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->lock, flags);
 162         if (!ec->curr || ec->curr->done)
 163                 ret = 1;
 164         spin_unlock_irqrestore(&ec->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         struct transaction *t = ec->curr;
 179
 180         spin_lock_irqsave(&ec->lock, flags);
 181         if (!t)
 182                 goto unlock;
 183         if (t->wlen > t->wi) {
 184                 if ((status & ACPI_EC_FLAG_IBF) == 0)
 185                         acpi_ec_write_data(ec,
 186                                 t->wdata[t->wi++]);
 187                 else
 188                         goto err;
 189         } else if (t->rlen > t->ri) {
 190                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
 191                         t->rdata[t->ri++] = acpi_ec_read_data(ec);
 192                         if (t->rlen == t->ri)
 193                                 t->done = true;
 194                 } else
 195                         goto err;
 196         } else if (t->wlen == t->wi &&
 197                    (status & ACPI_EC_FLAG_IBF) == 0)
 198                 t->done = true;
 199         goto unlock;
 200 err:
 201         /*
 202          * If SCI bit is set, then don't think it's a false IRQ
 203          * otherwise will take a not handled IRQ as a false one.
 204          */
 205         if (in_interrupt() && !(status & ACPI_EC_FLAG_SCI))
 206                 ++t->irq_count;
 207
 208 unlock:
 209         spin_unlock_irqrestore(&ec->lock, flags);
 210 }
 211
 212 static int acpi_ec_sync_query(struct acpi_ec *ec);
 213
 214 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 215 {
 216         if (state & ACPI_EC_FLAG_SCI) {
 217                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 218                         return acpi_ec_sync_query(ec);
 219         }
 220         return 0;
 221 }
 222
 223 static int ec_poll(struct acpi_ec *ec)
 224 {
 225         unsigned long flags;
 226         int repeat = 2; /* number of command restarts */
 227         while (repeat--) {
 228                 unsigned long delay = jiffies +
 229                         msecs_to_jiffies(ec_delay);
 230                 do {
 231                         /* don't sleep with disabled interrupts */
 232                         if (EC_FLAGS_MSI || irqs_disabled()) {
 233                                 udelay(ACPI_EC_MSI_UDELAY);
 234                                 if (ec_transaction_done(ec))
 235                                         return 0;
 236                         } else {
 237                                 if (wait_event_timeout(ec->wait,
 238                                                 ec_transaction_done(ec),
 239                                                 msecs_to_jiffies(1)))
 240                                         return 0;
 241                         }
 242                         advance_transaction(ec, acpi_ec_read_status(ec));
 243                 } while (time_before(jiffies, delay));
 244                 if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
 245                         break;
 246                 pr_debug(PREFIX "controller reset, restart transaction\n");
 247                 spin_lock_irqsave(&ec->lock, flags);
 248                 start_transaction(ec);
 249                 spin_unlock_irqrestore(&ec->lock, flags);
 250         }
 251         return -ETIME;
 252 }
 253
 254 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 255                                         struct transaction *t)
 256 {
 257         unsigned long tmp;
 258         int ret = 0;
 259         if (EC_FLAGS_MSI)
 260                 udelay(ACPI_EC_MSI_UDELAY);
 261         /* start transaction */
 262         spin_lock_irqsave(&ec->lock, tmp);
 263         /* following two actions should be kept atomic */
 264         ec->curr = t;
 265         start_transaction(ec);
 266         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 267                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 268         spin_unlock_irqrestore(&ec->lock, tmp);
 269         ret = ec_poll(ec);
 270         spin_lock_irqsave(&ec->lock, tmp);
 271         ec->curr = NULL;
 272         spin_unlock_irqrestore(&ec->lock, tmp);
 273         return ret;
 274 }
 275
 276 static int ec_check_ibf0(struct acpi_ec *ec)
 277 {
 278         u8 status = acpi_ec_read_status(ec);
 279         return (status & ACPI_EC_FLAG_IBF) == 0;
 280 }
 281
 282 static int ec_wait_ibf0(struct acpi_ec *ec)
 283 {
 284         unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
 285         /* interrupt wait manually if GPE mode is not active */
 286         while (time_before(jiffies, delay))
 287                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
 288                                         msecs_to_jiffies(1)))
 289                         return 0;
 290         return -ETIME;
 291 }
 292
 293 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 294 {
 295         int status;
 296         u32 glk;
 297         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 298                 return -EINVAL;
