drivers/acpi/ec.c

   1 /*
   2  *  ec.c - ACPI Embedded Controller Driver (v2.2)
   3  *
   4  *  Copyright (C) 2001-2014 Intel Corporation
   5  *    Author: 2014       Lv Zheng <lv.zheng@intel.com>
   6  *            2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
   7  *            2006       Denis Sadykov <denis.m.sadykov@intel.com>
   8  *            2004       Luming Yu <luming.yu@intel.com>
   9  *            2001, 2002 Andy Grover <andrew.grover@intel.com>
  10  *            2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
  11  *  Copyright (C) 2008      Alexey Starikovskiy <astarikovskiy@suse.de>
  12  *
  13  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  14  *
  15  *  This program is free software; you can redistribute it and/or modify
  16  *  it under the terms of the GNU General Public License as published by
  17  *  the Free Software Foundation; either version 2 of the License, or (at
  18  *  your option) any later version.
  19  *
  20  *  This program is distributed in the hope that it will be useful, but
  21  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  23  *  General Public License for more details.
  24  *
  25  *  You should have received a copy of the GNU General Public License along
  26  *  with this program; if not, write to the Free Software Foundation, Inc.,
  27  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  28  *
  29  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  30  */
  31
  32 /* Uncomment next line to get verbose printout */
  33 /* #define DEBUG */
  34 #define pr_fmt(fmt) "ACPI : EC: " fmt
  35
  36 #include <linux/kernel.h>
  37 #include <linux/module.h>
  38 #include <linux/init.h>
  39 #include <linux/types.h>
  40 #include <linux/delay.h>
  41 #include <linux/interrupt.h>
  42 #include <linux/list.h>
  43 #include <linux/spinlock.h>
  44 #include <linux/slab.h>
  45 #include <linux/acpi.h>
  46 #include <linux/dmi.h>
  47 #include <asm/io.h>
  48
  49 #include "internal.h"
  50
  51 #define ACPI_EC_CLASS                   "embedded_controller"
  52 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  53 #define ACPI_EC_FILE_INFO               "info"
  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_CMD        0x08    /* Input buffer contains a command */
  59 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  60 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  61
  62 /* EC commands */
  63 enum ec_command {
  64         ACPI_EC_COMMAND_READ = 0x80,
  65         ACPI_EC_COMMAND_WRITE = 0x81,
  66         ACPI_EC_BURST_ENABLE = 0x82,
  67         ACPI_EC_BURST_DISABLE = 0x83,
  68         ACPI_EC_COMMAND_QUERY = 0x84,
  69 };
  70
  71 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  72 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  73 #define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
  74 #define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
  75                                          * when trying to clear the EC */
  76
  77 enum {
  78         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  79         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  80         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
  81                                          * OpReg are installed */
  82         EC_FLAGS_BLOCKED,               /* Transactions are blocked */
  83 };
  84
  85 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
  86 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
  87
  88 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
  89 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
  90 module_param(ec_delay, uint, 0644);
  91 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
  92
  93 /*
  94  * If the number of false interrupts per one transaction exceeds
  95  * this threshold, will think there is a GPE storm happened and
  96  * will disable the GPE for normal transaction.
