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
  74 enum {
  75         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  76         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  77         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
  78                                          * OpReg are installed */
  79         EC_FLAGS_BLOCKED,               /* Transactions are blocked */
  80 };
  81
  82 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
  83 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
  84 module_param(ec_delay, uint, 0644);
  85 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
  86
  87 /*
  88  * If the number of false interrupts per one transaction exceeds
  89  * this threshold, will think there is a GPE storm happened and
  90  * will disable the GPE for normal transaction.
  91  */
  92 static unsigned int ec_storm_threshold  __read_mostly = 8;
  93 module_param(ec_storm_threshold, uint, 0644);
  94 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
  95
  96 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  97 /* External interfaces use first EC only, so remember */
  98 typedef int (*acpi_ec_query_func) (void *data);
  99
 100 struct acpi_ec_query_handler {
 101         struct list_head node;
 102         acpi_ec_query_func func;
 103         acpi_handle handle;
 104         void *data;
 105         u8 query_bit;
 106 };
 107
 108 struct transaction {
 109         const u8 *wdata;
 110         u8 *rdata;
 111         unsigned short irq_count;
 112         u8 command;
 113         u8 wi;
 114         u8 ri;
 115         u8 wlen;
 116         u8 rlen;
 117         bool done;
 118 };
 119
 120 struct acpi_ec *boot_ec, *first_ec;
 121 EXPORT_SYMBOL(first_ec);
 122
 123 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 124 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 125 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 126
 127 /* --------------------------------------------------------------------------
 128                              Transaction Management
 129    -------------------------------------------------------------------------- */
 130
 131 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 132 {
 133         u8 x = inb(ec->command_addr);
 134         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
 135         return x;
 136 }
 137
 138 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 139 {
 140         u8 x = inb(ec->data_addr);
 141         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
 142         return x;
 143 }
 144
 145 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 146 {
 147         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
 148         outb(command, ec->command_addr);
 149 }
 150
 151 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 152 {
 153         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
 154         outb(data, ec->data_addr);
 155 }
 156
 157 static int ec_transaction_done(struct acpi_ec *ec)
 158 {
 159         unsigned long flags;
 160         int ret = 0;
 161         spin_lock_irqsave(&ec->curr_lock, flags);
 162         if (!ec->curr || ec->curr->done)
 163                 ret = 1;
 164         spin_unlock_irqrestore(&ec->curr_lock, flags);
 165         return ret;
 166 }
 167
 168 static void start_transaction(struct acpi_ec *ec)
 169 {
 170         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 171         ec->curr->done = false;
 172         acpi_ec_write_cmd(ec, ec->curr->command);
 173 }
 174
 175 static void advance_transaction(struct acpi_ec *ec, u8 status)
 176 {
 177         unsigned long flags;
 178         spin_lock_irqsave(&ec->curr_lock, flags);
 179         if (!ec->curr)
 180                 goto unlock;
 181         if (ec->curr->wlen > ec->curr->wi) {
 182                 if ((status & ACPI_EC_FLAG_IBF) == 0)
 183                         acpi_ec_write_data(ec,
 184                                 ec->curr->wdata[ec->curr->wi++]);
 185                 else
 186                         goto err;
 187         } else if (ec->curr->rlen > ec->curr->ri) {
 188                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
 189                         ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
 190                         if (ec->curr->rlen == ec->curr->ri)
 191                                 ec->curr->done = true;
 192                 } else
 193                         goto err;
 194         } else if (ec->curr->wlen == ec->curr->wi &&
 195                    (status & ACPI_EC_FLAG_IBF) == 0)
 196                 ec->curr->done = true;
 197         goto unlock;
 198 err:
 199         /* false interrupt, state didn't change */
 200         if (in_interrupt())
 201                 ++ec->curr->irq_count;
 202 unlock:
 203         spin_unlock_irqrestore(&ec->curr_lock, flags);
 204 }
 205
 206 static int acpi_ec_sync_query(struct acpi_ec *ec);
 207
 208 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 209 {
