drivers/acpi/ec.c

   1 /*
   2  *  ec.c - ACPI Embedded Controller Driver (v2.2)
   3  *
   4  *  Copyright (C) 2001-2014 Intel Corporation
   5  *    Author: 2014       Lv Zheng <lv.zheng@intel.com>
   6  *            2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
   7  *            2006       Denis Sadykov <denis.m.sadykov@intel.com>
   8  *            2004       Luming Yu <luming.yu@intel.com>
   9  *            2001, 2002 Andy Grover <andrew.grover@intel.com>
  10  *            2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
  11  *  Copyright (C) 2008      Alexey Starikovskiy <astarikovskiy@suse.de>
  12  *
  13  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  14  *
  15  *  This program is free software; you can redistribute it and/or modify
  16  *  it under the terms of the GNU General Public License as published by
  17  *  the Free Software Foundation; either version 2 of the License, or (at
  18  *  your option) any later version.
  19  *
  20  *  This program is distributed in the hope that it will be useful, but
  21  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  23  *  General Public License for more details.
  24  *
  25  *  You should have received a copy of the GNU General Public License along
  26  *  with this program; if not, write to the Free Software Foundation, Inc.,
  27  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  28  *
  29  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  30  */
  31
  32 /* Uncomment next line to get verbose printout */
  33 /* #define DEBUG */
  34 #define pr_fmt(fmt) "ACPI : EC: " fmt
  35
  36 #include <linux/kernel.h>
  37 #include <linux/module.h>
  38 #include <linux/init.h>
  39 #include <linux/types.h>
  40 #include <linux/delay.h>
  41 #include <linux/interrupt.h>
  42 #include <linux/list.h>
  43 #include <linux/spinlock.h>
  44 #include <linux/slab.h>
  45 #include <linux/acpi.h>
  46 #include <linux/dmi.h>
  47 #include <asm/io.h>
  48
  49 #include "internal.h"
  50
  51 #define ACPI_EC_CLASS                   "embedded_controller"
  52 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  53 #define ACPI_EC_FILE_INFO               "info"
  54
  55 /* EC status register */
  56 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  57 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  58 #define ACPI_EC_FLAG_CMD        0x08    /* Input buffer contains a command */
  59 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  60 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  61
  62 /* EC commands */
  63 enum ec_command {
  64         ACPI_EC_COMMAND_READ = 0x80,
  65         ACPI_EC_COMMAND_WRITE = 0x81,
  66         ACPI_EC_BURST_ENABLE = 0x82,
  67         ACPI_EC_BURST_DISABLE = 0x83,
  68         ACPI_EC_COMMAND_QUERY = 0x84,
  69 };
  70
  71 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  72 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  73 #define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
  74 #define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
  75                                          * when trying to clear the EC */
  76
  77 enum {
  78         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  79         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  80         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
  81                                          * OpReg are installed */
  82         EC_FLAGS_BLOCKED,               /* Transactions are blocked */
  83 };
  84
  85 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
  86 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
  87
  88 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
  89 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
  90 module_param(ec_delay, uint, 0644);
  91 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
  92
  93 /*
  94  * If the number of false interrupts per one transaction exceeds
  95  * this threshold, will think there is a GPE storm happened and
  96  * will disable the GPE for normal transaction.
  97  */
  98 static unsigned int ec_storm_threshold  __read_mostly = 8;
  99 module_param(ec_storm_threshold, uint, 0644);
 100 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 101
 102 struct acpi_ec_query_handler {
 103         struct list_head node;
 104         acpi_ec_query_func func;
 105         acpi_handle handle;
 106         void *data;
 107         u8 query_bit;
 108 };
 109
 110 struct transaction {
 111         const u8 *wdata;
 112         u8 *rdata;
 113         unsigned short irq_count;
 114         u8 command;
 115         u8 wi;
 116         u8 ri;
 117         u8 wlen;
 118         u8 rlen;
 119         u8 flags;
 120 };
 121
 122 struct acpi_ec *boot_ec, *first_ec;
 123 EXPORT_SYMBOL(first_ec);
 124
 125 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 126 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 127 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 128 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 129
 130 /* --------------------------------------------------------------------------
 131                              Transaction Management
 132    -------------------------------------------------------------------------- */
