drivers/hid/hid-core.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  HID support for Linux
   4  *
   5  *  Copyright (c) 1999 Andreas Gal
   6  *  Copyright (c) 2000-2005 Vojtech Pavlik <[email protected]>
   7  *  Copyright (c) 2005 Michael Haboustak <[email protected]> for Concept2, Inc
   8  *  Copyright (c) 2006-2012 Jiri Kosina
   9  */
  10
  11 /*
  12  */
  13
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16 #include <linux/module.h>
  17 #include <linux/slab.h>
  18 #include <linux/init.h>
  19 #include <linux/kernel.h>
  20 #include <linux/list.h>
  21 #include <linux/mm.h>
  22 #include <linux/spinlock.h>
  23 #include <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                 hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
 661                 ret = 0;
 662         }
 663
 664         memset(&parser->local, 0, sizeof(parser->local));       /* Reset the local parser environment */
 665
 666         return ret;
 667 }
 668
 669 /*
 670  * Process a reserved item.
 671  */
 672
 673 static int hid_parser_reserved(struct hid_parser *parser, struct hid_item *item)
 674 {
 675         dbg_hid("reserved item type, tag 0x%x\n", item->tag);
 676         return 0;
 677 }
 678
 679 /*
 680  * Free a report and all registered fields. The field->usage and
 681  * field->value table's are allocated behind the field, so we need
 682  * only to free(field) itself.
 683  */
 684
 685 static void hid_free_report(struct hid_report *report)
 686 {
 687         unsigned n;
 688
 689         kfree(report->field_entries);
 690
 691         for (n = 0; n < report->maxfield; n++)
 692                 kvfree(report->field[n]);
 693         kfree(report);
 694 }
 695
 696 /*
 697  * Close report. This function returns the device
 698  * state to the point prior to hid_open_report().
 699  */
 700 static void hid_close_report(struct hid_device *device)
 701 {
 702         unsigned i, j;
 703
 704         for (i = 0; i < HID_REPORT_TYPES; i++) {
 705                 struct hid_report_enum *report_enum = device->report_enum + i;
 706
 707                 for (j = 0; j < HID_MAX_IDS; j++) {
 708                         struct hid_report *report = report_enum->report_id_hash[j];
 709                         if (report)
 710                                 hid_free_report(report);
 711                 }
 712                 memset(report_enum, 0, sizeof(*report_enum));
 713                 INIT_LIST_HEAD(&report_enum->report_list);
 714         }
 715
 716         /*
 717          * If the HID driver had a rdesc_fixup() callback, dev->rdesc
 718          * will be allocated by hid-core and needs to be freed.
 719          * Otherwise, it is either equal to dev_rdesc or bpf_rdesc, in
 720          * which cases it'll be freed later on device removal or destroy.
 721          */
 722         if (device->rdesc != device->dev_rdesc && device->rdesc != device->bpf_rdesc)
 723                 kfree(device->rdesc);
 724         device->rdesc = NULL;
 725         device->rsize = 0;
 726
 727         kfree(device->collection);
 728         device->collection = NULL;
 729         device->collection_size = 0;
 730         device->maxcollection = 0;
 731         device->maxapplication = 0;
 732
 733         device->status &= ~HID_STAT_PARSED;
 734 }
 735
 736 static inline void hid_free_bpf_rdesc(struct hid_device *hdev)
 737 {
 738         /* bpf_rdesc is either equal to dev_rdesc or allocated by call_hid_bpf_rdesc_fixup() */
 739         if (hdev->bpf_rdesc != hdev->dev_rdesc)
 740                 kfree(hdev->bpf_rdesc);
 741         hdev->bpf_rdesc = NULL;
 742 }
 743
 744 /*
 745  * Free a device structure, all reports, and all fields.
 746  */
 747
 748 void hiddev_free(struct kref *ref)
 749 {
 750         struct hid_device *hid = container_of(ref, struct hid_device, ref);
 751
 752         hid_close_report(hid);
 753         hid_free_bpf_rdesc(hid);
 754         kfree(hid->dev_rdesc);
 755         kfree(hid);
 756 }
 757
 758 static void hid_device_release(struct device *dev)
 759 {
 760         struct hid_device *hid = to_hid_device(dev);
 761
 762         kref_put(&hid->ref, hiddev_free);
 763 }
 764
 765 /*
 766  * Fetch a report description item from the data stream. We support long
 767  * items, though they are not used yet.
 768  */
 769
 770 static const u8 *fetch_item(const __u8 *start, const __u8 *end, struct hid_item *item)
 771 {
 772         u8 b;
 773
 774         if ((end - start) <= 0)
 775                 return NULL;
 776
 777         b = *start++;
 778
 779         item->type = (b >> 2) & 3;
 780         item->tag  = (b >> 4) & 15;
 781
 782         if (item->tag == HID_ITEM_TAG_LONG) {
 783
 784                 item->format = HID_ITEM_FORMAT_LONG;
 785
 786                 if ((end - start) < 2)
 787                         return NULL;
 788
 789                 item->size = *start++;
 790                 item->tag  = *start++;
 791
 792                 if ((end - start) < item->size)
 793                         return NULL;
 794
 795                 item->data.longdata = start;
 796                 start += item->size;
 797                 return start;
 798         }
 799
 800         item->format = HID_ITEM_FORMAT_SHORT;
 801         item->size = BIT(b & 3) >> 1; /* 0, 1, 2, 3 -> 0, 1, 2, 4 */
 802
 803         if (end - start < item->size)
 804                 return NULL;
 805
 806         switch (item->size) {
 807         case 0:
 808                 break;
 809
 810         case 1:
 811                 item->data.u8 = *start;
 812                 break;
 813
 814         case 2:
 815                 item->data.u16 = get_unaligned_le16(start);
 816                 break;
 817
 818         case 4:
 819                 item->data.u32 = get_unaligned_le32(start);
 820                 break;
 821         }
 822
 823         return start + item->size;
 824 }
 825
 826 static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)
 827 {
 828         struct hid_device *hid = parser->device;
 829
 830         if (usage == HID_DG_CONTACTID)
 831                 hid->group = HID_GROUP_MULTITOUCH;
 832 }
 833
 834 static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
 835 {
 836         if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
 837             parser->global.report_size == 8)
 838                 parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 839
 840         if (usage == 0xff0000c6 && parser->global.report_count == 1 &&
 841             parser->global.report_size == 8)
 842                 parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 843 }
 844
 845 static void hid_scan_collection(struct hid_parser *parser, unsigned type)
 846 {
 847         struct hid_device *hid = parser->device;
 848         int i;
 849
 850         if (((parser->global.usage_page << 16) == HID_UP_SENSOR) &&
 851             (type == HID_COLLECTION_PHYSICAL ||
 852              type == HID_COLLECTION_APPLICATION))
 853                 hid->group = HID_GROUP_SENSOR_HUB;
 854
 855         if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
 856             hid->product == USB_DEVICE_ID_MS_POWER_COVER &&
 857             hid->group == HID_GROUP_MULTITOUCH)
 858                 hid->group = HID_GROUP_GENERIC;
 859
 860         if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
 861                 for (i = 0; i < parser->local.usage_index; i++)
 862                         if (parser->local.usage[i] == HID_GD_POINTER)
 863                                 parser->scan_flags |= HID_SCAN_FLAG_GD_POINTER;
 864
 865         if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
 866                 parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
 867
 868         if ((parser->global.usage_page << 16) == HID_UP_GOOGLEVENDOR)
 869                 for (i = 0; i < parser->local.usage_index; i++)
 870                         if (parser->local.usage[i] ==
 871                                         (HID_UP_GOOGLEVENDOR | 0x0001))
 872                                 parser->device->group =
 873                                         HID_GROUP_VIVALDI;
 874 }
 875
 876 static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
 877 {
 878         __u32 data;
 879         int i;
 880
 881         hid_concatenate_last_usage_page(parser);
 882
 883         data = item_udata(item);
 884
 885         switch (item->tag) {
 886         case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 887                 hid_scan_collection(parser, data & 0xff);
 888                 break;
 889         case HID_MAIN_ITEM_TAG_END_COLLECTION:
 890                 break;
 891         case HID_MAIN_ITEM_TAG_INPUT:
 892                 /* ignore constant inputs, they will be ignored by hid-input */
 893                 if (data & HID_MAIN_ITEM_CONSTANT)
 894                         break;
 895                 for (i = 0; i < parser->local.usage_index; i++)
 896                         hid_scan_input_usage(parser, parser->local.usage[i]);
 897                 break;
 898         case HID_MAIN_ITEM_TAG_OUTPUT:
 899                 break;
 900         case HID_MAIN_ITEM_TAG_FEATURE:
 901                 for (i = 0; i < parser->local.usage_index; i++)
 902                         hid_scan_feature_usage(parser, parser->local.usage[i]);
 903                 break;
 904         }
 905
 906         /* Reset the local parser environment */
 907         memset(&parser->local, 0, sizeof(parser->local));
 908
 909         return 0;
 910 }
 911
 912 /*
 913  * Scan a report descriptor before the device is added to the bus.
 914  * Sets device groups and other properties that determine what driver
 915  * to load.
 916  */
 917 static int hid_scan_report(struct hid_device *hid)
 918 {
 919         struct hid_parser *parser;
 920         struct hid_item item;
 921         const __u8 *start = hid->dev_rdesc;
 922         const __u8 *end = start + hid->dev_rsize;
 923         static int (*dispatch_type[])(struct hid_parser *parser,
 924                                       struct hid_item *item) = {
 925                 hid_scan_main,
 926                 hid_parser_global,
 927                 hid_parser_local,
 928                 hid_parser_reserved
 929         };
 930
 931         parser = vzalloc(sizeof(struct hid_parser));
 932         if (!parser)
 933                 return -ENOMEM;
 934
 935         parser->device = hid;
 936         hid->group = HID_GROUP_GENERIC;
 937
 938         /*
 939          * The parsing is simpler than the one in hid_open_report() as we should
 940          * be robust against hid errors. Those errors will be raised by
 941          * hid_open_report() anyway.
 942          */
 943         while ((start = fetch_item(start, end, &item)) != NULL)
 944                 dispatch_type[item.type](parser, &item);
 945
 946         /*
 947          * Handle special flags set during scanning.
