Linux Audio

Check our new training course

Loading...
   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
 
 
 
 
 
  44static int hid_ignore_special_drivers = 0;
  45module_param_named(ignore_special_drivers, hid_ignore_special_drivers, int, 0600);
  46MODULE_PARM_DESC(ignore_special_drivers, "Ignore any special drivers and handle all devices by generic driver");
  47
  48/*
  49 * Register a new report for a device.
  50 */
  51
  52struct hid_report *hid_register_report(struct hid_device *device,
  53				       enum hid_report_type type, unsigned int id,
  54				       unsigned int application)
  55{
  56	struct hid_report_enum *report_enum = device->report_enum + type;
  57	struct hid_report *report;
  58
  59	if (id >= HID_MAX_IDS)
  60		return NULL;
  61	if (report_enum->report_id_hash[id])
  62		return report_enum->report_id_hash[id];
  63
  64	report = kzalloc(sizeof(struct hid_report), GFP_KERNEL);
  65	if (!report)
  66		return NULL;
  67
  68	if (id != 0)
  69		report_enum->numbered = 1;
  70
  71	report->id = id;
  72	report->type = type;
  73	report->size = 0;
  74	report->device = device;
  75	report->application = application;
  76	report_enum->report_id_hash[id] = report;
  77
  78	list_add_tail(&report->list, &report_enum->report_list);
  79	INIT_LIST_HEAD(&report->field_entry_list);
  80
  81	return report;
  82}
  83EXPORT_SYMBOL_GPL(hid_register_report);
  84
  85/*
  86 * Register a new field for this report.
  87 */
  88
  89static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages)
  90{
  91	struct hid_field *field;
  92
  93	if (report->maxfield == HID_MAX_FIELDS) {
  94		hid_err(report->device, "too many fields in report\n");
  95		return NULL;
  96	}
  97
  98	field = kzalloc((sizeof(struct hid_field) +
  99			 usages * sizeof(struct hid_usage) +
 100			 3 * usages * sizeof(unsigned int)), GFP_KERNEL);
 101	if (!field)
 102		return NULL;
 103
 104	field->index = report->maxfield++;
 105	report->field[field->index] = field;
 106	field->usage = (struct hid_usage *)(field + 1);
 107	field->value = (s32 *)(field->usage + usages);
 108	field->new_value = (s32 *)(field->value + usages);
 109	field->usages_priorities = (s32 *)(field->new_value + usages);
 110	field->report = report;
 111
 112	return field;
 113}
 114
 115/*
 116 * Open a collection. The type/usage is pushed on the stack.
 117 */
 118
 119static int open_collection(struct hid_parser *parser, unsigned type)
 120{
 121	struct hid_collection *collection;
 122	unsigned usage;
 123	int collection_index;
 124
 125	usage = parser->local.usage[0];
 126
 127	if (parser->collection_stack_ptr == parser->collection_stack_size) {
 128		unsigned int *collection_stack;
 129		unsigned int new_size = parser->collection_stack_size +
 130					HID_COLLECTION_STACK_SIZE;
 131
 132		collection_stack = krealloc(parser->collection_stack,
 133					    new_size * sizeof(unsigned int),
 134					    GFP_KERNEL);
 135		if (!collection_stack)
 136			return -ENOMEM;
 137
 138		parser->collection_stack = collection_stack;
 139		parser->collection_stack_size = new_size;
 140	}
 141
 142	if (parser->device->maxcollection == parser->device->collection_size) {
 143		collection = kmalloc(
 144				array3_size(sizeof(struct hid_collection),
 145					    parser->device->collection_size,
 146					    2),
 147				GFP_KERNEL);
 148		if (collection == NULL) {
 149			hid_err(parser->device, "failed to reallocate collection array\n");
 150			return -ENOMEM;
 151		}
 152		memcpy(collection, parser->device->collection,
 153			sizeof(struct hid_collection) *
 154			parser->device->collection_size);
 155		memset(collection + parser->device->collection_size, 0,
 156			sizeof(struct hid_collection) *
 157			parser->device->collection_size);
 158		kfree(parser->device->collection);
 159		parser->device->collection = collection;
 160		parser->device->collection_size *= 2;
 161	}
 162
 163	parser->collection_stack[parser->collection_stack_ptr++] =
 164		parser->device->maxcollection;
 165
 166	collection_index = parser->device->maxcollection++;
 167	collection = parser->device->collection + collection_index;
 168	collection->type = type;
 169	collection->usage = usage;
 170	collection->level = parser->collection_stack_ptr - 1;
 171	collection->parent_idx = (collection->level == 0) ? -1 :
 172		parser->collection_stack[collection->level - 1];
 173
 174	if (type == HID_COLLECTION_APPLICATION)
 175		parser->device->maxapplication++;
 176
 177	return 0;
 178}
 179
 180/*
 181 * Close a collection.
 182 */
 183
 184static int close_collection(struct hid_parser *parser)
 185{
 186	if (!parser->collection_stack_ptr) {
 187		hid_err(parser->device, "collection stack underflow\n");
 188		return -EINVAL;
 189	}
 190	parser->collection_stack_ptr--;
 191	return 0;
 192}
 193
 194/*
 195 * Climb up the stack, search for the specified collection type
 196 * and return the usage.
 197 */
 198
 199static unsigned hid_lookup_collection(struct hid_parser *parser, unsigned type)
 200{
 201	struct hid_collection *collection = parser->device->collection;
 202	int n;
 203
 204	for (n = parser->collection_stack_ptr - 1; n >= 0; n--) {
 205		unsigned index = parser->collection_stack[n];
 206		if (collection[index].type == type)
 207			return collection[index].usage;
 208	}
 209	return 0; /* we know nothing about this usage type */
 210}
 211
 212/*
 213 * Concatenate usage which defines 16 bits or less with the
 214 * currently defined usage page to form a 32 bit usage
 215 */
 216
 217static void complete_usage(struct hid_parser *parser, unsigned int index)
 218{
 219	parser->local.usage[index] &= 0xFFFF;
 220	parser->local.usage[index] |=
 221		(parser->global.usage_page & 0xFFFF) << 16;
 222}
 223
 224/*
 225 * Add a usage to the temporary parser table.
 226 */
 227
 228static int hid_add_usage(struct hid_parser *parser, unsigned usage, u8 size)
 229{
 230	if (parser->local.usage_index >= HID_MAX_USAGES) {
 231		hid_err(parser->device, "usage index exceeded\n");
 232		return -1;
 233	}
 234	parser->local.usage[parser->local.usage_index] = usage;
 235
 236	/*
 237	 * If Usage item only includes usage id, concatenate it with
 238	 * currently defined usage page
 239	 */
 240	if (size <= 2)
 241		complete_usage(parser, parser->local.usage_index);
 242
 243	parser->local.usage_size[parser->local.usage_index] = size;
 244	parser->local.collection_index[parser->local.usage_index] =
 245		parser->collection_stack_ptr ?
 246		parser->collection_stack[parser->collection_stack_ptr - 1] : 0;
 247	parser->local.usage_index++;
 248	return 0;
 249}
 250
 251/*
 252 * Register a new field for this report.
 253 */
 254
 255static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsigned flags)
 256{
 257	struct hid_report *report;
 258	struct hid_field *field;
 259	unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
 260	unsigned int usages;
 261	unsigned int offset;
 262	unsigned int i;
 263	unsigned int application;
 264
 265	application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
 266
 267	report = hid_register_report(parser->device, report_type,
 268				     parser->global.report_id, application);
 269	if (!report) {
 270		hid_err(parser->device, "hid_register_report failed\n");
 271		return -1;
 272	}
 273
 274	/* Handle both signed and unsigned cases properly */
 275	if ((parser->global.logical_minimum < 0 &&
 276		parser->global.logical_maximum <
 277		parser->global.logical_minimum) ||
 278		(parser->global.logical_minimum >= 0 &&
 279		(__u32)parser->global.logical_maximum <
 280		(__u32)parser->global.logical_minimum)) {
 281		dbg_hid("logical range invalid 0x%x 0x%x\n",
 282			parser->global.logical_minimum,
 283			parser->global.logical_maximum);
 284		return -1;
 285	}
 286
 287	offset = report->size;
 288	report->size += parser->global.report_size * parser->global.report_count;
 289
 290	if (parser->device->ll_driver->max_buffer_size)
 291		max_buffer_size = parser->device->ll_driver->max_buffer_size;
 292
 293	/* Total size check: Allow for possible report index byte */
 294	if (report->size > (max_buffer_size - 1) << 3) {
 295		hid_err(parser->device, "report is too long\n");
 296		return -1;
 297	}
 298
 299	if (!parser->local.usage_index) /* Ignore padding fields */
 300		return 0;
 301
 302	usages = max_t(unsigned, parser->local.usage_index,
 303				 parser->global.report_count);
 304
 305	field = hid_register_field(report, usages);
 306	if (!field)
 307		return 0;
 308
 309	field->physical = hid_lookup_collection(parser, HID_COLLECTION_PHYSICAL);
 310	field->logical = hid_lookup_collection(parser, HID_COLLECTION_LOGICAL);
 311	field->application = application;
 312
 313	for (i = 0; i < usages; i++) {
 314		unsigned j = i;
 315		/* Duplicate the last usage we parsed if we have excess values */
 316		if (i >= parser->local.usage_index)
 317			j = parser->local.usage_index - 1;
 318		field->usage[i].hid = parser->local.usage[j];
 319		field->usage[i].collection_index =
 320			parser->local.collection_index[j];
 321		field->usage[i].usage_index = i;
 322		field->usage[i].resolution_multiplier = 1;
 323	}
 324
 325	field->maxusage = usages;
 326	field->flags = flags;
 327	field->report_offset = offset;
 328	field->report_type = report_type;
 329	field->report_size = parser->global.report_size;
 330	field->report_count = parser->global.report_count;
 331	field->logical_minimum = parser->global.logical_minimum;
 332	field->logical_maximum = parser->global.logical_maximum;
 333	field->physical_minimum = parser->global.physical_minimum;
 334	field->physical_maximum = parser->global.physical_maximum;
 335	field->unit_exponent = parser->global.unit_exponent;
 336	field->unit = parser->global.unit;
 337
 338	return 0;
 339}
 340
 341/*
 342 * Read data value from item.
 343 */
 344
 345static u32 item_udata(struct hid_item *item)
 346{
 347	switch (item->size) {
 348	case 1: return item->data.u8;
 349	case 2: return item->data.u16;
 350	case 4: return item->data.u32;
 351	}
 352	return 0;
 353}
 354
 355static s32 item_sdata(struct hid_item *item)
 356{
 357	switch (item->size) {
 358	case 1: return item->data.s8;
 359	case 2: return item->data.s16;
 360	case 4: return item->data.s32;
 361	}
 362	return 0;
 363}
 364
 365/*
 366 * Process a global item.
 367 */
 368
 369static int hid_parser_global(struct hid_parser *parser, struct hid_item *item)
 370{
 371	__s32 raw_value;
 372	switch (item->tag) {
 373	case HID_GLOBAL_ITEM_TAG_PUSH:
 374
 375		if (parser->global_stack_ptr == HID_GLOBAL_STACK_SIZE) {
 376			hid_err(parser->device, "global environment stack overflow\n");
 377			return -1;
 378		}
 379
 380		memcpy(parser->global_stack + parser->global_stack_ptr++,
 381			&parser->global, sizeof(struct hid_global));
 382		return 0;
 383
 384	case HID_GLOBAL_ITEM_TAG_POP:
 385
 386		if (!parser->global_stack_ptr) {
 387			hid_err(parser->device, "global environment stack underflow\n");
 388			return -1;
 389		}
 390
 391		memcpy(&parser->global, parser->global_stack +
 392			--parser->global_stack_ptr, sizeof(struct hid_global));
 393		return 0;
 394
 395	case HID_GLOBAL_ITEM_TAG_USAGE_PAGE:
 396		parser->global.usage_page = item_udata(item);
 397		return 0;
 398
 399	case HID_GLOBAL_ITEM_TAG_LOGICAL_MINIMUM:
 400		parser->global.logical_minimum = item_sdata(item);
 401		return 0;
 402
 403	case HID_GLOBAL_ITEM_TAG_LOGICAL_MAXIMUM:
 404		if (parser->global.logical_minimum < 0)
 405			parser->global.logical_maximum = item_sdata(item);
 406		else
 407			parser->global.logical_maximum = item_udata(item);
 408		return 0;
 409
 410	case HID_GLOBAL_ITEM_TAG_PHYSICAL_MINIMUM:
 411		parser->global.physical_minimum = item_sdata(item);
 412		return 0;
 413
 414	case HID_GLOBAL_ITEM_TAG_PHYSICAL_MAXIMUM:
 415		if (parser->global.physical_minimum < 0)
 416			parser->global.physical_maximum = item_sdata(item);
 417		else
 418			parser->global.physical_maximum = item_udata(item);
 419		return 0;
 420
 421	case HID_GLOBAL_ITEM_TAG_UNIT_EXPONENT:
 422		/* Many devices provide unit exponent as a two's complement
 423		 * nibble due to the common misunderstanding of HID
 424		 * specification 1.11, 6.2.2.7 Global Items. Attempt to handle
 425		 * both this and the standard encoding. */
 426		raw_value = item_sdata(item);
 427		if (!(raw_value & 0xfffffff0))
 428			parser->global.unit_exponent = hid_snto32(raw_value, 4);
 429		else
 430			parser->global.unit_exponent = raw_value;
 431		return 0;
 432
 433	case HID_GLOBAL_ITEM_TAG_UNIT:
 434		parser->global.unit = item_udata(item);
 435		return 0;
 436
 437	case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
 438		parser->global.report_size = item_udata(item);
 439		if (parser->global.report_size > 256) {
 440			hid_err(parser->device, "invalid report_size %d\n",
 441					parser->global.report_size);
 442			return -1;
 443		}
 444		return 0;
 445
 446	case HID_GLOBAL_ITEM_TAG_REPORT_COUNT:
 447		parser->global.report_count = item_udata(item);
 448		if (parser->global.report_count > HID_MAX_USAGES) {
 449			hid_err(parser->device, "invalid report_count %d\n",
 450					parser->global.report_count);
 451			return -1;
 452		}
 453		return 0;
 454
 455	case HID_GLOBAL_ITEM_TAG_REPORT_ID:
 456		parser->global.report_id = item_udata(item);
 457		if (parser->global.report_id == 0 ||
 458		    parser->global.report_id >= HID_MAX_IDS) {
 459			hid_err(parser->device, "report_id %u is invalid\n",
 460				parser->global.report_id);
 461			return -1;
 462		}
 463		return 0;
 464
 465	default:
 466		hid_err(parser->device, "unknown global tag 0x%x\n", item->tag);
 467		return -1;
 468	}
 469}
 470
 471/*
 472 * Process a local item.
 473 */
 474
 475static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
 476{
 477	__u32 data;
 478	unsigned n;
 479	__u32 count;
 480
 481	data = item_udata(item);
 482
 483	switch (item->tag) {
 484	case HID_LOCAL_ITEM_TAG_DELIMITER:
 485
 486		if (data) {
 487			/*
 488			 * We treat items before the first delimiter
 489			 * as global to all usage sets (branch 0).
 490			 * In the moment we process only these global
 491			 * items and the first delimiter set.
 492			 */
 493			if (parser->local.delimiter_depth != 0) {
 494				hid_err(parser->device, "nested delimiters\n");
 495				return -1;
 496			}
 497			parser->local.delimiter_depth++;
 498			parser->local.delimiter_branch++;
 499		} else {
 500			if (parser->local.delimiter_depth < 1) {
 501				hid_err(parser->device, "bogus close delimiter\n");
 502				return -1;
 503			}
 504			parser->local.delimiter_depth--;
 505		}
 506		return 0;
 507
 508	case HID_LOCAL_ITEM_TAG_USAGE:
 509
 510		if (parser->local.delimiter_branch > 1) {
 511			dbg_hid("alternative usage ignored\n");
 512			return 0;
 513		}
 514
 515		return hid_add_usage(parser, data, item->size);
 516
 517	case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:
 518
 519		if (parser->local.delimiter_branch > 1) {
 520			dbg_hid("alternative usage ignored\n");
 521			return 0;
 522		}
 523
 524		parser->local.usage_minimum = data;
 525		return 0;
 526
 527	case HID_LOCAL_ITEM_TAG_USAGE_MAXIMUM:
 528
 529		if (parser->local.delimiter_branch > 1) {
 530			dbg_hid("alternative usage ignored\n");
 531			return 0;
 532		}
 533
 534		count = data - parser->local.usage_minimum;
 535		if (count + parser->local.usage_index >= HID_MAX_USAGES) {
 536			/*
 537			 * We do not warn if the name is not set, we are
 538			 * actually pre-scanning the device.
 539			 */
 540			if (dev_name(&parser->device->dev))
 541				hid_warn(parser->device,
 542					 "ignoring exceeding usage max\n");
 543			data = HID_MAX_USAGES - parser->local.usage_index +
 544				parser->local.usage_minimum - 1;
 545			if (data <= 0) {
 546				hid_err(parser->device,
 547					"no more usage index available\n");
 548				return -1;
 549			}
 550		}
 551
 552		for (n = parser->local.usage_minimum; n <= data; n++)
 553			if (hid_add_usage(parser, n, item->size)) {
 554				dbg_hid("hid_add_usage failed\n");
 555				return -1;
 556			}
 557		return 0;
 558
 559	default:
 560
 561		dbg_hid("unknown local item tag 0x%x\n", item->tag);
 562		return 0;
 563	}
 564	return 0;
 565}
 566
 567/*
 568 * Concatenate Usage Pages into Usages where relevant:
 569 * As per specification, 6.2.2.8: "When the parser encounters a main item it
 570 * concatenates the last declared Usage Page with a Usage to form a complete
 571 * usage value."
 572 */
 573
 574static void hid_concatenate_last_usage_page(struct hid_parser *parser)
 575{
 576	int i;
 577	unsigned int usage_page;
 578	unsigned int current_page;
 579
 580	if (!parser->local.usage_index)
 581		return;
 582
 583	usage_page = parser->global.usage_page;
 584
 585	/*
 586	 * Concatenate usage page again only if last declared Usage Page
 587	 * has not been already used in previous usages concatenation
 588	 */
 589	for (i = parser->local.usage_index - 1; i >= 0; i--) {
 590		if (parser->local.usage_size[i] > 2)
 591			/* Ignore extended usages */
 592			continue;
 593
 594		current_page = parser->local.usage[i] >> 16;
 595		if (current_page == usage_page)
 596			break;
 597
 598		complete_usage(parser, i);
 599	}
 600}
 601
 602/*
 603 * Process a main item.
 604 */
 605
 606static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
 607{
 608	__u32 data;
 609	int ret;
 610
 611	hid_concatenate_last_usage_page(parser);
 612
 613	data = item_udata(item);
 614
 615	switch (item->tag) {
 616	case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 617		ret = open_collection(parser, data & 0xff);
 618		break;
 619	case HID_MAIN_ITEM_TAG_END_COLLECTION:
 620		ret = close_collection(parser);
 621		break;
 622	case HID_MAIN_ITEM_TAG_INPUT:
 623		ret = hid_add_field(parser, HID_INPUT_REPORT, data);
 624		break;
 625	case HID_MAIN_ITEM_TAG_OUTPUT:
 626		ret = hid_add_field(parser, HID_OUTPUT_REPORT, data);
 627		break;
 628	case HID_MAIN_ITEM_TAG_FEATURE:
 629		ret = hid_add_field(parser, HID_FEATURE_REPORT, data);
 630		break;
 631	default:
 632		hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
 633		ret = 0;
 634	}
 635
 636	memset(&parser->local, 0, sizeof(parser->local));	/* Reset the local parser environment */
 637
 638	return ret;
 639}
 640
 641/*
 642 * Process a reserved item.
 643 */
 644
 645static int hid_parser_reserved(struct hid_parser *parser, struct hid_item *item)
 646{
 647	dbg_hid("reserved item type, tag 0x%x\n", item->tag);
 648	return 0;
 649}
 650
 651/*
 652 * Free a report and all registered fields. The field->usage and
