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 #ifdef DEBUG
 168 static const char *acpi_ec_cmd_string(u8 cmd)
 169 {
 170         switch (cmd) {
 171         case 0x80:
 172                 return "RD_EC";
 173         case 0x81:
 174                 return "WR_EC";
 175         case 0x82:
 176                 return "BE_EC";
 177         case 0x83:
 178                 return "BD_EC";
 179         case 0x84:
 180                 return "QR_EC";
 181         }
 182         return "UNKNOWN";
 183 }
 184 #else
 185 #define acpi_ec_cmd_string(cmd)         "UNDEF"
 186 #endif
 187
 188 static int ec_transaction_completed(struct acpi_ec *ec)
 189 {
 190         unsigned long flags;
 191         int ret = 0;
 192         spin_lock_irqsave(&ec->lock, flags);
 193         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
 194                 ret = 1;
 195         spin_unlock_irqrestore(&ec->lock, flags);
 196         return ret;
 197 }
 198
 199 static bool advance_transaction(struct acpi_ec *ec)
 200 {
 201         struct transaction *t;
 202         u8 status;
 203         bool wakeup = false;
 204
 205         pr_debug("===== %s (%d) =====\n",
 206                  in_interrupt() ? "IRQ" : "TASK", smp_processor_id());
 207         status = acpi_ec_read_status(ec);
 208         t = ec->curr;
 209         if (!t)
 210                 goto err;
 211         if (t->flags & ACPI_EC_COMMAND_POLL) {
 212                 if (t->wlen > t->wi) {
 213                         if ((status & ACPI_EC_FLAG_IBF) == 0)
 214                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
 215                         else
 216                                 goto err;
 217                 } else if (t->rlen > t->ri) {
 218                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
 219                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
 220                                 if (t->rlen == t->ri) {
 221                                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 222                                         if (t->command == ACPI_EC_COMMAND_QUERY)
 223                                                 pr_debug("***** Command(%s) hardware completion *****\n",
 224                                                          acpi_ec_cmd_string(t->command));
 225                                         wakeup = true;
 226                                 }
 227                         } else
 228                                 goto err;
 229                 } else if (t->wlen == t->wi &&
 230                            (status & ACPI_EC_FLAG_IBF) == 0) {
 231                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 232                         wakeup = true;
 233                 }
 234                 return wakeup;
 235         } else {
 236                 /*
 237                  * There is firmware refusing to respond QR_EC when SCI_EVT
 238                  * is not set, for which case, we complete the QR_EC
 239                  * without issuing it to the firmware.
 240                  * https://bugzilla.kernel.org/show_bug.cgi?id=86211
 241                  */
 242                 if (!(status & ACPI_EC_FLAG_SCI) &&
 243                     (t->command == ACPI_EC_COMMAND_QUERY)) {
 244                         t->flags |= ACPI_EC_COMMAND_POLL;
 245                         t->rdata[t->ri++] = 0x00;
 246                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
 247                         pr_debug("***** Command(%s) software completion *****\n",
 248                                  acpi_ec_cmd_string(t->command));
 249                         wakeup = true;
 250                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
 251                         acpi_ec_write_cmd(ec, t->command);
 252                         t->flags |= ACPI_EC_COMMAND_POLL;
 253                 } else
 254                         goto err;
 255                 return wakeup;
 256         }
 257 err:
 258         /*
 259          * If SCI bit is set, then don't think it's a false IRQ
 260          * otherwise will take a not handled IRQ as a false one.
