drivers/acpi/ec.c

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