1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  HID support for Linux
   4 *
   5 *  Copyright (c) 1999 Andreas Gal
   6 *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
   7 *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
   8 *  Copyright (c) 2006-2012 Jiri Kosina
   9 */
  10
  11/*
  12 */
  13
  14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16#include <linux/module.h>
  17#include <linux/slab.h>
  18#include <linux/init.h>
  19#include <linux/kernel.h>
  20#include <linux/list.h>
  21#include <linux/mm.h>
  22#include <linux/spinlock.h>
  23#include <asm/unaligned.h>
  24#include <asm/byteorder.h>
  25#include <linux/input.h>
  26#include <linux/wait.h>
  27#include <linux/vmalloc.h>
  28#include <linux/sched.h>
  29#include <linux/semaphore.h>
  30
  31#include <linux/hid.h>
  32#include <linux/hiddev.h>
  33#include <linux/hid-debug.h>
  34#include <linux/hidraw.h>
  35
  36#include "hid-ids.h"
  37
  38/*
  39 * Version Information
  40 */
  41
  42#define DRIVER_DESC "HID core driver"
  43
  44int hid_debug = 0;
  45module_param_named(debug, hid_debug, int, 0600);
  46MODULE_PARM_DESC(debug, "toggle HID debugging messages");
  47EXPORT_SYMBOL_GPL(hid_debug);
  48
  49static int hid_ignore_special_drivers = 0;
  50module_param_named(ignore_special_drivers, hid_ignore_special_drivers, int, 0600);
  51MODULE_PARM_DESC(ignore_special_drivers, "Ignore any special drivers and handle all devices by generic driver");
  52
  53/*
  54 * Register a new report for a device.
  55 */
  56
  57struct hid_report *hid_register_report(struct hid_device *device,
  58				       unsigned int type, unsigned int id,
  59				       unsigned int application)
  60{
  61	struct hid_report_enum *report_enum = device->report_enum + type;
  62	struct hid_report *report;
  63
  64	if (id >= HID_MAX_IDS)
  65		return NULL;
  66	if (report_enum->report_id_hash[id])
  67		return report_enum->report_id_hash[id];
  68
  69	report = kzalloc(sizeof(struct hid_report), GFP_KERNEL);
  70	if (!report)
  71		return NULL;
  72
  73	if (id != 0)
  74		report_enum->numbered = 1;
  75
  76	report->id = id;
  77	report->type = type;
  78	report->size = 0;
  79	report->device = device;
  80	report->application = application;
  81	report_enum->report_id_hash[id] = report;
  82
  83	list_add_tail(&report->list, &report_enum->report_list);
  84
  85	return report;
  86}
  87EXPORT_SYMBOL_GPL(hid_register_report);
  88
  89/*
  90 * Register a new field for this report.
  91 */
  92
  93static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages, unsigned values)
  94{
  95	struct hid_field *field;
  96
  97	if (report->maxfield == HID_MAX_FIELDS) {
  98		hid_err(report->device, "too many fields in report\n");
  99		return NULL;
 100	}
 101
 102	field = kzalloc((sizeof(struct hid_field) +
 103			 usages * sizeof(struct hid_usage) +
 104			 values * sizeof(unsigned)), GFP_KERNEL);
 105	if (!field)
 106		return NULL;
 107
 108	field->index = report->maxfield++;
 109	report->field[field->index] = field;
 110	field->usage = (struct hid_usage *)(field + 1);
 111	field->value = (s32 *)(field->usage + usages);
 112	field->report = report;
 113
 114	return field;
 115}
 116
 117/*
 118 * Open a collection. The type/usage is pushed on the stack.
 119 */
 120
 121static int open_collection(struct hid_parser *parser, unsigned type)
 122{
 123	struct hid_collection *collection;
 124	unsigned usage;
 125	int collection_index;
 126
 127	usage = parser->local.usage[0];
 128
 129	if (parser->collection_stack_ptr == parser->collection_stack_size) {
 130		unsigned int *collection_stack;
 131		unsigned int new_size = parser->collection_stack_size +
 132					HID_COLLECTION_STACK_SIZE;
 133
 134		collection_stack = krealloc(parser->collection_stack,
 135					    new_size * sizeof(unsigned int),
 136					    GFP_KERNEL);
 137		if (!collection_stack)
 138			return -ENOMEM;
 139
 140		parser->collection_stack = collection_stack;
 141		parser->collection_stack_size = new_size;
 142	}
 143
 144	if (parser->device->maxcollection == parser->device->collection_size) {
 145		collection = kmalloc(
 146				array3_size(sizeof(struct hid_collection),
 147					    parser->device->collection_size,
 148					    2),
 149				GFP_KERNEL);
 150		if (collection == NULL) {
 151			hid_err(parser->device, "failed to reallocate collection array\n");
 152			return -ENOMEM;
 153		}
 154		memcpy(collection, parser->device->collection,
 155			sizeof(struct hid_collection) *
 156			parser->device->collection_size);
 157		memset(collection + parser->device->collection_size, 0,
 158			sizeof(struct hid_collection) *
 159			parser->device->collection_size);
 160		kfree(parser->device->collection);
 161		parser->device->collection = collection;
 162		parser->device->collection_size *= 2;
 163	}
 164
 165	parser->collection_stack[parser->collection_stack_ptr++] =
 166		parser->device->maxcollection;
 167
 168	collection_index = parser->device->maxcollection++;
 169	collection = parser->device->collection + collection_index;
 170	collection->type = type;
 171	collection->usage = usage;
 172	collection->level = parser->collection_stack_ptr - 1;
 173	collection->parent_idx = (collection->level == 0) ? -1 :
 174		parser->collection_stack[collection->level - 1];
 175
 176	if (type == HID_COLLECTION_APPLICATION)
 177		parser->device->maxapplication++;
 178
 179	return 0;
 180}
 181
 182/*
 183 * Close a collection.
 184 */
 185
 186static int close_collection(struct hid_parser *parser)
 187{
 188	if (!parser->collection_stack_ptr) {
 189		hid_err(parser->device, "collection stack underflow\n");
 190		return -EINVAL;
 191	}
 192	parser->collection_stack_ptr--;
 193	return 0;
 194}
 195
 196/*
 197 * Climb up the stack, search for the specified collection type
 198 * and return the usage.
 199 */
 200
 201static unsigned hid_lookup_collection(struct hid_parser *parser, unsigned type)
 202{
 203	struct hid_collection *collection = parser->device->collection;
 204	int n;
 205
 206	for (n = parser->collection_stack_ptr - 1; n >= 0; n--) {
 207		unsigned index = parser->collection_stack[n];
 208		if (collection[index].type == type)
 209			return collection[index].usage;
 210	}
 211	return 0; /* we know nothing about this usage type */
 212}
 213
 214/*
 215 * Concatenate usage which defines 16 bits or less with the
 216 * currently defined usage page to form a 32 bit usage
 217 */
 218
 219static void complete_usage(struct hid_parser *parser, unsigned int index)
 220{
 221	parser->local.usage[index] &= 0xFFFF;
 222	parser->local.usage[index] |=
 223		(parser->global.usage_page & 0xFFFF) << 16;
 224}
 225
 226/*
 227 * Add a usage to the temporary parser table.
 228 */
 229
 230static int hid_add_usage(struct hid_parser *parser, unsigned usage, u8 size)
 231{
 232	if (parser->local.usage_index >= HID_MAX_USAGES) {
 233		hid_err(parser->device, "usage index exceeded\n");
 234		return -1;
 235	}
 236	parser->local.usage[parser->local.usage_index] = usage;
 237
 238	/*
 239	 * If Usage item only includes usage id, concatenate it with
 240	 * currently defined usage page
 241	 */
 242	if (size <= 2)
 243		complete_usage(parser, parser->local.usage_index);
 244
 245	parser->local.usage_size[parser->local.usage_index] = size;
 246	parser->local.collection_index[parser->local.usage_index] =
 247		parser->collection_stack_ptr ?
 248		parser->collection_stack[parser->collection_stack_ptr - 1] : 0;
 249	parser->local.usage_index++;
 250	return 0;
 251}
 252
 253/*
 254 * Register a new field for this report.
 255 */
 256
 257static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsigned flags)
 258{
 259	struct hid_report *report;
 260	struct hid_field *field;
 261	unsigned int usages;
 262	unsigned int offset;
 263	unsigned int i;
 264	unsigned int application;
 265
 266	application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
 267
 268	report = hid_register_report(parser->device, report_type,
 269				     parser->global.report_id, application);
 270	if (!report) {
 271		hid_err(parser->device, "hid_register_report failed\n");
 272		return -1;
 273	}
 274
 275	/* Handle both signed and unsigned cases properly */
 276	if ((parser->global.logical_minimum < 0 &&
 277		parser->global.logical_maximum <
 278		parser->global.logical_minimum) ||
 279		(parser->global.logical_minimum >= 0 &&
 280		(__u32)parser->global.logical_maximum <
 281		(__u32)parser->global.logical_minimum)) {
 282		dbg_hid("logical range invalid 0x%x 0x%x\n",
 283			parser->global.logical_minimum,
 284			parser->global.logical_maximum);
 285		return -1;
 286	}
 287
 288	offset = report->size;
 289	report->size += parser->global.report_size * parser->global.report_count;
 290
 291	/* Total size check: Allow for possible report index byte */
 292	if (report->size > (HID_MAX_BUFFER_SIZE - 1) << 3) {
 293		hid_err(parser->device, "report is too long\n");
 294		return -1;
 295	}
 296
 297	if (!parser->local.usage_index) /* Ignore padding fields */
 298		return 0;
 299
 300	usages = max_t(unsigned, parser->local.usage_index,
 301				 parser->global.report_count);
 302
 303	field = hid_register_field(report, usages, parser->global.report_count);
 304	if (!field)
 305		return 0;
 306
 307	field->physical = hid_lookup_collection(parser, HID_COLLECTION_PHYSICAL);
 308	field->logical = hid_lookup_collection(parser, HID_COLLECTION_LOGICAL);
 309	field->application = application;
 310
 311	for (i = 0; i < usages; i++) {
 312		unsigned j = i;
 313		/* Duplicate the last usage we parsed if we have excess values */
 314		if (i >= parser->local.usage_index)
 315			j = parser->local.usage_index - 1;
 316		field->usage[i].hid = parser->local.usage[j];
 317		field->usage[i].collection_index =
 318			parser->local.collection_index[j];
 319		field->usage[i].usage_index = i;
 320		field->usage[i].resolution_multiplier = 1;
 321	}
 322
 323	field->maxusage = usages;
 324	field->flags = flags;
 325	field->report_offset = offset;
 326	field->report_type = report_type;
 327	field->report_size = parser->global.report_size;
 328	field->report_count = parser->global.report_count;
 329	field->logical_minimum = parser->global.logical_minimum;
 330	field->logical_maximum = parser->global.logical_maximum;
 331	field->physical_minimum = parser->global.physical_minimum;
 332	field->physical_maximum = parser->global.physical_maximum;
 333	field->unit_exponent = parser->global.unit_exponent;
 334	field->unit = parser->global.unit;
 335
 336	return 0;
 337}
 338
 339/*
 340 * Read data value from item.