 948          */
 949         if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
 950             (hid->group == HID_GROUP_MULTITOUCH))
 951                 hid->group = HID_GROUP_MULTITOUCH_WIN_8;
 952
 953         /*
 954          * Vendor specific handlings
 955          */
 956         switch (hid->vendor) {
 957         case USB_VENDOR_ID_WACOM:
 958                 hid->group = HID_GROUP_WACOM;
 959                 break;
 960         case USB_VENDOR_ID_SYNAPTICS:
 961                 if (hid->group == HID_GROUP_GENERIC)
 962                         if ((parser->scan_flags & HID_SCAN_FLAG_VENDOR_SPECIFIC)
 963                             && (parser->scan_flags & HID_SCAN_FLAG_GD_POINTER))
 964                                 /*
 965                                  * hid-rmi should take care of them,
 966                                  * not hid-generic
 967                                  */
 968                                 hid->group = HID_GROUP_RMI;
 969                 break;
 970         }
 971
 972         kfree(parser->collection_stack);
 973         vfree(parser);
 974         return 0;
 975 }
 976
 977 /**
 978  * hid_parse_report - parse device report
 979  *
 980  * @hid: hid device
 981  * @start: report start
 982  * @size: report size
 983  *
 984  * Allocate the device report as read by the bus driver. This function should
 985  * only be called from parse() in ll drivers.
 986  */
 987 int hid_parse_report(struct hid_device *hid, const __u8 *start, unsigned size)
 988 {
 989         hid->dev_rdesc = kmemdup(start, size, GFP_KERNEL);
 990         if (!hid->dev_rdesc)
 991                 return -ENOMEM;
 992         hid->dev_rsize = size;
 993         return 0;
 994 }
 995 EXPORT_SYMBOL_GPL(hid_parse_report);
 996
 997 static const char * const hid_report_names[] = {
 998         "HID_INPUT_REPORT",
 999         "HID_OUTPUT_REPORT",
1000         "HID_FEATURE_REPORT",
1001 };
1002 /**
1003  * hid_validate_values - validate existing device report's value indexes
1004  *
1005  * @hid: hid device
1006  * @type: which report type to examine
1007  * @id: which report ID to examine (0 for first)
1008  * @field_index: which report field to examine
1009  * @report_counts: expected number of values
1010  *
1011  * Validate the number of values in a given field of a given report, after
1012  * parsing.
1013  */
1014 struct hid_report *hid_validate_values(struct hid_device *hid,
1015                                        enum hid_report_type type, unsigned int id,
1016                                        unsigned int field_index,
1017                                        unsigned int report_counts)
1018 {
1019         struct hid_report *report;
1020
1021         if (type > HID_FEATURE_REPORT) {
1022                 hid_err(hid, "invalid HID report type %u\n", type);
1023                 return NULL;
1024         }
1025
1026         if (id >= HID_MAX_IDS) {
1027                 hid_err(hid, "invalid HID report id %u\n", id);
1028                 return NULL;
1029         }
1030
1031         /*
1032          * Explicitly not using hid_get_report() here since it depends on
1033          * ->numbered being checked, which may not always be the case when
1034          * drivers go to access report values.
1035          */
1036         if (id == 0) {
1037                 /*
1038                  * Validating on id 0 means we should examine the first
1039                  * report in the list.
1040                  */
1041                 report = list_first_entry_or_null(
1042                                 &hid->report_enum[type].report_list,
1043                                 struct hid_report, list);
1044         } else {
1045                 report = hid->report_enum[type].report_id_hash[id];
1046         }
1047         if (!report) {
1048                 hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
1049                 return NULL;
1050         }
1051         if (report->maxfield <= field_index) {
1052                 hid_err(hid, "not enough fields in %s %u\n",
1053                         hid_report_names[type], id);
1054                 return NULL;
1055         }
1056         if (report->field[field_index]->report_count < report_counts) {
1057                 hid_err(hid, "not enough values in %s %u field %u\n",
1058                         hid_report_names[type], id, field_index);
1059                 return NULL;
1060         }
1061         return report;
1062 }
1063 EXPORT_SYMBOL_GPL(hid_validate_values);
1064
1065 static int hid_calculate_multiplier(struct hid_device *hid,
1066                                      struct hid_field *multiplier)
1067 {
1068         int m;
1069         __s32 v = *multiplier->value;
1070         __s32 lmin = multiplier->logical_minimum;
1071         __s32 lmax = multiplier->logical_maximum;
1072         __s32 pmin = multiplier->physical_minimum;
1073         __s32 pmax = multiplier->physical_maximum;
1074
1075         /*
1076          * "Because OS implementations will generally divide the control's
1077          * reported count by the Effective Resolution Multiplier, designers
1078          * should take care not to establish a potential Effective
1079          * Resolution Multiplier of zero."
1080          * HID Usage Table, v1.12, Section 4.3.1, p31
1081          */
1082         if (lmax - lmin == 0)
1083                 return 1;
1084         /*
1085          * Handling the unit exponent is left as an exercise to whoever
1086          * finds a device where that exponent is not 0.
1087          */
1088         m = ((v - lmin)/(lmax - lmin) * (pmax - pmin) + pmin);
1089         if (unlikely(multiplier->unit_exponent != 0)) {
1090                 hid_warn(hid,
1091                          "unsupported Resolution Multiplier unit exponent %d\n",
1092                          multiplier->unit_exponent);
1093         }
1094
1095         /* There are no devices with an effective multiplier > 255 */
1096         if (unlikely(m == 0 || m > 255 || m < -255)) {
1097                 hid_warn(hid, "unsupported Resolution Multiplier %d\n", m);
1098                 m = 1;
1099         }
1100
1101         return m;
1102 }
1103
1104 static void hid_apply_multiplier_to_field(struct hid_device *hid,
1105                                           struct hid_field *field,
1106                                           struct hid_collection *multiplier_collection,
1107                                           int effective_multiplier)
1108 {
1109         struct hid_collection *collection;
1110         struct hid_usage *usage;
1111         int i;
1112
1113         /*
1114          * If multiplier_collection is NULL, the multiplier applies
1115          * to all fields in the report.
1116          * Otherwise, it is the Logical Collection the multiplier applies to
1117          * but our field may be in a subcollection of that collection.
1118          */
1119         for (i = 0; i < field->maxusage; i++) {
1120                 usage = &field->usage[i];
1121
1122                 collection = &hid->collection[usage->collection_index];
1123                 while (collection->parent_idx != -1 &&
1124                        collection != multiplier_collection)
1125                         collection = &hid->collection[collection->parent_idx];
1126
1127                 if (collection->parent_idx != -1 ||
1128                     multiplier_collection == NULL)
1129                         usage->resolution_multiplier = effective_multiplier;
1130
1131         }
1132 }
1133
1134 static void hid_apply_multiplier(struct hid_device *hid,
1135                                  struct hid_field *multiplier)
1136 {
1137         struct hid_report_enum *rep_enum;
1138         struct hid_report *rep;
1139         struct hid_field *field;
1140         struct hid_collection *multiplier_collection;
1141         int effective_multiplier;
1142         int i;
1143
1144         /*
1145          * "The Resolution Multiplier control must be contained in the same
1146          * Logical Collection as the control(s) to which it is to be applied.
1147          * If no Resolution Multiplier is defined, then the Resolution
1148          * Multiplier defaults to 1.  If more than one control exists in a
1149          * Logical Collection, the Resolution Multiplier is associated with
1150          * all controls in the collection. If no Logical Collection is
1151          * defined, the Resolution Multiplier is associated with all
1152          * controls in the report."
1153          * HID Usage Table, v1.12, Section 4.3.1, p30
1154          *
1155          * Thus, search from the current collection upwards until we find a
1156          * logical collection. Then search all fields for that same parent
1157          * collection. Those are the fields the multiplier applies to.
1158          *
1159          * If we have more than one multiplier, it will overwrite the
1160          * applicable fields later.
1161          */
1162         multiplier_collection = &hid->collection[multiplier->usage->collection_index];
1163         while (multiplier_collection->parent_idx != -1 &&
1164                multiplier_collection->type != HID_COLLECTION_LOGICAL)
1165                 multiplier_collection = &hid->collection[multiplier_collection->parent_idx];
1166
1167         effective_multiplier = hid_calculate_multiplier(hid, multiplier);
1168
1169         rep_enum = &hid->report_enum[HID_INPUT_REPORT];
1170         list_for_each_entry(rep, &rep_enum->report_list, list) {
1171                 for (i = 0; i < rep->maxfield; i++) {
1172                         field = rep->field[i];
1173                         hid_apply_multiplier_to_field(hid, field,
1174                                                       multiplier_collection,
1175                                                       effective_multiplier);
1176                 }
1177         }
1178 }
1179
1180 /*
1181  * hid_setup_resolution_multiplier - set up all resolution multipliers
1182  *
1183  * @device: hid device
1184  *
1185  * Search for all Resolution Multiplier Feature Reports and apply their
1186  * value to all matching Input items. This only updates the internal struct
1187  * fields.
1188  *
1189  * The Resolution Multiplier is applied by the hardware. If the multiplier
1190  * is anything other than 1, the hardware will send pre-multiplied events
1191  * so that the same physical interaction generates an accumulated
1192  *      accumulated_value = value * * multiplier
1193  * This may be achieved by sending
1194  * - "value * multiplier" for each event, or
1195  * - "value" but "multiplier" times as frequently, or
1196  * - a combination of the above
1197  * The only guarantee is that the same physical interaction always generates
1198  * an accumulated 'value * multiplier'.
1199  *
1200  * This function must be called before any event processing and after
1201  * any SetRequest to the Resolution Multiplier.
1202  */
1203 void hid_setup_resolution_multiplier(struct hid_device *hid)
1204 {
1205         struct hid_report_enum *rep_enum;
1206         struct hid_report *rep;
1207         struct hid_usage *usage;
1208         int i, j;
1209
1210         rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
1211         list_for_each_entry(rep, &rep_enum->report_list, list) {
1212                 for (i = 0; i < rep->maxfield; i++) {
1213                         /* Ignore if report count is out of bounds. */
1214                         if (rep->field[i]->report_count < 1)
1215                                 continue;
1216
1217                         for (j = 0; j < rep->field[i]->maxusage; j++) {
1218                                 usage = &rep->field[i]->usage[j];
1219                                 if (usage->hid == HID_GD_RESOLUTION_MULTIPLIER)
1220                                         hid_apply_multiplier(hid,
1221                                                              rep->field[i]);
1222                         }
1223                 }
1224         }
1225 }
1226 EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier);
1227
1228 /**
1229  * hid_open_report - open a driver-specific device report
1230  *
1231  * @device: hid device
1232  *
1233  * Parse a report description into a hid_device structure. Reports are
1234  * enumerated, fields are attached to these reports.
1235  * 0 returned on success, otherwise nonzero error value.
1236  *
1237  * This function (or the equivalent hid_parse() macro) should only be
1238  * called from probe() in drivers, before starting the device.
