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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 /* Uncomment next line to get verbose print outs*/
  30 /* #define DEBUG */
  31
  32 #include <linux/kernel.h>
  33 #include <linux/module.h>
  34 #include <linux/init.h>
  35 #include <linux/types.h>
  36 #include <linux/delay.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/seq_file.h>
  39 #include <linux/interrupt.h>
  40 #include <linux/list.h>
  41 #include <asm/io.h>
  42 #include <acpi/acpi_bus.h>
  43 #include <acpi/acpi_drivers.h>
  44 #include <acpi/actypes.h>
  45
  46 #define ACPI_EC_CLASS                   "embedded_controller"
  47 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  48 #define ACPI_EC_FILE_INFO               "info"
  49
  50 #undef PREFIX
  51 #define PREFIX                          "ACPI: EC: "
  52
  53 /* EC status register */
  54 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  55 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  56 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  57 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  58
  59 /* EC commands */
  60 enum ec_command {
  61         ACPI_EC_COMMAND_READ = 0x80,
  62         ACPI_EC_COMMAND_WRITE = 0x81,
  63         ACPI_EC_BURST_ENABLE = 0x82,
  64         ACPI_EC_BURST_DISABLE = 0x83,
  65         ACPI_EC_COMMAND_QUERY = 0x84,
  66 };
  67
  68 /* EC events */
  69 enum ec_event {
  70         ACPI_EC_EVENT_OBF_1 = 1,        /* Output buffer full */
  71         ACPI_EC_EVENT_IBF_0,            /* Input buffer empty */
  72 };
  73
  74 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  75 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  76 #define ACPI_EC_UDELAY          100     /* Wait 100us before polling EC again */
  77
  78 enum {
  79         EC_FLAGS_WAIT_GPE = 0,          /* Don't check status until GPE arrives */
  80         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  81         EC_FLAGS_GPE_MODE,              /* Expect GPE to be sent for status change */
  82         EC_FLAGS_NO_ADDRESS_GPE,        /* Expect GPE only for non-address event */
  83         EC_FLAGS_ADDRESS,               /* Address is being written */
  84         EC_FLAGS_NO_WDATA_GPE,          /* Don't expect WDATA GPE event */
  85         EC_FLAGS_WDATA,                 /* Data is being written */
  86         EC_FLAGS_NO_OBF1_GPE,           /* Don't expect GPE before read */
  87         EC_FLAGS_RESCHEDULE_POLL        /* Re-schedule poll */
  88 };
  89
  90 static int acpi_ec_remove(struct acpi_device *device, int type);
  91 static int acpi_ec_start(struct acpi_device *device);
  92 static int acpi_ec_stop(struct acpi_device *device, int type);
  93 static int acpi_ec_add(struct acpi_device *device);
  94
  95 static const struct acpi_device_id ec_device_ids[] = {
  96         {"PNP0C09", 0},
  97         {"", 0},
  98 };
  99
 100 static struct acpi_driver acpi_ec_driver = {
 101         .name = "ec",
 102         .class = ACPI_EC_CLASS,
 103         .ids = ec_device_ids,
 104         .ops = {
 105                 .add = acpi_ec_add,
 106                 .remove = acpi_ec_remove,
 107                 .start = acpi_ec_start,
 108                 .stop = acpi_ec_stop,
 109                 },
 110 };
 111
 112 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
 113 /* External interfaces use first EC only, so remember */
 114 typedef int (*acpi_ec_query_func) (void *data);
 115
 116 struct acpi_ec_query_handler {
 117         struct list_head node;
 118         acpi_ec_query_func func;
 119         acpi_handle handle;
 120         void *data;
 121         u8 query_bit;
 122 };
 123
 124 static struct acpi_ec {
 125         acpi_handle handle;
 126         unsigned long gpe;
 127         unsigned long command_addr;
 128         unsigned long data_addr;
 129         unsigned long global_lock;
 130         unsigned long flags;
 131         struct mutex lock;
 132         wait_queue_head_t wait;
 133         struct list_head list;
 134         struct delayed_work work;
 135         u8 handlers_installed;
 136 } *boot_ec, *first_ec;
 137
 138 /* --------------------------------------------------------------------------
 139                              Transaction Management
 140    -------------------------------------------------------------------------- */
 141
 142 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 143 {
 144         u8 x = inb(ec->command_addr);
 145         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
 146         return x;
 147 }
 148
