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 void hiddev_free(struct kref *ref)
 706 {
 707         struct hid_device *hid = container_of(ref, struct hid_device, ref);
 708
 709         hid_close_report(hid);
 710         kfree(hid->dev_rdesc);
 711         kfree(hid);
 712 }
 713
 714 static void hid_device_release(struct device *dev)
 715 {
 716         struct hid_device *hid = to_hid_device(dev);
 717
 718         kref_put(&hid->ref, hiddev_free);
 719 }
 720
 721 /*
 722  * Fetch a report description item from the data stream. We support long
 723  * items, though they are not used yet.
 724  */
 725
 726 static u8 *fetch_item(__u8 *start, __u8 *end, struct hid_item *item)
 727 {
 728         u8 b;
 729
 730         if ((end - start) <= 0)
 731                 return NULL;
 732
 733         b = *start++;
 734
 735         item->type = (b >> 2) & 3;
 736         item->tag  = (b >> 4) & 15;
 737
 738         if (item->tag == HID_ITEM_TAG_LONG) {
 739
 740                 item->format = HID_ITEM_FORMAT_LONG;
 741
 742                 if ((end - start) < 2)
 743                         return NULL;
 744
 745                 item->size = *start++;
 746                 item->tag  = *start++;
 747
 748                 if ((end - start) < item->size)
 749                         return NULL;
 750
 751                 item->data.longdata = start;
 752                 start += item->size;
 753                 return start;
 754         }
 755
 756         item->format = HID_ITEM_FORMAT_SHORT;
 757         item->size = b & 3;
 758
 759         switch (item->size) {
 760         case 0:
 761                 return start;
 762
 763         case 1:
 764                 if ((end - start) < 1)
 765                         return NULL;
 766                 item->data.u8 = *start++;
 767                 return start;
 768
 769         case 2:
 770                 if ((end - start) < 2)
 771                         return NULL;
 772                 item->data.u16 = get_unaligned_le16(start);
 773                 start = (__u8 *)((__le16 *)start + 1);
 774                 return start;
 775
 776         case 3:
 777                 item->size++;
 778                 if ((end - start) < 4)
 779                         return NULL;
 780                 item->data.u32 = get_unaligned_le32(start);
 781                 start = (__u8 *)((__le32 *)start + 1);
 782                 return start;
 783         }
 784
 785         return NULL;
 786 }
 787
 788 static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)
 789 {
 790         struct hid_device *hid = parser->device;
 791
 792         if (usage == HID_DG_CONTACTID)
 793                 hid->group = HID_GROUP_MULTITOUCH;
 794 }
 795
 796 static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
 797 {
 798         if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
 799             parser->global.report_size == 8)
 800                 parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 801
 802         if (usage == 0xff0000c6 && parser->global.report_count == 1 &&
 803             parser->global.report_size == 8)
 804                 parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 805 }
 806
 807 static void hid_scan_collection(struct hid_parser *parser, unsigned type)
 808 {
 809         struct hid_device *hid = parser->device;
 810         int i;
 811
 812         if (((parser->global.usage_page << 16) == HID_UP_SENSOR) &&
 813             (type == HID_COLLECTION_PHYSICAL ||
 814              type == HID_COLLECTION_APPLICATION))
 815                 hid->group = HID_GROUP_SENSOR_HUB;
 816
 817         if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
 818             hid->product == USB_DEVICE_ID_MS_POWER_COVER &&
 819             hid->group == HID_GROUP_MULTITOUCH)
 820                 hid->group = HID_GROUP_GENERIC;
 821
 822         if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
 823                 for (i = 0; i < parser->local.usage_index; i++)
 824                         if (parser->local.usage[i] == HID_GD_POINTER)
 825                                 parser->scan_flags |= HID_SCAN_FLAG_GD_POINTER;
 826
 827         if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
 828                 parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
 829
 830         if ((parser->global.usage_page << 16) == HID_UP_GOOGLEVENDOR)
 831                 for (i = 0; i < parser->local.usage_index; i++)
 832                         if (parser->local.usage[i] ==
 833                                         (HID_UP_GOOGLEVENDOR | 0x0001))
 834                                 parser->device->group =
 835                                         HID_GROUP_VIVALDI;
 836 }
 837
 838 static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
 839 {
 840         __u32 data;
 841         int i;
 842
 843         hid_concatenate_last_usage_page(parser);
 844
 845         data = item_udata(item);
 846
 847         switch (item->tag) {
 848         case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 849                 hid_scan_collection(parser, data & 0xff);
 850                 break;
 851         case HID_MAIN_ITEM_TAG_END_COLLECTION:
 852                 break;
 853         case HID_MAIN_ITEM_TAG_INPUT:
 854                 /* ignore constant inputs, they will be ignored by hid-input */
 855                 if (data & HID_MAIN_ITEM_CONSTANT)
 856                         break;
 857                 for (i = 0; i < parser->local.usage_index; i++)
 858                         hid_scan_input_usage(parser, parser->local.usage[i]);
 859                 break;
 860         case HID_MAIN_ITEM_TAG_OUTPUT:
 861                 break;
 862         case HID_MAIN_ITEM_TAG_FEATURE:
 863                 for (i = 0; i < parser->local.usage_index; i++)
 864                         hid_scan_feature_usage(parser, parser->local.usage[i]);
 865                 break;
 866         }
 867
 868         /* Reset the local parser environment */
 869         memset(&parser->local, 0, sizeof(parser->local));
 870
 871         return 0;
 872 }
 873
 874 /*
 875  * Scan a report descriptor before the device is added to the bus.
 876  * Sets device groups and other properties that determine what driver
 877  * to load.
 878  */
 879 static int hid_scan_report(struct hid_device *hid)
 880 {
 881         struct hid_parser *parser;
 882         struct hid_item item;
 883         __u8 *start = hid->dev_rdesc;
 884         __u8 *end = start + hid->dev_rsize;
 885         static int (*dispatch_type[])(struct hid_parser *parser,
 886                                       struct hid_item *item) = {
 887                 hid_scan_main,
 888                 hid_parser_global,
 889                 hid_parser_local,
 890                 hid_parser_reserved
 891         };
 892
 893         parser = vzalloc(sizeof(struct hid_parser));
 894         if (!parser)
 895                 return -ENOMEM;
 896
 897         parser->device = hid;
 898         hid->group = HID_GROUP_GENERIC;
 899
 900         /*
 901          * The parsing is simpler than the one in hid_open_report() as we should
 902          * be robust against hid errors. Those errors will be raised by
 903          * hid_open_report() anyway.
 904          */
 905         while ((start = fetch_item(start, end, &item)) != NULL)
 906                 dispatch_type[item.type](parser, &item);
 907
 908         /*
 909          * Handle special flags set during scanning.
 910          */
 911         if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
 912             (hid->group == HID_GROUP_MULTITOUCH))
 913                 hid->group = HID_GROUP_MULTITOUCH_WIN_8;
 914
 915         /*
 916          * Vendor specific handlings
 917          */
 918         switch (hid->vendor) {
 919         case USB_VENDOR_ID_WACOM:
 920                 hid->group = HID_GROUP_WACOM;
 921                 break;
 922         case USB_VENDOR_ID_SYNAPTICS:
 923                 if (hid->group == HID_GROUP_GENERIC)
 924                         if ((parser->scan_flags & HID_SCAN_FLAG_VENDOR_SPECIFIC)
 925                             && (parser->scan_flags & HID_SCAN_FLAG_GD_POINTER))
 926                                 /*
 927                                  * hid-rmi should take care of them,
 928                                  * not hid-generic
 929                                  */
 930                                 hid->group = HID_GROUP_RMI;
 931                 break;
 932         }
 933
 934         kfree(parser->collection_stack);
 935         vfree(parser);
 936         return 0;
 937 }
 938
 939 /**
 940  * hid_parse_report - parse device report
 941  *
 942  * @hid: hid device
 943  * @start: report start
 944  * @size: report size
 945  *
 946  * Allocate the device report as read by the bus driver. This function should
 947  * only be called from parse() in ll drivers.
 948  */
 949 int hid_parse_report(struct hid_device *hid, __u8 *start, unsigned size)
 950 {
 951         hid->dev_rdesc = kmemdup(start, size, GFP_KERNEL);
 952         if (!hid->dev_rdesc)
 953                 return -ENOMEM;
 954         hid->dev_rsize = size;
 955         return 0;
 956 }
 957 EXPORT_SYMBOL_GPL(hid_parse_report);
 958
 959 static const char * const hid_report_names[] = {
 960         "HID_INPUT_REPORT",
 961         "HID_OUTPUT_REPORT",
 962         "HID_FEATURE_REPORT",
 963 };
 964 /**
 965  * hid_validate_values - validate existing device report's value indexes
 966  *
 967  * @hid: hid device
 968  * @type: which report type to examine
 969  * @id: which report ID to examine (0 for first)
 970  * @field_index: which report field to examine
 971  * @report_counts: expected number of values
 972  *
 973  * Validate the number of values in a given field of a given report, after
 974  * parsing.
 975  */
 976 struct hid_report *hid_validate_values(struct hid_device *hid,
 977                                        enum hid_report_type type, unsigned int id,
 978                                        unsigned int field_index,
 979                                        unsigned int report_counts)
 980 {
 981         struct hid_report *report;
 982
 983         if (type > HID_FEATURE_REPORT) {
 984                 hid_err(hid, "invalid HID report type %u\n", type);
 985                 return NULL;
 986         }
 987
 988         if (id >= HID_MAX_IDS) {
 989                 hid_err(hid, "invalid HID report id %u\n", id);
 990                 return NULL;
 991         }
 992
 993         /*
 994          * Explicitly not using hid_get_report() here since it depends on
 995          * ->numbered being checked, which may not always be the case when
 996          * drivers go to access report values.
 997          */
 998         if (id == 0) {
 999                 /*
1000                  * Validating on id 0 means we should examine the first
1001                  * report in the list.
