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 #define pr_fmt(fmt) "ACPI : EC: " fmt
  32
  33 #include <linux/kernel.h>
  34 #include <linux/module.h>
  35 #include <linux/init.h>
  36 #include <linux/types.h>
  37 #include <linux/delay.h>
  38 #include <linux/interrupt.h>
  39 #include <linux/list.h>
  40 #include <linux/spinlock.h>
  41 #include <linux/slab.h>
  42 #include <asm/io.h>
  43 #include <acpi/acpi_bus.h>
  44 #include <acpi/acpi_drivers.h>
  45 #include <linux/dmi.h>
  46
  47 #include "internal.h"
  48
  49 #define ACPI_EC_CLASS                   "embedded_controller"
  50 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  51 #define ACPI_EC_FILE_INFO               "info"
  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_MSI_UDELAY      550     /* Wait 550us for MSI EC */
  71
  72 enum {
  73         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  74         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  75         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
  76                                          * OpReg are installed */
  77         EC_FLAGS_BLOCKED,               /* Transactions are blocked */
  78 };
  79
  80 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
  81 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
  82 module_param(ec_delay, uint, 0644);
  83 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
  84
  85 /*
  86  * If the number of false interrupts per one transaction exceeds
  87  * this threshold, will think there is a GPE storm happened and
  88  * will disable the GPE for normal transaction.
  89  */
  90 static unsigned int ec_storm_threshold  __read_mostly = 8;
  91 module_param(ec_storm_threshold, uint, 0644);
  92 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
  93
  94 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  95 /* External interfaces use first EC only, so remember */
  96 typedef int (*acpi_ec_query_func) (void *data);
  97
  98 struct acpi_ec_query_handler {
  99         struct list_head node;
 100         acpi_ec_query_func func;
 101         acpi_handle handle;
 102         void *data;
 103         u8 query_bit;
 104 };
 105
 106 struct transaction {
 107         const u8 *wdata;
 108         u8 *rdata;
 109         unsigned short irq_count;
 110         u8 command;
 111         u8 wi;
 112         u8 ri;
 113         u8 wlen;
 114         u8 rlen;
 115         bool done;
 116 };
 117
 118 struct acpi_ec *boot_ec, *first_ec;
 119 EXPORT_SYMBOL(first_ec);
 120
 121 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 122 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 123 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 124
 125 /* --------------------------------------------------------------------------
 126                              Transaction Management
 127    -------------------------------------------------------------------------- */
 128
 129 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 130 {
 131         u8 x = inb(ec->command_addr);
 132         pr_debug("---> status = 0x%2.2x\n", x);
 133         return x;
 134 }
 135
 136 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 137 {
 138         u8 x = inb(ec->data_addr);
 139         pr_debug("---> data = 0x%2.2x\n", x);
 140         return x;
 141 }
 142
 143 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 144 {
 145         pr_debug("<--- command = 0x%2.2x\n", command);
 146         outb(command, ec->command_addr);
 147 }
 148
 149 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 150 {
 151         pr_debug("<--- data = 0x%2.2x\n", data);
 152         outb(data, ec->data_addr);
 153 }
 154
 155 static int ec_transaction_done(struct acpi_ec *ec)
 156 {
 157         unsigned long flags;
 158         int ret = 0;
 159         spin_lock_irqsave(&ec->lock, flags);
 160         if (!ec->curr || ec->curr->done)
 161                 ret = 1;
 162         spin_unlock_irqrestore(&ec->lock, flags);
 163         return ret;
 164 }
 165
 166 static void start_transaction(struct acpi_ec *ec)
 167 {
 168         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 169         ec->curr->done = false;
 170         acpi_ec_write_cmd(ec, ec->curr->command);
 171 }
 172
 173 static void advance_transaction(struct acpi_ec *ec, u8 status)
 174 {
 175         unsigned long flags;
 176         struct transaction *t = ec->curr;
 177
 178         spin_lock_irqsave(&ec->lock, flags);
 179         if (!t)
 180                 goto unlock;
 181         if (t->wlen > t->wi) {
 182                 if ((status & ACPI_EC_FLAG_IBF) == 0)
 183                         acpi_ec_write_data(ec,
 184                                 t->wdata[t->wi++]);
 185                 else
 186                         goto err;
 187         } else if (t->rlen > t->ri) {
 188                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
 189                         t->rdata[t->ri++] = acpi_ec_read_data(ec);
 190                         if (t->rlen == t->ri)
 191                                 t->done = true;
 192                 } else
 193                         goto err;
 194         } else if (t->wlen == t->wi &&
 195                    (status & ACPI_EC_FLAG_IBF) == 0)
 196                 t->done = true;
 197         goto unlock;
 198 err:
 199         /*
 200          * If SCI bit is set, then don't think it's a false IRQ
 201          * otherwise will take a not handled IRQ as a false one.