 341 */
 342
 343static u32 item_udata(struct hid_item *item)
 344{
 345	switch (item->size) {
 346	case 1: return item->data.u8;
 347	case 2: return item->data.u16;
 348	case 4: return item->data.u32;
 349	}
 350	return 0;
 351}
 352
 353static s32 item_sdata(struct hid_item *item)
 354{
 355	switch (item->size) {
 356	case 1: return item->data.s8;
 357	case 2: return item->data.s16;
 358	case 4: return item->data.s32;
 359	}
 360	return 0;
 361}
 362
 363/*
 364 * Process a global item.
 365 */
 366
 367static int hid_parser_global(struct hid_parser *parser, struct hid_item *item)
 368{
 369	__s32 raw_value;
 370	switch (item->tag) {
 371	case HID_GLOBAL_ITEM_TAG_PUSH:
 372
 373		if (parser->global_stack_ptr == HID_GLOBAL_STACK_SIZE) {
 374			hid_err(parser->device, "global environment stack overflow\n");
 375			return -1;
 376		}
 377
 378		memcpy(parser->global_stack + parser->global_stack_ptr++,
 379			&parser->global, sizeof(struct hid_global));
 380		return 0;
 381
 382	case HID_GLOBAL_ITEM_TAG_POP:
 383
 384		if (!parser->global_stack_ptr) {
 385			hid_err(parser->device, "global environment stack underflow\n");
 386			return -1;
 387		}
 388
 389		memcpy(&parser->global, parser->global_stack +
 390			--parser->global_stack_ptr, sizeof(struct hid_global));
 391		return 0;
 392
 393	case HID_GLOBAL_ITEM_TAG_USAGE_PAGE:
 394		parser->global.usage_page = item_udata(item);
 395		return 0;
 396
 397	case HID_GLOBAL_ITEM_TAG_LOGICAL_MINIMUM:
 398		parser->global.logical_minimum = item_sdata(item);
 399		return 0;
 400
 401	case HID_GLOBAL_ITEM_TAG_LOGICAL_MAXIMUM:
 402		if (parser->global.logical_minimum < 0)
 403			parser->global.logical_maximum = item_sdata(item);
 404		else
 405			parser->global.logical_maximum = item_udata(item);
 406		return 0;
 407
 408	case HID_GLOBAL_ITEM_TAG_PHYSICAL_MINIMUM:
 409		parser->global.physical_minimum = item_sdata(item);
 410		return 0;
 411
 412	case HID_GLOBAL_ITEM_TAG_PHYSICAL_MAXIMUM:
 413		if (parser->global.physical_minimum < 0)
 414			parser->global.physical_maximum = item_sdata(item);
 415		else
 416			parser->global.physical_maximum = item_udata(item);
 417		return 0;
 418
 419	case HID_GLOBAL_ITEM_TAG_UNIT_EXPONENT:
 420		/* Many devices provide unit exponent as a two's complement
 421		 * nibble due to the common misunderstanding of HID
 422		 * specification 1.11, 6.2.2.7 Global Items. Attempt to handle
 423		 * both this and the standard encoding. */
 424		raw_value = item_sdata(item);
 425		if (!(raw_value & 0xfffffff0))
 426			parser->global.unit_exponent = hid_snto32(raw_value, 4);
 427		else
 428			parser->global.unit_exponent = raw_value;
 429		return 0;
 430
 431	case HID_GLOBAL_ITEM_TAG_UNIT:
 432		parser->global.unit = item_udata(item);
 433		return 0;
 434
 435	case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
 436		parser->global.report_size = item_udata(item);
 437		if (parser->global.report_size > 256) {
 438			hid_err(parser->device, "invalid report_size %d\n",
 439					parser->global.report_size);
 440			return -1;
 441		}
 442		return 0;
 443
 444	case HID_GLOBAL_ITEM_TAG_REPORT_COUNT:
 445		parser->global.report_count = item_udata(item);
 446		if (parser->global.report_count > HID_MAX_USAGES) {
 447			hid_err(parser->device, "invalid report_count %d\n",
 448					parser->global.report_count);
 449			return -1;
 450		}
 451		return 0;
 452
 453	case HID_GLOBAL_ITEM_TAG_REPORT_ID:
 454		parser->global.report_id = item_udata(item);
 455		if (parser->global.report_id == 0 ||
 456		    parser->global.report_id >= HID_MAX_IDS) {
 457			hid_err(parser->device, "report_id %u is invalid\n",
 458				parser->global.report_id);
 459			return -1;
 460		}
 461		return 0;
 462
 463	default:
 464		hid_err(parser->device, "unknown global tag 0x%x\n", item->tag);
 465		return -1;
 466	}
 467}
 468
 469/*
 470 * Process a local item.
 471 */
 472
 473static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
 474{
 475	__u32 data;
 476	unsigned n;
 477	__u32 count;
 478
 479	data = item_udata(item);
 480
 481	switch (item->tag) {
 482	case HID_LOCAL_ITEM_TAG_DELIMITER:
 483
 484		if (data) {
 485			/*
 486			 * We treat items before the first delimiter
 487			 * as global to all usage sets (branch 0).
 488			 * In the moment we process only these global
 489			 * items and the first delimiter set.
 490			 */
 491			if (parser->local.delimiter_depth != 0) {
 492				hid_err(parser->device, "nested delimiters\n");
 493				return -1;
 494			}
 495			parser->local.delimiter_depth++;
 496			parser->local.delimiter_branch++;
 497		} else {
 498			if (parser->local.delimiter_depth < 1) {
 499				hid_err(parser->device, "bogus close delimiter\n");
 500				return -1;
 501			}
 502			parser->local.delimiter_depth--;
 503		}
 504		return 0;
 505
 506	case HID_LOCAL_ITEM_TAG_USAGE:
 507
 508		if (parser->local.delimiter_branch > 1) {
 509			dbg_hid("alternative usage ignored\n");
 510			return 0;
 511		}
 512
 513		return hid_add_usage(parser, data, item->size);
 514
 515	case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:
 516
 517		if (parser->local.delimiter_branch > 1) {
 518			dbg_hid("alternative usage ignored\n");
 519			return 0;
 520		}
 521
 522		parser->local.usage_minimum = data;
 523		return 0;
 524
 525	case HID_LOCAL_ITEM_TAG_USAGE_MAXIMUM:
 526
 527		if (parser->local.delimiter_branch > 1) {
 528			dbg_hid("alternative usage ignored\n");
 529			return 0;
 530		}
 531
 532		count = data - parser->local.usage_minimum;
 533		if (count + parser->local.usage_index >= HID_MAX_USAGES) {
 534			/*
 535			 * We do not warn if the name is not set, we are
 536			 * actually pre-scanning the device.
 537			 */
 538			if (dev_name(&parser->device->dev))
 539				hid_warn(parser->device,
 540					 "ignoring exceeding usage max\n");
 541			data = HID_MAX_USAGES - parser->local.usage_index +
 542				parser->local.usage_minimum - 1;
 543			if (data <= 0) {
 544				hid_err(parser->device,
 545					"no more usage index available\n");
 546				return -1;
 547			}
 548		}
 549
 550		for (n = parser->local.usage_minimum; n <= data; n++)
 551			if (hid_add_usage(parser, n, item->size)) {
 552				dbg_hid("hid_add_usage failed\n");
 553				return -1;
 554			}
 555		return 0;
 556
 557	default:
 558
 559		dbg_hid("unknown local item tag 0x%x\n", item->tag);
 560		return 0;
 561	}
 562	return 0;
 563}
 564
 565/*
 566 * Concatenate Usage Pages into Usages where relevant:
 567 * As per specification, 6.2.2.8: "When the parser encounters a main item it
 568 * concatenates the last declared Usage Page with a Usage to form a complete
 569 * usage value."
 570 */
 571
 572static void hid_concatenate_last_usage_page(struct hid_parser *parser)
 573{
 574	int i;
 575	unsigned int usage_page;
 576	unsigned int current_page;
 577
 578	if (!parser->local.usage_index)
 579		return;
 580
 581	usage_page = parser->global.usage_page;
 582
 583	/*
 584	 * Concatenate usage page again only if last declared Usage Page
 585	 * has not been already used in previous usages concatenation
 586	 */
 587	for (i = parser->local.usage_index - 1; i >= 0; i--) {
 588		if (parser->local.usage_size[i] > 2)
 589			/* Ignore extended usages */
 590			continue;
 591
 592		current_page = parser->local.usage[i] >> 16;
 593		if (current_page == usage_page)
 594			break;
 595
 596		complete_usage(parser, i);
 597	}
 598}
 599
 600/*
 601 * Process a main item.
 602 */
 603
 604static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
 605{
 606	__u32 data;
 607	int ret;
 608
 609	hid_concatenate_last_usage_page(parser);
 610
 611	data = item_udata(item);
 612
 613	switch (item->tag) {
 614	case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 615		ret = open_collection(parser, data & 0xff);
 616		break;
 617	case HID_MAIN_ITEM_TAG_END_COLLECTION:
 618		ret = close_collection(parser);
 619		break;
 620	case HID_MAIN_ITEM_TAG_INPUT:
 621		ret = hid_add_field(parser, HID_INPUT_REPORT, data);
 622		break;
 623	case HID_MAIN_ITEM_TAG_OUTPUT:
 624		ret = hid_add_field(parser, HID_OUTPUT_REPORT, data);
 625		break;
 626	case HID_MAIN_ITEM_TAG_FEATURE:
 627		ret = hid_add_field(parser, HID_FEATURE_REPORT, data);
 628		break;
 629	default:
 630		hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
 631		ret = 0;
 632	}
 633
 634	memset(&parser->local, 0, sizeof(parser->local));	/* Reset the local parser environment */
 635
 636	return ret;
 637}
 638
 639/*
 640 * Process a reserved item.
 641 */
 642
 643static int hid_parser_reserved(struct hid_parser *parser, struct hid_item *item)
 644{
 645	dbg_hid("reserved item type, tag 0x%x\n", item->tag);
 646	return 0;
 647}
 648
 649/*
 650 * Free a report and all registered fields. The field->usage and
 651 * field->value table's are allocated behind the field, so we need
 652 * only to free(field) itself.
 653 */
 654
 655static void hid_free_report(struct hid_report *report)
 656{
 657	unsigned n;
 658
 659	for (n = 0; n < report->maxfield; n++)
 660		kfree(report->field[n]);
 661	kfree(report);
 662}
 663
 664/*
 665 * Close report. This function returns the device
 666 * state to the point prior to hid_open_report().
