drivers/hid/hid-core.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  HID support for Linux
   4  *
   5  *  Copyright (c) 1999 Andreas Gal
   6  *  Copyright (c) 2000-2005 Vojtech Pavlik <[email protected]>
   7  *  Copyright (c) 2005 Michael Haboustak <[email protected]> for Concept2, Inc
   8  *  Copyright (c) 2006-2012 Jiri Kosina
   9  */
  10
  11 /*
  12  */
  13
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16 #include <linux/module.h>
  17 #include <linux/slab.h>
  18 #include <linux/init.h>
  19 #include <linux/kernel.h>
  20 #include <linux/list.h>
  21 #include <linux/mm.h>
  22 #include <linux/spinlock.h>
  23 #include <asm/unaligned.h>
  24 #include <asm/byteorder.h>
  25 #include <linux/input.h>
  26 #include <linux/wait.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/sched.h>
  29 #include <linux/semaphore.h>
  30
  31 #include <linux/hid.h>
  32 #include <linux/hiddev.h>
  33 #include <linux/hid-debug.h>
  34 #include <linux/hidraw.h>
  35
  36 #include "hid-ids.h"
  37
  38 /*
  39  * Version Information
  40  */
  41
  42 #define DRIVER_DESC "HID core driver"
  43
  44 int hid_debug = 0;
  45 module_param_named(debug, hid_debug, int, 0600);
  46 MODULE_PARM_DESC(debug, "toggle HID debugging messages");
  47 EXPORT_SYMBOL_GPL(hid_debug);
  48
  49 static int hid_ignore_special_drivers = 0;
  50 module_param_named(ignore_special_drivers, hid_ignore_special_drivers, int, 0600);
  51 MODULE_PARM_DESC(ignore_special_drivers, "Ignore any special drivers and handle all devices by generic driver");
  52
  53 /*
  54  * Register a new report for a device.
  55  */
  56
  57 struct hid_report *hid_register_report(struct hid_device *device,
  58                                        unsigned int type, unsigned int id,
  59                                        unsigned int application)
  60 {
  61         struct hid_report_enum *report_enum = device->report_enum + type;
  62         struct hid_report *report;
  63
  64         if (id >= HID_MAX_IDS)
  65                 return NULL;
  66         if (report_enum->report_id_hash[id])
  67                 return report_enum->report_id_hash[id];
  68
  69         report = kzalloc(sizeof(struct hid_report), GFP_KERNEL);
  70         if (!report)
  71                 return NULL;
  72
  73         if (id != 0)
  74                 report_enum->numbered = 1;
  75
  76         report->id = id;
  77         report->type = type;
  78         report->size = 0;
  79         report->device = device;
  80         report->application = application;
  81         report_enum->report_id_hash[id] = report;
  82
  83         list_add_tail(&report->list, &report_enum->report_list);
  84         INIT_LIST_HEAD(&report->field_entry_list);
  85
  86         return report;
  87 }
  88 EXPORT_SYMBOL_GPL(hid_register_report);
  89
  90 /*
  91  * Register a new field for this report.
  92  */
  93
  94 static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages)
  95 {
  96         struct hid_field *field;
  97
  98         if (report->maxfield == HID_MAX_FIELDS) {
  99                 hid_err(report->device, "too many fields in report\n");
 100                 return NULL;
 101         }
 102
 103         field = kzalloc((sizeof(struct hid_field) +
 104                          usages * sizeof(struct hid_usage) +
 105                          3 * usages * sizeof(unsigned int)), GFP_KERNEL);
 106         if (!field)
 107                 return NULL;
 108
 109         field->index = report->maxfield++;
 110         report->field[field->index] = field;
 111         field->usage = (struct hid_usage *)(field + 1);
 112         field->value = (s32 *)(field->usage + usages);
 113         field->new_value = (s32 *)(field->value + usages);
 114         field->usages_priorities = (s32 *)(field->new_value + usages);
 115         field->report = report;
 116
 117         return field;
 118 }
 119
 120 /*
 121  * Open a collection. The type/usage is pushed on the stack.
 122  */
 123
 124 static int open_collection(struct hid_parser *parser, unsigned type)
 125 {
 126         struct hid_collection *collection;
 127         unsigned usage;
 128         int collection_index;
 129
 130         usage = parser->local.usage[0];
 131
 132         if (parser->collection_stack_ptr == parser->collection_stack_size) {
 133                 unsigned int *collection_stack;
 134                 unsigned int new_size = parser->collection_stack_size +
 135                                         HID_COLLECTION_STACK_SIZE;
 136
 137                 collection_stack = krealloc(parser->collection_stack,
 138                                             new_size * sizeof(unsigned int),
 139                                             GFP_KERNEL);
 140                 if (!collection_stack)
 141                         return -ENOMEM;
 142
 143                 parser->collection_stack = collection_stack;
 144                 parser->collection_stack_size = new_size;
 145         }
 146
 147         if (parser->device->maxcollection == parser->device->collection_size) {
 148                 collection = kmalloc(
 149                                 array3_size(sizeof(struct hid_collection),
 150                                             parser->device->collection_size,
 151                                             2),
 152                                 GFP_KERNEL);
 153                 if (collection == NULL) {
 154                         hid_err(parser->device, "failed to reallocate collection array\n");
 155                         return -ENOMEM;
 156                 }
 157                 memcpy(collection, parser->device->collection,
 158                         sizeof(struct hid_collection) *
 159                         parser->device->collection_size);
 160                 memset(collection + parser->device->collection_size, 0,
 161                         sizeof(struct hid_collection) *
 162                         parser->device->collection_size);
 163                 kfree(parser->device->collection);
 164                 parser->device->collection = collection;
 165                 parser->device->collection_size *= 2;
 166         }
 167
 168         parser->collection_stack[parser->collection_stack_ptr++] =
 169                 parser->device->maxcollection;
 170
 171         collection_index = parser->device->maxcollection++;
 172         collection = parser->device->collection + collection_index;
 173         collection->type = type;
 174         collection->usage = usage;
 175         collection->level = parser->collection_stack_ptr - 1;
 176         collection->parent_idx = (collection->level == 0) ? -1 :
 177                 parser->collection_stack[collection->level - 1];
 178
 179         if (type == HID_COLLECTION_APPLICATION)
 180                 parser->device->maxapplication++;
 181
 182         return 0;
 183 }
 184
 185 /*
 186  * Close a collection.
 187  */
 188
 189 static int close_collection(struct hid_parser *parser)
 190 {
 191         if (!parser->collection_stack_ptr) {
 192                 hid_err(parser->device, "collection stack underflow\n");
 193                 return -EINVAL;
 194         }
 195         parser->collection_stack_ptr--;
 196         return 0;
 197 }
 198
 199 /*
 200  * Climb up the stack, search for the specified collection type
 201  * and return the usage.
 202  */
 203
 204 static unsigned hid_lookup_collection(struct hid_parser *parser, unsigned type)
 205 {
 206         struct hid_collection *collection = parser->device->collection;
 207         int n;
 208
 209         for (n = parser->collection_stack_ptr - 1; n >= 0; n--) {
 210                 unsigned index = parser->collection_stack[n];
 211                 if (collection[index].type == type)
 212                         return collection[index].usage;
 213         }
 214         return 0; /* we know nothing about this usage type */
 215 }
 216
 217 /*
 218  * Concatenate usage which defines 16 bits or less with the
 219  * currently defined usage page to form a 32 bit usage
 220  */
 221
 222 static void complete_usage(struct hid_parser *parser, unsigned int index)
 223 {
 224         parser->local.usage[index] &= 0xFFFF;
 225         parser->local.usage[index] |=
 226                 (parser->global.usage_page & 0xFFFF) << 16;
 227 }
 228
 229 /*
 230  * Add a usage to the temporary parser table.
 231  */
 232
 233 static int hid_add_usage(struct hid_parser *parser, unsigned usage, u8 size)
 234 {
 235         if (parser->local.usage_index >= HID_MAX_USAGES) {
 236                 hid_err(parser->device, "usage index exceeded\n");
 237                 return -1;
 238         }
 239         parser->local.usage[parser->local.usage_index] = usage;
 240
 241         /*
 242          * If Usage item only includes usage id, concatenate it with
 243          * currently defined usage page
 244          */
 245         if (size <= 2)
 246                 complete_usage(parser, parser->local.usage_index);
 247
 248         parser->local.usage_size[parser->local.usage_index] = size;
 249         parser->local.collection_index[parser->local.usage_index] =
 250                 parser->collection_stack_ptr ?
 251                 parser->collection_stack[parser->collection_stack_ptr - 1] : 0;
 252         parser->local.usage_index++;
 253         return 0;
 254 }
 255
 256 /*
 257  * Register a new field for this report.
 258  */
 259
 260 static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsigned flags)
 261 {
 262         struct hid_report *report;
 263         struct hid_field *field;
 264         unsigned int usages;
 265         unsigned int offset;
 266         unsigned int i;
 267         unsigned int application;
 268
 269         application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
 270
 271         report = hid_register_report(parser->device, report_type,
 272                                      parser->global.report_id, application);
 273         if (!report) {
 274                 hid_err(parser->device, "hid_register_report failed\n");
 275                 return -1;
 276         }
 277
 278         /* Handle both signed and unsigned cases properly */
 279         if ((parser->global.logical_minimum < 0 &&
 280                 parser->global.logical_maximum <
 281                 parser->global.logical_minimum) ||
 282                 (parser->global.logical_minimum >= 0 &&
 283                 (__u32)parser->global.logical_maximum <
 284                 (__u32)parser->global.logical_minimum)) {
 285                 dbg_hid("logical range invalid 0x%x 0x%x\n",
 286                         parser->global.logical_minimum,
 287                         parser->global.logical_maximum);
 288                 return -1;
 289         }
 290
 291         offset = report->size;
 292         report->size += parser->global.report_size * parser->global.report_count;
 293
 294         /* Total size check: Allow for possible report index byte */
 295         if (report->size > (HID_MAX_BUFFER_SIZE - 1) << 3) {
 296                 hid_err(parser->device, "report is too long\n");
 297                 return -1;
 298         }
 299
 300         if (!parser->local.usage_index) /* Ignore padding fields */
 301                 return 0;
 302
 303         usages = max_t(unsigned, parser->local.usage_index,
 304                                  parser->global.report_count);
 305
 306         field = hid_register_field(report, usages);
 307         if (!field)
 308                 return 0;
 309
 310         field->physical = hid_lookup_collection(parser, HID_COLLECTION_PHYSICAL);
 311         field->logical = hid_lookup_collection(parser, HID_COLLECTION_LOGICAL);
 312         field->application = application;
 313
 314         for (i = 0; i < usages; i++) {
 315                 unsigned j = i;
 316                 /* Duplicate the last usage we parsed if we have excess values */
 317                 if (i >= parser->local.usage_index)
 318                         j = parser->local.usage_index - 1;
 319                 field->usage[i].hid = parser->local.usage[j];
 320                 field->usage[i].collection_index =
 321                         parser->local.collection_index[j];
 322                 field->usage[i].usage_index = i;
 323                 field->usage[i].resolution_multiplier = 1;
 324         }
 325
 326         field->maxusage = usages;
 327         field->flags = flags;
 328         field->report_offset = offset;
 329         field->report_type = report_type;
 330         field->report_size = parser->global.report_size;
 331         field->report_count = parser->global.report_count;
 332         field->logical_minimum = parser->global.logical_minimum;
 333         field->logical_maximum = parser->global.logical_maximum;
 334         field->physical_minimum = parser->global.physical_minimum;
 335         field->physical_maximum = parser->global.physical_maximum;
 336         field->unit_exponent = parser->global.unit_exponent;
 337         field->unit = parser->global.unit;
 338
 339         return 0;
 340 }
 341
 342 /*
 343  * Read data value from item.
 344  */
 345
 346 static u32 item_udata(struct hid_item *item)
 347 {
 348         switch (item->size) {
 349         case 1: return item->data.u8;
 350         case 2: return item->data.u16;
 351         case 4: return item->data.u32;
 352         }
 353         return 0;
 354 }
 355
 356 static s32 item_sdata(struct hid_item *item)
 357 {
 358         switch (item->size) {
 359         case 1: return item->data.s8;
 360         case 2: return item->data.s16;
 361         case 4: return item->data.s32;
 362         }
 363         return 0;
 364 }
 365
 366 /*
 367  * Process a global item.
