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 <asm/io.h>
  43 #include <acpi/acpi_bus.h>
  44 #include <acpi/acpi_drivers.h>
  45 #include <linux/dmi.h>
  46
  47 #include "internal.h"
  48
  49 #define ACPI_EC_CLASS                   "embedded_controller"
  50 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  51 #define ACPI_EC_FILE_INFO               "info"
  52
  53 /* EC status register */
  54 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  55 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  56 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  57 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  58
  59 /* EC commands */
  60 enum ec_command {
  61         ACPI_EC_COMMAND_READ = 0x80,
  62         ACPI_EC_COMMAND_WRITE = 0x81,
  63         ACPI_EC_BURST_ENABLE = 0x82,
  64         ACPI_EC_BURST_DISABLE = 0x83,
  65         ACPI_EC_COMMAND_QUERY = 0x84,
  66 };
  67
  68 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  69 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  70 #define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
  71
  72 enum {
  73         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  74         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  75         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
  76                                          * OpReg are installed */
  77         EC_FLAGS_BLOCKED,               /* Transactions are blocked */
  78 };
  79
  80 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
  81 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
  82 module_param(ec_delay, uint, 0644);
  83 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
  84
  85 /*
  86  * If the number of false interrupts per one transaction exceeds
  87  * this threshold, will think there is a GPE storm happened and
  88  * will disable the GPE for normal transaction.
  89  */
  90 static unsigned int ec_storm_threshold  __read_mostly = 8;
  91 module_param(ec_storm_threshold, uint, 0644);
  92 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
  93
  94 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  95 /* External interfaces use first EC only, so remember */
  96 typedef int (*acpi_ec_query_func) (void *data);
  97
  98 struct acpi_ec_query_handler {
  99         struct list_head node;
 100         acpi_ec_query_func func;
 101         acpi_handle handle;
 102         void *data;
 103         u8 query_bit;
 104 };
 105
 106 struct transaction {
 107         const u8 *wdata;
 108         u8 *rdata;
 109         unsigned short irq_count;
 110         u8 command;
 111         u8 wi;
 112         u8 ri;
 113         u8 wlen;
 114         u8 rlen;
 115         bool done;
 116 };
 117
 118 struct acpi_ec *boot_ec, *first_ec;
 119 EXPORT_SYMBOL(first_ec);
 120
 121 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 122 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 123 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 124
 125 /* --------------------------------------------------------------------------
 126                              Transaction Management
 127    -------------------------------------------------------------------------- */
 128
 129 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 130 {
 131         u8 x = inb(ec->command_addr);
 132         pr_debug("---> status = 0x%2.2x\n", x);
 133         return x;
 134 }
 135
 136 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 137 {
 138         u8 x = inb(ec->data_addr);
 139         pr_debug("---> data = 0x%2.2x\n", x);
 140         return x;
 141 }
 142
 143 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 144 {
 145         pr_debug("<--- command = 0x%2.2x\n", command);
 146         outb(command, ec->command_addr);
 147 }
 148
 149 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 150 {
 151         pr_debug("<--- data = 0x%2.2x\n", data);
 152         outb(data, ec->data_addr);
 153 }
 154
 155 static int ec_transaction_done(struct acpi_ec *ec)
 156 {
 157         unsigned long flags;
 158         int ret = 0;
 159         spin_lock_irqsave(&ec->lock, flags);
 160         if (!ec->curr || ec->curr->done)
 161                 ret = 1;
 162         spin_unlock_irqrestore(&ec->lock, flags);
 163         return ret;
 164 }
 165
 166 static void start_transaction(struct acpi_ec *ec)
 167 {
 168         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 169         ec->curr->done = false;
 170         acpi_ec_write_cmd(ec, ec->curr->command);
 171 }
 172
 173 static void advance_transaction(struct acpi_ec *ec, u8 status)
 174 {
 175         unsigned long flags;
 176         struct transaction *t;
 177
 178         spin_lock_irqsave(&ec->lock, flags);
 179         t = ec->curr;
 180         if (!t)
 181                 goto unlock;
 182         if (t->wlen > t->wi) {
 183                 if ((status & ACPI_EC_FLAG_IBF) == 0)
 184                         acpi_ec_write_data(ec,
 185                                 t->wdata[t->wi++]);
 186                 else
 187                         goto err;
 188         } else if (t->rlen > t->ri) {
 189                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
 190                         t->rdata[t->ri++] = acpi_ec_read_data(ec);
 191                         if (t->rlen == t->ri)
 192                                 t->done = true;
 193                 } else
 194                         goto err;
 195         } else if (t->wlen == t->wi &&
 196                    (status & ACPI_EC_FLAG_IBF) == 0)
 197                 t->done = true;
 198         goto unlock;
 199 err:
 200         /*
 201          * If SCI bit is set, then don't think it's a false IRQ
 202          * otherwise will take a not handled IRQ as a false one.
