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 <linux/acpi.h>
  43 #include <linux/dmi.h>
  44 #include <asm/io.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 /* EC status register */
  53 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  54 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  55 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  56 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  57
  58 /* EC commands */
  59 enum ec_command {
  60         ACPI_EC_COMMAND_READ = 0x80,
  61         ACPI_EC_COMMAND_WRITE = 0x81,
  62         ACPI_EC_BURST_ENABLE = 0x82,
  63         ACPI_EC_BURST_DISABLE = 0x83,
  64         ACPI_EC_COMMAND_QUERY = 0x84,
  65 };
  66
  67 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  68 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  69 #define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
  70 #define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
  71                                          * when trying to clear the EC */
  72
  73 enum {
  74         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  75         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  76         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
  77                                          * OpReg are installed */
  78         EC_FLAGS_BLOCKED,               /* Transactions are blocked */
  79 };
  80
  81 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
  82 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
  83
  84 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
  85 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
  86 module_param(ec_delay, uint, 0644);
  87 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
  88
  89 /*
  90  * If the number of false interrupts per one transaction exceeds
  91  * this threshold, will think there is a GPE storm happened and
  92  * will disable the GPE for normal transaction.
  93  */
  94 static unsigned int ec_storm_threshold  __read_mostly = 8;
  95 module_param(ec_storm_threshold, uint, 0644);
  96 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
  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         u8 flags;
 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 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 125
 126 /* --------------------------------------------------------------------------
 127                              Transaction Management
 128    -------------------------------------------------------------------------- */
 129
 130 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 131 {
 132         u8 x = inb(ec->command_addr);
 133         pr_debug("---> status = 0x%2.2x\n", x);
 134         return x;
 135 }
 136
 137 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 138 {
 139         u8 x = inb(ec->data_addr);
 140         pr_debug("---> data = 0x%2.2x\n", x);
 141         return x;
 142 }
 143
 144 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 145 {
 146         pr_debug("<--- command = 0x%2.2x\n", command);
 147         outb(command, ec->command_addr);
 148 }
 149
 150 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 151 {
 152         pr_debug("<--- data = 0x%2.2x\n", data);
 153         outb(data, ec->data_addr);
 154 }
 155
 156 static int ec_transaction_completed(struct acpi_ec *ec)
 157 {
 158         unsigned long flags;
 159         int ret = 0;
 160         spin_lock_irqsave(&ec->lock, flags);
 161         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 162                 ret = 1;
 163         spin_unlock_irqrestore(&ec->lock, flags);
 164         return ret;
 165 }
 166
 167 static bool advance_transaction(struct acpi_ec *ec)
 168 {
 169         struct transaction *t;
 170         u8 status;
 171         bool wakeup = false;
 172
 173         pr_debug("===== %s =====\n", in_interrupt() ? "IRQ" : "TASK");
 174         status = acpi_ec_read_status(ec);
 175         t = ec->curr;
 176         if (!t)
 177                 goto err;
 178         if (t->flags & ACPI_EC_COMMAND_POLL) {
 179                 if (t->wlen > t->wi) {
 180                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 181                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 182                         else
 183                                 goto err;
 184                 } else if (t->rlen > t->ri) {
 185                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 186                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 187                                 if (t->rlen == t->ri) {
 188                                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 189                                         wakeup = true;
 190                                 }
 191                         } else
 192                                 goto err;
 193                 } else if (t->wlen == t->wi &&
 194                            (status & ACPI_EC_FLAG_IBF) == 0) {
 195                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 196                         wakeup = true;
 197                 }
 198                 return wakeup;
 199         } else {
 200                 if ((status & ACPI_EC_FLAG_IBF) == 0) {
 201                         acpi_ec_write_cmd(ec, t->command);
 202                         t->flags |= ACPI_EC_COMMAND_POLL;
 203                 } else
 204                         goto err;
 205                 return wakeup;
 206         }
 207 err:
 208         /*
 209          * If SCI bit is set, then don't think it's a false IRQ
 210          * otherwise will take a not handled IRQ as a false one.
