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
 138         pr_debug("EC_SC(R) = 0x%2.2x "
 139                  "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d\n",
 140                  x,
 141                  !!(x & ACPI_EC_FLAG_SCI),
 142                  !!(x & ACPI_EC_FLAG_BURST),
 143                  !!(x & ACPI_EC_FLAG_CMD),
 144                  !!(x & ACPI_EC_FLAG_IBF),
 145                  !!(x & ACPI_EC_FLAG_OBF));
 146         return x;
 147 }
 148
 149 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 150 {
 151         u8 x = inb(ec->data_addr);
 152
 153         pr_debug("EC_DATA(R) = 0x%2.2x\n", x);
 154         return x;
 155 }
 156
 157 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 158 {
 159         pr_debug("EC_SC(W) = 0x%2.2x\n", command);
 160         outb(command, ec->command_addr);
 161 }
 162
 163 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 164 {
 165         pr_debug("EC_DATA(W) = 0x%2.2x\n", data);
 166         outb(data, ec->data_addr);
 167 }
 168
 169 #ifdef DEBUG
 170 static const char *acpi_ec_cmd_string(u8 cmd)
 171 {
 172         switch (cmd) {
 173         case 0x80:
 174                 return "RD_EC";
 175         case 0x81:
 176                 return "WR_EC";
 177         case 0x82:
 178                 return "BE_EC";
 179         case 0x83:
 180                 return "BD_EC";
 181         case 0x84:
 182                 return "QR_EC";
 183         }
 184         return "UNKNOWN";
 185 }
 186 #else
 187 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 188 #endif
 189
 190 static int ec_transaction_completed(struct acpi_ec *ec)
 191 {
 192         unsigned long flags;
 193         int ret = 0;
 194
 195         spin_lock_irqsave(&ec->lock, flags);
 196         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 197                 ret = 1;
 198         spin_unlock_irqrestore(&ec->lock, flags);
 199         return ret;
 200 }
 201
 202 static bool advance_transaction(struct acpi_ec *ec)
 203 {
 204         struct transaction *t;
 205         u8 status;
 206         bool wakeup = false;
 207
 208         pr_debug("===== %s (%d) =====\n",
 209                  in_interrupt() ? "IRQ" : "TASK", smp_processor_id());
 210         status = acpi_ec_read_status(ec);
 211         t = ec->curr;
 212         if (!t)
 213                 goto err;
 214         if (t->flags & ACPI_EC_COMMAND_POLL) {
 215                 if (t->wlen > t->wi) {
 216                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 217                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 218                         else
 219                                 goto err;
 220                 } else if (t->rlen > t->ri) {
 221                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 222                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 223                                 if (t->rlen == t->ri) {
 224                                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 225                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 226                                                 pr_debug("***** Command(%s) hardware completion *****\n",
 227                                                          acpi_ec_cmd_string(t->command));
 228                                         wakeup = true;
 229                                 }
 230                         } else
 231                                 goto err;
 232                 } else if (t->wlen == t->wi &&
 233                            (status & ACPI_EC_FLAG_IBF) == 0) {
 234                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 235                         wakeup = true;
 236                 }
 237                 return wakeup;
 238         } else {
 239                 /*
 240                  * There is firmware refusing to respond QR_EC when SCI_EVT
 241                  * is not set, for which case, we complete the QR_EC
 242                  * without issuing it to the firmware.
 243                  * https://bugzilla.kernel.org/show_bug.cgi?id=86211
 244                  */
 245                 if (!(status & ACPI_EC_FLAG_SCI) &&
 246                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 247                         t->flags |= ACPI_EC_COMMAND_POLL;
 248                         t->rdata[t->ri++] = 0x00;
 249                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 250                         pr_debug("***** Command(%s) software completion *****\n",
 251                                  acpi_ec_cmd_string(t->command));
 252                         wakeup = true;
 253                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 254                         acpi_ec_write_cmd(ec, t->command);
 255                         t->flags |= ACPI_EC_COMMAND_POLL;
 256                 } else
 257                         goto err;
 258                 return wakeup;
 259         }
 260 err:
 261         /*
 262          * If SCI bit is set, then don't think it's a false IRQ
 263          * otherwise will take a not handled IRQ as a false one.
