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 <[email protected]>
   7  *  Copyright (c) 2005 Michael Haboustak <[email protected]> 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 = kvzalloc((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                 kvfree(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                         value &= m;
1452                 }
1453         }
1454
1455         __implement(report, offset, n, value);
1456 }
1457
1458 /*
1459  * Search an array for a value.
1460  */
1461
1462 static int search(__s32 *array, __s32 value, unsigned n)
1463 {
1464         while (n--) {
1465                 if (*array++ == value)
1466                         return 0;
1467         }
1468         return -1;
1469 }
1470
1471 /**
1472  * hid_match_report - check if driver's raw_event should be called
1473  *
1474  * @hid: hid device
1475  * @report: hid report to match against
1476  *
1477  * compare hid->driver->report_table->report_type to report->type
1478  */
1479 static int hid_match_report(struct hid_device *hid, struct hid_report *report)
1480 {
1481         const struct hid_report_id *id = hid->driver->report_table;
1482
1483         if (!id) /* NULL means all */
1484                 return 1;
1485
1486         for (; id->report_type != HID_TERMINATOR; id++)
1487                 if (id->report_type == HID_ANY_ID ||
1488                                 id->report_type == report->type)
1489                         return 1;
1490         return 0;
1491 }
1492
1493 /**
1494  * hid_match_usage - check if driver's event should be called
1495  *
1496  * @hid: hid device
1497  * @usage: usage to match against
1498  *
1499  * compare hid->driver->usage_table->usage_{type,code} to
1500  * usage->usage_{type,code}
1501  */
1502 static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage)
1503 {
1504         const struct hid_usage_id *id = hid->driver->usage_table;
1505
1506         if (!id) /* NULL means all */
1507                 return 1;
1508
1509         for (; id->usage_type != HID_ANY_ID - 1; id++)
1510                 if ((id->usage_hid == HID_ANY_ID ||
1511                                 id->usage_hid == usage->hid) &&
1512                                 (id->usage_type == HID_ANY_ID ||
1513                                 id->usage_type == usage->type) &&
1514                                 (id->usage_code == HID_ANY_ID ||
1515                                  id->usage_code == usage->code))
1516                         return 1;
1517         return 0;
1518 }
1519
1520 static void hid_process_event(struct hid_device *hid, struct hid_field *field,
1521                 struct hid_usage *usage, __s32 value, int interrupt)
1522 {
1523         struct hid_driver *hdrv = hid->driver;
1524         int ret;
1525
1526         if (!list_empty(&hid->debug_list))
1527                 hid_dump_input(hid, usage, value);
1528
1529         if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
1530                 ret = hdrv->event(hid, field, usage, value);
1531                 if (ret != 0) {
1532                         if (ret < 0)
1533                                 hid_err(hid, "%s's event failed with %d\n",
1534                                                 hdrv->name, ret);
1535                         return;
1536                 }
1537         }
1538
1539         if (hid->claimed & HID_CLAIMED_INPUT)
1540                 hidinput_hid_event(hid, field, usage, value);
1541         if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
1542                 hid->hiddev_hid_event(hid, field, usage, value);
1543 }
1544
1545 /*
1546  * Checks if the given value is valid within this field
1547  */
1548 static inline int hid_array_value_is_valid(struct hid_field *field,
1549                                            __s32 value)
1550 {
1551         __s32 min = field->logical_minimum;
1552
1553         /*
1554          * Value needs to be between logical min and max, and
1555          * (value - min) is used as an index in the usage array.
1556          * This array is of size field->maxusage
1557          */
1558         return value >= min &&
1559                value <= field->logical_maximum &&
1560                value - min < field->maxusage;
1561 }
1562
1563 /*
1564  * Fetch the field from the data. The field content is stored for next
1565  * report processing (we do differential reporting to the layer).
1566  */
1567 static void hid_input_fetch_field(struct hid_device *hid,
1568                                   struct hid_field *field,
1569                                   __u8 *data)
1570 {
1571         unsigned n;
1572         unsigned count = field->report_count;
1573         unsigned offset = field->report_offset;
1574         unsigned size = field->report_size;
1575         __s32 min = field->logical_minimum;
1576         __s32 *value;
1577
1578         value = field->new_value;
1579         memset(value, 0, count * sizeof(__s32));
1580         field->ignored = false;
1581
1582         for (n = 0; n < count; n++) {
1583
1584                 value[n] = min < 0 ?
1585                         snto32(hid_field_extract(hid, data, offset + n * size,
1586                                size), size) :
1587                         hid_field_extract(hid, data, offset + n * size, size);
1588
1589                 /* Ignore report if ErrorRollOver */
1590                 if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
1591                     hid_array_value_is_valid(field, value[n]) &&
1592                     field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1) {
1593                         field->ignored = true;
1594                         return;
1595                 }
1596         }
1597 }
1598
1599 /*
1600  * Process a received variable field.
1601  */
1602
1603 static void hid_input_var_field(struct hid_device *hid,
1604                                 struct hid_field *field,
1605                                 int interrupt)
1606 {
1607         unsigned int count = field->report_count;
1608         __s32 *value = field->new_value;
1609         unsigned int n;
1610
1611         for (n = 0; n < count; n++)
1612                 hid_process_event(hid,
1613                                   field,
1614                                   &field->usage[n],
1615                                   value[n],
1616                                   interrupt);
1617
1618         memcpy(field->value, value, count * sizeof(__s32));
1619 }
1620
1621 /*
1622  * Process a received array field. The field content is stored for
1623  * next report processing (we do differential reporting to the layer).
1624  */
1625
1626 static void hid_input_array_field(struct hid_device *hid,
1627                                   struct hid_field *field,
1628                                   int interrupt)
1629 {
1630         unsigned int n;
1631         unsigned int count = field->report_count;
1632         __s32 min = field->logical_minimum;
1633         __s32 *value;
1634
1635         value = field->new_value;
1636
1637         /* ErrorRollOver */
1638         if (field->ignored)
1639                 return;
1640
1641         for (n = 0; n < count; n++) {
1642                 if (hid_array_value_is_valid(field, field->value[n]) &&
1643                     search(value, field->value[n], count))
1644                         hid_process_event(hid,
1645                                           field,
1646                                           &field->usage[field->value[n] - min],
1647                                           0,
1648                                           interrupt);
1649
1650                 if (hid_array_value_is_valid(field, value[n]) &&
1651                     search(field->value, value[n], count))
1652                         hid_process_event(hid,
1653                                           field,
1654                                           &field->usage[value[n] - min],
1655                                           1,
1656                                           interrupt);
1657         }
1658
1659         memcpy(field->value, value, count * sizeof(__s32));
1660 }
1661
1662 /*
1663  * Analyse a received report, and fetch the data from it. The field
1664  * content is stored for next report processing (we do differential
1665  * reporting to the layer).