 133
 134 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 135 {
 136         u8 x = inb(ec->command_addr);
 137         pr_debug("EC_SC(R) = 0x%2.2x "
 138                  "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d\n",
 139                  x,
 140                  !!(x & ACPI_EC_FLAG_SCI),
 141                  !!(x & ACPI_EC_FLAG_BURST),
 142                  !!(x & ACPI_EC_FLAG_CMD),
 143                  !!(x & ACPI_EC_FLAG_IBF),
 144                  !!(x & ACPI_EC_FLAG_OBF));
 145         return x;
 146 }
 147
 148 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 149 {
 150         u8 x = inb(ec->data_addr);
 151         pr_debug("EC_DATA(R) = 0x%2.2x\n", x);
 152         return x;
 153 }
 154
 155 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 156 {
 157         pr_debug("EC_SC(W) = 0x%2.2x\n", command);
 158         outb(command, ec->command_addr);
 159 }
 160
 161 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 162 {
 163         pr_debug("EC_DATA(W) = 0x%2.2x\n", data);
 164         outb(data, ec->data_addr);
 165 }
 166
 167 #ifdef DEBUG
 168 static const char *acpi_ec_cmd_string(u8 cmd)
 169 {
 170         switch (cmd) {
 171         case 0x80:
 172                 return "RD_EC";
 173         case 0x81:
 174                 return "WR_EC";
 175         case 0x82:
 176                 return "BE_EC";
 177         case 0x83:
 178                 return "BD_EC";
 179         case 0x84:
 180                 return "QR_EC";
 181         }
 182         return "UNKNOWN";
 183 }
 184 #else
 185 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 186 #endif
 187
 188 static int ec_transaction_completed(struct acpi_ec *ec)
 189 {
 190         unsigned long flags;
 191         int ret = 0;
 192         spin_lock_irqsave(&ec->lock, flags);
 193         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 194                 ret = 1;
 195         spin_unlock_irqrestore(&ec->lock, flags);
 196         return ret;
 197 }
 198
 199 static bool advance_transaction(struct acpi_ec *ec)
 200 {
 201         struct transaction *t;
 202         u8 status;
 203         bool wakeup = false;
 204
 205         pr_debug("===== %s (%d) =====\n",
 206                  in_interrupt() ? "IRQ" : "TASK", smp_processor_id());
 207         status = acpi_ec_read_status(ec);
 208         t = ec->curr;
 209         if (!t)
 210                 goto err;
 211         if (t->flags & ACPI_EC_COMMAND_POLL) {
 212                 if (t->wlen > t->wi) {
 213                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 214                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 215                         else
 216                                 goto err;
 217                 } else if (t->rlen > t->ri) {
 218                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 219                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 220                                 if (t->rlen == t->ri) {
 221                                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 222                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 223                                                 pr_debug("***** Command(%s) hardware completion *****\n",
 224                                                          acpi_ec_cmd_string(t->command));
 225                                         wakeup = true;
 226                                 }
 227                         } else
 228                                 goto err;
 229                 } else if (t->wlen == t->wi &&
 230                            (status & ACPI_EC_FLAG_IBF) == 0) {
 231                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 232                         wakeup = true;
 233                 }
 234                 return wakeup;
 235         } else {
 236                 /*
 237                  * There is firmware refusing to respond QR_EC when SCI_EVT
 238                  * is not set, for which case, we complete the QR_EC
 239                  * without issuing it to the firmware.
 240                  * https://bugzilla.kernel.org/show_bug.cgi?id=86211
 241                  */
 242                 if (!(status & ACPI_EC_FLAG_SCI) &&
 243                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 244                         t->flags |= ACPI_EC_COMMAND_POLL;
 245                         t->rdata[t->ri++] = 0x00;
 246                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 247                         pr_debug("***** Command(%s) software completion *****\n",
 248                                  acpi_ec_cmd_string(t->command));
 249                         wakeup = true;
 250                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 251                         acpi_ec_write_cmd(ec, t->command);
 252                         t->flags |= ACPI_EC_COMMAND_POLL;
 253                 } else
 254                         goto err;
 255                 return wakeup;
 256         }
 257 err:
 258         /*
 259          * If SCI bit is set, then don't think it's a false IRQ
 260          * otherwise will take a not handled IRQ as a false one.