 211          */
 212         if (!(status & ACPI_EC_FLAG_SCI)) {
 213                 if (in_interrupt() && t)
 214                         ++t->irq_count;
 215         }
 216         return wakeup;
 217 }
 218
 219 static void start_transaction(struct acpi_ec *ec)
 220 {
 221         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 222         ec->curr->flags = 0;
 223         (void)advance_transaction(ec);
 224 }
 225
 226 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
 227
 228 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 229 {
 230         if (state & ACPI_EC_FLAG_SCI) {
 231                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 232                         return acpi_ec_sync_query(ec, NULL);
 233         }
 234         return 0;
 235 }
 236
 237 static int ec_poll(struct acpi_ec *ec)
 238 {
 239         unsigned long flags;
 240         int repeat = 5; /* number of command restarts */
 241         while (repeat--) {
 242                 unsigned long delay = jiffies +
 243                         msecs_to_jiffies(ec_delay);
 244                 do {
 245                         /* don't sleep with disabled interrupts */
 246                         if (EC_FLAGS_MSI || irqs_disabled()) {
 247                                 udelay(ACPI_EC_MSI_UDELAY);
 248                                 if (ec_transaction_completed(ec))
 249                                         return 0;
 250                         } else {
 251                                 if (wait_event_timeout(ec->wait,
 252                                                 ec_transaction_completed(ec),
 253                                                 msecs_to_jiffies(1)))
 254                                         return 0;
 255                         }
 256                         spin_lock_irqsave(&ec->lock, flags);
 257                         (void)advance_transaction(ec);
 258                         spin_unlock_irqrestore(&ec->lock, flags);
 259                 } while (time_before(jiffies, delay));
 260                 pr_debug("controller reset, restart transaction\n");
 261                 spin_lock_irqsave(&ec->lock, flags);
 262                 start_transaction(ec);
 263                 spin_unlock_irqrestore(&ec->lock, flags);
 264         }
 265         return -ETIME;
 266 }
 267
 268 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 269                                         struct transaction *t)
 270 {
 271         unsigned long tmp;
 272         int ret = 0;
 273         if (EC_FLAGS_MSI)
 274                 udelay(ACPI_EC_MSI_UDELAY);
 275         /* start transaction */
 276         spin_lock_irqsave(&ec->lock, tmp);
 277         /* following two actions should be kept atomic */
 278         ec->curr = t;
 279         start_transaction(ec);
 280         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 281                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 282         spin_unlock_irqrestore(&ec->lock, tmp);
 283         ret = ec_poll(ec);
 284         spin_lock_irqsave(&ec->lock, tmp);
 285         ec->curr = NULL;
 286         spin_unlock_irqrestore(&ec->lock, tmp);
 287         return ret;
 288 }
 289
 290 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 291 {
 292         int status;
 293         u32 glk;
 294         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 295                 return -EINVAL;
 296         if (t->rdata)
 297                 memset(t->rdata, 0, t->rlen);
 298         mutex_lock(&ec->mutex);
 299         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 300                 status = -EINVAL;
 301                 goto unlock;
 302         }
 303         if (ec->global_lock) {
 304                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 305                 if (ACPI_FAILURE(status)) {
 306                         status = -ENODEV;
 307                         goto unlock;
 308                 }
 309         }
 310         pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",
 311                         t->command, t->wdata ? t->wdata[0] : 0);
 312         /* disable GPE during transaction if storm is detected */
 313         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 314                 /* It has to be disabled, so that it doesn't trigger. */
 315                 acpi_disable_gpe(NULL, ec->gpe);
 316         }
 317
 318         status = acpi_ec_transaction_unlocked(ec, t);
 319
 320         /* check if we received SCI during transaction */
 321         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 322         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 323                 msleep(1);
 324                 /* It is safe to enable the GPE outside of the transaction. */
 325                 acpi_enable_gpe(NULL, ec->gpe);
 326         } else if (t->irq_count > ec_storm_threshold) {
 327                 pr_info("GPE storm detected(%d GPEs), "
 328                         "transactions will use polling mode\n",
 329                         t->irq_count);
