drivers/hid/hid-core.c

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