  97  */
  98 static unsigned int ec_storm_threshold  __read_mostly = 8;
  99 module_param(ec_storm_threshold, uint, 0644);
 100 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
 101
 102 struct acpi_ec_query_handler {
 103         struct list_head node;
 104         acpi_ec_query_func func;
 105         acpi_handle handle;
 106         void *data;
 107         u8 query_bit;
 108 };
 109
 110 struct transaction {
 111         const u8 *wdata;
 112         u8 *rdata;
 113         unsigned short irq_count;
 114         u8 command;
 115         u8 wi;
 116         u8 ri;
 117         u8 wlen;
 118         u8 rlen;
 119         u8 flags;
 120 };
 121
 122 struct acpi_ec *boot_ec, *first_ec;
 123 EXPORT_SYMBOL(first_ec);
 124
 125 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 126 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 127 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 128 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
 129
 130 /* --------------------------------------------------------------------------
 131                              Transaction Management
 132    -------------------------------------------------------------------------- */
 133
 134 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 135 {
 136         u8 x = inb(ec->command_addr);
 137         pr_debug("EC_SC(R) = 0x%2.2x "
 138                  "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d\n",
 139                  x,
 140                  !!(x & ACPI_EC_FLAG_SCI),
 141                  !!(x & ACPI_EC_FLAG_BURST),
 142                  !!(x & ACPI_EC_FLAG_CMD),
 143                  !!(x & ACPI_EC_FLAG_IBF),
 144                  !!(x & ACPI_EC_FLAG_OBF));
 145         return x;
 146 }
 147
 148 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 149 {
 150         u8 x = inb(ec->data_addr);
 151         pr_debug("EC_DATA(R) = 0x%2.2x\n", x);
 152         return x;
 153 }
 154
 155 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 156 {
 157         pr_debug("EC_SC(W) = 0x%2.2x\n", command);
 158         outb(command, ec->command_addr);
 159 }
 160
 161 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 162 {
 163         pr_debug("EC_DATA(W) = 0x%2.2x\n", data);
 164         outb(data, ec->data_addr);
 165 }
 166
 167 static int ec_transaction_completed(struct acpi_ec *ec)
 168 {
 169         unsigned long flags;
 170         int ret = 0;
 171         spin_lock_irqsave(&ec->lock, flags);
 172         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 173                 ret = 1;
 174         spin_unlock_irqrestore(&ec->lock, flags);
 175         return ret;
 176 }
 177
 178 static bool advance_transaction(struct acpi_ec *ec)
 179 {
 180         struct transaction *t;
 181         u8 status;
 182         bool wakeup = false;
 183
 184         pr_debug("===== %s =====\n", in_interrupt() ? "IRQ" : "TASK");
 185         status = acpi_ec_read_status(ec);
 186         t = ec->curr;
 187         if (!t)
 188                 goto err;
 189         if (t->flags & ACPI_EC_COMMAND_POLL) {
 190                 if (t->wlen > t->wi) {
 191                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 192                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 193                         else
 194                                 goto err;
 195                 } else if (t->rlen > t->ri) {
 196                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 197                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 198                                 if (t->rlen == t->ri) {
 199                                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 200                                         wakeup = true;
 201                                 }
 202                         } else
 203                                 goto err;
 204                 } else if (t->wlen == t->wi &&
 205                            (status & ACPI_EC_FLAG_IBF) == 0) {
 206                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 207                         wakeup = true;
 208                 }
 209                 return wakeup;
 210         } else {
 211                 if ((status & ACPI_EC_FLAG_IBF) == 0) {
 212                         acpi_ec_write_cmd(ec, t->command);
 213                         t->flags |= ACPI_EC_COMMAND_POLL;
 214                 } else
 215                         goto err;
 216                 return wakeup;
 217         }
 218 err:
 219         /*
 220          * If SCI bit is set, then don't think it's a false IRQ
 221          * otherwise will take a not handled IRQ as a false one.
 222          */
 223         if (!(status & ACPI_EC_FLAG_SCI)) {
 224                 if (in_interrupt() && t)
 225                         ++t->irq_count;
 226         }
 227         return wakeup;
 228 }
 229
 230 static void start_transaction(struct acpi_ec *ec)
 231 {
 232         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 233         ec->curr->flags = 0;
 234         (void)advance_transaction(ec);
 235 }
 236
 237 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
 238
 239 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 240 {
 241         if (state & ACPI_EC_FLAG_SCI) {
 242                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 243                         return acpi_ec_sync_query(ec, NULL);
 244         }
 245         return 0;
 246 }
 247
 248 static int ec_poll(struct acpi_ec *ec)
 249 {
 250         unsigned long flags;
 251         int repeat = 5; /* number of command restarts */
 252         while (repeat--) {
 253                 unsigned long delay = jiffies +
 254                         msecs_to_jiffies(ec_delay);
 255                 do {
 256                         /* don't sleep with disabled interrupts */
 257                         if (EC_FLAGS_MSI || irqs_disabled()) {
 258                                 udelay(ACPI_EC_MSI_UDELAY);
 259                                 if (ec_transaction_completed(ec))
 260                                         return 0;
 261                         } else {
 262                                 if (wait_event_timeout(ec->wait,
 263                                                 ec_transaction_completed(ec),
 264                                                 msecs_to_jiffies(1)))
 265                                         return 0;
 266                         }
 267                         spin_lock_irqsave(&ec->lock, flags);
 268                         (void)advance_transaction(ec);
