drivers/acpi/ec.c

   1 /*
   2  *  ec.c - ACPI Embedded Controller Driver (v2.1)
   3  *
   4  *  Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@suse.de>
   5  *  Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
   6  *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
   7  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   8  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   9  *
  10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or (at
  15  *  your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful, but
  18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  *  General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License along
  23  *  with this program; if not, write to the Free Software Foundation, Inc.,
  24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  25  *
  26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  27  */
  28
  29 /* Uncomment next line to get verbose printout */
  30 /* #define DEBUG */
  31 #define pr_fmt(fmt) "ACPI : EC: " fmt
  32
  33 #include <linux/kernel.h>
  34 #include <linux/module.h>
  35 #include <linux/init.h>
  36 #include <linux/types.h>
  37 #include <linux/delay.h>
  38 #include <linux/interrupt.h>
  39 #include <linux/list.h>
  40 #include <linux/spinlock.h>
  41 #include <linux/slab.h>
  42 #include <linux/acpi.h>
  43 #include <linux/dmi.h>
  44 #include <asm/io.h>
  45
  46 #include "internal.h"
  47
  48 #define ACPI_EC_CLASS                   "embedded_controller"
  49 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  50 #define ACPI_EC_FILE_INFO               "info"
  51
  52 /* EC status register */
  53 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  54 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  55 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  56 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  57
  58 /* EC commands */
  59 enum ec_command {
  60         ACPI_EC_COMMAND_READ = 0x80,
  61         ACPI_EC_COMMAND_WRITE = 0x81,
  62         ACPI_EC_BURST_ENABLE = 0x82,
  63         ACPI_EC_BURST_DISABLE = 0x83,
  64         ACPI_EC_COMMAND_QUERY = 0x84,
  65 };
  66
  67 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  68 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  69 #define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
  70 #define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
  71                                          * when trying to clear the EC */
  72
  73 enum {
  74         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  75         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  76         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
  77                                          * OpReg are installed */
  78         EC_FLAGS_BLOCKED,               /* Transactions are blocked */
  79 };
  80
  81 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
  82 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
  83
  84 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
  85 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
  86 module_param(ec_delay, uint, 0644);
  87 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
  88
  89 /*
  90  * If the number of false interrupts per one transaction exceeds
  91  * this threshold, will think there is a GPE storm happened and
  92  * will disable the GPE for normal transaction.
  93  */
  94 static unsigned int ec_storm_threshold  __read_mostly = 8;
  95 module_param(ec_storm_threshold, uint, 0644);
  96 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
  97
  98 struct acpi_ec_query_handler {
  99         struct list_head node;
 100         acpi_ec_query_func func;
 101         acpi_handle handle;
 102         void *data;
 103         u8 query_bit;
 104 };
 105
 106 struct transaction {
 107         const u8 *wdata;
 108         u8 *rdata;
 109         unsigned short irq_count;
 110         u8 command;
 111         u8 wi;
 112         u8 ri;
 113         u8 wlen;
 114         u8 rlen;
 115         u8 flags;
 116 };
 117
 118 struct acpi_ec *boot_ec, *first_ec;
 119 EXPORT_SYMBOL(first_ec);
 120
 121 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 122 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 123 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 124 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 125
 126 /* --------------------------------------------------------------------------
 127                              Transaction Management
 128    -------------------------------------------------------------------------- */
 129
 130 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 131 {
 132         u8 x = inb(ec->command_addr);
 133         pr_debug("---> status = 0x%2.2x\n", x);
 134         return x;
 135 }
 136
 137 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 138 {
 139         u8 x = inb(ec->data_addr);
 140         pr_debug("---> data = 0x%2.2x\n", x);
 141         return x;
 142 }
 143
 144 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 145 {
 146         pr_debug("<--- command = 0x%2.2x\n", command);
 147         outb(command, ec->command_addr);
 148 }
 149
 150 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 151 {
 152         pr_debug("<--- data = 0x%2.2x\n", data);
 153         outb(data, ec->data_addr);
