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 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
  82 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
  83 module_param(ec_delay, uint, 0644);
  84 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
  85
  86 /*
  87  * If the number of false interrupts per one transaction exceeds
  88  * this threshold, will think there is a GPE storm happened and
  89  * will disable the GPE for normal transaction.
  90  */
  91 static unsigned int ec_storm_threshold  __read_mostly = 8;
  92 module_param(ec_storm_threshold, uint, 0644);
  93 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
  94
  95 struct acpi_ec_query_handler {
  96         struct list_head node;
  97         acpi_ec_query_func func;
  98         acpi_handle handle;
  99         void *data;
 100         u8 query_bit;
 101 };
 102
 103 struct transaction {
 104         const u8 *wdata;
 105         u8 *rdata;
 106         unsigned short irq_count;
 107         u8 command;
 108         u8 wi;
 109         u8 ri;
 110         u8 wlen;
 111         u8 rlen;
 112         bool done;
 113 };
 114
 115 struct acpi_ec *boot_ec, *first_ec;
 116 EXPORT_SYMBOL(first_ec);
 117
 118 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 119 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 120 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 121 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 122
 123 /* --------------------------------------------------------------------------
 124                              Transaction Management
 125    -------------------------------------------------------------------------- */
 126
 127 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 128 {
 129         u8 x = inb(ec->command_addr);
 130         pr_debug("---> status = 0x%2.2x\n", x);
 131         return x;
 132 }
 133
 134 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 135 {
 136         u8 x = inb(ec->data_addr);
 137         pr_debug("---> data = 0x%2.2x\n", x);
 138         return x;
 139 }
 140
 141 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 142 {
 143         pr_debug("<--- command = 0x%2.2x\n", command);
 144         outb(command, ec->command_addr);
 145 }
 146
 147 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 148 {
 149         pr_debug("<--- data = 0x%2.2x\n", data);
 150         outb(data, ec->data_addr);
 151 }
 152
 153 static int ec_transaction_done(struct acpi_ec *ec)
 154 {
 155         unsigned long flags;
 156         int ret = 0;
 157         spin_lock_irqsave(&ec->lock, flags);
 158         if (!ec->curr || ec->curr->done)
 159                 ret = 1;
 160         spin_unlock_irqrestore(&ec->lock, flags);
 161         return ret;
 162 }
 163
 164 static void start_transaction(struct acpi_ec *ec)
 165 {
 166         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 167         ec->curr->done = false;
 168         acpi_ec_write_cmd(ec, ec->curr->command);
 169 }
 170
 171 static void advance_transaction(struct acpi_ec *ec, u8 status)
 172 {
 173         unsigned long flags;
 174         struct transaction *t;
 175
 176         spin_lock_irqsave(&ec->lock, flags);
 177         t = ec->curr;
 178         if (!t)
 179                 goto unlock;
 180         if (t->wlen > t->wi) {
 181                 if ((status & ACPI_EC_FLAG_IBF) == 0)
 182                         acpi_ec_write_data(ec,
 183                                 t->wdata[t->wi++]);
 184                 else
 185                         goto err;
 186         } else if (t->rlen > t->ri) {
 187                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
 188                         t->rdata[t->ri++] = acpi_ec_read_data(ec);
 189                         if (t->rlen == t->ri)
 190                                 t->done = true;
 191                 } else
 192                         goto err;
 193         } else if (t->wlen == t->wi &&
 194                    (status & ACPI_EC_FLAG_IBF) == 0)
 195                 t->done = true;
 196         goto unlock;
 197 err:
 198         /*
 199          * If SCI bit is set, then don't think it's a false IRQ
 200          * otherwise will take a not handled IRQ as a false one.