 368  */
 369
 370 static int hid_parser_global(struct hid_parser *parser, struct hid_item *item)
 371 {
 372         __s32 raw_value;
 373         switch (item->tag) {
 374         case HID_GLOBAL_ITEM_TAG_PUSH:
 375
 376                 if (parser->global_stack_ptr == HID_GLOBAL_STACK_SIZE) {
 377                         hid_err(parser->device, "global environment stack overflow\n");
 378                         return -1;
 379                 }
 380
 381                 memcpy(parser->global_stack + parser->global_stack_ptr++,
 382                         &parser->global, sizeof(struct hid_global));
 383                 return 0;
 384
 385         case HID_GLOBAL_ITEM_TAG_POP:
 386
 387                 if (!parser->global_stack_ptr) {
 388                         hid_err(parser->device, "global environment stack underflow\n");
 389                         return -1;
 390                 }
 391
 392                 memcpy(&parser->global, parser->global_stack +
 393                         --parser->global_stack_ptr, sizeof(struct hid_global));
 394                 return 0;
 395
 396         case HID_GLOBAL_ITEM_TAG_USAGE_PAGE:
 397                 parser->global.usage_page = item_udata(item);
 398                 return 0;
 399
 400         case HID_GLOBAL_ITEM_TAG_LOGICAL_MINIMUM:
 401                 parser->global.logical_minimum = item_sdata(item);
 402                 return 0;
 403
 404         case HID_GLOBAL_ITEM_TAG_LOGICAL_MAXIMUM:
 405                 if (parser->global.logical_minimum < 0)
 406                         parser->global.logical_maximum = item_sdata(item);
 407                 else
 408                         parser->global.logical_maximum = item_udata(item);
 409                 return 0;
 410
 411         case HID_GLOBAL_ITEM_TAG_PHYSICAL_MINIMUM:
 412                 parser->global.physical_minimum = item_sdata(item);
 413                 return 0;
 414
 415         case HID_GLOBAL_ITEM_TAG_PHYSICAL_MAXIMUM:
 416                 if (parser->global.physical_minimum < 0)
 417                         parser->global.physical_maximum = item_sdata(item);
 418                 else
 419                         parser->global.physical_maximum = item_udata(item);
 420                 return 0;
 421
 422         case HID_GLOBAL_ITEM_TAG_UNIT_EXPONENT:
 423                 /* Many devices provide unit exponent as a two's complement
 424                  * nibble due to the common misunderstanding of HID
 425                  * specification 1.11, 6.2.2.7 Global Items. Attempt to handle
 426                  * both this and the standard encoding. */
 427                 raw_value = item_sdata(item);
 428                 if (!(raw_value & 0xfffffff0))
 429                         parser->global.unit_exponent = hid_snto32(raw_value, 4);
 430                 else
 431                         parser->global.unit_exponent = raw_value;
 432                 return 0;
 433
 434         case HID_GLOBAL_ITEM_TAG_UNIT:
 435                 parser->global.unit = item_udata(item);
 436                 return 0;
 437
 438         case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
 439                 parser->global.report_size = item_udata(item);
 440                 if (parser->global.report_size > 256) {
 441                         hid_err(parser->device, "invalid report_size %d\n",
 442                                         parser->global.report_size);
 443                         return -1;
 444                 }
 445                 return 0;
 446
 447         case HID_GLOBAL_ITEM_TAG_REPORT_COUNT:
 448                 parser->global.report_count = item_udata(item);
 449                 if (parser->global.report_count > HID_MAX_USAGES) {
 450                         hid_err(parser->device, "invalid report_count %d\n",
 451                                         parser->global.report_count);
 452                         return -1;
 453                 }
 454                 return 0;
 455
 456         case HID_GLOBAL_ITEM_TAG_REPORT_ID:
 457                 parser->global.report_id = item_udata(item);
 458                 if (parser->global.report_id == 0 ||
 459                     parser->global.report_id >= HID_MAX_IDS) {
 460                         hid_err(parser->device, "report_id %u is invalid\n",
 461                                 parser->global.report_id);
 462                         return -1;
 463                 }
 464                 return 0;
 465
 466         default:
 467                 hid_err(parser->device, "unknown global tag 0x%x\n", item->tag);
 468                 return -1;
 469         }
 470 }
 471
 472 /*
 473  * Process a local item.
 474  */
 475
 476 static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
 477 {
 478         __u32 data;
 479         unsigned n;
 480         __u32 count;
 481
 482         data = item_udata(item);
 483
 484         switch (item->tag) {
 485         case HID_LOCAL_ITEM_TAG_DELIMITER:
 486
 487                 if (data) {
 488                         /*
 489                          * We treat items before the first delimiter
 490                          * as global to all usage sets (branch 0).
 491                          * In the moment we process only these global
 492                          * items and the first delimiter set.
 493                          */
 494                         if (parser->local.delimiter_depth != 0) {
 495                                 hid_err(parser->device, "nested delimiters\n");
 496                                 return -1;
 497                         }
 498                         parser->local.delimiter_depth++;
 499                         parser->local.delimiter_branch++;
 500                 } else {
 501                         if (parser->local.delimiter_depth < 1) {
 502                                 hid_err(parser->device, "bogus close delimiter\n");
 503                                 return -1;
 504                         }
 505                         parser->local.delimiter_depth--;
 506                 }
 507                 return 0;
 508
 509         case HID_LOCAL_ITEM_TAG_USAGE:
 510
 511                 if (parser->local.delimiter_branch > 1) {
 512                         dbg_hid("alternative usage ignored\n");
 513                         return 0;
 514                 }
 515
 516                 return hid_add_usage(parser, data, item->size);
 517
 518         case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:
 519
 520                 if (parser->local.delimiter_branch > 1) {
 521                         dbg_hid("alternative usage ignored\n");
 522                         return 0;
 523                 }
 524
 525                 parser->local.usage_minimum = data;
 526                 return 0;
 527
 528         case HID_LOCAL_ITEM_TAG_USAGE_MAXIMUM:
 529
 530                 if (parser->local.delimiter_branch > 1) {
 531                         dbg_hid("alternative usage ignored\n");
 532                         return 0;
 533                 }
 534
 535                 count = data - parser->local.usage_minimum;
 536                 if (count + parser->local.usage_index >= HID_MAX_USAGES) {
 537                         /*
 538                          * We do not warn if the name is not set, we are
 539                          * actually pre-scanning the device.
 540                          */
 541                         if (dev_name(&parser->device->dev))
 542                                 hid_warn(parser->device,
 543                                          "ignoring exceeding usage max\n");
 544                         data = HID_MAX_USAGES - parser->local.usage_index +
 545                                 parser->local.usage_minimum - 1;
 546                         if (data <= 0) {
 547                                 hid_err(parser->device,
 548                                         "no more usage index available\n");
 549                                 return -1;
 550                         }
 551                 }
 552
 553                 for (n = parser->local.usage_minimum; n <= data; n++)
 554                         if (hid_add_usage(parser, n, item->size)) {
 555                                 dbg_hid("hid_add_usage failed\n");
 556                                 return -1;
 557                         }
 558                 return 0;
 559
 560         default:
 561
 562                 dbg_hid("unknown local item tag 0x%x\n", item->tag);
 563                 return 0;
 564         }
 565         return 0;
 566 }
 567
 568 /*
 569  * Concatenate Usage Pages into Usages where relevant:
 570  * As per specification, 6.2.2.8: "When the parser encounters a main item it
 571  * concatenates the last declared Usage Page with a Usage to form a complete
 572  * usage value."
 573  */
 574
 575 static void hid_concatenate_last_usage_page(struct hid_parser *parser)
 576 {
 577         int i;
 578         unsigned int usage_page;
 579         unsigned int current_page;
 580
 581         if (!parser->local.usage_index)
 582                 return;
 583
 584         usage_page = parser->global.usage_page;
 585
 586         /*
 587          * Concatenate usage page again only if last declared Usage Page
 588          * has not been already used in previous usages concatenation
 589          */
 590         for (i = parser->local.usage_index - 1; i >= 0; i--) {
 591                 if (parser->local.usage_size[i] > 2)
 592                         /* Ignore extended usages */
 593                         continue;
 594
 595                 current_page = parser->local.usage[i] >> 16;
 596                 if (current_page == usage_page)
 597                         break;
 598
 599                 complete_usage(parser, i);
 600         }
 601 }
 602
 603 /*
 604  * Process a main item.
 605  */
 606
 607 static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
 608 {
 609         __u32 data;
 610         int ret;
 611
 612         hid_concatenate_last_usage_page(parser);
 613
 614         data = item_udata(item);
 615
 616         switch (item->tag) {
 617         case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 618                 ret = open_collection(parser, data & 0xff);
 619                 break;
 620         case HID_MAIN_ITEM_TAG_END_COLLECTION:
 621                 ret = close_collection(parser);
 622                 break;
 623         case HID_MAIN_ITEM_TAG_INPUT:
 624                 ret = hid_add_field(parser, HID_INPUT_REPORT, data);
 625                 break;
 626         case HID_MAIN_ITEM_TAG_OUTPUT:
 627                 ret = hid_add_field(parser, HID_OUTPUT_REPORT, data);
 628                 break;
 629         case HID_MAIN_ITEM_TAG_FEATURE:
 630                 ret = hid_add_field(parser, HID_FEATURE_REPORT, data);
 631                 break;
 632         default:
 633                 hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
 634                 ret = 0;
 635         }
 636
 637         memset(&parser->local, 0, sizeof(parser->local));       /* Reset the local parser environment */
 638
 639         return ret;
 640 }
 641
 642 /*
 643  * Process a reserved item.
 644  */
 645
 646 static int hid_parser_reserved(struct hid_parser *parser, struct hid_item *item)
 647 {
 648         dbg_hid("reserved item type, tag 0x%x\n", item->tag);
 649         return 0;
 650 }
 651
 652 /*
 653  * Free a report and all registered fields. The field->usage and
 654  * field->value table's are allocated behind the field, so we need
 655  * only to free(field) itself.
 656  */
 657
 658 static void hid_free_report(struct hid_report *report)
 659 {
 660         unsigned n;
 661
 662         kfree(report->field_entries);
 663
 664         for (n = 0; n < report->maxfield; n++)
 665                 kfree(report->field[n]);
 666         kfree(report);
 667 }
 668
 669 /*
 670  * Close report. This function returns the device
 671  * state to the point prior to hid_open_report().
 672  */
 673 static void hid_close_report(struct hid_device *device)
 674 {
 675         unsigned i, j;
 676
 677         for (i = 0; i < HID_REPORT_TYPES; i++) {
 678                 struct hid_report_enum *report_enum = device->report_enum + i;
 679
 680                 for (j = 0; j < HID_MAX_IDS; j++) {
 681                         struct hid_report *report = report_enum->report_id_hash[j];
 682                         if (report)
 683                                 hid_free_report(report);
 684                 }
 685                 memset(report_enum, 0, sizeof(*report_enum));
 686                 INIT_LIST_HEAD(&report_enum->report_list);
 687         }
 688
 689         kfree(device->rdesc);
 690         device->rdesc = NULL;
 691         device->rsize = 0;
 692
 693         kfree(device->collection);
 694         device->collection = NULL;
 695         device->collection_size = 0;
 696         device->maxcollection = 0;
 697         device->maxapplication = 0;
 698
 699         device->status &= ~HID_STAT_PARSED;
 700 }
 701
 702 /*
 703  * Free a device structure, all reports, and all fields.
 704  */
 705
 706 static void hid_device_release(struct device *dev)
 707 {
 708         struct hid_device *hid = to_hid_device(dev);
 709
 710         hid_close_report(hid);
 711         kfree(hid->dev_rdesc);
 712         kfree(hid);
 713 }
 714
 715 /*
 716  * Fetch a report description item from the data stream. We support long
 717  * items, though they are not used yet.