 667 */
 668static void hid_close_report(struct hid_device *device)
 669{
 670	unsigned i, j;
 671
 672	for (i = 0; i < HID_REPORT_TYPES; i++) {
 673		struct hid_report_enum *report_enum = device->report_enum + i;
 674
 675		for (j = 0; j < HID_MAX_IDS; j++) {
 676			struct hid_report *report = report_enum->report_id_hash[j];
 677			if (report)
 678				hid_free_report(report);
 679		}
 680		memset(report_enum, 0, sizeof(*report_enum));
 681		INIT_LIST_HEAD(&report_enum->report_list);
 682	}
 683
 684	kfree(device->rdesc);
 685	device->rdesc = NULL;
 686	device->rsize = 0;
 687
 688	kfree(device->collection);
 689	device->collection = NULL;
 690	device->collection_size = 0;
 691	device->maxcollection = 0;
 692	device->maxapplication = 0;
 693
 694	device->status &= ~HID_STAT_PARSED;
 695}
 696
 697/*
 698 * Free a device structure, all reports, and all fields.
 699 */
 700
 701static void hid_device_release(struct device *dev)
 702{
 703	struct hid_device *hid = to_hid_device(dev);
 704
 705	hid_close_report(hid);
 706	kfree(hid->dev_rdesc);
 707	kfree(hid);
 708}
 709
 710/*
 711 * Fetch a report description item from the data stream. We support long
 712 * items, though they are not used yet.
 713 */
 714
 715static u8 *fetch_item(__u8 *start, __u8 *end, struct hid_item *item)
 716{
 717	u8 b;
 718
 719	if ((end - start) <= 0)
 720		return NULL;
 721
 722	b = *start++;
 723
 724	item->type = (b >> 2) & 3;
 725	item->tag  = (b >> 4) & 15;
 726
 727	if (item->tag == HID_ITEM_TAG_LONG) {
 728
 729		item->format = HID_ITEM_FORMAT_LONG;
 730
 731		if ((end - start) < 2)
 732			return NULL;
 733
 734		item->size = *start++;
 735		item->tag  = *start++;
 736
 737		if ((end - start) < item->size)
 738			return NULL;
 739
 740		item->data.longdata = start;
 741		start += item->size;
 742		return start;
 743	}
 744
 745	item->format = HID_ITEM_FORMAT_SHORT;
 746	item->size = b & 3;
 747
 748	switch (item->size) {
 749	case 0:
 750		return start;
 751
 752	case 1:
 753		if ((end - start) < 1)
 754			return NULL;
 755		item->data.u8 = *start++;
 756		return start;
 757
 758	case 2:
 759		if ((end - start) < 2)
 760			return NULL;
 761		item->data.u16 = get_unaligned_le16(start);
 762		start = (__u8 *)((__le16 *)start + 1);
 763		return start;
 764
 765	case 3:
 766		item->size++;
 767		if ((end - start) < 4)
 768			return NULL;
 769		item->data.u32 = get_unaligned_le32(start);
 770		start = (__u8 *)((__le32 *)start + 1);
 771		return start;
 772	}
 773
 774	return NULL;
 775}
 776
 777static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)
 778{
 779	struct hid_device *hid = parser->device;
 780
 781	if (usage == HID_DG_CONTACTID)
 782		hid->group = HID_GROUP_MULTITOUCH;
 783}
 784
 785static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
 786{
 787	if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
 788	    parser->global.report_size == 8)
 789		parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 790
 791	if (usage == 0xff0000c6 && parser->global.report_count == 1 &&
 792	    parser->global.report_size == 8)
 793		parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 794}
 795
 796static void hid_scan_collection(struct hid_parser *parser, unsigned type)
 797{
 798	struct hid_device *hid = parser->device;
 799	int i;
 800
 801	if (((parser->global.usage_page << 16) == HID_UP_SENSOR) &&
 802	    type == HID_COLLECTION_PHYSICAL)
 803		hid->group = HID_GROUP_SENSOR_HUB;
 804
 805	if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
 806	    hid->product == USB_DEVICE_ID_MS_POWER_COVER &&
 807	    hid->group == HID_GROUP_MULTITOUCH)
 808		hid->group = HID_GROUP_GENERIC;
 809
 810	if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
 811		for (i = 0; i < parser->local.usage_index; i++)
 812			if (parser->local.usage[i] == HID_GD_POINTER)
 813				parser->scan_flags |= HID_SCAN_FLAG_GD_POINTER;
 814
 815	if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
 816		parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
 817}
 818
 819static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
 820{
 821	__u32 data;
 822	int i;
 823
 824	hid_concatenate_last_usage_page(parser);
 825
 826	data = item_udata(item);
 827
 828	switch (item->tag) {
 829	case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 830		hid_scan_collection(parser, data & 0xff);
 831		break;
 832	case HID_MAIN_ITEM_TAG_END_COLLECTION:
 833		break;
 834	case HID_MAIN_ITEM_TAG_INPUT:
 835		/* ignore constant inputs, they will be ignored by hid-input */
 836		if (data & HID_MAIN_ITEM_CONSTANT)
 837			break;
 838		for (i = 0; i < parser->local.usage_index; i++)
 839			hid_scan_input_usage(parser, parser->local.usage[i]);
 840		break;
 841	case HID_MAIN_ITEM_TAG_OUTPUT:
 842		break;
 843	case HID_MAIN_ITEM_TAG_FEATURE:
 844		for (i = 0; i < parser->local.usage_index; i++)
 845			hid_scan_feature_usage(parser, parser->local.usage[i]);
 846		break;
 847	}
 848
 849	/* Reset the local parser environment */
 850	memset(&parser->local, 0, sizeof(parser->local));
 851
 852	return 0;
 853}
 854
 855/*
 856 * Scan a report descriptor before the device is added to the bus.
 857 * Sets device groups and other properties that determine what driver
 858 * to load.
 859 */
 860static int hid_scan_report(struct hid_device *hid)
 861{
 862	struct hid_parser *parser;
 863	struct hid_item item;
 864	__u8 *start = hid->dev_rdesc;
 865	__u8 *end = start + hid->dev_rsize;
 866	static int (*dispatch_type[])(struct hid_parser *parser,
 867				      struct hid_item *item) = {
 868		hid_scan_main,
 869		hid_parser_global,
 870		hid_parser_local,
 871		hid_parser_reserved
 872	};
 873
 874	parser = vzalloc(sizeof(struct hid_parser));
 875	if (!parser)
 876		return -ENOMEM;
 877
 878	parser->device = hid;
 879	hid->group = HID_GROUP_GENERIC;
 880
 881	/*
 882	 * The parsing is simpler than the one in hid_open_report() as we should
 883	 * be robust against hid errors. Those errors will be raised by
 884	 * hid_open_report() anyway.
 885	 */
 886	while ((start = fetch_item(start, end, &item)) != NULL)
 887		dispatch_type[item.type](parser, &item);
 888
 889	/*
 890	 * Handle special flags set during scanning.
 891	 */
 892	if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
 893	    (hid->group == HID_GROUP_MULTITOUCH))
 894		hid->group = HID_GROUP_MULTITOUCH_WIN_8;
 895
 896	/*
 897	 * Vendor specific handlings
 898	 */
 899	switch (hid->vendor) {
 900	case USB_VENDOR_ID_WACOM:
 901		hid->group = HID_GROUP_WACOM;
 902		break;
 903	case USB_VENDOR_ID_SYNAPTICS:
 904		if (hid->group == HID_GROUP_GENERIC)
 905			if ((parser->scan_flags & HID_SCAN_FLAG_VENDOR_SPECIFIC)
 906			    && (parser->scan_flags & HID_SCAN_FLAG_GD_POINTER))
 907				/*
 908				 * hid-rmi should take care of them,
 909				 * not hid-generic
 910				 */
 911				hid->group = HID_GROUP_RMI;
 912		break;
 913	}
 914
 915	kfree(parser->collection_stack);
 916	vfree(parser);
 917	return 0;
 918}
 919
 920/**
 921 * hid_parse_report - parse device report
 922 *
 923 * @device: hid device
 924 * @start: report start
 925 * @size: report size
 926 *
 927 * Allocate the device report as read by the bus driver. This function should
 928 * only be called from parse() in ll drivers.
 929 */
 930int hid_parse_report(struct hid_device *hid, __u8 *start, unsigned size)
 931{
 932	hid->dev_rdesc = kmemdup(start, size, GFP_KERNEL);
 933	if (!hid->dev_rdesc)
 934		return -ENOMEM;
 935	hid->dev_rsize = size;
 936	return 0;
 937}
 938EXPORT_SYMBOL_GPL(hid_parse_report);
 939
 940static const char * const hid_report_names[] = {
 941	"HID_INPUT_REPORT",
 942	"HID_OUTPUT_REPORT",
 943	"HID_FEATURE_REPORT",
 944};
 945/**
 946 * hid_validate_values - validate existing device report's value indexes
 947 *
 948 * @device: hid device
 949 * @type: which report type to examine
 950 * @id: which report ID to examine (0 for first)
 951 * @field_index: which report field to examine
 952 * @report_counts: expected number of values
 953 *
 954 * Validate the number of values in a given field of a given report, after
 955 * parsing.
 956 */
 957struct hid_report *hid_validate_values(struct hid_device *hid,
 958				       unsigned int type, unsigned int id,
 959				       unsigned int field_index,
 960				       unsigned int report_counts)
 961{
 962	struct hid_report *report;
 963
 964	if (type > HID_FEATURE_REPORT) {
 965		hid_err(hid, "invalid HID report type %u\n", type);
 966		return NULL;
 967	}
 968
 969	if (id >= HID_MAX_IDS) {
 970		hid_err(hid, "invalid HID report id %u\n", id);
 971		return NULL;
 972	}
 973
 974	/*
 975	 * Explicitly not using hid_get_report() here since it depends on
 976	 * ->numbered being checked, which may not always be the case when
 977	 * drivers go to access report values.
 978	 */
 979	if (id == 0) {
 980		/*
 981		 * Validating on id 0 means we should examine the first
 982		 * report in the list.
 983		 */
 984		report = list_entry(
 985				hid->report_enum[type].report_list.next,
 986				struct hid_report, list);
 987	} else {
 988		report = hid->report_enum[type].report_id_hash[id];
 989	}
 990	if (!report) {
 991		hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
 992		return NULL;
 993	}
 994	if (report->maxfield <= field_index) {
 995		hid_err(hid, "not enough fields in %s %u\n",
 996			hid_report_names[type], id);
 997		return NULL;
 998	}
 999	if (report->field[field_index]->report_count < report_counts) {
1000		hid_err(hid, "not enough values in %s %u field %u\n",
1001			hid_report_names[type], id, field_index);
1002		return NULL;
1003	}
1004	return report;
1005}
1006EXPORT_SYMBOL_GPL(hid_validate_values);
1007
1008static int hid_calculate_multiplier(struct hid_device *hid,
1009				     struct hid_field *multiplier)
1010{
1011	int m;
1012	__s32 v = *multiplier->value;
1013	__s32 lmin = multiplier->logical_minimum;
1014	__s32 lmax = multiplier->logical_maximum;
1015	__s32 pmin = multiplier->physical_minimum;
1016	__s32 pmax = multiplier->physical_maximum;
1017
1018	/*
1019	 * "Because OS implementations will generally divide the control's
1020	 * reported count by the Effective Resolution Multiplier, designers
1021	 * should take care not to establish a potential Effective
1022	 * Resolution Multiplier of zero."