 201          */
 202         if (in_interrupt() && !(status & ACPI_EC_FLAG_SCI))
 203                 ++t->irq_count;
 204
 205 unlock:
 206         spin_unlock_irqrestore(&ec->lock, flags);
 207 }
 208
 209 static int acpi_ec_sync_query(struct acpi_ec *ec);
 210
 211 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 212 {
 213         if (state & ACPI_EC_FLAG_SCI) {
 214                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 215                         return acpi_ec_sync_query(ec);
 216         }
 217         return 0;
 218 }
 219
 220 static int ec_poll(struct acpi_ec *ec)
 221 {
 222         unsigned long flags;
 223         int repeat = 5; /* number of command restarts */
 224         while (repeat--) {
 225                 unsigned long delay = jiffies +
 226                         msecs_to_jiffies(ec_delay);
 227                 do {
 228                         /* don't sleep with disabled interrupts */
 229                         if (EC_FLAGS_MSI || irqs_disabled()) {
 230                                 udelay(ACPI_EC_MSI_UDELAY);
 231                                 if (ec_transaction_done(ec))
 232                                         return 0;
 233                         } else {
 234                                 if (wait_event_timeout(ec->wait,
 235                                                 ec_transaction_done(ec),
 236                                                 msecs_to_jiffies(1)))
 237                                         return 0;
 238                         }
 239                         advance_transaction(ec, acpi_ec_read_status(ec));
 240                 } while (time_before(jiffies, delay));
 241                 pr_debug("controller reset, restart transaction\n");
 242                 spin_lock_irqsave(&ec->lock, flags);
 243                 start_transaction(ec);
 244                 spin_unlock_irqrestore(&ec->lock, flags);
 245         }
 246         return -ETIME;
 247 }
 248
 249 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 250                                         struct transaction *t)
 251 {
 252         unsigned long tmp;
 253         int ret = 0;
 254         if (EC_FLAGS_MSI)
 255                 udelay(ACPI_EC_MSI_UDELAY);
 256         /* start transaction */
 257         spin_lock_irqsave(&ec->lock, tmp);
 258         /* following two actions should be kept atomic */
 259         ec->curr = t;
 260         start_transaction(ec);
 261         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 262                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 263         spin_unlock_irqrestore(&ec->lock, tmp);
 264         ret = ec_poll(ec);
 265         spin_lock_irqsave(&ec->lock, tmp);
 266         ec->curr = NULL;
 267         spin_unlock_irqrestore(&ec->lock, tmp);
 268         return ret;
 269 }
 270
 271 static int ec_check_ibf0(struct acpi_ec *ec)
 272 {
 273         u8 status = acpi_ec_read_status(ec);
 274         return (status & ACPI_EC_FLAG_IBF) == 0;
 275 }
 276
 277 static int ec_wait_ibf0(struct acpi_ec *ec)
 278 {
 279         unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
 280         /* interrupt wait manually if GPE mode is not active */
 281         while (time_before(jiffies, delay))
 282                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
 283                                         msecs_to_jiffies(1)))
 284                         return 0;
 285         return -ETIME;
 286 }
 287
 288 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 289 {
 290         int status;
 291         u32 glk;
 292         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 293                 return -EINVAL;
 294         if (t->rdata)
 295                 memset(t->rdata, 0, t->rlen);
 296         mutex_lock(&ec->mutex);
 297         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 298                 status = -EINVAL;
 299                 goto unlock;
 300         }
 301         if (ec->global_lock) {
 302                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 303                 if (ACPI_FAILURE(status)) {
 304                         status = -ENODEV;
 305                         goto unlock;
 306                 }
 307         }
 308         if (ec_wait_ibf0(ec)) {
 309                 pr_err("input buffer is not empty, "
 310                                 "aborting transaction\n");
 311                 status = -ETIME;
 312                 goto end;
 313         }
 314         pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",
 315                         t->command, t->wdata ? t->wdata[0] : 0);
 316         /* disable GPE during transaction if storm is detected */
 317         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 318                 /* It has to be disabled, so that it doesn't trigger. */
 319                 acpi_disable_gpe(NULL, ec->gpe);
 320         }
 321
 322         status = acpi_ec_transaction_unlocked(ec, t);
 323
 324         /* check if we received SCI during transaction */
 325         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 326         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 327                 msleep(1);
 328                 /* It is safe to enable the GPE outside of the transaction. */
 329                 acpi_enable_gpe(NULL, ec->gpe);
 330         } else if (t->irq_count > ec_storm_threshold) {