 330                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 331         }
 332         pr_debug("transaction end\n");
 333         if (ec->global_lock)
 334                 acpi_release_global_lock(glk);
 335 unlock:
 336         mutex_unlock(&ec->mutex);
 337         return status;
 338 }
 339
 340 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 341 {
 342         u8 d;
 343         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 344                                 .wdata = NULL, .rdata = &d,
 345                                 .wlen = 0, .rlen = 1};
 346
 347         return acpi_ec_transaction(ec, &t);
 348 }
 349
 350 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 351 {
 352         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 353                                 .wdata = NULL, .rdata = NULL,
 354                                 .wlen = 0, .rlen = 0};
 355
 356         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 357                                 acpi_ec_transaction(ec, &t) : 0;
 358 }
 359
 360 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 361 {
 362         int result;
 363         u8 d;
 364         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 365                                 .wdata = &address, .rdata = &d,
 366                                 .wlen = 1, .rlen = 1};
 367
 368         result = acpi_ec_transaction(ec, &t);
 369         *data = d;
 370         return result;
 371 }
 372
 373 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 374 {
 375         u8 wdata[2] = { address, data };
 376         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 377                                 .wdata = wdata, .rdata = NULL,
 378                                 .wlen = 2, .rlen = 0};
 379
 380         return acpi_ec_transaction(ec, &t);
 381 }
 382
 383 int ec_read(u8 addr, u8 *val)
 384 {
 385         int err;
 386         u8 temp_data;
 387
 388         if (!first_ec)
 389                 return -ENODEV;
 390
 391         err = acpi_ec_read(first_ec, addr, &temp_data);
 392
 393         if (!err) {
 394                 *val = temp_data;
 395                 return 0;
 396         } else
 397                 return err;
 398 }
 399
 400 EXPORT_SYMBOL(ec_read);
 401
 402 int ec_write(u8 addr, u8 val)
 403 {
 404         int err;
 405
 406         if (!first_ec)
 407                 return -ENODEV;
 408
 409         err = acpi_ec_write(first_ec, addr, val);
 410
 411         return err;
 412 }
 413
 414 EXPORT_SYMBOL(ec_write);
 415
 416 int ec_transaction(u8 command,
 417                    const u8 * wdata, unsigned wdata_len,
 418                    u8 * rdata, unsigned rdata_len)
 419 {
 420         struct transaction t = {.command = command,
 421                                 .wdata = wdata, .rdata = rdata,
 422                                 .wlen = wdata_len, .rlen = rdata_len};
 423         if (!first_ec)
 424                 return -ENODEV;
 425
 426         return acpi_ec_transaction(first_ec, &t);
 427 }
 428
 429 EXPORT_SYMBOL(ec_transaction);
 430
 431 /* Get the handle to the EC device */
 432 acpi_handle ec_get_handle(void)
 433 {
 434         if (!first_ec)
 435                 return NULL;
 436         return first_ec->handle;
 437 }
 438
 439 EXPORT_SYMBOL(ec_get_handle);
 440
 441 /*
 442  * Process _Q events that might have accumulated in the EC.
 443  * Run with locked ec mutex.
 444  */
 445 static void acpi_ec_clear(struct acpi_ec *ec)
 446 {
 447         int i, status;
 448         u8 value = 0;
 449
 450         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 451                 status = acpi_ec_sync_query(ec, &value);
 452                 if (status || !value)
 453                         break;
 454         }
 455
 456         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 457                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 458         else
 459                 pr_info("%d stale EC events cleared\n", i);
 460 }
 461
 462 void acpi_ec_block_transactions(void)
 463 {
 464         struct acpi_ec *ec = first_ec;
 465
 466         if (!ec)
 467                 return;
 468
 469         mutex_lock(&ec->mutex);
 470         /* Prevent transactions from being carried out */
 471         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 472         mutex_unlock(&ec->mutex);
 473 }
 474
 475 void acpi_ec_unblock_transactions(void)
 476 {
 477         struct acpi_ec *ec = first_ec;
 478
 479         if (!ec)
 480                 return;
 481
 482         mutex_lock(&ec->mutex);
 483         /* Allow transactions to be carried out again */
 484         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 485
 486         if (EC_FLAGS_CLEAR_ON_RESUME)
 487                 acpi_ec_clear(ec);
 488
 489         mutex_unlock(&ec->mutex);
 490 }
 491
 492 void acpi_ec_unblock_transactions_early(void)
 493 {
 494         /*
 495          * Allow transactions to happen again (this function is called from
 496          * atomic context during wakeup, so we don't need to acquire the mutex).