1239  */
1240 int hid_open_report(struct hid_device *device)
1241 {
1242         struct hid_parser *parser;
1243         struct hid_item item;
1244         unsigned int size;
1245         const __u8 *start;
1246         const __u8 *end;
1247         const __u8 *next;
1248         int ret;
1249         int i;
1250         static int (*dispatch_type[])(struct hid_parser *parser,
1251                                       struct hid_item *item) = {
1252                 hid_parser_main,
1253                 hid_parser_global,
1254                 hid_parser_local,
1255                 hid_parser_reserved
1256         };
1257
1258         if (WARN_ON(device->status & HID_STAT_PARSED))
1259                 return -EBUSY;
1260
1261         start = device->bpf_rdesc;
1262         if (WARN_ON(!start))
1263                 return -ENODEV;
1264         size = device->bpf_rsize;
1265
1266         if (device->driver->report_fixup) {
1267                 /*
1268                  * device->driver->report_fixup() needs to work
1269                  * on a copy of our report descriptor so it can
1270                  * change it.
1271                  */
1272                 __u8 *buf = kmemdup(start, size, GFP_KERNEL);
1273
1274                 if (buf == NULL)
1275                         return -ENOMEM;
1276
1277                 start = device->driver->report_fixup(device, buf, &size);
1278
1279                 /*
1280                  * The second kmemdup is required in case report_fixup() returns
1281                  * a static read-only memory, but we have no idea if that memory
1282                  * needs to be cleaned up or not at the end.
1283                  */
1284                 start = kmemdup(start, size, GFP_KERNEL);
1285                 kfree(buf);
1286                 if (start == NULL)
1287                         return -ENOMEM;
1288         }
1289
1290         device->rdesc = start;
1291         device->rsize = size;
1292
1293         parser = vzalloc(sizeof(struct hid_parser));
1294         if (!parser) {
1295                 ret = -ENOMEM;
1296                 goto alloc_err;
1297         }
1298
1299         parser->device = device;
1300
1301         end = start + size;
1302
1303         device->collection = kcalloc(HID_DEFAULT_NUM_COLLECTIONS,
1304                                      sizeof(struct hid_collection), GFP_KERNEL);
1305         if (!device->collection) {
1306                 ret = -ENOMEM;
1307                 goto err;
1308         }
1309         device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
1310         for (i = 0; i < HID_DEFAULT_NUM_COLLECTIONS; i++)
1311                 device->collection[i].parent_idx = -1;
1312
1313         ret = -EINVAL;
1314         while ((next = fetch_item(start, end, &item)) != NULL) {
1315                 start = next;
1316
1317                 if (item.format != HID_ITEM_FORMAT_SHORT) {
1318                         hid_err(device, "unexpected long global item\n");
1319                         goto err;
1320                 }
1321
1322                 if (dispatch_type[item.type](parser, &item)) {
1323                         hid_err(device, "item %u %u %u %u parsing failed\n",
1324                                 item.format, (unsigned)item.size,
1325                                 (unsigned)item.type, (unsigned)item.tag);
1326                         goto err;
1327                 }
1328
1329                 if (start == end) {
1330                         if (parser->collection_stack_ptr) {
1331                                 hid_err(device, "unbalanced collection at end of report description\n");
1332                                 goto err;
1333                         }
1334                         if (parser->local.delimiter_depth) {
1335                                 hid_err(device, "unbalanced delimiter at end of report description\n");
1336                                 goto err;
1337                         }
1338
1339                         /*
1340                          * fetch initial values in case the device's
1341                          * default multiplier isn't the recommended 1
1342                          */
1343                         hid_setup_resolution_multiplier(device);
1344
1345                         kfree(parser->collection_stack);
1346                         vfree(parser);
1347                         device->status |= HID_STAT_PARSED;
1348
1349                         return 0;
1350                 }
1351         }
1352
1353         hid_err(device, "item fetching failed at offset %u/%u\n",
1354                 size - (unsigned int)(end - start), size);
1355 err:
1356         kfree(parser->collection_stack);
1357 alloc_err:
1358         vfree(parser);
1359         hid_close_report(device);
1360         return ret;
1361 }
1362 EXPORT_SYMBOL_GPL(hid_open_report);
1363
1364 /*
1365  * Extract/implement a data field from/to a little endian report (bit array).
1366  *
1367  * Code sort-of follows HID spec:
1368  *     http://www.usb.org/developers/hidpage/HID1_11.pdf
1369  *
1370  * While the USB HID spec allows unlimited length bit fields in "report
1371  * descriptors", most devices never use more than 16 bits.
1372  * One model of UPS is claimed to report "LINEV" as a 32-bit field.
1373  * Search linux-kernel and linux-usb-devel archives for "hid-core extract".
1374  */
1375
1376 static u32 __extract(u8 *report, unsigned offset, int n)
1377 {
1378         unsigned int idx = offset / 8;
1379         unsigned int bit_nr = 0;
1380         unsigned int bit_shift = offset % 8;
1381         int bits_to_copy = 8 - bit_shift;
1382         u32 value = 0;
1383         u32 mask = n < 32 ? (1U << n) - 1 : ~0U;
1384
1385         while (n > 0) {
1386                 value |= ((u32)report[idx] >> bit_shift) << bit_nr;
1387                 n -= bits_to_copy;
1388                 bit_nr += bits_to_copy;
1389                 bits_to_copy = 8;
1390                 bit_shift = 0;
1391                 idx++;
1392         }
1393
1394         return value & mask;
1395 }
1396
1397 u32 hid_field_extract(const struct hid_device *hid, u8 *report,
1398                         unsigned offset, unsigned n)
1399 {
1400         if (n > 32) {
1401                 hid_warn_once(hid, "%s() called with n (%d) > 32! (%s)\n",
1402                               __func__, n, current->comm);
1403                 n = 32;
1404         }
1405
1406         return __extract(report, offset, n);
1407 }
1408 EXPORT_SYMBOL_GPL(hid_field_extract);
1409
1410 /*
1411  * "implement" : set bits in a little endian bit stream.
1412  * Same concepts as "extract" (see comments above).
1413  * The data mangled in the bit stream remains in little endian
1414  * order the whole time. It make more sense to talk about
1415  * endianness of register values by considering a register
1416  * a "cached" copy of the little endian bit stream.
1417  */
1418
1419 static void __implement(u8 *report, unsigned offset, int n, u32 value)
1420 {
1421         unsigned int idx = offset / 8;
1422         unsigned int bit_shift = offset % 8;
1423         int bits_to_set = 8 - bit_shift;
1424
1425         while (n - bits_to_set >= 0) {
1426                 report[idx] &= ~(0xff << bit_shift);
1427                 report[idx] |= value << bit_shift;
1428                 value >>= bits_to_set;
1429                 n -= bits_to_set;
1430                 bits_to_set = 8;
1431                 bit_shift = 0;
1432                 idx++;
1433         }
1434
1435         /* last nibble */
1436         if (n) {
1437                 u8 bit_mask = ((1U << n) - 1);
1438                 report[idx] &= ~(bit_mask << bit_shift);
1439                 report[idx] |= value << bit_shift;
1440         }
1441 }
1442
1443 static void implement(const struct hid_device *hid, u8 *report,
1444                       unsigned offset, unsigned n, u32 value)
1445 {
1446         if (unlikely(n > 32)) {
1447                 hid_warn(hid, "%s() called with n (%d) > 32! (%s)\n",
1448                          __func__, n, current->comm);
1449                 n = 32;
1450         } else if (n < 32) {
1451                 u32 m = (1U << n) - 1;
1452
1453                 if (unlikely(value > m)) {
1454                         hid_warn(hid,
1455                                  "%s() called with too large value %d (n: %d)! (%s)\n",
1456                                  __func__, value, n, current->comm);
1457                         value &= m;
1458                 }
1459         }
1460
1461         __implement(report, offset, n, value);
1462 }
1463
1464 /*
1465  * Search an array for a value.
1466  */
1467
1468 static int search(__s32 *array, __s32 value, unsigned n)
1469 {
1470         while (n--) {
1471                 if (*array++ == value)
1472                         return 0;
1473         }
1474         return -1;
1475 }
1476
1477 /**
1478  * hid_match_report - check if driver's raw_event should be called
1479  *
1480  * @hid: hid device
1481  * @report: hid report to match against
1482  *
1483  * compare hid->driver->report_table->report_type to report->type
1484  */
1485 static int hid_match_report(struct hid_device *hid, struct hid_report *report)
1486 {
1487         const struct hid_report_id *id = hid->driver->report_table;
1488
1489         if (!id) /* NULL means all */
1490                 return 1;
1491
1492         for (; id->report_type != HID_TERMINATOR; id++)
1493                 if (id->report_type == HID_ANY_ID ||
1494                                 id->report_type == report->type)
1495                         return 1;
1496         return 0;
1497 }
1498
1499 /**
1500  * hid_match_usage - check if driver's event should be called
1501  *
1502  * @hid: hid device
1503  * @usage: usage to match against
1504  *
1505  * compare hid->driver->usage_table->usage_{type,code} to
1506  * usage->usage_{type,code}
1507  */
1508 static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage)
1509 {
1510         const struct hid_usage_id *id = hid->driver->usage_table;
1511
1512         if (!id) /* NULL means all */
1513                 return 1;
1514
1515         for (; id->usage_type != HID_ANY_ID - 1; id++)
1516                 if ((id->usage_hid == HID_ANY_ID ||
1517                                 id->usage_hid == usage->hid) &&
1518                                 (id->usage_type == HID_ANY_ID ||
1519                                 id->usage_type == usage->type) &&
1520                                 (id->usage_code == HID_ANY_ID ||
1521                                  id->usage_code == usage->code))
1522                         return 1;
1523         return 0;
1524 }
1525
1526 static void hid_process_event(struct hid_device *hid, struct hid_field *field,
1527                 struct hid_usage *usage, __s32 value, int interrupt)
1528 {
1529         struct hid_driver *hdrv = hid->driver;
1530         int ret;
1531
1532         if (!list_empty(&hid->debug_list))
1533                 hid_dump_input(hid, usage, value);
1534
1535         if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
1536                 ret = hdrv->event(hid, field, usage, value);
1537                 if (ret != 0) {
1538                         if (ret < 0)
1539                                 hid_err(hid, "%s's event failed with %d\n",
1540                                                 hdrv->name, ret);
1541                         return;
1542                 }
1543         }
1544
1545         if (hid->claimed & HID_CLAIMED_INPUT)
1546                 hidinput_hid_event(hid, field, usage, value);
1547         if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
1548                 hid->hiddev_hid_event(hid, field, usage, value);
1549 }
1550
1551 /*
1552  * Checks if the given value is valid within this field
1553  */
1554 static inline int hid_array_value_is_valid(struct hid_field *field,
1555                                            __s32 value)
1556 {
1557         __s32 min = field->logical_minimum;
1558
1559         /*
1560          * Value needs to be between logical min and max, and
1561          * (value - min) is used as an index in the usage array.