 299         if (t->rdata)
 300                 memset(t->rdata, 0, t->rlen);
 301         mutex_lock(&ec->mutex);
 302         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 303                 status = -EINVAL;
 304                 goto unlock;
 305         }
 306         if (ec->global_lock) {
 307                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 308                 if (ACPI_FAILURE(status)) {
 309                         status = -ENODEV;
 310                         goto unlock;
 311                 }
 312         }
 313         if (ec_wait_ibf0(ec)) {
 314                 pr_err(PREFIX "input buffer is not empty, "
 315                                 "aborting transaction\n");
 316                 status = -ETIME;
 317                 goto end;
 318         }
 319         pr_debug(PREFIX "transaction start (cmd=0x%02x, addr=0x%02x)\n",
 320                         t->command, t->wdata ? t->wdata[0] : 0);
 321         /* disable GPE during transaction if storm is detected */
 322         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 323                 /* It has to be disabled, so that it doesn't trigger. */
 324                 acpi_disable_gpe(NULL, ec->gpe);
 325         }
 326
 327         status = acpi_ec_transaction_unlocked(ec, t);
 328
 329         /* check if we received SCI during transaction */
 330         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 331         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 332                 msleep(1);
 333                 /* It is safe to enable the GPE outside of the transaction. */
 334                 acpi_enable_gpe(NULL, ec->gpe);
 335         } else if (t->irq_count > ec_storm_threshold) {
 336                 pr_info(PREFIX "GPE storm detected(%d GPEs), "
 337                         "transactions will use polling mode\n",
 338                         t->irq_count);
 339                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 340         }
 341         pr_debug(PREFIX "transaction end\n");
 342 end:
 343         if (ec->global_lock)
 344                 acpi_release_global_lock(glk);
 345 unlock:
 346         mutex_unlock(&ec->mutex);
 347         return status;
 348 }
 349
 350 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 351 {
 352         u8 d;
 353         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 354                                 .wdata = NULL, .rdata = &d,
 355                                 .wlen = 0, .rlen = 1};
 356
 357         return acpi_ec_transaction(ec, &t);
 358 }
 359
 360 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 361 {
 362         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 363                                 .wdata = NULL, .rdata = NULL,
 364                                 .wlen = 0, .rlen = 0};
 365
 366         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 367                                 acpi_ec_transaction(ec, &t) : 0;
 368 }
 369
 370 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 371 {
 372         int result;
 373         u8 d;
 374         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 375                                 .wdata = &address, .rdata = &d,
 376                                 .wlen = 1, .rlen = 1};
 377
 378         result = acpi_ec_transaction(ec, &t);
 379         *data = d;
 380         return result;
 381 }
 382
 383 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 384 {
 385         u8 wdata[2] = { address, data };
 386         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 387                                 .wdata = wdata, .rdata = NULL,
 388                                 .wlen = 2, .rlen = 0};
 389
 390         return acpi_ec_transaction(ec, &t);
 391 }
 392
 393 /*
 394  * Externally callable EC access functions. For now, assume 1 EC only
 395  */
 396 int ec_burst_enable(void)
 397 {
 398         if (!first_ec)
 399                 return -ENODEV;
 400         return acpi_ec_burst_enable(first_ec);
 401 }
 402
 403 EXPORT_SYMBOL(ec_burst_enable);
 404
 405 int ec_burst_disable(void)
 406 {
 407         if (!first_ec)
 408                 return -ENODEV;
 409         return acpi_ec_burst_disable(first_ec);
 410 }
 411
 412 EXPORT_SYMBOL(ec_burst_disable);
 413
 414 int ec_read(u8 addr, u8 *val)
 415 {
 416         int err;
 417         u8 temp_data;
 418
 419         if (!first_ec)
 420                 return -ENODEV;
 421
 422         err = acpi_ec_read(first_ec, addr, &temp_data);
 423
 424         if (!err) {
 425                 *val = temp_data;
 426                 return 0;
 427         } else
 428                 return err;
 429 }
 430
 431 EXPORT_SYMBOL(ec_read);
 432
 433 int ec_write(u8 addr, u8 val)
 434 {
 435         int err;
 436
 437         if (!first_ec)
 438                 return -ENODEV;
 439
 440         err = acpi_ec_write(first_ec, addr, val);
 441
 442         return err;
 443 }
 444
 445 EXPORT_SYMBOL(ec_write);
 446
 447 int ec_transaction(u8 command,
 448                    const u8 * wdata, unsigned wdata_len,
 449                    u8 * rdata, unsigned rdata_len)
 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);