 261          */
 262         if (!(status & ACPI_EC_FLAG_SCI)) {
 263                 if (in_interrupt() && t)
 264                         ++t->irq_count;
 265         }
 266         return wakeup;
 267 }
 268
 269 static void start_transaction(struct acpi_ec *ec)
 270 {
 271         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 272         ec->curr->flags = 0;
 273         (void)advance_transaction(ec);
 274 }
 275
 276 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
 277
 278 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 279 {
 280         if (state & ACPI_EC_FLAG_SCI) {
 281                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 282                         return acpi_ec_sync_query(ec, NULL);
 283         }
 284         return 0;
 285 }
 286
 287 static int ec_poll(struct acpi_ec *ec)
 288 {
 289         unsigned long flags;
 290         int repeat = 5; /* number of command restarts */
 291         while (repeat--) {
 292                 unsigned long delay = jiffies +
 293                         msecs_to_jiffies(ec_delay);
 294                 do {
 295                         /* don't sleep with disabled interrupts */
 296                         if (EC_FLAGS_MSI || irqs_disabled()) {
 297                                 udelay(ACPI_EC_MSI_UDELAY);
 298                                 if (ec_transaction_completed(ec))
 299                                         return 0;
 300                         } else {
 301                                 if (wait_event_timeout(ec->wait,
 302                                                 ec_transaction_completed(ec),
 303                                                 msecs_to_jiffies(1)))
 304                                         return 0;
 305                         }
 306                         spin_lock_irqsave(&ec->lock, flags);
 307                         (void)advance_transaction(ec);
 308                         spin_unlock_irqrestore(&ec->lock, flags);
 309                 } while (time_before(jiffies, delay));
 310                 pr_debug("controller reset, restart transaction\n");
 311                 spin_lock_irqsave(&ec->lock, flags);
 312                 start_transaction(ec);
 313                 spin_unlock_irqrestore(&ec->lock, flags);
 314         }
 315         return -ETIME;
 316 }
 317
 318 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 319                                         struct transaction *t)
 320 {
 321         unsigned long tmp;
 322         int ret = 0;
 323         if (EC_FLAGS_MSI)
 324                 udelay(ACPI_EC_MSI_UDELAY);
 325         /* start transaction */
 326         spin_lock_irqsave(&ec->lock, tmp);
 327         /* following two actions should be kept atomic */
 328         ec->curr = t;
 329         pr_debug("***** Command(%s) started *****\n",
 330                  acpi_ec_cmd_string(t->command));
 331         start_transaction(ec);
 332         spin_unlock_irqrestore(&ec->lock, tmp);
 333         ret = ec_poll(ec);
 334         spin_lock_irqsave(&ec->lock, tmp);
 335         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
 336                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 337                 pr_debug("***** Event stopped *****\n");
 338         }
 339         pr_debug("***** Command(%s) stopped *****\n",
 340                  acpi_ec_cmd_string(t->command));
 341         ec->curr = NULL;
 342         spin_unlock_irqrestore(&ec->lock, tmp);
 343         return ret;
 344 }
 345
 346 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 347 {
 348         int status;
 349         u32 glk;
 350         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 351                 return -EINVAL;
 352         if (t->rdata)
 353                 memset(t->rdata, 0, t->rlen);
 354         mutex_lock(&ec->mutex);
 355         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 356                 status = -EINVAL;
 357                 goto unlock;
 358         }
 359         if (ec->global_lock) {
 360                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 361                 if (ACPI_FAILURE(status)) {
 362                         status = -ENODEV;
 363                         goto unlock;
 364                 }
 365         }
 366         /* disable GPE during transaction if storm is detected */
 367         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 368                 /* It has to be disabled, so that it doesn't trigger. */
 369                 acpi_disable_gpe(NULL, ec->gpe);
 370         }
 371
 372         status = acpi_ec_transaction_unlocked(ec, t);
 373
 374         /* check if we received SCI during transaction */
 375         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 376         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 377                 msleep(1);
 378                 /* It is safe to enable the GPE outside of the transaction. */
 379                 acpi_enable_gpe(NULL, ec->gpe);
 380         } else if (t->irq_count > ec_storm_threshold) {
 381                 pr_info("GPE storm detected(%d GPEs), "