 154 }
 155
 156 static int ec_transaction_completed(struct acpi_ec *ec)
 157 {
 158         unsigned long flags;
 159         int ret = 0;
 160         spin_lock_irqsave(&ec->lock, flags);
 161         if (!ec->curr || (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 162                 ret = 1;
 163         spin_unlock_irqrestore(&ec->lock, flags);
 164         return ret;
 165 }
 166
 167 static void advance_transaction(struct acpi_ec *ec)
 168 {
 169         struct transaction *t;
 170         u8 status;
 171
 172         pr_debug("===== %s =====\n", in_interrupt() ? "IRQ" : "TASK");
 173         status = acpi_ec_read_status(ec);
 174         t = ec->curr;
 175         if (!t)
 176                 goto err;
 177         if (t->flags & ACPI_EC_COMMAND_POLL) {
 178                 if (t->wlen > t->wi) {
 179                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 180                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 181                         else
 182                                 goto err;
 183                 } else if (t->rlen > t->ri) {
 184                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 185                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 186                                 if (t->rlen == t->ri)
 187                                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 188                         } else
 189                                 goto err;
 190                 } else if (t->wlen == t->wi &&
 191                            (status & ACPI_EC_FLAG_IBF) == 0)
 192                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 193                 return;
 194         } else {
 195                 if ((status & ACPI_EC_FLAG_IBF) == 0) {
 196                         acpi_ec_write_cmd(ec, t->command);
 197                         t->flags |= ACPI_EC_COMMAND_POLL;
 198                 } else
 199                         goto err;
 200                 return;
 201         }
 202 err:
 203         /*
 204          * If SCI bit is set, then don't think it's a false IRQ
 205          * otherwise will take a not handled IRQ as a false one.
 206          */
 207         if (!(status & ACPI_EC_FLAG_SCI)) {
 208                 if (in_interrupt() && t)
 209                         ++t->irq_count;
 210         }
 211 }
 212
 213 static void start_transaction(struct acpi_ec *ec)
 214 {
 215         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 216         ec->curr->flags = 0;
 217         advance_transaction(ec);
 218 }
 219
 220 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
 221
 222 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 223 {
 224         if (state & ACPI_EC_FLAG_SCI) {
 225                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 226                         return acpi_ec_sync_query(ec, NULL);
 227         }
 228         return 0;
 229 }
 230
 231 static int ec_poll(struct acpi_ec *ec)
 232 {
 233         unsigned long flags;
 234         int repeat = 5; /* number of command restarts */
 235         while (repeat--) {
 236                 unsigned long delay = jiffies +
 237                         msecs_to_jiffies(ec_delay);
 238                 do {
 239                         /* don't sleep with disabled interrupts */
 240                         if (EC_FLAGS_MSI || irqs_disabled()) {
 241                                 udelay(ACPI_EC_MSI_UDELAY);
 242                                 if (ec_transaction_completed(ec))
 243                                         return 0;
 244                         } else {
 245                                 if (wait_event_timeout(ec->wait,
 246                                                 ec_transaction_completed(ec),
 247                                                 msecs_to_jiffies(1)))
 248                                         return 0;
 249                         }
 250                         spin_lock_irqsave(&ec->lock, flags);
 251                         advance_transaction(ec);
 252                         spin_unlock_irqrestore(&ec->lock, flags);
 253                 } while (time_before(jiffies, delay));
 254                 pr_debug("controller reset, restart transaction\n");
 255                 spin_lock_irqsave(&ec->lock, flags);
 256                 start_transaction(ec);
 257                 spin_unlock_irqrestore(&ec->lock, flags);
 258         }
 259         return -ETIME;
 260 }
 261
 262 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 263                                         struct transaction *t)
 264 {
 265         unsigned long tmp;
 266         int ret = 0;
 267         if (EC_FLAGS_MSI)
 268                 udelay(ACPI_EC_MSI_UDELAY);
 269         /* start transaction */
 270         spin_lock_irqsave(&ec->lock, tmp);
 271         /* following two actions should be kept atomic */
 272         ec->curr = t;
 273         start_transaction(ec);
 274         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 275                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 276         spin_unlock_irqrestore(&ec->lock, tmp);
 277         ret = ec_poll(ec);
 278         spin_lock_irqsave(&ec->lock, tmp);
 279         ec->curr = NULL;
 280         spin_unlock_irqrestore(&ec->lock, tmp);
