drivers/hid/hid-core.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  HID support for Linux
   4  *
   5  *  Copyright (c) 1999 Andreas Gal
   6  *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
   7  *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
   8  *  Copyright (c) 2006-2012 Jiri Kosina
   9  */
  10
  11 /*
  12  */
  13
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16 #include <linux/module.h>
  17 #include <linux/slab.h>
  18 #include <linux/init.h>
  19 #include <linux/kernel.h>
  20 #include <linux/list.h>
  21 #include <linux/mm.h>
  22 #include <linux/spinlock.h>
  23 #include <linux/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  * Convert a signed n-bit integer to signed 32-bit integer.
  50  */
  51
  52 static s32 snto32(__u32 value, unsigned int n)
  53 {
  54         if (!value || !n)
  55                 return 0;
  56
  57         if (n > 32)
  58                 n = 32;
  59
  60         return sign_extend32(value, n - 1);
  61 }
  62
  63 /*
  64  * Convert a signed 32-bit integer to a signed n-bit integer.
  65  */
  66
  67 static u32 s32ton(__s32 value, unsigned int n)
  68 {
  69         s32 a = value >> (n - 1);
  70
  71         if (a && a != -1)
  72                 return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
  73         return value & ((1 << n) - 1);
  74 }
  75
  76 /*
  77  * Register a new report for a device.
  78  */
  79
  80 struct hid_report *hid_register_report(struct hid_device *device,
  81                                        enum hid_report_type type, unsigned int id,
  82                                        unsigned int application)
  83 {
  84         struct hid_report_enum *report_enum = device->report_enum + type;
  85         struct hid_report *report;
  86
  87         if (id >= HID_MAX_IDS)
  88                 return NULL;
  89         if (report_enum->report_id_hash[id])
  90                 return report_enum->report_id_hash[id];
  91
  92         report = kzalloc(sizeof(struct hid_report), GFP_KERNEL);
  93         if (!report)
  94                 return NULL;
  95
  96         if (id != 0)
  97                 report_enum->numbered = 1;
  98
  99         report->id = id;
 100         report->type = type;
 101         report->size = 0;
 102         report->device = device;
 103         report->application = application;
 104         report_enum->report_id_hash[id] = report;
 105
 106         list_add_tail(&report->list, &report_enum->report_list);
 107         INIT_LIST_HEAD(&report->field_entry_list);
 108
 109         return report;
 110 }
 111 EXPORT_SYMBOL_GPL(hid_register_report);
 112
 113 /*
 114  * Register a new field for this report.
 115  */
 116
 117 static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages)
 118 {
 119         struct hid_field *field;
 120
 121         if (report->maxfield == HID_MAX_FIELDS) {
 122                 hid_err(report->device, "too many fields in report\n");
 123                 return NULL;
 124         }
 125
 126         field = kvzalloc((sizeof(struct hid_field) +
 127                           usages * sizeof(struct hid_usage) +
 128                           3 * usages * sizeof(unsigned int)), GFP_KERNEL);
 129         if (!field)
 130                 return NULL;
 131
 132         field->index = report->maxfield++;
 133         report->field[field->index] = field;
 134         field->usage = (struct hid_usage *)(field + 1);
 135         field->value = (s32 *)(field->usage + usages);
 136         field->new_value = (s32 *)(field->value + usages);
 137         field->usages_priorities = (s32 *)(field->new_value + usages);
 138         field->report = report;
 139
 140         return field;
 141 }
 142
 143 /*
 144  * Open a collection. The type/usage is pushed on the stack.
 145  */
 146
 147 static int open_collection(struct hid_parser *parser, unsigned type)
 148 {
 149         struct hid_collection *collection;
 150         unsigned usage;
 151         int collection_index;
 152
 153         usage = parser->local.usage[0];
 154
 155         if (parser->collection_stack_ptr == parser->collection_stack_size) {
 156                 unsigned int *collection_stack;
 157                 unsigned int new_size = parser->collection_stack_size +
 158                                         HID_COLLECTION_STACK_SIZE;
 159
 160                 collection_stack = krealloc(parser->collection_stack,
 161                                             new_size * sizeof(unsigned int),
 162                                             GFP_KERNEL);
 163                 if (!collection_stack)
 164                         return -ENOMEM;
 165
 166                 parser->collection_stack = collection_stack;
 167                 parser->collection_stack_size = new_size;
 168         }
 169
 170         if (parser->device->maxcollection == parser->device->collection_size) {
 171                 collection = kmalloc(
 172                                 array3_size(sizeof(struct hid_collection),
 173                                             parser->device->collection_size,
 174                                             2),
 175                                 GFP_KERNEL);
 176                 if (collection == NULL) {
 177                         hid_err(parser->device, "failed to reallocate collection array\n");
 178                         return -ENOMEM;
 179                 }
 180                 memcpy(collection, parser->device->collection,
 181                         sizeof(struct hid_collection) *
 182                         parser->device->collection_size);
 183                 memset(collection + parser->device->collection_size, 0,
 184                         sizeof(struct hid_collection) *
 185                         parser->device->collection_size);
 186                 kfree(parser->device->collection);
 187                 parser->device->collection = collection;
 188                 parser->device->collection_size *= 2;
 189         }
 190
 191         parser->collection_stack[parser->collection_stack_ptr++] =
 192                 parser->device->maxcollection;
 193
 194         collection_index = parser->device->maxcollection++;
 195         collection = parser->device->collection + collection_index;
 196         collection->type = type;
 197         collection->usage = usage;
 198         collection->level = parser->collection_stack_ptr - 1;
 199         collection->parent_idx = (collection->level == 0) ? -1 :
 200                 parser->collection_stack[collection->level - 1];
 201
 202         if (type == HID_COLLECTION_APPLICATION)
 203                 parser->device->maxapplication++;
 204
 205         return 0;
 206 }
 207
 208 /*
 209  * Close a collection.
 210  */
 211
 212 static int close_collection(struct hid_parser *parser)
 213 {
 214         if (!parser->collection_stack_ptr) {
 215                 hid_err(parser->device, "collection stack underflow\n");
 216                 return -EINVAL;
 217         }
 218         parser->collection_stack_ptr--;
 219         return 0;
 220 }
 221
 222 /*
 223  * Climb up the stack, search for the specified collection type
 224  * and return the usage.
 225  */
 226
 227 static unsigned hid_lookup_collection(struct hid_parser *parser, unsigned type)
 228 {
 229         struct hid_collection *collection = parser->device->collection;
 230         int n;
 231
 232         for (n = parser->collection_stack_ptr - 1; n >= 0; n--) {
 233                 unsigned index = parser->collection_stack[n];
 234                 if (collection[index].type == type)
 235                         return collection[index].usage;
 236         }
 237         return 0; /* we know nothing about this usage type */
 238 }
 239
 240 /*
 241  * Concatenate usage which defines 16 bits or less with the
 242  * currently defined usage page to form a 32 bit usage
 243  */
 244
 245 static void complete_usage(struct hid_parser *parser, unsigned int index)
 246 {
 247         parser->local.usage[index] &= 0xFFFF;
 248         parser->local.usage[index] |=
 249                 (parser->global.usage_page & 0xFFFF) << 16;
 250 }
 251
 252 /*
 253  * Add a usage to the temporary parser table.
 254  */
 255
 256 static int hid_add_usage(struct hid_parser *parser, unsigned usage, u8 size)
 257 {
 258         if (parser->local.usage_index >= HID_MAX_USAGES) {
 259                 hid_err(parser->device, "usage index exceeded\n");
 260                 return -1;
 261         }
 262         parser->local.usage[parser->local.usage_index] = usage;
 263
 264         /*
 265          * If Usage item only includes usage id, concatenate it with
 266          * currently defined usage page
 267          */
 268         if (size <= 2)
 269                 complete_usage(parser, parser->local.usage_index);
 270
 271         parser->local.usage_size[parser->local.usage_index] = size;
 272         parser->local.collection_index[parser->local.usage_index] =
 273                 parser->collection_stack_ptr ?
 274                 parser->collection_stack[parser->collection_stack_ptr - 1] : 0;
 275         parser->local.usage_index++;
 276         return 0;
 277 }
 278
 279 /*
 280  * Register a new field for this report.
 281  */
 282
 283 static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsigned flags)
 284 {
 285         struct hid_report *report;
 286         struct hid_field *field;
 287         unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
 288         unsigned int usages;
 289         unsigned int offset;
 290         unsigned int i;
 291         unsigned int application;
 292
 293         application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
 294
 295         report = hid_register_report(parser->device, report_type,
 296                                      parser->global.report_id, application);
 297         if (!report) {
 298                 hid_err(parser->device, "hid_register_report failed\n");
 299                 return -1;
 300         }
 301
 302         /* Handle both signed and unsigned cases properly */
 303         if ((parser->global.logical_minimum < 0 &&
 304                 parser->global.logical_maximum <
 305                 parser->global.logical_minimum) ||
 306                 (parser->global.logical_minimum >= 0 &&
 307                 (__u32)parser->global.logical_maximum <
 308                 (__u32)parser->global.logical_minimum)) {
 309                 dbg_hid("logical range invalid 0x%x 0x%x\n",
 310                         parser->global.logical_minimum,
 311                         parser->global.logical_maximum);
 312                 return -1;
 313         }
 314
 315         offset = report->size;
 316         report->size += parser->global.report_size * parser->global.report_count;
 317
 318         if (parser->device->ll_driver->max_buffer_size)
 319                 max_buffer_size = parser->device->ll_driver->max_buffer_size;
 320
 321         /* Total size check: Allow for possible report index byte */
 322         if (report->size > (max_buffer_size - 1) << 3) {
 323                 hid_err(parser->device, "report is too long\n");
 324                 return -1;
 325         }
 326
 327         if (!parser->local.usage_index) /* Ignore padding fields */
 328                 return 0;
 329
 330         usages = max_t(unsigned, parser->local.usage_index,
 331                                  parser->global.report_count);
 332
 333         field = hid_register_field(report, usages);
 334         if (!field)
 335                 return 0;
 336
 337         field->physical = hid_lookup_collection(parser, HID_COLLECTION_PHYSICAL);
 338         field->logical = hid_lookup_collection(parser, HID_COLLECTION_LOGICAL);
 339         field->application = application;
 340
 341         for (i = 0; i < usages; i++) {
 342                 unsigned j = i;
 343                 /* Duplicate the last usage we parsed if we have excess values */
 344                 if (i >= parser->local.usage_index)
 345                         j = parser->local.usage_index - 1;
 346                 field->usage[i].hid = parser->local.usage[j];
 347                 field->usage[i].collection_index =
 348                         parser->local.collection_index[j];
 349                 field->usage[i].usage_index = i;
 350                 field->usage[i].resolution_multiplier = 1;
 351         }
 352
 353         field->maxusage = usages;
 354         field->flags = flags;
 355         field->report_offset = offset;
 356         field->report_type = report_type;
 357         field->report_size = parser->global.report_size;
 358         field->report_count = parser->global.report_count;
 359         field->logical_minimum = parser->global.logical_minimum;
 360         field->logical_maximum = parser->global.logical_maximum;
 361         field->physical_minimum = parser->global.physical_minimum;
 362         field->physical_maximum = parser->global.physical_maximum;
 363         field->unit_exponent = parser->global.unit_exponent;
 364         field->unit = parser->global.unit;
 365
 366         return 0;
 367 }
 368
 369 /*
 370  * Read data value from item.
 371  */
 372
 373 static u32 item_udata(struct hid_item *item)
 374 {
 375         switch (item->size) {
 376         case 1: return item->data.u8;
 377         case 2: return item->data.u16;
 378         case 4: return item->data.u32;
 379         }
 380         return 0;
 381 }
 382
 383 static s32 item_sdata(struct hid_item *item)
 384 {
 385         switch (item->size) {
 386         case 1: return item->data.s8;
 387         case 2: return item->data.s16;
 388         case 4: return item->data.s32;
 389         }
 390         return 0;
 391 }
 392
 393 /*
 394  * Process a global item.
