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 /* 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_GPE,                /* Don't use GPE mode */
  83         EC_FLAGS_RESCHEDULE_POLL        /* Re-schedule poll */
  84 };
  85
  86 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  87 /* External interfaces use first EC only, so remember */
  88 typedef int (*acpi_ec_query_func) (void *data);
  89
  90 struct acpi_ec_query_handler {
  91         struct list_head node;
  92         acpi_ec_query_func func;
  93         acpi_handle handle;
  94         void *data;
  95         u8 query_bit;
  96 };
  97
  98 static struct acpi_ec {
  99         acpi_handle handle;
 100         unsigned long gpe;
 101         unsigned long command_addr;
 102         unsigned long data_addr;
 103         unsigned long global_lock;
 104         unsigned long flags;
 105         struct mutex lock;
 106         wait_queue_head_t wait;
 107         struct list_head list;
 108         struct delayed_work work;
 109         atomic_t irq_count;
 110         u8 handlers_installed;
 111 } *boot_ec, *first_ec;
 112
 113 /* --------------------------------------------------------------------------
 114                              Transaction Management
 115    -------------------------------------------------------------------------- */
 116
 117 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 118 {
 119         u8 x = inb(ec->command_addr);
 120         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
 121         return x;
 122 }
 123
 124 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 125 {
 126         u8 x = inb(ec->data_addr);
 127         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
 128         return inb(ec->data_addr);
 129 }
 130
 131 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 132 {
 133         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
 134         outb(command, ec->command_addr);
 135 }
 136
 137 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 138 {
 139         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
 140         outb(data, ec->data_addr);
 141 }
 142
 143 static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
 144 {
 145         if (test_bit(EC_FLAGS_WAIT_GPE, &ec->flags))
 146                 return 0;
 147         if (event == ACPI_EC_EVENT_OBF_1) {
 148                 if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_OBF)
 149                         return 1;
 150         } else if (event == ACPI_EC_EVENT_IBF_0) {
 151                 if (!(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
 152                         return 1;
 153         }
 154
 155         return 0;
 156 }
 157
 158 static void ec_schedule_ec_poll(struct acpi_ec *ec)
 159 {
 160         if (test_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags))
 161                 schedule_delayed_work(&ec->work,
 162                                       msecs_to_jiffies(ACPI_EC_DELAY));
 163 }
 164
 165 static void ec_switch_to_poll_mode(struct acpi_ec *ec)
 166 {
 167         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
 168         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 169         acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 170         set_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
 171 }
 172
 173 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
 174 {
 175         atomic_set(&ec->irq_count, 0);
 176         if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&
 177             likely(!force_poll)) {
 178                 if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),
 179                                        msecs_to_jiffies(ACPI_EC_DELAY)))
 180                         return 0;
 181                 clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 182                 if (acpi_ec_check_status(ec, event)) {
 183                         /* missing GPEs, switch back to poll mode */
 184                         if (printk_ratelimit())
 185                                 pr_info(PREFIX "missing confirmations, "
 186                                                 "switch off interrupt mode.\n");
 187                         ec_switch_to_poll_mode(ec);
 188                         ec_schedule_ec_poll(ec);
 189                         return 0;
 190                 }
 191         } else {
 192                 unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 193                 clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 194                 while (time_before(jiffies, delay)) {
 195                         if (acpi_ec_check_status(ec, event))
 196                                 return 0;
 197                         udelay(ACPI_EC_UDELAY);
 198                 }
 199         }
 200         pr_err(PREFIX "acpi_ec_wait timeout, status = 0x%2.2x, event = %s\n",
 201                 acpi_ec_read_status(ec),
 202                 (event == ACPI_EC_EVENT_OBF_1) ? "\"b0=1\"" : "\"b1=0\"");
 203         return -ETIME;
 204 }
 205
 206 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
 207                                         const u8 * wdata, unsigned wdata_len,
 208                                         u8 * rdata, unsigned rdata_len,
 209                                         int force_poll)
 210 {
 211         int result = 0;
 212         set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 213         pr_debug(PREFIX "transaction start\n");