 281         return ret;
 282 }
 283
 284 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 285 {
 286         int status;
 287         u32 glk;
 288         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 289                 return -EINVAL;
 290         if (t->rdata)
 291                 memset(t->rdata, 0, t->rlen);
 292         mutex_lock(&ec->mutex);
 293         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 294                 status = -EINVAL;
 295                 goto unlock;
 296         }
 297         if (ec->global_lock) {
 298                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 299                 if (ACPI_FAILURE(status)) {
 300                         status = -ENODEV;
 301                         goto unlock;
 302                 }
 303         }
 304         pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",
 305                         t->command, t->wdata ? t->wdata[0] : 0);
 306         /* disable GPE during transaction if storm is detected */
 307         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 308                 /* It has to be disabled, so that it doesn't trigger. */
 309                 acpi_disable_gpe(NULL, ec->gpe);
 310         }
 311
 312         status = acpi_ec_transaction_unlocked(ec, t);
 313
 314         /* check if we received SCI during transaction */
 315         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 316         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 317                 msleep(1);
 318                 /* It is safe to enable the GPE outside of the transaction. */
 319                 acpi_enable_gpe(NULL, ec->gpe);
 320         } else if (t->irq_count > ec_storm_threshold) {
 321                 pr_info("GPE storm detected(%d GPEs), "
 322                         "transactions will use polling mode\n",
 323                         t->irq_count);
 324                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 325         }
 326         pr_debug("transaction end\n");
 327         if (ec->global_lock)
 328                 acpi_release_global_lock(glk);
 329 unlock:
 330         mutex_unlock(&ec->mutex);
 331         return status;
 332 }
 333
 334 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 335 {
 336         u8 d;
 337         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 338                                 .wdata = NULL, .rdata = &d,
 339                                 .wlen = 0, .rlen = 1};
 340
 341         return acpi_ec_transaction(ec, &t);
 342 }
 343
 344 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 345 {
 346         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 347                                 .wdata = NULL, .rdata = NULL,
 348                                 .wlen = 0, .rlen = 0};
 349
 350         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 351                                 acpi_ec_transaction(ec, &t) : 0;
 352 }
 353
 354 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 355 {
 356         int result;
 357         u8 d;
 358         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 359                                 .wdata = &address, .rdata = &d,
 360                                 .wlen = 1, .rlen = 1};
 361
 362         result = acpi_ec_transaction(ec, &t);
 363         *data = d;
 364         return result;
 365 }
 366
 367 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 368 {
 369         u8 wdata[2] = { address, data };
 370         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 371                                 .wdata = wdata, .rdata = NULL,
 372                                 .wlen = 2, .rlen = 0};
 373
 374         return acpi_ec_transaction(ec, &t);
 375 }
 376
 377 int ec_read(u8 addr, u8 *val)
 378 {
 379         int err;
 380         u8 temp_data;
 381
 382         if (!first_ec)
 383                 return -ENODEV;
 384
 385         err = acpi_ec_read(first_ec, addr, &temp_data);
 386
 387         if (!err) {
 388                 *val = temp_data;
 389                 return 0;
 390         } else
 391                 return err;
 392 }
 393
 394 EXPORT_SYMBOL(ec_read);
 395
 396 int ec_write(u8 addr, u8 val)
 397 {
 398         int err;
 399
 400         if (!first_ec)
 401                 return -ENODEV;
 402
 403         err = acpi_ec_write(first_ec, addr, val);
 404
 405         return err;
 406 }
 407
 408 EXPORT_SYMBOL(ec_write);
 409
 410 int ec_transaction(u8 command,
 411                    const u8 * wdata, unsigned wdata_len,
 412                    u8 * rdata, unsigned rdata_len)
 413 {
 414         struct transaction t = {.command = command,
 415                                 .wdata = wdata, .rdata = rdata,
 416                                 .wlen = wdata_len, .rlen = rdata_len};
 417         if (!first_ec)
 418                 return -ENODEV;
 419
 420         return acpi_ec_transaction(first_ec, &t);
 421 }
 422
 423 EXPORT_SYMBOL(ec_transaction);
 424
 425 /* Get the handle to the EC device */
 426 acpi_handle ec_get_handle(void)
 427 {
 428         if (!first_ec)
 429                 return NULL;
 430         return first_ec->handle;
 431 }
 432
 433 EXPORT_SYMBOL(ec_get_handle);
 434
 435 /*
 436  * Process _Q events that might have accumulated in the EC.
 437  * Run with locked ec mutex.