 264          */
 265         if (!(status & ACPI_EC_FLAG_SCI)) {
 266                 if (in_interrupt() && t)
 267                         ++t->irq_count;
 268         }
 269         return wakeup;
 270 }
 271
 272 static void start_transaction(struct acpi_ec *ec)
 273 {
 274         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 275         ec->curr->flags = 0;
 276         (void)advance_transaction(ec);
 277 }
 278
 279 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
 280
 281 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 282 {
 283         if (state & ACPI_EC_FLAG_SCI) {
 284                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 285                         return acpi_ec_sync_query(ec, NULL);
 286         }
 287         return 0;
 288 }
 289
 290 static int ec_poll(struct acpi_ec *ec)
 291 {
 292         unsigned long flags;
 293         int repeat = 5; /* number of command restarts */
 294
 295         while (repeat--) {
 296                 unsigned long delay = jiffies +
 297                         msecs_to_jiffies(ec_delay);
 298                 do {
 299                         /* don't sleep with disabled interrupts */
 300                         if (EC_FLAGS_MSI || irqs_disabled()) {
 301                                 udelay(ACPI_EC_MSI_UDELAY);
 302                                 if (ec_transaction_completed(ec))
 303                                         return 0;
 304                         } else {
 305                                 if (wait_event_timeout(ec->wait,
 306                                                 ec_transaction_completed(ec),
 307                                                 msecs_to_jiffies(1)))
 308                                         return 0;
 309                         }
 310                         spin_lock_irqsave(&ec->lock, flags);
 311                         (void)advance_transaction(ec);
 312                         spin_unlock_irqrestore(&ec->lock, flags);
 313                 } while (time_before(jiffies, delay));
 314                 pr_debug("controller reset, restart transaction\n");
 315                 spin_lock_irqsave(&ec->lock, flags);
 316                 start_transaction(ec);
 317                 spin_unlock_irqrestore(&ec->lock, flags);
 318         }
 319         return -ETIME;
 320 }
 321
 322 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 323                                         struct transaction *t)
 324 {
 325         unsigned long tmp;
 326         int ret = 0;
 327
 328         if (EC_FLAGS_MSI)
 329                 udelay(ACPI_EC_MSI_UDELAY);
 330         /* start transaction */
 331         spin_lock_irqsave(&ec->lock, tmp);
 332         /* following two actions should be kept atomic */
 333         ec->curr = t;
 334         pr_debug("***** Command(%s) started *****\n",
 335                  acpi_ec_cmd_string(t->command));
 336         start_transaction(ec);
 337         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 338                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 339                 pr_debug("***** Event stopped *****\n");
 340         }
 341         spin_unlock_irqrestore(&ec->lock, tmp);
 342         ret = ec_poll(ec);
 343         spin_lock_irqsave(&ec->lock, tmp);
 344         pr_debug("***** Command(%s) stopped *****\n",
 345                  acpi_ec_cmd_string(t->command));
 346         ec->curr = NULL;
 347         spin_unlock_irqrestore(&ec->lock, tmp);
 348         return ret;
 349 }
 350
 351 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 352 {
 353         int status;
 354         u32 glk;
 355
 356         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 357                 return -EINVAL;
 358         if (t->rdata)
 359                 memset(t->rdata, 0, t->rlen);
 360         mutex_lock(&ec->mutex);
 361         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 362                 status = -EINVAL;
 363                 goto unlock;
 364         }
 365         if (ec->global_lock) {
 366                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 367                 if (ACPI_FAILURE(status)) {
 368                         status = -ENODEV;
 369                         goto unlock;
 370                 }
 371         }
 372         /* disable GPE during transaction if storm is detected */
 373         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 374                 /* It has to be disabled, so that it doesn't trigger. */
 375                 acpi_disable_gpe(NULL, ec->gpe);
 376         }
 377
 378         status = acpi_ec_transaction_unlocked(ec, t);
 379
 380         /* check if we received SCI during transaction */
 381         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 382         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 383                 msleep(1);
 384                 /* It is safe to enable the GPE outside of the transaction. */
 385                 acpi_enable_gpe(NULL, ec->gpe);
 386         } else if (t->irq_count > ec_storm_threshold) {
 387                 pr_info("GPE storm detected(%d GPEs), "