 269                         spin_unlock_irqrestore(&ec->lock, flags);
 270                 } while (time_before(jiffies, delay));
 271                 pr_debug("controller reset, restart transaction\n");
 272                 spin_lock_irqsave(&ec->lock, flags);
 273                 start_transaction(ec);
 274                 spin_unlock_irqrestore(&ec->lock, flags);
 275         }
 276         return -ETIME;
 277 }
 278
 279 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 280                                         struct transaction *t)
 281 {
 282         unsigned long tmp;
 283         int ret = 0;
 284         if (EC_FLAGS_MSI)
 285                 udelay(ACPI_EC_MSI_UDELAY);
 286         /* start transaction */
 287         spin_lock_irqsave(&ec->lock, tmp);
 288         /* following two actions should be kept atomic */
 289         ec->curr = t;
 290         start_transaction(ec);
 291         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 292                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 293         spin_unlock_irqrestore(&ec->lock, tmp);
 294         ret = ec_poll(ec);
 295         spin_lock_irqsave(&ec->lock, tmp);
 296         ec->curr = NULL;
 297         spin_unlock_irqrestore(&ec->lock, tmp);
 298         return ret;
 299 }
 300
 301 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 302 {
 303         int status;
 304         u32 glk;
 305         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 306                 return -EINVAL;
 307         if (t->rdata)
 308                 memset(t->rdata, 0, t->rlen);
 309         mutex_lock(&ec->mutex);
 310         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 311                 status = -EINVAL;
 312                 goto unlock;
 313         }
 314         if (ec->global_lock) {
 315                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 316                 if (ACPI_FAILURE(status)) {
 317                         status = -ENODEV;
 318                         goto unlock;
 319                 }
 320         }
 321         pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",
 322                         t->command, t->wdata ? t->wdata[0] : 0);
 323         /* disable GPE during transaction if storm is detected */
 324         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 325                 /* It has to be disabled, so that it doesn't trigger. */
 326                 acpi_disable_gpe(NULL, ec->gpe);
 327         }
 328
 329         status = acpi_ec_transaction_unlocked(ec, t);
 330
 331         /* check if we received SCI during transaction */
 332         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 333         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 334                 msleep(1);
 335                 /* It is safe to enable the GPE outside of the transaction. */
 336                 acpi_enable_gpe(NULL, ec->gpe);
 337         } else if (t->irq_count > ec_storm_threshold) {
 338                 pr_info("GPE storm detected(%d GPEs), "
 339                         "transactions will use polling mode\n",
 340                         t->irq_count);
 341                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 342         }
 343         pr_debug("transaction end\n");
 344         if (ec->global_lock)
 345                 acpi_release_global_lock(glk);
 346 unlock:
 347         mutex_unlock(&ec->mutex);
 348         return status;
 349 }
 350
 351 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 352 {
 353         u8 d;
 354         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 355                                 .wdata = NULL, .rdata = &d,
 356                                 .wlen = 0, .rlen = 1};
 357
 358         return acpi_ec_transaction(ec, &t);
 359 }
 360
 361 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 362 {
 363         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 364                                 .wdata = NULL, .rdata = NULL,
 365                                 .wlen = 0, .rlen = 0};
 366
 367         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 368                                 acpi_ec_transaction(ec, &t) : 0;
 369 }
 370
 371 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 372 {
 373         int result;
 374         u8 d;
 375         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 376                                 .wdata = &address, .rdata = &d,
 377                                 .wlen = 1, .rlen = 1};
 378
 379         result = acpi_ec_transaction(ec, &t);
 380         *data = d;
 381         return result;
 382 }
 383
 384 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 385 {
 386         u8 wdata[2] = { address, data };
 387         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 388                                 .wdata = wdata, .rdata = NULL,
 389                                 .wlen = 2, .rlen = 0};
 390
 391         return acpi_ec_transaction(ec, &t);
 392 }
 393
 394 int ec_read(u8 addr, u8 *val)
 395 {
 396         int err;
 397         u8 temp_data;
 398
 399         if (!first_ec)
 400                 return -ENODEV;
 401
 402         err = acpi_ec_read(first_ec, addr, &temp_data);
 403
 404         if (!err) {
 405                 *val = temp_data;
 406                 return 0;
 407         } else
 408                 return err;
 409 }
 410
 411 EXPORT_SYMBOL(ec_read);
 412
 413 int ec_write(u8 addr, u8 val)
 414 {
 415         int err;
 416
 417         if (!first_ec)
 418                 return -ENODEV;
 419
 420         err = acpi_ec_write(first_ec, addr, val);
 421
 422         return err;
 423 }
 424
 425 EXPORT_SYMBOL(ec_write);
 426
 427 int ec_transaction(u8 command,
 428                    const u8 * wdata, unsigned wdata_len,
 429                    u8 * rdata, unsigned rdata_len)
 430 {
 431         struct transaction t = {.command = command,
 432                                 .wdata = wdata, .rdata = rdata,
 433                                 .wlen = wdata_len, .rlen = rdata_len};
 434         if (!first_ec)
 435                 return -ENODEV;
 436
 437         return acpi_ec_transaction(first_ec, &t);
 438 }
 439
 440 EXPORT_SYMBOL(ec_transaction);
 441
 442 /* Get the handle to the EC device */
 443 acpi_handle ec_get_handle(void)
 444 {
 445         if (!first_ec)
 446                 return NULL;
 447         return first_ec->handle;
 448 }
 449
 450 EXPORT_SYMBOL(ec_get_handle);
 451
 452 /*
 453  * Process _Q events that might have accumulated in the EC.
