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