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
  32 #include <linux/kernel.h>
  33 #include <linux/module.h>
  34 #include <linux/init.h>
  35 #include <linux/types.h>
  36 #include <linux/delay.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/list.h>
  39 #include <linux/spinlock.h>
  40 #include <linux/slab.h>
  41 #include <asm/io.h>
  42 #include <acpi/acpi_bus.h>
  43 #include <acpi/acpi_drivers.h>
  44 #include <linux/dmi.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 #undef PREFIX
  53 #define PREFIX                          "ACPI: EC: "
  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_BURST      0x10    /* burst mode */
  59 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  60
  61 /* EC commands */
  62 enum ec_command {
  63         ACPI_EC_COMMAND_READ = 0x80,
  64         ACPI_EC_COMMAND_WRITE = 0x81,
  65         ACPI_EC_BURST_ENABLE = 0x82,
  66         ACPI_EC_BURST_DISABLE = 0x83,
  67         ACPI_EC_COMMAND_QUERY = 0x84,
  68 };
  69
  70 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  71 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  72 #define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
  73 #define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
  74                                          * when trying to clear the EC */
  75
  76 enum {
  77         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  78         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  79         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
  80                                          * OpReg are installed */
  81         EC_FLAGS_BLOCKED,               /* Transactions are blocked */
  82 };
  83
  84 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
  85 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
  86
  87 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
  88 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
  89 module_param(ec_delay, uint, 0644);
  90 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
  91
  92 /*
  93  * If the number of false interrupts per one transaction exceeds
  94  * this threshold, will think there is a GPE storm happened and
  95  * will disable the GPE for normal transaction.
  96  */
  97 static unsigned int ec_storm_threshold  __read_mostly = 8;
  98 module_param(ec_storm_threshold, uint, 0644);
  99 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 100
 101 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
 102 /* External interfaces use first EC only, so remember */
 103 typedef int (*acpi_ec_query_func) (void *data);
 104
 105 struct acpi_ec_query_handler {
 106         struct list_head node;
 107         acpi_ec_query_func func;
 108         acpi_handle handle;
 109         void *data;
 110         u8 query_bit;
 111 };
 112
 113 struct transaction {
 114         const u8 *wdata;
 115         u8 *rdata;
 116         unsigned short irq_count;
 117         u8 command;
 118         u8 wi;
 119         u8 ri;
 120         u8 wlen;
 121         u8 rlen;
 122         u8 flags;
 123 };
 124
 125 struct acpi_ec *boot_ec, *first_ec;
 126 EXPORT_SYMBOL(first_ec);
 127
 128 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 129 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 130 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 131 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 132 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
 133
 134 /* --------------------------------------------------------------------------
 135                              Transaction Management
 136    -------------------------------------------------------------------------- */
 137
 138 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 139 {
 140         u8 x = inb(ec->command_addr);
 141         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
 142         return x;
 143 }
 144
 145 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 146 {
 147         u8 x = inb(ec->data_addr);
 148         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
 149         return x;
 150 }
 151
 152 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 153 {
 154         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
 155         outb(command, ec->command_addr);
 156 }
 157
 158 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 159 {
 160         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
 161         outb(data, ec->data_addr);
 162 }
 163
 164 static int ec_transaction_completed(struct acpi_ec *ec)
 165 {
 166         unsigned long flags;
 167         int ret = 0;
 168         spin_lock_irqsave(&ec->curr_lock, flags);
 169         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 170                 ret = 1;
 171         spin_unlock_irqrestore(&ec->curr_lock, flags);
 172         return ret;
 173 }
 174
 175 static bool advance_transaction(struct acpi_ec *ec)
 176 {
 177         struct transaction *t;
 178         u8 status;
 179         bool wakeup = false;
 180
 181         pr_debug(PREFIX "===== %s =====\n", in_interrupt() ? "IRQ" : "TASK");
 182         status = acpi_ec_read_status(ec);
 183         t = ec->curr;
 184         if (!t)
 185                 goto err;
 186         if (t->flags & ACPI_EC_COMMAND_POLL) {
 187                 if (t->wlen > t->wi) {
 188                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 189                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 190                         else
 191                                 goto err;
 192                 } else if (t->rlen > t->ri) {
 193                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 194                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 195                                 if (t->rlen == t->ri) {
 196                                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 197                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 198                                                 pr_debug("hardware QR_EC completion\n");
 199                                         wakeup = true;
 200                                 }
 201                         } else
 202                                 goto err;
 203                 } else if (t->wlen == t->wi &&
 204                            (status & ACPI_EC_FLAG_IBF) == 0) {
 205                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 206                         wakeup = true;
 207                 }
 208                 return wakeup;
 209         } else {
 210                 if (EC_FLAGS_QUERY_HANDSHAKE &&
 211                     !(status & ACPI_EC_FLAG_SCI) &&
 212                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 213                         t->flags |= ACPI_EC_COMMAND_POLL;
 214                         t->rdata[t->ri++] = 0x00;
 215                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 216                         pr_debug("software QR_EC completion\n");
 217                         wakeup = true;
 218                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 219                         acpi_ec_write_cmd(ec, t->command);
 220                         t->flags |= ACPI_EC_COMMAND_POLL;
 221                 } else
 222                         goto err;
 223                 return wakeup;
 224         }
 225 err:
 226         /*
 227          * If SCI bit is set, then don't think it's a false IRQ
 228          * otherwise will take a not handled IRQ as a false one.
