drivers/hid/hid-core.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  HID support for Linux
   4  *
   5  *  Copyright (c) 1999 Andreas Gal
   6  *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
   7  *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
   8  *  Copyright (c) 2006-2012 Jiri Kosina
   9  */
  10
  11 /*
  12  */
  13
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16 #include <linux/module.h>
  17 #include <linux/slab.h>
  18 #include <linux/init.h>
  19 #include <linux/kernel.h>
  20 #include <linux/list.h>
  21 #include <linux/mm.h>
  22 #include <linux/spinlock.h>
  23 #include <asm/unaligned.h>
  24 #include <asm/byteorder.h>
  25 #include <linux/input.h>
  26 #include <linux/wait.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/sched.h>
  29 #include <linux/semaphore.h>
  30
  31 #include <linux/hid.h>
  32 #include <linux/hiddev.h>
  33 #include <linux/hid-debug.h>
  34 #include <linux/hidraw.h>
  35
  36 #include "hid-ids.h"
  37
  38 /*
  39  * Version Information
  40  */
  41
  42 #define DRIVER_DESC "HID core driver"
  43
  44 static int hid_ignore_special_drivers = 0;
  45 module_param_named(ignore_special_drivers, hid_ignore_special_drivers, int, 0600);
  46 MODULE_PARM_DESC(ignore_special_drivers, "Ignore any special drivers and handle all devices by generic driver");
  47
  48 /*
  49  * Register a new report for a device.
  50  */
  51
  52 struct hid_report *hid_register_report(struct hid_device *device,
  53                                        enum hid_report_type type, unsigned int id,
  54                                        unsigned int application)
  55 {
  56         struct hid_report_enum *report_enum = device->report_enum + type;
  57         struct hid_report *report;
  58
  59         if (id >= HID_MAX_IDS)
  60                 return NULL;
  61         if (report_enum->report_id_hash[id])
  62                 return report_enum->report_id_hash[id];
  63
  64         report = kzalloc(sizeof(struct hid_report), GFP_KERNEL);
  65         if (!report)
  66                 return NULL;
  67
  68         if (id != 0)
  69                 report_enum->numbered = 1;
  70
  71         report->id = id;
  72         report->type = type;
  73         report->size = 0;
  74         report->device = device;
  75         report->application = application;
  76         report_enum->report_id_hash[id] = report;
  77
  78         list_add_tail(&report->list, &report_enum->report_list);
  79         INIT_LIST_HEAD(&report->field_entry_list);
  80
  81         return report;
  82 }
  83 EXPORT_SYMBOL_GPL(hid_register_report);
  84
  85 /*
  86  * Register a new field for this report.
  87  */
  88
  89 static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages)
  90 {
  91         struct hid_field *field;
  92
  93         if (report->maxfield == HID_MAX_FIELDS) {
  94                 hid_err(report->device, "too many fields in report\n");
  95                 return NULL;
  96         }
  97
  98         field = kzalloc((sizeof(struct hid_field) +
  99                          usages * sizeof(struct hid_usage) +
 100                          3 * usages * sizeof(unsigned int)), GFP_KERNEL);
 101         if (!field)
 102                 return NULL;
 103
 104         field->index = report->maxfield++;
 105         report->field[field->index] = field;
 106         field->usage = (struct hid_usage *)(field + 1);
 107         field->value = (s32 *)(field->usage + usages);
 108         field->new_value = (s32 *)(field->value + usages);
 109         field->usages_priorities = (s32 *)(field->new_value + usages);
 110         field->report = report;
 111
 112         return field;
 113 }
 114
 115 /*
 116  * Open a collection. The type/usage is pushed on the stack.
 117  */
 118
 119 static int open_collection(struct hid_parser *parser, unsigned type)
 120 {
 121         struct hid_collection *collection;
 122         unsigned usage;
 123         int collection_index;
 124
 125         usage = parser->local.usage[0];
 126
 127         if (parser->collection_stack_ptr == parser->collection_stack_size) {
 128                 unsigned int *collection_stack;
 129                 unsigned int new_size = parser->collection_stack_size +
 130                                         HID_COLLECTION_STACK_SIZE;
 131
 132                 collection_stack = krealloc(parser->collection_stack,
 133                                             new_size * sizeof(unsigned int),
 134                                             GFP_KERNEL);
 135                 if (!collection_stack)
 136                         return -ENOMEM;
 137
 138                 parser->collection_stack = collection_stack;
 139                 parser->collection_stack_size = new_size;
 140         }
 141
 142         if (parser->device->maxcollection == parser->device->collection_size) {
 143                 collection = kmalloc(
 144                                 array3_size(sizeof(struct hid_collection),
 145                                             parser->device->collection_size,
 146                                             2),
 147                                 GFP_KERNEL);
 148                 if (collection == NULL) {
 149                         hid_err(parser->device, "failed to reallocate collection array\n");
 150                         return -ENOMEM;
 151                 }
 152                 memcpy(collection, parser->device->collection,
 153                         sizeof(struct hid_collection) *
 154                         parser->device->collection_size);
 155                 memset(collection + parser->device->collection_size, 0,
 156                         sizeof(struct hid_collection) *
 157                         parser->device->collection_size);
 158                 kfree(parser->device->collection);
 159                 parser->device->collection = collection;
 160                 parser->device->collection_size *= 2;
 161         }
 162
 163         parser->collection_stack[parser->collection_stack_ptr++] =
 164                 parser->device->maxcollection;
 165
 166         collection_index = parser->device->maxcollection++;
 167         collection = parser->device->collection + collection_index;
 168         collection->type = type;
 169         collection->usage = usage;
 170         collection->level = parser->collection_stack_ptr - 1;
 171         collection->parent_idx = (collection->level == 0) ? -1 :
 172                 parser->collection_stack[collection->level - 1];
 173
 174         if (type == HID_COLLECTION_APPLICATION)
 175                 parser->device->maxapplication++;
 176
 177         return 0;
 178 }
 179
 180 /*
 181  * Close a collection.
 182  */
 183
 184 static int close_collection(struct hid_parser *parser)
 185 {
 186         if (!parser->collection_stack_ptr) {
 187                 hid_err(parser->device, "collection stack underflow\n");
 188                 return -EINVAL;
 189         }
 190         parser->collection_stack_ptr--;
 191         return 0;
 192 }
 193
 194 /*
 195  * Climb up the stack, search for the specified collection type
 196  * and return the usage.
 197  */
 198
 199 static unsigned hid_lookup_collection(struct hid_parser *parser, unsigned type)
 200 {
 201         struct hid_collection *collection = parser->device->collection;
 202         int n;
 203
 204         for (n = parser->collection_stack_ptr - 1; n >= 0; n--) {
 205                 unsigned index = parser->collection_stack[n];
 206                 if (collection[index].type == type)
 207                         return collection[index].usage;
 208         }
 209         return 0; /* we know nothing about this usage type */
 210 }
 211
 212 /*
 213  * Concatenate usage which defines 16 bits or less with the
 214  * currently defined usage page to form a 32 bit usage
 215  */
 216
 217 static void complete_usage(struct hid_parser *parser, unsigned int index)
 218 {
 219         parser->local.usage[index] &= 0xFFFF;
 220         parser->local.usage[index] |=
 221                 (parser->global.usage_page & 0xFFFF) << 16;
 222 }
 223
 224 /*
 225  * Add a usage to the temporary parser table.
 226  */
 227
 228 static int hid_add_usage(struct hid_parser *parser, unsigned usage, u8 size)
 229 {
 230         if (parser->local.usage_index >= HID_MAX_USAGES) {
 231                 hid_err(parser->device, "usage index exceeded\n");
 232                 return -1;
 233         }
 234         parser->local.usage[parser->local.usage_index] = usage;
 235
 236         /*
 237          * If Usage item only includes usage id, concatenate it with
 238          * currently defined usage page
 239          */
 240         if (size <= 2)
 241                 complete_usage(parser, parser->local.usage_index);
 242
 243         parser->local.usage_size[parser->local.usage_index] = size;
 244         parser->local.collection_index[parser->local.usage_index] =
 245                 parser->collection_stack_ptr ?
 246                 parser->collection_stack[parser->collection_stack_ptr - 1] : 0;
 247         parser->local.usage_index++;
 248         return 0;
 249 }
 250
 251 /*
 252  * Register a new field for this report.
 253  */
 254
 255 static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsigned flags)
 256 {
 257         struct hid_report *report;
 258         struct hid_field *field;
 259         unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
 260         unsigned int usages;
 261         unsigned int offset;
 262         unsigned int i;
 263         unsigned int application;
 264
 265         application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
 266
 267         report = hid_register_report(parser->device, report_type,
 268                                      parser->global.report_id, application);
 269         if (!report) {
 270                 hid_err(parser->device, "hid_register_report failed\n");
 271                 return -1;
 272         }
 273
 274         /* Handle both signed and unsigned cases properly */
 275         if ((parser->global.logical_minimum < 0 &&
 276                 parser->global.logical_maximum <
 277                 parser->global.logical_minimum) ||
 278                 (parser->global.logical_minimum >= 0 &&
 279                 (__u32)parser->global.logical_maximum <
 280                 (__u32)parser->global.logical_minimum)) {
 281                 dbg_hid("logical range invalid 0x%x 0x%x\n",
 282                         parser->global.logical_minimum,
 283                         parser->global.logical_maximum);
 284                 return -1;
 285         }
 286
 287         offset = report->size;
 288         report->size += parser->global.report_size * parser->global.report_count;
 289
 290         if (parser->device->ll_driver->max_buffer_size)
 291                 max_buffer_size = parser->device->ll_driver->max_buffer_size;
 292
 293         /* Total size check: Allow for possible report index byte */
 294         if (report->size > (max_buffer_size - 1) << 3) {
 295                 hid_err(parser->device, "report is too long\n");
 296                 return -1;
 297         }
 298
 299         if (!parser->local.usage_index) /* Ignore padding fields */
 300                 return 0;
 301
 302         usages = max_t(unsigned, parser->local.usage_index,
 303                                  parser->global.report_count);
 304
 305         field = hid_register_field(report, usages);
 306         if (!field)
 307                 return 0;
 308
 309         field->physical = hid_lookup_collection(parser, HID_COLLECTION_PHYSICAL);
 310         field->logical = hid_lookup_collection(parser, HID_COLLECTION_LOGICAL);
 311         field->application = application;
 312
 313         for (i = 0; i < usages; i++) {
 314                 unsigned j = i;
 315                 /* Duplicate the last usage we parsed if we have excess values */
 316                 if (i >= parser->local.usage_index)
 317                         j = parser->local.usage_index - 1;
 318                 field->usage[i].hid = parser->local.usage[j];
 319                 field->usage[i].collection_index =
 320                         parser->local.collection_index[j];
 321                 field->usage[i].usage_index = i;
 322                 field->usage[i].resolution_multiplier = 1;
 323         }
 324
 325         field->maxusage = usages;
 326         field->flags = flags;
 327         field->report_offset = offset;
 328         field->report_type = report_type;
 329         field->report_size = parser->global.report_size;
 330         field->report_count = parser->global.report_count;
 331         field->logical_minimum = parser->global.logical_minimum;
 332         field->logical_maximum = parser->global.logical_maximum;
 333         field->physical_minimum = parser->global.physical_minimum;
 334         field->physical_maximum = parser->global.physical_maximum;
 335         field->unit_exponent = parser->global.unit_exponent;
 336         field->unit = parser->global.unit;
 337
 338         return 0;
 339 }
 340
 341 /*
 342  * Read data value from item.
 343  */
 344
 345 static u32 item_udata(struct hid_item *item)
 346 {
 347         switch (item->size) {
 348         case 1: return item->data.u8;
 349         case 2: return item->data.u16;
 350         case 4: return item->data.u32;
 351         }
 352         return 0;
 353 }
 354
 355 static s32 item_sdata(struct hid_item *item)
 356 {
 357         switch (item->size) {
 358         case 1: return item->data.s8;
 359         case 2: return item->data.s16;
 360         case 4: return item->data.s32;
 361         }
 362         return 0;
 363 }
 364
 365 /*
 366  * Process a global item.