 438  */
 439 static void acpi_ec_clear(struct acpi_ec *ec)
 440 {
 441         int i, status;
 442         u8 value = 0;
 443
 444         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 445                 status = acpi_ec_sync_query(ec, &value);
 446                 if (status || !value)
 447                         break;
 448         }
 449
 450         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 451                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 452         else
 453                 pr_info("%d stale EC events cleared\n", i);
 454 }
 455
 456 void acpi_ec_block_transactions(void)
 457 {
 458         struct acpi_ec *ec = first_ec;
 459
 460         if (!ec)
 461                 return;
 462
 463         mutex_lock(&ec->mutex);
 464         /* Prevent transactions from being carried out */
 465         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 466         mutex_unlock(&ec->mutex);
 467 }
 468
 469 void acpi_ec_unblock_transactions(void)
 470 {
 471         struct acpi_ec *ec = first_ec;
 472
 473         if (!ec)
 474                 return;
 475
 476         mutex_lock(&ec->mutex);
 477         /* Allow transactions to be carried out again */
 478         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 479
 480         if (EC_FLAGS_CLEAR_ON_RESUME)
 481                 acpi_ec_clear(ec);
 482
 483         mutex_unlock(&ec->mutex);
 484 }
 485
 486 void acpi_ec_unblock_transactions_early(void)
 487 {
 488         /*
 489          * Allow transactions to happen again (this function is called from
 490          * atomic context during wakeup, so we don't need to acquire the mutex).
 491          */
 492         if (first_ec)
 493                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 494 }
 495
 496 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 497 {
 498         int result;
 499         u8 d;
 500         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 501                                 .wdata = NULL, .rdata = &d,
 502                                 .wlen = 0, .rlen = 1};
 503         if (!ec || !data)
 504                 return -EINVAL;
 505         /*
 506          * Query the EC to find out which _Qxx method we need to evaluate.
 507          * Note that successful completion of the query causes the ACPI_EC_SCI
 508          * bit to be cleared (and thus clearing the interrupt source).
 509          */
 510         result = acpi_ec_transaction_unlocked(ec, &t);
 511         if (result)
 512                 return result;
 513         if (!d)
 514                 return -ENODATA;
 515         *data = d;
 516         return 0;
 517 }
 518
 519 /* --------------------------------------------------------------------------
 520                                 Event Management
 521    -------------------------------------------------------------------------- */
 522 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 523                               acpi_handle handle, acpi_ec_query_func func,
 524                               void *data)
 525 {
 526         struct acpi_ec_query_handler *handler =
 527             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 528         if (!handler)
 529                 return -ENOMEM;
 530
 531         handler->query_bit = query_bit;
 532         handler->handle = handle;
 533         handler->func = func;
 534         handler->data = data;
 535         mutex_lock(&ec->mutex);
 536         list_add(&handler->node, &ec->list);
 537         mutex_unlock(&ec->mutex);
 538         return 0;
 539 }
 540
 541 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 542
 543 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 544 {
 545         struct acpi_ec_query_handler *handler, *tmp;
 546         mutex_lock(&ec->mutex);
 547         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 548                 if (query_bit == handler->query_bit) {
 549                         list_del(&handler->node);
 550                         kfree(handler);
 551                 }
 552         }
 553         mutex_unlock(&ec->mutex);
 554 }
 555
 556 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 557
 558 static void acpi_ec_run(void *cxt)
 559 {
 560         struct acpi_ec_query_handler *handler = cxt;
 561         if (!handler)
 562                 return;
 563         pr_debug("start query execution\n");
 564         if (handler->func)
 565                 handler->func(handler->data);
 566         else if (handler->handle)
 567                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 568         pr_debug("stop query execution\n");
 569         kfree(handler);
 570 }
 571
 572 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
 573 {
 574         u8 value = 0;
 575         int status;
 576         struct acpi_ec_query_handler *handler, *copy;
 577
 578         status = acpi_ec_query_unlocked(ec, &value);
 579         if (data)
 580                 *data = value;
 581         if (status)
 582                 return status;
 583
 584         list_for_each_entry(handler, &ec->list, node) {
 585                 if (value == handler->query_bit) {
 586                         /* have custom handler for this bit */
 587                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 588                         if (!copy)
 589                                 return -ENOMEM;
 590                         memcpy(copy, handler, sizeof(*copy));
 591                         pr_debug("push query execution (0x%2x) on queue\n",
 592                                 value);
 593                         return acpi_os_execute((copy->func) ?
