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)
  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                          usages * 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 max_buffer_size = HID_MAX_BUFFER_SIZE;
 262         unsigned int usages;
 263         unsigned int offset;
 264         unsigned int i;
 265         unsigned int application;
 266
 267         application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
 268
 269         report = hid_register_report(parser->device, report_type,
 270                                      parser->global.report_id, application);
 271         if (!report) {
 272                 hid_err(parser->device, "hid_register_report failed\n");
 273                 return -1;
 274         }
 275
 276         /* Handle both signed and unsigned cases properly */
 277         if ((parser->global.logical_minimum < 0 &&
 278                 parser->global.logical_maximum <
 279                 parser->global.logical_minimum) ||
 280                 (parser->global.logical_minimum >= 0 &&
 281                 (__u32)parser->global.logical_maximum <
 282                 (__u32)parser->global.logical_minimum)) {
 283                 dbg_hid("logical range invalid 0x%x 0x%x\n",
 284                         parser->global.logical_minimum,
 285                         parser->global.logical_maximum);
 286                 return -1;
 287         }
 288
 289         offset = report->size;
 290         report->size += parser->global.report_size * parser->global.report_count;
 291
 292         if (parser->device->ll_driver->max_buffer_size)
 293                 max_buffer_size = parser->device->ll_driver->max_buffer_size;
 294
 295         /* Total size check: Allow for possible report index byte */
 296         if (report->size > (max_buffer_size - 1) << 3) {
 297                 hid_err(parser->device, "report is too long\n");
 298                 return -1;
 299         }
 300
 301         if (!parser->local.usage_index) /* Ignore padding fields */
 302                 return 0;
 303
 304         usages = max_t(unsigned, parser->local.usage_index,
 305                                  parser->global.report_count);
 306
 307         field = hid_register_field(report, usages);
 308         if (!field)
 309                 return 0;
 310
 311         field->physical = hid_lookup_collection(parser, HID_COLLECTION_PHYSICAL);
 312         field->logical = hid_lookup_collection(parser, HID_COLLECTION_LOGICAL);
 313         field->application = application;
 314
 315         for (i = 0; i < usages; i++) {
 316                 unsigned j = i;
 317                 /* Duplicate the last usage we parsed if we have excess values */
 318                 if (i >= parser->local.usage_index)
 319                         j = parser->local.usage_index - 1;
 320                 field->usage[i].hid = parser->local.usage[j];
 321                 field->usage[i].collection_index =
 322                         parser->local.collection_index[j];
 323                 field->usage[i].usage_index = i;
 324                 field->usage[i].resolution_multiplier = 1;
 325         }
 326
 327         field->maxusage = usages;
 328         field->flags = flags;
 329         field->report_offset = offset;
 330         field->report_type = report_type;
 331         field->report_size = parser->global.report_size;
 332         field->report_count = parser->global.report_count;
 333         field->logical_minimum = parser->global.logical_minimum;
 334         field->logical_maximum = parser->global.logical_maximum;
 335         field->physical_minimum = parser->global.physical_minimum;
 336         field->physical_maximum = parser->global.physical_maximum;
 337         field->unit_exponent = parser->global.unit_exponent;
 338         field->unit = parser->global.unit;
 339
 340         return 0;
 341 }
 342
 343 /*
 344  * Read data value from item.
 345  */
 346
 347 static u32 item_udata(struct hid_item *item)
 348 {
 349         switch (item->size) {
 350         case 1: return item->data.u8;
 351         case 2: return item->data.u16;
 352         case 4: return item->data.u32;
 353         }
 354         return 0;
 355 }
 356
 357 static s32 item_sdata(struct hid_item *item)
 358 {
 359         switch (item->size) {
 360         case 1: return item->data.s8;
 361         case 2: return item->data.s16;
 362         case 4: return item->data.s32;
 363         }
 364         return 0;
 365 }
 366
 367 /*
 368  * Process a global item.
 369  */
 370
 371 static int hid_parser_global(struct hid_parser *parser, struct hid_item *item)
 372 {
 373         __s32 raw_value;
 374         switch (item->tag) {
 375         case HID_GLOBAL_ITEM_TAG_PUSH:
 376
 377                 if (parser->global_stack_ptr == HID_GLOBAL_STACK_SIZE) {
 378                         hid_err(parser->device, "global environment stack overflow\n");
 379                         return -1;
 380                 }
 381
 382                 memcpy(parser->global_stack + parser->global_stack_ptr++,
 383                         &parser->global, sizeof(struct hid_global));
 384                 return 0;
 385
 386         case HID_GLOBAL_ITEM_TAG_POP:
 387
 388                 if (!parser->global_stack_ptr) {
 389                         hid_err(parser->device, "global environment stack underflow\n");
 390                         return -1;
 391                 }
 392
 393                 memcpy(&parser->global, parser->global_stack +
 394                         --parser->global_stack_ptr, sizeof(struct hid_global));
 395                 return 0;
 396
 397         case HID_GLOBAL_ITEM_TAG_USAGE_PAGE:
 398                 parser->global.usage_page = item_udata(item);
 399                 return 0;
 400
 401         case HID_GLOBAL_ITEM_TAG_LOGICAL_MINIMUM:
 402                 parser->global.logical_minimum = item_sdata(item);
 403                 return 0;
 404
 405         case HID_GLOBAL_ITEM_TAG_LOGICAL_MAXIMUM:
 406                 if (parser->global.logical_minimum < 0)
 407                         parser->global.logical_maximum = item_sdata(item);
 408                 else
 409                         parser->global.logical_maximum = item_udata(item);
 410                 return 0;
 411
 412         case HID_GLOBAL_ITEM_TAG_PHYSICAL_MINIMUM:
 413                 parser->global.physical_minimum = item_sdata(item);
 414                 return 0;
 415
 416         case HID_GLOBAL_ITEM_TAG_PHYSICAL_MAXIMUM:
 417                 if (parser->global.physical_minimum < 0)
 418                         parser->global.physical_maximum = item_sdata(item);
 419                 else
 420                         parser->global.physical_maximum = item_udata(item);
 421                 return 0;
 422
 423         case HID_GLOBAL_ITEM_TAG_UNIT_EXPONENT:
 424                 /* Many devices provide unit exponent as a two's complement
 425                  * nibble due to the common misunderstanding of HID
 426                  * specification 1.11, 6.2.2.7 Global Items. Attempt to handle
 427                  * both this and the standard encoding. */
 428                 raw_value = item_sdata(item);
 429                 if (!(raw_value & 0xfffffff0))
 430                         parser->global.unit_exponent = hid_snto32(raw_value, 4);
 431                 else
 432                         parser->global.unit_exponent = raw_value;
 433                 return 0;
 434
 435         case HID_GLOBAL_ITEM_TAG_UNIT:
 436                 parser->global.unit = item_udata(item);
 437                 return 0;
 438
 439         case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
 440                 parser->global.report_size = item_udata(item);
 441                 if (parser->global.report_size > 256) {
 442                         hid_err(parser->device, "invalid report_size %d\n",
 443                                         parser->global.report_size);
 444                         return -1;
 445                 }
 446                 return 0;
 447
 448         case HID_GLOBAL_ITEM_TAG_REPORT_COUNT:
 449                 parser->global.report_count = item_udata(item);
 450                 if (parser->global.report_count > HID_MAX_USAGES) {
 451                         hid_err(parser->device, "invalid report_count %d\n",
 452                                         parser->global.report_count);
 453                         return -1;
 454                 }
 455                 return 0;
 456
 457         case HID_GLOBAL_ITEM_TAG_REPORT_ID:
 458                 parser->global.report_id = item_udata(item);
 459                 if (parser->global.report_id == 0 ||
 460                     parser->global.report_id >= HID_MAX_IDS) {
 461                         hid_err(parser->device, "report_id %u is invalid\n",
 462                                 parser->global.report_id);
 463                         return -1;
 464                 }
 465                 return 0;
 466
 467         default:
 468                 hid_err(parser->device, "unknown global tag 0x%x\n", item->tag);
 469                 return -1;
 470         }
 471 }
 472
 473 /*
 474  * Process a local item.
 475  */
 476
 477 static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
 478 {
 479         __u32 data;
 480         unsigned n;
 481         __u32 count;
 482
 483         data = item_udata(item);
 484
 485         switch (item->tag) {
 486         case HID_LOCAL_ITEM_TAG_DELIMITER:
 487
 488                 if (data) {
 489                         /*
 490                          * We treat items before the first delimiter
 491                          * as global to all usage sets (branch 0).
 492                          * In the moment we process only these global
 493                          * items and the first delimiter set.
 494                          */
 495                         if (parser->local.delimiter_depth != 0) {
 496                                 hid_err(parser->device, "nested delimiters\n");
 497                                 return -1;
 498                         }
 499                         parser->local.delimiter_depth++;
 500                         parser->local.delimiter_branch++;
 501                 } else {
 502                         if (parser->local.delimiter_depth < 1) {
 503                                 hid_err(parser->device, "bogus close delimiter\n");
 504                                 return -1;
 505                         }
 506                         parser->local.delimiter_depth--;
 507                 }
 508                 return 0;
 509
 510         case HID_LOCAL_ITEM_TAG_USAGE:
 511
 512                 if (parser->local.delimiter_branch > 1) {
 513                         dbg_hid("alternative usage ignored\n");
 514                         return 0;
 515                 }
 516
 517                 return hid_add_usage(parser, data, item->size);
 518
 519         case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:
 520
 521                 if (parser->local.delimiter_branch > 1) {
 522                         dbg_hid("alternative usage ignored\n");
 523                         return 0;
 524                 }
 525
 526                 parser->local.usage_minimum = data;
 527                 return 0;
 528
 529         case HID_LOCAL_ITEM_TAG_USAGE_MAXIMUM:
 530
 531                 if (parser->local.delimiter_branch > 1) {
 532                         dbg_hid("alternative usage ignored\n");
 533                         return 0;
 534                 }
 535
 536                 count = data - parser->local.usage_minimum;
 537                 if (count + parser->local.usage_index >= HID_MAX_USAGES) {
 538                         /*
 539                          * We do not warn if the name is not set, we are
 540                          * actually pre-scanning the device.