 458 }
 459
 460 EXPORT_SYMBOL(ec_transaction);
 461
 462 /* Get the handle to the EC device */
 463 acpi_handle ec_get_handle(void)
 464 {
 465         if (!first_ec)
 466                 return NULL;
 467         return first_ec->handle;
 468 }
 469
 470 EXPORT_SYMBOL(ec_get_handle);
 471
 472 void acpi_ec_block_transactions(void)
 473 {
 474         struct acpi_ec *ec = first_ec;
 475
 476         if (!ec)
 477                 return;
 478
 479         mutex_lock(&ec->mutex);
 480         /* Prevent transactions from being carried out */
 481         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 482         mutex_unlock(&ec->mutex);
 483 }
 484
 485 void acpi_ec_unblock_transactions(void)
 486 {
 487         struct acpi_ec *ec = first_ec;
 488
 489         if (!ec)
 490                 return;
 491
 492         mutex_lock(&ec->mutex);
 493         /* Allow transactions to be carried out again */
 494         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 495         mutex_unlock(&ec->mutex);
 496 }
 497
 498 void acpi_ec_unblock_transactions_early(void)
 499 {
 500         /*
 501          * Allow transactions to happen again (this function is called from
 502          * atomic context during wakeup, so we don't need to acquire the mutex).
 503          */
 504         if (first_ec)
 505                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 506 }
 507
 508 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 509 {
 510         int result;
 511         u8 d;
 512         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 513                                 .wdata = NULL, .rdata = &d,
 514                                 .wlen = 0, .rlen = 1};
 515         if (!ec || !data)
 516                 return -EINVAL;
 517         /*
 518          * Query the EC to find out which _Qxx method we need to evaluate.
 519          * Note that successful completion of the query causes the ACPI_EC_SCI
 520          * bit to be cleared (and thus clearing the interrupt source).
 521          */
 522         result = acpi_ec_transaction_unlocked(ec, &t);
 523         if (result)
 524                 return result;
 525         if (!d)
 526                 return -ENODATA;
 527         *data = d;
 528         return 0;
 529 }
 530
 531 /* --------------------------------------------------------------------------
 532                                 Event Management
 533    -------------------------------------------------------------------------- */
 534 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 535                               acpi_handle handle, acpi_ec_query_func func,
 536                               void *data)
 537 {
 538         struct acpi_ec_query_handler *handler =
 539             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 540         if (!handler)
 541                 return -ENOMEM;
 542
 543         handler->query_bit = query_bit;
 544         handler->handle = handle;
 545         handler->func = func;
 546         handler->data = data;
 547         mutex_lock(&ec->mutex);
 548         list_add(&handler->node, &ec->list);
 549         mutex_unlock(&ec->mutex);
 550         return 0;
 551 }
 552
 553 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 554
 555 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 556 {
 557         struct acpi_ec_query_handler *handler, *tmp;
 558         mutex_lock(&ec->mutex);
 559         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 560                 if (query_bit == handler->query_bit) {
 561                         list_del(&handler->node);
 562                         kfree(handler);
 563                 }
 564         }
 565         mutex_unlock(&ec->mutex);
 566 }
 567
 568 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 569
 570 static void acpi_ec_run(void *cxt)
 571 {
 572         struct acpi_ec_query_handler *handler = cxt;
 573         if (!handler)
 574                 return;
 575         pr_debug(PREFIX "start query execution\n");
 576         if (handler->func)
 577                 handler->func(handler->data);
 578         else if (handler->handle)
 579                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 580         pr_debug(PREFIX "stop query execution\n");
 581         kfree(handler);
 582 }
 583
 584 static int acpi_ec_sync_query(struct acpi_ec *ec)
 585 {
 586         u8 value = 0;
 587         int status;
 588         struct acpi_ec_query_handler *handler, *copy;
 589         if ((status = acpi_ec_query_unlocked(ec, &value)))
 590                 return status;
 591         list_for_each_entry(handler, &ec->list, node) {
 592                 if (value == handler->query_bit) {
 593                         /* have custom handler for this bit */
 594                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 595                         if (!copy)
 596                                 return -ENOMEM;
 597                         memcpy(copy, handler, sizeof(*copy));
 598                         pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
 599                         return acpi_os_execute((copy->func) ?