 653 * field->value table's are allocated behind the field, so we need
 654 * only to free(field) itself.
 655 */
 656
 657static void hid_free_report(struct hid_report *report)
 658{
 659	unsigned n;
 660
 661	kfree(report->field_entries);
 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 */
 672static 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
 705void 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
 714static 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
 726static 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
 788static 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
 796static 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
 807static 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	     type == HID_COLLECTION_APPLICATION))
 815		hid->group = HID_GROUP_SENSOR_HUB;
 816
 817	if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
 818	    hid->product == USB_DEVICE_ID_MS_POWER_COVER &&
 819	    hid->group == HID_GROUP_MULTITOUCH)
 820		hid->group = HID_GROUP_GENERIC;
 821
 822	if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
 823		for (i = 0; i < parser->local.usage_index; i++)
 824			if (parser->local.usage[i] == HID_GD_POINTER)
 825				parser->scan_flags |= HID_SCAN_FLAG_GD_POINTER;
 826
 827	if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
 828		parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
 829
 830	if ((parser->global.usage_page << 16) == HID_UP_GOOGLEVENDOR)
 831		for (i = 0; i < parser->local.usage_index; i++)
 832			if (parser->local.usage[i] ==
 833					(HID_UP_GOOGLEVENDOR | 0x0001))
 834				parser->device->group =
 835					HID_GROUP_VIVALDI;
 836}
 837
 838static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
 839{
 840	__u32 data;
 841	int i;
 842
 843	hid_concatenate_last_usage_page(parser);
 844
 845	data = item_udata(item);
 846
 847	switch (item->tag) {
 848	case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 849		hid_scan_collection(parser, data & 0xff);
 850		break;
 851	case HID_MAIN_ITEM_TAG_END_COLLECTION:
 852		break;
 853	case HID_MAIN_ITEM_TAG_INPUT:
 854		/* ignore constant inputs, they will be ignored by hid-input */
 855		if (data & HID_MAIN_ITEM_CONSTANT)
 856			break;
 857		for (i = 0; i < parser->local.usage_index; i++)
 858			hid_scan_input_usage(parser, parser->local.usage[i]);
 859		break;
 860	case HID_MAIN_ITEM_TAG_OUTPUT:
 861		break;
 862	case HID_MAIN_ITEM_TAG_FEATURE:
 863		for (i = 0; i < parser->local.usage_index; i++)
 864			hid_scan_feature_usage(parser, parser->local.usage[i]);
 865		break;
 866	}
 867
 868	/* Reset the local parser environment */
 869	memset(&parser->local, 0, sizeof(parser->local));
 870
 871	return 0;
 872}
 873
 874/*
 875 * Scan a report descriptor before the device is added to the bus.
 876 * Sets device groups and other properties that determine what driver
 877 * to load.
 878 */
 879static int hid_scan_report(struct hid_device *hid)
 880{
 881	struct hid_parser *parser;
 882	struct hid_item item;
 883	__u8 *start = hid->dev_rdesc;
 884	__u8 *end = start + hid->dev_rsize;
 885	static int (*dispatch_type[])(struct hid_parser *parser,
 886				      struct hid_item *item) = {
 887		hid_scan_main,
 888		hid_parser_global,
 889		hid_parser_local,
 890		hid_parser_reserved
 891	};
 892
 893	parser = vzalloc(sizeof(struct hid_parser));
 894	if (!parser)
 895		return -ENOMEM;
 896
 897	parser->device = hid;
 898	hid->group = HID_GROUP_GENERIC;
 899
 900	/*
 901	 * The parsing is simpler than the one in hid_open_report() as we should
 902	 * be robust against hid errors. Those errors will be raised by
 903	 * hid_open_report() anyway.
 904	 */
 905	while ((start = fetch_item(start, end, &item)) != NULL)
 906		dispatch_type[item.type](parser, &item);
 907
 908	/*
 909	 * Handle special flags set during scanning.
 910	 */
 911	if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
 912	    (hid->group == HID_GROUP_MULTITOUCH))
 913		hid->group = HID_GROUP_MULTITOUCH_WIN_8;
 914
 915	/*
 916	 * Vendor specific handlings
 917	 */
 918	switch (hid->vendor) {
 919	case USB_VENDOR_ID_WACOM:
 920		hid->group = HID_GROUP_WACOM;
 921		break;
 922	case USB_VENDOR_ID_SYNAPTICS:
 923		if (hid->group == HID_GROUP_GENERIC)
 924			if ((parser->scan_flags & HID_SCAN_FLAG_VENDOR_SPECIFIC)
 925			    && (parser->scan_flags & HID_SCAN_FLAG_GD_POINTER))
 926				/*
 927				 * hid-rmi should take care of them,
 928				 * not hid-generic
 929				 */
 930				hid->group = HID_GROUP_RMI;
 931		break;
 932	}
 933
 934	kfree(parser->collection_stack);
 935	vfree(parser);
 936	return 0;
 937}
 938
 939/**
 940 * hid_parse_report - parse device report
 941 *
 942 * @hid: hid device
 943 * @start: report start
 944 * @size: report size
 945 *
 946 * Allocate the device report as read by the bus driver. This function should
 947 * only be called from parse() in ll drivers.
 948 */
 949int hid_parse_report(struct hid_device *hid, __u8 *start, unsigned size)
 950{
 951	hid->dev_rdesc = kmemdup(start, size, GFP_KERNEL);
 952	if (!hid->dev_rdesc)
 953		return -ENOMEM;
 954	hid->dev_rsize = size;
 955	return 0;
 956}
 957EXPORT_SYMBOL_GPL(hid_parse_report);
 958
 959static const char * const hid_report_names[] = {
 960	"HID_INPUT_REPORT",
 961	"HID_OUTPUT_REPORT",
 962	"HID_FEATURE_REPORT",
 963};
 964/**
 965 * hid_validate_values - validate existing device report's value indexes
 966 *
 967 * @hid: hid device
 968 * @type: which report type to examine
 969 * @id: which report ID to examine (0 for first)
 970 * @field_index: which report field to examine
 971 * @report_counts: expected number of values
 972 *
 973 * Validate the number of values in a given field of a given report, after
 974 * parsing.
 975 */
 976struct hid_report *hid_validate_values(struct hid_device *hid,
 977				       enum hid_report_type type, unsigned int id,
 978				       unsigned int field_index,
 979				       unsigned int report_counts)
 980{
 981	struct hid_report *report;
 982
 983	if (type > HID_FEATURE_REPORT) {
 984		hid_err(hid, "invalid HID report type %u\n", type);
 985		return NULL;
 986	}
 987
 988	if (id >= HID_MAX_IDS) {
 989		hid_err(hid, "invalid HID report id %u\n", id);
 990		return NULL;
 991	}
 992
 993	/*
 994	 * Explicitly not using hid_get_report() here since it depends on
 995	 * ->numbered being checked, which may not always be the case when
 996	 * drivers go to access report values.
 997	 */
 998	if (id == 0) {
 999		/*
1000		 * Validating on id 0 means we should examine the first
1001		 * report in the list.
1002		 */
1003		report = list_first_entry_or_null(
1004				&hid->report_enum[type].report_list,
1005				struct hid_report, list);
1006	} else {
1007		report = hid->report_enum[type].report_id_hash[id];
1008	}
1009	if (!report) {
1010		hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
1011		return NULL;
1012	}
1013	if (report->maxfield <= field_index) {
1014		hid_err(hid, "not enough fields in %s %u\n",
1015			hid_report_names[type], id);
1016		return NULL;
1017	}
1018	if (report->field[field_index]->report_count < report_counts) {
1019		hid_err(hid, "not enough values in %s %u field %u\n",
1020			hid_report_names[type], id, field_index);
1021		return NULL;
1022	}
1023	return report;
1024}
1025EXPORT_SYMBOL_GPL(hid_validate_values);
1026
1027static int hid_calculate_multiplier(struct hid_device *hid,
1028				     struct hid_field *multiplier)
1029{
1030	int m;
1031	__s32 v = *multiplier->value;
1032	__s32 lmin = multiplier->logical_minimum;
1033	__s32 lmax = multiplier->logical_maximum;
1034	__s32 pmin = multiplier->physical_minimum;
1035	__s32 pmax = multiplier->physical_maximum;
1036
1037	/*
1038	 * "Because OS implementations will generally divide the control's
1039	 * reported count by the Effective Resolution Multiplier, designers
1040	 * should take care not to establish a potential Effective
1041	 * Resolution Multiplier of zero."
1042	 * HID Usage Table, v1.12, Section 4.3.1, p31
1043	 */
1044	if (lmax - lmin == 0)
1045		return 1;
1046	/*
1047	 * Handling the unit exponent is left as an exercise to whoever
1048	 * finds a device where that exponent is not 0.
1049	 */
1050	m = ((v - lmin)/(lmax - lmin) * (pmax - pmin) + pmin);
1051	if (unlikely(multiplier->unit_exponent != 0)) {
1052		hid_warn(hid,
1053			 "unsupported Resolution Multiplier unit exponent %d\n",
1054			 multiplier->unit_exponent);
1055	}
1056
1057	/* There are no devices with an effective multiplier > 255 */
1058	if (unlikely(m == 0 || m > 255 || m < -255)) {
1059		hid_warn(hid, "unsupported Resolution Multiplier %d\n", m);
1060		m = 1;
1061	}
1062
1063	return m;
1064}
1065
1066static void hid_apply_multiplier_to_field(struct hid_device *hid,
1067					  struct hid_field *field,
1068					  struct hid_collection *multiplier_collection,
1069					  int effective_multiplier)
1070{
1071	struct hid_collection *collection;
1072	struct hid_usage *usage;
1073	int i;
1074
1075	/*
1076	 * If multiplier_collection is NULL, the multiplier applies
1077	 * to all fields in the report.
1078	 * Otherwise, it is the Logical Collection the multiplier applies to
1079	 * but our field may be in a subcollection of that collection.
1080	 */
1081	for (i = 0; i < field->maxusage; i++) {
1082		usage = &field->usage[i];
1083
1084		collection = &hid->collection[usage->collection_index];
1085		while (collection->parent_idx != -1 &&
1086		       collection != multiplier_collection)
1087			collection = &hid->collection[collection->parent_idx];
1088
1089		if (collection->parent_idx != -1 ||
1090		    multiplier_collection == NULL)
1091			usage->resolution_multiplier = effective_multiplier;
1092
1093	}
1094}
1095
1096static void hid_apply_multiplier(struct hid_device *hid,
1097				 struct hid_field *multiplier)
1098{
1099	struct hid_report_enum *rep_enum;
1100	struct hid_report *rep;
1101	struct hid_field *field;
1102	struct hid_collection *multiplier_collection;
1103	int effective_multiplier;
1104	int i;
1105
1106	/*
1107	 * "The Resolution Multiplier control must be contained in the same
1108	 * Logical Collection as the control(s) to which it is to be applied.
1109	 * If no Resolution Multiplier is defined, then the Resolution
1110	 * Multiplier defaults to 1.  If more than one control exists in a
1111	 * Logical Collection, the Resolution Multiplier is associated with
1112	 * all controls in the collection. If no Logical Collection is
1113	 * defined, the Resolution Multiplier is associated with all
1114	 * controls in the report."
1115	 * HID Usage Table, v1.12, Section 4.3.1, p30
1116	 *
1117	 * Thus, search from the current collection upwards until we find a
1118	 * logical collection. Then search all fields for that same parent
1119	 * collection. Those are the fields the multiplier applies to.
1120	 *
1121	 * If we have more than one multiplier, it will overwrite the
1122	 * applicable fields later.
1123	 */
1124	multiplier_collection = &hid->collection[multiplier->usage->collection_index];
1125	while (multiplier_collection->parent_idx != -1 &&
1126	       multiplier_collection->type != HID_COLLECTION_LOGICAL)
1127		multiplier_collection = &hid->collection[multiplier_collection->parent_idx];
1128
1129	effective_multiplier = hid_calculate_multiplier(hid, multiplier);
1130
1131	rep_enum = &hid->report_enum[HID_INPUT_REPORT];
1132	list_for_each_entry(rep, &rep_enum->report_list, list) {
1133		for (i = 0; i < rep->maxfield; i++) {
1134			field = rep->field[i];
1135			hid_apply_multiplier_to_field(hid, field,
1136						      multiplier_collection,
1137						      effective_multiplier);
1138		}
1139	}
1140}
1141
1142/*
1143 * hid_setup_resolution_multiplier - set up all resolution multipliers
1144 *
1145 * @device: hid device
1146 *
1147 * Search for all Resolution Multiplier Feature Reports and apply their
1148 * value to all matching Input items. This only updates the internal struct
1149 * fields.
1150 *
1151 * The Resolution Multiplier is applied by the hardware. If the multiplier
1152 * is anything other than 1, the hardware will send pre-multiplied events
1153 * so that the same physical interaction generates an accumulated
1154 *	accumulated_value = value * * multiplier
1155 * This may be achieved by sending
1156 * - "value * multiplier" for each event, or
1157 * - "value" but "multiplier" times as frequently, or
1158 * - a combination of the above
1159 * The only guarantee is that the same physical interaction always generates
1160 * an accumulated 'value * multiplier'.
1161 *
1162 * This function must be called before any event processing and after
1163 * any SetRequest to the Resolution Multiplier.
1164 */
1165void hid_setup_resolution_multiplier(struct hid_device *hid)
1166{
1167	struct hid_report_enum *rep_enum;
1168	struct hid_report *rep;
1169	struct hid_usage *usage;
1170	int i, j;
1171
1172	rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
1173	list_for_each_entry(rep, &rep_enum->report_list, list) {
1174		for (i = 0; i < rep->maxfield; i++) {
1175			/* Ignore if report count is out of bounds. */
1176			if (rep->field[i]->report_count < 1)
1177				continue;
1178
1179			for (j = 0; j < rep->field[i]->maxusage; j++) {
1180				usage = &rep->field[i]->usage[j];
1181				if (usage->hid == HID_GD_RESOLUTION_MULTIPLIER)
1182					hid_apply_multiplier(hid,
1183							     rep->field[i]);
1184			}
1185		}
1186	}
1187}
1188EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier);
1189
1190/**
1191 * hid_open_report - open a driver-specific device report
1192 *
1193 * @device: hid device
1194 *
1195 * Parse a report description into a hid_device structure. Reports are
1196 * enumerated, fields are attached to these reports.
1197 * 0 returned on success, otherwise nonzero error value.
1198 *
1199 * This function (or the equivalent hid_parse() macro) should only be
1200 * called from probe() in drivers, before starting the device.
1201 */
1202int hid_open_report(struct hid_device *device)
1203{
1204	struct hid_parser *parser;
1205	struct hid_item item;
1206	unsigned int size;
1207	__u8 *start;
1208	__u8 *buf;
1209	__u8 *end;
1210	__u8 *next;
1211	int ret;
1212	int i;
1213	static int (*dispatch_type[])(struct hid_parser *parser,
1214				      struct hid_item *item) = {
1215		hid_parser_main,
1216		hid_parser_global,
1217		hid_parser_local,
1218		hid_parser_reserved
1219	};
1220
1221	if (WARN_ON(device->status & HID_STAT_PARSED))
1222		return -EBUSY;
1223
1224	start = device->dev_rdesc;
1225	if (WARN_ON(!start))
1226		return -ENODEV;
1227	size = device->dev_rsize;
1228
1229	/* call_hid_bpf_rdesc_fixup() ensures we work on a copy of rdesc */
1230	buf = call_hid_bpf_rdesc_fixup(device, start, &size);
1231	if (buf == NULL)
1232		return -ENOMEM;
1233
1234	if (device->driver->report_fixup)
1235		start = device->driver->report_fixup(device, buf, &size);
1236	else
1237		start = buf;
1238
1239	start = kmemdup(start, size, GFP_KERNEL);
1240	kfree(buf);
1241	if (start == NULL)
1242		return -ENOMEM;
1243
1244	device->rdesc = start;
1245	device->rsize = size;
1246
1247	parser = vzalloc(sizeof(struct hid_parser));
1248	if (!parser) {
1249		ret = -ENOMEM;
1250		goto alloc_err;
1251	}
1252
1253	parser->device = device;
1254
1255	end = start + size;
1256
1257	device->collection = kcalloc(HID_DEFAULT_NUM_COLLECTIONS,
1258				     sizeof(struct hid_collection), GFP_KERNEL);
1259	if (!device->collection) {
1260		ret = -ENOMEM;
1261		goto err;
1262	}
1263	device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
1264	for (i = 0; i < HID_DEFAULT_NUM_COLLECTIONS; i++)
1265		device->collection[i].parent_idx = -1;
1266
1267	ret = -EINVAL;
1268	while ((next = fetch_item(start, end, &item)) != NULL) {
1269		start = next;
1270
1271		if (item.format != HID_ITEM_FORMAT_SHORT) {
1272			hid_err(device, "unexpected long global item\n");
1273			goto err;
1274		}
1275
1276		if (dispatch_type[item.type](parser, &item)) {
1277			hid_err(device, "item %u %u %u %u parsing failed\n",
1278				item.format, (unsigned)item.size,
1279				(unsigned)item.type, (unsigned)item.tag);
1280			goto err;
1281		}
1282
1283		if (start == end) {
1284			if (parser->collection_stack_ptr) {
1285				hid_err(device, "unbalanced collection at end of report description\n");
1286				goto err;
1287			}
1288			if (parser->local.delimiter_depth) {
1289				hid_err(device, "unbalanced delimiter at end of report description\n");
1290				goto err;
1291			}
1292
1293			/*
1294			 * fetch initial values in case the device's
1295			 * default multiplier isn't the recommended 1
1296			 */
1297			hid_setup_resolution_multiplier(device);
1298
1299			kfree(parser->collection_stack);
1300			vfree(parser);
1301			device->status |= HID_STAT_PARSED;
1302
1303			return 0;
1304		}
1305	}
1306
1307	hid_err(device, "item fetching failed at offset %u/%u\n",
1308		size - (unsigned int)(end - start), size);
1309err:
1310	kfree(parser->collection_stack);
1311alloc_err:
1312	vfree(parser);
1313	hid_close_report(device);
1314	return ret;
1315}
1316EXPORT_SYMBOL_GPL(hid_open_report);
1317
1318/*
1319 * Convert a signed n-bit integer to signed 32-bit integer. Common
1320 * cases are done through the compiler, the screwed things has to be
1321 * done by hand.
1322 */
1323
1324static s32 snto32(__u32 value, unsigned n)
1325{
1326	if (!value || !n)
1327		return 0;
1328
1329	if (n > 32)
1330		n = 32;
1331
1332	switch (n) {
1333	case 8:  return ((__s8)value);
1334	case 16: return ((__s16)value);
1335	case 32: return ((__s32)value);
1336	}
1337	return value & (1 << (n - 1)) ? value | (~0U << n) : value;
1338}
1339
1340s32 hid_snto32(__u32 value, unsigned n)
1341{
1342	return snto32(value, n);
1343}
1344EXPORT_SYMBOL_GPL(hid_snto32);
1345
1346/*
1347 * Convert a signed 32-bit integer to a signed n-bit integer.
1348 */
1349
1350static u32 s32ton(__s32 value, unsigned n)
1351{
1352	s32 a = value >> (n - 1);
1353	if (a && a != -1)
1354		return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
1355	return value & ((1 << n) - 1);
1356}
1357
1358/*
1359 * Extract/implement a data field from/to a little endian report (bit array).
1360 *
1361 * Code sort-of follows HID spec:
1362 *     http://www.usb.org/developers/hidpage/HID1_11.pdf
1363 *
1364 * While the USB HID spec allows unlimited length bit fields in "report
1365 * descriptors", most devices never use more than 16 bits.
1366 * One model of UPS is claimed to report "LINEV" as a 32-bit field.
1367 * Search linux-kernel and linux-usb-devel archives for "hid-core extract".
1368 */
1369
