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