 395  */
 396
 397 static int hid_parser_global(struct hid_parser *parser, struct hid_item *item)
 398 {
 399         __s32 raw_value;
 400         switch (item->tag) {
 401         case HID_GLOBAL_ITEM_TAG_PUSH:
 402
 403                 if (parser->global_stack_ptr == HID_GLOBAL_STACK_SIZE) {
 404                         hid_err(parser->device, "global environment stack overflow\n");
 405                         return -1;
 406                 }
 407
 408                 memcpy(parser->global_stack + parser->global_stack_ptr++,
 409                         &parser->global, sizeof(struct hid_global));
 410                 return 0;
 411
 412         case HID_GLOBAL_ITEM_TAG_POP:
 413
 414                 if (!parser->global_stack_ptr) {
 415                         hid_err(parser->device, "global environment stack underflow\n");
 416                         return -1;
 417                 }
 418
 419                 memcpy(&parser->global, parser->global_stack +
 420                         --parser->global_stack_ptr, sizeof(struct hid_global));
 421                 return 0;
 422
 423         case HID_GLOBAL_ITEM_TAG_USAGE_PAGE:
 424                 parser->global.usage_page = item_udata(item);
 425                 return 0;
 426
 427         case HID_GLOBAL_ITEM_TAG_LOGICAL_MINIMUM:
 428                 parser->global.logical_minimum = item_sdata(item);
 429                 return 0;
 430
 431         case HID_GLOBAL_ITEM_TAG_LOGICAL_MAXIMUM:
 432                 if (parser->global.logical_minimum < 0)
 433                         parser->global.logical_maximum = item_sdata(item);
 434                 else
 435                         parser->global.logical_maximum = item_udata(item);
 436                 return 0;
 437
 438         case HID_GLOBAL_ITEM_TAG_PHYSICAL_MINIMUM:
 439                 parser->global.physical_minimum = item_sdata(item);
 440                 return 0;
 441
 442         case HID_GLOBAL_ITEM_TAG_PHYSICAL_MAXIMUM:
 443                 if (parser->global.physical_minimum < 0)
 444                         parser->global.physical_maximum = item_sdata(item);
 445                 else
 446                         parser->global.physical_maximum = item_udata(item);
 447                 return 0;
 448
 449         case HID_GLOBAL_ITEM_TAG_UNIT_EXPONENT:
 450                 /* Many devices provide unit exponent as a two's complement
 451                  * nibble due to the common misunderstanding of HID
 452                  * specification 1.11, 6.2.2.7 Global Items. Attempt to handle
 453                  * both this and the standard encoding. */
 454                 raw_value = item_sdata(item);
 455                 if (!(raw_value & 0xfffffff0))
 456                         parser->global.unit_exponent = snto32(raw_value, 4);
 457                 else
 458                         parser->global.unit_exponent = raw_value;
 459                 return 0;
 460
 461         case HID_GLOBAL_ITEM_TAG_UNIT:
 462                 parser->global.unit = item_udata(item);
 463                 return 0;
 464
 465         case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
 466                 parser->global.report_size = item_udata(item);
 467                 if (parser->global.report_size > 256) {
 468                         hid_err(parser->device, "invalid report_size %d\n",
 469                                         parser->global.report_size);
 470                         return -1;
 471                 }
 472                 return 0;
 473
 474         case HID_GLOBAL_ITEM_TAG_REPORT_COUNT:
 475                 parser->global.report_count = item_udata(item);
 476                 if (parser->global.report_count > HID_MAX_USAGES) {
 477                         hid_err(parser->device, "invalid report_count %d\n",
 478                                         parser->global.report_count);
 479                         return -1;
 480                 }
 481                 return 0;
 482
 483         case HID_GLOBAL_ITEM_TAG_REPORT_ID:
 484                 parser->global.report_id = item_udata(item);
 485                 if (parser->global.report_id == 0 ||
 486                     parser->global.report_id >= HID_MAX_IDS) {
 487                         hid_err(parser->device, "report_id %u is invalid\n",
 488                                 parser->global.report_id);
 489                         return -1;
 490                 }
 491                 return 0;
 492
 493         default:
 494                 hid_err(parser->device, "unknown global tag 0x%x\n", item->tag);
 495                 return -1;
 496         }
 497 }
 498
 499 /*
 500  * Process a local item.
 501  */
 502
 503 static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
 504 {
 505         __u32 data;
 506         unsigned n;
 507         __u32 count;
 508
 509         data = item_udata(item);
 510
 511         switch (item->tag) {
 512         case HID_LOCAL_ITEM_TAG_DELIMITER:
 513
 514                 if (data) {
 515                         /*
 516                          * We treat items before the first delimiter
 517                          * as global to all usage sets (branch 0).
 518                          * In the moment we process only these global
 519                          * items and the first delimiter set.
 520                          */
 521                         if (parser->local.delimiter_depth != 0) {
 522                                 hid_err(parser->device, "nested delimiters\n");
 523                                 return -1;
 524                         }
 525                         parser->local.delimiter_depth++;
 526                         parser->local.delimiter_branch++;
 527                 } else {
 528                         if (parser->local.delimiter_depth < 1) {
 529                                 hid_err(parser->device, "bogus close delimiter\n");
 530                                 return -1;
 531                         }
 532                         parser->local.delimiter_depth--;
 533                 }
 534                 return 0;
 535
 536         case HID_LOCAL_ITEM_TAG_USAGE:
 537
 538                 if (parser->local.delimiter_branch > 1) {
 539                         dbg_hid("alternative usage ignored\n");
 540                         return 0;
 541                 }
 542
 543                 return hid_add_usage(parser, data, item->size);
 544
 545         case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:
 546
 547                 if (parser->local.delimiter_branch > 1) {
 548                         dbg_hid("alternative usage ignored\n");
 549                         return 0;
 550                 }
 551
 552                 parser->local.usage_minimum = data;
 553                 return 0;
 554
 555         case HID_LOCAL_ITEM_TAG_USAGE_MAXIMUM:
 556
 557                 if (parser->local.delimiter_branch > 1) {
 558                         dbg_hid("alternative usage ignored\n");
 559                         return 0;
 560                 }
 561
 562                 count = data - parser->local.usage_minimum;
 563                 if (count + parser->local.usage_index >= HID_MAX_USAGES) {
 564                         /*
 565                          * We do not warn if the name is not set, we are
 566                          * actually pre-scanning the device.
 567                          */
 568                         if (dev_name(&parser->device->dev))
 569                                 hid_warn(parser->device,
 570                                          "ignoring exceeding usage max\n");
 571                         data = HID_MAX_USAGES - parser->local.usage_index +
 572                                 parser->local.usage_minimum - 1;
 573                         if (data <= 0) {
 574                                 hid_err(parser->device,
 575                                         "no more usage index available\n");
 576                                 return -1;
 577                         }
 578                 }
 579
 580                 for (n = parser->local.usage_minimum; n <= data; n++)
 581                         if (hid_add_usage(parser, n, item->size)) {
 582                                 dbg_hid("hid_add_usage failed\n");
 583                                 return -1;
 584                         }
 585                 return 0;
 586
 587         default:
 588
 589                 dbg_hid("unknown local item tag 0x%x\n", item->tag);
 590                 return 0;
 591         }
 592         return 0;
 593 }
 594
 595 /*
 596  * Concatenate Usage Pages into Usages where relevant:
 597  * As per specification, 6.2.2.8: "When the parser encounters a main item it
 598  * concatenates the last declared Usage Page with a Usage to form a complete
 599  * usage value."
 600  */
 601
 602 static void hid_concatenate_last_usage_page(struct hid_parser *parser)
 603 {
 604         int i;
 605         unsigned int usage_page;
 606         unsigned int current_page;
 607
 608         if (!parser->local.usage_index)
 609                 return;
 610
 611         usage_page = parser->global.usage_page;
 612
 613         /*
 614          * Concatenate usage page again only if last declared Usage Page
 615          * has not been already used in previous usages concatenation
 616          */
 617         for (i = parser->local.usage_index - 1; i >= 0; i--) {
 618                 if (parser->local.usage_size[i] > 2)
 619                         /* Ignore extended usages */
 620                         continue;
 621
 622                 current_page = parser->local.usage[i] >> 16;
 623                 if (current_page == usage_page)
 624                         break;
 625
 626                 complete_usage(parser, i);
 627         }
 628 }
 629
 630 /*
 631  * Process a main item.
 632  */
 633
 634 static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
 635 {
 636         __u32 data;
 637         int ret;
 638
 639         hid_concatenate_last_usage_page(parser);
 640
 641         data = item_udata(item);
 642
 643         switch (item->tag) {
 644         case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 645                 ret = open_collection(parser, data & 0xff);
 646                 break;
 647         case HID_MAIN_ITEM_TAG_END_COLLECTION:
 648                 ret = close_collection(parser);
 649                 break;
 650         case HID_MAIN_ITEM_TAG_INPUT:
 651                 ret = hid_add_field(parser, HID_INPUT_REPORT, data);
 652                 break;
 653         case HID_MAIN_ITEM_TAG_OUTPUT:
 654                 ret = hid_add_field(parser, HID_OUTPUT_REPORT, data);
 655                 break;
 656         case HID_MAIN_ITEM_TAG_FEATURE:
 657                 ret = hid_add_field(parser, HID_FEATURE_REPORT, data);
 658                 break;
 659         default:
 660                 if (item->tag >= HID_MAIN_ITEM_TAG_RESERVED_MIN &&
 661                         item->tag <= HID_MAIN_ITEM_TAG_RESERVED_MAX)
 662                         hid_warn(parser->device, "reserved main item tag 0x%x\n", item->tag);
 663                 else
 664                         hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
 665                 ret = 0;
 666         }
 667
 668         memset(&parser->local, 0, sizeof(parser->local));       /* Reset the local parser environment */
 669
 670         return ret;
 671 }
 672
 673 /*
 674  * Process a reserved item.
 675  */
 676
 677 static int hid_parser_reserved(struct hid_parser *parser, struct hid_item *item)
 678 {
 679         dbg_hid("reserved item type, tag 0x%x\n", item->tag);
 680         return 0;
 681 }
 682
 683 /*
 684  * Free a report and all registered fields. The field->usage and
 685  * field->value table's are allocated behind the field, so we need
 686  * only to free(field) itself.
 687  */
 688
 689 static void hid_free_report(struct hid_report *report)
 690 {
 691         unsigned n;
 692
 693         kfree(report->field_entries);
 694
 695         for (n = 0; n < report->maxfield; n++)
 696                 kvfree(report->field[n]);
 697         kfree(report);
 698 }
 699
 700 /*
 701  * Close report. This function returns the device
 702  * state to the point prior to hid_open_report().
 703  */
 704 static void hid_close_report(struct hid_device *device)
 705 {
 706         unsigned i, j;
 707
 708         for (i = 0; i < HID_REPORT_TYPES; i++) {
 709                 struct hid_report_enum *report_enum = device->report_enum + i;
 710
 711                 for (j = 0; j < HID_MAX_IDS; j++) {
 712                         struct hid_report *report = report_enum->report_id_hash[j];
 713                         if (report)
 714                                 hid_free_report(report);
 715                 }
 716                 memset(report_enum, 0, sizeof(*report_enum));
 717                 INIT_LIST_HEAD(&report_enum->report_list);
 718         }
 719
 720         /*
 721          * If the HID driver had a rdesc_fixup() callback, dev->rdesc
 722          * will be allocated by hid-core and needs to be freed.
 723          * Otherwise, it is either equal to dev_rdesc or bpf_rdesc, in
 724          * which cases it'll be freed later on device removal or destroy.
 725          */
 726         if (device->rdesc != device->dev_rdesc && device->rdesc != device->bpf_rdesc)
 727                 kfree(device->rdesc);
 728         device->rdesc = NULL;
 729         device->rsize = 0;
 730
 731         kfree(device->collection);
 732         device->collection = NULL;
 733         device->collection_size = 0;
 734         device->maxcollection = 0;
 735         device->maxapplication = 0;
 736
 737         device->status &= ~HID_STAT_PARSED;
 738 }
 739
 740 static inline void hid_free_bpf_rdesc(struct hid_device *hdev)
 741 {
 742         /* bpf_rdesc is either equal to dev_rdesc or allocated by call_hid_bpf_rdesc_fixup() */
 743         if (hdev->bpf_rdesc != hdev->dev_rdesc)
 744                 kfree(hdev->bpf_rdesc);
 745         hdev->bpf_rdesc = NULL;
 746 }
 747
 748 /*
 749  * Free a device structure, all reports, and all fields.
 750  */
 751
 752 void hiddev_free(struct kref *ref)
 753 {
 754         struct hid_device *hid = container_of(ref, struct hid_device, ref);
 755
 756         hid_close_report(hid);
 757         hid_free_bpf_rdesc(hid);
 758         kfree(hid->dev_rdesc);
 759         kfree(hid);
 760 }
 761
 762 static void hid_device_release(struct device *dev)
 763 {
 764         struct hid_device *hid = to_hid_device(dev);
 765
 766         kref_put(&hid->ref, hiddev_free);
 767 }
 768
 769 /*
 770  * Fetch a report description item from the data stream. We support long
 771  * items, though they are not used yet.