 382                         "transactions will use polling mode\n",
 383                         t->irq_count);
 384                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 385         }
 386         if (ec->global_lock)
 387                 acpi_release_global_lock(glk);
 388 unlock:
 389         mutex_unlock(&ec->mutex);
 390         return status;
 391 }
 392
 393 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 394 {
 395         u8 d;
 396         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 397                                 .wdata = NULL, .rdata = &d,
 398                                 .wlen = 0, .rlen = 1};
 399
 400         return acpi_ec_transaction(ec, &t);
 401 }
 402
 403 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 404 {
 405         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 406                                 .wdata = NULL, .rdata = NULL,
 407                                 .wlen = 0, .rlen = 0};
 408
 409         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 410                                 acpi_ec_transaction(ec, &t) : 0;
 411 }
 412
 413 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 414 {
 415         int result;
 416         u8 d;
 417         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 418                                 .wdata = &address, .rdata = &d,
 419                                 .wlen = 1, .rlen = 1};
 420
 421         result = acpi_ec_transaction(ec, &t);
 422         *data = d;
 423         return result;
 424 }
 425
 426 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 427 {
 428         u8 wdata[2] = { address, data };
 429         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 430                                 .wdata = wdata, .rdata = NULL,
 431                                 .wlen = 2, .rlen = 0};
 432
 433         return acpi_ec_transaction(ec, &t);
 434 }
 435
 436 int ec_read(u8 addr, u8 *val)
 437 {
 438         int err;
 439         u8 temp_data;
 440
 441         if (!first_ec)
 442                 return -ENODEV;
 443
 444         err = acpi_ec_read(first_ec, addr, &temp_data);
 445
 446         if (!err) {
 447                 *val = temp_data;
 448                 return 0;
 449         } else
 450                 return err;
 451 }
 452
 453 EXPORT_SYMBOL(ec_read);
 454
 455 int ec_write(u8 addr, u8 val)
 456 {
 457         int err;
 458
 459         if (!first_ec)
 460                 return -ENODEV;
 461
 462         err = acpi_ec_write(first_ec, addr, val);
 463
 464         return err;
 465 }
 466
 467 EXPORT_SYMBOL(ec_write);
 468
 469 int ec_transaction(u8 command,
 470                    const u8 * wdata, unsigned wdata_len,
 471                    u8 * rdata, unsigned rdata_len)
 472 {
 473         struct transaction t = {.command = command,
 474                                 .wdata = wdata, .rdata = rdata,
 475                                 .wlen = wdata_len, .rlen = rdata_len};
 476         if (!first_ec)
 477                 return -ENODEV;
 478
 479         return acpi_ec_transaction(first_ec, &t);
 480 }
 481
 482 EXPORT_SYMBOL(ec_transaction);
 483
 484 /* Get the handle to the EC device */
 485 acpi_handle ec_get_handle(void)
 486 {
 487         if (!first_ec)
 488                 return NULL;
 489         return first_ec->handle;
 490 }
 491
 492 EXPORT_SYMBOL(ec_get_handle);
 493
 494 /*
 495  * Process _Q events that might have accumulated in the EC.
 496  * Run with locked ec mutex.
 497  */
 498 static void acpi_ec_clear(struct acpi_ec *ec)
 499 {
 500         int i, status;
 501         u8 value = 0;
 502
 503         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
 504                 status = acpi_ec_sync_query(ec, &value);
 505                 if (status || !value)
 506                         break;
 507         }
 508
 509         if (unlikely(i == ACPI_EC_CLEAR_MAX))
 510                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
 511         else
 512                 pr_info("%d stale EC events cleared\n", i);
 513 }
 514
 515 void acpi_ec_block_transactions(void)
 516 {
 517         struct acpi_ec *ec = first_ec;
 518
 519         if (!ec)
 520                 return;
 521
 522         mutex_lock(&ec->mutex);
 523         /* Prevent transactions from being carried out */
 524         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 525         mutex_unlock(&ec->mutex);
 526 }
 527
 528 void acpi_ec_unblock_transactions(void)
 529 {
 530         struct acpi_ec *ec = first_ec;
 531
 532         if (!ec)
 533                 return;
 534
 535         mutex_lock(&ec->mutex);
 536         /* Allow transactions to be carried out again */
 537         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 538
 539         if (EC_FLAGS_CLEAR_ON_RESUME)
 540                 acpi_ec_clear(ec);
 541
 542         mutex_unlock(&ec->mutex);
 543 }
 544
 545 void acpi_ec_unblock_transactions_early(void)
 546 {
 547         /*
 548          * Allow transactions to happen again (this function is called from
 549          * atomic context during wakeup, so we don't need to acquire the mutex).