 261          */
 262         if (!(status & ACPI_EC_FLAG_SCI)) {
 263                 if (in_interrupt() && t)
 264                         ++t->irq_count;
 265         }
 266         return wakeup;
 267 }
 268
 269 static void start_transaction(struct acpi_ec *ec)
 270 {
 271         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 272         ec->curr->flags = 0;
 273         (void)advance_transaction(ec);
 274 }
 275
 276 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
 277
 278 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 279 {
 280         if (state & ACPI_EC_FLAG_SCI) {
 281                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 282                         return acpi_ec_sync_query(ec, NULL);
 283         }
 284         return 0;
 285 }
 286
 287 static int ec_poll(struct acpi_ec *ec)
 288 {
 289         unsigned long flags;
 290         int repeat = 5; /* number of command restarts */
 291         while (repeat--) {
 292                 unsigned long delay = jiffies +
 293                         msecs_to_jiffies(ec_delay);
 294                 do {
 295                         /* don't sleep with disabled interrupts */
 296                         if (EC_FLAGS_MSI || irqs_disabled()) {
 297                                 udelay(ACPI_EC_MSI_UDELAY);
 298                                 if (ec_transaction_completed(ec))
 299                                         return 0;
 300                         } else {
 301                                 if (wait_event_timeout(ec->wait,
 302                                                 ec_transaction_completed(ec),
 303                                                 msecs_to_jiffies(1)))
 304                                         return 0;
 305                         }
 306                         spin_lock_irqsave(&ec->lock, flags);
 307                         (void)advance_transaction(ec);
 308                         spin_unlock_irqrestore(&ec->lock, flags);
 309                 } while (time_before(jiffies, delay));
 310                 pr_debug("controller reset, restart transaction\n");
 311                 spin_lock_irqsave(&ec->lock, flags);
 312                 start_transaction(ec);
 313                 spin_unlock_irqrestore(&ec->lock, flags);
 314         }
 315         return -ETIME;
 316 }
 317
 318 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 319                                         struct transaction *t)
 320 {
 321         unsigned long tmp;
 322         int ret = 0;
 323         if (EC_FLAGS_MSI)
 324                 udelay(ACPI_EC_MSI_UDELAY);
 325         /* start transaction */
 326         spin_lock_irqsave(&ec->lock, tmp);
 327         /* following two actions should be kept atomic */
 328         ec->curr = t;
 329         pr_debug("***** Command(%s) started *****\n",
 330                  acpi_ec_cmd_string(t->command));
 331         start_transaction(ec);
 332         spin_unlock_irqrestore(&ec->lock, tmp);
 333         ret = ec_poll(ec);
 334         spin_lock_irqsave(&ec->lock, tmp);
 335         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 336                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 337         pr_debug("***** Command(%s) stopped *****\n",
 338                  acpi_ec_cmd_string(t->command));
 339         ec->curr = NULL;
 340         spin_unlock_irqrestore(&ec->lock, tmp);
 341         return ret;
 342 }
 343
 344 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 345 {
 346         int status;
 347         u32 glk;
 348         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 349                 return -EINVAL;
 350         if (t->rdata)
 351                 memset(t->rdata, 0, t->rlen);
 352         mutex_lock(&ec->mutex);
 353         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 354                 status = -EINVAL;
 355                 goto unlock;
 356         }
 357         if (ec->global_lock) {
 358                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 359                 if (ACPI_FAILURE(status)) {
 360                         status = -ENODEV;
 361                         goto unlock;
 362                 }
 363         }
 364         /* disable GPE during transaction if storm is detected */
 365         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 366                 /* It has to be disabled, so that it doesn't trigger. */
 367                 acpi_disable_gpe(NULL, ec->gpe);
 368         }
 369
 370         status = acpi_ec_transaction_unlocked(ec, t);
 371
 372         /* check if we received SCI during transaction */
 373         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 374         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 375                 msleep(1);
 376                 /* It is safe to enable the GPE outside of the transaction. */
 377                 acpi_enable_gpe(NULL, ec->gpe);
 378         } else if (t->irq_count > ec_storm_threshold) {
 379                 pr_info("GPE storm detected(%d GPEs), "
 380                         "transactions will use polling mode\n",
 381                         t->irq_count);
 382                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 383         }
 384         if (ec->global_lock)
 385                 acpi_release_global_lock(glk);
 386 unlock:
 387         mutex_unlock(&ec->mutex);
 388         return status;
 389 }
 390
 391 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 392 {