 497          */
 498         if (first_ec)
 499                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 500 }
 501
 502 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 503 {
 504         int result;
 505         u8 d;
 506         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 507                                 .wdata = NULL, .rdata = &d,
 508                                 .wlen = 0, .rlen = 1};
 509         if (!ec || !data)
 510                 return -EINVAL;
 511         /*
 512          * Query the EC to find out which _Qxx method we need to evaluate.
 513          * Note that successful completion of the query causes the ACPI_EC_SCI
 514          * bit to be cleared (and thus clearing the interrupt source).
 515          */
 516         result = acpi_ec_transaction_unlocked(ec, &t);
 517         if (result)
 518                 return result;
 519         if (!d)
 520                 return -ENODATA;
 521         *data = d;
 522         return 0;
 523 }
 524
 525 /* --------------------------------------------------------------------------
 526                                 Event Management
 527    -------------------------------------------------------------------------- */
 528 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 529                               acpi_handle handle, acpi_ec_query_func func,
 530                               void *data)
 531 {
 532         struct acpi_ec_query_handler *handler =
 533             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 534         if (!handler)
 535                 return -ENOMEM;
 536
 537         handler->query_bit = query_bit;
 538         handler->handle = handle;
 539         handler->func = func;
 540         handler->data = data;
 541         mutex_lock(&ec->mutex);
 542         list_add(&handler->node, &ec->list);
 543         mutex_unlock(&ec->mutex);
 544         return 0;
 545 }
 546
 547 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 548
 549 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 550 {
 551         struct acpi_ec_query_handler *handler, *tmp;
 552         mutex_lock(&ec->mutex);
 553         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 554                 if (query_bit == handler->query_bit) {
 555                         list_del(&handler->node);
 556                         kfree(handler);
 557                 }
 558         }
 559         mutex_unlock(&ec->mutex);
 560 }
 561
 562 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 563
 564 static void acpi_ec_run(void *cxt)
 565 {
 566         struct acpi_ec_query_handler *handler = cxt;
 567         if (!handler)
 568                 return;
 569         pr_debug("start query execution\n");
 570         if (handler->func)
 571                 handler->func(handler->data);
 572         else if (handler->handle)
 573                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 574         pr_debug("stop query execution\n");
 575         kfree(handler);
 576 }
 577
 578 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
 579 {
 580         u8 value = 0;
 581         int status;
 582         struct acpi_ec_query_handler *handler, *copy;
 583
 584         status = acpi_ec_query_unlocked(ec, &value);
 585         if (data)
 586                 *data = value;
 587         if (status)
 588                 return status;
 589
 590         list_for_each_entry(handler, &ec->list, node) {
 591                 if (value == handler->query_bit) {
 592                         /* have custom handler for this bit */
 593                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 594                         if (!copy)
 595                                 return -ENOMEM;
 596                         memcpy(copy, handler, sizeof(*copy));
 597                         pr_debug("push query execution (0x%2x) on queue\n",
 598                                 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, NULL);
 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("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         unsigned long flags;
 633         struct acpi_ec *ec = data;
 634
 635         spin_lock_irqsave(&ec->lock, flags);
 636         if (advance_transaction(ec))
 637                 wake_up(&ec->wait);
 638         spin_unlock_irqrestore(&ec->lock, flags);
 639         ec_check_sci(ec, acpi_ec_read_status(ec));
 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_disable_gpe(NULL, ec->gpe);
 782                         acpi_remove_gpe_handler(NULL, ec->gpe,
 783                                 &acpi_ec_gpe_handler);
 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
 850         /* Clear stale _Q events if hardware might require that */
 851         if (EC_FLAGS_CLEAR_ON_RESUME) {
 852                 mutex_lock(&ec->mutex);
 853                 acpi_ec_clear(ec);
 854                 mutex_unlock(&ec->mutex);
 855         }
 856         return ret;
 857 }
 858
 859 static int acpi_ec_remove(struct acpi_device *device)
 860 {
 861         struct acpi_ec *ec;
 862         struct acpi_ec_query_handler *handler, *tmp;
 863
 864         if (!device)
 865                 return -EINVAL;
 866
 867         ec = acpi_driver_data(device);
 868         ec_remove_handlers(ec);
 869         mutex_lock(&ec->mutex);
 870         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 871                 list_del(&handler->node);
 872                 kfree(handler);
 873         }
 874         mutex_unlock(&ec->mutex);
 875         release_region(ec->data_addr, 1);
 876         release_region(ec->command_addr, 1);
 877         device->driver_data = NULL;
 878         if (ec == first_ec)
 879                 first_ec = NULL;
 880         kfree(ec);
 881         return 0;
 882 }
 883
 884 static acpi_status
 885 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 886 {
 887         struct acpi_ec *ec = context;
 888
 889         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 890                 return AE_OK;
 891
 892         /*
 893          * The first address region returned is the data port, and
 894          * the second address region returned is the status/command
 895          * port.