 388                         "transactions will use polling mode\n",
 389                         t->irq_count);
 390                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 391         }
 392         if (ec->global_lock)
 393                 acpi_release_global_lock(glk);
 394 unlock:
 395         mutex_unlock(&ec->mutex);
 396         return status;
 397 }
 398
 399 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 400 {
 401         u8 d;
 402         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 403                                 .wdata = NULL, .rdata = &d,
 404                                 .wlen = 0, .rlen = 1};
 405
 406         return acpi_ec_transaction(ec, &t);
 407 }
 408
 409 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 410 {
 411         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 412                                 .wdata = NULL, .rdata = NULL,
 413                                 .wlen = 0, .rlen = 0};
 414
 415         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 416                                 acpi_ec_transaction(ec, &t) : 0;
 417 }
 418
 419 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
 420 {
 421         int result;
 422         u8 d;
 423         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 424                                 .wdata = &address, .rdata = &d,
 425                                 .wlen = 1, .rlen = 1};
 426
 427         result = acpi_ec_transaction(ec, &t);
 428         *data = d;
 429         return result;
 430 }
 431
 432 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 433 {
 434         u8 wdata[2] = { address, data };
 435         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 436                                 .wdata = wdata, .rdata = NULL,
 437                                 .wlen = 2, .rlen = 0};
 438
 439         return acpi_ec_transaction(ec, &t);
 440 }
 441
 442 int ec_read(u8 addr, u8 *val)
 443 {
 444         int err;
 445         u8 temp_data;
 446
 447         if (!first_ec)
 448                 return -ENODEV;
 449
 450         err = acpi_ec_read(first_ec, addr, &temp_data);
 451
 452         if (!err) {
 453                 *val = temp_data;
 454                 return 0;
 455         }
 456         return err;
 457 }
 458 EXPORT_SYMBOL(ec_read);
 459
 460 int ec_write(u8 addr, u8 val)
 461 {
 462         int err;
 463
 464         if (!first_ec)
 465                 return -ENODEV;
 466
 467         err = acpi_ec_write(first_ec, addr, val);
 468
 469         return err;
 470 }
 471 EXPORT_SYMBOL(ec_write);
 472
 473 int ec_transaction(u8 command,
 474                    const u8 *wdata, unsigned wdata_len,
 475                    u8 *rdata, unsigned rdata_len)
 476 {
 477         struct transaction t = {.command = command,
 478                                 .wdata = wdata, .rdata = rdata,
 479                                 .wlen = wdata_len, .rlen = rdata_len};
 480
 481         if (!first_ec)
 482                 return -ENODEV;
 483
 484         return acpi_ec_transaction(first_ec, &t);
 485 }
 486 EXPORT_SYMBOL(ec_transaction);
 487
 488 /* Get the handle to the EC device */
 489 acpi_handle ec_get_handle(void)
 490 {
 491         if (!first_ec)
 492                 return NULL;
 493         return first_ec->handle;
 494 }
 495 EXPORT_SYMBOL(ec_get_handle);
 496
 497 /*
 498  * Process _Q events that might have accumulated in the EC.
 499  * Run with locked ec mutex.
 500  */
 501 static void acpi_ec_clear(struct acpi_ec *ec)
 502 {
 503         int i, status;
 504         u8 value = 0;
 505
 506         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 507                 status = acpi_ec_sync_query(ec, &value);
 508                 if (status || !value)
 509                         break;
 510         }
 511
 512         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 513                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 514         else
 515                 pr_info("%d stale EC events cleared\n", i);
 516 }
 517
 518 void acpi_ec_block_transactions(void)
 519 {
 520         struct acpi_ec *ec = first_ec;
 521
 522         if (!ec)
 523                 return;
 524
 525         mutex_lock(&ec->mutex);
 526         /* Prevent transactions from being carried out */
 527         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 528         mutex_unlock(&ec->mutex);
 529 }
 530
 531 void acpi_ec_unblock_transactions(void)
 532 {
 533         struct acpi_ec *ec = first_ec;
 534
 535         if (!ec)
 536                 return;
 537
 538         mutex_lock(&ec->mutex);
 539         /* Allow transactions to be carried out again */
 540         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 541
 542         if (EC_FLAGS_CLEAR_ON_RESUME)
 543                 acpi_ec_clear(ec);
 544
 545         mutex_unlock(&ec->mutex);
 546 }
 547
 548 void acpi_ec_unblock_transactions_early(void)
 549 {
 550         /*
 551          * Allow transactions to happen again (this function is called from
 552          * atomic context during wakeup, so we don't need to acquire the mutex).