 594                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 595                                 acpi_ec_run, copy);
 596                 }
 597         }
 598         return 0;
 599 }
 600
 601 static void acpi_ec_gpe_query(void *ec_cxt)
 602 {
 603         struct acpi_ec *ec = ec_cxt;
 604         if (!ec)
 605                 return;
 606         mutex_lock(&ec->mutex);
 607         acpi_ec_sync_query(ec, NULL);
 608         mutex_unlock(&ec->mutex);
 609 }
 610
 611 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 612 {
 613         if (state & ACPI_EC_FLAG_SCI) {
 614                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 615                         pr_debug("push gpe query to the queue\n");
 616                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 617                                 acpi_ec_gpe_query, ec);
 618                 }
 619         }
 620         return 0;
 621 }
 622
 623 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 624         u32 gpe_number, void *data)
 625 {
 626         unsigned long flags;
 627         struct acpi_ec *ec = data;
 628
 629         spin_lock_irqsave(&ec->lock, flags);
 630         advance_transaction(ec);
 631         spin_unlock_irqrestore(&ec->lock, flags);
 632         if (ec_transaction_completed(ec)) {
 633                 wake_up(&ec->wait);
 634                 ec_check_sci(ec, acpi_ec_read_status(ec));
 635         }
 636         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 637 }
 638
 639 /* --------------------------------------------------------------------------
 640                              Address Space Management
 641    -------------------------------------------------------------------------- */
 642
 643 static acpi_status
 644 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 645                       u32 bits, u64 *value64,
 646                       void *handler_context, void *region_context)
 647 {
 648         struct acpi_ec *ec = handler_context;
 649         int result = 0, i, bytes = bits / 8;
 650         u8 *value = (u8 *)value64;
 651
 652         if ((address > 0xFF) || !value || !handler_context)
 653                 return AE_BAD_PARAMETER;
 654
 655         if (function != ACPI_READ && function != ACPI_WRITE)
 656                 return AE_BAD_PARAMETER;
 657
 658         if (EC_FLAGS_MSI || bits > 8)
 659                 acpi_ec_burst_enable(ec);
 660
 661         for (i = 0; i < bytes; ++i, ++address, ++value)
 662                 result = (function == ACPI_READ) ?
 663                         acpi_ec_read(ec, address, value) :
 664                         acpi_ec_write(ec, address, *value);
 665
 666         if (EC_FLAGS_MSI || bits > 8)
 667                 acpi_ec_burst_disable(ec);
 668
 669         switch (result) {
 670         case -EINVAL:
 671                 return AE_BAD_PARAMETER;
 672                 break;
 673         case -ENODEV:
 674                 return AE_NOT_FOUND;
 675                 break;
 676         case -ETIME:
 677                 return AE_TIME;
 678                 break;
 679         default:
 680                 return AE_OK;
 681         }
 682 }
 683
 684 /* --------------------------------------------------------------------------
 685                                Driver Interface
 686    -------------------------------------------------------------------------- */
 687 static acpi_status
 688 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 689
 690 static struct acpi_ec *make_acpi_ec(void)
 691 {
 692         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 693         if (!ec)
 694                 return NULL;
 695         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 696         mutex_init(&ec->mutex);
 697         init_waitqueue_head(&ec->wait);
 698         INIT_LIST_HEAD(&ec->list);
 699         spin_lock_init(&ec->lock);
 700         return ec;
 701 }
 702
 703 static acpi_status
 704 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 705                                void *context, void **return_value)
 706 {
 707         char node_name[5];
 708         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 709         struct acpi_ec *ec = context;
 710         int value = 0;
 711         acpi_status status;
 712
 713         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 714
 715         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 716                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 717         }
 718         return AE_OK;
 719 }
 720
 721 static acpi_status
 722 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 723 {
 724         acpi_status status;
 725         unsigned long long tmp = 0;
 726
 727         struct acpi_ec *ec = context;
 728
 729         /* clear addr values, ec_parse_io_ports depend on it */
 730         ec->command_addr = ec->data_addr = 0;
 731
 732         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 733                                      ec_parse_io_ports, ec);
 734         if (ACPI_FAILURE(status))
 735                 return status;
 736
 737         /* Get GPE bit assignment (EC events). */
 738         /* TODO: Add support for _GPE returning a package */
 739         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 740         if (ACPI_FAILURE(status))
 741                 return status;
 742         ec->gpe = tmp;
 743         /* Use the global lock for all EC transactions? */
 744         tmp = 0;
 745         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 746         ec->global_lock = tmp;
 747         ec->handle = handle;
 748         return AE_CTRL_TERMINATE;
 749 }