 550          */
 551         if (first_ec)
 552                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 553 }
 554
 555 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 556 {
 557         int result;
 558         u8 d;
 559         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 560                                 .wdata = NULL, .rdata = &d,
 561                                 .wlen = 0, .rlen = 1};
 562         if (!ec || !data)
 563                 return -EINVAL;
 564         /*
 565          * Query the EC to find out which _Qxx method we need to evaluate.
 566          * Note that successful completion of the query causes the ACPI_EC_SCI
 567          * bit to be cleared (and thus clearing the interrupt source).
 568          */
 569         result = acpi_ec_transaction_unlocked(ec, &t);
 570         if (result)
 571                 return result;
 572         if (!d)
 573                 return -ENODATA;
 574         *data = d;
 575         return 0;
 576 }
 577
 578 /* --------------------------------------------------------------------------
 579                                 Event Management
 580    -------------------------------------------------------------------------- */
 581 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 582                               acpi_handle handle, acpi_ec_query_func func,
 583                               void *data)
 584 {
 585         struct acpi_ec_query_handler *handler =
 586             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 587         if (!handler)
 588                 return -ENOMEM;
 589
 590         handler->query_bit = query_bit;
 591         handler->handle = handle;
 592         handler->func = func;
 593         handler->data = data;
 594         mutex_lock(&ec->mutex);
 595         list_add(&handler->node, &ec->list);
 596         mutex_unlock(&ec->mutex);
 597         return 0;
 598 }
 599
 600 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 601
 602 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 603 {
 604         struct acpi_ec_query_handler *handler, *tmp;
 605         mutex_lock(&ec->mutex);
 606         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 607                 if (query_bit == handler->query_bit) {
 608                         list_del(&handler->node);
 609                         kfree(handler);
 610                 }
 611         }
 612         mutex_unlock(&ec->mutex);
 613 }
 614
 615 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 616
 617 static void acpi_ec_run(void *cxt)
 618 {
 619         struct acpi_ec_query_handler *handler = cxt;
 620         if (!handler)
 621                 return;
 622         pr_debug("##### Query(0x%02x) started #####\n", handler->query_bit);
 623         if (handler->func)
 624                 handler->func(handler->data);
 625         else if (handler->handle)
 626                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 627         pr_debug("##### Query(0x%02x) stopped #####\n", handler->query_bit);
 628         kfree(handler);
 629 }
 630
 631 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
 632 {
 633         u8 value = 0;
 634         int status;
 635         struct acpi_ec_query_handler *handler, *copy;
 636
 637         status = acpi_ec_query_unlocked(ec, &value);
 638         if (data)
 639                 *data = value;
 640         if (status)
 641                 return status;
 642
 643         list_for_each_entry(handler, &ec->list, node) {
 644                 if (value == handler->query_bit) {
 645                         /* have custom handler for this bit */
 646                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 647                         if (!copy)
 648                                 return -ENOMEM;
 649                         memcpy(copy, handler, sizeof(*copy));
 650                         pr_debug("##### Query(0x%02x) scheduled #####\n",
 651                                  handler->query_bit);
 652                         return acpi_os_execute((copy->func) ?
