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 <[email protected]>
   6  *            2006, 2007 Alexey Starikovskiy <[email protected]>
   7  *            2006       Denis Sadykov <[email protected]>
   8  *            2004       Luming Yu <[email protected]>
   9  *            2001, 2002 Andy Grover <[email protected]>
  10  *            2001, 2002 Paul Diefenbaugh <[email protected]>
  11  *  Copyright (C) 2008      Alexey Starikovskiy <[email protected]>
  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                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 201                                                 pr_debug("hardware QR_EC completion\n");
 202                                         wakeup = true;
 203                                 }
 204                         } else
 205                                 goto err;
 206                 } else if (t->wlen == t->wi &&
 207                            (status & ACPI_EC_FLAG_IBF) == 0) {
 208                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 209                         wakeup = true;
 210                 }
 211                 return wakeup;
 212         } else {
 213                 /*
 214                  * There is firmware refusing to respond QR_EC when SCI_EVT
 215                  * is not set, for which case, we complete the QR_EC
 216                  * without issuing it to the firmware.
 217                  * https://bugzilla.kernel.org/show_bug.cgi?id=86211
 218                  */
 219                 if (!(status & ACPI_EC_FLAG_SCI) &&
 220                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 221                         t->flags |= ACPI_EC_COMMAND_POLL;
 222                         t->rdata[t->ri++] = 0x00;
 223                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 224                         pr_debug("software QR_EC completion\n");
 225                         wakeup = true;
 226                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 227                         acpi_ec_write_cmd(ec, t->command);
 228                         t->flags |= ACPI_EC_COMMAND_POLL;
 229                 } else
 230                         goto err;
 231                 return wakeup;
 232         }
 233 err:
 234         /*
 235          * If SCI bit is set, then don't think it's a false IRQ
 236          * otherwise will take a not handled IRQ as a false one.
 237          */
 238         if (!(status & ACPI_EC_FLAG_SCI)) {
 239                 if (in_interrupt() && t)
 240                         ++t->irq_count;
 241         }
 242         return wakeup;
 243 }
 244
 245 static void start_transaction(struct acpi_ec *ec)
 246 {
 247         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 248         ec->curr->flags = 0;
 249         (void)advance_transaction(ec);
 250 }
 251
 252 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
 253
 254 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 255 {
 256         if (state & ACPI_EC_FLAG_SCI) {
 257                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 258                         return acpi_ec_sync_query(ec, NULL);
 259         }
 260         return 0;
 261 }
 262
 263 static int ec_poll(struct acpi_ec *ec)
 264 {
 265         unsigned long flags;
 266         int repeat = 5; /* number of command restarts */
 267         while (repeat--) {
 268                 unsigned long delay = jiffies +
 269                         msecs_to_jiffies(ec_delay);
 270                 do {
 271                         /* don't sleep with disabled interrupts */
 272                         if (EC_FLAGS_MSI || irqs_disabled()) {
 273                                 udelay(ACPI_EC_MSI_UDELAY);
 274                                 if (ec_transaction_completed(ec))
 275                                         return 0;
 276                         } else {
 277                                 if (wait_event_timeout(ec->wait,
 278                                                 ec_transaction_completed(ec),
 279                                                 msecs_to_jiffies(1)))
 280                                         return 0;
 281                         }
 282                         spin_lock_irqsave(&ec->lock, flags);
 283                         (void)advance_transaction(ec);
 284                         spin_unlock_irqrestore(&ec->lock, flags);
 285                 } while (time_before(jiffies, delay));
 286                 pr_debug("controller reset, restart transaction\n");
 287                 spin_lock_irqsave(&ec->lock, flags);
 288                 start_transaction(ec);
 289                 spin_unlock_irqrestore(&ec->lock, flags);
 290         }
 291         return -ETIME;
 292 }
 293
 294 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 295                                         struct transaction *t)
 296 {
 297         unsigned long tmp;
 298         int ret = 0;
 299         if (EC_FLAGS_MSI)
 300                 udelay(ACPI_EC_MSI_UDELAY);
 301         /* start transaction */
 302         spin_lock_irqsave(&ec->lock, tmp);
 303         /* following two actions should be kept atomic */
 304         ec->curr = t;
 305         start_transaction(ec);
 306         spin_unlock_irqrestore(&ec->lock, tmp);
 307         ret = ec_poll(ec);
 308         spin_lock_irqsave(&ec->lock, tmp);