 229          */
 230         if (!(status & ACPI_EC_FLAG_SCI)) {
 231                 if (in_interrupt() && t)
 232                         ++t->irq_count;
 233         }
 234         return wakeup;
 235 }
 236
 237 static void start_transaction(struct acpi_ec *ec)
 238 {
 239         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 240         ec->curr->flags = 0;
 241         (void)advance_transaction(ec);
 242 }
 243
 244 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
 245
 246 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 247 {
 248         if (state & ACPI_EC_FLAG_SCI) {
 249                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 250                         return acpi_ec_sync_query(ec, NULL);
 251         }
 252         return 0;
 253 }
 254
 255 static int ec_poll(struct acpi_ec *ec)
 256 {
 257         unsigned long flags;
 258         int repeat = 5; /* number of command restarts */
 259         while (repeat--) {
 260                 unsigned long delay = jiffies +
 261                         msecs_to_jiffies(ec_delay);
 262                 do {
 263                         /* don't sleep with disabled interrupts */
 264                         if (EC_FLAGS_MSI || irqs_disabled()) {
 265                                 udelay(ACPI_EC_MSI_UDELAY);
 266                                 if (ec_transaction_completed(ec))
 267                                         return 0;
 268                         } else {
 269                                 if (wait_event_timeout(ec->wait,
 270                                                 ec_transaction_completed(ec),
 271                                                 msecs_to_jiffies(1)))
 272                                         return 0;
 273                         }
 274                         spin_lock_irqsave(&ec->curr_lock, flags);
 275                         (void)advance_transaction(ec);
 276                         spin_unlock_irqrestore(&ec->curr_lock, flags);
 277                 } while (time_before(jiffies, delay));
 278                 pr_debug(PREFIX "controller reset, restart transaction\n");
 279                 spin_lock_irqsave(&ec->curr_lock, flags);
 280                 start_transaction(ec);
 281                 spin_unlock_irqrestore(&ec->curr_lock, flags);
 282         }
 283         return -ETIME;
 284 }
 285
 286 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 287                                         struct transaction *t)
 288 {
 289         unsigned long tmp;
 290         int ret = 0;
 291         if (EC_FLAGS_MSI)
 292                 udelay(ACPI_EC_MSI_UDELAY);
 293         /* start transaction */
 294         spin_lock_irqsave(&ec->curr_lock, tmp);
 295         /* following two actions should be kept atomic */
 296         ec->curr = t;
 297         start_transaction(ec);
 298         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 299                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 300         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 301         ret = ec_poll(ec);
 302         spin_lock_irqsave(&ec->curr_lock, tmp);
 303         ec->curr = NULL;
 304         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 305         return ret;
 306 }
 307
 308 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 309 {
 310         int status;
 311         u32 glk;
 312         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 313                 return -EINVAL;
 314         if (t->rdata)
 315                 memset(t->rdata, 0, t->rlen);
 316         mutex_lock(&ec->lock);
 317         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 318                 status = -EINVAL;
 319                 goto unlock;
 320         }
 321         if (ec->global_lock) {
 322                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 323                 if (ACPI_FAILURE(status)) {
 324                         status = -ENODEV;
 325                         goto unlock;
 326                 }
 327         }
 328         pr_debug(PREFIX "transaction start (cmd=0x%02x, addr=0x%02x)\n",
 329                         t->command, t->wdata ? t->wdata[0] : 0);
 330         /* disable GPE during transaction if storm is detected */
 331         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 332                 /* It has to be disabled, so that it doesn't trigger. */
 333                 acpi_disable_gpe(NULL, ec->gpe);
