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 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
  82 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
  83 module_param(ec_delay, uint, 0644);
  84 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
  85
  86 /*
  87  * If the number of false interrupts per one transaction exceeds
  88  * this threshold, will think there is a GPE storm happened and
  89  * will disable the GPE for normal transaction.
  90  */
  91 static unsigned int ec_storm_threshold  __read_mostly = 8;
  92 module_param(ec_storm_threshold, uint, 0644);
  93 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
  94
  95 struct acpi_ec_query_handler {
  96         struct list_head node;
  97         acpi_ec_query_func func;
  98         acpi_handle handle;
  99         void *data;
 100         u8 query_bit;
 101 };
 102
 103 struct transaction {
 104         const u8 *wdata;
 105         u8 *rdata;
 106         unsigned short irq_count;
 107         u8 command;
 108         u8 wi;
 109         u8 ri;
 110         u8 wlen;
 111         u8 rlen;
 112         bool done;
 113 };
 114
 115 struct acpi_ec *boot_ec, *first_ec;
 116 EXPORT_SYMBOL(first_ec);
 117
 118 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 119 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 120 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 121 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 122
 123 /* --------------------------------------------------------------------------
 124                              Transaction Management
 125    -------------------------------------------------------------------------- */
 126
 127 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 128 {
 129         u8 x = inb(ec->command_addr);
 130         pr_debug("---> status = 0x%2.2x\n", x);
 131         return x;
 132 }
 133
 134 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 135 {
 136         u8 x = inb(ec->data_addr);
 137         pr_debug("---> data = 0x%2.2x\n", x);
 138         return x;
 139 }
 140
 141 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 142 {
 143         pr_debug("<--- command = 0x%2.2x\n", command);
 144         outb(command, ec->command_addr);
 145 }
 146
 147 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 148 {
 149         pr_debug("<--- data = 0x%2.2x\n", data);
 150         outb(data, ec->data_addr);
 151 }
 152
 153 static int ec_transaction_done(struct acpi_ec *ec)
 154 {
 155         unsigned long flags;
 156         int ret = 0;
 157         spin_lock_irqsave(&ec->lock, flags);
 158         if (!ec->curr || ec->curr->done)
 159                 ret = 1;
 160         spin_unlock_irqrestore(&ec->lock, flags);
 161         return ret;
 162 }
 163
 164 static void start_transaction(struct acpi_ec *ec)
 165 {
 166         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 167         ec->curr->done = false;
 168         acpi_ec_write_cmd(ec, ec->curr->command);
 169 }
 170
 171 static void advance_transaction(struct acpi_ec *ec, u8 status)
 172 {
 173         unsigned long flags;
 174         struct transaction *t;
 175
 176         spin_lock_irqsave(&ec->lock, flags);
 177         t = ec->curr;
 178         if (!t)
 179                 goto unlock;
 180         if (t->wlen > t->wi) {
 181                 if ((status & ACPI_EC_FLAG_IBF) == 0)
 182                         acpi_ec_write_data(ec,
 183                                 t->wdata[t->wi++]);
 184                 else
 185                         goto err;
 186         } else if (t->rlen > t->ri) {
 187                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
 188                         t->rdata[t->ri++] = acpi_ec_read_data(ec);
 189                         if (t->rlen == t->ri)
 190                                 t->done = true;
 191                 } else
 192                         goto err;
 193         } else if (t->wlen == t->wi &&
 194                    (status & ACPI_EC_FLAG_IBF) == 0)
 195                 t->done = true;
 196         goto unlock;
 197 err:
 198         /*
 199          * If SCI bit is set, then don't think it's a false IRQ
 200          * otherwise will take a not handled IRQ as a false one.