 653                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 654                                 acpi_ec_run, copy);
 655                 }
 656         }
 657         return 0;
 658 }
 659
 660 static void acpi_ec_gpe_query(void *ec_cxt)
 661 {
 662         struct acpi_ec *ec = ec_cxt;
 663         if (!ec)
 664                 return;
 665         mutex_lock(&ec->mutex);
 666         acpi_ec_sync_query(ec, NULL);
 667         mutex_unlock(&ec->mutex);
 668 }
 669
 670 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 671 {
 672         if (state & ACPI_EC_FLAG_SCI) {
 673                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 674                         pr_debug("***** Event started *****\n");
 675                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
 676                                 acpi_ec_gpe_query, ec);
 677                 }
 678         }
 679         return 0;
 680 }
 681
 682 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 683         u32 gpe_number, void *data)
 684 {
 685         unsigned long flags;
 686         struct acpi_ec *ec = data;
 687
 688         spin_lock_irqsave(&ec->lock, flags);
 689         if (advance_transaction(ec))
 690                 wake_up(&ec->wait);
 691         spin_unlock_irqrestore(&ec->lock, flags);
 692         ec_check_sci(ec, acpi_ec_read_status(ec));
 693         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 694 }
 695
 696 /* --------------------------------------------------------------------------
 697                              Address Space Management
 698    -------------------------------------------------------------------------- */
 699
 700 static acpi_status
 701 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 702                       u32 bits, u64 *value64,
 703                       void *handler_context, void *region_context)
 704 {
 705         struct acpi_ec *ec = handler_context;
 706         int result = 0, i, bytes = bits / 8;
 707         u8 *value = (u8 *)value64;
 708
 709         if ((address > 0xFF) || !value || !handler_context)
 710                 return AE_BAD_PARAMETER;
 711
 712         if (function != ACPI_READ && function != ACPI_WRITE)
 713                 return AE_BAD_PARAMETER;
 714
 715         if (EC_FLAGS_MSI || bits > 8)
 716                 acpi_ec_burst_enable(ec);
 717
 718         for (i = 0; i < bytes; ++i, ++address, ++value)
 719                 result = (function == ACPI_READ) ?
 720                         acpi_ec_read(ec, address, value) :
 721                         acpi_ec_write(ec, address, *value);
 722
 723         if (EC_FLAGS_MSI || bits > 8)
 724                 acpi_ec_burst_disable(ec);
 725
 726         switch (result) {
 727         case -EINVAL:
 728                 return AE_BAD_PARAMETER;
 729                 break;
 730         case -ENODEV:
 731                 return AE_NOT_FOUND;
 732                 break;
 733         case -ETIME:
 734                 return AE_TIME;
 735                 break;
 736         default:
 737                 return AE_OK;
 738         }
 739 }
 740
 741 /* --------------------------------------------------------------------------
 742                                Driver Interface
 743    -------------------------------------------------------------------------- */
 744 static acpi_status
 745 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 746
 747 static struct acpi_ec *make_acpi_ec(void)
 748 {
 749         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 750         if (!ec)
 751                 return NULL;
 752         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 753         mutex_init(&ec->mutex);
 754         init_waitqueue_head(&ec->wait);
 755         INIT_LIST_HEAD(&ec->list);
 756         spin_lock_init(&ec->lock);
 757         return ec;
 758 }
 759
 760 static acpi_status
 761 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 762                                void *context, void **return_value)
 763 {
 764         char node_name[5];
 765         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 766         struct acpi_ec *ec = context;
 767         int value = 0;
 768         acpi_status status;
 769
 770         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 771
 772         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 773                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 774         }
 775         return AE_OK;
 776 }
 777
 778 static acpi_status
 779 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 780 {
 781         acpi_status status;
 782         unsigned long long tmp = 0;
 783
 784         struct acpi_ec *ec = context;
 785
 786         /* clear addr values, ec_parse_io_ports depend on it */
 787         ec->command_addr = ec->data_addr = 0;
 788
 789         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 790                                      ec_parse_io_ports, ec);
 791         if (ACPI_FAILURE(status))
 792                 return status;
 793
 794         /* Get GPE bit assignment (EC events). */
 795         /* TODO: Add support for _GPE returning a package */
 796         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 797         if (ACPI_FAILURE(status))
 798                 return status;
 799         ec->gpe = tmp;
 800         /* Use the global lock for all EC transactions? */
 801         tmp = 0;
 802         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 803         ec->global_lock = tmp;
 804         ec->handle = handle;
 805         return AE_CTRL_TERMINATE;
 806 }
 807
 808 static int ec_install_handlers(struct acpi_ec *ec)
 809 {
 810         acpi_status status;
 811         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 812                 return 0;
 813         status = acpi_install_gpe_handler(NULL, ec->gpe,
 814                                   ACPI_GPE_EDGE_TRIGGERED,
 815                                   &acpi_ec_gpe_handler, ec);
 816         if (ACPI_FAILURE(status))
 817                 return -ENODEV;
 818
 819         acpi_enable_gpe(NULL, ec->gpe);
 820         status = acpi_install_address_space_handler(ec->handle,
 821                                                     ACPI_ADR_SPACE_EC,
 822                                                     &acpi_ec_space_handler,
 823                                                     NULL, ec);
 824         if (ACPI_FAILURE(status)) {
 825                 if (status == AE_NOT_FOUND) {
 826                         /*
 827                          * Maybe OS fails in evaluating the _REG object.
