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   1 /*
   2  *  ec.c - ACPI Embedded Controller Driver (v2.0)
   3  *
   4  *  Copyright (C) 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
   5  *  Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
   6  *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
   7  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   8  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   9  *
  10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or (at
  15  *  your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful, but
  18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  *  General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License along
  23  *  with this program; if not, write to the Free Software Foundation, Inc.,
  24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  25  *
  26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  27  */
  28
  29 #include <linux/kernel.h>
  30 #include <linux/module.h>
  31 #include <linux/init.h>
  32 #include <linux/types.h>
  33 #include <linux/delay.h>
  34 #include <linux/proc_fs.h>
  35 #include <linux/seq_file.h>
  36 #include <linux/interrupt.h>
  37 #include <linux/list.h>
  38 #include <asm/io.h>
  39 #include <acpi/acpi_bus.h>
  40 #include <acpi/acpi_drivers.h>
  41 #include <acpi/actypes.h>
  42
  43 #define ACPI_EC_CLASS                   "embedded_controller"
  44 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  45 #define ACPI_EC_FILE_INFO               "info"
  46
  47 #undef PREFIX
  48 #define PREFIX                          "ACPI: EC: "
  49
  50 /* EC status register */
  51 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  52 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  53 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  54 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  55
  56 /* EC commands */
  57 enum ec_command {
  58         ACPI_EC_COMMAND_READ = 0x80,
  59         ACPI_EC_COMMAND_WRITE = 0x81,
  60         ACPI_EC_BURST_ENABLE = 0x82,
  61         ACPI_EC_BURST_DISABLE = 0x83,
  62         ACPI_EC_COMMAND_QUERY = 0x84,
  63 };
  64
  65 /* EC events */
  66 enum ec_event {
  67         ACPI_EC_EVENT_OBF_1 = 1,        /* Output buffer full */
  68         ACPI_EC_EVENT_IBF_0,            /* Input buffer empty */
  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
  74 enum {
  75         EC_FLAGS_WAIT_GPE = 0,          /* Don't check status until GPE arrives */
  76         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  77         EC_FLAGS_GPE_MODE,              /* Expect GPE to be sent for status change */
  78         EC_FLAGS_NO_ADDRESS_GPE,        /* Expect GPE only for non-address event */
  79         EC_FLAGS_ADDRESS,               /* Address is being written */
  80 };
  81
  82 static int acpi_ec_remove(struct acpi_device *device, int type);
  83 static int acpi_ec_start(struct acpi_device *device);
  84 static int acpi_ec_stop(struct acpi_device *device, int type);
  85 static int acpi_ec_add(struct acpi_device *device);
  86
  87 static const struct acpi_device_id ec_device_ids[] = {
  88         {"PNP0C09", 0},
  89         {"", 0},
  90 };
  91
  92 static struct acpi_driver acpi_ec_driver = {
  93         .name = "ec",
  94         .class = ACPI_EC_CLASS,
  95         .ids = ec_device_ids,
  96         .ops = {
  97                 .add = acpi_ec_add,
  98                 .remove = acpi_ec_remove,
  99                 .start = acpi_ec_start,
 100                 .stop = acpi_ec_stop,
 101                 },
 102 };
 103
 104 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
 105 /* External interfaces use first EC only, so remember */
 106 typedef int (*acpi_ec_query_func) (void *data);
 107
 108 struct acpi_ec_query_handler {
 109         struct list_head node;
 110         acpi_ec_query_func func;
 111         acpi_handle handle;
 112         void *data;
 113         u8 query_bit;
 114 };
 115
 116 static struct acpi_ec {
 117         acpi_handle handle;
 118         unsigned long gpe;
 119         unsigned long command_addr;
 120         unsigned long data_addr;
 121         unsigned long global_lock;
 122         unsigned long flags;
 123         struct mutex lock;
 124         wait_queue_head_t wait;
 125         struct list_head list;
 126         u8 handlers_installed;
 127 } *boot_ec, *first_ec;
 128
 129 /* --------------------------------------------------------------------------
 130                              Transaction Management
 131    -------------------------------------------------------------------------- */
 132
 133 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 134 {
 135         return inb(ec->command_addr);
 136 }
 137
 138 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 139 {
 140         return inb(ec->data_addr);
 141 }
 142
 143 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 144 {
 145         outb(command, ec->command_addr);
 146 }
 147
 148 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 149 {
 150         outb(data, ec->data_addr);
 151 }
 152
 153 static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
 154 {
 155         if (test_bit(EC_FLAGS_WAIT_GPE, &ec->flags))
 156                 return 0;
 157         if (event == ACPI_EC_EVENT_OBF_1) {
 158                 if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_OBF)
 159                         return 1;
 160         } else if (event == ACPI_EC_EVENT_IBF_0) {
 161                 if (!(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
 162                         return 1;
 163         }
 164
 165         return 0;
 166 }
 167
 168 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 169 {
 170         int ret = 0;
 171         if (unlikely(test_bit(EC_FLAGS_ADDRESS, &ec->flags) &&
 172                      test_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags)))
 173                 force_poll = 1;