 600                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 601                                 acpi_ec_run, copy);
 602                 }
 603         }
 604         return 0;
 605 }
 606
 607 static void acpi_ec_gpe_query(void *ec_cxt)
 608 {
 609         struct acpi_ec *ec = ec_cxt;
 610         if (!ec)
 611                 return;
 612         mutex_lock(&ec->mutex);
 613         acpi_ec_sync_query(ec);
 614         mutex_unlock(&ec->mutex);
 615 }
 616
 617 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 618 {
 619         if (state & ACPI_EC_FLAG_SCI) {
 620                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 621                         pr_debug(PREFIX "push gpe query to the queue\n");
 622                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 623                                 acpi_ec_gpe_query, ec);
 624                 }
 625         }
 626         return 0;
 627 }
 628
 629 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 630         u32 gpe_number, void *data)
 631 {
 632         struct acpi_ec *ec = data;
 633         u8 status = acpi_ec_read_status(ec);
 634
 635         pr_debug(PREFIX "~~~> interrupt, status:0x%02x\n", status);
 636
 637         advance_transaction(ec, status);
 638         if (ec_transaction_done(ec) &&
 639             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 640                 wake_up(&ec->wait);
 641                 ec_check_sci(ec, acpi_ec_read_status(ec));
 642         }
 643         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 644 }
 645
 646 /* --------------------------------------------------------------------------
 647                              Address Space Management
 648    -------------------------------------------------------------------------- */
 649
 650 static acpi_status
 651 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 652                       u32 bits, u64 *value64,
 653                       void *handler_context, void *region_context)
 654 {
 655         struct acpi_ec *ec = handler_context;
 656         int result = 0, i, bytes = bits / 8;
 657         u8 *value = (u8 *)value64;
 658
 659         if ((address > 0xFF) || !value || !handler_context)
 660                 return AE_BAD_PARAMETER;
 661
 662         if (function != ACPI_READ && function != ACPI_WRITE)
 663                 return AE_BAD_PARAMETER;
 664
 665         if (EC_FLAGS_MSI || bits > 8)
 666                 acpi_ec_burst_enable(ec);
 667
 668         for (i = 0; i < bytes; ++i, ++address, ++value)
 669                 result = (function == ACPI_READ) ?