1023	 * HID Usage Table, v1.12, Section 4.3.1, p31
1024	 */
1025	if (lmax - lmin == 0)
1026		return 1;
1027	/*
1028	 * Handling the unit exponent is left as an exercise to whoever
1029	 * finds a device where that exponent is not 0.
1030	 */
1031	m = ((v - lmin)/(lmax - lmin) * (pmax - pmin) + pmin);
1032	if (unlikely(multiplier->unit_exponent != 0)) {
1033		hid_warn(hid,
1034			 "unsupported Resolution Multiplier unit exponent %d\n",
1035			 multiplier->unit_exponent);
1036	}
1037
1038	/* There are no devices with an effective multiplier > 255 */
1039	if (unlikely(m == 0 || m > 255 || m < -255)) {
1040		hid_warn(hid, "unsupported Resolution Multiplier %d\n", m);
1041		m = 1;
1042	}
1043
1044	return m;
1045}
1046
1047static void hid_apply_multiplier_to_field(struct hid_device *hid,
1048					  struct hid_field *field,
1049					  struct hid_collection *multiplier_collection,
1050					  int effective_multiplier)
1051{
1052	struct hid_collection *collection;
1053	struct hid_usage *usage;
1054	int i;
1055
1056	/*
1057	 * If multiplier_collection is NULL, the multiplier applies
1058	 * to all fields in the report.
1059	 * Otherwise, it is the Logical Collection the multiplier applies to
1060	 * but our field may be in a subcollection of that collection.
1061	 */
1062	for (i = 0; i < field->maxusage; i++) {
1063		usage = &field->usage[i];
1064
1065		collection = &hid->collection[usage->collection_index];
1066		while (collection->parent_idx != -1 &&
1067		       collection != multiplier_collection)
1068			collection = &hid->collection[collection->parent_idx];
1069
1070		if (collection->parent_idx != -1 ||
1071		    multiplier_collection == NULL)
1072			usage->resolution_multiplier = effective_multiplier;
1073
1074	}
1075}
1076
1077static void hid_apply_multiplier(struct hid_device *hid,
1078				 struct hid_field *multiplier)
1079{
1080	struct hid_report_enum *rep_enum;
1081	struct hid_report *rep;
1082	struct hid_field *field;
1083	struct hid_collection *multiplier_collection;
1084	int effective_multiplier;
1085	int i;
1086
1087	/*
1088	 * "The Resolution Multiplier control must be contained in the same
1089	 * Logical Collection as the control(s) to which it is to be applied.
1090	 * If no Resolution Multiplier is defined, then the Resolution
1091	 * Multiplier defaults to 1.  If more than one control exists in a
1092	 * Logical Collection, the Resolution Multiplier is associated with
1093	 * all controls in the collection. If no Logical Collection is
1094	 * defined, the Resolution Multiplier is associated with all
1095	 * controls in the report."
1096	 * HID Usage Table, v1.12, Section 4.3.1, p30
1097	 *
1098	 * Thus, search from the current collection upwards until we find a
1099	 * logical collection. Then search all fields for that same parent
1100	 * collection. Those are the fields the multiplier applies to.
1101	 *
1102	 * If we have more than one multiplier, it will overwrite the
1103	 * applicable fields later.
1104	 */
1105	multiplier_collection = &hid->collection[multiplier->usage->collection_index];
1106	while (multiplier_collection->parent_idx != -1 &&
1107	       multiplier_collection->type != HID_COLLECTION_LOGICAL)
1108		multiplier_collection = &hid->collection[multiplier_collection->parent_idx];
1109
1110	effective_multiplier = hid_calculate_multiplier(hid, multiplier);
1111
1112	rep_enum = &hid->report_enum[HID_INPUT_REPORT];
1113	list_for_each_entry(rep, &rep_enum->report_list, list) {
1114		for (i = 0; i < rep->maxfield; i++) {
1115			field = rep->field[i];
1116			hid_apply_multiplier_to_field(hid, field,
1117						      multiplier_collection,
1118						      effective_multiplier);
1119		}
1120	}
1121}
1122
1123/*
1124 * hid_setup_resolution_multiplier - set up all resolution multipliers
1125 *
1126 * @device: hid device
1127 *
1128 * Search for all Resolution Multiplier Feature Reports and apply their
1129 * value to all matching Input items. This only updates the internal struct
1130 * fields.
1131 *
1132 * The Resolution Multiplier is applied by the hardware. If the multiplier
1133 * is anything other than 1, the hardware will send pre-multiplied events
1134 * so that the same physical interaction generates an accumulated
1135 *	accumulated_value = value * * multiplier
1136 * This may be achieved by sending
1137 * - "value * multiplier" for each event, or
1138 * - "value" but "multiplier" times as frequently, or
1139 * - a combination of the above
1140 * The only guarantee is that the same physical interaction always generates
1141 * an accumulated 'value * multiplier'.
1142 *
1143 * This function must be called before any event processing and after
1144 * any SetRequest to the Resolution Multiplier.
1145 */
1146void hid_setup_resolution_multiplier(struct hid_device *hid)
1147{
1148	struct hid_report_enum *rep_enum;
1149	struct hid_report *rep;
1150	struct hid_usage *usage;
1151	int i, j;
1152
1153	rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
1154	list_for_each_entry(rep, &rep_enum->report_list, list) {
1155		for (i = 0; i < rep->maxfield; i++) {
1156			/* Ignore if report count is out of bounds. */
1157			if (rep->field[i]->report_count < 1)
1158				continue;
1159
1160			for (j = 0; j < rep->field[i]->maxusage; j++) {
1161				usage = &rep->field[i]->usage[j];
1162				if (usage->hid == HID_GD_RESOLUTION_MULTIPLIER)
1163					hid_apply_multiplier(hid,
1164							     rep->field[i]);
1165			}
1166		}
1167	}
1168}
1169EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier);
1170
1171/**
1172 * hid_open_report - open a driver-specific device report
1173 *
1174 * @device: hid device
1175 *
1176 * Parse a report description into a hid_device structure. Reports are
1177 * enumerated, fields are attached to these reports.
1178 * 0 returned on success, otherwise nonzero error value.
1179 *
1180 * This function (or the equivalent hid_parse() macro) should only be
1181 * called from probe() in drivers, before starting the device.
1182 */
1183int hid_open_report(struct hid_device *device)
1184{
1185	struct hid_parser *parser;
1186	struct hid_item item;
1187	unsigned int size;
1188	__u8 *start;
1189	__u8 *buf;
1190	__u8 *end;
1191	__u8 *next;
1192	int ret;
1193	static int (*dispatch_type[])(struct hid_parser *parser,
1194				      struct hid_item *item) = {
1195		hid_parser_main,
1196		hid_parser_global,
1197		hid_parser_local,
1198		hid_parser_reserved
1199	};
1200
1201	if (WARN_ON(device->status & HID_STAT_PARSED))
1202		return -EBUSY;
1203
1204	start = device->dev_rdesc;
1205	if (WARN_ON(!start))
1206		return -ENODEV;
1207	size = device->dev_rsize;
1208
1209	buf = kmemdup(start, size, GFP_KERNEL);
1210	if (buf == NULL)
1211		return -ENOMEM;
1212
1213	if (device->driver->report_fixup)
1214		start = device->driver->report_fixup(device, buf, &size);
1215	else
1216		start = buf;
1217
1218	start = kmemdup(start, size, GFP_KERNEL);
1219	kfree(buf);
1220	if (start == NULL)
1221		return -ENOMEM;
1222
1223	device->rdesc = start;
1224	device->rsize = size;
1225
1226	parser = vzalloc(sizeof(struct hid_parser));
1227	if (!parser) {
1228		ret = -ENOMEM;
1229		goto alloc_err;
1230	}
1231
1232	parser->device = device;
1233
1234	end = start + size;
1235
1236	device->collection = kcalloc(HID_DEFAULT_NUM_COLLECTIONS,
1237				     sizeof(struct hid_collection), GFP_KERNEL);
1238	if (!device->collection) {
1239		ret = -ENOMEM;
1240		goto err;
1241	}
1242	device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
1243
1244	ret = -EINVAL;
1245	while ((next = fetch_item(start, end, &item)) != NULL) {
1246		start = next;
1247
1248		if (item.format != HID_ITEM_FORMAT_SHORT) {
1249			hid_err(device, "unexpected long global item\n");
1250			goto err;
1251		}
1252
1253		if (dispatch_type[item.type](parser, &item)) {
1254			hid_err(device, "item %u %u %u %u parsing failed\n",
1255				item.format, (unsigned)item.size,
1256				(unsigned)item.type, (unsigned)item.tag);
1257			goto err;
1258		}
1259
1260		if (start == end) {
1261			if (parser->collection_stack_ptr) {
1262				hid_err(device, "unbalanced collection at end of report description\n");
1263				goto err;
1264			}
1265			if (parser->local.delimiter_depth) {
1266				hid_err(device, "unbalanced delimiter at end of report description\n");
1267				goto err;
1268			}
1269
1270			/*
1271			 * fetch initial values in case the device's
1272			 * default multiplier isn't the recommended 1
1273			 */
1274			hid_setup_resolution_multiplier(device);
1275
1276			kfree(parser->collection_stack);
1277			vfree(parser);
1278			device->status |= HID_STAT_PARSED;
1279
1280			return 0;
1281		}
1282	}
1283
1284	hid_err(device, "item fetching failed at offset %u/%u\n",
1285		size - (unsigned int)(end - start), size);
1286err:
1287	kfree(parser->collection_stack);
1288alloc_err:
1289	vfree(parser);
1290	hid_close_report(device);
1291	return ret;
1292}
1293EXPORT_SYMBOL_GPL(hid_open_report);
1294
1295/*
1296 * Convert a signed n-bit integer to signed 32-bit integer. Common
1297 * cases are done through the compiler, the screwed things has to be
1298 * done by hand.
1299 */
1300
1301static s32 snto32(__u32 value, unsigned n)
1302{
1303	switch (n) {
1304	case 8:  return ((__s8)value);
1305	case 16: return ((__s16)value);
1306	case 32: return ((__s32)value);
1307	}
1308	return value & (1 << (n - 1)) ? value | (~0U << n) : value;
1309}
1310
1311s32 hid_snto32(__u32 value, unsigned n)
1312{
1313	return snto32(value, n);
1314}
1315EXPORT_SYMBOL_GPL(hid_snto32);
1316
1317/*
1318 * Convert a signed 32-bit integer to a signed n-bit integer.