 896          */
 897         if (ec->data_addr == 0)
 898                 ec->data_addr = resource->data.io.minimum;
 899         else if (ec->command_addr == 0)
 900                 ec->command_addr = resource->data.io.minimum;
 901         else
 902                 return AE_CTRL_TERMINATE;
 903
 904         return AE_OK;
 905 }
 906
 907 int __init acpi_boot_ec_enable(void)
 908 {
 909         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 910                 return 0;
 911         if (!ec_install_handlers(boot_ec)) {
 912                 first_ec = boot_ec;
 913                 return 0;
 914         }
 915         return -EFAULT;
 916 }
 917
 918 static const struct acpi_device_id ec_device_ids[] = {
 919         {"PNP0C09", 0},
 920         {"", 0},
 921 };
 922
 923 /* Some BIOS do not survive early DSDT scan, skip it */
 924 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 925 {
 926         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 927         return 0;
 928 }
 929
 930 /* ASUStek often supplies us with broken ECDT, validate it */
 931 static int ec_validate_ecdt(const struct dmi_system_id *id)
 932 {
 933         EC_FLAGS_VALIDATE_ECDT = 1;
 934         return 0;
 935 }
 936
 937 /* MSI EC needs special treatment, enable it */
 938 static int ec_flag_msi(const struct dmi_system_id *id)
 939 {
 940         pr_debug("Detected MSI hardware, enabling workarounds.\n");
 941         EC_FLAGS_MSI = 1;
 942         EC_FLAGS_VALIDATE_ECDT = 1;
 943         return 0;
 944 }
 945
 946 /*
 947  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
 948  * the GPE storm threshold back to 20
 949  */
 950 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
 951 {
 952         pr_debug("Setting the EC GPE storm threshold to 20\n");
 953         ec_storm_threshold  = 20;
 954         return 0;
 955 }
 956
 957 /*
 958  * On some hardware it is necessary to clear events accumulated by the EC during
 959  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
 960  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
 961  *
 962  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
 963  *
 964  * Ideally, the EC should also be instructed NOT to accumulate events during
 965  * sleep (which Windows seems to do somehow), but the interface to control this
 966  * behaviour is not known at this time.
 967  *
 968  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
 969  * however it is very likely that other Samsung models are affected.
 970  *
 971  * On systems which don't accumulate _Q events during sleep, this extra check
 972  * should be harmless.
 973  */
 974 static int ec_clear_on_resume(const struct dmi_system_id *id)
 975 {
 976         pr_debug("Detected system needing EC poll on resume.\n");
 977         EC_FLAGS_CLEAR_ON_RESUME = 1;
 978         return 0;
 979 }
 980
 981 static struct dmi_system_id ec_dmi_table[] __initdata = {
 982         {
 983         ec_skip_dsdt_scan, "Compal JFL92", {
 984         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 985         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 986         {
 987         ec_flag_msi, "MSI hardware", {
 988         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
 989         {
 990         ec_flag_msi, "MSI hardware", {
 991         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
 992         {
 993         ec_flag_msi, "MSI hardware", {
 994         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
 995         {
 996         ec_flag_msi, "MSI hardware", {
 997         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
 998         {
 999         ec_flag_msi, "Quanta hardware", {
1000         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1001         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1002         {
1003         ec_flag_msi, "Quanta hardware", {
1004         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1005         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1006         {
1007         ec_validate_ecdt, "ASUS hardware", {
1008         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1009         {
1010         ec_validate_ecdt, "ASUS hardware", {
1011         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1012         {
1013         ec_enlarge_storm_threshold, "CLEVO hardware", {
1014         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1015         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1016         {
1017         ec_skip_dsdt_scan, "HP Folio 13", {
1018         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1019         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1020         {