 202          */
 203         if (in_interrupt() && !(status & ACPI_EC_FLAG_SCI))
 204                 ++t->irq_count;
 205
 206 unlock:
 207         spin_unlock_irqrestore(&ec->lock, flags);
 208 }
 209
 210 static int acpi_ec_sync_query(struct acpi_ec *ec);
 211
 212 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 213 {
 214         if (state & ACPI_EC_FLAG_SCI) {
 215                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 216                         return acpi_ec_sync_query(ec);
 217         }
 218         return 0;
 219 }
 220
 221 static int ec_poll(struct acpi_ec *ec)
 222 {
 223         unsigned long flags;
 224         int repeat = 5; /* number of command restarts */
 225         while (repeat--) {
 226                 unsigned long delay = jiffies +
 227                         msecs_to_jiffies(ec_delay);
 228                 do {
 229                         /* don't sleep with disabled interrupts */
 230                         if (EC_FLAGS_MSI || irqs_disabled()) {
 231                                 udelay(ACPI_EC_MSI_UDELAY);
 232                                 if (ec_transaction_done(ec))
 233                                         return 0;
 234                         } else {
 235                                 if (wait_event_timeout(ec->wait,
 236                                                 ec_transaction_done(ec),
 237                                                 msecs_to_jiffies(1)))
 238                                         return 0;
 239                         }
 240                         advance_transaction(ec, acpi_ec_read_status(ec));
 241                 } while (time_before(jiffies, delay));
 242                 pr_debug("controller reset, restart transaction\n");
 243                 spin_lock_irqsave(&ec->lock, flags);
 244                 start_transaction(ec);
 245                 spin_unlock_irqrestore(&ec->lock, flags);
 246         }
 247         return -ETIME;
 248 }
 249
 250 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 251                                         struct transaction *t)
 252 {
 253         unsigned long tmp;
 254         int ret = 0;
 255         if (EC_FLAGS_MSI)
 256                 udelay(ACPI_EC_MSI_UDELAY);
 257         /* start transaction */
 258         spin_lock_irqsave(&ec->lock, tmp);
 259         /* following two actions should be kept atomic */
 260         ec->curr = t;
 261         start_transaction(ec);
 262         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 263                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 264         spin_unlock_irqrestore(&ec->lock, tmp);
 265         ret = ec_poll(ec);
 266         spin_lock_irqsave(&ec->lock, tmp);
 267         ec->curr = NULL;
 268         spin_unlock_irqrestore(&ec->lock, tmp);
 269         return ret;
 270 }
 271
 272 static int ec_check_ibf0(struct acpi_ec *ec)
 273 {
 274         u8 status = acpi_ec_read_status(ec);
 275         return (status & ACPI_EC_FLAG_IBF) == 0;
 276 }
 277
 278 static int ec_wait_ibf0(struct acpi_ec *ec)
 279 {
 280         unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
 281         /* interrupt wait manually if GPE mode is not active */
 282         while (time_before(jiffies, delay))
 283                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
 284                                         msecs_to_jiffies(1)))
 285                         return 0;
 286         return -ETIME;
 287 }
 288
 289 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 290 {
 291         int status;
 292         u32 glk;
 293         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 294                 return -EINVAL;
 295         if (t->rdata)
 296                 memset(t->rdata, 0, t->rlen);
 297         mutex_lock(&ec->mutex);
 298         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 299                 status = -EINVAL;
 300                 goto unlock;
 301         }
 302         if (ec->global_lock) {
 303                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 304                 if (ACPI_FAILURE(status)) {
 305                         status = -ENODEV;
 306                         goto unlock;
 307                 }
 308         }
 309         if (ec_wait_ibf0(ec)) {
 310                 pr_err("input buffer is not empty, "
 311                                 "aborting transaction\n");
 312                 status = -ETIME;
 313                 goto end;
 314         }
 315         pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",
 316                         t->command, t->wdata ? t->wdata[0] : 0);
 317         /* disable GPE during transaction if storm is detected */