 367  */
 368
 369 static int hid_parser_global(struct hid_parser *parser, struct hid_item *item)
 370 {
 371         __s32 raw_value;
 372         switch (item->tag) {
 373         case HID_GLOBAL_ITEM_TAG_PUSH:
 374
 375                 if (parser->global_stack_ptr == HID_GLOBAL_STACK_SIZE) {
 376                         hid_err(parser->device, "global environment stack overflow\n");
 377                         return -1;
 378                 }
 379
 380                 memcpy(parser->global_stack + parser->global_stack_ptr++,
 381                         &parser->global, sizeof(struct hid_global));
 382                 return 0;
 383
 384         case HID_GLOBAL_ITEM_TAG_POP:
 385
 386                 if (!parser->global_stack_ptr) {
 387                         hid_err(parser->device, "global environment stack underflow\n");
 388                         return -1;
 389                 }
 390
 391                 memcpy(&parser->global, parser->global_stack +
 392                         --parser->global_stack_ptr, sizeof(struct hid_global));
 393                 return 0;
 394
 395         case HID_GLOBAL_ITEM_TAG_USAGE_PAGE:
 396                 parser->global.usage_page = item_udata(item);
 397                 return 0;
 398
 399         case HID_GLOBAL_ITEM_TAG_LOGICAL_MINIMUM:
 400                 parser->global.logical_minimum = item_sdata(item);
 401                 return 0;
 402
 403         case HID_GLOBAL_ITEM_TAG_LOGICAL_MAXIMUM:
 404                 if (parser->global.logical_minimum < 0)
 405                         parser->global.logical_maximum = item_sdata(item);
 406                 else
 407                         parser->global.logical_maximum = item_udata(item);
 408                 return 0;
 409
 410         case HID_GLOBAL_ITEM_TAG_PHYSICAL_MINIMUM:
 411                 parser->global.physical_minimum = item_sdata(item);
 412                 return 0;
 413
 414         case HID_GLOBAL_ITEM_TAG_PHYSICAL_MAXIMUM:
 415                 if (parser->global.physical_minimum < 0)
 416                         parser->global.physical_maximum = item_sdata(item);
 417                 else
 418                         parser->global.physical_maximum = item_udata(item);
 419                 return 0;
 420
 421         case HID_GLOBAL_ITEM_TAG_UNIT_EXPONENT:
 422                 /* Many devices provide unit exponent as a two's complement
 423                  * nibble due to the common misunderstanding of HID
 424                  * specification 1.11, 6.2.2.7 Global Items. Attempt to handle
 425                  * both this and the standard encoding. */
 426                 raw_value = item_sdata(item);
 427                 if (!(raw_value & 0xfffffff0))
 428                         parser->global.unit_exponent = hid_snto32(raw_value, 4);
 429                 else
 430                         parser->global.unit_exponent = raw_value;
 431                 return 0;
 432
 433         case HID_GLOBAL_ITEM_TAG_UNIT:
 434                 parser->global.unit = item_udata(item);
 435                 return 0;
 436
 437         case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
 438                 parser->global.report_size = item_udata(item);
 439                 if (parser->global.report_size > 256) {
 440                         hid_err(parser->device, "invalid report_size %d\n",
 441                                         parser->global.report_size);
 442                         return -1;
 443                 }
 444                 return 0;
 445
 446         case HID_GLOBAL_ITEM_TAG_REPORT_COUNT:
 447                 parser->global.report_count = item_udata(item);
 448                 if (parser->global.report_count > HID_MAX_USAGES) {
 449                         hid_err(parser->device, "invalid report_count %d\n",
 450                                         parser->global.report_count);
 451                         return -1;
 452                 }
 453                 return 0;
 454
 455         case HID_GLOBAL_ITEM_TAG_REPORT_ID:
 456                 parser->global.report_id = item_udata(item);
 457                 if (parser->global.report_id == 0 ||
 458                     parser->global.report_id >= HID_MAX_IDS) {
 459                         hid_err(parser->device, "report_id %u is invalid\n",
 460                                 parser->global.report_id);
 461                         return -1;
 462                 }
 463                 return 0;
 464
 465         default:
 466                 hid_err(parser->device, "unknown global tag 0x%x\n", item->tag);
 467                 return -1;
 468         }
 469 }
 470
 471 /*
 472  * Process a local item.
 473  */
 474
 475 static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
 476 {
 477         __u32 data;
 478         unsigned n;
 479         __u32 count;
 480
 481         data = item_udata(item);
 482
 483         switch (item->tag) {
 484         case HID_LOCAL_ITEM_TAG_DELIMITER:
 485
 486                 if (data) {
 487                         /*
 488                          * We treat items before the first delimiter
 489                          * as global to all usage sets (branch 0).
 490                          * In the moment we process only these global
 491                          * items and the first delimiter set.
 492                          */
 493                         if (parser->local.delimiter_depth != 0) {
 494                                 hid_err(parser->device, "nested delimiters\n");
 495                                 return -1;
 496                         }
 497                         parser->local.delimiter_depth++;
 498                         parser->local.delimiter_branch++;
 499                 } else {
 500                         if (parser->local.delimiter_depth < 1) {
 501                                 hid_err(parser->device, "bogus close delimiter\n");
 502                                 return -1;
 503                         }
 504                         parser->local.delimiter_depth--;
 505                 }
 506                 return 0;
 507
 508         case HID_LOCAL_ITEM_TAG_USAGE:
 509
 510                 if (parser->local.delimiter_branch > 1) {
 511                         dbg_hid("alternative usage ignored\n");
 512                         return 0;
 513                 }
 514
 515                 return hid_add_usage(parser, data, item->size);
 516
 517         case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:
 518
 519                 if (parser->local.delimiter_branch > 1) {
 520                         dbg_hid("alternative usage ignored\n");
 521                         return 0;
 522                 }
 523
 524                 parser->local.usage_minimum = data;
 525                 return 0;
 526
 527         case HID_LOCAL_ITEM_TAG_USAGE_MAXIMUM:
 528
 529                 if (parser->local.delimiter_branch > 1) {
 530                         dbg_hid("alternative usage ignored\n");
 531                         return 0;
 532                 }
 533
 534                 count = data - parser->local.usage_minimum;
 535                 if (count + parser->local.usage_index >= HID_MAX_USAGES) {
 536                         /*
 537                          * We do not warn if the name is not set, we are
 538                          * actually pre-scanning the device.
 539                          */
 540                         if (dev_name(&parser->device->dev))
 541                                 hid_warn(parser->device,
 542                                          "ignoring exceeding usage max\n");
 543                         data = HID_MAX_USAGES - parser->local.usage_index +
 544                                 parser->local.usage_minimum - 1;
 545                         if (data <= 0) {
 546                                 hid_err(parser->device,
 547                                         "no more usage index available\n");
 548                                 return -1;
 549                         }
 550                 }
 551
 552                 for (n = parser->local.usage_minimum; n <= data; n++)
 553                         if (hid_add_usage(parser, n, item->size)) {
 554                                 dbg_hid("hid_add_usage failed\n");
 555                                 return -1;
 556                         }
 557                 return 0;
 558
 559         default:
 560
 561                 dbg_hid("unknown local item tag 0x%x\n", item->tag);
 562                 return 0;
 563         }
 564         return 0;
 565 }
 566
 567 /*
 568  * Concatenate Usage Pages into Usages where relevant:
 569  * As per specification, 6.2.2.8: "When the parser encounters a main item it
 570  * concatenates the last declared Usage Page with a Usage to form a complete
 571  * usage value."
 572  */
 573
 574 static void hid_concatenate_last_usage_page(struct hid_parser *parser)
 575 {
 576         int i;
 577         unsigned int usage_page;
 578         unsigned int current_page;
 579
 580         if (!parser->local.usage_index)
 581                 return;
 582
 583         usage_page = parser->global.usage_page;
 584
 585         /*
 586          * Concatenate usage page again only if last declared Usage Page
 587          * has not been already used in previous usages concatenation
 588          */
 589         for (i = parser->local.usage_index - 1; i >= 0; i--) {
 590                 if (parser->local.usage_size[i] > 2)
 591                         /* Ignore extended usages */
 592                         continue;
 593
 594                 current_page = parser->local.usage[i] >> 16;
 595                 if (current_page == usage_page)
 596                         break;
 597
 598                 complete_usage(parser, i);
 599         }
 600 }
 601
 602 /*
 603  * Process a main item.
 604  */
 605
 606 static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
 607 {
 608         __u32 data;
 609         int ret;
 610
 611         hid_concatenate_last_usage_page(parser);
 612
 613         data = item_udata(item);
 614
 615         switch (item->tag) {
 616         case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 617                 ret = open_collection(parser, data & 0xff);
 618                 break;
 619         case HID_MAIN_ITEM_TAG_END_COLLECTION:
 620                 ret = close_collection(parser);
 621                 break;
 622         case HID_MAIN_ITEM_TAG_INPUT:
 623                 ret = hid_add_field(parser, HID_INPUT_REPORT, data);
 624                 break;
 625         case HID_MAIN_ITEM_TAG_OUTPUT:
 626                 ret = hid_add_field(parser, HID_OUTPUT_REPORT, data);
 627                 break;
 628         case HID_MAIN_ITEM_TAG_FEATURE:
 629                 ret = hid_add_field(parser, HID_FEATURE_REPORT, data);
 630                 break;
 631         default:
 632                 hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
 633                 ret = 0;
 634         }
 635
 636         memset(&parser->local, 0, sizeof(parser->local));       /* Reset the local parser environment */
 637
 638         return ret;
 639 }
 640
 641 /*
 642  * Process a reserved item.
 643  */
 644
 645 static int hid_parser_reserved(struct hid_parser *parser, struct hid_item *item)
 646 {
 647         dbg_hid("reserved item type, tag 0x%x\n", item->tag);
 648         return 0;
 649 }
 650
 651 /*
 652  * Free a report and all registered fields. The field->usage and
 653  * field->value table's are allocated behind the field, so we need
 654  * only to free(field) itself.
 655  */
 656
 657 static void hid_free_report(struct hid_report *report)
 658 {
 659         unsigned n;
 660
 661         kfree(report->field_entries);
 662
 663         for (n = 0; n < report->maxfield; n++)
 664                 kfree(report->field[n]);
 665         kfree(report);
 666 }
 667
 668 /*
 669  * Close report. This function returns the device
 670  * state to the point prior to hid_open_report().
 671  */
 672 static void hid_close_report(struct hid_device *device)
 673 {
 674         unsigned i, j;
 675
 676         for (i = 0; i < HID_REPORT_TYPES; i++) {
 677                 struct hid_report_enum *report_enum = device->report_enum + i;
 678
 679                 for (j = 0; j < HID_MAX_IDS; j++) {
 680                         struct hid_report *report = report_enum->report_id_hash[j];
 681                         if (report)
 682                                 hid_free_report(report);
 683                 }
 684                 memset(report_enum, 0, sizeof(*report_enum));
 685                 INIT_LIST_HEAD(&report_enum->report_list);
 686         }
 687
 688         kfree(device->rdesc);
 689         device->rdesc = NULL;
 690         device->rsize = 0;
 691
 692         kfree(device->collection);
 693         device->collection = NULL;
 694         device->collection_size = 0;
 695         device->maxcollection = 0;
 696         device->maxapplication = 0;
 697
 698         device->status &= ~HID_STAT_PARSED;
 699 }
 700
 701 /*
 702  * Free a device structure, all reports, and all fields.
 703  */
 704
 705 static void hid_device_release(struct device *dev)
 706 {
 707         struct hid_device *hid = to_hid_device(dev);
 708
 709         hid_close_report(hid);
 710         kfree(hid->dev_rdesc);
 711         kfree(hid);
 712 }
 713
 714 /*
 715  * Fetch a report description item from the data stream. We support long
 716  * items, though they are not used yet.
