drivers/hid/hid-core.c

   1 /*
   2  *  HID support for Linux
   3  *
   4  *  Copyright (c) 1999 Andreas Gal
   5  *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
   6  *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
   7  *  Copyright (c) 2006-2012 Jiri Kosina
   8  */
   9
  10 /*
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU General Public License as published by the Free
  13  * Software Foundation; either version 2 of the License, or (at your option)
  14  * any later version.
  15  */
  16
  17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  18
  19 #include <linux/module.h>
  20 #include <linux/slab.h>
  21 #include <linux/init.h>
  22 #include <linux/kernel.h>
  23 #include <linux/list.h>
  24 #include <linux/mm.h>
  25 #include <linux/spinlock.h>
  26 #include <asm/unaligned.h>
  27 #include <asm/byteorder.h>
  28 #include <linux/input.h>
  29 #include <linux/wait.h>
  30 #include <linux/vmalloc.h>
  31 #include <linux/sched.h>
  32 #include <linux/semaphore.h>
  33 #include <linux/async.h>
  34
  35 #include <linux/hid.h>
  36 #include <linux/hiddev.h>
  37 #include <linux/hid-debug.h>
  38 #include <linux/hidraw.h>
  39
  40 #include "hid-ids.h"
  41
  42 /*
  43  * Version Information
  44  */
  45
  46 #define DRIVER_DESC "HID core driver"
  47
  48 int hid_debug = 0;
  49 module_param_named(debug, hid_debug, int, 0600);
  50 MODULE_PARM_DESC(debug, "toggle HID debugging messages");
  51 EXPORT_SYMBOL_GPL(hid_debug);
  52
  53 static int hid_ignore_special_drivers = 0;
  54 module_param_named(ignore_special_drivers, hid_ignore_special_drivers, int, 0600);
  55 MODULE_PARM_DESC(ignore_special_drivers, "Ignore any special drivers and handle all devices by generic driver");
  56
  57 /*
  58  * Register a new report for a device.
  59  */
  60
  61 struct hid_report *hid_register_report(struct hid_device *device,
  62                                        unsigned int type, unsigned int id,
  63                                        unsigned int application)
  64 {
  65         struct hid_report_enum *report_enum = device->report_enum + type;
  66         struct hid_report *report;
  67
  68         if (id >= HID_MAX_IDS)
  69                 return NULL;
  70         if (report_enum->report_id_hash[id])
  71                 return report_enum->report_id_hash[id];
  72
  73         report = kzalloc(sizeof(struct hid_report), GFP_KERNEL);
  74         if (!report)
  75                 return NULL;
  76
  77         if (id != 0)
  78                 report_enum->numbered = 1;
  79
  80         report->id = id;
  81         report->type = type;
  82         report->size = 0;
  83         report->device = device;
  84         report->application = application;
  85         report_enum->report_id_hash[id] = report;
  86
  87         list_add_tail(&report->list, &report_enum->report_list);
  88
  89         return report;
  90 }
  91 EXPORT_SYMBOL_GPL(hid_register_report);
  92
  93 /*
  94  * Register a new field for this report.
  95  */
  96
  97 static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages, unsigned values)
  98 {
  99         struct hid_field *field;
 100
 101         if (report->maxfield == HID_MAX_FIELDS) {
 102                 hid_err(report->device, "too many fields in report\n");
 103                 return NULL;
 104         }
 105
 106         field = kzalloc((sizeof(struct hid_field) +
 107                          usages * sizeof(struct hid_usage) +
 108                          values * sizeof(unsigned)), GFP_KERNEL);
 109         if (!field)
 110                 return NULL;
 111
 112         field->index = report->maxfield++;
 113         report->field[field->index] = field;
 114         field->usage = (struct hid_usage *)(field + 1);
 115         field->value = (s32 *)(field->usage + usages);
 116         field->report = report;
 117
 118         return field;
 119 }
 120
 121 /*
 122  * Open a collection. The type/usage is pushed on the stack.
 123  */
 124
 125 static int open_collection(struct hid_parser *parser, unsigned type)
 126 {
 127         struct hid_collection *collection;
 128         unsigned usage;
 129         int collection_index;
 130
 131         usage = parser->local.usage[0];
 132
 133         if (parser->collection_stack_ptr == parser->collection_stack_size) {
 134                 unsigned int *collection_stack;
 135                 unsigned int new_size = parser->collection_stack_size +
 136                                         HID_COLLECTION_STACK_SIZE;
 137
 138                 collection_stack = krealloc(parser->collection_stack,
 139                                             new_size * sizeof(unsigned int),
 140                                             GFP_KERNEL);
 141                 if (!collection_stack)
 142                         return -ENOMEM;
 143
 144                 parser->collection_stack = collection_stack;
 145                 parser->collection_stack_size = new_size;
 146         }
 147
 148         if (parser->device->maxcollection == parser->device->collection_size) {
 149                 collection = kmalloc(
 150                                 array3_size(sizeof(struct hid_collection),
 151                                             parser->device->collection_size,
 152                                             2),
 153                                 GFP_KERNEL);
 154                 if (collection == NULL) {
 155                         hid_err(parser->device, "failed to reallocate collection array\n");
 156                         return -ENOMEM;
 157                 }
 158                 memcpy(collection, parser->device->collection,
 159                         sizeof(struct hid_collection) *
 160                         parser->device->collection_size);
 161                 memset(collection + parser->device->collection_size, 0,
 162                         sizeof(struct hid_collection) *
 163                         parser->device->collection_size);
 164                 kfree(parser->device->collection);
 165                 parser->device->collection = collection;
 166                 parser->device->collection_size *= 2;
 167         }
 168
 169         parser->collection_stack[parser->collection_stack_ptr++] =
 170                 parser->device->maxcollection;
 171
 172         collection_index = parser->device->maxcollection++;
 173         collection = parser->device->collection + collection_index;
 174         collection->type = type;
 175         collection->usage = usage;
 176         collection->level = parser->collection_stack_ptr - 1;
 177         collection->parent_idx = (collection->level == 0) ? -1 :
 178                 parser->collection_stack[collection->level - 1];
 179
 180         if (type == HID_COLLECTION_APPLICATION)
 181                 parser->device->maxapplication++;
 182
 183         return 0;
 184 }
 185
 186 /*
 187  * Close a collection.
 188  */
 189
 190 static int close_collection(struct hid_parser *parser)
 191 {
 192         if (!parser->collection_stack_ptr) {
 193                 hid_err(parser->device, "collection stack underflow\n");
 194                 return -EINVAL;
 195         }
 196         parser->collection_stack_ptr--;
 197         return 0;
 198 }
 199
 200 /*
 201  * Climb up the stack, search for the specified collection type
 202  * and return the usage.
 203  */
 204
 205 static unsigned hid_lookup_collection(struct hid_parser *parser, unsigned type)
 206 {
 207         struct hid_collection *collection = parser->device->collection;
 208         int n;
 209
 210         for (n = parser->collection_stack_ptr - 1; n >= 0; n--) {
 211                 unsigned index = parser->collection_stack[n];
 212                 if (collection[index].type == type)
 213                         return collection[index].usage;
 214         }
 215         return 0; /* we know nothing about this usage type */
 216 }
 217
 218 /*
 219  * Add a usage to the temporary parser table.
 220  */
 221
 222 static int hid_add_usage(struct hid_parser *parser, unsigned usage, u8 size)
 223 {
 224         if (parser->local.usage_index >= HID_MAX_USAGES) {
 225                 hid_err(parser->device, "usage index exceeded\n");
 226                 return -1;
 227         }
 228         parser->local.usage[parser->local.usage_index] = usage;
 229         parser->local.usage_size[parser->local.usage_index] = size;
 230         parser->local.collection_index[parser->local.usage_index] =
 231                 parser->collection_stack_ptr ?
 232                 parser->collection_stack[parser->collection_stack_ptr - 1] : 0;
 233         parser->local.usage_index++;
 234         return 0;
 235 }
 236
 237 /*
 238  * Register a new field for this report.
 239  */
 240
 241 static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsigned flags)
 242 {
 243         struct hid_report *report;
 244         struct hid_field *field;
 245         unsigned int usages;
 246         unsigned int offset;
 247         unsigned int i;
 248         unsigned int application;
 249
 250         application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
 251
 252         report = hid_register_report(parser->device, report_type,
 253                                      parser->global.report_id, application);
 254         if (!report) {
 255                 hid_err(parser->device, "hid_register_report failed\n");
 256                 return -1;
 257         }
 258
 259         /* Handle both signed and unsigned cases properly */
 260         if ((parser->global.logical_minimum < 0 &&
 261                 parser->global.logical_maximum <
 262                 parser->global.logical_minimum) ||
 263                 (parser->global.logical_minimum >= 0 &&
 264                 (__u32)parser->global.logical_maximum <
 265                 (__u32)parser->global.logical_minimum)) {
 266                 dbg_hid("logical range invalid 0x%x 0x%x\n",
 267                         parser->global.logical_minimum,
 268                         parser->global.logical_maximum);
 269                 return -1;
 270         }
 271
 272         offset = report->size;
 273         report->size += parser->global.report_size * parser->global.report_count;
 274
 275         if (!parser->local.usage_index) /* Ignore padding fields */
 276                 return 0;
 277
 278         usages = max_t(unsigned, parser->local.usage_index,
 279                                  parser->global.report_count);
 280
 281         field = hid_register_field(report, usages, parser->global.report_count);
 282         if (!field)
 283                 return 0;
 284
 285         field->physical = hid_lookup_collection(parser, HID_COLLECTION_PHYSICAL);
 286         field->logical = hid_lookup_collection(parser, HID_COLLECTION_LOGICAL);
 287         field->application = application;
 288
 289         for (i = 0; i < usages; i++) {
 290                 unsigned j = i;
 291                 /* Duplicate the last usage we parsed if we have excess values */
 292                 if (i >= parser->local.usage_index)
 293                         j = parser->local.usage_index - 1;
 294                 field->usage[i].hid = parser->local.usage[j];
 295                 field->usage[i].collection_index =
 296                         parser->local.collection_index[j];
 297                 field->usage[i].usage_index = i;
 298                 field->usage[i].resolution_multiplier = 1;
 299         }
 300
 301         field->maxusage = usages;
 302         field->flags = flags;
 303         field->report_offset = offset;
 304         field->report_type = report_type;
 305         field->report_size = parser->global.report_size;
 306         field->report_count = parser->global.report_count;
 307         field->logical_minimum = parser->global.logical_minimum;
 308         field->logical_maximum = parser->global.logical_maximum;
 309         field->physical_minimum = parser->global.physical_minimum;
 310         field->physical_maximum = parser->global.physical_maximum;
 311         field->unit_exponent = parser->global.unit_exponent;
 312         field->unit = parser->global.unit;
 313
 314         return 0;
 315 }
 316
 317 /*
 318  * Read data value from item.