 201          */
 202         if (in_interrupt() && !(status & ACPI_EC_FLAG_SCI))
 203                 ++t->irq_count;
 204
 205 unlock:
 206         spin_unlock_irqrestore(&ec->lock, flags);
 207 }
 208
 209 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
 210
 211 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 212 {
 213         if (state & ACPI_EC_FLAG_SCI) {
 214                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 215                         return acpi_ec_sync_query(ec, NULL);
 216         }
 217         return 0;
 218 }
 219
 220 static int ec_poll(struct acpi_ec *ec)
 221 {
 222         unsigned long flags;
 223         int repeat = 5; /* number of command restarts */
 224         while (repeat--) {
 225                 unsigned long delay = jiffies +
 226                         msecs_to_jiffies(ec_delay);
 227                 do {
 228                         /* don't sleep with disabled interrupts */
 229                         if (EC_FLAGS_MSI || irqs_disabled()) {
 230                                 udelay(ACPI_EC_MSI_UDELAY);
 231                                 if (ec_transaction_done(ec))
 232                                         return 0;
 233                         } else {
 234                                 if (wait_event_timeout(ec->wait,
 235                                                 ec_transaction_done(ec),
 236                                                 msecs_to_jiffies(1)))
 237                                         return 0;
 238                         }
 239                         advance_transaction(ec, acpi_ec_read_status(ec));
 240                 } while (time_before(jiffies, delay));
 241                 pr_debug("controller reset, restart transaction\n");
 242                 spin_lock_irqsave(&ec->lock, flags);
 243                 start_transaction(ec);
 244                 spin_unlock_irqrestore(&ec->lock, flags);
 245         }
 246         return -ETIME;
 247 }
 248
 249 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 250                                         struct transaction *t)
 251 {
 252         unsigned long tmp;
 253         int ret = 0;
 254         if (EC_FLAGS_MSI)
 255                 udelay(ACPI_EC_MSI_UDELAY);
 256         /* start transaction */
 257         spin_lock_irqsave(&ec->lock, tmp);
 258         /* following two actions should be kept atomic */
 259         ec->curr = t;
 260         start_transaction(ec);
 261         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 262                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 263         spin_unlock_irqrestore(&ec->lock, tmp);
 264         ret = ec_poll(ec);
 265         spin_lock_irqsave(&ec->lock, tmp);
 266         ec->curr = NULL;
 267         spin_unlock_irqrestore(&ec->lock, tmp);
 268         return ret;
 269 }
 270
 271 static int ec_check_ibf0(struct acpi_ec *ec)
 272 {
 273         u8 status = acpi_ec_read_status(ec);
 274         return (status & ACPI_EC_FLAG_IBF) == 0;
 275 }
 276
 277 static int ec_wait_ibf0(struct acpi_ec *ec)
 278 {
 279         unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
 280         /* interrupt wait manually if GPE mode is not active */
 281         while (time_before(jiffies, delay))
 282                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
 283                                         msecs_to_jiffies(1)))
 284                         return 0;
 285         return -ETIME;
 286 }
 287
 288 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 289 {
 290         int status;
 291         u32 glk;
 292         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 293                 return -EINVAL;
 294         if (t->rdata)
 295                 memset(t->rdata, 0, t->rlen);
 296         mutex_lock(&ec->mutex);
 297         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 298                 status = -EINVAL;
 299                 goto unlock;
 300         }
 301         if (ec->global_lock) {
 302                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 303                 if (ACPI_FAILURE(status)) {
 304                         status = -ENODEV;
 305                         goto unlock;
 306                 }
 307         }
 308         if (ec_wait_ibf0(ec)) {
 309                 pr_err("input buffer is not empty, "
 310                                 "aborting transaction\n");
 311                 status = -ETIME;
 312                 goto end;
 313         }
 314         pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",
 315                         t->command, t->wdata ? t->wdata[0] : 0);
 316         /* disable GPE during transaction if storm is detected */
 317         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 318                 /* It has to be disabled, so that it doesn't trigger. */
 319                 acpi_disable_gpe(NULL, ec->gpe);
 320         }
 321
 322         status = acpi_ec_transaction_unlocked(ec, t);
 323
 324         /* check if we received SCI during transaction */
 325         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 326         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 327                 msleep(1);
 328                 /* It is safe to enable the GPE outside of the transaction. */
 329                 acpi_enable_gpe(NULL, ec->gpe);