 717  */
 718
 719 static u8 *fetch_item(__u8 *start, __u8 *end, struct hid_item *item)
 720 {
 721         u8 b;
 722
 723         if ((end - start) <= 0)
 724                 return NULL;
 725
 726         b = *start++;
 727
 728         item->type = (b >> 2) & 3;
 729         item->tag  = (b >> 4) & 15;
 730
 731         if (item->tag == HID_ITEM_TAG_LONG) {
 732
 733                 item->format = HID_ITEM_FORMAT_LONG;
 734
 735                 if ((end - start) < 2)
 736                         return NULL;
 737
 738                 item->size = *start++;
 739                 item->tag  = *start++;
 740
 741                 if ((end - start) < item->size)
 742                         return NULL;
 743
 744                 item->data.longdata = start;
 745                 start += item->size;
 746                 return start;
 747         }
 748
 749         item->format = HID_ITEM_FORMAT_SHORT;
 750         item->size = b & 3;
 751
 752         switch (item->size) {
 753         case 0:
 754                 return start;
 755
 756         case 1:
 757                 if ((end - start) < 1)
 758                         return NULL;
 759                 item->data.u8 = *start++;
 760                 return start;
 761
 762         case 2:
 763                 if ((end - start) < 2)
 764                         return NULL;
 765                 item->data.u16 = get_unaligned_le16(start);
 766                 start = (__u8 *)((__le16 *)start + 1);
 767                 return start;
 768
 769         case 3:
 770                 item->size++;
 771                 if ((end - start) < 4)
 772                         return NULL;
 773                 item->data.u32 = get_unaligned_le32(start);
 774                 start = (__u8 *)((__le32 *)start + 1);
 775                 return start;
 776         }
 777
 778         return NULL;
 779 }
 780
 781 static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)
 782 {
 783         struct hid_device *hid = parser->device;
 784
 785         if (usage == HID_DG_CONTACTID)
 786                 hid->group = HID_GROUP_MULTITOUCH;
 787 }
 788
 789 static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
 790 {
 791         if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
 792             parser->global.report_size == 8)
 793                 parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 794
 795         if (usage == 0xff0000c6 && parser->global.report_count == 1 &&
 796             parser->global.report_size == 8)
 797                 parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 798 }
 799
 800 static void hid_scan_collection(struct hid_parser *parser, unsigned type)
 801 {
 802         struct hid_device *hid = parser->device;
 803         int i;
 804
 805         if (((parser->global.usage_page << 16) == HID_UP_SENSOR) &&
 806             (type == HID_COLLECTION_PHYSICAL ||
 807              type == HID_COLLECTION_APPLICATION))
 808                 hid->group = HID_GROUP_SENSOR_HUB;
 809
 810         if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
 811             hid->product == USB_DEVICE_ID_MS_POWER_COVER &&
 812             hid->group == HID_GROUP_MULTITOUCH)
 813                 hid->group = HID_GROUP_GENERIC;
 814
 815         if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
 816                 for (i = 0; i < parser->local.usage_index; i++)
 817                         if (parser->local.usage[i] == HID_GD_POINTER)
 818                                 parser->scan_flags |= HID_SCAN_FLAG_GD_POINTER;
 819
 820         if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
 821                 parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
 822
 823         if ((parser->global.usage_page << 16) == HID_UP_GOOGLEVENDOR)
 824                 for (i = 0; i < parser->local.usage_index; i++)
 825                         if (parser->local.usage[i] ==
 826                                         (HID_UP_GOOGLEVENDOR | 0x0001))
 827                                 parser->device->group =
 828                                         HID_GROUP_VIVALDI;
 829 }
 830
 831 static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
 832 {
 833         __u32 data;
 834         int i;
 835
 836         hid_concatenate_last_usage_page(parser);
 837
 838         data = item_udata(item);
 839
 840         switch (item->tag) {
 841         case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 842                 hid_scan_collection(parser, data & 0xff);
 843                 break;
 844         case HID_MAIN_ITEM_TAG_END_COLLECTION:
 845                 break;
 846         case HID_MAIN_ITEM_TAG_INPUT:
 847                 /* ignore constant inputs, they will be ignored by hid-input */
 848                 if (data & HID_MAIN_ITEM_CONSTANT)
 849                         break;
 850                 for (i = 0; i < parser->local.usage_index; i++)
 851                         hid_scan_input_usage(parser, parser->local.usage[i]);
 852                 break;
 853         case HID_MAIN_ITEM_TAG_OUTPUT:
 854                 break;
 855         case HID_MAIN_ITEM_TAG_FEATURE:
 856                 for (i = 0; i < parser->local.usage_index; i++)
 857                         hid_scan_feature_usage(parser, parser->local.usage[i]);
 858                 break;
 859         }
 860
 861         /* Reset the local parser environment */
 862         memset(&parser->local, 0, sizeof(parser->local));
 863
 864         return 0;
 865 }
 866
 867 /*
 868  * Scan a report descriptor before the device is added to the bus.
 869  * Sets device groups and other properties that determine what driver
 870  * to load.
 871  */
 872 static int hid_scan_report(struct hid_device *hid)
 873 {
 874         struct hid_parser *parser;
 875         struct hid_item item;
 876         __u8 *start = hid->dev_rdesc;
 877         __u8 *end = start + hid->dev_rsize;
 878         static int (*dispatch_type[])(struct hid_parser *parser,
 879                                       struct hid_item *item) = {
 880                 hid_scan_main,
 881                 hid_parser_global,
 882                 hid_parser_local,
 883                 hid_parser_reserved
 884         };
 885
 886         parser = vzalloc(sizeof(struct hid_parser));
 887         if (!parser)
 888                 return -ENOMEM;
 889
 890         parser->device = hid;
 891         hid->group = HID_GROUP_GENERIC;
 892
 893         /*
 894          * The parsing is simpler than the one in hid_open_report() as we should
 895          * be robust against hid errors. Those errors will be raised by
 896          * hid_open_report() anyway.
 897          */
 898         while ((start = fetch_item(start, end, &item)) != NULL)
 899                 dispatch_type[item.type](parser, &item);
 900
 901         /*
 902          * Handle special flags set during scanning.
 903          */
 904         if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
 905             (hid->group == HID_GROUP_MULTITOUCH))
 906                 hid->group = HID_GROUP_MULTITOUCH_WIN_8;
 907
 908         /*
 909          * Vendor specific handlings
 910          */
 911         switch (hid->vendor) {
 912         case USB_VENDOR_ID_WACOM:
 913                 hid->group = HID_GROUP_WACOM;
 914                 break;
 915         case USB_VENDOR_ID_SYNAPTICS:
 916                 if (hid->group == HID_GROUP_GENERIC)
 917                         if ((parser->scan_flags & HID_SCAN_FLAG_VENDOR_SPECIFIC)
 918                             && (parser->scan_flags & HID_SCAN_FLAG_GD_POINTER))
 919                                 /*
 920                                  * hid-rmi should take care of them,
 921                                  * not hid-generic
 922                                  */
 923                                 hid->group = HID_GROUP_RMI;
 924                 break;
 925         }
 926
 927         kfree(parser->collection_stack);
 928         vfree(parser);
 929         return 0;
 930 }
 931
 932 /**
 933  * hid_parse_report - parse device report
 934  *
 935  * @hid: hid device
 936  * @start: report start
 937  * @size: report size
 938  *
 939  * Allocate the device report as read by the bus driver. This function should
 940  * only be called from parse() in ll drivers.
 941  */
 942 int hid_parse_report(struct hid_device *hid, __u8 *start, unsigned size)
 943 {
 944         hid->dev_rdesc = kmemdup(start, size, GFP_KERNEL);
 945         if (!hid->dev_rdesc)
 946                 return -ENOMEM;
 947         hid->dev_rsize = size;
 948         return 0;
 949 }
 950 EXPORT_SYMBOL_GPL(hid_parse_report);
 951
 952 static const char * const hid_report_names[] = {
 953         "HID_INPUT_REPORT",
 954         "HID_OUTPUT_REPORT",
 955         "HID_FEATURE_REPORT",
 956 };
 957 /**
 958  * hid_validate_values - validate existing device report's value indexes
 959  *
 960  * @hid: hid device
 961  * @type: which report type to examine
 962  * @id: which report ID to examine (0 for first)
 963  * @field_index: which report field to examine
 964  * @report_counts: expected number of values
 965  *
 966  * Validate the number of values in a given field of a given report, after
 967  * parsing.
 968  */
 969 struct hid_report *hid_validate_values(struct hid_device *hid,
 970                                        enum hid_report_type type, unsigned int id,
 971                                        unsigned int field_index,
 972                                        unsigned int report_counts)
 973 {
 974         struct hid_report *report;
 975
 976         if (type > HID_FEATURE_REPORT) {
 977                 hid_err(hid, "invalid HID report type %u\n", type);
 978                 return NULL;
 979         }
 980
 981         if (id >= HID_MAX_IDS) {
 982                 hid_err(hid, "invalid HID report id %u\n", id);
 983                 return NULL;
 984         }
 985
 986         /*
 987          * Explicitly not using hid_get_report() here since it depends on
 988          * ->numbered being checked, which may not always be the case when
 989          * drivers go to access report values.
 990          */
 991         if (id == 0) {
 992                 /*
 993                  * Validating on id 0 means we should examine the first
 994                  * report in the list.
 995                  */
 996                 report = list_first_entry_or_null(
 997                                 &hid->report_enum[type].report_list,
 998                                 struct hid_report, list);
 999         } else {
1000                 report = hid->report_enum[type].report_id_hash[id];
1001         }
1002         if (!report) {
1003                 hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
1004                 return NULL;
1005         }
1006         if (report->maxfield <= field_index) {
1007                 hid_err(hid, "not enough fields in %s %u\n",
1008                         hid_report_names[type], id);
1009                 return NULL;
1010         }
1011         if (report->field[field_index]->report_count < report_counts) {
1012                 hid_err(hid, "not enough values in %s %u field %u\n",
1013                         hid_report_names[type], id, field_index);
1014                 return NULL;
1015         }
1016         return report;
1017 }
1018 EXPORT_SYMBOL_GPL(hid_validate_values);
1019
1020 static int hid_calculate_multiplier(struct hid_device *hid,
1021                                      struct hid_field *multiplier)
1022 {
1023         int m;
1024         __s32 v = *multiplier->value;
1025         __s32 lmin = multiplier->logical_minimum;
1026         __s32 lmax = multiplier->logical_maximum;
1027         __s32 pmin = multiplier->physical_minimum;
1028         __s32 pmax = multiplier->physical_maximum;
1029
1030         /*
1031          * "Because OS implementations will generally divide the control's
1032          * reported count by the Effective Resolution Multiplier, designers
1033          * should take care not to establish a potential Effective
1034          * Resolution Multiplier of zero."
1035          * HID Usage Table, v1.12, Section 4.3.1, p31
1036          */
1037         if (lmax - lmin == 0)
1038                 return 1;
1039         /*
1040          * Handling the unit exponent is left as an exercise to whoever
1041          * finds a device where that exponent is not 0.
1042          */
1043         m = ((v - lmin)/(lmax - lmin) * (pmax - pmin) + pmin);
1044         if (unlikely(multiplier->unit_exponent != 0)) {
1045                 hid_warn(hid,
1046                          "unsupported Resolution Multiplier unit exponent %d\n",
1047                          multiplier->unit_exponent);
1048         }
1049
1050         /* There are no devices with an effective multiplier > 255 */
1051         if (unlikely(m == 0 || m > 255 || m < -255)) {
1052                 hid_warn(hid, "unsupported Resolution Multiplier %d\n", m);
1053                 m = 1;
1054         }
1055
1056         return m;
1057 }
1058
1059 static void hid_apply_multiplier_to_field(struct hid_device *hid,
1060                                           struct hid_field *field,
1061                                           struct hid_collection *multiplier_collection,
1062                                           int effective_multiplier)
1063 {
1064         struct hid_collection *collection;
1065         struct hid_usage *usage;
1066         int i;
1067
1068         /*
1069          * If multiplier_collection is NULL, the multiplier applies
1070          * to all fields in the report.
1071          * Otherwise, it is the Logical Collection the multiplier applies to
1072          * but our field may be in a subcollection of that collection.
1073          */
1074         for (i = 0; i < field->maxusage; i++) {
1075                 usage = &field->usage[i];
1076
1077                 collection = &hid->collection[usage->collection_index];
1078                 while (collection->parent_idx != -1 &&
1079                        collection != multiplier_collection)
1080                         collection = &hid->collection[collection->parent_idx];
1081
1082                 if (collection->parent_idx != -1 ||
1083                     multiplier_collection == NULL)
1084                         usage->resolution_multiplier = effective_multiplier;
1085
1086         }
1087 }
1088
1089 static void hid_apply_multiplier(struct hid_device *hid,
1090                                  struct hid_field *multiplier)
1091 {
1092         struct hid_report_enum *rep_enum;
1093         struct hid_report *rep;
1094         struct hid_field *field;
1095         struct hid_collection *multiplier_collection;
1096         int effective_multiplier;
1097         int i;
1098
1099         /*
1100          * "The Resolution Multiplier control must be contained in the same
1101          * Logical Collection as the control(s) to which it is to be applied.
1102          * If no Resolution Multiplier is defined, then the Resolution
1103          * Multiplier defaults to 1.  If more than one control exists in a
1104          * Logical Collection, the Resolution Multiplier is associated with
1105          * all controls in the collection. If no Logical Collection is
1106          * defined, the Resolution Multiplier is associated with all
1107          * controls in the report."
1108          * HID Usage Table, v1.12, Section 4.3.1, p30
1109          *
1110          * Thus, search from the current collection upwards until we find a
1111          * logical collection. Then search all fields for that same parent
1112          * collection. Those are the fields the multiplier applies to.
1113          *
1114          * If we have more than one multiplier, it will overwrite the
1115          * applicable fields later.