 541                          */
 542                         if (dev_name(&parser->device->dev))
 543                                 hid_warn(parser->device,
 544                                          "ignoring exceeding usage max\n");
 545                         data = HID_MAX_USAGES - parser->local.usage_index +
 546                                 parser->local.usage_minimum - 1;
 547                         if (data <= 0) {
 548                                 hid_err(parser->device,
 549                                         "no more usage index available\n");
 550                                 return -1;
 551                         }
 552                 }
 553
 554                 for (n = parser->local.usage_minimum; n <= data; n++)
 555                         if (hid_add_usage(parser, n, item->size)) {
 556                                 dbg_hid("hid_add_usage failed\n");
 557                                 return -1;
 558                         }
 559                 return 0;
 560
 561         default:
 562
 563                 dbg_hid("unknown local item tag 0x%x\n", item->tag);
 564                 return 0;
 565         }
 566         return 0;
 567 }
 568
 569 /*
 570  * Concatenate Usage Pages into Usages where relevant:
 571  * As per specification, 6.2.2.8: "When the parser encounters a main item it
 572  * concatenates the last declared Usage Page with a Usage to form a complete
 573  * usage value."
 574  */
 575
 576 static void hid_concatenate_last_usage_page(struct hid_parser *parser)
 577 {
 578         int i;
 579         unsigned int usage_page;
 580         unsigned int current_page;
 581
 582         if (!parser->local.usage_index)
 583                 return;
 584
 585         usage_page = parser->global.usage_page;
 586
 587         /*
 588          * Concatenate usage page again only if last declared Usage Page
 589          * has not been already used in previous usages concatenation
 590          */
 591         for (i = parser->local.usage_index - 1; i >= 0; i--) {
 592                 if (parser->local.usage_size[i] > 2)
 593                         /* Ignore extended usages */
 594                         continue;
 595
 596                 current_page = parser->local.usage[i] >> 16;
 597                 if (current_page == usage_page)
 598                         break;
 599
 600                 complete_usage(parser, i);
 601         }
 602 }
 603
 604 /*
 605  * Process a main item.
 606  */
 607
 608 static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
 609 {
 610         __u32 data;
 611         int ret;
 612
 613         hid_concatenate_last_usage_page(parser);
 614
 615         data = item_udata(item);
 616
 617         switch (item->tag) {
 618         case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 619                 ret = open_collection(parser, data & 0xff);
 620                 break;
 621         case HID_MAIN_ITEM_TAG_END_COLLECTION:
 622                 ret = close_collection(parser);
 623                 break;
 624         case HID_MAIN_ITEM_TAG_INPUT:
 625                 ret = hid_add_field(parser, HID_INPUT_REPORT, data);
 626                 break;
 627         case HID_MAIN_ITEM_TAG_OUTPUT:
 628                 ret = hid_add_field(parser, HID_OUTPUT_REPORT, data);
 629                 break;
 630         case HID_MAIN_ITEM_TAG_FEATURE:
 631                 ret = hid_add_field(parser, HID_FEATURE_REPORT, data);
 632                 break;
 633         default:
 634                 hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
 635                 ret = 0;
 636         }
 637
 638         memset(&parser->local, 0, sizeof(parser->local));       /* Reset the local parser environment */
 639
 640         return ret;
 641 }
 642
 643 /*
 644  * Process a reserved item.
 645  */
 646
 647 static int hid_parser_reserved(struct hid_parser *parser, struct hid_item *item)
 648 {
 649         dbg_hid("reserved item type, tag 0x%x\n", item->tag);
 650         return 0;
 651 }
 652
 653 /*
 654  * Free a report and all registered fields. The field->usage and
 655  * field->value table's are allocated behind the field, so we need
 656  * only to free(field) itself.
 657  */
 658
 659 static void hid_free_report(struct hid_report *report)
 660 {
 661         unsigned n;
 662
 663         for (n = 0; n < report->maxfield; n++)
 664                 kfree(report->field[n]);
 665         kfree(report);
 666 }
 667
 668 /*
 669  * Close report. This function returns the device
 670  * state to the point prior to hid_open_report().
 671  */
 672 static void hid_close_report(struct hid_device *device)
 673 {
 674         unsigned i, j;
 675
 676         for (i = 0; i < HID_REPORT_TYPES; i++) {
 677                 struct hid_report_enum *report_enum = device->report_enum + i;
 678
 679                 for (j = 0; j < HID_MAX_IDS; j++) {
 680                         struct hid_report *report = report_enum->report_id_hash[j];
 681                         if (report)
 682                                 hid_free_report(report);
 683                 }
 684                 memset(report_enum, 0, sizeof(*report_enum));
 685                 INIT_LIST_HEAD(&report_enum->report_list);
 686         }
 687
 688         kfree(device->rdesc);
 689         device->rdesc = NULL;
 690         device->rsize = 0;
 691
 692         kfree(device->collection);
 693         device->collection = NULL;
 694         device->collection_size = 0;
 695         device->maxcollection = 0;
 696         device->maxapplication = 0;
 697
 698         device->status &= ~HID_STAT_PARSED;
 699 }
 700
 701 /*
 702  * Free a device structure, all reports, and all fields.
 703  */
 704
 705 void hiddev_free(struct kref *ref)
 706 {
 707         struct hid_device *hid = container_of(ref, struct hid_device, ref);
 708
 709         hid_close_report(hid);
 710         kfree(hid->dev_rdesc);
 711         kfree(hid);
 712 }
 713
 714 static void hid_device_release(struct device *dev)
 715 {
 716         struct hid_device *hid = to_hid_device(dev);
 717
 718         kref_put(&hid->ref, hiddev_free);
 719 }
 720
 721 /*
 722  * Fetch a report description item from the data stream. We support long
 723  * items, though they are not used yet.
 724  */
 725
 726 static u8 *fetch_item(__u8 *start, __u8 *end, struct hid_item *item)
 727 {
 728         u8 b;
 729
 730         if ((end - start) <= 0)
 731                 return NULL;
 732
 733         b = *start++;
 734
 735         item->type = (b >> 2) & 3;
 736         item->tag  = (b >> 4) & 15;
 737
 738         if (item->tag == HID_ITEM_TAG_LONG) {
 739
 740                 item->format = HID_ITEM_FORMAT_LONG;
 741
 742                 if ((end - start) < 2)
 743                         return NULL;
 744
 745                 item->size = *start++;
 746                 item->tag  = *start++;
 747
 748                 if ((end - start) < item->size)
 749                         return NULL;
 750
 751                 item->data.longdata = start;
 752                 start += item->size;
 753                 return start;
 754         }
 755
 756         item->format = HID_ITEM_FORMAT_SHORT;
 757         item->size = b & 3;
 758
 759         switch (item->size) {
 760         case 0:
 761                 return start;
 762
 763         case 1:
 764                 if ((end - start) < 1)
 765                         return NULL;
 766                 item->data.u8 = *start++;
 767                 return start;
 768
 769         case 2:
 770                 if ((end - start) < 2)
 771                         return NULL;
 772                 item->data.u16 = get_unaligned_le16(start);
 773                 start = (__u8 *)((__le16 *)start + 1);
 774                 return start;
 775
 776         case 3:
 777                 item->size++;
 778                 if ((end - start) < 4)
 779                         return NULL;
 780                 item->data.u32 = get_unaligned_le32(start);
 781                 start = (__u8 *)((__le32 *)start + 1);
 782                 return start;
 783         }
 784
 785         return NULL;
 786 }
 787
 788 static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)
 789 {
 790         struct hid_device *hid = parser->device;
 791
 792         if (usage == HID_DG_CONTACTID)
 793                 hid->group = HID_GROUP_MULTITOUCH;
 794 }
 795
 796 static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
 797 {
 798         if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
 799             parser->global.report_size == 8)
 800                 parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 801
 802         if (usage == 0xff0000c6 && parser->global.report_count == 1 &&
 803             parser->global.report_size == 8)
 804                 parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 805 }
 806
 807 static void hid_scan_collection(struct hid_parser *parser, unsigned type)
 808 {
 809         struct hid_device *hid = parser->device;
 810         int i;
 811
 812         if (((parser->global.usage_page << 16) == HID_UP_SENSOR) &&
 813             type == HID_COLLECTION_PHYSICAL)
 814                 hid->group = HID_GROUP_SENSOR_HUB;
 815
 816         if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
 817             hid->product == USB_DEVICE_ID_MS_POWER_COVER &&
 818             hid->group == HID_GROUP_MULTITOUCH)
 819                 hid->group = HID_GROUP_GENERIC;
 820
 821         if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
 822                 for (i = 0; i < parser->local.usage_index; i++)
 823                         if (parser->local.usage[i] == HID_GD_POINTER)
 824                                 parser->scan_flags |= HID_SCAN_FLAG_GD_POINTER;
 825
 826         if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
 827                 parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
 828
 829         if ((parser->global.usage_page << 16) == HID_UP_GOOGLEVENDOR)
 830                 for (i = 0; i < parser->local.usage_index; i++)
 831                         if (parser->local.usage[i] ==
 832                                         (HID_UP_GOOGLEVENDOR | 0x0001))
 833                                 parser->device->group =
 834                                         HID_GROUP_VIVALDI;
 835 }
 836
 837 static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
 838 {
 839         __u32 data;
 840         int i;
 841
 842         hid_concatenate_last_usage_page(parser);
 843
 844         data = item_udata(item);
 845
 846         switch (item->tag) {
 847         case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 848                 hid_scan_collection(parser, data & 0xff);
 849                 break;
 850         case HID_MAIN_ITEM_TAG_END_COLLECTION:
 851                 break;
 852         case HID_MAIN_ITEM_TAG_INPUT:
 853                 /* ignore constant inputs, they will be ignored by hid-input */
 854                 if (data & HID_MAIN_ITEM_CONSTANT)
 855                         break;
 856                 for (i = 0; i < parser->local.usage_index; i++)
 857                         hid_scan_input_usage(parser, parser->local.usage[i]);
 858                 break;
 859         case HID_MAIN_ITEM_TAG_OUTPUT:
 860                 break;
 861         case HID_MAIN_ITEM_TAG_FEATURE:
 862                 for (i = 0; i < parser->local.usage_index; i++)
 863                         hid_scan_feature_usage(parser, parser->local.usage[i]);
 864                 break;
 865         }
 866
 867         /* Reset the local parser environment */
 868         memset(&parser->local, 0, sizeof(parser->local));
 869
 870         return 0;
 871 }
 872
 873 /*
 874  * Scan a report descriptor before the device is added to the bus.