1370static u32 __extract(u8 *report, unsigned offset, int n)
1371{
1372	unsigned int idx = offset / 8;
1373	unsigned int bit_nr = 0;
1374	unsigned int bit_shift = offset % 8;
1375	int bits_to_copy = 8 - bit_shift;
1376	u32 value = 0;
1377	u32 mask = n < 32 ? (1U << n) - 1 : ~0U;
1378
1379	while (n > 0) {
1380		value |= ((u32)report[idx] >> bit_shift) << bit_nr;
1381		n -= bits_to_copy;
1382		bit_nr += bits_to_copy;
1383		bits_to_copy = 8;
1384		bit_shift = 0;
1385		idx++;
1386	}
1387
1388	return value & mask;
1389}
1390
1391u32 hid_field_extract(const struct hid_device *hid, u8 *report,
1392			unsigned offset, unsigned n)
1393{
1394	if (n > 32) {
1395		hid_warn_once(hid, "%s() called with n (%d) > 32! (%s)\n",
1396			      __func__, n, current->comm);
1397		n = 32;
1398	}
1399
1400	return __extract(report, offset, n);
1401}
1402EXPORT_SYMBOL_GPL(hid_field_extract);
1403
1404/*
1405 * "implement" : set bits in a little endian bit stream.
1406 * Same concepts as "extract" (see comments above).
1407 * The data mangled in the bit stream remains in little endian
1408 * order the whole time. It make more sense to talk about
1409 * endianness of register values by considering a register
1410 * a "cached" copy of the little endian bit stream.
1411 */
1412
1413static void __implement(u8 *report, unsigned offset, int n, u32 value)
1414{
1415	unsigned int idx = offset / 8;
1416	unsigned int bit_shift = offset % 8;
1417	int bits_to_set = 8 - bit_shift;
1418
1419	while (n - bits_to_set >= 0) {
1420		report[idx] &= ~(0xff << bit_shift);
1421		report[idx] |= value << bit_shift;
1422		value >>= bits_to_set;
1423		n -= bits_to_set;
1424		bits_to_set = 8;
1425		bit_shift = 0;
1426		idx++;
1427	}
1428
1429	/* last nibble */
1430	if (n) {
1431		u8 bit_mask = ((1U << n) - 1);
1432		report[idx] &= ~(bit_mask << bit_shift);
1433		report[idx] |= value << bit_shift;
1434	}
1435}
1436
1437static void implement(const struct hid_device *hid, u8 *report,
1438		      unsigned offset, unsigned n, u32 value)
1439{
1440	if (unlikely(n > 32)) {
1441		hid_warn(hid, "%s() called with n (%d) > 32! (%s)\n",
1442			 __func__, n, current->comm);
1443		n = 32;
1444	} else if (n < 32) {
1445		u32 m = (1U << n) - 1;
1446
1447		if (unlikely(value > m)) {
1448			hid_warn(hid,
1449				 "%s() called with too large value %d (n: %d)! (%s)\n",
1450				 __func__, value, n, current->comm);
1451			WARN_ON(1);
1452			value &= m;
1453		}
1454	}
1455
1456	__implement(report, offset, n, value);
1457}
1458
1459/*
1460 * Search an array for a value.
1461 */
1462
1463static int search(__s32 *array, __s32 value, unsigned n)
1464{
1465	while (n--) {
1466		if (*array++ == value)
1467			return 0;
1468	}
1469	return -1;
1470}
1471
1472/**
1473 * hid_match_report - check if driver's raw_event should be called
1474 *
1475 * @hid: hid device
1476 * @report: hid report to match against
1477 *
1478 * compare hid->driver->report_table->report_type to report->type
1479 */
1480static int hid_match_report(struct hid_device *hid, struct hid_report *report)
1481{
1482	const struct hid_report_id *id = hid->driver->report_table;
1483
1484	if (!id) /* NULL means all */
1485		return 1;
1486
1487	for (; id->report_type != HID_TERMINATOR; id++)
1488		if (id->report_type == HID_ANY_ID ||
1489				id->report_type == report->type)
1490			return 1;
1491	return 0;
1492}
1493
1494/**
1495 * hid_match_usage - check if driver's event should be called
1496 *
1497 * @hid: hid device
1498 * @usage: usage to match against
1499 *
1500 * compare hid->driver->usage_table->usage_{type,code} to
1501 * usage->usage_{type,code}
1502 */
1503static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage)
1504{
1505	const struct hid_usage_id *id = hid->driver->usage_table;
1506
1507	if (!id) /* NULL means all */
1508		return 1;
1509
1510	for (; id->usage_type != HID_ANY_ID - 1; id++)
1511		if ((id->usage_hid == HID_ANY_ID ||
1512				id->usage_hid == usage->hid) &&
1513				(id->usage_type == HID_ANY_ID ||
1514				id->usage_type == usage->type) &&
1515				(id->usage_code == HID_ANY_ID ||
1516				 id->usage_code == usage->code))
1517			return 1;
1518	return 0;
1519}
1520
1521static void hid_process_event(struct hid_device *hid, struct hid_field *field,
1522		struct hid_usage *usage, __s32 value, int interrupt)
1523{
1524	struct hid_driver *hdrv = hid->driver;
1525	int ret;
1526
1527	if (!list_empty(&hid->debug_list))
1528		hid_dump_input(hid, usage, value);
1529
1530	if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
1531		ret = hdrv->event(hid, field, usage, value);
1532		if (ret != 0) {
1533			if (ret < 0)
1534				hid_err(hid, "%s's event failed with %d\n",
1535						hdrv->name, ret);
1536			return;
1537		}
1538	}
1539
1540	if (hid->claimed & HID_CLAIMED_INPUT)
1541		hidinput_hid_event(hid, field, usage, value);
1542	if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
1543		hid->hiddev_hid_event(hid, field, usage, value);
1544}
1545
1546/*
1547 * Checks if the given value is valid within this field
1548 */
1549static inline int hid_array_value_is_valid(struct hid_field *field,
1550					   __s32 value)
1551{
1552	__s32 min = field->logical_minimum;
1553
1554	/*
1555	 * Value needs to be between logical min and max, and
1556	 * (value - min) is used as an index in the usage array.
1557	 * This array is of size field->maxusage
1558	 */
1559	return value >= min &&
1560	       value <= field->logical_maximum &&
1561	       value - min < field->maxusage;
1562}
1563
1564/*
1565 * Fetch the field from the data. The field content is stored for next
1566 * report processing (we do differential reporting to the layer).
1567 */
1568static void hid_input_fetch_field(struct hid_device *hid,
1569				  struct hid_field *field,
1570				  __u8 *data)
1571{
1572	unsigned n;
1573	unsigned count = field->report_count;
1574	unsigned offset = field->report_offset;
1575	unsigned size = field->report_size;
1576	__s32 min = field->logical_minimum;
1577	__s32 *value;
1578
1579	value = field->new_value;
1580	memset(value, 0, count * sizeof(__s32));
1581	field->ignored = false;
1582
1583	for (n = 0; n < count; n++) {
1584
1585		value[n] = min < 0 ?
1586			snto32(hid_field_extract(hid, data, offset + n * size,
1587			       size), size) :
1588			hid_field_extract(hid, data, offset + n * size, size);
1589
1590		/* Ignore report if ErrorRollOver */
1591		if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
1592		    hid_array_value_is_valid(field, value[n]) &&
1593		    field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1) {
1594			field->ignored = true;
1595			return;
1596		}
1597	}
1598}
1599
1600/*
1601 * Process a received variable field.
1602 */
1603
1604static void hid_input_var_field(struct hid_device *hid,
1605				struct hid_field *field,
1606				int interrupt)
1607{
1608	unsigned int count = field->report_count;
1609	__s32 *value = field->new_value;
1610	unsigned int n;
1611
1612	for (n = 0; n < count; n++)
1613		hid_process_event(hid,
1614				  field,
1615				  &field->usage[n],
1616				  value[n],
1617				  interrupt);
1618
1619	memcpy(field->value, value, count * sizeof(__s32));
1620}
1621
1622/*
1623 * Process a received array field. The field content is stored for
1624 * next report processing (we do differential reporting to the layer).
1625 */
1626
1627static void hid_input_array_field(struct hid_device *hid,
1628				  struct hid_field *field,
1629				  int interrupt)
1630{
1631	unsigned int n;
1632	unsigned int count = field->report_count;
1633	__s32 min = field->logical_minimum;
1634	__s32 *value;
1635
1636	value = field->new_value;
1637
1638	/* ErrorRollOver */
1639	if (field->ignored)
1640		return;
1641
1642	for (n = 0; n < count; n++) {
1643		if (hid_array_value_is_valid(field, field->value[n]) &&
1644		    search(value, field->value[n], count))
1645			hid_process_event(hid,
1646					  field,
1647					  &field->usage[field->value[n] - min],
1648					  0,
1649					  interrupt);
1650
1651		if (hid_array_value_is_valid(field, value[n]) &&
1652		    search(field->value, value[n], count))
1653			hid_process_event(hid,
1654					  field,
1655					  &field->usage[value[n] - min],
1656					  1,
1657					  interrupt);
1658	}
1659
1660	memcpy(field->value, value, count * sizeof(__s32));
1661}
1662
1663/*
1664 * Analyse a received report, and fetch the data from it. The field
1665 * content is stored for next report processing (we do differential
1666 * reporting to the layer).
1667 */
1668static void hid_process_report(struct hid_device *hid,
1669			       struct hid_report *report,
1670			       __u8 *data,
1671			       int interrupt)
1672{
1673	unsigned int a;
1674	struct hid_field_entry *entry;
1675	struct hid_field *field;
1676
1677	/* first retrieve all incoming values in data */
1678	for (a = 0; a < report->maxfield; a++)
1679		hid_input_fetch_field(hid, report->field[a], data);
1680
1681	if (!list_empty(&report->field_entry_list)) {
1682		/* INPUT_REPORT, we have a priority list of fields */
1683		list_for_each_entry(entry,
1684				    &report->field_entry_list,
1685				    list) {
1686			field = entry->field;
1687
1688			if (field->flags & HID_MAIN_ITEM_VARIABLE)
1689				hid_process_event(hid,
1690						  field,
1691						  &field->usage[entry->index],
1692						  field->new_value[entry->index],
1693						  interrupt);
1694			else
1695				hid_input_array_field(hid, field, interrupt);
1696		}
1697
1698		/* we need to do the memcpy at the end for var items */
1699		for (a = 0; a < report->maxfield; a++) {
1700			field = report->field[a];
1701
1702			if (field->flags & HID_MAIN_ITEM_VARIABLE)
1703				memcpy(field->value, field->new_value,
1704				       field->report_count * sizeof(__s32));
1705		}
1706	} else {
1707		/* FEATURE_REPORT, regular processing */
1708		for (a = 0; a < report->maxfield; a++) {
1709			field = report->field[a];
1710
1711			if (field->flags & HID_MAIN_ITEM_VARIABLE)
1712				hid_input_var_field(hid, field, interrupt);
1713			else
1714				hid_input_array_field(hid, field, interrupt);
1715		}
1716	}
1717}
1718
1719/*
1720 * Insert a given usage_index in a field in the list
1721 * of processed usages in the report.
1722 *
1723 * The elements of lower priority score are processed
1724 * first.
1725 */
1726static void __hid_insert_field_entry(struct hid_device *hid,
1727				     struct hid_report *report,
1728				     struct hid_field_entry *entry,
1729				     struct hid_field *field,
1730				     unsigned int usage_index)
1731{
1732	struct hid_field_entry *next;
1733
1734	entry->field = field;
1735	entry->index = usage_index;
1736	entry->priority = field->usages_priorities[usage_index];
1737
1738	/* insert the element at the correct position */
1739	list_for_each_entry(next,
1740			    &report->field_entry_list,
1741			    list) {
1742		/*
1743		 * the priority of our element is strictly higher
1744		 * than the next one, insert it before
1745		 */
1746		if (entry->priority > next->priority) {
1747			list_add_tail(&entry->list, &next->list);
1748			return;
1749		}
1750	}
1751
1752	/* lowest priority score: insert at the end */
1753	list_add_tail(&entry->list, &report->field_entry_list);
1754}
1755
1756static void hid_report_process_ordering(struct hid_device *hid,
1757					struct hid_report *report)
1758{
1759	struct hid_field *field;
1760	struct hid_field_entry *entries;
1761	unsigned int a, u, usages;
1762	unsigned int count = 0;
1763
1764	/* count the number of individual fields in the report */
1765	for (a = 0; a < report->maxfield; a++) {
1766		field = report->field[a];
1767
1768		if (field->flags & HID_MAIN_ITEM_VARIABLE)
1769			count += field->report_count;
1770		else
1771			count++;
1772	}
1773
1774	/* allocate the memory to process the fields */
1775	entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
1776	if (!entries)
1777		return;
1778
1779	report->field_entries = entries;
1780
1781	/*
1782	 * walk through all fields in the report and
1783	 * store them by priority order in report->field_entry_list
1784	 *
1785	 * - Var elements are individualized (field + usage_index)
1786	 * - Arrays are taken as one, we can not chose an order for them
1787	 */
1788	usages = 0;
1789	for (a = 0; a < report->maxfield; a++) {
1790		field = report->field[a];
1791
1792		if (field->flags & HID_MAIN_ITEM_VARIABLE) {
1793			for (u = 0; u < field->report_count; u++) {
1794				__hid_insert_field_entry(hid, report,
1795							 &entries[usages],
1796							 field, u);
1797				usages++;
1798			}
1799		} else {
1800			__hid_insert_field_entry(hid, report, &entries[usages],
1801						 field, 0);
1802			usages++;
1803		}
1804	}
1805}
1806
1807static void hid_process_ordering(struct hid_device *hid)
1808{
1809	struct hid_report *report;
1810	struct hid_report_enum *report_enum = &hid->report_enum[HID_INPUT_REPORT];
1811
1812	list_for_each_entry(report, &report_enum->report_list, list)
1813		hid_report_process_ordering(hid, report);
1814}
1815
1816/*
1817 * Output the field into the report.
1818 */
1819
1820static void hid_output_field(const struct hid_device *hid,
1821			     struct hid_field *field, __u8 *data)
1822{
1823	unsigned count = field->report_count;
1824	unsigned offset = field->report_offset;
1825	unsigned size = field->report_size;
1826	unsigned n;
1827
1828	for (n = 0; n < count; n++) {
1829		if (field->logical_minimum < 0)	/* signed values */
1830			implement(hid, data, offset + n * size, size,
1831				  s32ton(field->value[n], size));
1832		else				/* unsigned values */
1833			implement(hid, data, offset + n * size, size,
1834				  field->value[n]);
1835	}
1836}
1837
1838/*
1839 * Compute the size of a report.
1840 */
1841static size_t hid_compute_report_size(struct hid_report *report)
1842{
1843	if (report->size)
1844		return ((report->size - 1) >> 3) + 1;
1845
1846	return 0;
1847}
1848
1849/*
1850 * Create a report. 'data' has to be allocated using
1851 * hid_alloc_report_buf() so that it has proper size.
1852 */
1853
1854void hid_output_report(struct hid_report *report, __u8 *data)
1855{
1856	unsigned n;
1857
1858	if (report->id > 0)
1859		*data++ = report->id;
1860
1861	memset(data, 0, hid_compute_report_size(report));
1862	for (n = 0; n < report->maxfield; n++)
1863		hid_output_field(report->device, report->field[n], data);
1864}
1865EXPORT_SYMBOL_GPL(hid_output_report);
1866
1867/*
1868 * Allocator for buffer that is going to be passed to hid_output_report()
1869 */
1870u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
1871{
1872	/*
1873	 * 7 extra bytes are necessary to achieve proper functionality
1874	 * of implement() working on 8 byte chunks
1875	 */
1876
1877	u32 len = hid_report_len(report) + 7;
1878
1879	return kmalloc(len, flags);
1880}
1881EXPORT_SYMBOL_GPL(hid_alloc_report_buf);
1882
1883/*
1884 * Set a field value. The report this field belongs to has to be
1885 * created and transferred to the device, to set this value in the
1886 * device.
1887 */
1888
1889int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
1890{
1891	unsigned size;
1892
1893	if (!field)
1894		return -1;
1895
1896	size = field->report_size;
1897
1898	hid_dump_input(field->report->device, field->usage + offset, value);
1899
1900	if (offset >= field->report_count) {
1901		hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n",
1902				offset, field->report_count);
1903		return -1;
1904	}
1905	if (field->logical_minimum < 0) {
1906		if (value != snto32(s32ton(value, size), size)) {
1907			hid_err(field->report->device, "value %d is out of range\n", value);
1908			return -1;
1909		}
1910	}
1911	field->value[offset] = value;
1912	return 0;
1913}
1914EXPORT_SYMBOL_GPL(hid_set_field);
1915
1916static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
1917		const u8 *data)
1918{
1919	struct hid_report *report;
1920	unsigned int n = 0;	/* Normally report number is 0 */
1921
1922	/* Device uses numbered reports, data[0] is report number */
1923	if (report_enum->numbered)
1924		n = *data;
1925
1926	report = report_enum->report_id_hash[n];
1927	if (report == NULL)
1928		dbg_hid("undefined report_id %u received\n", n);
1929
1930	return report;
1931}
1932
1933/*
1934 * Implement a generic .request() callback, using .raw_request()
1935 * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
1936 */
1937int __hid_request(struct hid_device *hid, struct hid_report *report,
1938		enum hid_class_request reqtype)
1939{
1940	char *buf;
1941	int ret;
1942	u32 len;
1943
1944	buf = hid_alloc_report_buf(report, GFP_KERNEL);
1945	if (!buf)
1946		return -ENOMEM;
1947
1948	len = hid_report_len(report);
1949
1950	if (reqtype == HID_REQ_SET_REPORT)
1951		hid_output_report(report, buf);
1952
1953	ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
1954					  report->type, reqtype);
1955	if (ret < 0) {
1956		dbg_hid("unable to complete request: %d\n", ret);
1957		goto out;
1958	}
1959
1960	if (reqtype == HID_REQ_GET_REPORT)
1961		hid_input_report(hid, report->type, buf, ret, 0);
1962
1963	ret = 0;
1964
1965out:
1966	kfree(buf);
1967	return ret;
1968}
1969EXPORT_SYMBOL_GPL(__hid_request);
1970
1971int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
1972			 int interrupt)
1973{
1974	struct hid_report_enum *report_enum = hid->report_enum + type;
1975	struct hid_report *report;
1976	struct hid_driver *hdrv;
1977	int max_buffer_size = HID_MAX_BUFFER_SIZE;
1978	u32 rsize, csize = size;
1979	u8 *cdata = data;
1980	int ret = 0;
1981
1982	report = hid_get_report(report_enum, data);
1983	if (!report)
1984		goto out;
1985
1986	if (report_enum->numbered) {
1987		cdata++;
1988		csize--;
1989	}
1990
1991	rsize = hid_compute_report_size(report);
1992
1993	if (hid->ll_driver->max_buffer_size)
1994		max_buffer_size = hid->ll_driver->max_buffer_size;
1995
1996	if (report_enum->numbered && rsize >= max_buffer_size)
1997		rsize = max_buffer_size - 1;
1998	else if (rsize > max_buffer_size)
1999		rsize = max_buffer_size;
2000
2001	if (csize < rsize) {
2002		dbg_hid("report %d is too short, (%d < %d)\n", report->id,
2003				csize, rsize);
2004		memset(cdata + csize, 0, rsize - csize);
2005	}
2006
2007	if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
2008		hid->hiddev_report_event(hid, report);
2009	if (hid->claimed & HID_CLAIMED_HIDRAW) {
2010		ret = hidraw_report_event(hid, data, size);
2011		if (ret)
2012			goto out;
2013	}
2014
2015	if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
2016		hid_process_report(hid, report, cdata, interrupt);
2017		hdrv = hid->driver;
2018		if (hdrv && hdrv->report)
2019			hdrv->report(hid, report);
2020	}
2021