1562          * This array is of size field->maxusage
1563          */
1564         return value >= min &&
1565                value <= field->logical_maximum &&
1566                value - min < field->maxusage;
1567 }
1568
1569 /*
1570  * Fetch the field from the data. The field content is stored for next
1571  * report processing (we do differential reporting to the layer).
1572  */
1573 static void hid_input_fetch_field(struct hid_device *hid,
1574                                   struct hid_field *field,
1575                                   __u8 *data)
1576 {
1577         unsigned n;
1578         unsigned count = field->report_count;
1579         unsigned offset = field->report_offset;
1580         unsigned size = field->report_size;
1581         __s32 min = field->logical_minimum;
1582         __s32 *value;
1583
1584         value = field->new_value;
1585         memset(value, 0, count * sizeof(__s32));
1586         field->ignored = false;
1587
1588         for (n = 0; n < count; n++) {
1589
1590                 value[n] = min < 0 ?
1591                         snto32(hid_field_extract(hid, data, offset + n * size,
1592                                size), size) :
1593                         hid_field_extract(hid, data, offset + n * size, size);
1594
1595                 /* Ignore report if ErrorRollOver */
1596                 if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
1597                     hid_array_value_is_valid(field, value[n]) &&
1598                     field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1) {
1599                         field->ignored = true;
1600                         return;
1601                 }
1602         }
1603 }
1604
1605 /*
1606  * Process a received variable field.
1607  */
1608
1609 static void hid_input_var_field(struct hid_device *hid,
1610                                 struct hid_field *field,
1611                                 int interrupt)
1612 {
1613         unsigned int count = field->report_count;
1614         __s32 *value = field->new_value;
1615         unsigned int n;
1616
1617         for (n = 0; n < count; n++)
1618                 hid_process_event(hid,
1619                                   field,
1620                                   &field->usage[n],
1621                                   value[n],
1622                                   interrupt);
1623
1624         memcpy(field->value, value, count * sizeof(__s32));
1625 }
1626
1627 /*
1628  * Process a received array field. The field content is stored for
1629  * next report processing (we do differential reporting to the layer).
1630  */
1631
1632 static void hid_input_array_field(struct hid_device *hid,
1633                                   struct hid_field *field,
1634                                   int interrupt)
1635 {
1636         unsigned int n;
1637         unsigned int count = field->report_count;
1638         __s32 min = field->logical_minimum;
1639         __s32 *value;
1640
1641         value = field->new_value;
1642
1643         /* ErrorRollOver */
1644         if (field->ignored)
1645                 return;
1646
1647         for (n = 0; n < count; n++) {
1648                 if (hid_array_value_is_valid(field, field->value[n]) &&
1649                     search(value, field->value[n], count))
1650                         hid_process_event(hid,
1651                                           field,
1652                                           &field->usage[field->value[n] - min],
1653                                           0,
1654                                           interrupt);
1655
1656                 if (hid_array_value_is_valid(field, value[n]) &&
1657                     search(field->value, value[n], count))
1658                         hid_process_event(hid,
1659                                           field,
1660                                           &field->usage[value[n] - min],
1661                                           1,
1662                                           interrupt);
1663         }
1664
1665         memcpy(field->value, value, count * sizeof(__s32));
1666 }
1667
1668 /*
1669  * Analyse a received report, and fetch the data from it. The field
1670  * content is stored for next report processing (we do differential
1671  * reporting to the layer).
1672  */
1673 static void hid_process_report(struct hid_device *hid,
1674                                struct hid_report *report,
1675                                __u8 *data,
1676                                int interrupt)
1677 {
1678         unsigned int a;
1679         struct hid_field_entry *entry;
1680         struct hid_field *field;
1681
1682         /* first retrieve all incoming values in data */
1683         for (a = 0; a < report->maxfield; a++)
1684                 hid_input_fetch_field(hid, report->field[a], data);
1685
1686         if (!list_empty(&report->field_entry_list)) {
1687                 /* INPUT_REPORT, we have a priority list of fields */
1688                 list_for_each_entry(entry,
1689                                     &report->field_entry_list,
1690                                     list) {
1691                         field = entry->field;
1692
1693                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1694                                 hid_process_event(hid,
1695                                                   field,
1696                                                   &field->usage[entry->index],
1697                                                   field->new_value[entry->index],
1698                                                   interrupt);
1699                         else
1700                                 hid_input_array_field(hid, field, interrupt);
1701                 }
1702
1703                 /* we need to do the memcpy at the end for var items */
1704                 for (a = 0; a < report->maxfield; a++) {
1705                         field = report->field[a];
1706
1707                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1708                                 memcpy(field->value, field->new_value,
1709                                        field->report_count * sizeof(__s32));
1710                 }
1711         } else {
1712                 /* FEATURE_REPORT, regular processing */
1713                 for (a = 0; a < report->maxfield; a++) {
1714                         field = report->field[a];
1715
1716                         if (field->flags & HID_MAIN_ITEM_VARIABLE)
1717                                 hid_input_var_field(hid, field, interrupt);
1718                         else
1719                                 hid_input_array_field(hid, field, interrupt);
1720                 }
1721         }
1722 }
1723
1724 /*
1725  * Insert a given usage_index in a field in the list
1726  * of processed usages in the report.
1727  *
1728  * The elements of lower priority score are processed
1729  * first.
1730  */
1731 static void __hid_insert_field_entry(struct hid_device *hid,
1732                                      struct hid_report *report,
1733                                      struct hid_field_entry *entry,
1734                                      struct hid_field *field,
1735                                      unsigned int usage_index)
1736 {
1737         struct hid_field_entry *next;
1738
1739         entry->field = field;
1740         entry->index = usage_index;
1741         entry->priority = field->usages_priorities[usage_index];
1742
1743         /* insert the element at the correct position */
1744         list_for_each_entry(next,
1745                             &report->field_entry_list,
1746                             list) {
1747                 /*
1748                  * the priority of our element is strictly higher
1749                  * than the next one, insert it before
1750                  */
1751                 if (entry->priority > next->priority) {
1752                         list_add_tail(&entry->list, &next->list);
1753                         return;
1754                 }
1755         }
1756
1757         /* lowest priority score: insert at the end */
1758         list_add_tail(&entry->list, &report->field_entry_list);
1759 }
1760
1761 static void hid_report_process_ordering(struct hid_device *hid,
1762                                         struct hid_report *report)
1763 {
1764         struct hid_field *field;
1765         struct hid_field_entry *entries;
1766         unsigned int a, u, usages;
1767         unsigned int count = 0;
1768
1769         /* count the number of individual fields in the report */
1770         for (a = 0; a < report->maxfield; a++) {
1771                 field = report->field[a];
1772
1773                 if (field->flags & HID_MAIN_ITEM_VARIABLE)
1774                         count += field->report_count;
1775                 else
1776                         count++;
1777         }
1778
1779         /* allocate the memory to process the fields */
1780         entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
1781         if (!entries)
1782                 return;
1783
1784         report->field_entries = entries;
1785
1786         /*
1787          * walk through all fields in the report and
1788          * store them by priority order in report->field_entry_list
1789          *
1790          * - Var elements are individualized (field + usage_index)
1791          * - Arrays are taken as one, we can not chose an order for them
1792          */
1793         usages = 0;
1794         for (a = 0; a < report->maxfield; a++) {
1795                 field = report->field[a];
1796
1797                 if (field->flags & HID_MAIN_ITEM_VARIABLE) {
1798                         for (u = 0; u < field->report_count; u++) {
1799                                 __hid_insert_field_entry(hid, report,
1800                                                          &entries[usages],
1801                                                          field, u);
1802                                 usages++;
1803                         }
1804                 } else {
1805                         __hid_insert_field_entry(hid, report, &entries[usages],
1806                                                  field, 0);
1807                         usages++;
1808                 }
1809         }
1810 }
1811
1812 static void hid_process_ordering(struct hid_device *hid)
1813 {
1814         struct hid_report *report;
1815         struct hid_report_enum *report_enum = &hid->report_enum[HID_INPUT_REPORT];
1816
1817         list_for_each_entry(report, &report_enum->report_list, list)
1818                 hid_report_process_ordering(hid, report);
1819 }
1820
1821 /*
1822  * Output the field into the report.
1823  */
1824
1825 static void hid_output_field(const struct hid_device *hid,
1826                              struct hid_field *field, __u8 *data)
1827 {
1828         unsigned count = field->report_count;
1829         unsigned offset = field->report_offset;
1830         unsigned size = field->report_size;
1831         unsigned n;
1832
1833         for (n = 0; n < count; n++) {
1834                 if (field->logical_minimum < 0) /* signed values */
1835                         implement(hid, data, offset + n * size, size,
1836                                   s32ton(field->value[n], size));
1837                 else                            /* unsigned values */
1838                         implement(hid, data, offset + n * size, size,
1839                                   field->value[n]);
1840         }
1841 }
1842
1843 /*
1844  * Compute the size of a report.
1845  */
1846 static size_t hid_compute_report_size(struct hid_report *report)
1847 {
1848         if (report->size)
1849                 return ((report->size - 1) >> 3) + 1;
1850
1851         return 0;
1852 }
1853
1854 /*
1855  * Create a report. 'data' has to be allocated using
1856  * hid_alloc_report_buf() so that it has proper size.
1857  */
1858
1859 void hid_output_report(struct hid_report *report, __u8 *data)
1860 {
1861         unsigned n;
1862
1863         if (report->id > 0)
1864                 *data++ = report->id;
1865
1866         memset(data, 0, hid_compute_report_size(report));
1867         for (n = 0; n < report->maxfield; n++)
1868                 hid_output_field(report->device, report->field[n], data);
1869 }
1870 EXPORT_SYMBOL_GPL(hid_output_report);
1871
1872 /*
1873  * Allocator for buffer that is going to be passed to hid_output_report()
1874  */
1875 u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
1876 {
1877         /*
1878          * 7 extra bytes are necessary to achieve proper functionality
1879          * of implement() working on 8 byte chunks
1880          */
1881
1882         u32 len = hid_report_len(report) + 7;
1883
1884         return kzalloc(len, flags);
1885 }
1886 EXPORT_SYMBOL_GPL(hid_alloc_report_buf);
1887
1888 /*
1889  * Set a field value. The report this field belongs to has to be
1890  * created and transferred to the device, to set this value in the
1891  * device.