 875  * Sets device groups and other properties that determine what driver
 876  * to load.
 877  */
 878 static int hid_scan_report(struct hid_device *hid)
 879 {
 880         struct hid_parser *parser;
 881         struct hid_item item;
 882         __u8 *start = hid->dev_rdesc;
 883         __u8 *end = start + hid->dev_rsize;
 884         static int (*dispatch_type[])(struct hid_parser *parser,
 885                                       struct hid_item *item) = {
 886                 hid_scan_main,
 887                 hid_parser_global,
 888                 hid_parser_local,
 889                 hid_parser_reserved
 890         };
 891
 892         parser = vzalloc(sizeof(struct hid_parser));
 893         if (!parser)
 894                 return -ENOMEM;
 895
 896         parser->device = hid;
 897         hid->group = HID_GROUP_GENERIC;
 898
 899         /*
 900          * The parsing is simpler than the one in hid_open_report() as we should
 901          * be robust against hid errors. Those errors will be raised by
 902          * hid_open_report() anyway.
 903          */
 904         while ((start = fetch_item(start, end, &item)) != NULL)
 905                 dispatch_type[item.type](parser, &item);
 906
 907         /*
 908          * Handle special flags set during scanning.
 909          */
 910         if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
 911             (hid->group == HID_GROUP_MULTITOUCH))
 912                 hid->group = HID_GROUP_MULTITOUCH_WIN_8;
 913
 914         /*
 915          * Vendor specific handlings
 916          */
 917         switch (hid->vendor) {
 918         case USB_VENDOR_ID_WACOM:
 919                 hid->group = HID_GROUP_WACOM;
 920                 break;
 921         case USB_VENDOR_ID_SYNAPTICS:
 922                 if (hid->group == HID_GROUP_GENERIC)
 923                         if ((parser->scan_flags & HID_SCAN_FLAG_VENDOR_SPECIFIC)
 924                             && (parser->scan_flags & HID_SCAN_FLAG_GD_POINTER))
 925                                 /*
 926                                  * hid-rmi should take care of them,
 927                                  * not hid-generic
 928                                  */
 929                                 hid->group = HID_GROUP_RMI;
 930                 break;
 931         }
 932
 933         kfree(parser->collection_stack);
 934         vfree(parser);
 935         return 0;
 936 }
 937
 938 /**
 939  * hid_parse_report - parse device report
 940  *
 941  * @hid: hid device
 942  * @start: report start
 943  * @size: report size
 944  *
 945  * Allocate the device report as read by the bus driver. This function should
 946  * only be called from parse() in ll drivers.
 947  */
 948 int hid_parse_report(struct hid_device *hid, __u8 *start, unsigned size)
 949 {
 950         hid->dev_rdesc = kmemdup(start, size, GFP_KERNEL);
 951         if (!hid->dev_rdesc)
 952                 return -ENOMEM;
 953         hid->dev_rsize = size;
 954         return 0;
 955 }
 956 EXPORT_SYMBOL_GPL(hid_parse_report);
 957
 958 static const char * const hid_report_names[] = {
 959         "HID_INPUT_REPORT",
 960         "HID_OUTPUT_REPORT",
 961         "HID_FEATURE_REPORT",
 962 };
 963 /**
 964  * hid_validate_values - validate existing device report's value indexes
 965  *
 966  * @hid: hid device
 967  * @type: which report type to examine
 968  * @id: which report ID to examine (0 for first)
 969  * @field_index: which report field to examine
 970  * @report_counts: expected number of values
 971  *
 972  * Validate the number of values in a given field of a given report, after
 973  * parsing.
 974  */
 975 struct hid_report *hid_validate_values(struct hid_device *hid,
 976                                        unsigned int type, unsigned int id,
 977                                        unsigned int field_index,
 978                                        unsigned int report_counts)
 979 {
 980         struct hid_report *report;
 981
 982         if (type > HID_FEATURE_REPORT) {
 983                 hid_err(hid, "invalid HID report type %u\n", type);
 984                 return NULL;
 985         }
 986
 987         if (id >= HID_MAX_IDS) {
 988                 hid_err(hid, "invalid HID report id %u\n", id);
 989                 return NULL;
 990         }
 991
 992         /*
 993          * Explicitly not using hid_get_report() here since it depends on
 994          * ->numbered being checked, which may not always be the case when
 995          * drivers go to access report values.
 996          */
 997         if (id == 0) {
 998                 /*
 999                  * Validating on id 0 means we should examine the first
1000                  * report in the list.
1001                  */
1002                 report = list_first_entry_or_null(
1003                                 &hid->report_enum[type].report_list,
1004                                 struct hid_report, list);
1005         } else {
1006                 report = hid->report_enum[type].report_id_hash[id];
1007         }
1008         if (!report) {
1009                 hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
1010                 return NULL;
1011         }
1012         if (report->maxfield <= field_index) {
1013                 hid_err(hid, "not enough fields in %s %u\n",
1014                         hid_report_names[type], id);
1015                 return NULL;
1016         }
1017         if (report->field[field_index]->report_count < report_counts) {
1018                 hid_err(hid, "not enough values in %s %u field %u\n",
1019                         hid_report_names[type], id, field_index);
1020                 return NULL;
1021         }
1022         return report;
1023 }
1024 EXPORT_SYMBOL_GPL(hid_validate_values);
1025
1026 static int hid_calculate_multiplier(struct hid_device *hid,
1027                                      struct hid_field *multiplier)
1028 {
1029         int m;
1030         __s32 v = *multiplier->value;
1031         __s32 lmin = multiplier->logical_minimum;
1032         __s32 lmax = multiplier->logical_maximum;
1033         __s32 pmin = multiplier->physical_minimum;
1034         __s32 pmax = multiplier->physical_maximum;
1035
1036         /*
1037          * "Because OS implementations will generally divide the control's
1038          * reported count by the Effective Resolution Multiplier, designers
1039          * should take care not to establish a potential Effective
1040          * Resolution Multiplier of zero."
1041          * HID Usage Table, v1.12, Section 4.3.1, p31
1042          */
1043         if (lmax - lmin == 0)
1044                 return 1;
1045         /*
1046          * Handling the unit exponent is left as an exercise to whoever
1047          * finds a device where that exponent is not 0.
1048          */
1049         m = ((v - lmin)/(lmax - lmin) * (pmax - pmin) + pmin);
1050         if (unlikely(multiplier->unit_exponent != 0)) {
1051                 hid_warn(hid,
1052                          "unsupported Resolution Multiplier unit exponent %d\n",
1053                          multiplier->unit_exponent);
1054         }
1055
1056         /* There are no devices with an effective multiplier > 255 */
1057         if (unlikely(m == 0 || m > 255 || m < -255)) {
1058                 hid_warn(hid, "unsupported Resolution Multiplier %d\n", m);
1059                 m = 1;
1060         }
1061
1062         return m;
1063 }
1064
1065 static void hid_apply_multiplier_to_field(struct hid_device *hid,
1066                                           struct hid_field *field,
1067                                           struct hid_collection *multiplier_collection,
1068                                           int effective_multiplier)
1069 {
1070         struct hid_collection *collection;
1071         struct hid_usage *usage;
1072         int i;
1073
1074         /*
1075          * If multiplier_collection is NULL, the multiplier applies
1076          * to all fields in the report.
1077          * Otherwise, it is the Logical Collection the multiplier applies to
1078          * but our field may be in a subcollection of that collection.
1079          */
1080         for (i = 0; i < field->maxusage; i++) {
1081                 usage = &field->usage[i];
1082
1083                 collection = &hid->collection[usage->collection_index];
1084                 while (collection->parent_idx != -1 &&
1085                        collection != multiplier_collection)
1086                         collection = &hid->collection[collection->parent_idx];
1087
1088                 if (collection->parent_idx != -1 ||
1089                     multiplier_collection == NULL)
1090                         usage->resolution_multiplier = effective_multiplier;
1091
1092         }
1093 }
1094
1095 static void hid_apply_multiplier(struct hid_device *hid,
1096                                  struct hid_field *multiplier)
1097 {
1098         struct hid_report_enum *rep_enum;
1099         struct hid_report *rep;
1100         struct hid_field *field;
1101         struct hid_collection *multiplier_collection;
1102         int effective_multiplier;
1103         int i;
1104
1105         /*
1106          * "The Resolution Multiplier control must be contained in the same
1107          * Logical Collection as the control(s) to which it is to be applied.
1108          * If no Resolution Multiplier is defined, then the Resolution
1109          * Multiplier defaults to 1.  If more than one control exists in a
1110          * Logical Collection, the Resolution Multiplier is associated with
1111          * all controls in the collection. If no Logical Collection is
1112          * defined, the Resolution Multiplier is associated with all
1113          * controls in the report."
1114          * HID Usage Table, v1.12, Section 4.3.1, p30
1115          *
1116          * Thus, search from the current collection upwards until we find a
1117          * logical collection. Then search all fields for that same parent
1118          * collection. Those are the fields the multiplier applies to.
1119          *
1120          * If we have more than one multiplier, it will overwrite the
1121          * applicable fields later.
1122          */
1123         multiplier_collection = &hid->collection[multiplier->usage->collection_index];
1124         while (multiplier_collection->parent_idx != -1 &&
1125                multiplier_collection->type != HID_COLLECTION_LOGICAL)
1126                 multiplier_collection = &hid->collection[multiplier_collection->parent_idx];
1127
1128         effective_multiplier = hid_calculate_multiplier(hid, multiplier);
1129
1130         rep_enum = &hid->report_enum[HID_INPUT_REPORT];
1131         list_for_each_entry(rep, &rep_enum->report_list, list) {
1132                 for (i = 0; i < rep->maxfield; i++) {
1133                         field = rep->field[i];
1134                         hid_apply_multiplier_to_field(hid, field,
1135                                                       multiplier_collection,
1136                                                       effective_multiplier);
1137                 }
1138         }
1139 }
1140
1141 /*
1142  * hid_setup_resolution_multiplier - set up all resolution multipliers
1143  *
1144  * @device: hid device
1145  *
1146  * Search for all Resolution Multiplier Feature Reports and apply their
1147  * value to all matching Input items. This only updates the internal struct
1148  * fields.