 149 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 150 {
 151         u8 x = inb(ec->data_addr);
 152         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
 153         return inb(ec->data_addr);
 154 }
 155
 156 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 157 {
 158         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
 159         outb(command, ec->command_addr);
 160 }
 161
 162 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 163 {
 164         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
 165         outb(data, ec->data_addr);
 166 }
 167
 168 static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
 169 {
 170         if (test_bit(EC_FLAGS_WAIT_GPE, &ec->flags))
 171                 return 0;
 172         if (event == ACPI_EC_EVENT_OBF_1) {
 173                 if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_OBF)
 174                         return 1;
 175         } else if (event == ACPI_EC_EVENT_IBF_0) {
 176                 if (!(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
 177                         return 1;
 178         }
 179
 180         return 0;
 181 }
 182
 183 static void ec_schedule_ec_poll(struct acpi_ec *ec)
 184 {
 185         if (test_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags))
 186                 schedule_delayed_work(&ec->work,
 187                                       msecs_to_jiffies(ACPI_EC_DELAY));
 188 }
 189
 190 static void ec_switch_to_poll_mode(struct acpi_ec *ec)
 191 {
 192         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 193         acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 194         set_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
 195 }
 196
 197 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 198 {
 199         int ret = 0;
 200
 201         if (unlikely(event == ACPI_EC_EVENT_OBF_1 &&
 202                      test_bit(EC_FLAGS_NO_OBF1_GPE, &ec->flags)))
 203                 force_poll = 1;
 204         if (unlikely(test_bit(EC_FLAGS_ADDRESS, &ec->flags) &&
 205                      test_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags)))
 206                 force_poll = 1;
 207         if (unlikely(test_bit(EC_FLAGS_WDATA, &ec->flags) &&
 208                      test_bit(EC_FLAGS_NO_WDATA_GPE, &ec->flags)))
 209                 force_poll = 1;
 210         if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&
 211             likely(!force_poll)) {
 212                 if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),
 213                                        msecs_to_jiffies(ACPI_EC_DELAY)))
 214                         goto end;
 215                 clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 216                 if (acpi_ec_check_status(ec, event)) {
 217                         if (event == ACPI_EC_EVENT_OBF_1) {
 218                                 /* miss OBF_1 GPE, don't expect it */
 219                                 pr_info(PREFIX "missing OBF confirmation, "
 220                                         "don't expect it any longer.\n");
 221                                 set_bit(EC_FLAGS_NO_OBF1_GPE, &ec->flags);
 222                         } else if (test_bit(EC_FLAGS_ADDRESS, &ec->flags)) {
 223                                 /* miss address GPE, don't expect it anymore */
 224                                 pr_info(PREFIX "missing address confirmation, "
 225                                         "don't expect it any longer.\n");
 226                                 set_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags);
 227                         } else if (test_bit(EC_FLAGS_WDATA, &ec->flags)) {
 228                                 /* miss write data GPE, don't expect it */
 229                                 pr_info(PREFIX "missing write data confirmation, "
 230                                         "don't expect it any longer.\n");
 231                                 set_bit(EC_FLAGS_NO_WDATA_GPE, &ec->flags);
 232                         } else {
 233                                 /* missing GPEs, switch back to poll mode */
 234                                 if (printk_ratelimit())
 235                                         pr_info(PREFIX "missing confirmations, "
 236                                                 "switch off interrupt mode.\n");
 237                                 ec_switch_to_poll_mode(ec);
 238                                 ec_schedule_ec_poll(ec);
 239                         }
 240                         goto end;
 241                 }