1892  */
1893
1894 int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
1895 {
1896         unsigned size;
1897
1898         if (!field)
1899                 return -1;
1900
1901         size = field->report_size;
1902
1903         hid_dump_input(field->report->device, field->usage + offset, value);
1904
1905         if (offset >= field->report_count) {
1906                 hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n",
1907                                 offset, field->report_count);
1908                 return -1;
1909         }
1910         if (field->logical_minimum < 0) {
1911                 if (value != snto32(s32ton(value, size), size)) {
1912                         hid_err(field->report->device, "value %d is out of range\n", value);
1913                         return -1;
1914                 }
1915         }
1916         field->value[offset] = value;
1917         return 0;
1918 }
1919 EXPORT_SYMBOL_GPL(hid_set_field);
1920
1921 struct hid_field *hid_find_field(struct hid_device *hdev, unsigned int report_type,
1922                                  unsigned int application, unsigned int usage)
1923 {
1924         struct list_head *report_list = &hdev->report_enum[report_type].report_list;
1925         struct hid_report *report;
1926         int i, j;
1927
1928         list_for_each_entry(report, report_list, list) {
1929                 if (report->application != application)
1930                         continue;
1931
1932                 for (i = 0; i < report->maxfield; i++) {
1933                         struct hid_field *field = report->field[i];
1934
1935                         for (j = 0; j < field->maxusage; j++) {
1936                                 if (field->usage[j].hid == usage)
1937                                         return field;
1938                         }
1939                 }
1940         }
1941
1942         return NULL;
1943 }
1944 EXPORT_SYMBOL_GPL(hid_find_field);
1945
1946 static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
1947                 const u8 *data)
1948 {
1949         struct hid_report *report;
1950         unsigned int n = 0;     /* Normally report number is 0 */
1951
1952         /* Device uses numbered reports, data[0] is report number */
1953         if (report_enum->numbered)
1954                 n = *data;
1955
1956         report = report_enum->report_id_hash[n];
1957         if (report == NULL)
1958                 dbg_hid("undefined report_id %u received\n", n);
1959
1960         return report;
1961 }
1962
1963 /*
1964  * Implement a generic .request() callback, using .raw_request()
1965  * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
1966  */
1967 int __hid_request(struct hid_device *hid, struct hid_report *report,
1968                 enum hid_class_request reqtype)
1969 {
1970         char *buf;
1971         int ret;
1972         u32 len;
1973
1974         buf = hid_alloc_report_buf(report, GFP_KERNEL);
1975         if (!buf)
1976                 return -ENOMEM;
1977
1978         len = hid_report_len(report);
1979
1980         if (reqtype == HID_REQ_SET_REPORT)
1981                 hid_output_report(report, buf);
1982
1983         ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
1984                                           report->type, reqtype);
1985         if (ret < 0) {
1986                 dbg_hid("unable to complete request: %d\n", ret);
1987                 goto out;
1988         }
1989
1990         if (reqtype == HID_REQ_GET_REPORT)
1991                 hid_input_report(hid, report->type, buf, ret, 0);
1992
1993         ret = 0;
1994
1995 out:
1996         kfree(buf);
1997         return ret;
1998 }
1999 EXPORT_SYMBOL_GPL(__hid_request);
2000
2001 int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
2002                          int interrupt)
2003 {
2004         struct hid_report_enum *report_enum = hid->report_enum + type;
2005         struct hid_report *report;
2006         struct hid_driver *hdrv;
2007         int max_buffer_size = HID_MAX_BUFFER_SIZE;
2008         u32 rsize, csize = size;
2009         u8 *cdata = data;
2010         int ret = 0;
2011
2012         report = hid_get_report(report_enum, data);
2013         if (!report)
2014                 goto out;
2015
2016         if (report_enum->numbered) {
2017                 cdata++;
2018                 csize--;
2019         }
2020
2021         rsize = hid_compute_report_size(report);
2022
2023         if (hid->ll_driver->max_buffer_size)
2024                 max_buffer_size = hid->ll_driver->max_buffer_size;
2025
2026         if (report_enum->numbered && rsize >= max_buffer_size)
2027                 rsize = max_buffer_size - 1;
2028         else if (rsize > max_buffer_size)
2029                 rsize = max_buffer_size;
2030
2031         if (csize < rsize) {
2032                 dbg_hid("report %d is too short, (%d < %d)\n", report->id,
2033                                 csize, rsize);
2034                 memset(cdata + csize, 0, rsize - csize);
2035         }
2036
2037         if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
2038                 hid->hiddev_report_event(hid, report);
2039         if (hid->claimed & HID_CLAIMED_HIDRAW) {
2040                 ret = hidraw_report_event(hid, data, size);
2041                 if (ret)
2042                         goto out;
2043         }
2044
2045         if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
2046                 hid_process_report(hid, report, cdata, interrupt);
2047                 hdrv = hid->driver;
2048                 if (hdrv && hdrv->report)
2049                         hdrv->report(hid, report);
2050         }
2051
2052         if (hid->claimed & HID_CLAIMED_INPUT)
2053                 hidinput_report_event(hid, report);
2054 out:
2055         return ret;
2056 }
2057 EXPORT_SYMBOL_GPL(hid_report_raw_event);
2058
2059
2060 static int __hid_input_report(struct hid_device *hid, enum hid_report_type type,
2061                               u8 *data, u32 size, int interrupt, u64 source, bool from_bpf,
2062                               bool lock_already_taken)
2063 {
2064         struct hid_report_enum *report_enum;
2065         struct hid_driver *hdrv;
2066         struct hid_report *report;
2067         int ret = 0;
2068
2069         if (!hid)
2070                 return -ENODEV;
2071
2072         ret = down_trylock(&hid->driver_input_lock);
2073         if (lock_already_taken && !ret) {
2074                 up(&hid->driver_input_lock);
2075                 return -EINVAL;
2076         } else if (!lock_already_taken && ret) {
2077                 return -EBUSY;
2078         }
2079
2080         if (!hid->driver) {
2081                 ret = -ENODEV;
2082                 goto unlock;
2083         }
2084         report_enum = hid->report_enum + type;
2085         hdrv = hid->driver;
2086
2087         data = dispatch_hid_bpf_device_event(hid, type, data, &size, interrupt, source, from_bpf);
2088         if (IS_ERR(data)) {
2089                 ret = PTR_ERR(data);
2090                 goto unlock;
2091         }
2092
2093         if (!size) {
2094                 dbg_hid("empty report\n");
2095                 ret = -1;
2096                 goto unlock;
2097         }
2098
2099         /* Avoid unnecessary overhead if debugfs is disabled */
2100         if (!list_empty(&hid->debug_list))
2101                 hid_dump_report(hid, type, data, size);
2102
2103         report = hid_get_report(report_enum, data);
2104
2105         if (!report) {
2106                 ret = -1;
2107                 goto unlock;
2108         }
2109
2110         if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
2111                 ret = hdrv->raw_event(hid, report, data, size);
2112                 if (ret < 0)
2113                         goto unlock;
2114         }
2115
2116         ret = hid_report_raw_event(hid, type, data, size, interrupt);
2117
2118 unlock:
2119         if (!lock_already_taken)
2120                 up(&hid->driver_input_lock);
2121         return ret;
2122 }
2123
2124 /**
2125  * hid_input_report - report data from lower layer (usb, bt...)
2126  *
2127  * @hid: hid device
2128  * @type: HID report type (HID_*_REPORT)
2129  * @data: report contents
2130  * @size: size of data parameter
2131  * @interrupt: distinguish between interrupt and control transfers
2132  *
2133  * This is data entry for lower layers.
2134  */
2135 int hid_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
2136                      int interrupt)
2137 {
2138         return __hid_input_report(hid, type, data, size, interrupt, 0,
2139                                   false, /* from_bpf */
2140                                   false /* lock_already_taken */);
2141 }
2142 EXPORT_SYMBOL_GPL(hid_input_report);
2143
2144 bool hid_match_one_id(const struct hid_device *hdev,
2145                       const struct hid_device_id *id)
2146 {
2147         return (id->bus == HID_BUS_ANY || id->bus == hdev->bus) &&
2148                 (id->group == HID_GROUP_ANY || id->group == hdev->group) &&
2149                 (id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&
2150                 (id->product == HID_ANY_ID || id->product == hdev->product);
2151 }
2152
2153 const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
2154                 const struct hid_device_id *id)
2155 {
2156         for (; id->bus; id++)
2157                 if (hid_match_one_id(hdev, id))
2158                         return id;
2159
2160         return NULL;
2161 }
2162 EXPORT_SYMBOL_GPL(hid_match_id);
2163
2164 static const struct hid_device_id hid_hiddev_list[] = {
2165         { HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS) },
2166         { HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS1) },
2167         { }
2168 };
2169
2170 static bool hid_hiddev(struct hid_device *hdev)
2171 {
2172         return !!hid_match_id(hdev, hid_hiddev_list);
2173 }
2174
2175
2176 static ssize_t
2177 read_report_descriptor(struct file *filp, struct kobject *kobj,
2178                 struct bin_attribute *attr,
2179                 char *buf, loff_t off, size_t count)
2180 {
2181         struct device *dev = kobj_to_dev(kobj);
2182         struct hid_device *hdev = to_hid_device(dev);
2183
2184         if (off >= hdev->rsize)
2185                 return 0;
2186
2187         if (off + count > hdev->rsize)
2188                 count = hdev->rsize - off;
2189
2190         memcpy(buf, hdev->rdesc + off, count);