 772  */
 773
 774 static const u8 *fetch_item(const __u8 *start, const __u8 *end, struct hid_item *item)
 775 {
 776         u8 b;
 777
 778         if ((end - start) <= 0)
 779                 return NULL;
 780
 781         b = *start++;
 782
 783         item->type = (b >> 2) & 3;
 784         item->tag  = (b >> 4) & 15;
 785
 786         if (item->tag == HID_ITEM_TAG_LONG) {
 787
 788                 item->format = HID_ITEM_FORMAT_LONG;
 789
 790                 if ((end - start) < 2)
 791                         return NULL;
 792
 793                 item->size = *start++;
 794                 item->tag  = *start++;
 795
 796                 if ((end - start) < item->size)
 797                         return NULL;
 798
 799                 item->data.longdata = start;
 800                 start += item->size;
 801                 return start;
 802         }
 803
 804         item->format = HID_ITEM_FORMAT_SHORT;
 805         item->size = BIT(b & 3) >> 1; /* 0, 1, 2, 3 -> 0, 1, 2, 4 */
 806
 807         if (end - start < item->size)
 808                 return NULL;
 809
 810         switch (item->size) {
 811         case 0:
 812                 break;
 813
 814         case 1:
 815                 item->data.u8 = *start;
 816                 break;
 817
 818         case 2:
 819                 item->data.u16 = get_unaligned_le16(start);
 820                 break;
 821
 822         case 4:
 823                 item->data.u32 = get_unaligned_le32(start);
 824                 break;
 825         }
 826
 827         return start + item->size;
 828 }
 829
 830 static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)
 831 {
 832         struct hid_device *hid = parser->device;
 833
 834         if (usage == HID_DG_CONTACTID)
 835                 hid->group = HID_GROUP_MULTITOUCH;
 836 }
 837
 838 static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
 839 {
 840         if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
 841             parser->global.report_size == 8)
 842                 parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 843
 844         if (usage == 0xff0000c6 && parser->global.report_count == 1 &&
 845             parser->global.report_size == 8)
 846                 parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 847 }
 848
 849 static void hid_scan_collection(struct hid_parser *parser, unsigned type)
 850 {
 851         struct hid_device *hid = parser->device;
 852         int i;
 853
 854         if (((parser->global.usage_page << 16) == HID_UP_SENSOR) &&
 855             (type == HID_COLLECTION_PHYSICAL ||
 856              type == HID_COLLECTION_APPLICATION))
 857                 hid->group = HID_GROUP_SENSOR_HUB;
 858
 859         if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
 860             hid->product == USB_DEVICE_ID_MS_POWER_COVER &&
 861             hid->group == HID_GROUP_MULTITOUCH)
 862                 hid->group = HID_GROUP_GENERIC;
 863
 864         if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
 865                 for (i = 0; i < parser->local.usage_index; i++)
 866                         if (parser->local.usage[i] == HID_GD_POINTER)
 867                                 parser->scan_flags |= HID_SCAN_FLAG_GD_POINTER;
 868
 869         if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
 870                 parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
 871
 872         if ((parser->global.usage_page << 16) == HID_UP_GOOGLEVENDOR)
 873                 for (i = 0; i < parser->local.usage_index; i++)
 874                         if (parser->local.usage[i] ==
 875                                         (HID_UP_GOOGLEVENDOR | 0x0001))
 876                                 parser->device->group =
 877                                         HID_GROUP_VIVALDI;
 878 }
 879
 880 static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
 881 {
 882         __u32 data;
 883         int i;
 884
 885         hid_concatenate_last_usage_page(parser);
 886
 887         data = item_udata(item);
 888
 889         switch (item->tag) {
 890         case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 891                 hid_scan_collection(parser, data & 0xff);
 892                 break;
 893         case HID_MAIN_ITEM_TAG_END_COLLECTION:
 894                 break;
 895         case HID_MAIN_ITEM_TAG_INPUT:
 896                 /* ignore constant inputs, they will be ignored by hid-input */
 897                 if (data & HID_MAIN_ITEM_CONSTANT)
 898                         break;
 899                 for (i = 0; i < parser->local.usage_index; i++)
 900                         hid_scan_input_usage(parser, parser->local.usage[i]);
 901                 break;
 902         case HID_MAIN_ITEM_TAG_OUTPUT:
 903                 break;
 904         case HID_MAIN_ITEM_TAG_FEATURE:
 905                 for (i = 0; i < parser->local.usage_index; i++)
 906                         hid_scan_feature_usage(parser, parser->local.usage[i]);
 907                 break;
 908         }
 909
 910         /* Reset the local parser environment */
 911         memset(&parser->local, 0, sizeof(parser->local));
 912
 913         return 0;
 914 }
 915
 916 /*
 917  * Scan a report descriptor before the device is added to the bus.
 918  * Sets device groups and other properties that determine what driver
 919  * to load.
 920  */
 921 static int hid_scan_report(struct hid_device *hid)
 922 {
 923         struct hid_parser *parser;
 924         struct hid_item item;
 925         const __u8 *start = hid->dev_rdesc;
 926         const __u8 *end = start + hid->dev_rsize;
 927         static int (*dispatch_type[])(struct hid_parser *parser,
 928                                       struct hid_item *item) = {
 929                 hid_scan_main,
 930                 hid_parser_global,
 931                 hid_parser_local,
 932                 hid_parser_reserved
 933         };
 934
 935         parser = vzalloc(sizeof(struct hid_parser));
 936         if (!parser)
 937                 return -ENOMEM;
 938
 939         parser->device = hid;
 940         hid->group = HID_GROUP_GENERIC;
 941
 942         /*
 943          * The parsing is simpler than the one in hid_open_report() as we should
 944          * be robust against hid errors. Those errors will be raised by
 945          * hid_open_report() anyway.
 946          */
 947         while ((start = fetch_item(start, end, &item)) != NULL)
 948                 dispatch_type[item.type](parser, &item);
 949
 950         /*
 951          * Handle special flags set during scanning.
 952          */
 953         if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
 954             (hid->group == HID_GROUP_MULTITOUCH))
 955                 hid->group = HID_GROUP_MULTITOUCH_WIN_8;
 956
 957         /*
 958          * Vendor specific handlings
 959          */
 960         switch (hid->vendor) {
 961         case USB_VENDOR_ID_WACOM:
 962                 hid->group = HID_GROUP_WACOM;
 963                 break;
 964         case USB_VENDOR_ID_SYNAPTICS:
 965                 if (hid->group == HID_GROUP_GENERIC)
 966                         if ((parser->scan_flags & HID_SCAN_FLAG_VENDOR_SPECIFIC)
 967                             && (parser->scan_flags & HID_SCAN_FLAG_GD_POINTER))
 968                                 /*
 969                                  * hid-rmi should take care of them,
 970                                  * not hid-generic
 971                                  */
 972                                 hid->group = HID_GROUP_RMI;
 973                 break;
 974         }
 975
 976         kfree(parser->collection_stack);
 977         vfree(parser);
 978         return 0;
 979 }
 980
 981 /**
 982  * hid_parse_report - parse device report
 983  *
 984  * @hid: hid device
 985  * @start: report start
 986  * @size: report size
 987  *
 988  * Allocate the device report as read by the bus driver. This function should
 989  * only be called from parse() in ll drivers.
 990  */
 991 int hid_parse_report(struct hid_device *hid, const __u8 *start, unsigned size)
 992 {
 993         hid->dev_rdesc = kmemdup(start, size, GFP_KERNEL);
 994         if (!hid->dev_rdesc)
 995                 return -ENOMEM;
 996         hid->dev_rsize = size;
 997         return 0;
 998 }
 999 EXPORT_SYMBOL_GPL(hid_parse_report);
1000
1001 static const char * const hid_report_names[] = {
1002         "HID_INPUT_REPORT",
1003         "HID_OUTPUT_REPORT",
1004         "HID_FEATURE_REPORT",
1005 };
1006 /**
1007  * hid_validate_values - validate existing device report's value indexes
1008  *
1009  * @hid: hid device
1010  * @type: which report type to examine
1011  * @id: which report ID to examine (0 for first)
1012  * @field_index: which report field to examine
1013  * @report_counts: expected number of values
1014  *
1015  * Validate the number of values in a given field of a given report, after
1016  * parsing.
1017  */
1018 struct hid_report *hid_validate_values(struct hid_device *hid,
1019                                        enum hid_report_type type, unsigned int id,
1020                                        unsigned int field_index,
1021                                        unsigned int report_counts)
1022 {
1023         struct hid_report *report;
1024
1025         if (type > HID_FEATURE_REPORT) {
1026                 hid_err(hid, "invalid HID report type %u\n", type);
1027                 return NULL;
1028         }
1029
1030         if (id >= HID_MAX_IDS) {
1031                 hid_err(hid, "invalid HID report id %u\n", id);
1032                 return NULL;
1033         }
1034
1035         /*
1036          * Explicitly not using hid_get_report() here since it depends on
1037          * ->numbered being checked, which may not always be the case when
1038          * drivers go to access report values.
1039          */
1040         if (id == 0) {
1041                 /*
1042                  * Validating on id 0 means we should examine the first
1043                  * report in the list.
1044                  */
1045                 report = list_first_entry_or_null(
1046                                 &hid->report_enum[type].report_list,
1047                                 struct hid_report, list);
1048         } else {
1049                 report = hid->report_enum[type].report_id_hash[id];
1050         }
1051         if (!report) {
1052                 hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
1053                 return NULL;
1054         }
1055         if (report->maxfield <= field_index) {
1056                 hid_err(hid, "not enough fields in %s %u\n",
1057                         hid_report_names[type], id);
1058                 return NULL;
1059         }
1060         if (report->field[field_index]->report_count < report_counts) {
1061                 hid_err(hid, "not enough values in %s %u field %u\n",
1062                         hid_report_names[type], id, field_index);
1063                 return NULL;
1064         }
1065         return report;
1066 }
1067 EXPORT_SYMBOL_GPL(hid_validate_values);
1068
1069 static int hid_calculate_multiplier(struct hid_device *hid,
1070                                      struct hid_field *multiplier)
1071 {
1072         int m;
1073         __s32 v = *multiplier->value;
1074         __s32 lmin = multiplier->logical_minimum;
1075         __s32 lmax = multiplier->logical_maximum;
1076         __s32 pmin = multiplier->physical_minimum;
1077         __s32 pmax = multiplier->physical_maximum;
1078
1079         /*
1080          * "Because OS implementations will generally divide the control's
1081          * reported count by the Effective Resolution Multiplier, designers
1082          * should take care not to establish a potential Effective
1083          * Resolution Multiplier of zero."
1084          * HID Usage Table, v1.12, Section 4.3.1, p31
1085          */
1086         if (lmax - lmin == 0)
1087                 return 1;
1088         /*
1089          * Handling the unit exponent is left as an exercise to whoever
1090          * finds a device where that exponent is not 0.
1091          */
1092         m = ((v - lmin)/(lmax - lmin) * (pmax - pmin) + pmin);
1093         if (unlikely(multiplier->unit_exponent != 0)) {
1094                 hid_warn(hid,
1095                          "unsupported Resolution Multiplier unit exponent %d\n",
1096                          multiplier->unit_exponent);
1097         }
1098
1099         /* There are no devices with an effective multiplier > 255 */
1100         if (unlikely(m == 0 || m > 255 || m < -255)) {
1101                 hid_warn(hid, "unsupported Resolution Multiplier %d\n", m);
1102                 m = 1;
1103         }
1104
1105         return m;
1106 }
1107
1108 static void hid_apply_multiplier_to_field(struct hid_device *hid,
1109                                           struct hid_field *field,
1110                                           struct hid_collection *multiplier_collection,
1111                                           int effective_multiplier)
1112 {
1113         struct hid_collection *collection;
1114         struct hid_usage *usage;
1115         int i;
1116
1117         /*
1118          * If multiplier_collection is NULL, the multiplier applies
1119          * to all fields in the report.
1120          * Otherwise, it is the Logical Collection the multiplier applies to
1121          * but our field may be in a subcollection of that collection.
1122          */
1123         for (i = 0; i < field->maxusage; i++) {
1124                 usage = &field->usage[i];
1125
1126                 collection = &hid->collection[usage->collection_index];
1127                 while (collection->parent_idx != -1 &&
1128                        collection != multiplier_collection)
1129                         collection = &hid->collection[collection->parent_idx];
1130
1131                 if (collection->parent_idx != -1 ||
1132                     multiplier_collection == NULL)
1133                         usage->resolution_multiplier = effective_multiplier;
1134
1135         }
1136 }
1137
1138 static void hid_apply_multiplier(struct hid_device *hid,
1139                                  struct hid_field *multiplier)
1140 {
1141         struct hid_report_enum *rep_enum;
1142         struct hid_report *rep;
1143         struct hid_field *field;
1144         struct hid_collection *multiplier_collection;
1145         int effective_multiplier;
1146         int i;
1147
1148         /*
1149          * "The Resolution Multiplier control must be contained in the same
1150          * Logical Collection as the control(s) to which it is to be applied.
1151          * If no Resolution Multiplier is defined, then the Resolution
1152          * Multiplier defaults to 1.  If more than one control exists in a
1153          * Logical Collection, the Resolution Multiplier is associated with
1154          * all controls in the collection. If no Logical Collection is
1155          * defined, the Resolution Multiplier is associated with all
1156          * controls in the report."
1157          * HID Usage Table, v1.12, Section 4.3.1, p30
1158          *
1159          * Thus, search from the current collection upwards until we find a
1160          * logical collection. Then search all fields for that same parent
1161          * collection. Those are the fields the multiplier applies to.
1162          *
1163          * If we have more than one multiplier, it will overwrite the
1164          * applicable fields later.
1165          */
1166         multiplier_collection = &hid->collection[multiplier->usage->collection_index];
1167         while (multiplier_collection->parent_idx != -1 &&
1168                multiplier_collection->type != HID_COLLECTION_LOGICAL)
1169                 multiplier_collection = &hid->collection[multiplier_collection->parent_idx];
1170         if (multiplier_collection->type != HID_COLLECTION_LOGICAL)
1171                 multiplier_collection = NULL;
1172
1173         effective_multiplier = hid_calculate_multiplier(hid, multiplier);
1174
1175         rep_enum = &hid->report_enum[HID_INPUT_REPORT];
1176         list_for_each_entry(rep, &rep_enum->report_list, list) {
1177                 for (i = 0; i < rep->maxfield; i++) {
1178                         field = rep->field[i];
1179                         hid_apply_multiplier_to_field(hid, field,
1180                                                       multiplier_collection,
1181                                                       effective_multiplier);
1182                 }
1183         }
1184 }
1185
1186 /*
1187  * hid_setup_resolution_multiplier - set up all resolution multipliers
1188  *
1189  * @device: hid device
1190  *
1191  * Search for all Resolution Multiplier Feature Reports and apply their
1192  * value to all matching Input items. This only updates the internal struct
1193  * fields.