 454  * Run with locked ec mutex.
 455  */
 456 static void acpi_ec_clear(struct acpi_ec *ec)
 457 {
 458         int i, status;
 459         u8 value = 0;
 460
 461         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 462                 status = acpi_ec_sync_query(ec, &value);
 463                 if (status || !value)
 464                         break;
 465         }
 466
 467         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 468                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 469         else
 470                 pr_info("%d stale EC events cleared\n", i);
 471 }
 472
 473 void acpi_ec_block_transactions(void)
 474 {
 475         struct acpi_ec *ec = first_ec;
 476
 477         if (!ec)
 478                 return;
 479
 480         mutex_lock(&ec->mutex);
 481         /* Prevent transactions from being carried out */
 482         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 483         mutex_unlock(&ec->mutex);
 484 }
 485
 486 void acpi_ec_unblock_transactions(void)
 487 {
 488         struct acpi_ec *ec = first_ec;
 489
 490         if (!ec)
 491                 return;
 492
 493         mutex_lock(&ec->mutex);
 494         /* Allow transactions to be carried out again */
 495         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 496
 497         if (EC_FLAGS_CLEAR_ON_RESUME)
 498                 acpi_ec_clear(ec);
 499
 500         mutex_unlock(&ec->mutex);
 501 }
 502
 503 void acpi_ec_unblock_transactions_early(void)
 504 {
 505         /*
 506          * Allow transactions to happen again (this function is called from
 507          * atomic context during wakeup, so we don't need to acquire the mutex).
 508          */
 509         if (first_ec)
 510                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 511 }
 512
 513 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 514 {
 515         int result;
 516         u8 d;
 517         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 518                                 .wdata = NULL, .rdata = &d,
 519                                 .wlen = 0, .rlen = 1};
 520         if (!ec || !data)
 521                 return -EINVAL;
 522         /*
 523          * Query the EC to find out which _Qxx method we need to evaluate.
 524          * Note that successful completion of the query causes the ACPI_EC_SCI
 525          * bit to be cleared (and thus clearing the interrupt source).
 526          */
 527         result = acpi_ec_transaction_unlocked(ec, &t);
 528         if (result)
 529                 return result;
 530         if (!d)
 531                 return -ENODATA;
 532         *data = d;
 533         return 0;
 534 }
 535
 536 /* --------------------------------------------------------------------------
 537                                 Event Management
 538    -------------------------------------------------------------------------- */
 539 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 540                               acpi_handle handle, acpi_ec_query_func func,
 541                               void *data)
 542 {
 543         struct acpi_ec_query_handler *handler =
 544             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 545         if (!handler)
 546                 return -ENOMEM;
 547
 548         handler->query_bit = query_bit;
 549         handler->handle = handle;
 550         handler->func = func;
 551         handler->data = data;
 552         mutex_lock(&ec->mutex);
 553         list_add(&handler->node, &ec->list);
 554         mutex_unlock(&ec->mutex);
 555         return 0;
 556 }
 557
 558 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 559
 560 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 561 {
 562         struct acpi_ec_query_handler *handler, *tmp;
 563         mutex_lock(&ec->mutex);
 564         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 565                 if (query_bit == handler->query_bit) {
 566                         list_del(&handler->node);
 567                         kfree(handler);
 568                 }
 569         }
 570         mutex_unlock(&ec->mutex);
 571 }
 572
 573 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 574
 575 static void acpi_ec_run(void *cxt)
 576 {
 577         struct acpi_ec_query_handler *handler = cxt;
 578         if (!handler)
 579                 return;
 580         pr_debug("start query execution\n");
 581         if (handler->func)
 582                 handler->func(handler->data);
 583         else if (handler->handle)
 584                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 585         pr_debug("stop query execution\n");
 586         kfree(handler);
 587 }
 588
 589 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
 590 {
 591         u8 value = 0;
 592         int status;
 593         struct acpi_ec_query_handler *handler, *copy;
 594
 595         status = acpi_ec_query_unlocked(ec, &value);
 596         if (data)
 597                 *data = value;
 598         if (status)
 599                 return status;
 600
 601         list_for_each_entry(handler, &ec->list, node) {
 602                 if (value == handler->query_bit) {
 603                         /* have custom handler for this bit */
 604                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 605                         if (!copy)
 606                                 return -ENOMEM;
 607                         memcpy(copy, handler, sizeof(*copy));
 608                         pr_debug("push query execution (0x%2x) on queue\n",
 609                                 value);
 610                         return acpi_os_execute((copy->func) ?