2191
2192         return count;
2193 }
2194
2195 static ssize_t
2196 show_country(struct device *dev, struct device_attribute *attr,
2197                 char *buf)
2198 {
2199         struct hid_device *hdev = to_hid_device(dev);
2200
2201         return sprintf(buf, "%02x\n", hdev->country & 0xff);
2202 }
2203
2204 static struct bin_attribute dev_bin_attr_report_desc = {
2205         .attr = { .name = "report_descriptor", .mode = 0444 },
2206         .read = read_report_descriptor,
2207         .size = HID_MAX_DESCRIPTOR_SIZE,
2208 };
2209
2210 static const struct device_attribute dev_attr_country = {
2211         .attr = { .name = "country", .mode = 0444 },
2212         .show = show_country,
2213 };
2214
2215 int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
2216 {
2217         static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
2218                 "Joystick", "Gamepad", "Keyboard", "Keypad",
2219                 "Multi-Axis Controller"
2220         };
2221         const char *type, *bus;
2222         char buf[64] = "";
2223         unsigned int i;
2224         int len;
2225         int ret;
2226
2227         ret = hid_bpf_connect_device(hdev);
2228         if (ret)
2229                 return ret;
2230
2231         if (hdev->quirks & HID_QUIRK_HIDDEV_FORCE)
2232                 connect_mask |= (HID_CONNECT_HIDDEV_FORCE | HID_CONNECT_HIDDEV);
2233         if (hdev->quirks & HID_QUIRK_HIDINPUT_FORCE)
2234                 connect_mask |= HID_CONNECT_HIDINPUT_FORCE;
2235         if (hdev->bus != BUS_USB)
2236                 connect_mask &= ~HID_CONNECT_HIDDEV;
2237         if (hid_hiddev(hdev))
2238                 connect_mask |= HID_CONNECT_HIDDEV_FORCE;
2239
2240         if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,
2241                                 connect_mask & HID_CONNECT_HIDINPUT_FORCE))
2242                 hdev->claimed |= HID_CLAIMED_INPUT;
2243
2244         if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect &&
2245                         !hdev->hiddev_connect(hdev,
2246                                 connect_mask & HID_CONNECT_HIDDEV_FORCE))
2247                 hdev->claimed |= HID_CLAIMED_HIDDEV;
2248         if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))
2249                 hdev->claimed |= HID_CLAIMED_HIDRAW;
2250
2251         if (connect_mask & HID_CONNECT_DRIVER)
2252                 hdev->claimed |= HID_CLAIMED_DRIVER;
2253
2254         /* Drivers with the ->raw_event callback set are not required to connect
2255          * to any other listener. */
2256         if (!hdev->claimed && !hdev->driver->raw_event) {
2257                 hid_err(hdev, "device has no listeners, quitting\n");
2258                 return -ENODEV;
2259         }
2260
2261         hid_process_ordering(hdev);
2262
2263         if ((hdev->claimed & HID_CLAIMED_INPUT) &&
2264                         (connect_mask & HID_CONNECT_FF) && hdev->ff_init)
2265                 hdev->ff_init(hdev);
2266
2267         len = 0;
2268         if (hdev->claimed & HID_CLAIMED_INPUT)
2269                 len += sprintf(buf + len, "input");
2270         if (hdev->claimed & HID_CLAIMED_HIDDEV)
2271                 len += sprintf(buf + len, "%shiddev%d", len ? "," : "",
2272                                 ((struct hiddev *)hdev->hiddev)->minor);
2273         if (hdev->claimed & HID_CLAIMED_HIDRAW)
2274                 len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
2275                                 ((struct hidraw *)hdev->hidraw)->minor);
2276
2277         type = "Device";
2278         for (i = 0; i < hdev->maxcollection; i++) {
2279                 struct hid_collection *col = &hdev->collection[i];
2280                 if (col->type == HID_COLLECTION_APPLICATION &&
2281                    (col->usage & HID_USAGE_PAGE) == HID_UP_GENDESK &&
2282                    (col->usage & 0xffff) < ARRAY_SIZE(types)) {
2283                         type = types[col->usage & 0xffff];
2284                         break;
2285                 }
2286         }
2287
2288         switch (hdev->bus) {
2289         case BUS_USB:
2290                 bus = "USB";
2291                 break;
2292         case BUS_BLUETOOTH:
2293                 bus = "BLUETOOTH";
2294                 break;
2295         case BUS_I2C:
2296                 bus = "I2C";
2297                 break;
2298         case BUS_VIRTUAL:
2299                 bus = "VIRTUAL";
2300                 break;
2301         case BUS_INTEL_ISHTP:
2302         case BUS_AMD_SFH:
2303                 bus = "SENSOR HUB";
2304                 break;
2305         default:
2306                 bus = "<UNKNOWN>";
2307         }
2308
2309         ret = device_create_file(&hdev->dev, &dev_attr_country);
2310         if (ret)
2311                 hid_warn(hdev,
2312                          "can't create sysfs country code attribute err: %d\n", ret);
2313
2314         hid_info(hdev, "%s: %s HID v%x.%02x %s [%s] on %s\n",
2315                  buf, bus, hdev->version >> 8, hdev->version & 0xff,
2316                  type, hdev->name, hdev->phys);
2317
2318         return 0;
2319 }
2320 EXPORT_SYMBOL_GPL(hid_connect);
2321
2322 void hid_disconnect(struct hid_device *hdev)
2323 {
2324         device_remove_file(&hdev->dev, &dev_attr_country);
2325         if (hdev->claimed & HID_CLAIMED_INPUT)
2326                 hidinput_disconnect(hdev);
2327         if (hdev->claimed & HID_CLAIMED_HIDDEV)
2328                 hdev->hiddev_disconnect(hdev);
2329         if (hdev->claimed & HID_CLAIMED_HIDRAW)
2330                 hidraw_disconnect(hdev);
2331         hdev->claimed = 0;
2332
2333         hid_bpf_disconnect_device(hdev);
2334 }
2335 EXPORT_SYMBOL_GPL(hid_disconnect);
2336
2337 /**
2338  * hid_hw_start - start underlying HW
2339  * @hdev: hid device
2340  * @connect_mask: which outputs to connect, see HID_CONNECT_*
2341  *
2342  * Call this in probe function *after* hid_parse. This will setup HW
2343  * buffers and start the device (if not defeirred to device open).
2344  * hid_hw_stop must be called if this was successful.
2345  */
2346 int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask)
2347 {
2348         int error;
2349
2350         error = hdev->ll_driver->start(hdev);
2351         if (error)
2352                 return error;
2353
2354         if (connect_mask) {
2355                 error = hid_connect(hdev, connect_mask);
2356                 if (error) {
2357                         hdev->ll_driver->stop(hdev);
2358                         return error;
2359                 }
2360         }
2361
2362         return 0;
2363 }
2364 EXPORT_SYMBOL_GPL(hid_hw_start);
2365
2366 /**
2367  * hid_hw_stop - stop underlying HW
2368  * @hdev: hid device
2369  *
2370  * This is usually called from remove function or from probe when something
2371  * failed and hid_hw_start was called already.
2372  */
2373 void hid_hw_stop(struct hid_device *hdev)
2374 {
2375         hid_disconnect(hdev);
2376         hdev->ll_driver->stop(hdev);
2377 }
2378 EXPORT_SYMBOL_GPL(hid_hw_stop);
2379
2380 /**
2381  * hid_hw_open - signal underlying HW to start delivering events
2382  * @hdev: hid device
2383  *
2384  * Tell underlying HW to start delivering events from the device.
2385  * This function should be called sometime after successful call
2386  * to hid_hw_start().
2387  */
2388 int hid_hw_open(struct hid_device *hdev)
2389 {
2390         int ret;
2391
2392         ret = mutex_lock_killable(&hdev->ll_open_lock);
2393         if (ret)
2394                 return ret;
2395
2396         if (!hdev->ll_open_count++) {
2397                 ret = hdev->ll_driver->open(hdev);
2398                 if (ret)
2399                         hdev->ll_open_count--;
2400         }
2401
2402         mutex_unlock(&hdev->ll_open_lock);
2403         return ret;
2404 }
2405 EXPORT_SYMBOL_GPL(hid_hw_open);
2406
2407 /**
2408  * hid_hw_close - signal underlaying HW to stop delivering events
2409  *
2410  * @hdev: hid device
2411  *
2412  * This function indicates that we are not interested in the events
2413  * from this device anymore. Delivery of events may or may not stop,
2414  * depending on the number of users still outstanding.
2415  */
2416 void hid_hw_close(struct hid_device *hdev)
2417 {
2418         mutex_lock(&hdev->ll_open_lock);
2419         if (!--hdev->ll_open_count)
2420                 hdev->ll_driver->close(hdev);
2421         mutex_unlock(&hdev->ll_open_lock);
2422 }
2423 EXPORT_SYMBOL_GPL(hid_hw_close);
2424
2425 /**
2426  * hid_hw_request - send report request to device
2427  *
2428  * @hdev: hid device
2429  * @report: report to send
2430  * @reqtype: hid request type
2431  */
2432 void hid_hw_request(struct hid_device *hdev,
2433                     struct hid_report *report, enum hid_class_request reqtype)
2434 {
2435         if (hdev->ll_driver->request)
2436                 return hdev->ll_driver->request(hdev, report, reqtype);
2437
2438         __hid_request(hdev, report, reqtype);
2439 }
2440 EXPORT_SYMBOL_GPL(hid_hw_request);
2441
2442 int __hid_hw_raw_request(struct hid_device *hdev,
2443                          unsigned char reportnum, __u8 *buf,
2444                          size_t len, enum hid_report_type rtype,
2445                          enum hid_class_request reqtype,
2446                          u64 source, bool from_bpf)
2447 {
2448         unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
2449         int ret;
2450
2451         if (hdev->ll_driver->max_buffer_size)
2452                 max_buffer_size = hdev->ll_driver->max_buffer_size;
2453
2454         if (len < 1 || len > max_buffer_size || !buf)
2455                 return -EINVAL;
2456
2457         ret = dispatch_hid_bpf_raw_requests(hdev, reportnum, buf, len, rtype,
2458                                             reqtype, source, from_bpf);
2459         if (ret)
2460                 return ret;
2461
2462         return hdev->ll_driver->raw_request(hdev, reportnum, buf, len,
2463                                             rtype, reqtype);
2464 }
2465
2466 /**
2467  * hid_hw_raw_request - send report request to device
2468  *
2469  * @hdev: hid device
2470  * @reportnum: report ID
2471  * @buf: in/out data to transfer
2472  * @len: length of buf
2473  * @rtype: HID report type
2474  * @reqtype: HID_REQ_GET_REPORT or HID_REQ_SET_REPORT
2475  *
2476  * Return: count of data transferred, negative if error
2477  *
2478  * Same behavior as hid_hw_request, but with raw buffers instead.