 318         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 319                 /* It has to be disabled, so that it doesn't trigger. */
 320                 acpi_disable_gpe(NULL, ec->gpe);
 321         }
 322
 323         status = acpi_ec_transaction_unlocked(ec, t);
 324
 325         /* check if we received SCI during transaction */
 326         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 327         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 328                 msleep(1);
 329                 /* It is safe to enable the GPE outside of the transaction. */
 330                 acpi_enable_gpe(NULL, ec->gpe);
 331         } else if (t->irq_count > ec_storm_threshold) {
 332                 pr_info("GPE storm detected(%d GPEs), "
 333                         "transactions will use polling mode\n",
 334                         t->irq_count);
 335                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 336         }
 337         pr_debug("transaction end\n");
 338 end:
 339         if (ec->global_lock)
 340                 acpi_release_global_lock(glk);
 341 unlock:
 342         mutex_unlock(&ec->mutex);
 343         return status;
 344 }
 345
 346 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 347 {
 348         u8 d;
 349         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 350                                 .wdata = NULL, .rdata = &d,
 351                                 .wlen = 0, .rlen = 1};
 352
 353         return acpi_ec_transaction(ec, &t);
 354 }
 355
 356 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 357 {
 358         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 359                                 .wdata = NULL, .rdata = NULL,
 360                                 .wlen = 0, .rlen = 0};
 361
 362         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 363                                 acpi_ec_transaction(ec, &t) : 0;
 364 }
 365
 366 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 367 {
 368         int result;
 369         u8 d;
 370         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 371                                 .wdata = &address, .rdata = &d,
 372                                 .wlen = 1, .rlen = 1};
 373
 374         result = acpi_ec_transaction(ec, &t);
 375         *data = d;
 376         return result;
 377 }
 378
 379 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 380 {
 381         u8 wdata[2] = { address, data };
 382         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 383                                 .wdata = wdata, .rdata = NULL,
 384                                 .wlen = 2, .rlen = 0};
 385
 386         return acpi_ec_transaction(ec, &t);
 387 }
 388
 389 /*
 390  * Externally callable EC access functions. For now, assume 1 EC only
 391  */
 392 int ec_burst_enable(void)
 393 {
 394         if (!first_ec)
 395                 return -ENODEV;
 396         return acpi_ec_burst_enable(first_ec);
 397 }
 398
 399 EXPORT_SYMBOL(ec_burst_enable);
 400
 401 int ec_burst_disable(void)
 402 {
 403         if (!first_ec)
 404                 return -ENODEV;
 405         return acpi_ec_burst_disable(first_ec);
 406 }
 407
 408 EXPORT_SYMBOL(ec_burst_disable);
 409
 410 int ec_read(u8 addr, u8 *val)
 411 {
 412         int err;
 413         u8 temp_data;
 414
 415         if (!first_ec)
 416                 return -ENODEV;
 417
 418         err = acpi_ec_read(first_ec, addr, &temp_data);
 419
 420         if (!err) {
 421                 *val = temp_data;
 422                 return 0;
 423         } else
 424                 return err;
 425 }
 426
 427 EXPORT_SYMBOL(ec_read);
 428
 429 int ec_write(u8 addr, u8 val)
 430 {
 431         int err;
 432
 433         if (!first_ec)
 434                 return -ENODEV;
 435
 436         err = acpi_ec_write(first_ec, addr, val);
 437
 438         return err;
 439 }
 440
 441 EXPORT_SYMBOL(ec_write);
 442
 443 int ec_transaction(u8 command,
 444                    const u8 * wdata, unsigned wdata_len,
 445                    u8 * rdata, unsigned rdata_len)
 446 {
 447         struct transaction t = {.command = command,
 448                                 .wdata = wdata, .rdata = rdata,
 449                                 .wlen = wdata_len, .rlen = rdata_len};
 450         if (!first_ec)
 451                 return -ENODEV;
 452
 453         return acpi_ec_transaction(first_ec, &t);
 454 }
 455
 456 EXPORT_SYMBOL(ec_transaction);
 457
 458 /* Get the handle to the EC device */
 459 acpi_handle ec_get_handle(void)
 460 {
 461         if (!first_ec)
 462                 return NULL;
 463         return first_ec->handle;
 464 }
 465
 466 EXPORT_SYMBOL(ec_get_handle);
 467
 468 void acpi_ec_block_transactions(void)
 469 {
 470         struct acpi_ec *ec = first_ec;
 471
 472         if (!ec)