 611                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 612                                 acpi_ec_run, copy);
 613                 }
 614         }
 615         return 0;
 616 }
 617
 618 static void acpi_ec_gpe_query(void *ec_cxt)
 619 {
 620         struct acpi_ec *ec = ec_cxt;
 621         if (!ec)
 622                 return;
 623         mutex_lock(&ec->mutex);
 624         acpi_ec_sync_query(ec, NULL);
 625         mutex_unlock(&ec->mutex);
 626 }
 627
 628 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 629 {
 630         if (state & ACPI_EC_FLAG_SCI) {
 631                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 632                         pr_debug("push gpe query to the queue\n");
 633                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 634                                 acpi_ec_gpe_query, ec);
 635                 }
 636         }
 637         return 0;
 638 }
 639
 640 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 641         u32 gpe_number, void *data)
 642 {
 643         unsigned long flags;
 644         struct acpi_ec *ec = data;
 645
 646         spin_lock_irqsave(&ec->lock, flags);
 647         if (advance_transaction(ec))
 648                 wake_up(&ec->wait);
 649         spin_unlock_irqrestore(&ec->lock, flags);
 650         ec_check_sci(ec, acpi_ec_read_status(ec));
 651         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 652 }
 653
 654 /* --------------------------------------------------------------------------
 655                              Address Space Management
 656    -------------------------------------------------------------------------- */
 657
 658 static acpi_status
 659 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 660                       u32 bits, u64 *value64,
 661                       void *handler_context, void *region_context)
 662 {
 663         struct acpi_ec *ec = handler_context;
 664         int result = 0, i, bytes = bits / 8;
 665         u8 *value = (u8 *)value64;
 666
 667         if ((address > 0xFF) || !value || !handler_context)
 668                 return AE_BAD_PARAMETER;
 669
 670         if (function != ACPI_READ && function != ACPI_WRITE)
 671                 return AE_BAD_PARAMETER;
 672
 673         if (EC_FLAGS_MSI || bits > 8)
 674                 acpi_ec_burst_enable(ec);
 675
 676         for (i = 0; i < bytes; ++i, ++address, ++value)
 677                 result = (function == ACPI_READ) ?
 678                         acpi_ec_read(ec, address, value) :
 679                         acpi_ec_write(ec, address, *value);
 680
 681         if (EC_FLAGS_MSI || bits > 8)
 682                 acpi_ec_burst_disable(ec);
 683
 684         switch (result) {
 685         case -EINVAL:
 686                 return AE_BAD_PARAMETER;
 687                 break;
 688         case -ENODEV:
 689                 return AE_NOT_FOUND;
 690                 break;
 691         case -ETIME:
 692                 return AE_TIME;
 693                 break;
 694         default:
 695                 return AE_OK;
 696         }
 697 }
 698
 699 /* --------------------------------------------------------------------------
 700                                Driver Interface
 701    -------------------------------------------------------------------------- */
 702 static acpi_status
 703 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 704
 705 static struct acpi_ec *make_acpi_ec(void)
 706 {
 707         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 708         if (!ec)
 709                 return NULL;
 710         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 711         mutex_init(&ec->mutex);
 712         init_waitqueue_head(&ec->wait);
 713         INIT_LIST_HEAD(&ec->list);
 714         spin_lock_init(&ec->lock);
 715         return ec;
 716 }
 717
 718 static acpi_status
 719 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 720                                void *context, void **return_value)
 721 {
 722         char node_name[5];
 723         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 724         struct acpi_ec *ec = context;
 725         int value = 0;
 726         acpi_status status;
 727
 728         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 729
 730         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 731                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 732         }
 733         return AE_OK;
 734 }
 735
 736 static acpi_status
 737 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 738 {
 739         acpi_status status;
 740         unsigned long long tmp = 0;
 741
 742         struct acpi_ec *ec = context;
 743
 744         /* clear addr values, ec_parse_io_ports depend on it */
 745         ec->command_addr = ec->data_addr = 0;
 746
 747         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 748                                      ec_parse_io_ports, ec);
 749         if (ACPI_FAILURE(status))
 750                 return status;
 751
 752         /* Get GPE bit assignment (EC events). */
 753         /* TODO: Add support for _GPE returning a package */
 754         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 755         if (ACPI_FAILURE(status))
 756                 return status;
 757         ec->gpe = tmp;
 758         /* Use the global lock for all EC transactions? */
 759         tmp = 0;
 760         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 761         ec->global_lock = tmp;
 762         ec->handle = handle;
 763         return AE_CTRL_TERMINATE;
 764 }
 765
 766 static int ec_install_handlers(struct acpi_ec *ec)