 334         }
 335
 336         status = acpi_ec_transaction_unlocked(ec, t);
 337
 338         /* check if we received SCI during transaction */
 339         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 340         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 341                 msleep(1);
 342                 /* It is safe to enable the GPE outside of the transaction. */
 343                 acpi_enable_gpe(NULL, ec->gpe);
 344         } else if (t->irq_count > ec_storm_threshold) {
 345                 pr_info(PREFIX "GPE storm detected(%d GPEs), "
 346                         "transactions will use polling mode\n",
 347                         t->irq_count);
 348                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 349         }
 350         pr_debug(PREFIX "transaction end\n");
 351         if (ec->global_lock)
 352                 acpi_release_global_lock(glk);
 353 unlock:
 354         mutex_unlock(&ec->lock);
 355         return status;
 356 }
 357
 358 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 359 {
 360         u8 d;
 361         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 362                                 .wdata = NULL, .rdata = &d,
 363                                 .wlen = 0, .rlen = 1};
 364
 365         return acpi_ec_transaction(ec, &t);
 366 }
 367
 368 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 369 {
 370         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 371                                 .wdata = NULL, .rdata = NULL,
 372                                 .wlen = 0, .rlen = 0};
 373
 374         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 375                                 acpi_ec_transaction(ec, &t) : 0;
 376 }
 377
 378 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 379 {
 380         int result;
 381         u8 d;
 382         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 383                                 .wdata = &address, .rdata = &d,
 384                                 .wlen = 1, .rlen = 1};
 385
 386         result = acpi_ec_transaction(ec, &t);
 387         *data = d;
 388         return result;
 389 }
 390
 391 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 392 {
 393         u8 wdata[2] = { address, data };
 394         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 395                                 .wdata = wdata, .rdata = NULL,
 396                                 .wlen = 2, .rlen = 0};
 397
 398         return acpi_ec_transaction(ec, &t);
 399 }
 400
 401 /*
 402  * Externally callable EC access functions. For now, assume 1 EC only
 403  */
 404 int ec_burst_enable(void)
 405 {
 406         if (!first_ec)
 407                 return -ENODEV;
 408         return acpi_ec_burst_enable(first_ec);
 409 }
 410
 411 EXPORT_SYMBOL(ec_burst_enable);
 412
 413 int ec_burst_disable(void)
 414 {
 415         if (!first_ec)
 416                 return -ENODEV;
 417         return acpi_ec_burst_disable(first_ec);
 418 }
 419
 420 EXPORT_SYMBOL(ec_burst_disable);
 421
 422 int ec_read(u8 addr, u8 *val)
 423 {
 424         int err;
 425         u8 temp_data;
 426
 427         if (!first_ec)
 428                 return -ENODEV;
 429
 430         err = acpi_ec_read(first_ec, addr, &temp_data);
 431
 432         if (!err) {
 433                 *val = temp_data;
 434                 return 0;
 435         } else
 436                 return err;
 437 }
 438
 439 EXPORT_SYMBOL(ec_read);
 440
 441 int ec_write(u8 addr, u8 val)
 442 {
 443         int err;
 444
 445         if (!first_ec)
 446                 return -ENODEV;
 447
 448         err = acpi_ec_write(first_ec, addr, val);
 449
 450         return err;
 451 }
 452
 453 EXPORT_SYMBOL(ec_write);
 454
 455 int ec_transaction(u8 command,
 456                    const u8 * wdata, unsigned wdata_len,
 457                    u8 * rdata, unsigned rdata_len)
 458 {
 459         struct transaction t = {.command = command,
 460                                 .wdata = wdata, .rdata = rdata,
 461                                 .wlen = wdata_len, .rlen = rdata_len};
 462         if (!first_ec)
 463                 return -ENODEV;
 464
 465         return acpi_ec_transaction(first_ec, &t);
 466 }
 467
 468 EXPORT_SYMBOL(ec_transaction);
 469
 470 /*
 471  * Process _Q events that might have accumulated in the EC.
 472  * Run with locked ec mutex.