 214         acpi_ec_write_cmd(ec, command);
 215         for (; wdata_len > 0; --wdata_len) {
 216                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
 217                 if (result) {
 218                         pr_err(PREFIX
 219                                "write_cmd timeout, command = %d\n", command);
 220                         goto end;
 221                 }
 222                 set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 223                 acpi_ec_write_data(ec, *(wdata++));
 224         }
 225
 226         if (!rdata_len) {
 227                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
 228                 if (result) {
 229                         pr_err(PREFIX
 230                                "finish-write timeout, command = %d\n", command);
 231                         goto end;
 232                 }
 233         } else if (command == ACPI_EC_COMMAND_QUERY)
 234                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 235
 236         for (; rdata_len > 0; --rdata_len) {
 237                 result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, force_poll);
 238                 if (result) {
 239                         pr_err(PREFIX "read timeout, command = %d\n", command);
 240                         goto end;
 241                 }
 242                 /* Don't expect GPE after last read */
 243                 if (rdata_len > 1)
 244                         set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 245                 *(rdata++) = acpi_ec_read_data(ec);
 246         }
 247       end:
 248         pr_debug(PREFIX "transaction end\n");
 249         return result;
 250 }
 251
 252 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
 253                                const u8 * wdata, unsigned wdata_len,
 254                                u8 * rdata, unsigned rdata_len,
 255                                int force_poll)
 256 {
 257         int status;
 258         u32 glk;
 259
 260         if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
 261                 return -EINVAL;
 262
 263         if (rdata)
 264                 memset(rdata, 0, rdata_len);
 265
 266         mutex_lock(&ec->lock);
 267         if (ec->global_lock) {
 268                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 269                 if (ACPI_FAILURE(status)) {
 270                         mutex_unlock(&ec->lock);
 271                         return -ENODEV;
 272                 }
 273         }
 274
 275         status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
 276         if (status) {
 277                 pr_err(PREFIX "input buffer is not empty, "
 278                                 "aborting transaction\n");
 279                 goto end;
 280         }
 281
 282         status = acpi_ec_transaction_unlocked(ec, command,
 283                                               wdata, wdata_len,
 284                                               rdata, rdata_len,
 285                                               force_poll);
 286
 287       end:
 288
 289         if (ec->global_lock)
 290                 acpi_release_global_lock(glk);
 291         mutex_unlock(&ec->lock);
 292
 293         return status;
 294 }
 295
 296 /*
 297  * Note: samsung nv5000 doesn't work with ec burst mode.
 298  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 299  */
 300 int acpi_ec_burst_enable(struct acpi_ec *ec)
 301 {
 302         u8 d;
 303         return acpi_ec_transaction(ec, ACPI_EC_BURST_ENABLE, NULL, 0, &d, 1, 0);
 304 }
 305
 306 int acpi_ec_burst_disable(struct acpi_ec *ec)
 307 {
 308         return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0, 0);
 309 }
 310
 311 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 312 {
 313         int result;
 314         u8 d;
 315
 316         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
 317                                      &address, 1, &d, 1, 0);
 318         *data = d;
 319         return result;
 320 }
 321
 322 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 323 {
 324         u8 wdata[2] = { address, data };
 325         return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
 326                                    wdata, 2, NULL, 0, 0);
 327 }
 328
 329 /*
 330  * Externally callable EC access functions. For now, assume 1 EC only
 331  */
 332 int ec_burst_enable(void)
 333 {
 334         if (!first_ec)
 335                 return -ENODEV;
 336         return acpi_ec_burst_enable(first_ec);
 337 }
 338
 339 EXPORT_SYMBOL(ec_burst_enable);
 340
 341 int ec_burst_disable(void)
 342 {
 343         if (!first_ec)
 344                 return -ENODEV;
 345         return acpi_ec_burst_disable(first_ec);
 346 }
 347
 348 EXPORT_SYMBOL(ec_burst_disable);
 349
 350 int ec_read(u8 addr, u8 * val)
 351 {
 352         int err;
 353         u8 temp_data;
 354
 355         if (!first_ec)
 356                 return -ENODEV;
 357
 358         err = acpi_ec_read(first_ec, addr, &temp_data);
 359
 360         if (!err) {
 361                 *val = temp_data;
 362                 return 0;
 363         } else
 364                 return err;
 365 }
 366
 367 EXPORT_SYMBOL(ec_read);
 368
 369 int ec_write(u8 addr, u8 val)
 370 {
 371         int err;
 372
 373         if (!first_ec)
 374                 return -ENODEV;
 375
 376         err = acpi_ec_write(first_ec, addr, val);
 377
 378         return err;