1666  */
1667 static void hid_process_report(struct hid_device *hid,
1668                                struct hid_report *report,
1669                                __u8 *data,
1670                                int interrupt)
1671 {
1672         unsigned int a;
1673         struct hid_field_entry *entry;
1674         struct hid_field *field;
1675
1676         /* first retrieve all incoming values in data */
1677         for (a = 0; a < report->maxfield; a++)
1678                 hid_input_fetch_field(hid, report->field[a], data);
1679
1680         if (!list_empty(&report->field_entry_list)) {
1681                 /* INPUT_REPORT, we have a priority list of fields */
1682                 list_for_each_entry(entry,
1683                                     &report->field_entry_list,
1684                                     list) {
1685                         field = entry->field;
1686
1687                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1688                                 hid_process_event(hid,
1689                                                   field,
1690                                                   &field->usage[entry->index],
1691                                                   field->new_value[entry->index],
1692                                                   interrupt);
1693                         else
1694                                 hid_input_array_field(hid, field, interrupt);
1695                 }
1696
1697                 /* we need to do the memcpy at the end for var items */
1698                 for (a = 0; a < report->maxfield; a++) {
1699                         field = report->field[a];
1700
1701                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1702                                 memcpy(field->value, field->new_value,
1703                                        field->report_count * sizeof(__s32));
1704                 }
1705         } else {
1706                 /* FEATURE_REPORT, regular processing */
1707                 for (a = 0; a < report->maxfield; a++) {
1708                         field = report->field[a];
1709
1710                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1711                                 hid_input_var_field(hid, field, interrupt);
1712                         else
1713                                 hid_input_array_field(hid, field, interrupt);
1714                 }
1715         }
1716 }
1717
1718 /*
1719  * Insert a given usage_index in a field in the list
1720  * of processed usages in the report.
1721  *
1722  * The elements of lower priority score are processed
1723  * first.
1724  */
1725 static void __hid_insert_field_entry(struct hid_device *hid,
1726                                      struct hid_report *report,
1727                                      struct hid_field_entry *entry,
1728                                      struct hid_field *field,
1729                                      unsigned int usage_index)
1730 {
1731         struct hid_field_entry *next;
1732
1733         entry->field = field;
1734         entry->index = usage_index;
1735         entry->priority = field->usages_priorities[usage_index];
1736
1737         /* insert the element at the correct position */
1738         list_for_each_entry(next,
1739                             &report->field_entry_list,
1740                             list) {
1741                 /*
1742                  * the priority of our element is strictly higher
1743                  * than the next one, insert it before
1744                  */
1745                 if (entry->priority > next->priority) {
1746                         list_add_tail(&entry->list, &next->list);
1747                         return;
1748                 }
1749         }
1750
1751         /* lowest priority score: insert at the end */
1752         list_add_tail(&entry->list, &report->field_entry_list);
1753 }
1754
1755 static void hid_report_process_ordering(struct hid_device *hid,
1756                                         struct hid_report *report)
1757 {
1758         struct hid_field *field;
1759         struct hid_field_entry *entries;
1760         unsigned int a, u, usages;
1761         unsigned int count = 0;
1762
1763         /* count the number of individual fields in the report */
1764         for (a = 0; a < report->maxfield; a++) {
1765                 field = report->field[a];
1766
1767                 if (field->flags & HID_MAIN_ITEM_VARIABLE)
1768                         count += field->report_count;
1769                 else
1770                         count++;
1771         }
1772
1773         /* allocate the memory to process the fields */
1774         entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
1775         if (!entries)
1776                 return;
1777
1778         report->field_entries = entries;
1779
1780         /*
1781          * walk through all fields in the report and
1782          * store them by priority order in report->field_entry_list
1783          *
1784          * - Var elements are individualized (field + usage_index)
1785          * - Arrays are taken as one, we can not chose an order for them
1786          */
1787         usages = 0;
1788         for (a = 0; a < report->maxfield; a++) {
1789                 field = report->field[a];
1790
1791                 if (field->flags & HID_MAIN_ITEM_VARIABLE) {
1792                         for (u = 0; u < field->report_count; u++) {
1793                                 __hid_insert_field_entry(hid, report,
1794                                                          &entries[usages],
1795                                                          field, u);
1796                                 usages++;
1797                         }
1798                 } else {
1799                         __hid_insert_field_entry(hid, report, &entries[usages],
1800                                                  field, 0);
1801                         usages++;
1802                 }
1803         }
1804 }
1805
1806 static void hid_process_ordering(struct hid_device *hid)
1807 {
1808         struct hid_report *report;
1809         struct hid_report_enum *report_enum = &hid->report_enum[HID_INPUT_REPORT];
1810
1811         list_for_each_entry(report, &report_enum->report_list, list)
1812                 hid_report_process_ordering(hid, report);
1813 }
1814
1815 /*
1816  * Output the field into the report.
1817  */
1818
1819 static void hid_output_field(const struct hid_device *hid,
1820                              struct hid_field *field, __u8 *data)
1821 {
1822         unsigned count = field->report_count;
1823         unsigned offset = field->report_offset;
1824         unsigned size = field->report_size;
1825         unsigned n;
1826
1827         for (n = 0; n < count; n++) {
1828                 if (field->logical_minimum < 0) /* signed values */
1829                         implement(hid, data, offset + n * size, size,
1830                                   s32ton(field->value[n], size));
1831                 else                            /* unsigned values */
1832                         implement(hid, data, offset + n * size, size,
1833                                   field->value[n]);
1834         }
1835 }
1836
1837 /*
1838  * Compute the size of a report.
1839  */
1840 static size_t hid_compute_report_size(struct hid_report *report)
1841 {
1842         if (report->size)
1843                 return ((report->size - 1) >> 3) + 1;
1844
1845         return 0;
1846 }
1847
1848 /*
1849  * Create a report. 'data' has to be allocated using
1850  * hid_alloc_report_buf() so that it has proper size.
1851  */
1852
1853 void hid_output_report(struct hid_report *report, __u8 *data)
1854 {
1855         unsigned n;
1856
1857         if (report->id > 0)
1858                 *data++ = report->id;
1859
1860         memset(data, 0, hid_compute_report_size(report));
1861         for (n = 0; n < report->maxfield; n++)
1862                 hid_output_field(report->device, report->field[n], data);
1863 }
1864 EXPORT_SYMBOL_GPL(hid_output_report);
1865
1866 /*
1867  * Allocator for buffer that is going to be passed to hid_output_report()
1868  */
1869 u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
1870 {
1871         /*
1872          * 7 extra bytes are necessary to achieve proper functionality
1873          * of implement() working on 8 byte chunks
1874          */
1875
1876         u32 len = hid_report_len(report) + 7;
1877
1878         return kmalloc(len, flags);
1879 }
1880 EXPORT_SYMBOL_GPL(hid_alloc_report_buf);
1881
1882 /*
1883  * Set a field value. The report this field belongs to has to be
1884  * created and transferred to the device, to set this value in the
1885  * device.