 718  */
 719
 720 static u8 *fetch_item(__u8 *start, __u8 *end, struct hid_item *item)
 721 {
 722         u8 b;
 723
 724         if ((end - start) <= 0)
 725                 return NULL;
 726
 727         b = *start++;
 728
 729         item->type = (b >> 2) & 3;
 730         item->tag  = (b >> 4) & 15;
 731
 732         if (item->tag == HID_ITEM_TAG_LONG) {
 733
 734                 item->format = HID_ITEM_FORMAT_LONG;
 735
 736                 if ((end - start) < 2)
 737                         return NULL;
 738
 739                 item->size = *start++;
 740                 item->tag  = *start++;
 741
 742                 if ((end - start) < item->size)
 743                         return NULL;
 744
 745                 item->data.longdata = start;
 746                 start += item->size;
 747                 return start;
 748         }
 749
 750         item->format = HID_ITEM_FORMAT_SHORT;
 751         item->size = b & 3;
 752
 753         switch (item->size) {
 754         case 0:
 755                 return start;
 756
 757         case 1:
 758                 if ((end - start) < 1)
 759                         return NULL;
 760                 item->data.u8 = *start++;
 761                 return start;
 762
 763         case 2:
 764                 if ((end - start) < 2)
 765                         return NULL;
 766                 item->data.u16 = get_unaligned_le16(start);
 767                 start = (__u8 *)((__le16 *)start + 1);
 768                 return start;
 769
 770         case 3:
 771                 item->size++;
 772                 if ((end - start) < 4)
 773                         return NULL;
 774                 item->data.u32 = get_unaligned_le32(start);
 775                 start = (__u8 *)((__le32 *)start + 1);
 776                 return start;
 777         }
 778
 779         return NULL;
 780 }
 781
 782 static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)
 783 {
 784         struct hid_device *hid = parser->device;
 785
 786         if (usage == HID_DG_CONTACTID)
 787                 hid->group = HID_GROUP_MULTITOUCH;
 788 }
 789
 790 static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
 791 {
 792         if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
 793             parser->global.report_size == 8)
 794                 parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 795
 796         if (usage == 0xff0000c6 && parser->global.report_count == 1 &&
 797             parser->global.report_size == 8)
 798                 parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 799 }
 800
 801 static void hid_scan_collection(struct hid_parser *parser, unsigned type)
 802 {
 803         struct hid_device *hid = parser->device;
 804         int i;
 805
 806         if (((parser->global.usage_page << 16) == HID_UP_SENSOR) &&
 807             type == HID_COLLECTION_PHYSICAL)
 808                 hid->group = HID_GROUP_SENSOR_HUB;
 809
 810         if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
 811             hid->product == USB_DEVICE_ID_MS_POWER_COVER &&
 812             hid->group == HID_GROUP_MULTITOUCH)
 813                 hid->group = HID_GROUP_GENERIC;
 814
 815         if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
 816                 for (i = 0; i < parser->local.usage_index; i++)
 817                         if (parser->local.usage[i] == HID_GD_POINTER)
 818                                 parser->scan_flags |= HID_SCAN_FLAG_GD_POINTER;
 819
 820         if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
 821                 parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
 822
 823         if ((parser->global.usage_page << 16) == HID_UP_GOOGLEVENDOR)
 824                 for (i = 0; i < parser->local.usage_index; i++)
 825                         if (parser->local.usage[i] ==
 826                                         (HID_UP_GOOGLEVENDOR | 0x0001))
 827                                 parser->device->group =
 828                                         HID_GROUP_VIVALDI;
 829 }
 830
 831 static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
 832 {
 833         __u32 data;
 834         int i;
 835
 836         hid_concatenate_last_usage_page(parser);
 837
 838         data = item_udata(item);
 839
 840         switch (item->tag) {
 841         case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 842                 hid_scan_collection(parser, data & 0xff);
 843                 break;
 844         case HID_MAIN_ITEM_TAG_END_COLLECTION:
 845                 break;
 846         case HID_MAIN_ITEM_TAG_INPUT:
 847                 /* ignore constant inputs, they will be ignored by hid-input */
 848                 if (data & HID_MAIN_ITEM_CONSTANT)
 849                         break;
 850                 for (i = 0; i < parser->local.usage_index; i++)
 851                         hid_scan_input_usage(parser, parser->local.usage[i]);
 852                 break;
 853         case HID_MAIN_ITEM_TAG_OUTPUT:
 854                 break;
 855         case HID_MAIN_ITEM_TAG_FEATURE:
 856                 for (i = 0; i < parser->local.usage_index; i++)
 857                         hid_scan_feature_usage(parser, parser->local.usage[i]);
 858                 break;
 859         }
 860
 861         /* Reset the local parser environment */
 862         memset(&parser->local, 0, sizeof(parser->local));
 863
 864         return 0;
 865 }
 866
 867 /*
 868  * Scan a report descriptor before the device is added to the bus.
 869  * Sets device groups and other properties that determine what driver
 870  * to load.
 871  */
 872 static int hid_scan_report(struct hid_device *hid)
 873 {
 874         struct hid_parser *parser;
 875         struct hid_item item;
 876         __u8 *start = hid->dev_rdesc;
 877         __u8 *end = start + hid->dev_rsize;
 878         static int (*dispatch_type[])(struct hid_parser *parser,
 879                                       struct hid_item *item) = {
 880                 hid_scan_main,
 881                 hid_parser_global,
 882                 hid_parser_local,
 883                 hid_parser_reserved
 884         };
 885
 886         parser = vzalloc(sizeof(struct hid_parser));
 887         if (!parser)
 888                 return -ENOMEM;
 889
 890         parser->device = hid;
 891         hid->group = HID_GROUP_GENERIC;
 892
 893         /*
 894          * The parsing is simpler than the one in hid_open_report() as we should
 895          * be robust against hid errors. Those errors will be raised by
 896          * hid_open_report() anyway.
 897          */
 898         while ((start = fetch_item(start, end, &item)) != NULL)
 899                 dispatch_type[item.type](parser, &item);
 900
 901         /*
 902          * Handle special flags set during scanning.
 903          */
 904         if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
 905             (hid->group == HID_GROUP_MULTITOUCH))
 906                 hid->group = HID_GROUP_MULTITOUCH_WIN_8;
 907
 908         /*
 909          * Vendor specific handlings
 910          */
 911         switch (hid->vendor) {
 912         case USB_VENDOR_ID_WACOM:
 913                 hid->group = HID_GROUP_WACOM;
 914                 break;
 915         case USB_VENDOR_ID_SYNAPTICS:
 916                 if (hid->group == HID_GROUP_GENERIC)
 917                         if ((parser->scan_flags & HID_SCAN_FLAG_VENDOR_SPECIFIC)
 918                             && (parser->scan_flags & HID_SCAN_FLAG_GD_POINTER))
 919                                 /*
 920                                  * hid-rmi should take care of them,
 921                                  * not hid-generic
 922                                  */
 923                                 hid->group = HID_GROUP_RMI;
 924                 break;
 925         }
 926
 927         kfree(parser->collection_stack);
 928         vfree(parser);
 929         return 0;
 930 }
 931
 932 /**
 933  * hid_parse_report - parse device report
 934  *
 935  * @hid: hid device
 936  * @start: report start
 937  * @size: report size
 938  *
 939  * Allocate the device report as read by the bus driver. This function should
 940  * only be called from parse() in ll drivers.
 941  */
 942 int hid_parse_report(struct hid_device *hid, __u8 *start, unsigned size)
 943 {
 944         hid->dev_rdesc = kmemdup(start, size, GFP_KERNEL);
 945         if (!hid->dev_rdesc)
 946                 return -ENOMEM;
 947         hid->dev_rsize = size;
 948         return 0;
 949 }
 950 EXPORT_SYMBOL_GPL(hid_parse_report);
 951
 952 static const char * const hid_report_names[] = {
 953         "HID_INPUT_REPORT",
 954         "HID_OUTPUT_REPORT",
 955         "HID_FEATURE_REPORT",
 956 };
 957 /**
 958  * hid_validate_values - validate existing device report's value indexes
 959  *
 960  * @hid: hid device
 961  * @type: which report type to examine
 962  * @id: which report ID to examine (0 for first)
 963  * @field_index: which report field to examine
 964  * @report_counts: expected number of values
 965  *
 966  * Validate the number of values in a given field of a given report, after
 967  * parsing.
 968  */
 969 struct hid_report *hid_validate_values(struct hid_device *hid,
 970                                        unsigned int type, unsigned int id,
 971                                        unsigned int field_index,
 972                                        unsigned int report_counts)
 973 {
 974         struct hid_report *report;
 975
 976         if (type > HID_FEATURE_REPORT) {
 977                 hid_err(hid, "invalid HID report type %u\n", type);
 978                 return NULL;
 979         }
 980
 981         if (id >= HID_MAX_IDS) {
 982                 hid_err(hid, "invalid HID report id %u\n", id);
 983                 return NULL;
 984         }
 985
 986         /*
 987          * Explicitly not using hid_get_report() here since it depends on
 988          * ->numbered being checked, which may not always be the case when
 989          * drivers go to access report values.
 990          */
 991         if (id == 0) {
 992                 /*
 993                  * Validating on id 0 means we should examine the first
 994                  * report in the list.
 995                  */
 996                 report = list_entry(
 997                                 hid->report_enum[type].report_list.next,
 998                                 struct hid_report, list);
 999         } else {
1000                 report = hid->report_enum[type].report_id_hash[id];
1001         }
1002         if (!report) {
1003                 hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
1004                 return NULL;
1005         }
1006         if (report->maxfield <= field_index) {
1007                 hid_err(hid, "not enough fields in %s %u\n",
1008                         hid_report_names[type], id);
1009                 return NULL;
1010         }
1011         if (report->field[field_index]->report_count < report_counts) {
1012                 hid_err(hid, "not enough values in %s %u field %u\n",
1013                         hid_report_names[type], id, field_index);
1014                 return NULL;
1015         }
1016         return report;
1017 }
1018 EXPORT_SYMBOL_GPL(hid_validate_values);
1019
1020 static int hid_calculate_multiplier(struct hid_device *hid,
1021                                      struct hid_field *multiplier)
1022 {
1023         int m;
1024         __s32 v = *multiplier->value;
1025         __s32 lmin = multiplier->logical_minimum;
1026         __s32 lmax = multiplier->logical_maximum;
1027         __s32 pmin = multiplier->physical_minimum;
1028         __s32 pmax = multiplier->physical_maximum;
1029
1030         /*
1031          * "Because OS implementations will generally divide the control's
1032          * reported count by the Effective Resolution Multiplier, designers
1033          * should take care not to establish a potential Effective
1034          * Resolution Multiplier of zero."
1035          * HID Usage Table, v1.12, Section 4.3.1, p31
1036          */
1037         if (lmax - lmin == 0)
1038                 return 1;
1039         /*
1040          * Handling the unit exponent is left as an exercise to whoever
1041          * finds a device where that exponent is not 0.
1042          */
1043         m = ((v - lmin)/(lmax - lmin) * (pmax - pmin) + pmin);
1044         if (unlikely(multiplier->unit_exponent != 0)) {
1045                 hid_warn(hid,
1046                          "unsupported Resolution Multiplier unit exponent %d\n",
1047                          multiplier->unit_exponent);
1048         }
1049
1050         /* There are no devices with an effective multiplier > 255 */
1051         if (unlikely(m == 0 || m > 255 || m < -255)) {
1052                 hid_warn(hid, "unsupported Resolution Multiplier %d\n", m);
1053                 m = 1;
1054         }
1055
1056         return m;
1057 }
1058
1059 static void hid_apply_multiplier_to_field(struct hid_device *hid,
1060                                           struct hid_field *field,
1061                                           struct hid_collection *multiplier_collection,
1062                                           int effective_multiplier)
1063 {
1064         struct hid_collection *collection;
1065         struct hid_usage *usage;
1066         int i;
1067
1068         /*
1069          * If multiplier_collection is NULL, the multiplier applies
1070          * to all fields in the report.
1071          * Otherwise, it is the Logical Collection the multiplier applies to
1072          * but our field may be in a subcollection of that collection.
1073          */
1074         for (i = 0; i < field->maxusage; i++) {
1075                 usage = &field->usage[i];
1076
1077                 collection = &hid->collection[usage->collection_index];
1078                 while (collection->parent_idx != -1 &&
1079                        collection != multiplier_collection)
1080                         collection = &hid->collection[collection->parent_idx];
1081
1082                 if (collection->parent_idx != -1 ||
1083                     multiplier_collection == NULL)
1084                         usage->resolution_multiplier = effective_multiplier;
1085
1086         }
1087 }
1088
1089 static void hid_apply_multiplier(struct hid_device *hid,
1090                                  struct hid_field *multiplier)
1091 {
1092         struct hid_report_enum *rep_enum;
1093         struct hid_report *rep;
1094         struct hid_field *field;
1095         struct hid_collection *multiplier_collection;
1096         int effective_multiplier;
1097         int i;
1098
1099         /*
1100          * "The Resolution Multiplier control must be contained in the same
1101          * Logical Collection as the control(s) to which it is to be applied.
1102          * If no Resolution Multiplier is defined, then the Resolution
1103          * Multiplier defaults to 1.  If more than one control exists in a
1104          * Logical Collection, the Resolution Multiplier is associated with
1105          * all controls in the collection. If no Logical Collection is
1106          * defined, the Resolution Multiplier is associated with all
1107          * controls in the report."