 242         } else {
 243                 unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 244                 clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 245                 while (time_before(jiffies, delay)) {
 246                         if (acpi_ec_check_status(ec, event))
 247                                 goto end;
 248                         udelay(ACPI_EC_UDELAY);
 249                 }
 250         }
 251         pr_err(PREFIX "acpi_ec_wait timeout,"
 252                                " status = %d, expect_event = %d\n",
 253                                acpi_ec_read_status(ec), event);
 254         ret = -ETIME;
 255       end:
 256         clear_bit(EC_FLAGS_ADDRESS, &ec->flags);
 257         return ret;
 258 }
 259
 260 static int acpi_ec_transaction_unlocked(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 result = 0;
 266         set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 267         acpi_ec_write_cmd(ec, command);
 268         pr_debug(PREFIX "transaction start\n");
 269         for (; wdata_len > 0; --wdata_len) {
 270                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
 271                 if (result) {
 272                         pr_err(PREFIX
 273                                "write_cmd timeout, command = %d\n", command);
 274                         goto end;
 275                 }
 276                 /* mark the address byte written to EC */
 277                 if (rdata_len + wdata_len > 1)
 278                         set_bit(EC_FLAGS_ADDRESS, &ec->flags);
 279                 set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 280                 acpi_ec_write_data(ec, *(wdata++));
 281         }
 282
 283         if (!rdata_len) {
 284                 set_bit(EC_FLAGS_WDATA, &ec->flags);
 285                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
 286                 if (result) {
 287                         pr_err(PREFIX
 288                                "finish-write timeout, command = %d\n", command);
 289                         goto end;
 290                 }
 291         } else if (command == ACPI_EC_COMMAND_QUERY)
 292                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 293
 294         for (; rdata_len > 0; --rdata_len) {
 295                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, force_poll);
 296                 if (result) {
 297                         pr_err(PREFIX "read timeout, command = %d\n", command);
 298                         goto end;
 299                 }
 300                 /* Don't expect GPE after last read */
 301                 if (rdata_len > 1)
 302                         set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 303                 *(rdata++) = acpi_ec_read_data(ec);
 304         }
 305       end:
 306         pr_debug(PREFIX "transaction end\n");
 307         return result;
 308 }
 309
 310 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
 311                                const u8 * wdata, unsigned wdata_len,
 312                                u8 * rdata, unsigned rdata_len,
 313                                int force_poll)
 314 {
 315         int status;
 316         u32 glk;
 317
 318         if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
 319                 return -EINVAL;
 320
 321         if (rdata)
 322                 memset(rdata, 0, rdata_len);
 323
 324         mutex_lock(&ec->lock);
 325         if (ec->global_lock) {
 326                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 327                 if (ACPI_FAILURE(status)) {
 328                         mutex_unlock(&ec->lock);
 329                         return -ENODEV;
 330                 }
 331         }
 332
 333         status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
 334         if (status) {
 335                 pr_err(PREFIX "input buffer is not empty, "
 336                                 "aborting transaction\n");
 337                 goto end;
 338         }
 339
 340         status = acpi_ec_transaction_unlocked(ec, command,
 341                                               wdata, wdata_len,
 342                                               rdata, rdata_len,
 343                                               force_poll);
 344
 345       end:
 346
 347         if (ec->global_lock)
 348                 acpi_release_global_lock(glk);
 349         mutex_unlock(&ec->lock);
 350
 351         return status;
 352 }
 353
 354 /*
 355  * Note: samsung nv5000 doesn't work with ec burst mode.