1886  */
1887
1888 int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
1889 {
1890         unsigned size;
1891
1892         if (!field)
1893                 return -1;
1894
1895         size = field->report_size;
1896
1897         hid_dump_input(field->report->device, field->usage + offset, value);
1898
1899         if (offset >= field->report_count) {
1900                 hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n",
1901                                 offset, field->report_count);
1902                 return -1;
1903         }
1904         if (field->logical_minimum < 0) {
1905                 if (value != snto32(s32ton(value, size), size)) {
1906                         hid_err(field->report->device, "value %d is out of range\n", value);
1907                         return -1;
1908                 }
1909         }
1910         field->value[offset] = value;
1911         return 0;
1912 }
1913 EXPORT_SYMBOL_GPL(hid_set_field);
1914
1915 static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
1916                 const u8 *data)
1917 {
1918         struct hid_report *report;
1919         unsigned int n = 0;     /* Normally report number is 0 */
1920
1921         /* Device uses numbered reports, data[0] is report number */
1922         if (report_enum->numbered)
1923                 n = *data;
1924
1925         report = report_enum->report_id_hash[n];
1926         if (report == NULL)
1927                 dbg_hid("undefined report_id %u received\n", n);
1928
1929         return report;
1930 }
1931
1932 /*
1933  * Implement a generic .request() callback, using .raw_request()
1934  * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
1935  */
1936 int __hid_request(struct hid_device *hid, struct hid_report *report,
1937                 enum hid_class_request reqtype)
1938 {
1939         char *buf;
1940         int ret;
1941         u32 len;
1942
1943         buf = hid_alloc_report_buf(report, GFP_KERNEL);
1944         if (!buf)
1945                 return -ENOMEM;
1946
1947         len = hid_report_len(report);
1948
1949         if (reqtype == HID_REQ_SET_REPORT)
1950                 hid_output_report(report, buf);
1951
1952         ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
1953                                           report->type, reqtype);
1954         if (ret < 0) {
1955                 dbg_hid("unable to complete request: %d\n", ret);
1956                 goto out;
1957         }
1958
1959         if (reqtype == HID_REQ_GET_REPORT)
1960                 hid_input_report(hid, report->type, buf, ret, 0);
1961
1962         ret = 0;
1963
1964 out:
1965         kfree(buf);
1966         return ret;
1967 }
1968 EXPORT_SYMBOL_GPL(__hid_request);
1969
1970 int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
1971                          int interrupt)
1972 {
1973         struct hid_report_enum *report_enum = hid->report_enum + type;
1974         struct hid_report *report;
1975         struct hid_driver *hdrv;
1976         int max_buffer_size = HID_MAX_BUFFER_SIZE;
1977         u32 rsize, csize = size;
1978         u8 *cdata = data;
1979         int ret = 0;
1980
1981         report = hid_get_report(report_enum, data);
1982         if (!report)
1983                 goto out;
1984
1985         if (report_enum->numbered) {
1986                 cdata++;
1987                 csize--;
1988         }
1989
1990         rsize = hid_compute_report_size(report);
1991
1992         if (hid->ll_driver->max_buffer_size)
1993                 max_buffer_size = hid->ll_driver->max_buffer_size;
1994
1995         if (report_enum->numbered && rsize >= max_buffer_size)
1996                 rsize = max_buffer_size - 1;
1997         else if (rsize > max_buffer_size)
1998                 rsize = max_buffer_size;
1999
2000         if (csize < rsize) {
2001                 dbg_hid("report %d is too short, (%d < %d)\n", report->id,
2002                                 csize, rsize);
2003                 memset(cdata + csize, 0, rsize - csize);
2004         }
2005
2006         if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
2007                 hid->hiddev_report_event(hid, report);
2008         if (hid->claimed & HID_CLAIMED_HIDRAW) {
2009                 ret = hidraw_report_event(hid, data, size);
2010                 if (ret)
2011                         goto out;
2012         }
2013
2014         if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
2015                 hid_process_report(hid, report, cdata, interrupt);
2016                 hdrv = hid->driver;
2017                 if (hdrv && hdrv->report)
2018                         hdrv->report(hid, report);
2019         }
2020
2021         if (hid->claimed & HID_CLAIMED_INPUT)
2022                 hidinput_report_event(hid, report);
2023 out:
2024         return ret;
2025 }
2026 EXPORT_SYMBOL_GPL(hid_report_raw_event);
2027
2028
2029 static int __hid_input_report(struct hid_device *hid, enum hid_report_type type,
2030                               u8 *data, u32 size, int interrupt, u64 source, bool from_bpf,
2031                               bool lock_already_taken)
2032 {
2033         struct hid_report_enum *report_enum;
2034         struct hid_driver *hdrv;
2035         struct hid_report *report;
2036         int ret = 0;
2037
2038         if (!hid)
2039                 return -ENODEV;
2040
2041         ret = down_trylock(&hid->driver_input_lock);
2042         if (lock_already_taken && !ret) {
2043                 up(&hid->driver_input_lock);
2044                 return -EINVAL;
2045         } else if (!lock_already_taken && ret) {
2046                 return -EBUSY;
2047         }
2048
2049         if (!hid->driver) {
2050                 ret = -ENODEV;
2051                 goto unlock;
2052         }
2053         report_enum = hid->report_enum + type;
2054         hdrv = hid->driver;
2055
2056         data = dispatch_hid_bpf_device_event(hid, type, data, &size, interrupt, source, from_bpf);
2057         if (IS_ERR(data)) {
2058                 ret = PTR_ERR(data);
2059                 goto unlock;
2060         }
2061
2062         if (!size) {
2063                 dbg_hid("empty report\n");
2064                 ret = -1;
2065                 goto unlock;
2066         }
2067
2068         /* Avoid unnecessary overhead if debugfs is disabled */
2069         if (!list_empty(&hid->debug_list))
2070                 hid_dump_report(hid, type, data, size);
2071
2072         report = hid_get_report(report_enum, data);
2073
2074         if (!report) {
2075                 ret = -1;
2076                 goto unlock;
2077         }
2078
2079         if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
2080                 ret = hdrv->raw_event(hid, report, data, size);
2081                 if (ret < 0)
2082                         goto unlock;
2083         }
2084
2085         ret = hid_report_raw_event(hid, type, data, size, interrupt);
2086
2087 unlock:
2088         if (!lock_already_taken)
2089                 up(&hid->driver_input_lock);
2090         return ret;
2091 }
2092
2093 /**
2094  * hid_input_report - report data from lower layer (usb, bt...)
2095  *
2096  * @hid: hid device
2097  * @type: HID report type (HID_*_REPORT)
2098  * @data: report contents
2099  * @size: size of data parameter
2100  * @interrupt: distinguish between interrupt and control transfers
2101  *
2102  * This is data entry for lower layers.
