drivers/hid/hid-core.c

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