1108          * HID Usage Table, v1.12, Section 4.3.1, p30
1109          *
1110          * Thus, search from the current collection upwards until we find a
1111          * logical collection. Then search all fields for that same parent
1112          * collection. Those are the fields the multiplier applies to.
1113          *
1114          * If we have more than one multiplier, it will overwrite the
1115          * applicable fields later.
1116          */
1117         multiplier_collection = &hid->collection[multiplier->usage->collection_index];
1118         while (multiplier_collection->parent_idx != -1 &&
1119                multiplier_collection->type != HID_COLLECTION_LOGICAL)
1120                 multiplier_collection = &hid->collection[multiplier_collection->parent_idx];
1121
1122         effective_multiplier = hid_calculate_multiplier(hid, multiplier);
1123
1124         rep_enum = &hid->report_enum[HID_INPUT_REPORT];
1125         list_for_each_entry(rep, &rep_enum->report_list, list) {
1126                 for (i = 0; i < rep->maxfield; i++) {
1127                         field = rep->field[i];
1128                         hid_apply_multiplier_to_field(hid, field,
1129                                                       multiplier_collection,
1130                                                       effective_multiplier);
1131                 }
1132         }
1133 }
1134
1135 /*
1136  * hid_setup_resolution_multiplier - set up all resolution multipliers
1137  *
1138  * @device: hid device
1139  *
1140  * Search for all Resolution Multiplier Feature Reports and apply their
1141  * value to all matching Input items. This only updates the internal struct
1142  * fields.
1143  *
1144  * The Resolution Multiplier is applied by the hardware. If the multiplier
1145  * is anything other than 1, the hardware will send pre-multiplied events
1146  * so that the same physical interaction generates an accumulated
1147  *      accumulated_value = value * * multiplier
1148  * This may be achieved by sending
1149  * - "value * multiplier" for each event, or
1150  * - "value" but "multiplier" times as frequently, or
1151  * - a combination of the above
1152  * The only guarantee is that the same physical interaction always generates
1153  * an accumulated 'value * multiplier'.
1154  *
1155  * This function must be called before any event processing and after
1156  * any SetRequest to the Resolution Multiplier.
1157  */
1158 void hid_setup_resolution_multiplier(struct hid_device *hid)
1159 {
1160         struct hid_report_enum *rep_enum;
1161         struct hid_report *rep;
1162         struct hid_usage *usage;
1163         int i, j;
1164
1165         rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
1166         list_for_each_entry(rep, &rep_enum->report_list, list) {
1167                 for (i = 0; i < rep->maxfield; i++) {
1168                         /* Ignore if report count is out of bounds. */
1169                         if (rep->field[i]->report_count < 1)
1170                                 continue;
1171
1172                         for (j = 0; j < rep->field[i]->maxusage; j++) {
1173                                 usage = &rep->field[i]->usage[j];
1174                                 if (usage->hid == HID_GD_RESOLUTION_MULTIPLIER)
1175                                         hid_apply_multiplier(hid,
1176                                                              rep->field[i]);
1177                         }
1178                 }
1179         }
1180 }
1181 EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier);
1182
1183 /**
1184  * hid_open_report - open a driver-specific device report
1185  *
1186  * @device: hid device
1187  *
1188  * Parse a report description into a hid_device structure. Reports are
1189  * enumerated, fields are attached to these reports.
1190  * 0 returned on success, otherwise nonzero error value.
1191  *
1192  * This function (or the equivalent hid_parse() macro) should only be
1193  * called from probe() in drivers, before starting the device.
1194  */
1195 int hid_open_report(struct hid_device *device)
1196 {
1197         struct hid_parser *parser;
1198         struct hid_item item;
1199         unsigned int size;
1200         __u8 *start;
1201         __u8 *buf;
1202         __u8 *end;
1203         __u8 *next;
1204         int ret;
1205         static int (*dispatch_type[])(struct hid_parser *parser,
1206                                       struct hid_item *item) = {
1207                 hid_parser_main,
1208                 hid_parser_global,
1209                 hid_parser_local,
1210                 hid_parser_reserved
1211         };
1212
1213         if (WARN_ON(device->status & HID_STAT_PARSED))
1214                 return -EBUSY;
1215
1216         start = device->dev_rdesc;
1217         if (WARN_ON(!start))
1218                 return -ENODEV;
1219         size = device->dev_rsize;
1220
1221         buf = kmemdup(start, size, GFP_KERNEL);
1222         if (buf == NULL)
1223                 return -ENOMEM;
1224
1225         if (device->driver->report_fixup)
1226                 start = device->driver->report_fixup(device, buf, &size);
1227         else
1228                 start = buf;
1229
1230         start = kmemdup(start, size, GFP_KERNEL);
1231         kfree(buf);
1232         if (start == NULL)
1233                 return -ENOMEM;
1234
1235         device->rdesc = start;
1236         device->rsize = size;
1237
1238         parser = vzalloc(sizeof(struct hid_parser));
1239         if (!parser) {
1240                 ret = -ENOMEM;
1241                 goto alloc_err;
1242         }
1243
1244         parser->device = device;
1245
1246         end = start + size;
1247
1248         device->collection = kcalloc(HID_DEFAULT_NUM_COLLECTIONS,
1249                                      sizeof(struct hid_collection), GFP_KERNEL);
1250         if (!device->collection) {
1251                 ret = -ENOMEM;
1252                 goto err;
1253         }
1254         device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
1255
1256         ret = -EINVAL;
1257         while ((next = fetch_item(start, end, &item)) != NULL) {
1258                 start = next;
1259
1260                 if (item.format != HID_ITEM_FORMAT_SHORT) {
1261                         hid_err(device, "unexpected long global item\n");
1262                         goto err;
1263                 }
1264
1265                 if (dispatch_type[item.type](parser, &item)) {
1266                         hid_err(device, "item %u %u %u %u parsing failed\n",
1267                                 item.format, (unsigned)item.size,
1268                                 (unsigned)item.type, (unsigned)item.tag);
1269                         goto err;
1270                 }
1271
1272                 if (start == end) {
1273                         if (parser->collection_stack_ptr) {
1274                                 hid_err(device, "unbalanced collection at end of report description\n");
1275                                 goto err;
1276                         }
1277                         if (parser->local.delimiter_depth) {
1278                                 hid_err(device, "unbalanced delimiter at end of report description\n");
1279                                 goto err;
1280                         }
1281
1282                         /*
1283                          * fetch initial values in case the device's
1284                          * default multiplier isn't the recommended 1
1285                          */
1286                         hid_setup_resolution_multiplier(device);
1287
1288                         kfree(parser->collection_stack);
1289                         vfree(parser);
1290                         device->status |= HID_STAT_PARSED;
1291
1292                         return 0;
1293                 }
1294         }
1295
1296         hid_err(device, "item fetching failed at offset %u/%u\n",
1297                 size - (unsigned int)(end - start), size);
1298 err:
1299         kfree(parser->collection_stack);
1300 alloc_err:
1301         vfree(parser);
1302         hid_close_report(device);
1303         return ret;
1304 }
1305 EXPORT_SYMBOL_GPL(hid_open_report);
1306
1307 /*
1308  * Convert a signed n-bit integer to signed 32-bit integer. Common
1309  * cases are done through the compiler, the screwed things has to be
1310  * done by hand.
1311  */
1312
1313 static s32 snto32(__u32 value, unsigned n)
1314 {
1315         if (!value || !n)
1316                 return 0;
1317
1318         switch (n) {
1319         case 8:  return ((__s8)value);
1320         case 16: return ((__s16)value);
1321         case 32: return ((__s32)value);
1322         }
1323         return value & (1 << (n - 1)) ? value | (~0U << n) : value;
1324 }
1325
1326 s32 hid_snto32(__u32 value, unsigned n)
1327 {
1328         return snto32(value, n);
1329 }
1330 EXPORT_SYMBOL_GPL(hid_snto32);
1331
1332 /*
1333  * Convert a signed 32-bit integer to a signed n-bit integer.
1334  */
1335
1336 static u32 s32ton(__s32 value, unsigned n)
1337 {
1338         s32 a = value >> (n - 1);
1339         if (a && a != -1)
1340                 return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
1341         return value & ((1 << n) - 1);
1342 }
1343
1344 /*
1345  * Extract/implement a data field from/to a little endian report (bit array).
1346  *
1347  * Code sort-of follows HID spec:
1348  *     http://www.usb.org/developers/hidpage/HID1_11.pdf
1349  *
1350  * While the USB HID spec allows unlimited length bit fields in "report
1351  * descriptors", most devices never use more than 16 bits.
1352  * One model of UPS is claimed to report "LINEV" as a 32-bit field.
1353  * Search linux-kernel and linux-usb-devel archives for "hid-core extract".
1354  */
1355
1356 static u32 __extract(u8 *report, unsigned offset, int n)
1357 {
1358         unsigned int idx = offset / 8;
1359         unsigned int bit_nr = 0;
1360         unsigned int bit_shift = offset % 8;
1361         int bits_to_copy = 8 - bit_shift;
1362         u32 value = 0;
1363         u32 mask = n < 32 ? (1U << n) - 1 : ~0U;
1364
1365         while (n > 0) {
1366                 value |= ((u32)report[idx] >> bit_shift) << bit_nr;
1367                 n -= bits_to_copy;
1368                 bit_nr += bits_to_copy;
1369                 bits_to_copy = 8;
1370                 bit_shift = 0;
1371                 idx++;
1372         }
1373
1374         return value & mask;
1375 }
1376
1377 u32 hid_field_extract(const struct hid_device *hid, u8 *report,
1378                         unsigned offset, unsigned n)
1379 {
1380         if (n > 32) {
1381                 hid_warn_once(hid, "%s() called with n (%d) > 32! (%s)\n",
1382                               __func__, n, current->comm);
1383                 n = 32;
1384         }
1385
1386         return __extract(report, offset, n);
1387 }
1388 EXPORT_SYMBOL_GPL(hid_field_extract);
1389
1390 /*
1391  * "implement" : set bits in a little endian bit stream.
1392  * Same concepts as "extract" (see comments above).
1393  * The data mangled in the bit stream remains in little endian
1394  * order the whole time. It make more sense to talk about
1395  * endianness of register values by considering a register
1396  * a "cached" copy of the little endian bit stream.
1397  */
1398
1399 static void __implement(u8 *report, unsigned offset, int n, u32 value)
1400 {
1401         unsigned int idx = offset / 8;
1402         unsigned int bit_shift = offset % 8;
1403         int bits_to_set = 8 - bit_shift;
1404
1405         while (n - bits_to_set >= 0) {
1406                 report[idx] &= ~(0xff << bit_shift);
1407                 report[idx] |= value << bit_shift;
1408                 value >>= bits_to_set;
1409                 n -= bits_to_set;
1410                 bits_to_set = 8;
1411                 bit_shift = 0;
1412                 idx++;
1413         }
1414
1415         /* last nibble */
1416         if (n) {
1417                 u8 bit_mask = ((1U << n) - 1);
1418                 report[idx] &= ~(bit_mask << bit_shift);
1419                 report[idx] |= value << bit_shift;
1420         }
1421 }
1422
1423 static void implement(const struct hid_device *hid, u8 *report,
1424                       unsigned offset, unsigned n, u32 value)
1425 {
1426         if (unlikely(n > 32)) {
1427                 hid_warn(hid, "%s() called with n (%d) > 32! (%s)\n",
1428                          __func__, n, current->comm);
1429                 n = 32;
1430         } else if (n < 32) {
1431                 u32 m = (1U << n) - 1;
1432
1433                 if (unlikely(value > m)) {
1434                         hid_warn(hid,
1435                                  "%s() called with too large value %d (n: %d)! (%s)\n",
1436                                  __func__, value, n, current->comm);
1437                         WARN_ON(1);
1438                         value &= m;
1439                 }
1440         }
1441
1442         __implement(report, offset, n, value);
1443 }
1444
1445 /*
1446  * Search an array for a value.