1194  *
1195  * The Resolution Multiplier is applied by the hardware. If the multiplier
1196  * is anything other than 1, the hardware will send pre-multiplied events
1197  * so that the same physical interaction generates an accumulated
1198  *      accumulated_value = value * * multiplier
1199  * This may be achieved by sending
1200  * - "value * multiplier" for each event, or
1201  * - "value" but "multiplier" times as frequently, or
1202  * - a combination of the above
1203  * The only guarantee is that the same physical interaction always generates
1204  * an accumulated 'value * multiplier'.
1205  *
1206  * This function must be called before any event processing and after
1207  * any SetRequest to the Resolution Multiplier.
1208  */
1209 void hid_setup_resolution_multiplier(struct hid_device *hid)
1210 {
1211         struct hid_report_enum *rep_enum;
1212         struct hid_report *rep;
1213         struct hid_usage *usage;
1214         int i, j;
1215
1216         rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
1217         list_for_each_entry(rep, &rep_enum->report_list, list) {
1218                 for (i = 0; i < rep->maxfield; i++) {
1219                         /* Ignore if report count is out of bounds. */
1220                         if (rep->field[i]->report_count < 1)
1221                                 continue;
1222
1223                         for (j = 0; j < rep->field[i]->maxusage; j++) {
1224                                 usage = &rep->field[i]->usage[j];
1225                                 if (usage->hid == HID_GD_RESOLUTION_MULTIPLIER)
1226                                         hid_apply_multiplier(hid,
1227                                                              rep->field[i]);
1228                         }
1229                 }
1230         }
1231 }
1232 EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier);
1233
1234 /**
1235  * hid_open_report - open a driver-specific device report
1236  *
1237  * @device: hid device
1238  *
1239  * Parse a report description into a hid_device structure. Reports are
1240  * enumerated, fields are attached to these reports.
1241  * 0 returned on success, otherwise nonzero error value.
1242  *
1243  * This function (or the equivalent hid_parse() macro) should only be
1244  * called from probe() in drivers, before starting the device.
1245  */
1246 int hid_open_report(struct hid_device *device)
1247 {
1248         struct hid_parser *parser;
1249         struct hid_item item;
1250         unsigned int size;
1251         const __u8 *start;
1252         const __u8 *end;
1253         const __u8 *next;
1254         int ret;
1255         int i;
1256         static int (*dispatch_type[])(struct hid_parser *parser,
1257                                       struct hid_item *item) = {
1258                 hid_parser_main,
1259                 hid_parser_global,
1260                 hid_parser_local,
1261                 hid_parser_reserved
1262         };
1263
1264         if (WARN_ON(device->status & HID_STAT_PARSED))
1265                 return -EBUSY;
1266
1267         start = device->bpf_rdesc;
1268         if (WARN_ON(!start))
1269                 return -ENODEV;
1270         size = device->bpf_rsize;
1271
1272         if (device->driver->report_fixup) {
1273                 /*
1274                  * device->driver->report_fixup() needs to work
1275                  * on a copy of our report descriptor so it can
1276                  * change it.
1277                  */
1278                 __u8 *buf = kmemdup(start, size, GFP_KERNEL);
1279
1280                 if (buf == NULL)
1281                         return -ENOMEM;
1282
1283                 start = device->driver->report_fixup(device, buf, &size);
1284
1285                 /*
1286                  * The second kmemdup is required in case report_fixup() returns
1287                  * a static read-only memory, but we have no idea if that memory
1288                  * needs to be cleaned up or not at the end.
1289                  */
1290                 start = kmemdup(start, size, GFP_KERNEL);
1291                 kfree(buf);
1292                 if (start == NULL)
1293                         return -ENOMEM;
1294         }
1295
1296         device->rdesc = start;
1297         device->rsize = size;
1298
1299         parser = vzalloc(sizeof(struct hid_parser));
1300         if (!parser) {
1301                 ret = -ENOMEM;
1302                 goto alloc_err;
1303         }
1304
1305         parser->device = device;
1306
1307         end = start + size;
1308
1309         device->collection = kcalloc(HID_DEFAULT_NUM_COLLECTIONS,
1310                                      sizeof(struct hid_collection), GFP_KERNEL);
1311         if (!device->collection) {
1312                 ret = -ENOMEM;
1313                 goto err;
1314         }
1315         device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
1316         for (i = 0; i < HID_DEFAULT_NUM_COLLECTIONS; i++)
1317                 device->collection[i].parent_idx = -1;
1318
1319         ret = -EINVAL;
1320         while ((next = fetch_item(start, end, &item)) != NULL) {
1321                 start = next;
1322
1323                 if (item.format != HID_ITEM_FORMAT_SHORT) {
1324                         hid_err(device, "unexpected long global item\n");
1325                         goto err;
1326                 }
1327
1328                 if (dispatch_type[item.type](parser, &item)) {
1329                         hid_err(device, "item %u %u %u %u parsing failed\n",
1330                                 item.format, (unsigned)item.size,
1331                                 (unsigned)item.type, (unsigned)item.tag);
1332                         goto err;
1333                 }
1334
1335                 if (start == end) {
1336                         if (parser->collection_stack_ptr) {
1337                                 hid_err(device, "unbalanced collection at end of report description\n");
1338                                 goto err;
1339                         }
1340                         if (parser->local.delimiter_depth) {
1341                                 hid_err(device, "unbalanced delimiter at end of report description\n");
1342                                 goto err;
1343                         }
1344
1345                         /*
1346                          * fetch initial values in case the device's
1347                          * default multiplier isn't the recommended 1
1348                          */
1349                         hid_setup_resolution_multiplier(device);
1350
1351                         kfree(parser->collection_stack);
1352                         vfree(parser);
1353                         device->status |= HID_STAT_PARSED;
1354
1355                         return 0;
1356                 }
1357         }
1358
1359         hid_err(device, "item fetching failed at offset %u/%u\n",
1360                 size - (unsigned int)(end - start), size);
1361 err:
1362         kfree(parser->collection_stack);
1363 alloc_err:
1364         vfree(parser);
1365         hid_close_report(device);
1366         return ret;
1367 }
1368 EXPORT_SYMBOL_GPL(hid_open_report);
1369
1370 /*
1371  * Extract/implement a data field from/to a little endian report (bit array).
1372  *
1373  * Code sort-of follows HID spec:
1374  *     http://www.usb.org/developers/hidpage/HID1_11.pdf
1375  *
1376  * While the USB HID spec allows unlimited length bit fields in "report
1377  * descriptors", most devices never use more than 16 bits.
1378  * One model of UPS is claimed to report "LINEV" as a 32-bit field.
1379  * Search linux-kernel and linux-usb-devel archives for "hid-core extract".
1380  */
1381
1382 static u32 __extract(u8 *report, unsigned offset, int n)
1383 {
1384         unsigned int idx = offset / 8;
1385         unsigned int bit_nr = 0;
1386         unsigned int bit_shift = offset % 8;
1387         int bits_to_copy = 8 - bit_shift;
1388         u32 value = 0;
1389         u32 mask = n < 32 ? (1U << n) - 1 : ~0U;
1390
1391         while (n > 0) {
1392                 value |= ((u32)report[idx] >> bit_shift) << bit_nr;
1393                 n -= bits_to_copy;
1394                 bit_nr += bits_to_copy;
1395                 bits_to_copy = 8;
1396                 bit_shift = 0;
1397                 idx++;
1398         }
1399
1400         return value & mask;
1401 }
1402
1403 u32 hid_field_extract(const struct hid_device *hid, u8 *report,
1404                         unsigned offset, unsigned n)
1405 {
1406         if (n > 32) {
1407                 hid_warn_once(hid, "%s() called with n (%d) > 32! (%s)\n",
1408                               __func__, n, current->comm);
1409                 n = 32;
1410         }
1411
1412         return __extract(report, offset, n);
1413 }
1414 EXPORT_SYMBOL_GPL(hid_field_extract);
1415
1416 /*
1417  * "implement" : set bits in a little endian bit stream.
1418  * Same concepts as "extract" (see comments above).
1419  * The data mangled in the bit stream remains in little endian
1420  * order the whole time. It make more sense to talk about
1421  * endianness of register values by considering a register
1422  * a "cached" copy of the little endian bit stream.
1423  */
1424
1425 static void __implement(u8 *report, unsigned offset, int n, u32 value)
1426 {
1427         unsigned int idx = offset / 8;
1428         unsigned int bit_shift = offset % 8;
1429         int bits_to_set = 8 - bit_shift;
1430
1431         while (n - bits_to_set >= 0) {
1432                 report[idx] &= ~(0xff << bit_shift);
1433                 report[idx] |= value << bit_shift;
1434                 value >>= bits_to_set;
1435                 n -= bits_to_set;
1436                 bits_to_set = 8;
1437                 bit_shift = 0;
1438                 idx++;
1439         }
1440
1441         /* last nibble */
1442         if (n) {
1443                 u8 bit_mask = ((1U << n) - 1);
1444                 report[idx] &= ~(bit_mask << bit_shift);
1445                 report[idx] |= value << bit_shift;
1446         }
1447 }
1448
1449 static void implement(const struct hid_device *hid, u8 *report,
1450                       unsigned offset, unsigned n, u32 value)
1451 {
1452         if (unlikely(n > 32)) {
1453                 hid_warn(hid, "%s() called with n (%d) > 32! (%s)\n",
1454                          __func__, n, current->comm);
1455                 n = 32;
1456         } else if (n < 32) {
1457                 u32 m = (1U << n) - 1;
1458
1459                 if (unlikely(value > m)) {
1460                         hid_warn(hid,
1461                                  "%s() called with too large value %d (n: %d)! (%s)\n",
1462                                  __func__, value, n, current->comm);
1463                         value &= m;
1464                 }
1465         }
1466
1467         __implement(report, offset, n, value);
1468 }
1469
1470 /*
1471  * Search an array for a value.
1472  */
1473
1474 static int search(__s32 *array, __s32 value, unsigned n)
1475 {
1476         while (n--) {
1477                 if (*array++ == value)
1478                         return 0;
1479         }
1480         return -1;
1481 }
1482
1483 /**
1484  * hid_match_report - check if driver's raw_event should be called
1485  *
1486  * @hid: hid device
1487  * @report: hid report to match against
1488  *
1489  * compare hid->driver->report_table->report_type to report->type
1490  */
1491 static int hid_match_report(struct hid_device *hid, struct hid_report *report)
1492 {
1493         const struct hid_report_id *id = hid->driver->report_table;
1494
1495         if (!id) /* NULL means all */
1496                 return 1;
1497
1498         for (; id->report_type != HID_TERMINATOR; id++)
1499                 if (id->report_type == HID_ANY_ID ||
1500                                 id->report_type == report->type)
1501                         return 1;
1502         return 0;
1503 }
1504
1505 /**
1506  * hid_match_usage - check if driver's event should be called
1507  *
1508  * @hid: hid device
1509  * @usage: usage to match against
1510  *
1511  * compare hid->driver->usage_table->usage_{type,code} to
1512  * usage->usage_{type,code}
1513  */
1514 static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage)
1515 {
1516         const struct hid_usage_id *id = hid->driver->usage_table;
1517
1518         if (!id) /* NULL means all */
1519                 return 1;
1520
1521         for (; id->usage_type != HID_ANY_ID - 1; id++)
1522                 if ((id->usage_hid == HID_ANY_ID ||
1523                                 id->usage_hid == usage->hid) &&
1524                                 (id->usage_type == HID_ANY_ID ||
1525                                 id->usage_type == usage->type) &&
1526                                 (id->usage_code == HID_ANY_ID ||
1527                                  id->usage_code == usage->code))
1528                         return 1;
1529         return 0;
1530 }
1531
1532 static void hid_process_event(struct hid_device *hid, struct hid_field *field,
1533                 struct hid_usage *usage, __s32 value, int interrupt)
1534 {
1535         struct hid_driver *hdrv = hid->driver;
1536         int ret;
1537
1538         if (!list_empty(&hid->debug_list))
1539                 hid_dump_input(hid, usage, value);
1540
1541         if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
1542                 ret = hdrv->event(hid, field, usage, value);
1543                 if (ret != 0) {
1544                         if (ret < 0)
1545                                 hid_err(hid, "%s's event failed with %d\n",
1546                                                 hdrv->name, ret);
1547                         return;
1548                 }
1549         }
1550
1551         if (hid->claimed & HID_CLAIMED_INPUT)
1552                 hidinput_hid_event(hid, field, usage, value);
1553         if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
1554                 hid->hiddev_hid_event(hid, field, usage, value);
1555 }
1556
1557 /*
1558  * Checks if the given value is valid within this field
1559  */
1560 static inline int hid_array_value_is_valid(struct hid_field *field,
1561                                            __s32 value)
1562 {
1563         __s32 min = field->logical_minimum;
1564
1565         /*
1566          * Value needs to be between logical min and max, and
1567          * (value - min) is used as an index in the usage array.