 210         if (state & ACPI_EC_FLAG_SCI) {
 211                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 212                         return acpi_ec_sync_query(ec);
 213         }
 214         return 0;
 215 }
 216
 217 static int ec_poll(struct acpi_ec *ec)
 218 {
 219         unsigned long flags;
 220         int repeat = 5; /* number of command restarts */
 221         while (repeat--) {
 222                 unsigned long delay = jiffies +
 223                         msecs_to_jiffies(ec_delay);
 224                 do {
 225                         /* don't sleep with disabled interrupts */
 226                         if (EC_FLAGS_MSI || irqs_disabled()) {
 227                                 udelay(ACPI_EC_MSI_UDELAY);
 228                                 if (ec_transaction_done(ec))
 229                                         return 0;
 230                         } else {
 231                                 if (wait_event_timeout(ec->wait,
 232                                                 ec_transaction_done(ec),
 233                                                 msecs_to_jiffies(1)))
 234                                         return 0;
 235                         }
 236                         advance_transaction(ec, acpi_ec_read_status(ec));
 237                 } while (time_before(jiffies, delay));
 238                 pr_debug(PREFIX "controller reset, restart transaction\n");
 239                 spin_lock_irqsave(&ec->curr_lock, flags);
 240                 start_transaction(ec);
 241                 spin_unlock_irqrestore(&ec->curr_lock, flags);
 242         }
 243         return -ETIME;
 244 }
 245
 246 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 247                                         struct transaction *t)
 248 {
 249         unsigned long tmp;
 250         int ret = 0;
 251         if (EC_FLAGS_MSI)
 252                 udelay(ACPI_EC_MSI_UDELAY);
 253         /* start transaction */
 254         spin_lock_irqsave(&ec->curr_lock, tmp);
 255         /* following two actions should be kept atomic */
 256         ec->curr = t;
 257         start_transaction(ec);
 258         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 259                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 260         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 261         ret = ec_poll(ec);
 262         spin_lock_irqsave(&ec->curr_lock, tmp);
 263         ec->curr = NULL;
 264         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 265         return ret;
 266 }
 267
 268 static int ec_check_ibf0(struct acpi_ec *ec)
 269 {
 270         u8 status = acpi_ec_read_status(ec);
 271         return (status & ACPI_EC_FLAG_IBF) == 0;
 272 }
 273
 274 static int ec_wait_ibf0(struct acpi_ec *ec)
 275 {
 276         unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
 277         /* interrupt wait manually if GPE mode is not active */
 278         while (time_before(jiffies, delay))
 279                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
 280                                         msecs_to_jiffies(1)))
 281                         return 0;
 282         return -ETIME;
 283 }
 284
 285 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 286 {
 287         int status;
 288         u32 glk;
 289         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 290                 return -EINVAL;
 291         if (t->rdata)
 292                 memset(t->rdata, 0, t->rlen);
 293         mutex_lock(&ec->lock);
 294         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 295                 status = -EINVAL;
 296                 goto unlock;
 297         }
 298         if (ec->global_lock) {
 299                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 300                 if (ACPI_FAILURE(status)) {
 301                         status = -ENODEV;
 302                         goto unlock;
 303                 }
 304         }
 305         if (ec_wait_ibf0(ec)) {
 306                 pr_err(PREFIX "input buffer is not empty, "
 307                                 "aborting transaction\n");
 308                 status = -ETIME;
 309                 goto end;
 310         }
 311         pr_debug(PREFIX "transaction start\n");
 312         /* disable GPE during transaction if storm is detected */
 313         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 314                 /* It has to be disabled, so that it doesn't trigger. */
 315                 acpi_disable_gpe(NULL, ec->gpe);
 316         }
 317
 318         status = acpi_ec_transaction_unlocked(ec, t);
 319
 320         /* check if we received SCI during transaction */
 321         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 322         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 323                 msleep(1);
 324                 /* It is safe to enable the GPE outside of the transaction. */
 325                 acpi_enable_gpe(NULL, ec->gpe);
