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