 750
 751 static int ec_install_handlers(struct acpi_ec *ec)
 752 {
 753         acpi_status status;
 754         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 755                 return 0;
 756         status = acpi_install_gpe_handler(NULL, ec->gpe,
 757                                   ACPI_GPE_EDGE_TRIGGERED,
 758                                   &acpi_ec_gpe_handler, ec);
 759         if (ACPI_FAILURE(status))
 760                 return -ENODEV;
 761
 762         acpi_enable_gpe(NULL, ec->gpe);
 763         status = acpi_install_address_space_handler(ec->handle,
 764                                                     ACPI_ADR_SPACE_EC,
 765                                                     &acpi_ec_space_handler,
 766                                                     NULL, ec);
 767         if (ACPI_FAILURE(status)) {
 768                 if (status == AE_NOT_FOUND) {
 769                         /*
 770                          * Maybe OS fails in evaluating the _REG object.
 771                          * The AE_NOT_FOUND error will be ignored and OS
 772                          * continue to initialize EC.
 773                          */
 774                         pr_err("Fail in evaluating the _REG object"
 775                                 " of EC device. Broken bios is suspected.\n");
 776                 } else {
 777                         acpi_disable_gpe(NULL, ec->gpe);
 778                         acpi_remove_gpe_handler(NULL, ec->gpe,
 779                                 &acpi_ec_gpe_handler);
 780                         return -ENODEV;
 781                 }
 782         }
 783
 784         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 785         return 0;
 786 }
 787
 788 static void ec_remove_handlers(struct acpi_ec *ec)
 789 {
 790         acpi_disable_gpe(NULL, ec->gpe);
 791         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 792                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 793                 pr_err("failed to remove space handler\n");
 794         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 795                                 &acpi_ec_gpe_handler)))
 796                 pr_err("failed to remove gpe handler\n");
 797         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 798 }
 799
 800 static int acpi_ec_add(struct acpi_device *device)
 801 {
 802         struct acpi_ec *ec = NULL;
 803         int ret;
 804
 805         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 806         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 807
 808         /* Check for boot EC */
 809         if (boot_ec &&
 810             (boot_ec->handle == device->handle ||
 811              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 812                 ec = boot_ec;
 813                 boot_ec = NULL;
 814         } else {
 815                 ec = make_acpi_ec();
 816                 if (!ec)
 817                         return -ENOMEM;
 818         }
 819         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 820                 AE_CTRL_TERMINATE) {
 821                         kfree(ec);
 822                         return -EINVAL;
 823         }
 824
 825         /* Find and register all query methods */
 826         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 827                             acpi_ec_register_query_methods, NULL, ec, NULL);
 828
 829         if (!first_ec)
 830                 first_ec = ec;
 831         device->driver_data = ec;
 832
 833         ret = !!request_region(ec->data_addr, 1, "EC data");
 834         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
 835         ret = !!request_region(ec->command_addr, 1, "EC cmd");
 836         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
 837
 838         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 839                           ec->gpe, ec->command_addr, ec->data_addr);
 840
 841         ret = ec_install_handlers(ec);
 842
 843         /* EC is fully operational, allow queries */
 844         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 845
 846         /* Clear stale _Q events if hardware might require that */
 847         if (EC_FLAGS_CLEAR_ON_RESUME) {
 848                 mutex_lock(&ec->mutex);
 849                 acpi_ec_clear(ec);
 850                 mutex_unlock(&ec->mutex);
 851         }
 852         return ret;
 853 }
 854
 855 static int acpi_ec_remove(struct acpi_device *device)
 856 {
 857         struct acpi_ec *ec;
 858         struct acpi_ec_query_handler *handler, *tmp;
 859
 860         if (!device)
 861                 return -EINVAL;
 862
 863         ec = acpi_driver_data(device);
 864         ec_remove_handlers(ec);
 865         mutex_lock(&ec->mutex);
 866         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 867                 list_del(&handler->node);
 868                 kfree(handler);
 869         }
 870         mutex_unlock(&ec->mutex);
 871         release_region(ec->data_addr, 1);
 872         release_region(ec->command_addr, 1);
 873         device->driver_data = NULL;
 874         if (ec == first_ec)
 875                 first_ec = NULL;
 876         kfree(ec);
 877         return 0;
 878 }
 879
 880 static acpi_status
 881 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 882 {
 883         struct acpi_ec *ec = context;
 884
 885         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 886                 return AE_OK;
 887
 888         /*
 889          * The first address region returned is the data port, and
 890          * the second address region returned is the status/command
 891          * port.