 174         if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&
 175             likely(!force_poll)) {
 176                 if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),
 177                                        msecs_to_jiffies(ACPI_EC_DELAY)))
 178                         goto end;
 179                 clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 180                 if (acpi_ec_check_status(ec, event)) {
 181                         if (test_bit(EC_FLAGS_ADDRESS, &ec->flags)) {
 182                                 /* miss address GPE, don't expect it anymore */
 183                                 printk(KERN_INFO PREFIX "missing address confirmation,"
 184                                         "don't expect it any longer.\n");
 185                                 set_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags);
 186                         } else {
 187                                 /* missing GPEs, switch back to poll mode */
 188                                 printk(KERN_INFO PREFIX "missing confirmations,"
 189                                         "switch off interrupt mode.\n");
 190                                 clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 191                         }
 192                         goto end;
 193                 }
 194         } else {
 195                 unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 196                 clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 197                 while (time_before(jiffies, delay)) {
 198                         if (acpi_ec_check_status(ec, event))
 199                                 goto end;
 200                 }
 201         }
 202         printk(KERN_ERR PREFIX "acpi_ec_wait timeout,"
 203                                " status = %d, expect_event = %d\n",
 204                                acpi_ec_read_status(ec), event);
 205         ret = -ETIME;
 206       end:
 207         clear_bit(EC_FLAGS_ADDRESS, &ec->flags);
 208         return ret;
 209 }
 210
 211 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
 212                                         const u8 * wdata, unsigned wdata_len,
 213                                         u8 * rdata, unsigned rdata_len,
 214                                         int force_poll)
 215 {
 216         int result = 0;
 217         set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 218         acpi_ec_write_cmd(ec, command);
 219
 220         for (; wdata_len > 0; --wdata_len) {
 221                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
 222                 if (result) {
 223                         printk(KERN_ERR PREFIX
 224                                "write_cmd timeout, command = %d\n", command);
 225                         goto end;
 226                 }
 227                 /* mark the address byte written to EC */
 228                 if (rdata_len + wdata_len > 1)
 229                         set_bit(EC_FLAGS_ADDRESS, &ec->flags);
 230                 set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 231                 acpi_ec_write_data(ec, *(wdata++));
 232         }
 233
 234         if (!rdata_len) {
 235                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
 236                 if (result) {
 237                         printk(KERN_ERR PREFIX
 238                                "finish-write timeout, command = %d\n", command);
 239                         goto end;
 240                 }
 241         } else if (command == ACPI_EC_COMMAND_QUERY)
 242                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 243
 244         for (; rdata_len > 0; --rdata_len) {
 245                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, force_poll);
 246                 if (result) {
 247                         printk(KERN_ERR PREFIX "read timeout, command = %d\n",
 248                                command);
 249                         goto end;
 250                 }
 251                 /* Don't expect GPE after last read */
 252                 if (rdata_len > 1)
 253                         set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 254                 *(rdata++) = acpi_ec_read_data(ec);
 255         }
 256       end:
 257         return result;
 258 }
 259
 260 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
 261                                const u8 * wdata, unsigned wdata_len,
 262                                u8 * rdata, unsigned rdata_len,
 263                                int force_poll)
 264 {
 265         int status;
 266         u32 glk;
 267
 268         if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
 269                 return -EINVAL;
 270
 271         if (rdata)
 272                 memset(rdata, 0, rdata_len);
 273
 274         mutex_lock(&ec->lock);
 275         if (ec->global_lock) {
 276                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 277                 if (ACPI_FAILURE(status)) {
 278                         mutex_unlock(&ec->lock);
 279                         return -ENODEV;
 280                 }
 281         }
 282
 283         status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
 284         if (status) {
 285                 printk(KERN_ERR PREFIX
 286                        "input buffer is not empty, aborting transaction\n");
 287                 goto end;
 288         }
 289
 290         status = acpi_ec_transaction_unlocked(ec, command,
 291                                               wdata, wdata_len,
 292                                               rdata, rdata_len,
 293                                               force_poll);
 294
 295       end:
 296
 297         if (ec->global_lock)
 298                 acpi_release_global_lock(glk);
 299         mutex_unlock(&ec->lock);
 300
 301         return status;
 302 }
 303
 304 /*
 305  * Note: samsung nv5000 doesn't work with ec burst mode.