 203          */
 204         if (in_interrupt() && !(status & ACPI_EC_FLAG_SCI))
 205                 ++t->irq_count;
 206
 207 unlock:
 208         spin_unlock_irqrestore(&ec->lock, flags);
 209 }
 210
 211 static int acpi_ec_sync_query(struct acpi_ec *ec);
 212
 213 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 214 {
 215         if (state & ACPI_EC_FLAG_SCI) {
 216                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 217                         return acpi_ec_sync_query(ec);
 218         }
 219         return 0;
 220 }
 221
 222 static int ec_poll(struct acpi_ec *ec)
 223 {
 224         unsigned long flags;
 225         int repeat = 5; /* number of command restarts */
 226         while (repeat--) {
 227                 unsigned long delay = jiffies +
 228                         msecs_to_jiffies(ec_delay);
 229                 do {
 230                         /* don't sleep with disabled interrupts */
 231                         if (EC_FLAGS_MSI || irqs_disabled()) {
 232                                 udelay(ACPI_EC_MSI_UDELAY);
 233                                 if (ec_transaction_done(ec))
 234                                         return 0;
 235                         } else {
 236                                 if (wait_event_timeout(ec->wait,
 237                                                 ec_transaction_done(ec),
 238                                                 msecs_to_jiffies(1)))
 239                                         return 0;
 240                         }
 241                         advance_transaction(ec, acpi_ec_read_status(ec));
 242                 } while (time_before(jiffies, delay));
 243                 pr_debug("controller reset, restart transaction\n");
 244                 spin_lock_irqsave(&ec->lock, flags);
 245                 start_transaction(ec);
 246                 spin_unlock_irqrestore(&ec->lock, flags);
 247         }
 248         return -ETIME;
 249 }
 250
 251 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 252                                         struct transaction *t)
 253 {
 254         unsigned long tmp;
 255         int ret = 0;
 256         if (EC_FLAGS_MSI)
 257                 udelay(ACPI_EC_MSI_UDELAY);
 258         /* start transaction */
 259         spin_lock_irqsave(&ec->lock, tmp);
 260         /* following two actions should be kept atomic */
 261         ec->curr = t;
 262         start_transaction(ec);
 263         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 264                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 265         spin_unlock_irqrestore(&ec->lock, tmp);
 266         ret = ec_poll(ec);
 267         spin_lock_irqsave(&ec->lock, tmp);
 268         ec->curr = NULL;
 269         spin_unlock_irqrestore(&ec->lock, tmp);
 270         return ret;
 271 }
 272
 273 static int ec_check_ibf0(struct acpi_ec *ec)
 274 {
 275         u8 status = acpi_ec_read_status(ec);
 276         return (status & ACPI_EC_FLAG_IBF) == 0;
 277 }
 278
 279 static int ec_wait_ibf0(struct acpi_ec *ec)
 280 {
 281         unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
 282         /* interrupt wait manually if GPE mode is not active */
 283         while (time_before(jiffies, delay))
 284                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
 285                                         msecs_to_jiffies(1)))
 286                         return 0;
 287         return -ETIME;
 288 }
 289
 290 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 291 {
 292         int status;
 293         u32 glk;
 294         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 295                 return -EINVAL;
 296         if (t->rdata)
 297                 memset(t->rdata, 0, t->rlen);
 298         mutex_lock(&ec->mutex);
 299         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 300                 status = -EINVAL;
 301                 goto unlock;
 302         }
 303         if (ec->global_lock) {
 304                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 305                 if (ACPI_FAILURE(status)) {
 306                         status = -ENODEV;
 307                         goto unlock;
 308                 }
 309         }
 310         if (ec_wait_ibf0(ec)) {
 311                 pr_err("input buffer is not empty, "
 312                                 "aborting transaction\n");
 313                 status = -ETIME;
 314                 goto end;
 315         }
 316         pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",