2479  */
2480 int hid_hw_raw_request(struct hid_device *hdev,
2481                        unsigned char reportnum, __u8 *buf,
2482                        size_t len, enum hid_report_type rtype, enum hid_class_request reqtype)
2483 {
2484         return __hid_hw_raw_request(hdev, reportnum, buf, len, rtype, reqtype, 0, false);
2485 }
2486 EXPORT_SYMBOL_GPL(hid_hw_raw_request);
2487
2488 int __hid_hw_output_report(struct hid_device *hdev, __u8 *buf, size_t len, u64 source,
2489                            bool from_bpf)
2490 {
2491         unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
2492         int ret;
2493
2494         if (hdev->ll_driver->max_buffer_size)
2495                 max_buffer_size = hdev->ll_driver->max_buffer_size;
2496
2497         if (len < 1 || len > max_buffer_size || !buf)
2498                 return -EINVAL;
2499
2500         ret = dispatch_hid_bpf_output_report(hdev, buf, len, source, from_bpf);
2501         if (ret)
2502                 return ret;
2503
2504         if (hdev->ll_driver->output_report)
2505                 return hdev->ll_driver->output_report(hdev, buf, len);
2506
2507         return -ENOSYS;
2508 }
2509
2510 /**
2511  * hid_hw_output_report - send output report to device
2512  *
2513  * @hdev: hid device
2514  * @buf: raw data to transfer
2515  * @len: length of buf
2516  *
2517  * Return: count of data transferred, negative if error
2518  */
2519 int hid_hw_output_report(struct hid_device *hdev, __u8 *buf, size_t len)
2520 {
2521         return __hid_hw_output_report(hdev, buf, len, 0, false);
2522 }
2523 EXPORT_SYMBOL_GPL(hid_hw_output_report);
2524
2525 #ifdef CONFIG_PM
2526 int hid_driver_suspend(struct hid_device *hdev, pm_message_t state)
2527 {
2528         if (hdev->driver && hdev->driver->suspend)
2529                 return hdev->driver->suspend(hdev, state);
2530
2531         return 0;
2532 }
2533 EXPORT_SYMBOL_GPL(hid_driver_suspend);
2534
2535 int hid_driver_reset_resume(struct hid_device *hdev)
2536 {
2537         if (hdev->driver && hdev->driver->reset_resume)
2538                 return hdev->driver->reset_resume(hdev);
2539
2540         return 0;
2541 }
2542 EXPORT_SYMBOL_GPL(hid_driver_reset_resume);
2543
2544 int hid_driver_resume(struct hid_device *hdev)
2545 {
2546         if (hdev->driver && hdev->driver->resume)
2547                 return hdev->driver->resume(hdev);
2548
2549         return 0;
2550 }
2551 EXPORT_SYMBOL_GPL(hid_driver_resume);
2552 #endif /* CONFIG_PM */
2553
2554 struct hid_dynid {
2555         struct list_head list;
2556         struct hid_device_id id;
2557 };
2558
2559 /**
2560  * new_id_store - add a new HID device ID to this driver and re-probe devices
2561  * @drv: target device driver
2562  * @buf: buffer for scanning device ID data
2563  * @count: input size
2564  *
2565  * Adds a new dynamic hid device ID to this driver,
2566  * and causes the driver to probe for all devices again.
2567  */
2568 static ssize_t new_id_store(struct device_driver *drv, const char *buf,
2569                 size_t count)
2570 {
2571         struct hid_driver *hdrv = to_hid_driver(drv);
2572         struct hid_dynid *dynid;
2573         __u32 bus, vendor, product;
2574         unsigned long driver_data = 0;
2575         int ret;
2576
2577         ret = sscanf(buf, "%x %x %x %lx",
2578                         &bus, &vendor, &product, &driver_data);
2579         if (ret < 3)
2580                 return -EINVAL;
2581
2582         dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
2583         if (!dynid)
2584                 return -ENOMEM;
2585
2586         dynid->id.bus = bus;
2587         dynid->id.group = HID_GROUP_ANY;
2588         dynid->id.vendor = vendor;
2589         dynid->id.product = product;
2590         dynid->id.driver_data = driver_data;
2591
2592         spin_lock(&hdrv->dyn_lock);
2593         list_add_tail(&dynid->list, &hdrv->dyn_list);
2594         spin_unlock(&hdrv->dyn_lock);
2595
2596         ret = driver_attach(&hdrv->driver);
2597
2598         return ret ? : count;
2599 }
2600 static DRIVER_ATTR_WO(new_id);
2601
2602 static struct attribute *hid_drv_attrs[] = {
2603         &driver_attr_new_id.attr,
2604         NULL,
2605 };
2606 ATTRIBUTE_GROUPS(hid_drv);
2607
2608 static void hid_free_dynids(struct hid_driver *hdrv)
2609 {
2610         struct hid_dynid *dynid, *n;
2611
2612         spin_lock(&hdrv->dyn_lock);
2613         list_for_each_entry_safe(dynid, n, &hdrv->dyn_list, list) {
2614                 list_del(&dynid->list);
2615                 kfree(dynid);
2616         }
2617         spin_unlock(&hdrv->dyn_lock);
2618 }
2619
2620 const struct hid_device_id *hid_match_device(struct hid_device *hdev,
2621                                              struct hid_driver *hdrv)
2622 {
2623         struct hid_dynid *dynid;
2624
2625         spin_lock(&hdrv->dyn_lock);
2626         list_for_each_entry(dynid, &hdrv->dyn_list, list) {
2627                 if (hid_match_one_id(hdev, &dynid->id)) {
2628                         spin_unlock(&hdrv->dyn_lock);
2629                         return &dynid->id;
2630                 }
2631         }
2632         spin_unlock(&hdrv->dyn_lock);
2633
2634         return hid_match_id(hdev, hdrv->id_table);
2635 }
2636 EXPORT_SYMBOL_GPL(hid_match_device);
2637
2638 static int hid_bus_match(struct device *dev, const struct device_driver *drv)
2639 {
2640         struct hid_driver *hdrv = to_hid_driver(drv);
2641         struct hid_device *hdev = to_hid_device(dev);
2642
2643         return hid_match_device(hdev, hdrv) != NULL;
2644 }
2645
2646 /**
2647  * hid_compare_device_paths - check if both devices share the same path
2648  * @hdev_a: hid device
2649  * @hdev_b: hid device
2650  * @separator: char to use as separator
2651  *
2652  * Check if two devices share the same path up to the last occurrence of
2653  * the separator char. Both paths must exist (i.e., zero-length paths
2654  * don't match).
2655  */
2656 bool hid_compare_device_paths(struct hid_device *hdev_a,
2657                               struct hid_device *hdev_b, char separator)
2658 {
2659         int n1 = strrchr(hdev_a->phys, separator) - hdev_a->phys;
2660         int n2 = strrchr(hdev_b->phys, separator) - hdev_b->phys;
2661
2662         if (n1 != n2 || n1 <= 0 || n2 <= 0)
2663                 return false;
2664
2665         return !strncmp(hdev_a->phys, hdev_b->phys, n1);
2666 }
2667 EXPORT_SYMBOL_GPL(hid_compare_device_paths);
2668
2669 static bool hid_check_device_match(struct hid_device *hdev,
2670                                    struct hid_driver *hdrv,
2671                                    const struct hid_device_id **id)
2672 {
2673         *id = hid_match_device(hdev, hdrv);
2674         if (!*id)
2675                 return false;
2676
2677         if (hdrv->match)
2678                 return hdrv->match(hdev, hid_ignore_special_drivers);
2679
2680         /*
2681          * hid-generic implements .match(), so we must be dealing with a
2682          * different HID driver here, and can simply check if
2683          * hid_ignore_special_drivers or HID_QUIRK_IGNORE_SPECIAL_DRIVER
2684          * are set or not.
2685          */
2686         return !hid_ignore_special_drivers && !(hdev->quirks & HID_QUIRK_IGNORE_SPECIAL_DRIVER);
2687 }
2688
2689 static int __hid_device_probe(struct hid_device *hdev, struct hid_driver *hdrv)
2690 {
2691         const struct hid_device_id *id;
2692         int ret;
2693
2694         if (!hdev->bpf_rsize) {
2695                 /* in case a bpf program gets detached, we need to free the old one */
2696                 hid_free_bpf_rdesc(hdev);
2697
2698                 /* keep this around so we know we called it once */
2699                 hdev->bpf_rsize = hdev->dev_rsize;
2700
2701                 /* call_hid_bpf_rdesc_fixup will always return a valid pointer */
2702                 hdev->bpf_rdesc = call_hid_bpf_rdesc_fixup(hdev, hdev->dev_rdesc,
2703                                                            &hdev->bpf_rsize);
2704         }
2705
2706         if (!hid_check_device_match(hdev, hdrv, &id))
2707                 return -ENODEV;
2708
2709         hdev->devres_group_id = devres_open_group(&hdev->dev, NULL, GFP_KERNEL);
2710         if (!hdev->devres_group_id)
2711                 return -ENOMEM;
2712
2713         /* reset the quirks that has been previously set */
2714         hdev->quirks = hid_lookup_quirk(hdev);
2715         hdev->driver = hdrv;
2716
2717         if (hdrv->probe) {
2718                 ret = hdrv->probe(hdev, id);
2719         } else { /* default probe */
2720                 ret = hid_open_report(hdev);
2721                 if (!ret)
2722                         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
2723         }
2724
2725         /*
2726          * Note that we are not closing the devres group opened above so
2727          * even resources that were attached to the device after probe is
2728          * run are released when hid_device_remove() is executed. This is
2729          * needed as some drivers would allocate additional resources,
2730          * for example when updating firmware.
2731          */
2732
2733         if (ret) {
2734                 devres_release_group(&hdev->dev, hdev->devres_group_id);
2735                 hid_close_report(hdev);
2736                 hdev->driver = NULL;
2737         }
2738
2739         return ret;
2740 }
2741
2742 static int hid_device_probe(struct device *dev)
2743 {
2744         struct hid_device *hdev = to_hid_device(dev);
2745         struct hid_driver *hdrv = to_hid_driver(dev->driver);
2746         int ret = 0;
2747
2748         if (down_interruptible(&hdev->driver_input_lock))
2749                 return -EINTR;
2750
2751         hdev->io_started = false;
2752         clear_bit(ffs(HID_STAT_REPROBED), &hdev->status);
2753
2754         if (!hdev->driver)
2755                 ret = __hid_device_probe(hdev, hdrv);
2756
2757         if (!hdev->io_started)
2758                 up(&hdev->driver_input_lock);
2759
2760         return ret;
2761 }
2762
2763 static void hid_device_remove(struct device *dev)
2764 {
2765         struct hid_device *hdev = to_hid_device(dev);
2766         struct hid_driver *hdrv;
2767
2768         down(&hdev->driver_input_lock);
2769         hdev->io_started = false;
2770
2771         hdrv = hdev->driver;
2772         if (hdrv) {
2773                 if (hdrv->remove)
2774                         hdrv->remove(hdev);
2775                 else /* default remove */
2776                         hid_hw_stop(hdev);
2777
2778                 /* Release all devres resources allocated by the driver */
2779                 devres_release_group(&hdev->dev, hdev->devres_group_id);
2780
2781                 hid_close_report(hdev);
2782                 hdev->driver = NULL;
2783         }
2784
2785         if (!hdev->io_started)
2786                 up(&hdev->driver_input_lock);
2787 }
2788
2789 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
2790                              char *buf)
2791 {
2792         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
2793
2794         return scnprintf(buf, PAGE_SIZE, "hid:b%04Xg%04Xv%08Xp%08X\n",
2795                          hdev->bus, hdev->group, hdev->vendor, hdev->product);
2796 }
2797 static DEVICE_ATTR_RO(modalias);
2798
2799 static struct attribute *hid_dev_attrs[] = {
2800         &dev_attr_modalias.attr,
2801         NULL,
2802 };
2803 static struct bin_attribute *hid_dev_bin_attrs[] = {
2804         &dev_bin_attr_report_desc,
2805         NULL
2806 };
2807 static const struct attribute_group hid_dev_group = {
2808         .attrs = hid_dev_attrs,
2809         .bin_attrs = hid_dev_bin_attrs,
2810 };
2811 __ATTRIBUTE_GROUPS(hid_dev);
2812
2813 static int hid_uevent(const struct device *dev, struct kobj_uevent_env *env)
2814 {
2815         const struct hid_device *hdev = to_hid_device(dev);
2816
2817         if (add_uevent_var(env, "HID_ID=%04X:%08X:%08X",
2818                         hdev->bus, hdev->vendor, hdev->product))
2819                 return -ENOMEM;
2820
2821         if (add_uevent_var(env, "HID_NAME=%s", hdev->name))
2822                 return -ENOMEM;
2823
2824         if (add_uevent_var(env, "HID_PHYS=%s", hdev->phys))
2825                 return -ENOMEM;
2826
2827         if (add_uevent_var(env, "HID_UNIQ=%s", hdev->uniq))
2828                 return -ENOMEM;
2829
2830         if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",
2831                            hdev->bus, hdev->group, hdev->vendor, hdev->product))
2832                 return -ENOMEM;
2833
2834         return 0;
2835 }
2836
2837 const struct bus_type hid_bus_type = {
2838         .name           = "hid",
2839         .dev_groups     = hid_dev_groups,
2840         .drv_groups     = hid_drv_groups,
2841         .match          = hid_bus_match,
2842         .probe          = hid_device_probe,
2843         .remove         = hid_device_remove,
2844         .uevent         = hid_uevent,
2845 };
2846 EXPORT_SYMBOL(hid_bus_type);
2847
2848 int hid_add_device(struct hid_device *hdev)
2849 {
2850         static atomic_t id = ATOMIC_INIT(0);
2851         int ret;
2852
2853         if (WARN_ON(hdev->status & HID_STAT_ADDED))
2854                 return -EBUSY;
2855
2856         hdev->quirks = hid_lookup_quirk(hdev);
2857
2858         /* we need to kill them here, otherwise they will stay allocated to
2859          * wait for coming driver */
2860         if (hid_ignore(hdev))
2861                 return -ENODEV;
2862
2863         /*
2864          * Check for the mandatory transport channel.