 306  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 307  */
 308 int acpi_ec_burst_enable(struct acpi_ec *ec)
 309 {
 310         u8 d;
 311         return acpi_ec_transaction(ec, ACPI_EC_BURST_ENABLE, NULL, 0, &d, 1, 0);
 312 }
 313
 314 int acpi_ec_burst_disable(struct acpi_ec *ec)
 315 {
 316         return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0, 0);
 317 }
 318
 319 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 320 {
 321         int result;
 322         u8 d;
 323
 324         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
 325                                      &address, 1, &d, 1, 0);
 326         *data = d;
 327         return result;
 328 }
 329
 330 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 331 {
 332         u8 wdata[2] = { address, data };
 333         return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
 334                                    wdata, 2, NULL, 0, 0);
 335 }
 336
 337 /*
 338  * Externally callable EC access functions. For now, assume 1 EC only
 339  */
 340 int ec_burst_enable(void)
 341 {
 342         if (!first_ec)
 343                 return -ENODEV;
 344         return acpi_ec_burst_enable(first_ec);
 345 }
 346
 347 EXPORT_SYMBOL(ec_burst_enable);
 348
 349 int ec_burst_disable(void)
 350 {
 351         if (!first_ec)
 352                 return -ENODEV;
 353         return acpi_ec_burst_disable(first_ec);
 354 }
 355
 356 EXPORT_SYMBOL(ec_burst_disable);
 357
 358 int ec_read(u8 addr, u8 * val)
 359 {
 360         int err;
 361         u8 temp_data;
 362
 363         if (!first_ec)
 364                 return -ENODEV;
 365
 366         err = acpi_ec_read(first_ec, addr, &temp_data);
 367
 368         if (!err) {
 369                 *val = temp_data;
 370                 return 0;
 371         } else
 372                 return err;
 373 }
 374
 375 EXPORT_SYMBOL(ec_read);
 376
 377 int ec_write(u8 addr, u8 val)
 378 {
 379         int err;
 380
 381         if (!first_ec)
 382                 return -ENODEV;
 383
 384         err = acpi_ec_write(first_ec, addr, val);
 385
 386         return err;
 387 }
 388
 389 EXPORT_SYMBOL(ec_write);
 390
 391 int ec_transaction(u8 command,
 392                    const u8 * wdata, unsigned wdata_len,
 393                    u8 * rdata, unsigned rdata_len,
 394                    int force_poll)
 395 {
 396         if (!first_ec)
 397                 return -ENODEV;
 398
 399         return acpi_ec_transaction(first_ec, command, wdata,
 400                                    wdata_len, rdata, rdata_len,
 401                                    force_poll);
 402 }
 403
 404 EXPORT_SYMBOL(ec_transaction);
 405
 406 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 407 {
 408         int result;
 409         u8 d;
 410
 411         if (!ec || !data)
 412                 return -EINVAL;
 413
 414         /*
 415          * Query the EC to find out which _Qxx method we need to evaluate.