2103  */
2104 int hid_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
2105                      int interrupt)
2106 {
2107         return __hid_input_report(hid, type, data, size, interrupt, 0,
2108                                   false, /* from_bpf */
2109                                   false /* lock_already_taken */);
2110 }
2111 EXPORT_SYMBOL_GPL(hid_input_report);
2112
2113 bool hid_match_one_id(const struct hid_device *hdev,
2114                       const struct hid_device_id *id)
2115 {
2116         return (id->bus == HID_BUS_ANY || id->bus == hdev->bus) &&
2117                 (id->group == HID_GROUP_ANY || id->group == hdev->group) &&
2118                 (id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&
2119                 (id->product == HID_ANY_ID || id->product == hdev->product);
2120 }
2121
2122 const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
2123                 const struct hid_device_id *id)
2124 {
2125         for (; id->bus; id++)
2126                 if (hid_match_one_id(hdev, id))
2127                         return id;
2128
2129         return NULL;
2130 }
2131 EXPORT_SYMBOL_GPL(hid_match_id);
2132
2133 static const struct hid_device_id hid_hiddev_list[] = {
2134         { HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS) },
2135         { HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS1) },
2136         { }
2137 };
2138
2139 static bool hid_hiddev(struct hid_device *hdev)
2140 {
2141         return !!hid_match_id(hdev, hid_hiddev_list);
2142 }
2143
2144
2145 static ssize_t
2146 read_report_descriptor(struct file *filp, struct kobject *kobj,
2147                 struct bin_attribute *attr,
2148                 char *buf, loff_t off, size_t count)
2149 {
2150         struct device *dev = kobj_to_dev(kobj);
2151         struct hid_device *hdev = to_hid_device(dev);
2152
2153         if (off >= hdev->rsize)
2154                 return 0;
2155
2156         if (off + count > hdev->rsize)
2157                 count = hdev->rsize - off;
2158
2159         memcpy(buf, hdev->rdesc + off, count);
2160
2161         return count;
2162 }
2163
2164 static ssize_t
2165 show_country(struct device *dev, struct device_attribute *attr,
2166                 char *buf)
2167 {
2168         struct hid_device *hdev = to_hid_device(dev);
2169
2170         return sprintf(buf, "%02x\n", hdev->country & 0xff);
2171 }
2172
2173 static struct bin_attribute dev_bin_attr_report_desc = {
2174         .attr = { .name = "report_descriptor", .mode = 0444 },
2175         .read = read_report_descriptor,
2176         .size = HID_MAX_DESCRIPTOR_SIZE,
2177 };
2178
2179 static const struct device_attribute dev_attr_country = {
2180         .attr = { .name = "country", .mode = 0444 },
2181         .show = show_country,
2182 };
2183
2184 int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
2185 {
2186         static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
2187                 "Joystick", "Gamepad", "Keyboard", "Keypad",
2188                 "Multi-Axis Controller"
2189         };
2190         const char *type, *bus;
2191         char buf[64] = "";
2192         unsigned int i;
2193         int len;
2194         int ret;
2195
2196         ret = hid_bpf_connect_device(hdev);
2197         if (ret)
2198                 return ret;
2199
2200         if (hdev->quirks & HID_QUIRK_HIDDEV_FORCE)
2201                 connect_mask |= (HID_CONNECT_HIDDEV_FORCE | HID_CONNECT_HIDDEV);
2202         if (hdev->quirks & HID_QUIRK_HIDINPUT_FORCE)
2203                 connect_mask |= HID_CONNECT_HIDINPUT_FORCE;
2204         if (hdev->bus != BUS_USB)
2205                 connect_mask &= ~HID_CONNECT_HIDDEV;
2206         if (hid_hiddev(hdev))
2207                 connect_mask |= HID_CONNECT_HIDDEV_FORCE;
2208
2209         if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,
2210                                 connect_mask & HID_CONNECT_HIDINPUT_FORCE))
2211                 hdev->claimed |= HID_CLAIMED_INPUT;
2212
2213         if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect &&
2214                         !hdev->hiddev_connect(hdev,
2215                                 connect_mask & HID_CONNECT_HIDDEV_FORCE))
2216                 hdev->claimed |= HID_CLAIMED_HIDDEV;
2217         if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))
2218                 hdev->claimed |= HID_CLAIMED_HIDRAW;
2219
2220         if (connect_mask & HID_CONNECT_DRIVER)
2221                 hdev->claimed |= HID_CLAIMED_DRIVER;
2222
2223         /* Drivers with the ->raw_event callback set are not required to connect
2224          * to any other listener. */
2225         if (!hdev->claimed && !hdev->driver->raw_event) {
2226                 hid_err(hdev, "device has no listeners, quitting\n");
2227                 return -ENODEV;
2228         }
2229
2230         hid_process_ordering(hdev);
2231
2232         if ((hdev->claimed & HID_CLAIMED_INPUT) &&
2233                         (connect_mask & HID_CONNECT_FF) && hdev->ff_init)
2234                 hdev->ff_init(hdev);
2235
2236         len = 0;
2237         if (hdev->claimed & HID_CLAIMED_INPUT)
2238                 len += sprintf(buf + len, "input");
2239         if (hdev->claimed & HID_CLAIMED_HIDDEV)
2240                 len += sprintf(buf + len, "%shiddev%d", len ? "," : "",
2241                                 ((struct hiddev *)hdev->hiddev)->minor);
2242         if (hdev->claimed & HID_CLAIMED_HIDRAW)
2243                 len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
2244                                 ((struct hidraw *)hdev->hidraw)->minor);
2245
2246         type = "Device";
2247         for (i = 0; i < hdev->maxcollection; i++) {
2248                 struct hid_collection *col = &hdev->collection[i];
2249                 if (col->type == HID_COLLECTION_APPLICATION &&
2250                    (col->usage & HID_USAGE_PAGE) == HID_UP_GENDESK &&
2251                    (col->usage & 0xffff) < ARRAY_SIZE(types)) {
2252                         type = types[col->usage & 0xffff];
2253                         break;
2254                 }
2255         }
2256
2257         switch (hdev->bus) {
2258         case BUS_USB:
2259                 bus = "USB";
2260                 break;
2261         case BUS_BLUETOOTH:
2262                 bus = "BLUETOOTH";
2263                 break;
2264         case BUS_I2C:
2265                 bus = "I2C";
2266                 break;
2267         case BUS_VIRTUAL:
2268                 bus = "VIRTUAL";
2269                 break;
2270         case BUS_INTEL_ISHTP:
2271         case BUS_AMD_SFH:
2272                 bus = "SENSOR HUB";
2273                 break;
2274         default:
2275                 bus = "<UNKNOWN>";
2276         }
2277
2278         ret = device_create_file(&hdev->dev, &dev_attr_country);
2279         if (ret)
2280                 hid_warn(hdev,
2281                          "can't create sysfs country code attribute err: %d\n", ret);
2282
2283         hid_info(hdev, "%s: %s HID v%x.%02x %s [%s] on %s\n",
2284                  buf, bus, hdev->version >> 8, hdev->version & 0xff,
2285                  type, hdev->name, hdev->phys);
2286
2287         return 0;
2288 }
2289 EXPORT_SYMBOL_GPL(hid_connect);
2290
2291 void hid_disconnect(struct hid_device *hdev)
2292 {
2293         device_remove_file(&hdev->dev, &dev_attr_country);
2294         if (hdev->claimed & HID_CLAIMED_INPUT)
2295                 hidinput_disconnect(hdev);
2296         if (hdev->claimed & HID_CLAIMED_HIDDEV)
2297                 hdev->hiddev_disconnect(hdev);
2298         if (hdev->claimed & HID_CLAIMED_HIDRAW)
2299                 hidraw_disconnect(hdev);
2300         hdev->claimed = 0;
2301
2302         hid_bpf_disconnect_device(hdev);
2303 }
2304 EXPORT_SYMBOL_GPL(hid_disconnect);
2305
2306 /**
2307  * hid_hw_start - start underlying HW
2308  * @hdev: hid device
2309  * @connect_mask: which outputs to connect, see HID_CONNECT_*
2310  *
2311  * Call this in probe function *after* hid_parse. This will setup HW
2312  * buffers and start the device (if not defeirred to device open).