 309         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 310                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 311         ec->curr = NULL;
 312         spin_unlock_irqrestore(&ec->lock, tmp);
 313         return ret;
 314 }
 315
 316 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 317 {
 318         int status;
 319         u32 glk;
 320         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 321                 return -EINVAL;
 322         if (t->rdata)
 323                 memset(t->rdata, 0, t->rlen);
 324         mutex_lock(&ec->mutex);
 325         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 326                 status = -EINVAL;
 327                 goto unlock;
 328         }
 329         if (ec->global_lock) {
 330                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 331                 if (ACPI_FAILURE(status)) {
 332                         status = -ENODEV;
 333                         goto unlock;
 334                 }
 335         }
 336         pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",
 337                         t->command, t->wdata ? t->wdata[0] : 0);
 338         /* disable GPE during transaction if storm is detected */
 339         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 340                 /* It has to be disabled, so that it doesn't trigger. */
 341                 acpi_disable_gpe(NULL, ec->gpe);
 342         }
 343
 344         status = acpi_ec_transaction_unlocked(ec, t);
 345
 346         /* check if we received SCI during transaction */
 347         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 348         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 349                 msleep(1);
 350                 /* It is safe to enable the GPE outside of the transaction. */
 351                 acpi_enable_gpe(NULL, ec->gpe);
 352         } else if (t->irq_count > ec_storm_threshold) {
 353                 pr_info("GPE storm detected(%d GPEs), "
 354                         "transactions will use polling mode\n",
 355                         t->irq_count);
 356                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 357         }
 358         pr_debug("transaction end\n");
 359         if (ec->global_lock)
 360                 acpi_release_global_lock(glk);
 361 unlock:
 362         mutex_unlock(&ec->mutex);
 363         return status;
 364 }
 365
 366 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 367 {
 368         u8 d;
 369         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 370                                 .wdata = NULL, .rdata = &d,
 371                                 .wlen = 0, .rlen = 1};
 372
 373         return acpi_ec_transaction(ec, &t);
 374 }
 375
 376 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 377 {
 378         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 379                                 .wdata = NULL, .rdata = NULL,
 380                                 .wlen = 0, .rlen = 0};
 381
 382         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 383                                 acpi_ec_transaction(ec, &t) : 0;
 384 }
 385
 386 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 387 {
 388         int result;
 389         u8 d;
 390         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 391                                 .wdata = &address, .rdata = &d,
 392                                 .wlen = 1, .rlen = 1};
 393
 394         result = acpi_ec_transaction(ec, &t);
 395         *data = d;
 396         return result;
 397 }
 398
 399 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 400 {
 401         u8 wdata[2] = { address, data };
 402         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 403                                 .wdata = wdata, .rdata = NULL,
 404                                 .wlen = 2, .rlen = 0};
 405
 406         return acpi_ec_transaction(ec, &t);
 407 }
 408
 409 int ec_read(u8 addr, u8 *val)
 410 {
 411         int err;
 412         u8 temp_data;
 413
 414         if (!first_ec)
 415                 return -ENODEV;
 416
 417         err = acpi_ec_read(first_ec, addr, &temp_data);
 418
 419         if (!err) {
 420                 *val = temp_data;
 421                 return 0;
 422         } else
 423                 return err;
 424 }
 425
 426 EXPORT_SYMBOL(ec_read);
 427
 428 int ec_write(u8 addr, u8 val)
 429 {
 430         int err;
 431
 432         if (!first_ec)
 433                 return -ENODEV;
 434
 435         err = acpi_ec_write(first_ec, addr, val);
 436
 437         return err;
 438 }
 439
 440 EXPORT_SYMBOL(ec_write);
 441
 442 int ec_transaction(u8 command,
 443                    const u8 * wdata, unsigned wdata_len,
 444                    u8 * rdata, unsigned rdata_len)
 445 {
 446         struct transaction t = {.command = command,
 447                                 .wdata = wdata, .rdata = rdata,
 448                                 .wlen = wdata_len, .rlen = rdata_len};
 449         if (!first_ec)
 450                 return -ENODEV;
 451
 452         return acpi_ec_transaction(first_ec, &t);
 453 }
 454
 455 EXPORT_SYMBOL(ec_transaction);
 456
 457 /* Get the handle to the EC device */
 458 acpi_handle ec_get_handle(void)
 459 {
 460         if (!first_ec)
 461                 return NULL;
 462         return first_ec->handle;
 463 }
 464
 465 EXPORT_SYMBOL(ec_get_handle);
 466
 467 /*
 468  * Process _Q events that might have accumulated in the EC.