 319  */
 320
 321 static u32 item_udata(struct hid_item *item)
 322 {
 323         switch (item->size) {
 324         case 1: return item->data.u8;
 325         case 2: return item->data.u16;
 326         case 4: return item->data.u32;
 327         }
 328         return 0;
 329 }
 330
 331 static s32 item_sdata(struct hid_item *item)
 332 {
 333         switch (item->size) {
 334         case 1: return item->data.s8;
 335         case 2: return item->data.s16;
 336         case 4: return item->data.s32;
 337         }
 338         return 0;
 339 }
 340
 341 /*
 342  * Process a global item.
 343  */
 344
 345 static int hid_parser_global(struct hid_parser *parser, struct hid_item *item)
 346 {
 347         __s32 raw_value;
 348         switch (item->tag) {
 349         case HID_GLOBAL_ITEM_TAG_PUSH:
 350
 351                 if (parser->global_stack_ptr == HID_GLOBAL_STACK_SIZE) {
 352                         hid_err(parser->device, "global environment stack overflow\n");
 353                         return -1;
 354                 }
 355
 356                 memcpy(parser->global_stack + parser->global_stack_ptr++,
 357                         &parser->global, sizeof(struct hid_global));
 358                 return 0;
 359
 360         case HID_GLOBAL_ITEM_TAG_POP:
 361
 362                 if (!parser->global_stack_ptr) {
 363                         hid_err(parser->device, "global environment stack underflow\n");
 364                         return -1;
 365                 }
 366
 367                 memcpy(&parser->global, parser->global_stack +
 368                         --parser->global_stack_ptr, sizeof(struct hid_global));
 369                 return 0;
 370
 371         case HID_GLOBAL_ITEM_TAG_USAGE_PAGE:
 372                 parser->global.usage_page = item_udata(item);
 373                 return 0;
 374
 375         case HID_GLOBAL_ITEM_TAG_LOGICAL_MINIMUM:
 376                 parser->global.logical_minimum = item_sdata(item);
 377                 return 0;
 378
 379         case HID_GLOBAL_ITEM_TAG_LOGICAL_MAXIMUM:
 380                 if (parser->global.logical_minimum < 0)
 381                         parser->global.logical_maximum = item_sdata(item);
 382                 else
 383                         parser->global.logical_maximum = item_udata(item);
 384                 return 0;
 385
 386         case HID_GLOBAL_ITEM_TAG_PHYSICAL_MINIMUM:
 387                 parser->global.physical_minimum = item_sdata(item);
 388                 return 0;
 389
 390         case HID_GLOBAL_ITEM_TAG_PHYSICAL_MAXIMUM:
 391                 if (parser->global.physical_minimum < 0)
 392                         parser->global.physical_maximum = item_sdata(item);
 393                 else
 394                         parser->global.physical_maximum = item_udata(item);
 395                 return 0;
 396
 397         case HID_GLOBAL_ITEM_TAG_UNIT_EXPONENT:
 398                 /* Many devices provide unit exponent as a two's complement
 399                  * nibble due to the common misunderstanding of HID
 400                  * specification 1.11, 6.2.2.7 Global Items. Attempt to handle
 401                  * both this and the standard encoding. */
 402                 raw_value = item_sdata(item);
 403                 if (!(raw_value & 0xfffffff0))
 404                         parser->global.unit_exponent = hid_snto32(raw_value, 4);
 405                 else
 406                         parser->global.unit_exponent = raw_value;
 407                 return 0;
 408
 409         case HID_GLOBAL_ITEM_TAG_UNIT:
 410                 parser->global.unit = item_udata(item);
 411                 return 0;
 412
 413         case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
 414                 parser->global.report_size = item_udata(item);
 415                 if (parser->global.report_size > 256) {
 416                         hid_err(parser->device, "invalid report_size %d\n",
 417                                         parser->global.report_size);
 418                         return -1;
 419                 }
 420                 return 0;
 421
 422         case HID_GLOBAL_ITEM_TAG_REPORT_COUNT:
 423                 parser->global.report_count = item_udata(item);
 424                 if (parser->global.report_count > HID_MAX_USAGES) {
 425                         hid_err(parser->device, "invalid report_count %d\n",
 426                                         parser->global.report_count);
 427                         return -1;
 428                 }
 429                 return 0;
 430
 431         case HID_GLOBAL_ITEM_TAG_REPORT_ID:
 432                 parser->global.report_id = item_udata(item);
 433                 if (parser->global.report_id == 0 ||
 434                     parser->global.report_id >= HID_MAX_IDS) {
 435                         hid_err(parser->device, "report_id %u is invalid\n",
 436                                 parser->global.report_id);
 437                         return -1;
 438                 }
 439                 return 0;
 440
 441         default:
 442                 hid_err(parser->device, "unknown global tag 0x%x\n", item->tag);
 443                 return -1;
 444         }
 445 }
 446
 447 /*
 448  * Process a local item.
 449  */
 450
 451 static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
 452 {
 453         __u32 data;
 454         unsigned n;
 455         __u32 count;
 456
 457         data = item_udata(item);
 458
 459         switch (item->tag) {
 460         case HID_LOCAL_ITEM_TAG_DELIMITER:
 461
 462                 if (data) {
 463                         /*
 464                          * We treat items before the first delimiter
 465                          * as global to all usage sets (branch 0).
 466                          * In the moment we process only these global
 467                          * items and the first delimiter set.
 468                          */
 469                         if (parser->local.delimiter_depth != 0) {
 470                                 hid_err(parser->device, "nested delimiters\n");
 471                                 return -1;
 472                         }
 473                         parser->local.delimiter_depth++;
 474                         parser->local.delimiter_branch++;
 475                 } else {
 476                         if (parser->local.delimiter_depth < 1) {
 477                                 hid_err(parser->device, "bogus close delimiter\n");
 478                                 return -1;
 479                         }
 480                         parser->local.delimiter_depth--;
 481                 }
 482                 return 0;
 483
 484         case HID_LOCAL_ITEM_TAG_USAGE:
 485
 486                 if (parser->local.delimiter_branch > 1) {
 487                         dbg_hid("alternative usage ignored\n");
 488                         return 0;
 489                 }
 490
 491                 return hid_add_usage(parser, data, item->size);
 492
 493         case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:
 494
 495                 if (parser->local.delimiter_branch > 1) {
 496                         dbg_hid("alternative usage ignored\n");
 497                         return 0;
 498                 }
 499
 500                 parser->local.usage_minimum = data;
 501                 return 0;
 502
 503         case HID_LOCAL_ITEM_TAG_USAGE_MAXIMUM:
 504
 505                 if (parser->local.delimiter_branch > 1) {
 506                         dbg_hid("alternative usage ignored\n");
 507                         return 0;
 508                 }
 509
 510                 count = data - parser->local.usage_minimum;
 511                 if (count + parser->local.usage_index >= HID_MAX_USAGES) {
 512                         /*
 513                          * We do not warn if the name is not set, we are
 514                          * actually pre-scanning the device.
 515                          */
 516                         if (dev_name(&parser->device->dev))
 517                                 hid_warn(parser->device,
 518                                          "ignoring exceeding usage max\n");
 519                         data = HID_MAX_USAGES - parser->local.usage_index +
 520                                 parser->local.usage_minimum - 1;
 521                         if (data <= 0) {
 522                                 hid_err(parser->device,
 523                                         "no more usage index available\n");
 524                                 return -1;
 525                         }
 526                 }
 527
 528                 for (n = parser->local.usage_minimum; n <= data; n++)
 529                         if (hid_add_usage(parser, n, item->size)) {
 530                                 dbg_hid("hid_add_usage failed\n");
 531                                 return -1;
 532                         }
 533                 return 0;
 534
 535         default:
 536
 537                 dbg_hid("unknown local item tag 0x%x\n", item->tag);
 538                 return 0;
 539         }
 540         return 0;
 541 }
 542
 543 /*
 544  * Concatenate Usage Pages into Usages where relevant:
 545  * As per specification, 6.2.2.8: "When the parser encounters a main item it
 546  * concatenates the last declared Usage Page with a Usage to form a complete
 547  * usage value."
 548  */
 549
 550 static void hid_concatenate_usage_page(struct hid_parser *parser)
 551 {
 552         int i;
 553
 554         for (i = 0; i < parser->local.usage_index; i++)
 555                 if (parser->local.usage_size[i] <= 2)
 556                         parser->local.usage[i] += parser->global.usage_page << 16;
 557 }
 558
 559 /*
 560  * Process a main item.
 561  */
 562
 563 static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
 564 {
 565         __u32 data;
 566         int ret;
 567
 568         hid_concatenate_usage_page(parser);
 569
 570         data = item_udata(item);
 571
 572         switch (item->tag) {
 573         case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 574                 ret = open_collection(parser, data & 0xff);
 575                 break;
 576         case HID_MAIN_ITEM_TAG_END_COLLECTION:
 577                 ret = close_collection(parser);
 578                 break;
 579         case HID_MAIN_ITEM_TAG_INPUT:
 580                 ret = hid_add_field(parser, HID_INPUT_REPORT, data);
 581                 break;
 582         case HID_MAIN_ITEM_TAG_OUTPUT:
 583                 ret = hid_add_field(parser, HID_OUTPUT_REPORT, data);
 584                 break;
 585         case HID_MAIN_ITEM_TAG_FEATURE:
 586                 ret = hid_add_field(parser, HID_FEATURE_REPORT, data);
 587                 break;
 588         default:
 589                 hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
 590                 ret = 0;
 591         }
 592
 593         memset(&parser->local, 0, sizeof(parser->local));       /* Reset the local parser environment */
 594
 595         return ret;
 596 }
 597
 598 /*
 599  * Process a reserved item.
 600  */
 601
 602 static int hid_parser_reserved(struct hid_parser *parser, struct hid_item *item)
 603 {
 604         dbg_hid("reserved item type, tag 0x%x\n", item->tag);
 605         return 0;
 606 }
 607
 608 /*
 609  * Free a report and all registered fields. The field->usage and
 610  * field->value table's are allocated behind the field, so we need
 611  * only to free(field) itself.
 612  */
 613
 614 static void hid_free_report(struct hid_report *report)
 615 {
 616         unsigned n;
 617
 618         for (n = 0; n < report->maxfield; n++)
 619                 kfree(report->field[n]);
 620         kfree(report);
 621 }
 622
 623 /*
 624  * Close report. This function returns the device
 625  * state to the point prior to hid_open_report().
 626  */
 627 static void hid_close_report(struct hid_device *device)
 628 {
 629         unsigned i, j;
 630
 631         for (i = 0; i < HID_REPORT_TYPES; i++) {
 632                 struct hid_report_enum *report_enum = device->report_enum + i;
 633
 634                 for (j = 0; j < HID_MAX_IDS; j++) {
 635                         struct hid_report *report = report_enum->report_id_hash[j];
 636                         if (report)
 637                                 hid_free_report(report);
 638                 }
 639                 memset(report_enum, 0, sizeof(*report_enum));
 640                 INIT_LIST_HEAD(&report_enum->report_list);
 641         }
 642
 643         kfree(device->rdesc);
 644         device->rdesc = NULL;
 645         device->rsize = 0;
 646
 647         kfree(device->collection);
 648         device->collection = NULL;
 649         device->collection_size = 0;
 650         device->maxcollection = 0;
 651         device->maxapplication = 0;
 652
 653         device->status &= ~HID_STAT_PARSED;
 654 }
 655
 656 /*
 657  * Free a device structure, all reports, and all fields.