1002                  */
1003                 report = list_first_entry_or_null(
1004                                 &hid->report_enum[type].report_list,
1005                                 struct hid_report, list);
1006         } else {
1007                 report = hid->report_enum[type].report_id_hash[id];
1008         }
1009         if (!report) {
1010                 hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
1011                 return NULL;
1012         }
1013         if (report->maxfield <= field_index) {
1014                 hid_err(hid, "not enough fields in %s %u\n",
1015                         hid_report_names[type], id);
1016                 return NULL;
1017         }
1018         if (report->field[field_index]->report_count < report_counts) {
1019                 hid_err(hid, "not enough values in %s %u field %u\n",
1020                         hid_report_names[type], id, field_index);
1021                 return NULL;
1022         }
1023         return report;
1024 }
1025 EXPORT_SYMBOL_GPL(hid_validate_values);
1026
1027 static int hid_calculate_multiplier(struct hid_device *hid,
1028                                      struct hid_field *multiplier)
1029 {
1030         int m;
1031         __s32 v = *multiplier->value;
1032         __s32 lmin = multiplier->logical_minimum;
1033         __s32 lmax = multiplier->logical_maximum;
1034         __s32 pmin = multiplier->physical_minimum;
1035         __s32 pmax = multiplier->physical_maximum;
1036
1037         /*
1038          * "Because OS implementations will generally divide the control's
1039          * reported count by the Effective Resolution Multiplier, designers
1040          * should take care not to establish a potential Effective
1041          * Resolution Multiplier of zero."
1042          * HID Usage Table, v1.12, Section 4.3.1, p31
1043          */
1044         if (lmax - lmin == 0)
1045                 return 1;
1046         /*
1047          * Handling the unit exponent is left as an exercise to whoever
1048          * finds a device where that exponent is not 0.
1049          */
1050         m = ((v - lmin)/(lmax - lmin) * (pmax - pmin) + pmin);
1051         if (unlikely(multiplier->unit_exponent != 0)) {
1052                 hid_warn(hid,
1053                          "unsupported Resolution Multiplier unit exponent %d\n",
1054                          multiplier->unit_exponent);
1055         }
1056
1057         /* There are no devices with an effective multiplier > 255 */
1058         if (unlikely(m == 0 || m > 255 || m < -255)) {
1059                 hid_warn(hid, "unsupported Resolution Multiplier %d\n", m);
1060                 m = 1;
1061         }
1062
1063         return m;
1064 }
1065
1066 static void hid_apply_multiplier_to_field(struct hid_device *hid,
1067                                           struct hid_field *field,
1068                                           struct hid_collection *multiplier_collection,
1069                                           int effective_multiplier)
1070 {
1071         struct hid_collection *collection;
1072         struct hid_usage *usage;
1073         int i;
1074
1075         /*
1076          * If multiplier_collection is NULL, the multiplier applies
1077          * to all fields in the report.
1078          * Otherwise, it is the Logical Collection the multiplier applies to
1079          * but our field may be in a subcollection of that collection.
1080          */
1081         for (i = 0; i < field->maxusage; i++) {
1082                 usage = &field->usage[i];
1083
1084                 collection = &hid->collection[usage->collection_index];
1085                 while (collection->parent_idx != -1 &&
1086                        collection != multiplier_collection)
1087                         collection = &hid->collection[collection->parent_idx];
1088
1089                 if (collection->parent_idx != -1 ||
1090                     multiplier_collection == NULL)
1091                         usage->resolution_multiplier = effective_multiplier;
1092
1093         }
1094 }
1095
1096 static void hid_apply_multiplier(struct hid_device *hid,
1097                                  struct hid_field *multiplier)
1098 {
1099         struct hid_report_enum *rep_enum;
1100         struct hid_report *rep;
1101         struct hid_field *field;
1102         struct hid_collection *multiplier_collection;
1103         int effective_multiplier;
1104         int i;
1105
1106         /*
1107          * "The Resolution Multiplier control must be contained in the same
1108          * Logical Collection as the control(s) to which it is to be applied.
1109          * If no Resolution Multiplier is defined, then the Resolution
1110          * Multiplier defaults to 1.  If more than one control exists in a
1111          * Logical Collection, the Resolution Multiplier is associated with
1112          * all controls in the collection. If no Logical Collection is
1113          * defined, the Resolution Multiplier is associated with all
1114          * controls in the report."
1115          * HID Usage Table, v1.12, Section 4.3.1, p30
1116          *
1117          * Thus, search from the current collection upwards until we find a
1118          * logical collection. Then search all fields for that same parent
1119          * collection. Those are the fields the multiplier applies to.
1120          *
1121          * If we have more than one multiplier, it will overwrite the
1122          * applicable fields later.
1123          */
1124         multiplier_collection = &hid->collection[multiplier->usage->collection_index];
1125         while (multiplier_collection->parent_idx != -1 &&
1126                multiplier_collection->type != HID_COLLECTION_LOGICAL)
1127                 multiplier_collection = &hid->collection[multiplier_collection->parent_idx];
1128
1129         effective_multiplier = hid_calculate_multiplier(hid, multiplier);
1130
1131         rep_enum = &hid->report_enum[HID_INPUT_REPORT];
1132         list_for_each_entry(rep, &rep_enum->report_list, list) {
1133                 for (i = 0; i < rep->maxfield; i++) {
1134                         field = rep->field[i];
1135                         hid_apply_multiplier_to_field(hid, field,
1136                                                       multiplier_collection,
1137                                                       effective_multiplier);
1138                 }
1139         }
1140 }
1141
1142 /*
1143  * hid_setup_resolution_multiplier - set up all resolution multipliers
1144  *
1145  * @device: hid device
1146  *
1147  * Search for all Resolution Multiplier Feature Reports and apply their
1148  * value to all matching Input items. This only updates the internal struct
1149  * fields.
1150  *
1151  * The Resolution Multiplier is applied by the hardware. If the multiplier
1152  * is anything other than 1, the hardware will send pre-multiplied events
1153  * so that the same physical interaction generates an accumulated
1154  *      accumulated_value = value * * multiplier
1155  * This may be achieved by sending
1156  * - "value * multiplier" for each event, or
1157  * - "value" but "multiplier" times as frequently, or
1158  * - a combination of the above
1159  * The only guarantee is that the same physical interaction always generates
1160  * an accumulated 'value * multiplier'.
1161  *
1162  * This function must be called before any event processing and after
1163  * any SetRequest to the Resolution Multiplier.
1164  */
1165 void hid_setup_resolution_multiplier(struct hid_device *hid)
1166 {
1167         struct hid_report_enum *rep_enum;
1168         struct hid_report *rep;
1169         struct hid_usage *usage;
1170         int i, j;
1171
1172         rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
1173         list_for_each_entry(rep, &rep_enum->report_list, list) {
1174                 for (i = 0; i < rep->maxfield; i++) {
1175                         /* Ignore if report count is out of bounds. */
1176                         if (rep->field[i]->report_count < 1)
1177                                 continue;
1178
1179                         for (j = 0; j < rep->field[i]->maxusage; j++) {
1180                                 usage = &rep->field[i]->usage[j];
1181                                 if (usage->hid == HID_GD_RESOLUTION_MULTIPLIER)
1182                                         hid_apply_multiplier(hid,
1183                                                              rep->field[i]);
1184                         }
1185                 }
1186         }
1187 }
1188 EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier);
1189
1190 /**
1191  * hid_open_report - open a driver-specific device report
1192  *
1193  * @device: hid device
1194  *
1195  * Parse a report description into a hid_device structure. Reports are
1196  * enumerated, fields are attached to these reports.
1197  * 0 returned on success, otherwise nonzero error value.
1198  *
1199  * This function (or the equivalent hid_parse() macro) should only be
1200  * called from probe() in drivers, before starting the device.
1201  */
1202 int hid_open_report(struct hid_device *device)
1203 {
1204         struct hid_parser *parser;
1205         struct hid_item item;
1206         unsigned int size;
1207         __u8 *start;
1208         __u8 *buf;
1209         __u8 *end;
1210         __u8 *next;
1211         int ret;
1212         int i;
1213         static int (*dispatch_type[])(struct hid_parser *parser,
1214                                       struct hid_item *item) = {
1215                 hid_parser_main,
1216                 hid_parser_global,
1217                 hid_parser_local,
1218                 hid_parser_reserved
1219         };
1220
1221         if (WARN_ON(device->status & HID_STAT_PARSED))
1222                 return -EBUSY;
1223
1224         start = device->dev_rdesc;
1225         if (WARN_ON(!start))
1226                 return -ENODEV;
1227         size = device->dev_rsize;
1228
1229         /* call_hid_bpf_rdesc_fixup() ensures we work on a copy of rdesc */
1230         buf = call_hid_bpf_rdesc_fixup(device, start, &size);
1231         if (buf == NULL)
1232                 return -ENOMEM;
1233
1234         if (device->driver->report_fixup)
1235                 start = device->driver->report_fixup(device, buf, &size);
1236         else
1237                 start = buf;
1238
1239         start = kmemdup(start, size, GFP_KERNEL);
1240         kfree(buf);
1241         if (start == NULL)
1242                 return -ENOMEM;
1243
1244         device->rdesc = start;
1245         device->rsize = size;
1246
1247         parser = vzalloc(sizeof(struct hid_parser));
1248         if (!parser) {
1249                 ret = -ENOMEM;
1250                 goto alloc_err;
1251         }
1252
1253         parser->device = device;
1254
1255         end = start + size;
1256
1257         device->collection = kcalloc(HID_DEFAULT_NUM_COLLECTIONS,
1258                                      sizeof(struct hid_collection), GFP_KERNEL);
1259         if (!device->collection) {
1260                 ret = -ENOMEM;
1261                 goto err;
1262         }
1263         device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
1264         for (i = 0; i < HID_DEFAULT_NUM_COLLECTIONS; i++)
1265                 device->collection[i].parent_idx = -1;
1266
1267         ret = -EINVAL;
1268         while ((next = fetch_item(start, end, &item)) != NULL) {
1269                 start = next;
1270
1271                 if (item.format != HID_ITEM_FORMAT_SHORT) {
1272                         hid_err(device, "unexpected long global item\n");
1273                         goto err;
1274                 }
1275
1276                 if (dispatch_type[item.type](parser, &item)) {
1277                         hid_err(device, "item %u %u %u %u parsing failed\n",
1278                                 item.format, (unsigned)item.size,
1279                                 (unsigned)item.type, (unsigned)item.tag);
1280                         goto err;
1281                 }
1282
1283                 if (start == end) {
1284                         if (parser->collection_stack_ptr) {
1285                                 hid_err(device, "unbalanced collection at end of report description\n");
1286                                 goto err;
1287                         }
1288                         if (parser->local.delimiter_depth) {
1289                                 hid_err(device, "unbalanced delimiter at end of report description\n");
1290                                 goto err;
1291                         }
1292
1293                         /*
1294                          * fetch initial values in case the device's
1295                          * default multiplier isn't the recommended 1
1296                          */
1297                         hid_setup_resolution_multiplier(device);
1298
1299                         kfree(parser->collection_stack);
1300                         vfree(parser);
1301                         device->status |= HID_STAT_PARSED;
1302
1303                         return 0;
1304                 }
1305         }
1306
1307         hid_err(device, "item fetching failed at offset %u/%u\n",
1308                 size - (unsigned int)(end - start), size);
1309 err:
1310         kfree(parser->collection_stack);
1311 alloc_err:
1312         vfree(parser);
1313         hid_close_report(device);
1314         return ret;
1315 }
1316 EXPORT_SYMBOL_GPL(hid_open_report);
1317
1318 /*
1319  * Convert a signed n-bit integer to signed 32-bit integer. Common
1320  * cases are done through the compiler, the screwed things has to be
1321  * done by hand.