1319 */
1320
1321static u32 s32ton(__s32 value, unsigned n)
1322{
1323	s32 a = value >> (n - 1);
1324	if (a && a != -1)
1325		return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
1326	return value & ((1 << n) - 1);
1327}
1328
1329/*
1330 * Extract/implement a data field from/to a little endian report (bit array).
1331 *
1332 * Code sort-of follows HID spec:
1333 *     http://www.usb.org/developers/hidpage/HID1_11.pdf
1334 *
1335 * While the USB HID spec allows unlimited length bit fields in "report
1336 * descriptors", most devices never use more than 16 bits.
1337 * One model of UPS is claimed to report "LINEV" as a 32-bit field.
1338 * Search linux-kernel and linux-usb-devel archives for "hid-core extract".
1339 */
1340
1341static u32 __extract(u8 *report, unsigned offset, int n)
1342{
1343	unsigned int idx = offset / 8;
1344	unsigned int bit_nr = 0;
1345	unsigned int bit_shift = offset % 8;
1346	int bits_to_copy = 8 - bit_shift;
1347	u32 value = 0;
1348	u32 mask = n < 32 ? (1U << n) - 1 : ~0U;
1349
1350	while (n > 0) {
1351		value |= ((u32)report[idx] >> bit_shift) << bit_nr;
1352		n -= bits_to_copy;
1353		bit_nr += bits_to_copy;
1354		bits_to_copy = 8;
1355		bit_shift = 0;
1356		idx++;
1357	}
1358
1359	return value & mask;
1360}
1361
1362u32 hid_field_extract(const struct hid_device *hid, u8 *report,
1363			unsigned offset, unsigned n)
1364{
1365	if (n > 32) {
1366		hid_warn_once(hid, "%s() called with n (%d) > 32! (%s)\n",
1367			      __func__, n, current->comm);
1368		n = 32;
1369	}
1370
1371	return __extract(report, offset, n);
1372}
1373EXPORT_SYMBOL_GPL(hid_field_extract);
1374
1375/*
1376 * "implement" : set bits in a little endian bit stream.
1377 * Same concepts as "extract" (see comments above).
1378 * The data mangled in the bit stream remains in little endian
1379 * order the whole time. It make more sense to talk about
1380 * endianness of register values by considering a register
1381 * a "cached" copy of the little endian bit stream.
1382 */
1383
1384static void __implement(u8 *report, unsigned offset, int n, u32 value)
1385{
1386	unsigned int idx = offset / 8;
1387	unsigned int bit_shift = offset % 8;
1388	int bits_to_set = 8 - bit_shift;
1389
1390	while (n - bits_to_set >= 0) {
1391		report[idx] &= ~(0xff << bit_shift);
1392		report[idx] |= value << bit_shift;
1393		value >>= bits_to_set;
1394		n -= bits_to_set;
1395		bits_to_set = 8;
1396		bit_shift = 0;
1397		idx++;
1398	}
1399
1400	/* last nibble */
1401	if (n) {
1402		u8 bit_mask = ((1U << n) - 1);
1403		report[idx] &= ~(bit_mask << bit_shift);
1404		report[idx] |= value << bit_shift;
1405	}
1406}
1407
1408static void implement(const struct hid_device *hid, u8 *report,
1409		      unsigned offset, unsigned n, u32 value)
1410{
1411	if (unlikely(n > 32)) {
1412		hid_warn(hid, "%s() called with n (%d) > 32! (%s)\n",
1413			 __func__, n, current->comm);
1414		n = 32;
1415	} else if (n < 32) {
1416		u32 m = (1U << n) - 1;
1417
1418		if (unlikely(value > m)) {
1419			hid_warn(hid,
1420				 "%s() called with too large value %d (n: %d)! (%s)\n",
1421				 __func__, value, n, current->comm);
1422			WARN_ON(1);
1423			value &= m;
1424		}
1425	}
1426
1427	__implement(report, offset, n, value);
1428}
1429
1430/*
1431 * Search an array for a value.
1432 */
1433
1434static int search(__s32 *array, __s32 value, unsigned n)
1435{
1436	while (n--) {
1437		if (*array++ == value)
1438			return 0;
1439	}
1440	return -1;
1441}
1442
1443/**
1444 * hid_match_report - check if driver's raw_event should be called
1445 *
1446 * @hid: hid device
1447 * @report_type: type to match against
1448 *
1449 * compare hid->driver->report_table->report_type to report->type
1450 */
1451static int hid_match_report(struct hid_device *hid, struct hid_report *report)
1452{
1453	const struct hid_report_id *id = hid->driver->report_table;
1454
1455	if (!id) /* NULL means all */
1456		return 1;
1457
1458	for (; id->report_type != HID_TERMINATOR; id++)
1459		if (id->report_type == HID_ANY_ID ||
1460				id->report_type == report->type)
1461			return 1;
1462	return 0;
1463}
1464
1465/**
1466 * hid_match_usage - check if driver's event should be called
1467 *
1468 * @hid: hid device
1469 * @usage: usage to match against
1470 *
1471 * compare hid->driver->usage_table->usage_{type,code} to
1472 * usage->usage_{type,code}
1473 */
1474static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage)
1475{
1476	const struct hid_usage_id *id = hid->driver->usage_table;
1477
1478	if (!id) /* NULL means all */
1479		return 1;
1480
1481	for (; id->usage_type != HID_ANY_ID - 1; id++)
1482		if ((id->usage_hid == HID_ANY_ID ||
1483				id->usage_hid == usage->hid) &&
1484				(id->usage_type == HID_ANY_ID ||
1485				id->usage_type == usage->type) &&
1486				(id->usage_code == HID_ANY_ID ||
1487				 id->usage_code == usage->code))
1488			return 1;
1489	return 0;
1490}
1491
1492static void hid_process_event(struct hid_device *hid, struct hid_field *field,
1493		struct hid_usage *usage, __s32 value, int interrupt)
1494{
1495	struct hid_driver *hdrv = hid->driver;
1496	int ret;
1497
1498	if (!list_empty(&hid->debug_list))
1499		hid_dump_input(hid, usage, value);
1500
1501	if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
1502		ret = hdrv->event(hid, field, usage, value);
1503		if (ret != 0) {
1504			if (ret < 0)
1505				hid_err(hid, "%s's event failed with %d\n",
1506						hdrv->name, ret);
1507			return;
1508		}
1509	}
1510
1511	if (hid->claimed & HID_CLAIMED_INPUT)
1512		hidinput_hid_event(hid, field, usage, value);
1513	if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
1514		hid->hiddev_hid_event(hid, field, usage, value);
1515}
1516
1517/*
1518 * Analyse a received field, and fetch the data from it. The field
1519 * content is stored for next report processing (we do differential
1520 * reporting to the layer).
1521 */
1522
1523static void hid_input_field(struct hid_device *hid, struct hid_field *field,
1524			    __u8 *data, int interrupt)
1525{
1526	unsigned n;
1527	unsigned count = field->report_count;
1528	unsigned offset = field->report_offset;
1529	unsigned size = field->report_size;
1530	__s32 min = field->logical_minimum;
1531	__s32 max = field->logical_maximum;
1532	__s32 *value;
1533
1534	value = kmalloc_array(count, sizeof(__s32), GFP_ATOMIC);
1535	if (!value)
1536		return;
1537
1538	for (n = 0; n < count; n++) {
1539
1540		value[n] = min < 0 ?
1541			snto32(hid_field_extract(hid, data, offset + n * size,
1542			       size), size) :
1543			hid_field_extract(hid, data, offset + n * size, size);
1544
1545		/* Ignore report if ErrorRollOver */
1546		if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
1547		    value[n] >= min && value[n] <= max &&
1548		    value[n] - min < field->maxusage &&
1549		    field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1)
1550			goto exit;
1551	}
1552
1553	for (n = 0; n < count; n++) {
1554
1555		if (HID_MAIN_ITEM_VARIABLE & field->flags) {
1556			hid_process_event(hid, field, &field->usage[n], value[n], interrupt);
1557			continue;
1558		}
1559
1560		if (field->value[n] >= min && field->value[n] <= max
1561			&& field->value[n] - min < field->maxusage
1562			&& field->usage[field->value[n] - min].hid
1563			&& search(value, field->value[n], count))
1564				hid_process_event(hid, field, &field->usage[field->value[n] - min], 0, interrupt);
1565
1566		if (value[n] >= min && value[n] <= max
1567			&& value[n] - min < field->maxusage
1568			&& field->usage[value[n] - min].hid
1569			&& search(field->value, value[n], count))
1570				hid_process_event(hid, field, &field->usage[value[n] - min], 1, interrupt);
1571	}
1572
1573	memcpy(field->value, value, count * sizeof(__s32));
1574exit:
1575	kfree(value);
1576}
1577
1578/*
1579 * Output the field into the report.
1580 */
1581
1582static void hid_output_field(const struct hid_device *hid,
1583			     struct hid_field *field, __u8 *data)
1584{
1585	unsigned count = field->report_count;
1586	unsigned offset = field->report_offset;
1587	unsigned size = field->report_size;
1588	unsigned n;
1589
1590	for (n = 0; n < count; n++) {
1591		if (field->logical_minimum < 0)	/* signed values */
1592			implement(hid, data, offset + n * size, size,
1593				  s32ton(field->value[n], size));
1594		else				/* unsigned values */
1595			implement(hid, data, offset + n * size, size,
1596				  field->value[n]);
1597	}
1598}
1599
1600/*
1601 * Compute the size of a report.
1602 */
1603static size_t hid_compute_report_size(struct hid_report *report)
1604{
1605	if (report->size)
1606		return ((report->size - 1) >> 3) + 1;
1607
1608	return 0;
1609}
1610
1611/*
1612 * Create a report. 'data' has to be allocated using
1613 * hid_alloc_report_buf() so that it has proper size.
1614 */
1615
1616void hid_output_report(struct hid_report *report, __u8 *data)
1617{
1618	unsigned n;
1619
1620	if (report->id > 0)
1621		*data++ = report->id;
1622
1623	memset(data, 0, hid_compute_report_size(report));
1624	for (n = 0; n < report->maxfield; n++)
1625		hid_output_field(report->device, report->field[n], data);
1626}
1627EXPORT_SYMBOL_GPL(hid_output_report);
1628
1629/*
1630 * Allocator for buffer that is going to be passed to hid_output_report()
1631 */
1632u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
1633{
1634	/*
1635	 * 7 extra bytes are necessary to achieve proper functionality
1636	 * of implement() working on 8 byte chunks
1637	 */
1638
1639	u32 len = hid_report_len(report) + 7;
1640
1641	return kmalloc(len, flags);
1642}
1643EXPORT_SYMBOL_GPL(hid_alloc_report_buf);
1644
1645/*
1646 * Set a field value. The report this field belongs to has to be
1647 * created and transferred to the device, to set this value in the
1648 * device.