 356  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 357  */
 358 int acpi_ec_burst_enable(struct acpi_ec *ec)
 359 {
 360         u8 d;
 361         return acpi_ec_transaction(ec, ACPI_EC_BURST_ENABLE, NULL, 0, &d, 1, 0);
 362 }
 363
 364 int acpi_ec_burst_disable(struct acpi_ec *ec)
 365 {
 366         return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0, 0);
 367 }
 368
 369 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 370 {
 371         int result;
 372         u8 d;
 373
 374         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
 375                                      &address, 1, &d, 1, 0);
 376         *data = d;
 377         return result;
 378 }
 379
 380 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 381 {
 382         u8 wdata[2] = { address, data };
 383         return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
 384                                    wdata, 2, NULL, 0, 0);
 385 }
 386
 387 /*
 388  * Externally callable EC access functions. For now, assume 1 EC only
 389  */
 390 int ec_burst_enable(void)
 391 {
 392         if (!first_ec)
 393                 return -ENODEV;
 394         return acpi_ec_burst_enable(first_ec);
 395 }
 396
 397 EXPORT_SYMBOL(ec_burst_enable);
 398
 399 int ec_burst_disable(void)
 400 {
 401         if (!first_ec)
 402                 return -ENODEV;
 403         return acpi_ec_burst_disable(first_ec);
 404 }
 405
 406 EXPORT_SYMBOL(ec_burst_disable);
 407
 408 int ec_read(u8 addr, u8 * val)
 409 {
 410         int err;
 411         u8 temp_data;
 412
 413         if (!first_ec)
 414                 return -ENODEV;
 415
 416         err = acpi_ec_read(first_ec, addr, &temp_data);
 417
 418         if (!err) {
 419                 *val = temp_data;
 420                 return 0;
 421         } else
 422                 return err;
 423 }
 424
 425 EXPORT_SYMBOL(ec_read);
 426
 427 int ec_write(u8 addr, u8 val)
 428 {
 429         int err;
 430
 431         if (!first_ec)
 432                 return -ENODEV;
 433
 434         err = acpi_ec_write(first_ec, addr, val);
 435
 436         return err;
 437 }
 438
 439 EXPORT_SYMBOL(ec_write);
 440
 441 int ec_transaction(u8 command,
 442                    const u8 * wdata, unsigned wdata_len,
 443                    u8 * rdata, unsigned rdata_len,
 444                    int force_poll)
 445 {
 446         if (!first_ec)
 447                 return -ENODEV;
 448
 449         return acpi_ec_transaction(first_ec, command, wdata,
 450                                    wdata_len, rdata, rdata_len,
 451                                    force_poll);
 452 }
 453
 454 EXPORT_SYMBOL(ec_transaction);
 455
 456 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 457 {
 458         int result;
 459         u8 d;
 460
 461         if (!ec || !data)
 462                 return -EINVAL;
 463
 464         /*
 465          * Query the EC to find out which _Qxx method we need to evaluate.
 466          * Note that successful completion of the query causes the ACPI_EC_SCI
 467          * bit to be cleared (and thus clearing the interrupt source).
 468          */
 469
 470         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
 471         if (result)
 472                 return result;
 473
 474         if (!d)
 475                 return -ENODATA;
 476
 477         *data = d;
 478         return 0;
 479 }
 480
 481 /* --------------------------------------------------------------------------
 482                                 Event Management
 483    -------------------------------------------------------------------------- */
 484 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 485                               acpi_handle handle, acpi_ec_query_func func,
 486                               void *data)
 487 {
 488         struct acpi_ec_query_handler *handler =
 489             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 490         if (!handler)
 491                 return -ENOMEM;
 492
 493         handler->query_bit = query_bit;
 494         handler->handle = handle;
 495         handler->func = func;
 496         handler->data = data;
 497         mutex_lock(&ec->lock);
 498         list_add(&handler->node, &ec->list);
 499         mutex_unlock(&ec->lock);
 500         return 0;
 501 }
 502
 503 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 504
 505 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 506 {
 507         struct acpi_ec_query_handler *handler, *tmp;
 508         mutex_lock(&ec->lock);
 509         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 510                 if (query_bit == handler->query_bit) {