 658  */
 659
 660 static void hid_device_release(struct device *dev)
 661 {
 662         struct hid_device *hid = to_hid_device(dev);
 663
 664         hid_close_report(hid);
 665         kfree(hid->dev_rdesc);
 666         kfree(hid);
 667 }
 668
 669 /*
 670  * Fetch a report description item from the data stream. We support long
 671  * items, though they are not used yet.
 672  */
 673
 674 static u8 *fetch_item(__u8 *start, __u8 *end, struct hid_item *item)
 675 {
 676         u8 b;
 677
 678         if ((end - start) <= 0)
 679                 return NULL;
 680
 681         b = *start++;
 682
 683         item->type = (b >> 2) & 3;
 684         item->tag  = (b >> 4) & 15;
 685
 686         if (item->tag == HID_ITEM_TAG_LONG) {
 687
 688                 item->format = HID_ITEM_FORMAT_LONG;
 689
 690                 if ((end - start) < 2)
 691                         return NULL;
 692
 693                 item->size = *start++;
 694                 item->tag  = *start++;
 695
 696                 if ((end - start) < item->size)
 697                         return NULL;
 698
 699                 item->data.longdata = start;
 700                 start += item->size;
 701                 return start;
 702         }
 703
 704         item->format = HID_ITEM_FORMAT_SHORT;
 705         item->size = b & 3;
 706
 707         switch (item->size) {
 708         case 0:
 709                 return start;
 710
 711         case 1:
 712                 if ((end - start) < 1)
 713                         return NULL;
 714                 item->data.u8 = *start++;
 715                 return start;
 716
 717         case 2:
 718                 if ((end - start) < 2)
 719                         return NULL;
 720                 item->data.u16 = get_unaligned_le16(start);
 721                 start = (__u8 *)((__le16 *)start + 1);
 722                 return start;
 723
 724         case 3:
 725                 item->size++;
 726                 if ((end - start) < 4)
 727                         return NULL;
 728                 item->data.u32 = get_unaligned_le32(start);
 729                 start = (__u8 *)((__le32 *)start + 1);
 730                 return start;
 731         }
 732
 733         return NULL;
 734 }
 735
 736 static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)
 737 {
 738         struct hid_device *hid = parser->device;
 739
 740         if (usage == HID_DG_CONTACTID)
 741                 hid->group = HID_GROUP_MULTITOUCH;
 742 }
 743
 744 static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
 745 {
 746         if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
 747             parser->global.report_size == 8)
 748                 parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 749 }
 750
 751 static void hid_scan_collection(struct hid_parser *parser, unsigned type)
 752 {
 753         struct hid_device *hid = parser->device;
 754         int i;
 755
 756         if (((parser->global.usage_page << 16) == HID_UP_SENSOR) &&
 757             type == HID_COLLECTION_PHYSICAL)
 758                 hid->group = HID_GROUP_SENSOR_HUB;
 759
 760         if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
 761             hid->product == USB_DEVICE_ID_MS_POWER_COVER &&
 762             hid->group == HID_GROUP_MULTITOUCH)
 763                 hid->group = HID_GROUP_GENERIC;
 764
 765         if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
 766                 for (i = 0; i < parser->local.usage_index; i++)
 767                         if (parser->local.usage[i] == HID_GD_POINTER)
 768                                 parser->scan_flags |= HID_SCAN_FLAG_GD_POINTER;
 769
 770         if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
 771                 parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
 772 }
 773
 774 static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
 775 {
 776         __u32 data;
 777         int i;
 778
 779         hid_concatenate_usage_page(parser);
 780
 781         data = item_udata(item);
 782
 783         switch (item->tag) {
 784         case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 785                 hid_scan_collection(parser, data & 0xff);
 786                 break;
 787         case HID_MAIN_ITEM_TAG_END_COLLECTION:
 788                 break;
 789         case HID_MAIN_ITEM_TAG_INPUT:
 790                 /* ignore constant inputs, they will be ignored by hid-input */
 791                 if (data & HID_MAIN_ITEM_CONSTANT)
 792                         break;
 793                 for (i = 0; i < parser->local.usage_index; i++)
 794                         hid_scan_input_usage(parser, parser->local.usage[i]);
 795                 break;
 796         case HID_MAIN_ITEM_TAG_OUTPUT:
 797                 break;
 798         case HID_MAIN_ITEM_TAG_FEATURE:
 799                 for (i = 0; i < parser->local.usage_index; i++)
 800                         hid_scan_feature_usage(parser, parser->local.usage[i]);
 801                 break;
 802         }
 803
 804         /* Reset the local parser environment */
 805         memset(&parser->local, 0, sizeof(parser->local));
 806
 807         return 0;
 808 }
 809
 810 /*
 811  * Scan a report descriptor before the device is added to the bus.
 812  * Sets device groups and other properties that determine what driver
 813  * to load.
 814  */
 815 static int hid_scan_report(struct hid_device *hid)
 816 {
 817         struct hid_parser *parser;
 818         struct hid_item item;
 819         __u8 *start = hid->dev_rdesc;
 820         __u8 *end = start + hid->dev_rsize;
 821         static int (*dispatch_type[])(struct hid_parser *parser,
 822                                       struct hid_item *item) = {
 823                 hid_scan_main,
 824                 hid_parser_global,
 825                 hid_parser_local,
 826                 hid_parser_reserved
 827         };
 828
 829         parser = vzalloc(sizeof(struct hid_parser));
 830         if (!parser)
 831                 return -ENOMEM;
 832
 833         parser->device = hid;
 834         hid->group = HID_GROUP_GENERIC;
 835
 836         /*
 837          * The parsing is simpler than the one in hid_open_report() as we should
 838          * be robust against hid errors. Those errors will be raised by
 839          * hid_open_report() anyway.
 840          */
 841         while ((start = fetch_item(start, end, &item)) != NULL)
 842                 dispatch_type[item.type](parser, &item);
 843
 844         /*
 845          * Handle special flags set during scanning.
 846          */
 847         if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
 848             (hid->group == HID_GROUP_MULTITOUCH))
 849                 hid->group = HID_GROUP_MULTITOUCH_WIN_8;
 850
 851         /*
 852          * Vendor specific handlings
 853          */
 854         switch (hid->vendor) {
 855         case USB_VENDOR_ID_WACOM:
 856                 hid->group = HID_GROUP_WACOM;
 857                 break;
 858         case USB_VENDOR_ID_SYNAPTICS:
 859                 if (hid->group == HID_GROUP_GENERIC)
 860                         if ((parser->scan_flags & HID_SCAN_FLAG_VENDOR_SPECIFIC)
 861                             && (parser->scan_flags & HID_SCAN_FLAG_GD_POINTER))
 862                                 /*
 863                                  * hid-rmi should take care of them,
 864                                  * not hid-generic
 865                                  */
 866                                 hid->group = HID_GROUP_RMI;
 867                 break;
 868         }
 869
 870         kfree(parser->collection_stack);
 871         vfree(parser);
 872         return 0;
 873 }
 874
 875 /**
 876  * hid_parse_report - parse device report
 877  *
 878  * @device: hid device
 879  * @start: report start
 880  * @size: report size
 881  *
 882  * Allocate the device report as read by the bus driver. This function should
 883  * only be called from parse() in ll drivers.
 884  */
 885 int hid_parse_report(struct hid_device *hid, __u8 *start, unsigned size)
 886 {
 887         hid->dev_rdesc = kmemdup(start, size, GFP_KERNEL);
 888         if (!hid->dev_rdesc)
 889                 return -ENOMEM;
 890         hid->dev_rsize = size;
 891         return 0;
 892 }
 893 EXPORT_SYMBOL_GPL(hid_parse_report);
 894
 895 static const char * const hid_report_names[] = {
 896         "HID_INPUT_REPORT",
 897         "HID_OUTPUT_REPORT",
 898         "HID_FEATURE_REPORT",
 899 };
 900 /**
 901  * hid_validate_values - validate existing device report's value indexes
 902  *
 903  * @device: hid device
 904  * @type: which report type to examine
 905  * @id: which report ID to examine (0 for first)
 906  * @field_index: which report field to examine
 907  * @report_counts: expected number of values
 908  *
 909  * Validate the number of values in a given field of a given report, after
 910  * parsing.
 911  */
 912 struct hid_report *hid_validate_values(struct hid_device *hid,
 913                                        unsigned int type, unsigned int id,
 914                                        unsigned int field_index,
 915                                        unsigned int report_counts)
 916 {
 917         struct hid_report *report;
 918
 919         if (type > HID_FEATURE_REPORT) {
 920                 hid_err(hid, "invalid HID report type %u\n", type);
 921                 return NULL;
 922         }
 923
 924         if (id >= HID_MAX_IDS) {
 925                 hid_err(hid, "invalid HID report id %u\n", id);
 926                 return NULL;
 927         }
 928
 929         /*
 930          * Explicitly not using hid_get_report() here since it depends on
 931          * ->numbered being checked, which may not always be the case when
 932          * drivers go to access report values.
 933          */
 934         if (id == 0) {
 935                 /*
 936                  * Validating on id 0 means we should examine the first
 937                  * report in the list.
 938                  */
 939                 report = list_entry(
 940                                 hid->report_enum[type].report_list.next,
 941                                 struct hid_report, list);
 942         } else {
 943                 report = hid->report_enum[type].report_id_hash[id];
 944         }
 945         if (!report) {
 946                 hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
 947                 return NULL;
 948         }
 949         if (report->maxfield <= field_index) {
 950                 hid_err(hid, "not enough fields in %s %u\n",
 951                         hid_report_names[type], id);
 952                 return NULL;
 953         }
 954         if (report->field[field_index]->report_count < report_counts) {
 955                 hid_err(hid, "not enough values in %s %u field %u\n",
 956                         hid_report_names[type], id, field_index);
 957                 return NULL;
 958         }
 959         return report;
 960 }
 961 EXPORT_SYMBOL_GPL(hid_validate_values);
 962
 963 static int hid_calculate_multiplier(struct hid_device *hid,
 964                                      struct hid_field *multiplier)
 965 {
 966         int m;
 967         __s32 v = *multiplier->value;
 968         __s32 lmin = multiplier->logical_minimum;
 969         __s32 lmax = multiplier->logical_maximum;
 970         __s32 pmin = multiplier->physical_minimum;
 971         __s32 pmax = multiplier->physical_maximum;
 972
 973         /*
 974          * "Because OS implementations will generally divide the control's
 975          * reported count by the Effective Resolution Multiplier, designers
 976          * should take care not to establish a potential Effective
 977          * Resolution Multiplier of zero."
 978          * HID Usage Table, v1.12, Section 4.3.1, p31
 979          */
 980         if (lmax - lmin == 0)
 981                 return 1;
 982         /*
 983          * Handling the unit exponent is left as an exercise to whoever
 984          * finds a device where that exponent is not 0.