 892          */
 893         if (ec->data_addr == 0)
 894                 ec->data_addr = resource->data.io.minimum;
 895         else if (ec->command_addr == 0)
 896                 ec->command_addr = resource->data.io.minimum;
 897         else
 898                 return AE_CTRL_TERMINATE;
 899
 900         return AE_OK;
 901 }
 902
 903 int __init acpi_boot_ec_enable(void)
 904 {
 905         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 906                 return 0;
 907         if (!ec_install_handlers(boot_ec)) {
 908                 first_ec = boot_ec;
 909                 return 0;
 910         }
 911         return -EFAULT;
 912 }
 913
 914 static const struct acpi_device_id ec_device_ids[] = {
 915         {"PNP0C09", 0},
 916         {"", 0},
 917 };
 918
 919 /* Some BIOS do not survive early DSDT scan, skip it */
 920 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 921 {
 922         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 923         return 0;
 924 }
 925
 926 /* ASUStek often supplies us with broken ECDT, validate it */
 927 static int ec_validate_ecdt(const struct dmi_system_id *id)
 928 {
 929         EC_FLAGS_VALIDATE_ECDT = 1;
 930         return 0;
 931 }
 932
 933 /* MSI EC needs special treatment, enable it */
 934 static int ec_flag_msi(const struct dmi_system_id *id)
 935 {
 936         pr_debug("Detected MSI hardware, enabling workarounds.\n");
 937         EC_FLAGS_MSI = 1;
 938         EC_FLAGS_VALIDATE_ECDT = 1;
 939         return 0;
 940 }
 941
 942 /*
 943  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
 944  * the GPE storm threshold back to 20
 945  */
 946 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
 947 {
 948         pr_debug("Setting the EC GPE storm threshold to 20\n");
 949         ec_storm_threshold  = 20;
 950         return 0;
 951 }
 952
 953 /*
 954  * On some hardware it is necessary to clear events accumulated by the EC during
 955  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
 956  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
 957  *
 958  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
 959  *
 960  * Ideally, the EC should also be instructed NOT to accumulate events during
 961  * sleep (which Windows seems to do somehow), but the interface to control this
 962  * behaviour is not known at this time.
 963  *
 964  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
 965  * however it is very likely that other Samsung models are affected.
 966  *
 967  * On systems which don't accumulate _Q events during sleep, this extra check
 968  * should be harmless.