1649 */
1650
1651int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
1652{
1653	unsigned size;
1654
1655	if (!field)
1656		return -1;
1657
1658	size = field->report_size;
1659
1660	hid_dump_input(field->report->device, field->usage + offset, value);
1661
1662	if (offset >= field->report_count) {
1663		hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n",
1664				offset, field->report_count);
1665		return -1;
1666	}
1667	if (field->logical_minimum < 0) {
1668		if (value != snto32(s32ton(value, size), size)) {
1669			hid_err(field->report->device, "value %d is out of range\n", value);
1670			return -1;
1671		}
1672	}
1673	field->value[offset] = value;
1674	return 0;
1675}
1676EXPORT_SYMBOL_GPL(hid_set_field);
1677
1678static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
1679		const u8 *data)
1680{
1681	struct hid_report *report;
1682	unsigned int n = 0;	/* Normally report number is 0 */
1683
1684	/* Device uses numbered reports, data[0] is report number */
1685	if (report_enum->numbered)
1686		n = *data;
1687
1688	report = report_enum->report_id_hash[n];
1689	if (report == NULL)
1690		dbg_hid("undefined report_id %u received\n", n);
1691
1692	return report;
1693}
1694
1695/*
1696 * Implement a generic .request() callback, using .raw_request()
1697 * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
1698 */
1699int __hid_request(struct hid_device *hid, struct hid_report *report,
1700		int reqtype)
1701{
1702	char *buf;
1703	int ret;
1704	u32 len;
1705
1706	buf = hid_alloc_report_buf(report, GFP_KERNEL);
1707	if (!buf)
1708		return -ENOMEM;
1709
1710	len = hid_report_len(report);
1711
1712	if (reqtype == HID_REQ_SET_REPORT)
1713		hid_output_report(report, buf);
1714
1715	ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
1716					  report->type, reqtype);
1717	if (ret < 0) {
1718		dbg_hid("unable to complete request: %d\n", ret);
1719		goto out;
1720	}
1721
1722	if (reqtype == HID_REQ_GET_REPORT)
1723		hid_input_report(hid, report->type, buf, ret, 0);
1724
1725	ret = 0;
1726
1727out:
1728	kfree(buf);
1729	return ret;
1730}
1731EXPORT_SYMBOL_GPL(__hid_request);
1732
1733int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, u32 size,
1734		int interrupt)
1735{
1736	struct hid_report_enum *report_enum = hid->report_enum + type;
1737	struct hid_report *report;
1738	struct hid_driver *hdrv;
1739	unsigned int a;
1740	u32 rsize, csize = size;
1741	u8 *cdata = data;
1742	int ret = 0;
1743
1744	report = hid_get_report(report_enum, data);
1745	if (!report)
1746		goto out;
1747
1748	if (report_enum->numbered) {
1749		cdata++;
1750		csize--;
1751	}
1752
1753	rsize = hid_compute_report_size(report);
1754
1755	if (report_enum->numbered && rsize >= HID_MAX_BUFFER_SIZE)
1756		rsize = HID_MAX_BUFFER_SIZE - 1;
1757	else if (rsize > HID_MAX_BUFFER_SIZE)
1758		rsize = HID_MAX_BUFFER_SIZE;
1759
1760	if (csize < rsize) {
1761		dbg_hid("report %d is too short, (%d < %d)\n", report->id,
1762				csize, rsize);
1763		memset(cdata + csize, 0, rsize - csize);
1764	}
1765
1766	if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
1767		hid->hiddev_report_event(hid, report);
1768	if (hid->claimed & HID_CLAIMED_HIDRAW) {
1769		ret = hidraw_report_event(hid, data, size);
1770		if (ret)
1771			goto out;
1772	}
1773
1774	if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
1775		for (a = 0; a < report->maxfield; a++)
1776			hid_input_field(hid, report->field[a], cdata, interrupt);
1777		hdrv = hid->driver;
1778		if (hdrv && hdrv->report)
1779			hdrv->report(hid, report);
1780	}
1781
1782	if (hid->claimed & HID_CLAIMED_INPUT)
1783		hidinput_report_event(hid, report);
1784out:
1785	return ret;
1786}
1787EXPORT_SYMBOL_GPL(hid_report_raw_event);
1788
1789/**
1790 * hid_input_report - report data from lower layer (usb, bt...)
1791 *
1792 * @hid: hid device
1793 * @type: HID report type (HID_*_REPORT)
1794 * @data: report contents
1795 * @size: size of data parameter
1796 * @interrupt: distinguish between interrupt and control transfers
1797 *
1798 * This is data entry for lower layers.
1799 */
1800int hid_input_report(struct hid_device *hid, int type, u8 *data, u32 size, int interrupt)
1801{
1802	struct hid_report_enum *report_enum;
1803	struct hid_driver *hdrv;
1804	struct hid_report *report;
1805	int ret = 0;
1806
1807	if (!hid)
1808		return -ENODEV;
1809
1810	if (down_trylock(&hid->driver_input_lock))
1811		return -EBUSY;
1812
1813	if (!hid->driver) {
1814		ret = -ENODEV;
1815		goto unlock;
1816	}
1817	report_enum = hid->report_enum + type;
1818	hdrv = hid->driver;
1819
1820	if (!size) {
1821		dbg_hid("empty report\n");
1822		ret = -1;
1823		goto unlock;
1824	}
1825
1826	/* Avoid unnecessary overhead if debugfs is disabled */
1827	if (!list_empty(&hid->debug_list))
1828		hid_dump_report(hid, type, data, size);
1829
1830	report = hid_get_report(report_enum, data);
1831
1832	if (!report) {
1833		ret = -1;
1834		goto unlock;
1835	}
1836
1837	if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
1838		ret = hdrv->raw_event(hid, report, data, size);
1839		if (ret < 0)
1840			goto unlock;
1841	}
1842
1843	ret = hid_report_raw_event(hid, type, data, size, interrupt);
1844
1845unlock:
1846	up(&hid->driver_input_lock);
1847	return ret;
1848}
1849EXPORT_SYMBOL_GPL(hid_input_report);
1850
1851bool hid_match_one_id(const struct hid_device *hdev,
1852		      const struct hid_device_id *id)
1853{
1854	return (id->bus == HID_BUS_ANY || id->bus == hdev->bus) &&
1855		(id->group == HID_GROUP_ANY || id->group == hdev->group) &&
1856		(id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&
1857		(id->product == HID_ANY_ID || id->product == hdev->product);
1858}
1859
1860const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
1861		const struct hid_device_id *id)
1862{
1863	for (; id->bus; id++)
1864		if (hid_match_one_id(hdev, id))
1865			return id;
1866
1867	return NULL;
1868}
1869
1870static const struct hid_device_id hid_hiddev_list[] = {
1871	{ HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS) },
1872	{ HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS1) },
1873	{ }
1874};
1875
1876static bool hid_hiddev(struct hid_device *hdev)
1877{
1878	return !!hid_match_id(hdev, hid_hiddev_list);
1879}
1880
1881
1882static ssize_t
1883read_report_descriptor(struct file *filp, struct kobject *kobj,
1884		struct bin_attribute *attr,
1885		char *buf, loff_t off, size_t count)
1886{
1887	struct device *dev = kobj_to_dev(kobj);
1888	struct hid_device *hdev = to_hid_device(dev);
1889
1890	if (off >= hdev->rsize)
1891		return 0;
1892
1893	if (off + count > hdev->rsize)
1894		count = hdev->rsize - off;
1895
1896	memcpy(buf, hdev->rdesc + off, count);
1897
1898	return count;
1899}
1900
1901static ssize_t
1902show_country(struct device *dev, struct device_attribute *attr,
1903		char *buf)
1904{
1905	struct hid_device *hdev = to_hid_device(dev);
1906
1907	return sprintf(buf, "%02x\n", hdev->country & 0xff);
1908}
1909
1910static struct bin_attribute dev_bin_attr_report_desc = {
1911	.attr = { .name = "report_descriptor", .mode = 0444 },
1912	.read = read_report_descriptor,
1913	.size = HID_MAX_DESCRIPTOR_SIZE,
1914};
1915
1916static const struct device_attribute dev_attr_country = {
1917	.attr = { .name = "country", .mode = 0444 },
1918	.show = show_country,
1919};
1920
1921int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
1922{
1923	static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
1924		"Joystick", "Gamepad", "Keyboard", "Keypad",
1925		"Multi-Axis Controller"
1926	};
1927	const char *type, *bus;
1928	char buf[64] = "";
1929	unsigned int i;
1930	int len;
1931	int ret;
1932
1933	if (hdev->quirks & HID_QUIRK_HIDDEV_FORCE)
1934		connect_mask |= (HID_CONNECT_HIDDEV_FORCE | HID_CONNECT_HIDDEV);
1935	if (hdev->quirks & HID_QUIRK_HIDINPUT_FORCE)
1936		connect_mask |= HID_CONNECT_HIDINPUT_FORCE;
1937	if (hdev->bus != BUS_USB)
1938		connect_mask &= ~HID_CONNECT_HIDDEV;
1939	if (hid_hiddev(hdev))
1940		connect_mask |= HID_CONNECT_HIDDEV_FORCE;
1941
1942	if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,
1943				connect_mask & HID_CONNECT_HIDINPUT_FORCE))
1944		hdev->claimed |= HID_CLAIMED_INPUT;
1945
1946	if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect &&
1947			!hdev->hiddev_connect(hdev,
1948				connect_mask & HID_CONNECT_HIDDEV_FORCE))
1949		hdev->claimed |= HID_CLAIMED_HIDDEV;
1950	if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))
1951		hdev->claimed |= HID_CLAIMED_HIDRAW;
1952
1953	if (connect_mask & HID_CONNECT_DRIVER)
1954		hdev->claimed |= HID_CLAIMED_DRIVER;
1955
1956	/* Drivers with the ->raw_event callback set are not required to connect
1957	 * to any other listener. */
1958	if (!hdev->claimed && !hdev->driver->raw_event) {
1959		hid_err(hdev, "device has no listeners, quitting\n");
1960		return -ENODEV;
1961	}
1962
1963	if ((hdev->claimed & HID_CLAIMED_INPUT) &&
1964			(connect_mask & HID_CONNECT_FF) && hdev->ff_init)
1965		hdev->ff_init(hdev);
1966
1967	len = 0;
1968	if (hdev->claimed & HID_CLAIMED_INPUT)
1969		len += sprintf(buf + len, "input");
1970	if (hdev->claimed & HID_CLAIMED_HIDDEV)
1971		len += sprintf(buf + len, "%shiddev%d", len ? "," : "",
1972				((struct hiddev *)hdev->hiddev)->minor);
1973	if (hdev->claimed & HID_CLAIMED_HIDRAW)
1974		len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
1975				((struct hidraw *)hdev->hidraw)->minor);
1976
1977	type = "Device";
1978	for (i = 0; i < hdev->maxcollection; i++) {
1979		struct hid_collection *col = &hdev->collection[i];
1980		if (col->type == HID_COLLECTION_APPLICATION &&
1981		   (col->usage & HID_USAGE_PAGE) == HID_UP_GENDESK &&
1982		   (col->usage & 0xffff) < ARRAY_SIZE(types)) {
1983			type = types[col->usage & 0xffff];
1984			break;
1985		}
1986	}
1987
1988	switch (hdev->bus) {
1989	case BUS_USB:
1990		bus = "USB";
1991		break;
1992	case BUS_BLUETOOTH:
1993		bus = "BLUETOOTH";
1994		break;
1995	case BUS_I2C:
1996		bus = "I2C";
1997		break;
1998	default:
1999		bus = "<UNKNOWN>";
2000	}
2001
2002	ret = device_create_file(&hdev->dev, &dev_attr_country);
2003	if (ret)
2004		hid_warn(hdev,
2005			 "can't create sysfs country code attribute err: %d\n", ret);
2006
2007	hid_info(hdev, "%s: %s HID v%x.%02x %s [%s] on %s\n",
2008		 buf, bus, hdev->version >> 8, hdev->version & 0xff,
2009		 type, hdev->name, hdev->phys);
2010
2011	return 0;
2012}
2013EXPORT_SYMBOL_GPL(hid_connect);
2014
2015void hid_disconnect(struct hid_device *hdev)
2016{
2017	device_remove_file(&hdev->dev, &dev_attr_country);
2018	if (hdev->claimed & HID_CLAIMED_INPUT)
2019		hidinput_disconnect(hdev);
2020	if (hdev->claimed & HID_CLAIMED_HIDDEV)
2021		hdev->hiddev_disconnect(hdev);
2022	if (hdev->claimed & HID_CLAIMED_HIDRAW)
2023		hidraw_disconnect(hdev);
2024	hdev->claimed = 0;
2025}
2026EXPORT_SYMBOL_GPL(hid_disconnect);
2027
2028/**
2029 * hid_hw_start - start underlying HW
2030 * @hdev: hid device
2031 * @connect_mask: which outputs to connect, see HID_CONNECT_*
2032 *
2033 * Call this in probe function *after* hid_parse. This will setup HW
2034 * buffers and start the device (if not defeirred to device open).