2022	if (hid->claimed & HID_CLAIMED_INPUT)
2023		hidinput_report_event(hid, report);
2024out:
2025	return ret;
2026}
2027EXPORT_SYMBOL_GPL(hid_report_raw_event);
2028
2029/**
2030 * hid_input_report - report data from lower layer (usb, bt...)
2031 *
2032 * @hid: hid device
2033 * @type: HID report type (HID_*_REPORT)
2034 * @data: report contents
2035 * @size: size of data parameter
2036 * @interrupt: distinguish between interrupt and control transfers
2037 *
2038 * This is data entry for lower layers.
2039 */
2040int hid_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
2041		     int interrupt)
2042{
2043	struct hid_report_enum *report_enum;
2044	struct hid_driver *hdrv;
2045	struct hid_report *report;
2046	int ret = 0;
2047
2048	if (!hid)
2049		return -ENODEV;
2050
2051	if (down_trylock(&hid->driver_input_lock))
2052		return -EBUSY;
2053
2054	if (!hid->driver) {
2055		ret = -ENODEV;
2056		goto unlock;
2057	}
2058	report_enum = hid->report_enum + type;
2059	hdrv = hid->driver;
2060
2061	data = dispatch_hid_bpf_device_event(hid, type, data, &size, interrupt);
2062	if (IS_ERR(data)) {
2063		ret = PTR_ERR(data);
2064		goto unlock;
2065	}
2066
2067	if (!size) {
2068		dbg_hid("empty report\n");
2069		ret = -1;
2070		goto unlock;
2071	}
2072
2073	/* Avoid unnecessary overhead if debugfs is disabled */
2074	if (!list_empty(&hid->debug_list))
2075		hid_dump_report(hid, type, data, size);
2076
2077	report = hid_get_report(report_enum, data);
2078
2079	if (!report) {
2080		ret = -1;
2081		goto unlock;
2082	}
2083
2084	if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
2085		ret = hdrv->raw_event(hid, report, data, size);
2086		if (ret < 0)
2087			goto unlock;
2088	}
2089
2090	ret = hid_report_raw_event(hid, type, data, size, interrupt);
2091
2092unlock:
2093	up(&hid->driver_input_lock);
2094	return ret;
2095}
2096EXPORT_SYMBOL_GPL(hid_input_report);
2097
2098bool hid_match_one_id(const struct hid_device *hdev,
2099		      const struct hid_device_id *id)
2100{
2101	return (id->bus == HID_BUS_ANY || id->bus == hdev->bus) &&
2102		(id->group == HID_GROUP_ANY || id->group == hdev->group) &&
2103		(id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&
2104		(id->product == HID_ANY_ID || id->product == hdev->product);
2105}
2106
2107const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
2108		const struct hid_device_id *id)
2109{
2110	for (; id->bus; id++)
2111		if (hid_match_one_id(hdev, id))
2112			return id;
2113
2114	return NULL;
2115}
2116EXPORT_SYMBOL_GPL(hid_match_id);
2117
2118static const struct hid_device_id hid_hiddev_list[] = {
2119	{ HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS) },
2120	{ HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS1) },
2121	{ }
2122};
2123
2124static bool hid_hiddev(struct hid_device *hdev)
2125{
2126	return !!hid_match_id(hdev, hid_hiddev_list);
2127}
2128
2129
2130static ssize_t
2131read_report_descriptor(struct file *filp, struct kobject *kobj,
2132		struct bin_attribute *attr,
2133		char *buf, loff_t off, size_t count)
2134{
2135	struct device *dev = kobj_to_dev(kobj);
2136	struct hid_device *hdev = to_hid_device(dev);
2137
2138	if (off >= hdev->rsize)
2139		return 0;
2140
2141	if (off + count > hdev->rsize)
2142		count = hdev->rsize - off;
2143
2144	memcpy(buf, hdev->rdesc + off, count);
2145
2146	return count;
2147}
2148
2149static ssize_t
2150show_country(struct device *dev, struct device_attribute *attr,
2151		char *buf)
2152{
2153	struct hid_device *hdev = to_hid_device(dev);
2154
2155	return sprintf(buf, "%02x\n", hdev->country & 0xff);
2156}
2157
2158static struct bin_attribute dev_bin_attr_report_desc = {
2159	.attr = { .name = "report_descriptor", .mode = 0444 },
2160	.read = read_report_descriptor,
2161	.size = HID_MAX_DESCRIPTOR_SIZE,
2162};
2163
2164static const struct device_attribute dev_attr_country = {
2165	.attr = { .name = "country", .mode = 0444 },
2166	.show = show_country,
2167};
2168
2169int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
2170{
2171	static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
2172		"Joystick", "Gamepad", "Keyboard", "Keypad",
2173		"Multi-Axis Controller"
2174	};
2175	const char *type, *bus;
2176	char buf[64] = "";
2177	unsigned int i;
2178	int len;
2179	int ret;
2180
2181	ret = hid_bpf_connect_device(hdev);
2182	if (ret)
2183		return ret;
2184
2185	if (hdev->quirks & HID_QUIRK_HIDDEV_FORCE)
2186		connect_mask |= (HID_CONNECT_HIDDEV_FORCE | HID_CONNECT_HIDDEV);
2187	if (hdev->quirks & HID_QUIRK_HIDINPUT_FORCE)
2188		connect_mask |= HID_CONNECT_HIDINPUT_FORCE;
2189	if (hdev->bus != BUS_USB)
2190		connect_mask &= ~HID_CONNECT_HIDDEV;
2191	if (hid_hiddev(hdev))
2192		connect_mask |= HID_CONNECT_HIDDEV_FORCE;
2193
2194	if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,
2195				connect_mask & HID_CONNECT_HIDINPUT_FORCE))
2196		hdev->claimed |= HID_CLAIMED_INPUT;
2197
2198	if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect &&
2199			!hdev->hiddev_connect(hdev,
2200				connect_mask & HID_CONNECT_HIDDEV_FORCE))
2201		hdev->claimed |= HID_CLAIMED_HIDDEV;
2202	if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))
2203		hdev->claimed |= HID_CLAIMED_HIDRAW;
2204
2205	if (connect_mask & HID_CONNECT_DRIVER)
2206		hdev->claimed |= HID_CLAIMED_DRIVER;
2207
2208	/* Drivers with the ->raw_event callback set are not required to connect
2209	 * to any other listener. */
2210	if (!hdev->claimed && !hdev->driver->raw_event) {
2211		hid_err(hdev, "device has no listeners, quitting\n");
2212		return -ENODEV;
2213	}
2214
2215	hid_process_ordering(hdev);
2216
2217	if ((hdev->claimed & HID_CLAIMED_INPUT) &&
2218			(connect_mask & HID_CONNECT_FF) && hdev->ff_init)
2219		hdev->ff_init(hdev);
2220
2221	len = 0;
2222	if (hdev->claimed & HID_CLAIMED_INPUT)
2223		len += sprintf(buf + len, "input");
2224	if (hdev->claimed & HID_CLAIMED_HIDDEV)
2225		len += sprintf(buf + len, "%shiddev%d", len ? "," : "",
2226				((struct hiddev *)hdev->hiddev)->minor);
2227	if (hdev->claimed & HID_CLAIMED_HIDRAW)
2228		len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
2229				((struct hidraw *)hdev->hidraw)->minor);
2230
2231	type = "Device";
2232	for (i = 0; i < hdev->maxcollection; i++) {
2233		struct hid_collection *col = &hdev->collection[i];
2234		if (col->type == HID_COLLECTION_APPLICATION &&
2235		   (col->usage & HID_USAGE_PAGE) == HID_UP_GENDESK &&
2236		   (col->usage & 0xffff) < ARRAY_SIZE(types)) {
2237			type = types[col->usage & 0xffff];
2238			break;
2239		}
2240	}
2241
2242	switch (hdev->bus) {
2243	case BUS_USB:
2244		bus = "USB";
2245		break;
2246	case BUS_BLUETOOTH:
2247		bus = "BLUETOOTH";
2248		break;
2249	case BUS_I2C:
2250		bus = "I2C";
2251		break;
2252	case BUS_VIRTUAL:
2253		bus = "VIRTUAL";
2254		break;
2255	case BUS_INTEL_ISHTP:
2256	case BUS_AMD_SFH:
2257		bus = "SENSOR HUB";
2258		break;
2259	default:
2260		bus = "<UNKNOWN>";
2261	}
2262
2263	ret = device_create_file(&hdev->dev, &dev_attr_country);
2264	if (ret)
2265		hid_warn(hdev,
2266			 "can't create sysfs country code attribute err: %d\n", ret);
2267
2268	hid_info(hdev, "%s: %s HID v%x.%02x %s [%s] on %s\n",
2269		 buf, bus, hdev->version >> 8, hdev->version & 0xff,
2270		 type, hdev->name, hdev->phys);
2271
2272	return 0;
2273}
2274EXPORT_SYMBOL_GPL(hid_connect);
2275
2276void hid_disconnect(struct hid_device *hdev)
2277{
2278	device_remove_file(&hdev->dev, &dev_attr_country);
2279	if (hdev->claimed & HID_CLAIMED_INPUT)
2280		hidinput_disconnect(hdev);
2281	if (hdev->claimed & HID_CLAIMED_HIDDEV)
2282		hdev->hiddev_disconnect(hdev);
2283	if (hdev->claimed & HID_CLAIMED_HIDRAW)
2284		hidraw_disconnect(hdev);
2285	hdev->claimed = 0;
2286
2287	hid_bpf_disconnect_device(hdev);
2288}
2289EXPORT_SYMBOL_GPL(hid_disconnect);
2290
2291/**
2292 * hid_hw_start - start underlying HW
2293 * @hdev: hid device
2294 * @connect_mask: which outputs to connect, see HID_CONNECT_*
2295 *
2296 * Call this in probe function *after* hid_parse. This will setup HW
2297 * buffers and start the device (if not defeirred to device open).
2298 * hid_hw_stop must be called if this was successful.
2299 */
2300int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask)
2301{
2302	int error;
2303
2304	error = hdev->ll_driver->start(hdev);
2305	if (error)
2306		return error;
2307
2308	if (connect_mask) {
2309		error = hid_connect(hdev, connect_mask);
2310		if (error) {
2311			hdev->ll_driver->stop(hdev);
2312			return error;
2313		}
2314	}
2315
2316	return 0;
2317}
2318EXPORT_SYMBOL_GPL(hid_hw_start);
2319
2320/**
2321 * hid_hw_stop - stop underlying HW
2322 * @hdev: hid device
2323 *
2324 * This is usually called from remove function or from probe when something
2325 * failed and hid_hw_start was called already.
2326 */
2327void hid_hw_stop(struct hid_device *hdev)
2328{
2329	hid_disconnect(hdev);
2330	hdev->ll_driver->stop(hdev);
2331}
2332EXPORT_SYMBOL_GPL(hid_hw_stop);
2333
2334/**
2335 * hid_hw_open - signal underlying HW to start delivering events
2336 * @hdev: hid device
2337 *
2338 * Tell underlying HW to start delivering events from the device.
2339 * This function should be called sometime after successful call
2340 * to hid_hw_start().
2341 */
2342int hid_hw_open(struct hid_device *hdev)
2343{
2344	int ret;
2345
2346	ret = mutex_lock_killable(&hdev->ll_open_lock);
2347	if (ret)
2348		return ret;
2349
2350	if (!hdev->ll_open_count++) {
2351		ret = hdev->ll_driver->open(hdev);
2352		if (ret)
2353			hdev->ll_open_count--;
2354	}
2355
2356	mutex_unlock(&hdev->ll_open_lock);
2357	return ret;
2358}
2359EXPORT_SYMBOL_GPL(hid_hw_open);
2360
2361/**
2362 * hid_hw_close - signal underlaying HW to stop delivering events
2363 *
2364 * @hdev: hid device
2365 *
2366 * This function indicates that we are not interested in the events
2367 * from this device anymore. Delivery of events may or may not stop,
2368 * depending on the number of users still outstanding.
2369 */
2370void hid_hw_close(struct hid_device *hdev)
2371{
2372	mutex_lock(&hdev->ll_open_lock);
2373	if (!--hdev->ll_open_count)
2374		hdev->ll_driver->close(hdev);
2375	mutex_unlock(&hdev->ll_open_lock);
2376}
2377EXPORT_SYMBOL_GPL(hid_hw_close);
2378
2379/**
2380 * hid_hw_request - send report request to device
2381 *
2382 * @hdev: hid device
2383 * @report: report to send
2384 * @reqtype: hid request type
2385 */
2386void hid_hw_request(struct hid_device *hdev,
2387		    struct hid_report *report, enum hid_class_request reqtype)
2388{
2389	if (hdev->ll_driver->request)
2390		return hdev->ll_driver->request(hdev, report, reqtype);
2391
2392	__hid_request(hdev, report, reqtype);
2393}
2394EXPORT_SYMBOL_GPL(hid_hw_request);
2395
2396/**
2397 * hid_hw_raw_request - send report request to device
2398 *
2399 * @hdev: hid device
2400 * @reportnum: report ID
2401 * @buf: in/out data to transfer
2402 * @len: length of buf
2403 * @rtype: HID report type
2404 * @reqtype: HID_REQ_GET_REPORT or HID_REQ_SET_REPORT
2405 *
2406 * Return: count of data transferred, negative if error
2407 *
2408 * Same behavior as hid_hw_request, but with raw buffers instead.
2409 */
2410int hid_hw_raw_request(struct hid_device *hdev,
2411		       unsigned char reportnum, __u8 *buf,
2412		       size_t len, enum hid_report_type rtype, enum hid_class_request reqtype)
2413{
2414	unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
2415
2416	if (hdev->ll_driver->max_buffer_size)
2417		max_buffer_size = hdev->ll_driver->max_buffer_size;
2418
2419	if (len < 1 || len > max_buffer_size || !buf)
2420		return -EINVAL;
2421
2422	return hdev->ll_driver->raw_request(hdev, reportnum, buf, len,
2423					    rtype, reqtype);
2424}
2425EXPORT_SYMBOL_GPL(hid_hw_raw_request);
2426
2427/**
2428 * hid_hw_output_report - send output report to device
2429 *
2430 * @hdev: hid device
2431 * @buf: raw data to transfer
2432 * @len: length of buf
2433 *
2434 * Return: count of data transferred, negative if error
2435 */
2436int hid_hw_output_report(struct hid_device *hdev, __u8 *buf, size_t len)
2437{
2438	unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
2439
2440	if (hdev->ll_driver->max_buffer_size)
2441		max_buffer_size = hdev->ll_driver->max_buffer_size;
2442
2443	if (len < 1 || len > max_buffer_size || !buf)
2444		return -EINVAL;
2445
2446	if (hdev->ll_driver->output_report)
2447		return hdev->ll_driver->output_report(hdev, buf, len);
2448
2449	return -ENOSYS;
2450}
2451EXPORT_SYMBOL_GPL(hid_hw_output_report);
2452
2453#ifdef CONFIG_PM
2454int hid_driver_suspend(struct hid_device *hdev, pm_message_t state)
2455{
2456	if (hdev->driver && hdev->driver->suspend)
2457		return hdev->driver->suspend(hdev, state);
2458
2459	return 0;
2460}
2461EXPORT_SYMBOL_GPL(hid_driver_suspend);
2462
2463int hid_driver_reset_resume(struct hid_device *hdev)
2464{
2465	if (hdev->driver && hdev->driver->reset_resume)
2466		return hdev->driver->reset_resume(hdev);
2467
2468	return 0;
2469}
2470EXPORT_SYMBOL_GPL(hid_driver_reset_resume);
2471
2472int hid_driver_resume(struct hid_device *hdev)
2473{
2474	if (hdev->driver && hdev->driver->resume)
2475		return hdev->driver->resume(hdev);
2476
2477	return 0;
2478}
2479EXPORT_SYMBOL_GPL(hid_driver_resume);
2480#endif /* CONFIG_PM */
2481
2482struct hid_dynid {
2483	struct list_head list;
2484	struct hid_device_id id;
2485};
2486
2487/**
2488 * new_id_store - add a new HID device ID to this driver and re-probe devices
2489 * @drv: target device driver
2490 * @buf: buffer for scanning device ID data
2491 * @count: input size
2492 *
2493 * Adds a new dynamic hid device ID to this driver,
2494 * and causes the driver to probe for all devices again.
2495 */
2496static ssize_t new_id_store(struct device_driver *drv, const char *buf,
2497		size_t count)
2498{
2499	struct hid_driver *hdrv = to_hid_driver(drv);
2500	struct hid_dynid *dynid;
2501	__u32 bus, vendor, product;
2502	unsigned long driver_data = 0;
2503	int ret;
2504
2505	ret = sscanf(buf, "%x %x %x %lx",
2506			&bus, &vendor, &product, &driver_data);
2507	if (ret < 3)
2508		return -EINVAL;
2509
2510	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
2511	if (!dynid)
2512		return -ENOMEM;
2513
2514	dynid->id.bus = bus;
2515	dynid->id.group = HID_GROUP_ANY;
2516	dynid->id.vendor = vendor;
2517	dynid->id.product = product;
2518	dynid->id.driver_data = driver_data;
2519
2520	spin_lock(&hdrv->dyn_lock);
2521	list_add_tail(&dynid->list, &hdrv->dyn_list);
2522	spin_unlock(&hdrv->dyn_lock);
2523
2524	ret = driver_attach(&hdrv->driver);
2525
2526	return ret ? : count;
2527}
2528static DRIVER_ATTR_WO(new_id);
2529
2530static struct attribute *hid_drv_attrs[] = {
2531	&driver_attr_new_id.attr,
2532	NULL,
2533};
2534ATTRIBUTE_GROUPS(hid_drv);
2535
2536static void hid_free_dynids(struct hid_driver *hdrv)
2537{
2538	struct hid_dynid *dynid, *n;
2539
2540	spin_lock(&hdrv->dyn_lock);
2541	list_for_each_entry_safe(dynid, n, &hdrv->dyn_list, list) {
2542		list_del(&dynid->list);
2543		kfree(dynid);
2544	}
2545	spin_unlock(&hdrv->dyn_lock);
2546}
2547
2548const struct hid_device_id *hid_match_device(struct hid_device *hdev,
2549					     struct hid_driver *hdrv)
2550{
2551	struct hid_dynid *dynid;
2552
2553	spin_lock(&hdrv->dyn_lock);
2554	list_for_each_entry(dynid, &hdrv->dyn_list, list) {
2555		if (hid_match_one_id(hdev, &dynid->id)) {
2556			spin_unlock(&hdrv->dyn_lock);
2557			return &dynid->id;
2558		}
2559	}
2560	spin_unlock(&hdrv->dyn_lock);
2561
2562	return hid_match_id(hdev, hdrv->id_table);
2563}
2564EXPORT_SYMBOL_GPL(hid_match_device);
2565
2566static int hid_bus_match(struct device *dev, struct device_driver *drv)
2567{
2568	struct hid_driver *hdrv = to_hid_driver(drv);
2569	struct hid_device *hdev = to_hid_device(dev);
2570
2571	return hid_match_device(hdev, hdrv) != NULL;
2572}
2573
2574/**
2575 * hid_compare_device_paths - check if both devices share the same path
2576 * @hdev_a: hid device
2577 * @hdev_b: hid device
2578 * @separator: char to use as separator
2579 *
2580 * Check if two devices share the same path up to the last occurrence of
2581 * the separator char. Both paths must exist (i.e., zero-length paths
2582 * don't match).
2583 */
2584bool hid_compare_device_paths(struct hid_device *hdev_a,
2585			      struct hid_device *hdev_b, char separator)
2586{
2587	int n1 = strrchr(hdev_a->phys, separator) - hdev_a->phys;
2588	int n2 = strrchr(hdev_b->phys, separator) - hdev_b->phys;
2589
2590	if (n1 != n2 || n1 <= 0 || n2 <= 0)
2591		return false;
2592
2593	return !strncmp(hdev_a->phys, hdev_b->phys, n1);
2594}
2595EXPORT_SYMBOL_GPL(hid_compare_device_paths);
2596
2597static bool hid_check_device_match(struct hid_device *hdev,
2598				   struct hid_driver *hdrv,
2599				   const struct hid_device_id **id)
2600{
2601	*id = hid_match_device(hdev, hdrv);
2602	if (!*id)
2603		return false;
2604
2605	if (hdrv->match)
2606		return hdrv->match(hdev, hid_ignore_special_drivers);
2607
2608	/*
2609	 * hid-generic implements .match(), so we must be dealing with a
2610	 * different HID driver here, and can simply check if
2611	 * hid_ignore_special_drivers is set or not.
2612	 */
2613	return !hid_ignore_special_drivers;
2614}
2615
2616static int __hid_device_probe(struct hid_device *hdev, struct hid_driver *hdrv)
2617{
2618	const struct hid_device_id *id;
2619	int ret;
2620
2621	if (!hid_check_device_match(hdev, hdrv, &id))
2622		return -ENODEV;
2623
2624	hdev->devres_group_id = devres_open_group(&hdev->dev, NULL, GFP_KERNEL);
2625	if (!hdev->devres_group_id)
2626		return -ENOMEM;
2627
2628	/* reset the quirks that has been previously set */
2629	hdev->quirks = hid_lookup_quirk(hdev);
2630	hdev->driver = hdrv;
2631
2632	if (hdrv->probe) {
2633		ret = hdrv->probe(hdev, id);
2634	} else { /* default probe */
2635		ret = hid_open_report(hdev);
2636		if (!ret)
2637			ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
2638	}
2639
2640	/*
2641	 * Note that we are not closing the devres group opened above so
2642	 * even resources that were attached to the device after probe is
2643	 * run are released when hid_device_remove() is executed. This is
2644	 * needed as some drivers would allocate additional resources,
2645	 * for example when updating firmware.
2646	 */
2647
2648	if (ret) {
2649		devres_release_group(&hdev->dev, hdev->devres_group_id);
2650		hid_close_report(hdev);
2651		hdev->driver = NULL;
2652	}
2653
2654	return ret;
2655}
2656
2657static int hid_device_probe(struct device *dev)
2658{
2659	struct hid_device *hdev = to_hid_device(dev);
2660	struct hid_driver *hdrv = to_hid_driver(dev->driver);
 