 985          */
 986         m = ((v - lmin)/(lmax - lmin) * (pmax - pmin) + pmin);
 987         if (unlikely(multiplier->unit_exponent != 0)) {
 988                 hid_warn(hid,
 989                          "unsupported Resolution Multiplier unit exponent %d\n",
 990                          multiplier->unit_exponent);
 991         }
 992
 993         /* There are no devices with an effective multiplier > 255 */
 994         if (unlikely(m == 0 || m > 255 || m < -255)) {
 995                 hid_warn(hid, "unsupported Resolution Multiplier %d\n", m);
 996                 m = 1;
 997         }
 998
 999         return m;
1000 }
1001
1002 static void hid_apply_multiplier_to_field(struct hid_device *hid,
1003                                           struct hid_field *field,
1004                                           struct hid_collection *multiplier_collection,
1005                                           int effective_multiplier)
1006 {
1007         struct hid_collection *collection;
1008         struct hid_usage *usage;
1009         int i;
1010
1011         /*
1012          * If multiplier_collection is NULL, the multiplier applies
1013          * to all fields in the report.
1014          * Otherwise, it is the Logical Collection the multiplier applies to
1015          * but our field may be in a subcollection of that collection.
1016          */
1017         for (i = 0; i < field->maxusage; i++) {
1018                 usage = &field->usage[i];
1019
1020                 collection = &hid->collection[usage->collection_index];
1021                 while (collection->parent_idx != -1 &&
1022                        collection != multiplier_collection)
1023                         collection = &hid->collection[collection->parent_idx];
1024
1025                 if (collection->parent_idx != -1 ||
1026                     multiplier_collection == NULL)
1027                         usage->resolution_multiplier = effective_multiplier;
1028
1029         }
1030 }
1031
1032 static void hid_apply_multiplier(struct hid_device *hid,
1033                                  struct hid_field *multiplier)
1034 {
1035         struct hid_report_enum *rep_enum;
1036         struct hid_report *rep;
1037         struct hid_field *field;
1038         struct hid_collection *multiplier_collection;
1039         int effective_multiplier;
1040         int i;
1041
1042         /*
1043          * "The Resolution Multiplier control must be contained in the same
1044          * Logical Collection as the control(s) to which it is to be applied.
1045          * If no Resolution Multiplier is defined, then the Resolution
1046          * Multiplier defaults to 1.  If more than one control exists in a
1047          * Logical Collection, the Resolution Multiplier is associated with
1048          * all controls in the collection. If no Logical Collection is
1049          * defined, the Resolution Multiplier is associated with all
1050          * controls in the report."
1051          * HID Usage Table, v1.12, Section 4.3.1, p30
1052          *
1053          * Thus, search from the current collection upwards until we find a
1054          * logical collection. Then search all fields for that same parent
1055          * collection. Those are the fields the multiplier applies to.
1056          *
1057          * If we have more than one multiplier, it will overwrite the
1058          * applicable fields later.
1059          */
1060         multiplier_collection = &hid->collection[multiplier->usage->collection_index];
1061         while (multiplier_collection->parent_idx != -1 &&
1062                multiplier_collection->type != HID_COLLECTION_LOGICAL)
1063                 multiplier_collection = &hid->collection[multiplier_collection->parent_idx];
1064
1065         effective_multiplier = hid_calculate_multiplier(hid, multiplier);
1066
1067         rep_enum = &hid->report_enum[HID_INPUT_REPORT];
1068         list_for_each_entry(rep, &rep_enum->report_list, list) {
1069                 for (i = 0; i < rep->maxfield; i++) {
1070                         field = rep->field[i];
1071                         hid_apply_multiplier_to_field(hid, field,
1072                                                       multiplier_collection,
1073                                                       effective_multiplier);
1074                 }
1075         }
1076 }
1077
1078 /*
1079  * hid_setup_resolution_multiplier - set up all resolution multipliers
1080  *
1081  * @device: hid device
1082  *
1083  * Search for all Resolution Multiplier Feature Reports and apply their
1084  * value to all matching Input items. This only updates the internal struct
1085  * fields.
1086  *
1087  * The Resolution Multiplier is applied by the hardware. If the multiplier
1088  * is anything other than 1, the hardware will send pre-multiplied events
1089  * so that the same physical interaction generates an accumulated
1090  *      accumulated_value = value * * multiplier
1091  * This may be achieved by sending
1092  * - "value * multiplier" for each event, or
1093  * - "value" but "multiplier" times as frequently, or
1094  * - a combination of the above
1095  * The only guarantee is that the same physical interaction always generates
1096  * an accumulated 'value * multiplier'.
1097  *
1098  * This function must be called before any event processing and after
1099  * any SetRequest to the Resolution Multiplier.
1100  */
1101 void hid_setup_resolution_multiplier(struct hid_device *hid)
1102 {
1103         struct hid_report_enum *rep_enum;
1104         struct hid_report *rep;
1105         struct hid_usage *usage;
1106         int i, j;
1107
1108         rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
1109         list_for_each_entry(rep, &rep_enum->report_list, list) {
1110                 for (i = 0; i < rep->maxfield; i++) {
1111                         /* Ignore if report count is out of bounds. */
1112                         if (rep->field[i]->report_count < 1)
1113                                 continue;
1114
1115                         for (j = 0; j < rep->field[i]->maxusage; j++) {
1116                                 usage = &rep->field[i]->usage[j];
1117                                 if (usage->hid == HID_GD_RESOLUTION_MULTIPLIER)
1118                                         hid_apply_multiplier(hid,
1119                                                              rep->field[i]);
1120                         }
1121                 }
1122         }
1123 }
1124 EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier);
1125
1126 /**
1127  * hid_open_report - open a driver-specific device report
1128  *
1129  * @device: hid device
1130  *
1131  * Parse a report description into a hid_device structure. Reports are
1132  * enumerated, fields are attached to these reports.
1133  * 0 returned on success, otherwise nonzero error value.
1134  *
1135  * This function (or the equivalent hid_parse() macro) should only be
1136  * called from probe() in drivers, before starting the device.
1137  */
1138 int hid_open_report(struct hid_device *device)
1139 {
1140         struct hid_parser *parser;
1141         struct hid_item item;
1142         unsigned int size;
1143         __u8 *start;
1144         __u8 *buf;
1145         __u8 *end;
1146         int ret;
1147         static int (*dispatch_type[])(struct hid_parser *parser,
1148                                       struct hid_item *item) = {
1149                 hid_parser_main,
1150                 hid_parser_global,
1151                 hid_parser_local,
1152                 hid_parser_reserved
1153         };
1154
1155         if (WARN_ON(device->status & HID_STAT_PARSED))
1156                 return -EBUSY;
1157
1158         start = device->dev_rdesc;
1159         if (WARN_ON(!start))
1160                 return -ENODEV;
1161         size = device->dev_rsize;
1162
1163         buf = kmemdup(start, size, GFP_KERNEL);
1164         if (buf == NULL)
1165                 return -ENOMEM;
1166
1167         if (device->driver->report_fixup)
1168                 start = device->driver->report_fixup(device, buf, &size);
1169         else
1170                 start = buf;
1171
1172         start = kmemdup(start, size, GFP_KERNEL);
1173         kfree(buf);
1174         if (start == NULL)
1175                 return -ENOMEM;
1176
1177         device->rdesc = start;
1178         device->rsize = size;
1179
1180         parser = vzalloc(sizeof(struct hid_parser));
1181         if (!parser) {
1182                 ret = -ENOMEM;
1183                 goto alloc_err;
1184         }
1185
1186         parser->device = device;
1187
1188         end = start + size;
1189
1190         device->collection = kcalloc(HID_DEFAULT_NUM_COLLECTIONS,
1191                                      sizeof(struct hid_collection), GFP_KERNEL);
1192         if (!device->collection) {
1193                 ret = -ENOMEM;
1194                 goto err;
1195         }
1196         device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
1197
1198         ret = -EINVAL;
1199         while ((start = fetch_item(start, end, &item)) != NULL) {
1200
1201                 if (item.format != HID_ITEM_FORMAT_SHORT) {
1202                         hid_err(device, "unexpected long global item\n");
1203                         goto err;
1204                 }
1205
1206                 if (dispatch_type[item.type](parser, &item)) {
1207                         hid_err(device, "item %u %u %u %u parsing failed\n",
1208                                 item.format, (unsigned)item.size,
1209                                 (unsigned)item.type, (unsigned)item.tag);
1210                         goto err;
1211                 }
1212
1213                 if (start == end) {
1214                         if (parser->collection_stack_ptr) {
1215                                 hid_err(device, "unbalanced collection at end of report description\n");
1216                                 goto err;
1217                         }
1218                         if (parser->local.delimiter_depth) {
1219                                 hid_err(device, "unbalanced delimiter at end of report description\n");
1220                                 goto err;
1221                         }
1222
1223                         /*
1224                          * fetch initial values in case the device's
1225                          * default multiplier isn't the recommended 1
1226                          */
1227                         hid_setup_resolution_multiplier(device);
1228
1229                         kfree(parser->collection_stack);
1230                         vfree(parser);
1231                         device->status |= HID_STAT_PARSED;
1232
1233                         return 0;
1234                 }
1235         }
1236
1237         hid_err(device, "item fetching failed at offset %d\n", (int)(end - start));
1238 err:
1239         kfree(parser->collection_stack);
1240 alloc_err:
1241         vfree(parser);
1242         hid_close_report(device);
1243         return ret;
1244 }
1245 EXPORT_SYMBOL_GPL(hid_open_report);
1246
1247 /*
1248  * Convert a signed n-bit integer to signed 32-bit integer. Common
1249  * cases are done through the compiler, the screwed things has to be
1250  * done by hand.
1251  */
1252
1253 static s32 snto32(__u32 value, unsigned n)
1254 {
1255         switch (n) {
1256         case 8:  return ((__s8)value);
1257         case 16: return ((__s16)value);
1258         case 32: return ((__s32)value);
1259         }
1260         return value & (1 << (n - 1)) ? value | (~0U << n) : value;
1261 }
1262
1263 s32 hid_snto32(__u32 value, unsigned n)
1264 {
1265         return snto32(value, n);
1266 }
1267 EXPORT_SYMBOL_GPL(hid_snto32);
1268
1269 /*
1270  * Convert a signed 32-bit integer to a signed n-bit integer.
1271  */
1272
1273 static u32 s32ton(__s32 value, unsigned n)
1274 {
1275         s32 a = value >> (n - 1);
1276         if (a && a != -1)
1277                 return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
1278         return value & ((1 << n) - 1);
1279 }
1280
1281 /*
1282  * Extract/implement a data field from/to a little endian report (bit array).
1283  *
1284  * Code sort-of follows HID spec:
1285  *     http://www.usb.org/developers/hidpage/HID1_11.pdf
1286  *
1287  * While the USB HID spec allows unlimited length bit fields in "report
1288  * descriptors", most devices never use more than 16 bits.
1289  * One model of UPS is claimed to report "LINEV" as a 32-bit field.