 393         u8 d;
 394         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 395                                 .wdata = NULL, .rdata = &d,
 396                                 .wlen = 0, .rlen = 1};
 397
 398         return acpi_ec_transaction(ec, &t);
 399 }
 400
 401 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 402 {
 403         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 404                                 .wdata = NULL, .rdata = NULL,
 405                                 .wlen = 0, .rlen = 0};
 406
 407         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 408                                 acpi_ec_transaction(ec, &t) : 0;
 409 }
 410
 411 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 412 {
 413         int result;
 414         u8 d;
 415         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 416                                 .wdata = &address, .rdata = &d,
 417                                 .wlen = 1, .rlen = 1};
 418
 419         result = acpi_ec_transaction(ec, &t);
 420         *data = d;
 421         return result;
 422 }
 423
 424 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 425 {
 426         u8 wdata[2] = { address, data };
 427         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 428                                 .wdata = wdata, .rdata = NULL,
 429                                 .wlen = 2, .rlen = 0};
 430
 431         return acpi_ec_transaction(ec, &t);
 432 }
 433
 434 int ec_read(u8 addr, u8 *val)
 435 {
 436         int err;
 437         u8 temp_data;
 438
 439         if (!first_ec)
 440                 return -ENODEV;
 441
 442         err = acpi_ec_read(first_ec, addr, &temp_data);
 443
 444         if (!err) {
 445                 *val = temp_data;
 446                 return 0;
 447         } else
 448                 return err;
 449 }
 450
 451 EXPORT_SYMBOL(ec_read);
 452
 453 int ec_write(u8 addr, u8 val)
 454 {
 455         int err;
 456
 457         if (!first_ec)
 458                 return -ENODEV;
 459
 460         err = acpi_ec_write(first_ec, addr, val);
 461
 462         return err;
 463 }
 464
 465 EXPORT_SYMBOL(ec_write);
 466
 467 int ec_transaction(u8 command,
 468                    const u8 * wdata, unsigned wdata_len,
 469                    u8 * rdata, unsigned rdata_len)
 470 {
 471         struct transaction t = {.command = command,
 472                                 .wdata = wdata, .rdata = rdata,
 473                                 .wlen = wdata_len, .rlen = rdata_len};
 474         if (!first_ec)
 475                 return -ENODEV;
 476
 477         return acpi_ec_transaction(first_ec, &t);
 478 }
 479
 480 EXPORT_SYMBOL(ec_transaction);
 481
 482 /* Get the handle to the EC device */
 483 acpi_handle ec_get_handle(void)
 484 {
 485         if (!first_ec)
 486                 return NULL;
 487         return first_ec->handle;
 488 }
 489
 490 EXPORT_SYMBOL(ec_get_handle);
 491
 492 /*
 493  * Process _Q events that might have accumulated in the EC.
 494  * Run with locked ec mutex.
 495  */
 496 static void acpi_ec_clear(struct acpi_ec *ec)
 497 {
 498         int i, status;
 499         u8 value = 0;
 500
 501         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 502                 status = acpi_ec_sync_query(ec, &value);
 503                 if (status || !value)
 504                         break;
 505         }
 506
 507         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 508                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 509         else
 510                 pr_info("%d stale EC events cleared\n", i);
 511 }
 512
 513 void acpi_ec_block_transactions(void)
 514 {
 515         struct acpi_ec *ec = first_ec;
 516
 517         if (!ec)
 518                 return;
 519
 520         mutex_lock(&ec->mutex);
 521         /* Prevent transactions from being carried out */
 522         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 523         mutex_unlock(&ec->mutex);
 524 }
 525
 526 void acpi_ec_unblock_transactions(void)
 527 {
 528         struct acpi_ec *ec = first_ec;
 529
 530         if (!ec)
 531                 return;
 532
 533         mutex_lock(&ec->mutex);
 534         /* Allow transactions to be carried out again */
 535         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 536
 537         if (EC_FLAGS_CLEAR_ON_RESUME)
 538                 acpi_ec_clear(ec);
 539
 540         mutex_unlock(&ec->mutex);
 541 }
 542
 543 void acpi_ec_unblock_transactions_early(void)
 544 {
 545         /*
 546          * Allow transactions to happen again (this function is called from
 547          * atomic context during wakeup, so we don't need to acquire the mutex).
 548          */
 549         if (first_ec)
 550                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 551 }
 552
 553 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 554 {
 555         int result;
 556         u8 d;
 557         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 558                                 .wdata = NULL, .rdata = &d,
 559                                 .wlen = 0, .rlen = 1};
 560         if (!ec || !data)
 561                 return -EINVAL;
 562         /*
 563          * Query the EC to find out which _Qxx method we need to evaluate.
 564          * Note that successful completion of the query causes the ACPI_EC_SCI
 565          * bit to be cleared (and thus clearing the interrupt source).