 331                 pr_info("GPE storm detected(%d GPEs), "
 332                         "transactions will use polling mode\n",
 333                         t->irq_count);
 334                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 335         }
 336         pr_debug("transaction end\n");
 337 end:
 338         if (ec->global_lock)
 339                 acpi_release_global_lock(glk);
 340 unlock:
 341         mutex_unlock(&ec->mutex);
 342         return status;
 343 }
 344
 345 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 346 {
 347         u8 d;
 348         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 349                                 .wdata = NULL, .rdata = &d,
 350                                 .wlen = 0, .rlen = 1};
 351
 352         return acpi_ec_transaction(ec, &t);
 353 }
 354
 355 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 356 {
 357         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 358                                 .wdata = NULL, .rdata = NULL,
 359                                 .wlen = 0, .rlen = 0};
 360
 361         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 362                                 acpi_ec_transaction(ec, &t) : 0;
 363 }
 364
 365 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 366 {
 367         int result;
 368         u8 d;
 369         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 370                                 .wdata = &address, .rdata = &d,
 371                                 .wlen = 1, .rlen = 1};
 372
 373         result = acpi_ec_transaction(ec, &t);
 374         *data = d;
 375         return result;
 376 }
 377
 378 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 379 {
 380         u8 wdata[2] = { address, data };
 381         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 382                                 .wdata = wdata, .rdata = NULL,
 383                                 .wlen = 2, .rlen = 0};
 384
 385         return acpi_ec_transaction(ec, &t);
 386 }
 387
 388 int ec_read(u8 addr, u8 *val)
 389 {
 390         int err;
 391         u8 temp_data;
 392
 393         if (!first_ec)
 394                 return -ENODEV;
 395
 396         err = acpi_ec_read(first_ec, addr, &temp_data);
 397
 398         if (!err) {
 399                 *val = temp_data;
 400                 return 0;
 401         } else
 402                 return err;
 403 }
 404
 405 EXPORT_SYMBOL(ec_read);
 406
 407 int ec_write(u8 addr, u8 val)
 408 {
 409         int err;
 410
 411         if (!first_ec)
 412                 return -ENODEV;
 413
 414         err = acpi_ec_write(first_ec, addr, val);
 415
 416         return err;
 417 }
 418
 419 EXPORT_SYMBOL(ec_write);
 420
 421 int ec_transaction(u8 command,
 422                    const u8 * wdata, unsigned wdata_len,
 423                    u8 * rdata, unsigned rdata_len)
 424 {
 425         struct transaction t = {.command = command,
 426                                 .wdata = wdata, .rdata = rdata,
 427                                 .wlen = wdata_len, .rlen = rdata_len};
 428         if (!first_ec)
 429                 return -ENODEV;
 430
 431         return acpi_ec_transaction(first_ec, &t);
 432 }
 433
 434 EXPORT_SYMBOL(ec_transaction);
 435
 436 /* Get the handle to the EC device */
 437 acpi_handle ec_get_handle(void)
 438 {
 439         if (!first_ec)
 440                 return NULL;
 441         return first_ec->handle;
 442 }
 443
 444 EXPORT_SYMBOL(ec_get_handle);
 445
 446 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 *data);
 447
 448 /*
 449  * Clears stale _Q events that might have accumulated in the EC.
 450  * Run with locked ec mutex.
 451  */
 452 static void acpi_ec_clear(struct acpi_ec *ec)
 453 {
 454         int i, status;
 455         u8 value = 0;
 456
 457         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 458                 status = acpi_ec_query_unlocked(ec, &value);
 459                 if (status || !value)
 460                         break;
 461         }
 462
 463         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 464                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 465         else
 466                 pr_info("%d stale EC events cleared\n", i);
 467 }
 468
 469 void acpi_ec_block_transactions(void)
 470 {
 471         struct acpi_ec *ec = first_ec;
 472
 473         if (!ec)
 474                 return;
 475
 476         mutex_lock(&ec->mutex);
 477         /* Prevent transactions from being carried out */
 478         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 479         mutex_unlock(&ec->mutex);
 480 }
 481
 482 void acpi_ec_unblock_transactions(void)
 483 {
 484         struct acpi_ec *ec = first_ec;
 485
 486         if (!ec)
 487                 return;
 488
 489         mutex_lock(&ec->mutex);
 490         /* Allow transactions to be carried out again */
 491         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 492
 493         if (EC_FLAGS_CLEAR_ON_RESUME)
 494                 acpi_ec_clear(ec);
 495
 496         mutex_unlock(&ec->mutex);
 497 }
 498
 499 void acpi_ec_unblock_transactions_early(void)
 500 {
 501         /*
 502          * Allow transactions to happen again (this function is called from
 503          * atomic context during wakeup, so we don't need to acquire the mutex).