2313  * hid_hw_stop must be called if this was successful.
2314  */
2315 int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask)
2316 {
2317         int error;
2318
2319         error = hdev->ll_driver->start(hdev);
2320         if (error)
2321                 return error;
2322
2323         if (connect_mask) {
2324                 error = hid_connect(hdev, connect_mask);
2325                 if (error) {
2326                         hdev->ll_driver->stop(hdev);
2327                         return error;
2328                 }
2329         }
2330
2331         return 0;
2332 }
2333 EXPORT_SYMBOL_GPL(hid_hw_start);
2334
2335 /**
2336  * hid_hw_stop - stop underlying HW
2337  * @hdev: hid device
2338  *
2339  * This is usually called from remove function or from probe when something
2340  * failed and hid_hw_start was called already.
2341  */
2342 void hid_hw_stop(struct hid_device *hdev)
2343 {
2344         hid_disconnect(hdev);
2345         hdev->ll_driver->stop(hdev);
2346 }
2347 EXPORT_SYMBOL_GPL(hid_hw_stop);
2348
2349 /**
2350  * hid_hw_open - signal underlying HW to start delivering events
2351  * @hdev: hid device
2352  *
2353  * Tell underlying HW to start delivering events from the device.
2354  * This function should be called sometime after successful call
2355  * to hid_hw_start().
2356  */
2357 int hid_hw_open(struct hid_device *hdev)
2358 {
2359         int ret;
2360
2361         ret = mutex_lock_killable(&hdev->ll_open_lock);
2362         if (ret)
2363                 return ret;
2364
2365         if (!hdev->ll_open_count++) {
2366                 ret = hdev->ll_driver->open(hdev);
2367                 if (ret)
2368                         hdev->ll_open_count--;
2369         }
2370
2371         mutex_unlock(&hdev->ll_open_lock);
2372         return ret;
2373 }
2374 EXPORT_SYMBOL_GPL(hid_hw_open);
2375
2376 /**
2377  * hid_hw_close - signal underlaying HW to stop delivering events
2378  *
2379  * @hdev: hid device
2380  *
2381  * This function indicates that we are not interested in the events
2382  * from this device anymore. Delivery of events may or may not stop,
2383  * depending on the number of users still outstanding.
2384  */
2385 void hid_hw_close(struct hid_device *hdev)
2386 {
2387         mutex_lock(&hdev->ll_open_lock);
2388         if (!--hdev->ll_open_count)
2389                 hdev->ll_driver->close(hdev);
2390         mutex_unlock(&hdev->ll_open_lock);
2391 }
2392 EXPORT_SYMBOL_GPL(hid_hw_close);
2393
2394 /**
2395  * hid_hw_request - send report request to device
2396  *
2397  * @hdev: hid device
2398  * @report: report to send
2399  * @reqtype: hid request type
2400  */
2401 void hid_hw_request(struct hid_device *hdev,
2402                     struct hid_report *report, enum hid_class_request reqtype)
2403 {
2404         if (hdev->ll_driver->request)
2405                 return hdev->ll_driver->request(hdev, report, reqtype);
2406
2407         __hid_request(hdev, report, reqtype);
2408 }
2409 EXPORT_SYMBOL_GPL(hid_hw_request);
2410
2411 int __hid_hw_raw_request(struct hid_device *hdev,
2412                          unsigned char reportnum, __u8 *buf,
2413                          size_t len, enum hid_report_type rtype,
2414                          enum hid_class_request reqtype,
2415                          u64 source, bool from_bpf)
2416 {
2417         unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
2418         int ret;
2419
2420         if (hdev->ll_driver->max_buffer_size)
2421                 max_buffer_size = hdev->ll_driver->max_buffer_size;
2422
2423         if (len < 1 || len > max_buffer_size || !buf)
2424                 return -EINVAL;
2425
2426         ret = dispatch_hid_bpf_raw_requests(hdev, reportnum, buf, len, rtype,
2427                                             reqtype, source, from_bpf);
2428         if (ret)
2429                 return ret;
2430
2431         return hdev->ll_driver->raw_request(hdev, reportnum, buf, len,
2432                                             rtype, reqtype);
2433 }
2434
2435 /**
2436  * hid_hw_raw_request - send report request to device
2437  *
2438  * @hdev: hid device
2439  * @reportnum: report ID
2440  * @buf: in/out data to transfer
2441  * @len: length of buf
2442  * @rtype: HID report type
2443  * @reqtype: HID_REQ_GET_REPORT or HID_REQ_SET_REPORT
2444  *
2445  * Return: count of data transferred, negative if error
2446  *
2447  * Same behavior as hid_hw_request, but with raw buffers instead.