 326         } else if (t->irq_count > ec_storm_threshold) {
 327                 pr_info(PREFIX "GPE storm detected, "
 328                         "transactions will use polling mode\n");
 329                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 330         }
 331         pr_debug(PREFIX "transaction end\n");
 332 end:
 333         if (ec->global_lock)
 334                 acpi_release_global_lock(glk);
 335 unlock:
 336         mutex_unlock(&ec->lock);
 337         return status;
 338 }
 339
 340 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 341 {
 342         u8 d;
 343         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 344                                 .wdata = NULL, .rdata = &d,
 345                                 .wlen = 0, .rlen = 1};
 346
 347         return acpi_ec_transaction(ec, &t);
 348 }
 349
 350 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 351 {
 352         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 353                                 .wdata = NULL, .rdata = NULL,
 354                                 .wlen = 0, .rlen = 0};
 355
 356         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 357                                 acpi_ec_transaction(ec, &t) : 0;
 358 }
 359
 360 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 361 {
 362         int result;
 363         u8 d;
 364         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 365                                 .wdata = &address, .rdata = &d,
 366                                 .wlen = 1, .rlen = 1};
 367
 368         result = acpi_ec_transaction(ec, &t);
 369         *data = d;
 370         return result;
 371 }
 372
 373 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 374 {
 375         u8 wdata[2] = { address, data };
 376         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 377                                 .wdata = wdata, .rdata = NULL,
 378                                 .wlen = 2, .rlen = 0};
 379
 380         return acpi_ec_transaction(ec, &t);
 381 }
 382
 383 /*
 384  * Externally callable EC access functions. For now, assume 1 EC only
 385  */
 386 int ec_burst_enable(void)
 387 {
 388         if (!first_ec)
 389                 return -ENODEV;
 390         return acpi_ec_burst_enable(first_ec);
 391 }
 392
 393 EXPORT_SYMBOL(ec_burst_enable);
 394
 395 int ec_burst_disable(void)
 396 {
 397         if (!first_ec)
 398                 return -ENODEV;
 399         return acpi_ec_burst_disable(first_ec);
 400 }
 401
 402 EXPORT_SYMBOL(ec_burst_disable);
 403
 404 int ec_read(u8 addr, u8 * val)
 405 {
 406         int err;
 407         u8 temp_data;
 408
 409         if (!first_ec)
 410                 return -ENODEV;
 411
 412         err = acpi_ec_read(first_ec, addr, &temp_data);
 413
 414         if (!err) {
 415                 *val = temp_data;
 416                 return 0;
 417         } else
 418                 return err;
 419 }
 420
 421 EXPORT_SYMBOL(ec_read);
 422
 423 int ec_write(u8 addr, u8 val)
 424 {
 425         int err;
 426
 427         if (!first_ec)
 428                 return -ENODEV;
 429
 430         err = acpi_ec_write(first_ec, addr, val);
 431
 432         return err;
 433 }
 434
 435 EXPORT_SYMBOL(ec_write);
 436
 437 int ec_transaction(u8 command,
 438                    const u8 * wdata, unsigned wdata_len,
 439                    u8 * rdata, unsigned rdata_len)
 440 {
 441         struct transaction t = {.command = command,
 442                                 .wdata = wdata, .rdata = rdata,
 443                                 .wlen = wdata_len, .rlen = rdata_len};
 444         if (!first_ec)
 445                 return -ENODEV;
 446
 447         return acpi_ec_transaction(first_ec, &t);
 448 }
 449
 450 EXPORT_SYMBOL(ec_transaction);
 451
 452 /* Get the handle to the EC device */
 453 acpi_handle ec_get_handle(void)
 454 {
 455         if (!first_ec)
 456                 return NULL;
 457         return first_ec->handle;
 458 }
 459
 460 EXPORT_SYMBOL(ec_get_handle);
 461
 462 void acpi_ec_block_transactions(void)
 463 {
 464         struct acpi_ec *ec = first_ec;
 465
 466         if (!ec)
 467                 return;
 468
 469         mutex_lock(&ec->lock);
 470         /* Prevent transactions from being carried out */
 471         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 472         mutex_unlock(&ec->lock);
 473 }
 474
 475 void acpi_ec_unblock_transactions(void)
 476 {
 477         struct acpi_ec *ec = first_ec;
 478
 479         if (!ec)
 480                 return;
 481
 482         mutex_lock(&ec->lock);
 483         /* Allow transactions to be carried out again */
 484         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 485         mutex_unlock(&ec->lock);
 486 }
 487
 488 void acpi_ec_unblock_transactions_early(void)
 489 {
 490         /*
 491          * Allow transactions to happen again (this function is called from
 492          * atomic context during wakeup, so we don't need to acquire the mutex).