 473                 return;
 474
 475         mutex_lock(&ec->mutex);
 476         /* Prevent transactions from being carried out */
 477         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 478         mutex_unlock(&ec->mutex);
 479 }
 480
 481 void acpi_ec_unblock_transactions(void)
 482 {
 483         struct acpi_ec *ec = first_ec;
 484
 485         if (!ec)
 486                 return;
 487
 488         mutex_lock(&ec->mutex);
 489         /* Allow transactions to be carried out again */
 490         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 491         mutex_unlock(&ec->mutex);
 492 }
 493
 494 void acpi_ec_unblock_transactions_early(void)
 495 {
 496         /*
 497          * Allow transactions to happen again (this function is called from
 498          * atomic context during wakeup, so we don't need to acquire the mutex).
 499          */
 500         if (first_ec)
 501                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 502 }
 503
 504 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 505 {
 506         int result;
 507         u8 d;
 508         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 509                                 .wdata = NULL, .rdata = &d,
 510                                 .wlen = 0, .rlen = 1};
 511         if (!ec || !data)
 512                 return -EINVAL;
 513         /*
 514          * Query the EC to find out which _Qxx method we need to evaluate.
 515          * Note that successful completion of the query causes the ACPI_EC_SCI
 516          * bit to be cleared (and thus clearing the interrupt source).
 517          */
 518         result = acpi_ec_transaction_unlocked(ec, &t);
 519         if (result)
 520                 return result;
 521         if (!d)
 522                 return -ENODATA;
 523         *data = d;
 524         return 0;
 525 }
 526
 527 /* --------------------------------------------------------------------------
 528                                 Event Management
 529    -------------------------------------------------------------------------- */
 530 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 531                               acpi_handle handle, acpi_ec_query_func func,
 532                               void *data)
 533 {
 534         struct acpi_ec_query_handler *handler =
 535             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 536         if (!handler)
 537                 return -ENOMEM;
 538
 539         handler->query_bit = query_bit;
 540         handler->handle = handle;
 541         handler->func = func;
 542         handler->data = data;
 543         mutex_lock(&ec->mutex);
 544         list_add(&handler->node, &ec->list);
 545         mutex_unlock(&ec->mutex);
 546         return 0;
 547 }
 548
 549 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 550
 551 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 552 {
 553         struct acpi_ec_query_handler *handler, *tmp;
 554         mutex_lock(&ec->mutex);
 555         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 556                 if (query_bit == handler->query_bit) {
 557                         list_del(&handler->node);
 558                         kfree(handler);
 559                 }
 560         }
 561         mutex_unlock(&ec->mutex);
 562 }
 563
 564 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 565
 566 static void acpi_ec_run(void *cxt)
 567 {
 568         struct acpi_ec_query_handler *handler = cxt;
 569         if (!handler)
 570                 return;
 571         pr_debug("start query execution\n");
 572         if (handler->func)
 573                 handler->func(handler->data);
 574         else if (handler->handle)
 575                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 576         pr_debug("stop query execution\n");
 577         kfree(handler);
 578 }
 579
 580 static int acpi_ec_sync_query(struct acpi_ec *ec)
 581 {
 582         u8 value = 0;
 583         int status;
 584         struct acpi_ec_query_handler *handler, *copy;
 585         if ((status = acpi_ec_query_unlocked(ec, &value)))
 586                 return status;
 587         list_for_each_entry(handler, &ec->list, node) {
 588                 if (value == handler->query_bit) {
 589                         /* have custom handler for this bit */
 590                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 591                         if (!copy)
 592                                 return -ENOMEM;
 593                         memcpy(copy, handler, sizeof(*copy));
 594                         pr_debug("push query execution (0x%2x) on queue\n",
 595                                 value);
 596                         return acpi_os_execute((copy->func) ?