1322  */
1323
1324 static s32 snto32(__u32 value, unsigned n)
1325 {
1326         if (!value || !n)
1327                 return 0;
1328
1329         if (n > 32)
1330                 n = 32;
1331
1332         switch (n) {
1333         case 8:  return ((__s8)value);
1334         case 16: return ((__s16)value);
1335         case 32: return ((__s32)value);
1336         }
1337         return value & (1 << (n - 1)) ? value | (~0U << n) : value;
1338 }
1339
1340 s32 hid_snto32(__u32 value, unsigned n)
1341 {
1342         return snto32(value, n);
1343 }
1344 EXPORT_SYMBOL_GPL(hid_snto32);
1345
1346 /*
1347  * Convert a signed 32-bit integer to a signed n-bit integer.
1348  */
1349
1350 static u32 s32ton(__s32 value, unsigned n)
1351 {
1352         s32 a = value >> (n - 1);
1353         if (a && a != -1)
1354                 return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
1355         return value & ((1 << n) - 1);
1356 }
1357
1358 /*
1359  * Extract/implement a data field from/to a little endian report (bit array).
1360  *
1361  * Code sort-of follows HID spec:
1362  *     http://www.usb.org/developers/hidpage/HID1_11.pdf
1363  *
1364  * While the USB HID spec allows unlimited length bit fields in "report
1365  * descriptors", most devices never use more than 16 bits.
1366  * One model of UPS is claimed to report "LINEV" as a 32-bit field.
1367  * Search linux-kernel and linux-usb-devel archives for "hid-core extract".
1368  */
1369
1370 static u32 __extract(u8 *report, unsigned offset, int n)
1371 {
1372         unsigned int idx = offset / 8;
1373         unsigned int bit_nr = 0;
1374         unsigned int bit_shift = offset % 8;
1375         int bits_to_copy = 8 - bit_shift;
1376         u32 value = 0;
1377         u32 mask = n < 32 ? (1U << n) - 1 : ~0U;
1378
1379         while (n > 0) {
1380                 value |= ((u32)report[idx] >> bit_shift) << bit_nr;
1381                 n -= bits_to_copy;
1382                 bit_nr += bits_to_copy;
1383                 bits_to_copy = 8;
1384                 bit_shift = 0;
1385                 idx++;
1386         }
1387
1388         return value & mask;
1389 }
1390
1391 u32 hid_field_extract(const struct hid_device *hid, u8 *report,
1392                         unsigned offset, unsigned n)
1393 {
1394         if (n > 32) {
1395                 hid_warn_once(hid, "%s() called with n (%d) > 32! (%s)\n",
1396                               __func__, n, current->comm);
1397                 n = 32;
1398         }
1399
1400         return __extract(report, offset, n);
1401 }
1402 EXPORT_SYMBOL_GPL(hid_field_extract);
1403
1404 /*
1405  * "implement" : set bits in a little endian bit stream.
1406  * Same concepts as "extract" (see comments above).
1407  * The data mangled in the bit stream remains in little endian
1408  * order the whole time. It make more sense to talk about
1409  * endianness of register values by considering a register
1410  * a "cached" copy of the little endian bit stream.
1411  */
1412
1413 static void __implement(u8 *report, unsigned offset, int n, u32 value)
1414 {
1415         unsigned int idx = offset / 8;
1416         unsigned int bit_shift = offset % 8;
1417         int bits_to_set = 8 - bit_shift;
1418
1419         while (n - bits_to_set >= 0) {
1420                 report[idx] &= ~(0xff << bit_shift);
1421                 report[idx] |= value << bit_shift;
1422                 value >>= bits_to_set;
1423                 n -= bits_to_set;
1424                 bits_to_set = 8;
1425                 bit_shift = 0;
1426                 idx++;
1427         }
1428
1429         /* last nibble */
1430         if (n) {
1431                 u8 bit_mask = ((1U << n) - 1);
1432                 report[idx] &= ~(bit_mask << bit_shift);
1433                 report[idx] |= value << bit_shift;
1434         }
1435 }
1436
1437 static void implement(const struct hid_device *hid, u8 *report,
1438                       unsigned offset, unsigned n, u32 value)
1439 {
1440         if (unlikely(n > 32)) {
1441                 hid_warn(hid, "%s() called with n (%d) > 32! (%s)\n",
1442                          __func__, n, current->comm);
1443                 n = 32;
1444         } else if (n < 32) {
1445                 u32 m = (1U << n) - 1;
1446
1447                 if (unlikely(value > m)) {
1448                         hid_warn(hid,
1449                                  "%s() called with too large value %d (n: %d)! (%s)\n",
1450                                  __func__, value, n, current->comm);
1451                         WARN_ON(1);
1452                         value &= m;
1453                 }
1454         }
1455
1456         __implement(report, offset, n, value);
1457 }
1458
1459 /*
1460  * Search an array for a value.
1461  */
1462
1463 static int search(__s32 *array, __s32 value, unsigned n)
1464 {
1465         while (n--) {
1466                 if (*array++ == value)
1467                         return 0;
1468         }
1469         return -1;
1470 }
1471
1472 /**
1473  * hid_match_report - check if driver's raw_event should be called
1474  *
1475  * @hid: hid device
1476  * @report: hid report to match against
1477  *
1478  * compare hid->driver->report_table->report_type to report->type
1479  */
1480 static int hid_match_report(struct hid_device *hid, struct hid_report *report)
1481 {
1482         const struct hid_report_id *id = hid->driver->report_table;
1483
1484         if (!id) /* NULL means all */
1485                 return 1;
1486
1487         for (; id->report_type != HID_TERMINATOR; id++)
1488                 if (id->report_type == HID_ANY_ID ||
1489                                 id->report_type == report->type)
1490                         return 1;
1491         return 0;
1492 }
1493
1494 /**
1495  * hid_match_usage - check if driver's event should be called
1496  *
1497  * @hid: hid device
1498  * @usage: usage to match against
1499  *
1500  * compare hid->driver->usage_table->usage_{type,code} to
1501  * usage->usage_{type,code}
1502  */
1503 static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage)
1504 {
1505         const struct hid_usage_id *id = hid->driver->usage_table;
1506
1507         if (!id) /* NULL means all */
1508                 return 1;
1509
1510         for (; id->usage_type != HID_ANY_ID - 1; id++)
1511                 if ((id->usage_hid == HID_ANY_ID ||
1512                                 id->usage_hid == usage->hid) &&
1513                                 (id->usage_type == HID_ANY_ID ||
1514                                 id->usage_type == usage->type) &&
1515                                 (id->usage_code == HID_ANY_ID ||
1516                                  id->usage_code == usage->code))
1517                         return 1;
1518         return 0;
1519 }
1520
1521 static void hid_process_event(struct hid_device *hid, struct hid_field *field,
1522                 struct hid_usage *usage, __s32 value, int interrupt)
1523 {
1524         struct hid_driver *hdrv = hid->driver;
1525         int ret;
1526
1527         if (!list_empty(&hid->debug_list))
1528                 hid_dump_input(hid, usage, value);
1529
1530         if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
1531                 ret = hdrv->event(hid, field, usage, value);
1532                 if (ret != 0) {
1533                         if (ret < 0)
1534                                 hid_err(hid, "%s's event failed with %d\n",
1535                                                 hdrv->name, ret);
1536                         return;
1537                 }
1538         }
1539
1540         if (hid->claimed & HID_CLAIMED_INPUT)
1541                 hidinput_hid_event(hid, field, usage, value);
1542         if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
1543                 hid->hiddev_hid_event(hid, field, usage, value);
1544 }
1545
1546 /*
1547  * Checks if the given value is valid within this field
1548  */
1549 static inline int hid_array_value_is_valid(struct hid_field *field,
1550                                            __s32 value)
1551 {
1552         __s32 min = field->logical_minimum;
1553
1554         /*
1555          * Value needs to be between logical min and max, and
1556          * (value - min) is used as an index in the usage array.