 511                         list_del(&handler->node);
 512                         kfree(handler);
 513                 }
 514         }
 515         mutex_unlock(&ec->lock);
 516 }
 517
 518 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 519
 520 static void acpi_ec_gpe_query(void *ec_cxt)
 521 {
 522         struct acpi_ec *ec = ec_cxt;
 523         u8 value = 0;
 524         struct acpi_ec_query_handler *handler, copy;
 525
 526         if (!ec || acpi_ec_query(ec, &value))
 527                 return;
 528         mutex_lock(&ec->lock);
 529         list_for_each_entry(handler, &ec->list, node) {
 530                 if (value == handler->query_bit) {
 531                         /* have custom handler for this bit */
 532                         memcpy(&copy, handler, sizeof(copy));
 533                         mutex_unlock(&ec->lock);
 534                         if (copy.func) {
 535                                 copy.func(copy.data);
 536                         } else if (copy.handle) {
 537                                 acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
 538                         }
 539                         return;
 540                 }
 541         }
 542         mutex_unlock(&ec->lock);
 543 }
 544
 545 static u32 acpi_ec_gpe_handler(void *data)
 546 {
 547         acpi_status status = AE_OK;
 548         struct acpi_ec *ec = data;
 549         u8 state = acpi_ec_read_status(ec);
 550
 551         pr_debug(PREFIX "~~~> interrupt\n");
 552         clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 553         if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
 554                 wake_up(&ec->wait);
 555
 556         if (state & ACPI_EC_FLAG_SCI) {
 557                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 558                         status = acpi_os_execute(OSL_EC_BURST_HANDLER,
 559                                 acpi_ec_gpe_query, ec);
 560         } else if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 561                    in_interrupt()) {
 562                 /* this is non-query, must be confirmation */
 563                 if (printk_ratelimit())
 564                         pr_info(PREFIX "non-query interrupt received,"
 565                                 " switching to interrupt mode\n");
 566                 set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 567                 clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
 568         }
 569         ec_schedule_ec_poll(ec);
 570         return ACPI_SUCCESS(status) ?
 571             ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 572 }
 573
 574 static void do_ec_poll(struct work_struct *work)
 575 {
 576         struct acpi_ec *ec = container_of(work, struct acpi_ec, work.work);
 577         (void)acpi_ec_gpe_handler(ec);
 578 }
 579
 580 /* --------------------------------------------------------------------------
 581                              Address Space Management
 582    -------------------------------------------------------------------------- */
 583
 584 static acpi_status
 585 acpi_ec_space_setup(acpi_handle region_handle,
 586                     u32 function, void *handler_context, void **return_context)
 587 {
 588         /*
 589          * The EC object is in the handler context and is needed
 590          * when calling the acpi_ec_space_handler.
 591          */
 592         *return_context = (function != ACPI_REGION_DEACTIVATE) ?
 593             handler_context : NULL;
 594
 595         return AE_OK;
 596 }
 597
 598 static acpi_status
 599 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 600                       u32 bits, acpi_integer *value,
 601                       void *handler_context, void *region_context)
 602 {
 603         struct acpi_ec *ec = handler_context;
 604         int result = 0, i;
 605         u8 temp = 0;
 606
 607         if ((address > 0xFF) || !value || !handler_context)
 608                 return AE_BAD_PARAMETER;
 609
 610         if (function != ACPI_READ && function != ACPI_WRITE)
 611                 return AE_BAD_PARAMETER;
 612
 613         if (bits != 8 && acpi_strict)
 614                 return AE_BAD_PARAMETER;
 615
 616         acpi_ec_burst_enable(ec);
 617
 618         if (function == ACPI_READ) {
 619                 result = acpi_ec_read(ec, address, &temp);
 620                 *value = temp;
 621         } else {
 622                 temp = 0xff & (*value);
 623                 result = acpi_ec_write(ec, address, temp);
 624         }
 625
 626         for (i = 8; unlikely(bits - i > 0); i += 8) {
 627                 ++address;