1447  */
1448
1449 static int search(__s32 *array, __s32 value, unsigned n)
1450 {
1451         while (n--) {
1452                 if (*array++ == value)
1453                         return 0;
1454         }
1455         return -1;
1456 }
1457
1458 /**
1459  * hid_match_report - check if driver's raw_event should be called
1460  *
1461  * @hid: hid device
1462  * @report: hid report to match against
1463  *
1464  * compare hid->driver->report_table->report_type to report->type
1465  */
1466 static int hid_match_report(struct hid_device *hid, struct hid_report *report)
1467 {
1468         const struct hid_report_id *id = hid->driver->report_table;
1469
1470         if (!id) /* NULL means all */
1471                 return 1;
1472
1473         for (; id->report_type != HID_TERMINATOR; id++)
1474                 if (id->report_type == HID_ANY_ID ||
1475                                 id->report_type == report->type)
1476                         return 1;
1477         return 0;
1478 }
1479
1480 /**
1481  * hid_match_usage - check if driver's event should be called
1482  *
1483  * @hid: hid device
1484  * @usage: usage to match against
1485  *
1486  * compare hid->driver->usage_table->usage_{type,code} to
1487  * usage->usage_{type,code}
1488  */
1489 static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage)
1490 {
1491         const struct hid_usage_id *id = hid->driver->usage_table;
1492
1493         if (!id) /* NULL means all */
1494                 return 1;
1495
1496         for (; id->usage_type != HID_ANY_ID - 1; id++)
1497                 if ((id->usage_hid == HID_ANY_ID ||
1498                                 id->usage_hid == usage->hid) &&
1499                                 (id->usage_type == HID_ANY_ID ||
1500                                 id->usage_type == usage->type) &&
1501                                 (id->usage_code == HID_ANY_ID ||
1502                                  id->usage_code == usage->code))
1503                         return 1;
1504         return 0;
1505 }
1506
1507 static void hid_process_event(struct hid_device *hid, struct hid_field *field,
1508                 struct hid_usage *usage, __s32 value, int interrupt)
1509 {
1510         struct hid_driver *hdrv = hid->driver;
1511         int ret;
1512
1513         if (!list_empty(&hid->debug_list))
1514                 hid_dump_input(hid, usage, value);
1515
1516         if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
1517                 ret = hdrv->event(hid, field, usage, value);
1518                 if (ret != 0) {
1519                         if (ret < 0)
1520                                 hid_err(hid, "%s's event failed with %d\n",
1521                                                 hdrv->name, ret);
1522                         return;
1523                 }
1524         }
1525
1526         if (hid->claimed & HID_CLAIMED_INPUT)
1527                 hidinput_hid_event(hid, field, usage, value);
1528         if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
1529                 hid->hiddev_hid_event(hid, field, usage, value);
1530 }
1531
1532 /*
1533  * Checks if the given value is valid within this field
1534  */
1535 static inline int hid_array_value_is_valid(struct hid_field *field,
1536                                            __s32 value)
1537 {
1538         __s32 min = field->logical_minimum;
1539
1540         /*
1541          * Value needs to be between logical min and max, and
1542          * (value - min) is used as an index in the usage array.
1543          * This array is of size field->maxusage
1544          */
1545         return value >= min &&
1546                value <= field->logical_maximum &&
1547                value - min < field->maxusage;
1548 }
1549
1550 /*
1551  * Fetch the field from the data. The field content is stored for next
1552  * report processing (we do differential reporting to the layer).
1553  */
1554 static void hid_input_fetch_field(struct hid_device *hid,
1555                                   struct hid_field *field,
1556                                   __u8 *data)
1557 {
1558         unsigned n;
1559         unsigned count = field->report_count;
1560         unsigned offset = field->report_offset;
1561         unsigned size = field->report_size;
1562         __s32 min = field->logical_minimum;
1563         __s32 *value;
1564
1565         value = field->new_value;
1566         memset(value, 0, count * sizeof(__s32));
1567         field->ignored = false;
1568
1569         for (n = 0; n < count; n++) {
1570
1571                 value[n] = min < 0 ?
1572                         snto32(hid_field_extract(hid, data, offset + n * size,
1573                                size), size) :
1574                         hid_field_extract(hid, data, offset + n * size, size);
1575
1576                 /* Ignore report if ErrorRollOver */
1577                 if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
1578                     hid_array_value_is_valid(field, value[n]) &&
1579                     field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1) {
1580                         field->ignored = true;
1581                         return;
1582                 }
1583         }
1584 }
1585
1586 /*
1587  * Process a received variable field.
1588  */
1589
1590 static void hid_input_var_field(struct hid_device *hid,
1591                                 struct hid_field *field,
1592                                 int interrupt)
1593 {
1594         unsigned int count = field->report_count;
1595         __s32 *value = field->new_value;
1596         unsigned int n;
1597
1598         for (n = 0; n < count; n++)
1599                 hid_process_event(hid,
1600                                   field,
1601                                   &field->usage[n],
1602                                   value[n],
1603                                   interrupt);
1604
1605         memcpy(field->value, value, count * sizeof(__s32));
1606 }
1607
1608 /*
1609  * Process a received array field. The field content is stored for
1610  * next report processing (we do differential reporting to the layer).
1611  */
1612
1613 static void hid_input_array_field(struct hid_device *hid,
1614                                   struct hid_field *field,
1615                                   int interrupt)
1616 {
1617         unsigned int n;
1618         unsigned int count = field->report_count;
1619         __s32 min = field->logical_minimum;
1620         __s32 *value;
1621
1622         value = field->new_value;
1623
1624         /* ErrorRollOver */
1625         if (field->ignored)
1626                 return;
1627
1628         for (n = 0; n < count; n++) {
1629                 if (hid_array_value_is_valid(field, field->value[n]) &&
1630                     search(value, field->value[n], count))
1631                         hid_process_event(hid,
1632                                           field,
1633                                           &field->usage[field->value[n] - min],
1634                                           0,
1635                                           interrupt);
1636
1637                 if (hid_array_value_is_valid(field, value[n]) &&
1638                     search(field->value, value[n], count))
1639                         hid_process_event(hid,
1640                                           field,
1641                                           &field->usage[value[n] - min],
1642                                           1,
1643                                           interrupt);
1644         }
1645
1646         memcpy(field->value, value, count * sizeof(__s32));
1647 }
1648
1649 /*
1650  * Analyse a received report, and fetch the data from it. The field
1651  * content is stored for next report processing (we do differential
1652  * reporting to the layer).
1653  */
1654 static void hid_process_report(struct hid_device *hid,
1655                                struct hid_report *report,
1656                                __u8 *data,
1657                                int interrupt)
1658 {
1659         unsigned int a;
1660         struct hid_field_entry *entry;
1661         struct hid_field *field;
1662
1663         /* first retrieve all incoming values in data */
1664         for (a = 0; a < report->maxfield; a++)
1665                 hid_input_fetch_field(hid, report->field[a], data);
1666
1667         if (!list_empty(&report->field_entry_list)) {
1668                 /* INPUT_REPORT, we have a priority list of fields */
1669                 list_for_each_entry(entry,
1670                                     &report->field_entry_list,
1671                                     list) {
1672                         field = entry->field;
1673
1674                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1675                                 hid_process_event(hid,
1676                                                   field,
1677                                                   &field->usage[entry->index],
1678                                                   field->new_value[entry->index],
1679                                                   interrupt);
1680                         else
1681                                 hid_input_array_field(hid, field, interrupt);
1682                 }
1683
1684                 /* we need to do the memcpy at the end for var items */
1685                 for (a = 0; a < report->maxfield; a++) {
1686                         field = report->field[a];
1687
1688                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1689                                 memcpy(field->value, field->new_value,
1690                                        field->report_count * sizeof(__s32));
1691                 }
1692         } else {
1693                 /* FEATURE_REPORT, regular processing */
1694                 for (a = 0; a < report->maxfield; a++) {
1695                         field = report->field[a];
1696
1697                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1698                                 hid_input_var_field(hid, field, interrupt);
1699                         else
1700                                 hid_input_array_field(hid, field, interrupt);
1701                 }
1702         }
1703 }
1704
1705 /*
1706  * Insert a given usage_index in a field in the list
1707  * of processed usages in the report.
1708  *
1709  * The elements of lower priority score are processed
1710  * first.
1711  */
1712 static void __hid_insert_field_entry(struct hid_device *hid,
1713                                      struct hid_report *report,
1714                                      struct hid_field_entry *entry,
1715                                      struct hid_field *field,
1716                                      unsigned int usage_index)
1717 {
1718         struct hid_field_entry *next;
1719
1720         entry->field = field;
1721         entry->index = usage_index;
1722         entry->priority = field->usages_priorities[usage_index];
1723
1724         /* insert the element at the correct position */
1725         list_for_each_entry(next,
1726                             &report->field_entry_list,
1727                             list) {
1728                 /*
1729                  * the priority of our element is strictly higher
1730                  * than the next one, insert it before
1731                  */
1732                 if (entry->priority > next->priority) {
1733                         list_add_tail(&entry->list, &next->list);
1734                         return;
1735                 }
1736         }
1737
1738         /* lowest priority score: insert at the end */
1739         list_add_tail(&entry->list, &report->field_entry_list);
1740 }
1741
1742 static void hid_report_process_ordering(struct hid_device *hid,
1743                                         struct hid_report *report)
1744 {
1745         struct hid_field *field;
1746         struct hid_field_entry *entries;
1747         unsigned int a, u, usages;
1748         unsigned int count = 0;
1749
1750         /* count the number of individual fields in the report */
1751         for (a = 0; a < report->maxfield; a++) {
1752                 field = report->field[a];
1753
1754                 if (field->flags & HID_MAIN_ITEM_VARIABLE)
1755                         count += field->report_count;
1756                 else
1757                         count++;
1758         }
1759
1760         /* allocate the memory to process the fields */
1761         entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
1762         if (!entries)
1763                 return;
1764
1765         report->field_entries = entries;
1766
1767         /*
1768          * walk through all fields in the report and
1769          * store them by priority order in report->field_entry_list
1770          *
1771          * - Var elements are individualized (field + usage_index)
1772          * - Arrays are taken as one, we can not chose an order for them
1773          */
1774         usages = 0;
1775         for (a = 0; a < report->maxfield; a++) {
1776                 field = report->field[a];
1777
1778                 if (field->flags & HID_MAIN_ITEM_VARIABLE) {
1779                         for (u = 0; u < field->report_count; u++) {
1780                                 __hid_insert_field_entry(hid, report,
1781                                                          &entries[usages],
1782                                                          field, u);
1783                                 usages++;
1784                         }
1785                 } else {
1786                         __hid_insert_field_entry(hid, report, &entries[usages],
1787                                                  field, 0);
1788                         usages++;
1789                 }
1790         }
1791 }
1792
1793 static void hid_process_ordering(struct hid_device *hid)
1794 {
1795         struct hid_report *report;
1796         struct hid_report_enum *report_enum = &hid->report_enum[HID_INPUT_REPORT];
1797
1798         list_for_each_entry(report, &report_enum->report_list, list)
1799                 hid_report_process_ordering(hid, report);
1800 }
1801
1802 /*
1803  * Output the field into the report.
1804  */
1805
1806 static void hid_output_field(const struct hid_device *hid,
1807                              struct hid_field *field, __u8 *data)
1808 {
1809         unsigned count = field->report_count;
1810         unsigned offset = field->report_offset;
1811         unsigned size = field->report_size;
1812         unsigned n;
1813
1814         for (n = 0; n < count; n++) {
1815                 if (field->logical_minimum < 0) /* signed values */
1816                         implement(hid, data, offset + n * size, size,
1817                                   s32ton(field->value[n], size));
1818                 else                            /* unsigned values */
1819                         implement(hid, data, offset + n * size, size,
1820                                   field->value[n]);
1821         }
1822 }
1823
1824 /*
1825  * Compute the size of a report.
1826  */
1827 static size_t hid_compute_report_size(struct hid_report *report)
1828 {
1829         if (report->size)
1830                 return ((report->size - 1) >> 3) + 1;
1831
1832         return 0;
1833 }
1834
1835 /*
1836  * Create a report. 'data' has to be allocated using
1837  * hid_alloc_report_buf() so that it has proper size.
1838  */
1839
1840 void hid_output_report(struct hid_report *report, __u8 *data)
1841 {
1842         unsigned n;
1843
1844         if (report->id > 0)
1845                 *data++ = report->id;
1846
1847         memset(data, 0, hid_compute_report_size(report));
1848         for (n = 0; n < report->maxfield; n++)
1849                 hid_output_field(report->device, report->field[n], data);
1850 }
1851 EXPORT_SYMBOL_GPL(hid_output_report);
1852
1853 /*
1854  * Allocator for buffer that is going to be passed to hid_output_report()
1855  */
1856 u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
1857 {
1858         /*
1859          * 7 extra bytes are necessary to achieve proper functionality
1860          * of implement() working on 8 byte chunks
1861          */
1862
1863         u32 len = hid_report_len(report) + 7;
1864
1865         return kmalloc(len, flags);
1866 }
1867 EXPORT_SYMBOL_GPL(hid_alloc_report_buf);
1868
1869 /*
1870  * Set a field value. The report this field belongs to has to be
1871  * created and transferred to the device, to set this value in the
1872  * device.