 416          * Note that successful completion of the query causes the ACPI_EC_SCI
 417          * bit to be cleared (and thus clearing the interrupt source).
 418          */
 419
 420         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
 421         if (result)
 422                 return result;
 423
 424         if (!d)
 425                 return -ENODATA;
 426
 427         *data = d;
 428         return 0;
 429 }
 430
 431 /* --------------------------------------------------------------------------
 432                                 Event Management
 433    -------------------------------------------------------------------------- */
 434 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 435                               acpi_handle handle, acpi_ec_query_func func,
 436                               void *data)
 437 {
 438         struct acpi_ec_query_handler *handler =
 439             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 440         if (!handler)
 441                 return -ENOMEM;
 442
 443         handler->query_bit = query_bit;
 444         handler->handle = handle;
 445         handler->func = func;
 446         handler->data = data;
 447         mutex_lock(&ec->lock);
 448         list_add(&handler->node, &ec->list);
 449         mutex_unlock(&ec->lock);
 450         return 0;
 451 }
 452
 453 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 454
 455 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 456 {
 457         struct acpi_ec_query_handler *handler, *tmp;
 458         mutex_lock(&ec->lock);
 459         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 460                 if (query_bit == handler->query_bit) {
 461                         list_del(&handler->node);
 462                         kfree(handler);
 463                 }
 464         }
 465         mutex_unlock(&ec->lock);
 466 }
 467
 468 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 469
 470 static void acpi_ec_gpe_query(void *ec_cxt)
 471 {
 472         struct acpi_ec *ec = ec_cxt;
 473         u8 value = 0;
 474         struct acpi_ec_query_handler *handler, copy;
 475
 476         if (!ec || acpi_ec_query(ec, &value))
 477                 return;
 478         mutex_lock(&ec->lock);
 479         list_for_each_entry(handler, &ec->list, node) {
 480                 if (value == handler->query_bit) {
 481                         /* have custom handler for this bit */
 482                         memcpy(&copy, handler, sizeof(copy));
 483                         mutex_unlock(&ec->lock);
 484                         if (copy.func) {
 485                                 copy.func(copy.data);
 486                         } else if (copy.handle) {
 487                                 acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
 488                         }
 489                         return;
 490                 }
 491         }
 492         mutex_unlock(&ec->lock);
 493 }
 494
 495 static u32 acpi_ec_gpe_handler(void *data)
 496 {
 497         acpi_status status = AE_OK;
 498         struct acpi_ec *ec = data;
 499
 500         clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 501         if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
 502                 wake_up(&ec->wait);
 503
 504         if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_SCI) {
 505                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 506                         status = acpi_os_execute(OSL_EC_BURST_HANDLER,
 507                                 acpi_ec_gpe_query, ec);
 508         } else if (unlikely(!test_bit(EC_FLAGS_GPE_MODE, &ec->flags))) {
 509                 /* this is non-query, must be confirmation */
 510                 printk(KERN_INFO PREFIX "non-query interrupt received,"
 511                         " switching to interrupt mode\n");
 512                 set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 513         }
 514
 515         return ACPI_SUCCESS(status) ?
 516             ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 517 }
 518
 519 /* --------------------------------------------------------------------------
 520                              Address Space Management
 521    -------------------------------------------------------------------------- */
 522
 523 static acpi_status
 524 acpi_ec_space_setup(acpi_handle region_handle,
 525                     u32 function, void *handler_context, void **return_context)
 526 {
 527         /*
 528          * The EC object is in the handler context and is needed
 529          * when calling the acpi_ec_space_handler.
 530          */
 531         *return_context = (function != ACPI_REGION_DEACTIVATE) ?