 330         } else if (t->irq_count > ec_storm_threshold) {
 331                 pr_info("GPE storm detected(%d GPEs), "
 332                         "transactions will use polling mode\n",
 333                         t->irq_count);
 334                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 335         }
 336         pr_debug("transaction end\n");
 337 end:
 338         if (ec->global_lock)
 339                 acpi_release_global_lock(glk);
 340 unlock:
 341         mutex_unlock(&ec->mutex);
 342         return status;
 343 }
 344
 345 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 346 {
 347         u8 d;
 348         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 349                                 .wdata = NULL, .rdata = &d,
 350                                 .wlen = 0, .rlen = 1};
 351
 352         return acpi_ec_transaction(ec, &t);
 353 }
 354
 355 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 356 {
 357         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 358                                 .wdata = NULL, .rdata = NULL,
 359                                 .wlen = 0, .rlen = 0};
 360
 361         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 362                                 acpi_ec_transaction(ec, &t) : 0;
 363 }
 364
 365 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 366 {
 367         int result;
 368         u8 d;
 369         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 370                                 .wdata = &address, .rdata = &d,
 371                                 .wlen = 1, .rlen = 1};
 372
 373         result = acpi_ec_transaction(ec, &t);
 374         *data = d;
 375         return result;
 376 }
 377
 378 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 379 {
 380         u8 wdata[2] = { address, data };
 381         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 382                                 .wdata = wdata, .rdata = NULL,
 383                                 .wlen = 2, .rlen = 0};
 384
 385         return acpi_ec_transaction(ec, &t);
 386 }
 387
 388 int ec_read(u8 addr, u8 *val)
 389 {
 390         int err;
 391         u8 temp_data;
 392
 393         if (!first_ec)
 394                 return -ENODEV;
 395
 396         err = acpi_ec_read(first_ec, addr, &temp_data);
 397
 398         if (!err) {
 399                 *val = temp_data;
 400                 return 0;
 401         } else
 402                 return err;
 403 }
 404
 405 EXPORT_SYMBOL(ec_read);
 406
 407 int ec_write(u8 addr, u8 val)
 408 {
 409         int err;
 410
 411         if (!first_ec)
 412                 return -ENODEV;
 413
 414         err = acpi_ec_write(first_ec, addr, val);
 415
 416         return err;
 417 }
 418
 419 EXPORT_SYMBOL(ec_write);
 420
 421 int ec_transaction(u8 command,
 422                    const u8 * wdata, unsigned wdata_len,
 423                    u8 * rdata, unsigned rdata_len)
 424 {
 425         struct transaction t = {.command = command,
 426                                 .wdata = wdata, .rdata = rdata,
 427                                 .wlen = wdata_len, .rlen = rdata_len};
 428         if (!first_ec)
 429                 return -ENODEV;
 430
 431         return acpi_ec_transaction(first_ec, &t);
 432 }
 433
 434 EXPORT_SYMBOL(ec_transaction);
 435
 436 /* Get the handle to the EC device */
 437 acpi_handle ec_get_handle(void)
 438 {
 439         if (!first_ec)
 440                 return NULL;
 441         return first_ec->handle;
 442 }
 443
 444 EXPORT_SYMBOL(ec_get_handle);
 445
 446 /*
 447  * Process _Q events that might have accumulated in the EC.
 448  * Run with locked ec mutex.
 449  */
 450 static void acpi_ec_clear(struct acpi_ec *ec)
 451 {
 452         int i, status;
 453         u8 value = 0;
 454
 455         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 456                 status = acpi_ec_sync_query(ec, &value);
 457                 if (status || !value)
 458                         break;
 459         }
 460
 461         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 462                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 463         else
 464                 pr_info("%d stale EC events cleared\n", i);
 465 }
 466
 467 void acpi_ec_block_transactions(void)
 468 {
 469         struct acpi_ec *ec = first_ec;
 470
 471         if (!ec)
 472                 return;
 473
 474         mutex_lock(&ec->mutex);
 475         /* Prevent transactions from being carried out */
 476         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 477         mutex_unlock(&ec->mutex);
 478 }
 479
 480 void acpi_ec_unblock_transactions(void)
 481 {
 482         struct acpi_ec *ec = first_ec;
 483
 484         if (!ec)
 485                 return;
 486
 487         mutex_lock(&ec->mutex);
 488         /* Allow transactions to be carried out again */
 489         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 490
 491         if (EC_FLAGS_CLEAR_ON_RESUME)
 492                 acpi_ec_clear(ec);
 493
 494         mutex_unlock(&ec->mutex);
 495 }
 496
 497 void acpi_ec_unblock_transactions_early(void)
 498 {
 499         /*
 500          * Allow transactions to happen again (this function is called from
 501          * atomic context during wakeup, so we don't need to acquire the mutex).