1149  *
1150  * The Resolution Multiplier is applied by the hardware. If the multiplier
1151  * is anything other than 1, the hardware will send pre-multiplied events
1152  * so that the same physical interaction generates an accumulated
1153  *      accumulated_value = value * * multiplier
1154  * This may be achieved by sending
1155  * - "value * multiplier" for each event, or
1156  * - "value" but "multiplier" times as frequently, or
1157  * - a combination of the above
1158  * The only guarantee is that the same physical interaction always generates
1159  * an accumulated 'value * multiplier'.
1160  *
1161  * This function must be called before any event processing and after
1162  * any SetRequest to the Resolution Multiplier.
1163  */
1164 void hid_setup_resolution_multiplier(struct hid_device *hid)
1165 {
1166         struct hid_report_enum *rep_enum;
1167         struct hid_report *rep;
1168         struct hid_usage *usage;
1169         int i, j;
1170
1171         rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
1172         list_for_each_entry(rep, &rep_enum->report_list, list) {
1173                 for (i = 0; i < rep->maxfield; i++) {
1174                         /* Ignore if report count is out of bounds. */
1175                         if (rep->field[i]->report_count < 1)
1176                                 continue;
1177
1178                         for (j = 0; j < rep->field[i]->maxusage; j++) {
1179                                 usage = &rep->field[i]->usage[j];
1180                                 if (usage->hid == HID_GD_RESOLUTION_MULTIPLIER)
1181                                         hid_apply_multiplier(hid,
1182                                                              rep->field[i]);
1183                         }
1184                 }
1185         }
1186 }
1187 EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier);
1188
1189 /**
1190  * hid_open_report - open a driver-specific device report
1191  *
1192  * @device: hid device
1193  *
1194  * Parse a report description into a hid_device structure. Reports are
1195  * enumerated, fields are attached to these reports.
1196  * 0 returned on success, otherwise nonzero error value.
1197  *
1198  * This function (or the equivalent hid_parse() macro) should only be
1199  * called from probe() in drivers, before starting the device.
1200  */
1201 int hid_open_report(struct hid_device *device)
1202 {
1203         struct hid_parser *parser;
1204         struct hid_item item;
1205         unsigned int size;
1206         __u8 *start;
1207         __u8 *buf;
1208         __u8 *end;
1209         __u8 *next;
1210         int ret;
1211         int i;
1212         static int (*dispatch_type[])(struct hid_parser *parser,
1213                                       struct hid_item *item) = {
1214                 hid_parser_main,
1215                 hid_parser_global,
1216                 hid_parser_local,
1217                 hid_parser_reserved
1218         };
1219
1220         if (WARN_ON(device->status & HID_STAT_PARSED))
1221                 return -EBUSY;
1222
1223         start = device->dev_rdesc;
1224         if (WARN_ON(!start))
1225                 return -ENODEV;
1226         size = device->dev_rsize;
1227
1228         buf = kmemdup(start, size, GFP_KERNEL);
1229         if (buf == NULL)
1230                 return -ENOMEM;
1231
1232         if (device->driver->report_fixup)
1233                 start = device->driver->report_fixup(device, buf, &size);
1234         else
1235                 start = buf;
1236
1237         start = kmemdup(start, size, GFP_KERNEL);
1238         kfree(buf);
1239         if (start == NULL)
1240                 return -ENOMEM;
1241
1242         device->rdesc = start;
1243         device->rsize = size;
1244
1245         parser = vzalloc(sizeof(struct hid_parser));
1246         if (!parser) {
1247                 ret = -ENOMEM;
1248                 goto alloc_err;
1249         }
1250
1251         parser->device = device;
1252
1253         end = start + size;
1254
1255         device->collection = kcalloc(HID_DEFAULT_NUM_COLLECTIONS,
1256                                      sizeof(struct hid_collection), GFP_KERNEL);
1257         if (!device->collection) {
1258                 ret = -ENOMEM;
1259                 goto err;
1260         }
1261         device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
1262         for (i = 0; i < HID_DEFAULT_NUM_COLLECTIONS; i++)
1263                 device->collection[i].parent_idx = -1;
1264
1265         ret = -EINVAL;
1266         while ((next = fetch_item(start, end, &item)) != NULL) {
1267                 start = next;
1268
1269                 if (item.format != HID_ITEM_FORMAT_SHORT) {
1270                         hid_err(device, "unexpected long global item\n");
1271                         goto err;
1272                 }
1273
1274                 if (dispatch_type[item.type](parser, &item)) {
1275                         hid_err(device, "item %u %u %u %u parsing failed\n",
1276                                 item.format, (unsigned)item.size,
1277                                 (unsigned)item.type, (unsigned)item.tag);
1278                         goto err;
1279                 }
1280
1281                 if (start == end) {
1282                         if (parser->collection_stack_ptr) {
1283                                 hid_err(device, "unbalanced collection at end of report description\n");
1284                                 goto err;
1285                         }
1286                         if (parser->local.delimiter_depth) {
1287                                 hid_err(device, "unbalanced delimiter at end of report description\n");
1288                                 goto err;
1289                         }
1290
1291                         /*
1292                          * fetch initial values in case the device's
1293                          * default multiplier isn't the recommended 1
1294                          */
1295                         hid_setup_resolution_multiplier(device);
1296
1297                         kfree(parser->collection_stack);
1298                         vfree(parser);
1299                         device->status |= HID_STAT_PARSED;
1300
1301                         return 0;
1302                 }
1303         }
1304
1305         hid_err(device, "item fetching failed at offset %u/%u\n",
1306                 size - (unsigned int)(end - start), size);
1307 err:
1308         kfree(parser->collection_stack);
1309 alloc_err:
1310         vfree(parser);
1311         hid_close_report(device);
1312         return ret;
1313 }
1314 EXPORT_SYMBOL_GPL(hid_open_report);
1315
1316 /*
1317  * Convert a signed n-bit integer to signed 32-bit integer. Common
1318  * cases are done through the compiler, the screwed things has to be
1319  * done by hand.
1320  */
1321
1322 static s32 snto32(__u32 value, unsigned n)
1323 {
1324         if (!value || !n)
1325                 return 0;
1326
1327         if (n > 32)
1328                 n = 32;
1329
1330         switch (n) {
1331         case 8:  return ((__s8)value);
1332         case 16: return ((__s16)value);
1333         case 32: return ((__s32)value);
1334         }
1335         return value & (1 << (n - 1)) ? value | (~0U << n) : value;
1336 }
1337
1338 s32 hid_snto32(__u32 value, unsigned n)
1339 {
1340         return snto32(value, n);
1341 }
1342 EXPORT_SYMBOL_GPL(hid_snto32);
1343
1344 /*
1345  * Convert a signed 32-bit integer to a signed n-bit integer.
1346  */
1347
1348 static u32 s32ton(__s32 value, unsigned n)
1349 {
1350         s32 a = value >> (n - 1);
1351         if (a && a != -1)
1352                 return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
1353         return value & ((1 << n) - 1);
1354 }
1355
1356 /*
1357  * Extract/implement a data field from/to a little endian report (bit array).
1358  *
1359  * Code sort-of follows HID spec:
1360  *     http://www.usb.org/developers/hidpage/HID1_11.pdf
1361  *
1362  * While the USB HID spec allows unlimited length bit fields in "report
1363  * descriptors", most devices never use more than 16 bits.
1364  * One model of UPS is claimed to report "LINEV" as a 32-bit field.
1365  * Search linux-kernel and linux-usb-devel archives for "hid-core extract".
1366  */
1367
1368 static u32 __extract(u8 *report, unsigned offset, int n)
1369 {
1370         unsigned int idx = offset / 8;
1371         unsigned int bit_nr = 0;
1372         unsigned int bit_shift = offset % 8;
1373         int bits_to_copy = 8 - bit_shift;
1374         u32 value = 0;
1375         u32 mask = n < 32 ? (1U << n) - 1 : ~0U;
1376
1377         while (n > 0) {
1378                 value |= ((u32)report[idx] >> bit_shift) << bit_nr;
1379                 n -= bits_to_copy;
1380                 bit_nr += bits_to_copy;
1381                 bits_to_copy = 8;
1382                 bit_shift = 0;
1383                 idx++;
1384         }
1385
1386         return value & mask;
1387 }
1388
1389 u32 hid_field_extract(const struct hid_device *hid, u8 *report,
1390                         unsigned offset, unsigned n)
1391 {
1392         if (n > 32) {
1393                 hid_warn_once(hid, "%s() called with n (%d) > 32! (%s)\n",
1394                               __func__, n, current->comm);
1395                 n = 32;
1396         }
1397
1398         return __extract(report, offset, n);
1399 }
1400 EXPORT_SYMBOL_GPL(hid_field_extract);
1401
1402 /*
1403  * "implement" : set bits in a little endian bit stream.
1404  * Same concepts as "extract" (see comments above).
1405  * The data mangled in the bit stream remains in little endian
1406  * order the whole time. It make more sense to talk about
1407  * endianness of register values by considering a register
1408  * a "cached" copy of the little endian bit stream.
1409  */
1410
1411 static void __implement(u8 *report, unsigned offset, int n, u32 value)
1412 {
1413         unsigned int idx = offset / 8;
1414         unsigned int bit_shift = offset % 8;
1415         int bits_to_set = 8 - bit_shift;
1416
1417         while (n - bits_to_set >= 0) {
1418                 report[idx] &= ~(0xff << bit_shift);
1419                 report[idx] |= value << bit_shift;
1420                 value >>= bits_to_set;
1421                 n -= bits_to_set;
1422                 bits_to_set = 8;
1423                 bit_shift = 0;
1424                 idx++;
1425         }
1426
1427         /* last nibble */
1428         if (n) {
1429                 u8 bit_mask = ((1U << n) - 1);
1430                 report[idx] &= ~(bit_mask << bit_shift);
1431                 report[idx] |= value << bit_shift;
1432         }
1433 }
1434
1435 static void implement(const struct hid_device *hid, u8 *report,
1436                       unsigned offset, unsigned n, u32 value)
1437 {
1438         if (unlikely(n > 32)) {
1439                 hid_warn(hid, "%s() called with n (%d) > 32! (%s)\n",
1440                          __func__, n, current->comm);
1441                 n = 32;
1442         } else if (n < 32) {
1443                 u32 m = (1U << n) - 1;
1444
1445                 if (unlikely(value > m)) {
1446                         hid_warn(hid,
1447                                  "%s() called with too large value %d (n: %d)! (%s)\n",
1448                                  __func__, value, n, current->comm);
1449                         WARN_ON(1);
1450                         value &= m;
1451                 }
1452         }
1453
1454         __implement(report, offset, n, value);
1455 }
1456
1457 /*
1458  * Search an array for a value.