 469  * Run with locked ec mutex.
 470  */
 471 static void acpi_ec_clear(struct acpi_ec *ec)
 472 {
 473         int i, status;
 474         u8 value = 0;
 475
 476         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 477                 status = acpi_ec_sync_query(ec, &value);
 478                 if (status || !value)
 479                         break;
 480         }
 481
 482         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 483                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 484         else
 485                 pr_info("%d stale EC events cleared\n", i);
 486 }
 487
 488 void acpi_ec_block_transactions(void)
 489 {
 490         struct acpi_ec *ec = first_ec;
 491
 492         if (!ec)
 493                 return;
 494
 495         mutex_lock(&ec->mutex);
 496         /* Prevent transactions from being carried out */
 497         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 498         mutex_unlock(&ec->mutex);
 499 }
 500
 501 void acpi_ec_unblock_transactions(void)
 502 {
 503         struct acpi_ec *ec = first_ec;
 504
 505         if (!ec)
 506                 return;
 507
 508         mutex_lock(&ec->mutex);
 509         /* Allow transactions to be carried out again */
 510         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 511
 512         if (EC_FLAGS_CLEAR_ON_RESUME)
 513                 acpi_ec_clear(ec);
 514
 515         mutex_unlock(&ec->mutex);
 516 }
 517
 518 void acpi_ec_unblock_transactions_early(void)
 519 {
 520         /*
 521          * Allow transactions to happen again (this function is called from
 522          * atomic context during wakeup, so we don't need to acquire the mutex).
 523          */
 524         if (first_ec)
 525                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 526 }
 527
 528 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 529 {
 530         int result;
 531         u8 d;
 532         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 533                                 .wdata = NULL, .rdata = &d,
 534                                 .wlen = 0, .rlen = 1};
 535         if (!ec || !data)
 536                 return -EINVAL;
 537         /*
 538          * Query the EC to find out which _Qxx method we need to evaluate.
 539          * Note that successful completion of the query causes the ACPI_EC_SCI
 540          * bit to be cleared (and thus clearing the interrupt source).
 541          */
 542         result = acpi_ec_transaction_unlocked(ec, &t);
 543         if (result)
 544                 return result;
 545         if (!d)
 546                 return -ENODATA;
 547         *data = d;
 548         return 0;
 549 }
 550
 551 /* --------------------------------------------------------------------------
 552                                 Event Management
 553    -------------------------------------------------------------------------- */
 554 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 555                               acpi_handle handle, acpi_ec_query_func func,
 556                               void *data)
 557 {
 558         struct acpi_ec_query_handler *handler =
 559             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 560         if (!handler)
 561                 return -ENOMEM;
 562
 563         handler->query_bit = query_bit;
 564         handler->handle = handle;
 565         handler->func = func;
 566         handler->data = data;
 567         mutex_lock(&ec->mutex);
 568         list_add(&handler->node, &ec->list);
 569         mutex_unlock(&ec->mutex);
 570         return 0;
 571 }
 572
 573 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 574
 575 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 576 {
 577         struct acpi_ec_query_handler *handler, *tmp;
 578         mutex_lock(&ec->mutex);
 579         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 580                 if (query_bit == handler->query_bit) {
 581                         list_del(&handler->node);
 582                         kfree(handler);
 583                 }
 584         }
 585         mutex_unlock(&ec->mutex);
 586 }
 587
 588 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 589
 590 static void acpi_ec_run(void *cxt)
 591 {
 592         struct acpi_ec_query_handler *handler = cxt;
 593         if (!handler)
 594                 return;
 595         pr_debug("start query execution\n");
 596         if (handler->func)
 597                 handler->func(handler->data);
 598         else if (handler->handle)
 599                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 600         pr_debug("stop query execution\n");
 601         kfree(handler);
 602 }
 603
 604 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
 605 {
 606         u8 value = 0;
 607         int status;
 608         struct acpi_ec_query_handler *handler, *copy;
 609
 610         status = acpi_ec_query_unlocked(ec, &value);
 611         if (data)
 612                 *data = value;
 613         if (status)
 614                 return status;
 615
 616         list_for_each_entry(handler, &ec->list, node) {
 617                 if (value == handler->query_bit) {
 618                         /* have custom handler for this bit */
 619                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 620                         if (!copy)
 621                                 return -ENOMEM;
 622                         memcpy(copy, handler, sizeof(*copy));
 623                         pr_debug("push query execution (0x%2x) on queue\n",
 624                                 value);
 625                         return acpi_os_execute((copy->func) ?