2035 * hid_hw_stop must be called if this was successful.
2036 */
2037int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask)
2038{
2039	int error;
2040
2041	error = hdev->ll_driver->start(hdev);
2042	if (error)
2043		return error;
2044
2045	if (connect_mask) {
2046		error = hid_connect(hdev, connect_mask);
2047		if (error) {
2048			hdev->ll_driver->stop(hdev);
2049			return error;
2050		}
2051	}
2052
2053	return 0;
2054}
2055EXPORT_SYMBOL_GPL(hid_hw_start);
2056
2057/**
2058 * hid_hw_stop - stop underlying HW
2059 * @hdev: hid device
2060 *
2061 * This is usually called from remove function or from probe when something
2062 * failed and hid_hw_start was called already.
2063 */
2064void hid_hw_stop(struct hid_device *hdev)
2065{
2066	hid_disconnect(hdev);
2067	hdev->ll_driver->stop(hdev);
2068}
2069EXPORT_SYMBOL_GPL(hid_hw_stop);
2070
2071/**
2072 * hid_hw_open - signal underlying HW to start delivering events
2073 * @hdev: hid device
2074 *
2075 * Tell underlying HW to start delivering events from the device.
2076 * This function should be called sometime after successful call
2077 * to hid_hw_start().
2078 */
2079int hid_hw_open(struct hid_device *hdev)
2080{
2081	int ret;
2082
2083	ret = mutex_lock_killable(&hdev->ll_open_lock);
2084	if (ret)
2085		return ret;
2086
2087	if (!hdev->ll_open_count++) {
2088		ret = hdev->ll_driver->open(hdev);
2089		if (ret)
2090			hdev->ll_open_count--;
2091	}
2092
2093	mutex_unlock(&hdev->ll_open_lock);
2094	return ret;
2095}
2096EXPORT_SYMBOL_GPL(hid_hw_open);
2097
2098/**
2099 * hid_hw_close - signal underlaying HW to stop delivering events
2100 *
2101 * @hdev: hid device
2102 *
2103 * This function indicates that we are not interested in the events
2104 * from this device anymore. Delivery of events may or may not stop,
2105 * depending on the number of users still outstanding.
2106 */
2107void hid_hw_close(struct hid_device *hdev)
2108{
2109	mutex_lock(&hdev->ll_open_lock);
2110	if (!--hdev->ll_open_count)
2111		hdev->ll_driver->close(hdev);
2112	mutex_unlock(&hdev->ll_open_lock);
2113}
2114EXPORT_SYMBOL_GPL(hid_hw_close);
2115
2116struct hid_dynid {
2117	struct list_head list;
2118	struct hid_device_id id;
2119};
2120
2121/**
2122 * store_new_id - add a new HID device ID to this driver and re-probe devices
2123 * @driver: target device driver
2124 * @buf: buffer for scanning device ID data
2125 * @count: input size
2126 *
2127 * Adds a new dynamic hid device ID to this driver,
2128 * and causes the driver to probe for all devices again.
2129 */
2130static ssize_t new_id_store(struct device_driver *drv, const char *buf,
2131		size_t count)
2132{
2133	struct hid_driver *hdrv = to_hid_driver(drv);
2134	struct hid_dynid *dynid;
2135	__u32 bus, vendor, product;
2136	unsigned long driver_data = 0;
2137	int ret;
2138
2139	ret = sscanf(buf, "%x %x %x %lx",
2140			&bus, &vendor, &product, &driver_data);
2141	if (ret < 3)
2142		return -EINVAL;
2143
2144	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
2145	if (!dynid)
2146		return -ENOMEM;
2147
2148	dynid->id.bus = bus;
2149	dynid->id.group = HID_GROUP_ANY;
2150	dynid->id.vendor = vendor;
2151	dynid->id.product = product;
2152	dynid->id.driver_data = driver_data;
2153
2154	spin_lock(&hdrv->dyn_lock);
2155	list_add_tail(&dynid->list, &hdrv->dyn_list);
2156	spin_unlock(&hdrv->dyn_lock);
2157
2158	ret = driver_attach(&hdrv->driver);
2159
2160	return ret ? : count;
2161}
2162static DRIVER_ATTR_WO(new_id);
2163
2164static struct attribute *hid_drv_attrs[] = {
2165	&driver_attr_new_id.attr,
2166	NULL,
2167};
2168ATTRIBUTE_GROUPS(hid_drv);
2169
2170static void hid_free_dynids(struct hid_driver *hdrv)
2171{
2172	struct hid_dynid *dynid, *n;
2173
2174	spin_lock(&hdrv->dyn_lock);
2175	list_for_each_entry_safe(dynid, n, &hdrv->dyn_list, list) {
2176		list_del(&dynid->list);
2177		kfree(dynid);
2178	}
2179	spin_unlock(&hdrv->dyn_lock);
2180}
2181
2182const struct hid_device_id *hid_match_device(struct hid_device *hdev,
2183					     struct hid_driver *hdrv)
2184{
2185	struct hid_dynid *dynid;
2186
2187	spin_lock(&hdrv->dyn_lock);
2188	list_for_each_entry(dynid, &hdrv->dyn_list, list) {
2189		if (hid_match_one_id(hdev, &dynid->id)) {
2190			spin_unlock(&hdrv->dyn_lock);
2191			return &dynid->id;
2192		}
2193	}
2194	spin_unlock(&hdrv->dyn_lock);
2195
2196	return hid_match_id(hdev, hdrv->id_table);
2197}
2198EXPORT_SYMBOL_GPL(hid_match_device);
2199
2200static int hid_bus_match(struct device *dev, struct device_driver *drv)
2201{
2202	struct hid_driver *hdrv = to_hid_driver(drv);
2203	struct hid_device *hdev = to_hid_device(dev);
2204
2205	return hid_match_device(hdev, hdrv) != NULL;
2206}
2207
2208/**
2209 * hid_compare_device_paths - check if both devices share the same path
2210 * @hdev_a: hid device
2211 * @hdev_b: hid device
2212 * @separator: char to use as separator
2213 *
2214 * Check if two devices share the same path up to the last occurrence of
2215 * the separator char. Both paths must exist (i.e., zero-length paths
2216 * don't match).
2217 */
2218bool hid_compare_device_paths(struct hid_device *hdev_a,
2219			      struct hid_device *hdev_b, char separator)
2220{
2221	int n1 = strrchr(hdev_a->phys, separator) - hdev_a->phys;
2222	int n2 = strrchr(hdev_b->phys, separator) - hdev_b->phys;
2223
2224	if (n1 != n2 || n1 <= 0 || n2 <= 0)
2225		return false;
2226
2227	return !strncmp(hdev_a->phys, hdev_b->phys, n1);
2228}
2229EXPORT_SYMBOL_GPL(hid_compare_device_paths);
2230
2231static int hid_device_probe(struct device *dev)
2232{
2233	struct hid_driver *hdrv = to_hid_driver(dev->driver);
2234	struct hid_device *hdev = to_hid_device(dev);
2235	const struct hid_device_id *id;
2236	int ret = 0;
2237
2238	if (down_interruptible(&hdev->driver_input_lock)) {
2239		ret = -EINTR;
2240		goto end;
2241	}
2242	hdev->io_started = false;
2243
2244	clear_bit(ffs(HID_STAT_REPROBED), &hdev->status);
2245
2246	if (!hdev->driver) {
2247		id = hid_match_device(hdev, hdrv);
2248		if (id == NULL) {
2249			ret = -ENODEV;
2250			goto unlock;
2251		}
2252
2253		if (hdrv->match) {
2254			if (!hdrv->match(hdev, hid_ignore_special_drivers)) {
2255				ret = -ENODEV;
2256				goto unlock;
2257			}
2258		} else {
2259			/*
2260			 * hid-generic implements .match(), so if
2261			 * hid_ignore_special_drivers is set, we can safely
2262			 * return.