 
2661	int ret = 0;
2662
2663	if (down_interruptible(&hdev->driver_input_lock))
2664		return -EINTR;
2665
 
2666	hdev->io_started = false;
 
2667	clear_bit(ffs(HID_STAT_REPROBED), &hdev->status);
2668
2669	if (!hdev->driver)
2670		ret = __hid_device_probe(hdev, hdrv);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2671
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2672	if (!hdev->io_started)
2673		up(&hdev->driver_input_lock);
2674
2675	return ret;
2676}
2677
2678static void hid_device_remove(struct device *dev)
2679{
2680	struct hid_device *hdev = to_hid_device(dev);
2681	struct hid_driver *hdrv;
2682
2683	down(&hdev->driver_input_lock);
2684	hdev->io_started = false;
2685
2686	hdrv = hdev->driver;
2687	if (hdrv) {
2688		if (hdrv->remove)
2689			hdrv->remove(hdev);
2690		else /* default remove */
2691			hid_hw_stop(hdev);
2692
2693		/* Release all devres resources allocated by the driver */
2694		devres_release_group(&hdev->dev, hdev->devres_group_id);
2695
2696		hid_close_report(hdev);
2697		hdev->driver = NULL;
2698	}
2699
2700	if (!hdev->io_started)
2701		up(&hdev->driver_input_lock);
2702}
2703
2704static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
2705			     char *buf)
2706{
2707	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
2708
2709	return scnprintf(buf, PAGE_SIZE, "hid:b%04Xg%04Xv%08Xp%08X\n",
2710			 hdev->bus, hdev->group, hdev->vendor, hdev->product);
2711}
2712static DEVICE_ATTR_RO(modalias);
2713
2714static struct attribute *hid_dev_attrs[] = {
2715	&dev_attr_modalias.attr,
2716	NULL,
2717};
2718static struct bin_attribute *hid_dev_bin_attrs[] = {
2719	&dev_bin_attr_report_desc,
2720	NULL
2721};
2722static const struct attribute_group hid_dev_group = {
2723	.attrs = hid_dev_attrs,
2724	.bin_attrs = hid_dev_bin_attrs,
2725};
2726__ATTRIBUTE_GROUPS(hid_dev);
2727
2728static int hid_uevent(const struct device *dev, struct kobj_uevent_env *env)
2729{
2730	const struct hid_device *hdev = to_hid_device(dev);
2731
2732	if (add_uevent_var(env, "HID_ID=%04X:%08X:%08X",
2733			hdev->bus, hdev->vendor, hdev->product))
2734		return -ENOMEM;
2735
2736	if (add_uevent_var(env, "HID_NAME=%s", hdev->name))
2737		return -ENOMEM;
2738
2739	if (add_uevent_var(env, "HID_PHYS=%s", hdev->phys))
2740		return -ENOMEM;
2741
2742	if (add_uevent_var(env, "HID_UNIQ=%s", hdev->uniq))
2743		return -ENOMEM;
2744
2745	if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",
2746			   hdev->bus, hdev->group, hdev->vendor, hdev->product))
2747		return -ENOMEM;
2748
2749	return 0;
2750}
2751
2752const struct bus_type hid_bus_type = {
2753	.name		= "hid",
2754	.dev_groups	= hid_dev_groups,
2755	.drv_groups	= hid_drv_groups,
2756	.match		= hid_bus_match,
2757	.probe		= hid_device_probe,
2758	.remove		= hid_device_remove,
2759	.uevent		= hid_uevent,
2760};
2761EXPORT_SYMBOL(hid_bus_type);
2762
2763int hid_add_device(struct hid_device *hdev)
2764{
2765	static atomic_t id = ATOMIC_INIT(0);
2766	int ret;
2767
2768	if (WARN_ON(hdev->status & HID_STAT_ADDED))
2769		return -EBUSY;
2770
2771	hdev->quirks = hid_lookup_quirk(hdev);
2772
2773	/* we need to kill them here, otherwise they will stay allocated to
2774	 * wait for coming driver */
2775	if (hid_ignore(hdev))
2776		return -ENODEV;
2777
2778	/*
2779	 * Check for the mandatory transport channel.
2780	 */
2781	 if (!hdev->ll_driver->raw_request) {
2782		hid_err(hdev, "transport driver missing .raw_request()\n");
2783		return -EINVAL;
2784	 }
2785
2786	/*
2787	 * Read the device report descriptor once and use as template
2788	 * for the driver-specific modifications.
2789	 */
2790	ret = hdev->ll_driver->parse(hdev);
2791	if (ret)
2792		return ret;
2793	if (!hdev->dev_rdesc)
2794		return -ENODEV;
2795
2796	/*
2797	 * Scan generic devices for group information
2798	 */
2799	if (hid_ignore_special_drivers) {
2800		hdev->group = HID_GROUP_GENERIC;
2801	} else if (!hdev->group &&
2802		   !(hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)) {
2803		ret = hid_scan_report(hdev);
2804		if (ret)
2805			hid_warn(hdev, "bad device descriptor (%d)\n", ret);
2806	}
2807
2808	hdev->id = atomic_inc_return(&id);
2809
2810	/* XXX hack, any other cleaner solution after the driver core
2811	 * is converted to allow more than 20 bytes as the device name? */
2812	dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
2813		     hdev->vendor, hdev->product, hdev->id);
2814
2815	hid_debug_register(hdev, dev_name(&hdev->dev));
2816	ret = device_add(&hdev->dev);
2817	if (!ret)
2818		hdev->status |= HID_STAT_ADDED;
2819	else
2820		hid_debug_unregister(hdev);
2821
2822	return ret;
2823}
2824EXPORT_SYMBOL_GPL(hid_add_device);
2825
2826/**
2827 * hid_allocate_device - allocate new hid device descriptor
2828 *
2829 * Allocate and initialize hid device, so that hid_destroy_device might be
2830 * used to free it.
2831 *
2832 * New hid_device pointer is returned on success, otherwise ERR_PTR encoded
2833 * error value.
2834 */
2835struct hid_device *hid_allocate_device(void)
2836{
2837	struct hid_device *hdev;
2838	int ret = -ENOMEM;
2839
2840	hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
2841	if (hdev == NULL)
2842		return ERR_PTR(ret);
2843
2844	device_initialize(&hdev->dev);
2845	hdev->dev.release = hid_device_release;
2846	hdev->dev.bus = &hid_bus_type;
2847	device_enable_async_suspend(&hdev->dev);
2848
2849	hid_close_report(hdev);
2850
2851	init_waitqueue_head(&hdev->debug_wait);
2852	INIT_LIST_HEAD(&hdev->debug_list);
2853	spin_lock_init(&hdev->debug_list_lock);
2854	sema_init(&hdev->driver_input_lock, 1);
2855	mutex_init(&hdev->ll_open_lock);
2856	kref_init(&hdev->ref);
2857
2858	hid_bpf_device_init(hdev);
2859
2860	return hdev;
2861}
2862EXPORT_SYMBOL_GPL(hid_allocate_device);
2863
2864static void hid_remove_device(struct hid_device *hdev)
2865{
2866	if (hdev->status & HID_STAT_ADDED) {
2867		device_del(&hdev->dev);
2868		hid_debug_unregister(hdev);
2869		hdev->status &= ~HID_STAT_ADDED;
2870	}
2871	kfree(hdev->dev_rdesc);
2872	hdev->dev_rdesc = NULL;
2873	hdev->dev_rsize = 0;
2874}
2875
2876/**
2877 * hid_destroy_device - free previously allocated device
2878 *
2879 * @hdev: hid device
2880 *
2881 * If you allocate hid_device through hid_allocate_device, you should ever
2882 * free by this function.
2883 */
2884void hid_destroy_device(struct hid_device *hdev)
2885{
2886	hid_bpf_destroy_device(hdev);
2887	hid_remove_device(hdev);
2888	put_device(&hdev->dev);
2889}
2890EXPORT_SYMBOL_GPL(hid_destroy_device);
2891
2892
2893static int __hid_bus_reprobe_drivers(struct device *dev, void *data)
2894{
2895	struct hid_driver *hdrv = data;
2896	struct hid_device *hdev = to_hid_device(dev);
2897
2898	if (hdev->driver == hdrv &&
2899	    !hdrv->match(hdev, hid_ignore_special_drivers) &&
2900	    !test_and_set_bit(ffs(HID_STAT_REPROBED), &hdev->status))
2901		return device_reprobe(dev);
2902
2903	return 0;
2904}
2905
2906static int __hid_bus_driver_added(struct device_driver *drv, void *data)
2907{
2908	struct hid_driver *hdrv = to_hid_driver(drv);
2909
2910	if (hdrv->match) {
2911		bus_for_each_dev(&hid_bus_type, NULL, hdrv,
2912				 __hid_bus_reprobe_drivers);
2913	}
2914
2915	return 0;
2916}
2917
2918static int __bus_removed_driver(struct device_driver *drv, void *data)
2919{
2920	return bus_rescan_devices(&hid_bus_type);
2921}
2922
2923int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
2924		const char *mod_name)
2925{
2926	int ret;
2927
2928	hdrv->driver.name = hdrv->name;
2929	hdrv->driver.bus = &hid_bus_type;
2930	hdrv->driver.owner = owner;
2931	hdrv->driver.mod_name = mod_name;
2932
2933	INIT_LIST_HEAD(&hdrv->dyn_list);
2934	spin_lock_init(&hdrv->dyn_lock);
2935
2936	ret = driver_register(&hdrv->driver);
2937
2938	if (ret == 0)
2939		bus_for_each_drv(&hid_bus_type, NULL, NULL,
2940				 __hid_bus_driver_added);
2941
2942	return ret;
2943}
2944EXPORT_SYMBOL_GPL(__hid_register_driver);
2945
2946void hid_unregister_driver(struct hid_driver *hdrv)
2947{
2948	driver_unregister(&hdrv->driver);
2949	hid_free_dynids(hdrv);
2950
2951	bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver);
2952}
2953EXPORT_SYMBOL_GPL(hid_unregister_driver);
2954
2955int hid_check_keys_pressed(struct hid_device *hid)
2956{
2957	struct hid_input *hidinput;
2958	int i;
2959
2960	if (!(hid->claimed & HID_CLAIMED_INPUT))
2961		return 0;
2962
2963	list_for_each_entry(hidinput, &hid->inputs, list) {
2964		for (i = 0; i < BITS_TO_LONGS(KEY_MAX); i++)
2965			if (hidinput->input->key[i])
2966				return 1;
2967	}
2968
2969	return 0;
2970}
2971EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
2972
2973#ifdef CONFIG_HID_BPF
2974static struct hid_bpf_ops hid_ops = {
2975	.hid_get_report = hid_get_report,
2976	.hid_hw_raw_request = hid_hw_raw_request,
2977	.owner = THIS_MODULE,
2978	.bus_type = &hid_bus_type,
2979};
2980#endif
2981
2982static int __init hid_init(void)
2983{
2984	int ret;
2985
 
 
 
 
2986	ret = bus_register(&hid_bus_type);
2987	if (ret) {
2988		pr_err("can't register hid bus\n");
2989		goto err;
2990	}
2991
2992#ifdef CONFIG_HID_BPF
2993	hid_bpf_ops = &hid_ops;
2994#endif
2995
2996	ret = hidraw_init();
2997	if (ret)
2998		goto err_bus;
2999
3000	hid_debug_init();
3001
3002	return 0;
3003err_bus:
3004	bus_unregister(&hid_bus_type);
3005err:
3006	return ret;
3007}
3008
3009static void __exit hid_exit(void)
3010{
3011#ifdef CONFIG_HID_BPF
3012	hid_bpf_ops = NULL;
3013#endif
3014	hid_debug_exit();
3015	hidraw_exit();
3016	bus_unregister(&hid_bus_type);
3017	hid_quirks_exit(HID_BUS_ANY);
3018}
3019
3020module_init(hid_init);
3021module_exit(hid_exit);
3022
3023MODULE_AUTHOR("Andreas Gal");
3024MODULE_AUTHOR("Vojtech Pavlik");
3025MODULE_AUTHOR("Jiri Kosina");
3026MODULE_LICENSE("GPL");
   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				       enum hid_report_type 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	INIT_LIST_HEAD(&report->field_entry_list);
  85
  86	return report;
  87}
  88EXPORT_SYMBOL_GPL(hid_register_report);
  89
  90/*
  91 * Register a new field for this report.
  92 */
  93
  94static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages)
  95{
  96	struct hid_field *field;
  97
  98	if (report->maxfield == HID_MAX_FIELDS) {
  99		hid_err(report->device, "too many fields in report\n");
 100		return NULL;
 101	}
 102
 103	field = kzalloc((sizeof(struct hid_field) +
 104			 usages * sizeof(struct hid_usage) +
 105			 3 * usages * sizeof(unsigned int)), GFP_KERNEL);
 106	if (!field)
 107		return NULL;
 108
 109	field->index = report->maxfield++;
 110	report->field[field->index] = field;
 111	field->usage = (struct hid_usage *)(field + 1);
 112	field->value = (s32 *)(field->usage + usages);
 113	field->new_value = (s32 *)(field->value + usages);
 114	field->usages_priorities = (s32 *)(field->new_value + usages);
 115	field->report = report;
 116
 117	return field;
 118}
 119
 120/*
 121 * Open a collection. The type/usage is pushed on the stack.
 122 */
 123
 124static int open_collection(struct hid_parser *parser, unsigned type)
 125{
 126	struct hid_collection *collection;
 127	unsigned usage;
 128	int collection_index;
 129
 130	usage = parser->local.usage[0];
 131
 132	if (parser->collection_stack_ptr == parser->collection_stack_size) {
 133		unsigned int *collection_stack;
 134		unsigned int new_size = parser->collection_stack_size +
 135					HID_COLLECTION_STACK_SIZE;
 136
 137		collection_stack = krealloc(parser->collection_stack,
 138					    new_size * sizeof(unsigned int),
 139					    GFP_KERNEL);
 140		if (!collection_stack)
 141			return -ENOMEM;
 142
 143		parser->collection_stack = collection_stack;
 144		parser->collection_stack_size = new_size;
 145	}
 146
 147	if (parser->device->maxcollection == parser->device->collection_size) {
 148		collection = kmalloc(
 149				array3_size(sizeof(struct hid_collection),
 150					    parser->device->collection_size,
 151					    2),
 152				GFP_KERNEL);
 153		if (collection == NULL) {
 154			hid_err(parser->device, "failed to reallocate collection array\n");
 155			return -ENOMEM;
 156		}
 157		memcpy(collection, parser->device->collection,
 158			sizeof(struct hid_collection) *
 159			parser->device->collection_size);
 160		memset(collection + parser->device->collection_size, 0,
 161			sizeof(struct hid_collection) *
 162			parser->device->collection_size);
 163		kfree(parser->device->collection);
 164		parser->device->collection = collection;
 165		parser->device->collection_size *= 2;
 166	}
 167
 168	parser->collection_stack[parser->collection_stack_ptr++] =
 169		parser->device->maxcollection;
 170
 171	collection_index = parser->device->maxcollection++;
 172	collection = parser->device->collection + collection_index;
 173	collection->type = type;
 174	collection->usage = usage;
 175	collection->level = parser->collection_stack_ptr - 1;
 176	collection->parent_idx = (collection->level == 0) ? -1 :
 177		parser->collection_stack[collection->level - 1];
 178
 179	if (type == HID_COLLECTION_APPLICATION)
 180		parser->device->maxapplication++;
 181
 182	return 0;
 183}
 184
 185/*
 186 * Close a collection.
 187 */
 188
 189static int close_collection(struct hid_parser *parser)
 190{
 191	if (!parser->collection_stack_ptr) {
 192		hid_err(parser->device, "collection stack underflow\n");
 193		return -EINVAL;
 194	}
 195	parser->collection_stack_ptr--;
 196	return 0;
 197}
 198
 199/*
 200 * Climb up the stack, search for the specified collection type
 201 * and return the usage.
 202 */
 203
 204static unsigned hid_lookup_collection(struct hid_parser *parser, unsigned type)
 205{
 206	struct hid_collection *collection = parser->device->collection;
 207	int n;
 208
 209	for (n = parser->collection_stack_ptr - 1; n >= 0; n--) {
 210		unsigned index = parser->collection_stack[n];
 211		if (collection[index].type == type)
 212			return collection[index].usage;
 213	}
 214	return 0; /* we know nothing about this usage type */
 215}
 216
 217/*
 218 * Concatenate usage which defines 16 bits or less with the
 219 * currently defined usage page to form a 32 bit usage
 220 */
 221
 222static void complete_usage(struct hid_parser *parser, unsigned int index)
 223{
 224	parser->local.usage[index] &= 0xFFFF;
 225	parser->local.usage[index] |=
 226		(parser->global.usage_page & 0xFFFF) << 16;
 227}
 228
 229/*
 230 * Add a usage to the temporary parser table.
 231 */
 232
 233static int hid_add_usage(struct hid_parser *parser, unsigned usage, u8 size)
 234{
 235	if (parser->local.usage_index >= HID_MAX_USAGES) {
 236		hid_err(parser->device, "usage index exceeded\n");
 237		return -1;
 238	}
 239	parser->local.usage[parser->local.usage_index] = usage;
 240
 241	/*
 242	 * If Usage item only includes usage id, concatenate it with
 243	 * currently defined usage page
 244	 */
 245	if (size <= 2)
 246		complete_usage(parser, parser->local.usage_index);
 247
 248	parser->local.usage_size[parser->local.usage_index] = size;
 249	parser->local.collection_index[parser->local.usage_index] =
 250		parser->collection_stack_ptr ?
 251		parser->collection_stack[parser->collection_stack_ptr - 1] : 0;
 252	parser->local.usage_index++;
 253	return 0;
 254}
 255
 256/*
 257 * Register a new field for this report.
 258 */
 259
 260static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsigned flags)
 261{
 262	struct hid_report *report;
 263	struct hid_field *field;
 