 628                 if (function == ACPI_READ) {
 629                         result = acpi_ec_read(ec, address, &temp);
 630                         (*value) |= ((acpi_integer)temp) << i;
 631                 } else {
 632                         temp = 0xff & ((*value) >> i);
 633                         result = acpi_ec_write(ec, address, temp);
 634                 }
 635         }
 636
 637         acpi_ec_burst_disable(ec);
 638
 639         switch (result) {
 640         case -EINVAL:
 641                 return AE_BAD_PARAMETER;
 642                 break;
 643         case -ENODEV:
 644                 return AE_NOT_FOUND;
 645                 break;
 646         case -ETIME:
 647                 return AE_TIME;
 648                 break;
 649         default:
 650                 return AE_OK;
 651         }
 652 }
 653
 654 /* --------------------------------------------------------------------------
 655                               FS Interface (/proc)
 656    -------------------------------------------------------------------------- */
 657
 658 static struct proc_dir_entry *acpi_ec_dir;
 659
 660 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 661 {
 662         struct acpi_ec *ec = seq->private;
 663
 664         if (!ec)
 665                 goto end;
 666
 667         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 668         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 669                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 670         seq_printf(seq, "use global lock:\t%s\n",
 671                    ec->global_lock ? "yes" : "no");
 672       end:
 673         return 0;
 674 }
 675
 676 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 677 {
 678         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 679 }
 680
 681 static struct file_operations acpi_ec_info_ops = {
 682         .open = acpi_ec_info_open_fs,
 683         .read = seq_read,
 684         .llseek = seq_lseek,
 685         .release = single_release,
 686         .owner = THIS_MODULE,
 687 };
 688
 689 static int acpi_ec_add_fs(struct acpi_device *device)
 690 {
 691         struct proc_dir_entry *entry = NULL;
 692
 693         if (!acpi_device_dir(device)) {
 694                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 695                                                      acpi_ec_dir);
 696                 if (!acpi_device_dir(device))
 697                         return -ENODEV;
 698         }
 699
 700         entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
 701                                   acpi_device_dir(device));
 702         if (!entry)
 703                 return -ENODEV;
 704         else {
 705                 entry->proc_fops = &acpi_ec_info_ops;
 706                 entry->data = acpi_driver_data(device);
 707                 entry->owner = THIS_MODULE;
 708         }
 709
 710         return 0;
 711 }
 712
 713 static int acpi_ec_remove_fs(struct acpi_device *device)
 714 {
 715
 716         if (acpi_device_dir(device)) {
 717                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 718                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 719                 acpi_device_dir(device) = NULL;
 720         }
 721
 722         return 0;
 723 }
 724
 725 /* --------------------------------------------------------------------------
 726                                Driver Interface
 727    -------------------------------------------------------------------------- */
 728 static acpi_status
 729 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 730
 731 static struct acpi_ec *make_acpi_ec(void)
 732 {
 733         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 734         if (!ec)
 735                 return NULL;
 736         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 737         mutex_init(&ec->lock);
 738         init_waitqueue_head(&ec->wait);
 739         INIT_LIST_HEAD(&ec->list);
 740         INIT_DELAYED_WORK_DEFERRABLE(&ec->work, do_ec_poll);
 741         return ec;
 742 }
 743
 744 static acpi_status
 745 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 746                                void *context, void **return_value)
 747 {
 748         struct acpi_namespace_node *node = handle;
 749         struct acpi_ec *ec = context;
 750         int value = 0;
 751         if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
 752                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 753         }
 754         return AE_OK;
 755 }
 756
 757 static acpi_status
 758 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 759 {