 597                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 598                                 acpi_ec_run, copy);
 599                 }
 600         }
 601         return 0;
 602 }
 603
 604 static void acpi_ec_gpe_query(void *ec_cxt)
 605 {
 606         struct acpi_ec *ec = ec_cxt;
 607         if (!ec)
 608                 return;
 609         mutex_lock(&ec->mutex);
 610         acpi_ec_sync_query(ec);
 611         mutex_unlock(&ec->mutex);
 612 }
 613
 614 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 615 {
 616         if (state & ACPI_EC_FLAG_SCI) {
 617                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 618                         pr_debug("push gpe query to the queue\n");
 619                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 620                                 acpi_ec_gpe_query, ec);
 621                 }
 622         }
 623         return 0;
 624 }
 625
 626 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 627         u32 gpe_number, void *data)
 628 {
 629         struct acpi_ec *ec = data;
 630         u8 status = acpi_ec_read_status(ec);
 631
 632         pr_debug("~~~> interrupt, status:0x%02x\n", status);
 633
 634         advance_transaction(ec, status);
 635         if (ec_transaction_done(ec) &&
 636             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 637                 wake_up(&ec->wait);
 638                 ec_check_sci(ec, acpi_ec_read_status(ec));
 639         }
 640         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 641 }
 642
 643 /* --------------------------------------------------------------------------
 644                              Address Space Management
 645    -------------------------------------------------------------------------- */
 646
 647 static acpi_status
 648 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 649                       u32 bits, u64 *value64,
 650                       void *handler_context, void *region_context)
 651 {
 652         struct acpi_ec *ec = handler_context;
 653         int result = 0, i, bytes = bits / 8;
 654         u8 *value = (u8 *)value64;
 655
 656         if ((address > 0xFF) || !value || !handler_context)
 657                 return AE_BAD_PARAMETER;
 658
 659         if (function != ACPI_READ && function != ACPI_WRITE)
 660                 return AE_BAD_PARAMETER;
 661
 662         if (EC_FLAGS_MSI || bits > 8)
 663                 acpi_ec_burst_enable(ec);
 664
 665         for (i = 0; i < bytes; ++i, ++address, ++value)
 666                 result = (function == ACPI_READ) ?
 667                         acpi_ec_read(ec, address, value) :
 668                         acpi_ec_write(ec, address, *value);
 669
 670         if (EC_FLAGS_MSI || bits > 8)
 671                 acpi_ec_burst_disable(ec);
 672
 673         switch (result) {
 674         case -EINVAL:
 675                 return AE_BAD_PARAMETER;
 676                 break;
 677         case -ENODEV:
 678                 return AE_NOT_FOUND;
 679                 break;
 680         case -ETIME:
 681                 return AE_TIME;
 682                 break;
 683         default:
 684                 return AE_OK;
 685         }
 686 }
 687
 688 /* --------------------------------------------------------------------------
 689                                Driver Interface
 690    -------------------------------------------------------------------------- */
 691 static acpi_status
 692 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 693
 694 static struct acpi_ec *make_acpi_ec(void)
 695 {
 696         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 697         if (!ec)
 698                 return NULL;
 699         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 700         mutex_init(&ec->mutex);
 701         init_waitqueue_head(&ec->wait);
 702         INIT_LIST_HEAD(&ec->list);
 703         spin_lock_init(&ec->lock);
 704         return ec;
 705 }
 706
 707 static acpi_status
 708 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 709                                void *context, void **return_value)
 710 {
 711         char node_name[5];
 712         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 713         struct acpi_ec *ec = context;
 714         int value = 0;
 715         acpi_status status;
 716
 717         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 718
 719         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 720                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 721         }
 722         return AE_OK;
 723 }
 724
 725 static acpi_status
 726 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 727 {
 728         acpi_status status;
 729         unsigned long long tmp = 0;