1873  */
1874
1875 int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
1876 {
1877         unsigned size;
1878
1879         if (!field)
1880                 return -1;
1881
1882         size = field->report_size;
1883
1884         hid_dump_input(field->report->device, field->usage + offset, value);
1885
1886         if (offset >= field->report_count) {
1887                 hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n",
1888                                 offset, field->report_count);
1889                 return -1;
1890         }
1891         if (field->logical_minimum < 0) {
1892                 if (value != snto32(s32ton(value, size), size)) {
1893                         hid_err(field->report->device, "value %d is out of range\n", value);
1894                         return -1;
1895                 }
1896         }
1897         field->value[offset] = value;
1898         return 0;
1899 }
1900 EXPORT_SYMBOL_GPL(hid_set_field);
1901
1902 static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
1903                 const u8 *data)
1904 {
1905         struct hid_report *report;
1906         unsigned int n = 0;     /* Normally report number is 0 */
1907
1908         /* Device uses numbered reports, data[0] is report number */
1909         if (report_enum->numbered)
1910                 n = *data;
1911
1912         report = report_enum->report_id_hash[n];
1913         if (report == NULL)
1914                 dbg_hid("undefined report_id %u received\n", n);
1915
1916         return report;
1917 }
1918
1919 /*
1920  * Implement a generic .request() callback, using .raw_request()
1921  * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
1922  */
1923 int __hid_request(struct hid_device *hid, struct hid_report *report,
1924                 int reqtype)
1925 {
1926         char *buf;
1927         int ret;
1928         u32 len;
1929
1930         buf = hid_alloc_report_buf(report, GFP_KERNEL);
1931         if (!buf)
1932                 return -ENOMEM;
1933
1934         len = hid_report_len(report);
1935
1936         if (reqtype == HID_REQ_SET_REPORT)
1937                 hid_output_report(report, buf);
1938
1939         ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
1940                                           report->type, reqtype);
1941         if (ret < 0) {
1942                 dbg_hid("unable to complete request: %d\n", ret);
1943                 goto out;
1944         }
1945
1946         if (reqtype == HID_REQ_GET_REPORT)
1947                 hid_input_report(hid, report->type, buf, ret, 0);
1948
1949         ret = 0;
1950
1951 out:
1952         kfree(buf);
1953         return ret;
1954 }
1955 EXPORT_SYMBOL_GPL(__hid_request);
1956
1957 int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, u32 size,
1958                 int interrupt)
1959 {
1960         struct hid_report_enum *report_enum = hid->report_enum + type;
1961         struct hid_report *report;
1962         struct hid_driver *hdrv;
1963         u32 rsize, csize = size;
1964         u8 *cdata = data;
1965         int ret = 0;
1966
1967         report = hid_get_report(report_enum, data);
1968         if (!report)
1969                 goto out;
1970
1971         if (report_enum->numbered) {
1972                 cdata++;
1973                 csize--;
1974         }
1975
1976         rsize = hid_compute_report_size(report);
1977
1978         if (report_enum->numbered && rsize >= HID_MAX_BUFFER_SIZE)
1979                 rsize = HID_MAX_BUFFER_SIZE - 1;
1980         else if (rsize > HID_MAX_BUFFER_SIZE)
1981                 rsize = HID_MAX_BUFFER_SIZE;
1982
1983         if (csize < rsize) {
1984                 dbg_hid("report %d is too short, (%d < %d)\n", report->id,
1985                                 csize, rsize);
1986                 memset(cdata + csize, 0, rsize - csize);
1987         }
1988
1989         if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
1990                 hid->hiddev_report_event(hid, report);
1991         if (hid->claimed & HID_CLAIMED_HIDRAW) {
1992                 ret = hidraw_report_event(hid, data, size);
1993                 if (ret)
1994                         goto out;
1995         }
1996
1997         if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
1998                 hid_process_report(hid, report, cdata, interrupt);
1999                 hdrv = hid->driver;
2000                 if (hdrv && hdrv->report)
2001                         hdrv->report(hid, report);
2002         }
2003
2004         if (hid->claimed & HID_CLAIMED_INPUT)
2005                 hidinput_report_event(hid, report);
2006 out:
2007         return ret;
2008 }
2009 EXPORT_SYMBOL_GPL(hid_report_raw_event);
2010
2011 /**
2012  * hid_input_report - report data from lower layer (usb, bt...)
2013  *
2014  * @hid: hid device
2015  * @type: HID report type (HID_*_REPORT)
2016  * @data: report contents
2017  * @size: size of data parameter
2018  * @interrupt: distinguish between interrupt and control transfers
2019  *
2020  * This is data entry for lower layers.
2021  */
2022 int hid_input_report(struct hid_device *hid, int type, u8 *data, u32 size, int interrupt)
2023 {
2024         struct hid_report_enum *report_enum;
2025         struct hid_driver *hdrv;
2026         struct hid_report *report;
2027         int ret = 0;
2028
2029         if (!hid)
2030                 return -ENODEV;
2031
2032         if (down_trylock(&hid->driver_input_lock))
2033                 return -EBUSY;
2034
2035         if (!hid->driver) {
2036                 ret = -ENODEV;
2037                 goto unlock;
2038         }
2039         report_enum = hid->report_enum + type;
2040         hdrv = hid->driver;
2041
2042         if (!size) {
2043                 dbg_hid("empty report\n");
2044                 ret = -1;
2045                 goto unlock;
2046         }
2047
2048         /* Avoid unnecessary overhead if debugfs is disabled */
2049         if (!list_empty(&hid->debug_list))
2050                 hid_dump_report(hid, type, data, size);
2051
2052         report = hid_get_report(report_enum, data);
2053
2054         if (!report) {
2055                 ret = -1;
2056                 goto unlock;
2057         }
2058
2059         if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
2060                 ret = hdrv->raw_event(hid, report, data, size);
2061                 if (ret < 0)
2062                         goto unlock;
2063         }
2064
2065         ret = hid_report_raw_event(hid, type, data, size, interrupt);
2066
2067 unlock:
2068         up(&hid->driver_input_lock);
2069         return ret;
2070 }
2071 EXPORT_SYMBOL_GPL(hid_input_report);
2072
2073 bool hid_match_one_id(const struct hid_device *hdev,
2074                       const struct hid_device_id *id)
2075 {
2076         return (id->bus == HID_BUS_ANY || id->bus == hdev->bus) &&
2077                 (id->group == HID_GROUP_ANY || id->group == hdev->group) &&
2078                 (id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&
2079                 (id->product == HID_ANY_ID || id->product == hdev->product);
2080 }
2081
2082 const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
2083                 const struct hid_device_id *id)
2084 {
2085         for (; id->bus; id++)
2086                 if (hid_match_one_id(hdev, id))
2087                         return id;
2088
2089         return NULL;
2090 }
2091
2092 static const struct hid_device_id hid_hiddev_list[] = {
2093         { HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS) },
2094         { HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS1) },
2095         { }
2096 };
2097
2098 static bool hid_hiddev(struct hid_device *hdev)
2099 {
2100         return !!hid_match_id(hdev, hid_hiddev_list);
2101 }
2102
2103
2104 static ssize_t
2105 read_report_descriptor(struct file *filp, struct kobject *kobj,
2106                 struct bin_attribute *attr,
2107                 char *buf, loff_t off, size_t count)
2108 {
2109         struct device *dev = kobj_to_dev(kobj);
2110         struct hid_device *hdev = to_hid_device(dev);
2111
2112         if (off >= hdev->rsize)
2113                 return 0;
2114
2115         if (off + count > hdev->rsize)
2116                 count = hdev->rsize - off;
2117
2118         memcpy(buf, hdev->rdesc + off, count);
2119
2120         return count;
2121 }
2122
2123 static ssize_t
2124 show_country(struct device *dev, struct device_attribute *attr,
2125                 char *buf)
2126 {
2127         struct hid_device *hdev = to_hid_device(dev);
2128
2129         return sprintf(buf, "%02x\n", hdev->country & 0xff);
2130 }
2131
2132 static struct bin_attribute dev_bin_attr_report_desc = {
2133         .attr = { .name = "report_descriptor", .mode = 0444 },
2134         .read = read_report_descriptor,
2135         .size = HID_MAX_DESCRIPTOR_SIZE,
2136 };
2137
2138 static const struct device_attribute dev_attr_country = {
2139         .attr = { .name = "country", .mode = 0444 },
2140         .show = show_country,
2141 };
2142
2143 int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
2144 {
2145         static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
2146                 "Joystick", "Gamepad", "Keyboard", "Keypad",
2147                 "Multi-Axis Controller"
2148         };
2149         const char *type, *bus;
2150         char buf[64] = "";
2151         unsigned int i;
2152         int len;
2153         int ret;
2154
2155         if (hdev->quirks & HID_QUIRK_HIDDEV_FORCE)
2156                 connect_mask |= (HID_CONNECT_HIDDEV_FORCE | HID_CONNECT_HIDDEV);
2157         if (hdev->quirks & HID_QUIRK_HIDINPUT_FORCE)
2158                 connect_mask |= HID_CONNECT_HIDINPUT_FORCE;
2159         if (hdev->bus != BUS_USB)
2160                 connect_mask &= ~HID_CONNECT_HIDDEV;
2161         if (hid_hiddev(hdev))
2162                 connect_mask |= HID_CONNECT_HIDDEV_FORCE;
2163
2164         if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,
2165                                 connect_mask & HID_CONNECT_HIDINPUT_FORCE))
2166                 hdev->claimed |= HID_CLAIMED_INPUT;
2167
2168         if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect &&
2169                         !hdev->hiddev_connect(hdev,
2170                                 connect_mask & HID_CONNECT_HIDDEV_FORCE))
2171                 hdev->claimed |= HID_CLAIMED_HIDDEV;
2172         if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))
2173                 hdev->claimed |= HID_CLAIMED_HIDRAW;
2174
2175         if (connect_mask & HID_CONNECT_DRIVER)
2176                 hdev->claimed |= HID_CLAIMED_DRIVER;
2177
2178         /* Drivers with the ->raw_event callback set are not required to connect
2179          * to any other listener. */
2180         if (!hdev->claimed && !hdev->driver->raw_event) {
2181                 hid_err(hdev, "device has no listeners, quitting\n");
2182                 return -ENODEV;
2183         }
2184
2185         hid_process_ordering(hdev);
2186
2187         if ((hdev->claimed & HID_CLAIMED_INPUT) &&
2188                         (connect_mask & HID_CONNECT_FF) && hdev->ff_init)
2189                 hdev->ff_init(hdev);
2190
2191         len = 0;
2192         if (hdev->claimed & HID_CLAIMED_INPUT)
2193                 len += sprintf(buf + len, "input");
2194         if (hdev->claimed & HID_CLAIMED_HIDDEV)
2195                 len += sprintf(buf + len, "%shiddev%d", len ? "," : "",
2196                                 ((struct hiddev *)hdev->hiddev)->minor);
2197         if (hdev->claimed & HID_CLAIMED_HIDRAW)
2198                 len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
2199                                 ((struct hidraw *)hdev->hidraw)->minor);
2200
2201         type = "Device";
2202         for (i = 0; i < hdev->maxcollection; i++) {
2203                 struct hid_collection *col = &hdev->collection[i];
2204                 if (col->type == HID_COLLECTION_APPLICATION &&
2205                    (col->usage & HID_USAGE_PAGE) == HID_UP_GENDESK &&
2206                    (col->usage & 0xffff) < ARRAY_SIZE(types)) {
2207                         type = types[col->usage & 0xffff];
2208                         break;
2209                 }
2210         }
2211
2212         switch (hdev->bus) {
2213         case BUS_USB:
2214                 bus = "USB";
2215                 break;
2216         case BUS_BLUETOOTH:
2217                 bus = "BLUETOOTH";
2218                 break;
2219         case BUS_I2C:
2220                 bus = "I2C";
2221                 break;
2222         case BUS_VIRTUAL:
2223                 bus = "VIRTUAL";
2224                 break;
2225         case BUS_INTEL_ISHTP:
2226         case BUS_AMD_SFH:
2227                 bus = "SENSOR HUB";
2228                 break;
2229         default:
2230                 bus = "<UNKNOWN>";
2231         }
2232
2233         ret = device_create_file(&hdev->dev, &dev_attr_country);
2234         if (ret)
2235                 hid_warn(hdev,
2236                          "can't create sysfs country code attribute err: %d\n", ret);
2237
2238         hid_info(hdev, "%s: %s HID v%x.%02x %s [%s] on %s\n",
2239                  buf, bus, hdev->version >> 8, hdev->version & 0xff,
2240                  type, hdev->name, hdev->phys);
2241
2242         return 0;
2243 }
2244 EXPORT_SYMBOL_GPL(hid_connect);
2245
2246 void hid_disconnect(struct hid_device *hdev)
2247 {
2248         device_remove_file(&hdev->dev, &dev_attr_country);
2249         if (hdev->claimed & HID_CLAIMED_INPUT)
2250                 hidinput_disconnect(hdev);
2251         if (hdev->claimed & HID_CLAIMED_HIDDEV)
2252                 hdev->hiddev_disconnect(hdev);
2253         if (hdev->claimed & HID_CLAIMED_HIDRAW)
2254                 hidraw_disconnect(hdev);
2255         hdev->claimed = 0;
2256 }
2257 EXPORT_SYMBOL_GPL(hid_disconnect);
2258
2259 /**
2260  * hid_hw_start - start underlying HW
2261  * @hdev: hid device
2262  * @connect_mask: which outputs to connect, see HID_CONNECT_*
2263  *
2264  * Call this in probe function *after* hid_parse. This will setup HW
2265  * buffers and start the device (if not defeirred to device open).