1557          * This array is of size field->maxusage
1558          */
1559         return value >= min &&
1560                value <= field->logical_maximum &&
1561                value - min < field->maxusage;
1562 }
1563
1564 /*
1565  * Fetch the field from the data. The field content is stored for next
1566  * report processing (we do differential reporting to the layer).
1567  */
1568 static void hid_input_fetch_field(struct hid_device *hid,
1569                                   struct hid_field *field,
1570                                   __u8 *data)
1571 {
1572         unsigned n;
1573         unsigned count = field->report_count;
1574         unsigned offset = field->report_offset;
1575         unsigned size = field->report_size;
1576         __s32 min = field->logical_minimum;
1577         __s32 *value;
1578
1579         value = field->new_value;
1580         memset(value, 0, count * sizeof(__s32));
1581         field->ignored = false;
1582
1583         for (n = 0; n < count; n++) {
1584
1585                 value[n] = min < 0 ?
1586                         snto32(hid_field_extract(hid, data, offset + n * size,
1587                                size), size) :
1588                         hid_field_extract(hid, data, offset + n * size, size);
1589
1590                 /* Ignore report if ErrorRollOver */
1591                 if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
1592                     hid_array_value_is_valid(field, value[n]) &&
1593                     field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1) {
1594                         field->ignored = true;
1595                         return;
1596                 }
1597         }
1598 }
1599
1600 /*
1601  * Process a received variable field.
1602  */
1603
1604 static void hid_input_var_field(struct hid_device *hid,
1605                                 struct hid_field *field,
1606                                 int interrupt)
1607 {
1608         unsigned int count = field->report_count;
1609         __s32 *value = field->new_value;
1610         unsigned int n;
1611
1612         for (n = 0; n < count; n++)
1613                 hid_process_event(hid,
1614                                   field,
1615                                   &field->usage[n],
1616                                   value[n],
1617                                   interrupt);
1618
1619         memcpy(field->value, value, count * sizeof(__s32));
1620 }
1621
1622 /*
1623  * Process a received array field. The field content is stored for
1624  * next report processing (we do differential reporting to the layer).
1625  */
1626
1627 static void hid_input_array_field(struct hid_device *hid,
1628                                   struct hid_field *field,
1629                                   int interrupt)
1630 {
1631         unsigned int n;
1632         unsigned int count = field->report_count;
1633         __s32 min = field->logical_minimum;
1634         __s32 *value;
1635
1636         value = field->new_value;
1637
1638         /* ErrorRollOver */
1639         if (field->ignored)
1640                 return;
1641
1642         for (n = 0; n < count; n++) {
1643                 if (hid_array_value_is_valid(field, field->value[n]) &&
1644                     search(value, field->value[n], count))
1645                         hid_process_event(hid,
1646                                           field,
1647                                           &field->usage[field->value[n] - min],
1648                                           0,
1649                                           interrupt);
1650
1651                 if (hid_array_value_is_valid(field, value[n]) &&
1652                     search(field->value, value[n], count))
1653                         hid_process_event(hid,
1654                                           field,
1655                                           &field->usage[value[n] - min],
1656                                           1,
1657                                           interrupt);
1658         }
1659
1660         memcpy(field->value, value, count * sizeof(__s32));
1661 }
1662
1663 /*
1664  * Analyse a received report, and fetch the data from it. The field
1665  * content is stored for next report processing (we do differential
1666  * reporting to the layer).
1667  */
1668 static void hid_process_report(struct hid_device *hid,
1669                                struct hid_report *report,
1670                                __u8 *data,
1671                                int interrupt)
1672 {
1673         unsigned int a;
1674         struct hid_field_entry *entry;
1675         struct hid_field *field;
1676
1677         /* first retrieve all incoming values in data */
1678         for (a = 0; a < report->maxfield; a++)
1679                 hid_input_fetch_field(hid, report->field[a], data);
1680
1681         if (!list_empty(&report->field_entry_list)) {
1682                 /* INPUT_REPORT, we have a priority list of fields */
1683                 list_for_each_entry(entry,
1684                                     &report->field_entry_list,
1685                                     list) {
1686                         field = entry->field;
1687
1688                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1689                                 hid_process_event(hid,
1690                                                   field,
1691                                                   &field->usage[entry->index],
1692                                                   field->new_value[entry->index],
1693                                                   interrupt);
1694                         else
1695                                 hid_input_array_field(hid, field, interrupt);
1696                 }
1697
1698                 /* we need to do the memcpy at the end for var items */
1699                 for (a = 0; a < report->maxfield; a++) {
1700                         field = report->field[a];
1701
1702                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1703                                 memcpy(field->value, field->new_value,
1704                                        field->report_count * sizeof(__s32));
1705                 }
1706         } else {
1707                 /* FEATURE_REPORT, regular processing */
1708                 for (a = 0; a < report->maxfield; a++) {
1709                         field = report->field[a];
1710
1711                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1712                                 hid_input_var_field(hid, field, interrupt);
1713                         else
1714                                 hid_input_array_field(hid, field, interrupt);
1715                 }
1716         }
1717 }
1718
1719 /*
1720  * Insert a given usage_index in a field in the list
1721  * of processed usages in the report.
1722  *
1723  * The elements of lower priority score are processed
1724  * first.
1725  */
1726 static void __hid_insert_field_entry(struct hid_device *hid,
1727                                      struct hid_report *report,
1728                                      struct hid_field_entry *entry,
1729                                      struct hid_field *field,
1730                                      unsigned int usage_index)
1731 {
1732         struct hid_field_entry *next;
1733
1734         entry->field = field;
1735         entry->index = usage_index;
1736         entry->priority = field->usages_priorities[usage_index];
1737
1738         /* insert the element at the correct position */
1739         list_for_each_entry(next,
1740                             &report->field_entry_list,
1741                             list) {
1742                 /*
1743                  * the priority of our element is strictly higher
1744                  * than the next one, insert it before
1745                  */
1746                 if (entry->priority > next->priority) {
1747                         list_add_tail(&entry->list, &next->list);
1748                         return;
1749                 }
1750         }
1751
1752         /* lowest priority score: insert at the end */
1753         list_add_tail(&entry->list, &report->field_entry_list);
1754 }
1755
1756 static void hid_report_process_ordering(struct hid_device *hid,
1757                                         struct hid_report *report)
1758 {
1759         struct hid_field *field;
1760         struct hid_field_entry *entries;
1761         unsigned int a, u, usages;
1762         unsigned int count = 0;
1763
1764         /* count the number of individual fields in the report */
1765         for (a = 0; a < report->maxfield; a++) {
1766                 field = report->field[a];
1767
1768                 if (field->flags & HID_MAIN_ITEM_VARIABLE)
1769                         count += field->report_count;
1770                 else
1771                         count++;
1772         }
1773
1774         /* allocate the memory to process the fields */
1775         entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
1776         if (!entries)
1777                 return;
1778
1779         report->field_entries = entries;
1780
1781         /*
1782          * walk through all fields in the report and
1783          * store them by priority order in report->field_entry_list
1784          *
1785          * - Var elements are individualized (field + usage_index)
1786          * - Arrays are taken as one, we can not chose an order for them
1787          */
1788         usages = 0;
1789         for (a = 0; a < report->maxfield; a++) {
1790                 field = report->field[a];
1791
1792                 if (field->flags & HID_MAIN_ITEM_VARIABLE) {
1793                         for (u = 0; u < field->report_count; u++) {
1794                                 __hid_insert_field_entry(hid, report,
1795                                                          &entries[usages],
1796                                                          field, u);
1797                                 usages++;
1798                         }
1799                 } else {
1800                         __hid_insert_field_entry(hid, report, &entries[usages],
1801                                                  field, 0);
1802                         usages++;
1803                 }
1804         }
1805 }
1806
1807 static void hid_process_ordering(struct hid_device *hid)
1808 {
1809         struct hid_report *report;
1810         struct hid_report_enum *report_enum = &hid->report_enum[HID_INPUT_REPORT];
1811
1812         list_for_each_entry(report, &report_enum->report_list, list)
1813                 hid_report_process_ordering(hid, report);
1814 }
1815
1816 /*
1817  * Output the field into the report.
1818  */
1819
1820 static void hid_output_field(const struct hid_device *hid,
1821                              struct hid_field *field, __u8 *data)
1822 {
1823         unsigned count = field->report_count;
1824         unsigned offset = field->report_offset;
1825         unsigned size = field->report_size;
1826         unsigned n;
1827
1828         for (n = 0; n < count; n++) {
1829                 if (field->logical_minimum < 0) /* signed values */
1830                         implement(hid, data, offset + n * size, size,
1831                                   s32ton(field->value[n], size));
1832                 else                            /* unsigned values */
1833                         implement(hid, data, offset + n * size, size,
1834                                   field->value[n]);
1835         }
1836 }
1837
1838 /*
1839  * Compute the size of a report.
1840  */
1841 static size_t hid_compute_report_size(struct hid_report *report)
1842 {
1843         if (report->size)
1844                 return ((report->size - 1) >> 3) + 1;
1845
1846         return 0;
1847 }
1848
1849 /*
1850  * Create a report. 'data' has to be allocated using
1851  * hid_alloc_report_buf() so that it has proper size.
1852  */
1853
1854 void hid_output_report(struct hid_report *report, __u8 *data)
1855 {
1856         unsigned n;
1857
1858         if (report->id > 0)
1859                 *data++ = report->id;
1860
1861         memset(data, 0, hid_compute_report_size(report));
1862         for (n = 0; n < report->maxfield; n++)
1863                 hid_output_field(report->device, report->field[n], data);
1864 }
1865 EXPORT_SYMBOL_GPL(hid_output_report);
1866
1867 /*
1868  * Allocator for buffer that is going to be passed to hid_output_report()
1869  */
1870 u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
1871 {
1872         /*
1873          * 7 extra bytes are necessary to achieve proper functionality
1874          * of implement() working on 8 byte chunks
1875          */
1876
1877         u32 len = hid_report_len(report) + 7;
1878
1879         return kmalloc(len, flags);
1880 }
1881 EXPORT_SYMBOL_GPL(hid_alloc_report_buf);
1882
1883 /*
1884  * Set a field value. The report this field belongs to has to be
1885  * created and transferred to the device, to set this value in the
1886  * device.