 317                         t->command, t->wdata ? t->wdata[0] : 0);
 318         /* disable GPE during transaction if storm is detected */
 319         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 320                 /* It has to be disabled, so that it doesn't trigger. */
 321                 acpi_disable_gpe(NULL, ec->gpe);
 322         }
 323
 324         status = acpi_ec_transaction_unlocked(ec, t);
 325
 326         /* check if we received SCI during transaction */
 327         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 328         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 329                 msleep(1);
 330                 /* It is safe to enable the GPE outside of the transaction. */
 331                 acpi_enable_gpe(NULL, ec->gpe);
 332         } else if (t->irq_count > ec_storm_threshold) {
 333                 pr_info("GPE storm detected(%d GPEs), "
 334                         "transactions will use polling mode\n",
 335                         t->irq_count);
 336                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 337         }
 338         pr_debug("transaction end\n");
 339 end:
 340         if (ec->global_lock)
 341                 acpi_release_global_lock(glk);
 342 unlock:
 343         mutex_unlock(&ec->mutex);
 344         return status;
 345 }
 346
 347 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 348 {
 349         u8 d;
 350         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 351                                 .wdata = NULL, .rdata = &d,
 352                                 .wlen = 0, .rlen = 1};
 353
 354         return acpi_ec_transaction(ec, &t);
 355 }
 356
 357 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 358 {
 359         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 360                                 .wdata = NULL, .rdata = NULL,
 361                                 .wlen = 0, .rlen = 0};
 362
 363         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 364                                 acpi_ec_transaction(ec, &t) : 0;
 365 }
 366
 367 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 368 {
 369         int result;
 370         u8 d;
 371         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 372                                 .wdata = &address, .rdata = &d,
 373                                 .wlen = 1, .rlen = 1};
 374
 375         result = acpi_ec_transaction(ec, &t);
 376         *data = d;
 377         return result;
 378 }
 379
 380 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 381 {
 382         u8 wdata[2] = { address, data };
 383         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 384                                 .wdata = wdata, .rdata = NULL,
 385                                 .wlen = 2, .rlen = 0};
 386
 387         return acpi_ec_transaction(ec, &t);
 388 }
 389
 390 /*
 391  * Externally callable EC access functions. For now, assume 1 EC only
 392  */
 393 int ec_burst_enable(void)
 394 {
 395         if (!first_ec)
 396                 return -ENODEV;
 397         return acpi_ec_burst_enable(first_ec);
 398 }
 399
 400 EXPORT_SYMBOL(ec_burst_enable);
 401
 402 int ec_burst_disable(void)
 403 {
 404         if (!first_ec)
 405                 return -ENODEV;
 406         return acpi_ec_burst_disable(first_ec);
 407 }
 408
 409 EXPORT_SYMBOL(ec_burst_disable);
 410
 411 int ec_read(u8 addr, u8 *val)
 412 {
 413         int err;
 414         u8 temp_data;
 415
 416         if (!first_ec)
 417                 return -ENODEV;
 418
 419         err = acpi_ec_read(first_ec, addr, &temp_data);
 420
 421         if (!err) {
 422                 *val = temp_data;
 423                 return 0;
 424         } else
 425                 return err;
 426 }
 427
 428 EXPORT_SYMBOL(ec_read);
 429
 430 int ec_write(u8 addr, u8 val)
 431 {
 432         int err;
 433
 434         if (!first_ec)
 435                 return -ENODEV;
 436
 437         err = acpi_ec_write(first_ec, addr, val);
 438
 439         return err;
 440 }
 441
 442 EXPORT_SYMBOL(ec_write);
 443
 444 int ec_transaction(u8 command,
 445                    const u8 * wdata, unsigned wdata_len,
 446                    u8 * rdata, unsigned rdata_len)
 447 {
 448         struct transaction t = {.command = command,
 449                                 .wdata = wdata, .rdata = rdata,
 450                                 .wlen = wdata_len, .rlen = rdata_len};
 451         if (!first_ec)
 452                 return -ENODEV;
 453
 454         return acpi_ec_transaction(first_ec, &t);