 553          */
 554         if (first_ec)
 555                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 556 }
 557
 558 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 *data)
 559 {
 560         int result;
 561         u8 d;
 562         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 563                                 .wdata = NULL, .rdata = &d,
 564                                 .wlen = 0, .rlen = 1};
 565
 566         if (!ec || !data)
 567                 return -EINVAL;
 568         /*
 569          * Query the EC to find out which _Qxx method we need to evaluate.
 570          * Note that successful completion of the query causes the ACPI_EC_SCI
 571          * bit to be cleared (and thus clearing the interrupt source).
 572          */
 573         result = acpi_ec_transaction_unlocked(ec, &t);
 574         if (result)
 575                 return result;
 576         if (!d)
 577                 return -ENODATA;
 578         *data = d;
 579         return 0;
 580 }
 581
 582 /* --------------------------------------------------------------------------
 583                                 Event Management
 584    -------------------------------------------------------------------------- */
 585 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 586                               acpi_handle handle, acpi_ec_query_func func,
 587                               void *data)
 588 {
 589         struct acpi_ec_query_handler *handler =
 590             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 591
 592         if (!handler)
 593                 return -ENOMEM;
 594
 595         handler->query_bit = query_bit;
 596         handler->handle = handle;
 597         handler->func = func;
 598         handler->data = data;
 599         mutex_lock(&ec->mutex);
 600         list_add(&handler->node, &ec->list);
 601         mutex_unlock(&ec->mutex);
 602         return 0;
 603 }
 604 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 605
 606 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 607 {
 608         struct acpi_ec_query_handler *handler, *tmp;
 609
 610         mutex_lock(&ec->mutex);
 611         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 612                 if (query_bit == handler->query_bit) {
 613                         list_del(&handler->node);
 614                         kfree(handler);
 615                 }
 616         }
 617         mutex_unlock(&ec->mutex);
 618 }
 619 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 620
 621 static void acpi_ec_run(void *cxt)
 622 {
 623         struct acpi_ec_query_handler *handler = cxt;
 624
 625         if (!handler)
 626                 return;
 627         pr_debug("##### Query(0x%02x) started #####\n", handler->query_bit);
 628         if (handler->func)
 629                 handler->func(handler->data);
 630         else if (handler->handle)
 631                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 632         pr_debug("##### Query(0x%02x) stopped #####\n", handler->query_bit);
 633         kfree(handler);
 634 }
 635
 636 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
 637 {
 638         u8 value = 0;
 639         int status;
 640         struct acpi_ec_query_handler *handler, *copy;
 641
 642         status = acpi_ec_query_unlocked(ec, &value);
 643         if (data)
 644                 *data = value;
 645         if (status)
 646                 return status;
 647
 648         list_for_each_entry(handler, &ec->list, node) {
 649                 if (value == handler->query_bit) {
 650                         /* have custom handler for this bit */
 651                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 652                         if (!copy)
 653                                 return -ENOMEM;
 654                         memcpy(copy, handler, sizeof(*copy));
 655                         pr_debug("##### Query(0x%02x) scheduled #####\n",
 656                                  handler->query_bit);
 657                         return acpi_os_execute((copy->func) ?