1887  */
1888
1889 int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
1890 {
1891         unsigned size;
1892
1893         if (!field)
1894                 return -1;
1895
1896         size = field->report_size;
1897
1898         hid_dump_input(field->report->device, field->usage + offset, value);
1899
1900         if (offset >= field->report_count) {
1901                 hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n",
1902                                 offset, field->report_count);
1903                 return -1;
1904         }
1905         if (field->logical_minimum < 0) {
1906                 if (value != snto32(s32ton(value, size), size)) {
1907                         hid_err(field->report->device, "value %d is out of range\n", value);
1908                         return -1;
1909                 }
1910         }
1911         field->value[offset] = value;
1912         return 0;
1913 }
1914 EXPORT_SYMBOL_GPL(hid_set_field);
1915
1916 static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
1917                 const u8 *data)
1918 {
1919         struct hid_report *report;
1920         unsigned int n = 0;     /* Normally report number is 0 */
1921
1922         /* Device uses numbered reports, data[0] is report number */
1923         if (report_enum->numbered)
1924                 n = *data;
1925
1926         report = report_enum->report_id_hash[n];
1927         if (report == NULL)
1928                 dbg_hid("undefined report_id %u received\n", n);
1929
1930         return report;
1931 }
1932
1933 /*
1934  * Implement a generic .request() callback, using .raw_request()
1935  * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
1936  */
1937 int __hid_request(struct hid_device *hid, struct hid_report *report,
1938                 enum hid_class_request reqtype)
1939 {
1940         char *buf;
1941         int ret;
1942         u32 len;
1943
1944         buf = hid_alloc_report_buf(report, GFP_KERNEL);
1945         if (!buf)
1946                 return -ENOMEM;
1947
1948         len = hid_report_len(report);
1949
1950         if (reqtype == HID_REQ_SET_REPORT)
1951                 hid_output_report(report, buf);
1952
1953         ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
1954                                           report->type, reqtype);
1955         if (ret < 0) {
1956                 dbg_hid("unable to complete request: %d\n", ret);
1957                 goto out;
1958         }
1959
1960         if (reqtype == HID_REQ_GET_REPORT)
1961                 hid_input_report(hid, report->type, buf, ret, 0);
1962
1963         ret = 0;
1964
1965 out:
1966         kfree(buf);
1967         return ret;
1968 }
1969 EXPORT_SYMBOL_GPL(__hid_request);
1970
1971 int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
1972                          int interrupt)
1973 {
1974         struct hid_report_enum *report_enum = hid->report_enum + type;
1975         struct hid_report *report;
1976         struct hid_driver *hdrv;
1977         int max_buffer_size = HID_MAX_BUFFER_SIZE;
1978         u32 rsize, csize = size;
1979         u8 *cdata = data;
1980         int ret = 0;
1981
1982         report = hid_get_report(report_enum, data);
1983         if (!report)
1984                 goto out;
1985
1986         if (report_enum->numbered) {
1987                 cdata++;
1988                 csize--;
1989         }
1990
1991         rsize = hid_compute_report_size(report);
1992
1993         if (hid->ll_driver->max_buffer_size)
1994                 max_buffer_size = hid->ll_driver->max_buffer_size;
1995
1996         if (report_enum->numbered && rsize >= max_buffer_size)
1997                 rsize = max_buffer_size - 1;
1998         else if (rsize > max_buffer_size)
1999                 rsize = max_buffer_size;
2000
2001         if (csize < rsize) {
2002                 dbg_hid("report %d is too short, (%d < %d)\n", report->id,
2003                                 csize, rsize);
2004                 memset(cdata + csize, 0, rsize - csize);
2005         }
2006
2007         if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
2008                 hid->hiddev_report_event(hid, report);
2009         if (hid->claimed & HID_CLAIMED_HIDRAW) {
2010                 ret = hidraw_report_event(hid, data, size);
2011                 if (ret)
2012                         goto out;
2013         }
2014
2015         if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
2016                 hid_process_report(hid, report, cdata, interrupt);
2017                 hdrv = hid->driver;
2018                 if (hdrv && hdrv->report)
2019                         hdrv->report(hid, report);
2020         }
2021
2022         if (hid->claimed & HID_CLAIMED_INPUT)
2023                 hidinput_report_event(hid, report);
2024 out:
2025         return ret;
2026 }
2027 EXPORT_SYMBOL_GPL(hid_report_raw_event);
2028
2029 /**
2030  * hid_input_report - report data from lower layer (usb, bt...)
2031  *
2032  * @hid: hid device
2033  * @type: HID report type (HID_*_REPORT)
2034  * @data: report contents
2035  * @size: size of data parameter
2036  * @interrupt: distinguish between interrupt and control transfers
2037  *
2038  * This is data entry for lower layers.
2039  */
2040 int hid_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
2041                      int interrupt)
2042 {
2043         struct hid_report_enum *report_enum;
2044         struct hid_driver *hdrv;
2045         struct hid_report *report;
2046         int ret = 0;
2047
2048         if (!hid)
2049                 return -ENODEV;
2050
2051         if (down_trylock(&hid->driver_input_lock))
2052                 return -EBUSY;
2053
2054         if (!hid->driver) {
2055                 ret = -ENODEV;
2056                 goto unlock;
2057         }
2058         report_enum = hid->report_enum + type;
2059         hdrv = hid->driver;
2060
2061         data = dispatch_hid_bpf_device_event(hid, type, data, &size, interrupt);
2062         if (IS_ERR(data)) {
2063                 ret = PTR_ERR(data);
2064                 goto unlock;
2065         }
2066
2067         if (!size) {
2068                 dbg_hid("empty report\n");
2069                 ret = -1;
2070                 goto unlock;
2071         }
2072
2073         /* Avoid unnecessary overhead if debugfs is disabled */
2074         if (!list_empty(&hid->debug_list))
2075                 hid_dump_report(hid, type, data, size);
2076
2077         report = hid_get_report(report_enum, data);
2078
2079         if (!report) {
2080                 ret = -1;
2081                 goto unlock;
2082         }
2083
2084         if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
2085                 ret = hdrv->raw_event(hid, report, data, size);
2086                 if (ret < 0)
2087                         goto unlock;
2088         }
2089
2090         ret = hid_report_raw_event(hid, type, data, size, interrupt);
2091
2092 unlock:
2093         up(&hid->driver_input_lock);
2094         return ret;
2095 }
2096 EXPORT_SYMBOL_GPL(hid_input_report);
2097
2098 bool hid_match_one_id(const struct hid_device *hdev,
2099                       const struct hid_device_id *id)
2100 {
2101         return (id->bus == HID_BUS_ANY || id->bus == hdev->bus) &&
2102                 (id->group == HID_GROUP_ANY || id->group == hdev->group) &&
2103                 (id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&
2104                 (id->product == HID_ANY_ID || id->product == hdev->product);
2105 }
2106
2107 const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
2108                 const struct hid_device_id *id)
2109 {
2110         for (; id->bus; id++)
2111                 if (hid_match_one_id(hdev, id))
2112                         return id;
2113
2114         return NULL;
2115 }
2116 EXPORT_SYMBOL_GPL(hid_match_id);
2117
2118 static const struct hid_device_id hid_hiddev_list[] = {
2119         { HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS) },
2120         { HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS1) },
2121         { }
2122 };
2123
2124 static bool hid_hiddev(struct hid_device *hdev)
2125 {
2126         return !!hid_match_id(hdev, hid_hiddev_list);
2127 }
2128
2129
2130 static ssize_t
2131 read_report_descriptor(struct file *filp, struct kobject *kobj,
2132                 struct bin_attribute *attr,
2133                 char *buf, loff_t off, size_t count)
2134 {
2135         struct device *dev = kobj_to_dev(kobj);
2136         struct hid_device *hdev = to_hid_device(dev);
2137
2138         if (off >= hdev->rsize)
2139                 return 0;
2140
2141         if (off + count > hdev->rsize)
2142                 count = hdev->rsize - off;
2143
2144         memcpy(buf, hdev->rdesc + off, count);
2145
2146         return count;
2147 }
2148
2149 static ssize_t
2150 show_country(struct device *dev, struct device_attribute *attr,
2151                 char *buf)
2152 {
2153         struct hid_device *hdev = to_hid_device(dev);
2154
2155         return sprintf(buf, "%02x\n", hdev->country & 0xff);
2156 }
2157
2158 static struct bin_attribute dev_bin_attr_report_desc = {
2159         .attr = { .name = "report_descriptor", .mode = 0444 },
2160         .read = read_report_descriptor,
2161         .size = HID_MAX_DESCRIPTOR_SIZE,
2162 };
2163
2164 static const struct device_attribute dev_attr_country = {
2165         .attr = { .name = "country", .mode = 0444 },
2166         .show = show_country,
2167 };
2168
2169 int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
2170 {
2171         static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
2172                 "Joystick", "Gamepad", "Keyboard", "Keypad",
2173                 "Multi-Axis Controller"
2174         };
2175         const char *type, *bus;
2176         char buf[64] = "";
2177         unsigned int i;
2178         int len;
2179         int ret;
2180
2181         ret = hid_bpf_connect_device(hdev);
2182         if (ret)
2183                 return ret;
2184
2185         if (hdev->quirks & HID_QUIRK_HIDDEV_FORCE)
2186                 connect_mask |= (HID_CONNECT_HIDDEV_FORCE | HID_CONNECT_HIDDEV);
2187         if (hdev->quirks & HID_QUIRK_HIDINPUT_FORCE)
2188                 connect_mask |= HID_CONNECT_HIDINPUT_FORCE;
2189         if (hdev->bus != BUS_USB)
2190                 connect_mask &= ~HID_CONNECT_HIDDEV;
2191         if (hid_hiddev(hdev))
2192                 connect_mask |= HID_CONNECT_HIDDEV_FORCE;
2193
2194         if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,