 473  */
 474 static void acpi_ec_clear(struct acpi_ec *ec)
 475 {
 476         int i, status;
 477         u8 value = 0;
 478
 479         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 480                 status = acpi_ec_sync_query(ec, &value);
 481                 if (status || !value)
 482                         break;
 483         }
 484
 485         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 486                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 487         else
 488                 pr_info("%d stale EC events cleared\n", i);
 489 }
 490
 491 void acpi_ec_block_transactions(void)
 492 {
 493         struct acpi_ec *ec = first_ec;
 494
 495         if (!ec)
 496                 return;
 497
 498         mutex_lock(&ec->lock);
 499         /* Prevent transactions from being carried out */
 500         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 501         mutex_unlock(&ec->lock);
 502 }
 503
 504 void acpi_ec_unblock_transactions(void)
 505 {
 506         struct acpi_ec *ec = first_ec;
 507
 508         if (!ec)
 509                 return;
 510
 511         mutex_lock(&ec->lock);
 512         /* Allow transactions to be carried out again */
 513         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 514
 515         if (EC_FLAGS_CLEAR_ON_RESUME)
 516                 acpi_ec_clear(ec);
 517
 518         mutex_unlock(&ec->lock);
 519 }
 520
 521 void acpi_ec_unblock_transactions_early(void)
 522 {
 523         /*
 524          * Allow transactions to happen again (this function is called from
 525          * atomic context during wakeup, so we don't need to acquire the mutex).
 526          */
 527         if (first_ec)
 528                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 529 }
 530
 531 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 532 {
 533         int result;
 534         u8 d;
 535         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 536                                 .wdata = NULL, .rdata = &d,
 537                                 .wlen = 0, .rlen = 1};
 538         if (!ec || !data)
 539                 return -EINVAL;
 540         /*
 541          * Query the EC to find out which _Qxx method we need to evaluate.
 542          * Note that successful completion of the query causes the ACPI_EC_SCI
 543          * bit to be cleared (and thus clearing the interrupt source).
 544          */
 545         result = acpi_ec_transaction_unlocked(ec, &t);
 546         if (result)
 547                 return result;
 548         if (!d)
 549                 return -ENODATA;
 550         *data = d;
 551         return 0;
 552 }
 553
 554 /* --------------------------------------------------------------------------
 555                                 Event Management
 556    -------------------------------------------------------------------------- */
 557 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 558                               acpi_handle handle, acpi_ec_query_func func,
 559                               void *data)
 560 {
 561         struct acpi_ec_query_handler *handler =
 562             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 563         if (!handler)
 564                 return -ENOMEM;
 565
 566         handler->query_bit = query_bit;
 567         handler->handle = handle;
 568         handler->func = func;
 569         handler->data = data;
 570         mutex_lock(&ec->lock);
 571         list_add(&handler->node, &ec->list);
 572         mutex_unlock(&ec->lock);
 573         return 0;
 574 }
 575
 576 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 577
 578 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 579 {
 580         struct acpi_ec_query_handler *handler, *tmp;
 581         mutex_lock(&ec->lock);
 582         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 583                 if (query_bit == handler->query_bit) {
 584                         list_del(&handler->node);
 585                         kfree(handler);
 586                 }
 587         }
 588         mutex_unlock(&ec->lock);
 589 }
 590
 591 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 592
 593 static void acpi_ec_run(void *cxt)
 594 {
 595         struct acpi_ec_query_handler *handler = cxt;
 596         if (!handler)
 597                 return;
 598         pr_debug(PREFIX "start query execution\n");
 599         if (handler->func)
 600                 handler->func(handler->data);
 601         else if (handler->handle)
 602                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 603         pr_debug(PREFIX "stop query execution\n");
 604         kfree(handler);
 605 }
 606
 607 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
 608 {
 609         u8 value = 0;
 610         int status;
 611         struct acpi_ec_query_handler *handler, *copy;
 612
 613         status = acpi_ec_query_unlocked(ec, &value);
 614         if (data)
 615                 *data = value;
 616         if (status)
 617                 return status;
 618
 619         list_for_each_entry(handler, &ec->list, node) {
 620                 if (value == handler->query_bit) {
 621                         /* have custom handler for this bit */
 622                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 623                         if (!copy)
 624                                 return -ENOMEM;
 625                         memcpy(copy, handler, sizeof(*copy));
 626                         pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
 627                         return acpi_os_execute((copy->func) ?