 767 {
 768         acpi_status status;
 769         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 770                 return 0;
 771         status = acpi_install_gpe_handler(NULL, ec->gpe,
 772                                   ACPI_GPE_EDGE_TRIGGERED,
 773                                   &acpi_ec_gpe_handler, ec);
 774         if (ACPI_FAILURE(status))
 775                 return -ENODEV;
 776
 777         acpi_enable_gpe(NULL, ec->gpe);
 778         status = acpi_install_address_space_handler(ec->handle,
 779                                                     ACPI_ADR_SPACE_EC,
 780                                                     &acpi_ec_space_handler,
 781                                                     NULL, ec);
 782         if (ACPI_FAILURE(status)) {
 783                 if (status == AE_NOT_FOUND) {
 784                         /*
 785                          * Maybe OS fails in evaluating the _REG object.
 786                          * The AE_NOT_FOUND error will be ignored and OS
 787                          * continue to initialize EC.
 788                          */
 789                         pr_err("Fail in evaluating the _REG object"
 790                                 " of EC device. Broken bios is suspected.\n");
 791                 } else {
 792                         acpi_disable_gpe(NULL, ec->gpe);
 793                         acpi_remove_gpe_handler(NULL, ec->gpe,
 794                                 &acpi_ec_gpe_handler);
 795                         return -ENODEV;
 796                 }
 797         }
 798
 799         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 800         return 0;
 801 }
 802
 803 static void ec_remove_handlers(struct acpi_ec *ec)
 804 {
 805         acpi_disable_gpe(NULL, ec->gpe);
 806         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 807                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 808                 pr_err("failed to remove space handler\n");
 809         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 810                                 &acpi_ec_gpe_handler)))
 811                 pr_err("failed to remove gpe handler\n");
 812         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 813 }
 814
 815 static int acpi_ec_add(struct acpi_device *device)
 816 {
 817         struct acpi_ec *ec = NULL;
 818         int ret;
 819
 820         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 821         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 822
 823         /* Check for boot EC */
 824         if (boot_ec &&
 825             (boot_ec->handle == device->handle ||
 826              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 827                 ec = boot_ec;
 828                 boot_ec = NULL;
 829         } else {
 830                 ec = make_acpi_ec();
 831                 if (!ec)
 832                         return -ENOMEM;
 833         }
 834         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 835                 AE_CTRL_TERMINATE) {
 836                         kfree(ec);
 837                         return -EINVAL;
 838         }
 839
 840         /* Find and register all query methods */
 841         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 842                             acpi_ec_register_query_methods, NULL, ec, NULL);
 843
 844         if (!first_ec)
 845                 first_ec = ec;
 846         device->driver_data = ec;
 847
 848         ret = !!request_region(ec->data_addr, 1, "EC data");
 849         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
 850         ret = !!request_region(ec->command_addr, 1, "EC cmd");
 851         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
 852
 853         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 854                           ec->gpe, ec->command_addr, ec->data_addr);
 855
 856         ret = ec_install_handlers(ec);
 857
 858         /* EC is fully operational, allow queries */
 859         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 860
 861         /* Clear stale _Q events if hardware might require that */
 862         if (EC_FLAGS_CLEAR_ON_RESUME) {
 863                 mutex_lock(&ec->mutex);
 864                 acpi_ec_clear(ec);
 865                 mutex_unlock(&ec->mutex);
 866         }
 867         return ret;
 868 }
 869
 870 static int acpi_ec_remove(struct acpi_device *device)
 871 {
 872         struct acpi_ec *ec;
 873         struct acpi_ec_query_handler *handler, *tmp;
 874
 875         if (!device)
 876                 return -EINVAL;
 877
 878         ec = acpi_driver_data(device);
 879         ec_remove_handlers(ec);
 880         mutex_lock(&ec->mutex);
 881         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 882                 list_del(&handler->node);
 883                 kfree(handler);
 884         }
 885         mutex_unlock(&ec->mutex);
 886         release_region(ec->data_addr, 1);
 887         release_region(ec->command_addr, 1);
 888         device->driver_data = NULL;
 889         if (ec == first_ec)
 890                 first_ec = NULL;
 891         kfree(ec);
 892         return 0;
 893 }
 894
 895 static acpi_status
 896 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 897 {
 898         struct acpi_ec *ec = context;
 899
 900         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 901                 return AE_OK;
 902
 903         /*
 904          * The first address region returned is the data port, and
 905          * the second address region returned is the status/command
 906          * port.