2195                                 connect_mask & HID_CONNECT_HIDINPUT_FORCE))
2196                 hdev->claimed |= HID_CLAIMED_INPUT;
2197
2198         if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect &&
2199                         !hdev->hiddev_connect(hdev,
2200                                 connect_mask & HID_CONNECT_HIDDEV_FORCE))
2201                 hdev->claimed |= HID_CLAIMED_HIDDEV;
2202         if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))
2203                 hdev->claimed |= HID_CLAIMED_HIDRAW;
2204
2205         if (connect_mask & HID_CONNECT_DRIVER)
2206                 hdev->claimed |= HID_CLAIMED_DRIVER;
2207
2208         /* Drivers with the ->raw_event callback set are not required to connect
2209          * to any other listener. */
2210         if (!hdev->claimed && !hdev->driver->raw_event) {
2211                 hid_err(hdev, "device has no listeners, quitting\n");
2212                 return -ENODEV;
2213         }
2214
2215         hid_process_ordering(hdev);
2216
2217         if ((hdev->claimed & HID_CLAIMED_INPUT) &&
2218                         (connect_mask & HID_CONNECT_FF) && hdev->ff_init)
2219                 hdev->ff_init(hdev);
2220
2221         len = 0;
2222         if (hdev->claimed & HID_CLAIMED_INPUT)
2223                 len += sprintf(buf + len, "input");
2224         if (hdev->claimed & HID_CLAIMED_HIDDEV)
2225                 len += sprintf(buf + len, "%shiddev%d", len ? "," : "",
2226                                 ((struct hiddev *)hdev->hiddev)->minor);
2227         if (hdev->claimed & HID_CLAIMED_HIDRAW)
2228                 len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
2229                                 ((struct hidraw *)hdev->hidraw)->minor);
2230
2231         type = "Device";
2232         for (i = 0; i < hdev->maxcollection; i++) {
2233                 struct hid_collection *col = &hdev->collection[i];
2234                 if (col->type == HID_COLLECTION_APPLICATION &&
2235                    (col->usage & HID_USAGE_PAGE) == HID_UP_GENDESK &&
2236                    (col->usage & 0xffff) < ARRAY_SIZE(types)) {
2237                         type = types[col->usage & 0xffff];
2238                         break;
2239                 }
2240         }
2241
2242         switch (hdev->bus) {
2243         case BUS_USB:
2244                 bus = "USB";
2245                 break;
2246         case BUS_BLUETOOTH:
2247                 bus = "BLUETOOTH";
2248                 break;
2249         case BUS_I2C:
2250                 bus = "I2C";
2251                 break;
2252         case BUS_VIRTUAL:
2253                 bus = "VIRTUAL";
2254                 break;
2255         case BUS_INTEL_ISHTP:
2256         case BUS_AMD_SFH:
2257                 bus = "SENSOR HUB";
2258                 break;
2259         default:
2260                 bus = "<UNKNOWN>";
2261         }
2262
2263         ret = device_create_file(&hdev->dev, &dev_attr_country);
2264         if (ret)
2265                 hid_warn(hdev,
2266                          "can't create sysfs country code attribute err: %d\n", ret);
2267
2268         hid_info(hdev, "%s: %s HID v%x.%02x %s [%s] on %s\n",
2269                  buf, bus, hdev->version >> 8, hdev->version & 0xff,
2270                  type, hdev->name, hdev->phys);
2271
2272         return 0;
2273 }
2274 EXPORT_SYMBOL_GPL(hid_connect);
2275
2276 void hid_disconnect(struct hid_device *hdev)
2277 {
2278         device_remove_file(&hdev->dev, &dev_attr_country);
2279         if (hdev->claimed & HID_CLAIMED_INPUT)
2280                 hidinput_disconnect(hdev);
2281         if (hdev->claimed & HID_CLAIMED_HIDDEV)
2282                 hdev->hiddev_disconnect(hdev);
2283         if (hdev->claimed & HID_CLAIMED_HIDRAW)
2284                 hidraw_disconnect(hdev);
2285         hdev->claimed = 0;
2286
2287         hid_bpf_disconnect_device(hdev);
2288 }
2289 EXPORT_SYMBOL_GPL(hid_disconnect);
2290
2291 /**
2292  * hid_hw_start - start underlying HW
2293  * @hdev: hid device
2294  * @connect_mask: which outputs to connect, see HID_CONNECT_*
2295  *
2296  * Call this in probe function *after* hid_parse. This will setup HW
2297  * buffers and start the device (if not defeirred to device open).
2298  * hid_hw_stop must be called if this was successful.
2299  */
2300 int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask)
2301 {
2302         int error;
2303
2304         error = hdev->ll_driver->start(hdev);
2305         if (error)
2306                 return error;
2307
2308         if (connect_mask) {
2309                 error = hid_connect(hdev, connect_mask);
2310                 if (error) {
2311                         hdev->ll_driver->stop(hdev);
2312                         return error;
2313                 }
2314         }
2315
2316         return 0;
2317 }
2318 EXPORT_SYMBOL_GPL(hid_hw_start);
2319
2320 /**
2321  * hid_hw_stop - stop underlying HW
2322  * @hdev: hid device
2323  *
2324  * This is usually called from remove function or from probe when something
2325  * failed and hid_hw_start was called already.
2326  */
2327 void hid_hw_stop(struct hid_device *hdev)
2328 {
2329         hid_disconnect(hdev);
2330         hdev->ll_driver->stop(hdev);
2331 }
2332 EXPORT_SYMBOL_GPL(hid_hw_stop);
2333
2334 /**
2335  * hid_hw_open - signal underlying HW to start delivering events
2336  * @hdev: hid device
2337  *
2338  * Tell underlying HW to start delivering events from the device.
2339  * This function should be called sometime after successful call
2340  * to hid_hw_start().
2341  */
2342 int hid_hw_open(struct hid_device *hdev)
2343 {
2344         int ret;
2345
2346         ret = mutex_lock_killable(&hdev->ll_open_lock);
2347         if (ret)
2348                 return ret;
2349
2350         if (!hdev->ll_open_count++) {
2351                 ret = hdev->ll_driver->open(hdev);
2352                 if (ret)
2353                         hdev->ll_open_count--;
2354         }
2355
2356         mutex_unlock(&hdev->ll_open_lock);
2357         return ret;
2358 }
2359 EXPORT_SYMBOL_GPL(hid_hw_open);
2360
2361 /**
2362  * hid_hw_close - signal underlaying HW to stop delivering events
2363  *
2364  * @hdev: hid device
2365  *
2366  * This function indicates that we are not interested in the events
2367  * from this device anymore. Delivery of events may or may not stop,
2368  * depending on the number of users still outstanding.
2369  */
2370 void hid_hw_close(struct hid_device *hdev)
2371 {
2372         mutex_lock(&hdev->ll_open_lock);
2373         if (!--hdev->ll_open_count)
2374                 hdev->ll_driver->close(hdev);
2375         mutex_unlock(&hdev->ll_open_lock);
2376 }
2377 EXPORT_SYMBOL_GPL(hid_hw_close);
2378
2379 /**
2380  * hid_hw_request - send report request to device
2381  *
2382  * @hdev: hid device
2383  * @report: report to send
2384  * @reqtype: hid request type
2385  */
2386 void hid_hw_request(struct hid_device *hdev,
2387                     struct hid_report *report, enum hid_class_request reqtype)
2388 {
2389         if (hdev->ll_driver->request)
2390                 return hdev->ll_driver->request(hdev, report, reqtype);
2391
2392         __hid_request(hdev, report, reqtype);
2393 }
2394 EXPORT_SYMBOL_GPL(hid_hw_request);
2395
2396 /**
2397  * hid_hw_raw_request - send report request to device
2398  *
2399  * @hdev: hid device
2400  * @reportnum: report ID
2401  * @buf: in/out data to transfer
2402  * @len: length of buf
2403  * @rtype: HID report type
2404  * @reqtype: HID_REQ_GET_REPORT or HID_REQ_SET_REPORT
2405  *
2406  * Return: count of data transferred, negative if error
2407  *
2408  * Same behavior as hid_hw_request, but with raw buffers instead.
2409  */
2410 int hid_hw_raw_request(struct hid_device *hdev,
2411                        unsigned char reportnum, __u8 *buf,
2412                        size_t len, enum hid_report_type rtype, enum hid_class_request reqtype)
2413 {
2414         unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
2415
2416         if (hdev->ll_driver->max_buffer_size)
2417                 max_buffer_size = hdev->ll_driver->max_buffer_size;
2418
2419         if (len < 1 || len > max_buffer_size || !buf)
2420                 return -EINVAL;
2421
2422         return hdev->ll_driver->raw_request(hdev, reportnum, buf, len,
2423                                             rtype, reqtype);
2424 }
2425 EXPORT_SYMBOL_GPL(hid_hw_raw_request);
2426
2427 /**
2428  * hid_hw_output_report - send output report to device
2429  *
2430  * @hdev: hid device
2431  * @buf: raw data to transfer
2432  * @len: length of buf
2433  *
2434  * Return: count of data transferred, negative if error
2435  */
2436 int hid_hw_output_report(struct hid_device *hdev, __u8 *buf, size_t len)
2437 {
2438         unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
2439
2440         if (hdev->ll_driver->max_buffer_size)
2441                 max_buffer_size = hdev->ll_driver->max_buffer_size;
2442
2443         if (len < 1 || len > max_buffer_size || !buf)
2444                 return -EINVAL;
2445
2446         if (hdev->ll_driver->output_report)
2447                 return hdev->ll_driver->output_report(hdev, buf, len);
2448
2449         return -ENOSYS;
2450 }
2451 EXPORT_SYMBOL_GPL(hid_hw_output_report);
2452
2453 #ifdef CONFIG_PM
2454 int hid_driver_suspend(struct hid_device *hdev, pm_message_t state)
2455 {
2456         if (hdev->driver && hdev->driver->suspend)
2457                 return hdev->driver->suspend(hdev, state);
2458
2459         return 0;
2460 }
2461 EXPORT_SYMBOL_GPL(hid_driver_suspend);
2462
2463 int hid_driver_reset_resume(struct hid_device *hdev)
2464 {
2465         if (hdev->driver && hdev->driver->reset_resume)
2466                 return hdev->driver->reset_resume(hdev);
2467
2468         return 0;
2469 }
2470 EXPORT_SYMBOL_GPL(hid_driver_reset_resume);
2471
2472 int hid_driver_resume(struct hid_device *hdev)
2473 {
2474         if (hdev->driver && hdev->driver->resume)
2475                 return hdev->driver->resume(hdev);
2476
2477         return 0;
2478 }
2479 EXPORT_SYMBOL_GPL(hid_driver_resume);
2480 #endif /* CONFIG_PM */
2481
2482 struct hid_dynid {
2483         struct list_head list;
2484         struct hid_device_id id;
2485 };
2486
2487 /**
2488  * new_id_store - add a new HID device ID to this driver and re-probe devices
2489  * @drv: target device driver
2490  * @buf: buffer for scanning device ID data
2491  * @count: input size
2492  *
2493  * Adds a new dynamic hid device ID to this driver,
2494  * and causes the driver to probe for all devices again.