2448  */
2449 int hid_hw_raw_request(struct hid_device *hdev,
2450                        unsigned char reportnum, __u8 *buf,
2451                        size_t len, enum hid_report_type rtype, enum hid_class_request reqtype)
2452 {
2453         return __hid_hw_raw_request(hdev, reportnum, buf, len, rtype, reqtype, 0, false);
2454 }
2455 EXPORT_SYMBOL_GPL(hid_hw_raw_request);
2456
2457 int __hid_hw_output_report(struct hid_device *hdev, __u8 *buf, size_t len, u64 source,
2458                            bool from_bpf)
2459 {
2460         unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
2461         int ret;
2462
2463         if (hdev->ll_driver->max_buffer_size)
2464                 max_buffer_size = hdev->ll_driver->max_buffer_size;
2465
2466         if (len < 1 || len > max_buffer_size || !buf)
2467                 return -EINVAL;
2468
2469         ret = dispatch_hid_bpf_output_report(hdev, buf, len, source, from_bpf);
2470         if (ret)
2471                 return ret;
2472
2473         if (hdev->ll_driver->output_report)
2474                 return hdev->ll_driver->output_report(hdev, buf, len);
2475
2476         return -ENOSYS;
2477 }
2478
2479 /**
2480  * hid_hw_output_report - send output report to device
2481  *
2482  * @hdev: hid device
2483  * @buf: raw data to transfer
2484  * @len: length of buf
2485  *
2486  * Return: count of data transferred, negative if error
2487  */
2488 int hid_hw_output_report(struct hid_device *hdev, __u8 *buf, size_t len)
2489 {
2490         return __hid_hw_output_report(hdev, buf, len, 0, false);
2491 }
2492 EXPORT_SYMBOL_GPL(hid_hw_output_report);
2493
2494 #ifdef CONFIG_PM
2495 int hid_driver_suspend(struct hid_device *hdev, pm_message_t state)
2496 {
2497         if (hdev->driver && hdev->driver->suspend)
2498                 return hdev->driver->suspend(hdev, state);
2499
2500         return 0;
2501 }
2502 EXPORT_SYMBOL_GPL(hid_driver_suspend);
2503
2504 int hid_driver_reset_resume(struct hid_device *hdev)
2505 {
2506         if (hdev->driver && hdev->driver->reset_resume)
2507                 return hdev->driver->reset_resume(hdev);
2508
2509         return 0;
2510 }
2511 EXPORT_SYMBOL_GPL(hid_driver_reset_resume);
2512
2513 int hid_driver_resume(struct hid_device *hdev)
2514 {
2515         if (hdev->driver && hdev->driver->resume)
2516                 return hdev->driver->resume(hdev);
2517
2518         return 0;
2519 }
2520 EXPORT_SYMBOL_GPL(hid_driver_resume);
2521 #endif /* CONFIG_PM */
2522
2523 struct hid_dynid {
2524         struct list_head list;
2525         struct hid_device_id id;
2526 };
2527
2528 /**
2529  * new_id_store - add a new HID device ID to this driver and re-probe devices
2530  * @drv: target device driver
2531  * @buf: buffer for scanning device ID data
2532  * @count: input size
2533  *
2534  * Adds a new dynamic hid device ID to this driver,
2535  * and causes the driver to probe for all devices again.
2536  */
2537 static ssize_t new_id_store(struct device_driver *drv, const char *buf,
2538                 size_t count)
2539 {
2540         struct hid_driver *hdrv = to_hid_driver(drv);
2541         struct hid_dynid *dynid;
2542         __u32 bus, vendor, product;
2543         unsigned long driver_data = 0;
2544         int ret;
2545
2546         ret = sscanf(buf, "%x %x %x %lx",
2547                         &bus, &vendor, &product, &driver_data);
2548         if (ret < 3)
2549                 return -EINVAL;
2550
2551         dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
2552         if (!dynid)
2553                 return -ENOMEM;
2554
2555         dynid->id.bus = bus;
2556         dynid->id.group = HID_GROUP_ANY;
2557         dynid->id.vendor = vendor;
2558         dynid->id.product = product;
2559         dynid->id.driver_data = driver_data;
2560
2561         spin_lock(&hdrv->dyn_lock);
2562         list_add_tail(&dynid->list, &hdrv->dyn_list);
2563         spin_unlock(&hdrv->dyn_lock);
2564
2565         ret = driver_attach(&hdrv->driver);
2566
2567         return ret ? : count;
2568 }
2569 static DRIVER_ATTR_WO(new_id);
2570
2571 static struct attribute *hid_drv_attrs[] = {
2572         &driver_attr_new_id.attr,
2573         NULL,
2574 };
2575 ATTRIBUTE_GROUPS(hid_drv);
2576
2577 static void hid_free_dynids(struct hid_driver *hdrv)
2578 {
2579         struct hid_dynid *dynid, *n;
2580
2581         spin_lock(&hdrv->dyn_lock);
2582         list_for_each_entry_safe(dynid, n, &hdrv->dyn_list, list) {
2583                 list_del(&dynid->list);
2584                 kfree(dynid);
2585         }
2586         spin_unlock(&hdrv->dyn_lock);
2587 }
2588
2589 const struct hid_device_id *hid_match_device(struct hid_device *hdev,
2590                                              struct hid_driver *hdrv)
2591 {
2592         struct hid_dynid *dynid;
2593
2594         spin_lock(&hdrv->dyn_lock);
2595         list_for_each_entry(dynid, &hdrv->dyn_list, list) {
2596                 if (hid_match_one_id(hdev, &dynid->id)) {
2597                         spin_unlock(&hdrv->dyn_lock);
2598                         return &dynid->id;
2599                 }
2600         }
2601         spin_unlock(&hdrv->dyn_lock);
2602
2603         return hid_match_id(hdev, hdrv->id_table);
2604 }
2605 EXPORT_SYMBOL_GPL(hid_match_device);
2606
2607 static int hid_bus_match(struct device *dev, const struct device_driver *drv)
2608 {
2609         struct hid_driver *hdrv = to_hid_driver(drv);
2610         struct hid_device *hdev = to_hid_device(dev);
2611
2612         return hid_match_device(hdev, hdrv) != NULL;
2613 }
2614
2615 /**
2616  * hid_compare_device_paths - check if both devices share the same path
2617  * @hdev_a: hid device
2618  * @hdev_b: hid device
2619  * @separator: char to use as separator
2620  *
2621  * Check if two devices share the same path up to the last occurrence of
2622  * the separator char. Both paths must exist (i.e., zero-length paths
2623  * don't match).
2624  */
2625 bool hid_compare_device_paths(struct hid_device *hdev_a,
2626                               struct hid_device *hdev_b, char separator)
2627 {
2628         int n1 = strrchr(hdev_a->phys, separator) - hdev_a->phys;
2629         int n2 = strrchr(hdev_b->phys, separator) - hdev_b->phys;
2630
2631         if (n1 != n2 || n1 <= 0 || n2 <= 0)
2632                 return false;
2633
2634         return !strncmp(hdev_a->phys, hdev_b->phys, n1);
2635 }
2636 EXPORT_SYMBOL_GPL(hid_compare_device_paths);
2637
2638 static bool hid_check_device_match(struct hid_device *hdev,
2639                                    struct hid_driver *hdrv,
2640                                    const struct hid_device_id **id)
2641 {
2642         *id = hid_match_device(hdev, hdrv);
2643         if (!*id)
2644                 return false;
2645
2646         if (hdrv->match)
2647                 return hdrv->match(hdev, hid_ignore_special_drivers);
2648
2649         /*
2650          * hid-generic implements .match(), so we must be dealing with a
2651          * different HID driver here, and can simply check if
2652          * hid_ignore_special_drivers is set or not.