 493          */
 494         if (first_ec)
 495                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 496 }
 497
 498 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 499 {
 500         int result;
 501         u8 d;
 502         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 503                                 .wdata = NULL, .rdata = &d,
 504                                 .wlen = 0, .rlen = 1};
 505         if (!ec || !data)
 506                 return -EINVAL;
 507         /*
 508          * Query the EC to find out which _Qxx method we need to evaluate.
 509          * Note that successful completion of the query causes the ACPI_EC_SCI
 510          * bit to be cleared (and thus clearing the interrupt source).
 511          */
 512         result = acpi_ec_transaction_unlocked(ec, &t);
 513         if (result)
 514                 return result;
 515         if (!d)
 516                 return -ENODATA;
 517         *data = d;
 518         return 0;
 519 }
 520
 521 /* --------------------------------------------------------------------------
 522                                 Event Management
 523    -------------------------------------------------------------------------- */
 524 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 525                               acpi_handle handle, acpi_ec_query_func func,
 526                               void *data)
 527 {
 528         struct acpi_ec_query_handler *handler =
 529             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 530         if (!handler)
 531                 return -ENOMEM;
 532
 533         handler->query_bit = query_bit;
 534         handler->handle = handle;
 535         handler->func = func;
 536         handler->data = data;
 537         mutex_lock(&ec->lock);
 538         list_add(&handler->node, &ec->list);
 539         mutex_unlock(&ec->lock);
 540         return 0;
 541 }
 542
 543 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 544
 545 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 546 {
 547         struct acpi_ec_query_handler *handler, *tmp;
 548         mutex_lock(&ec->lock);
 549         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 550                 if (query_bit == handler->query_bit) {
 551                         list_del(&handler->node);
 552                         kfree(handler);
 553                 }
 554         }
 555         mutex_unlock(&ec->lock);
 556 }
 557
 558 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 559
 560 static void acpi_ec_run(void *cxt)
 561 {
 562         struct acpi_ec_query_handler *handler = cxt;
 563         if (!handler)
 564                 return;
 565         pr_debug(PREFIX "start query execution\n");
 566         if (handler->func)
 567                 handler->func(handler->data);
 568         else if (handler->handle)
 569                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 570         pr_debug(PREFIX "stop query execution\n");
 571         kfree(handler);
 572 }
 573
 574 static int acpi_ec_sync_query(struct acpi_ec *ec)
 575 {
 576         u8 value = 0;
 577         int status;
 578         struct acpi_ec_query_handler *handler, *copy;
 579         if ((status = acpi_ec_query_unlocked(ec, &value)))
 580                 return status;
 581         list_for_each_entry(handler, &ec->list, node) {
 582                 if (value == handler->query_bit) {
 583                         /* have custom handler for this bit */
 584                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 585                         if (!copy)
 586                                 return -ENOMEM;
 587                         memcpy(copy, handler, sizeof(*copy));
 588                         pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
 589                         return acpi_os_execute((copy->func) ?