1568          * This array is of size field->maxusage
1569          */
1570         return value >= min &&
1571                value <= field->logical_maximum &&
1572                value - min < field->maxusage;
1573 }
1574
1575 /*
1576  * Fetch the field from the data. The field content is stored for next
1577  * report processing (we do differential reporting to the layer).
1578  */
1579 static void hid_input_fetch_field(struct hid_device *hid,
1580                                   struct hid_field *field,
1581                                   __u8 *data)
1582 {
1583         unsigned n;
1584         unsigned count = field->report_count;
1585         unsigned offset = field->report_offset;
1586         unsigned size = field->report_size;
1587         __s32 min = field->logical_minimum;
1588         __s32 *value;
1589
1590         value = field->new_value;
1591         memset(value, 0, count * sizeof(__s32));
1592         field->ignored = false;
1593
1594         for (n = 0; n < count; n++) {
1595
1596                 value[n] = min < 0 ?
1597                         snto32(hid_field_extract(hid, data, offset + n * size,
1598                                size), size) :
1599                         hid_field_extract(hid, data, offset + n * size, size);
1600
1601                 /* Ignore report if ErrorRollOver */
1602                 if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
1603                     hid_array_value_is_valid(field, value[n]) &&
1604                     field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1) {
1605                         field->ignored = true;
1606                         return;
1607                 }
1608         }
1609 }
1610
1611 /*
1612  * Process a received variable field.
1613  */
1614
1615 static void hid_input_var_field(struct hid_device *hid,
1616                                 struct hid_field *field,
1617                                 int interrupt)
1618 {
1619         unsigned int count = field->report_count;
1620         __s32 *value = field->new_value;
1621         unsigned int n;
1622
1623         for (n = 0; n < count; n++)
1624                 hid_process_event(hid,
1625                                   field,
1626                                   &field->usage[n],
1627                                   value[n],
1628                                   interrupt);
1629
1630         memcpy(field->value, value, count * sizeof(__s32));
1631 }
1632
1633 /*
1634  * Process a received array field. The field content is stored for
1635  * next report processing (we do differential reporting to the layer).
1636  */
1637
1638 static void hid_input_array_field(struct hid_device *hid,
1639                                   struct hid_field *field,
1640                                   int interrupt)
1641 {
1642         unsigned int n;
1643         unsigned int count = field->report_count;
1644         __s32 min = field->logical_minimum;
1645         __s32 *value;
1646
1647         value = field->new_value;
1648
1649         /* ErrorRollOver */
1650         if (field->ignored)
1651                 return;
1652
1653         for (n = 0; n < count; n++) {
1654                 if (hid_array_value_is_valid(field, field->value[n]) &&
1655                     search(value, field->value[n], count))
1656                         hid_process_event(hid,
1657                                           field,
1658                                           &field->usage[field->value[n] - min],
1659                                           0,
1660                                           interrupt);
1661
1662                 if (hid_array_value_is_valid(field, value[n]) &&
1663                     search(field->value, value[n], count))
1664                         hid_process_event(hid,
1665                                           field,
1666                                           &field->usage[value[n] - min],
1667                                           1,
1668                                           interrupt);
1669         }
1670
1671         memcpy(field->value, value, count * sizeof(__s32));
1672 }
1673
1674 /*
1675  * Analyse a received report, and fetch the data from it. The field
1676  * content is stored for next report processing (we do differential
1677  * reporting to the layer).
1678  */
1679 static void hid_process_report(struct hid_device *hid,
1680                                struct hid_report *report,
1681                                __u8 *data,
1682                                int interrupt)
1683 {
1684         unsigned int a;
1685         struct hid_field_entry *entry;
1686         struct hid_field *field;
1687
1688         /* first retrieve all incoming values in data */
1689         for (a = 0; a < report->maxfield; a++)
1690                 hid_input_fetch_field(hid, report->field[a], data);
1691
1692         if (!list_empty(&report->field_entry_list)) {
1693                 /* INPUT_REPORT, we have a priority list of fields */
1694                 list_for_each_entry(entry,
1695                                     &report->field_entry_list,
1696                                     list) {
1697                         field = entry->field;
1698
1699                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1700                                 hid_process_event(hid,
1701                                                   field,
1702                                                   &field->usage[entry->index],
1703                                                   field->new_value[entry->index],
1704                                                   interrupt);
1705                         else
1706                                 hid_input_array_field(hid, field, interrupt);
1707                 }
1708
1709                 /* we need to do the memcpy at the end for var items */
1710                 for (a = 0; a < report->maxfield; a++) {
1711                         field = report->field[a];
1712
1713                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1714                                 memcpy(field->value, field->new_value,
1715                                        field->report_count * sizeof(__s32));
1716                 }
1717         } else {
1718                 /* FEATURE_REPORT, regular processing */
1719                 for (a = 0; a < report->maxfield; a++) {
1720                         field = report->field[a];
1721
1722                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1723                                 hid_input_var_field(hid, field, interrupt);
1724                         else
1725                                 hid_input_array_field(hid, field, interrupt);
1726                 }
1727         }
1728 }
1729
1730 /*
1731  * Insert a given usage_index in a field in the list
1732  * of processed usages in the report.
1733  *
1734  * The elements of lower priority score are processed
1735  * first.
1736  */
1737 static void __hid_insert_field_entry(struct hid_device *hid,
1738                                      struct hid_report *report,
1739                                      struct hid_field_entry *entry,
1740                                      struct hid_field *field,
1741                                      unsigned int usage_index)
1742 {
1743         struct hid_field_entry *next;
1744
1745         entry->field = field;
1746         entry->index = usage_index;
1747         entry->priority = field->usages_priorities[usage_index];
1748
1749         /* insert the element at the correct position */
1750         list_for_each_entry(next,
1751                             &report->field_entry_list,
1752                             list) {
1753                 /*
1754                  * the priority of our element is strictly higher
1755                  * than the next one, insert it before
1756                  */
1757                 if (entry->priority > next->priority) {
1758                         list_add_tail(&entry->list, &next->list);
1759                         return;
1760                 }
1761         }
1762
1763         /* lowest priority score: insert at the end */
1764         list_add_tail(&entry->list, &report->field_entry_list);
1765 }
1766
1767 static void hid_report_process_ordering(struct hid_device *hid,
1768                                         struct hid_report *report)
1769 {
1770         struct hid_field *field;
1771         struct hid_field_entry *entries;
1772         unsigned int a, u, usages;
1773         unsigned int count = 0;
1774
1775         /* count the number of individual fields in the report */
1776         for (a = 0; a < report->maxfield; a++) {
1777                 field = report->field[a];
1778
1779                 if (field->flags & HID_MAIN_ITEM_VARIABLE)
1780                         count += field->report_count;
1781                 else
1782                         count++;
1783         }
1784
1785         /* allocate the memory to process the fields */
1786         entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
1787         if (!entries)
1788                 return;
1789
1790         report->field_entries = entries;
1791
1792         /*
1793          * walk through all fields in the report and
1794          * store them by priority order in report->field_entry_list
1795          *
1796          * - Var elements are individualized (field + usage_index)
1797          * - Arrays are taken as one, we can not chose an order for them
1798          */
1799         usages = 0;
1800         for (a = 0; a < report->maxfield; a++) {
1801                 field = report->field[a];
1802
1803                 if (field->flags & HID_MAIN_ITEM_VARIABLE) {
1804                         for (u = 0; u < field->report_count; u++) {
1805                                 __hid_insert_field_entry(hid, report,
1806                                                          &entries[usages],
1807                                                          field, u);
1808                                 usages++;
1809                         }
1810                 } else {
1811                         __hid_insert_field_entry(hid, report, &entries[usages],
1812                                                  field, 0);
1813                         usages++;
1814                 }
1815         }
1816 }
1817
1818 static void hid_process_ordering(struct hid_device *hid)
1819 {
1820         struct hid_report *report;
1821         struct hid_report_enum *report_enum = &hid->report_enum[HID_INPUT_REPORT];
1822
1823         list_for_each_entry(report, &report_enum->report_list, list)
1824                 hid_report_process_ordering(hid, report);
1825 }
1826
1827 /*
1828  * Output the field into the report.
1829  */
1830
1831 static void hid_output_field(const struct hid_device *hid,
1832                              struct hid_field *field, __u8 *data)
1833 {
1834         unsigned count = field->report_count;
1835         unsigned offset = field->report_offset;
1836         unsigned size = field->report_size;
1837         unsigned n;
1838
1839         for (n = 0; n < count; n++) {
1840                 if (field->logical_minimum < 0) /* signed values */
1841                         implement(hid, data, offset + n * size, size,
1842                                   s32ton(field->value[n], size));
1843                 else                            /* unsigned values */
1844                         implement(hid, data, offset + n * size, size,
1845                                   field->value[n]);
1846         }
1847 }
1848
1849 /*
1850  * Compute the size of a report.
1851  */
1852 static size_t hid_compute_report_size(struct hid_report *report)
1853 {
1854         if (report->size)
1855                 return ((report->size - 1) >> 3) + 1;
1856
1857         return 0;
1858 }
1859
1860 /*
1861  * Create a report. 'data' has to be allocated using
1862  * hid_alloc_report_buf() so that it has proper size.
1863  */
1864
1865 void hid_output_report(struct hid_report *report, __u8 *data)
1866 {
1867         unsigned n;
1868
1869         if (report->id > 0)
1870                 *data++ = report->id;
1871
1872         memset(data, 0, hid_compute_report_size(report));
1873         for (n = 0; n < report->maxfield; n++)
1874                 hid_output_field(report->device, report->field[n], data);
1875 }
1876 EXPORT_SYMBOL_GPL(hid_output_report);
1877
1878 /*
1879  * Allocator for buffer that is going to be passed to hid_output_report()
1880  */
1881 u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
1882 {
1883         /*
1884          * 7 extra bytes are necessary to achieve proper functionality
1885          * of implement() working on 8 byte chunks
1886          */
1887
1888         u32 len = hid_report_len(report) + 7;
1889
1890         return kzalloc(len, flags);
1891 }
1892 EXPORT_SYMBOL_GPL(hid_alloc_report_buf);
1893
1894 /*
1895  * Set a field value. The report this field belongs to has to be
1896  * created and transferred to the device, to set this value in the
1897  * device.