1459  */
1460
1461 static int search(__s32 *array, __s32 value, unsigned n)
1462 {
1463         while (n--) {
1464                 if (*array++ == value)
1465                         return 0;
1466         }
1467         return -1;
1468 }
1469
1470 /**
1471  * hid_match_report - check if driver's raw_event should be called
1472  *
1473  * @hid: hid device
1474  * @report: hid report to match against
1475  *
1476  * compare hid->driver->report_table->report_type to report->type
1477  */
1478 static int hid_match_report(struct hid_device *hid, struct hid_report *report)
1479 {
1480         const struct hid_report_id *id = hid->driver->report_table;
1481
1482         if (!id) /* NULL means all */
1483                 return 1;
1484
1485         for (; id->report_type != HID_TERMINATOR; id++)
1486                 if (id->report_type == HID_ANY_ID ||
1487                                 id->report_type == report->type)
1488                         return 1;
1489         return 0;
1490 }
1491
1492 /**
1493  * hid_match_usage - check if driver's event should be called
1494  *
1495  * @hid: hid device
1496  * @usage: usage to match against
1497  *
1498  * compare hid->driver->usage_table->usage_{type,code} to
1499  * usage->usage_{type,code}
1500  */
1501 static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage)
1502 {
1503         const struct hid_usage_id *id = hid->driver->usage_table;
1504
1505         if (!id) /* NULL means all */
1506                 return 1;
1507
1508         for (; id->usage_type != HID_ANY_ID - 1; id++)
1509                 if ((id->usage_hid == HID_ANY_ID ||
1510                                 id->usage_hid == usage->hid) &&
1511                                 (id->usage_type == HID_ANY_ID ||
1512                                 id->usage_type == usage->type) &&
1513                                 (id->usage_code == HID_ANY_ID ||
1514                                  id->usage_code == usage->code))
1515                         return 1;
1516         return 0;
1517 }
1518
1519 static void hid_process_event(struct hid_device *hid, struct hid_field *field,
1520                 struct hid_usage *usage, __s32 value, int interrupt)
1521 {
1522         struct hid_driver *hdrv = hid->driver;
1523         int ret;
1524
1525         if (!list_empty(&hid->debug_list))
1526                 hid_dump_input(hid, usage, value);
1527
1528         if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
1529                 ret = hdrv->event(hid, field, usage, value);
1530                 if (ret != 0) {
1531                         if (ret < 0)
1532                                 hid_err(hid, "%s's event failed with %d\n",
1533                                                 hdrv->name, ret);
1534                         return;
1535                 }
1536         }
1537
1538         if (hid->claimed & HID_CLAIMED_INPUT)
1539                 hidinput_hid_event(hid, field, usage, value);
1540         if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
1541                 hid->hiddev_hid_event(hid, field, usage, value);
1542 }
1543
1544 /*
1545  * Analyse a received field, and fetch the data from it. The field
1546  * content is stored for next report processing (we do differential
1547  * reporting to the layer).
1548  */
1549
1550 static void hid_input_field(struct hid_device *hid, struct hid_field *field,
1551                             __u8 *data, int interrupt)
1552 {
1553         unsigned n;
1554         unsigned count = field->report_count;
1555         unsigned offset = field->report_offset;
1556         unsigned size = field->report_size;
1557         __s32 min = field->logical_minimum;
1558         __s32 max = field->logical_maximum;
1559         __s32 *value;
1560
1561         value = kmalloc_array(count, sizeof(__s32), GFP_ATOMIC);
1562         if (!value)
1563                 return;
1564
1565         for (n = 0; n < count; n++) {
1566
1567                 value[n] = min < 0 ?
1568                         snto32(hid_field_extract(hid, data, offset + n * size,
1569                                size), size) :
1570                         hid_field_extract(hid, data, offset + n * size, size);
1571
1572                 /* Ignore report if ErrorRollOver */
1573                 if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
1574                     value[n] >= min && value[n] <= max &&
1575                     value[n] - min < field->maxusage &&
1576                     field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1)
1577                         goto exit;
1578         }
1579
1580         for (n = 0; n < count; n++) {
1581
1582                 if (HID_MAIN_ITEM_VARIABLE & field->flags) {
1583                         hid_process_event(hid, field, &field->usage[n], value[n], interrupt);
1584                         continue;
1585                 }
1586
1587                 if (field->value[n] >= min && field->value[n] <= max
1588                         && field->value[n] - min < field->maxusage
1589                         && field->usage[field->value[n] - min].hid
1590                         && search(value, field->value[n], count))
1591                                 hid_process_event(hid, field, &field->usage[field->value[n] - min], 0, interrupt);
1592
1593                 if (value[n] >= min && value[n] <= max
1594                         && value[n] - min < field->maxusage
1595                         && field->usage[value[n] - min].hid
1596                         && search(field->value, value[n], count))
1597                                 hid_process_event(hid, field, &field->usage[value[n] - min], 1, interrupt);
1598         }
1599
1600         memcpy(field->value, value, count * sizeof(__s32));
1601 exit:
1602         kfree(value);
1603 }
1604
1605 /*
1606  * Output the field into the report.
1607  */
1608
1609 static void hid_output_field(const struct hid_device *hid,
1610                              struct hid_field *field, __u8 *data)
1611 {
1612         unsigned count = field->report_count;
1613         unsigned offset = field->report_offset;
1614         unsigned size = field->report_size;
1615         unsigned n;
1616
1617         for (n = 0; n < count; n++) {
1618                 if (field->logical_minimum < 0) /* signed values */
1619                         implement(hid, data, offset + n * size, size,
1620                                   s32ton(field->value[n], size));
1621                 else                            /* unsigned values */
1622                         implement(hid, data, offset + n * size, size,
1623                                   field->value[n]);
1624         }
1625 }
1626
1627 /*
1628  * Compute the size of a report.
1629  */
1630 static size_t hid_compute_report_size(struct hid_report *report)
1631 {
1632         if (report->size)
1633                 return ((report->size - 1) >> 3) + 1;
1634
1635         return 0;
1636 }
1637
1638 /*
1639  * Create a report. 'data' has to be allocated using
1640  * hid_alloc_report_buf() so that it has proper size.
1641  */
1642
1643 void hid_output_report(struct hid_report *report, __u8 *data)
1644 {
1645         unsigned n;
1646
1647         if (report->id > 0)
1648                 *data++ = report->id;
1649
1650         memset(data, 0, hid_compute_report_size(report));
1651         for (n = 0; n < report->maxfield; n++)
1652                 hid_output_field(report->device, report->field[n], data);
1653 }
1654 EXPORT_SYMBOL_GPL(hid_output_report);
1655
1656 /*
1657  * Allocator for buffer that is going to be passed to hid_output_report()
1658  */
1659 u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
1660 {
1661         /*
1662          * 7 extra bytes are necessary to achieve proper functionality
1663          * of implement() working on 8 byte chunks
1664          */
1665
1666         u32 len = hid_report_len(report) + 7;
1667
1668         return kmalloc(len, flags);
1669 }
1670 EXPORT_SYMBOL_GPL(hid_alloc_report_buf);
1671
1672 /*
1673  * Set a field value. The report this field belongs to has to be
1674  * created and transferred to the device, to set this value in the
1675  * device.
1676  */
1677
1678 int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
1679 {
1680         unsigned size;
1681
1682         if (!field)
1683                 return -1;
1684
1685         size = field->report_size;
1686
1687         hid_dump_input(field->report->device, field->usage + offset, value);
1688
1689         if (offset >= field->report_count) {
1690                 hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n",
1691                                 offset, field->report_count);
1692                 return -1;
1693         }
1694         if (field->logical_minimum < 0) {
1695                 if (value != snto32(s32ton(value, size), size)) {
1696                         hid_err(field->report->device, "value %d is out of range\n", value);
1697                         return -1;
1698                 }
1699         }
1700         field->value[offset] = value;
1701         return 0;
1702 }
1703 EXPORT_SYMBOL_GPL(hid_set_field);
1704
1705 static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
1706                 const u8 *data)
1707 {
1708         struct hid_report *report;
1709         unsigned int n = 0;     /* Normally report number is 0 */
1710
1711         /* Device uses numbered reports, data[0] is report number */
1712         if (report_enum->numbered)
1713                 n = *data;
1714
1715         report = report_enum->report_id_hash[n];
1716         if (report == NULL)
1717                 dbg_hid("undefined report_id %u received\n", n);
1718
1719         return report;
1720 }
1721
1722 /*
1723  * Implement a generic .request() callback, using .raw_request()
1724  * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
1725  */
1726 int __hid_request(struct hid_device *hid, struct hid_report *report,
1727                 int reqtype)
1728 {
1729         char *buf;
1730         int ret;
1731         u32 len;
1732
1733         buf = hid_alloc_report_buf(report, GFP_KERNEL);
1734         if (!buf)
1735                 return -ENOMEM;
1736
1737         len = hid_report_len(report);
1738
1739         if (reqtype == HID_REQ_SET_REPORT)
1740                 hid_output_report(report, buf);
1741
1742         ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
1743                                           report->type, reqtype);
1744         if (ret < 0) {
1745                 dbg_hid("unable to complete request: %d\n", ret);
1746                 goto out;
1747         }
1748
1749         if (reqtype == HID_REQ_GET_REPORT)
1750                 hid_input_report(hid, report->type, buf, ret, 0);
1751
1752         ret = 0;
1753
1754 out:
1755         kfree(buf);
1756         return ret;
1757 }
1758 EXPORT_SYMBOL_GPL(__hid_request);
1759
1760 int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, u32 size,
1761                 int interrupt)
1762 {
1763         struct hid_report_enum *report_enum = hid->report_enum + type;
1764         struct hid_report *report;
1765         struct hid_driver *hdrv;
1766         int max_buffer_size = HID_MAX_BUFFER_SIZE;
1767         unsigned int a;
1768         u32 rsize, csize = size;
1769         u8 *cdata = data;
1770         int ret = 0;
1771
1772         report = hid_get_report(report_enum, data);
1773         if (!report)
1774                 goto out;
1775
1776         if (report_enum->numbered) {
1777                 cdata++;
1778                 csize--;
1779         }
1780
1781         rsize = hid_compute_report_size(report);
1782
1783         if (hid->ll_driver->max_buffer_size)
1784                 max_buffer_size = hid->ll_driver->max_buffer_size;
1785
1786         if (report_enum->numbered && rsize >= max_buffer_size)
1787                 rsize = max_buffer_size - 1;
1788         else if (rsize > max_buffer_size)
1789                 rsize = max_buffer_size;
1790
1791         if (csize < rsize) {
1792                 dbg_hid("report %d is too short, (%d < %d)\n", report->id,
1793                                 csize, rsize);
1794                 memset(cdata + csize, 0, rsize - csize);
1795         }
1796
1797         if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
1798                 hid->hiddev_report_event(hid, report);
1799         if (hid->claimed & HID_CLAIMED_HIDRAW) {
1800                 ret = hidraw_report_event(hid, data, size);
1801                 if (ret)
1802                         goto out;
1803         }
1804
1805         if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
1806                 for (a = 0; a < report->maxfield; a++)
1807                         hid_input_field(hid, report->field[a], cdata, interrupt);
1808                 hdrv = hid->driver;
1809                 if (hdrv && hdrv->report)
1810                         hdrv->report(hid, report);
1811         }
1812
1813         if (hid->claimed & HID_CLAIMED_INPUT)
1814                 hidinput_report_event(hid, report);
1815 out:
1816         return ret;
1817 }
1818 EXPORT_SYMBOL_GPL(hid_report_raw_event);
1819
1820 /**
1821  * hid_input_report - report data from lower layer (usb, bt...)