 626                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 627                                 acpi_ec_run, copy);
 628                 }
 629         }
 630         return 0;
 631 }
 632
 633 static void acpi_ec_gpe_query(void *ec_cxt)
 634 {
 635         struct acpi_ec *ec = ec_cxt;
 636         if (!ec)
 637                 return;
 638         mutex_lock(&ec->mutex);
 639         acpi_ec_sync_query(ec, NULL);
 640         mutex_unlock(&ec->mutex);
 641 }
 642
 643 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 644 {
 645         if (state & ACPI_EC_FLAG_SCI) {
 646                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 647                         pr_debug("push gpe query to the queue\n");
 648                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 649                                 acpi_ec_gpe_query, ec);
 650                 }
 651         }
 652         return 0;
 653 }
 654
 655 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 656         u32 gpe_number, void *data)
 657 {
 658         unsigned long flags;
 659         struct acpi_ec *ec = data;
 660
 661         spin_lock_irqsave(&ec->lock, flags);
 662         if (advance_transaction(ec))
 663                 wake_up(&ec->wait);
 664         spin_unlock_irqrestore(&ec->lock, flags);
 665         ec_check_sci(ec, acpi_ec_read_status(ec));
 666         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 667 }
 668
 669 /* --------------------------------------------------------------------------
 670                              Address Space Management
 671    -------------------------------------------------------------------------- */
 672
 673 static acpi_status
 674 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 675                       u32 bits, u64 *value64,
 676                       void *handler_context, void *region_context)
 677 {
 678         struct acpi_ec *ec = handler_context;
 679         int result = 0, i, bytes = bits / 8;
 680         u8 *value = (u8 *)value64;
 681
 682         if ((address > 0xFF) || !value || !handler_context)
 683                 return AE_BAD_PARAMETER;
 684
 685         if (function != ACPI_READ && function != ACPI_WRITE)
 686                 return AE_BAD_PARAMETER;
 687
 688         if (EC_FLAGS_MSI || bits > 8)
 689                 acpi_ec_burst_enable(ec);
 690
 691         for (i = 0; i < bytes; ++i, ++address, ++value)
 692                 result = (function == ACPI_READ) ?
 693                         acpi_ec_read(ec, address, value) :
 694                         acpi_ec_write(ec, address, *value);
 695
 696         if (EC_FLAGS_MSI || bits > 8)
 697                 acpi_ec_burst_disable(ec);
 698
 699         switch (result) {
 700         case -EINVAL:
 701                 return AE_BAD_PARAMETER;
 702                 break;
 703         case -ENODEV:
 704                 return AE_NOT_FOUND;
 705                 break;
 706         case -ETIME:
 707                 return AE_TIME;
 708                 break;
 709         default:
 710                 return AE_OK;
 711         }
 712 }
 713
 714 /* --------------------------------------------------------------------------
 715                                Driver Interface
 716    -------------------------------------------------------------------------- */
 717 static acpi_status
 718 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 719
 720 static struct acpi_ec *make_acpi_ec(void)
 721 {
 722         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 723         if (!ec)
 724                 return NULL;
 725         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 726         mutex_init(&ec->mutex);
 727         init_waitqueue_head(&ec->wait);
 728         INIT_LIST_HEAD(&ec->list);
 729         spin_lock_init(&ec->lock);
 730         return ec;
 731 }
 732
 733 static acpi_status
 734 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 735                                void *context, void **return_value)
 736 {
 737         char node_name[5];
 738         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 739         struct acpi_ec *ec = context;
 740         int value = 0;
 741         acpi_status status;
 742
 743         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 744
 745         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 746                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 747         }
 748         return AE_OK;
 749 }
 750
 751 static acpi_status
 752 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 753 {
 754         acpi_status status;
 755         unsigned long long tmp = 0;
 756
 757         struct acpi_ec *ec = context;
 758
 759         /* clear addr values, ec_parse_io_ports depend on it */
 760         ec->command_addr = ec->data_addr = 0;
 761
 762         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 763                                      ec_parse_io_ports, ec);
 764         if (ACPI_FAILURE(status))
 765                 return status;
 766
 767         /* Get GPE bit assignment (EC events). */
 768         /* TODO: Add support for _GPE returning a package */
 769         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 770         if (ACPI_FAILURE(status))
 771                 return status;
 772         ec->gpe = tmp;
 773         /* Use the global lock for all EC transactions? */
 774         tmp = 0;
 775         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 776         ec->global_lock = tmp;
 777         ec->handle = handle;
 778         return AE_CTRL_TERMINATE;
 779 }
 780
 781 static int ec_install_handlers(struct acpi_ec *ec)