 502          */
 503         if (first_ec)
 504                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 505 }
 506
 507 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 508 {
 509         int result;
 510         u8 d;
 511         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 512                                 .wdata = NULL, .rdata = &d,
 513                                 .wlen = 0, .rlen = 1};
 514         if (!ec || !data)
 515                 return -EINVAL;
 516         /*
 517          * Query the EC to find out which _Qxx method we need to evaluate.
 518          * Note that successful completion of the query causes the ACPI_EC_SCI
 519          * bit to be cleared (and thus clearing the interrupt source).
 520          */
 521         result = acpi_ec_transaction_unlocked(ec, &t);
 522         if (result)
 523                 return result;
 524         if (!d)
 525                 return -ENODATA;
 526         *data = d;
 527         return 0;
 528 }
 529
 530 /* --------------------------------------------------------------------------
 531                                 Event Management
 532    -------------------------------------------------------------------------- */
 533 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 534                               acpi_handle handle, acpi_ec_query_func func,
 535                               void *data)
 536 {
 537         struct acpi_ec_query_handler *handler =
 538             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 539         if (!handler)
 540                 return -ENOMEM;
 541
 542         handler->query_bit = query_bit;
 543         handler->handle = handle;
 544         handler->func = func;
 545         handler->data = data;
 546         mutex_lock(&ec->mutex);
 547         list_add(&handler->node, &ec->list);
 548         mutex_unlock(&ec->mutex);
 549         return 0;
 550 }
 551
 552 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 553
 554 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 555 {
 556         struct acpi_ec_query_handler *handler, *tmp;
 557         mutex_lock(&ec->mutex);
 558         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 559                 if (query_bit == handler->query_bit) {
 560                         list_del(&handler->node);
 561                         kfree(handler);
 562                 }
 563         }
 564         mutex_unlock(&ec->mutex);
 565 }
 566
 567 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 568
 569 static void acpi_ec_run(void *cxt)
 570 {
 571         struct acpi_ec_query_handler *handler = cxt;
 572         if (!handler)
 573                 return;
 574         pr_debug("start query execution\n");
 575         if (handler->func)
 576                 handler->func(handler->data);
 577         else if (handler->handle)
 578                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 579         pr_debug("stop query execution\n");
 580         kfree(handler);
 581 }
 582
 583 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
 584 {
 585         u8 value = 0;
 586         int status;
 587         struct acpi_ec_query_handler *handler, *copy;
 588
 589         status = acpi_ec_query_unlocked(ec, &value);
 590         if (data)
 591                 *data = value;
 592         if (status)
 593                 return status;
 594
 595         list_for_each_entry(handler, &ec->list, node) {
 596                 if (value == handler->query_bit) {
 597                         /* have custom handler for this bit */
 598                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 599                         if (!copy)
 600                                 return -ENOMEM;
 601                         memcpy(copy, handler, sizeof(*copy));
 602                         pr_debug("push query execution (0x%2x) on queue\n",
 603                                 value);
 604                         return acpi_os_execute((copy->func) ?