 532             handler_context : NULL;
 533
 534         return AE_OK;
 535 }
 536
 537 static acpi_status
 538 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 539                       u32 bits, acpi_integer *value,
 540                       void *handler_context, void *region_context)
 541 {
 542         struct acpi_ec *ec = handler_context;
 543         int result = 0, i = 0;
 544         u8 temp = 0;
 545
 546         if ((address > 0xFF) || !value || !handler_context)
 547                 return AE_BAD_PARAMETER;
 548
 549         if (function != ACPI_READ && function != ACPI_WRITE)
 550                 return AE_BAD_PARAMETER;
 551
 552         if (bits != 8 && acpi_strict)
 553                 return AE_BAD_PARAMETER;
 554
 555         while (bits - i > 0) {
 556                 if (function == ACPI_READ) {
 557                         result = acpi_ec_read(ec, address, &temp);
 558                         (*value) |= ((acpi_integer)temp) << i;
 559                 } else {
 560                         temp = 0xff & ((*value) >> i);
 561                         result = acpi_ec_write(ec, address, temp);
 562                 }
 563                 i += 8;
 564                 ++address;
 565         }
 566
 567         switch (result) {
 568         case -EINVAL:
 569                 return AE_BAD_PARAMETER;
 570                 break;
 571         case -ENODEV:
 572                 return AE_NOT_FOUND;
 573                 break;
 574         case -ETIME:
 575                 return AE_TIME;
 576                 break;
 577         default:
 578                 return AE_OK;
 579         }
 580 }
 581
 582 /* --------------------------------------------------------------------------
 583                               FS Interface (/proc)
 584    -------------------------------------------------------------------------- */
 585
 586 static struct proc_dir_entry *acpi_ec_dir;
 587
 588 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 589 {
 590         struct acpi_ec *ec = seq->private;
 591
 592         if (!ec)
 593                 goto end;
 594
 595         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 596         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 597                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 598         seq_printf(seq, "use global lock:\t%s\n",
 599                    ec->global_lock ? "yes" : "no");
 600       end:
 601         return 0;
 602 }
 603
 604 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 605 {
 606         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 607 }
 608
 609 static struct file_operations acpi_ec_info_ops = {
 610         .open = acpi_ec_info_open_fs,
 611         .read = seq_read,
 612         .llseek = seq_lseek,
 613         .release = single_release,
 614         .owner = THIS_MODULE,
 615 };
 616
 617 static int acpi_ec_add_fs(struct acpi_device *device)
 618 {
 619         struct proc_dir_entry *entry = NULL;
 620
 621         if (!acpi_device_dir(device)) {
 622                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 623                                                      acpi_ec_dir);
 624                 if (!acpi_device_dir(device))
 625                         return -ENODEV;
 626         }
 627
 628         entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
 629                                   acpi_device_dir(device));
 630         if (!entry)
 631                 return -ENODEV;
 632         else {
 633                 entry->proc_fops = &acpi_ec_info_ops;
 634                 entry->data = acpi_driver_data(device);
 635                 entry->owner = THIS_MODULE;
 636         }
 637
 638         return 0;
 639 }
 640
 641 static int acpi_ec_remove_fs(struct acpi_device *device)
 642 {
 643
 644         if (acpi_device_dir(device)) {
 645                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 646                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 647                 acpi_device_dir(device) = NULL;
 648         }
 649
 650         return 0;
 651 }
 652
 653 /* --------------------------------------------------------------------------
 654                                Driver Interface
 655    -------------------------------------------------------------------------- */
 656 static acpi_status
 657 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 658
 659 static struct acpi_ec *make_acpi_ec(void)
 660 {
 661         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 662         if (!ec)
 663                 return NULL;
 664         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 665         mutex_init(&ec->lock);
 666         init_waitqueue_head(&ec->wait);
 667         INIT_LIST_HEAD(&ec->list);
 668         return ec;
 669 }
 670
 671 static acpi_status
 672 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 673                                void *context, void **return_value)