 379 }
 380
 381 EXPORT_SYMBOL(ec_write);
 382
 383 int ec_transaction(u8 command,
 384                    const u8 * wdata, unsigned wdata_len,
 385                    u8 * rdata, unsigned rdata_len,
 386                    int force_poll)
 387 {
 388         if (!first_ec)
 389                 return -ENODEV;
 390
 391         return acpi_ec_transaction(first_ec, command, wdata,
 392                                    wdata_len, rdata, rdata_len,
 393                                    force_poll);
 394 }
 395
 396 EXPORT_SYMBOL(ec_transaction);
 397
 398 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 399 {
 400         int result;
 401         u8 d;
 402
 403         if (!ec || !data)
 404                 return -EINVAL;
 405
 406         /*
 407          * Query the EC to find out which _Qxx method we need to evaluate.
 408          * Note that successful completion of the query causes the ACPI_EC_SCI
 409          * bit to be cleared (and thus clearing the interrupt source).
 410          */
 411
 412         result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
 413         if (result)
 414                 return result;
 415
 416         if (!d)
 417                 return -ENODATA;
 418
 419         *data = d;
 420         return 0;
 421 }
 422
 423 /* --------------------------------------------------------------------------
 424                                 Event Management
 425    -------------------------------------------------------------------------- */
 426 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 427                               acpi_handle handle, acpi_ec_query_func func,
 428                               void *data)
 429 {
 430         struct acpi_ec_query_handler *handler =
 431             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 432         if (!handler)
 433                 return -ENOMEM;
 434
 435         handler->query_bit = query_bit;
 436         handler->handle = handle;
 437         handler->func = func;
 438         handler->data = data;
 439         mutex_lock(&ec->lock);
 440         list_add(&handler->node, &ec->list);
 441         mutex_unlock(&ec->lock);
 442         return 0;
 443 }
 444
 445 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 446
 447 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 448 {
 449         struct acpi_ec_query_handler *handler, *tmp;
 450         mutex_lock(&ec->lock);
 451         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 452                 if (query_bit == handler->query_bit) {
 453                         list_del(&handler->node);
 454                         kfree(handler);
 455                 }
 456         }
 457         mutex_unlock(&ec->lock);
 458 }
 459
 460 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 461
 462 static void acpi_ec_gpe_query(void *ec_cxt)
 463 {
 464         struct acpi_ec *ec = ec_cxt;
 465         u8 value = 0;
 466         struct acpi_ec_query_handler *handler, copy;
 467
 468         if (!ec || acpi_ec_query(ec, &value))
 469                 return;
 470         mutex_lock(&ec->lock);
 471         list_for_each_entry(handler, &ec->list, node) {
 472                 if (value == handler->query_bit) {
 473                         /* have custom handler for this bit */
 474                         memcpy(&copy, handler, sizeof(copy));
 475                         mutex_unlock(&ec->lock);
 476                         if (copy.func) {
 477                                 copy.func(copy.data);
 478                         } else if (copy.handle) {
 479                                 acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
 480                         }
 481                         return;
 482                 }
 483         }
 484         mutex_unlock(&ec->lock);
 485 }
 486
 487 static u32 acpi_ec_gpe_handler(void *data)
 488 {
 489         acpi_status status = AE_OK;
 490         struct acpi_ec *ec = data;
 491         u8 state = acpi_ec_read_status(ec);
 492
 493         pr_debug(PREFIX "~~~> interrupt\n");
 494         atomic_inc(&ec->irq_count);
 495         if (atomic_read(&ec->irq_count) > 5) {
 496                 pr_err(PREFIX "GPE storm detected, disabling EC GPE\n");
 497                 ec_switch_to_poll_mode(ec);
 498                 goto end;
 499         }
 500         clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
 501         if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
 502                 wake_up(&ec->wait);
 503
 504         if (state & ACPI_EC_FLAG_SCI) {
 505                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 506                         status = acpi_os_execute(OSL_EC_BURST_HANDLER,
 507                                 acpi_ec_gpe_query, ec);
 508         } else if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 509                    !test_bit(EC_FLAGS_NO_GPE, &ec->flags) &&
 510                    in_interrupt()) {
 511                 /* this is non-query, must be confirmation */
 512                 if (printk_ratelimit())
 513                         pr_info(PREFIX "non-query interrupt received,"
 514                                 " switching to interrupt mode\n");
 515                 set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 516                 clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
 517         }
 518 end:
 519         ec_schedule_ec_poll(ec);
 520         return ACPI_SUCCESS(status) ?