1116          */
1117         multiplier_collection = &hid->collection[multiplier->usage->collection_index];
1118         while (multiplier_collection->parent_idx != -1 &&
1119                multiplier_collection->type != HID_COLLECTION_LOGICAL)
1120                 multiplier_collection = &hid->collection[multiplier_collection->parent_idx];
1121
1122         effective_multiplier = hid_calculate_multiplier(hid, multiplier);
1123
1124         rep_enum = &hid->report_enum[HID_INPUT_REPORT];
1125         list_for_each_entry(rep, &rep_enum->report_list, list) {
1126                 for (i = 0; i < rep->maxfield; i++) {
1127                         field = rep->field[i];
1128                         hid_apply_multiplier_to_field(hid, field,
1129                                                       multiplier_collection,
1130                                                       effective_multiplier);
1131                 }
1132         }
1133 }
1134
1135 /*
1136  * hid_setup_resolution_multiplier - set up all resolution multipliers
1137  *
1138  * @device: hid device
1139  *
1140  * Search for all Resolution Multiplier Feature Reports and apply their
1141  * value to all matching Input items. This only updates the internal struct
1142  * fields.
1143  *
1144  * The Resolution Multiplier is applied by the hardware. If the multiplier
1145  * is anything other than 1, the hardware will send pre-multiplied events
1146  * so that the same physical interaction generates an accumulated
1147  *      accumulated_value = value * * multiplier
1148  * This may be achieved by sending
1149  * - "value * multiplier" for each event, or
1150  * - "value" but "multiplier" times as frequently, or
1151  * - a combination of the above
1152  * The only guarantee is that the same physical interaction always generates
1153  * an accumulated 'value * multiplier'.
1154  *
1155  * This function must be called before any event processing and after
1156  * any SetRequest to the Resolution Multiplier.
1157  */
1158 void hid_setup_resolution_multiplier(struct hid_device *hid)
1159 {
1160         struct hid_report_enum *rep_enum;
1161         struct hid_report *rep;
1162         struct hid_usage *usage;
1163         int i, j;
1164
1165         rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
1166         list_for_each_entry(rep, &rep_enum->report_list, list) {
1167                 for (i = 0; i < rep->maxfield; i++) {
1168                         /* Ignore if report count is out of bounds. */
1169                         if (rep->field[i]->report_count < 1)
1170                                 continue;
1171
1172                         for (j = 0; j < rep->field[i]->maxusage; j++) {
1173                                 usage = &rep->field[i]->usage[j];
1174                                 if (usage->hid == HID_GD_RESOLUTION_MULTIPLIER)
1175                                         hid_apply_multiplier(hid,
1176                                                              rep->field[i]);
1177                         }
1178                 }
1179         }
1180 }
1181 EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier);
1182
1183 /**
1184  * hid_open_report - open a driver-specific device report
1185  *
1186  * @device: hid device
1187  *
1188  * Parse a report description into a hid_device structure. Reports are
1189  * enumerated, fields are attached to these reports.
1190  * 0 returned on success, otherwise nonzero error value.
1191  *
1192  * This function (or the equivalent hid_parse() macro) should only be
1193  * called from probe() in drivers, before starting the device.
1194  */
1195 int hid_open_report(struct hid_device *device)
1196 {
1197         struct hid_parser *parser;
1198         struct hid_item item;
1199         unsigned int size;
1200         __u8 *start;
1201         __u8 *buf;
1202         __u8 *end;
1203         __u8 *next;
1204         int ret;
1205         int i;
1206         static int (*dispatch_type[])(struct hid_parser *parser,
1207                                       struct hid_item *item) = {
1208                 hid_parser_main,
1209                 hid_parser_global,
1210                 hid_parser_local,
1211                 hid_parser_reserved
1212         };
1213
1214         if (WARN_ON(device->status & HID_STAT_PARSED))
1215                 return -EBUSY;
1216
1217         start = device->dev_rdesc;
1218         if (WARN_ON(!start))
1219                 return -ENODEV;
1220         size = device->dev_rsize;
1221
1222         /* call_hid_bpf_rdesc_fixup() ensures we work on a copy of rdesc */
1223         buf = call_hid_bpf_rdesc_fixup(device, start, &size);
1224         if (buf == NULL)
1225                 return -ENOMEM;
1226
1227         if (device->driver->report_fixup)
1228                 start = device->driver->report_fixup(device, buf, &size);
1229         else
1230                 start = buf;
1231
1232         start = kmemdup(start, size, GFP_KERNEL);
1233         kfree(buf);
1234         if (start == NULL)
1235                 return -ENOMEM;
1236
1237         device->rdesc = start;
1238         device->rsize = size;
1239
1240         parser = vzalloc(sizeof(struct hid_parser));
1241         if (!parser) {
1242                 ret = -ENOMEM;
1243                 goto alloc_err;
1244         }
1245
1246         parser->device = device;
1247
1248         end = start + size;
1249
1250         device->collection = kcalloc(HID_DEFAULT_NUM_COLLECTIONS,
1251                                      sizeof(struct hid_collection), GFP_KERNEL);
1252         if (!device->collection) {
1253                 ret = -ENOMEM;
1254                 goto err;
1255         }
1256         device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
1257         for (i = 0; i < HID_DEFAULT_NUM_COLLECTIONS; i++)
1258                 device->collection[i].parent_idx = -1;
1259
1260         ret = -EINVAL;
1261         while ((next = fetch_item(start, end, &item)) != NULL) {
1262                 start = next;
1263
1264                 if (item.format != HID_ITEM_FORMAT_SHORT) {
1265                         hid_err(device, "unexpected long global item\n");
1266                         goto err;
1267                 }
1268
1269                 if (dispatch_type[item.type](parser, &item)) {
1270                         hid_err(device, "item %u %u %u %u parsing failed\n",
1271                                 item.format, (unsigned)item.size,
1272                                 (unsigned)item.type, (unsigned)item.tag);
1273                         goto err;
1274                 }
1275
1276                 if (start == end) {
1277                         if (parser->collection_stack_ptr) {
1278                                 hid_err(device, "unbalanced collection at end of report description\n");
1279                                 goto err;
1280                         }
1281                         if (parser->local.delimiter_depth) {
1282                                 hid_err(device, "unbalanced delimiter at end of report description\n");
1283                                 goto err;
1284                         }
1285
1286                         /*
1287                          * fetch initial values in case the device's
1288                          * default multiplier isn't the recommended 1
1289                          */
1290                         hid_setup_resolution_multiplier(device);
1291
1292                         kfree(parser->collection_stack);
1293                         vfree(parser);
1294                         device->status |= HID_STAT_PARSED;
1295
1296                         return 0;
1297                 }
1298         }
1299
1300         hid_err(device, "item fetching failed at offset %u/%u\n",
1301                 size - (unsigned int)(end - start), size);
1302 err:
1303         kfree(parser->collection_stack);
1304 alloc_err:
1305         vfree(parser);
1306         hid_close_report(device);
1307         return ret;
1308 }
1309 EXPORT_SYMBOL_GPL(hid_open_report);
1310
1311 /*
1312  * Convert a signed n-bit integer to signed 32-bit integer. Common
1313  * cases are done through the compiler, the screwed things has to be
1314  * done by hand.
1315  */
1316
1317 static s32 snto32(__u32 value, unsigned n)
1318 {
1319         if (!value || !n)
1320                 return 0;
1321
1322         if (n > 32)
1323                 n = 32;
1324
1325         switch (n) {
1326         case 8:  return ((__s8)value);
1327         case 16: return ((__s16)value);
1328         case 32: return ((__s32)value);
1329         }
1330         return value & (1 << (n - 1)) ? value | (~0U << n) : value;
1331 }
1332
1333 s32 hid_snto32(__u32 value, unsigned n)
1334 {
1335         return snto32(value, n);
1336 }
1337 EXPORT_SYMBOL_GPL(hid_snto32);
1338
1339 /*
1340  * Convert a signed 32-bit integer to a signed n-bit integer.
1341  */
1342
1343 static u32 s32ton(__s32 value, unsigned n)
1344 {
1345         s32 a = value >> (n - 1);
1346         if (a && a != -1)
1347                 return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
1348         return value & ((1 << n) - 1);
1349 }
1350
1351 /*
1352  * Extract/implement a data field from/to a little endian report (bit array).
1353  *
1354  * Code sort-of follows HID spec:
1355  *     http://www.usb.org/developers/hidpage/HID1_11.pdf
1356  *
1357  * While the USB HID spec allows unlimited length bit fields in "report
1358  * descriptors", most devices never use more than 16 bits.
1359  * One model of UPS is claimed to report "LINEV" as a 32-bit field.
1360  * Search linux-kernel and linux-usb-devel archives for "hid-core extract".
1361  */
1362
1363 static u32 __extract(u8 *report, unsigned offset, int n)
1364 {
1365         unsigned int idx = offset / 8;
1366         unsigned int bit_nr = 0;
1367         unsigned int bit_shift = offset % 8;
1368         int bits_to_copy = 8 - bit_shift;
1369         u32 value = 0;
1370         u32 mask = n < 32 ? (1U << n) - 1 : ~0U;
1371
1372         while (n > 0) {
1373                 value |= ((u32)report[idx] >> bit_shift) << bit_nr;
1374                 n -= bits_to_copy;
1375                 bit_nr += bits_to_copy;
1376                 bits_to_copy = 8;
1377                 bit_shift = 0;
1378                 idx++;
1379         }
1380
1381         return value & mask;
1382 }
1383
1384 u32 hid_field_extract(const struct hid_device *hid, u8 *report,
1385                         unsigned offset, unsigned n)
1386 {
1387         if (n > 32) {
1388                 hid_warn_once(hid, "%s() called with n (%d) > 32! (%s)\n",
1389                               __func__, n, current->comm);
1390                 n = 32;
1391         }
1392
1393         return __extract(report, offset, n);
1394 }
1395 EXPORT_SYMBOL_GPL(hid_field_extract);
1396
1397 /*
1398  * "implement" : set bits in a little endian bit stream.
1399  * Same concepts as "extract" (see comments above).
1400  * The data mangled in the bit stream remains in little endian
1401  * order the whole time. It make more sense to talk about
1402  * endianness of register values by considering a register
1403  * a "cached" copy of the little endian bit stream.
1404  */
1405
1406 static void __implement(u8 *report, unsigned offset, int n, u32 value)
1407 {
1408         unsigned int idx = offset / 8;
1409         unsigned int bit_shift = offset % 8;
1410         int bits_to_set = 8 - bit_shift;
1411
1412         while (n - bits_to_set >= 0) {
1413                 report[idx] &= ~(0xff << bit_shift);
1414                 report[idx] |= value << bit_shift;
1415                 value >>= bits_to_set;
1416                 n -= bits_to_set;
1417                 bits_to_set = 8;
1418                 bit_shift = 0;
1419                 idx++;
1420         }
1421
1422         /* last nibble */
1423         if (n) {
1424                 u8 bit_mask = ((1U << n) - 1);
1425                 report[idx] &= ~(bit_mask << bit_shift);
1426                 report[idx] |= value << bit_shift;
1427         }
1428 }
1429
1430 static void implement(const struct hid_device *hid, u8 *report,
1431                       unsigned offset, unsigned n, u32 value)
1432 {
1433         if (unlikely(n > 32)) {
1434                 hid_warn(hid, "%s() called with n (%d) > 32! (%s)\n",
1435                          __func__, n, current->comm);
1436                 n = 32;
1437         } else if (n < 32) {
1438                 u32 m = (1U << n) - 1;
1439
1440                 if (unlikely(value > m)) {
1441                         hid_warn(hid,
1442                                  "%s() called with too large value %d (n: %d)! (%s)\n",
1443                                  __func__, value, n, current->comm);
1444                         WARN_ON(1);
1445                         value &= m;
1446                 }
1447         }
1448
1449         __implement(report, offset, n, value);
1450 }
1451
1452 /*
1453  * Search an array for a value.
