849
 850 static acpi_status
 851 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 852 {
 853         struct acpi_ec *ec = context;
 854
 855         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 856                 return AE_OK;
 857
 858         /*
 859          * The first address region returned is the data port, and
 860          * the second address region returned is the status/command
 861          * port.
 862          */
 863         if (ec->data_addr == 0)
 864                 ec->data_addr = resource->data.io.minimum;
 865         else if (ec->command_addr == 0)
 866                 ec->command_addr = resource->data.io.minimum;
 867         else
 868                 return AE_CTRL_TERMINATE;
 869
 870         return AE_OK;
 871 }
 872
 873 static int ec_install_handlers(struct acpi_ec *ec)
 874 {
 875         acpi_status status;
 876         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 877                 return 0;
 878         status = acpi_install_gpe_handler(NULL, ec->gpe,
 879                                   ACPI_GPE_EDGE_TRIGGERED,
 880                                   &acpi_ec_gpe_handler, ec);
 881         if (ACPI_FAILURE(status))
 882                 return -ENODEV;
 883         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 884         acpi_enable_gpe(NULL, ec->gpe);
 885         status = acpi_install_address_space_handler(ec->handle,
 886                                                     ACPI_ADR_SPACE_EC,
 887                                                     &acpi_ec_space_handler,
 888                                                     NULL, ec);
 889         if (ACPI_FAILURE(status)) {
 890                 if (status == AE_NOT_FOUND) {
 891                         /*
 892                          * Maybe OS fails in evaluating the _REG object.
 893                          * The AE_NOT_FOUND error will be ignored and OS
 894                          * continue to initialize EC.
 895                          */
 896                         printk(KERN_ERR "Fail in evaluating the _REG object"
 897                                 " of EC device. Broken bios is suspected.\n");
 898                 } else {
 899                         acpi_remove_gpe_handler(NULL, ec->gpe,
 900                                 &acpi_ec_gpe_handler);
 901                         return -ENODEV;
 902                 }
 903         }
 904
 905         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 906         return 0;
 907 }
 908
 909 static int acpi_ec_start(struct acpi_device *device)
 910 {
 911         struct acpi_ec *ec;
 912         int ret = 0;
 913
 914         if (!device)
 915                 return -EINVAL;
 916
 917         ec = acpi_driver_data(device);
 918
 919         if (!ec)
 920                 return -EINVAL;
 921
 922         ret = ec_install_handlers(ec);
 923
 924         /* EC is fully operational, allow queries */
 925         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 926         return ret;
 927 }
 928
 929 static int acpi_ec_stop(struct acpi_device *device, int type)
 930 {
 931         struct acpi_ec *ec;
 932         if (!device)
 933                 return -EINVAL;
 934         ec = acpi_driver_data(device);
 935         if (!ec)
 936                 return -EINVAL;
 937         ec_remove_handlers(ec);
 938
 939         return 0;
 940 }
 941
 942 int __init acpi_boot_ec_enable(void)
 943 {
 944         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 945                 return 0;
 946         if (!ec_install_handlers(boot_ec)) {
 947                 first_ec = boot_ec;
 948                 return 0;
 949         }
 950         return -EFAULT;
 951 }
 952
 953 static const struct acpi_device_id ec_device_ids[] = {
 954         {"PNP0C09", 0},
 955         {"", 0},
 956 };
 957
 958 int __init acpi_ec_ecdt_probe(void)
 959 {
 960         acpi_status status;
 961         struct acpi_ec *saved_ec = NULL;
 962         struct acpi_table_ecdt *ecdt_ptr;
 963
 964         boot_ec = make_acpi_ec();
 965         if (!boot_ec)
 966                 return -ENOMEM;
 967         /*
 968          * Generate a boot ec context
 969          */
 970         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 971                                 (struct acpi_table_header **)&ecdt_ptr);
 972         if (ACPI_SUCCESS(status)) {
 973                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
 974                 boot_ec->command_addr = ecdt_ptr->control.address;
 975                 boot_ec->data_addr = ecdt_ptr->data.address;
 976                 boot_ec->gpe = ecdt_ptr->gpe;
 977                 boot_ec->handle = ACPI_ROOT_OBJECT;
 978                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
 979                 /* Don't trust ECDT, which comes from ASUSTek */
 980                 if (!dmi_name_in_vendors("ASUS"))
 981                         goto install;
 982                 saved_ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 983                 if (!saved_ec)
 984                         return -ENOMEM;
 985                 memcpy(saved_ec, boot_ec, sizeof(*saved_ec));
 986         /* fall through */
 987         }
 988         /* This workaround is needed only on some broken machines,
 989          * which require early EC, but fail to provide ECDT */
 990         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
 991         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
 992                                         boot_ec, NULL);
 993         /* Check that acpi_get_devices actually find something */
 994         if (ACPI_FAILURE(status) || !boot_ec->handle)
 995                 goto error;
 996         if (saved_ec) {
 997                 /* try to find good ECDT from ASUSTek */
 998                 if (saved_ec->command_addr != boot_ec->command_addr ||
 999                     saved_ec->data_addr != boot_ec->data_addr ||
1000                     saved_ec->gpe != boot_ec->gpe ||
1001                     saved_ec->handle != boot_ec->handle)
1002                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1003                         "ECDT tables, which are very hard to workaround. "
1004                         "Trying to use DSDT EC info instead. Please send "
1005                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1006                 kfree(saved_ec);
1007                 saved_ec = NULL;
1008         } else {
1009                 /* We really need to limit this workaround, the only ASUS,
1010                 * which needs it, has fake EC._INI method, so use it as flag.
1011                 * Keep boot_ec struct as it will be needed soon.
1012                 */
1013                 acpi_handle dummy;
1014                 if (!dmi_name_in_vendors("ASUS") ||
1015                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1016                                                         &dummy)))
1017                         return -ENODEV;
1018         }
1019 install:
1020         if (!ec_install_handlers(boot_ec)) {
1021                 first_ec = boot_ec;
1022                 return 0;
1023         }
1024 error:
1025         kfree(boot_ec);
1026         boot_ec = NULL;
1027         return -ENODEV;
1028 }
1029
1030 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1031 {
1032         struct acpi_ec *ec = acpi_driver_data(device);
1033         /* Stop using GPE */
1034         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
1035         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
1036         acpi_disable_gpe(NULL, ec->gpe);
1037         return 0;
1038 }
1039
1040 static int acpi_ec_resume(struct acpi_device *device)
1041 {
1042         struct acpi_ec *ec = acpi_driver_data(device);
1043         /* Enable use of GPE back */
1044         clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
1045         acpi_enable_gpe(NULL, ec->gpe);
1046         return 0;
1047 }
1048
1049 static struct acpi_driver acpi_ec_driver = {
1050         .name = "ec",
1051         .class = ACPI_EC_CLASS,
1052         .ids = ec_device_ids,
1053         .ops = {
1054                 .add = acpi_ec_add,
1055                 .remove = acpi_ec_remove,
1056                 .start = acpi_ec_start,
1057                 .stop = acpi_ec_stop,
1058                 .suspend = acpi_ec_suspend,
1059                 .resume = acpi_ec_resume,
1060                 },
1061 };
1062
1063 static int __init acpi_ec_init(void)
1064 {
1065         int result = 0;
1066
1067         if (acpi_disabled)
1068                 return 0;
1069
1070         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1071         if (!acpi_ec_dir)
1072                 return -ENODEV;
1073
1074         /* Now register the driver for the EC */
1075         result = acpi_bus_register_driver(&acpi_ec_driver);
1076         if (result < 0) {
1077                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1078                 return -ENODEV;
1079         }
1080
1081         return result;
1082 }
1083
1084 subsys_initcall(acpi_ec_init);
1085
1086 /* EC driver currently not unloadable */
1087 #if 0
1088 static void __exit acpi_ec_exit(void)
1089 {
1090
1091         acpi_bus_unregister_driver(&acpi_ec_driver);
1092
1093         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1094
1095         return;
1096 }
1097 #endif  /* 0 */