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