 674 {
 675         struct acpi_namespace_node *node = handle;
 676         struct acpi_ec *ec = context;
 677         int value = 0;
 678         if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
 679                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 680         }
 681         return AE_OK;
 682 }
 683
 684 static acpi_status
 685 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 686 {
 687         acpi_status status;
 688
 689         struct acpi_ec *ec = context;
 690         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 691                                      ec_parse_io_ports, ec);
 692         if (ACPI_FAILURE(status))
 693                 return status;
 694
 695         /* Get GPE bit assignment (EC events). */
 696         /* TODO: Add support for _GPE returning a package */
 697         status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
 698         if (ACPI_FAILURE(status))
 699                 return status;
 700         /* Find and register all query methods */
 701         acpi_walk_namespace(ACPI_TYPE_METHOD, handle, 1,
 702                             acpi_ec_register_query_methods, ec, NULL);
 703         /* Use the global lock for all EC transactions? */
 704         acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
 705         ec->handle = handle;
 706         return AE_CTRL_TERMINATE;
 707 }
 708
 709 static void ec_remove_handlers(struct acpi_ec *ec)
 710 {
 711         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 712                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 713                 printk(KERN_ERR PREFIX "failed to remove space handler\n");
 714         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 715                                 &acpi_ec_gpe_handler)))
 716                 printk(KERN_ERR PREFIX "failed to remove gpe handler\n");
 717         ec->handlers_installed = 0;
 718 }
 719
 720 static int acpi_ec_add(struct acpi_device *device)
 721 {
 722         struct acpi_ec *ec = NULL;
 723
 724         if (!device)
 725                 return -EINVAL;
 726         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 727         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 728
 729         /* Check for boot EC */
 730         if (boot_ec) {
 731                 if (boot_ec->handle == device->handle) {
 732                         /* Pre-loaded EC from DSDT, just move pointer */
 733                         ec = boot_ec;
 734                         boot_ec = NULL;
 735                         goto end;
 736                 } else if (boot_ec->handle == ACPI_ROOT_OBJECT) {
 737                         /* ECDT-based EC, time to shut it down */
 738                         ec_remove_handlers(boot_ec);
 739                         kfree(boot_ec);
 740                         first_ec = boot_ec = NULL;
 741                 }
 742         }
 743
 744         ec = make_acpi_ec();
 745         if (!ec)
 746                 return -ENOMEM;
 747
 748         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 749             AE_CTRL_TERMINATE) {
 750                 kfree(ec);
 751                 return -EINVAL;
 752         }
 753         ec->handle = device->handle;
 754       end:
 755         if (!first_ec)
 756                 first_ec = ec;
 757         acpi_driver_data(device) = ec;
 758         acpi_ec_add_fs(device);
 759         printk(KERN_INFO PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 760                           ec->gpe, ec->command_addr, ec->data_addr);
 761         printk(KERN_INFO PREFIX "driver started in %s mode\n",
 762                 (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
 763         return 0;
 764 }
 765
 766 static int acpi_ec_remove(struct acpi_device *device, int type)
 767 {
 768         struct acpi_ec *ec;
 769         struct acpi_ec_query_handler *handler, *tmp;
 770
 771         if (!device)
 772                 return -EINVAL;
 773
 774         ec = acpi_driver_data(device);
 775         mutex_lock(&ec->lock);
 776         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 777                 list_del(&handler->node);
 778                 kfree(handler);
 779         }
 780         mutex_unlock(&ec->lock);
 781         acpi_ec_remove_fs(device);
 782         acpi_driver_data(device) = NULL;
 783         if (ec == first_ec)
 784                 first_ec = NULL;
 785         kfree(ec);
 786         return 0;
 787 }
 788
 789 static acpi_status
 790 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 791 {
 792         struct acpi_ec *ec = context;
 793
 794         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 795                 return AE_OK;
 796
 797         /*
 798          * The first address region returned is the data port, and
 799          * the second address region returned is the status/command
 800          * port.