 605                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 606                                 acpi_ec_run, copy);
 607                 }
 608         }
 609         return 0;
 610 }
 611
 612 static void acpi_ec_gpe_query(void *ec_cxt)
 613 {
 614         struct acpi_ec *ec = ec_cxt;
 615         if (!ec)
 616                 return;
 617         mutex_lock(&ec->mutex);
 618         acpi_ec_sync_query(ec, NULL);
 619         mutex_unlock(&ec->mutex);
 620 }
 621
 622 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 623 {
 624         if (state & ACPI_EC_FLAG_SCI) {
 625                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 626                         pr_debug("push gpe query to the queue\n");
 627                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 628                                 acpi_ec_gpe_query, ec);
 629                 }
 630         }
 631         return 0;
 632 }
 633
 634 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 635         u32 gpe_number, void *data)
 636 {
 637         struct acpi_ec *ec = data;
 638         u8 status = acpi_ec_read_status(ec);
 639
 640         pr_debug("~~~> interrupt, status:0x%02x\n", status);
 641
 642         advance_transaction(ec, status);
 643         if (ec_transaction_done(ec) &&
 644             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 645                 wake_up(&ec->wait);
 646                 ec_check_sci(ec, acpi_ec_read_status(ec));
 647         }
 648         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 649 }
 650
 651 /* --------------------------------------------------------------------------
 652                              Address Space Management
 653    -------------------------------------------------------------------------- */
 654
 655 static acpi_status
 656 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 657                       u32 bits, u64 *value64,
 658                       void *handler_context, void *region_context)
 659 {
 660         struct acpi_ec *ec = handler_context;
 661         int result = 0, i, bytes = bits / 8;
 662         u8 *value = (u8 *)value64;
 663
 664         if ((address > 0xFF) || !value || !handler_context)
 665                 return AE_BAD_PARAMETER;
 666
 667         if (function != ACPI_READ && function != ACPI_WRITE)
 668                 return AE_BAD_PARAMETER;
 669
 670         if (EC_FLAGS_MSI || bits > 8)
 671                 acpi_ec_burst_enable(ec);
 672
 673         for (i = 0; i < bytes; ++i, ++address, ++value)
 674                 result = (function == ACPI_READ) ?
 675                         acpi_ec_read(ec, address, value) :
 676                         acpi_ec_write(ec, address, *value);
 677
 678         if (EC_FLAGS_MSI || bits > 8)
 679                 acpi_ec_burst_disable(ec);
 680
 681         switch (result) {
 682         case -EINVAL:
 683                 return AE_BAD_PARAMETER;
 684                 break;
 685         case -ENODEV:
 686                 return AE_NOT_FOUND;
 687                 break;
 688         case -ETIME:
 689                 return AE_TIME;
 690                 break;
 691         default:
 692                 return AE_OK;
 693         }
 694 }
 695
 696 /* --------------------------------------------------------------------------
 697                                Driver Interface
 698    -------------------------------------------------------------------------- */
 699 static acpi_status
 700 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 701
 702 static struct acpi_ec *make_acpi_ec(void)
 703 {
 704         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 705         if (!ec)
 706                 return NULL;
 707         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 708         mutex_init(&ec->mutex);
 709         init_waitqueue_head(&ec->wait);
 710         INIT_LIST_HEAD(&ec->list);
 711         spin_lock_init(&ec->lock);
 712         return ec;
 713 }
 714
 715 static acpi_status
 716 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 717                                void *context, void **return_value)
 718 {
 719         char node_name[5];
 720         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 721         struct acpi_ec *ec = context;
 722         int value = 0;
 723         acpi_status status;
 724
 725         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 726
 727         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 728                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 729         }
 730         return AE_OK;
 731 }
 732
 733 static acpi_status
 734 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 735 {
 736         acpi_status status;
 737         unsigned long long tmp = 0;
 738
 739         struct acpi_ec *ec = context;
 740
 741         /* clear addr values, ec_parse_io_ports depend on it */
 742         ec->command_addr = ec->data_addr = 0;
 743
 744         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 745                                      ec_parse_io_ports, ec);
 746         if (ACPI_FAILURE(status))
 747                 return status;
 748
 749         /* Get GPE bit assignment (EC events). */
 750         /* TODO: Add support for _GPE returning a package */
 751         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 752         if (ACPI_FAILURE(status))
 753                 return status;
 754         ec->gpe = tmp;
 755         /* Use the global lock for all EC transactions? */
 756         tmp = 0;
 757         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 758         ec->global_lock = tmp;
 759         ec->handle = handle;
 760         return AE_CTRL_TERMINATE;
 761 }
 762
 763 static int ec_install_handlers(struct acpi_ec *ec)
 764 {
 765         acpi_status status;
 766         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 767                 return 0;
 768         status = acpi_install_gpe_handler(NULL, ec->gpe,
 769                                   ACPI_GPE_EDGE_TRIGGERED,
 770                                   &acpi_ec_gpe_handler, ec);
 771         if (ACPI_FAILURE(status))
 772                 return -ENODEV;
 773
 774         acpi_enable_gpe(NULL, ec->gpe);
 775         status = acpi_install_address_space_handler(ec->handle,
 776                                                     ACPI_ADR_SPACE_EC,
 777                                                     &acpi_ec_space_handler,
 778                                                     NULL, ec);
 779         if (ACPI_FAILURE(status)) {
 780                 if (status == AE_NOT_FOUND) {
 781                         /*
 782                          * Maybe OS fails in evaluating the _REG object.