2865          */
2866          if (!hdev->ll_driver->raw_request) {
2867                 hid_err(hdev, "transport driver missing .raw_request()\n");
2868                 return -EINVAL;
2869          }
2870
2871         /*
2872          * Read the device report descriptor once and use as template
2873          * for the driver-specific modifications.
2874          */
2875         ret = hdev->ll_driver->parse(hdev);
2876         if (ret)
2877                 return ret;
2878         if (!hdev->dev_rdesc)
2879                 return -ENODEV;
2880
2881         /*
2882          * Scan generic devices for group information
2883          */
2884         if (hid_ignore_special_drivers) {
2885                 hdev->group = HID_GROUP_GENERIC;
2886         } else if (!hdev->group &&
2887                    !(hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)) {
2888                 ret = hid_scan_report(hdev);
2889                 if (ret)
2890                         hid_warn(hdev, "bad device descriptor (%d)\n", ret);
2891         }
2892
2893         hdev->id = atomic_inc_return(&id);
2894
2895         /* XXX hack, any other cleaner solution after the driver core
2896          * is converted to allow more than 20 bytes as the device name? */
2897         dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
2898                      hdev->vendor, hdev->product, hdev->id);
2899
2900         hid_debug_register(hdev, dev_name(&hdev->dev));
2901         ret = device_add(&hdev->dev);
2902         if (!ret)
2903                 hdev->status |= HID_STAT_ADDED;
2904         else
2905                 hid_debug_unregister(hdev);
2906
2907         return ret;
2908 }
2909 EXPORT_SYMBOL_GPL(hid_add_device);
2910
2911 /**
2912  * hid_allocate_device - allocate new hid device descriptor
2913  *
2914  * Allocate and initialize hid device, so that hid_destroy_device might be
2915  * used to free it.
2916  *
2917  * New hid_device pointer is returned on success, otherwise ERR_PTR encoded
2918  * error value.
2919  */
2920 struct hid_device *hid_allocate_device(void)
2921 {
2922         struct hid_device *hdev;
2923         int ret = -ENOMEM;
2924
2925         hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
2926         if (hdev == NULL)
2927                 return ERR_PTR(ret);
2928
2929         device_initialize(&hdev->dev);
2930         hdev->dev.release = hid_device_release;
2931         hdev->dev.bus = &hid_bus_type;
2932         device_enable_async_suspend(&hdev->dev);
2933
2934         hid_close_report(hdev);
2935
2936         init_waitqueue_head(&hdev->debug_wait);
2937         INIT_LIST_HEAD(&hdev->debug_list);
2938         spin_lock_init(&hdev->debug_list_lock);
2939         sema_init(&hdev->driver_input_lock, 1);
2940         mutex_init(&hdev->ll_open_lock);
2941         kref_init(&hdev->ref);
2942
2943         ret = hid_bpf_device_init(hdev);
2944         if (ret)
2945                 goto out_err;
2946
2947         return hdev;
2948
2949 out_err:
2950         hid_destroy_device(hdev);
2951         return ERR_PTR(ret);
2952 }
2953 EXPORT_SYMBOL_GPL(hid_allocate_device);
2954
2955 static void hid_remove_device(struct hid_device *hdev)
2956 {
2957         if (hdev->status & HID_STAT_ADDED) {
2958                 device_del(&hdev->dev);
2959                 hid_debug_unregister(hdev);
2960                 hdev->status &= ~HID_STAT_ADDED;
2961         }
2962         hid_free_bpf_rdesc(hdev);
2963         kfree(hdev->dev_rdesc);
2964         hdev->dev_rdesc = NULL;
2965         hdev->dev_rsize = 0;
2966         hdev->bpf_rsize = 0;
2967 }
2968
2969 /**
2970  * hid_destroy_device - free previously allocated device
2971  *
2972  * @hdev: hid device
2973  *
2974  * If you allocate hid_device through hid_allocate_device, you should ever
2975  * free by this function.
2976  */
2977 void hid_destroy_device(struct hid_device *hdev)
2978 {
2979         hid_bpf_destroy_device(hdev);
2980         hid_remove_device(hdev);
2981         put_device(&hdev->dev);
2982 }
2983 EXPORT_SYMBOL_GPL(hid_destroy_device);
2984
2985
2986 static int __hid_bus_reprobe_drivers(struct device *dev, void *data)
2987 {
2988         struct hid_driver *hdrv = data;
2989         struct hid_device *hdev = to_hid_device(dev);
2990
2991         if (hdev->driver == hdrv &&
2992             !hdrv->match(hdev, hid_ignore_special_drivers) &&
2993             !test_and_set_bit(ffs(HID_STAT_REPROBED), &hdev->status))
2994                 return device_reprobe(dev);
2995
2996         return 0;
2997 }
2998
2999 static int __hid_bus_driver_added(struct device_driver *drv, void *data)
3000 {
3001         struct hid_driver *hdrv = to_hid_driver(drv);
3002
3003         if (hdrv->match) {
3004                 bus_for_each_dev(&hid_bus_type, NULL, hdrv,
3005                                  __hid_bus_reprobe_drivers);
3006         }
3007
3008         return 0;
3009 }
3010
3011 static int __bus_removed_driver(struct device_driver *drv, void *data)
3012 {
3013         return bus_rescan_devices(&hid_bus_type);
3014 }
3015
3016 int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
3017                 const char *mod_name)
3018 {
3019         int ret;
3020
3021         hdrv->driver.name = hdrv->name;
3022         hdrv->driver.bus = &hid_bus_type;
3023         hdrv->driver.owner = owner;
3024         hdrv->driver.mod_name = mod_name;
3025
3026         INIT_LIST_HEAD(&hdrv->dyn_list);
3027         spin_lock_init(&hdrv->dyn_lock);
3028
3029         ret = driver_register(&hdrv->driver);
3030
3031         if (ret == 0)
3032                 bus_for_each_drv(&hid_bus_type, NULL, NULL,
3033                                  __hid_bus_driver_added);
3034
3035         return ret;
3036 }
3037 EXPORT_SYMBOL_GPL(__hid_register_driver);
3038
3039 void hid_unregister_driver(struct hid_driver *hdrv)
3040 {
3041         driver_unregister(&hdrv->driver);
3042         hid_free_dynids(hdrv);
3043
3044         bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver);
3045 }
3046 EXPORT_SYMBOL_GPL(hid_unregister_driver);
3047
3048 int hid_check_keys_pressed(struct hid_device *hid)
3049 {
3050         struct hid_input *hidinput;
3051         int i;
3052
3053         if (!(hid->claimed & HID_CLAIMED_INPUT))
3054                 return 0;
3055
3056         list_for_each_entry(hidinput, &hid->inputs, list) {
3057                 for (i = 0; i < BITS_TO_LONGS(KEY_MAX); i++)
3058                         if (hidinput->input->key[i])
3059                                 return 1;
3060         }
3061
3062         return 0;
3063 }
3064 EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
3065
3066 #ifdef CONFIG_HID_BPF
3067 static const struct hid_ops __hid_ops = {
3068         .hid_get_report = hid_get_report,
3069         .hid_hw_raw_request = __hid_hw_raw_request,
3070         .hid_hw_output_report = __hid_hw_output_report,
3071         .hid_input_report = __hid_input_report,
3072         .owner = THIS_MODULE,
3073         .bus_type = &hid_bus_type,
3074 };
3075 #endif
3076
3077 static int __init hid_init(void)
3078 {
3079         int ret;
3080
3081         ret = bus_register(&hid_bus_type);
3082         if (ret) {
3083                 pr_err("can't register hid bus\n");
3084                 goto err;
3085         }
3086
3087 #ifdef CONFIG_HID_BPF
3088         hid_ops = &__hid_ops;
3089 #endif
3090
3091         ret = hidraw_init();
3092         if (ret)
3093                 goto err_bus;
3094
3095         hid_debug_init();
3096
3097         return 0;
3098 err_bus:
3099         bus_unregister(&hid_bus_type);
3100 err:
3101         return ret;
3102 }
3103
3104 static void __exit hid_exit(void)
3105 {
3106 #ifdef CONFIG_HID_BPF
3107         hid_ops = NULL;
3108 #endif
3109         hid_debug_exit();
3110         hidraw_exit();
3111         bus_unregister(&hid_bus_type);
3112         hid_quirks_exit(HID_BUS_ANY);
3113 }
3114
3115 module_init(hid_init);
3116 module_exit(hid_exit);
3117
3118 MODULE_AUTHOR("Andreas Gal");
3119 MODULE_AUTHOR("Vojtech Pavlik");
3120 MODULE_AUTHOR("Jiri Kosina");
3121 MODULE_DESCRIPTION("HID support for Linux");
3122 MODULE_LICENSE("GPL");