 521             ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
 522 }
 523
 524 static void do_ec_poll(struct work_struct *work)
 525 {
 526         struct acpi_ec *ec = container_of(work, struct acpi_ec, work.work);
 527         atomic_set(&ec->irq_count, 0);
 528         (void)acpi_ec_gpe_handler(ec);
 529 }
 530
 531 /* --------------------------------------------------------------------------
 532                              Address Space Management
 533    -------------------------------------------------------------------------- */
 534
 535 static acpi_status
 536 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 537                       u32 bits, acpi_integer *value,
 538                       void *handler_context, void *region_context)
 539 {
 540         struct acpi_ec *ec = handler_context;
 541         int result = 0, i;
 542         u8 temp = 0;
 543
 544         if ((address > 0xFF) || !value || !handler_context)
 545                 return AE_BAD_PARAMETER;
 546
 547         if (function != ACPI_READ && function != ACPI_WRITE)
 548                 return AE_BAD_PARAMETER;
 549
 550         if (bits != 8 && acpi_strict)
 551                 return AE_BAD_PARAMETER;
 552
 553         acpi_ec_burst_enable(ec);
 554
 555         if (function == ACPI_READ) {
 556                 result = acpi_ec_read(ec, address, &temp);
 557                 *value = temp;
 558         } else {
 559                 temp = 0xff & (*value);
 560                 result = acpi_ec_write(ec, address, temp);
 561         }
 562
 563         for (i = 8; unlikely(bits - i > 0); i += 8) {
 564                 ++address;
 565                 if (function == ACPI_READ) {
 566                         result = acpi_ec_read(ec, address, &temp);
 567                         (*value) |= ((acpi_integer)temp) << i;
 568                 } else {
 569                         temp = 0xff & ((*value) >> i);
 570                         result = acpi_ec_write(ec, address, temp);
 571                 }
 572         }
 573
 574         acpi_ec_burst_disable(ec);
 575
 576         switch (result) {
 577         case -EINVAL:
 578                 return AE_BAD_PARAMETER;
 579                 break;
 580         case -ENODEV:
 581                 return AE_NOT_FOUND;
 582                 break;
 583         case -ETIME:
 584                 return AE_TIME;
 585                 break;
 586         default:
 587                 return AE_OK;
 588         }
 589 }
 590
 591 /* --------------------------------------------------------------------------
 592                               FS Interface (/proc)
 593    -------------------------------------------------------------------------- */
 594
 595 static struct proc_dir_entry *acpi_ec_dir;
 596
 597 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 598 {
 599         struct acpi_ec *ec = seq->private;
 600
 601         if (!ec)
 602                 goto end;
 603
 604         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 605         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 606                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 607         seq_printf(seq, "use global lock:\t%s\n",
 608                    ec->global_lock ? "yes" : "no");
 609       end:
 610         return 0;
 611 }
 612
 613 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 614 {
 615         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 616 }
 617
 618 static struct file_operations acpi_ec_info_ops = {
 619         .open = acpi_ec_info_open_fs,
 620         .read = seq_read,
 621         .llseek = seq_lseek,
 622         .release = single_release,
 623         .owner = THIS_MODULE,
 624 };
 625
 626 static int acpi_ec_add_fs(struct acpi_device *device)
 627 {
 628         struct proc_dir_entry *entry = NULL;
 629
 630         if (!acpi_device_dir(device)) {
 631                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 632                                                      acpi_ec_dir);
 633                 if (!acpi_device_dir(device))
 634                         return -ENODEV;
 635         }
 636
 637         entry = create_proc_entry(ACPI_EC_FILE_INFO, S_IRUGO,
 638                                   acpi_device_dir(device));
 639         if (!entry)
 640                 return -ENODEV;
 641         else {
 642                 entry->proc_fops = &acpi_ec_info_ops;
 643                 entry->data = acpi_driver_data(device);