1454  */
1455
1456 static int search(__s32 *array, __s32 value, unsigned n)
1457 {
1458         while (n--) {
1459                 if (*array++ == value)
1460                         return 0;
1461         }
1462         return -1;
1463 }
1464
1465 /**
1466  * hid_match_report - check if driver's raw_event should be called
1467  *
1468  * @hid: hid device
1469  * @report: hid report to match against
1470  *
1471  * compare hid->driver->report_table->report_type to report->type
1472  */
1473 static int hid_match_report(struct hid_device *hid, struct hid_report *report)
1474 {
1475         const struct hid_report_id *id = hid->driver->report_table;
1476
1477         if (!id) /* NULL means all */
1478                 return 1;
1479
1480         for (; id->report_type != HID_TERMINATOR; id++)
1481                 if (id->report_type == HID_ANY_ID ||
1482                                 id->report_type == report->type)
1483                         return 1;
1484         return 0;
1485 }
1486
1487 /**
1488  * hid_match_usage - check if driver's event should be called
1489  *
1490  * @hid: hid device
1491  * @usage: usage to match against
1492  *
1493  * compare hid->driver->usage_table->usage_{type,code} to
1494  * usage->usage_{type,code}
1495  */
1496 static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage)
1497 {
1498         const struct hid_usage_id *id = hid->driver->usage_table;
1499
1500         if (!id) /* NULL means all */
1501                 return 1;
1502
1503         for (; id->usage_type != HID_ANY_ID - 1; id++)
1504                 if ((id->usage_hid == HID_ANY_ID ||
1505                                 id->usage_hid == usage->hid) &&
1506                                 (id->usage_type == HID_ANY_ID ||
1507                                 id->usage_type == usage->type) &&
1508                                 (id->usage_code == HID_ANY_ID ||
1509                                  id->usage_code == usage->code))
1510                         return 1;
1511         return 0;
1512 }
1513
1514 static void hid_process_event(struct hid_device *hid, struct hid_field *field,
1515                 struct hid_usage *usage, __s32 value, int interrupt)
1516 {
1517         struct hid_driver *hdrv = hid->driver;
1518         int ret;
1519
1520         if (!list_empty(&hid->debug_list))
1521                 hid_dump_input(hid, usage, value);
1522
1523         if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
1524                 ret = hdrv->event(hid, field, usage, value);
1525                 if (ret != 0) {
1526                         if (ret < 0)
1527                                 hid_err(hid, "%s's event failed with %d\n",
1528                                                 hdrv->name, ret);
1529                         return;
1530                 }
1531         }
1532
1533         if (hid->claimed & HID_CLAIMED_INPUT)
1534                 hidinput_hid_event(hid, field, usage, value);
1535         if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
1536                 hid->hiddev_hid_event(hid, field, usage, value);
1537 }
1538
1539 /*
1540  * Checks if the given value is valid within this field
1541  */
1542 static inline int hid_array_value_is_valid(struct hid_field *field,
1543                                            __s32 value)
1544 {
1545         __s32 min = field->logical_minimum;
1546
1547         /*
1548          * Value needs to be between logical min and max, and
1549          * (value - min) is used as an index in the usage array.
1550          * This array is of size field->maxusage
1551          */
1552         return value >= min &&
1553                value <= field->logical_maximum &&
1554                value - min < field->maxusage;
1555 }
1556
1557 /*
1558  * Fetch the field from the data. The field content is stored for next
1559  * report processing (we do differential reporting to the layer).
1560  */
1561 static void hid_input_fetch_field(struct hid_device *hid,
1562                                   struct hid_field *field,
1563                                   __u8 *data)
1564 {
1565         unsigned n;
1566         unsigned count = field->report_count;
1567         unsigned offset = field->report_offset;
1568         unsigned size = field->report_size;
1569         __s32 min = field->logical_minimum;
1570         __s32 *value;
1571
1572         value = field->new_value;
1573         memset(value, 0, count * sizeof(__s32));
1574         field->ignored = false;
1575
1576         for (n = 0; n < count; n++) {
1577
1578                 value[n] = min < 0 ?
1579                         snto32(hid_field_extract(hid, data, offset + n * size,
1580                                size), size) :
1581                         hid_field_extract(hid, data, offset + n * size, size);
1582
1583                 /* Ignore report if ErrorRollOver */
1584                 if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
1585                     hid_array_value_is_valid(field, value[n]) &&
1586                     field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1) {
1587                         field->ignored = true;
1588                         return;
1589                 }
1590         }
1591 }
1592
1593 /*
1594  * Process a received variable field.
1595  */
1596
1597 static void hid_input_var_field(struct hid_device *hid,
1598                                 struct hid_field *field,
1599                                 int interrupt)
1600 {
1601         unsigned int count = field->report_count;
1602         __s32 *value = field->new_value;
1603         unsigned int n;
1604
1605         for (n = 0; n < count; n++)
1606                 hid_process_event(hid,
1607                                   field,
1608                                   &field->usage[n],
1609                                   value[n],
1610                                   interrupt);
1611
1612         memcpy(field->value, value, count * sizeof(__s32));
1613 }
1614
1615 /*
1616  * Process a received array field. The field content is stored for
1617  * next report processing (we do differential reporting to the layer).
1618  */
1619
1620 static void hid_input_array_field(struct hid_device *hid,
1621                                   struct hid_field *field,
1622                                   int interrupt)
1623 {
1624         unsigned int n;
1625         unsigned int count = field->report_count;
1626         __s32 min = field->logical_minimum;
1627         __s32 *value;
1628
1629         value = field->new_value;
1630
1631         /* ErrorRollOver */
1632         if (field->ignored)
1633                 return;
1634
1635         for (n = 0; n < count; n++) {
1636                 if (hid_array_value_is_valid(field, field->value[n]) &&
1637                     search(value, field->value[n], count))
1638                         hid_process_event(hid,
1639                                           field,
1640                                           &field->usage[field->value[n] - min],
1641                                           0,
1642                                           interrupt);
1643
1644                 if (hid_array_value_is_valid(field, value[n]) &&
1645                     search(field->value, value[n], count))
1646                         hid_process_event(hid,
1647                                           field,
1648                                           &field->usage[value[n] - min],
1649                                           1,
1650                                           interrupt);
1651         }
1652
1653         memcpy(field->value, value, count * sizeof(__s32));
1654 }
1655
1656 /*
1657  * Analyse a received report, and fetch the data from it. The field
1658  * content is stored for next report processing (we do differential
1659  * reporting to the layer).
1660  */
1661 static void hid_process_report(struct hid_device *hid,
1662                                struct hid_report *report,
1663                                __u8 *data,
1664                                int interrupt)
1665 {
1666         unsigned int a;
1667         struct hid_field_entry *entry;
1668         struct hid_field *field;
1669
1670         /* first retrieve all incoming values in data */
1671         for (a = 0; a < report->maxfield; a++)
1672                 hid_input_fetch_field(hid, report->field[a], data);
1673
1674         if (!list_empty(&report->field_entry_list)) {
1675                 /* INPUT_REPORT, we have a priority list of fields */
1676                 list_for_each_entry(entry,
1677                                     &report->field_entry_list,
1678                                     list) {
1679                         field = entry->field;
1680
1681                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1682                                 hid_process_event(hid,
1683                                                   field,
1684                                                   &field->usage[entry->index],
1685                                                   field->new_value[entry->index],
1686                                                   interrupt);
1687                         else
1688                                 hid_input_array_field(hid, field, interrupt);
1689                 }
1690
1691                 /* we need to do the memcpy at the end for var items */
1692                 for (a = 0; a < report->maxfield; a++) {
1693                         field = report->field[a];
1694
1695                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1696                                 memcpy(field->value, field->new_value,
1697                                        field->report_count * sizeof(__s32));
1698                 }
1699         } else {
1700                 /* FEATURE_REPORT, regular processing */
1701                 for (a = 0; a < report->maxfield; a++) {
1702                         field = report->field[a];
1703
1704                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1705                                 hid_input_var_field(hid, field, interrupt);
1706                         else
1707                                 hid_input_array_field(hid, field, interrupt);
1708                 }
1709         }
1710 }
1711
1712 /*
1713  * Insert a given usage_index in a field in the list
1714  * of processed usages in the report.
1715  *
1716  * The elements of lower priority score are processed
1717  * first.
1718  */
1719 static void __hid_insert_field_entry(struct hid_device *hid,
1720                                      struct hid_report *report,
1721                                      struct hid_field_entry *entry,
1722                                      struct hid_field *field,
1723                                      unsigned int usage_index)
1724 {
1725         struct hid_field_entry *next;
1726
1727         entry->field = field;
1728         entry->index = usage_index;
1729         entry->priority = field->usages_priorities[usage_index];
1730
1731         /* insert the element at the correct position */
1732         list_for_each_entry(next,
1733                             &report->field_entry_list,
1734                             list) {
1735                 /*
1736                  * the priority of our element is strictly higher
1737                  * than the next one, insert it before
1738                  */
1739                 if (entry->priority > next->priority) {
1740                         list_add_tail(&entry->list, &next->list);
1741                         return;
1742                 }
1743         }
1744
1745         /* lowest priority score: insert at the end */
1746         list_add_tail(&entry->list, &report->field_entry_list);
1747 }
1748
1749 static void hid_report_process_ordering(struct hid_device *hid,
1750                                         struct hid_report *report)
1751 {
1752         struct hid_field *field;
1753         struct hid_field_entry *entries;
1754         unsigned int a, u, usages;
1755         unsigned int count = 0;
1756
1757         /* count the number of individual fields in the report */
1758         for (a = 0; a < report->maxfield; a++) {
1759                 field = report->field[a];
1760
1761                 if (field->flags & HID_MAIN_ITEM_VARIABLE)
1762                         count += field->report_count;
1763                 else
1764                         count++;
1765         }
1766
1767         /* allocate the memory to process the fields */
1768         entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
1769         if (!entries)
1770                 return;
1771
1772         report->field_entries = entries;
1773
1774         /*
1775          * walk through all fields in the report and
1776          * store them by priority order in report->field_entry_list
1777          *
1778          * - Var elements are individualized (field + usage_index)
1779          * - Arrays are taken as one, we can not chose an order for them
1780          */
1781         usages = 0;
1782         for (a = 0; a < report->maxfield; a++) {
1783                 field = report->field[a];
1784
1785                 if (field->flags & HID_MAIN_ITEM_VARIABLE) {
1786                         for (u = 0; u < field->report_count; u++) {
1787                                 __hid_insert_field_entry(hid, report,
1788                                                          &entries[usages],
1789                                                          field, u);
1790                                 usages++;
1791                         }
1792                 } else {
1793                         __hid_insert_field_entry(hid, report, &entries[usages],
1794                                                  field, 0);
1795                         usages++;
1796                 }
1797         }
1798 }
1799
1800 static void hid_process_ordering(struct hid_device *hid)
1801 {
1802         struct hid_report *report;
1803         struct hid_report_enum *report_enum = &hid->report_enum[HID_INPUT_REPORT];
1804
1805         list_for_each_entry(report, &report_enum->report_list, list)
1806                 hid_report_process_ordering(hid, report);
1807 }
1808
1809 /*
1810  * Output the field into the report.
1811  */
1812
1813 static void hid_output_field(const struct hid_device *hid,
1814                              struct hid_field *field, __u8 *data)
1815 {
1816         unsigned count = field->report_count;
1817         unsigned offset = field->report_offset;
1818         unsigned size = field->report_size;
1819         unsigned n;
1820
1821         for (n = 0; n < count; n++) {
1822                 if (field->logical_minimum < 0) /* signed values */
1823                         implement(hid, data, offset + n * size, size,
1824                                   s32ton(field->value[n], size));
1825                 else                            /* unsigned values */
1826                         implement(hid, data, offset + n * size, size,
1827                                   field->value[n]);
1828         }
1829 }
1830
1831 /*
1832  * Compute the size of a report.
1833  */
1834 static size_t hid_compute_report_size(struct hid_report *report)
1835 {
1836         if (report->size)
1837                 return ((report->size - 1) >> 3) + 1;
1838
1839         return 0;
1840 }
1841
1842 /*
1843  * Create a report. 'data' has to be allocated using
1844  * hid_alloc_report_buf() so that it has proper size.
1845  */
1846
1847 void hid_output_report(struct hid_report *report, __u8 *data)
1848 {
1849         unsigned n;
1850
1851         if (report->id > 0)
1852                 *data++ = report->id;
1853
1854         memset(data, 0, hid_compute_report_size(report));
1855         for (n = 0; n < report->maxfield; n++)
1856                 hid_output_field(report->device, report->field[n], data);
1857 }
1858 EXPORT_SYMBOL_GPL(hid_output_report);
1859
1860 /*
1861  * Allocator for buffer that is going to be passed to hid_output_report()
1862  */
1863 u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
1864 {
1865         /*
1866          * 7 extra bytes are necessary to achieve proper functionality
1867          * of implement() working on 8 byte chunks
1868          */
1869
1870         u32 len = hid_report_len(report) + 7;
1871
1872         return kmalloc(len, flags);
1873 }
1874 EXPORT_SYMBOL_GPL(hid_alloc_report_buf);
1875
1876 /*
1877  * Set a field value. The report this field belongs to has to be
1878  * created and transferred to the device, to set this value in the
1879  * device.