1822  *
1823  * @hid: hid device
1824  * @type: HID report type (HID_*_REPORT)
1825  * @data: report contents
1826  * @size: size of data parameter
1827  * @interrupt: distinguish between interrupt and control transfers
1828  *
1829  * This is data entry for lower layers.
1830  */
1831 int hid_input_report(struct hid_device *hid, int type, u8 *data, u32 size, int interrupt)
1832 {
1833         struct hid_report_enum *report_enum;
1834         struct hid_driver *hdrv;
1835         struct hid_report *report;
1836         int ret = 0;
1837
1838         if (!hid)
1839                 return -ENODEV;
1840
1841         if (down_trylock(&hid->driver_input_lock))
1842                 return -EBUSY;
1843
1844         if (!hid->driver) {
1845                 ret = -ENODEV;
1846                 goto unlock;
1847         }
1848         report_enum = hid->report_enum + type;
1849         hdrv = hid->driver;
1850
1851         if (!size) {
1852                 dbg_hid("empty report\n");
1853                 ret = -1;
1854                 goto unlock;
1855         }
1856
1857         /* Avoid unnecessary overhead if debugfs is disabled */
1858         if (!list_empty(&hid->debug_list))
1859                 hid_dump_report(hid, type, data, size);
1860
1861         report = hid_get_report(report_enum, data);
1862
1863         if (!report) {
1864                 ret = -1;
1865                 goto unlock;
1866         }
1867
1868         if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
1869                 ret = hdrv->raw_event(hid, report, data, size);
1870                 if (ret < 0)
1871                         goto unlock;
1872         }
1873
1874         ret = hid_report_raw_event(hid, type, data, size, interrupt);
1875
1876 unlock:
1877         up(&hid->driver_input_lock);
1878         return ret;
1879 }
1880 EXPORT_SYMBOL_GPL(hid_input_report);
1881
1882 bool hid_match_one_id(const struct hid_device *hdev,
1883                       const struct hid_device_id *id)
1884 {
1885         return (id->bus == HID_BUS_ANY || id->bus == hdev->bus) &&
1886                 (id->group == HID_GROUP_ANY || id->group == hdev->group) &&
1887                 (id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&
1888                 (id->product == HID_ANY_ID || id->product == hdev->product);
1889 }
1890
1891 const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
1892                 const struct hid_device_id *id)
1893 {
1894         for (; id->bus; id++)
1895                 if (hid_match_one_id(hdev, id))
1896                         return id;
1897
1898         return NULL;
1899 }
1900
1901 static const struct hid_device_id hid_hiddev_list[] = {
1902         { HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS) },
1903         { HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS1) },
1904         { }
1905 };
1906
1907 static bool hid_hiddev(struct hid_device *hdev)
1908 {
1909         return !!hid_match_id(hdev, hid_hiddev_list);
1910 }
1911
1912
1913 static ssize_t
1914 read_report_descriptor(struct file *filp, struct kobject *kobj,
1915                 struct bin_attribute *attr,
1916                 char *buf, loff_t off, size_t count)
1917 {
1918         struct device *dev = kobj_to_dev(kobj);
1919         struct hid_device *hdev = to_hid_device(dev);
1920
1921         if (off >= hdev->rsize)
1922                 return 0;
1923
1924         if (off + count > hdev->rsize)
1925                 count = hdev->rsize - off;
1926
1927         memcpy(buf, hdev->rdesc + off, count);
1928
1929         return count;
1930 }
1931
1932 static ssize_t
1933 show_country(struct device *dev, struct device_attribute *attr,
1934                 char *buf)
1935 {
1936         struct hid_device *hdev = to_hid_device(dev);
1937
1938         return sprintf(buf, "%02x\n", hdev->country & 0xff);
1939 }
1940
1941 static struct bin_attribute dev_bin_attr_report_desc = {
1942         .attr = { .name = "report_descriptor", .mode = 0444 },
1943         .read = read_report_descriptor,
1944         .size = HID_MAX_DESCRIPTOR_SIZE,
1945 };
1946
1947 static const struct device_attribute dev_attr_country = {
1948         .attr = { .name = "country", .mode = 0444 },
1949         .show = show_country,
1950 };
1951
1952 int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
1953 {
1954         static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
1955                 "Joystick", "Gamepad", "Keyboard", "Keypad",
1956                 "Multi-Axis Controller"
1957         };
1958         const char *type, *bus;
1959         char buf[64] = "";
1960         unsigned int i;
1961         int len;
1962         int ret;
1963
1964         if (hdev->quirks & HID_QUIRK_HIDDEV_FORCE)
1965                 connect_mask |= (HID_CONNECT_HIDDEV_FORCE | HID_CONNECT_HIDDEV);
1966         if (hdev->quirks & HID_QUIRK_HIDINPUT_FORCE)
1967                 connect_mask |= HID_CONNECT_HIDINPUT_FORCE;
1968         if (hdev->bus != BUS_USB)
1969                 connect_mask &= ~HID_CONNECT_HIDDEV;
1970         if (hid_hiddev(hdev))
1971                 connect_mask |= HID_CONNECT_HIDDEV_FORCE;
1972
1973         if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,
1974                                 connect_mask & HID_CONNECT_HIDINPUT_FORCE))
1975                 hdev->claimed |= HID_CLAIMED_INPUT;
1976
1977         if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect &&
1978                         !hdev->hiddev_connect(hdev,
1979                                 connect_mask & HID_CONNECT_HIDDEV_FORCE))
1980                 hdev->claimed |= HID_CLAIMED_HIDDEV;
1981         if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))
1982                 hdev->claimed |= HID_CLAIMED_HIDRAW;
1983
1984         if (connect_mask & HID_CONNECT_DRIVER)
1985                 hdev->claimed |= HID_CLAIMED_DRIVER;
1986
1987         /* Drivers with the ->raw_event callback set are not required to connect
1988          * to any other listener. */
1989         if (!hdev->claimed && !hdev->driver->raw_event) {
1990                 hid_err(hdev, "device has no listeners, quitting\n");
1991                 return -ENODEV;
1992         }
1993
1994         if ((hdev->claimed & HID_CLAIMED_INPUT) &&
1995                         (connect_mask & HID_CONNECT_FF) && hdev->ff_init)
1996                 hdev->ff_init(hdev);
1997
1998         len = 0;
1999         if (hdev->claimed & HID_CLAIMED_INPUT)
2000                 len += sprintf(buf + len, "input");
2001         if (hdev->claimed & HID_CLAIMED_HIDDEV)
2002                 len += sprintf(buf + len, "%shiddev%d", len ? "," : "",
2003                                 ((struct hiddev *)hdev->hiddev)->minor);
2004         if (hdev->claimed & HID_CLAIMED_HIDRAW)
2005                 len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
2006                                 ((struct hidraw *)hdev->hidraw)->minor);
2007
2008         type = "Device";
2009         for (i = 0; i < hdev->maxcollection; i++) {
2010                 struct hid_collection *col = &hdev->collection[i];
2011                 if (col->type == HID_COLLECTION_APPLICATION &&
2012                    (col->usage & HID_USAGE_PAGE) == HID_UP_GENDESK &&
2013                    (col->usage & 0xffff) < ARRAY_SIZE(types)) {
2014                         type = types[col->usage & 0xffff];
2015                         break;
2016                 }
2017         }
2018
2019         switch (hdev->bus) {
2020         case BUS_USB:
2021                 bus = "USB";
2022                 break;
2023         case BUS_BLUETOOTH:
2024                 bus = "BLUETOOTH";
2025                 break;
2026         case BUS_I2C:
2027                 bus = "I2C";
2028                 break;
2029         case BUS_VIRTUAL:
2030                 bus = "VIRTUAL";
2031                 break;
2032         default:
2033                 bus = "<UNKNOWN>";
2034         }
2035
2036         ret = device_create_file(&hdev->dev, &dev_attr_country);
2037         if (ret)
2038                 hid_warn(hdev,
2039                          "can't create sysfs country code attribute err: %d\n", ret);
2040
2041         hid_info(hdev, "%s: %s HID v%x.%02x %s [%s] on %s\n",
2042                  buf, bus, hdev->version >> 8, hdev->version & 0xff,
2043                  type, hdev->name, hdev->phys);
2044
2045         return 0;
2046 }
2047 EXPORT_SYMBOL_GPL(hid_connect);
2048
2049 void hid_disconnect(struct hid_device *hdev)
2050 {
2051         device_remove_file(&hdev->dev, &dev_attr_country);
2052         if (hdev->claimed & HID_CLAIMED_INPUT)
2053                 hidinput_disconnect(hdev);
2054         if (hdev->claimed & HID_CLAIMED_HIDDEV)
2055                 hdev->hiddev_disconnect(hdev);
2056         if (hdev->claimed & HID_CLAIMED_HIDRAW)
2057                 hidraw_disconnect(hdev);
2058         hdev->claimed = 0;
2059 }
2060 EXPORT_SYMBOL_GPL(hid_disconnect);
2061
2062 /**
2063  * hid_hw_start - start underlying HW
2064  * @hdev: hid device
2065  * @connect_mask: which outputs to connect, see HID_CONNECT_*
2066  *
2067  * Call this in probe function *after* hid_parse. This will setup HW
2068  * buffers and start the device (if not defeirred to device open).