2266  * hid_hw_stop must be called if this was successful.
2267  */
2268 int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask)
2269 {
2270         int error;
2271
2272         error = hdev->ll_driver->start(hdev);
2273         if (error)
2274                 return error;
2275
2276         if (connect_mask) {
2277                 error = hid_connect(hdev, connect_mask);
2278                 if (error) {
2279                         hdev->ll_driver->stop(hdev);
2280                         return error;
2281                 }
2282         }
2283
2284         return 0;
2285 }
2286 EXPORT_SYMBOL_GPL(hid_hw_start);
2287
2288 /**
2289  * hid_hw_stop - stop underlying HW
2290  * @hdev: hid device
2291  *
2292  * This is usually called from remove function or from probe when something
2293  * failed and hid_hw_start was called already.
2294  */
2295 void hid_hw_stop(struct hid_device *hdev)
2296 {
2297         hid_disconnect(hdev);
2298         hdev->ll_driver->stop(hdev);
2299 }
2300 EXPORT_SYMBOL_GPL(hid_hw_stop);
2301
2302 /**
2303  * hid_hw_open - signal underlying HW to start delivering events
2304  * @hdev: hid device
2305  *
2306  * Tell underlying HW to start delivering events from the device.
2307  * This function should be called sometime after successful call
2308  * to hid_hw_start().
2309  */
2310 int hid_hw_open(struct hid_device *hdev)
2311 {
2312         int ret;
2313
2314         ret = mutex_lock_killable(&hdev->ll_open_lock);
2315         if (ret)
2316                 return ret;
2317
2318         if (!hdev->ll_open_count++) {
2319                 ret = hdev->ll_driver->open(hdev);
2320                 if (ret)
2321                         hdev->ll_open_count--;
2322         }
2323
2324         mutex_unlock(&hdev->ll_open_lock);
2325         return ret;
2326 }
2327 EXPORT_SYMBOL_GPL(hid_hw_open);
2328
2329 /**
2330  * hid_hw_close - signal underlaying HW to stop delivering events
2331  *
2332  * @hdev: hid device
2333  *
2334  * This function indicates that we are not interested in the events
2335  * from this device anymore. Delivery of events may or may not stop,
2336  * depending on the number of users still outstanding.
2337  */
2338 void hid_hw_close(struct hid_device *hdev)
2339 {
2340         mutex_lock(&hdev->ll_open_lock);
2341         if (!--hdev->ll_open_count)
2342                 hdev->ll_driver->close(hdev);
2343         mutex_unlock(&hdev->ll_open_lock);
2344 }
2345 EXPORT_SYMBOL_GPL(hid_hw_close);
2346
2347 /**
2348  * hid_hw_request - send report request to device
2349  *
2350  * @hdev: hid device
2351  * @report: report to send
2352  * @reqtype: hid request type
2353  */
2354 void hid_hw_request(struct hid_device *hdev,
2355                     struct hid_report *report, int reqtype)
2356 {
2357         if (hdev->ll_driver->request)
2358                 return hdev->ll_driver->request(hdev, report, reqtype);
2359
2360         __hid_request(hdev, report, reqtype);
2361 }
2362 EXPORT_SYMBOL_GPL(hid_hw_request);
2363
2364 /**
2365  * hid_hw_raw_request - send report request to device
2366  *
2367  * @hdev: hid device
2368  * @reportnum: report ID
2369  * @buf: in/out data to transfer
2370  * @len: length of buf
2371  * @rtype: HID report type
2372  * @reqtype: HID_REQ_GET_REPORT or HID_REQ_SET_REPORT
2373  *
2374  * Return: count of data transferred, negative if error
2375  *
2376  * Same behavior as hid_hw_request, but with raw buffers instead.
2377  */
2378 int hid_hw_raw_request(struct hid_device *hdev,
2379                        unsigned char reportnum, __u8 *buf,
2380                        size_t len, unsigned char rtype, int reqtype)
2381 {
2382         if (len < 1 || len > HID_MAX_BUFFER_SIZE || !buf)
2383                 return -EINVAL;
2384
2385         return hdev->ll_driver->raw_request(hdev, reportnum, buf, len,
2386                                             rtype, reqtype);
2387 }
2388 EXPORT_SYMBOL_GPL(hid_hw_raw_request);
2389
2390 /**
2391  * hid_hw_output_report - send output report to device
2392  *
2393  * @hdev: hid device
2394  * @buf: raw data to transfer
2395  * @len: length of buf
2396  *
2397  * Return: count of data transferred, negative if error
2398  */
2399 int hid_hw_output_report(struct hid_device *hdev, __u8 *buf, size_t len)
2400 {
2401         if (len < 1 || len > HID_MAX_BUFFER_SIZE || !buf)
2402                 return -EINVAL;
2403
2404         if (hdev->ll_driver->output_report)
2405                 return hdev->ll_driver->output_report(hdev, buf, len);
2406
2407         return -ENOSYS;
2408 }
2409 EXPORT_SYMBOL_GPL(hid_hw_output_report);
2410
2411 #ifdef CONFIG_PM
2412 int hid_driver_suspend(struct hid_device *hdev, pm_message_t state)
2413 {
2414         if (hdev->driver && hdev->driver->suspend)
2415                 return hdev->driver->suspend(hdev, state);
2416
2417         return 0;
2418 }
2419 EXPORT_SYMBOL_GPL(hid_driver_suspend);
2420
2421 int hid_driver_reset_resume(struct hid_device *hdev)
2422 {
2423         if (hdev->driver && hdev->driver->reset_resume)
2424                 return hdev->driver->reset_resume(hdev);
2425
2426         return 0;
2427 }
2428 EXPORT_SYMBOL_GPL(hid_driver_reset_resume);
2429
2430 int hid_driver_resume(struct hid_device *hdev)
2431 {
2432         if (hdev->driver && hdev->driver->resume)
2433                 return hdev->driver->resume(hdev);
2434
2435         return 0;
2436 }
2437 EXPORT_SYMBOL_GPL(hid_driver_resume);
2438 #endif /* CONFIG_PM */
2439
2440 struct hid_dynid {
2441         struct list_head list;
2442         struct hid_device_id id;
2443 };
2444
2445 /**
2446  * new_id_store - add a new HID device ID to this driver and re-probe devices
2447  * @drv: target device driver
2448  * @buf: buffer for scanning device ID data
2449  * @count: input size
2450  *
2451  * Adds a new dynamic hid device ID to this driver,
2452  * and causes the driver to probe for all devices again.
2453  */
2454 static ssize_t new_id_store(struct device_driver *drv, const char *buf,
2455                 size_t count)
2456 {
2457         struct hid_driver *hdrv = to_hid_driver(drv);
2458         struct hid_dynid *dynid;
2459         __u32 bus, vendor, product;
2460         unsigned long driver_data = 0;
2461         int ret;
2462
2463         ret = sscanf(buf, "%x %x %x %lx",
2464                         &bus, &vendor, &product, &driver_data);
2465         if (ret < 3)
2466                 return -EINVAL;
2467
2468         dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
2469         if (!dynid)
2470                 return -ENOMEM;
2471
2472         dynid->id.bus = bus;
2473         dynid->id.group = HID_GROUP_ANY;
2474         dynid->id.vendor = vendor;
2475         dynid->id.product = product;
2476         dynid->id.driver_data = driver_data;
2477
2478         spin_lock(&hdrv->dyn_lock);
2479         list_add_tail(&dynid->list, &hdrv->dyn_list);
2480         spin_unlock(&hdrv->dyn_lock);
2481
2482         ret = driver_attach(&hdrv->driver);
2483
2484         return ret ? : count;
2485 }
2486 static DRIVER_ATTR_WO(new_id);
2487
2488 static struct attribute *hid_drv_attrs[] = {
2489         &driver_attr_new_id.attr,
2490         NULL,
2491 };
2492 ATTRIBUTE_GROUPS(hid_drv);
2493
2494 static void hid_free_dynids(struct hid_driver *hdrv)
2495 {
2496         struct hid_dynid *dynid, *n;
2497
2498         spin_lock(&hdrv->dyn_lock);
2499         list_for_each_entry_safe(dynid, n, &hdrv->dyn_list, list) {
2500                 list_del(&dynid->list);
2501                 kfree(dynid);
2502         }
2503         spin_unlock(&hdrv->dyn_lock);
2504 }
2505
2506 const struct hid_device_id *hid_match_device(struct hid_device *hdev,
2507                                              struct hid_driver *hdrv)
2508 {
2509         struct hid_dynid *dynid;
2510
2511         spin_lock(&hdrv->dyn_lock);
2512         list_for_each_entry(dynid, &hdrv->dyn_list, list) {
2513                 if (hid_match_one_id(hdev, &dynid->id)) {
2514                         spin_unlock(&hdrv->dyn_lock);
2515                         return &dynid->id;
2516                 }
2517         }
2518         spin_unlock(&hdrv->dyn_lock);
2519
2520         return hid_match_id(hdev, hdrv->id_table);
2521 }
2522 EXPORT_SYMBOL_GPL(hid_match_device);
2523
2524 static int hid_bus_match(struct device *dev, struct device_driver *drv)
2525 {
2526         struct hid_driver *hdrv = to_hid_driver(drv);
2527         struct hid_device *hdev = to_hid_device(dev);
2528
2529         return hid_match_device(hdev, hdrv) != NULL;
2530 }
2531
2532 /**
2533  * hid_compare_device_paths - check if both devices share the same path
2534  * @hdev_a: hid device
2535  * @hdev_b: hid device
2536  * @separator: char to use as separator
2537  *
2538  * Check if two devices share the same path up to the last occurrence of
2539  * the separator char. Both paths must exist (i.e., zero-length paths
2540  * don't match).
2541  */
2542 bool hid_compare_device_paths(struct hid_device *hdev_a,
2543                               struct hid_device *hdev_b, char separator)
2544 {
2545         int n1 = strrchr(hdev_a->phys, separator) - hdev_a->phys;
2546         int n2 = strrchr(hdev_b->phys, separator) - hdev_b->phys;
2547
2548         if (n1 != n2 || n1 <= 0 || n2 <= 0)
2549                 return false;
2550
2551         return !strncmp(hdev_a->phys, hdev_b->phys, n1);
2552 }
2553 EXPORT_SYMBOL_GPL(hid_compare_device_paths);
2554
2555 static int hid_device_probe(struct device *dev)
2556 {
2557         struct hid_driver *hdrv = to_hid_driver(dev->driver);
2558         struct hid_device *hdev = to_hid_device(dev);
2559         const struct hid_device_id *id;
2560         int ret = 0;
2561
2562         if (down_interruptible(&hdev->driver_input_lock)) {
2563                 ret = -EINTR;
2564                 goto end;
2565         }
2566         hdev->io_started = false;
2567
2568         clear_bit(ffs(HID_STAT_REPROBED), &hdev->status);
2569
2570         if (!hdev->driver) {
2571                 id = hid_match_device(hdev, hdrv);
2572                 if (id == NULL) {
2573                         ret = -ENODEV;
2574                         goto unlock;
2575                 }
2576
2577                 if (hdrv->match) {
2578                         if (!hdrv->match(hdev, hid_ignore_special_drivers)) {
2579                                 ret = -ENODEV;
2580                                 goto unlock;
2581                         }
2582                 } else {
2583                         /*
2584                          * hid-generic implements .match(), so if
2585                          * hid_ignore_special_drivers is set, we can safely
2586                          * return.