 969  */
 970 static int ec_clear_on_resume(const struct dmi_system_id *id)
 971 {
 972         pr_debug("Detected system needing EC poll on resume.\n");
 973         EC_FLAGS_CLEAR_ON_RESUME = 1;
 974         return 0;
 975 }
 976
 977 static struct dmi_system_id ec_dmi_table[] __initdata = {
 978         {
 979         ec_skip_dsdt_scan, "Compal JFL92", {
 980         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 981         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 982         {
 983         ec_flag_msi, "MSI hardware", {
 984         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
 985         {
 986         ec_flag_msi, "MSI hardware", {
 987         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
 988         {
 989         ec_flag_msi, "MSI hardware", {
 990         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
 991         {
 992         ec_flag_msi, "MSI hardware", {
 993         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
 994         {
 995         ec_flag_msi, "Quanta hardware", {
 996         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
 997         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
 998         {
 999         ec_flag_msi, "Quanta hardware", {
1000         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1001         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1002         {
1003         ec_validate_ecdt, "ASUS hardware", {
1004         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1005         {
1006         ec_validate_ecdt, "ASUS hardware", {
1007         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1008         {
1009         ec_enlarge_storm_threshold, "CLEVO hardware", {
1010         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1011         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1012         {
1013         ec_skip_dsdt_scan, "HP Folio 13", {
1014         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1015         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1016         {
1017         ec_validate_ecdt, "ASUS hardware", {
1018         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1019         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1020         {
1021         ec_clear_on_resume, "Samsung hardware", {
1022         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1023         {},
1024 };
1025
1026 int __init acpi_ec_ecdt_probe(void)
1027 {
1028         acpi_status status;
1029         struct acpi_ec *saved_ec = NULL;
1030         struct acpi_table_ecdt *ecdt_ptr;
1031
1032         boot_ec = make_acpi_ec();
1033         if (!boot_ec)
1034                 return -ENOMEM;
1035         /*
1036          * Generate a boot ec context
1037          */
1038         dmi_check_system(ec_dmi_table);
1039         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1040                                 (struct acpi_table_header **)&ecdt_ptr);
1041         if (ACPI_SUCCESS(status)) {
1042                 pr_info("EC description table is found, configuring boot EC\n");
1043                 boot_ec->command_addr = ecdt_ptr->control.address;
1044                 boot_ec->data_addr = ecdt_ptr->data.address;
1045                 boot_ec->gpe = ecdt_ptr->gpe;
1046                 boot_ec->handle = ACPI_ROOT_OBJECT;
1047                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1048                 /* Don't trust ECDT, which comes from ASUSTek */
1049                 if (!EC_FLAGS_VALIDATE_ECDT)
1050                         goto install;
1051                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1052                 if (!saved_ec)
1053                         return -ENOMEM;
1054         /* fall through */
1055         }
1056
1057         if (EC_FLAGS_SKIP_DSDT_SCAN)
1058                 return -ENODEV;
1059
1060         /* This workaround is needed only on some broken machines,
1061          * which require early EC, but fail to provide ECDT */
1062         pr_debug("Look up EC in DSDT\n");
1063         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1064                                         boot_ec, NULL);
1065         /* Check that acpi_get_devices actually find something */
1066         if (ACPI_FAILURE(status) || !boot_ec->handle)
1067                 goto error;
1068         if (saved_ec) {
1069                 /* try to find good ECDT from ASUSTek */
1070                 if (saved_ec->command_addr != boot_ec->command_addr ||
1071                     saved_ec->data_addr != boot_ec->data_addr ||
1072                     saved_ec->gpe != boot_ec->gpe ||
1073                     saved_ec->handle != boot_ec->handle)
1074                         pr_info("ASUSTek keeps feeding us with broken "
1075                         "ECDT tables, which are very hard to workaround. "
1076                         "Trying to use DSDT EC info instead. Please send "
1077                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1078                 kfree(saved_ec);
1079                 saved_ec = NULL;
1080         } else {
1081                 /* We really need to limit this workaround, the only ASUS,
1082                 * which needs it, has fake EC._INI method, so use it as flag.
1083                 * Keep boot_ec struct as it will be needed soon.
1084                 */
1085                 if (!dmi_name_in_vendors("ASUS") ||
1086                     !acpi_has_method(boot_ec->handle, "_INI"))
1087                         return -ENODEV;
1088         }
1089 install:
1090         if (!ec_install_handlers(boot_ec)) {
1091                 first_ec = boot_ec;
1092                 return 0;
1093         }
1094 error:
1095         kfree(boot_ec);
1096         boot_ec = NULL;
1097         return -ENODEV;
1098 }
1099
1100 static struct acpi_driver acpi_ec_driver = {
1101         .name = "ec",
1102         .class = ACPI_EC_CLASS,
1103         .ids = ec_device_ids,
1104         .ops = {
1105                 .add = acpi_ec_add,
1106                 .remove = acpi_ec_remove,
1107                 },
1108 };
1109
1110 int __init acpi_ec_init(void)
1111 {
1112         int result = 0;
1113
1114         /* Now register the driver for the EC */
1115         result = acpi_bus_register_driver(&acpi_ec_driver);
1116         if (result < 0)
1117                 return -ENODEV;
1118
1119         return result;
1120 }
1121
1122 /* EC driver currently not unloadable */
1123 #if 0
1124 static void __exit acpi_ec_exit(void)
1125 {
1126
1127         acpi_bus_unregister_driver(&acpi_ec_driver);
1128         return;
1129 }
1130 #endif  /* 0 */