 590                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 591                                 acpi_ec_run, copy);
 592                 }
 593         }
 594         return 0;
 595 }
 596
 597 static void acpi_ec_gpe_query(void *ec_cxt)
 598 {
 599         struct acpi_ec *ec = ec_cxt;
 600         if (!ec)
 601                 return;
 602         mutex_lock(&ec->lock);
 603         acpi_ec_sync_query(ec);
 604         mutex_unlock(&ec->lock);
 605 }
 606
 607 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 608 {
 609         if (state & ACPI_EC_FLAG_SCI) {
 610                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 611                         pr_debug(PREFIX "push gpe query to the queue\n");
 612                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 613                                 acpi_ec_gpe_query, ec);
 614                 }
 615         }
 616         return 0;
 617 }
 618
 619 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 620         u32 gpe_number, void *data)
 621 {
 622         struct acpi_ec *ec = data;
 623
 624         pr_debug(PREFIX "~~~> interrupt\n");
 625
 626         advance_transaction(ec, acpi_ec_read_status(ec));
 627         if (ec_transaction_done(ec) &&
 628             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 629                 wake_up(&ec->wait);
 630                 ec_check_sci(ec, acpi_ec_read_status(ec));
 631         }
 632         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 633 }
 634
 635 /* --------------------------------------------------------------------------
 636                              Address Space Management
 637    -------------------------------------------------------------------------- */
 638
 639 static acpi_status
 640 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 641                       u32 bits, u64 *value64,
 642                       void *handler_context, void *region_context)
 643 {
 644         struct acpi_ec *ec = handler_context;
 645         int result = 0, i, bytes = bits / 8;
 646         u8 *value = (u8 *)value64;
 647
 648         if ((address > 0xFF) || !value || !handler_context)
 649                 return AE_BAD_PARAMETER;
 650
 651         if (function != ACPI_READ && function != ACPI_WRITE)
 652                 return AE_BAD_PARAMETER;
 653
 654         if (EC_FLAGS_MSI || bits > 8)
 655                 acpi_ec_burst_enable(ec);
 656
 657         for (i = 0; i < bytes; ++i, ++address, ++value)
 658                 result = (function == ACPI_READ) ?
 659                         acpi_ec_read(ec, address, value) :
 660                         acpi_ec_write(ec, address, *value);
 661
 662         if (EC_FLAGS_MSI || bits > 8)
 663                 acpi_ec_burst_disable(ec);
 664
 665         switch (result) {
 666         case -EINVAL:
 667                 return AE_BAD_PARAMETER;
 668                 break;
 669         case -ENODEV:
 670                 return AE_NOT_FOUND;
 671                 break;
 672         case -ETIME:
 673                 return AE_TIME;
 674                 break;
 675         default:
 676                 return AE_OK;
 677         }
 678 }
 679
 680 /* --------------------------------------------------------------------------
 681                                Driver Interface
 682    -------------------------------------------------------------------------- */
 683 static acpi_status
 684 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 685
 686 static struct acpi_ec *make_acpi_ec(void)
 687 {
 688         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 689         if (!ec)
 690                 return NULL;
 691         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 692         mutex_init(&ec->lock);
 693         init_waitqueue_head(&ec->wait);
 694         INIT_LIST_HEAD(&ec->list);
 695         spin_lock_init(&ec->curr_lock);
 696         return ec;
 697 }
 698
 699 static acpi_status
 700 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 701                                void *context, void **return_value)
 702 {
 703         char node_name[5];
 704         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 705         struct acpi_ec *ec = context;
 706         int value = 0;
 707         acpi_status status;
 708
 709         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 710
 711         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 712                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 713         }
 714         return AE_OK;
 715 }
 716
 717 static acpi_status
 718 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 719 {
 720         acpi_status status;
 721         unsigned long long tmp = 0;
 722
 723         struct acpi_ec *ec = context;
 724
 725         /* clear addr values, ec_parse_io_ports depend on it */
 726         ec->command_addr = ec->data_addr = 0;
 727
 728         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 729                                      ec_parse_io_ports, ec);
 730         if (ACPI_FAILURE(status))
 731                 return status;
 732
 733         /* Get GPE bit assignment (EC events). */
 734         /* TODO: Add support for _GPE returning a package */
 735         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 736         if (ACPI_FAILURE(status))
 737                 return status;
 738         ec->gpe = tmp;
 739         /* Use the global lock for all EC transactions? */
 740         tmp = 0;
 741         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 742         ec->global_lock = tmp;