2587                          */
2588                         if (hid_ignore_special_drivers) {
2589                                 ret = -ENODEV;
2590                                 goto unlock;
2591                         }
2592                 }
2593
2594                 /* reset the quirks that has been previously set */
2595                 hdev->quirks = hid_lookup_quirk(hdev);
2596                 hdev->driver = hdrv;
2597                 if (hdrv->probe) {
2598                         ret = hdrv->probe(hdev, id);
2599                 } else { /* default probe */
2600                         ret = hid_open_report(hdev);
2601                         if (!ret)
2602                                 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
2603                 }
2604                 if (ret) {
2605                         hid_close_report(hdev);
2606                         hdev->driver = NULL;
2607                 }
2608         }
2609 unlock:
2610         if (!hdev->io_started)
2611                 up(&hdev->driver_input_lock);
2612 end:
2613         return ret;
2614 }
2615
2616 static void hid_device_remove(struct device *dev)
2617 {
2618         struct hid_device *hdev = to_hid_device(dev);
2619         struct hid_driver *hdrv;
2620
2621         down(&hdev->driver_input_lock);
2622         hdev->io_started = false;
2623
2624         hdrv = hdev->driver;
2625         if (hdrv) {
2626                 if (hdrv->remove)
2627                         hdrv->remove(hdev);
2628                 else /* default remove */
2629                         hid_hw_stop(hdev);
2630                 hid_close_report(hdev);
2631                 hdev->driver = NULL;
2632         }
2633
2634         if (!hdev->io_started)
2635                 up(&hdev->driver_input_lock);
2636 }
2637
2638 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
2639                              char *buf)
2640 {
2641         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
2642
2643         return scnprintf(buf, PAGE_SIZE, "hid:b%04Xg%04Xv%08Xp%08X\n",
2644                          hdev->bus, hdev->group, hdev->vendor, hdev->product);
2645 }
2646 static DEVICE_ATTR_RO(modalias);
2647
2648 static struct attribute *hid_dev_attrs[] = {
2649         &dev_attr_modalias.attr,
2650         NULL,
2651 };
2652 static struct bin_attribute *hid_dev_bin_attrs[] = {
2653         &dev_bin_attr_report_desc,
2654         NULL
2655 };
2656 static const struct attribute_group hid_dev_group = {
2657         .attrs = hid_dev_attrs,
2658         .bin_attrs = hid_dev_bin_attrs,
2659 };
2660 __ATTRIBUTE_GROUPS(hid_dev);
2661
2662 static int hid_uevent(struct device *dev, struct kobj_uevent_env *env)
2663 {
2664         struct hid_device *hdev = to_hid_device(dev);
2665
2666         if (add_uevent_var(env, "HID_ID=%04X:%08X:%08X",
2667                         hdev->bus, hdev->vendor, hdev->product))
2668                 return -ENOMEM;
2669
2670         if (add_uevent_var(env, "HID_NAME=%s", hdev->name))
2671                 return -ENOMEM;
2672
2673         if (add_uevent_var(env, "HID_PHYS=%s", hdev->phys))
2674                 return -ENOMEM;
2675
2676         if (add_uevent_var(env, "HID_UNIQ=%s", hdev->uniq))
2677                 return -ENOMEM;
2678
2679         if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",
2680                            hdev->bus, hdev->group, hdev->vendor, hdev->product))
2681                 return -ENOMEM;
2682
2683         return 0;
2684 }
2685
2686 struct bus_type hid_bus_type = {
2687         .name           = "hid",
2688         .dev_groups     = hid_dev_groups,
2689         .drv_groups     = hid_drv_groups,
2690         .match          = hid_bus_match,
2691         .probe          = hid_device_probe,
2692         .remove         = hid_device_remove,
2693         .uevent         = hid_uevent,
2694 };
2695 EXPORT_SYMBOL(hid_bus_type);
2696
2697 int hid_add_device(struct hid_device *hdev)
2698 {
2699         static atomic_t id = ATOMIC_INIT(0);
2700         int ret;
2701
2702         if (WARN_ON(hdev->status & HID_STAT_ADDED))
2703                 return -EBUSY;
2704
2705         hdev->quirks = hid_lookup_quirk(hdev);
2706
2707         /* we need to kill them here, otherwise they will stay allocated to
2708          * wait for coming driver */
2709         if (hid_ignore(hdev))
2710                 return -ENODEV;
2711
2712         /*
2713          * Check for the mandatory transport channel.
2714          */
2715          if (!hdev->ll_driver->raw_request) {
2716                 hid_err(hdev, "transport driver missing .raw_request()\n");
2717                 return -EINVAL;
2718          }
2719
2720         /*
2721          * Read the device report descriptor once and use as template
2722          * for the driver-specific modifications.
2723          */
2724         ret = hdev->ll_driver->parse(hdev);
2725         if (ret)
2726                 return ret;
2727         if (!hdev->dev_rdesc)
2728                 return -ENODEV;
2729
2730         /*
2731          * Scan generic devices for group information
2732          */
2733         if (hid_ignore_special_drivers) {
2734                 hdev->group = HID_GROUP_GENERIC;
2735         } else if (!hdev->group &&
2736                    !(hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)) {
2737                 ret = hid_scan_report(hdev);
2738                 if (ret)
2739                         hid_warn(hdev, "bad device descriptor (%d)\n", ret);
2740         }
2741
2742         /* XXX hack, any other cleaner solution after the driver core
2743          * is converted to allow more than 20 bytes as the device name? */
2744         dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
2745                      hdev->vendor, hdev->product, atomic_inc_return(&id));
2746
2747         hid_debug_register(hdev, dev_name(&hdev->dev));
2748         ret = device_add(&hdev->dev);
2749         if (!ret)
2750                 hdev->status |= HID_STAT_ADDED;
2751         else
2752                 hid_debug_unregister(hdev);
2753
2754         return ret;
2755 }
2756 EXPORT_SYMBOL_GPL(hid_add_device);
2757
2758 /**
2759  * hid_allocate_device - allocate new hid device descriptor
2760  *
2761  * Allocate and initialize hid device, so that hid_destroy_device might be
2762  * used to free it.
2763  *
2764  * New hid_device pointer is returned on success, otherwise ERR_PTR encoded
2765  * error value.
2766  */
2767 struct hid_device *hid_allocate_device(void)
2768 {
2769         struct hid_device *hdev;
2770         int ret = -ENOMEM;
2771
2772         hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
2773         if (hdev == NULL)
2774                 return ERR_PTR(ret);
2775
2776         device_initialize(&hdev->dev);
2777         hdev->dev.release = hid_device_release;
2778         hdev->dev.bus = &hid_bus_type;
2779         device_enable_async_suspend(&hdev->dev);
2780
2781         hid_close_report(hdev);
2782
2783         init_waitqueue_head(&hdev->debug_wait);
2784         INIT_LIST_HEAD(&hdev->debug_list);
2785         spin_lock_init(&hdev->debug_list_lock);
2786         sema_init(&hdev->driver_input_lock, 1);
2787         mutex_init(&hdev->ll_open_lock);
2788
2789         return hdev;
2790 }
2791 EXPORT_SYMBOL_GPL(hid_allocate_device);
2792
2793 static void hid_remove_device(struct hid_device *hdev)
2794 {
2795         if (hdev->status & HID_STAT_ADDED) {
2796                 device_del(&hdev->dev);
2797                 hid_debug_unregister(hdev);
2798                 hdev->status &= ~HID_STAT_ADDED;
2799         }
2800         kfree(hdev->dev_rdesc);
2801         hdev->dev_rdesc = NULL;
2802         hdev->dev_rsize = 0;
2803 }
2804
2805 /**
2806  * hid_destroy_device - free previously allocated device
2807  *
2808  * @hdev: hid device
2809  *
2810  * If you allocate hid_device through hid_allocate_device, you should ever
2811  * free by this function.
2812  */
2813 void hid_destroy_device(struct hid_device *hdev)
2814 {
2815         hid_remove_device(hdev);
2816         put_device(&hdev->dev);
2817 }
2818 EXPORT_SYMBOL_GPL(hid_destroy_device);
2819
2820
2821 static int __hid_bus_reprobe_drivers(struct device *dev, void *data)
2822 {
2823         struct hid_driver *hdrv = data;
2824         struct hid_device *hdev = to_hid_device(dev);
2825
2826         if (hdev->driver == hdrv &&
2827             !hdrv->match(hdev, hid_ignore_special_drivers) &&
2828             !test_and_set_bit(ffs(HID_STAT_REPROBED), &hdev->status))
2829                 return device_reprobe(dev);
2830
2831         return 0;
2832 }
2833
2834 static int __hid_bus_driver_added(struct device_driver *drv, void *data)
2835 {
2836         struct hid_driver *hdrv = to_hid_driver(drv);
2837
2838         if (hdrv->match) {
2839                 bus_for_each_dev(&hid_bus_type, NULL, hdrv,
2840                                  __hid_bus_reprobe_drivers);
2841         }
2842
2843         return 0;
2844 }
2845
2846 static int __bus_removed_driver(struct device_driver *drv, void *data)
2847 {
2848         return bus_rescan_devices(&hid_bus_type);
2849 }
2850
2851 int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
2852                 const char *mod_name)
2853 {
2854         int ret;
2855
2856         hdrv->driver.name = hdrv->name;
2857         hdrv->driver.bus = &hid_bus_type;
2858         hdrv->driver.owner = owner;
2859         hdrv->driver.mod_name = mod_name;
2860
2861         INIT_LIST_HEAD(&hdrv->dyn_list);
2862         spin_lock_init(&hdrv->dyn_lock);
2863
2864         ret = driver_register(&hdrv->driver);
2865
2866         if (ret == 0)
2867                 bus_for_each_drv(&hid_bus_type, NULL, NULL,
2868                                  __hid_bus_driver_added);
2869
2870         return ret;
2871 }
2872 EXPORT_SYMBOL_GPL(__hid_register_driver);
2873
2874 void hid_unregister_driver(struct hid_driver *hdrv)
2875 {
2876         driver_unregister(&hdrv->driver);
2877         hid_free_dynids(hdrv);
2878
2879         bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver);
2880 }
2881 EXPORT_SYMBOL_GPL(hid_unregister_driver);
2882
2883 int hid_check_keys_pressed(struct hid_device *hid)
2884 {
2885         struct hid_input *hidinput;
2886         int i;
2887
2888         if (!(hid->claimed & HID_CLAIMED_INPUT))
2889                 return 0;
2890
2891         list_for_each_entry(hidinput, &hid->inputs, list) {
2892                 for (i = 0; i < BITS_TO_LONGS(KEY_MAX); i++)
2893                         if (hidinput->input->key[i])
2894                                 return 1;
2895         }
2896
2897         return 0;
2898 }
2899 EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
2900
2901 static int __init hid_init(void)
2902 {
2903         int ret;
2904
2905         if (hid_debug)
2906                 pr_warn("hid_debug is now used solely for parser and driver debugging.\n"
2907                         "debugfs is now used for inspecting the device (report descriptor, reports)\n");
2908
2909         ret = bus_register(&hid_bus_type);
2910         if (ret) {
2911                 pr_err("can't register hid bus\n");
2912                 goto err;
2913         }
2914
2915         ret = hidraw_init();
2916         if (ret)
2917                 goto err_bus;
2918
2919         hid_debug_init();
2920
2921         return 0;
2922 err_bus:
2923         bus_unregister(&hid_bus_type);
2924 err:
2925         return ret;
2926 }
2927
2928 static void __exit hid_exit(void)
2929 {
2930         hid_debug_exit();
2931         hidraw_exit();
2932         bus_unregister(&hid_bus_type);
2933         hid_quirks_exit(HID_BUS_ANY);
2934 }
2935
2936 module_init(hid_init);
2937 module_exit(hid_exit);
2938
2939 MODULE_AUTHOR("Andreas Gal");
2940 MODULE_AUTHOR("Vojtech Pavlik");
2941 MODULE_AUTHOR("Jiri Kosina");
2942 MODULE_LICENSE("GPL");