 783                          * The AE_NOT_FOUND error will be ignored and OS
 784                          * continue to initialize EC.
 785                          */
 786                         pr_err("Fail in evaluating the _REG object"
 787                                 " of EC device. Broken bios is suspected.\n");
 788                 } else {
 789                         acpi_disable_gpe(NULL, ec->gpe);
 790                         acpi_remove_gpe_handler(NULL, ec->gpe,
 791                                 &acpi_ec_gpe_handler);
 792                         return -ENODEV;
 793                 }
 794         }
 795
 796         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 797         return 0;
 798 }
 799
 800 static void ec_remove_handlers(struct acpi_ec *ec)
 801 {
 802         acpi_disable_gpe(NULL, ec->gpe);
 803         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 804                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 805                 pr_err("failed to remove space handler\n");
 806         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 807                                 &acpi_ec_gpe_handler)))
 808                 pr_err("failed to remove gpe handler\n");
 809         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 810 }
 811
 812 static int acpi_ec_add(struct acpi_device *device)
 813 {
 814         struct acpi_ec *ec = NULL;
 815         int ret;
 816
 817         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 818         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 819
 820         /* Check for boot EC */
 821         if (boot_ec &&
 822             (boot_ec->handle == device->handle ||
 823              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 824                 ec = boot_ec;
 825                 boot_ec = NULL;
 826         } else {
 827                 ec = make_acpi_ec();
 828                 if (!ec)
 829                         return -ENOMEM;
 830         }
 831         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 832                 AE_CTRL_TERMINATE) {
 833                         kfree(ec);
 834                         return -EINVAL;
 835         }
 836
 837         /* Find and register all query methods */
 838         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 839                             acpi_ec_register_query_methods, NULL, ec, NULL);
 840
 841         if (!first_ec)
 842                 first_ec = ec;
 843         device->driver_data = ec;
 844
 845         ret = !!request_region(ec->data_addr, 1, "EC data");
 846         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
 847         ret = !!request_region(ec->command_addr, 1, "EC cmd");
 848         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
 849
 850         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 851                           ec->gpe, ec->command_addr, ec->data_addr);
 852
 853         ret = ec_install_handlers(ec);
 854
 855         /* EC is fully operational, allow queries */
 856         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 857
 858         /* Clear stale _Q events if hardware might require that */
 859         if (EC_FLAGS_CLEAR_ON_RESUME) {
 860                 mutex_lock(&ec->mutex);
 861                 acpi_ec_clear(ec);
 862                 mutex_unlock(&ec->mutex);
 863         }
 864         return ret;
 865 }
 866
 867 static int acpi_ec_remove(struct acpi_device *device)
 868 {
 869         struct acpi_ec *ec;
 870         struct acpi_ec_query_handler *handler, *tmp;
 871
 872         if (!device)
 873                 return -EINVAL;
 874
 875         ec = acpi_driver_data(device);
 876         ec_remove_handlers(ec);
 877         mutex_lock(&ec->mutex);
 878         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 879                 list_del(&handler->node);
 880                 kfree(handler);
 881         }
 882         mutex_unlock(&ec->mutex);
 883         release_region(ec->data_addr, 1);
 884         release_region(ec->command_addr, 1);
 885         device->driver_data = NULL;
 886         if (ec == first_ec)
 887                 first_ec = NULL;
 888         kfree(ec);
 889         return 0;
 890 }
 891
 892 static acpi_status
 893 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 894 {
 895         struct acpi_ec *ec = context;
 896
 897         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 898                 return AE_OK;
 899
 900         /*
 901          * The first address region returned is the data port, and
 902          * the second address region returned is the status/command
 903          * port.