 743         ec->handle = handle;
 744         return AE_CTRL_TERMINATE;
 745 }
 746
 747 static int ec_install_handlers(struct acpi_ec *ec)
 748 {
 749         acpi_status status;
 750         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 751                 return 0;
 752         status = acpi_install_gpe_handler(NULL, ec->gpe,
 753                                   ACPI_GPE_EDGE_TRIGGERED,
 754                                   &acpi_ec_gpe_handler, ec);
 755         if (ACPI_FAILURE(status))
 756                 return -ENODEV;
 757
 758         acpi_enable_gpe(NULL, ec->gpe);
 759         status = acpi_install_address_space_handler(ec->handle,
 760                                                     ACPI_ADR_SPACE_EC,
 761                                                     &acpi_ec_space_handler,
 762                                                     NULL, ec);
 763         if (ACPI_FAILURE(status)) {
 764                 if (status == AE_NOT_FOUND) {
 765                         /*
 766                          * Maybe OS fails in evaluating the _REG object.
 767                          * The AE_NOT_FOUND error will be ignored and OS
 768                          * continue to initialize EC.
 769                          */
 770                         printk(KERN_ERR "Fail in evaluating the _REG object"
 771                                 " of EC device. Broken bios is suspected.\n");
 772                 } else {
 773                         acpi_remove_gpe_handler(NULL, ec->gpe,
 774                                 &acpi_ec_gpe_handler);
 775                         acpi_disable_gpe(NULL, ec->gpe);
 776                         return -ENODEV;
 777                 }
 778         }
 779
 780         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 781         return 0;
 782 }
 783
 784 static void ec_remove_handlers(struct acpi_ec *ec)
 785 {
 786         acpi_disable_gpe(NULL, ec->gpe);
 787         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 788                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 789                 pr_err(PREFIX "failed to remove space handler\n");
 790         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 791                                 &acpi_ec_gpe_handler)))
 792                 pr_err(PREFIX "failed to remove gpe handler\n");
 793         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 794 }
 795
 796 static int acpi_ec_add(struct acpi_device *device)
 797 {
 798         struct acpi_ec *ec = NULL;
 799         int ret;
 800
 801         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 802         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 803
 804         /* Check for boot EC */
 805         if (boot_ec &&
 806             (boot_ec->handle == device->handle ||
 807              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 808                 ec = boot_ec;
 809                 boot_ec = NULL;
 810         } else {
 811                 ec = make_acpi_ec();
 812                 if (!ec)
 813                         return -ENOMEM;
 814         }
 815         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 816                 AE_CTRL_TERMINATE) {
 817                         kfree(ec);
 818                         return -EINVAL;
 819         }
 820
 821         /* Find and register all query methods */
 822         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 823                             acpi_ec_register_query_methods, NULL, ec, NULL);
 824
 825         if (!first_ec)
 826                 first_ec = ec;
 827         device->driver_data = ec;
 828
 829         ret = !!request_region(ec->data_addr, 1, "EC data");
 830         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
 831         ret = !!request_region(ec->command_addr, 1, "EC cmd");
 832         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
 833
 834         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 835                           ec->gpe, ec->command_addr, ec->data_addr);
 836
 837         ret = ec_install_handlers(ec);
 838
 839         /* EC is fully operational, allow queries */
 840         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 841         return ret;
 842 }
 843
 844 static int acpi_ec_remove(struct acpi_device *device, int type)
 845 {
 846         struct acpi_ec *ec;
 847         struct acpi_ec_query_handler *handler, *tmp;
 848
 849         if (!device)
 850                 return -EINVAL;
 851
 852         ec = acpi_driver_data(device);
 853         ec_remove_handlers(ec);
 854         mutex_lock(&ec->lock);
 855         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 856                 list_del(&handler->node);
 857                 kfree(handler);
 858         }
 859         mutex_unlock(&ec->lock);
 860         release_region(ec->data_addr, 1);
 861         release_region(ec->command_addr, 1);
 862         device->driver_data = NULL;
 863         if (ec == first_ec)
 864                 first_ec = NULL;
 865         kfree(ec);
 866         return 0;
 867 }
 868
 869 static acpi_status
 870 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 871 {
 872         struct acpi_ec *ec = context;
 873
 874         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 875                 return AE_OK;
 876
 877         /*
 878          * The first address region returned is the data port, and
 879          * the second address region returned is the status/command
 880          * port.