 782 {
 783         acpi_status status;
 784         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 785                 return 0;
 786         status = acpi_install_gpe_handler(NULL, ec->gpe,
 787                                   ACPI_GPE_EDGE_TRIGGERED,
 788                                   &acpi_ec_gpe_handler, ec);
 789         if (ACPI_FAILURE(status))
 790                 return -ENODEV;
 791
 792         acpi_enable_gpe(NULL, ec->gpe);
 793         status = acpi_install_address_space_handler(ec->handle,
 794                                                     ACPI_ADR_SPACE_EC,
 795                                                     &acpi_ec_space_handler,
 796                                                     NULL, ec);
 797         if (ACPI_FAILURE(status)) {
 798                 if (status == AE_NOT_FOUND) {
 799                         /*
 800                          * Maybe OS fails in evaluating the _REG object.
 801                          * The AE_NOT_FOUND error will be ignored and OS
 802                          * continue to initialize EC.
 803                          */
 804                         pr_err("Fail in evaluating the _REG object"
 805                                 " of EC device. Broken bios is suspected.\n");
 806                 } else {
 807                         acpi_disable_gpe(NULL, ec->gpe);
 808                         acpi_remove_gpe_handler(NULL, ec->gpe,
 809                                 &acpi_ec_gpe_handler);
 810                         return -ENODEV;
 811                 }
 812         }
 813
 814         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 815         return 0;
 816 }
 817
 818 static void ec_remove_handlers(struct acpi_ec *ec)
 819 {
 820         acpi_disable_gpe(NULL, ec->gpe);
 821         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 822                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 823                 pr_err("failed to remove space handler\n");
 824         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 825                                 &acpi_ec_gpe_handler)))
 826                 pr_err("failed to remove gpe handler\n");
 827         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 828 }
 829
 830 static int acpi_ec_add(struct acpi_device *device)
 831 {
 832         struct acpi_ec *ec = NULL;
 833         int ret;
 834
 835         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 836         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 837
 838         /* Check for boot EC */
 839         if (boot_ec &&
 840             (boot_ec->handle == device->handle ||
 841              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 842                 ec = boot_ec;
 843                 boot_ec = NULL;
 844         } else {
 845                 ec = make_acpi_ec();
 846                 if (!ec)
 847                         return -ENOMEM;
 848         }
 849         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 850                 AE_CTRL_TERMINATE) {
 851                         kfree(ec);
 852                         return -EINVAL;
 853         }
 854
 855         /* Find and register all query methods */
 856         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 857                             acpi_ec_register_query_methods, NULL, ec, NULL);
 858
 859         if (!first_ec)
 860                 first_ec = ec;
 861         device->driver_data = ec;
 862
 863         ret = !!request_region(ec->data_addr, 1, "EC data");
 864         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
 865         ret = !!request_region(ec->command_addr, 1, "EC cmd");
 866         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
 867
 868         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 869                           ec->gpe, ec->command_addr, ec->data_addr);
 870
 871         ret = ec_install_handlers(ec);
 872
 873         /* EC is fully operational, allow queries */
 874         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 875
 876         /* Clear stale _Q events if hardware might require that */
 877         if (EC_FLAGS_CLEAR_ON_RESUME) {
 878                 mutex_lock(&ec->mutex);
 879                 acpi_ec_clear(ec);
 880                 mutex_unlock(&ec->mutex);
 881         }
 882         return ret;
 883 }
 884
 885 static int acpi_ec_remove(struct acpi_device *device)
 886 {
 887         struct acpi_ec *ec;
 888         struct acpi_ec_query_handler *handler, *tmp;
 889
 890         if (!device)
 891                 return -EINVAL;
 892
 893         ec = acpi_driver_data(device);
 894         ec_remove_handlers(ec);
 895         mutex_lock(&ec->mutex);
 896         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 897                 list_del(&handler->node);
 898                 kfree(handler);
 899         }
 900         mutex_unlock(&ec->mutex);
 901         release_region(ec->data_addr, 1);
 902         release_region(ec->command_addr, 1);
 903         device->driver_data = NULL;
 904         if (ec == first_ec)
 905                 first_ec = NULL;
 906         kfree(ec);
 907         return 0;
 908 }
 909
 910 static acpi_status
 911 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 912 {
 913         struct acpi_ec *ec = context;
 914
 915         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 916                 return AE_OK;
 917
 918         /*
 919          * The first address region returned is the data port, and
 920          * the second address region returned is the status/command
 921          * port.