 455 }
 456
 457 EXPORT_SYMBOL(ec_transaction);
 458
 459 /* Get the handle to the EC device */
 460 acpi_handle ec_get_handle(void)
 461 {
 462         if (!first_ec)
 463                 return NULL;
 464         return first_ec->handle;
 465 }
 466
 467 EXPORT_SYMBOL(ec_get_handle);
 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         mutex_unlock(&ec->mutex);
 493 }
 494
 495 void acpi_ec_unblock_transactions_early(void)
 496 {
 497         /*
 498          * Allow transactions to happen again (this function is called from
 499          * atomic context during wakeup, so we don't need to acquire the mutex).
 500          */
 501         if (first_ec)
 502                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 503 }
 504
 505 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 506 {
 507         int result;
 508         u8 d;
 509         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 510                                 .wdata = NULL, .rdata = &d,
 511                                 .wlen = 0, .rlen = 1};
 512         if (!ec || !data)
 513                 return -EINVAL;
 514         /*
 515          * Query the EC to find out which _Qxx method we need to evaluate.
 516          * Note that successful completion of the query causes the ACPI_EC_SCI
 517          * bit to be cleared (and thus clearing the interrupt source).
 518          */
 519         result = acpi_ec_transaction_unlocked(ec, &t);
 520         if (result)
 521                 return result;
 522         if (!d)
 523                 return -ENODATA;
 524         *data = d;
 525         return 0;
 526 }
 527
 528 /* --------------------------------------------------------------------------
 529                                 Event Management
 530    -------------------------------------------------------------------------- */
 531 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 532                               acpi_handle handle, acpi_ec_query_func func,
 533                               void *data)
 534 {
 535         struct acpi_ec_query_handler *handler =
 536             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 537         if (!handler)
 538                 return -ENOMEM;
 539
 540         handler->query_bit = query_bit;
 541         handler->handle = handle;
 542         handler->func = func;
 543         handler->data = data;
 544         mutex_lock(&ec->mutex);
 545         list_add(&handler->node, &ec->list);
 546         mutex_unlock(&ec->mutex);
 547         return 0;
 548 }
 549
 550 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 551
 552 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 553 {
 554         struct acpi_ec_query_handler *handler, *tmp;
 555         mutex_lock(&ec->mutex);
 556         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 557                 if (query_bit == handler->query_bit) {
 558                         list_del(&handler->node);
 559                         kfree(handler);
 560                 }
 561         }
 562         mutex_unlock(&ec->mutex);
 563 }
 564
 565 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 566
 567 static void acpi_ec_run(void *cxt)
 568 {
 569         struct acpi_ec_query_handler *handler = cxt;
 570         if (!handler)
 571                 return;
 572         pr_debug("start query execution\n");
 573         if (handler->func)
 574                 handler->func(handler->data);
 575         else if (handler->handle)
 576                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 577         pr_debug("stop query execution\n");
 578         kfree(handler);
 579 }
 580
 581 static int acpi_ec_sync_query(struct acpi_ec *ec)
 582 {
 583         u8 value = 0;
 584         int status;
 585         struct acpi_ec_query_handler *handler, *copy;
 586         if ((status = acpi_ec_query_unlocked(ec, &value)))
 587                 return status;
 588         list_for_each_entry(handler, &ec->list, node) {
 589                 if (value == handler->query_bit) {
 590                         /* have custom handler for this bit */
 591                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 592                         if (!copy)
 593                                 return -ENOMEM;
 594                         memcpy(copy, handler, sizeof(*copy));
 595                         pr_debug("push query execution (0x%2x) on queue\n",
 596                                 value);
 597                         return acpi_os_execute((copy->func) ?