1880  */
1881
1882 int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
1883 {
1884         unsigned size;
1885
1886         if (!field)
1887                 return -1;
1888
1889         size = field->report_size;
1890
1891         hid_dump_input(field->report->device, field->usage + offset, value);
1892
1893         if (offset >= field->report_count) {
1894                 hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n",
1895                                 offset, field->report_count);
1896                 return -1;
1897         }
1898         if (field->logical_minimum < 0) {
1899                 if (value != snto32(s32ton(value, size), size)) {
1900                         hid_err(field->report->device, "value %d is out of range\n", value);
1901                         return -1;
1902                 }
1903         }
1904         field->value[offset] = value;
1905         return 0;
1906 }
1907 EXPORT_SYMBOL_GPL(hid_set_field);
1908
1909 static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
1910                 const u8 *data)
1911 {
1912         struct hid_report *report;
1913         unsigned int n = 0;     /* Normally report number is 0 */
1914
1915         /* Device uses numbered reports, data[0] is report number */
1916         if (report_enum->numbered)
1917                 n = *data;
1918
1919         report = report_enum->report_id_hash[n];
1920         if (report == NULL)
1921                 dbg_hid("undefined report_id %u received\n", n);
1922
1923         return report;
1924 }
1925
1926 /*
1927  * Implement a generic .request() callback, using .raw_request()
1928  * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
1929  */
1930 int __hid_request(struct hid_device *hid, struct hid_report *report,
1931                 enum hid_class_request reqtype)
1932 {
1933         char *buf;
1934         int ret;
1935         u32 len;
1936
1937         buf = hid_alloc_report_buf(report, GFP_KERNEL);
1938         if (!buf)
1939                 return -ENOMEM;
1940
1941         len = hid_report_len(report);
1942
1943         if (reqtype == HID_REQ_SET_REPORT)
1944                 hid_output_report(report, buf);
1945
1946         ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
1947                                           report->type, reqtype);
1948         if (ret < 0) {
1949                 dbg_hid("unable to complete request: %d\n", ret);
1950                 goto out;
1951         }
1952
1953         if (reqtype == HID_REQ_GET_REPORT)
1954                 hid_input_report(hid, report->type, buf, ret, 0);
1955
1956         ret = 0;
1957
1958 out:
1959         kfree(buf);
1960         return ret;
1961 }
1962 EXPORT_SYMBOL_GPL(__hid_request);
1963
1964 int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
1965                          int interrupt)
1966 {
1967         struct hid_report_enum *report_enum = hid->report_enum + type;
1968         struct hid_report *report;
1969         struct hid_driver *hdrv;
1970         int max_buffer_size = HID_MAX_BUFFER_SIZE;
1971         u32 rsize, csize = size;
1972         u8 *cdata = data;
1973         int ret = 0;
1974
1975         report = hid_get_report(report_enum, data);
1976         if (!report)
1977                 goto out;
1978
1979         if (report_enum->numbered) {
1980                 cdata++;
1981                 csize--;
1982         }
1983
1984         rsize = hid_compute_report_size(report);
1985
1986         if (hid->ll_driver->max_buffer_size)
1987                 max_buffer_size = hid->ll_driver->max_buffer_size;
1988
1989         if (report_enum->numbered && rsize >= max_buffer_size)
1990                 rsize = max_buffer_size - 1;
1991         else if (rsize > max_buffer_size)
1992                 rsize = max_buffer_size;
1993
1994         if (csize < rsize) {
1995                 dbg_hid("report %d is too short, (%d < %d)\n", report->id,
1996                                 csize, rsize);
1997                 memset(cdata + csize, 0, rsize - csize);
1998         }
1999
2000         if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
2001                 hid->hiddev_report_event(hid, report);
2002         if (hid->claimed & HID_CLAIMED_HIDRAW) {
2003                 ret = hidraw_report_event(hid, data, size);
2004                 if (ret)
2005                         goto out;
2006         }
2007
2008         if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
2009                 hid_process_report(hid, report, cdata, interrupt);
2010                 hdrv = hid->driver;
2011                 if (hdrv && hdrv->report)
2012                         hdrv->report(hid, report);
2013         }
2014
2015         if (hid->claimed & HID_CLAIMED_INPUT)
2016                 hidinput_report_event(hid, report);
2017 out:
2018         return ret;
2019 }
2020 EXPORT_SYMBOL_GPL(hid_report_raw_event);
2021
2022 /**
2023  * hid_input_report - report data from lower layer (usb, bt...)
2024  *
2025  * @hid: hid device
2026  * @type: HID report type (HID_*_REPORT)
2027  * @data: report contents
2028  * @size: size of data parameter
2029  * @interrupt: distinguish between interrupt and control transfers
2030  *
2031  * This is data entry for lower layers.
2032  */
2033 int hid_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
2034                      int interrupt)
2035 {
2036         struct hid_report_enum *report_enum;
2037         struct hid_driver *hdrv;
2038         struct hid_report *report;
2039         int ret = 0;
2040
2041         if (!hid)
2042                 return -ENODEV;
2043
2044         if (down_trylock(&hid->driver_input_lock))
2045                 return -EBUSY;
2046
2047         if (!hid->driver) {
2048                 ret = -ENODEV;
2049                 goto unlock;
2050         }
2051         report_enum = hid->report_enum + type;
2052         hdrv = hid->driver;
2053
2054         data = dispatch_hid_bpf_device_event(hid, type, data, &size, interrupt);
2055         if (IS_ERR(data)) {
2056                 ret = PTR_ERR(data);
2057                 goto unlock;
2058         }
2059
2060         if (!size) {
2061                 dbg_hid("empty report\n");
2062                 ret = -1;
2063                 goto unlock;
2064         }
2065
2066         /* Avoid unnecessary overhead if debugfs is disabled */
2067         if (!list_empty(&hid->debug_list))
2068                 hid_dump_report(hid, type, data, size);
2069
2070         report = hid_get_report(report_enum, data);
2071
2072         if (!report) {
2073                 ret = -1;
2074                 goto unlock;
2075         }
2076
2077         if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
2078                 ret = hdrv->raw_event(hid, report, data, size);
2079                 if (ret < 0)
2080                         goto unlock;
2081         }
2082
2083         ret = hid_report_raw_event(hid, type, data, size, interrupt);
2084
2085 unlock:
2086         up(&hid->driver_input_lock);
2087         return ret;
2088 }
2089 EXPORT_SYMBOL_GPL(hid_input_report);
2090
2091 bool hid_match_one_id(const struct hid_device *hdev,
2092                       const struct hid_device_id *id)
2093 {
2094         return (id->bus == HID_BUS_ANY || id->bus == hdev->bus) &&
2095                 (id->group == HID_GROUP_ANY || id->group == hdev->group) &&
2096                 (id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&
2097                 (id->product == HID_ANY_ID || id->product == hdev->product);
2098 }
2099
2100 const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
2101                 const struct hid_device_id *id)
2102 {
2103         for (; id->bus; id++)
2104                 if (hid_match_one_id(hdev, id))
2105                         return id;
2106
2107         return NULL;
2108 }
2109 EXPORT_SYMBOL_GPL(hid_match_id);
2110
2111 static const struct hid_device_id hid_hiddev_list[] = {
2112         { HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS) },
2113         { HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS1) },
2114         { }
2115 };
2116
2117 static bool hid_hiddev(struct hid_device *hdev)
2118 {
2119         return !!hid_match_id(hdev, hid_hiddev_list);
2120 }
2121
2122
2123 static ssize_t
2124 read_report_descriptor(struct file *filp, struct kobject *kobj,
2125                 struct bin_attribute *attr,
2126                 char *buf, loff_t off, size_t count)
2127 {
2128         struct device *dev = kobj_to_dev(kobj);
2129         struct hid_device *hdev = to_hid_device(dev);
2130
2131         if (off >= hdev->rsize)
2132                 return 0;
2133
2134         if (off + count > hdev->rsize)
2135                 count = hdev->rsize - off;
2136
2137         memcpy(buf, hdev->rdesc + off, count);
2138
2139         return count;
2140 }
2141
2142 static ssize_t
2143 show_country(struct device *dev, struct device_attribute *attr,
2144                 char *buf)
2145 {
2146         struct hid_device *hdev = to_hid_device(dev);
2147
2148         return sprintf(buf, "%02x\n", hdev->country & 0xff);
2149 }
2150
2151 static struct bin_attribute dev_bin_attr_report_desc = {
2152         .attr = { .name = "report_descriptor", .mode = 0444 },
2153         .read = read_report_descriptor,
2154         .size = HID_MAX_DESCRIPTOR_SIZE,
2155 };
2156
2157 static const struct device_attribute dev_attr_country = {
2158         .attr = { .name = "country", .mode = 0444 },
2159         .show = show_country,
2160 };
2161
2162 int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
2163 {
2164         static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
2165                 "Joystick", "Gamepad", "Keyboard", "Keypad",
2166                 "Multi-Axis Controller"
2167         };
2168         const char *type, *bus;
2169         char buf[64] = "";
2170         unsigned int i;
2171         int len;
2172         int ret;
2173
2174         ret = hid_bpf_connect_device(hdev);
2175         if (ret)
2176                 return ret;
2177
2178         if (hdev->quirks & HID_QUIRK_HIDDEV_FORCE)
2179                 connect_mask |= (HID_CONNECT_HIDDEV_FORCE | HID_CONNECT_HIDDEV);
2180         if (hdev->quirks & HID_QUIRK_HIDINPUT_FORCE)
2181                 connect_mask |= HID_CONNECT_HIDINPUT_FORCE;
2182         if (hdev->bus != BUS_USB)
2183                 connect_mask &= ~HID_CONNECT_HIDDEV;
2184         if (hid_hiddev(hdev))
2185                 connect_mask |= HID_CONNECT_HIDDEV_FORCE;
2186
2187         if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,
2188                                 connect_mask & HID_CONNECT_HIDINPUT_FORCE))
2189                 hdev->claimed |= HID_CLAIMED_INPUT;
2190
2191         if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect &&
2192                         !hdev->hiddev_connect(hdev,
2193                                 connect_mask & HID_CONNECT_HIDDEV_FORCE))
2194                 hdev->claimed |= HID_CLAIMED_HIDDEV;
2195         if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))
2196                 hdev->claimed |= HID_CLAIMED_HIDRAW;
2197
2198         if (connect_mask & HID_CONNECT_DRIVER)
2199                 hdev->claimed |= HID_CLAIMED_DRIVER;
2200
2201         /* Drivers with the ->raw_event callback set are not required to connect
2202          * to any other listener. */
2203         if (!hdev->claimed && !hdev->driver->raw_event) {
2204                 hid_err(hdev, "device has no listeners, quitting\n");
2205                 return -ENODEV;
2206         }
2207
2208         hid_process_ordering(hdev);
2209
2210         if ((hdev->claimed & HID_CLAIMED_INPUT) &&
2211                         (connect_mask & HID_CONNECT_FF) && hdev->ff_init)
2212                 hdev->ff_init(hdev);
2213
2214         len = 0;
2215         if (hdev->claimed & HID_CLAIMED_INPUT)
2216                 len += sprintf(buf + len, "input");
2217         if (hdev->claimed & HID_CLAIMED_HIDDEV)
2218                 len += sprintf(buf + len, "%shiddev%d", len ? "," : "",
2219                                 ((struct hiddev *)hdev->hiddev)->minor);
2220         if (hdev->claimed & HID_CLAIMED_HIDRAW)
2221                 len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
2222                                 ((struct hidraw *)hdev->hidraw)->minor);
2223
2224         type = "Device";
2225         for (i = 0; i < hdev->maxcollection; i++) {
2226                 struct hid_collection *col = &hdev->collection[i];
2227                 if (col->type == HID_COLLECTION_APPLICATION &&
2228                    (col->usage & HID_USAGE_PAGE) == HID_UP_GENDESK &&
2229                    (col->usage & 0xffff) < ARRAY_SIZE(types)) {
2230                         type = types[col->usage & 0xffff];
2231                         break;
2232                 }
2233         }
2234
2235         switch (hdev->bus) {
2236         case BUS_USB:
2237                 bus = "USB";
2238                 break;
2239         case BUS_BLUETOOTH:
2240                 bus = "BLUETOOTH";
2241                 break;
2242         case BUS_I2C:
2243                 bus = "I2C";
2244                 break;
2245         case BUS_VIRTUAL:
2246                 bus = "VIRTUAL";
2247                 break;
2248         case BUS_INTEL_ISHTP:
2249         case BUS_AMD_SFH:
2250                 bus = "SENSOR HUB";
2251                 break;
2252         default:
2253                 bus = "<UNKNOWN>";
2254         }
2255
2256         ret = device_create_file(&hdev->dev, &dev_attr_country);
2257         if (ret)
2258                 hid_warn(hdev,
2259                          "can't create sysfs country code attribute err: %d\n", ret);
2260
2261         hid_info(hdev, "%s: %s HID v%x.%02x %s [%s] on %s\n",
2262                  buf, bus, hdev->version >> 8, hdev->version & 0xff,
2263                  type, hdev->name, hdev->phys);
2264
2265         return 0;
2266 }
2267 EXPORT_SYMBOL_GPL(hid_connect);
2268
2269 void hid_disconnect(struct hid_device *hdev)
2270 {
2271         device_remove_file(&hdev->dev, &dev_attr_country);
2272         if (hdev->claimed & HID_CLAIMED_INPUT)
2273                 hidinput_disconnect(hdev);
2274         if (hdev->claimed & HID_CLAIMED_HIDDEV)
2275                 hdev->hiddev_disconnect(hdev);
2276         if (hdev->claimed & HID_CLAIMED_HIDRAW)
2277                 hidraw_disconnect(hdev);
2278         hdev->claimed = 0;
2279
2280         hid_bpf_disconnect_device(hdev);
2281 }
2282 EXPORT_SYMBOL_GPL(hid_disconnect);
2283
2284 /**
2285  * hid_hw_start - start underlying HW
2286  * @hdev: hid device
2287  * @connect_mask: which outputs to connect, see HID_CONNECT_*
2288  *
2289  * Call this in probe function *after* hid_parse. This will setup HW
2290  * buffers and start the device (if not defeirred to device open).