 658                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 659                                 acpi_ec_run, copy);
 660                 }
 661         }
 662         return 0;
 663 }
 664
 665 static void acpi_ec_gpe_query(void *ec_cxt)
 666 {
 667         struct acpi_ec *ec = ec_cxt;
 668
 669         if (!ec)
 670                 return;
 671         mutex_lock(&ec->mutex);
 672         acpi_ec_sync_query(ec, NULL);
 673         mutex_unlock(&ec->mutex);
 674 }
 675
 676 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 677 {
 678         if (state & ACPI_EC_FLAG_SCI) {
 679                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 680                         pr_debug("***** Event started *****\n");
 681                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 682                                 acpi_ec_gpe_query, ec);
 683                 }
 684         }
 685         return 0;
 686 }
 687
 688 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 689         u32 gpe_number, void *data)
 690 {
 691         unsigned long flags;
 692         struct acpi_ec *ec = data;
 693
 694         spin_lock_irqsave(&ec->lock, flags);
 695         if (advance_transaction(ec))
 696                 wake_up(&ec->wait);
 697         spin_unlock_irqrestore(&ec->lock, flags);
 698         ec_check_sci(ec, acpi_ec_read_status(ec));
 699         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 700 }
 701
 702 /* --------------------------------------------------------------------------
 703  *                           Address Space Management
 704  * -------------------------------------------------------------------------- */
 705
 706 static acpi_status
 707 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 708                       u32 bits, u64 *value64,
 709                       void *handler_context, void *region_context)
 710 {
 711         struct acpi_ec *ec = handler_context;
 712         int result = 0, i, bytes = bits / 8;
 713         u8 *value = (u8 *)value64;
 714
 715         if ((address > 0xFF) || !value || !handler_context)
 716                 return AE_BAD_PARAMETER;
 717
 718         if (function != ACPI_READ && function != ACPI_WRITE)
 719                 return AE_BAD_PARAMETER;
 720
 721         if (EC_FLAGS_MSI || bits > 8)
 722                 acpi_ec_burst_enable(ec);
 723
 724         for (i = 0; i < bytes; ++i, ++address, ++value)
 725                 result = (function == ACPI_READ) ?
 726                         acpi_ec_read(ec, address, value) :
 727                         acpi_ec_write(ec, address, *value);
 728
 729         if (EC_FLAGS_MSI || bits > 8)
 730                 acpi_ec_burst_disable(ec);
 731
 732         switch (result) {
 733         case -EINVAL:
 734                 return AE_BAD_PARAMETER;
 735         case -ENODEV:
 736                 return AE_NOT_FOUND;
 737         case -ETIME:
 738                 return AE_TIME;
 739         default:
 740                 return AE_OK;
 741         }
 742 }
 743
 744 /* --------------------------------------------------------------------------
 745  *                             Driver Interface
 746  * -------------------------------------------------------------------------- */
 747
 748 static acpi_status
 749 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 750
 751 static struct acpi_ec *make_acpi_ec(void)
 752 {
 753         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 754
 755         if (!ec)
 756                 return NULL;
 757         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 758         mutex_init(&ec->mutex);
 759         init_waitqueue_head(&ec->wait);
 760         INIT_LIST_HEAD(&ec->list);
 761         spin_lock_init(&ec->lock);
 762         return ec;
 763 }
 764
 765 static acpi_status
 766 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 767                                void *context, void **return_value)
 768 {
 769         char node_name[5];
 770         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 771         struct acpi_ec *ec = context;
 772         int value = 0;
 773         acpi_status status;
 774
 775         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 776
 777         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
 778                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 779         return AE_OK;
 780 }
 781
 782 static acpi_status
 783 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 784 {
 785         acpi_status status;
 786         unsigned long long tmp = 0;
 787         struct acpi_ec *ec = context;
 788
 789         /* clear addr values, ec_parse_io_ports depend on it */
 790         ec->command_addr = ec->data_addr = 0;
 791
 792         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 793                                      ec_parse_io_ports, ec);
 794         if (ACPI_FAILURE(status))
 795                 return status;
 796
 797         /* Get GPE bit assignment (EC events). */
 798         /* TODO: Add support for _GPE returning a package */
 799         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 800         if (ACPI_FAILURE(status))
 801                 return status;
 802         ec->gpe = tmp;
 803         /* Use the global lock for all EC transactions? */
 804         tmp = 0;
 805         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 806         ec->global_lock = tmp;
 807         ec->handle = handle;
 808         return AE_CTRL_TERMINATE;
 809 }
 810
 811 static int ec_install_handlers(struct acpi_ec *ec)
 812 {
 813         acpi_status status;
 814
 815         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 816                 return 0;
 817         status = acpi_install_gpe_handler(NULL, ec->gpe,
 818                                   ACPI_GPE_EDGE_TRIGGERED,
 819                                   &acpi_ec_gpe_handler, ec);
 820         if (ACPI_FAILURE(status))
 821                 return -ENODEV;
 822
 823         acpi_enable_gpe(NULL, ec->gpe);
 824         status = acpi_install_address_space_handler(ec->handle,
 825                                                     ACPI_ADR_SPACE_EC,
 826                                                     &acpi_ec_space_handler,
 827                                                     NULL, ec);
 828         if (ACPI_FAILURE(status)) {
 829                 if (status == AE_NOT_FOUND) {
 830                         /*
 831                          * Maybe OS fails in evaluating the _REG object.