 598                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 599                                 acpi_ec_run, copy);
 600                 }
 601         }
 602         return 0;
 603 }
 604
 605 static void acpi_ec_gpe_query(void *ec_cxt)
 606 {
 607         struct acpi_ec *ec = ec_cxt;
 608         if (!ec)
 609                 return;
 610         mutex_lock(&ec->mutex);
 611         acpi_ec_sync_query(ec);
 612         mutex_unlock(&ec->mutex);
 613 }
 614
 615 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 616 {
 617         if (state & ACPI_EC_FLAG_SCI) {
 618                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 619                         pr_debug("push gpe query to the queue\n");
 620                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 621                                 acpi_ec_gpe_query, ec);
 622                 }
 623         }
 624         return 0;
 625 }
 626
 627 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 628         u32 gpe_number, void *data)
 629 {
 630         struct acpi_ec *ec = data;
 631         u8 status = acpi_ec_read_status(ec);
 632
 633         pr_debug("~~~> interrupt, status:0x%02x\n", status);
 634
 635         advance_transaction(ec, status);
 636         if (ec_transaction_done(ec) &&
 637             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 638                 wake_up(&ec->wait);
 639                 ec_check_sci(ec, acpi_ec_read_status(ec));
 640         }
 641         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 642 }
 643
 644 /* --------------------------------------------------------------------------
 645                              Address Space Management
 646    -------------------------------------------------------------------------- */
 647
 648 static acpi_status
 649 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 650                       u32 bits, u64 *value64,
 651                       void *handler_context, void *region_context)
 652 {
 653         struct acpi_ec *ec = handler_context;
 654         int result = 0, i, bytes = bits / 8;
 655         u8 *value = (u8 *)value64;
 656
 657         if ((address > 0xFF) || !value || !handler_context)
 658                 return AE_BAD_PARAMETER;
 659
 660         if (function != ACPI_READ && function != ACPI_WRITE)
 661                 return AE_BAD_PARAMETER;
 662
 663         if (EC_FLAGS_MSI || bits > 8)
 664                 acpi_ec_burst_enable(ec);
 665
 666         for (i = 0; i < bytes; ++i, ++address, ++value)
 667                 result = (function == ACPI_READ) ?
 668                         acpi_ec_read(ec, address, value) :
 669                         acpi_ec_write(ec, address, *value);
 670
 671         if (EC_FLAGS_MSI || bits > 8)
 672                 acpi_ec_burst_disable(ec);
 673
 674         switch (result) {
 675         case -EINVAL:
 676                 return AE_BAD_PARAMETER;
 677                 break;
 678         case -ENODEV:
 679                 return AE_NOT_FOUND;
 680                 break;
 681         case -ETIME:
 682                 return AE_TIME;
 683                 break;
 684         default:
 685                 return AE_OK;
 686         }
 687 }
 688
 689 /* --------------------------------------------------------------------------
 690                                Driver Interface
 691    -------------------------------------------------------------------------- */
 692 static acpi_status
 693 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 694
 695 static struct acpi_ec *make_acpi_ec(void)
 696 {
 697         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 698         if (!ec)
 699                 return NULL;
 700         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 701         mutex_init(&ec->mutex);
 702         init_waitqueue_head(&ec->wait);
 703         INIT_LIST_HEAD(&ec->list);
 704         spin_lock_init(&ec->lock);
 705         return ec;
 706 }
 707
 708 static acpi_status
 709 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 710                                void *context, void **return_value)
 711 {
 712         char node_name[5];
 713         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 714         struct acpi_ec *ec = context;
 715         int value = 0;
 716         acpi_status status;
 717
 718         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 719
 720         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 721                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 722         }
 723         return AE_OK;
 724 }
 725
 726 static acpi_status
 727 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 728 {
 729         acpi_status status;
 730         unsigned long long tmp = 0;
 731
 732         struct acpi_ec *ec = context;
 733
 734         /* clear addr values, ec_parse_io_ports depend on it */
 735         ec->command_addr = ec->data_addr = 0;
 736
 737         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 738                                      ec_parse_io_ports, ec);
 739         if (ACPI_FAILURE(status))
 740                 return status;
 741
 742         /* Get GPE bit assignment (EC events). */
 743         /* TODO: Add support for _GPE returning a package */
 744         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 745         if (ACPI_FAILURE(status))
 746                 return status;
 747         ec->gpe = tmp;
 748         /* Use the global lock for all EC transactions? */
 749         tmp = 0;