 566          */
 567         result = acpi_ec_transaction_unlocked(ec, &t);
 568         if (result)
 569                 return result;
 570         if (!d)
 571                 return -ENODATA;
 572         *data = d;
 573         return 0;
 574 }
 575
 576 /* --------------------------------------------------------------------------
 577                                 Event Management
 578    -------------------------------------------------------------------------- */
 579 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 580                               acpi_handle handle, acpi_ec_query_func func,
 581                               void *data)
 582 {
 583         struct acpi_ec_query_handler *handler =
 584             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 585         if (!handler)
 586                 return -ENOMEM;
 587
 588         handler->query_bit = query_bit;
 589         handler->handle = handle;
 590         handler->func = func;
 591         handler->data = data;
 592         mutex_lock(&ec->mutex);
 593         list_add(&handler->node, &ec->list);
 594         mutex_unlock(&ec->mutex);
 595         return 0;
 596 }
 597
 598 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 599
 600 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 601 {
 602         struct acpi_ec_query_handler *handler, *tmp;
 603         mutex_lock(&ec->mutex);
 604         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 605                 if (query_bit == handler->query_bit) {
 606                         list_del(&handler->node);
 607                         kfree(handler);
 608                 }
 609         }
 610         mutex_unlock(&ec->mutex);
 611 }
 612
 613 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 614
 615 static void acpi_ec_run(void *cxt)
 616 {
 617         struct acpi_ec_query_handler *handler = cxt;
 618         if (!handler)
 619                 return;
 620         pr_debug("start query execution\n");
 621         if (handler->func)
 622                 handler->func(handler->data);
 623         else if (handler->handle)
 624                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 625         pr_debug("stop query execution\n");
 626         kfree(handler);
 627 }
 628
 629 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
 630 {
 631         u8 value = 0;
 632         int status;
 633         struct acpi_ec_query_handler *handler, *copy;
 634
 635         status = acpi_ec_query_unlocked(ec, &value);
 636         if (data)
 637                 *data = value;
 638         if (status)
 639                 return status;
 640
 641         list_for_each_entry(handler, &ec->list, node) {
 642                 if (value == handler->query_bit) {
 643                         /* have custom handler for this bit */
 644                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 645                         if (!copy)
 646                                 return -ENOMEM;
 647                         memcpy(copy, handler, sizeof(*copy));
 648                         pr_debug("push query execution (0x%2x) on queue\n",
 649                                 value);
 650                         return acpi_os_execute((copy->func) ?
 651                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 652                                 acpi_ec_run, copy);
 653                 }
 654         }
 655         return 0;
 656 }
 657
 658 static void acpi_ec_gpe_query(void *ec_cxt)
 659 {
 660         struct acpi_ec *ec = ec_cxt;
 661         if (!ec)
 662                 return;
 663         mutex_lock(&ec->mutex);
 664         acpi_ec_sync_query(ec, NULL);
 665         mutex_unlock(&ec->mutex);
 666 }
 667
 668 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 669 {
 670         if (state & ACPI_EC_FLAG_SCI) {
 671                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 672                         pr_debug("push gpe query to the queue\n");
 673                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 674                                 acpi_ec_gpe_query, ec);
 675                 }
 676         }
 677         return 0;
 678 }
 679
 680 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 681         u32 gpe_number, void *data)
 682 {
 683         unsigned long flags;
 684         struct acpi_ec *ec = data;
 685
 686         spin_lock_irqsave(&ec->lock, flags);
 687         if (advance_transaction(ec))
 688                 wake_up(&ec->wait);
 689         spin_unlock_irqrestore(&ec->lock, flags);
 690         ec_check_sci(ec, acpi_ec_read_status(ec));
 691         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 692 }
 693
 694 /* --------------------------------------------------------------------------
 695                              Address Space Management
 696    -------------------------------------------------------------------------- */
 697
 698 static acpi_status
 699 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 700                       u32 bits, u64 *value64,
 701                       void *handler_context, void *region_context)
 702 {
 703         struct acpi_ec *ec = handler_context;
 704         int result = 0, i, bytes = bits / 8;
 705         u8 *value = (u8 *)value64;
 706
 707         if ((address > 0xFF) || !value || !handler_context)
 708                 return AE_BAD_PARAMETER;
 709
 710         if (function != ACPI_READ && function != ACPI_WRITE)
 711                 return AE_BAD_PARAMETER;
 712
 713         if (EC_FLAGS_MSI || bits > 8)
 714                 acpi_ec_burst_enable(ec);
 715
 716         for (i = 0; i < bytes; ++i, ++address, ++value)
 717                 result = (function == ACPI_READ) ?