1898  */
1899
1900 int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
1901 {
1902         unsigned size;
1903
1904         if (!field)
1905                 return -1;
1906
1907         size = field->report_size;
1908
1909         hid_dump_input(field->report->device, field->usage + offset, value);
1910
1911         if (offset >= field->report_count) {
1912                 hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n",
1913                                 offset, field->report_count);
1914                 return -1;
1915         }
1916         if (field->logical_minimum < 0) {
1917                 if (value != snto32(s32ton(value, size), size)) {
1918                         hid_err(field->report->device, "value %d is out of range\n", value);
1919                         return -1;
1920                 }
1921         }
1922         field->value[offset] = value;
1923         return 0;
1924 }
1925 EXPORT_SYMBOL_GPL(hid_set_field);
1926
1927 struct hid_field *hid_find_field(struct hid_device *hdev, unsigned int report_type,
1928                                  unsigned int application, unsigned int usage)
1929 {
1930         struct list_head *report_list = &hdev->report_enum[report_type].report_list;
1931         struct hid_report *report;
1932         int i, j;
1933
1934         list_for_each_entry(report, report_list, list) {
1935                 if (report->application != application)
1936                         continue;
1937
1938                 for (i = 0; i < report->maxfield; i++) {
1939                         struct hid_field *field = report->field[i];
1940
1941                         for (j = 0; j < field->maxusage; j++) {
1942                                 if (field->usage[j].hid == usage)
1943                                         return field;
1944                         }
1945                 }
1946         }
1947
1948         return NULL;
1949 }
1950 EXPORT_SYMBOL_GPL(hid_find_field);
1951
1952 static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
1953                 const u8 *data)
1954 {
1955         struct hid_report *report;
1956         unsigned int n = 0;     /* Normally report number is 0 */
1957
1958         /* Device uses numbered reports, data[0] is report number */
1959         if (report_enum->numbered)
1960                 n = *data;
1961
1962         report = report_enum->report_id_hash[n];
1963         if (report == NULL)
1964                 dbg_hid("undefined report_id %u received\n", n);
1965
1966         return report;
1967 }
1968
1969 /*
1970  * Implement a generic .request() callback, using .raw_request()
1971  * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
1972  */
1973 int __hid_request(struct hid_device *hid, struct hid_report *report,
1974                 enum hid_class_request reqtype)
1975 {
1976         char *buf;
1977         int ret;
1978         u32 len;
1979
1980         buf = hid_alloc_report_buf(report, GFP_KERNEL);
1981         if (!buf)
1982                 return -ENOMEM;
1983
1984         len = hid_report_len(report);
1985
1986         if (reqtype == HID_REQ_SET_REPORT)
1987                 hid_output_report(report, buf);
1988
1989         ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
1990                                           report->type, reqtype);
1991         if (ret < 0) {
1992                 dbg_hid("unable to complete request: %d\n", ret);
1993                 goto out;
1994         }
1995
1996         if (reqtype == HID_REQ_GET_REPORT)
1997                 hid_input_report(hid, report->type, buf, ret, 0);
1998
1999         ret = 0;
2000
2001 out:
2002         kfree(buf);
2003         return ret;
2004 }
2005 EXPORT_SYMBOL_GPL(__hid_request);
2006
2007 int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
2008                          int interrupt)
2009 {
2010         struct hid_report_enum *report_enum = hid->report_enum + type;
2011         struct hid_report *report;
2012         struct hid_driver *hdrv;
2013         int max_buffer_size = HID_MAX_BUFFER_SIZE;
2014         u32 rsize, csize = size;
2015         u8 *cdata = data;
2016         int ret = 0;
2017
2018         report = hid_get_report(report_enum, data);
2019         if (!report)
2020                 goto out;
2021
2022         if (report_enum->numbered) {
2023                 cdata++;
2024                 csize--;
2025         }
2026
2027         rsize = hid_compute_report_size(report);
2028
2029         if (hid->ll_driver->max_buffer_size)
2030                 max_buffer_size = hid->ll_driver->max_buffer_size;
2031
2032         if (report_enum->numbered && rsize >= max_buffer_size)
2033                 rsize = max_buffer_size - 1;
2034         else if (rsize > max_buffer_size)
2035                 rsize = max_buffer_size;
2036
2037         if (csize < rsize) {
2038                 dbg_hid("report %d is too short, (%d < %d)\n", report->id,
2039                                 csize, rsize);
2040                 memset(cdata + csize, 0, rsize - csize);
2041         }
2042
2043         if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
2044                 hid->hiddev_report_event(hid, report);
2045         if (hid->claimed & HID_CLAIMED_HIDRAW) {
2046                 ret = hidraw_report_event(hid, data, size);
2047                 if (ret)
2048                         goto out;
2049         }
2050
2051         if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
2052                 hid_process_report(hid, report, cdata, interrupt);
2053                 hdrv = hid->driver;
2054                 if (hdrv && hdrv->report)
2055                         hdrv->report(hid, report);
2056         }
2057
2058         if (hid->claimed & HID_CLAIMED_INPUT)
2059                 hidinput_report_event(hid, report);
2060 out:
2061         return ret;
2062 }
2063 EXPORT_SYMBOL_GPL(hid_report_raw_event);
2064
2065
2066 static int __hid_input_report(struct hid_device *hid, enum hid_report_type type,
2067                               u8 *data, u32 size, int interrupt, u64 source, bool from_bpf,
2068                               bool lock_already_taken)
2069 {
2070         struct hid_report_enum *report_enum;
2071         struct hid_driver *hdrv;
2072         struct hid_report *report;
2073         int ret = 0;
2074
2075         if (!hid)
2076                 return -ENODEV;
2077
2078         ret = down_trylock(&hid->driver_input_lock);
2079         if (lock_already_taken && !ret) {
2080                 up(&hid->driver_input_lock);
2081                 return -EINVAL;
2082         } else if (!lock_already_taken && ret) {
2083                 return -EBUSY;
2084         }
2085
2086         if (!hid->driver) {
2087                 ret = -ENODEV;
2088                 goto unlock;
2089         }
2090         report_enum = hid->report_enum + type;
2091         hdrv = hid->driver;
2092
2093         data = dispatch_hid_bpf_device_event(hid, type, data, &size, interrupt, source, from_bpf);
2094         if (IS_ERR(data)) {
2095                 ret = PTR_ERR(data);
2096                 goto unlock;
2097         }
2098
2099         if (!size) {
2100                 dbg_hid("empty report\n");
2101                 ret = -1;
2102                 goto unlock;
2103         }
2104
2105         /* Avoid unnecessary overhead if debugfs is disabled */
2106         if (!list_empty(&hid->debug_list))
2107                 hid_dump_report(hid, type, data, size);
2108
2109         report = hid_get_report(report_enum, data);
2110
2111         if (!report) {
2112                 ret = -1;
2113                 goto unlock;
2114         }
2115
2116         if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
2117                 ret = hdrv->raw_event(hid, report, data, size);
2118                 if (ret < 0)
2119                         goto unlock;
2120         }
2121
2122         ret = hid_report_raw_event(hid, type, data, size, interrupt);
2123
2124 unlock:
2125         if (!lock_already_taken)
2126                 up(&hid->driver_input_lock);
2127         return ret;
2128 }
2129
2130 /**
2131  * hid_input_report - report data from lower layer (usb, bt...)
2132  *
2133  * @hid: hid device
2134  * @type: HID report type (HID_*_REPORT)
2135  * @data: report contents
2136  * @size: size of data parameter
2137  * @interrupt: distinguish between interrupt and control transfers
2138  *
2139  * This is data entry for lower layers.
2140  */
2141 int hid_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
2142                      int interrupt)
2143 {
2144         return __hid_input_report(hid, type, data, size, interrupt, 0,
2145                                   false, /* from_bpf */
2146                                   false /* lock_already_taken */);
2147 }
2148 EXPORT_SYMBOL_GPL(hid_input_report);
2149
2150 bool hid_match_one_id(const struct hid_device *hdev,
2151                       const struct hid_device_id *id)
2152 {
2153         return (id->bus == HID_BUS_ANY || id->bus == hdev->bus) &&
2154                 (id->group == HID_GROUP_ANY || id->group == hdev->group) &&
2155                 (id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&
2156                 (id->product == HID_ANY_ID || id->product == hdev->product);
2157 }
2158
2159 const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
2160                 const struct hid_device_id *id)
2161 {
2162         for (; id->bus; id++)
2163                 if (hid_match_one_id(hdev, id))
2164                         return id;
2165
2166         return NULL;
2167 }
2168 EXPORT_SYMBOL_GPL(hid_match_id);
2169
2170 static const struct hid_device_id hid_hiddev_list[] = {
2171         { HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS) },
2172         { HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS1) },
2173         { }
2174 };
2175
2176 static bool hid_hiddev(struct hid_device *hdev)
2177 {
2178         return !!hid_match_id(hdev, hid_hiddev_list);
2179 }
2180
2181
2182 static ssize_t
2183 report_descriptor_read(struct file *filp, struct kobject *kobj,
2184                        const struct bin_attribute *attr,
2185                        char *buf, loff_t off, size_t count)
2186 {
2187         struct device *dev = kobj_to_dev(kobj);
2188         struct hid_device *hdev = to_hid_device(dev);
2189
2190         if (off >= hdev->rsize)
2191                 return 0;
2192
2193         if (off + count > hdev->rsize)
2194                 count = hdev->rsize - off;
2195
2196         memcpy(buf, hdev->rdesc + off, count);
2197
2198         return count;
2199 }
2200
2201 static ssize_t
2202 country_show(struct device *dev, struct device_attribute *attr,
2203              char *buf)
2204 {
2205         struct hid_device *hdev = to_hid_device(dev);
2206
2207         return sprintf(buf, "%02x\n", hdev->country & 0xff);
2208 }
2209
2210 static const BIN_ATTR_RO(report_descriptor, HID_MAX_DESCRIPTOR_SIZE);
2211
2212 static const DEVICE_ATTR_RO(country);
2213
2214 int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
2215 {
2216         static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
2217                 "Joystick", "Gamepad", "Keyboard", "Keypad",
2218                 "Multi-Axis Controller"
2219         };
2220         const char *type, *bus;
2221         char buf[64] = "";
2222         unsigned int i;
2223         int len;
2224         int ret;
2225
2226         ret = hid_bpf_connect_device(hdev);
2227         if (ret)
2228                 return ret;
2229
2230         if (hdev->quirks & HID_QUIRK_HIDDEV_FORCE)
2231                 connect_mask |= (HID_CONNECT_HIDDEV_FORCE | HID_CONNECT_HIDDEV);
2232         if (hdev->quirks & HID_QUIRK_HIDINPUT_FORCE)
2233                 connect_mask |= HID_CONNECT_HIDINPUT_FORCE;
2234         if (hdev->bus != BUS_USB)
2235                 connect_mask &= ~HID_CONNECT_HIDDEV;
2236         if (hid_hiddev(hdev))
2237                 connect_mask |= HID_CONNECT_HIDDEV_FORCE;
2238
2239         if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,
2240                                 connect_mask & HID_CONNECT_HIDINPUT_FORCE))
2241                 hdev->claimed |= HID_CLAIMED_INPUT;
2242
2243         if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect &&
2244                         !hdev->hiddev_connect(hdev,
2245                                 connect_mask & HID_CONNECT_HIDDEV_FORCE))
2246                 hdev->claimed |= HID_CLAIMED_HIDDEV;
2247         if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))
2248                 hdev->claimed |= HID_CLAIMED_HIDRAW;
2249
2250         if (connect_mask & HID_CONNECT_DRIVER)
2251                 hdev->claimed |= HID_CLAIMED_DRIVER;
2252
2253         /* Drivers with the ->raw_event callback set are not required to connect
2254          * to any other listener. */
2255         if (!hdev->claimed && !hdev->driver->raw_event) {
2256                 hid_err(hdev, "device has no listeners, quitting\n");
2257                 return -ENODEV;
2258         }
2259
2260         hid_process_ordering(hdev);
2261
2262         if ((hdev->claimed & HID_CLAIMED_INPUT) &&
2263                         (connect_mask & HID_CONNECT_FF) && hdev->ff_init)
2264                 hdev->ff_init(hdev);
2265
2266         len = 0;
2267         if (hdev->claimed & HID_CLAIMED_INPUT)
2268                 len += sprintf(buf + len, "input");
2269         if (hdev->claimed & HID_CLAIMED_HIDDEV)
2270                 len += sprintf(buf + len, "%shiddev%d", len ? "," : "",
2271                                 ((struct hiddev *)hdev->hiddev)->minor);
2272         if (hdev->claimed & HID_CLAIMED_HIDRAW)
2273                 len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
2274                                 ((struct hidraw *)hdev->hidraw)->minor);
2275
2276         type = "Device";
2277         for (i = 0; i < hdev->maxcollection; i++) {
2278                 struct hid_collection *col = &hdev->collection[i];
2279                 if (col->type == HID_COLLECTION_APPLICATION &&
2280                    (col->usage & HID_USAGE_PAGE) == HID_UP_GENDESK &&
2281                    (col->usage & 0xffff) < ARRAY_SIZE(types)) {
2282                         type = types[col->usage & 0xffff];
2283                         break;
2284                 }
2285         }
2286
2287         switch (hdev->bus) {
2288         case BUS_USB:
2289                 bus = "USB";
2290                 break;
2291         case BUS_BLUETOOTH:
2292                 bus = "BLUETOOTH";
2293                 break;
2294         case BUS_I2C:
2295                 bus = "I2C";
2296                 break;
2297         case BUS_VIRTUAL:
2298                 bus = "VIRTUAL";
2299                 break;
2300         case BUS_INTEL_ISHTP:
2301         case BUS_AMD_SFH:
2302                 bus = "SENSOR HUB";
2303                 break;
2304         default:
2305                 bus = "<UNKNOWN>";
2306         }
2307
2308         ret = device_create_file(&hdev->dev, &dev_attr_country);
2309         if (ret)
2310                 hid_warn(hdev,
2311                          "can't create sysfs country code attribute err: %d\n", ret);
2312
2313         hid_info(hdev, "%s: %s HID v%x.%02x %s [%s] on %s\n",
2314                  buf, bus, hdev->version >> 8, hdev->version & 0xff,
2315                  type, hdev->name, hdev->phys);
2316
2317         return 0;
2318 }
2319 EXPORT_SYMBOL_GPL(hid_connect);
2320
2321 void hid_disconnect(struct hid_device *hdev)
2322 {
2323         device_remove_file(&hdev->dev, &dev_attr_country);
2324         if (hdev->claimed & HID_CLAIMED_INPUT)
2325                 hidinput_disconnect(hdev);
2326         if (hdev->claimed & HID_CLAIMED_HIDDEV)
2327                 hdev->hiddev_disconnect(hdev);
2328         if (hdev->claimed & HID_CLAIMED_HIDRAW)
2329                 hidraw_disconnect(hdev);
2330         hdev->claimed = 0;
2331
2332         hid_bpf_disconnect_device(hdev);
2333 }
2334 EXPORT_SYMBOL_GPL(hid_disconnect);
2335
2336 /**
2337  * hid_hw_start - start underlying HW
2338  * @hdev: hid device
2339  * @connect_mask: which outputs to connect, see HID_CONNECT_*
2340  *
2341  * Call this in probe function *after* hid_parse. This will setup HW
2342  * buffers and start the device (if not defeirred to device open).
2343  * hid_hw_stop must be called if this was successful.
2344  */
2345 int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask)
2346 {
2347         int error;
2348
2349         error = hdev->ll_driver->start(hdev);
2350         if (error)
2351                 return error;
2352
2353         if (connect_mask) {
2354                 error = hid_connect(hdev, connect_mask);
2355                 if (error) {
2356                         hdev->ll_driver->stop(hdev);
2357                         return error;
2358                 }
2359         }
2360
2361         return 0;
2362 }
2363 EXPORT_SYMBOL_GPL(hid_hw_start);
2364
2365 /**
2366  * hid_hw_stop - stop underlying HW
2367  * @hdev: hid device
2368  *
2369  * This is usually called from remove function or from probe when something
2370  * failed and hid_hw_start was called already.
2371  */
2372 void hid_hw_stop(struct hid_device *hdev)
2373 {
2374         hid_disconnect(hdev);
2375         hdev->ll_driver->stop(hdev);
2376 }
2377 EXPORT_SYMBOL_GPL(hid_hw_stop);
2378
2379 /**
2380  * hid_hw_open - signal underlying HW to start delivering events
2381  * @hdev: hid device
2382  *
2383  * Tell underlying HW to start delivering events from the device.