1290  * Search linux-kernel and linux-usb-devel archives for "hid-core extract".
1291  */
1292
1293 static u32 __extract(u8 *report, unsigned offset, int n)
1294 {
1295         unsigned int idx = offset / 8;
1296         unsigned int bit_nr = 0;
1297         unsigned int bit_shift = offset % 8;
1298         int bits_to_copy = 8 - bit_shift;
1299         u32 value = 0;
1300         u32 mask = n < 32 ? (1U << n) - 1 : ~0U;
1301
1302         while (n > 0) {
1303                 value |= ((u32)report[idx] >> bit_shift) << bit_nr;
1304                 n -= bits_to_copy;
1305                 bit_nr += bits_to_copy;
1306                 bits_to_copy = 8;
1307                 bit_shift = 0;
1308                 idx++;
1309         }
1310
1311         return value & mask;
1312 }
1313
1314 u32 hid_field_extract(const struct hid_device *hid, u8 *report,
1315                         unsigned offset, unsigned n)
1316 {
1317         if (n > 256) {
1318                 hid_warn(hid, "hid_field_extract() called with n (%d) > 256! (%s)\n",
1319                          n, current->comm);
1320                 n = 256;
1321         }
1322
1323         return __extract(report, offset, n);
1324 }
1325 EXPORT_SYMBOL_GPL(hid_field_extract);
1326
1327 /*
1328  * "implement" : set bits in a little endian bit stream.
1329  * Same concepts as "extract" (see comments above).
1330  * The data mangled in the bit stream remains in little endian
1331  * order the whole time. It make more sense to talk about
1332  * endianness of register values by considering a register
1333  * a "cached" copy of the little endian bit stream.
1334  */
1335
1336 static void __implement(u8 *report, unsigned offset, int n, u32 value)
1337 {
1338         unsigned int idx = offset / 8;
1339         unsigned int bit_shift = offset % 8;
1340         int bits_to_set = 8 - bit_shift;
1341
1342         while (n - bits_to_set >= 0) {
1343                 report[idx] &= ~(0xff << bit_shift);
1344                 report[idx] |= value << bit_shift;
1345                 value >>= bits_to_set;
1346                 n -= bits_to_set;
1347                 bits_to_set = 8;
1348                 bit_shift = 0;
1349                 idx++;
1350         }
1351
1352         /* last nibble */
1353         if (n) {
1354                 u8 bit_mask = ((1U << n) - 1);
1355                 report[idx] &= ~(bit_mask << bit_shift);
1356                 report[idx] |= value << bit_shift;
1357         }
1358 }
1359
1360 static void implement(const struct hid_device *hid, u8 *report,
1361                       unsigned offset, unsigned n, u32 value)
1362 {
1363         if (unlikely(n > 32)) {
1364                 hid_warn(hid, "%s() called with n (%d) > 32! (%s)\n",
1365                          __func__, n, current->comm);
1366                 n = 32;
1367         } else if (n < 32) {
1368                 u32 m = (1U << n) - 1;
1369
1370                 if (unlikely(value > m)) {
1371                         hid_warn(hid,
1372                                  "%s() called with too large value %d (n: %d)! (%s)\n",
1373                                  __func__, value, n, current->comm);
1374                         WARN_ON(1);
1375                         value &= m;
1376                 }
1377         }
1378
1379         __implement(report, offset, n, value);
1380 }
1381
1382 /*
1383  * Search an array for a value.
1384  */
1385
1386 static int search(__s32 *array, __s32 value, unsigned n)
1387 {
1388         while (n--) {
1389                 if (*array++ == value)
1390                         return 0;
1391         }
1392         return -1;
1393 }
1394
1395 /**
1396  * hid_match_report - check if driver's raw_event should be called
1397  *
1398  * @hid: hid device
1399  * @report_type: type to match against
1400  *
1401  * compare hid->driver->report_table->report_type to report->type
1402  */
1403 static int hid_match_report(struct hid_device *hid, struct hid_report *report)
1404 {
1405         const struct hid_report_id *id = hid->driver->report_table;
1406
1407         if (!id) /* NULL means all */
1408                 return 1;
1409
1410         for (; id->report_type != HID_TERMINATOR; id++)
1411                 if (id->report_type == HID_ANY_ID ||
1412                                 id->report_type == report->type)
1413                         return 1;
1414         return 0;
1415 }
1416
1417 /**
1418  * hid_match_usage - check if driver's event should be called
1419  *
1420  * @hid: hid device
1421  * @usage: usage to match against
1422  *
1423  * compare hid->driver->usage_table->usage_{type,code} to
1424  * usage->usage_{type,code}
1425  */
1426 static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage)
1427 {
1428         const struct hid_usage_id *id = hid->driver->usage_table;
1429
1430         if (!id) /* NULL means all */
1431                 return 1;
1432
1433         for (; id->usage_type != HID_ANY_ID - 1; id++)
1434                 if ((id->usage_hid == HID_ANY_ID ||
1435                                 id->usage_hid == usage->hid) &&
1436                                 (id->usage_type == HID_ANY_ID ||
1437                                 id->usage_type == usage->type) &&
1438                                 (id->usage_code == HID_ANY_ID ||
1439                                  id->usage_code == usage->code))
1440                         return 1;
1441         return 0;
1442 }
1443
1444 static void hid_process_event(struct hid_device *hid, struct hid_field *field,
1445                 struct hid_usage *usage, __s32 value, int interrupt)
1446 {
1447         struct hid_driver *hdrv = hid->driver;
1448         int ret;
1449
1450         if (!list_empty(&hid->debug_list))
1451                 hid_dump_input(hid, usage, value);
1452
1453         if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
1454                 ret = hdrv->event(hid, field, usage, value);
1455                 if (ret != 0) {
1456                         if (ret < 0)
1457                                 hid_err(hid, "%s's event failed with %d\n",
1458                                                 hdrv->name, ret);
1459                         return;
1460                 }
1461         }
1462
1463         if (hid->claimed & HID_CLAIMED_INPUT)
1464                 hidinput_hid_event(hid, field, usage, value);
1465         if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
1466                 hid->hiddev_hid_event(hid, field, usage, value);
1467 }
1468
1469 /*
1470  * Analyse a received field, and fetch the data from it. The field
1471  * content is stored for next report processing (we do differential
1472  * reporting to the layer).
1473  */
1474
1475 static void hid_input_field(struct hid_device *hid, struct hid_field *field,
1476                             __u8 *data, int interrupt)
1477 {
1478         unsigned n;
1479         unsigned count = field->report_count;
1480         unsigned offset = field->report_offset;
1481         unsigned size = field->report_size;
1482         __s32 min = field->logical_minimum;
1483         __s32 max = field->logical_maximum;
1484         __s32 *value;
1485
1486         value = kmalloc_array(count, sizeof(__s32), GFP_ATOMIC);
1487         if (!value)
1488                 return;
1489
1490         for (n = 0; n < count; n++) {
1491
1492                 value[n] = min < 0 ?
1493                         snto32(hid_field_extract(hid, data, offset + n * size,
1494                                size), size) :
1495                         hid_field_extract(hid, data, offset + n * size, size);
1496
1497                 /* Ignore report if ErrorRollOver */
1498                 if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
1499                     value[n] >= min && value[n] <= max &&
1500                     value[n] - min < field->maxusage &&
1501                     field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1)
1502                         goto exit;
1503         }
1504
1505         for (n = 0; n < count; n++) {
1506
1507                 if (HID_MAIN_ITEM_VARIABLE & field->flags) {
1508                         hid_process_event(hid, field, &field->usage[n], value[n], interrupt);
1509                         continue;
1510                 }
1511
1512                 if (field->value[n] >= min && field->value[n] <= max
1513                         && field->value[n] - min < field->maxusage
1514                         && field->usage[field->value[n] - min].hid
1515                         && search(value, field->value[n], count))
1516                                 hid_process_event(hid, field, &field->usage[field->value[n] - min], 0, interrupt);
1517
1518                 if (value[n] >= min && value[n] <= max
1519                         && value[n] - min < field->maxusage
1520                         && field->usage[value[n] - min].hid
1521                         && search(field->value, value[n], count))
1522                                 hid_process_event(hid, field, &field->usage[value[n] - min], 1, interrupt);
1523         }
1524
1525         memcpy(field->value, value, count * sizeof(__s32));
1526 exit:
1527         kfree(value);
1528 }
1529
1530 /*
1531  * Output the field into the report.
1532  */
1533
1534 static void hid_output_field(const struct hid_device *hid,
1535                              struct hid_field *field, __u8 *data)
1536 {
1537         unsigned count = field->report_count;
1538         unsigned offset = field->report_offset;
1539         unsigned size = field->report_size;
1540         unsigned n;
1541
1542         for (n = 0; n < count; n++) {
1543                 if (field->logical_minimum < 0) /* signed values */
1544                         implement(hid, data, offset + n * size, size,
1545                                   s32ton(field->value[n], size));
1546                 else                            /* unsigned values */
1547                         implement(hid, data, offset + n * size, size,
1548                                   field->value[n]);
1549         }
1550 }
1551
1552 /*
1553  * Create a report. 'data' has to be allocated using
1554  * hid_alloc_report_buf() so that it has proper size.
1555  */
1556
1557 void hid_output_report(struct hid_report *report, __u8 *data)
1558 {
1559         unsigned n;
1560
1561         if (report->id > 0)
1562                 *data++ = report->id;
1563
1564         memset(data, 0, ((report->size - 1) >> 3) + 1);
1565         for (n = 0; n < report->maxfield; n++)
1566                 hid_output_field(report->device, report->field[n], data);
1567 }
1568 EXPORT_SYMBOL_GPL(hid_output_report);
1569
1570 /*
1571  * Allocator for buffer that is going to be passed to hid_output_report()
1572  */
1573 u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
1574 {
1575         /*
1576          * 7 extra bytes are necessary to achieve proper functionality
1577          * of implement() working on 8 byte chunks
1578          */
1579
1580         u32 len = hid_report_len(report) + 7;
1581
1582         return kmalloc(len, flags);
1583 }
1584 EXPORT_SYMBOL_GPL(hid_alloc_report_buf);
1585
1586 /*
1587  * Set a field value. The report this field belongs to has to be
1588  * created and transferred to the device, to set this value in the
1589  * device.