 904          */
 905         if (ec->data_addr == 0)
 906                 ec->data_addr = resource->data.io.minimum;
 907         else if (ec->command_addr == 0)
 908                 ec->command_addr = resource->data.io.minimum;
 909         else
 910                 return AE_CTRL_TERMINATE;
 911
 912         return AE_OK;
 913 }
 914
 915 int __init acpi_boot_ec_enable(void)
 916 {
 917         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 918                 return 0;
 919         if (!ec_install_handlers(boot_ec)) {
 920                 first_ec = boot_ec;
 921                 return 0;
 922         }
 923         return -EFAULT;
 924 }
 925
 926 static const struct acpi_device_id ec_device_ids[] = {
 927         {"PNP0C09", 0},
 928         {"", 0},
 929 };
 930
 931 /* Some BIOS do not survive early DSDT scan, skip it */
 932 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 933 {
 934         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 935         return 0;
 936 }
 937
 938 /* ASUStek often supplies us with broken ECDT, validate it */
 939 static int ec_validate_ecdt(const struct dmi_system_id *id)
 940 {
 941         EC_FLAGS_VALIDATE_ECDT = 1;
 942         return 0;
 943 }
 944
 945 /* MSI EC needs special treatment, enable it */
 946 static int ec_flag_msi(const struct dmi_system_id *id)
 947 {
 948         pr_debug("Detected MSI hardware, enabling workarounds.\n");
 949         EC_FLAGS_MSI = 1;
 950         EC_FLAGS_VALIDATE_ECDT = 1;
 951         return 0;
 952 }
 953
 954 /*
 955  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
 956  * the GPE storm threshold back to 20
 957  */
 958 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
 959 {
 960         pr_debug("Setting the EC GPE storm threshold to 20\n");
 961         ec_storm_threshold  = 20;
 962         return 0;
 963 }
 964
 965 /*
 966  * On some hardware it is necessary to clear events accumulated by the EC during
 967  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
 968  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
 969  *
 970  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
 971  *
 972  * Ideally, the EC should also be instructed NOT to accumulate events during
 973  * sleep (which Windows seems to do somehow), but the interface to control this
 974  * behaviour is not known at this time.
 975  *
 976  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
 977  * however it is very likely that other Samsung models are affected.
 978  *
 979  * On systems which don't accumulate _Q events during sleep, this extra check
 980  * should be harmless.
 981  */
 982 static int ec_clear_on_resume(const struct dmi_system_id *id)
 983 {
 984         pr_debug("Detected system needing EC poll on resume.\n");
 985         EC_FLAGS_CLEAR_ON_RESUME = 1;
 986         return 0;
 987 }
 988
 989 static struct dmi_system_id ec_dmi_table[] __initdata = {
 990         {
 991         ec_skip_dsdt_scan, "Compal JFL92", {
 992         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 993         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 994         {
 995         ec_flag_msi, "MSI hardware", {
 996         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
 997         {
 998         ec_flag_msi, "MSI hardware", {
 999         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1000         {
1001         ec_flag_msi, "MSI hardware", {
1002         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1003         {
1004         ec_flag_msi, "MSI hardware", {
1005         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1006         {
1007         ec_flag_msi, "Quanta hardware", {
1008         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1009         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1010         {
1011         ec_flag_msi, "Quanta hardware", {
1012         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1013         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1014         {
1015         ec_validate_ecdt, "ASUS hardware", {
1016         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1017         {
1018         ec_validate_ecdt, "ASUS hardware", {
1019         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1020         {
1021         ec_enlarge_storm_threshold, "CLEVO hardware", {
1022         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1023         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1024         {
1025         ec_skip_dsdt_scan, "HP Folio 13", {
1026         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1027         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1028         {