 504          */
 505         if (first_ec)
 506                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 507 }
 508
 509 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 510 {
 511         int result;
 512         u8 d;
 513         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 514                                 .wdata = NULL, .rdata = &d,
 515                                 .wlen = 0, .rlen = 1};
 516         if (!ec || !data)
 517                 return -EINVAL;
 518         /*
 519          * Query the EC to find out which _Qxx method we need to evaluate.
 520          * Note that successful completion of the query causes the ACPI_EC_SCI
 521          * bit to be cleared (and thus clearing the interrupt source).
 522          */
 523         result = acpi_ec_transaction_unlocked(ec, &t);
 524         if (result)
 525                 return result;
 526         if (!d)
 527                 return -ENODATA;
 528         *data = d;
 529         return 0;
 530 }
 531
 532 /* --------------------------------------------------------------------------
 533                                 Event Management
 534    -------------------------------------------------------------------------- */
 535 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 536                               acpi_handle handle, acpi_ec_query_func func,
 537                               void *data)
 538 {
 539         struct acpi_ec_query_handler *handler =
 540             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 541         if (!handler)
 542                 return -ENOMEM;
 543
 544         handler->query_bit = query_bit;
 545         handler->handle = handle;
 546         handler->func = func;
 547         handler->data = data;
 548         mutex_lock(&ec->mutex);
 549         list_add(&handler->node, &ec->list);
 550         mutex_unlock(&ec->mutex);
 551         return 0;
 552 }
 553
 554 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 555
 556 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 557 {
 558         struct acpi_ec_query_handler *handler, *tmp;
 559         mutex_lock(&ec->mutex);
 560         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 561                 if (query_bit == handler->query_bit) {
 562                         list_del(&handler->node);
 563                         kfree(handler);
 564                 }
 565         }
 566         mutex_unlock(&ec->mutex);
 567 }
 568
 569 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 570
 571 static void acpi_ec_run(void *cxt)
 572 {
 573         struct acpi_ec_query_handler *handler = cxt;
 574         if (!handler)
 575                 return;
 576         pr_debug("start query execution\n");
 577         if (handler->func)
 578                 handler->func(handler->data);
 579         else if (handler->handle)
 580                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 581         pr_debug("stop query execution\n");
 582         kfree(handler);
 583 }
 584
 585 static int acpi_ec_sync_query(struct acpi_ec *ec)
 586 {
 587         u8 value = 0;
 588         int status;
 589         struct acpi_ec_query_handler *handler, *copy;
 590         if ((status = acpi_ec_query_unlocked(ec, &value)))
 591                 return status;
 592         list_for_each_entry(handler, &ec->list, node) {
 593                 if (value == handler->query_bit) {
 594                         /* have custom handler for this bit */
 595                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 596                         if (!copy)
 597                                 return -ENOMEM;
 598                         memcpy(copy, handler, sizeof(*copy));
 599                         pr_debug("push query execution (0x%2x) on queue\n",
 600                                 value);
 601                         return acpi_os_execute((copy->func) ?
