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