 628                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 629                                 acpi_ec_run, copy);
 630                 }
 631         }
 632         return 0;
 633 }
 634
 635 static void acpi_ec_gpe_query(void *ec_cxt)
 636 {
 637         struct acpi_ec *ec = ec_cxt;
 638         if (!ec)
 639                 return;
 640         mutex_lock(&ec->lock);
 641         acpi_ec_sync_query(ec, NULL);
 642         mutex_unlock(&ec->lock);
 643 }
 644
 645 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 646 {
 647         if (state & ACPI_EC_FLAG_SCI) {
 648                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 649                         pr_debug(PREFIX "push gpe query to the queue\n");
 650                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 651                                 acpi_ec_gpe_query, ec);
 652                 }
 653         }
 654         return 0;
 655 }
 656
 657 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 658         u32 gpe_number, void *data)
 659 {
 660         unsigned long flags;
 661         struct acpi_ec *ec = data;
 662
 663         spin_lock_irqsave(&ec->curr_lock, flags);
 664         if (advance_transaction(ec))
 665                 wake_up(&ec->wait);
 666         spin_unlock_irqrestore(&ec->curr_lock, flags);
 667         ec_check_sci(ec, acpi_ec_read_status(ec));
 668         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 669 }
 670
 671 /* --------------------------------------------------------------------------
 672                              Address Space Management
 673    -------------------------------------------------------------------------- */
 674
 675 static acpi_status
 676 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 677                       u32 bits, u64 *value64,
 678                       void *handler_context, void *region_context)
 679 {
 680         struct acpi_ec *ec = handler_context;
 681         int result = 0, i, bytes = bits / 8;
 682         u8 *value = (u8 *)value64;
 683
 684         if ((address > 0xFF) || !value || !handler_context)
 685                 return AE_BAD_PARAMETER;
 686
 687         if (function != ACPI_READ && function != ACPI_WRITE)
 688                 return AE_BAD_PARAMETER;
 689
 690         if (EC_FLAGS_MSI || bits > 8)
 691                 acpi_ec_burst_enable(ec);
 692
 693         for (i = 0; i < bytes; ++i, ++address, ++value)
 694                 result = (function == ACPI_READ) ?
 695                         acpi_ec_read(ec, address, value) :
 696                         acpi_ec_write(ec, address, *value);
 697
 698         if (EC_FLAGS_MSI || bits > 8)
 699                 acpi_ec_burst_disable(ec);
 700
 701         switch (result) {
 702         case -EINVAL:
 703                 return AE_BAD_PARAMETER;
 704                 break;
 705         case -ENODEV:
 706                 return AE_NOT_FOUND;
 707                 break;
 708         case -ETIME:
 709                 return AE_TIME;
 710                 break;
 711         default:
 712                 return AE_OK;
 713         }
 714 }
 715
 716 /* --------------------------------------------------------------------------
 717                                Driver Interface
 718    -------------------------------------------------------------------------- */
 719 static acpi_status
 720 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 721
 722 static struct acpi_ec *make_acpi_ec(void)
 723 {
 724         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 725         if (!ec)
 726                 return NULL;
 727         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 728         mutex_init(&ec->lock);
 729         init_waitqueue_head(&ec->wait);
 730         INIT_LIST_HEAD(&ec->list);
 731         spin_lock_init(&ec->curr_lock);
 732         return ec;
 733 }
 734
 735 static acpi_status
 736 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 737                                void *context, void **return_value)
 738 {
 739         char node_name[5];
 740         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 741         struct acpi_ec *ec = context;
 742         int value = 0;
 743         acpi_status status;
 744
 745         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 746
 747         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 748                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 749         }
 750         return AE_OK;
 751 }
 752
 753 static acpi_status
 754 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 755 {
 756         acpi_status status;
 757         unsigned long long tmp = 0;
 758
 759         struct acpi_ec *ec = context;
 760
 761         /* clear addr values, ec_parse_io_ports depend on it */
 762         ec->command_addr = ec->data_addr = 0;
 763
 764         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 765                                      ec_parse_io_ports, ec);
 766         if (ACPI_FAILURE(status))
 767                 return status;
 768
 769         /* Get GPE bit assignment (EC events). */
 770         /* TODO: Add support for _GPE returning a package */
 771         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 772         if (ACPI_FAILURE(status))
 773                 return status;
 774         ec->gpe = tmp;
 775         /* Use the global lock for all EC transactions? */
 776         tmp = 0;
 777         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 778         ec->global_lock = tmp;
 779         ec->handle = handle;
 780         return AE_CTRL_TERMINATE;
 781 }
 782
 783 static int ec_install_handlers(struct acpi_ec *ec)
 784 {
 785         acpi_status status;
 786         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 787                 return 0;
 788         status = acpi_install_gpe_handler(NULL, ec->gpe,
 789                                   ACPI_GPE_EDGE_TRIGGERED,
 790                                   &acpi_ec_gpe_handler, ec);
 791         if (ACPI_FAILURE(status))
 792                 return -ENODEV;
 793
 794         acpi_enable_gpe(NULL, ec->gpe);
 795         status = acpi_install_address_space_handler(ec->handle,
 796                                                     ACPI_ADR_SPACE_EC,
 797                                                     &acpi_ec_space_handler,
 798                                                     NULL, ec);
 799         if (ACPI_FAILURE(status)) {
 800                 if (status == AE_NOT_FOUND) {
 801                         /*
 802                          * Maybe OS fails in evaluating the _REG object.