 832                          * The AE_NOT_FOUND error will be ignored and OS
 833                          * continue to initialize EC.
 834                          */
 835                         pr_err("Fail in evaluating the _REG object"
 836                                 " of EC device. Broken bios is suspected.\n");
 837                 } else {
 838                         acpi_disable_gpe(NULL, ec->gpe);
 839                         acpi_remove_gpe_handler(NULL, ec->gpe,
 840                                 &acpi_ec_gpe_handler);
 841                         return -ENODEV;
 842                 }
 843         }
 844
 845         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 846         return 0;
 847 }
 848
 849 static void ec_remove_handlers(struct acpi_ec *ec)
 850 {
 851         acpi_disable_gpe(NULL, ec->gpe);
 852         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 853                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 854                 pr_err("failed to remove space handler\n");
 855         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 856                                 &acpi_ec_gpe_handler)))
 857                 pr_err("failed to remove gpe handler\n");
 858         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 859 }
 860
 861 static int acpi_ec_add(struct acpi_device *device)
 862 {
 863         struct acpi_ec *ec = NULL;
 864         int ret;
 865
 866         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 867         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 868
 869         /* Check for boot EC */
 870         if (boot_ec &&
 871             (boot_ec->handle == device->handle ||
 872              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 873                 ec = boot_ec;
 874                 boot_ec = NULL;
 875         } else {
 876                 ec = make_acpi_ec();
 877                 if (!ec)
 878                         return -ENOMEM;
 879         }
 880         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 881                 AE_CTRL_TERMINATE) {
 882                         kfree(ec);
 883                         return -EINVAL;
 884         }
 885
 886         /* Find and register all query methods */
 887         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 888                             acpi_ec_register_query_methods, NULL, ec, NULL);
 889
 890         if (!first_ec)
 891                 first_ec = ec;
 892         device->driver_data = ec;
 893
 894         ret = !!request_region(ec->data_addr, 1, "EC data");
 895         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
 896         ret = !!request_region(ec->command_addr, 1, "EC cmd");
 897         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
 898
 899         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 900                           ec->gpe, ec->command_addr, ec->data_addr);
 901
 902         ret = ec_install_handlers(ec);
 903
 904         /* EC is fully operational, allow queries */
 905         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 906
 907         /* Clear stale _Q events if hardware might require that */
 908         if (EC_FLAGS_CLEAR_ON_RESUME) {
 909                 mutex_lock(&ec->mutex);
 910                 acpi_ec_clear(ec);
 911                 mutex_unlock(&ec->mutex);
 912         }
 913         return ret;
 914 }
 915
 916 static int acpi_ec_remove(struct acpi_device *device)
 917 {
 918         struct acpi_ec *ec;
 919         struct acpi_ec_query_handler *handler, *tmp;
 920
 921         if (!device)
 922                 return -EINVAL;
 923
 924         ec = acpi_driver_data(device);
 925         ec_remove_handlers(ec);
 926         mutex_lock(&ec->mutex);
 927         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 928                 list_del(&handler->node);
 929                 kfree(handler);
 930         }
 931         mutex_unlock(&ec->mutex);
 932         release_region(ec->data_addr, 1);
 933         release_region(ec->command_addr, 1);
 934         device->driver_data = NULL;
 935         if (ec == first_ec)
 936                 first_ec = NULL;
 937         kfree(ec);
 938         return 0;
 939 }
 940
 941 static acpi_status
 942 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 943 {
 944         struct acpi_ec *ec = context;
 945
 946         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 947                 return AE_OK;
 948
 949         /*
 950          * The first address region returned is the data port, and
 951          * the second address region returned is the status/command
 952          * port.