 881          */
 882         if (ec->data_addr == 0)
 883                 ec->data_addr = resource->data.io.minimum;
 884         else if (ec->command_addr == 0)
 885                 ec->command_addr = resource->data.io.minimum;
 886         else
 887                 return AE_CTRL_TERMINATE;
 888
 889         return AE_OK;
 890 }
 891
 892 int __init acpi_boot_ec_enable(void)
 893 {
 894         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 895                 return 0;
 896         if (!ec_install_handlers(boot_ec)) {
 897                 first_ec = boot_ec;
 898                 return 0;
 899         }
 900         return -EFAULT;
 901 }
 902
 903 static const struct acpi_device_id ec_device_ids[] = {
 904         {"PNP0C09", 0},
 905         {"", 0},
 906 };
 907
 908 /* Some BIOS do not survive early DSDT scan, skip it */
 909 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 910 {
 911         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 912         return 0;
 913 }
 914
 915 /* ASUStek often supplies us with broken ECDT, validate it */
 916 static int ec_validate_ecdt(const struct dmi_system_id *id)
 917 {
 918         EC_FLAGS_VALIDATE_ECDT = 1;
 919         return 0;
 920 }
 921
 922 /* MSI EC needs special treatment, enable it */
 923 static int ec_flag_msi(const struct dmi_system_id *id)
 924 {
 925         printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
 926         EC_FLAGS_MSI = 1;
 927         EC_FLAGS_VALIDATE_ECDT = 1;
 928         return 0;
 929 }
 930
 931 /*
 932  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
 933  * the GPE storm threshold back to 20
 934  */
 935 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
 936 {
 937         pr_debug("Setting the EC GPE storm threshold to 20\n");
 938         ec_storm_threshold  = 20;
 939         return 0;
 940 }
 941
 942 static struct dmi_system_id __initdata ec_dmi_table[] = {
 943         {
 944         ec_skip_dsdt_scan, "Compal JFL92", {
 945         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 946         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 947         {
 948         ec_flag_msi, "MSI hardware", {
 949         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
 950         {
 951         ec_flag_msi, "MSI hardware", {
 952         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
 953         {
 954         ec_flag_msi, "MSI hardware", {
 955         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
 956         {
 957         ec_flag_msi, "MSI hardware", {
 958         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
 959         {
 960         ec_flag_msi, "Quanta hardware", {
 961         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
 962         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
 963         {
 964         ec_flag_msi, "Quanta hardware", {
 965         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
 966         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
 967         {
 968         ec_validate_ecdt, "ASUS hardware", {
 969         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
 970         {
 971         ec_validate_ecdt, "ASUS hardware", {
 972         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
 973         {
 974         ec_enlarge_storm_threshold, "CLEVO hardware", {
 975         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
 976         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
 977         {
 978         ec_skip_dsdt_scan, "HP Folio 13", {
 979         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 980         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
 981         {
 982         ec_validate_ecdt, "ASUS hardware", {
 983         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
 984         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
 985         {},
 986 };
 987
 988 int __init acpi_ec_ecdt_probe(void)
 989 {
 990         acpi_status status;
 991         struct acpi_ec *saved_ec = NULL;
 992         struct acpi_table_ecdt *ecdt_ptr;
 993
 994         boot_ec = make_acpi_ec();