 730
 731         struct acpi_ec *ec = context;
 732
 733         /* clear addr values, ec_parse_io_ports depend on it */
 734         ec->command_addr = ec->data_addr = 0;
 735
 736         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 737                                      ec_parse_io_ports, ec);
 738         if (ACPI_FAILURE(status))
 739                 return status;
 740
 741         /* Get GPE bit assignment (EC events). */
 742         /* TODO: Add support for _GPE returning a package */
 743         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 744         if (ACPI_FAILURE(status))
 745                 return status;
 746         ec->gpe = tmp;
 747         /* Use the global lock for all EC transactions? */
 748         tmp = 0;
 749         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 750         ec->global_lock = tmp;
 751         ec->handle = handle;
 752         return AE_CTRL_TERMINATE;
 753 }
 754
 755 static int ec_install_handlers(struct acpi_ec *ec)
 756 {
 757         acpi_status status;
 758         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 759                 return 0;
 760         status = acpi_install_gpe_handler(NULL, ec->gpe,
 761                                   ACPI_GPE_EDGE_TRIGGERED,
 762                                   &acpi_ec_gpe_handler, ec);
 763         if (ACPI_FAILURE(status))
 764                 return -ENODEV;
 765
 766         acpi_enable_gpe(NULL, ec->gpe);
 767         status = acpi_install_address_space_handler(ec->handle,
 768                                                     ACPI_ADR_SPACE_EC,
 769                                                     &acpi_ec_space_handler,
 770                                                     NULL, ec);
 771         if (ACPI_FAILURE(status)) {
 772                 if (status == AE_NOT_FOUND) {
 773                         /*
 774                          * Maybe OS fails in evaluating the _REG object.
 775                          * The AE_NOT_FOUND error will be ignored and OS
 776                          * continue to initialize EC.
 777                          */
 778                         pr_err("Fail in evaluating the _REG object"
 779                                 " of EC device. Broken bios is suspected.\n");
 780                 } else {
 781                         acpi_remove_gpe_handler(NULL, ec->gpe,
 782                                 &acpi_ec_gpe_handler);
 783                         acpi_disable_gpe(NULL, ec->gpe);
 784                         return -ENODEV;
 785                 }
 786         }
 787
 788         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 789         return 0;
 790 }
 791
 792 static void ec_remove_handlers(struct acpi_ec *ec)
 793 {
 794         acpi_disable_gpe(NULL, ec->gpe);
 795         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 796                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 797                 pr_err("failed to remove space handler\n");
 798         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 799                                 &acpi_ec_gpe_handler)))
 800                 pr_err("failed to remove gpe handler\n");
 801         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 802 }
 803
 804 static int acpi_ec_add(struct acpi_device *device)
 805 {
 806         struct acpi_ec *ec = NULL;
 807         int ret;
 808
 809         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 810         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 811
 812         /* Check for boot EC */
 813         if (boot_ec &&
 814             (boot_ec->handle == device->handle ||
 815              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 816                 ec = boot_ec;
 817                 boot_ec = NULL;
 818         } else {
 819                 ec = make_acpi_ec();
 820                 if (!ec)
 821                         return -ENOMEM;
 822         }
 823         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 824                 AE_CTRL_TERMINATE) {
 825                         kfree(ec);
 826                         return -EINVAL;
 827         }
 828
 829         /* Find and register all query methods */
 830         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 831                             acpi_ec_register_query_methods, NULL, ec, NULL);
 832
 833         if (!first_ec)
 834                 first_ec = ec;
 835         device->driver_data = ec;
 836
 837         ret = !!request_region(ec->data_addr, 1, "EC data");
 838         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
 839         ret = !!request_region(ec->command_addr, 1, "EC cmd");
 840         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
 841