1590  */
1591
1592 int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
1593 {
1594         unsigned size;
1595
1596         if (!field)
1597                 return -1;
1598
1599         size = field->report_size;
1600
1601         hid_dump_input(field->report->device, field->usage + offset, value);
1602
1603         if (offset >= field->report_count) {
1604                 hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n",
1605                                 offset, field->report_count);
1606                 return -1;
1607         }
1608         if (field->logical_minimum < 0) {
1609                 if (value != snto32(s32ton(value, size), size)) {
1610                         hid_err(field->report->device, "value %d is out of range\n", value);
1611                         return -1;
1612                 }
1613         }
1614         field->value[offset] = value;
1615         return 0;
1616 }
1617 EXPORT_SYMBOL_GPL(hid_set_field);
1618
1619 static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
1620                 const u8 *data)
1621 {
1622         struct hid_report *report;
1623         unsigned int n = 0;     /* Normally report number is 0 */
1624
1625         /* Device uses numbered reports, data[0] is report number */
1626         if (report_enum->numbered)
1627                 n = *data;
1628
1629         report = report_enum->report_id_hash[n];
1630         if (report == NULL)
1631                 dbg_hid("undefined report_id %u received\n", n);
1632
1633         return report;
1634 }
1635
1636 /*
1637  * Implement a generic .request() callback, using .raw_request()
1638  * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
1639  */
1640 int __hid_request(struct hid_device *hid, struct hid_report *report,
1641                 int reqtype)
1642 {
1643         char *buf;
1644         int ret;
1645         u32 len;
1646
1647         buf = hid_alloc_report_buf(report, GFP_KERNEL);
1648         if (!buf)
1649                 return -ENOMEM;
1650
1651         len = hid_report_len(report);
1652
1653         if (reqtype == HID_REQ_SET_REPORT)
1654                 hid_output_report(report, buf);
1655
1656         ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
1657                                           report->type, reqtype);
1658         if (ret < 0) {
1659                 dbg_hid("unable to complete request: %d\n", ret);
1660                 goto out;
1661         }
1662
1663         if (reqtype == HID_REQ_GET_REPORT)
1664                 hid_input_report(hid, report->type, buf, ret, 0);
1665
1666         ret = 0;
1667
1668 out:
1669         kfree(buf);
1670         return ret;
1671 }
1672 EXPORT_SYMBOL_GPL(__hid_request);
1673
1674 int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, u32 size,
1675                 int interrupt)
1676 {
1677         struct hid_report_enum *report_enum = hid->report_enum + type;
1678         struct hid_report *report;
1679         struct hid_driver *hdrv;
1680         unsigned int a;
1681         u32 rsize, csize = size;
1682         u8 *cdata = data;
1683         int ret = 0;
1684
1685         report = hid_get_report(report_enum, data);
1686         if (!report)
1687                 goto out;
1688
1689         if (report_enum->numbered) {
1690                 cdata++;
1691                 csize--;
1692         }
1693
1694         rsize = ((report->size - 1) >> 3) + 1;
1695
1696         if (rsize > HID_MAX_BUFFER_SIZE)
1697                 rsize = HID_MAX_BUFFER_SIZE;
1698
1699         if (csize < rsize) {
1700                 dbg_hid("report %d is too short, (%d < %d)\n", report->id,
1701                                 csize, rsize);
1702                 memset(cdata + csize, 0, rsize - csize);
1703         }
1704
1705         if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
1706                 hid->hiddev_report_event(hid, report);
1707         if (hid->claimed & HID_CLAIMED_HIDRAW) {
1708                 ret = hidraw_report_event(hid, data, size);
1709                 if (ret)
1710                         goto out;
1711         }
1712
1713         if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
1714                 for (a = 0; a < report->maxfield; a++)
1715                         hid_input_field(hid, report->field[a], cdata, interrupt);
1716                 hdrv = hid->driver;
1717                 if (hdrv && hdrv->report)
1718                         hdrv->report(hid, report);
1719         }
1720
1721         if (hid->claimed & HID_CLAIMED_INPUT)
1722                 hidinput_report_event(hid, report);
1723 out:
1724         return ret;
1725 }
1726 EXPORT_SYMBOL_GPL(hid_report_raw_event);
1727
1728 /**
1729  * hid_input_report - report data from lower layer (usb, bt...)
1730  *
1731  * @hid: hid device
1732  * @type: HID report type (HID_*_REPORT)
1733  * @data: report contents
1734  * @size: size of data parameter
1735  * @interrupt: distinguish between interrupt and control transfers
1736  *
1737  * This is data entry for lower layers.
1738  */
1739 int hid_input_report(struct hid_device *hid, int type, u8 *data, u32 size, int interrupt)
1740 {
1741         struct hid_report_enum *report_enum;
1742         struct hid_driver *hdrv;
1743         struct hid_report *report;
1744         int ret = 0;
1745
1746         if (!hid)
1747                 return -ENODEV;
1748
1749         if (down_trylock(&hid->driver_input_lock))
1750                 return -EBUSY;
1751
1752         if (!hid->driver) {
1753                 ret = -ENODEV;
1754                 goto unlock;
1755         }
1756         report_enum = hid->report_enum + type;
1757         hdrv = hid->driver;
1758
1759         if (!size) {
1760                 dbg_hid("empty report\n");
1761                 ret = -1;
1762                 goto unlock;
1763         }
1764
1765         /* Avoid unnecessary overhead if debugfs is disabled */
1766         if (!list_empty(&hid->debug_list))
1767                 hid_dump_report(hid, type, data, size);
1768
1769         report = hid_get_report(report_enum, data);
1770
1771         if (!report) {
1772                 ret = -1;
1773                 goto unlock;
1774         }
1775
1776         if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
1777                 ret = hdrv->raw_event(hid, report, data, size);
1778                 if (ret < 0)
1779                         goto unlock;
1780         }
1781
1782         ret = hid_report_raw_event(hid, type, data, size, interrupt);
1783
1784 unlock:
1785         up(&hid->driver_input_lock);
1786         return ret;
1787 }
1788 EXPORT_SYMBOL_GPL(hid_input_report);
1789
1790 bool hid_match_one_id(const struct hid_device *hdev,
1791                       const struct hid_device_id *id)
1792 {
1793         return (id->bus == HID_BUS_ANY || id->bus == hdev->bus) &&
1794                 (id->group == HID_GROUP_ANY || id->group == hdev->group) &&
1795                 (id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&
1796                 (id->product == HID_ANY_ID || id->product == hdev->product);
1797 }
1798
1799 const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
1800                 const struct hid_device_id *id)
1801 {
1802         for (; id->bus; id++)
1803                 if (hid_match_one_id(hdev, id))
1804                         return id;
1805
1806         return NULL;
1807 }
1808
1809 static const struct hid_device_id hid_hiddev_list[] = {
1810         { HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS) },
1811         { HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS1) },
1812         { }
1813 };
1814
1815 static bool hid_hiddev(struct hid_device *hdev)
1816 {
1817         return !!hid_match_id(hdev, hid_hiddev_list);
1818 }
1819
1820
1821 static ssize_t
1822 read_report_descriptor(struct file *filp, struct kobject *kobj,
1823                 struct bin_attribute *attr,
1824                 char *buf, loff_t off, size_t count)
1825 {
1826         struct device *dev = kobj_to_dev(kobj);
1827         struct hid_device *hdev = to_hid_device(dev);
1828
1829         if (off >= hdev->rsize)
1830                 return 0;
1831
1832         if (off + count > hdev->rsize)
1833                 count = hdev->rsize - off;
1834
1835         memcpy(buf, hdev->rdesc + off, count);
1836
1837         return count;
1838 }
1839
1840 static ssize_t
1841 show_country(struct device *dev, struct device_attribute *attr,
1842                 char *buf)
1843 {
1844         struct hid_device *hdev = to_hid_device(dev);
1845
1846         return sprintf(buf, "%02x\n", hdev->country & 0xff);
1847 }
1848
1849 static struct bin_attribute dev_bin_attr_report_desc = {
1850         .attr = { .name = "report_descriptor", .mode = 0444 },
1851         .read = read_report_descriptor,
1852         .size = HID_MAX_DESCRIPTOR_SIZE,
1853 };
1854
1855 static const struct device_attribute dev_attr_country = {
1856         .attr = { .name = "country", .mode = 0444 },
1857         .show = show_country,
1858 };
1859
1860 int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
1861 {
1862         static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
1863                 "Joystick", "Gamepad", "Keyboard", "Keypad",
1864                 "Multi-Axis Controller"
1865         };
1866         const char *type, *bus;
1867         char buf[64] = "";
1868         unsigned int i;
1869         int len;
1870         int ret;
1871
1872         if (hdev->quirks & HID_QUIRK_HIDDEV_FORCE)
1873                 connect_mask |= (HID_CONNECT_HIDDEV_FORCE | HID_CONNECT_HIDDEV);
1874         if (hdev->quirks & HID_QUIRK_HIDINPUT_FORCE)
1875                 connect_mask |= HID_CONNECT_HIDINPUT_FORCE;
1876         if (hdev->bus != BUS_USB)
1877                 connect_mask &= ~HID_CONNECT_HIDDEV;
1878         if (hid_hiddev(hdev))
1879                 connect_mask |= HID_CONNECT_HIDDEV_FORCE;
1880
1881         if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,
1882                                 connect_mask & HID_CONNECT_HIDINPUT_FORCE))
1883                 hdev->claimed |= HID_CLAIMED_INPUT;
1884
1885         if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect &&
1886                         !hdev->hiddev_connect(hdev,
1887                                 connect_mask & HID_CONNECT_HIDDEV_FORCE))
1888                 hdev->claimed |= HID_CLAIMED_HIDDEV;
1889         if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))
1890                 hdev->claimed |= HID_CLAIMED_HIDRAW;
1891
1892         if (connect_mask & HID_CONNECT_DRIVER)
1893                 hdev->claimed |= HID_CLAIMED_DRIVER;
1894
1895         /* Drivers with the ->raw_event callback set are not required to connect
1896          * to any other listener. */
1897         if (!hdev->claimed && !hdev->driver->raw_event) {
1898                 hid_err(hdev, "device has no listeners, quitting\n");
1899                 return -ENODEV;
1900         }
1901
1902         if ((hdev->claimed & HID_CLAIMED_INPUT) &&
1903                         (connect_mask & HID_CONNECT_FF) && hdev->ff_init)
1904                 hdev->ff_init(hdev);
1905
1906         len = 0;
1907         if (hdev->claimed & HID_CLAIMED_INPUT)
1908                 len += sprintf(buf + len, "input");
1909         if (hdev->claimed & HID_CLAIMED_HIDDEV)
1910                 len += sprintf(buf + len, "%shiddev%d", len ? "," : "",
1911                                 ((struct hiddev *)hdev->hiddev)->minor);
1912         if (hdev->claimed & HID_CLAIMED_HIDRAW)
1913                 len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
1914                                 ((struct hidraw *)hdev->hidraw)->minor);
1915
1916         type = "Device";
1917         for (i = 0; i < hdev->maxcollection; i++) {
1918                 struct hid_collection *col = &hdev->collection[i];
1919                 if (col->type == HID_COLLECTION_APPLICATION &&
1920                    (col->usage & HID_USAGE_PAGE) == HID_UP_GENDESK &&
1921                    (col->usage & 0xffff) < ARRAY_SIZE(types)) {
1922                         type = types[col->usage & 0xffff];
1923                         break;
1924                 }
1925         }
1926
1927         switch (hdev->bus) {
1928         case BUS_USB:
1929                 bus = "USB";
1930                 break;
1931         case BUS_BLUETOOTH:
1932                 bus = "BLUETOOTH";
1933                 break;
1934         case BUS_I2C:
1935                 bus = "I2C";
1936                 break;
1937         default:
1938                 bus = "<UNKNOWN>";
1939         }
1940
1941         ret = device_create_file(&hdev->dev, &dev_attr_country);
1942         if (ret)
1943                 hid_warn(hdev,
1944                          "can't create sysfs country code attribute err: %d\n", ret);
1945
1946         hid_info(hdev, "%s: %s HID v%x.%02x %s [%s] on %s\n",
1947                  buf, bus, hdev->version >> 8, hdev->version & 0xff,
1948                  type, hdev->name, hdev->phys);
1949
1950         return 0;
1951 }
1952 EXPORT_SYMBOL_GPL(hid_connect);
1953
1954 void hid_disconnect(struct hid_device *hdev)
1955 {
1956         device_remove_file(&hdev->dev, &dev_attr_country);
1957         if (hdev->claimed & HID_CLAIMED_INPUT)
1958                 hidinput_disconnect(hdev);
1959         if (hdev->claimed & HID_CLAIMED_HIDDEV)
1960                 hdev->hiddev_disconnect(hdev);
1961         if (hdev->claimed & HID_CLAIMED_HIDRAW)
1962                 hidraw_disconnect(hdev);
1963         hdev->claimed = 0;
1964 }
1965 EXPORT_SYMBOL_GPL(hid_disconnect);
1966
1967 /**
1968  * hid_hw_start - start underlying HW
1969  * @hdev: hid device
1970  * @connect_mask: which outputs to connect, see HID_CONNECT_*
1971  *
1972  * Call this in probe function *after* hid_parse. This will setup HW
1973  * buffers and start the device (if not defeirred to device open).