 750         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 751         ec->global_lock = tmp;
 752         ec->handle = handle;
 753         return AE_CTRL_TERMINATE;
 754 }
 755
 756 static int ec_install_handlers(struct acpi_ec *ec)
 757 {
 758         acpi_status status;
 759         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 760                 return 0;
 761         status = acpi_install_gpe_handler(NULL, ec->gpe,
 762                                   ACPI_GPE_EDGE_TRIGGERED,
 763                                   &acpi_ec_gpe_handler, ec);
 764         if (ACPI_FAILURE(status))
 765                 return -ENODEV;
 766
 767         acpi_enable_gpe(NULL, ec->gpe);
 768         status = acpi_install_address_space_handler(ec->handle,
 769                                                     ACPI_ADR_SPACE_EC,
 770                                                     &acpi_ec_space_handler,
 771                                                     NULL, ec);
 772         if (ACPI_FAILURE(status)) {
 773                 if (status == AE_NOT_FOUND) {
 774                         /*
 775                          * Maybe OS fails in evaluating the _REG object.
 776                          * The AE_NOT_FOUND error will be ignored and OS
 777                          * continue to initialize EC.
 778                          */
 779                         pr_err("Fail in evaluating the _REG object"
 780                                 " of EC device. Broken bios is suspected.\n");
 781                 } else {
 782                         acpi_remove_gpe_handler(NULL, ec->gpe,
 783                                 &acpi_ec_gpe_handler);
 784                         acpi_disable_gpe(NULL, ec->gpe);
 785                         return -ENODEV;
 786                 }
 787         }
 788
 789         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 790         return 0;
 791 }
 792
 793 static void ec_remove_handlers(struct acpi_ec *ec)
 794 {
 795         acpi_disable_gpe(NULL, ec->gpe);
 796         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 797                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 798                 pr_err("failed to remove space handler\n");
 799         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 800                                 &acpi_ec_gpe_handler)))
 801                 pr_err("failed to remove gpe handler\n");
 802         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 803 }
 804
 805 static int acpi_ec_add(struct acpi_device *device)
 806 {
 807         struct acpi_ec *ec = NULL;
 808         int ret;
 809
 810         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 811         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 812
 813         /* Check for boot EC */
 814         if (boot_ec &&
 815             (boot_ec->handle == device->handle ||
 816              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 817                 ec = boot_ec;
 818                 boot_ec = NULL;
 819         } else {
 820                 ec = make_acpi_ec();
 821                 if (!ec)
 822                         return -ENOMEM;
 823         }
 824         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 825                 AE_CTRL_TERMINATE) {
 826                         kfree(ec);
 827                         return -EINVAL;
 828         }
 829
 830         /* Find and register all query methods */
 831         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 832                             acpi_ec_register_query_methods, NULL, ec, NULL);
 833
 834         if (!first_ec)
 835                 first_ec = ec;
 836         device->driver_data = ec;
 837
 838         ret = !!request_region(ec->data_addr, 1, "EC data");
 839         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
 840         ret = !!request_region(ec->command_addr, 1, "EC cmd");
 841         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
 842
 843         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 844                           ec->gpe, ec->command_addr, ec->data_addr);
 845
 846         ret = ec_install_handlers(ec);
 847
 848         /* EC is fully operational, allow queries */
 849         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 850         return ret;
 851 }
 852
 853 static int acpi_ec_remove(struct acpi_device *device)
 854 {
 855         struct acpi_ec *ec;
 856         struct acpi_ec_query_handler *handler, *tmp;
 857
 858         if (!device)
 859                 return -EINVAL;
 860
 861         ec = acpi_driver_data(device);
 862         ec_remove_handlers(ec);
 863         mutex_lock(&ec->mutex);
 864         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 865                 list_del(&handler->node);
 866                 kfree(handler);
 867         }
 868         mutex_unlock(&ec->mutex);
 869         release_region(ec->data_addr, 1);
 870         release_region(ec->command_addr, 1);
 871         device->driver_data = NULL;
 872         if (ec == first_ec)
 873                 first_ec = NULL;
 874         kfree(ec);
 875         return 0;
 876 }
 877
 878 static acpi_status
 879 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 880 {
 881         struct acpi_ec *ec = context;
 882
 883         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 884                 return AE_OK;
 885
 886         /*
 887          * The first address region returned is the data port, and
 888          * the second address region returned is the status/command
 889          * port.