 922          */
 923         if (ec->data_addr == 0)
 924                 ec->data_addr = resource->data.io.minimum;
 925         else if (ec->command_addr == 0)
 926                 ec->command_addr = resource->data.io.minimum;
 927         else
 928                 return AE_CTRL_TERMINATE;
 929
 930         return AE_OK;
 931 }
 932
 933 int __init acpi_boot_ec_enable(void)
 934 {
 935         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 936                 return 0;
 937         if (!ec_install_handlers(boot_ec)) {
 938                 first_ec = boot_ec;
 939                 return 0;
 940         }
 941         return -EFAULT;
 942 }
 943
 944 static const struct acpi_device_id ec_device_ids[] = {
 945         {"PNP0C09", 0},
 946         {"", 0},
 947 };
 948
 949 /* Some BIOS do not survive early DSDT scan, skip it */
 950 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 951 {
 952         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 953         return 0;
 954 }
 955
 956 /* ASUStek often supplies us with broken ECDT, validate it */
 957 static int ec_validate_ecdt(const struct dmi_system_id *id)
 958 {
 959         EC_FLAGS_VALIDATE_ECDT = 1;
 960         return 0;
 961 }
 962
 963 /* MSI EC needs special treatment, enable it */
 964 static int ec_flag_msi(const struct dmi_system_id *id)
 965 {
 966         pr_debug("Detected MSI hardware, enabling workarounds.\n");
 967         EC_FLAGS_MSI = 1;
 968         EC_FLAGS_VALIDATE_ECDT = 1;
 969         return 0;
 970 }
 971
 972 /*
 973  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
 974  * the GPE storm threshold back to 20
 975  */
 976 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
 977 {
 978         pr_debug("Setting the EC GPE storm threshold to 20\n");
 979         ec_storm_threshold  = 20;
 980         return 0;
 981 }
 982
 983 /*
 984  * On some hardware it is necessary to clear events accumulated by the EC during
 985  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
 986  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
 987  *
 988  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
 989  *
 990  * Ideally, the EC should also be instructed NOT to accumulate events during
 991  * sleep (which Windows seems to do somehow), but the interface to control this
 992  * behaviour is not known at this time.
 993  *
 994  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
 995  * however it is very likely that other Samsung models are affected.
 996  *
 997  * On systems which don't accumulate _Q events during sleep, this extra check
 998  * should be harmless.
 999  */
1000 static int ec_clear_on_resume(const struct dmi_system_id *id)
1001 {
1002         pr_debug("Detected system needing EC poll on resume.\n");
1003         EC_FLAGS_CLEAR_ON_RESUME = 1;
1004         return 0;
1005 }
1006
1007 static struct dmi_system_id ec_dmi_table[] __initdata = {
1008         {
1009         ec_skip_dsdt_scan, "Compal JFL92", {
1010         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1011         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1012         {
1013         ec_flag_msi, "MSI hardware", {
1014         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1015         {
1016         ec_flag_msi, "MSI hardware", {
1017         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1018         {
1019         ec_flag_msi, "MSI hardware", {
1020         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1021         {
1022         ec_flag_msi, "MSI hardware", {
1023         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1024         {
1025         ec_flag_msi, "Quanta hardware", {
1026         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1027         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1028         {
1029         ec_flag_msi, "Quanta hardware", {
1030         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1031         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1032         {
1033         ec_flag_msi, "Clevo W350etq", {
1034         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
1035         DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
1036         {
1037         ec_validate_ecdt, "ASUS hardware", {
1038         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1039         {
1040         ec_validate_ecdt, "ASUS hardware", {
1041         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1042         {
1043         ec_enlarge_storm_threshold, "CLEVO hardware", {
1044         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1045         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1046         {
1047         ec_skip_dsdt_scan, "HP Folio 13", {