2384  * This function should be called sometime after successful call
2385  * to hid_hw_start().
2386  */
2387 int hid_hw_open(struct hid_device *hdev)
2388 {
2389         int ret;
2390
2391         ret = mutex_lock_killable(&hdev->ll_open_lock);
2392         if (ret)
2393                 return ret;
2394
2395         if (!hdev->ll_open_count++) {
2396                 ret = hdev->ll_driver->open(hdev);
2397                 if (ret)
2398                         hdev->ll_open_count--;
2399
2400                 if (hdev->driver->on_hid_hw_open)
2401                         hdev->driver->on_hid_hw_open(hdev);
2402         }
2403
2404         mutex_unlock(&hdev->ll_open_lock);
2405         return ret;
2406 }
2407 EXPORT_SYMBOL_GPL(hid_hw_open);
2408
2409 /**
2410  * hid_hw_close - signal underlaying HW to stop delivering events
2411  *
2412  * @hdev: hid device
2413  *
2414  * This function indicates that we are not interested in the events
2415  * from this device anymore. Delivery of events may or may not stop,
2416  * depending on the number of users still outstanding.
2417  */
2418 void hid_hw_close(struct hid_device *hdev)
2419 {
2420         mutex_lock(&hdev->ll_open_lock);
2421         if (!--hdev->ll_open_count) {
2422                 hdev->ll_driver->close(hdev);
2423
2424                 if (hdev->driver->on_hid_hw_close)
2425                         hdev->driver->on_hid_hw_close(hdev);
2426         }
2427         mutex_unlock(&hdev->ll_open_lock);
2428 }
2429 EXPORT_SYMBOL_GPL(hid_hw_close);
2430
2431 /**
2432  * hid_hw_request - send report request to device
2433  *
2434  * @hdev: hid device
2435  * @report: report to send
2436  * @reqtype: hid request type
2437  */
2438 void hid_hw_request(struct hid_device *hdev,
2439                     struct hid_report *report, enum hid_class_request reqtype)
2440 {
2441         if (hdev->ll_driver->request)
2442                 return hdev->ll_driver->request(hdev, report, reqtype);
2443
2444         __hid_request(hdev, report, reqtype);
2445 }
2446 EXPORT_SYMBOL_GPL(hid_hw_request);
2447
2448 int __hid_hw_raw_request(struct hid_device *hdev,
2449                          unsigned char reportnum, __u8 *buf,
2450                          size_t len, enum hid_report_type rtype,
2451                          enum hid_class_request reqtype,
2452                          u64 source, bool from_bpf)
2453 {
2454         unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
2455         int ret;
2456
2457         if (hdev->ll_driver->max_buffer_size)
2458                 max_buffer_size = hdev->ll_driver->max_buffer_size;
2459
2460         if (len < 1 || len > max_buffer_size || !buf)
2461                 return -EINVAL;
2462
2463         ret = dispatch_hid_bpf_raw_requests(hdev, reportnum, buf, len, rtype,
2464                                             reqtype, source, from_bpf);
2465         if (ret)
2466                 return ret;
2467
2468         return hdev->ll_driver->raw_request(hdev, reportnum, buf, len,
2469                                             rtype, reqtype);
2470 }
2471
2472 /**
2473  * hid_hw_raw_request - send report request to device
2474  *
2475  * @hdev: hid device
2476  * @reportnum: report ID
2477  * @buf: in/out data to transfer
2478  * @len: length of buf
2479  * @rtype: HID report type
2480  * @reqtype: HID_REQ_GET_REPORT or HID_REQ_SET_REPORT
2481  *
2482  * Return: count of data transferred, negative if error
2483  *
2484  * Same behavior as hid_hw_request, but with raw buffers instead.
2485  */
2486 int hid_hw_raw_request(struct hid_device *hdev,
2487                        unsigned char reportnum, __u8 *buf,
2488                        size_t len, enum hid_report_type rtype, enum hid_class_request reqtype)
2489 {
2490         return __hid_hw_raw_request(hdev, reportnum, buf, len, rtype, reqtype, 0, false);
2491 }
2492 EXPORT_SYMBOL_GPL(hid_hw_raw_request);
2493
2494 int __hid_hw_output_report(struct hid_device *hdev, __u8 *buf, size_t len, u64 source,
2495                            bool from_bpf)
2496 {
2497         unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
2498         int ret;
2499
2500         if (hdev->ll_driver->max_buffer_size)
2501                 max_buffer_size = hdev->ll_driver->max_buffer_size;
2502
2503         if (len < 1 || len > max_buffer_size || !buf)
2504                 return -EINVAL;
2505
2506         ret = dispatch_hid_bpf_output_report(hdev, buf, len, source, from_bpf);
2507         if (ret)
2508                 return ret;
2509
2510         if (hdev->ll_driver->output_report)
2511                 return hdev->ll_driver->output_report(hdev, buf, len);
2512
2513         return -ENOSYS;
2514 }
2515
2516 /**
2517  * hid_hw_output_report - send output report to device
2518  *
2519  * @hdev: hid device
2520  * @buf: raw data to transfer
2521  * @len: length of buf
2522  *
2523  * Return: count of data transferred, negative if error
2524  */
2525 int hid_hw_output_report(struct hid_device *hdev, __u8 *buf, size_t len)
2526 {
2527         return __hid_hw_output_report(hdev, buf, len, 0, false);
2528 }
2529 EXPORT_SYMBOL_GPL(hid_hw_output_report);
2530
2531 #ifdef CONFIG_PM
2532 int hid_driver_suspend(struct hid_device *hdev, pm_message_t state)
2533 {
2534         if (hdev->driver && hdev->driver->suspend)
2535                 return hdev->driver->suspend(hdev, state);
2536
2537         return 0;
2538 }
2539 EXPORT_SYMBOL_GPL(hid_driver_suspend);
2540
2541 int hid_driver_reset_resume(struct hid_device *hdev)
2542 {
2543         if (hdev->driver && hdev->driver->reset_resume)
2544                 return hdev->driver->reset_resume(hdev);
2545
2546         return 0;
2547 }
2548 EXPORT_SYMBOL_GPL(hid_driver_reset_resume);
2549
2550 int hid_driver_resume(struct hid_device *hdev)
2551 {
2552         if (hdev->driver && hdev->driver->resume)
2553                 return hdev->driver->resume(hdev);
2554
2555         return 0;
2556 }
2557 EXPORT_SYMBOL_GPL(hid_driver_resume);
2558 #endif /* CONFIG_PM */
2559
2560 struct hid_dynid {
2561         struct list_head list;
2562         struct hid_device_id id;
2563 };
2564
2565 /**
2566  * new_id_store - add a new HID device ID to this driver and re-probe devices
2567  * @drv: target device driver
2568  * @buf: buffer for scanning device ID data
2569  * @count: input size
2570  *
2571  * Adds a new dynamic hid device ID to this driver,
2572  * and causes the driver to probe for all devices again.
2573  */
2574 static ssize_t new_id_store(struct device_driver *drv, const char *buf,
2575                 size_t count)
2576 {
2577         struct hid_driver *hdrv = to_hid_driver(drv);
2578         struct hid_dynid *dynid;
2579         __u32 bus, vendor, product;
2580         unsigned long driver_data = 0;
2581         int ret;
2582
2583         ret = sscanf(buf, "%x %x %x %lx",
2584                         &bus, &vendor, &product, &driver_data);
2585         if (ret < 3)
2586                 return -EINVAL;
2587
2588         dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
2589         if (!dynid)
2590                 return -ENOMEM;
2591
2592         dynid->id.bus = bus;
2593         dynid->id.group = HID_GROUP_ANY;
2594         dynid->id.vendor = vendor;
2595         dynid->id.product = product;
2596         dynid->id.driver_data = driver_data;
2597
2598         spin_lock(&hdrv->dyn_lock);
2599         list_add_tail(&dynid->list, &hdrv->dyn_list);
2600         spin_unlock(&hdrv->dyn_lock);
2601
2602         ret = driver_attach(&hdrv->driver);
2603
2604         return ret ? : count;
2605 }
2606 static DRIVER_ATTR_WO(new_id);
2607
2608 static struct attribute *hid_drv_attrs[] = {
2609         &driver_attr_new_id.attr,
2610         NULL,
2611 };
2612 ATTRIBUTE_GROUPS(hid_drv);
2613
2614 static void hid_free_dynids(struct hid_driver *hdrv)
2615 {
2616         struct hid_dynid *dynid, *n;
2617
2618         spin_lock(&hdrv->dyn_lock);
2619         list_for_each_entry_safe(dynid, n, &hdrv->dyn_list, list) {
2620                 list_del(&dynid->list);
2621                 kfree(dynid);
2622         }
2623         spin_unlock(&hdrv->dyn_lock);
2624 }
2625
2626 const struct hid_device_id *hid_match_device(struct hid_device *hdev,
2627                                              struct hid_driver *hdrv)
2628 {
2629         struct hid_dynid *dynid;
2630
2631         spin_lock(&hdrv->dyn_lock);
2632         list_for_each_entry(dynid, &hdrv->dyn_list, list) {
2633                 if (hid_match_one_id(hdev, &dynid->id)) {
2634                         spin_unlock(&hdrv->dyn_lock);
2635                         return &dynid->id;
2636                 }
2637         }
2638         spin_unlock(&hdrv->dyn_lock);
2639
2640         return hid_match_id(hdev, hdrv->id_table);
2641 }
2642 EXPORT_SYMBOL_GPL(hid_match_device);
2643
2644 static int hid_bus_match(struct device *dev, const struct device_driver *drv)
2645 {
2646         struct hid_driver *hdrv = to_hid_driver(drv);
2647         struct hid_device *hdev = to_hid_device(dev);
2648
2649         return hid_match_device(hdev, hdrv) != NULL;
2650 }
2651
2652 /**
2653  * hid_compare_device_paths - check if both devices share the same path
2654  * @hdev_a: hid device
2655  * @hdev_b: hid device
2656  * @separator: char to use as separator
2657  *
2658  * Check if two devices share the same path up to the last occurrence of
2659  * the separator char. Both paths must exist (i.e., zero-length paths
2660  * don't match).
2661  */
2662 bool hid_compare_device_paths(struct hid_device *hdev_a,
2663                               struct hid_device *hdev_b, char separator)
2664 {
2665         int n1 = strrchr(hdev_a->phys, separator) - hdev_a->phys;
2666         int n2 = strrchr(hdev_b->phys, separator) - hdev_b->phys;
2667
2668         if (n1 != n2 || n1 <= 0 || n2 <= 0)
2669                 return false;
2670
2671         return !strncmp(hdev_a->phys, hdev_b->phys, n1);
2672 }
2673 EXPORT_SYMBOL_GPL(hid_compare_device_paths);
2674
2675 static bool hid_check_device_match(struct hid_device *hdev,
2676                                    struct hid_driver *hdrv,
2677                                    const struct hid_device_id **id)
2678 {
2679         *id = hid_match_device(hdev, hdrv);
2680         if (!*id)
2681                 return false;
2682
2683         if (hdrv->match)
2684                 return hdrv->match(hdev, hid_ignore_special_drivers);
2685
2686         /*
2687          * hid-generic implements .match(), so we must be dealing with a
2688          * different HID driver here, and can simply check if
2689          * hid_ignore_special_drivers or HID_QUIRK_IGNORE_SPECIAL_DRIVER
2690          * are set or not.
2691          */
2692         return !hid_ignore_special_drivers && !(hdev->quirks & HID_QUIRK_IGNORE_SPECIAL_DRIVER);
2693 }
2694
2695 static int __hid_device_probe(struct hid_device *hdev, struct hid_driver *hdrv)
2696 {
2697         const struct hid_device_id *id;
2698         int ret;
2699
2700         if (!hdev->bpf_rsize) {
2701                 /* in case a bpf program gets detached, we need to free the old one */
2702                 hid_free_bpf_rdesc(hdev);
2703
2704                 /* keep this around so we know we called it once */
2705                 hdev->bpf_rsize = hdev->dev_rsize;
2706
2707                 /* call_hid_bpf_rdesc_fixup will always return a valid pointer */
2708                 hdev->bpf_rdesc = call_hid_bpf_rdesc_fixup(hdev, hdev->dev_rdesc,
2709                                                            &hdev->bpf_rsize);
2710         }
2711
2712         if (!hid_check_device_match(hdev, hdrv, &id))
2713                 return -ENODEV;
2714
2715         hdev->devres_group_id = devres_open_group(&hdev->dev, NULL, GFP_KERNEL);
2716         if (!hdev->devres_group_id)
2717                 return -ENOMEM;
2718
2719         /* reset the quirks that has been previously set */
2720         hdev->quirks = hid_lookup_quirk(hdev);
2721         hdev->driver = hdrv;
2722
2723         if (hdrv->probe) {
2724                 ret = hdrv->probe(hdev, id);
2725         } else { /* default probe */
2726                 ret = hid_open_report(hdev);
2727                 if (!ret)
2728                         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
2729         }
2730
2731         /*
2732          * Note that we are not closing the devres group opened above so
2733          * even resources that were attached to the device after probe is
2734          * run are released when hid_device_remove() is executed. This is
2735          * needed as some drivers would allocate additional resources,
2736          * for example when updating firmware.