 890          */
 891         if (ec->data_addr == 0)
 892                 ec->data_addr = resource->data.io.minimum;
 893         else if (ec->command_addr == 0)
 894                 ec->command_addr = resource->data.io.minimum;
 895         else
 896                 return AE_CTRL_TERMINATE;
 897
 898         return AE_OK;
 899 }
 900
 901 int __init acpi_boot_ec_enable(void)
 902 {
 903         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 904                 return 0;
 905         if (!ec_install_handlers(boot_ec)) {
 906                 first_ec = boot_ec;
 907                 return 0;
 908         }
 909         return -EFAULT;
 910 }
 911
 912 static const struct acpi_device_id ec_device_ids[] = {
 913         {"PNP0C09", 0},
 914         {"", 0},
 915 };
 916
 917 /* Some BIOS do not survive early DSDT scan, skip it */
 918 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 919 {
 920         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 921         return 0;
 922 }
 923
 924 /* ASUStek often supplies us with broken ECDT, validate it */
 925 static int ec_validate_ecdt(const struct dmi_system_id *id)
 926 {
 927         EC_FLAGS_VALIDATE_ECDT = 1;
 928         return 0;
 929 }
 930
 931 /* MSI EC needs special treatment, enable it */
 932 static int ec_flag_msi(const struct dmi_system_id *id)
 933 {
 934         pr_debug("Detected MSI hardware, enabling workarounds.\n");
 935         EC_FLAGS_MSI = 1;
 936         EC_FLAGS_VALIDATE_ECDT = 1;
 937         return 0;
 938 }
 939
 940 /*
 941  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
 942  * the GPE storm threshold back to 20
 943  */
 944 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
 945 {
 946         pr_debug("Setting the EC GPE storm threshold to 20\n");
 947         ec_storm_threshold  = 20;
 948         return 0;
 949 }
 950
 951 static struct dmi_system_id ec_dmi_table[] __initdata = {
 952         {
 953         ec_skip_dsdt_scan, "Compal JFL92", {
 954         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 955         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 956         {
 957         ec_flag_msi, "MSI hardware", {
 958         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
 959         {
 960         ec_flag_msi, "MSI hardware", {
 961         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
 962         {
 963         ec_flag_msi, "MSI hardware", {
 964         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
 965         {
 966         ec_flag_msi, "MSI hardware", {
 967         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
 968         {
 969         ec_flag_msi, "Quanta hardware", {
 970         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
 971         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
 972         {
 973         ec_flag_msi, "Quanta hardware", {
 974         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
 975         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
 976         {
 977         ec_validate_ecdt, "ASUS hardware", {
 978         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
 979         {
 980         ec_validate_ecdt, "ASUS hardware", {
 981         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
 982         {
 983         ec_enlarge_storm_threshold, "CLEVO hardware", {
 984         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
 985         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
 986         {
 987         ec_skip_dsdt_scan, "HP Folio 13", {
 988         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 989         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
 990         {
 991         ec_validate_ecdt, "ASUS hardware", {
 992         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
 993         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
 994         {},
 995 };
 996
 997 int __init acpi_ec_ecdt_probe(void)
 998 {
 999         acpi_status status;
1000         struct acpi_ec *saved_ec = NULL;