 718                         acpi_ec_read(ec, address, value) :
 719                         acpi_ec_write(ec, address, *value);
 720
 721         if (EC_FLAGS_MSI || bits > 8)
 722                 acpi_ec_burst_disable(ec);
 723
 724         switch (result) {
 725         case -EINVAL:
 726                 return AE_BAD_PARAMETER;
 727                 break;
 728         case -ENODEV:
 729                 return AE_NOT_FOUND;
 730                 break;
 731         case -ETIME:
 732                 return AE_TIME;
 733                 break;
 734         default:
 735                 return AE_OK;
 736         }
 737 }
 738
 739 /* --------------------------------------------------------------------------
 740                                Driver Interface
 741    -------------------------------------------------------------------------- */
 742 static acpi_status
 743 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 744
 745 static struct acpi_ec *make_acpi_ec(void)
 746 {
 747         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 748         if (!ec)
 749                 return NULL;
 750         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 751         mutex_init(&ec->mutex);
 752         init_waitqueue_head(&ec->wait);
 753         INIT_LIST_HEAD(&ec->list);
 754         spin_lock_init(&ec->lock);
 755         return ec;
 756 }
 757
 758 static acpi_status
 759 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 760                                void *context, void **return_value)
 761 {
 762         char node_name[5];
 763         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 764         struct acpi_ec *ec = context;
 765         int value = 0;
 766         acpi_status status;
 767
 768         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 769
 770         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 771                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 772         }
 773         return AE_OK;
 774 }
 775
 776 static acpi_status
 777 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 778 {
 779         acpi_status status;
 780         unsigned long long tmp = 0;
 781
 782         struct acpi_ec *ec = context;
 783
 784         /* clear addr values, ec_parse_io_ports depend on it */
 785         ec->command_addr = ec->data_addr = 0;
 786
 787         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 788                                      ec_parse_io_ports, ec);
 789         if (ACPI_FAILURE(status))
 790                 return status;
 791
 792         /* Get GPE bit assignment (EC events). */
 793         /* TODO: Add support for _GPE returning a package */
 794         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 795         if (ACPI_FAILURE(status))
 796                 return status;
 797         ec->gpe = tmp;
 798         /* Use the global lock for all EC transactions? */
 799         tmp = 0;
 800         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 801         ec->global_lock = tmp;
 802         ec->handle = handle;
 803         return AE_CTRL_TERMINATE;
 804 }
 805
 806 static int ec_install_handlers(struct acpi_ec *ec)
 807 {
 808         acpi_status status;
 809         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 810                 return 0;
 811         status = acpi_install_gpe_handler(NULL, ec->gpe,
 812                                   ACPI_GPE_EDGE_TRIGGERED,
 813                                   &acpi_ec_gpe_handler, ec);
 814         if (ACPI_FAILURE(status))
 815                 return -ENODEV;
 816
 817         acpi_enable_gpe(NULL, ec->gpe);
 818         status = acpi_install_address_space_handler(ec->handle,
 819                                                     ACPI_ADR_SPACE_EC,
 820                                                     &acpi_ec_space_handler,
 821                                                     NULL, ec);
 822         if (ACPI_FAILURE(status)) {
 823                 if (status == AE_NOT_FOUND) {
 824                         /*
 825                          * Maybe OS fails in evaluating the _REG object.
 826                          * The AE_NOT_FOUND error will be ignored and OS
 827                          * continue to initialize EC.
 828                          */
 829                         pr_err("Fail in evaluating the _REG object"
 830                                 " of EC device. Broken bios is suspected.\n");
 831                 } else {
 832                         acpi_disable_gpe(NULL, ec->gpe);
 833                         acpi_remove_gpe_handler(NULL, ec->gpe,
 834                                 &acpi_ec_gpe_handler);
 835                         return -ENODEV;
 836                 }
 837         }
 838
 839         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 840         return 0;
 841 }
 842
 843 static void ec_remove_handlers(struct acpi_ec *ec)
 844 {
 845         acpi_disable_gpe(NULL, ec->gpe);
 846         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 847                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 848                 pr_err("failed to remove space handler\n");
 849         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 850                                 &acpi_ec_gpe_handler)))
 851                 pr_err("failed to remove gpe handler\n");
 852         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 853 }
 854
 855 static int acpi_ec_add(struct acpi_device *device)
 856 {
 857         struct acpi_ec *ec = NULL;
 858         int ret;
 859
 860         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 861         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 862
 863         /* Check for boot EC */
 864         if (boot_ec &&
 865             (boot_ec->handle == device->handle ||
 866              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 867                 ec = boot_ec;
 868                 boot_ec = NULL;
 869         } else {
 870                 ec = make_acpi_ec();
 871                 if (!ec)
 872                         return -ENOMEM;
 873         }
 874         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 875                 AE_CTRL_TERMINATE) {
 876                         kfree(ec);
 877                         return -EINVAL;
 878         }
 879
 880         /* Find and register all query methods */
 881         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 882                             acpi_ec_register_query_methods, NULL, ec, NULL);
 883
 884         if (!first_ec)
 885                 first_ec = ec;
 886         device->driver_data = ec;
 887
 888         ret = !!request_region(ec->data_addr, 1, "EC data");
 889         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
 890         ret = !!request_region(ec->command_addr, 1, "EC cmd");
 891         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
 892
 893         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 894                           ec->gpe, ec->command_addr, ec->data_addr);
 895
 896         ret = ec_install_handlers(ec);
 897
 898         /* EC is fully operational, allow queries */
 899         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 900
 901         /* Clear stale _Q events if hardware might require that */
 902         if (EC_FLAGS_CLEAR_ON_RESUME) {
 903                 mutex_lock(&ec->mutex);
 904                 acpi_ec_clear(ec);
 905                 mutex_unlock(&ec->mutex);
 906         }
 907         return ret;
 908 }
 909
 910 static int acpi_ec_remove(struct acpi_device *device)
 911 {
 912         struct acpi_ec *ec;
 913         struct acpi_ec_query_handler *handler, *tmp;
 914
 915         if (!device)
 916                 return -EINVAL;
 917
 918         ec = acpi_driver_data(device);
 919         ec_remove_handlers(ec);
 920         mutex_lock(&ec->mutex);
 921         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 922                 list_del(&handler->node);
 923                 kfree(handler);
 924         }
 925         mutex_unlock(&ec->mutex);
 926         release_region(ec->data_addr, 1);
 927         release_region(ec->command_addr, 1);
 928         device->driver_data = NULL;
 929         if (ec == first_ec)
 930                 first_ec = NULL;
 931         kfree(ec);
 932         return 0;
 933 }
 934
 935 static acpi_status
 936 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 937 {
 938         struct acpi_ec *ec = context;
 939
 940         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 941                 return AE_OK;
 942
 943         /*
 944          * The first address region returned is the data port, and
 945          * the second address region returned is the status/command
 946          * port.