 828                          * The AE_NOT_FOUND error will be ignored and OS
 829                          * continue to initialize EC.
 830                          */
 831                         pr_err("Fail in evaluating the _REG object"
 832                                 " of EC device. Broken bios is suspected.\n");
 833                 } else {
 834                         acpi_disable_gpe(NULL, ec->gpe);
 835                         acpi_remove_gpe_handler(NULL, ec->gpe,
 836                                 &acpi_ec_gpe_handler);
 837                         return -ENODEV;
 838                 }
 839         }
 840
 841         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 842         return 0;
 843 }
 844
 845 static void ec_remove_handlers(struct acpi_ec *ec)
 846 {
 847         acpi_disable_gpe(NULL, ec->gpe);
 848         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 849                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 850                 pr_err("failed to remove space handler\n");
 851         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 852                                 &acpi_ec_gpe_handler)))
 853                 pr_err("failed to remove gpe handler\n");
 854         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 855 }
 856
 857 static int acpi_ec_add(struct acpi_device *device)
 858 {
 859         struct acpi_ec *ec = NULL;
 860         int ret;
 861
 862         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 863         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 864
 865         /* Check for boot EC */
 866         if (boot_ec &&
 867             (boot_ec->handle == device->handle ||
 868              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 869                 ec = boot_ec;
 870                 boot_ec = NULL;
 871         } else {
 872                 ec = make_acpi_ec();
 873                 if (!ec)
 874                         return -ENOMEM;
 875         }
 876         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 877                 AE_CTRL_TERMINATE) {
 878                         kfree(ec);
 879                         return -EINVAL;
 880         }
 881
 882         /* Find and register all query methods */
 883         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 884                             acpi_ec_register_query_methods, NULL, ec, NULL);
 885
 886         if (!first_ec)
 887                 first_ec = ec;
 888         device->driver_data = ec;
 889
 890         ret = !!request_region(ec->data_addr, 1, "EC data");
 891         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
 892         ret = !!request_region(ec->command_addr, 1, "EC cmd");
 893         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
 894
 895         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 896                           ec->gpe, ec->command_addr, ec->data_addr);
 897
 898         ret = ec_install_handlers(ec);
 899
 900         /* EC is fully operational, allow queries */
 901         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 902
 903         /* Clear stale _Q events if hardware might require that */
 904         if (EC_FLAGS_CLEAR_ON_RESUME) {
 905                 mutex_lock(&ec->mutex);
 906                 acpi_ec_clear(ec);
 907                 mutex_unlock(&ec->mutex);
 908         }
 909         return ret;
 910 }
 911
 912 static int acpi_ec_remove(struct acpi_device *device)
 913 {
 914         struct acpi_ec *ec;
 915         struct acpi_ec_query_handler *handler, *tmp;
 916
 917         if (!device)
 918                 return -EINVAL;
 919
 920         ec = acpi_driver_data(device);
 921         ec_remove_handlers(ec);
 922         mutex_lock(&ec->mutex);
 923         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 924                 list_del(&handler->node);
 925                 kfree(handler);
 926         }
 927         mutex_unlock(&ec->mutex);
 928         release_region(ec->data_addr, 1);
 929         release_region(ec->command_addr, 1);
 930         device->driver_data = NULL;
 931         if (ec == first_ec)
 932                 first_ec = NULL;
 933         kfree(ec);
 934         return 0;
 935 }
 936
 937 static acpi_status
 938 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 939 {
 940         struct acpi_ec *ec = context;
 941
 942         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 943                 return AE_OK;
 944
 945         /*
 946          * The first address region returned is the data port, and
 947          * the second address region returned is the status/command
 948          * port.