 803                          * The AE_NOT_FOUND error will be ignored and OS
 804                          * continue to initialize EC.
 805                          */
 806                         printk(KERN_ERR "Fail in evaluating the _REG object"
 807                                 " of EC device. Broken bios is suspected.\n");
 808                 } else {
 809                         acpi_remove_gpe_handler(NULL, ec->gpe,
 810                                 &acpi_ec_gpe_handler);
 811                         acpi_disable_gpe(NULL, ec->gpe);
 812                         return -ENODEV;
 813                 }
 814         }
 815
 816         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 817         return 0;
 818 }
 819
 820 static void ec_remove_handlers(struct acpi_ec *ec)
 821 {
 822         acpi_disable_gpe(NULL, ec->gpe);
 823         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 824                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 825                 pr_err(PREFIX "failed to remove space handler\n");
 826         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 827                                 &acpi_ec_gpe_handler)))
 828                 pr_err(PREFIX "failed to remove gpe handler\n");
 829         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 830 }
 831
 832 static int acpi_ec_add(struct acpi_device *device)
 833 {
 834         struct acpi_ec *ec = NULL;
 835         int ret;
 836
 837         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 838         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 839
 840         /* Check for boot EC */
 841         if (boot_ec &&
 842             (boot_ec->handle == device->handle ||
 843              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 844                 ec = boot_ec;
 845                 boot_ec = NULL;
 846         } else {
 847                 ec = make_acpi_ec();
 848                 if (!ec)
 849                         return -ENOMEM;
 850         }
 851         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 852                 AE_CTRL_TERMINATE) {
 853                         kfree(ec);
 854                         return -EINVAL;
 855         }
 856
 857         /* Find and register all query methods */
 858         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 859                             acpi_ec_register_query_methods, NULL, ec, NULL);
 860
 861         if (!first_ec)
 862                 first_ec = ec;
 863         device->driver_data = ec;
 864
 865         WARN(!request_region(ec->data_addr, 1, "EC data"),
 866              "Could not request EC data io port 0x%lx", ec->data_addr);
 867         WARN(!request_region(ec->command_addr, 1, "EC cmd"),
 868              "Could not request EC cmd io port 0x%lx", ec->command_addr);
 869
 870         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 871                           ec->gpe, ec->command_addr, ec->data_addr);
 872
 873         ret = ec_install_handlers(ec);
 874
 875         /* EC is fully operational, allow queries */
 876         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 877
 878         /* Clear stale _Q events if hardware might require that */
 879         if (EC_FLAGS_CLEAR_ON_RESUME) {
 880                 mutex_lock(&ec->lock);
 881                 acpi_ec_clear(ec);
 882                 mutex_unlock(&ec->lock);
 883         }
 884         return ret;
 885 }
 886
 887 static int acpi_ec_remove(struct acpi_device *device, int type)
 888 {
 889         struct acpi_ec *ec;
 890         struct acpi_ec_query_handler *handler, *tmp;
 891
 892         if (!device)
 893                 return -EINVAL;
 894
 895         ec = acpi_driver_data(device);
 896         ec_remove_handlers(ec);
 897         mutex_lock(&ec->lock);
 898         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 899                 list_del(&handler->node);
 900                 kfree(handler);
 901         }
 902         mutex_unlock(&ec->lock);
 903         release_region(ec->data_addr, 1);
 904         release_region(ec->command_addr, 1);
 905         device->driver_data = NULL;
 906         if (ec == first_ec)
 907                 first_ec = NULL;
 908         kfree(ec);
 909         return 0;
 910 }
 911
 912 static acpi_status
 913 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 914 {
 915         struct acpi_ec *ec = context;
 916
 917         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 918                 return AE_OK;
 919
 920         /*
 921          * The first address region returned is the data port, and
 922          * the second address region returned is the status/command
 923          * port.