2291  * hid_hw_stop must be called if this was successful.
2292  */
2293 int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask)
2294 {
2295         int error;
2296
2297         error = hdev->ll_driver->start(hdev);
2298         if (error)
2299                 return error;
2300
2301         if (connect_mask) {
2302                 error = hid_connect(hdev, connect_mask);
2303                 if (error) {
2304                         hdev->ll_driver->stop(hdev);
2305                         return error;
2306                 }
2307         }
2308
2309         return 0;
2310 }
2311 EXPORT_SYMBOL_GPL(hid_hw_start);
2312
2313 /**
2314  * hid_hw_stop - stop underlying HW
2315  * @hdev: hid device
2316  *
2317  * This is usually called from remove function or from probe when something
2318  * failed and hid_hw_start was called already.
2319  */
2320 void hid_hw_stop(struct hid_device *hdev)
2321 {
2322         hid_disconnect(hdev);
2323         hdev->ll_driver->stop(hdev);
2324 }
2325 EXPORT_SYMBOL_GPL(hid_hw_stop);
2326
2327 /**
2328  * hid_hw_open - signal underlying HW to start delivering events
2329  * @hdev: hid device
2330  *
2331  * Tell underlying HW to start delivering events from the device.
2332  * This function should be called sometime after successful call
2333  * to hid_hw_start().
2334  */
2335 int hid_hw_open(struct hid_device *hdev)
2336 {
2337         int ret;
2338
2339         ret = mutex_lock_killable(&hdev->ll_open_lock);
2340         if (ret)
2341                 return ret;
2342
2343         if (!hdev->ll_open_count++) {
2344                 ret = hdev->ll_driver->open(hdev);
2345                 if (ret)
2346                         hdev->ll_open_count--;
2347         }
2348
2349         mutex_unlock(&hdev->ll_open_lock);
2350         return ret;
2351 }
2352 EXPORT_SYMBOL_GPL(hid_hw_open);
2353
2354 /**
2355  * hid_hw_close - signal underlaying HW to stop delivering events
2356  *
2357  * @hdev: hid device
2358  *
2359  * This function indicates that we are not interested in the events
2360  * from this device anymore. Delivery of events may or may not stop,
2361  * depending on the number of users still outstanding.
2362  */
2363 void hid_hw_close(struct hid_device *hdev)
2364 {
2365         mutex_lock(&hdev->ll_open_lock);
2366         if (!--hdev->ll_open_count)
2367                 hdev->ll_driver->close(hdev);
2368         mutex_unlock(&hdev->ll_open_lock);
2369 }
2370 EXPORT_SYMBOL_GPL(hid_hw_close);
2371
2372 /**
2373  * hid_hw_request - send report request to device
2374  *
2375  * @hdev: hid device
2376  * @report: report to send
2377  * @reqtype: hid request type
2378  */
2379 void hid_hw_request(struct hid_device *hdev,
2380                     struct hid_report *report, enum hid_class_request reqtype)
2381 {
2382         if (hdev->ll_driver->request)
2383                 return hdev->ll_driver->request(hdev, report, reqtype);
2384
2385         __hid_request(hdev, report, reqtype);
2386 }
2387 EXPORT_SYMBOL_GPL(hid_hw_request);
2388
2389 /**
2390  * hid_hw_raw_request - send report request to device
2391  *
2392  * @hdev: hid device
2393  * @reportnum: report ID
2394  * @buf: in/out data to transfer
2395  * @len: length of buf
2396  * @rtype: HID report type
2397  * @reqtype: HID_REQ_GET_REPORT or HID_REQ_SET_REPORT
2398  *
2399  * Return: count of data transferred, negative if error
2400  *
2401  * Same behavior as hid_hw_request, but with raw buffers instead.
2402  */
2403 int hid_hw_raw_request(struct hid_device *hdev,
2404                        unsigned char reportnum, __u8 *buf,
2405                        size_t len, enum hid_report_type rtype, enum hid_class_request reqtype)
2406 {
2407         unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
2408
2409         if (hdev->ll_driver->max_buffer_size)
2410                 max_buffer_size = hdev->ll_driver->max_buffer_size;
2411
2412         if (len < 1 || len > max_buffer_size || !buf)
2413                 return -EINVAL;
2414
2415         return hdev->ll_driver->raw_request(hdev, reportnum, buf, len,
2416                                             rtype, reqtype);
2417 }
2418 EXPORT_SYMBOL_GPL(hid_hw_raw_request);
2419
2420 /**
2421  * hid_hw_output_report - send output report to device
2422  *
2423  * @hdev: hid device
2424  * @buf: raw data to transfer
2425  * @len: length of buf
2426  *
2427  * Return: count of data transferred, negative if error
2428  */
2429 int hid_hw_output_report(struct hid_device *hdev, __u8 *buf, size_t len)
2430 {
2431         unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
2432
2433         if (hdev->ll_driver->max_buffer_size)
2434                 max_buffer_size = hdev->ll_driver->max_buffer_size;
2435
2436         if (len < 1 || len > max_buffer_size || !buf)
2437                 return -EINVAL;
2438
2439         if (hdev->ll_driver->output_report)
2440                 return hdev->ll_driver->output_report(hdev, buf, len);
2441
2442         return -ENOSYS;
2443 }
2444 EXPORT_SYMBOL_GPL(hid_hw_output_report);
2445
2446 #ifdef CONFIG_PM
2447 int hid_driver_suspend(struct hid_device *hdev, pm_message_t state)
2448 {
2449         if (hdev->driver && hdev->driver->suspend)
2450                 return hdev->driver->suspend(hdev, state);
2451
2452         return 0;
2453 }
2454 EXPORT_SYMBOL_GPL(hid_driver_suspend);
2455
2456 int hid_driver_reset_resume(struct hid_device *hdev)
2457 {
2458         if (hdev->driver && hdev->driver->reset_resume)
2459                 return hdev->driver->reset_resume(hdev);
2460
2461         return 0;
2462 }
2463 EXPORT_SYMBOL_GPL(hid_driver_reset_resume);
2464
2465 int hid_driver_resume(struct hid_device *hdev)
2466 {
2467         if (hdev->driver && hdev->driver->resume)
2468                 return hdev->driver->resume(hdev);
2469
2470         return 0;
2471 }
2472 EXPORT_SYMBOL_GPL(hid_driver_resume);
2473 #endif /* CONFIG_PM */
2474
2475 struct hid_dynid {
2476         struct list_head list;
2477         struct hid_device_id id;
2478 };
2479
2480 /**
2481  * new_id_store - add a new HID device ID to this driver and re-probe devices
2482  * @drv: target device driver
2483  * @buf: buffer for scanning device ID data
2484  * @count: input size
2485  *
2486  * Adds a new dynamic hid device ID to this driver,
2487  * and causes the driver to probe for all devices again.
2488  */
2489 static ssize_t new_id_store(struct device_driver *drv, const char *buf,
2490                 size_t count)
2491 {
2492         struct hid_driver *hdrv = to_hid_driver(drv);
2493         struct hid_dynid *dynid;
2494         __u32 bus, vendor, product;
2495         unsigned long driver_data = 0;
2496         int ret;
2497
2498         ret = sscanf(buf, "%x %x %x %lx",
2499                         &bus, &vendor, &product, &driver_data);
2500         if (ret < 3)
2501                 return -EINVAL;
2502
2503         dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
2504         if (!dynid)
2505                 return -ENOMEM;
2506
2507         dynid->id.bus = bus;
2508         dynid->id.group = HID_GROUP_ANY;
2509         dynid->id.vendor = vendor;
2510         dynid->id.product = product;
2511         dynid->id.driver_data = driver_data;
2512
2513         spin_lock(&hdrv->dyn_lock);
2514         list_add_tail(&dynid->list, &hdrv->dyn_list);
2515         spin_unlock(&hdrv->dyn_lock);
2516
2517         ret = driver_attach(&hdrv->driver);
2518
2519         return ret ? : count;
2520 }
2521 static DRIVER_ATTR_WO(new_id);
2522
2523 static struct attribute *hid_drv_attrs[] = {
2524         &driver_attr_new_id.attr,
2525         NULL,
2526 };
2527 ATTRIBUTE_GROUPS(hid_drv);
2528
2529 static void hid_free_dynids(struct hid_driver *hdrv)
2530 {
2531         struct hid_dynid *dynid, *n;
2532
2533         spin_lock(&hdrv->dyn_lock);
2534         list_for_each_entry_safe(dynid, n, &hdrv->dyn_list, list) {
2535                 list_del(&dynid->list);
2536                 kfree(dynid);
2537         }
2538         spin_unlock(&hdrv->dyn_lock);
2539 }
2540
2541 const struct hid_device_id *hid_match_device(struct hid_device *hdev,
2542                                              struct hid_driver *hdrv)
2543 {
2544         struct hid_dynid *dynid;
2545
2546         spin_lock(&hdrv->dyn_lock);
2547         list_for_each_entry(dynid, &hdrv->dyn_list, list) {
2548                 if (hid_match_one_id(hdev, &dynid->id)) {
2549                         spin_unlock(&hdrv->dyn_lock);
2550                         return &dynid->id;
2551                 }
2552         }
2553         spin_unlock(&hdrv->dyn_lock);
2554
2555         return hid_match_id(hdev, hdrv->id_table);
2556 }
2557 EXPORT_SYMBOL_GPL(hid_match_device);
2558
2559 static int hid_bus_match(struct device *dev, struct device_driver *drv)
2560 {
2561         struct hid_driver *hdrv = to_hid_driver(drv);
2562         struct hid_device *hdev = to_hid_device(dev);
2563
2564         return hid_match_device(hdev, hdrv) != NULL;
2565 }
2566
2567 /**
2568  * hid_compare_device_paths - check if both devices share the same path
2569  * @hdev_a: hid device
2570  * @hdev_b: hid device
2571  * @separator: char to use as separator
2572  *
2573  * Check if two devices share the same path up to the last occurrence of
2574  * the separator char. Both paths must exist (i.e., zero-length paths
2575  * don't match).
2576  */
2577 bool hid_compare_device_paths(struct hid_device *hdev_a,
2578                               struct hid_device *hdev_b, char separator)
2579 {
2580         int n1 = strrchr(hdev_a->phys, separator) - hdev_a->phys;
2581         int n2 = strrchr(hdev_b->phys, separator) - hdev_b->phys;
2582
2583         if (n1 != n2 || n1 <= 0 || n2 <= 0)
2584                 return false;
2585
2586         return !strncmp(hdev_a->phys, hdev_b->phys, n1);
2587 }
2588 EXPORT_SYMBOL_GPL(hid_compare_device_paths);
2589
2590 static int hid_device_probe(struct device *dev)
2591 {
2592         struct hid_driver *hdrv = to_hid_driver(dev->driver);
2593         struct hid_device *hdev = to_hid_device(dev);
2594         const struct hid_device_id *id;
2595         int ret = 0;
2596
2597         if (down_interruptible(&hdev->driver_input_lock)) {
2598                 ret = -EINTR;
2599                 goto end;
2600         }
2601         hdev->io_started = false;
2602
2603         clear_bit(ffs(HID_STAT_REPROBED), &hdev->status);
2604
2605         if (!hdev->driver) {
2606                 id = hid_match_device(hdev, hdrv);
2607                 if (id == NULL) {
2608                         ret = -ENODEV;
2609                         goto unlock;
2610                 }
2611
2612                 if (hdrv->match) {
2613                         if (!hdrv->match(hdev, hid_ignore_special_drivers)) {
2614                                 ret = -ENODEV;
2615                                 goto unlock;
2616                         }
2617                 } else {
2618                         /*
2619                          * hid-generic implements .match(), so if
2620                          * hid_ignore_special_drivers is set, we can safely
2621                          * return.