 264	unsigned int usages;
 265	unsigned int offset;
 266	unsigned int i;
 267	unsigned int application;
 268
 269	application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
 270
 271	report = hid_register_report(parser->device, report_type,
 272				     parser->global.report_id, application);
 273	if (!report) {
 274		hid_err(parser->device, "hid_register_report failed\n");
 275		return -1;
 276	}
 277
 278	/* Handle both signed and unsigned cases properly */
 279	if ((parser->global.logical_minimum < 0 &&
 280		parser->global.logical_maximum <
 281		parser->global.logical_minimum) ||
 282		(parser->global.logical_minimum >= 0 &&
 283		(__u32)parser->global.logical_maximum <
 284		(__u32)parser->global.logical_minimum)) {
 285		dbg_hid("logical range invalid 0x%x 0x%x\n",
 286			parser->global.logical_minimum,
 287			parser->global.logical_maximum);
 288		return -1;
 289	}
 290
 291	offset = report->size;
 292	report->size += parser->global.report_size * parser->global.report_count;
 293
 
 
 
 294	/* Total size check: Allow for possible report index byte */
 295	if (report->size > (HID_MAX_BUFFER_SIZE - 1) << 3) {
 296		hid_err(parser->device, "report is too long\n");
 297		return -1;
 298	}
 299
 300	if (!parser->local.usage_index) /* Ignore padding fields */
 301		return 0;
 302
 303	usages = max_t(unsigned, parser->local.usage_index,
 304				 parser->global.report_count);
 305
 306	field = hid_register_field(report, usages);
 307	if (!field)
 308		return 0;
 309
 310	field->physical = hid_lookup_collection(parser, HID_COLLECTION_PHYSICAL);
 311	field->logical = hid_lookup_collection(parser, HID_COLLECTION_LOGICAL);
 312	field->application = application;
 313
 314	for (i = 0; i < usages; i++) {
 315		unsigned j = i;
 316		/* Duplicate the last usage we parsed if we have excess values */
 317		if (i >= parser->local.usage_index)
 318			j = parser->local.usage_index - 1;
 319		field->usage[i].hid = parser->local.usage[j];
 320		field->usage[i].collection_index =
 321			parser->local.collection_index[j];
 322		field->usage[i].usage_index = i;
 323		field->usage[i].resolution_multiplier = 1;
 324	}
 325
 326	field->maxusage = usages;
 327	field->flags = flags;
 328	field->report_offset = offset;
 329	field->report_type = report_type;
 330	field->report_size = parser->global.report_size;
 331	field->report_count = parser->global.report_count;
 332	field->logical_minimum = parser->global.logical_minimum;
 333	field->logical_maximum = parser->global.logical_maximum;
 334	field->physical_minimum = parser->global.physical_minimum;
 335	field->physical_maximum = parser->global.physical_maximum;
 336	field->unit_exponent = parser->global.unit_exponent;
 337	field->unit = parser->global.unit;
 338
 339	return 0;
 340}
 341
 342/*
 343 * Read data value from item.
 344 */
 345
 346static u32 item_udata(struct hid_item *item)
 347{
 348	switch (item->size) {
 349	case 1: return item->data.u8;
 350	case 2: return item->data.u16;
 351	case 4: return item->data.u32;
 352	}
 353	return 0;
 354}
 355
 356static s32 item_sdata(struct hid_item *item)
 357{
 358	switch (item->size) {
 359	case 1: return item->data.s8;
 360	case 2: return item->data.s16;
 361	case 4: return item->data.s32;
 362	}
 363	return 0;
 364}
 365
 366/*
 367 * Process a global item.
 368 */
 369
 370static int hid_parser_global(struct hid_parser *parser, struct hid_item *item)
 371{
 372	__s32 raw_value;
 373	switch (item->tag) {
 374	case HID_GLOBAL_ITEM_TAG_PUSH:
 375
 376		if (parser->global_stack_ptr == HID_GLOBAL_STACK_SIZE) {
 377			hid_err(parser->device, "global environment stack overflow\n");
 378			return -1;
 379		}
 380
 381		memcpy(parser->global_stack + parser->global_stack_ptr++,
 382			&parser->global, sizeof(struct hid_global));
 383		return 0;
 384
 385	case HID_GLOBAL_ITEM_TAG_POP:
 386
 387		if (!parser->global_stack_ptr) {
 388			hid_err(parser->device, "global environment stack underflow\n");
 389			return -1;
 390		}
 391
 392		memcpy(&parser->global, parser->global_stack +
 393			--parser->global_stack_ptr, sizeof(struct hid_global));
 394		return 0;
 395
 396	case HID_GLOBAL_ITEM_TAG_USAGE_PAGE:
 397		parser->global.usage_page = item_udata(item);
 398		return 0;
 399
 400	case HID_GLOBAL_ITEM_TAG_LOGICAL_MINIMUM:
 401		parser->global.logical_minimum = item_sdata(item);
 402		return 0;
 403
 404	case HID_GLOBAL_ITEM_TAG_LOGICAL_MAXIMUM:
 405		if (parser->global.logical_minimum < 0)
 406			parser->global.logical_maximum = item_sdata(item);
 407		else
 408			parser->global.logical_maximum = item_udata(item);
 409		return 0;
 410
 411	case HID_GLOBAL_ITEM_TAG_PHYSICAL_MINIMUM:
 412		parser->global.physical_minimum = item_sdata(item);
 413		return 0;
 414
 415	case HID_GLOBAL_ITEM_TAG_PHYSICAL_MAXIMUM:
 416		if (parser->global.physical_minimum < 0)
 417			parser->global.physical_maximum = item_sdata(item);
 418		else
 419			parser->global.physical_maximum = item_udata(item);
 420		return 0;
 421
 422	case HID_GLOBAL_ITEM_TAG_UNIT_EXPONENT:
 423		/* Many devices provide unit exponent as a two's complement
 424		 * nibble due to the common misunderstanding of HID
 425		 * specification 1.11, 6.2.2.7 Global Items. Attempt to handle
 426		 * both this and the standard encoding. */
 427		raw_value = item_sdata(item);
 428		if (!(raw_value & 0xfffffff0))
 429			parser->global.unit_exponent = hid_snto32(raw_value, 4);
 430		else
 431			parser->global.unit_exponent = raw_value;
 432		return 0;
 433
 434	case HID_GLOBAL_ITEM_TAG_UNIT:
 435		parser->global.unit = item_udata(item);
 436		return 0;
 437
 438	case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
 439		parser->global.report_size = item_udata(item);
 440		if (parser->global.report_size > 256) {
 441			hid_err(parser->device, "invalid report_size %d\n",
 442					parser->global.report_size);
 443			return -1;
 444		}
 445		return 0;
 446
 447	case HID_GLOBAL_ITEM_TAG_REPORT_COUNT:
 448		parser->global.report_count = item_udata(item);
 449		if (parser->global.report_count > HID_MAX_USAGES) {
 450			hid_err(parser->device, "invalid report_count %d\n",
 451					parser->global.report_count);
 452			return -1;
 453		}
 454		return 0;
 455
 456	case HID_GLOBAL_ITEM_TAG_REPORT_ID:
 457		parser->global.report_id = item_udata(item);
 458		if (parser->global.report_id == 0 ||
 459		    parser->global.report_id >= HID_MAX_IDS) {
 460			hid_err(parser->device, "report_id %u is invalid\n",
 461				parser->global.report_id);
 462			return -1;
 463		}
 464		return 0;
 465
 466	default:
 467		hid_err(parser->device, "unknown global tag 0x%x\n", item->tag);
 468		return -1;
 469	}
 470}
 471
 472/*
 473 * Process a local item.
 474 */
 475
 476static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
 477{
 478	__u32 data;
 479	unsigned n;
 480	__u32 count;
 481
 482	data = item_udata(item);
 483
 484	switch (item->tag) {
 485	case HID_LOCAL_ITEM_TAG_DELIMITER:
 486
 487		if (data) {
 488			/*
 489			 * We treat items before the first delimiter
 490			 * as global to all usage sets (branch 0).
 491			 * In the moment we process only these global
 492			 * items and the first delimiter set.
 493			 */
 494			if (parser->local.delimiter_depth != 0) {
 495				hid_err(parser->device, "nested delimiters\n");
 496				return -1;
 497			}
 498			parser->local.delimiter_depth++;
 499			parser->local.delimiter_branch++;
 500		} else {
 501			if (parser->local.delimiter_depth < 1) {
 502				hid_err(parser->device, "bogus close delimiter\n");
 503				return -1;
 504			}
 505			parser->local.delimiter_depth--;
 506		}
 507		return 0;
 508
 509	case HID_LOCAL_ITEM_TAG_USAGE:
 510
 511		if (parser->local.delimiter_branch > 1) {
 512			dbg_hid("alternative usage ignored\n");
 513			return 0;
 514		}
 515
 516		return hid_add_usage(parser, data, item->size);
 517
 518	case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:
 519
 520		if (parser->local.delimiter_branch > 1) {
 521			dbg_hid("alternative usage ignored\n");
 522			return 0;
 523		}
 524
 525		parser->local.usage_minimum = data;
 526		return 0;
 527
 528	case HID_LOCAL_ITEM_TAG_USAGE_MAXIMUM:
 529
 530		if (parser->local.delimiter_branch > 1) {
 531			dbg_hid("alternative usage ignored\n");
 532			return 0;
 533		}
 534
 535		count = data - parser->local.usage_minimum;
 536		if (count + parser->local.usage_index >= HID_MAX_USAGES) {
 537			/*
 538			 * We do not warn if the name is not set, we are
 539			 * actually pre-scanning the device.
 540			 */
 541			if (dev_name(&parser->device->dev))
 542				hid_warn(parser->device,
 543					 "ignoring exceeding usage max\n");
 544			data = HID_MAX_USAGES - parser->local.usage_index +
 545				parser->local.usage_minimum - 1;
 546			if (data <= 0) {
 547				hid_err(parser->device,
 548					"no more usage index available\n");
 549				return -1;
 550			}
 551		}
 552
 553		for (n = parser->local.usage_minimum; n <= data; n++)
 554			if (hid_add_usage(parser, n, item->size)) {
 555				dbg_hid("hid_add_usage failed\n");
 556				return -1;
 557			}
 558		return 0;
 559
 560	default:
 561
 562		dbg_hid("unknown local item tag 0x%x\n", item->tag);
 563		return 0;
 564	}
 565	return 0;
 566}
 567
 568/*
 569 * Concatenate Usage Pages into Usages where relevant:
 570 * As per specification, 6.2.2.8: "When the parser encounters a main item it
 571 * concatenates the last declared Usage Page with a Usage to form a complete
 572 * usage value."
 573 */
 574
 575static void hid_concatenate_last_usage_page(struct hid_parser *parser)
 576{
 577	int i;
 578	unsigned int usage_page;
 579	unsigned int current_page;
 580
 581	if (!parser->local.usage_index)
 582		return;
 583
 584	usage_page = parser->global.usage_page;
 585
 586	/*
 587	 * Concatenate usage page again only if last declared Usage Page
 588	 * has not been already used in previous usages concatenation
 589	 */
 590	for (i = parser->local.usage_index - 1; i >= 0; i--) {
 591		if (parser->local.usage_size[i] > 2)
 592			/* Ignore extended usages */
 593			continue;
 594
 595		current_page = parser->local.usage[i] >> 16;
 596		if (current_page == usage_page)
 597			break;
 598
 599		complete_usage(parser, i);
 600	}
 601}
 602
 603/*
 604 * Process a main item.
 605 */
 606
 607static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
 608{
 609	__u32 data;
 610	int ret;
 611
 612	hid_concatenate_last_usage_page(parser);
 613
 614	data = item_udata(item);
 615
 616	switch (item->tag) {
 617	case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 618		ret = open_collection(parser, data & 0xff);
 619		break;
 620	case HID_MAIN_ITEM_TAG_END_COLLECTION:
 621		ret = close_collection(parser);
 622		break;
 623	case HID_MAIN_ITEM_TAG_INPUT:
 624		ret = hid_add_field(parser, HID_INPUT_REPORT, data);
 625		break;
 626	case HID_MAIN_ITEM_TAG_OUTPUT:
 627		ret = hid_add_field(parser, HID_OUTPUT_REPORT, data);
 628		break;
 629	case HID_MAIN_ITEM_TAG_FEATURE:
 630		ret = hid_add_field(parser, HID_FEATURE_REPORT, data);
 631		break;
 632	default:
 633		hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
 634		ret = 0;
 635	}
 636
 637	memset(&parser->local, 0, sizeof(parser->local));	/* Reset the local parser environment */
 638
 639	return ret;
 640}
 641
 642/*
 643 * Process a reserved item.
 644 */
 645
 646static int hid_parser_reserved(struct hid_parser *parser, struct hid_item *item)
 647{
 648	dbg_hid("reserved item type, tag 0x%x\n", item->tag);
 649	return 0;
 650}
 651
 652/*
 653 * Free a report and all registered fields. The field->usage and
 654 * field->value table's are allocated behind the field, so we need
 655 * only to free(field) itself.
 656 */
 657
 658static void hid_free_report(struct hid_report *report)
 659{
 660	unsigned n;
 661
 662	kfree(report->field_entries);
 663
 664	for (n = 0; n < report->maxfield; n++)
 665		kfree(report->field[n]);
 666	kfree(report);
 667}
 668
 669/*
 670 * Close report. This function returns the device
 671 * state to the point prior to hid_open_report().
 672 */
 673static void hid_close_report(struct hid_device *device)
 674{
 675	unsigned i, j;
 676
 677	for (i = 0; i < HID_REPORT_TYPES; i++) {
 678		struct hid_report_enum *report_enum = device->report_enum + i;
 679
 680		for (j = 0; j < HID_MAX_IDS; j++) {
 681			struct hid_report *report = report_enum->report_id_hash[j];
 682			if (report)
 683				hid_free_report(report);
 684		}
 685		memset(report_enum, 0, sizeof(*report_enum));
 686		INIT_LIST_HEAD(&report_enum->report_list);
 687	}
 688
 689	kfree(device->rdesc);
 690	device->rdesc = NULL;
 691	device->rsize = 0;
 692
 693	kfree(device->collection);
 694	device->collection = NULL;
 695	device->collection_size = 0;
 696	device->maxcollection = 0;
 697	device->maxapplication = 0;
 698
 699	device->status &= ~HID_STAT_PARSED;
 700}
 701
 702/*
 703 * Free a device structure, all reports, and all fields.
 704 */
 705
 706static void hid_device_release(struct device *dev)
 707{
 708	struct hid_device *hid = to_hid_device(dev);
 709
 710	hid_close_report(hid);
 711	kfree(hid->dev_rdesc);
 712	kfree(hid);
 713}
 714
 
 
 
 
 
 
 
 715/*
 716 * Fetch a report description item from the data stream. We support long
 717 * items, though they are not used yet.
 718 */
 719
 720static u8 *fetch_item(__u8 *start, __u8 *end, struct hid_item *item)
 721{
 722	u8 b;
 723
 724	if ((end - start) <= 0)
 725		return NULL;
 726
 727	b = *start++;
 728
 729	item->type = (b >> 2) & 3;
 730	item->tag  = (b >> 4) & 15;
 731
 732	if (item->tag == HID_ITEM_TAG_LONG) {
 733
 734		item->format = HID_ITEM_FORMAT_LONG;
 735
 736		if ((end - start) < 2)
 737			return NULL;
 738
 739		item->size = *start++;
 740		item->tag  = *start++;
 741
 742		if ((end - start) < item->size)
 743			return NULL;
 744
 745		item->data.longdata = start;
 746		start += item->size;
 747		return start;
 748	}
 749
 750	item->format = HID_ITEM_FORMAT_SHORT;
 751	item->size = b & 3;
 752
 753	switch (item->size) {
 754	case 0:
 755		return start;
 756
 757	case 1:
 758		if ((end - start) < 1)
 759			return NULL;
 760		item->data.u8 = *start++;
 761		return start;
 762
 763	case 2:
 764		if ((end - start) < 2)
 765			return NULL;
 766		item->data.u16 = get_unaligned_le16(start);
 767		start = (__u8 *)((__le16 *)start + 1);
 768		return start;
 769
 770	case 3:
 771		item->size++;
 772		if ((end - start) < 4)
 773			return NULL;
 774		item->data.u32 = get_unaligned_le32(start);
 775		start = (__u8 *)((__le32 *)start + 1);
 776		return start;
 777	}
 778
 779	return NULL;
 780}
 781
 782static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)
 783{
 784	struct hid_device *hid = parser->device;
 785
 786	if (usage == HID_DG_CONTACTID)
 787		hid->group = HID_GROUP_MULTITOUCH;
 788}
 789
 790static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
 791{
 792	if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
 793	    parser->global.report_size == 8)
 794		parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 795
 796	if (usage == 0xff0000c6 && parser->global.report_count == 1 &&
 797	    parser->global.report_size == 8)
 798		parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
 799}
 800
 801static void hid_scan_collection(struct hid_parser *parser, unsigned type)
 802{
 803	struct hid_device *hid = parser->device;
 804	int i;
 805
 806	if (((parser->global.usage_page << 16) == HID_UP_SENSOR) &&
 807	    type == HID_COLLECTION_PHYSICAL)
 