 907          */
 908         if (ec->data_addr == 0)
 909                 ec->data_addr = resource->data.io.minimum;
 910         else if (ec->command_addr == 0)
 911                 ec->command_addr = resource->data.io.minimum;
 912         else
 913                 return AE_CTRL_TERMINATE;
 914
 915         return AE_OK;
 916 }
 917
 918 int __init acpi_boot_ec_enable(void)
 919 {
 920         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 921                 return 0;
 922         if (!ec_install_handlers(boot_ec)) {
 923                 first_ec = boot_ec;
 924                 return 0;
 925         }
 926         return -EFAULT;
 927 }
 928
 929 static const struct acpi_device_id ec_device_ids[] = {
 930         {"PNP0C09", 0},
 931         {"", 0},
 932 };
 933
 934 /* Some BIOS do not survive early DSDT scan, skip it */
 935 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 936 {
 937         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 938         return 0;
 939 }
 940
 941 /* ASUStek often supplies us with broken ECDT, validate it */
 942 static int ec_validate_ecdt(const struct dmi_system_id *id)
 943 {
 944         EC_FLAGS_VALIDATE_ECDT = 1;
 945         return 0;
 946 }
 947
 948 /* MSI EC needs special treatment, enable it */
 949 static int ec_flag_msi(const struct dmi_system_id *id)
 950 {
 951         pr_debug("Detected MSI hardware, enabling workarounds.\n");
 952         EC_FLAGS_MSI = 1;
 953         EC_FLAGS_VALIDATE_ECDT = 1;
 954         return 0;
 955 }
 956
 957 /*
 958  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
 959  * the GPE storm threshold back to 20
 960  */
 961 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
 962 {
 963         pr_debug("Setting the EC GPE storm threshold to 20\n");
 964         ec_storm_threshold  = 20;
 965         return 0;
 966 }
 967
 968 /*
 969  * On some hardware it is necessary to clear events accumulated by the EC during
 970  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
 971  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
 972  *
 973  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
 974  *
 975  * Ideally, the EC should also be instructed NOT to accumulate events during
 976  * sleep (which Windows seems to do somehow), but the interface to control this
 977  * behaviour is not known at this time.
 978  *
 979  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
 980  * however it is very likely that other Samsung models are affected.
 981  *
 982  * On systems which don't accumulate _Q events during sleep, this extra check
 983  * should be harmless.