 602                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 603                                 acpi_ec_run, copy);
 604                 }
 605         }
 606         return 0;
 607 }
 608
 609 static void acpi_ec_gpe_query(void *ec_cxt)
 610 {
 611         struct acpi_ec *ec = ec_cxt;
 612         if (!ec)
 613                 return;
 614         mutex_lock(&ec->mutex);
 615         acpi_ec_sync_query(ec);
 616         mutex_unlock(&ec->mutex);
 617 }
 618
 619 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 620 {
 621         if (state & ACPI_EC_FLAG_SCI) {
 622                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 623                         pr_debug("push gpe query to the queue\n");
 624                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 625                                 acpi_ec_gpe_query, ec);
 626                 }
 627         }
 628         return 0;
 629 }
 630
 631 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 632         u32 gpe_number, void *data)
 633 {
 634         struct acpi_ec *ec = data;
 635         u8 status = acpi_ec_read_status(ec);
 636
 637         pr_debug("~~~> interrupt, status:0x%02x\n", status);
 638
 639         advance_transaction(ec, status);
 640         if (ec_transaction_done(ec) &&
 641             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 642                 wake_up(&ec->wait);
 643                 ec_check_sci(ec, acpi_ec_read_status(ec));
 644         }
 645         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 646 }
 647
 648 /* --------------------------------------------------------------------------
 649                              Address Space Management
 650    -------------------------------------------------------------------------- */
 651
 652 static acpi_status
 653 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 654                       u32 bits, u64 *value64,
 655                       void *handler_context, void *region_context)
 656 {
 657         struct acpi_ec *ec = handler_context;
 658         int result = 0, i, bytes = bits / 8;
 659         u8 *value = (u8 *)value64;
 660
 661         if ((address > 0xFF) || !value || !handler_context)
 662                 return AE_BAD_PARAMETER;
 663
 664         if (function != ACPI_READ && function != ACPI_WRITE)
 665                 return AE_BAD_PARAMETER;
 666
 667         if (EC_FLAGS_MSI || bits > 8)
 668                 acpi_ec_burst_enable(ec);
 669
 670         for (i = 0; i < bytes; ++i, ++address, ++value)
 671                 result = (function == ACPI_READ) ?
 672                         acpi_ec_read(ec, address, value) :
 673                         acpi_ec_write(ec, address, *value);
 674
 675         if (EC_FLAGS_MSI || bits > 8)
 676                 acpi_ec_burst_disable(ec);
 677
 678         switch (result) {
 679         case -EINVAL:
 680                 return AE_BAD_PARAMETER;
 681                 break;
 682         case -ENODEV:
 683                 return AE_NOT_FOUND;
 684                 break;
 685         case -ETIME:
 686                 return AE_TIME;
 687                 break;
 688         default:
 689                 return AE_OK;
 690         }
 691 }
 692
 693 /* --------------------------------------------------------------------------
 694                                Driver Interface
 695    -------------------------------------------------------------------------- */
 696 static acpi_status
 697 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 698
 699 static struct acpi_ec *make_acpi_ec(void)
 700 {
 701         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 702         if (!ec)
 703                 return NULL;
 704         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 705         mutex_init(&ec->mutex);
 706         init_waitqueue_head(&ec->wait);
 707         INIT_LIST_HEAD(&ec->list);
 708         spin_lock_init(&ec->lock);
 709         return ec;
 710 }
 711
 712 static acpi_status
 713 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 714                                void *context, void **return_value)
 715 {
 716         char node_name[5];
 717         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 718         struct acpi_ec *ec = context;
 719         int value = 0;
 720         acpi_status status;
 721
 722         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 723
 724         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 725                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 726         }
 727         return AE_OK;
 728 }
 729
 730 static acpi_status
 731 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 732 {
 733         acpi_status status;
 734         unsigned long long tmp = 0;
 735
 736         struct acpi_ec *ec = context;
 737
 738         /* clear addr values, ec_parse_io_ports depend on it */
 739         ec->command_addr = ec->data_addr = 0;
 740
 741         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 742                                      ec_parse_io_ports, ec);
 743         if (ACPI_FAILURE(status))
 744                 return status;
 745
 746         /* Get GPE bit assignment (EC events). */
 747         /* TODO: Add support for _GPE returning a package */
 748         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 749         if (ACPI_FAILURE(status))
 750                 return status;
 751         ec->gpe = tmp;
 752         /* Use the global lock for all EC transactions? */
 753         tmp = 0;
 754         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 755         ec->global_lock = tmp;
 756         ec->handle = handle;
 757         return AE_CTRL_TERMINATE;
 758 }
 759
 760 static int ec_install_handlers(struct acpi_ec *ec)
 761 {
 762         acpi_status status;
 763         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 764                 return 0;
 765         status = acpi_install_gpe_handler(NULL, ec->gpe,
 766                                   ACPI_GPE_EDGE_TRIGGERED,
 767                                   &acpi_ec_gpe_handler, ec);
 768         if (ACPI_FAILURE(status))
 769                 return -ENODEV;
 770
 771         acpi_enable_gpe(NULL, ec->gpe);
 772         status = acpi_install_address_space_handler(ec->handle,
 773                                                     ACPI_ADR_SPACE_EC,
 774                                                     &acpi_ec_space_handler,
 775                                                     NULL, ec);
 776         if (ACPI_FAILURE(status)) {
 777                 if (status == AE_NOT_FOUND) {
 778                         /*
 779                          * Maybe OS fails in evaluating the _REG object.