 808		hid->group = HID_GROUP_SENSOR_HUB;
 809
 810	if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
 811	    hid->product == USB_DEVICE_ID_MS_POWER_COVER &&
 812	    hid->group == HID_GROUP_MULTITOUCH)
 813		hid->group = HID_GROUP_GENERIC;
 814
 815	if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
 816		for (i = 0; i < parser->local.usage_index; i++)
 817			if (parser->local.usage[i] == HID_GD_POINTER)
 818				parser->scan_flags |= HID_SCAN_FLAG_GD_POINTER;
 819
 820	if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
 821		parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
 822
 823	if ((parser->global.usage_page << 16) == HID_UP_GOOGLEVENDOR)
 824		for (i = 0; i < parser->local.usage_index; i++)
 825			if (parser->local.usage[i] ==
 826					(HID_UP_GOOGLEVENDOR | 0x0001))
 827				parser->device->group =
 828					HID_GROUP_VIVALDI;
 829}
 830
 831static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
 832{
 833	__u32 data;
 834	int i;
 835
 836	hid_concatenate_last_usage_page(parser);
 837
 838	data = item_udata(item);
 839
 840	switch (item->tag) {
 841	case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
 842		hid_scan_collection(parser, data & 0xff);
 843		break;
 844	case HID_MAIN_ITEM_TAG_END_COLLECTION:
 845		break;
 846	case HID_MAIN_ITEM_TAG_INPUT:
 847		/* ignore constant inputs, they will be ignored by hid-input */
 848		if (data & HID_MAIN_ITEM_CONSTANT)
 849			break;
 850		for (i = 0; i < parser->local.usage_index; i++)
 851			hid_scan_input_usage(parser, parser->local.usage[i]);
 852		break;
 853	case HID_MAIN_ITEM_TAG_OUTPUT:
 854		break;
 855	case HID_MAIN_ITEM_TAG_FEATURE:
 856		for (i = 0; i < parser->local.usage_index; i++)
 857			hid_scan_feature_usage(parser, parser->local.usage[i]);
 858		break;
 859	}
 860
 861	/* Reset the local parser environment */
 862	memset(&parser->local, 0, sizeof(parser->local));
 863
 864	return 0;
 865}
 866
 867/*
 868 * Scan a report descriptor before the device is added to the bus.
 869 * Sets device groups and other properties that determine what driver
 870 * to load.
 871 */
 872static int hid_scan_report(struct hid_device *hid)
 873{
 874	struct hid_parser *parser;
 875	struct hid_item item;
 876	__u8 *start = hid->dev_rdesc;
 877	__u8 *end = start + hid->dev_rsize;
 878	static int (*dispatch_type[])(struct hid_parser *parser,
 879				      struct hid_item *item) = {
 880		hid_scan_main,
 881		hid_parser_global,
 882		hid_parser_local,
 883		hid_parser_reserved
 884	};
 885
 886	parser = vzalloc(sizeof(struct hid_parser));
 887	if (!parser)
 888		return -ENOMEM;
 889
 890	parser->device = hid;
 891	hid->group = HID_GROUP_GENERIC;
 892
 893	/*
 894	 * The parsing is simpler than the one in hid_open_report() as we should
 895	 * be robust against hid errors. Those errors will be raised by
 896	 * hid_open_report() anyway.
 897	 */
 898	while ((start = fetch_item(start, end, &item)) != NULL)
 899		dispatch_type[item.type](parser, &item);
 900
 901	/*
 902	 * Handle special flags set during scanning.
 903	 */
 904	if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
 905	    (hid->group == HID_GROUP_MULTITOUCH))
 906		hid->group = HID_GROUP_MULTITOUCH_WIN_8;
 907
 908	/*
 909	 * Vendor specific handlings
 910	 */
 911	switch (hid->vendor) {
 912	case USB_VENDOR_ID_WACOM:
 913		hid->group = HID_GROUP_WACOM;
 914		break;
 915	case USB_VENDOR_ID_SYNAPTICS:
 916		if (hid->group == HID_GROUP_GENERIC)
 917			if ((parser->scan_flags & HID_SCAN_FLAG_VENDOR_SPECIFIC)
 918			    && (parser->scan_flags & HID_SCAN_FLAG_GD_POINTER))
 919				/*
 920				 * hid-rmi should take care of them,
 921				 * not hid-generic
 922				 */
 923				hid->group = HID_GROUP_RMI;
 924		break;
 925	}
 926
 927	kfree(parser->collection_stack);
 928	vfree(parser);
 929	return 0;
 930}
 931
 932/**
 933 * hid_parse_report - parse device report
 934 *
 935 * @hid: hid device
 936 * @start: report start
 937 * @size: report size
 938 *
 939 * Allocate the device report as read by the bus driver. This function should
 940 * only be called from parse() in ll drivers.
 941 */
 942int hid_parse_report(struct hid_device *hid, __u8 *start, unsigned size)
 943{
 944	hid->dev_rdesc = kmemdup(start, size, GFP_KERNEL);
 945	if (!hid->dev_rdesc)
 946		return -ENOMEM;
 947	hid->dev_rsize = size;
 948	return 0;
 949}
 950EXPORT_SYMBOL_GPL(hid_parse_report);
 951
 952static const char * const hid_report_names[] = {
 953	"HID_INPUT_REPORT",
 954	"HID_OUTPUT_REPORT",
 955	"HID_FEATURE_REPORT",
 956};
 957/**
 958 * hid_validate_values - validate existing device report's value indexes
 959 *
 960 * @hid: hid device
 961 * @type: which report type to examine
 962 * @id: which report ID to examine (0 for first)
 963 * @field_index: which report field to examine
 964 * @report_counts: expected number of values
 965 *
 966 * Validate the number of values in a given field of a given report, after
 967 * parsing.
 968 */
 969struct hid_report *hid_validate_values(struct hid_device *hid,
 970				       enum hid_report_type type, unsigned int id,
 971				       unsigned int field_index,
 972				       unsigned int report_counts)
 973{
 974	struct hid_report *report;
 975
 976	if (type > HID_FEATURE_REPORT) {
 977		hid_err(hid, "invalid HID report type %u\n", type);
 978		return NULL;
 979	}
 980
 981	if (id >= HID_MAX_IDS) {
 982		hid_err(hid, "invalid HID report id %u\n", id);
 983		return NULL;
 984	}
 985
 986	/*
 987	 * Explicitly not using hid_get_report() here since it depends on
 988	 * ->numbered being checked, which may not always be the case when
 989	 * drivers go to access report values.
 990	 */
 991	if (id == 0) {
 992		/*
 993		 * Validating on id 0 means we should examine the first
 994		 * report in the list.
 995		 */
 996		report = list_first_entry_or_null(
 997				&hid->report_enum[type].report_list,
 998				struct hid_report, list);
 999	} else {
1000		report = hid->report_enum[type].report_id_hash[id];
1001	}
1002	if (!report) {
1003		hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
1004		return NULL;
1005	}
1006	if (report->maxfield <= field_index) {
1007		hid_err(hid, "not enough fields in %s %u\n",
1008			hid_report_names[type], id);
1009		return NULL;
1010	}
1011	if (report->field[field_index]->report_count < report_counts) {
1012		hid_err(hid, "not enough values in %s %u field %u\n",
1013			hid_report_names[type], id, field_index);
1014		return NULL;
1015	}
1016	return report;
1017}
1018EXPORT_SYMBOL_GPL(hid_validate_values);
1019
1020static int hid_calculate_multiplier(struct hid_device *hid,
1021				     struct hid_field *multiplier)
1022{
1023	int m;
1024	__s32 v = *multiplier->value;
1025	__s32 lmin = multiplier->logical_minimum;
1026	__s32 lmax = multiplier->logical_maximum;
1027	__s32 pmin = multiplier->physical_minimum;
1028	__s32 pmax = multiplier->physical_maximum;
1029
1030	/*
1031	 * "Because OS implementations will generally divide the control's
1032	 * reported count by the Effective Resolution Multiplier, designers
1033	 * should take care not to establish a potential Effective
1034	 * Resolution Multiplier of zero."
1035	 * HID Usage Table, v1.12, Section 4.3.1, p31
1036	 */
1037	if (lmax - lmin == 0)
1038		return 1;
1039	/*
1040	 * Handling the unit exponent is left as an exercise to whoever
1041	 * finds a device where that exponent is not 0.
1042	 */
1043	m = ((v - lmin)/(lmax - lmin) * (pmax - pmin) + pmin);
1044	if (unlikely(multiplier->unit_exponent != 0)) {
1045		hid_warn(hid,
1046			 "unsupported Resolution Multiplier unit exponent %d\n",
1047			 multiplier->unit_exponent);
1048	}
1049
1050	/* There are no devices with an effective multiplier > 255 */
1051	if (unlikely(m == 0 || m > 255 || m < -255)) {
1052		hid_warn(hid, "unsupported Resolution Multiplier %d\n", m);
1053		m = 1;
1054	}
1055
1056	return m;
1057}
1058
1059static void hid_apply_multiplier_to_field(struct hid_device *hid,
1060					  struct hid_field *field,
1061					  struct hid_collection *multiplier_collection,
1062					  int effective_multiplier)
1063{
1064	struct hid_collection *collection;
1065	struct hid_usage *usage;
1066	int i;
1067
1068	/*
1069	 * If multiplier_collection is NULL, the multiplier applies
1070	 * to all fields in the report.
1071	 * Otherwise, it is the Logical Collection the multiplier applies to
1072	 * but our field may be in a subcollection of that collection.
1073	 */
1074	for (i = 0; i < field->maxusage; i++) {
1075		usage = &field->usage[i];
1076
1077		collection = &hid->collection[usage->collection_index];
1078		while (collection->parent_idx != -1 &&
1079		       collection != multiplier_collection)
1080			collection = &hid->collection[collection->parent_idx];
1081
1082		if (collection->parent_idx != -1 ||
1083		    multiplier_collection == NULL)
1084			usage->resolution_multiplier = effective_multiplier;
1085
1086	}
1087}
1088
1089static void hid_apply_multiplier(struct hid_device *hid,
1090				 struct hid_field *multiplier)
1091{
1092	struct hid_report_enum *rep_enum;
1093	struct hid_report *rep;
1094	struct hid_field *field;
1095	struct hid_collection *multiplier_collection;
1096	int effective_multiplier;
1097	int i;
1098
1099	/*
1100	 * "The Resolution Multiplier control must be contained in the same
1101	 * Logical Collection as the control(s) to which it is to be applied.
1102	 * If no Resolution Multiplier is defined, then the Resolution
1103	 * Multiplier defaults to 1.  If more than one control exists in a
1104	 * Logical Collection, the Resolution Multiplier is associated with
1105	 * all controls in the collection. If no Logical Collection is
1106	 * defined, the Resolution Multiplier is associated with all
1107	 * controls in the report."
1108	 * HID Usage Table, v1.12, Section 4.3.1, p30
1109	 *
1110	 * Thus, search from the current collection upwards until we find a
1111	 * logical collection. Then search all fields for that same parent
1112	 * collection. Those are the fields the multiplier applies to.
1113	 *
1114	 * If we have more than one multiplier, it will overwrite the
1115	 * applicable fields later.
1116	 */
1117	multiplier_collection = &hid->collection[multiplier->usage->collection_index];
1118	while (multiplier_collection->parent_idx != -1 &&
1119	       multiplier_collection->type != HID_COLLECTION_LOGICAL)
1120		multiplier_collection = &hid->collection[multiplier_collection->parent_idx];
1121
1122	effective_multiplier = hid_calculate_multiplier(hid, multiplier);
1123
1124	rep_enum = &hid->report_enum[HID_INPUT_REPORT];
1125	list_for_each_entry(rep, &rep_enum->report_list, list) {
1126		for (i = 0; i < rep->maxfield; i++) {
1127			field = rep->field[i];
1128			hid_apply_multiplier_to_field(hid, field,
1129						      multiplier_collection,
1130						      effective_multiplier);
1131		}
1132	}
1133}
1134
1135/*
1136 * hid_setup_resolution_multiplier - set up all resolution multipliers
1137 *
1138 * @device: hid device
1139 *
1140 * Search for all Resolution Multiplier Feature Reports and apply their
1141 * value to all matching Input items. This only updates the internal struct
1142 * fields.
1143 *
1144 * The Resolution Multiplier is applied by the hardware. If the multiplier
1145 * is anything other than 1, the hardware will send pre-multiplied events
1146 * so that the same physical interaction generates an accumulated
1147 *	accumulated_value = value * * multiplier
1148 * This may be achieved by sending
1149 * - "value * multiplier" for each event, or
1150 * - "value" but "multiplier" times as frequently, or
1151 * - a combination of the above
1152 * The only guarantee is that the same physical interaction always generates
1153 * an accumulated 'value * multiplier'.
1154 *
1155 * This function must be called before any event processing and after
1156 * any SetRequest to the Resolution Multiplier.
1157 */
1158void hid_setup_resolution_multiplier(struct hid_device *hid)
1159{
1160	struct hid_report_enum *rep_enum;
1161	struct hid_report *rep;
1162	struct hid_usage *usage;
1163	int i, j;
1164
1165	rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
1166	list_for_each_entry(rep, &rep_enum->report_list, list) {
1167		for (i = 0; i < rep->maxfield; i++) {
1168			/* Ignore if report count is out of bounds. */
1169			if (rep->field[i]->report_count < 1)
1170				continue;
1171
1172			for (j = 0; j < rep->field[i]->maxusage; j++) {
1173				usage = &rep->field[i]->usage[j];
1174				if (usage->hid == HID_GD_RESOLUTION_MULTIPLIER)
1175					hid_apply_multiplier(hid,
1176							     rep->field[i]);
1177			}
1178		}
1179	}
1180}
1181EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier);
1182
1183/**
1184 * hid_open_report - open a driver-specific device report
1185 *
1186 * @device: hid device
1187 *
1188 * Parse a report description into a hid_device structure. Reports are
1189 * enumerated, fields are attached to these reports.
1190 * 0 returned on success, otherwise nonzero error value.
1191 *
1192 * This function (or the equivalent hid_parse() macro) should only be
1193 * called from probe() in drivers, before starting the device.
1194 */
1195int hid_open_report(struct hid_device *device)
1196{
1197	struct hid_parser *parser;
1198	struct hid_item item;
1199	unsigned int size;
1200	__u8 *start;
1201	__u8 *buf;
1202	__u8 *end;
1203	__u8 *next;
1204	int ret;
1205	int i;
1206	static int (*dispatch_type[])(struct hid_parser *parser,
1207				      struct hid_item *item) = {
1208		hid_parser_main,
1209		hid_parser_global,
1210		hid_parser_local,
1211		hid_parser_reserved
1212	};
1213
1214	if (WARN_ON(device->status & HID_STAT_PARSED))
1215		return -EBUSY;
1216
1217	start = device->dev_rdesc;
1218	if (WARN_ON(!start))
1219		return -ENODEV;
1220	size = device->dev_rsize;
1221
1222	buf = kmemdup(start, size, GFP_KERNEL);
 