 670                         acpi_ec_read(ec, address, value) :
 671                         acpi_ec_write(ec, address, *value);
 672
 673         if (EC_FLAGS_MSI || bits > 8)
 674                 acpi_ec_burst_disable(ec);
 675
 676         switch (result) {
 677         case -EINVAL:
 678                 return AE_BAD_PARAMETER;
 679                 break;
 680         case -ENODEV:
 681                 return AE_NOT_FOUND;
 682                 break;
 683         case -ETIME:
 684                 return AE_TIME;
 685                 break;
 686         default:
 687                 return AE_OK;
 688         }
 689 }
 690
 691 /* --------------------------------------------------------------------------
 692                                Driver Interface
 693    -------------------------------------------------------------------------- */
 694 static acpi_status
 695 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 696
 697 static struct acpi_ec *make_acpi_ec(void)
 698 {
 699         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 700         if (!ec)
 701                 return NULL;
 702         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 703         mutex_init(&ec->mutex);
 704         init_waitqueue_head(&ec->wait);
 705         INIT_LIST_HEAD(&ec->list);
 706         spin_lock_init(&ec->lock);
 707         return ec;
 708 }
 709
 710 static acpi_status
 711 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 712                                void *context, void **return_value)
 713 {
 714         char node_name[5];
 715         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 716         struct acpi_ec *ec = context;
 717         int value = 0;
 718         acpi_status status;
 719
 720         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 721
 722         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 723                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 724         }
 725         return AE_OK;
 726 }
 727
 728 static acpi_status
 729 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 730 {
 731         acpi_status status;
 732         unsigned long long tmp = 0;
 733
 734         struct acpi_ec *ec = context;
 735
 736         /* clear addr values, ec_parse_io_ports depend on it */
 737         ec->command_addr = ec->data_addr = 0;
 738
 739         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 740                                      ec_parse_io_ports, ec);
 741         if (ACPI_FAILURE(status))
 742                 return status;
 743
 744         /* Get GPE bit assignment (EC events). */
 745         /* TODO: Add support for _GPE returning a package */
 746         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 747         if (ACPI_FAILURE(status))
 748                 return status;
 749         ec->gpe = tmp;
 750         /* Use the global lock for all EC transactions? */
 751         tmp = 0;
 752         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 753         ec->global_lock = tmp;
 754         ec->handle = handle;
 755         return AE_CTRL_TERMINATE;
 756 }
 757
 758 static int ec_install_handlers(struct acpi_ec *ec)
 759 {
 760         acpi_status status;
 761         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 762                 return 0;
 763         status = acpi_install_gpe_handler(NULL, ec->gpe,
 764                                   ACPI_GPE_EDGE_TRIGGERED,
 765                                   &acpi_ec_gpe_handler, ec);
 766         if (ACPI_FAILURE(status))
 767                 return -ENODEV;
 768
 769         acpi_enable_gpe(NULL, ec->gpe);
 770         status = acpi_install_address_space_handler(ec->handle,
 771                                                     ACPI_ADR_SPACE_EC,
 772                                                     &acpi_ec_space_handler,
 773                                                     NULL, ec);
 774         if (ACPI_FAILURE(status)) {
 775                 if (status == AE_NOT_FOUND) {
 776                         /*
 777                          * Maybe OS fails in evaluating the _REG object.
 778                          * The AE_NOT_FOUND error will be ignored and OS
 779                          * continue to initialize EC.
 780                          */
 781                         printk(KERN_ERR "Fail in evaluating the _REG object"
 782                                 " of EC device. Broken bios is suspected.\n");
 783                 } else {
 784                         acpi_remove_gpe_handler(NULL, ec->gpe,
 785                                 &acpi_ec_gpe_handler);
 786                         acpi_disable_gpe(NULL, ec->gpe);
 787                         return -ENODEV;
 788                 }
 789         }
 790
 791         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 792         return 0;
 793 }
 794
 795 static void ec_remove_handlers(struct acpi_ec *ec)
 796 {
 797         acpi_disable_gpe(NULL, ec->gpe);
 798         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 799                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 800                 pr_err(PREFIX "failed to remove space handler\n");
 801         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 802                                 &acpi_ec_gpe_handler)))
 803                 pr_err(PREFIX "failed to remove gpe handler\n");
 804         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 805 }