 924          */
 925         if (ec->data_addr == 0)
 926                 ec->data_addr = resource->data.io.minimum;
 927         else if (ec->command_addr == 0)
 928                 ec->command_addr = resource->data.io.minimum;
 929         else
 930                 return AE_CTRL_TERMINATE;
 931
 932         return AE_OK;
 933 }
 934
 935 int __init acpi_boot_ec_enable(void)
 936 {
 937         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 938                 return 0;
 939         if (!ec_install_handlers(boot_ec)) {
 940                 first_ec = boot_ec;
 941                 return 0;
 942         }
 943         return -EFAULT;
 944 }
 945
 946 static const struct acpi_device_id ec_device_ids[] = {
 947         {"PNP0C09", 0},
 948         {"", 0},
 949 };
 950
 951 /* Some BIOS do not survive early DSDT scan, skip it */
 952 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 953 {
 954         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 955         return 0;
 956 }
 957
 958 /* ASUStek often supplies us with broken ECDT, validate it */
 959 static int ec_validate_ecdt(const struct dmi_system_id *id)
 960 {
 961         EC_FLAGS_VALIDATE_ECDT = 1;
 962         return 0;
 963 }
 964
 965 /* MSI EC needs special treatment, enable it */
 966 static int ec_flag_msi(const struct dmi_system_id *id)
 967 {
 968         printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
 969         EC_FLAGS_MSI = 1;
 970         EC_FLAGS_VALIDATE_ECDT = 1;
 971         return 0;
 972 }
 973
 974 /*
 975  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
 976  * the GPE storm threshold back to 20
 977  */
 978 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
 979 {
 980         pr_debug("Setting the EC GPE storm threshold to 20\n");
 981         ec_storm_threshold  = 20;
 982         return 0;
 983 }
 984
 985 /*
 986  * Acer EC firmware refuses to respond QR_EC when SCI_EVT is not set, for
 987  * which case, we complete the QR_EC without issuing it to the firmware.
 988  * https://bugzilla.kernel.org/show_bug.cgi?id=86211
 989  */
 990 static int ec_flag_query_handshake(const struct dmi_system_id *id)
 991 {
 992         pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
 993         EC_FLAGS_QUERY_HANDSHAKE = 1;
 994         return 0;
 995 }
 996
 997 /*
 998  * On some hardware it is necessary to clear events accumulated by the EC during
 999  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1000  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1001  *
1002  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1003  *
1004  * Ideally, the EC should also be instructed NOT to accumulate events during
1005  * sleep (which Windows seems to do somehow), but the interface to control this
1006  * behaviour is not known at this time.
1007  *
1008  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1009  * however it is very likely that other Samsung models are affected.
1010  *
1011  * On systems which don't accumulate _Q events during sleep, this extra check
1012  * should be harmless.