1001         struct acpi_table_ecdt *ecdt_ptr;
1002
1003         boot_ec = make_acpi_ec();
1004         if (!boot_ec)
1005                 return -ENOMEM;
1006         /*
1007          * Generate a boot ec context
1008          */
1009         dmi_check_system(ec_dmi_table);
1010         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1011                                 (struct acpi_table_header **)&ecdt_ptr);
1012         if (ACPI_SUCCESS(status)) {
1013                 pr_info("EC description table is found, configuring boot EC\n");
1014                 boot_ec->command_addr = ecdt_ptr->control.address;
1015                 boot_ec->data_addr = ecdt_ptr->data.address;
1016                 boot_ec->gpe = ecdt_ptr->gpe;
1017                 boot_ec->handle = ACPI_ROOT_OBJECT;
1018                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1019                 /* Don't trust ECDT, which comes from ASUSTek */
1020                 if (!EC_FLAGS_VALIDATE_ECDT)
1021                         goto install;
1022                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1023                 if (!saved_ec)
1024                         return -ENOMEM;
1025         /* fall through */
1026         }
1027
1028         if (EC_FLAGS_SKIP_DSDT_SCAN)
1029                 return -ENODEV;
1030
1031         /* This workaround is needed only on some broken machines,
1032          * which require early EC, but fail to provide ECDT */
1033         pr_debug("Look up EC in DSDT\n");
1034         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1035                                         boot_ec, NULL);
1036         /* Check that acpi_get_devices actually find something */
1037         if (ACPI_FAILURE(status) || !boot_ec->handle)
1038                 goto error;
1039         if (saved_ec) {
1040                 /* try to find good ECDT from ASUSTek */
1041                 if (saved_ec->command_addr != boot_ec->command_addr ||
1042                     saved_ec->data_addr != boot_ec->data_addr ||
1043                     saved_ec->gpe != boot_ec->gpe ||
1044                     saved_ec->handle != boot_ec->handle)
1045                         pr_info("ASUSTek keeps feeding us with broken "
1046                         "ECDT tables, which are very hard to workaround. "
1047                         "Trying to use DSDT EC info instead. Please send "
1048                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1049                 kfree(saved_ec);
1050                 saved_ec = NULL;
1051         } else {
1052                 /* We really need to limit this workaround, the only ASUS,
1053                 * which needs it, has fake EC._INI method, so use it as flag.
1054                 * Keep boot_ec struct as it will be needed soon.
1055                 */
1056                 if (!dmi_name_in_vendors("ASUS") ||
1057                     !acpi_has_method(boot_ec->handle, "_INI"))
1058                         return -ENODEV;
1059         }
1060 install:
1061         if (!ec_install_handlers(boot_ec)) {
1062                 first_ec = boot_ec;
1063                 return 0;
1064         }
1065 error:
1066         kfree(boot_ec);
1067         boot_ec = NULL;
1068         return -ENODEV;
1069 }
1070
1071 static struct acpi_driver acpi_ec_driver = {
1072         .name = "ec",
1073         .class = ACPI_EC_CLASS,
1074         .ids = ec_device_ids,
1075         .ops = {
1076                 .add = acpi_ec_add,
1077                 .remove = acpi_ec_remove,
1078                 },
1079 };
1080
1081 int __init acpi_ec_init(void)
1082 {
1083         int result = 0;
1084
1085         /* Now register the driver for the EC */
1086         result = acpi_bus_register_driver(&acpi_ec_driver);
1087         if (result < 0)
1088                 return -ENODEV;
1089
1090         return result;
1091 }
1092
1093 /* EC driver currently not unloadable */
1094 #if 0
1095 static void __exit acpi_ec_exit(void)
1096 {
1097
1098         acpi_bus_unregister_driver(&acpi_ec_driver);
1099         return;
1100 }
1101 #endif  /* 0 */