 953          */
 954         if (ec->data_addr == 0)
 955                 ec->data_addr = resource->data.io.minimum;
 956         else if (ec->command_addr == 0)
 957                 ec->command_addr = resource->data.io.minimum;
 958         else
 959                 return AE_CTRL_TERMINATE;
 960
 961         return AE_OK;
 962 }
 963
 964 int __init acpi_boot_ec_enable(void)
 965 {
 966         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 967                 return 0;
 968         if (!ec_install_handlers(boot_ec)) {
 969                 first_ec = boot_ec;
 970                 return 0;
 971         }
 972         return -EFAULT;
 973 }
 974
 975 static const struct acpi_device_id ec_device_ids[] = {
 976         {"PNP0C09", 0},
 977         {"", 0},
 978 };
 979
 980 /* Some BIOS do not survive early DSDT scan, skip it */
 981 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 982 {
 983         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 984         return 0;
 985 }
 986
 987 /* ASUStek often supplies us with broken ECDT, validate it */
 988 static int ec_validate_ecdt(const struct dmi_system_id *id)
 989 {
 990         EC_FLAGS_VALIDATE_ECDT = 1;
 991         return 0;
 992 }
 993
 994 /* MSI EC needs special treatment, enable it */
 995 static int ec_flag_msi(const struct dmi_system_id *id)
 996 {
 997         pr_debug("Detected MSI hardware, enabling workarounds.\n");
 998         EC_FLAGS_MSI = 1;
 999         EC_FLAGS_VALIDATE_ECDT = 1;
1000         return 0;
1001 }
1002
1003 /*
1004  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
1005  * the GPE storm threshold back to 20
1006  */
1007 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
1008 {
1009         pr_debug("Setting the EC GPE storm threshold to 20\n");
1010         ec_storm_threshold  = 20;
1011         return 0;
1012 }
1013
1014 /*
1015  * On some hardware it is necessary to clear events accumulated by the EC during
1016  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1017  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1018  *
1019  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1020  *
1021  * Ideally, the EC should also be instructed NOT to accumulate events during
1022  * sleep (which Windows seems to do somehow), but the interface to control this
1023  * behaviour is not known at this time.
1024  *
1025  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1026  * however it is very likely that other Samsung models are affected.
1027  *
1028  * On systems which don't accumulate _Q events during sleep, this extra check
1029  * should be harmless.
1030  */
1031 static int ec_clear_on_resume(const struct dmi_system_id *id)
1032 {
1033         pr_debug("Detected system needing EC poll on resume.\n");
1034         EC_FLAGS_CLEAR_ON_RESUME = 1;
1035         return 0;
1036 }
1037
1038 static struct dmi_system_id ec_dmi_table[] __initdata = {
1039         {
1040         ec_skip_dsdt_scan, "Compal JFL92", {
1041         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1042         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1043         {
1044         ec_flag_msi, "MSI hardware", {
1045         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1046         {
1047         ec_flag_msi, "MSI hardware", {
1048         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1049         {
1050         ec_flag_msi, "MSI hardware", {
1051         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1052         {
1053         ec_flag_msi, "MSI hardware", {
1054         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1055         {
1056         ec_flag_msi, "Quanta hardware", {
1057         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1058         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1059         {
1060         ec_flag_msi, "Quanta hardware", {
1061         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1062         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1063         {
1064         ec_flag_msi, "Clevo W350etq", {
1065         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
1066         DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
1067         {
1068         ec_validate_ecdt, "ASUS hardware", {
1069         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1070         {
1071         ec_validate_ecdt, "ASUS hardware", {
1072         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1073         {
1074         ec_enlarge_storm_threshold, "CLEVO hardware", {
1075         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1076         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1077         {
1078         ec_skip_dsdt_scan, "HP Folio 13", {