1021         ec_validate_ecdt, "ASUS hardware", {
1022         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1023         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1024         {
1025         ec_clear_on_resume, "Samsung hardware", {
1026         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1027         {},
1028 };
1029
1030 int __init acpi_ec_ecdt_probe(void)
1031 {
1032         acpi_status status;
1033         struct acpi_ec *saved_ec = NULL;
1034         struct acpi_table_ecdt *ecdt_ptr;
1035
1036         boot_ec = make_acpi_ec();
1037         if (!boot_ec)
1038                 return -ENOMEM;
1039         /*
1040          * Generate a boot ec context
1041          */
1042         dmi_check_system(ec_dmi_table);
1043         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1044                                 (struct acpi_table_header **)&ecdt_ptr);
1045         if (ACPI_SUCCESS(status)) {
1046                 pr_info("EC description table is found, configuring boot EC\n");
1047                 boot_ec->command_addr = ecdt_ptr->control.address;
1048                 boot_ec->data_addr = ecdt_ptr->data.address;
1049                 boot_ec->gpe = ecdt_ptr->gpe;
1050                 boot_ec->handle = ACPI_ROOT_OBJECT;
1051                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1052                 /* Don't trust ECDT, which comes from ASUSTek */
1053                 if (!EC_FLAGS_VALIDATE_ECDT)
1054                         goto install;
1055                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1056                 if (!saved_ec)
1057                         return -ENOMEM;
1058         /* fall through */
1059         }
1060
1061         if (EC_FLAGS_SKIP_DSDT_SCAN)
1062                 return -ENODEV;
1063
1064         /* This workaround is needed only on some broken machines,
1065          * which require early EC, but fail to provide ECDT */
1066         pr_debug("Look up EC in DSDT\n");
1067         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1068                                         boot_ec, NULL);
1069         /* Check that acpi_get_devices actually find something */
1070         if (ACPI_FAILURE(status) || !boot_ec->handle)
1071                 goto error;
1072         if (saved_ec) {
1073                 /* try to find good ECDT from ASUSTek */
1074                 if (saved_ec->command_addr != boot_ec->command_addr ||
1075                     saved_ec->data_addr != boot_ec->data_addr ||
1076                     saved_ec->gpe != boot_ec->gpe ||
1077                     saved_ec->handle != boot_ec->handle)
1078                         pr_info("ASUSTek keeps feeding us with broken "
1079                         "ECDT tables, which are very hard to workaround. "
1080                         "Trying to use DSDT EC info instead. Please send "
1081                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1082                 kfree(saved_ec);
1083                 saved_ec = NULL;
1084         } else {
1085                 /* We really need to limit this workaround, the only ASUS,
1086                 * which needs it, has fake EC._INI method, so use it as flag.
1087                 * Keep boot_ec struct as it will be needed soon.
1088                 */
1089                 if (!dmi_name_in_vendors("ASUS") ||
1090                     !acpi_has_method(boot_ec->handle, "_INI"))
1091                         return -ENODEV;
1092         }
1093 install:
1094         if (!ec_install_handlers(boot_ec)) {
1095                 first_ec = boot_ec;
1096                 return 0;
1097         }
1098 error:
1099         kfree(boot_ec);
1100         boot_ec = NULL;
1101         return -ENODEV;
1102 }
1103
1104 static struct acpi_driver acpi_ec_driver = {
1105         .name = "ec",
1106         .class = ACPI_EC_CLASS,
1107         .ids = ec_device_ids,
1108         .ops = {
1109                 .add = acpi_ec_add,
1110                 .remove = acpi_ec_remove,
1111                 },
1112 };
1113
1114 int __init acpi_ec_init(void)
1115 {
1116         int result = 0;
1117
1118         /* Now register the driver for the EC */
1119         result = acpi_bus_register_driver(&acpi_ec_driver);
1120         if (result < 0)
1121                 return -ENODEV;
1122
1123         return result;
1124 }
1125
1126 /* EC driver currently not unloadable */
1127 #if 0
1128 static void __exit acpi_ec_exit(void)
1129 {
1130
1131         acpi_bus_unregister_driver(&acpi_ec_driver);
1132         return;
1133 }
1134 #endif  /* 0 */