1974  * hid_hw_stop must be called if this was successful.
1975  */
1976 int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask)
1977 {
1978         int error;
1979
1980         error = hdev->ll_driver->start(hdev);
1981         if (error)
1982                 return error;
1983
1984         if (connect_mask) {
1985                 error = hid_connect(hdev, connect_mask);
1986                 if (error) {
1987                         hdev->ll_driver->stop(hdev);
1988                         return error;
1989                 }
1990         }
1991
1992         return 0;
1993 }
1994 EXPORT_SYMBOL_GPL(hid_hw_start);
1995
1996 /**
1997  * hid_hw_stop - stop underlying HW
1998  * @hdev: hid device
1999  *
2000  * This is usually called from remove function or from probe when something
2001  * failed and hid_hw_start was called already.
2002  */
2003 void hid_hw_stop(struct hid_device *hdev)
2004 {
2005         hid_disconnect(hdev);
2006         hdev->ll_driver->stop(hdev);
2007 }
2008 EXPORT_SYMBOL_GPL(hid_hw_stop);
2009
2010 /**
2011  * hid_hw_open - signal underlying HW to start delivering events
2012  * @hdev: hid device
2013  *
2014  * Tell underlying HW to start delivering events from the device.
2015  * This function should be called sometime after successful call
2016  * to hid_hw_start().
2017  */
2018 int hid_hw_open(struct hid_device *hdev)
2019 {
2020         int ret;
2021
2022         ret = mutex_lock_killable(&hdev->ll_open_lock);
2023         if (ret)
2024                 return ret;
2025
2026         if (!hdev->ll_open_count++) {
2027                 ret = hdev->ll_driver->open(hdev);
2028                 if (ret)
2029                         hdev->ll_open_count--;
2030         }
2031
2032         mutex_unlock(&hdev->ll_open_lock);
2033         return ret;
2034 }
2035 EXPORT_SYMBOL_GPL(hid_hw_open);
2036
2037 /**
2038  * hid_hw_close - signal underlaying HW to stop delivering events
2039  *
2040  * @hdev: hid device
2041  *
2042  * This function indicates that we are not interested in the events
2043  * from this device anymore. Delivery of events may or may not stop,
2044  * depending on the number of users still outstanding.
2045  */
2046 void hid_hw_close(struct hid_device *hdev)
2047 {
2048         mutex_lock(&hdev->ll_open_lock);
2049         if (!--hdev->ll_open_count)
2050                 hdev->ll_driver->close(hdev);
2051         mutex_unlock(&hdev->ll_open_lock);
2052 }
2053 EXPORT_SYMBOL_GPL(hid_hw_close);
2054
2055 struct hid_dynid {
2056         struct list_head list;
2057         struct hid_device_id id;
2058 };
2059
2060 /**
2061  * store_new_id - add a new HID device ID to this driver and re-probe devices
2062  * @driver: target device driver
2063  * @buf: buffer for scanning device ID data
2064  * @count: input size
2065  *
2066  * Adds a new dynamic hid device ID to this driver,
2067  * and causes the driver to probe for all devices again.
2068  */
2069 static ssize_t new_id_store(struct device_driver *drv, const char *buf,
2070                 size_t count)
2071 {
2072         struct hid_driver *hdrv = to_hid_driver(drv);
2073         struct hid_dynid *dynid;
2074         __u32 bus, vendor, product;
2075         unsigned long driver_data = 0;
2076         int ret;
2077
2078         ret = sscanf(buf, "%x %x %x %lx",
2079                         &bus, &vendor, &product, &driver_data);
2080         if (ret < 3)
2081                 return -EINVAL;
2082
2083         dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
2084         if (!dynid)
2085                 return -ENOMEM;
2086
2087         dynid->id.bus = bus;
2088         dynid->id.group = HID_GROUP_ANY;
2089         dynid->id.vendor = vendor;
2090         dynid->id.product = product;
2091         dynid->id.driver_data = driver_data;
2092
2093         spin_lock(&hdrv->dyn_lock);
2094         list_add_tail(&dynid->list, &hdrv->dyn_list);
2095         spin_unlock(&hdrv->dyn_lock);
2096
2097         ret = driver_attach(&hdrv->driver);
2098
2099         return ret ? : count;
2100 }
2101 static DRIVER_ATTR_WO(new_id);
2102
2103 static struct attribute *hid_drv_attrs[] = {
2104         &driver_attr_new_id.attr,
2105         NULL,
2106 };
2107 ATTRIBUTE_GROUPS(hid_drv);
2108
2109 static void hid_free_dynids(struct hid_driver *hdrv)
2110 {
2111         struct hid_dynid *dynid, *n;
2112
2113         spin_lock(&hdrv->dyn_lock);
2114         list_for_each_entry_safe(dynid, n, &hdrv->dyn_list, list) {
2115                 list_del(&dynid->list);
2116                 kfree(dynid);
2117         }
2118         spin_unlock(&hdrv->dyn_lock);
2119 }
2120
2121 const struct hid_device_id *hid_match_device(struct hid_device *hdev,
2122                                              struct hid_driver *hdrv)
2123 {
2124         struct hid_dynid *dynid;
2125
2126         spin_lock(&hdrv->dyn_lock);
2127         list_for_each_entry(dynid, &hdrv->dyn_list, list) {
2128                 if (hid_match_one_id(hdev, &dynid->id)) {
2129                         spin_unlock(&hdrv->dyn_lock);
2130                         return &dynid->id;
2131                 }
2132         }
2133         spin_unlock(&hdrv->dyn_lock);
2134
2135         return hid_match_id(hdev, hdrv->id_table);
2136 }
2137 EXPORT_SYMBOL_GPL(hid_match_device);
2138
2139 static int hid_bus_match(struct device *dev, struct device_driver *drv)
2140 {
2141         struct hid_driver *hdrv = to_hid_driver(drv);
2142         struct hid_device *hdev = to_hid_device(dev);
2143
2144         return hid_match_device(hdev, hdrv) != NULL;
2145 }
2146
2147 /**
2148  * hid_compare_device_paths - check if both devices share the same path
2149  * @hdev_a: hid device
2150  * @hdev_b: hid device
2151  * @separator: char to use as separator
2152  *
2153  * Check if two devices share the same path up to the last occurrence of
2154  * the separator char. Both paths must exist (i.e., zero-length paths
2155  * don't match).
2156  */
2157 bool hid_compare_device_paths(struct hid_device *hdev_a,
2158                               struct hid_device *hdev_b, char separator)
2159 {
2160         int n1 = strrchr(hdev_a->phys, separator) - hdev_a->phys;
2161         int n2 = strrchr(hdev_b->phys, separator) - hdev_b->phys;
2162
2163         if (n1 != n2 || n1 <= 0 || n2 <= 0)
2164                 return false;
2165
2166         return !strncmp(hdev_a->phys, hdev_b->phys, n1);
2167 }
2168 EXPORT_SYMBOL_GPL(hid_compare_device_paths);
2169
2170 static int hid_device_probe(struct device *dev)
2171 {
2172         struct hid_driver *hdrv = to_hid_driver(dev->driver);
2173         struct hid_device *hdev = to_hid_device(dev);
2174         const struct hid_device_id *id;
2175         int ret = 0;
2176
2177         if (down_interruptible(&hdev->driver_input_lock)) {
2178                 ret = -EINTR;
2179                 goto end;
2180         }
2181         hdev->io_started = false;
2182
2183         clear_bit(ffs(HID_STAT_REPROBED), &hdev->status);
2184
2185         if (!hdev->driver) {
2186                 id = hid_match_device(hdev, hdrv);
2187                 if (id == NULL) {
2188                         ret = -ENODEV;
2189                         goto unlock;
2190                 }
2191
2192                 if (hdrv->match) {
2193                         if (!hdrv->match(hdev, hid_ignore_special_drivers)) {
2194                                 ret = -ENODEV;
2195                                 goto unlock;
2196                         }
2197                 } else {
2198                         /*
2199                          * hid-generic implements .match(), so if
2200                          * hid_ignore_special_drivers is set, we can safely
2201                          * return.