2737          */
2738
2739         if (ret) {
2740                 devres_release_group(&hdev->dev, hdev->devres_group_id);
2741                 hid_close_report(hdev);
2742                 hdev->driver = NULL;
2743         }
2744
2745         return ret;
2746 }
2747
2748 static int hid_device_probe(struct device *dev)
2749 {
2750         struct hid_device *hdev = to_hid_device(dev);
2751         struct hid_driver *hdrv = to_hid_driver(dev->driver);
2752         int ret = 0;
2753
2754         if (down_interruptible(&hdev->driver_input_lock))
2755                 return -EINTR;
2756
2757         hdev->io_started = false;
2758         clear_bit(ffs(HID_STAT_REPROBED), &hdev->status);
2759
2760         if (!hdev->driver)
2761                 ret = __hid_device_probe(hdev, hdrv);
2762
2763         if (!hdev->io_started)
2764                 up(&hdev->driver_input_lock);
2765
2766         return ret;
2767 }
2768
2769 static void hid_device_remove(struct device *dev)
2770 {
2771         struct hid_device *hdev = to_hid_device(dev);
2772         struct hid_driver *hdrv;
2773
2774         down(&hdev->driver_input_lock);
2775         hdev->io_started = false;
2776
2777         hdrv = hdev->driver;
2778         if (hdrv) {
2779                 if (hdrv->remove)
2780                         hdrv->remove(hdev);
2781                 else /* default remove */
2782                         hid_hw_stop(hdev);
2783
2784                 /* Release all devres resources allocated by the driver */
2785                 devres_release_group(&hdev->dev, hdev->devres_group_id);
2786
2787                 hid_close_report(hdev);
2788                 hdev->driver = NULL;
2789         }
2790
2791         if (!hdev->io_started)
2792                 up(&hdev->driver_input_lock);
2793 }
2794
2795 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
2796                              char *buf)
2797 {
2798         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
2799
2800         return scnprintf(buf, PAGE_SIZE, "hid:b%04Xg%04Xv%08Xp%08X\n",
2801                          hdev->bus, hdev->group, hdev->vendor, hdev->product);
2802 }
2803 static DEVICE_ATTR_RO(modalias);
2804
2805 static struct attribute *hid_dev_attrs[] = {
2806         &dev_attr_modalias.attr,
2807         NULL,
2808 };
2809 static const struct bin_attribute *hid_dev_bin_attrs[] = {
2810         &bin_attr_report_descriptor,
2811         NULL
2812 };
2813 static const struct attribute_group hid_dev_group = {
2814         .attrs = hid_dev_attrs,
2815         .bin_attrs_new = hid_dev_bin_attrs,
2816 };
2817 __ATTRIBUTE_GROUPS(hid_dev);
2818
2819 static int hid_uevent(const struct device *dev, struct kobj_uevent_env *env)
2820 {
2821         const struct hid_device *hdev = to_hid_device(dev);
2822
2823         if (add_uevent_var(env, "HID_ID=%04X:%08X:%08X",
2824                         hdev->bus, hdev->vendor, hdev->product))
2825                 return -ENOMEM;
2826
2827         if (add_uevent_var(env, "HID_NAME=%s", hdev->name))
2828                 return -ENOMEM;
2829
2830         if (add_uevent_var(env, "HID_PHYS=%s", hdev->phys))
2831                 return -ENOMEM;
2832
2833         if (add_uevent_var(env, "HID_UNIQ=%s", hdev->uniq))
2834                 return -ENOMEM;
2835
2836         if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",
2837                            hdev->bus, hdev->group, hdev->vendor, hdev->product))
2838                 return -ENOMEM;
2839
2840         return 0;
2841 }
2842
2843 const struct bus_type hid_bus_type = {
2844         .name           = "hid",
2845         .dev_groups     = hid_dev_groups,
2846         .drv_groups     = hid_drv_groups,
2847         .match          = hid_bus_match,
2848         .probe          = hid_device_probe,
2849         .remove         = hid_device_remove,
2850         .uevent         = hid_uevent,
2851 };
2852 EXPORT_SYMBOL(hid_bus_type);
2853
2854 int hid_add_device(struct hid_device *hdev)
2855 {
2856         static atomic_t id = ATOMIC_INIT(0);
2857         int ret;
2858
2859         if (WARN_ON(hdev->status & HID_STAT_ADDED))
2860                 return -EBUSY;
2861
2862         hdev->quirks = hid_lookup_quirk(hdev);
2863
2864         /* we need to kill them here, otherwise they will stay allocated to
2865          * wait for coming driver */
2866         if (hid_ignore(hdev))
2867                 return -ENODEV;
2868
2869         /*
2870          * Check for the mandatory transport channel.
2871          */
2872          if (!hdev->ll_driver->raw_request) {
2873                 hid_err(hdev, "transport driver missing .raw_request()\n");
2874                 return -EINVAL;
2875          }
2876
2877         /*
2878          * Read the device report descriptor once and use as template
2879          * for the driver-specific modifications.
2880          */
2881         ret = hdev->ll_driver->parse(hdev);
2882         if (ret)
2883                 return ret;
2884         if (!hdev->dev_rdesc)
2885                 return -ENODEV;
2886
2887         /*
2888          * Scan generic devices for group information
2889          */
2890         if (hid_ignore_special_drivers) {
2891                 hdev->group = HID_GROUP_GENERIC;
2892         } else if (!hdev->group &&
2893                    !(hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)) {
2894                 ret = hid_scan_report(hdev);
2895                 if (ret)
2896                         hid_warn(hdev, "bad device descriptor (%d)\n", ret);
2897         }
2898
2899         hdev->id = atomic_inc_return(&id);
2900
2901         /* XXX hack, any other cleaner solution after the driver core
2902          * is converted to allow more than 20 bytes as the device name? */
2903         dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
2904                      hdev->vendor, hdev->product, hdev->id);
2905
2906         hid_debug_register(hdev, dev_name(&hdev->dev));
2907         ret = device_add(&hdev->dev);
2908         if (!ret)
2909                 hdev->status |= HID_STAT_ADDED;
2910         else
2911                 hid_debug_unregister(hdev);
2912
2913         return ret;
2914 }
2915 EXPORT_SYMBOL_GPL(hid_add_device);
2916
2917 /**
2918  * hid_allocate_device - allocate new hid device descriptor
2919  *
2920  * Allocate and initialize hid device, so that hid_destroy_device might be
2921  * used to free it.
2922  *
2923  * New hid_device pointer is returned on success, otherwise ERR_PTR encoded
2924  * error value.
2925  */
2926 struct hid_device *hid_allocate_device(void)
2927 {
2928         struct hid_device *hdev;
2929         int ret = -ENOMEM;
2930
2931         hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
2932         if (hdev == NULL)
2933                 return ERR_PTR(ret);
2934
2935         device_initialize(&hdev->dev);
2936         hdev->dev.release = hid_device_release;
2937         hdev->dev.bus = &hid_bus_type;
2938         device_enable_async_suspend(&hdev->dev);
2939
2940         hid_close_report(hdev);
2941
2942         init_waitqueue_head(&hdev->debug_wait);
2943         INIT_LIST_HEAD(&hdev->debug_list);
2944         spin_lock_init(&hdev->debug_list_lock);
2945         sema_init(&hdev->driver_input_lock, 1);
2946         mutex_init(&hdev->ll_open_lock);
2947         kref_init(&hdev->ref);
2948
2949         ret = hid_bpf_device_init(hdev);
2950         if (ret)
2951                 goto out_err;
2952
2953         return hdev;
2954
2955 out_err:
2956         hid_destroy_device(hdev);
2957         return ERR_PTR(ret);
2958 }
2959 EXPORT_SYMBOL_GPL(hid_allocate_device);
2960
2961 static void hid_remove_device(struct hid_device *hdev)
2962 {
2963         if (hdev->status & HID_STAT_ADDED) {
2964                 device_del(&hdev->dev);
2965                 hid_debug_unregister(hdev);
2966                 hdev->status &= ~HID_STAT_ADDED;
2967         }
2968         hid_free_bpf_rdesc(hdev);
2969         kfree(hdev->dev_rdesc);
2970         hdev->dev_rdesc = NULL;
2971         hdev->dev_rsize = 0;
2972         hdev->bpf_rsize = 0;
2973 }
2974
2975 /**
2976  * hid_destroy_device - free previously allocated device
2977  *
2978  * @hdev: hid device
2979  *
2980  * If you allocate hid_device through hid_allocate_device, you should ever
2981  * free by this function.
2982  */
2983 void hid_destroy_device(struct hid_device *hdev)
2984 {
2985         hid_bpf_destroy_device(hdev);
2986         hid_remove_device(hdev);
2987         put_device(&hdev->dev);
2988 }
2989 EXPORT_SYMBOL_GPL(hid_destroy_device);
2990
2991
2992 static int __hid_bus_reprobe_drivers(struct device *dev, void *data)
2993 {
2994         struct hid_driver *hdrv = data;
2995         struct hid_device *hdev = to_hid_device(dev);
2996
2997         if (hdev->driver == hdrv &&
2998             !hdrv->match(hdev, hid_ignore_special_drivers) &&
2999             !test_and_set_bit(ffs(HID_STAT_REPROBED), &hdev->status))
3000                 return device_reprobe(dev);
3001
3002         return 0;
3003 }
3004
3005 static int __hid_bus_driver_added(struct device_driver *drv, void *data)
3006 {
3007         struct hid_driver *hdrv = to_hid_driver(drv);
3008
3009         if (hdrv->match) {
3010                 bus_for_each_dev(&hid_bus_type, NULL, hdrv,
3011                                  __hid_bus_reprobe_drivers);
3012         }
3013
3014         return 0;
3015 }
3016
3017 static int __bus_removed_driver(struct device_driver *drv, void *data)
3018 {
3019         return bus_rescan_devices(&hid_bus_type);
3020 }
3021
3022 int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
3023                 const char *mod_name)
3024 {
3025         int ret;
3026
3027         hdrv->driver.name = hdrv->name;
3028         hdrv->driver.bus = &hid_bus_type;
3029         hdrv->driver.owner = owner;
3030         hdrv->driver.mod_name = mod_name;
3031
3032         INIT_LIST_HEAD(&hdrv->dyn_list);
3033         spin_lock_init(&hdrv->dyn_lock);
3034
3035         ret = driver_register(&hdrv->driver);
3036
3037         if (ret == 0)
3038                 bus_for_each_drv(&hid_bus_type, NULL, NULL,
3039                                  __hid_bus_driver_added);
3040
3041         return ret;
3042 }
3043 EXPORT_SYMBOL_GPL(__hid_register_driver);
3044
3045 void hid_unregister_driver(struct hid_driver *hdrv)
3046 {
3047         driver_unregister(&hdrv->driver);
3048         hid_free_dynids(hdrv);
3049
3050         bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver);
3051 }
3052 EXPORT_SYMBOL_GPL(hid_unregister_driver);
3053
3054 int hid_check_keys_pressed(struct hid_device *hid)
3055 {
3056         struct hid_input *hidinput;
3057         int i;
3058
3059         if (!(hid->claimed & HID_CLAIMED_INPUT))
3060                 return 0;
3061
3062         list_for_each_entry(hidinput, &hid->inputs, list) {
3063                 for (i = 0; i < BITS_TO_LONGS(KEY_MAX); i++)
3064                         if (hidinput->input->key[i])
3065                                 return 1;
3066         }
3067
3068         return 0;
3069 }
3070 EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
3071
3072 #ifdef CONFIG_HID_BPF
3073 static const struct hid_ops __hid_ops = {
3074         .hid_get_report = hid_get_report,
3075         .hid_hw_raw_request = __hid_hw_raw_request,
3076         .hid_hw_output_report = __hid_hw_output_report,
3077         .hid_input_report = __hid_input_report,
3078         .owner = THIS_MODULE,
3079         .bus_type = &hid_bus_type,
3080 };
3081 #endif
3082
3083 static int __init hid_init(void)
3084 {
3085         int ret;
3086
3087         ret = bus_register(&hid_bus_type);
3088         if (ret) {
3089                 pr_err("can't register hid bus\n");
3090                 goto err;
3091         }
3092
3093 #ifdef CONFIG_HID_BPF
3094         hid_ops = &__hid_ops;
3095 #endif
3096
3097         ret = hidraw_init();
3098         if (ret)
3099                 goto err_bus;
3100
3101         hid_debug_init();
3102
3103         return 0;
3104 err_bus:
3105         bus_unregister(&hid_bus_type);
3106 err:
3107         return ret;
3108 }
3109
3110 static void __exit hid_exit(void)
3111 {
3112 #ifdef CONFIG_HID_BPF
3113         hid_ops = NULL;
3114 #endif
3115         hid_debug_exit();
3116         hidraw_exit();
3117         bus_unregister(&hid_bus_type);
3118         hid_quirks_exit(HID_BUS_ANY);
3119 }
3120
3121 module_init(hid_init);
3122 module_exit(hid_exit);
3123
3124 MODULE_AUTHOR("Andreas Gal");
3125 MODULE_AUTHOR("Vojtech Pavlik");
3126 MODULE_AUTHOR("Jiri Kosina");
3127 MODULE_DESCRIPTION("HID support for Linux");
3128 MODULE_LICENSE("GPL");