2069  * hid_hw_stop must be called if this was successful.
2070  */
2071 int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask)
2072 {
2073         int error;
2074
2075         error = hdev->ll_driver->start(hdev);
2076         if (error)
2077                 return error;
2078
2079         if (connect_mask) {
2080                 error = hid_connect(hdev, connect_mask);
2081                 if (error) {
2082                         hdev->ll_driver->stop(hdev);
2083                         return error;
2084                 }
2085         }
2086
2087         return 0;
2088 }
2089 EXPORT_SYMBOL_GPL(hid_hw_start);
2090
2091 /**
2092  * hid_hw_stop - stop underlying HW
2093  * @hdev: hid device
2094  *
2095  * This is usually called from remove function or from probe when something
2096  * failed and hid_hw_start was called already.
2097  */
2098 void hid_hw_stop(struct hid_device *hdev)
2099 {
2100         hid_disconnect(hdev);
2101         hdev->ll_driver->stop(hdev);
2102 }
2103 EXPORT_SYMBOL_GPL(hid_hw_stop);
2104
2105 /**
2106  * hid_hw_open - signal underlying HW to start delivering events
2107  * @hdev: hid device
2108  *
2109  * Tell underlying HW to start delivering events from the device.
2110  * This function should be called sometime after successful call
2111  * to hid_hw_start().
2112  */
2113 int hid_hw_open(struct hid_device *hdev)
2114 {
2115         int ret;
2116
2117         ret = mutex_lock_killable(&hdev->ll_open_lock);
2118         if (ret)
2119                 return ret;
2120
2121         if (!hdev->ll_open_count++) {
2122                 ret = hdev->ll_driver->open(hdev);
2123                 if (ret)
2124                         hdev->ll_open_count--;
2125         }
2126
2127         mutex_unlock(&hdev->ll_open_lock);
2128         return ret;
2129 }
2130 EXPORT_SYMBOL_GPL(hid_hw_open);
2131
2132 /**
2133  * hid_hw_close - signal underlaying HW to stop delivering events
2134  *
2135  * @hdev: hid device
2136  *
2137  * This function indicates that we are not interested in the events
2138  * from this device anymore. Delivery of events may or may not stop,
2139  * depending on the number of users still outstanding.
2140  */
2141 void hid_hw_close(struct hid_device *hdev)
2142 {
2143         mutex_lock(&hdev->ll_open_lock);
2144         if (!--hdev->ll_open_count)
2145                 hdev->ll_driver->close(hdev);
2146         mutex_unlock(&hdev->ll_open_lock);
2147 }
2148 EXPORT_SYMBOL_GPL(hid_hw_close);
2149
2150 struct hid_dynid {
2151         struct list_head list;
2152         struct hid_device_id id;
2153 };
2154
2155 /**
2156  * store_new_id - add a new HID device ID to this driver and re-probe devices
2157  * @drv: target device driver
2158  * @buf: buffer for scanning device ID data
2159  * @count: input size
2160  *
2161  * Adds a new dynamic hid device ID to this driver,
2162  * and causes the driver to probe for all devices again.
2163  */
2164 static ssize_t new_id_store(struct device_driver *drv, const char *buf,
2165                 size_t count)
2166 {
2167         struct hid_driver *hdrv = to_hid_driver(drv);
2168         struct hid_dynid *dynid;
2169         __u32 bus, vendor, product;
2170         unsigned long driver_data = 0;
2171         int ret;
2172
2173         ret = sscanf(buf, "%x %x %x %lx",
2174                         &bus, &vendor, &product, &driver_data);
2175         if (ret < 3)
2176                 return -EINVAL;
2177
2178         dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
2179         if (!dynid)
2180                 return -ENOMEM;
2181
2182         dynid->id.bus = bus;
2183         dynid->id.group = HID_GROUP_ANY;
2184         dynid->id.vendor = vendor;
2185         dynid->id.product = product;
2186         dynid->id.driver_data = driver_data;
2187
2188         spin_lock(&hdrv->dyn_lock);
2189         list_add_tail(&dynid->list, &hdrv->dyn_list);
2190         spin_unlock(&hdrv->dyn_lock);
2191
2192         ret = driver_attach(&hdrv->driver);
2193
2194         return ret ? : count;
2195 }
2196 static DRIVER_ATTR_WO(new_id);
2197
2198 static struct attribute *hid_drv_attrs[] = {
2199         &driver_attr_new_id.attr,
2200         NULL,
2201 };
2202 ATTRIBUTE_GROUPS(hid_drv);
2203
2204 static void hid_free_dynids(struct hid_driver *hdrv)
2205 {
2206         struct hid_dynid *dynid, *n;
2207
2208         spin_lock(&hdrv->dyn_lock);
2209         list_for_each_entry_safe(dynid, n, &hdrv->dyn_list, list) {
2210                 list_del(&dynid->list);
2211                 kfree(dynid);
2212         }
2213         spin_unlock(&hdrv->dyn_lock);
2214 }
2215
2216 const struct hid_device_id *hid_match_device(struct hid_device *hdev,
2217                                              struct hid_driver *hdrv)
2218 {
2219         struct hid_dynid *dynid;
2220
2221         spin_lock(&hdrv->dyn_lock);
2222         list_for_each_entry(dynid, &hdrv->dyn_list, list) {
2223                 if (hid_match_one_id(hdev, &dynid->id)) {
2224                         spin_unlock(&hdrv->dyn_lock);
2225                         return &dynid->id;
2226                 }
2227         }
2228         spin_unlock(&hdrv->dyn_lock);
2229
2230         return hid_match_id(hdev, hdrv->id_table);
2231 }
2232 EXPORT_SYMBOL_GPL(hid_match_device);
2233
2234 static int hid_bus_match(struct device *dev, struct device_driver *drv)
2235 {
2236         struct hid_driver *hdrv = to_hid_driver(drv);
2237         struct hid_device *hdev = to_hid_device(dev);
2238
2239         return hid_match_device(hdev, hdrv) != NULL;
2240 }
2241
2242 /**
2243  * hid_compare_device_paths - check if both devices share the same path
2244  * @hdev_a: hid device
2245  * @hdev_b: hid device
2246  * @separator: char to use as separator
2247  *
2248  * Check if two devices share the same path up to the last occurrence of
2249  * the separator char. Both paths must exist (i.e., zero-length paths
2250  * don't match).
2251  */
2252 bool hid_compare_device_paths(struct hid_device *hdev_a,
2253                               struct hid_device *hdev_b, char separator)
2254 {
2255         int n1 = strrchr(hdev_a->phys, separator) - hdev_a->phys;
2256         int n2 = strrchr(hdev_b->phys, separator) - hdev_b->phys;
2257
2258         if (n1 != n2 || n1 <= 0 || n2 <= 0)
2259                 return false;
2260
2261         return !strncmp(hdev_a->phys, hdev_b->phys, n1);
2262 }
2263 EXPORT_SYMBOL_GPL(hid_compare_device_paths);
2264
2265 static int hid_device_probe(struct device *dev)
2266 {
2267         struct hid_driver *hdrv = to_hid_driver(dev->driver);
2268         struct hid_device *hdev = to_hid_device(dev);
2269         const struct hid_device_id *id;
2270         int ret = 0;
2271
2272         if (down_interruptible(&hdev->driver_input_lock)) {
2273                 ret = -EINTR;
2274                 goto end;
2275         }
2276         hdev->io_started = false;
2277
2278         clear_bit(ffs(HID_STAT_REPROBED), &hdev->status);
2279
2280         if (!hdev->driver) {
2281                 id = hid_match_device(hdev, hdrv);
2282                 if (id == NULL) {
2283                         ret = -ENODEV;
2284                         goto unlock;
2285                 }
2286
2287                 if (hdrv->match) {
2288                         if (!hdrv->match(hdev, hid_ignore_special_drivers)) {
2289                                 ret = -ENODEV;
2290                                 goto unlock;
2291                         }
2292                 } else {
2293                         /*
2294                          * hid-generic implements .match(), so if
2295                          * hid_ignore_special_drivers is set, we can safely
2296                          * return.