 644                 entry->owner = THIS_MODULE;
 645         }
 646
 647         return 0;
 648 }
 649
 650 static int acpi_ec_remove_fs(struct acpi_device *device)
 651 {
 652
 653         if (acpi_device_dir(device)) {
 654                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 655                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 656                 acpi_device_dir(device) = NULL;
 657         }
 658
 659         return 0;
 660 }
 661
 662 /* --------------------------------------------------------------------------
 663                                Driver Interface
 664    -------------------------------------------------------------------------- */
 665 static acpi_status
 666 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 667
 668 static struct acpi_ec *make_acpi_ec(void)
 669 {
 670         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 671         if (!ec)
 672                 return NULL;
 673         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 674         mutex_init(&ec->lock);
 675         init_waitqueue_head(&ec->wait);
 676         INIT_LIST_HEAD(&ec->list);
 677         INIT_DELAYED_WORK_DEFERRABLE(&ec->work, do_ec_poll);
 678         atomic_set(&ec->irq_count, 0);
 679         return ec;
 680 }
 681
 682 static acpi_status
 683 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 684                                void *context, void **return_value)
 685 {
 686         struct acpi_namespace_node *node = handle;
 687         struct acpi_ec *ec = context;
 688         int value = 0;
 689         if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
 690                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 691         }
 692         return AE_OK;
 693 }
 694
 695 static acpi_status
 696 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 697 {
 698         acpi_status status;
 699
 700         struct acpi_ec *ec = context;
 701         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 702                                      ec_parse_io_ports, ec);
 703         if (ACPI_FAILURE(status))
 704                 return status;
 705
 706         /* Get GPE bit assignment (EC events). */
 707         /* TODO: Add support for _GPE returning a package */
 708         status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
 709         if (ACPI_FAILURE(status))
 710                 return status;
 711         /* Use the global lock for all EC transactions? */
 712         acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
 713         ec->handle = handle;
 714         return AE_CTRL_TERMINATE;
 715 }
 716
 717 static void ec_poll_stop(struct acpi_ec *ec)
 718 {
 719         clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
 720         cancel_delayed_work(&ec->work);
 721 }
 722
 723 static void ec_remove_handlers(struct acpi_ec *ec)
 724 {
 725         ec_poll_stop(ec);
 726         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 727                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 728                 pr_err(PREFIX "failed to remove space handler\n");
 729         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 730                                 &acpi_ec_gpe_handler)))
 731                 pr_err(PREFIX "failed to remove gpe handler\n");
 732         ec->handlers_installed = 0;
 733 }
 734
 735 static int acpi_ec_add(struct acpi_device *device)
 736 {
 737         struct acpi_ec *ec = NULL;
 738
 739         if (!device)
 740                 return -EINVAL;
 741         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 742         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 743
 744         /* Check for boot EC */
 745         if (boot_ec &&
 746             (boot_ec->handle == device->handle ||
 747              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 748                 ec = boot_ec;
 749                 boot_ec = NULL;
 750         } else {
 751                 ec = make_acpi_ec();
 752                 if (!ec)
 753                         return -ENOMEM;
 754                 if (ec_parse_device(device->handle, 0, ec, NULL) !=
 755                     AE_CTRL_TERMINATE) {
 756                         kfree(ec);
 757                         return -EINVAL;
 758                 }
 759         }
 760
 761         ec->handle = device->handle;
 762
 763         /* Find and register all query methods */