 984  */
 985 static int ec_clear_on_resume(const struct dmi_system_id *id)
 986 {
 987         pr_debug("Detected system needing EC poll on resume.\n");
 988         EC_FLAGS_CLEAR_ON_RESUME = 1;
 989         return 0;
 990 }
 991
 992 static struct dmi_system_id ec_dmi_table[] __initdata = {
 993         {
 994         ec_skip_dsdt_scan, "Compal JFL92", {
 995         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 996         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 997         {
 998         ec_flag_msi, "MSI hardware", {
 999         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1000         {
1001         ec_flag_msi, "MSI hardware", {
1002         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1003         {
1004         ec_flag_msi, "MSI hardware", {
1005         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1006         {
1007         ec_flag_msi, "MSI hardware", {
1008         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1009         {
1010         ec_flag_msi, "Quanta hardware", {
1011         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1012         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1013         {
1014         ec_flag_msi, "Quanta hardware", {
1015         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1016         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1017         {
1018         ec_validate_ecdt, "ASUS hardware", {
1019         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1020         {
1021         ec_validate_ecdt, "ASUS hardware", {
1022         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1023         {
1024         ec_enlarge_storm_threshold, "CLEVO hardware", {
1025         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1026         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1027         {
1028         ec_skip_dsdt_scan, "HP Folio 13", {
1029         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1030         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1031         {
1032         ec_validate_ecdt, "ASUS hardware", {
1033         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1034         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1035         {
1036         ec_clear_on_resume, "Samsung hardware", {
1037         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1038         {},
1039 };
1040
1041 int __init acpi_ec_ecdt_probe(void)
1042 {
1043         acpi_status status;
1044         struct acpi_ec *saved_ec = NULL;
1045         struct acpi_table_ecdt *ecdt_ptr;
1046
1047         boot_ec = make_acpi_ec();
1048         if (!boot_ec)
1049                 return -ENOMEM;
1050         /*
1051          * Generate a boot ec context
1052          */
1053         dmi_check_system(ec_dmi_table);
1054         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1055                                 (struct acpi_table_header **)&ecdt_ptr);
1056         if (ACPI_SUCCESS(status)) {
1057                 pr_info("EC description table is found, configuring boot EC\n");
1058                 boot_ec->command_addr = ecdt_ptr->control.address;
1059                 boot_ec->data_addr = ecdt_ptr->data.address;
1060                 boot_ec->gpe = ecdt_ptr->gpe;
1061                 boot_ec->handle = ACPI_ROOT_OBJECT;
1062                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1063                 /* Don't trust ECDT, which comes from ASUSTek */
1064                 if (!EC_FLAGS_VALIDATE_ECDT)
1065                         goto install;
1066                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1067                 if (!saved_ec)
1068                         return -ENOMEM;
1069         /* fall through */
1070         }
1071
1072         if (EC_FLAGS_SKIP_DSDT_SCAN) {
1073                 kfree(saved_ec);
1074                 return -ENODEV;
1075         }
1076
1077         /* This workaround is needed only on some broken machines,
1078          * which require early EC, but fail to provide ECDT */
1079         pr_debug("Look up EC in DSDT\n");
1080         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1081                                         boot_ec, NULL);
1082         /* Check that acpi_get_devices actually find something */
1083         if (ACPI_FAILURE(status) || !boot_ec->handle)
1084                 goto error;
1085         if (saved_ec) {
1086                 /* try to find good ECDT from ASUSTek */
1087                 if (saved_ec->command_addr != boot_ec->command_addr ||
1088                     saved_ec->data_addr != boot_ec->data_addr ||
1089                     saved_ec->gpe != boot_ec->gpe ||
1090                     saved_ec->handle != boot_ec->handle)
1091                         pr_info("ASUSTek keeps feeding us with broken "
1092                         "ECDT tables, which are very hard to workaround. "
1093                         "Trying to use DSDT EC info instead. Please send "
1094                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1095                 kfree(saved_ec);
1096                 saved_ec = NULL;
1097         } else {
1098                 /* We really need to limit this workaround, the only ASUS,
1099                 * which needs it, has fake EC._INI method, so use it as flag.
1100                 * Keep boot_ec struct as it will be needed soon.
1101                 */
1102                 if (!dmi_name_in_vendors("ASUS") ||
1103                     !acpi_has_method(boot_ec->handle, "_INI"))
1104                         return -ENODEV;
1105         }
1106 install:
1107         if (!ec_install_handlers(boot_ec)) {
1108                 first_ec = boot_ec;
1109                 return 0;
1110         }
1111 error:
1112         kfree(boot_ec);
1113         kfree(saved_ec);
1114         boot_ec = NULL;
1115         return -ENODEV;
1116 }
1117
1118 static struct acpi_driver acpi_ec_driver = {
1119         .name = "ec",
1120         .class = ACPI_EC_CLASS,
1121         .ids = ec_device_ids,
1122         .ops = {
1123                 .add = acpi_ec_add,
1124                 .remove = acpi_ec_remove,
1125                 },
1126 };
1127
1128 int __init acpi_ec_init(void)
1129 {
1130         int result = 0;
1131
1132         /* Now register the driver for the EC */
1133         result = acpi_bus_register_driver(&acpi_ec_driver);
1134         if (result < 0)
1135                 return -ENODEV;
1136
1137         return result;
1138 }
1139
1140 /* EC driver currently not unloadable */
1141 #if 0
1142 static void __exit acpi_ec_exit(void)
1143 {
1144
1145         acpi_bus_unregister_driver(&acpi_ec_driver);
1146         return;
1147 }
1148 #endif  /* 0 */