 949          */
 950         if (ec->data_addr == 0)
 951                 ec->data_addr = resource->data.io.minimum;
 952         else if (ec->command_addr == 0)
 953                 ec->command_addr = resource->data.io.minimum;
 954         else
 955                 return AE_CTRL_TERMINATE;
 956
 957         return AE_OK;
 958 }
 959
 960 int __init acpi_boot_ec_enable(void)
 961 {
 962         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 963                 return 0;
 964         if (!ec_install_handlers(boot_ec)) {
 965                 first_ec = boot_ec;
 966                 return 0;
 967         }
 968         return -EFAULT;
 969 }
 970
 971 static const struct acpi_device_id ec_device_ids[] = {
 972         {"PNP0C09", 0},
 973         {"", 0},
 974 };
 975
 976 /* Some BIOS do not survive early DSDT scan, skip it */
 977 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 978 {
 979         EC_FLAGS_SKIP_DSDT_SCAN = 1;
 980         return 0;
 981 }
 982
 983 /* ASUStek often supplies us with broken ECDT, validate it */
 984 static int ec_validate_ecdt(const struct dmi_system_id *id)
 985 {
 986         EC_FLAGS_VALIDATE_ECDT = 1;
 987         return 0;
 988 }
 989
 990 /* MSI EC needs special treatment, enable it */
 991 static int ec_flag_msi(const struct dmi_system_id *id)
 992 {
 993         pr_debug("Detected MSI hardware, enabling workarounds.\n");
 994         EC_FLAGS_MSI = 1;
 995         EC_FLAGS_VALIDATE_ECDT = 1;
 996         return 0;
 997 }
 998
 999 /*
1000  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
1001  * the GPE storm threshold back to 20
1002  */
1003 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
1004 {
1005         pr_debug("Setting the EC GPE storm threshold to 20\n");
1006         ec_storm_threshold  = 20;
1007         return 0;
1008 }
1009
1010 /*
1011  * On some hardware it is necessary to clear events accumulated by the EC during
1012  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1013  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1014  *
1015  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1016  *
1017  * Ideally, the EC should also be instructed NOT to accumulate events during
1018  * sleep (which Windows seems to do somehow), but the interface to control this
1019  * behaviour is not known at this time.
1020  *
1021  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1022  * however it is very likely that other Samsung models are affected.
1023  *
1024  * On systems which don't accumulate _Q events during sleep, this extra check
1025  * should be harmless.
1026  */
1027 static int ec_clear_on_resume(const struct dmi_system_id *id)
1028 {
1029         pr_debug("Detected system needing EC poll on resume.\n");
1030         EC_FLAGS_CLEAR_ON_RESUME = 1;
1031         return 0;
1032 }
1033
1034 static struct dmi_system_id ec_dmi_table[] __initdata = {
1035         {
1036         ec_skip_dsdt_scan, "Compal JFL92", {
1037         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1038         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1039         {
1040         ec_flag_msi, "MSI hardware", {
1041         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1042         {
1043         ec_flag_msi, "MSI hardware", {
1044         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1045         {
1046         ec_flag_msi, "MSI hardware", {
1047         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1048         {
1049         ec_flag_msi, "MSI hardware", {
1050         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1051         {
1052         ec_flag_msi, "Quanta hardware", {
1053         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1054         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1055         {
1056         ec_flag_msi, "Quanta hardware", {
1057         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1058         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1059         {
1060         ec_flag_msi, "Clevo W350etq", {
1061         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
1062         DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
1063         {
1064         ec_validate_ecdt, "ASUS hardware", {
1065         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1066         {
1067         ec_validate_ecdt, "ASUS hardware", {
1068         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1069         {
1070         ec_enlarge_storm_threshold, "CLEVO hardware", {
1071         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1072         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1073         {
1074         ec_skip_dsdt_scan, "HP Folio 13", {