 780                          * The AE_NOT_FOUND error will be ignored and OS
 781                          * continue to initialize EC.
 782                          */
 783                         pr_err("Fail in evaluating the _REG object"
 784                                 " of EC device. Broken bios is suspected.\n");
 785                 } else {
 786                         acpi_disable_gpe(NULL, ec->gpe);
 787                         acpi_remove_gpe_handler(NULL, ec->gpe,
 788                                 &acpi_ec_gpe_handler);
 789                         return -ENODEV;
 790                 }
 791         }
 792
 793         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 794         return 0;
 795 }
 796
 797 static void ec_remove_handlers(struct acpi_ec *ec)
 798 {
 799         acpi_disable_gpe(NULL, ec->gpe);
 800         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 801                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 802                 pr_err("failed to remove space handler\n");
 803         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 804                                 &acpi_ec_gpe_handler)))
 805                 pr_err("failed to remove gpe handler\n");
 806         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 807 }
 808
 809 static int acpi_ec_add(struct acpi_device *device)
 810 {
 811         struct acpi_ec *ec = NULL;
 812         int ret;
 813
 814         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 815         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 816
 817         /* Check for boot EC */
 818         if (boot_ec &&
 819             (boot_ec->handle == device->handle ||
 820              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 821                 ec = boot_ec;
 822                 boot_ec = NULL;
 823         } else {
 824                 ec = make_acpi_ec();
 825                 if (!ec)
 826                         return -ENOMEM;
 827         }
 828         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 829                 AE_CTRL_TERMINATE) {
 830                         kfree(ec);
 831                         return -EINVAL;
 832         }
 833
 834         /* Find and register all query methods */
 835         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 836                             acpi_ec_register_query_methods, NULL, ec, NULL);
 837
 838         if (!first_ec)
 839                 first_ec = ec;
 840         device->driver_data = ec;
 841
 842         ret = !!request_region(ec->data_addr, 1, "EC data");
 843         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
 844         ret = !!request_region(ec->command_addr, 1, "EC cmd");
 845         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
 846
 847         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 848                           ec->gpe, ec->command_addr, ec->data_addr);
 849
 850         ret = ec_install_handlers(ec);
 851
 852         /* EC is fully operational, allow queries */
 853         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 854
 855         /* Clear stale _Q events if hardware might require that */
 856         if (EC_FLAGS_CLEAR_ON_RESUME) {
 857                 mutex_lock(&ec->mutex);
 858                 acpi_ec_clear(ec);
 859                 mutex_unlock(&ec->mutex);
 860         }
 861         return ret;
 862 }
 863
 864 static int acpi_ec_remove(struct acpi_device *device)
 865 {
 866         struct acpi_ec *ec;
 867         struct acpi_ec_query_handler *handler, *tmp;
 868
 869         if (!device)
 870                 return -EINVAL;
 871
 872         ec = acpi_driver_data(device);
 873         ec_remove_handlers(ec);
 874         mutex_lock(&ec->mutex);
 875         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 876                 list_del(&handler->node);
 877                 kfree(handler);
 878         }
 879         mutex_unlock(&ec->mutex);
 880         release_region(ec->data_addr, 1);
 881         release_region(ec->command_addr, 1);
 882         device->driver_data = NULL;
 883         if (ec == first_ec)
 884                 first_ec = NULL;
 885         kfree(ec);
 886         return 0;
 887 }
 888
 889 static acpi_status
 890 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 891 {
 892         struct acpi_ec *ec = context;
 893
 894         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 895                 return AE_OK;
 896
 897         /*
 898          * The first address region returned is the data port, and
 899          * the second address region returned is the status/command
 900          * port.