 842         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 843                           ec->gpe, ec->command_addr, ec->data_addr);
 844
 845         ret = ec_install_handlers(ec);
 846
 847         /* EC is fully operational, allow queries */
 848         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 849         return ret;
 850 }
 851
 852 static int acpi_ec_remove(struct acpi_device *device)
 853 {
 854         struct acpi_ec *ec;
 855         struct acpi_ec_query_handler *handler, *tmp;
 856
 857         if (!device)
 858                 return -EINVAL;
 859
 860         ec = acpi_driver_data(device);
 861         ec_remove_handlers(ec);
 862         mutex_lock(&ec->mutex);
 863         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 864                 list_del(&handler->node);
 865                 kfree(handler);
 866         }
 867         mutex_unlock(&ec->mutex);
 868         release_region(ec->data_addr, 1);
 869         release_region(ec->command_addr, 1);
 870         device->driver_data = NULL;
 871         if (ec == first_ec)
 872                 first_ec = NULL;
 873         kfree(ec);
 874         return 0;
 875 }
 876
 877 static acpi_status
 878 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 879 {
 880         struct acpi_ec *ec = context;
 881
 882         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 883                 return AE_OK;
 884
 885         /*
 886          * The first address region returned is the data port, and
 887          * the second address region returned is the status/command
 888          * port.
 889          */
 890         if (ec->data_addr == 0)
 891                 ec->data_addr = resource->data.io.minimum;
 892         else if (ec->command_addr == 0)
 893                 ec->command_addr = resource->data.io.minimum;
 894         else
 895                 return AE_CTRL_TERMINATE;
 896
 897         return AE_OK;
 898 }
 899
 900 int __init acpi_boot_ec_enable(void)
 901 {
 902         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 903                 return 0;
 904         if (!ec_install_handlers(boot_ec)) {
 905                 first_ec = boot_ec;
 906                 return 0;
 907         }
 908         return -EFAULT;
 909 }
 910
 911 static const struct acpi_device_id ec_device_ids[] = {
 912         {"PNP0C09", 0},
 913         {"", 0},
 914 };
 915
 916 /* Some BIOS do not survive early DSDT scan, skip it */
 917 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 918 {
 919         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 920         return 0;
 921 }
 922
 923 /* ASUStek often supplies us with broken ECDT, validate it */
 924 static int ec_validate_ecdt(const struct dmi_system_id *id)
 925 {
 926         EC_FLAGS_VALIDATE_ECDT = 1;
 927         return 0;
 928 }
 929
 930 /* MSI EC needs special treatment, enable it */
 931 static int ec_flag_msi(const struct dmi_system_id *id)
 932 {
 933         pr_debug("Detected MSI hardware, enabling workarounds.\n");
 934         EC_FLAGS_MSI = 1;
 935         EC_FLAGS_VALIDATE_ECDT = 1;
 936         return 0;
 937 }
 938
 939 /*
 940  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
 941  * the GPE storm threshold back to 20
 942  */
 943 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
 944 {
 945         pr_debug("Setting the EC GPE storm threshold to 20\n");
 946         ec_storm_threshold  = 20;
 947         return 0;
 948 }
 949
 950 static struct dmi_system_id ec_dmi_table[] __initdata = {
 951         {
 952         ec_skip_dsdt_scan, "Compal JFL92", {
 953         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 954         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 955         {
 956         ec_flag_msi, "MSI hardware", {
 957         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
 958         {
 959         ec_flag_msi, "MSI hardware", {
 960         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
 961         {
 962         ec_flag_msi, "MSI hardware", {
 963         DMI_MATCH(DMI_CHASSIS_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, "Quanta hardware", {
 969         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
 970         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
 971         {
 972         ec_flag_msi, "Quanta hardware", {
 973         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
 974         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
 975         {
 976         ec_validate_ecdt, "ASUS hardware", {
 977         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
 978         {
 979         ec_validate_ecdt, "ASUS hardware", {
 980         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
 981         {
 982         ec_enlarge_storm_threshold, "CLEVO hardware", {