 947          */
 948         if (ec->data_addr == 0)
 949                 ec->data_addr = resource->data.io.minimum;
 950         else if (ec->command_addr == 0)
 951                 ec->command_addr = resource->data.io.minimum;
 952         else
 953                 return AE_CTRL_TERMINATE;
 954
 955         return AE_OK;
 956 }
 957
 958 int __init acpi_boot_ec_enable(void)
 959 {
 960         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 961                 return 0;
 962         if (!ec_install_handlers(boot_ec)) {
 963                 first_ec = boot_ec;
 964                 return 0;
 965         }
 966         return -EFAULT;
 967 }
 968
 969 static const struct acpi_device_id ec_device_ids[] = {
 970         {"PNP0C09", 0},
 971         {"", 0},
 972 };
 973
 974 /* Some BIOS do not survive early DSDT scan, skip it */
 975 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 976 {
 977         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 978         return 0;
 979 }
 980
 981 /* ASUStek often supplies us with broken ECDT, validate it */
 982 static int ec_validate_ecdt(const struct dmi_system_id *id)
 983 {
 984         EC_FLAGS_VALIDATE_ECDT = 1;
 985         return 0;
 986 }
 987
 988 /* MSI EC needs special treatment, enable it */
 989 static int ec_flag_msi(const struct dmi_system_id *id)
 990 {
 991         pr_debug("Detected MSI hardware, enabling workarounds.\n");
 992         EC_FLAGS_MSI = 1;
 993         EC_FLAGS_VALIDATE_ECDT = 1;
 994         return 0;
 995 }
 996
 997 /*
 998  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
 999  * the GPE storm threshold back to 20
1000  */
1001 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
1002 {
1003         pr_debug("Setting the EC GPE storm threshold to 20\n");
1004         ec_storm_threshold  = 20;
1005         return 0;
1006 }
1007
1008 /*
1009  * On some hardware it is necessary to clear events accumulated by the EC during
1010  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1011  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1012  *
1013  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1014  *
1015  * Ideally, the EC should also be instructed NOT to accumulate events during
1016  * sleep (which Windows seems to do somehow), but the interface to control this
1017  * behaviour is not known at this time.
1018  *
1019  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1020  * however it is very likely that other Samsung models are affected.
1021  *
1022  * On systems which don't accumulate _Q events during sleep, this extra check
1023  * should be harmless.