 760         acpi_status status;
 761
 762         struct acpi_ec *ec = context;
 763         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 764                                      ec_parse_io_ports, ec);
 765         if (ACPI_FAILURE(status))
 766                 return status;
 767
 768         /* Get GPE bit assignment (EC events). */
 769         /* TODO: Add support for _GPE returning a package */
 770         status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
 771         if (ACPI_FAILURE(status))
 772                 return status;
 773         /* Find and register all query methods */
 774         acpi_walk_namespace(ACPI_TYPE_METHOD, handle, 1,
 775                             acpi_ec_register_query_methods, ec, NULL);
 776         /* Use the global lock for all EC transactions? */
 777         acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
 778         ec->handle = handle;
 779         return AE_CTRL_TERMINATE;
 780 }
 781
 782 static void ec_poll_stop(struct acpi_ec *ec)
 783 {
 784         clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
 785         cancel_delayed_work(&ec->work);
 786 }
 787
 788 static void ec_remove_handlers(struct acpi_ec *ec)
 789 {
 790         ec_poll_stop(ec);
 791         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 792                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 793                 pr_err(PREFIX "failed to remove space handler\n");
 794         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 795                                 &acpi_ec_gpe_handler)))
 796                 pr_err(PREFIX "failed to remove gpe handler\n");
 797         ec->handlers_installed = 0;
 798 }
 799
 800 static int acpi_ec_add(struct acpi_device *device)
 801 {
 802         struct acpi_ec *ec = NULL;
 803
 804         if (!device)
 805                 return -EINVAL;
 806         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 807         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 808
 809         /* Check for boot EC */
 810         if (boot_ec) {
 811                 if (boot_ec->handle == device->handle) {
 812                         /* Pre-loaded EC from DSDT, just move pointer */
 813                         ec = boot_ec;
 814                         boot_ec = NULL;
 815                         goto end;
 816                 } else if (boot_ec->handle == ACPI_ROOT_OBJECT) {
 817                         /* ECDT-based EC, time to shut it down */
 818                         ec_remove_handlers(boot_ec);
 819                         kfree(boot_ec);
 820                         first_ec = boot_ec = NULL;
 821                 }
 822         }
 823
 824         ec = make_acpi_ec();
 825         if (!ec)
 826                 return -ENOMEM;
 827
 828         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 829             AE_CTRL_TERMINATE) {
 830                 kfree(ec);
 831                 return -EINVAL;
 832         }
 833         ec->handle = device->handle;
 834       end:
 835         if (!first_ec)
 836                 first_ec = ec;
 837         acpi_driver_data(device) = ec;
 838         acpi_ec_add_fs(device);
 839         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 840                           ec->gpe, ec->command_addr, ec->data_addr);
 841         pr_info(PREFIX "driver started in %s mode\n",
 842                 (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
 843         return 0;
 844 }
 845
 846 static int acpi_ec_remove(struct acpi_device *device, int type)
 847 {
 848         struct acpi_ec *ec;
 849         struct acpi_ec_query_handler *handler, *tmp;
 850
 851         if (!device)
 852                 return -EINVAL;
 853
 854         ec = acpi_driver_data(device);
 855         mutex_lock(&ec->lock);
 856         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 857                 list_del(&handler->node);
 858                 kfree(handler);
 859         }
 860         mutex_unlock(&ec->lock);
 861         acpi_ec_remove_fs(device);
 862         acpi_driver_data(device) = NULL;
 863         if (ec == first_ec)
 864                 first_ec = NULL;
 865         kfree(ec);
 866         return 0;
 867 }
 868
 869 static acpi_status
 870 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 871 {
 872         struct acpi_ec *ec = context;
 873
 874         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 875                 return AE_OK;
 876
 877         /*
 878          * The first address region returned is the data port, and
 879          * the second address region returned is the status/command
 880          * port.