 806
 807 static int acpi_ec_add(struct acpi_device *device)
 808 {
 809         struct acpi_ec *ec = NULL;
 810         int ret;
 811
 812         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 813         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 814
 815         /* Check for boot EC */
 816         if (boot_ec &&
 817             (boot_ec->handle == device->handle ||
 818              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 819                 ec = boot_ec;
 820                 boot_ec = NULL;
 821         } else {
 822                 ec = make_acpi_ec();
 823                 if (!ec)
 824                         return -ENOMEM;
 825         }
 826         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 827                 AE_CTRL_TERMINATE) {
 828                         kfree(ec);
 829                         return -EINVAL;
 830         }
 831
 832         /* Find and register all query methods */
 833         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 834                             acpi_ec_register_query_methods, NULL, ec, NULL);
 835
 836         if (!first_ec)
 837                 first_ec = ec;
 838         device->driver_data = ec;
 839
 840         ret = !!request_region(ec->data_addr, 1, "EC data");
 841         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
 842         ret = !!request_region(ec->command_addr, 1, "EC cmd");
 843         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
 844
 845         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 846                           ec->gpe, ec->command_addr, ec->data_addr);
 847
 848         ret = ec_install_handlers(ec);
 849
 850         /* EC is fully operational, allow queries */
 851         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 852         return ret;
 853 }
 854
 855 static int acpi_ec_remove(struct acpi_device *device)
 856 {
 857         struct acpi_ec *ec;
 858         struct acpi_ec_query_handler *handler, *tmp;
 859
 860         if (!device)
 861                 return -EINVAL;
 862
 863         ec = acpi_driver_data(device);
 864         ec_remove_handlers(ec);
 865         mutex_lock(&ec->mutex);
 866         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 867                 list_del(&handler->node);
 868                 kfree(handler);
 869         }
 870         mutex_unlock(&ec->mutex);
 871         release_region(ec->data_addr, 1);
 872         release_region(ec->command_addr, 1);
 873         device->driver_data = NULL;
 874         if (ec == first_ec)
 875                 first_ec = NULL;
 876         kfree(ec);
 877         return 0;
 878 }
 879
 880 static acpi_status
 881 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 882 {
 883         struct acpi_ec *ec = context;
 884
 885         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 886                 return AE_OK;
 887
 888         /*
 889          * The first address region returned is the data port, and
 890          * the second address region returned is the status/command
 891          * port.
 892          */
 893         if (ec->data_addr == 0)
 894                 ec->data_addr = resource->data.io.minimum;
 895         else if (ec->command_addr == 0)
 896                 ec->command_addr = resource->data.io.minimum;
 897         else
 898                 return AE_CTRL_TERMINATE;
 899
 900         return AE_OK;
 901 }
 902
 903 int __init acpi_boot_ec_enable(void)
 904 {
 905         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 906                 return 0;
 907         if (!ec_install_handlers(boot_ec)) {
 908                 first_ec = boot_ec;
 909                 return 0;
 910         }
 911         return -EFAULT;
 912 }
 913
 914 static const struct acpi_device_id ec_device_ids[] = {
 915         {"PNP0C09", 0},
 916         {"", 0},
 917 };
 918
 919 /* Some BIOS do not survive early DSDT scan, skip it */
 920 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 921 {
 922         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 923         return 0;
 924 }
 925
 926 /* ASUStek often supplies us with broken ECDT, validate it */
 927 static int ec_validate_ecdt(const struct dmi_system_id *id)
 928 {
 929         EC_FLAGS_VALIDATE_ECDT = 1;
 930         return 0;
 931 }
 932
 933 /* MSI EC needs special treatment, enable it */
 934 static int ec_flag_msi(const struct dmi_system_id *id)
 935 {
 936         printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
 937         EC_FLAGS_MSI = 1;
 938         EC_FLAGS_VALIDATE_ECDT = 1;
 939         return 0;
 940 }
 941
 942 /*
 943  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
 944  * the GPE storm threshold back to 20
 945  */
 946 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
 947 {
 948         pr_debug("Setting the EC GPE storm threshold to 20\n");
 949         ec_storm_threshold  = 20;
 950         return 0;
 951 }
 952
 953 static struct dmi_system_id __initdata ec_dmi_table[] = {
 954         {
 955         ec_skip_dsdt_scan, "Compal JFL92", {
 956         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 957         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 958         {
 959         ec_flag_msi, "MSI hardware", {
 960         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
 961         {
 962         ec_flag_msi, "MSI hardware", {
 963         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
 964         {