 901          */
 902         if (ec->data_addr == 0)
 903                 ec->data_addr = resource->data.io.minimum;
 904         else if (ec->command_addr == 0)
 905                 ec->command_addr = resource->data.io.minimum;
 906         else
 907                 return AE_CTRL_TERMINATE;
 908
 909         return AE_OK;
 910 }
 911
 912 int __init acpi_boot_ec_enable(void)
 913 {
 914         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 915                 return 0;
 916         if (!ec_install_handlers(boot_ec)) {
 917                 first_ec = boot_ec;
 918                 return 0;
 919         }
 920         return -EFAULT;
 921 }
 922
 923 static const struct acpi_device_id ec_device_ids[] = {
 924         {"PNP0C09", 0},
 925         {"", 0},
 926 };
 927
 928 /* Some BIOS do not survive early DSDT scan, skip it */
 929 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 930 {
 931         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 932         return 0;
 933 }
 934
 935 /* ASUStek often supplies us with broken ECDT, validate it */
 936 static int ec_validate_ecdt(const struct dmi_system_id *id)
 937 {
 938         EC_FLAGS_VALIDATE_ECDT = 1;
 939         return 0;
 940 }
 941
 942 /* MSI EC needs special treatment, enable it */
 943 static int ec_flag_msi(const struct dmi_system_id *id)
 944 {
 945         pr_debug("Detected MSI hardware, enabling workarounds.\n");
 946         EC_FLAGS_MSI = 1;
 947         EC_FLAGS_VALIDATE_ECDT = 1;
 948         return 0;
 949 }
 950
 951 /*
 952  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
 953  * the GPE storm threshold back to 20
 954  */
 955 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
 956 {
 957         pr_debug("Setting the EC GPE storm threshold to 20\n");
 958         ec_storm_threshold  = 20;
 959         return 0;
 960 }
 961
 962 /*
 963  * On some hardware it is necessary to clear events accumulated by the EC during
 964  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
 965  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
 966  *
 967  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
 968  *
 969  * Ideally, the EC should also be instructed NOT to accumulate events during
 970  * sleep (which Windows seems to do somehow), but the interface to control this
 971  * behaviour is not known at this time.
 972  *
 973  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
 974  * however it is very likely that other Samsung models are affected.
 975  *
 976  * On systems which don't accumulate _Q events during sleep, this extra check
 977  * should be harmless.
 978  */
 979 static int ec_clear_on_resume(const struct dmi_system_id *id)
 980 {
 981         pr_debug("Detected system needing EC poll on resume.\n");
 982         EC_FLAGS_CLEAR_ON_RESUME = 1;
 983         return 0;
 984 }
 985
 986 static struct dmi_system_id ec_dmi_table[] __initdata = {
 987         {
 988         ec_skip_dsdt_scan, "Compal JFL92", {
 989         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 990         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 991         {
 992         ec_flag_msi, "MSI hardware", {
 993         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
 994         {
 995         ec_flag_msi, "MSI hardware", {
 996         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
 997         {
 998         ec_flag_msi, "MSI hardware", {
 999         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1000         {
1001         ec_flag_msi, "MSI hardware", {
1002         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1003         {
1004         ec_flag_msi, "Quanta hardware", {
1005         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1006         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1007         {
1008         ec_flag_msi, "Quanta hardware", {
1009         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1010         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1011         {
1012         ec_validate_ecdt, "ASUS hardware", {
1013         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1014         {
1015         ec_validate_ecdt, "ASUS hardware", {
1016         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1017         {
1018         ec_enlarge_storm_threshold, "CLEVO hardware", {
1019         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1020         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1021         {
1022         ec_skip_dsdt_scan, "HP Folio 13", {
1023         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1024         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1025         {