2495  */
2496 static ssize_t new_id_store(struct device_driver *drv, const char *buf,
2497                 size_t count)
2498 {
2499         struct hid_driver *hdrv = to_hid_driver(drv);
2500         struct hid_dynid *dynid;
2501         __u32 bus, vendor, product;
2502         unsigned long driver_data = 0;
2503         int ret;
2504
2505         ret = sscanf(buf, "%x %x %x %lx",
2506                         &bus, &vendor, &product, &driver_data);
2507         if (ret < 3)
2508                 return -EINVAL;
2509
2510         dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
2511         if (!dynid)
2512                 return -ENOMEM;
2513
2514         dynid->id.bus = bus;
2515         dynid->id.group = HID_GROUP_ANY;
2516         dynid->id.vendor = vendor;
2517         dynid->id.product = product;
2518         dynid->id.driver_data = driver_data;
2519
2520         spin_lock(&hdrv->dyn_lock);
2521         list_add_tail(&dynid->list, &hdrv->dyn_list);
2522         spin_unlock(&hdrv->dyn_lock);
2523
2524         ret = driver_attach(&hdrv->driver);
2525
2526         return ret ? : count;
2527 }
2528 static DRIVER_ATTR_WO(new_id);
2529
2530 static struct attribute *hid_drv_attrs[] = {
2531         &driver_attr_new_id.attr,
2532         NULL,
2533 };
2534 ATTRIBUTE_GROUPS(hid_drv);
2535
2536 static void hid_free_dynids(struct hid_driver *hdrv)
2537 {
2538         struct hid_dynid *dynid, *n;
2539
2540         spin_lock(&hdrv->dyn_lock);
2541         list_for_each_entry_safe(dynid, n, &hdrv->dyn_list, list) {
2542                 list_del(&dynid->list);
2543                 kfree(dynid);
2544         }
2545         spin_unlock(&hdrv->dyn_lock);
2546 }
2547
2548 const struct hid_device_id *hid_match_device(struct hid_device *hdev,
2549                                              struct hid_driver *hdrv)
2550 {
2551         struct hid_dynid *dynid;
2552
2553         spin_lock(&hdrv->dyn_lock);
2554         list_for_each_entry(dynid, &hdrv->dyn_list, list) {
2555                 if (hid_match_one_id(hdev, &dynid->id)) {
2556                         spin_unlock(&hdrv->dyn_lock);
2557                         return &dynid->id;
2558                 }
2559         }
2560         spin_unlock(&hdrv->dyn_lock);
2561
2562         return hid_match_id(hdev, hdrv->id_table);
2563 }
2564 EXPORT_SYMBOL_GPL(hid_match_device);
2565
2566 static int hid_bus_match(struct device *dev, struct device_driver *drv)
2567 {
2568         struct hid_driver *hdrv = to_hid_driver(drv);
2569         struct hid_device *hdev = to_hid_device(dev);
2570
2571         return hid_match_device(hdev, hdrv) != NULL;
2572 }
2573
2574 /**
2575  * hid_compare_device_paths - check if both devices share the same path
2576  * @hdev_a: hid device
2577  * @hdev_b: hid device
2578  * @separator: char to use as separator
2579  *
2580  * Check if two devices share the same path up to the last occurrence of
2581  * the separator char. Both paths must exist (i.e., zero-length paths
2582  * don't match).
2583  */
2584 bool hid_compare_device_paths(struct hid_device *hdev_a,
2585                               struct hid_device *hdev_b, char separator)
2586 {
2587         int n1 = strrchr(hdev_a->phys, separator) - hdev_a->phys;
2588         int n2 = strrchr(hdev_b->phys, separator) - hdev_b->phys;
2589
2590         if (n1 != n2 || n1 <= 0 || n2 <= 0)
2591                 return false;
2592
2593         return !strncmp(hdev_a->phys, hdev_b->phys, n1);
2594 }
2595 EXPORT_SYMBOL_GPL(hid_compare_device_paths);
2596
2597 static bool hid_check_device_match(struct hid_device *hdev,
2598                                    struct hid_driver *hdrv,
2599                                    const struct hid_device_id **id)
2600 {
2601         *id = hid_match_device(hdev, hdrv);
2602         if (!*id)
2603                 return false;
2604
2605         if (hdrv->match)
2606                 return hdrv->match(hdev, hid_ignore_special_drivers);
2607
2608         /*
2609          * hid-generic implements .match(), so we must be dealing with a
2610          * different HID driver here, and can simply check if
2611          * hid_ignore_special_drivers is set or not.
2612          */
2613         return !hid_ignore_special_drivers;
2614 }
2615
2616 static int __hid_device_probe(struct hid_device *hdev, struct hid_driver *hdrv)
2617 {
2618         const struct hid_device_id *id;
2619         int ret;
2620
2621         if (!hid_check_device_match(hdev, hdrv, &id))
2622                 return -ENODEV;
2623
2624         hdev->devres_group_id = devres_open_group(&hdev->dev, NULL, GFP_KERNEL);
2625         if (!hdev->devres_group_id)
2626                 return -ENOMEM;
2627
2628         /* reset the quirks that has been previously set */
2629         hdev->quirks = hid_lookup_quirk(hdev);
2630         hdev->driver = hdrv;
2631
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
2640         /*
2641          * Note that we are not closing the devres group opened above so
2642          * even resources that were attached to the device after probe is
2643          * run are released when hid_device_remove() is executed. This is
2644          * needed as some drivers would allocate additional resources,
2645          * for example when updating firmware.
2646          */
2647
2648         if (ret) {
2649                 devres_release_group(&hdev->dev, hdev->devres_group_id);
2650                 hid_close_report(hdev);
2651                 hdev->driver = NULL;
2652         }
2653
2654         return ret;
2655 }
2656
2657 static int hid_device_probe(struct device *dev)
2658 {
2659         struct hid_device *hdev = to_hid_device(dev);
2660         struct hid_driver *hdrv = to_hid_driver(dev->driver);
2661         int ret = 0;
2662
2663         if (down_interruptible(&hdev->driver_input_lock))
2664                 return -EINTR;
2665
2666         hdev->io_started = false;
2667         clear_bit(ffs(HID_STAT_REPROBED), &hdev->status);
2668
2669         if (!hdev->driver)
2670                 ret = __hid_device_probe(hdev, hdrv);
2671
2672         if (!hdev->io_started)
2673                 up(&hdev->driver_input_lock);
2674
2675         return ret;
2676 }
2677
2678 static void hid_device_remove(struct device *dev)
2679 {
2680         struct hid_device *hdev = to_hid_device(dev);
2681         struct hid_driver *hdrv;
2682
2683         down(&hdev->driver_input_lock);
2684         hdev->io_started = false;
2685
2686         hdrv = hdev->driver;
2687         if (hdrv) {
2688                 if (hdrv->remove)
2689                         hdrv->remove(hdev);
2690                 else /* default remove */
2691                         hid_hw_stop(hdev);
2692
2693                 /* Release all devres resources allocated by the driver */
2694                 devres_release_group(&hdev->dev, hdev->devres_group_id);
2695
2696                 hid_close_report(hdev);
2697                 hdev->driver = NULL;
2698         }
2699
2700         if (!hdev->io_started)
2701                 up(&hdev->driver_input_lock);
2702 }
2703
2704 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
2705                              char *buf)
2706 {
2707         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
2708
2709         return scnprintf(buf, PAGE_SIZE, "hid:b%04Xg%04Xv%08Xp%08X\n",
2710                          hdev->bus, hdev->group, hdev->vendor, hdev->product);
2711 }
2712 static DEVICE_ATTR_RO(modalias);
2713
2714 static struct attribute *hid_dev_attrs[] = {
2715         &dev_attr_modalias.attr,
2716         NULL,
2717 };
2718 static struct bin_attribute *hid_dev_bin_attrs[] = {
2719         &dev_bin_attr_report_desc,
2720         NULL
2721 };
2722 static const struct attribute_group hid_dev_group = {
2723         .attrs = hid_dev_attrs,
2724         .bin_attrs = hid_dev_bin_attrs,
2725 };
2726 __ATTRIBUTE_GROUPS(hid_dev);
2727
2728 static int hid_uevent(const struct device *dev, struct kobj_uevent_env *env)
2729 {
2730         const struct hid_device *hdev = to_hid_device(dev);
2731
2732         if (add_uevent_var(env, "HID_ID=%04X:%08X:%08X",
2733                         hdev->bus, hdev->vendor, hdev->product))
2734                 return -ENOMEM;
2735
2736         if (add_uevent_var(env, "HID_NAME=%s", hdev->name))
2737                 return -ENOMEM;
2738
2739         if (add_uevent_var(env, "HID_PHYS=%s", hdev->phys))
2740                 return -ENOMEM;
2741
2742         if (add_uevent_var(env, "HID_UNIQ=%s", hdev->uniq))
2743                 return -ENOMEM;
2744
2745         if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",
2746                            hdev->bus, hdev->group, hdev->vendor, hdev->product))
2747                 return -ENOMEM;
2748
2749         return 0;
2750 }
2751
2752 struct bus_type hid_bus_type = {
2753         .name           = "hid",
2754         .dev_groups     = hid_dev_groups,
2755         .drv_groups     = hid_drv_groups,
2756         .match          = hid_bus_match,
2757         .probe          = hid_device_probe,
2758         .remove         = hid_device_remove,
2759         .uevent         = hid_uevent,
2760 };
2761 EXPORT_SYMBOL(hid_bus_type);
2762
2763 int hid_add_device(struct hid_device *hdev)
2764 {
2765         static atomic_t id = ATOMIC_INIT(0);
2766         int ret;
2767
2768         if (WARN_ON(hdev->status & HID_STAT_ADDED))
2769                 return -EBUSY;
2770
2771         hdev->quirks = hid_lookup_quirk(hdev);
2772
2773         /* we need to kill them here, otherwise they will stay allocated to
2774          * wait for coming driver */
2775         if (hid_ignore(hdev))
2776                 return -ENODEV;
2777
2778         /*
2779          * Check for the mandatory transport channel.