1048         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1049         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1050         {
1051         ec_validate_ecdt, "ASUS hardware", {
1052         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1053         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1054         {
1055         ec_clear_on_resume, "Samsung hardware", {
1056         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1057         {},
1058 };
1059
1060 int __init acpi_ec_ecdt_probe(void)
1061 {
1062         acpi_status status;
1063         struct acpi_ec *saved_ec = NULL;
1064         struct acpi_table_ecdt *ecdt_ptr;
1065
1066         boot_ec = make_acpi_ec();
1067         if (!boot_ec)
1068                 return -ENOMEM;
1069         /*
1070          * Generate a boot ec context
1071          */
1072         dmi_check_system(ec_dmi_table);
1073         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1074                                 (struct acpi_table_header **)&ecdt_ptr);
1075         if (ACPI_SUCCESS(status)) {
1076                 pr_info("EC description table is found, configuring boot EC\n");
1077                 boot_ec->command_addr = ecdt_ptr->control.address;
1078                 boot_ec->data_addr = ecdt_ptr->data.address;
1079                 boot_ec->gpe = ecdt_ptr->gpe;
1080                 boot_ec->handle = ACPI_ROOT_OBJECT;
1081                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1082                 /* Don't trust ECDT, which comes from ASUSTek */
1083                 if (!EC_FLAGS_VALIDATE_ECDT)
1084                         goto install;
1085                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1086                 if (!saved_ec)
1087                         return -ENOMEM;
1088         /* fall through */
1089         }
1090
1091         if (EC_FLAGS_SKIP_DSDT_SCAN) {
1092                 kfree(saved_ec);
1093                 return -ENODEV;
1094         }
1095
1096         /* This workaround is needed only on some broken machines,
1097          * which require early EC, but fail to provide ECDT */
1098         pr_debug("Look up EC in DSDT\n");
1099         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1100                                         boot_ec, NULL);
1101         /* Check that acpi_get_devices actually find something */
1102         if (ACPI_FAILURE(status) || !boot_ec->handle)
1103                 goto error;
1104         if (saved_ec) {
1105                 /* try to find good ECDT from ASUSTek */
1106                 if (saved_ec->command_addr != boot_ec->command_addr ||
1107                     saved_ec->data_addr != boot_ec->data_addr ||
1108                     saved_ec->gpe != boot_ec->gpe ||
1109                     saved_ec->handle != boot_ec->handle)
1110                         pr_info("ASUSTek keeps feeding us with broken "
1111                         "ECDT tables, which are very hard to workaround. "
1112                         "Trying to use DSDT EC info instead. Please send "
1113                         "output of acpidump to [email protected]\n");
1114                 kfree(saved_ec);
1115                 saved_ec = NULL;
1116         } else {
1117                 /* We really need to limit this workaround, the only ASUS,
1118                 * which needs it, has fake EC._INI method, so use it as flag.
1119                 * Keep boot_ec struct as it will be needed soon.
1120                 */
1121                 if (!dmi_name_in_vendors("ASUS") ||
1122                     !acpi_has_method(boot_ec->handle, "_INI"))
1123                         return -ENODEV;
1124         }
1125 install:
1126         if (!ec_install_handlers(boot_ec)) {
1127                 first_ec = boot_ec;
1128                 return 0;
1129         }
1130 error:
1131         kfree(boot_ec);
1132         kfree(saved_ec);
1133         boot_ec = NULL;
1134         return -ENODEV;
1135 }
1136
1137 static struct acpi_driver acpi_ec_driver = {
1138         .name = "ec",
1139         .class = ACPI_EC_CLASS,
1140         .ids = ec_device_ids,
1141         .ops = {
1142                 .add = acpi_ec_add,
1143                 .remove = acpi_ec_remove,
1144                 },
1145 };
1146
1147 int __init acpi_ec_init(void)
1148 {
1149         int result = 0;
1150
1151         /* Now register the driver for the EC */
1152         result = acpi_bus_register_driver(&acpi_ec_driver);
1153         if (result < 0)
1154                 return -ENODEV;
1155
1156         return result;
1157 }
1158
1159 /* EC driver currently not unloadable */
1160 #if 0
1161 static void __exit acpi_ec_exit(void)
1162 {
1163
1164         acpi_bus_unregister_driver(&acpi_ec_driver);
1165         return;
1166 }
1167 #endif  /* 0 */