 801          */
 802         if (ec->data_addr == 0)
 803                 ec->data_addr = resource->data.io.minimum;
 804         else if (ec->command_addr == 0)
 805                 ec->command_addr = resource->data.io.minimum;
 806         else
 807                 return AE_CTRL_TERMINATE;
 808
 809         return AE_OK;
 810 }
 811
 812 static int ec_install_handlers(struct acpi_ec *ec)
 813 {
 814         acpi_status status;
 815         if (ec->handlers_installed)
 816                 return 0;
 817         status = acpi_install_gpe_handler(NULL, ec->gpe,
 818                                           ACPI_GPE_EDGE_TRIGGERED,
 819                                           &acpi_ec_gpe_handler, ec);
 820         if (ACPI_FAILURE(status))
 821                 return -ENODEV;
 822
 823         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 824         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 825
 826         status = acpi_install_address_space_handler(ec->handle,
 827                                                     ACPI_ADR_SPACE_EC,
 828                                                     &acpi_ec_space_handler,
 829                                                     &acpi_ec_space_setup, ec);
 830         if (ACPI_FAILURE(status)) {
 831                 acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 832                 return -ENODEV;
 833         }
 834
 835         ec->handlers_installed = 1;
 836         return 0;
 837 }
 838
 839 static int acpi_ec_start(struct acpi_device *device)
 840 {
 841         struct acpi_ec *ec;
 842         int ret = 0;
 843
 844         if (!device)
 845                 return -EINVAL;
 846
 847         ec = acpi_driver_data(device);
 848
 849         if (!ec)
 850                 return -EINVAL;
 851
 852         ret = ec_install_handlers(ec);
 853
 854         /* EC is fully operational, allow queries */
 855         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 856         return ret;
 857 }
 858
 859 static int acpi_ec_stop(struct acpi_device *device, int type)
 860 {
 861         struct acpi_ec *ec;
 862         if (!device)
 863                 return -EINVAL;
 864         ec = acpi_driver_data(device);
 865         if (!ec)
 866                 return -EINVAL;
 867         ec_remove_handlers(ec);
 868
 869         return 0;
 870 }
 871
 872 int __init acpi_ec_ecdt_probe(void)
 873 {
 874         int ret;
 875         acpi_status status;
 876         struct acpi_table_ecdt *ecdt_ptr;
 877
 878         boot_ec = make_acpi_ec();
 879         if (!boot_ec)
 880                 return -ENOMEM;
 881         /*
 882          * Generate a boot ec context
 883          */
 884         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 885                                 (struct acpi_table_header **)&ecdt_ptr);
 886         if (ACPI_SUCCESS(status)) {
 887                 printk(KERN_INFO PREFIX "EC description table is found, configuring boot EC\n");
 888                 boot_ec->command_addr = ecdt_ptr->control.address;
 889                 boot_ec->data_addr = ecdt_ptr->data.address;
 890                 boot_ec->gpe = ecdt_ptr->gpe;
 891                 boot_ec->handle = ACPI_ROOT_OBJECT;
 892         } else {
 893                 /* This workaround is needed only on some broken machines,
 894                  * which require early EC, but fail to provide ECDT */
 895                 acpi_handle x;
 896                 printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
 897                 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
 898                                                 boot_ec, NULL);
 899                 /* Check that acpi_get_devices actually find something */
 900                 if (ACPI_FAILURE(status) || !boot_ec->handle)
 901                         goto error;
 902                 /* We really need to limit this workaround, the only ASUS,
 903                  * which needs it, has fake EC._INI method, so use it as flag.
 904                  */
 905                 if (ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI", &x)))
 906                         goto error;
 907         }
 908
 909         ret = ec_install_handlers(boot_ec);
 910         if (!ret) {
 911                 first_ec = boot_ec;
 912                 return 0;
 913         }
 914       error:
 915         kfree(boot_ec);
 916         boot_ec = NULL;
 917         return -ENODEV;
 918 }
 919
 920 static int __init acpi_ec_init(void)
 921 {
 922         int result = 0;
 923
 924         if (acpi_disabled)
 925                 return 0;
 926
 927         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
 928         if (!acpi_ec_dir)
 929                 return -ENODEV;
 930
 931         /* Now register the driver for the EC */
 932         result = acpi_bus_register_driver(&acpi_ec_driver);
 933         if (result < 0) {
 934                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 935                 return -ENODEV;
 936         }
 937
 938         return result;
 939 }
 940
 941 subsys_initcall(acpi_ec_init);
 942
 943 /* EC driver currently not unloadable */
 944 #if 0
 945 static void __exit acpi_ec_exit(void)
 946 {
 947
 948         acpi_bus_unregister_driver(&acpi_ec_driver);
 949
 950         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 951
 952         return;
 953 }
 954 #endif  /* 0 */