 965         ec_flag_msi, "MSI hardware", {
 966         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
 967         {
 968         ec_flag_msi, "MSI hardware", {
 969         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
 970         {
 971         ec_flag_msi, "Quanta hardware", {
 972         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
 973         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
 974         {
 975         ec_flag_msi, "Quanta hardware", {
 976         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
 977         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
 978         {
 979         ec_validate_ecdt, "ASUS hardware", {
 980         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
 981         {
 982         ec_validate_ecdt, "ASUS hardware", {
 983         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
 984         {
 985         ec_enlarge_storm_threshold, "CLEVO hardware", {
 986         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
 987         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
 988         {},
 989 };
 990
 991 int __init acpi_ec_ecdt_probe(void)
 992 {
 993         acpi_status status;
 994         struct acpi_ec *saved_ec = NULL;
 995         struct acpi_table_ecdt *ecdt_ptr;
 996
 997         boot_ec = make_acpi_ec();
 998         if (!boot_ec)
 999                 return -ENOMEM;
1000         /*
1001          * Generate a boot ec context
1002          */
1003         dmi_check_system(ec_dmi_table);
1004         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1005                                 (struct acpi_table_header **)&ecdt_ptr);
1006         if (ACPI_SUCCESS(status)) {
1007                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
1008                 boot_ec->command_addr = ecdt_ptr->control.address;
1009                 boot_ec->data_addr = ecdt_ptr->data.address;
1010                 boot_ec->gpe = ecdt_ptr->gpe;
1011                 boot_ec->handle = ACPI_ROOT_OBJECT;
1012                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1013                 /* Don't trust ECDT, which comes from ASUSTek */
1014                 if (!EC_FLAGS_VALIDATE_ECDT)
1015                         goto install;
1016                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1017                 if (!saved_ec)
1018                         return -ENOMEM;
1019         /* fall through */
1020         }
1021
1022         if (EC_FLAGS_SKIP_DSDT_SCAN)
1023                 return -ENODEV;
1024
1025         /* This workaround is needed only on some broken machines,
1026          * which require early EC, but fail to provide ECDT */
1027         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1028         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1029                                         boot_ec, NULL);
1030         /* Check that acpi_get_devices actually find something */
1031         if (ACPI_FAILURE(status) || !boot_ec->handle)
1032                 goto error;
1033         if (saved_ec) {
1034                 /* try to find good ECDT from ASUSTek */
1035                 if (saved_ec->command_addr != boot_ec->command_addr ||
1036                     saved_ec->data_addr != boot_ec->data_addr ||
1037                     saved_ec->gpe != boot_ec->gpe ||
1038                     saved_ec->handle != boot_ec->handle)
1039                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1040                         "ECDT tables, which are very hard to workaround. "
1041                         "Trying to use DSDT EC info instead. Please send "
1042                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1043                 kfree(saved_ec);
1044                 saved_ec = NULL;
1045         } else {
1046                 /* We really need to limit this workaround, the only ASUS,
1047                 * which needs it, has fake EC._INI method, so use it as flag.
1048                 * Keep boot_ec struct as it will be needed soon.
1049                 */
1050                 acpi_handle dummy;
1051                 if (!dmi_name_in_vendors("ASUS") ||
1052                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1053                                                         &dummy)))
1054                         return -ENODEV;
1055         }
1056 install:
1057         if (!ec_install_handlers(boot_ec)) {
1058                 first_ec = boot_ec;
1059                 return 0;
1060         }
1061 error:
1062         kfree(boot_ec);
1063         boot_ec = NULL;
1064         return -ENODEV;
1065 }
1066
1067 static struct acpi_driver acpi_ec_driver = {
1068         .name = "ec",
1069         .class = ACPI_EC_CLASS,
1070         .ids = ec_device_ids,
1071         .ops = {
1072                 .add = acpi_ec_add,
1073                 .remove = acpi_ec_remove,
1074                 },
1075 };
1076
1077 int __init acpi_ec_init(void)
1078 {
1079         int result = 0;
1080
1081         /* Now register the driver for the EC */
1082         result = acpi_bus_register_driver(&acpi_ec_driver);
1083         if (result < 0)
1084                 return -ENODEV;
1085
1086         return result;
1087 }
1088
1089 /* EC driver currently not unloadable */
1090 #if 0
1091 static void __exit acpi_ec_exit(void)
1092 {
1093
1094         acpi_bus_unregister_driver(&acpi_ec_driver);
1095         return;
1096 }
1097 #endif  /* 0 */