2653          */
2654         return !hid_ignore_special_drivers;
2655 }
2656
2657 static int __hid_device_probe(struct hid_device *hdev, struct hid_driver *hdrv)
2658 {
2659         const struct hid_device_id *id;
2660         int ret;
2661
2662         if (!hid_check_device_match(hdev, hdrv, &id))
2663                 return -ENODEV;
2664
2665         hdev->devres_group_id = devres_open_group(&hdev->dev, NULL, GFP_KERNEL);
2666         if (!hdev->devres_group_id)
2667                 return -ENOMEM;
2668
2669         /* reset the quirks that has been previously set */
2670         hdev->quirks = hid_lookup_quirk(hdev);
2671         hdev->driver = hdrv;
2672
2673         if (hdrv->probe) {
2674                 ret = hdrv->probe(hdev, id);
2675         } else { /* default probe */
2676                 ret = hid_open_report(hdev);
2677                 if (!ret)
2678                         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
2679         }
2680
2681         /*
2682          * Note that we are not closing the devres group opened above so
2683          * even resources that were attached to the device after probe is
2684          * run are released when hid_device_remove() is executed. This is
2685          * needed as some drivers would allocate additional resources,
2686          * for example when updating firmware.
2687          */
2688
2689         if (ret) {
2690                 devres_release_group(&hdev->dev, hdev->devres_group_id);
2691                 hid_close_report(hdev);
2692                 hdev->driver = NULL;
2693         }
2694
2695         return ret;
2696 }
2697
2698 static int hid_device_probe(struct device *dev)
2699 {
2700         struct hid_device *hdev = to_hid_device(dev);
2701         struct hid_driver *hdrv = to_hid_driver(dev->driver);
2702         int ret = 0;
2703
2704         if (down_interruptible(&hdev->driver_input_lock))
2705                 return -EINTR;
2706
2707         hdev->io_started = false;
2708         clear_bit(ffs(HID_STAT_REPROBED), &hdev->status);
2709
2710         if (!hdev->driver)
2711                 ret = __hid_device_probe(hdev, hdrv);
2712
2713         if (!hdev->io_started)
2714                 up(&hdev->driver_input_lock);
2715
2716         return ret;
2717 }
2718
2719 static void hid_device_remove(struct device *dev)
2720 {
2721         struct hid_device *hdev = to_hid_device(dev);
2722         struct hid_driver *hdrv;
2723
2724         down(&hdev->driver_input_lock);
2725         hdev->io_started = false;
2726
2727         hdrv = hdev->driver;
2728         if (hdrv) {
2729                 if (hdrv->remove)
2730                         hdrv->remove(hdev);
2731                 else /* default remove */
2732                         hid_hw_stop(hdev);
2733
2734                 /* Release all devres resources allocated by the driver */
2735                 devres_release_group(&hdev->dev, hdev->devres_group_id);
2736
2737                 hid_close_report(hdev);
2738                 hdev->driver = NULL;
2739         }
2740
2741         if (!hdev->io_started)
2742                 up(&hdev->driver_input_lock);
2743 }
2744
2745 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
2746                              char *buf)
2747 {
2748         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
2749
2750         return scnprintf(buf, PAGE_SIZE, "hid:b%04Xg%04Xv%08Xp%08X\n",
2751                          hdev->bus, hdev->group, hdev->vendor, hdev->product);
2752 }
2753 static DEVICE_ATTR_RO(modalias);
2754
2755 static struct attribute *hid_dev_attrs[] = {
2756         &dev_attr_modalias.attr,
2757         NULL,
2758 };
2759 static struct bin_attribute *hid_dev_bin_attrs[] = {
2760         &dev_bin_attr_report_desc,
2761         NULL
2762 };
2763 static const struct attribute_group hid_dev_group = {
2764         .attrs = hid_dev_attrs,
2765         .bin_attrs = hid_dev_bin_attrs,
2766 };
2767 __ATTRIBUTE_GROUPS(hid_dev);
2768
2769 static int hid_uevent(const struct device *dev, struct kobj_uevent_env *env)
2770 {
2771         const struct hid_device *hdev = to_hid_device(dev);
2772
2773         if (add_uevent_var(env, "HID_ID=%04X:%08X:%08X",
2774                         hdev->bus, hdev->vendor, hdev->product))
2775                 return -ENOMEM;
2776
2777         if (add_uevent_var(env, "HID_NAME=%s", hdev->name))
2778                 return -ENOMEM;
2779
2780         if (add_uevent_var(env, "HID_PHYS=%s", hdev->phys))
2781                 return -ENOMEM;
2782
2783         if (add_uevent_var(env, "HID_UNIQ=%s", hdev->uniq))
2784                 return -ENOMEM;
2785
2786         if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",
2787                            hdev->bus, hdev->group, hdev->vendor, hdev->product))
2788                 return -ENOMEM;
2789
2790         return 0;
2791 }
2792
2793 const struct bus_type hid_bus_type = {
2794         .name           = "hid",
2795         .dev_groups     = hid_dev_groups,
2796         .drv_groups     = hid_drv_groups,
2797         .match          = hid_bus_match,
2798         .probe          = hid_device_probe,
2799         .remove         = hid_device_remove,
2800         .uevent         = hid_uevent,
2801 };
2802 EXPORT_SYMBOL(hid_bus_type);
2803
2804 int hid_add_device(struct hid_device *hdev)
2805 {
2806         static atomic_t id = ATOMIC_INIT(0);
2807         int ret;
2808
2809         if (WARN_ON(hdev->status & HID_STAT_ADDED))
2810                 return -EBUSY;
2811
2812         hdev->quirks = hid_lookup_quirk(hdev);
2813
2814         /* we need to kill them here, otherwise they will stay allocated to
2815          * wait for coming driver */
2816         if (hid_ignore(hdev))
2817                 return -ENODEV;
2818
2819         /*
2820          * Check for the mandatory transport channel.
2821          */
2822          if (!hdev->ll_driver->raw_request) {
2823                 hid_err(hdev, "transport driver missing .raw_request()\n");
2824                 return -EINVAL;
2825          }
2826
2827         /*
2828          * Read the device report descriptor once and use as template
2829          * for the driver-specific modifications.
2830          */
2831         ret = hdev->ll_driver->parse(hdev);
2832         if (ret)
2833                 return ret;
2834         if (!hdev->dev_rdesc)
2835                 return -ENODEV;
2836
2837         /*
2838          * Scan generic devices for group information
2839          */
2840         if (hid_ignore_special_drivers) {
2841                 hdev->group = HID_GROUP_GENERIC;
2842         } else if (!hdev->group &&
2843                    !(hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)) {
2844                 ret = hid_scan_report(hdev);
2845                 if (ret)
2846                         hid_warn(hdev, "bad device descriptor (%d)\n", ret);
2847         }
2848
2849         hdev->id = atomic_inc_return(&id);
2850
2851         /* XXX hack, any other cleaner solution after the driver core
2852          * is converted to allow more than 20 bytes as the device name? */
2853         dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
2854                      hdev->vendor, hdev->product, hdev->id);
2855
2856         hid_debug_register(hdev, dev_name(&hdev->dev));
2857         ret = device_add(&hdev->dev);
2858         if (!ret)
2859                 hdev->status |= HID_STAT_ADDED;
2860         else
2861                 hid_debug_unregister(hdev);
2862
2863         return ret;
2864 }
2865 EXPORT_SYMBOL_GPL(hid_add_device);
2866
2867 /**
2868  * hid_allocate_device - allocate new hid device descriptor
2869  *
2870  * Allocate and initialize hid device, so that hid_destroy_device might be
2871  * used to free it.