1079         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1080         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1081         {
1082         ec_validate_ecdt, "ASUS hardware", {
1083         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1084         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1085         {
1086         ec_clear_on_resume, "Samsung hardware", {
1087         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1088         {},
1089 };
1090
1091 int __init acpi_ec_ecdt_probe(void)
1092 {
1093         acpi_status status;
1094         struct acpi_ec *saved_ec = NULL;
1095         struct acpi_table_ecdt *ecdt_ptr;
1096
1097         boot_ec = make_acpi_ec();
1098         if (!boot_ec)
1099                 return -ENOMEM;
1100         /*
1101          * Generate a boot ec context
1102          */
1103         dmi_check_system(ec_dmi_table);
1104         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1105                                 (struct acpi_table_header **)&ecdt_ptr);
1106         if (ACPI_SUCCESS(status)) {
1107                 pr_info("EC description table is found, configuring boot EC\n");
1108                 boot_ec->command_addr = ecdt_ptr->control.address;
1109                 boot_ec->data_addr = ecdt_ptr->data.address;
1110                 boot_ec->gpe = ecdt_ptr->gpe;
1111                 boot_ec->handle = ACPI_ROOT_OBJECT;
1112                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id,
1113                                 &boot_ec->handle);
1114                 /* Don't trust ECDT, which comes from ASUSTek */
1115                 if (!EC_FLAGS_VALIDATE_ECDT)
1116                         goto install;
1117                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1118                 if (!saved_ec)
1119                         return -ENOMEM;
1120         /* fall through */
1121         }
1122
1123         if (EC_FLAGS_SKIP_DSDT_SCAN) {
1124                 kfree(saved_ec);
1125                 return -ENODEV;
1126         }
1127
1128         /* This workaround is needed only on some broken machines,
1129          * which require early EC, but fail to provide ECDT */
1130         pr_debug("Look up EC in DSDT\n");
1131         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1132                                         boot_ec, NULL);
1133         /* Check that acpi_get_devices actually find something */
1134         if (ACPI_FAILURE(status) || !boot_ec->handle)
1135                 goto error;
1136         if (saved_ec) {
1137                 /* try to find good ECDT from ASUSTek */
1138                 if (saved_ec->command_addr != boot_ec->command_addr ||
1139                     saved_ec->data_addr != boot_ec->data_addr ||
1140                     saved_ec->gpe != boot_ec->gpe ||
1141                     saved_ec->handle != boot_ec->handle)
1142                         pr_info("ASUSTek keeps feeding us with broken "
1143                         "ECDT tables, which are very hard to workaround. "
1144                         "Trying to use DSDT EC info instead. Please send "
1145                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1146                 kfree(saved_ec);
1147                 saved_ec = NULL;
1148         } else {
1149                 /* We really need to limit this workaround, the only ASUS,
1150                 * which needs it, has fake EC._INI method, so use it as flag.
1151                 * Keep boot_ec struct as it will be needed soon.
1152                 */
1153                 if (!dmi_name_in_vendors("ASUS") ||
1154                     !acpi_has_method(boot_ec->handle, "_INI"))
1155                         return -ENODEV;
1156         }
1157 install:
1158         if (!ec_install_handlers(boot_ec)) {
1159                 first_ec = boot_ec;
1160                 return 0;
1161         }
1162 error:
1163         kfree(boot_ec);
1164         kfree(saved_ec);
1165         boot_ec = NULL;
1166         return -ENODEV;
1167 }
1168
1169 static struct acpi_driver acpi_ec_driver = {
1170         .name = "ec",
1171         .class = ACPI_EC_CLASS,
1172         .ids = ec_device_ids,
1173         .ops = {
1174                 .add = acpi_ec_add,
1175                 .remove = acpi_ec_remove,
1176                 },
1177 };
1178
1179 int __init acpi_ec_init(void)
1180 {
1181         int result = 0;
1182
1183         /* Now register the driver for the EC */
1184         result = acpi_bus_register_driver(&acpi_ec_driver);
1185         if (result < 0)
1186                 return -ENODEV;
1187
1188         return result;
1189 }
1190
1191 /* EC driver currently not unloadable */
1192 #if 0
1193 static void __exit acpi_ec_exit(void)
1194 {
1195
1196         acpi_bus_unregister_driver(&acpi_ec_driver);
1197 }
1198 #endif  /* 0 */