 881          */
 882         if (ec->data_addr == 0)
 883                 ec->data_addr = resource->data.io.minimum;
 884         else if (ec->command_addr == 0)
 885                 ec->command_addr = resource->data.io.minimum;
 886         else
 887                 return AE_CTRL_TERMINATE;
 888
 889         return AE_OK;
 890 }
 891
 892 static int ec_install_handlers(struct acpi_ec *ec)
 893 {
 894         acpi_status status;
 895         if (ec->handlers_installed)
 896                 return 0;
 897         status = acpi_install_gpe_handler(NULL, ec->gpe,
 898                                           ACPI_GPE_EDGE_TRIGGERED,
 899                                           &acpi_ec_gpe_handler, ec);
 900         if (ACPI_FAILURE(status))
 901                 return -ENODEV;
 902
 903         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 904         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 905
 906         status = acpi_install_address_space_handler(ec->handle,
 907                                                     ACPI_ADR_SPACE_EC,
 908                                                     &acpi_ec_space_handler,
 909                                                     &acpi_ec_space_setup, ec);
 910         if (ACPI_FAILURE(status)) {
 911                 acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 912                 return -ENODEV;
 913         }
 914
 915         ec->handlers_installed = 1;
 916         return 0;
 917 }
 918
 919 static int acpi_ec_start(struct acpi_device *device)
 920 {
 921         struct acpi_ec *ec;
 922         int ret = 0;
 923
 924         if (!device)
 925                 return -EINVAL;
 926
 927         ec = acpi_driver_data(device);
 928
 929         if (!ec)
 930                 return -EINVAL;
 931
 932         ret = ec_install_handlers(ec);
 933
 934         /* EC is fully operational, allow queries */
 935         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 936         ec_schedule_ec_poll(ec);
 937         return ret;
 938 }
 939
 940 static int acpi_ec_stop(struct acpi_device *device, int type)
 941 {
 942         struct acpi_ec *ec;
 943         if (!device)
 944                 return -EINVAL;
 945         ec = acpi_driver_data(device);
 946         if (!ec)
 947                 return -EINVAL;
 948         ec_remove_handlers(ec);
 949
 950         return 0;
 951 }
 952
 953 int __init acpi_boot_ec_enable(void)
 954 {
 955         if (!boot_ec || boot_ec->handlers_installed)
 956                 return 0;
 957         if (!ec_install_handlers(boot_ec)) {
 958                 first_ec = boot_ec;
 959                 return 0;
 960         }
 961         return -EFAULT;
 962 }
 963
 964 int __init acpi_ec_ecdt_probe(void)
 965 {
 966         int ret;
 967         acpi_status status;
 968         struct acpi_table_ecdt *ecdt_ptr;
 969
 970         boot_ec = make_acpi_ec();
 971         if (!boot_ec)
 972                 return -ENOMEM;
 973         /*
 974          * Generate a boot ec context
 975          */
 976         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 977                                 (struct acpi_table_header **)&ecdt_ptr);
 978         if (ACPI_SUCCESS(status)) {
 979                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
 980                 boot_ec->command_addr = ecdt_ptr->control.address;
 981                 boot_ec->data_addr = ecdt_ptr->data.address;
 982                 boot_ec->gpe = ecdt_ptr->gpe;
 983                 boot_ec->handle = ACPI_ROOT_OBJECT;
 984         } else {
 985                 /* This workaround is needed only on some broken machines,
 986                  * which require early EC, but fail to provide ECDT */
 987                 acpi_handle x;
 988                 printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
 989                 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
 990                                                 boot_ec, NULL);
 991                 /* Check that acpi_get_devices actually find something */
 992                 if (ACPI_FAILURE(status) || !boot_ec->handle)
 993                         goto error;
 994                 /* We really need to limit this workaround, the only ASUS,
 995                  * which needs it, has fake EC._INI method, so use it as flag.
 996                  * Keep boot_ec struct as it will be needed soon.
 997                  */
 998                 if (ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI", &x)))
 999                         return -ENODEV;
1000         }
1001
1002         ret = ec_install_handlers(boot_ec);
1003         if (!ret) {
1004                 first_ec = boot_ec;
1005                 return 0;
1006         }
1007       error:
1008         kfree(boot_ec);
1009         boot_ec = NULL;
1010         return -ENODEV;
1011 }
1012
1013 static int __init acpi_ec_init(void)
1014 {
1015         int result = 0;
1016
1017         if (acpi_disabled)
1018                 return 0;
1019
1020         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1021         if (!acpi_ec_dir)
1022                 return -ENODEV;
1023
1024         /* Now register the driver for the EC */
1025         result = acpi_bus_register_driver(&acpi_ec_driver);
1026         if (result < 0) {
1027                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1028                 return -ENODEV;
1029         }
1030
1031         return result;
1032 }
1033
1034 subsys_initcall(acpi_ec_init);
1035
1036 /* EC driver currently not unloadable */
1037 #if 0
1038 static void __exit acpi_ec_exit(void)
1039 {
1040
1041         acpi_bus_unregister_driver(&acpi_ec_driver);
1042
1043         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1044
1045         return;
1046 }
1047 #endif  /* 0 */