1029         ec_validate_ecdt, "ASUS hardware", {
1030         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1031         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1032         {
1033         ec_clear_on_resume, "Samsung hardware", {
1034         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1035         {},
1036 };
1037
1038 int __init acpi_ec_ecdt_probe(void)
1039 {
1040         acpi_status status;
1041         struct acpi_ec *saved_ec = NULL;
1042         struct acpi_table_ecdt *ecdt_ptr;
1043
1044         boot_ec = make_acpi_ec();
1045         if (!boot_ec)
1046                 return -ENOMEM;
1047         /*
1048          * Generate a boot ec context
1049          */
1050         dmi_check_system(ec_dmi_table);
1051         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1052                                 (struct acpi_table_header **)&ecdt_ptr);
1053         if (ACPI_SUCCESS(status)) {
1054                 pr_info("EC description table is found, configuring boot EC\n");
1055                 boot_ec->command_addr = ecdt_ptr->control.address;
1056                 boot_ec->data_addr = ecdt_ptr->data.address;
1057                 boot_ec->gpe = ecdt_ptr->gpe;
1058                 boot_ec->handle = ACPI_ROOT_OBJECT;
1059                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1060                 /* Don't trust ECDT, which comes from ASUSTek */
1061                 if (!EC_FLAGS_VALIDATE_ECDT)
1062                         goto install;
1063                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1064                 if (!saved_ec)
1065                         return -ENOMEM;
1066         /* fall through */
1067         }
1068
1069         if (EC_FLAGS_SKIP_DSDT_SCAN)
1070                 return -ENODEV;
1071
1072         /* This workaround is needed only on some broken machines,
1073          * which require early EC, but fail to provide ECDT */
1074         pr_debug("Look up EC in DSDT\n");
1075         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1076                                         boot_ec, NULL);
1077         /* Check that acpi_get_devices actually find something */
1078         if (ACPI_FAILURE(status) || !boot_ec->handle)
1079                 goto error;
1080         if (saved_ec) {
1081                 /* try to find good ECDT from ASUSTek */
1082                 if (saved_ec->command_addr != boot_ec->command_addr ||
1083                     saved_ec->data_addr != boot_ec->data_addr ||
1084                     saved_ec->gpe != boot_ec->gpe ||
1085                     saved_ec->handle != boot_ec->handle)
1086                         pr_info("ASUSTek keeps feeding us with broken "
1087                         "ECDT tables, which are very hard to workaround. "
1088                         "Trying to use DSDT EC info instead. Please send "
1089                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1090                 kfree(saved_ec);
1091                 saved_ec = NULL;
1092         } else {
1093                 /* We really need to limit this workaround, the only ASUS,
1094                 * which needs it, has fake EC._INI method, so use it as flag.
1095                 * Keep boot_ec struct as it will be needed soon.
1096                 */
1097                 if (!dmi_name_in_vendors("ASUS") ||
1098                     !acpi_has_method(boot_ec->handle, "_INI"))
1099                         return -ENODEV;
1100         }
1101 install:
1102         if (!ec_install_handlers(boot_ec)) {
1103                 first_ec = boot_ec;
1104                 return 0;
1105         }
1106 error:
1107         kfree(boot_ec);
1108         boot_ec = NULL;
1109         return -ENODEV;
1110 }
1111
1112 static struct acpi_driver acpi_ec_driver = {
1113         .name = "ec",
1114         .class = ACPI_EC_CLASS,
1115         .ids = ec_device_ids,
1116         .ops = {
1117                 .add = acpi_ec_add,
1118                 .remove = acpi_ec_remove,
1119                 },
1120 };
1121
1122 int __init acpi_ec_init(void)
1123 {
1124         int result = 0;
1125
1126         /* Now register the driver for the EC */
1127         result = acpi_bus_register_driver(&acpi_ec_driver);
1128         if (result < 0)
1129                 return -ENODEV;
1130
1131         return result;
1132 }
1133
1134 /* EC driver currently not unloadable */
1135 #if 0
1136 static void __exit acpi_ec_exit(void)
1137 {
1138
1139         acpi_bus_unregister_driver(&acpi_ec_driver);
1140         return;
1141 }
1142 #endif  /* 0 */