2202                          */
2203                         if (hid_ignore_special_drivers) {
2204                                 ret = -ENODEV;
2205                                 goto unlock;
2206                         }
2207                 }
2208
2209                 /* reset the quirks that has been previously set */
2210                 hdev->quirks = hid_lookup_quirk(hdev);
2211                 hdev->driver = hdrv;
2212                 if (hdrv->probe) {
2213                         ret = hdrv->probe(hdev, id);
2214                 } else { /* default probe */
2215                         ret = hid_open_report(hdev);
2216                         if (!ret)
2217                                 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
2218                 }
2219                 if (ret) {
2220                         hid_close_report(hdev);
2221                         hdev->driver = NULL;
2222                 }
2223         }
2224 unlock:
2225         if (!hdev->io_started)
2226                 up(&hdev->driver_input_lock);
2227 end:
2228         return ret;
2229 }
2230
2231 static int hid_device_remove(struct device *dev)
2232 {
2233         struct hid_device *hdev = to_hid_device(dev);
2234         struct hid_driver *hdrv;
2235         int ret = 0;
2236
2237         if (down_interruptible(&hdev->driver_input_lock)) {
2238                 ret = -EINTR;
2239                 goto end;
2240         }
2241         hdev->io_started = false;
2242
2243         hdrv = hdev->driver;
2244         if (hdrv) {
2245                 if (hdrv->remove)
2246                         hdrv->remove(hdev);
2247                 else /* default remove */
2248                         hid_hw_stop(hdev);
2249                 hid_close_report(hdev);
2250                 hdev->driver = NULL;
2251         }
2252
2253         if (!hdev->io_started)
2254                 up(&hdev->driver_input_lock);
2255 end:
2256         return ret;
2257 }
2258
2259 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
2260                              char *buf)
2261 {
2262         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
2263
2264         return scnprintf(buf, PAGE_SIZE, "hid:b%04Xg%04Xv%08Xp%08X\n",
2265                          hdev->bus, hdev->group, hdev->vendor, hdev->product);
2266 }
2267 static DEVICE_ATTR_RO(modalias);
2268
2269 static struct attribute *hid_dev_attrs[] = {
2270         &dev_attr_modalias.attr,
2271         NULL,
2272 };
2273 static struct bin_attribute *hid_dev_bin_attrs[] = {
2274         &dev_bin_attr_report_desc,
2275         NULL
2276 };
2277 static const struct attribute_group hid_dev_group = {
2278         .attrs = hid_dev_attrs,
2279         .bin_attrs = hid_dev_bin_attrs,
2280 };
2281 __ATTRIBUTE_GROUPS(hid_dev);
2282
2283 static int hid_uevent(struct device *dev, struct kobj_uevent_env *env)
2284 {
2285         struct hid_device *hdev = to_hid_device(dev);
2286
2287         if (add_uevent_var(env, "HID_ID=%04X:%08X:%08X",
2288                         hdev->bus, hdev->vendor, hdev->product))
2289                 return -ENOMEM;
2290
2291         if (add_uevent_var(env, "HID_NAME=%s", hdev->name))
2292                 return -ENOMEM;
2293
2294         if (add_uevent_var(env, "HID_PHYS=%s", hdev->phys))
2295                 return -ENOMEM;
2296
2297         if (add_uevent_var(env, "HID_UNIQ=%s", hdev->uniq))
2298                 return -ENOMEM;
2299
2300         if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",
2301                            hdev->bus, hdev->group, hdev->vendor, hdev->product))
2302                 return -ENOMEM;
2303
2304         return 0;
2305 }
2306
2307 struct bus_type hid_bus_type = {
2308         .name           = "hid",
2309         .dev_groups     = hid_dev_groups,
2310         .drv_groups     = hid_drv_groups,
2311         .match          = hid_bus_match,
2312         .probe          = hid_device_probe,
2313         .remove         = hid_device_remove,
2314         .uevent         = hid_uevent,
2315 };
2316 EXPORT_SYMBOL(hid_bus_type);
2317
2318 int hid_add_device(struct hid_device *hdev)
2319 {
2320         static atomic_t id = ATOMIC_INIT(0);
2321         int ret;
2322
2323         if (WARN_ON(hdev->status & HID_STAT_ADDED))
2324                 return -EBUSY;
2325
2326         hdev->quirks = hid_lookup_quirk(hdev);
2327
2328         /* we need to kill them here, otherwise they will stay allocated to
2329          * wait for coming driver */
2330         if (hid_ignore(hdev))
2331                 return -ENODEV;
2332
2333         /*
2334          * Check for the mandatory transport channel.
2335          */
2336          if (!hdev->ll_driver->raw_request) {
2337                 hid_err(hdev, "transport driver missing .raw_request()\n");
2338                 return -EINVAL;
2339          }
2340
2341         /*
2342          * Read the device report descriptor once and use as template
2343          * for the driver-specific modifications.
2344          */
2345         ret = hdev->ll_driver->parse(hdev);
2346         if (ret)
2347                 return ret;
2348         if (!hdev->dev_rdesc)
2349                 return -ENODEV;
2350
2351         /*
2352          * Scan generic devices for group information
2353          */
2354         if (hid_ignore_special_drivers) {
2355                 hdev->group = HID_GROUP_GENERIC;
2356         } else if (!hdev->group &&
2357                    !(hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)) {
2358                 ret = hid_scan_report(hdev);
2359                 if (ret)
2360                         hid_warn(hdev, "bad device descriptor (%d)\n", ret);
2361         }
2362
2363         /* XXX hack, any other cleaner solution after the driver core
2364          * is converted to allow more than 20 bytes as the device name? */
2365         dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
2366                      hdev->vendor, hdev->product, atomic_inc_return(&id));
2367
2368         /*
2369          * Try loading the module for the device before the add, so that we do
2370          * not first have hid-generic binding only to have it replaced
2371          * immediately afterwards with a specialized driver.
2372          */
2373         if (!current_is_async())
2374                 request_module("hid:b%04Xg%04Xv%08Xp%08X", hdev->bus,
2375                                hdev->group, hdev->vendor, hdev->product);
2376
2377         hid_debug_register(hdev, dev_name(&hdev->dev));
2378         ret = device_add(&hdev->dev);
2379         if (!ret)
2380                 hdev->status |= HID_STAT_ADDED;
2381         else
2382                 hid_debug_unregister(hdev);
2383
2384         return ret;
2385 }
2386 EXPORT_SYMBOL_GPL(hid_add_device);
2387
2388 /**
2389  * hid_allocate_device - allocate new hid device descriptor
2390  *
2391  * Allocate and initialize hid device, so that hid_destroy_device might be
2392  * used to free it.
2393  *
2394  * New hid_device pointer is returned on success, otherwise ERR_PTR encoded
2395  * error value.
2396  */
2397 struct hid_device *hid_allocate_device(void)
2398 {
2399         struct hid_device *hdev;
2400         int ret = -ENOMEM;
2401
2402         hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
2403         if (hdev == NULL)
2404                 return ERR_PTR(ret);
2405
2406         device_initialize(&hdev->dev);
2407         hdev->dev.release = hid_device_release;
2408         hdev->dev.bus = &hid_bus_type;
2409         device_enable_async_suspend(&hdev->dev);
2410
2411         hid_close_report(hdev);
2412
2413         init_waitqueue_head(&hdev->debug_wait);
2414         INIT_LIST_HEAD(&hdev->debug_list);
2415         spin_lock_init(&hdev->debug_list_lock);
2416         sema_init(&hdev->driver_input_lock, 1);
2417         mutex_init(&hdev->ll_open_lock);
2418
2419         return hdev;
2420 }
2421 EXPORT_SYMBOL_GPL(hid_allocate_device);
2422
2423 static void hid_remove_device(struct hid_device *hdev)
2424 {
2425         if (hdev->status & HID_STAT_ADDED) {
2426                 device_del(&hdev->dev);
2427                 hid_debug_unregister(hdev);
2428                 hdev->status &= ~HID_STAT_ADDED;
2429         }
2430         kfree(hdev->dev_rdesc);
2431         hdev->dev_rdesc = NULL;
2432         hdev->dev_rsize = 0;
2433 }
2434
2435 /**
2436  * hid_destroy_device - free previously allocated device
2437  *
2438  * @hdev: hid device
2439  *
2440  * If you allocate hid_device through hid_allocate_device, you should ever
2441  * free by this function.
2442  */
2443 void hid_destroy_device(struct hid_device *hdev)
2444 {
2445         hid_remove_device(hdev);
2446         put_device(&hdev->dev);
2447 }
2448 EXPORT_SYMBOL_GPL(hid_destroy_device);
2449
2450
2451 static int __hid_bus_reprobe_drivers(struct device *dev, void *data)
2452 {
2453         struct hid_driver *hdrv = data;
2454         struct hid_device *hdev = to_hid_device(dev);
2455
2456         if (hdev->driver == hdrv &&
2457             !hdrv->match(hdev, hid_ignore_special_drivers) &&
2458             !test_and_set_bit(ffs(HID_STAT_REPROBED), &hdev->status))
2459                 return device_reprobe(dev);
2460
2461         return 0;
2462 }
2463
2464 static int __hid_bus_driver_added(struct device_driver *drv, void *data)
2465 {
2466         struct hid_driver *hdrv = to_hid_driver(drv);
2467
2468         if (hdrv->match) {
2469                 bus_for_each_dev(&hid_bus_type, NULL, hdrv,
2470                                  __hid_bus_reprobe_drivers);
2471         }
2472
2473         return 0;
2474 }
2475
2476 static int __bus_removed_driver(struct device_driver *drv, void *data)
2477 {
2478         return bus_rescan_devices(&hid_bus_type);
2479 }
2480
2481 int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
2482                 const char *mod_name)
2483 {
2484         int ret;
2485
2486         hdrv->driver.name = hdrv->name;
2487         hdrv->driver.bus = &hid_bus_type;
2488         hdrv->driver.owner = owner;
2489         hdrv->driver.mod_name = mod_name;
2490
2491         INIT_LIST_HEAD(&hdrv->dyn_list);
2492         spin_lock_init(&hdrv->dyn_lock);
2493
2494         ret = driver_register(&hdrv->driver);
2495
2496         if (ret == 0)
2497                 bus_for_each_drv(&hid_bus_type, NULL, NULL,
2498                                  __hid_bus_driver_added);
2499
2500         return ret;
2501 }
2502 EXPORT_SYMBOL_GPL(__hid_register_driver);
2503
2504 void hid_unregister_driver(struct hid_driver *hdrv)
2505 {
2506         driver_unregister(&hdrv->driver);
2507         hid_free_dynids(hdrv);
2508
2509         bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver);
2510 }
2511 EXPORT_SYMBOL_GPL(hid_unregister_driver);
2512
2513 int hid_check_keys_pressed(struct hid_device *hid)
2514 {
2515         struct hid_input *hidinput;
2516         int i;
2517
2518         if (!(hid->claimed & HID_CLAIMED_INPUT))
2519                 return 0;
2520
2521         list_for_each_entry(hidinput, &hid->inputs, list) {
2522                 for (i = 0; i < BITS_TO_LONGS(KEY_MAX); i++)
2523                         if (hidinput->input->key[i])
2524                                 return 1;
2525         }
2526
2527         return 0;
2528 }
2529
2530 EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
2531
2532 static int __init hid_init(void)
2533 {
2534         int ret;
2535
2536         if (hid_debug)
2537                 pr_warn("hid_debug is now used solely for parser and driver debugging.\n"
2538                         "debugfs is now used for inspecting the device (report descriptor, reports)\n");
2539
2540         ret = bus_register(&hid_bus_type);
2541         if (ret) {
2542                 pr_err("can't register hid bus\n");
2543                 goto err;
2544         }
2545
2546         ret = hidraw_init();
2547         if (ret)
2548                 goto err_bus;
2549
2550         hid_debug_init();
2551
2552         return 0;
2553 err_bus:
2554         bus_unregister(&hid_bus_type);
2555 err:
2556         return ret;
2557 }
2558
2559 static void __exit hid_exit(void)
2560 {
2561         hid_debug_exit();
2562         hidraw_exit();
2563         bus_unregister(&hid_bus_type);
2564         hid_quirks_exit(HID_BUS_ANY);
2565 }
2566
2567 module_init(hid_init);
2568 module_exit(hid_exit);
2569
2570 MODULE_AUTHOR("Andreas Gal");
2571 MODULE_AUTHOR("Vojtech Pavlik");
2572 MODULE_AUTHOR("Jiri Kosina");
2573 MODULE_LICENSE("GPL");