2622                          */
2623                         if (hid_ignore_special_drivers) {
2624                                 ret = -ENODEV;
2625                                 goto unlock;
2626                         }
2627                 }
2628
2629                 /* reset the quirks that has been previously set */
2630                 hdev->quirks = hid_lookup_quirk(hdev);
2631                 hdev->driver = hdrv;
2632                 if (hdrv->probe) {
2633                         ret = hdrv->probe(hdev, id);
2634                 } else { /* default probe */
2635                         ret = hid_open_report(hdev);
2636                         if (!ret)
2637                                 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
2638                 }
2639                 if (ret) {
2640                         hid_close_report(hdev);
2641                         hdev->driver = NULL;
2642                 }
2643         }
2644 unlock:
2645         if (!hdev->io_started)
2646                 up(&hdev->driver_input_lock);
2647 end:
2648         return ret;
2649 }
2650
2651 static void hid_device_remove(struct device *dev)
2652 {
2653         struct hid_device *hdev = to_hid_device(dev);
2654         struct hid_driver *hdrv;
2655
2656         down(&hdev->driver_input_lock);
2657         hdev->io_started = false;
2658
2659         hdrv = hdev->driver;
2660         if (hdrv) {
2661                 if (hdrv->remove)
2662                         hdrv->remove(hdev);
2663                 else /* default remove */
2664                         hid_hw_stop(hdev);
2665                 hid_close_report(hdev);
2666                 hdev->driver = NULL;
2667         }
2668
2669         if (!hdev->io_started)
2670                 up(&hdev->driver_input_lock);
2671 }
2672
2673 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
2674                              char *buf)
2675 {
2676         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
2677
2678         return scnprintf(buf, PAGE_SIZE, "hid:b%04Xg%04Xv%08Xp%08X\n",
2679                          hdev->bus, hdev->group, hdev->vendor, hdev->product);
2680 }
2681 static DEVICE_ATTR_RO(modalias);
2682
2683 static struct attribute *hid_dev_attrs[] = {
2684         &dev_attr_modalias.attr,
2685         NULL,
2686 };
2687 static struct bin_attribute *hid_dev_bin_attrs[] = {
2688         &dev_bin_attr_report_desc,
2689         NULL
2690 };
2691 static const struct attribute_group hid_dev_group = {
2692         .attrs = hid_dev_attrs,
2693         .bin_attrs = hid_dev_bin_attrs,
2694 };
2695 __ATTRIBUTE_GROUPS(hid_dev);
2696
2697 static int hid_uevent(const struct device *dev, struct kobj_uevent_env *env)
2698 {
2699         const struct hid_device *hdev = to_hid_device(dev);
2700
2701         if (add_uevent_var(env, "HID_ID=%04X:%08X:%08X",
2702                         hdev->bus, hdev->vendor, hdev->product))
2703                 return -ENOMEM;
2704
2705         if (add_uevent_var(env, "HID_NAME=%s", hdev->name))
2706                 return -ENOMEM;
2707
2708         if (add_uevent_var(env, "HID_PHYS=%s", hdev->phys))
2709                 return -ENOMEM;
2710
2711         if (add_uevent_var(env, "HID_UNIQ=%s", hdev->uniq))
2712                 return -ENOMEM;
2713
2714         if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",
2715                            hdev->bus, hdev->group, hdev->vendor, hdev->product))
2716                 return -ENOMEM;
2717
2718         return 0;
2719 }
2720
2721 struct bus_type hid_bus_type = {
2722         .name           = "hid",
2723         .dev_groups     = hid_dev_groups,
2724         .drv_groups     = hid_drv_groups,
2725         .match          = hid_bus_match,
2726         .probe          = hid_device_probe,
2727         .remove         = hid_device_remove,
2728         .uevent         = hid_uevent,
2729 };
2730 EXPORT_SYMBOL(hid_bus_type);
2731
2732 int hid_add_device(struct hid_device *hdev)
2733 {
2734         static atomic_t id = ATOMIC_INIT(0);
2735         int ret;
2736
2737         if (WARN_ON(hdev->status & HID_STAT_ADDED))
2738                 return -EBUSY;
2739
2740         hdev->quirks = hid_lookup_quirk(hdev);
2741
2742         /* we need to kill them here, otherwise they will stay allocated to
2743          * wait for coming driver */
2744         if (hid_ignore(hdev))
2745                 return -ENODEV;
2746
2747         /*
2748          * Check for the mandatory transport channel.
2749          */
2750          if (!hdev->ll_driver->raw_request) {
2751                 hid_err(hdev, "transport driver missing .raw_request()\n");
2752                 return -EINVAL;
2753          }
2754
2755         /*
2756          * Read the device report descriptor once and use as template
2757          * for the driver-specific modifications.
2758          */
2759         ret = hdev->ll_driver->parse(hdev);
2760         if (ret)
2761                 return ret;
2762         if (!hdev->dev_rdesc)
2763                 return -ENODEV;
2764
2765         /*
2766          * Scan generic devices for group information
2767          */
2768         if (hid_ignore_special_drivers) {
2769                 hdev->group = HID_GROUP_GENERIC;
2770         } else if (!hdev->group &&
2771                    !(hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)) {
2772                 ret = hid_scan_report(hdev);
2773                 if (ret)
2774                         hid_warn(hdev, "bad device descriptor (%d)\n", ret);
2775         }
2776
2777         hdev->id = atomic_inc_return(&id);
2778
2779         /* XXX hack, any other cleaner solution after the driver core
2780          * is converted to allow more than 20 bytes as the device name? */
2781         dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
2782                      hdev->vendor, hdev->product, hdev->id);
2783
2784         hid_debug_register(hdev, dev_name(&hdev->dev));
2785         ret = device_add(&hdev->dev);
2786         if (!ret)
2787                 hdev->status |= HID_STAT_ADDED;
2788         else
2789                 hid_debug_unregister(hdev);
2790
2791         return ret;
2792 }
2793 EXPORT_SYMBOL_GPL(hid_add_device);
2794
2795 /**
2796  * hid_allocate_device - allocate new hid device descriptor
2797  *
2798  * Allocate and initialize hid device, so that hid_destroy_device might be
2799  * used to free it.
2800  *
2801  * New hid_device pointer is returned on success, otherwise ERR_PTR encoded
2802  * error value.
2803  */
2804 struct hid_device *hid_allocate_device(void)
2805 {
2806         struct hid_device *hdev;
2807         int ret = -ENOMEM;
2808
2809         hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
2810         if (hdev == NULL)
2811                 return ERR_PTR(ret);
2812
2813         device_initialize(&hdev->dev);
2814         hdev->dev.release = hid_device_release;
2815         hdev->dev.bus = &hid_bus_type;
2816         device_enable_async_suspend(&hdev->dev);
2817
2818         hid_close_report(hdev);
2819
2820         init_waitqueue_head(&hdev->debug_wait);
2821         INIT_LIST_HEAD(&hdev->debug_list);
2822         spin_lock_init(&hdev->debug_list_lock);
2823         sema_init(&hdev->driver_input_lock, 1);
2824         mutex_init(&hdev->ll_open_lock);
2825
2826         hid_bpf_device_init(hdev);
2827
2828         return hdev;
2829 }
2830 EXPORT_SYMBOL_GPL(hid_allocate_device);
2831
2832 static void hid_remove_device(struct hid_device *hdev)
2833 {
2834         if (hdev->status & HID_STAT_ADDED) {
2835                 device_del(&hdev->dev);
2836                 hid_debug_unregister(hdev);
2837                 hdev->status &= ~HID_STAT_ADDED;
2838         }
2839         kfree(hdev->dev_rdesc);
2840         hdev->dev_rdesc = NULL;
2841         hdev->dev_rsize = 0;
2842 }
2843
2844 /**
2845  * hid_destroy_device - free previously allocated device
2846  *
2847  * @hdev: hid device
2848  *
2849  * If you allocate hid_device through hid_allocate_device, you should ever
2850  * free by this function.
2851  */
2852 void hid_destroy_device(struct hid_device *hdev)
2853 {
2854         hid_bpf_destroy_device(hdev);
2855         hid_remove_device(hdev);
2856         put_device(&hdev->dev);
2857 }
2858 EXPORT_SYMBOL_GPL(hid_destroy_device);
2859
2860
2861 static int __hid_bus_reprobe_drivers(struct device *dev, void *data)
2862 {
2863         struct hid_driver *hdrv = data;
2864         struct hid_device *hdev = to_hid_device(dev);
2865
2866         if (hdev->driver == hdrv &&
2867             !hdrv->match(hdev, hid_ignore_special_drivers) &&
2868             !test_and_set_bit(ffs(HID_STAT_REPROBED), &hdev->status))
2869                 return device_reprobe(dev);
2870
2871         return 0;
2872 }
2873
2874 static int __hid_bus_driver_added(struct device_driver *drv, void *data)
2875 {
2876         struct hid_driver *hdrv = to_hid_driver(drv);
2877
2878         if (hdrv->match) {
2879                 bus_for_each_dev(&hid_bus_type, NULL, hdrv,
2880                                  __hid_bus_reprobe_drivers);
2881         }
2882
2883         return 0;
2884 }
2885
2886 static int __bus_removed_driver(struct device_driver *drv, void *data)
2887 {
2888         return bus_rescan_devices(&hid_bus_type);
2889 }
2890
2891 int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
2892                 const char *mod_name)
2893 {
2894         int ret;
2895
2896         hdrv->driver.name = hdrv->name;
2897         hdrv->driver.bus = &hid_bus_type;
2898         hdrv->driver.owner = owner;
2899         hdrv->driver.mod_name = mod_name;
2900
2901         INIT_LIST_HEAD(&hdrv->dyn_list);
2902         spin_lock_init(&hdrv->dyn_lock);
2903
2904         ret = driver_register(&hdrv->driver);
2905
2906         if (ret == 0)
2907                 bus_for_each_drv(&hid_bus_type, NULL, NULL,
2908                                  __hid_bus_driver_added);
2909
2910         return ret;
2911 }
2912 EXPORT_SYMBOL_GPL(__hid_register_driver);
2913
2914 void hid_unregister_driver(struct hid_driver *hdrv)
2915 {
2916         driver_unregister(&hdrv->driver);
2917         hid_free_dynids(hdrv);
2918
2919         bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver);
2920 }
2921 EXPORT_SYMBOL_GPL(hid_unregister_driver);
2922
2923 int hid_check_keys_pressed(struct hid_device *hid)
2924 {
2925         struct hid_input *hidinput;
2926         int i;
2927
2928         if (!(hid->claimed & HID_CLAIMED_INPUT))
2929                 return 0;
2930
2931         list_for_each_entry(hidinput, &hid->inputs, list) {
2932                 for (i = 0; i < BITS_TO_LONGS(KEY_MAX); i++)
2933                         if (hidinput->input->key[i])
2934                                 return 1;
2935         }
2936
2937         return 0;
2938 }
2939 EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
2940
2941 #ifdef CONFIG_HID_BPF
2942 static struct hid_bpf_ops hid_ops = {
2943         .hid_get_report = hid_get_report,
2944         .hid_hw_raw_request = hid_hw_raw_request,
2945         .owner = THIS_MODULE,
2946         .bus_type = &hid_bus_type,
2947 };
2948 #endif
2949
2950 static int __init hid_init(void)
2951 {
2952         int ret;
2953
2954         ret = bus_register(&hid_bus_type);
2955         if (ret) {
2956                 pr_err("can't register hid bus\n");
2957                 goto err;
2958         }
2959
2960 #ifdef CONFIG_HID_BPF
2961         hid_bpf_ops = &hid_ops;
2962 #endif
2963
2964         ret = hidraw_init();
2965         if (ret)
2966                 goto err_bus;
2967
2968         hid_debug_init();
2969
2970         return 0;
2971 err_bus:
2972         bus_unregister(&hid_bus_type);
2973 err:
2974         return ret;
2975 }
2976
2977 static void __exit hid_exit(void)
2978 {
2979 #ifdef CONFIG_HID_BPF
2980         hid_bpf_ops = NULL;
2981 #endif
2982         hid_debug_exit();
2983         hidraw_exit();
2984         bus_unregister(&hid_bus_type);
2985         hid_quirks_exit(HID_BUS_ANY);
2986 }
2987
2988 module_init(hid_init);
2989 module_exit(hid_exit);
2990
2991 MODULE_AUTHOR("Andreas Gal");
2992 MODULE_AUTHOR("Vojtech Pavlik");
2993 MODULE_AUTHOR("Jiri Kosina");
2994 MODULE_LICENSE("GPL");