1075         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1076         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1077         {
1078         ec_validate_ecdt, "ASUS hardware", {
1079         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1080         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1081         {
1082         ec_clear_on_resume, "Samsung hardware", {
1083         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1084         {},
1085 };
1086
1087 int __init acpi_ec_ecdt_probe(void)
1088 {
1089         acpi_status status;
1090         struct acpi_ec *saved_ec = NULL;
1091         struct acpi_table_ecdt *ecdt_ptr;
1092
1093         boot_ec = make_acpi_ec();
1094         if (!boot_ec)
1095                 return -ENOMEM;
1096         /*
1097          * Generate a boot ec context
1098          */
1099         dmi_check_system(ec_dmi_table);
1100         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1101                                 (struct acpi_table_header **)&ecdt_ptr);
1102         if (ACPI_SUCCESS(status)) {
1103                 pr_info("EC description table is found, configuring boot EC\n");
1104                 boot_ec->command_addr = ecdt_ptr->control.address;
1105                 boot_ec->data_addr = ecdt_ptr->data.address;
1106                 boot_ec->gpe = ecdt_ptr->gpe;
1107                 boot_ec->handle = ACPI_ROOT_OBJECT;
1108                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1109                 /* Don't trust ECDT, which comes from ASUSTek */
1110                 if (!EC_FLAGS_VALIDATE_ECDT)
1111                         goto install;
1112                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1113                 if (!saved_ec)
1114                         return -ENOMEM;
1115         /* fall through */
1116         }
1117
1118         if (EC_FLAGS_SKIP_DSDT_SCAN) {
1119                 kfree(saved_ec);
1120                 return -ENODEV;
1121         }
1122
1123         /* This workaround is needed only on some broken machines,
1124          * which require early EC, but fail to provide ECDT */
1125         pr_debug("Look up EC in DSDT\n");
1126         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1127                                         boot_ec, NULL);
1128         /* Check that acpi_get_devices actually find something */
1129         if (ACPI_FAILURE(status) || !boot_ec->handle)
1130                 goto error;
1131         if (saved_ec) {
1132                 /* try to find good ECDT from ASUSTek */
1133                 if (saved_ec->command_addr != boot_ec->command_addr ||
1134                     saved_ec->data_addr != boot_ec->data_addr ||
1135                     saved_ec->gpe != boot_ec->gpe ||
1136                     saved_ec->handle != boot_ec->handle)
1137                         pr_info("ASUSTek keeps feeding us with broken "
1138                         "ECDT tables, which are very hard to workaround. "
1139                         "Trying to use DSDT EC info instead. Please send "
1140                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1141                 kfree(saved_ec);
1142                 saved_ec = NULL;
1143         } else {
1144                 /* We really need to limit this workaround, the only ASUS,
1145                 * which needs it, has fake EC._INI method, so use it as flag.
1146                 * Keep boot_ec struct as it will be needed soon.
1147                 */
1148                 if (!dmi_name_in_vendors("ASUS") ||
1149                     !acpi_has_method(boot_ec->handle, "_INI"))
1150                         return -ENODEV;
1151         }
1152 install:
1153         if (!ec_install_handlers(boot_ec)) {
1154                 first_ec = boot_ec;
1155                 return 0;
1156         }
1157 error:
1158         kfree(boot_ec);
1159         kfree(saved_ec);
1160         boot_ec = NULL;
1161         return -ENODEV;
1162 }
1163
1164 static struct acpi_driver acpi_ec_driver = {
1165         .name = "ec",
1166         .class = ACPI_EC_CLASS,
1167         .ids = ec_device_ids,
1168         .ops = {
1169                 .add = acpi_ec_add,
1170                 .remove = acpi_ec_remove,
1171                 },
1172 };
1173
1174 int __init acpi_ec_init(void)
1175 {
1176         int result = 0;
1177
1178         /* Now register the driver for the EC */
1179         result = acpi_bus_register_driver(&acpi_ec_driver);
1180         if (result < 0)
1181                 return -ENODEV;
1182
1183         return result;
1184 }
1185
1186 /* EC driver currently not unloadable */
1187 #if 0
1188 static void __exit acpi_ec_exit(void)
1189 {
1190
1191         acpi_bus_unregister_driver(&acpi_ec_driver);
1192         return;
1193 }
1194 #endif  /* 0 */