1026         ec_validate_ecdt, "ASUS hardware", {
1027         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1028         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1029         {
1030         ec_clear_on_resume, "Samsung hardware", {
1031         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1032         {},
1033 };
1034
1035 int __init acpi_ec_ecdt_probe(void)
1036 {
1037         acpi_status status;
1038         struct acpi_ec *saved_ec = NULL;
1039         struct acpi_table_ecdt *ecdt_ptr;
1040
1041         boot_ec = make_acpi_ec();
1042         if (!boot_ec)
1043                 return -ENOMEM;
1044         /*
1045          * Generate a boot ec context
1046          */
1047         dmi_check_system(ec_dmi_table);
1048         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1049                                 (struct acpi_table_header **)&ecdt_ptr);
1050         if (ACPI_SUCCESS(status)) {
1051                 pr_info("EC description table is found, configuring boot EC\n");
1052                 boot_ec->command_addr = ecdt_ptr->control.address;
1053                 boot_ec->data_addr = ecdt_ptr->data.address;
1054                 boot_ec->gpe = ecdt_ptr->gpe;
1055                 boot_ec->handle = ACPI_ROOT_OBJECT;
1056                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1057                 /* Don't trust ECDT, which comes from ASUSTek */
1058                 if (!EC_FLAGS_VALIDATE_ECDT)
1059                         goto install;
1060                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1061                 if (!saved_ec)
1062                         return -ENOMEM;
1063         /* fall through */
1064         }
1065
1066         if (EC_FLAGS_SKIP_DSDT_SCAN)
1067                 return -ENODEV;
1068
1069         /* This workaround is needed only on some broken machines,
1070          * which require early EC, but fail to provide ECDT */
1071         pr_debug("Look up EC in DSDT\n");
1072         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1073                                         boot_ec, NULL);
1074         /* Check that acpi_get_devices actually find something */
1075         if (ACPI_FAILURE(status) || !boot_ec->handle)
1076                 goto error;
1077         if (saved_ec) {
1078                 /* try to find good ECDT from ASUSTek */
1079                 if (saved_ec->command_addr != boot_ec->command_addr ||
1080                     saved_ec->data_addr != boot_ec->data_addr ||
1081                     saved_ec->gpe != boot_ec->gpe ||
1082                     saved_ec->handle != boot_ec->handle)
1083                         pr_info("ASUSTek keeps feeding us with broken "
1084                         "ECDT tables, which are very hard to workaround. "
1085                         "Trying to use DSDT EC info instead. Please send "
1086                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1087                 kfree(saved_ec);
1088                 saved_ec = NULL;
1089         } else {
1090                 /* We really need to limit this workaround, the only ASUS,
1091                 * which needs it, has fake EC._INI method, so use it as flag.
1092                 * Keep boot_ec struct as it will be needed soon.
1093                 */
1094                 if (!dmi_name_in_vendors("ASUS") ||
1095                     !acpi_has_method(boot_ec->handle, "_INI"))
1096                         return -ENODEV;
1097         }
1098 install:
1099         if (!ec_install_handlers(boot_ec)) {
1100                 first_ec = boot_ec;
1101                 return 0;
1102         }
1103 error:
1104         kfree(boot_ec);
1105         boot_ec = NULL;
1106         return -ENODEV;
1107 }
1108
1109 static struct acpi_driver acpi_ec_driver = {
1110         .name = "ec",
1111         .class = ACPI_EC_CLASS,
1112         .ids = ec_device_ids,
1113         .ops = {
1114                 .add = acpi_ec_add,
1115                 .remove = acpi_ec_remove,
1116                 },
1117 };
1118
1119 int __init acpi_ec_init(void)
1120 {
1121         int result = 0;
1122
1123         /* Now register the driver for the EC */
1124         result = acpi_bus_register_driver(&acpi_ec_driver);
1125         if (result < 0)
1126                 return -ENODEV;
1127
1128         return result;
1129 }
1130
1131 /* EC driver currently not unloadable */
1132 #if 0
1133 static void __exit acpi_ec_exit(void)
1134 {
1135
1136         acpi_bus_unregister_driver(&acpi_ec_driver);
1137         return;
1138 }
1139 #endif  /* 0 */