 764         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 765                             acpi_ec_register_query_methods, ec, NULL);
 766
 767         if (!first_ec)
 768                 first_ec = ec;
 769         acpi_driver_data(device) = ec;
 770         acpi_ec_add_fs(device);
 771         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 772                           ec->gpe, ec->command_addr, ec->data_addr);
 773         pr_info(PREFIX "driver started in %s mode\n",
 774                 (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
 775         return 0;
 776 }
 777
 778 static int acpi_ec_remove(struct acpi_device *device, int type)
 779 {
 780         struct acpi_ec *ec;
 781         struct acpi_ec_query_handler *handler, *tmp;
 782
 783         if (!device)
 784                 return -EINVAL;
 785
 786         ec = acpi_driver_data(device);
 787         mutex_lock(&ec->lock);
 788         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 789                 list_del(&handler->node);
 790                 kfree(handler);
 791         }
 792         mutex_unlock(&ec->lock);
 793         acpi_ec_remove_fs(device);
 794         acpi_driver_data(device) = NULL;
 795         if (ec == first_ec)
 796                 first_ec = NULL;
 797         kfree(ec);
 798         return 0;
 799 }
 800
 801 static acpi_status
 802 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 803 {
 804         struct acpi_ec *ec = context;
 805
 806         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 807                 return AE_OK;
 808
 809         /*
 810          * The first address region returned is the data port, and
 811          * the second address region returned is the status/command
 812          * port.
 813          */
 814         if (ec->data_addr == 0)
 815                 ec->data_addr = resource->data.io.minimum;
 816         else if (ec->command_addr == 0)
 817                 ec->command_addr = resource->data.io.minimum;
 818         else
 819                 return AE_CTRL_TERMINATE;
 820
 821         return AE_OK;
 822 }
 823
 824 static int ec_install_handlers(struct acpi_ec *ec)
 825 {
 826         acpi_status status;
 827         if (ec->handlers_installed)
 828                 return 0;
 829         status = acpi_install_gpe_handler(NULL, ec->gpe,
 830                                           ACPI_GPE_EDGE_TRIGGERED,
 831                                           &acpi_ec_gpe_handler, ec);
 832         if (ACPI_FAILURE(status))
 833                 return -ENODEV;
 834
 835         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 836         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 837
 838         status = acpi_install_address_space_handler(ec->handle,
 839                                                     ACPI_ADR_SPACE_EC,
 840                                                     &acpi_ec_space_handler,
 841                                                     NULL, ec);
 842         if (ACPI_FAILURE(status)) {
 843                 acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
 844                 return -ENODEV;
 845         }
 846
 847         ec->handlers_installed = 1;
 848         return 0;
 849 }
 850
 851 static int acpi_ec_start(struct acpi_device *device)
 852 {
 853         struct acpi_ec *ec;
 854         int ret = 0;
 855
 856         if (!device)
 857                 return -EINVAL;
 858
 859         ec = acpi_driver_data(device);
 860
 861         if (!ec)
 862                 return -EINVAL;
 863
 864         ret = ec_install_handlers(ec);
 865
 866         /* EC is fully operational, allow queries */
 867         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 868         ec_schedule_ec_poll(ec);
 869         return ret;
 870 }
 871
 872 static int acpi_ec_stop(struct acpi_device *device, int type)
 873 {
 874         struct acpi_ec *ec;
 875         if (!device)
 876                 return -EINVAL;
 877         ec = acpi_driver_data(device);
 878         if (!ec)
 879                 return -EINVAL;
 880         ec_remove_handlers(ec);
 881
 882         return 0;
 883 }
 884
 885 int __init acpi_boot_ec_enable(void)
 886 {
 887         if (!boot_ec || boot_ec->handlers_installed)
 888                 return 0;
 889         if (!ec_install_handlers(boot_ec)) {
 890                 first_ec = boot_ec;
 891                 return 0;
 892         }
 893         return -EFAULT;
 894 }
 895
 896 static const struct acpi_device_id ec_device_ids[] = {
