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