 983         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
 984         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
 985         {
 986         ec_skip_dsdt_scan, "HP Folio 13", {
 987         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 988         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
 989         {
 990         ec_validate_ecdt, "ASUS hardware", {
 991         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
 992         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
 993         {},
 994 };
 995
 996 int __init acpi_ec_ecdt_probe(void)
 997 {
 998         acpi_status status;
 999         struct acpi_ec *saved_ec = NULL;
1000         struct acpi_table_ecdt *ecdt_ptr;
1001
1002         boot_ec = make_acpi_ec();
1003         if (!boot_ec)
1004                 return -ENOMEM;
1005         /*
1006          * Generate a boot ec context
1007          */
1008         dmi_check_system(ec_dmi_table);
1009         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1010                                 (struct acpi_table_header **)&ecdt_ptr);
1011         if (ACPI_SUCCESS(status)) {
1012                 pr_info("EC description table is found, configuring boot EC\n");
1013                 boot_ec->command_addr = ecdt_ptr->control.address;
1014                 boot_ec->data_addr = ecdt_ptr->data.address;
1015                 boot_ec->gpe = ecdt_ptr->gpe;
1016                 boot_ec->handle = ACPI_ROOT_OBJECT;
1017                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1018                 /* Don't trust ECDT, which comes from ASUSTek */
1019                 if (!EC_FLAGS_VALIDATE_ECDT)
1020                         goto install;
1021                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1022                 if (!saved_ec)
1023                         return -ENOMEM;
1024         /* fall through */
1025         }
1026
1027         if (EC_FLAGS_SKIP_DSDT_SCAN)
1028                 return -ENODEV;
1029
1030         /* This workaround is needed only on some broken machines,
1031          * which require early EC, but fail to provide ECDT */
1032         pr_debug("Look up EC in DSDT\n");
1033         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1034                                         boot_ec, NULL);
1035         /* Check that acpi_get_devices actually find something */
1036         if (ACPI_FAILURE(status) || !boot_ec->handle)
1037                 goto error;
1038         if (saved_ec) {
1039                 /* try to find good ECDT from ASUSTek */
1040                 if (saved_ec->command_addr != boot_ec->command_addr ||
1041                     saved_ec->data_addr != boot_ec->data_addr ||
1042                     saved_ec->gpe != boot_ec->gpe ||
1043                     saved_ec->handle != boot_ec->handle)
1044                         pr_info("ASUSTek keeps feeding us with broken "
1045                         "ECDT tables, which are very hard to workaround. "
1046                         "Trying to use DSDT EC info instead. Please send "
1047                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1048                 kfree(saved_ec);
1049                 saved_ec = NULL;
1050         } else {
1051                 /* We really need to limit this workaround, the only ASUS,
1052                 * which needs it, has fake EC._INI method, so use it as flag.
1053                 * Keep boot_ec struct as it will be needed soon.
1054                 */
1055                 if (!dmi_name_in_vendors("ASUS") ||
1056                     !acpi_has_method(boot_ec->handle, "_INI"))
1057                         return -ENODEV;
1058         }
1059 install:
1060         if (!ec_install_handlers(boot_ec)) {
1061                 first_ec = boot_ec;
1062                 return 0;
1063         }
1064 error:
1065         kfree(boot_ec);
1066         boot_ec = NULL;
1067         return -ENODEV;
1068 }
1069
1070 static struct acpi_driver acpi_ec_driver = {
1071         .name = "ec",
1072         .class = ACPI_EC_CLASS,
1073         .ids = ec_device_ids,
1074         .ops = {
1075                 .add = acpi_ec_add,
1076                 .remove = acpi_ec_remove,
1077                 },
1078 };
1079
1080 int __init acpi_ec_init(void)
1081 {
1082         int result = 0;
1083
1084         /* Now register the driver for the EC */
1085         result = acpi_bus_register_driver(&acpi_ec_driver);
1086         if (result < 0)
1087                 return -ENODEV;
1088
1089         return result;
1090 }
1091
1092 /* EC driver currently not unloadable */
1093 #if 0
1094 static void __exit acpi_ec_exit(void)
1095 {
1096
1097         acpi_bus_unregister_driver(&acpi_ec_driver);
1098         return;
1099 }
1100 #endif  /* 0 */