2872  *
2873  * New hid_device pointer is returned on success, otherwise ERR_PTR encoded
2874  * error value.
2875  */
2876 struct hid_device *hid_allocate_device(void)
2877 {
2878         struct hid_device *hdev;
2879         int ret = -ENOMEM;
2880
2881         hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
2882         if (hdev == NULL)
2883                 return ERR_PTR(ret);
2884
2885         device_initialize(&hdev->dev);
2886         hdev->dev.release = hid_device_release;
2887         hdev->dev.bus = &hid_bus_type;
2888         device_enable_async_suspend(&hdev->dev);
2889
2890         hid_close_report(hdev);
2891
2892         init_waitqueue_head(&hdev->debug_wait);
2893         INIT_LIST_HEAD(&hdev->debug_list);
2894         spin_lock_init(&hdev->debug_list_lock);
2895         sema_init(&hdev->driver_input_lock, 1);
2896         mutex_init(&hdev->ll_open_lock);
2897         kref_init(&hdev->ref);
2898
2899         ret = hid_bpf_device_init(hdev);
2900         if (ret)
2901                 goto out_err;
2902
2903         return hdev;
2904
2905 out_err:
2906         hid_destroy_device(hdev);
2907         return ERR_PTR(ret);
2908 }
2909 EXPORT_SYMBOL_GPL(hid_allocate_device);
2910
2911 static void hid_remove_device(struct hid_device *hdev)
2912 {
2913         if (hdev->status & HID_STAT_ADDED) {
2914                 device_del(&hdev->dev);
2915                 hid_debug_unregister(hdev);
2916                 hdev->status &= ~HID_STAT_ADDED;
2917         }
2918         kfree(hdev->dev_rdesc);
2919         hdev->dev_rdesc = NULL;
2920         hdev->dev_rsize = 0;
2921 }
2922
2923 /**
2924  * hid_destroy_device - free previously allocated device
2925  *
2926  * @hdev: hid device
2927  *
2928  * If you allocate hid_device through hid_allocate_device, you should ever
2929  * free by this function.
2930  */
2931 void hid_destroy_device(struct hid_device *hdev)
2932 {
2933         hid_bpf_destroy_device(hdev);
2934         hid_remove_device(hdev);
2935         put_device(&hdev->dev);
2936 }
2937 EXPORT_SYMBOL_GPL(hid_destroy_device);
2938
2939
2940 static int __hid_bus_reprobe_drivers(struct device *dev, void *data)
2941 {
2942         struct hid_driver *hdrv = data;
2943         struct hid_device *hdev = to_hid_device(dev);
2944
2945         if (hdev->driver == hdrv &&
2946             !hdrv->match(hdev, hid_ignore_special_drivers) &&
2947             !test_and_set_bit(ffs(HID_STAT_REPROBED), &hdev->status))
2948                 return device_reprobe(dev);
2949
2950         return 0;
2951 }
2952
2953 static int __hid_bus_driver_added(struct device_driver *drv, void *data)
2954 {
2955         struct hid_driver *hdrv = to_hid_driver(drv);
2956
2957         if (hdrv->match) {
2958                 bus_for_each_dev(&hid_bus_type, NULL, hdrv,
2959                                  __hid_bus_reprobe_drivers);
2960         }
2961
2962         return 0;
2963 }
2964
2965 static int __bus_removed_driver(struct device_driver *drv, void *data)
2966 {
2967         return bus_rescan_devices(&hid_bus_type);
2968 }
2969
2970 int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
2971                 const char *mod_name)
2972 {
2973         int ret;
2974
2975         hdrv->driver.name = hdrv->name;
2976         hdrv->driver.bus = &hid_bus_type;
2977         hdrv->driver.owner = owner;
2978         hdrv->driver.mod_name = mod_name;
2979
2980         INIT_LIST_HEAD(&hdrv->dyn_list);
2981         spin_lock_init(&hdrv->dyn_lock);
2982
2983         ret = driver_register(&hdrv->driver);
2984
2985         if (ret == 0)
2986                 bus_for_each_drv(&hid_bus_type, NULL, NULL,
2987                                  __hid_bus_driver_added);
2988
2989         return ret;
2990 }
2991 EXPORT_SYMBOL_GPL(__hid_register_driver);
2992
2993 void hid_unregister_driver(struct hid_driver *hdrv)
2994 {
2995         driver_unregister(&hdrv->driver);
2996         hid_free_dynids(hdrv);
2997
2998         bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver);
2999 }
3000 EXPORT_SYMBOL_GPL(hid_unregister_driver);
3001
3002 int hid_check_keys_pressed(struct hid_device *hid)
3003 {
3004         struct hid_input *hidinput;
3005         int i;
3006
3007         if (!(hid->claimed & HID_CLAIMED_INPUT))
3008                 return 0;
3009
3010         list_for_each_entry(hidinput, &hid->inputs, list) {
3011                 for (i = 0; i < BITS_TO_LONGS(KEY_MAX); i++)
3012                         if (hidinput->input->key[i])
3013                                 return 1;
3014         }
3015
3016         return 0;
3017 }
3018 EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
3019
3020 #ifdef CONFIG_HID_BPF
3021 static struct hid_ops __hid_ops = {
3022         .hid_get_report = hid_get_report,
3023         .hid_hw_raw_request = __hid_hw_raw_request,
3024         .hid_hw_output_report = __hid_hw_output_report,
3025         .hid_input_report = __hid_input_report,
3026         .owner = THIS_MODULE,
3027         .bus_type = &hid_bus_type,
3028 };
3029 #endif
3030
3031 static int __init hid_init(void)
3032 {
3033         int ret;
3034
3035         ret = bus_register(&hid_bus_type);
3036         if (ret) {
3037                 pr_err("can't register hid bus\n");
3038                 goto err;
3039         }
3040
3041 #ifdef CONFIG_HID_BPF
3042         hid_ops = &__hid_ops;
3043 #endif
3044
3045         ret = hidraw_init();
3046         if (ret)
3047                 goto err_bus;
3048
3049         hid_debug_init();
3050
3051         return 0;
3052 err_bus:
3053         bus_unregister(&hid_bus_type);
3054 err:
3055         return ret;
3056 }
3057
3058 static void __exit hid_exit(void)
3059 {
3060 #ifdef CONFIG_HID_BPF
3061         hid_ops = NULL;
3062 #endif
3063         hid_debug_exit();
3064         hidraw_exit();
3065         bus_unregister(&hid_bus_type);
3066         hid_quirks_exit(HID_BUS_ANY);
3067 }
3068
3069 module_init(hid_init);
3070 module_exit(hid_exit);
3071
3072 MODULE_AUTHOR("Andreas Gal");
3073 MODULE_AUTHOR("Vojtech Pavlik");
3074 MODULE_AUTHOR("Jiri Kosina");
3075 MODULE_DESCRIPTION("HID support for Linux");
3076 MODULE_LICENSE("GPL");