1013  */
1014 static int ec_clear_on_resume(const struct dmi_system_id *id)
1015 {
1016         pr_debug("Detected system needing EC poll on resume.\n");
1017         EC_FLAGS_CLEAR_ON_RESUME = 1;
1018         return 0;
1019 }
1020
1021 static struct dmi_system_id __initdata ec_dmi_table[] = {
1022         {
1023         ec_skip_dsdt_scan, "Compal JFL92", {
1024         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1025         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1026         {
1027         ec_flag_msi, "MSI hardware", {
1028         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1029         {
1030         ec_flag_msi, "MSI hardware", {
1031         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1032         {
1033         ec_flag_msi, "MSI hardware", {
1034         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1035         {
1036         ec_flag_msi, "MSI hardware", {
1037         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1038         {
1039         ec_flag_msi, "Quanta hardware", {
1040         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1041         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1042         {
1043         ec_flag_msi, "Quanta hardware", {
1044         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1045         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1046         {
1047         ec_validate_ecdt, "ASUS hardware", {
1048         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1049         {
1050         ec_validate_ecdt, "ASUS hardware", {
1051         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1052         {
1053         ec_enlarge_storm_threshold, "CLEVO hardware", {
1054         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1055         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1056         {
1057         ec_validate_ecdt, "ASUS hardware", {
1058         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1059         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1060         {
1061         ec_clear_on_resume, "Samsung hardware", {
1062         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1063         {
1064         ec_flag_query_handshake, "Acer hardware", {
1065         DMI_MATCH(DMI_SYS_VENDOR, "Acer"), }, NULL},
1066         {},
1067 };
1068
1069 int __init acpi_ec_ecdt_probe(void)
1070 {
1071         acpi_status status;
1072         struct acpi_ec *saved_ec = NULL;
1073         struct acpi_table_ecdt *ecdt_ptr;
1074
1075         boot_ec = make_acpi_ec();
1076         if (!boot_ec)
1077                 return -ENOMEM;
1078         /*
1079          * Generate a boot ec context
1080          */
1081         dmi_check_system(ec_dmi_table);
1082         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1083                                 (struct acpi_table_header **)&ecdt_ptr);
1084         if (ACPI_SUCCESS(status)) {
1085                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
1086                 boot_ec->command_addr = ecdt_ptr->control.address;
1087                 boot_ec->data_addr = ecdt_ptr->data.address;
1088                 boot_ec->gpe = ecdt_ptr->gpe;
1089                 boot_ec->handle = ACPI_ROOT_OBJECT;
1090                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1091                 /* Don't trust ECDT, which comes from ASUSTek */
1092                 if (!EC_FLAGS_VALIDATE_ECDT)
1093                         goto install;
1094                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1095                 if (!saved_ec)
1096                         return -ENOMEM;
1097         /* fall through */
1098         }
1099
1100         if (EC_FLAGS_SKIP_DSDT_SCAN)
1101                 return -ENODEV;
1102
1103         /* This workaround is needed only on some broken machines,
1104          * which require early EC, but fail to provide ECDT */
1105         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1106         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1107                                         boot_ec, NULL);
1108         /* Check that acpi_get_devices actually find something */
1109         if (ACPI_FAILURE(status) || !boot_ec->handle)
1110                 goto error;
1111         if (saved_ec) {
1112                 /* try to find good ECDT from ASUSTek */
1113                 if (saved_ec->command_addr != boot_ec->command_addr ||
1114                     saved_ec->data_addr != boot_ec->data_addr ||
1115                     saved_ec->gpe != boot_ec->gpe ||
1116                     saved_ec->handle != boot_ec->handle)
1117                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1118                         "ECDT tables, which are very hard to workaround. "
1119                         "Trying to use DSDT EC info instead. Please send "
1120                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1121                 kfree(saved_ec);
1122                 saved_ec = NULL;
1123         } else {
1124                 /* We really need to limit this workaround, the only ASUS,
1125                 * which needs it, has fake EC._INI method, so use it as flag.
1126                 * Keep boot_ec struct as it will be needed soon.
1127                 */
1128                 acpi_handle dummy;
1129                 if (!dmi_name_in_vendors("ASUS") ||
1130                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1131                                                         &dummy)))
1132                         return -ENODEV;
1133         }
1134 install:
1135         if (!ec_install_handlers(boot_ec)) {
1136                 first_ec = boot_ec;
1137                 return 0;
1138         }
1139 error:
1140         kfree(boot_ec);
1141         boot_ec = NULL;
1142         return -ENODEV;
1143 }
1144
1145 static struct acpi_driver acpi_ec_driver = {
1146         .name = "ec",
1147         .class = ACPI_EC_CLASS,
1148         .ids = ec_device_ids,
1149         .ops = {
1150                 .add = acpi_ec_add,
1151                 .remove = acpi_ec_remove,
1152                 },
1153 };
1154
1155 int __init acpi_ec_init(void)
1156 {
1157         int result = 0;
1158
1159         /* Now register the driver for the EC */
1160         result = acpi_bus_register_driver(&acpi_ec_driver);
1161         if (result < 0)
1162                 return -ENODEV;
1163
1164         return result;
1165 }
1166
1167 /* EC driver currently not unloadable */
1168 #if 0
1169 static void __exit acpi_ec_exit(void)
1170 {
1171
1172         acpi_bus_unregister_driver(&acpi_ec_driver);
1173         return;
1174 }
1175 #endif  /* 0 */