 995         if (!boot_ec)
 996                 return -ENOMEM;
 997         /*
 998          * Generate a boot ec context
 999          */
1000         dmi_check_system(ec_dmi_table);
1001         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1002                                 (struct acpi_table_header **)&ecdt_ptr);
1003         if (ACPI_SUCCESS(status)) {
1004                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
1005                 boot_ec->command_addr = ecdt_ptr->control.address;
1006                 boot_ec->data_addr = ecdt_ptr->data.address;
1007                 boot_ec->gpe = ecdt_ptr->gpe;
1008                 boot_ec->handle = ACPI_ROOT_OBJECT;
1009                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1010                 /* Don't trust ECDT, which comes from ASUSTek */
1011                 if (!EC_FLAGS_VALIDATE_ECDT)
1012                         goto install;
1013                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1014                 if (!saved_ec)
1015                         return -ENOMEM;
1016         /* fall through */
1017         }
1018
1019         if (EC_FLAGS_SKIP_DSDT_SCAN)
1020                 return -ENODEV;
1021
1022         /* This workaround is needed only on some broken machines,
1023          * which require early EC, but fail to provide ECDT */
1024         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1025         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1026                                         boot_ec, NULL);
1027         /* Check that acpi_get_devices actually find something */
1028         if (ACPI_FAILURE(status) || !boot_ec->handle)
1029                 goto error;
1030         if (saved_ec) {
1031                 /* try to find good ECDT from ASUSTek */
1032                 if (saved_ec->command_addr != boot_ec->command_addr ||
1033                     saved_ec->data_addr != boot_ec->data_addr ||
1034                     saved_ec->gpe != boot_ec->gpe ||
1035                     saved_ec->handle != boot_ec->handle)
1036                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1037                         "ECDT tables, which are very hard to workaround. "
1038                         "Trying to use DSDT EC info instead. Please send "
1039                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1040                 kfree(saved_ec);
1041                 saved_ec = NULL;
1042         } else {
1043                 /* We really need to limit this workaround, the only ASUS,
1044                 * which needs it, has fake EC._INI method, so use it as flag.
1045                 * Keep boot_ec struct as it will be needed soon.
1046                 */
1047                 acpi_handle dummy;
1048                 if (!dmi_name_in_vendors("ASUS") ||
1049                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1050                                                         &dummy)))
1051                         return -ENODEV;
1052         }
1053 install:
1054         if (!ec_install_handlers(boot_ec)) {
1055                 first_ec = boot_ec;
1056                 return 0;
1057         }
1058 error:
1059         kfree(boot_ec);
1060         boot_ec = NULL;
1061         return -ENODEV;
1062 }
1063
1064 static struct acpi_driver acpi_ec_driver = {
1065         .name = "ec",
1066         .class = ACPI_EC_CLASS,
1067         .ids = ec_device_ids,
1068         .ops = {
1069                 .add = acpi_ec_add,
1070                 .remove = acpi_ec_remove,
1071                 },
1072 };
1073
1074 int __init acpi_ec_init(void)
1075 {
1076         int result = 0;
1077
1078         /* Now register the driver for the EC */
1079         result = acpi_bus_register_driver(&acpi_ec_driver);
1080         if (result < 0)
1081                 return -ENODEV;
1082
1083         return result;
1084 }
1085
1086 /* EC driver currently not unloadable */
1087 #if 0
1088 static void __exit acpi_ec_exit(void)
1089 {
1090
1091         acpi_bus_unregister_driver(&acpi_ec_driver);
1092         return;
1093 }
1094 #endif  /* 0 */