1223	if (buf == NULL)
1224		return -ENOMEM;
1225
1226	if (device->driver->report_fixup)
1227		start = device->driver->report_fixup(device, buf, &size);
1228	else
1229		start = buf;
1230
1231	start = kmemdup(start, size, GFP_KERNEL);
1232	kfree(buf);
1233	if (start == NULL)
1234		return -ENOMEM;
1235
1236	device->rdesc = start;
1237	device->rsize = size;
1238
1239	parser = vzalloc(sizeof(struct hid_parser));
1240	if (!parser) {
1241		ret = -ENOMEM;
1242		goto alloc_err;
1243	}
1244
1245	parser->device = device;
1246
1247	end = start + size;
1248
1249	device->collection = kcalloc(HID_DEFAULT_NUM_COLLECTIONS,
1250				     sizeof(struct hid_collection), GFP_KERNEL);
1251	if (!device->collection) {
1252		ret = -ENOMEM;
1253		goto err;
1254	}
1255	device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
1256	for (i = 0; i < HID_DEFAULT_NUM_COLLECTIONS; i++)
1257		device->collection[i].parent_idx = -1;
1258
1259	ret = -EINVAL;
1260	while ((next = fetch_item(start, end, &item)) != NULL) {
1261		start = next;
1262
1263		if (item.format != HID_ITEM_FORMAT_SHORT) {
1264			hid_err(device, "unexpected long global item\n");
1265			goto err;
1266		}
1267
1268		if (dispatch_type[item.type](parser, &item)) {
1269			hid_err(device, "item %u %u %u %u parsing failed\n",
1270				item.format, (unsigned)item.size,
1271				(unsigned)item.type, (unsigned)item.tag);
1272			goto err;
1273		}
1274
1275		if (start == end) {
1276			if (parser->collection_stack_ptr) {
1277				hid_err(device, "unbalanced collection at end of report description\n");
1278				goto err;
1279			}
1280			if (parser->local.delimiter_depth) {
1281				hid_err(device, "unbalanced delimiter at end of report description\n");
1282				goto err;
1283			}
1284
1285			/*
1286			 * fetch initial values in case the device's
1287			 * default multiplier isn't the recommended 1
1288			 */
1289			hid_setup_resolution_multiplier(device);
1290
1291			kfree(parser->collection_stack);
1292			vfree(parser);
1293			device->status |= HID_STAT_PARSED;
1294
1295			return 0;
1296		}
1297	}
1298
1299	hid_err(device, "item fetching failed at offset %u/%u\n",
1300		size - (unsigned int)(end - start), size);
1301err:
1302	kfree(parser->collection_stack);
1303alloc_err:
1304	vfree(parser);
1305	hid_close_report(device);
1306	return ret;
1307}
1308EXPORT_SYMBOL_GPL(hid_open_report);
1309
1310/*
1311 * Convert a signed n-bit integer to signed 32-bit integer. Common
1312 * cases are done through the compiler, the screwed things has to be
1313 * done by hand.
1314 */
1315
1316static s32 snto32(__u32 value, unsigned n)
1317{
1318	if (!value || !n)
1319		return 0;
1320
1321	if (n > 32)
1322		n = 32;
1323
1324	switch (n) {
1325	case 8:  return ((__s8)value);
1326	case 16: return ((__s16)value);
1327	case 32: return ((__s32)value);
1328	}
1329	return value & (1 << (n - 1)) ? value | (~0U << n) : value;
1330}
1331
1332s32 hid_snto32(__u32 value, unsigned n)
1333{
1334	return snto32(value, n);
1335}
1336EXPORT_SYMBOL_GPL(hid_snto32);
1337
1338/*
1339 * Convert a signed 32-bit integer to a signed n-bit integer.
1340 */
1341
1342static u32 s32ton(__s32 value, unsigned n)
1343{
1344	s32 a = value >> (n - 1);
1345	if (a && a != -1)
1346		return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
1347	return value & ((1 << n) - 1);
1348}
1349
1350/*
1351 * Extract/implement a data field from/to a little endian report (bit array).
1352 *
1353 * Code sort-of follows HID spec:
1354 *     http://www.usb.org/developers/hidpage/HID1_11.pdf
1355 *
1356 * While the USB HID spec allows unlimited length bit fields in "report
1357 * descriptors", most devices never use more than 16 bits.
1358 * One model of UPS is claimed to report "LINEV" as a 32-bit field.
1359 * Search linux-kernel and linux-usb-devel archives for "hid-core extract".
1360 */
1361
1362static u32 __extract(u8 *report, unsigned offset, int n)
1363{
1364	unsigned int idx = offset / 8;
1365	unsigned int bit_nr = 0;
1366	unsigned int bit_shift = offset % 8;
1367	int bits_to_copy = 8 - bit_shift;
1368	u32 value = 0;
1369	u32 mask = n < 32 ? (1U << n) - 1 : ~0U;
1370
1371	while (n > 0) {
1372		value |= ((u32)report[idx] >> bit_shift) << bit_nr;
1373		n -= bits_to_copy;
1374		bit_nr += bits_to_copy;
1375		bits_to_copy = 8;
1376		bit_shift = 0;
1377		idx++;
1378	}
1379
1380	return value & mask;
1381}
1382
1383u32 hid_field_extract(const struct hid_device *hid, u8 *report,
1384			unsigned offset, unsigned n)
1385{
1386	if (n > 32) {
1387		hid_warn_once(hid, "%s() called with n (%d) > 32! (%s)\n",
1388			      __func__, n, current->comm);
1389		n = 32;
1390	}
1391
1392	return __extract(report, offset, n);
1393}
1394EXPORT_SYMBOL_GPL(hid_field_extract);
1395
1396/*
1397 * "implement" : set bits in a little endian bit stream.
1398 * Same concepts as "extract" (see comments above).
1399 * The data mangled in the bit stream remains in little endian
1400 * order the whole time. It make more sense to talk about
1401 * endianness of register values by considering a register
1402 * a "cached" copy of the little endian bit stream.
1403 */
1404
1405static void __implement(u8 *report, unsigned offset, int n, u32 value)
1406{
1407	unsigned int idx = offset / 8;
1408	unsigned int bit_shift = offset % 8;
1409	int bits_to_set = 8 - bit_shift;
1410
1411	while (n - bits_to_set >= 0) {
1412		report[idx] &= ~(0xff << bit_shift);
1413		report[idx] |= value << bit_shift;
1414		value >>= bits_to_set;
1415		n -= bits_to_set;
1416		bits_to_set = 8;
1417		bit_shift = 0;
1418		idx++;
1419	}
1420
1421	/* last nibble */
1422	if (n) {
1423		u8 bit_mask = ((1U << n) - 1);
1424		report[idx] &= ~(bit_mask << bit_shift);
1425		report[idx] |= value << bit_shift;
1426	}
1427}
1428
1429static void implement(const struct hid_device *hid, u8 *report,
1430		      unsigned offset, unsigned n, u32 value)
1431{
1432	if (unlikely(n > 32)) {
1433		hid_warn(hid, "%s() called with n (%d) > 32! (%s)\n",
1434			 __func__, n, current->comm);
1435		n = 32;
1436	} else if (n < 32) {
1437		u32 m = (1U << n) - 1;
1438
1439		if (unlikely(value > m)) {
1440			hid_warn(hid,
1441				 "%s() called with too large value %d (n: %d)! (%s)\n",
1442				 __func__, value, n, current->comm);
1443			WARN_ON(1);
1444			value &= m;
1445		}
1446	}
1447
1448	__implement(report, offset, n, value);
1449}
1450
1451/*
1452 * Search an array for a value.
1453 */
1454
1455static int search(__s32 *array, __s32 value, unsigned n)
1456{
1457	while (n--) {
1458		if (*array++ == value)
1459			return 0;
1460	}
1461	return -1;
1462}
1463
1464/**
1465 * hid_match_report - check if driver's raw_event should be called
1466 *
1467 * @hid: hid device
1468 * @report: hid report to match against
1469 *
1470 * compare hid->driver->report_table->report_type to report->type
1471 */
1472static int hid_match_report(struct hid_device *hid, struct hid_report *report)
1473{
1474	const struct hid_report_id *id = hid->driver->report_table;
1475
1476	if (!id) /* NULL means all */
1477		return 1;
1478
1479	for (; id->report_type != HID_TERMINATOR; id++)
1480		if (id->report_type == HID_ANY_ID ||
1481				id->report_type == report->type)
1482			return 1;
1483	return 0;
1484}
1485
1486/**
1487 * hid_match_usage - check if driver's event should be called
1488 *
1489 * @hid: hid device
1490 * @usage: usage to match against
1491 *
1492 * compare hid->driver->usage_table->usage_{type,code} to
1493 * usage->usage_{type,code}
1494 */
1495static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage)
1496{
1497	const struct hid_usage_id *id = hid->driver->usage_table;
1498
1499	if (!id) /* NULL means all */
1500		return 1;
1501
1502	for (; id->usage_type != HID_ANY_ID - 1; id++)
1503		if ((id->usage_hid == HID_ANY_ID ||
1504				id->usage_hid == usage->hid) &&
1505				(id->usage_type == HID_ANY_ID ||
1506				id->usage_type == usage->type) &&
1507				(id->usage_code == HID_ANY_ID ||
1508				 id->usage_code == usage->code))
1509			return 1;
1510	return 0;
1511}
1512
1513static void hid_process_event(struct hid_device *hid, struct hid_field *field,
1514		struct hid_usage *usage, __s32 value, int interrupt)
1515{
1516	struct hid_driver *hdrv = hid->driver;
1517	int ret;
1518
1519	if (!list_empty(&hid->debug_list))
1520		hid_dump_input(hid, usage, value);
1521
1522	if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
1523		ret = hdrv->event(hid, field, usage, value);
1524		if (ret != 0) {
1525			if (ret < 0)
1526				hid_err(hid, "%s's event failed with %d\n",
1527						hdrv->name, ret);
1528			return;
1529		}
1530	}
1531
1532	if (hid->claimed & HID_CLAIMED_INPUT)
1533		hidinput_hid_event(hid, field, usage, value);
1534	if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
1535		hid->hiddev_hid_event(hid, field, usage, value);
1536}
1537
1538/*
1539 * Checks if the given value is valid within this field
1540 */
1541static inline int hid_array_value_is_valid(struct hid_field *field,
1542					   __s32 value)
1543{
1544	__s32 min = field->logical_minimum;
1545
1546	/*
1547	 * Value needs to be between logical min and max, and
1548	 * (value - min) is used as an index in the usage array.
1549	 * This array is of size field->maxusage
1550	 */
1551	return value >= min &&
1552	       value <= field->logical_maximum &&
1553	       value - min < field->maxusage;
1554}
1555
1556/*
1557 * Fetch the field from the data. The field content is stored for next
1558 * report processing (we do differential reporting to the layer).
1559 */
1560static void hid_input_fetch_field(struct hid_device *hid,
1561				  struct hid_field *field,
1562				  __u8 *data)
1563{
1564	unsigned n;
1565	unsigned count = field->report_count;
1566	unsigned offset = field->report_offset;
1567	unsigned size = field->report_size;
1568	__s32 min = field->logical_minimum;
1569	__s32 *value;
1570
1571	value = field->new_value;
1572	memset(value, 0, count * sizeof(__s32));
1573	field->ignored = false;
1574
1575	for (n = 0; n < count; n++) {
1576
1577		value[n] = min < 0 ?
1578			snto32(hid_field_extract(hid, data, offset + n * size,
1579			       size), size) :
1580			hid_field_extract(hid, data, offset + n * size, size);
1581
1582		/* Ignore report if ErrorRollOver */
1583		if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
1584		    hid_array_value_is_valid(field, value[n]) &&
1585		    field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1) {
1586			field->ignored = true;
1587			return;
1588		}
1589	}
1590}
1591
1592/*
1593 * Process a received variable field.
1594 */
1595
1596static void hid_input_var_field(struct hid_device *hid,
1597				struct hid_field *field,
1598				int interrupt)
1599{
1600	unsigned int count = field->report_count;
1601	__s32 *value = field->new_value;
1602	unsigned int n;
1603
1604	for (n = 0; n < count; n++)
1605		hid_process_event(hid,
1606				  field,
1607				  &field->usage[n],
1608				  value[n],
1609				  interrupt);
1610
1611	memcpy(field->value, value, count * sizeof(__s32));
1612}
1613
1614/*
1615 * Process a received array field. The field content is stored for
1616 * next report processing (we do differential reporting to the layer).
1617 */
1618
1619static void hid_input_array_field(struct hid_device *hid,
1620				  struct hid_field *field,
1621				  int interrupt)
1622{
1623	unsigned int n;
1624	unsigned int count = field->report_count;
1625	__s32 min = field->logical_minimum;
1626	__s32 *value;
1627
1628	value = field->new_value;
1629
1630	/* ErrorRollOver */
1631	if (field->ignored)
1632		return;
1633
1634	for (n = 0; n < count; n++) {
1635		if (hid_array_value_is_valid(field, field->value[n]) &&
1636		    search(value, field->value[n], count))
1637			hid_process_event(hid,
1638					  field,
1639					  &field->usage[field->value[n] - min],
1640					  0,
1641					  interrupt);
1642
1643		if (hid_array_value_is_valid(field, value[n]) &&
1644		    search(field->value, value[n], count))
1645			hid_process_event(hid,
1646					  field,
1647					  &field->usage[value[n] - min],
1648					  1,
1649					  interrupt);
1650	}
1651
1652	memcpy(field->value, value, count * sizeof(__s32));
1653}
1654
1655/*
1656 * Analyse a received report, and fetch the data from it. The field
1657 * content is stored for next report processing (we do differential
1658 * reporting to the layer).
1659 */
1660static void hid_process_report(struct hid_device *hid,
1661			       struct hid_report *report,
1662			       __u8 *data,
1663			       int interrupt)
1664{
1665	unsigned int a;
1666	struct hid_field_entry *entry;
1667	struct hid_field *field;
1668
1669	/* first retrieve all incoming values in data */
1670	for (a = 0; a < report->maxfield; a++)
1671		hid_input_fetch_field(hid, report->field[a], data);
1672
1673	if (!list_empty(&report->field_entry_list)) {
1674		/* INPUT_REPORT, we have a priority list of fields */
1675		list_for_each_entry(entry,
1676				    &report->field_entry_list,
1677				    list) {
1678			field = entry->field;
1679
1680			if (field->flags & HID_MAIN_ITEM_VARIABLE)
1681				hid_process_event(hid,
1682						  field,
1683						  &field->usage[entry->index],
1684						  field->new_value[entry->index],
1685						  interrupt);
1686			else
1687				hid_input_array_field(hid, field, interrupt);
1688		}
1689
1690		/* we need to do the memcpy at the end for var items */
1691		for (a = 0; a < report->maxfield; a++) {
1692			field = report->field[a];
1693
1694			if (field->flags & HID_MAIN_ITEM_VARIABLE)
1695				memcpy(field->value, field->new_value,
1696				       field->report_count * sizeof(__s32));
1697		}
1698	} else {
1699		/* FEATURE_REPORT, regular processing */
1700		for (a = 0; a < report->maxfield; a++) {
1701			field = report->field[a];
1702
1703			if (field->flags & HID_MAIN_ITEM_VARIABLE)
1704				hid_input_var_field(hid, field, interrupt);
1705			else
1706				hid_input_array_field(hid, field, interrupt);
1707		}
1708	}
1709}
1710
1711/*
1712 * Insert a given usage_index in a field in the list
1713 * of processed usages in the report.
1714 *
1715 * The elements of lower priority score are processed
1716 * first.
1717 */
1718static void __hid_insert_field_entry(struct hid_device *hid,
1719				     struct hid_report *report,
1720				     struct hid_field_entry *entry,
1721				     struct hid_field *field,
1722				     unsigned int usage_index)
1723{
1724	struct hid_field_entry *next;
1725
1726	entry->field = field;
1727	entry->index = usage_index;
1728	entry->priority = field->usages_priorities[usage_index];
1729
1730	/* insert the element at the correct position */
1731	list_for_each_entry(next,
1732			    &report->field_entry_list,
1733			    list) {
1734		/*
1735		 * the priority of our element is strictly higher
1736		 * than the next one, insert it before
1737		 */
1738		if (entry->priority > next->priority) {
1739			list_add_tail(&entry->list, &next->list);
1740			return;
1741		}
1742	}
1743
1744	/* lowest priority score: insert at the end */
1745	list_add_tail(&entry->list, &report->field_entry_list);
1746}
1747
1748static void hid_report_process_ordering(struct hid_device *hid,
1749					struct hid_report *report)
1750{
1751	struct hid_field *field;
1752	struct hid_field_entry *entries;
1753	unsigned int a, u, usages;
1754	unsigned int count = 0;
1755
1756	/* count the number of individual fields in the report */
1757	for (a = 0; a < report->maxfield; a++) {
1758		field = report->field[a];
1759
1760		if (field->flags & HID_MAIN_ITEM_VARIABLE)
1761			count += field->report_count;
1762		else
1763			count++;
1764	}
1765
1766	/* allocate the memory to process the fields */
1767	entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
1768	if (!entries)
1769		return;
1770
1771	report->field_entries = entries;
1772
1773	/*
1774	 * walk through all fields in the report and
1775	 * store them by priority order in report->field_entry_list
1776	 *
1777	 * - Var elements are individualized (field + usage_index)
1778	 * - Arrays are taken as one, we can not chose an order for them
1779	 */
1780	usages = 0;
1781	for (a = 0; a < report->maxfield; a++) {
1782		field = report->field[a];
1783
1784		if (field->flags & HID_MAIN_ITEM_VARIABLE) {
1785			for (u = 0; u < field->report_count; u++) {
1786				__hid_insert_field_entry(hid, report,
1787							 &entries[usages],
1788							 field, u);
1789				usages++;
1790			}
1791		} else {
1792			__hid_insert_field_entry(hid, report, &entries[usages],
1793						 field, 0);
1794			usages++;
1795		}
1796	}
1797}
1798
1799static void hid_process_ordering(struct hid_device *hid)
1800{
1801	struct hid_report *report;
1802	struct hid_report_enum *report_enum = &hid->report_enum[HID_INPUT_REPORT];
1803
1804	list_for_each_entry(report, &report_enum->report_list, list)
1805		hid_report_process_ordering(hid, report);
1806}
1807
1808/*
1809 * Output the field into the report.
1810 */
1811
1812static void hid_output_field(const struct hid_device *hid,
1813			     struct hid_field *field, __u8 *data)
1814{
1815	unsigned count = field->report_count;
1816	unsigned offset = field->report_offset;
1817	unsigned size = field->report_size;
1818	unsigned n;
1819
1820	for (n = 0; n < count; n++) {
1821		if (field->logical_minimum < 0)	/* signed values */
1822			implement(hid, data, offset + n * size, size,
1823				  s32ton(field->value[n], size));
1824		else				/* unsigned values */
1825			implement(hid, data, offset + n * size, size,
1826				  field->value[n]);
1827	}
1828}
1829
1830/*
1831 * Compute the size of a report.
1832 */
1833static size_t hid_compute_report_size(struct hid_report *report)
1834{
1835	if (report->size)
1836		return ((report->size - 1) >> 3) + 1;
1837
1838	return 0;
1839}
1840
1841/*
1842 * Create a report. 'data' has to be allocated using
1843 * hid_alloc_report_buf() so that it has proper size.
1844 */
1845
1846void hid_output_report(struct hid_report *report, __u8 *data)
1847{
1848	unsigned n;
1849
1850	if (report->id > 0)
1851		*data++ = report->id;
1852
1853	memset(data, 0, hid_compute_report_size(report));
1854	for (n = 0; n < report->maxfield; n++)
1855		hid_output_field(report->device, report->field[n], data);
1856}
1857EXPORT_SYMBOL_GPL(hid_output_report);
1858
1859/*
1860 * Allocator for buffer that is going to be passed to hid_output_report()
1861 */
1862u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
1863{
1864	/*
1865	 * 7 extra bytes are necessary to achieve proper functionality
1866	 * of implement() working on 8 byte chunks
1867	 */
1868
1869	u32 len = hid_report_len(report) + 7;
1870
1871	return kmalloc(len, flags);
1872}
1873EXPORT_SYMBOL_GPL(hid_alloc_report_buf);
1874
1875/*
1876 * Set a field value. The report this field belongs to has to be
1877 * created and transferred to the device, to set this value in the
1878 * device.
1879 */
1880
1881int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
1882{
1883	unsigned size;
1884
1885	if (!field)
1886		return -1;
1887
1888	size = field->report_size;
1889
1890	hid_dump_input(field->report->device, field->usage + offset, value);
1891
1892	if (offset >= field->report_count) {
1893		hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n",
1894				offset, field->report_count);
1895		return -1;
1896	}
1897	if (field->logical_minimum < 0) {
1898		if (value != snto32(s32ton(value, size), size)) {
1899			hid_err(field->report->device, "value %d is out of range\n", value);
1900			return -1;
1901		}
1902	}
1903	field->value[offset] = value;
1904	return 0;
1905}
1906EXPORT_SYMBOL_GPL(hid_set_field);
1907
1908static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
1909		const u8 *data)
1910{
1911	struct hid_report *report;
1912	unsigned int n = 0;	/* Normally report number is 0 */
1913
1914	/* Device uses numbered reports, data[0] is report number */
1915	if (report_enum->numbered)
1916		n = *data;
1917
1918	report = report_enum->report_id_hash[n];
1919	if (report == NULL)
1920		dbg_hid("undefined report_id %u received\n", n);
1921
1922	return report;
1923}
1924
1925/*
1926 * Implement a generic .request() callback, using .raw_request()
1927 * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
1928 */
1929int __hid_request(struct hid_device *hid, struct hid_report *report,
1930		enum hid_class_request reqtype)
1931{
1932	char *buf;
1933	int ret;
1934	u32 len;
1935
1936	buf = hid_alloc_report_buf(report, GFP_KERNEL);
1937	if (!buf)
1938		return -ENOMEM;
1939
1940	len = hid_report_len(report);
1941
1942	if (reqtype == HID_REQ_SET_REPORT)
1943		hid_output_report(report, buf);
1944
1945	ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
1946					  report->type, reqtype);
1947	if (ret < 0) {
1948		dbg_hid("unable to complete request: %d\n", ret);
1949		goto out;
1950	}
1951
1952	if (reqtype == HID_REQ_GET_REPORT)
1953		hid_input_report(hid, report->type, buf, ret, 0);
1954
1955	ret = 0;
1956
1957out:
1958	kfree(buf);
1959	return ret;
1960}
1961EXPORT_SYMBOL_GPL(__hid_request);
1962
1963int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
1964			 int interrupt)
1965{
1966	struct hid_report_enum *report_enum = hid->report_enum + type;
1967	struct hid_report *report;
1968	struct hid_driver *hdrv;
 
1969	u32 rsize, csize = size;
1970	u8 *cdata = data;
1971	int ret = 0;
1972
1973	report = hid_get_report(report_enum, data);
1974	if (!report)
1975		goto out;
1976
1977	if (report_enum->numbered) {
1978		cdata++;
1979		csize--;
1980	}
1981
1982	rsize = hid_compute_report_size(report);
1983
1984	if (report_enum->numbered && rsize >= HID_MAX_BUFFER_SIZE)
1985		rsize = HID_MAX_BUFFER_SIZE - 1;
1986	else if (rsize > HID_MAX_BUFFER_SIZE)
1987		rsize = HID_MAX_BUFFER_SIZE;
 
 
 
1988
1989	if (csize < rsize) {
1990		dbg_hid("report %d is too short, (%d < %d)\n", report->id,
1991				csize, rsize);
1992		memset(cdata + csize, 0, rsize - csize);
1993	}
1994
1995	if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
1996		hid->hiddev_report_event(hid, report);
1997	if (hid->claimed & HID_CLAIMED_HIDRAW) {
1998		ret = hidraw_report_event(hid, data, size);
1999		if (ret)
2000			goto out;
2001	}
2002
2003	if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
2004		hid_process_report(hid, report, cdata, interrupt);
2005		hdrv = hid->driver;
2006		if (hdrv && hdrv->report)
2007			hdrv->report(hid, report);
2008	}
2009
2010	if (hid->claimed & HID_CLAIMED_INPUT)
2011		hidinput_report_event(hid, report);
2012out:
2013	return ret;
2014}
2015EXPORT_SYMBOL_GPL(hid_report_raw_event);
2016
2017/**
2018 * hid_input_report - report data from lower layer (usb, bt...)
2019 *
2020 * @hid: hid device
2021 * @type: HID report type (HID_*_REPORT)
2022 * @data: report contents
2023 * @size: size of data parameter
2024 * @interrupt: distinguish between interrupt and control transfers
2025 *
2026 * This is data entry for lower layers.
2027 */
2028int hid_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
2029		     int interrupt)
2030{
2031	struct hid_report_enum *report_enum;
2032	struct hid_driver *hdrv;
2033	struct hid_report *report;
2034	int ret = 0;
2035
2036	if (!hid)
2037		return -ENODEV;
2038
2039	if (down_trylock(&hid->driver_input_lock))
2040		return -EBUSY;
2041
2042	if (!hid->driver) {
2043		ret = -ENODEV;
2044		goto unlock;
2045	}
2046	report_enum = hid->report_enum + type;
2047	hdrv = hid->driver;
2048
 
 
 
 
 
 
2049	if (!size) {
2050		dbg_hid("empty report\n");
2051		ret = -1;
2052		goto unlock;
2053	}
2054
2055	/* