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/interrupt.h>
  38 #include <linux/list.h>
  39 #include <linux/spinlock.h>
  40 #include <linux/slab.h>
  41 #include <asm/io.h>
  42 #include <acpi/acpi_bus.h>
  43 #include <acpi/acpi_drivers.h>
  44 #include <linux/dmi.h>
  45
  46 #include "internal.h"
  47
  48 #define ACPI_EC_CLASS                   "embedded_controller"
  49 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  50 #define ACPI_EC_FILE_INFO               "info"
  51
  52 #undef PREFIX
  53 #define PREFIX                          "ACPI: EC: "
  54
  55 /* EC status register */
  56 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  57 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  58 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  59 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  60
  61 /* EC commands */
  62 enum ec_command {
  63         ACPI_EC_COMMAND_READ = 0x80,
  64         ACPI_EC_COMMAND_WRITE = 0x81,
  65         ACPI_EC_BURST_ENABLE = 0x82,
  66         ACPI_EC_BURST_DISABLE = 0x83,
  67         ACPI_EC_COMMAND_QUERY = 0x84,
  68 };
  69
  70 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  71 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  72 #define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
  73
  74 enum {
  75         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  76         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  77         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
  78                                          * OpReg are installed */
  79         EC_FLAGS_BLOCKED,               /* Transactions are blocked */
  80 };
  81
  82 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
  83 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
  84 module_param(ec_delay, uint, 0644);
  85 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
  86
  87 /*
  88  * If the number of false interrupts per one transaction exceeds
  89  * this threshold, will think there is a GPE storm happened and
  90  * will disable the GPE for normal transaction.
  91  */
  92 static unsigned int ec_storm_threshold  __read_mostly = 8;
  93 module_param(ec_storm_threshold, uint, 0644);
  94 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
  95
  96 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  97 /* External interfaces use first EC only, so remember */
  98 typedef int (*acpi_ec_query_func) (void *data);
  99
 100 struct acpi_ec_query_handler {
 101         struct list_head node;
 102         acpi_ec_query_func func;
 103         acpi_handle handle;
 104         void *data;
 105         u8 query_bit;
 106 };
 107
 108 struct transaction {
 109         const u8 *wdata;
 110         u8 *rdata;
 111         unsigned short irq_count;
 112         u8 command;
 113         u8 wi;
 114         u8 ri;
 115         u8 wlen;
 116         u8 rlen;
 117         bool done;
 118 };
 119
 120 struct acpi_ec *boot_ec, *first_ec;
 121 EXPORT_SYMBOL(first_ec);
 122
 123 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 124 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 125 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 126
 127 /* --------------------------------------------------------------------------
 128                              Transaction Management
 129    -------------------------------------------------------------------------- */
 130
 131 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 132 {
 133         u8 x = inb(ec->command_addr);
 134         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
 135         return x;
 136 }
 137
 138 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 139 {
 140         u8 x = inb(ec->data_addr);
 141         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
 142         return x;
 143 }
 144
 145 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 146 {
 147         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
 148         outb(command, ec->command_addr);
 149 }
 150
 151 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 152 {
 153         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
 154         outb(data, ec->data_addr);
 155 }
 156
 157 static int ec_transaction_done(struct acpi_ec *ec)
 158 {
 159         unsigned long flags;
 160         int ret = 0;
 161         spin_lock_irqsave(&ec->curr_lock, flags);
 162         if (!ec->curr || ec->curr->done)
 163                 ret = 1;
 164         spin_unlock_irqrestore(&ec->curr_lock, flags);
 165         return ret;
 166 }
 167
 168 static void start_transaction(struct acpi_ec *ec)
 169 {
 170         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 171         ec->curr->done = false;
 172         acpi_ec_write_cmd(ec, ec->curr->command);
 173 }
 174
 175 static void advance_transaction(struct acpi_ec *ec, u8 status)
 176 {
 177         unsigned long flags;
 178         spin_lock_irqsave(&ec->curr_lock, flags);
 179         if (!ec->curr)
 180                 goto unlock;
 181         if (ec->curr->wlen > ec->curr->wi) {
 182                 if ((status & ACPI_EC_FLAG_IBF) == 0)
 183                         acpi_ec_write_data(ec,
 184                                 ec->curr->wdata[ec->curr->wi++]);
 185                 else
 186                         goto err;
 187         } else if (ec->curr->rlen > ec->curr->ri) {
 188                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
 189                         ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
 190                         if (ec->curr->rlen == ec->curr->ri)
 191                                 ec->curr->done = true;
 192                 } else
 193                         goto err;
 194         } else if (ec->curr->wlen == ec->curr->wi &&
 195                    (status & ACPI_EC_FLAG_IBF) == 0)
 196                 ec->curr->done = true;
 197         goto unlock;
 198 err:
 199         /* false interrupt, state didn't change */
 200         if (in_interrupt())
 201                 ++ec->curr->irq_count;
 202 unlock:
 203         spin_unlock_irqrestore(&ec->curr_lock, flags);
 204 }
 205
 206 static int acpi_ec_sync_query(struct acpi_ec *ec);
 207
 208 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 209 {
 210         if (state & ACPI_EC_FLAG_SCI) {
 211                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 212                         return acpi_ec_sync_query(ec);
 213         }
 214         return 0;
 215 }
 216
 217 static int ec_poll(struct acpi_ec *ec)
 218 {
 219         unsigned long flags;
 220         int repeat = 2; /* number of command restarts */
 221         while (repeat--) {
 222                 unsigned long delay = jiffies +
 223                         msecs_to_jiffies(ec_delay);
 224                 do {
 225                         /* don't sleep with disabled interrupts */
 226                         if (EC_FLAGS_MSI || irqs_disabled()) {
 227                                 udelay(ACPI_EC_MSI_UDELAY);
 228                                 if (ec_transaction_done(ec))
 229                                         return 0;
 230                         } else {
 231                                 if (wait_event_timeout(ec->wait,
 232                                                 ec_transaction_done(ec),
 233                                                 msecs_to_jiffies(1)))
 234                                         return 0;
 235                         }
 236                         advance_transaction(ec, acpi_ec_read_status(ec));
 237                 } while (time_before(jiffies, delay));
 238                 if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
 239                         break;
 240                 pr_debug(PREFIX "controller reset, restart transaction\n");
 241                 spin_lock_irqsave(&ec->curr_lock, flags);
 242                 start_transaction(ec);
 243                 spin_unlock_irqrestore(&ec->curr_lock, flags);
 244         }
 245         return -ETIME;
 246 }
 247
 248 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 249                                         struct transaction *t)
 250 {
 251         unsigned long tmp;
 252         int ret = 0;
 253         if (EC_FLAGS_MSI)
 254                 udelay(ACPI_EC_MSI_UDELAY);
 255         /* start transaction */
 256         spin_lock_irqsave(&ec->curr_lock, tmp);
 257         /* following two actions should be kept atomic */
 258         ec->curr = t;
 259         start_transaction(ec);
 260         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 261                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 262         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 263         ret = ec_poll(ec);
 264         spin_lock_irqsave(&ec->curr_lock, tmp);
 265         ec->curr = NULL;
 266         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 267         return ret;
 268 }
 269
 270 static int ec_check_ibf0(struct acpi_ec *ec)
 271 {
 272         u8 status = acpi_ec_read_status(ec);
 273         return (status & ACPI_EC_FLAG_IBF) == 0;
 274 }
 275
 276 static int ec_wait_ibf0(struct acpi_ec *ec)
 277 {
 278         unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
 279         /* interrupt wait manually if GPE mode is not active */
 280         while (time_before(jiffies, delay))
 281                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
 282                                         msecs_to_jiffies(1)))
 283                         return 0;
 284         return -ETIME;
 285 }
 286
 287 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 288 {
 289         int status;
 290         u32 glk;
 291         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 292                 return -EINVAL;
 293         if (t->rdata)
 294                 memset(t->rdata, 0, t->rlen);
 295         mutex_lock(&ec->lock);
 296         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 297                 status = -EINVAL;
 298                 goto unlock;
 299         }
 300         if (ec->global_lock) {
 301                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 302                 if (ACPI_FAILURE(status)) {
 303                         status = -ENODEV;
 304                         goto unlock;
 305                 }
 306         }
 307         if (ec_wait_ibf0(ec)) {
 308                 pr_err(PREFIX "input buffer is not empty, "
 309                                 "aborting transaction\n");
 310                 status = -ETIME;
 311                 goto end;
 312         }
 313         pr_debug(PREFIX "transaction start\n");
 314         /* disable GPE during transaction if storm is detected */
 315         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 316                 /* It has to be disabled, so that it doesn't trigger. */
 317                 acpi_disable_gpe(NULL, ec->gpe);
 318         }
 319
 320         status = acpi_ec_transaction_unlocked(ec, t);
 321
 322         /* check if we received SCI during transaction */
 323         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 324         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 325                 msleep(1);
 326                 /* It is safe to enable the GPE outside of the transaction. */
 327                 acpi_enable_gpe(NULL, ec->gpe);
 328         } else if (t->irq_count > ec_storm_threshold) {
 329                 pr_info(PREFIX "GPE storm detected, "
 330                         "transactions will use polling mode\n");
 331                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 332         }
 333         pr_debug(PREFIX "transaction end\n");
 334 end:
 335         if (ec->global_lock)
 336                 acpi_release_global_lock(glk);
 337 unlock:
 338         mutex_unlock(&ec->lock);
 339         return status;
 340 }
 341
 342 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 343 {
 344         u8 d;
 345         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 346                                 .wdata = NULL, .rdata = &d,
 347                                 .wlen = 0, .rlen = 1};
 348
 349         return acpi_ec_transaction(ec, &t);
 350 }
 351
 352 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 353 {
 354         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 355                                 .wdata = NULL, .rdata = NULL,
 356                                 .wlen = 0, .rlen = 0};
 357
 358         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 359                                 acpi_ec_transaction(ec, &t) : 0;
 360 }
 361
 362 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 363 {
 364         int result;
 365         u8 d;
 366         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 367                                 .wdata = &address, .rdata = &d,
 368                                 .wlen = 1, .rlen = 1};
 369
 370         result = acpi_ec_transaction(ec, &t);
 371         *data = d;
 372         return result;
 373 }
 374
 375 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 376 {
 377         u8 wdata[2] = { address, data };
 378         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 379                                 .wdata = wdata, .rdata = NULL,
 380                                 .wlen = 2, .rlen = 0};
 381
 382         return acpi_ec_transaction(ec, &t);
 383 }
 384
 385 /*
 386  * Externally callable EC access functions. For now, assume 1 EC only
 387  */
 388 int ec_burst_enable(void)
 389 {
 390         if (!first_ec)
 391                 return -ENODEV;
 392         return acpi_ec_burst_enable(first_ec);
 393 }
 394
 395 EXPORT_SYMBOL(ec_burst_enable);
 396
 397 int ec_burst_disable(void)
 398 {
 399         if (!first_ec)
 400                 return -ENODEV;
 401         return acpi_ec_burst_disable(first_ec);
 402 }
 403
 404 EXPORT_SYMBOL(ec_burst_disable);
 405
 406 int ec_read(u8 addr, u8 * val)
 407 {
 408         int err;
 409         u8 temp_data;
 410
 411         if (!first_ec)
 412                 return -ENODEV;
 413
 414         err = acpi_ec_read(first_ec, addr, &temp_data);
 415
 416         if (!err) {
 417                 *val = temp_data;
 418                 return 0;
 419         } else
 420                 return err;
 421 }
 422
 423 EXPORT_SYMBOL(ec_read);
 424
 425 int ec_write(u8 addr, u8 val)
 426 {
 427         int err;
 428
 429         if (!first_ec)
 430                 return -ENODEV;
 431
 432         err = acpi_ec_write(first_ec, addr, val);
 433
 434         return err;
 435 }
 436
 437 EXPORT_SYMBOL(ec_write);
 438
 439 int ec_transaction(u8 command,
 440                    const u8 * wdata, unsigned wdata_len,
 441                    u8 * rdata, unsigned rdata_len)
 442 {
 443         struct transaction t = {.command = command,
 444                                 .wdata = wdata, .rdata = rdata,
 445                                 .wlen = wdata_len, .rlen = rdata_len};
 446         if (!first_ec)
 447                 return -ENODEV;
 448
 449         return acpi_ec_transaction(first_ec, &t);
 450 }
 451
 452 EXPORT_SYMBOL(ec_transaction);
 453
 454 void acpi_ec_block_transactions(void)
 455 {
 456         struct acpi_ec *ec = first_ec;
 457
 458         if (!ec)
 459                 return;
 460
 461         mutex_lock(&ec->lock);
 462         /* Prevent transactions from being carried out */
 463         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 464         mutex_unlock(&ec->lock);
 465 }
 466
 467 void acpi_ec_unblock_transactions(void)
 468 {
 469         struct acpi_ec *ec = first_ec;
 470
 471         if (!ec)
 472                 return;
 473
 474         mutex_lock(&ec->lock);
 475         /* Allow transactions to be carried out again */
 476         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 477         mutex_unlock(&ec->lock);
 478 }
 479
 480 void acpi_ec_unblock_transactions_early(void)
 481 {
 482         /*
 483          * Allow transactions to happen again (this function is called from
 484          * atomic context during wakeup, so we don't need to acquire the mutex).
 485          */
 486         if (first_ec)
 487                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 488 }
 489
 490 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 491 {
 492         int result;
 493         u8 d;
 494         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 495                                 .wdata = NULL, .rdata = &d,
 496                                 .wlen = 0, .rlen = 1};
 497         if (!ec || !data)
 498                 return -EINVAL;
 499         /*
 500          * Query the EC to find out which _Qxx method we need to evaluate.
 501          * Note that successful completion of the query causes the ACPI_EC_SCI
 502          * bit to be cleared (and thus clearing the interrupt source).
 503          */
 504         result = acpi_ec_transaction_unlocked(ec, &t);
 505         if (result)
 506                 return result;
 507         if (!d)
 508                 return -ENODATA;
 509         *data = d;
 510         return 0;
 511 }
 512
 513 /* --------------------------------------------------------------------------
 514                                 Event Management
 515    -------------------------------------------------------------------------- */
 516 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 517                               acpi_handle handle, acpi_ec_query_func func,
 518                               void *data)
 519 {
 520         struct acpi_ec_query_handler *handler =
 521             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 522         if (!handler)
 523                 return -ENOMEM;
 524
 525         handler->query_bit = query_bit;
 526         handler->handle = handle;
 527         handler->func = func;
 528         handler->data = data;
 529         mutex_lock(&ec->lock);
 530         list_add(&handler->node, &ec->list);
 531         mutex_unlock(&ec->lock);
 532         return 0;
 533 }
 534
 535 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 536
 537 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 538 {
 539         struct acpi_ec_query_handler *handler, *tmp;
 540         mutex_lock(&ec->lock);
 541         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 542                 if (query_bit == handler->query_bit) {
 543                         list_del(&handler->node);
 544                         kfree(handler);
 545                 }
 546         }
 547         mutex_unlock(&ec->lock);
 548 }
 549
 550 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 551
 552 static void acpi_ec_run(void *cxt)
 553 {
 554         struct acpi_ec_query_handler *handler = cxt;
 555         if (!handler)
 556                 return;
 557         pr_debug(PREFIX "start query execution\n");
 558         if (handler->func)
 559                 handler->func(handler->data);
 560         else if (handler->handle)
 561                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 562         pr_debug(PREFIX "stop query execution\n");
 563         kfree(handler);
 564 }
 565
 566 static int acpi_ec_sync_query(struct acpi_ec *ec)
 567 {
 568         u8 value = 0;
 569         int status;
 570         struct acpi_ec_query_handler *handler, *copy;
 571         if ((status = acpi_ec_query_unlocked(ec, &value)))
 572                 return status;
 573         list_for_each_entry(handler, &ec->list, node) {
 574                 if (value == handler->query_bit) {
 575                         /* have custom handler for this bit */
 576                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 577                         if (!copy)
 578                                 return -ENOMEM;
 579                         memcpy(copy, handler, sizeof(*copy));
 580                         pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
 581                         return acpi_os_execute((copy->func) ?
 582                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 583                                 acpi_ec_run, copy);
 584                 }
 585         }
 586         return 0;
 587 }
 588
 589 static void acpi_ec_gpe_query(void *ec_cxt)
 590 {
 591         struct acpi_ec *ec = ec_cxt;
 592         if (!ec)
 593                 return;
 594         mutex_lock(&ec->lock);
 595         acpi_ec_sync_query(ec);
 596         mutex_unlock(&ec->lock);
 597 }
 598
 599 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 600 {
 601         if (state & ACPI_EC_FLAG_SCI) {
 602                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 603                         pr_debug(PREFIX "push gpe query to the queue\n");
 604                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 605                                 acpi_ec_gpe_query, ec);
 606                 }
 607         }
 608         return 0;
 609 }
 610
 611 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 612         u32 gpe_number, void *data)
 613 {
 614         struct acpi_ec *ec = data;
 615
 616         pr_debug(PREFIX "~~~> interrupt\n");
 617
 618         advance_transaction(ec, acpi_ec_read_status(ec));
 619         if (ec_transaction_done(ec) &&
 620             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 621                 wake_up(&ec->wait);
 622                 ec_check_sci(ec, acpi_ec_read_status(ec));
 623         }
 624         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 625 }
 626
 627 /* --------------------------------------------------------------------------
 628                              Address Space Management
 629    -------------------------------------------------------------------------- */
 630
 631 static acpi_status
 632 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 633                       u32 bits, u64 *value64,
 634                       void *handler_context, void *region_context)
 635 {
 636         struct acpi_ec *ec = handler_context;
 637         int result = 0, i, bytes = bits / 8;
 638         u8 *value = (u8 *)value64;
 639
 640         if ((address > 0xFF) || !value || !handler_context)
 641                 return AE_BAD_PARAMETER;
 642
 643         if (function != ACPI_READ && function != ACPI_WRITE)
 644                 return AE_BAD_PARAMETER;
 645
 646         if (EC_FLAGS_MSI || bits > 8)
 647                 acpi_ec_burst_enable(ec);
 648
 649         for (i = 0; i < bytes; ++i, ++address, ++value)
 650                 result = (function == ACPI_READ) ?
 651                         acpi_ec_read(ec, address, value) :
 652                         acpi_ec_write(ec, address, *value);
 653
 654         if (EC_FLAGS_MSI || bits > 8)
 655                 acpi_ec_burst_disable(ec);
 656
 657         switch (result) {
 658         case -EINVAL:
 659                 return AE_BAD_PARAMETER;
 660                 break;
 661         case -ENODEV:
 662                 return AE_NOT_FOUND;
 663                 break;
 664         case -ETIME:
 665                 return AE_TIME;
 666                 break;
 667         default:
 668                 return AE_OK;
 669         }
 670 }
 671
 672 /* --------------------------------------------------------------------------
 673                                Driver Interface
 674    -------------------------------------------------------------------------- */
 675 static acpi_status
 676 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 677
 678 static struct acpi_ec *make_acpi_ec(void)
 679 {
 680         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 681         if (!ec)
 682                 return NULL;
 683         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 684         mutex_init(&ec->lock);
 685         init_waitqueue_head(&ec->wait);
 686         INIT_LIST_HEAD(&ec->list);
 687         spin_lock_init(&ec->curr_lock);
 688         return ec;
 689 }
 690
 691 static acpi_status
 692 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 693                                void *context, void **return_value)
 694 {
 695         char node_name[5];
 696         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 697         struct acpi_ec *ec = context;
 698         int value = 0;
 699         acpi_status status;
 700
 701         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 702
 703         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 704                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 705         }
 706         return AE_OK;
 707 }
 708
 709 static acpi_status
 710 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 711 {
 712         acpi_status status;
 713         unsigned long long tmp = 0;
 714
 715         struct acpi_ec *ec = context;
 716
 717         /* clear addr values, ec_parse_io_ports depend on it */
 718         ec->command_addr = ec->data_addr = 0;
 719
 720         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 721                                      ec_parse_io_ports, ec);
 722         if (ACPI_FAILURE(status))
 723                 return status;
 724
 725         /* Get GPE bit assignment (EC events). */
 726         /* TODO: Add support for _GPE returning a package */
 727         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 728         if (ACPI_FAILURE(status))
 729                 return status;
 730         ec->gpe = tmp;
 731         /* Use the global lock for all EC transactions? */
 732         tmp = 0;
 733         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 734         ec->global_lock = tmp;
 735         ec->handle = handle;
 736         return AE_CTRL_TERMINATE;
 737 }
 738
 739 static int ec_install_handlers(struct acpi_ec *ec)
 740 {
 741         acpi_status status;
 742         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 743                 return 0;
 744         status = acpi_install_gpe_handler(NULL, ec->gpe,
 745                                   ACPI_GPE_EDGE_TRIGGERED,
 746                                   &acpi_ec_gpe_handler, ec);
 747         if (ACPI_FAILURE(status))
 748                 return -ENODEV;
 749
 750         acpi_enable_gpe(NULL, ec->gpe);
 751         status = acpi_install_address_space_handler(ec->handle,
 752                                                     ACPI_ADR_SPACE_EC,
 753                                                     &acpi_ec_space_handler,
 754                                                     NULL, ec);
 755         if (ACPI_FAILURE(status)) {
 756                 if (status == AE_NOT_FOUND) {
 757                         /*
 758                          * Maybe OS fails in evaluating the _REG object.
 759                          * The AE_NOT_FOUND error will be ignored and OS
 760                          * continue to initialize EC.
 761                          */
 762                         printk(KERN_ERR "Fail in evaluating the _REG object"
 763                                 " of EC device. Broken bios is suspected.\n");
 764                 } else {
 765                         acpi_remove_gpe_handler(NULL, ec->gpe,
 766                                 &acpi_ec_gpe_handler);
 767                         acpi_disable_gpe(NULL, ec->gpe);
 768                         return -ENODEV;
 769                 }
 770         }
 771
 772         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 773         return 0;
 774 }
 775
 776 static void ec_remove_handlers(struct acpi_ec *ec)
 777 {
 778         acpi_disable_gpe(NULL, ec->gpe);
 779         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 780                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 781                 pr_err(PREFIX "failed to remove space handler\n");
 782         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 783                                 &acpi_ec_gpe_handler)))
 784                 pr_err(PREFIX "failed to remove gpe handler\n");
 785         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 786 }
 787
 788 static int acpi_ec_add(struct acpi_device *device)
 789 {
 790         struct acpi_ec *ec = NULL;
 791         int ret;
 792
 793         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 794         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 795
 796         /* Check for boot EC */
 797         if (boot_ec &&
 798             (boot_ec->handle == device->handle ||
 799              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 800                 ec = boot_ec;
 801                 boot_ec = NULL;
 802         } else {
 803                 ec = make_acpi_ec();
 804                 if (!ec)
 805                         return -ENOMEM;
 806         }
 807         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 808                 AE_CTRL_TERMINATE) {
 809                         kfree(ec);
 810                         return -EINVAL;
 811         }
 812
 813         /* Find and register all query methods */
 814         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 815                             acpi_ec_register_query_methods, NULL, ec, NULL);
 816
 817         if (!first_ec)
 818                 first_ec = ec;
 819         device->driver_data = ec;
 820
 821         WARN(!request_region(ec->data_addr, 1, "EC data"),
 822              "Could not request EC data io port 0x%lx", ec->data_addr);
 823         WARN(!request_region(ec->command_addr, 1, "EC cmd"),
 824              "Could not request EC cmd io port 0x%lx", ec->command_addr);
 825
 826         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 827                           ec->gpe, ec->command_addr, ec->data_addr);
 828
 829         ret = ec_install_handlers(ec);
 830
 831         /* EC is fully operational, allow queries */
 832         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 833         return ret;
 834 }
 835
 836 static int acpi_ec_remove(struct acpi_device *device, int type)
 837 {
 838         struct acpi_ec *ec;
 839         struct acpi_ec_query_handler *handler, *tmp;
 840
 841         if (!device)
 842                 return -EINVAL;
 843
 844         ec = acpi_driver_data(device);
 845         ec_remove_handlers(ec);
 846         mutex_lock(&ec->lock);
 847         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 848                 list_del(&handler->node);
 849                 kfree(handler);
 850         }
 851         mutex_unlock(&ec->lock);
 852         release_region(ec->data_addr, 1);
 853         release_region(ec->command_addr, 1);
 854         device->driver_data = NULL;
 855         if (ec == first_ec)
 856                 first_ec = NULL;
 857         kfree(ec);
 858         return 0;
 859 }
 860
 861 static acpi_status
 862 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 863 {
 864         struct acpi_ec *ec = context;
 865
 866         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 867                 return AE_OK;
 868
 869         /*
 870          * The first address region returned is the data port, and
 871          * the second address region returned is the status/command
 872          * port.
 873          */
 874         if (ec->data_addr == 0)
 875                 ec->data_addr = resource->data.io.minimum;
 876         else if (ec->command_addr == 0)
 877                 ec->command_addr = resource->data.io.minimum;
 878         else
 879                 return AE_CTRL_TERMINATE;
 880
 881         return AE_OK;
 882 }
 883
 884 int __init acpi_boot_ec_enable(void)
 885 {
 886         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 887                 return 0;
 888         if (!ec_install_handlers(boot_ec)) {
 889                 first_ec = boot_ec;
 890                 return 0;
 891         }
 892         return -EFAULT;
 893 }
 894
 895 static const struct acpi_device_id ec_device_ids[] = {
 896         {"PNP0C09", 0},
 897         {"", 0},
 898 };
 899
 900 /* Some BIOS do not survive early DSDT scan, skip it */
 901 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 902 {
 903         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 904         return 0;
 905 }
 906
 907 /* ASUStek often supplies us with broken ECDT, validate it */
 908 static int ec_validate_ecdt(const struct dmi_system_id *id)
 909 {
 910         EC_FLAGS_VALIDATE_ECDT = 1;
 911         return 0;
 912 }
 913
 914 /* MSI EC needs special treatment, enable it */
 915 static int ec_flag_msi(const struct dmi_system_id *id)
 916 {
 917         printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
 918         EC_FLAGS_MSI = 1;
 919         EC_FLAGS_VALIDATE_ECDT = 1;
 920         return 0;
 921 }
 922
 923 /*
 924  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
 925  * the GPE storm threshold back to 20
 926  */
 927 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
 928 {
 929         pr_debug("Setting the EC GPE storm threshold to 20\n");
 930         ec_storm_threshold  = 20;
 931         return 0;
 932 }
 933
 934 static struct dmi_system_id __initdata ec_dmi_table[] = {
 935         {
 936         ec_skip_dsdt_scan, "Compal JFL92", {
 937         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 938         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 939         {
 940         ec_flag_msi, "MSI hardware", {
 941         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
 942         {
 943         ec_flag_msi, "MSI hardware", {
 944         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
 945         {
 946         ec_flag_msi, "MSI hardware", {
 947         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
 948         {
 949         ec_flag_msi, "MSI hardware", {
 950         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
 951         {
 952         ec_flag_msi, "Quanta hardware", {
 953         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
 954         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
 955         {
 956         ec_flag_msi, "Quanta hardware", {
 957         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
 958         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
 959         {
 960         ec_validate_ecdt, "ASUS hardware", {
 961         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
 962         {
 963         ec_validate_ecdt, "ASUS hardware", {
 964         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
 965         {
 966         ec_enlarge_storm_threshold, "CLEVO hardware", {
 967         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
 968         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
 969         {},
 970 };
 971
 972 int __init acpi_ec_ecdt_probe(void)
 973 {
 974         acpi_status status;
 975         struct acpi_ec *saved_ec = NULL;
 976         struct acpi_table_ecdt *ecdt_ptr;
 977
 978         boot_ec = make_acpi_ec();
 979         if (!boot_ec)
 980                 return -ENOMEM;
 981         /*
 982          * Generate a boot ec context
 983          */
 984         dmi_check_system(ec_dmi_table);
 985         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 986                                 (struct acpi_table_header **)&ecdt_ptr);
 987         if (ACPI_SUCCESS(status)) {
 988                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
 989                 boot_ec->command_addr = ecdt_ptr->control.address;
 990                 boot_ec->data_addr = ecdt_ptr->data.address;
 991                 boot_ec->gpe = ecdt_ptr->gpe;
 992                 boot_ec->handle = ACPI_ROOT_OBJECT;
 993                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
 994                 /* Don't trust ECDT, which comes from ASUSTek */
 995                 if (!EC_FLAGS_VALIDATE_ECDT)
 996                         goto install;
 997                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
 998                 if (!saved_ec)
 999                         return -ENOMEM;
1000         /* fall through */
1001         }
1002
1003         if (EC_FLAGS_SKIP_DSDT_SCAN)
1004                 return -ENODEV;
1005
1006         /* This workaround is needed only on some broken machines,
1007          * which require early EC, but fail to provide ECDT */
1008         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1009         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1010                                         boot_ec, NULL);
1011         /* Check that acpi_get_devices actually find something */
1012         if (ACPI_FAILURE(status) || !boot_ec->handle)
1013                 goto error;
1014         if (saved_ec) {
1015                 /* try to find good ECDT from ASUSTek */
1016                 if (saved_ec->command_addr != boot_ec->command_addr ||
1017                     saved_ec->data_addr != boot_ec->data_addr ||
1018                     saved_ec->gpe != boot_ec->gpe ||
1019                     saved_ec->handle != boot_ec->handle)
1020                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1021                         "ECDT tables, which are very hard to workaround. "
1022                         "Trying to use DSDT EC info instead. Please send "
1023                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1024                 kfree(saved_ec);
1025                 saved_ec = NULL;
1026         } else {
1027                 /* We really need to limit this workaround, the only ASUS,
1028                 * which needs it, has fake EC._INI method, so use it as flag.
1029                 * Keep boot_ec struct as it will be needed soon.
1030                 */
1031                 acpi_handle dummy;
1032                 if (!dmi_name_in_vendors("ASUS") ||
1033                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1034                                                         &dummy)))
1035                         return -ENODEV;
1036         }
1037 install:
1038         if (!ec_install_handlers(boot_ec)) {
1039                 first_ec = boot_ec;
1040                 return 0;
1041         }
1042 error:
1043         kfree(boot_ec);
1044         boot_ec = NULL;
1045         return -ENODEV;
1046 }
1047
1048 static struct acpi_driver acpi_ec_driver = {
1049         .name = "ec",
1050         .class = ACPI_EC_CLASS,
1051         .ids = ec_device_ids,
1052         .ops = {
1053                 .add = acpi_ec_add,
1054                 .remove = acpi_ec_remove,
1055                 },
1056 };
1057
1058 int __init acpi_ec_init(void)
1059 {
1060         int result = 0;
1061
1062         /* Now register the driver for the EC */
1063         result = acpi_bus_register_driver(&acpi_ec_driver);
1064         if (result < 0)
1065                 return -ENODEV;
1066
1067         return result;
1068 }
1069
1070 /* EC driver currently not unloadable */
1071 #if 0
1072 static void __exit acpi_ec_exit(void)
1073 {
1074
1075         acpi_bus_unregister_driver(&acpi_ec_driver);
1076         return;
1077 }
1078 #endif  /* 0 */