 897         {"PNP0C09", 0},
 898         {"", 0},
 899 };
 900
 901 int __init acpi_ec_ecdt_probe(void)
 902 {
 903         int ret;
 904         acpi_status status;
 905         struct acpi_table_ecdt *ecdt_ptr;
 906
 907         boot_ec = make_acpi_ec();
 908         if (!boot_ec)
 909                 return -ENOMEM;
 910         /*
 911          * Generate a boot ec context
 912          */
 913         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 914                                 (struct acpi_table_header **)&ecdt_ptr);
 915         if (ACPI_SUCCESS(status)) {
 916                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
 917                 boot_ec->command_addr = ecdt_ptr->control.address;
 918                 boot_ec->data_addr = ecdt_ptr->data.address;
 919                 boot_ec->gpe = ecdt_ptr->gpe;
 920                 boot_ec->handle = ACPI_ROOT_OBJECT;
 921                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
 922         } else {
 923                 /* This workaround is needed only on some broken machines,
 924                  * which require early EC, but fail to provide ECDT */
 925                 acpi_handle x;
 926                 printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
 927                 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
 928                                                 boot_ec, NULL);
 929                 /* Check that acpi_get_devices actually find something */
 930                 if (ACPI_FAILURE(status) || !boot_ec->handle)
 931                         goto error;
 932                 /* We really need to limit this workaround, the only ASUS,
 933                  * which needs it, has fake EC._INI method, so use it as flag.
 934                  * Keep boot_ec struct as it will be needed soon.
 935                  */
 936                 if (ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI", &x)))
 937                         return -ENODEV;
 938         }
 939
 940         ret = ec_install_handlers(boot_ec);
 941         if (!ret) {
 942                 first_ec = boot_ec;
 943                 return 0;
 944         }
 945       error:
 946         kfree(boot_ec);
 947         boot_ec = NULL;
 948         return -ENODEV;
 949 }
 950
 951 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
 952 {
 953         struct acpi_ec *ec = acpi_driver_data(device);
 954         /* Stop using GPE */
 955         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
 956         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 957         acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 958         return 0;
 959 }
 960
 961 static int acpi_ec_resume(struct acpi_device *device)
 962 {
 963         struct acpi_ec *ec = acpi_driver_data(device);
 964         /* Enable use of GPE back */
 965         clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
 966         acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
 967         return 0;
 968 }
 969
 970 static struct acpi_driver acpi_ec_driver = {
 971         .name = "ec",
 972         .class = ACPI_EC_CLASS,
 973         .ids = ec_device_ids,
 974         .ops = {
 975                 .add = acpi_ec_add,
 976                 .remove = acpi_ec_remove,
 977                 .start = acpi_ec_start,
 978                 .stop = acpi_ec_stop,
 979                 .suspend = acpi_ec_suspend,
 980                 .resume = acpi_ec_resume,
 981                 },
 982 };
 983
 984 static int __init acpi_ec_init(void)
 985 {
 986         int result = 0;
 987
 988         if (acpi_disabled)
 989                 return 0;
 990
 991         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
 992         if (!acpi_ec_dir)
 993                 return -ENODEV;
 994
 995         /* Now register the driver for the EC */
 996         result = acpi_bus_register_driver(&acpi_ec_driver);
 997         if (result < 0) {
 998                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
 999                 return -ENODEV;
1000         }
1001
1002         return result;
1003 }
1004
1005 subsys_initcall(acpi_ec_init);
1006
1007 /* EC driver currently not unloadable */
1008 #if 0
1009 static void __exit acpi_ec_exit(void)
1010 {
1011
1012         acpi_bus_unregister_driver(&acpi_ec_driver);
1013
1014         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1015
1016         return;
1017 }
1018 #endif  /* 0 */