2263			 */
2264			if (hid_ignore_special_drivers) {
2265				ret = -ENODEV;
2266				goto unlock;
2267			}
2268		}
2269
2270		/* reset the quirks that has been previously set */
2271		hdev->quirks = hid_lookup_quirk(hdev);
2272		hdev->driver = hdrv;
2273		if (hdrv->probe) {
2274			ret = hdrv->probe(hdev, id);
2275		} else { /* default probe */
2276			ret = hid_open_report(hdev);
2277			if (!ret)
2278				ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
2279		}
2280		if (ret) {
2281			hid_close_report(hdev);
2282			hdev->driver = NULL;
2283		}
2284	}
2285unlock:
2286	if (!hdev->io_started)
2287		up(&hdev->driver_input_lock);
2288end:
2289	return ret;
2290}
2291
2292static int hid_device_remove(struct device *dev)
2293{
2294	struct hid_device *hdev = to_hid_device(dev);
2295	struct hid_driver *hdrv;
2296	int ret = 0;
2297
2298	if (down_interruptible(&hdev->driver_input_lock)) {
2299		ret = -EINTR;
2300		goto end;
2301	}
2302	hdev->io_started = false;
2303
2304	hdrv = hdev->driver;
2305	if (hdrv) {
2306		if (hdrv->remove)
2307			hdrv->remove(hdev);
2308		else /* default remove */
2309			hid_hw_stop(hdev);
2310		hid_close_report(hdev);
2311		hdev->driver = NULL;
2312	}
2313
2314	if (!hdev->io_started)
2315		up(&hdev->driver_input_lock);
2316end:
2317	return ret;
2318}
2319
2320static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
2321			     char *buf)
2322{
2323	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
2324
2325	return scnprintf(buf, PAGE_SIZE, "hid:b%04Xg%04Xv%08Xp%08X\n",
2326			 hdev->bus, hdev->group, hdev->vendor, hdev->product);
2327}
2328static DEVICE_ATTR_RO(modalias);
2329
2330static struct attribute *hid_dev_attrs[] = {
2331	&dev_attr_modalias.attr,
2332	NULL,
2333};
2334static struct bin_attribute *hid_dev_bin_attrs[] = {
2335	&dev_bin_attr_report_desc,
2336	NULL
2337};
2338static const struct attribute_group hid_dev_group = {
2339	.attrs = hid_dev_attrs,
2340	.bin_attrs = hid_dev_bin_attrs,
2341};
2342__ATTRIBUTE_GROUPS(hid_dev);
2343
2344static int hid_uevent(struct device *dev, struct kobj_uevent_env *env)
2345{
2346	struct hid_device *hdev = to_hid_device(dev);
2347
2348	if (add_uevent_var(env, "HID_ID=%04X:%08X:%08X",
2349			hdev->bus, hdev->vendor, hdev->product))
2350		return -ENOMEM;
2351
2352	if (add_uevent_var(env, "HID_NAME=%s", hdev->name))
2353		return -ENOMEM;
2354
2355	if (add_uevent_var(env, "HID_PHYS=%s", hdev->phys))
2356		return -ENOMEM;
2357
2358	if (add_uevent_var(env, "HID_UNIQ=%s", hdev->uniq))
2359		return -ENOMEM;
2360
2361	if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",
2362			   hdev->bus, hdev->group, hdev->vendor, hdev->product))
2363		return -ENOMEM;
2364
2365	return 0;
2366}
2367
2368struct bus_type hid_bus_type = {
2369	.name		= "hid",
2370	.dev_groups	= hid_dev_groups,
2371	.drv_groups	= hid_drv_groups,
2372	.match		= hid_bus_match,
2373	.probe		= hid_device_probe,
2374	.remove		= hid_device_remove,
2375	.uevent		= hid_uevent,
2376};
2377EXPORT_SYMBOL(hid_bus_type);
2378
2379int hid_add_device(struct hid_device *hdev)
2380{
2381	static atomic_t id = ATOMIC_INIT(0);
2382	int ret;
2383
2384	if (WARN_ON(hdev->status & HID_STAT_ADDED))
2385		return -EBUSY;
2386
2387	hdev->quirks = hid_lookup_quirk(hdev);
2388
2389	/* we need to kill them here, otherwise they will stay allocated to
2390	 * wait for coming driver */
2391	if (hid_ignore(hdev))
2392		return -ENODEV;
2393
2394	/*
2395	 * Check for the mandatory transport channel.
2396	 */
2397	 if (!hdev->ll_driver->raw_request) {
2398		hid_err(hdev, "transport driver missing .raw_request()\n");
2399		return -EINVAL;
2400	 }
2401
2402	/*
2403	 * Read the device report descriptor once and use as template
2404	 * for the driver-specific modifications.
2405	 */
2406	ret = hdev->ll_driver->parse(hdev);
2407	if (ret)
2408		return ret;
2409	if (!hdev->dev_rdesc)
2410		return -ENODEV;
2411
2412	/*
2413	 * Scan generic devices for group information
2414	 */
2415	if (hid_ignore_special_drivers) {
2416		hdev->group = HID_GROUP_GENERIC;
2417	} else if (!hdev->group &&
2418		   !(hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)) {
2419		ret = hid_scan_report(hdev);
2420		if (ret)
2421			hid_warn(hdev, "bad device descriptor (%d)\n", ret);
2422	}
2423
2424	/* XXX hack, any other cleaner solution after the driver core
2425	 * is converted to allow more than 20 bytes as the device name? */
2426	dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
2427		     hdev->vendor, hdev->product, atomic_inc_return(&id));
2428
2429	hid_debug_register(hdev, dev_name(&hdev->dev));
2430	ret = device_add(&hdev->dev);
2431	if (!ret)
2432		hdev->status |= HID_STAT_ADDED;
2433	else
2434		hid_debug_unregister(hdev);
2435
2436	return ret;
2437}
2438EXPORT_SYMBOL_GPL(hid_add_device);
2439
2440/**
2441 * hid_allocate_device - allocate new hid device descriptor
2442 *
2443 * Allocate and initialize hid device, so that hid_destroy_device might be
2444 * used to free it.
2445 *
2446 * New hid_device pointer is returned on success, otherwise ERR_PTR encoded
2447 * error value.
2448 */
2449struct hid_device *hid_allocate_device(void)
2450{
2451	struct hid_device *hdev;
2452	int ret = -ENOMEM;
2453
2454	hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
2455	if (hdev == NULL)
2456		return ERR_PTR(ret);
2457
2458	device_initialize(&hdev->dev);
2459	hdev->dev.release = hid_device_release;
2460	hdev->dev.bus = &hid_bus_type;
2461	device_enable_async_suspend(&hdev->dev);
2462
2463	hid_close_report(hdev);
2464
2465	init_waitqueue_head(&hdev->debug_wait);
2466	INIT_LIST_HEAD(&hdev->debug_list);
2467	spin_lock_init(&hdev->debug_list_lock);
2468	sema_init(&hdev->driver_input_lock, 1);
2469	mutex_init(&hdev->ll_open_lock);
2470
2471	return hdev;
2472}
2473EXPORT_SYMBOL_GPL(hid_allocate_device);
2474
2475static void hid_remove_device(struct hid_device *hdev)
2476{
2477	if (hdev->status & HID_STAT_ADDED) {
2478		device_del(&hdev->dev);
2479		hid_debug_unregister(hdev);
2480		hdev->status &= ~HID_STAT_ADDED;
2481	}
2482	kfree(hdev->dev_rdesc);
2483	hdev->dev_rdesc = NULL;
2484	hdev->dev_rsize = 0;
2485}
2486
2487/**
2488 * hid_destroy_device - free previously allocated device
2489 *
2490 * @hdev: hid device
2491 *
2492 * If you allocate hid_device through hid_allocate_device, you should ever
2493 * free by this function.
2494 */
2495void hid_destroy_device(struct hid_device *hdev)
2496{
2497	hid_remove_device(hdev);
2498	put_device(&hdev->dev);
2499}
2500EXPORT_SYMBOL_GPL(hid_destroy_device);
2501
2502
2503static int __hid_bus_reprobe_drivers(struct device *dev, void *data)
2504{
2505	struct hid_driver *hdrv = data;
2506	struct hid_device *hdev = to_hid_device(dev);
2507
2508	if (hdev->driver == hdrv &&
2509	    !hdrv->match(hdev, hid_ignore_special_drivers) &&
2510	    !test_and_set_bit(ffs(HID_STAT_REPROBED), &hdev->status))
2511		return device_reprobe(dev);
2512
2513	return 0;
2514}
2515
2516static int __hid_bus_driver_added(struct device_driver *drv, void *data)
2517{
2518	struct hid_driver *hdrv = to_hid_driver(drv);
2519
2520	if (hdrv->match) {
2521		bus_for_each_dev(&hid_bus_type, NULL, hdrv,
2522				 __hid_bus_reprobe_drivers);
2523	}
2524
2525	return 0;
2526}
2527
2528static int __bus_removed_driver(struct device_driver *drv, void *data)
2529{
2530	return bus_rescan_devices(&hid_bus_type);
2531}
2532
2533int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
2534		const char *mod_name)
2535{
2536	int ret;
2537
2538	hdrv->driver.name = hdrv->name;
2539	hdrv->driver.bus = &hid_bus_type;
2540	hdrv->driver.owner = owner;
2541	hdrv->driver.mod_name = mod_name;
2542
2543	INIT_LIST_HEAD(&hdrv->dyn_list);
2544	spin_lock_init(&hdrv->dyn_lock);
2545
2546	ret = driver_register(&hdrv->driver);
2547
2548	if (ret == 0)
2549		bus_for_each_drv(&hid_bus_type, NULL, NULL,
2550				 __hid_bus_driver_added);
2551
2552	return ret;
2553}
2554EXPORT_SYMBOL_GPL(__hid_register_driver);
2555
2556void hid_unregister_driver(struct hid_driver *hdrv)
2557{
2558	driver_unregister(&hdrv->driver);
2559	hid_free_dynids(hdrv);
2560
2561	bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver);
2562}
2563EXPORT_SYMBOL_GPL(hid_unregister_driver);
2564
2565int hid_check_keys_pressed(struct hid_device *hid)
2566{
2567	struct hid_input *hidinput;
2568	int i;
2569
2570	if (!(hid->claimed & HID_CLAIMED_INPUT))
2571		return 0;
2572
2573	list_for_each_entry(hidinput, &hid->inputs, list) {
2574		for (i = 0; i < BITS_TO_LONGS(KEY_MAX); i++)
2575			if (hidinput->input->key[i])
2576				return 1;
2577	}
2578
2579	return 0;
2580}
2581
2582EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
2583
2584static int __init hid_init(void)
2585{
2586	int ret;
2587
2588	if (hid_debug)
2589		pr_warn("hid_debug is now used solely for parser and driver debugging.\n"
2590			"debugfs is now used for inspecting the device (report descriptor, reports)\n");
2591
2592	ret = bus_register(&hid_bus_type);
2593	if (ret) {
2594		pr_err("can't register hid bus\n");
2595		goto err;
2596	}
2597
2598	ret = hidraw_init();
2599	if (ret)
2600		goto err_bus;
2601
2602	hid_debug_init();
2603
2604	return 0;
2605err_bus:
2606	bus_unregister(&hid_bus_type);
2607err:
2608	return ret;
2609}
2610
2611static void __exit hid_exit(void)
2612{
2613	hid_debug_exit();
2614	hidraw_exit();
2615	bus_unregister(&hid_bus_type);
2616	hid_quirks_exit(HID_BUS_ANY);
2617}
2618
2619module_init(hid_init);
2620module_exit(hid_exit);
2621
2622MODULE_AUTHOR("Andreas Gal");
2623MODULE_AUTHOR("Vojtech Pavlik");
2624MODULE_AUTHOR("Jiri Kosina");
2625MODULE_LICENSE("GPL");