2780          */
2781          if (!hdev->ll_driver->raw_request) {
2782                 hid_err(hdev, "transport driver missing .raw_request()\n");
2783                 return -EINVAL;
2784          }
2785
2786         /*
2787          * Read the device report descriptor once and use as template
2788          * for the driver-specific modifications.
2789          */
2790         ret = hdev->ll_driver->parse(hdev);
2791         if (ret)
2792                 return ret;
2793         if (!hdev->dev_rdesc)
2794                 return -ENODEV;
2795
2796         /*
2797          * Scan generic devices for group information
2798          */
2799         if (hid_ignore_special_drivers) {
2800                 hdev->group = HID_GROUP_GENERIC;
2801         } else if (!hdev->group &&
2802                    !(hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)) {
2803                 ret = hid_scan_report(hdev);
2804                 if (ret)
2805                         hid_warn(hdev, "bad device descriptor (%d)\n", ret);
2806         }
2807
2808         hdev->id = atomic_inc_return(&id);
2809
2810         /* XXX hack, any other cleaner solution after the driver core
2811          * is converted to allow more than 20 bytes as the device name? */
2812         dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
2813                      hdev->vendor, hdev->product, hdev->id);
2814
2815         hid_debug_register(hdev, dev_name(&hdev->dev));
2816         ret = device_add(&hdev->dev);
2817         if (!ret)
2818                 hdev->status |= HID_STAT_ADDED;
2819         else
2820                 hid_debug_unregister(hdev);
2821
2822         return ret;
2823 }
2824 EXPORT_SYMBOL_GPL(hid_add_device);
2825
2826 /**
2827  * hid_allocate_device - allocate new hid device descriptor
2828  *
2829  * Allocate and initialize hid device, so that hid_destroy_device might be
2830  * used to free it.
2831  *
2832  * New hid_device pointer is returned on success, otherwise ERR_PTR encoded
2833  * error value.
2834  */
2835 struct hid_device *hid_allocate_device(void)
2836 {
2837         struct hid_device *hdev;
2838         int ret = -ENOMEM;
2839
2840         hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
2841         if (hdev == NULL)
2842                 return ERR_PTR(ret);
2843
2844         device_initialize(&hdev->dev);
2845         hdev->dev.release = hid_device_release;
2846         hdev->dev.bus = &hid_bus_type;
2847         device_enable_async_suspend(&hdev->dev);
2848
2849         hid_close_report(hdev);
2850
2851         init_waitqueue_head(&hdev->debug_wait);
2852         INIT_LIST_HEAD(&hdev->debug_list);
2853         spin_lock_init(&hdev->debug_list_lock);
2854         sema_init(&hdev->driver_input_lock, 1);
2855         mutex_init(&hdev->ll_open_lock);
2856         kref_init(&hdev->ref);
2857
2858         hid_bpf_device_init(hdev);
2859
2860         return hdev;
2861 }
2862 EXPORT_SYMBOL_GPL(hid_allocate_device);
2863
2864 static void hid_remove_device(struct hid_device *hdev)
2865 {
2866         if (hdev->status & HID_STAT_ADDED) {
2867                 device_del(&hdev->dev);
2868                 hid_debug_unregister(hdev);
2869                 hdev->status &= ~HID_STAT_ADDED;
2870         }
2871         kfree(hdev->dev_rdesc);
2872         hdev->dev_rdesc = NULL;
2873         hdev->dev_rsize = 0;
2874 }
2875
2876 /**
2877  * hid_destroy_device - free previously allocated device
2878  *
2879  * @hdev: hid device
2880  *
2881  * If you allocate hid_device through hid_allocate_device, you should ever
2882  * free by this function.
2883  */
2884 void hid_destroy_device(struct hid_device *hdev)
2885 {
2886         hid_bpf_destroy_device(hdev);
2887         hid_remove_device(hdev);
2888         put_device(&hdev->dev);
2889 }
2890 EXPORT_SYMBOL_GPL(hid_destroy_device);
2891
2892
2893 static int __hid_bus_reprobe_drivers(struct device *dev, void *data)
2894 {
2895         struct hid_driver *hdrv = data;
2896         struct hid_device *hdev = to_hid_device(dev);
2897
2898         if (hdev->driver == hdrv &&
2899             !hdrv->match(hdev, hid_ignore_special_drivers) &&
2900             !test_and_set_bit(ffs(HID_STAT_REPROBED), &hdev->status))
2901                 return device_reprobe(dev);
2902
2903         return 0;
2904 }
2905
2906 static int __hid_bus_driver_added(struct device_driver *drv, void *data)
2907 {
2908         struct hid_driver *hdrv = to_hid_driver(drv);
2909
2910         if (hdrv->match) {
2911                 bus_for_each_dev(&hid_bus_type, NULL, hdrv,
2912                                  __hid_bus_reprobe_drivers);
2913         }
2914
2915         return 0;
2916 }
2917
2918 static int __bus_removed_driver(struct device_driver *drv, void *data)
2919 {
2920         return bus_rescan_devices(&hid_bus_type);
2921 }
2922
2923 int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
2924                 const char *mod_name)
2925 {
2926         int ret;
2927
2928         hdrv->driver.name = hdrv->name;
2929         hdrv->driver.bus = &hid_bus_type;
2930         hdrv->driver.owner = owner;
2931         hdrv->driver.mod_name = mod_name;
2932
2933         INIT_LIST_HEAD(&hdrv->dyn_list);
2934         spin_lock_init(&hdrv->dyn_lock);
2935
2936         ret = driver_register(&hdrv->driver);
2937
2938         if (ret == 0)
2939                 bus_for_each_drv(&hid_bus_type, NULL, NULL,
2940                                  __hid_bus_driver_added);
2941
2942         return ret;
2943 }
2944 EXPORT_SYMBOL_GPL(__hid_register_driver);
2945
2946 void hid_unregister_driver(struct hid_driver *hdrv)
2947 {
2948         driver_unregister(&hdrv->driver);
2949         hid_free_dynids(hdrv);
2950
2951         bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver);
2952 }
2953 EXPORT_SYMBOL_GPL(hid_unregister_driver);
2954
2955 int hid_check_keys_pressed(struct hid_device *hid)
2956 {
2957         struct hid_input *hidinput;
2958         int i;
2959
2960         if (!(hid->claimed & HID_CLAIMED_INPUT))
2961                 return 0;
2962
2963         list_for_each_entry(hidinput, &hid->inputs, list) {
2964                 for (i = 0; i < BITS_TO_LONGS(KEY_MAX); i++)
2965                         if (hidinput->input->key[i])
2966                                 return 1;
2967         }
2968
2969         return 0;
2970 }
2971 EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
2972
2973 #ifdef CONFIG_HID_BPF
2974 static struct hid_bpf_ops hid_ops = {
2975         .hid_get_report = hid_get_report,
2976         .hid_hw_raw_request = hid_hw_raw_request,
2977         .owner = THIS_MODULE,
2978         .bus_type = &hid_bus_type,
2979 };
2980 #endif
2981
2982 static int __init hid_init(void)
2983 {
2984         int ret;
2985
2986         ret = bus_register(&hid_bus_type);
2987         if (ret) {
2988                 pr_err("can't register hid bus\n");
2989                 goto err;
2990         }
2991
2992 #ifdef CONFIG_HID_BPF
2993         hid_bpf_ops = &hid_ops;
2994 #endif
2995
2996         ret = hidraw_init();
2997         if (ret)
2998                 goto err_bus;
2999
3000         hid_debug_init();
3001
3002         return 0;
3003 err_bus:
3004         bus_unregister(&hid_bus_type);
3005 err:
3006         return ret;
3007 }
3008
3009 static void __exit hid_exit(void)
3010 {
3011 #ifdef CONFIG_HID_BPF
3012         hid_bpf_ops = NULL;
3013 #endif
3014         hid_debug_exit();
3015         hidraw_exit();
3016         bus_unregister(&hid_bus_type);
3017         hid_quirks_exit(HID_BUS_ANY);
3018 }
3019
3020 module_init(hid_init);
3021 module_exit(hid_exit);
3022
3023 MODULE_AUTHOR("Andreas Gal");
3024 MODULE_AUTHOR("Vojtech Pavlik");
3025 MODULE_AUTHOR("Jiri Kosina");
3026 MODULE_LICENSE("GPL");