2297                          */
2298                         if (hid_ignore_special_drivers) {
2299                                 ret = -ENODEV;
2300                                 goto unlock;
2301                         }
2302                 }
2303
2304                 /* reset the quirks that has been previously set */
2305                 hdev->quirks = hid_lookup_quirk(hdev);
2306                 hdev->driver = hdrv;
2307                 if (hdrv->probe) {
2308                         ret = hdrv->probe(hdev, id);
2309                 } else { /* default probe */
2310                         ret = hid_open_report(hdev);
2311                         if (!ret)
2312                                 ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
2313                 }
2314                 if (ret) {
2315                         hid_close_report(hdev);
2316                         hdev->driver = NULL;
2317                 }
2318         }
2319 unlock:
2320         if (!hdev->io_started)
2321                 up(&hdev->driver_input_lock);
2322 end:
2323         return ret;
2324 }
2325
2326 static int hid_device_remove(struct device *dev)
2327 {
2328         struct hid_device *hdev = to_hid_device(dev);
2329         struct hid_driver *hdrv;
2330
2331         down(&hdev->driver_input_lock);
2332         hdev->io_started = false;
2333
2334         hdrv = hdev->driver;
2335         if (hdrv) {
2336                 if (hdrv->remove)
2337                         hdrv->remove(hdev);
2338                 else /* default remove */
2339                         hid_hw_stop(hdev);
2340                 hid_close_report(hdev);
2341                 hdev->driver = NULL;
2342         }
2343
2344         if (!hdev->io_started)
2345                 up(&hdev->driver_input_lock);
2346
2347         return 0;
2348 }
2349
2350 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
2351                              char *buf)
2352 {
2353         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
2354
2355         return scnprintf(buf, PAGE_SIZE, "hid:b%04Xg%04Xv%08Xp%08X\n",
2356                          hdev->bus, hdev->group, hdev->vendor, hdev->product);
2357 }
2358 static DEVICE_ATTR_RO(modalias);
2359
2360 static struct attribute *hid_dev_attrs[] = {
2361         &dev_attr_modalias.attr,
2362         NULL,
2363 };
2364 static struct bin_attribute *hid_dev_bin_attrs[] = {
2365         &dev_bin_attr_report_desc,
2366         NULL
2367 };
2368 static const struct attribute_group hid_dev_group = {
2369         .attrs = hid_dev_attrs,
2370         .bin_attrs = hid_dev_bin_attrs,
2371 };
2372 __ATTRIBUTE_GROUPS(hid_dev);
2373
2374 static int hid_uevent(struct device *dev, struct kobj_uevent_env *env)
2375 {
2376         struct hid_device *hdev = to_hid_device(dev);
2377
2378         if (add_uevent_var(env, "HID_ID=%04X:%08X:%08X",
2379                         hdev->bus, hdev->vendor, hdev->product))
2380                 return -ENOMEM;
2381
2382         if (add_uevent_var(env, "HID_NAME=%s", hdev->name))
2383                 return -ENOMEM;
2384
2385         if (add_uevent_var(env, "HID_PHYS=%s", hdev->phys))
2386                 return -ENOMEM;
2387
2388         if (add_uevent_var(env, "HID_UNIQ=%s", hdev->uniq))
2389                 return -ENOMEM;
2390
2391         if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",
2392                            hdev->bus, hdev->group, hdev->vendor, hdev->product))
2393                 return -ENOMEM;
2394
2395         return 0;
2396 }
2397
2398 struct bus_type hid_bus_type = {
2399         .name           = "hid",
2400         .dev_groups     = hid_dev_groups,
2401         .drv_groups     = hid_drv_groups,
2402         .match          = hid_bus_match,
2403         .probe          = hid_device_probe,
2404         .remove         = hid_device_remove,
2405         .uevent         = hid_uevent,
2406 };
2407 EXPORT_SYMBOL(hid_bus_type);
2408
2409 int hid_add_device(struct hid_device *hdev)
2410 {
2411         static atomic_t id = ATOMIC_INIT(0);
2412         int ret;
2413
2414         if (WARN_ON(hdev->status & HID_STAT_ADDED))
2415                 return -EBUSY;
2416
2417         hdev->quirks = hid_lookup_quirk(hdev);
2418
2419         /* we need to kill them here, otherwise they will stay allocated to
2420          * wait for coming driver */
2421         if (hid_ignore(hdev))
2422                 return -ENODEV;
2423
2424         /*
2425          * Check for the mandatory transport channel.
2426          */
2427          if (!hdev->ll_driver->raw_request) {
2428                 hid_err(hdev, "transport driver missing .raw_request()\n");
2429                 return -EINVAL;
2430          }
2431
2432         /*
2433          * Read the device report descriptor once and use as template
2434          * for the driver-specific modifications.
2435          */
2436         ret = hdev->ll_driver->parse(hdev);
2437         if (ret)
2438                 return ret;
2439         if (!hdev->dev_rdesc)
2440                 return -ENODEV;
2441
2442         /*
2443          * Scan generic devices for group information
2444          */
2445         if (hid_ignore_special_drivers) {
2446                 hdev->group = HID_GROUP_GENERIC;
2447         } else if (!hdev->group &&
2448                    !(hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)) {
2449                 ret = hid_scan_report(hdev);
2450                 if (ret)
2451                         hid_warn(hdev, "bad device descriptor (%d)\n", ret);
2452         }
2453
2454         hdev->id = atomic_inc_return(&id);
2455
2456         /* XXX hack, any other cleaner solution after the driver core
2457          * is converted to allow more than 20 bytes as the device name? */
2458         dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
2459                      hdev->vendor, hdev->product, hdev->id);
2460
2461         hid_debug_register(hdev, dev_name(&hdev->dev));
2462         ret = device_add(&hdev->dev);
2463         if (!ret)
2464                 hdev->status |= HID_STAT_ADDED;
2465         else
2466                 hid_debug_unregister(hdev);
2467
2468         return ret;
2469 }
2470 EXPORT_SYMBOL_GPL(hid_add_device);
2471
2472 /**
2473  * hid_allocate_device - allocate new hid device descriptor
2474  *
2475  * Allocate and initialize hid device, so that hid_destroy_device might be
2476  * used to free it.
2477  *
2478  * New hid_device pointer is returned on success, otherwise ERR_PTR encoded
2479  * error value.
2480  */
2481 struct hid_device *hid_allocate_device(void)
2482 {
2483         struct hid_device *hdev;
2484         int ret = -ENOMEM;
2485
2486         hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
2487         if (hdev == NULL)
2488                 return ERR_PTR(ret);
2489
2490         device_initialize(&hdev->dev);
2491         hdev->dev.release = hid_device_release;
2492         hdev->dev.bus = &hid_bus_type;
2493         device_enable_async_suspend(&hdev->dev);
2494
2495         hid_close_report(hdev);
2496
2497         init_waitqueue_head(&hdev->debug_wait);
2498         INIT_LIST_HEAD(&hdev->debug_list);
2499         spin_lock_init(&hdev->debug_list_lock);
2500         sema_init(&hdev->driver_input_lock, 1);
2501         mutex_init(&hdev->ll_open_lock);
2502         kref_init(&hdev->ref);
2503
2504         return hdev;
2505 }
2506 EXPORT_SYMBOL_GPL(hid_allocate_device);
2507
2508 static void hid_remove_device(struct hid_device *hdev)
2509 {
2510         if (hdev->status & HID_STAT_ADDED) {
2511                 device_del(&hdev->dev);
2512                 hid_debug_unregister(hdev);
2513                 hdev->status &= ~HID_STAT_ADDED;
2514         }
2515         kfree(hdev->dev_rdesc);
2516         hdev->dev_rdesc = NULL;
2517         hdev->dev_rsize = 0;
2518 }
2519
2520 /**
2521  * hid_destroy_device - free previously allocated device
2522  *
2523  * @hdev: hid device
2524  *
2525  * If you allocate hid_device through hid_allocate_device, you should ever
2526  * free by this function.
2527  */
2528 void hid_destroy_device(struct hid_device *hdev)
2529 {
2530         hid_remove_device(hdev);
2531         put_device(&hdev->dev);
2532 }
2533 EXPORT_SYMBOL_GPL(hid_destroy_device);
2534
2535
2536 static int __hid_bus_reprobe_drivers(struct device *dev, void *data)
2537 {
2538         struct hid_driver *hdrv = data;
2539         struct hid_device *hdev = to_hid_device(dev);
2540
2541         if (hdev->driver == hdrv &&
2542             !hdrv->match(hdev, hid_ignore_special_drivers) &&
2543             !test_and_set_bit(ffs(HID_STAT_REPROBED), &hdev->status))
2544                 return device_reprobe(dev);
2545
2546         return 0;
2547 }
2548
2549 static int __hid_bus_driver_added(struct device_driver *drv, void *data)
2550 {
2551         struct hid_driver *hdrv = to_hid_driver(drv);
2552
2553         if (hdrv->match) {
2554                 bus_for_each_dev(&hid_bus_type, NULL, hdrv,
2555                                  __hid_bus_reprobe_drivers);
2556         }
2557
2558         return 0;
2559 }
2560
2561 static int __bus_removed_driver(struct device_driver *drv, void *data)
2562 {
2563         return bus_rescan_devices(&hid_bus_type);
2564 }
2565
2566 int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
2567                 const char *mod_name)
2568 {
2569         int ret;
2570
2571         hdrv->driver.name = hdrv->name;
2572         hdrv->driver.bus = &hid_bus_type;
2573         hdrv->driver.owner = owner;
2574         hdrv->driver.mod_name = mod_name;
2575
2576         INIT_LIST_HEAD(&hdrv->dyn_list);
2577         spin_lock_init(&hdrv->dyn_lock);
2578
2579         ret = driver_register(&hdrv->driver);
2580
2581         if (ret == 0)
2582                 bus_for_each_drv(&hid_bus_type, NULL, NULL,
2583                                  __hid_bus_driver_added);
2584
2585         return ret;
2586 }
2587 EXPORT_SYMBOL_GPL(__hid_register_driver);
2588
2589 void hid_unregister_driver(struct hid_driver *hdrv)
2590 {
2591         driver_unregister(&hdrv->driver);
2592         hid_free_dynids(hdrv);
2593
2594         bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver);
2595 }
2596 EXPORT_SYMBOL_GPL(hid_unregister_driver);
2597
2598 int hid_check_keys_pressed(struct hid_device *hid)
2599 {
2600         struct hid_input *hidinput;
2601         int i;
2602
2603         if (!(hid->claimed & HID_CLAIMED_INPUT))
2604                 return 0;
2605
2606         list_for_each_entry(hidinput, &hid->inputs, list) {
2607                 for (i = 0; i < BITS_TO_LONGS(KEY_MAX); i++)
2608                         if (hidinput->input->key[i])
2609                                 return 1;
2610         }
2611
2612         return 0;
2613 }
2614
2615 EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
2616
2617 static int __init hid_init(void)
2618 {
2619         int ret;
2620
2621         if (hid_debug)
2622                 pr_warn("hid_debug is now used solely for parser and driver debugging.\n"
2623                         "debugfs is now used for inspecting the device (report descriptor, reports)\n");
2624
2625         ret = bus_register(&hid_bus_type);
2626         if (ret) {
2627                 pr_err("can't register hid bus\n");
2628                 goto err;
2629         }
2630
2631         ret = hidraw_init();
2632         if (ret)
2633                 goto err_bus;
2634
2635         hid_debug_init();
2636
2637         return 0;
2638 err_bus:
2639         bus_unregister(&hid_bus_type);
2640 err:
2641         return ret;
2642 }
2643
2644 static void __exit hid_exit(void)
2645 {
2646         hid_debug_exit();
2647         hidraw_exit();
2648         bus_unregister(&hid_bus_type);
2649         hid_quirks_exit(HID_BUS_ANY);
2650 }
2651
2652 module_init(hid_init);
2653 module_exit(hid_exit);
2654
2655 MODULE_AUTHOR("Andreas Gal");
2656 MODULE_AUTHOR("Vojtech Pavlik");
2657 MODULE_AUTHOR("Jiri Kosina");
2658 MODULE_LICENSE("GPL");