1024  */
1025 static int ec_clear_on_resume(const struct dmi_system_id *id)
1026 {
1027         pr_debug("Detected system needing EC poll on resume.\n");
1028         EC_FLAGS_CLEAR_ON_RESUME = 1;
1029         return 0;
1030 }
1031
1032 static struct dmi_system_id ec_dmi_table[] __initdata = {
1033         {
1034         ec_skip_dsdt_scan, "Compal JFL92", {
1035         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1036         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1037         {
1038         ec_flag_msi, "MSI hardware", {
1039         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1040         {
1041         ec_flag_msi, "MSI hardware", {
1042         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1043         {
1044         ec_flag_msi, "MSI hardware", {
1045         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1046         {
1047         ec_flag_msi, "MSI hardware", {
1048         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1049         {
1050         ec_flag_msi, "Quanta hardware", {
1051         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1052         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1053         {
1054         ec_flag_msi, "Quanta hardware", {
1055         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1056         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1057         {
1058         ec_flag_msi, "Clevo W350etq", {
1059         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
1060         DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
1061         {
1062         ec_validate_ecdt, "ASUS hardware", {
1063         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1064         {
1065         ec_validate_ecdt, "ASUS hardware", {
1066         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1067         {
1068         ec_enlarge_storm_threshold, "CLEVO hardware", {
1069         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1070         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1071         {
1072         ec_skip_dsdt_scan, "HP Folio 13", {
1073         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1074         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1075         {
1076         ec_validate_ecdt, "ASUS hardware", {
1077         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1078         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1079         {
1080         ec_clear_on_resume, "Samsung hardware", {
1081         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1082         {},
1083 };
1084
1085 int __init acpi_ec_ecdt_probe(void)
1086 {
1087         acpi_status status;
1088         struct acpi_ec *saved_ec = NULL;
1089         struct acpi_table_ecdt *ecdt_ptr;
1090
1091         boot_ec = make_acpi_ec();
1092         if (!boot_ec)
1093                 return -ENOMEM;
1094         /*
1095          * Generate a boot ec context
1096          */
1097         dmi_check_system(ec_dmi_table);
1098         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1099                                 (struct acpi_table_header **)&ecdt_ptr);
1100         if (ACPI_SUCCESS(status)) {
1101                 pr_info("EC description table is found, configuring boot EC\n");
1102                 boot_ec->command_addr = ecdt_ptr->control.address;
1103                 boot_ec->data_addr = ecdt_ptr->data.address;
1104                 boot_ec->gpe = ecdt_ptr->gpe;
1105                 boot_ec->handle = ACPI_ROOT_OBJECT;
1106                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1107                 /* Don't trust ECDT, which comes from ASUSTek */
1108                 if (!EC_FLAGS_VALIDATE_ECDT)
1109                         goto install;
1110                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1111                 if (!saved_ec)
1112                         return -ENOMEM;
1113         /* fall through */
1114         }
1115
1116         if (EC_FLAGS_SKIP_DSDT_SCAN) {
1117                 kfree(saved_ec);
1118                 return -ENODEV;
1119         }
1120
1121         /* This workaround is needed only on some broken machines,
1122          * which require early EC, but fail to provide ECDT */
1123         pr_debug("Look up EC in DSDT\n");
1124         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1125                                         boot_ec, NULL);
1126         /* Check that acpi_get_devices actually find something */
1127         if (ACPI_FAILURE(status) || !boot_ec->handle)
1128                 goto error;
1129         if (saved_ec) {
1130                 /* try to find good ECDT from ASUSTek */
1131                 if (saved_ec->command_addr != boot_ec->command_addr ||
1132                     saved_ec->data_addr != boot_ec->data_addr ||
1133                     saved_ec->gpe != boot_ec->gpe ||
1134                     saved_ec->handle != boot_ec->handle)
1135                         pr_info("ASUSTek keeps feeding us with broken "
1136                         "ECDT tables, which are very hard to workaround. "
1137                         "Trying to use DSDT EC info instead. Please send "
1138                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1139                 kfree(saved_ec);
1140                 saved_ec = NULL;
1141         } else {
1142                 /* We really need to limit this workaround, the only ASUS,
1143                 * which needs it, has fake EC._INI method, so use it as flag.
1144                 * Keep boot_ec struct as it will be needed soon.
1145                 */
1146                 if (!dmi_name_in_vendors("ASUS") ||
1147                     !acpi_has_method(boot_ec->handle, "_INI"))
1148                         return -ENODEV;
1149         }
1150 install:
1151         if (!ec_install_handlers(boot_ec)) {
1152                 first_ec = boot_ec;
1153                 return 0;
1154         }
1155 error:
1156         kfree(boot_ec);
1157         kfree(saved_ec);
1158         boot_ec = NULL;
1159         return -ENODEV;
1160 }
1161
1162 static struct acpi_driver acpi_ec_driver = {
1163         .name = "ec",
1164         .class = ACPI_EC_CLASS,
1165         .ids = ec_device_ids,
1166         .ops = {
1167                 .add = acpi_ec_add,
1168                 .remove = acpi_ec_remove,
1169                 },
1170 };
1171
1172 int __init acpi_ec_init(void)
1173 {
1174         int result = 0;
1175
1176         /* Now register the driver for the EC */
1177         result = acpi_bus_register_driver(&acpi_ec_driver);
1178         if (result < 0)
1179                 return -ENODEV;
1180
1181         return result;
1182 }
1183
1184 /* EC driver currently not unloadable */
1185 #if 0
1186 static void __exit acpi_ec_exit(void)
1187 {
1188
1189         acpi_bus_unregister_driver(&acpi_ec_driver);
1190         return;
1191 }
1192 #endif  /* 0 */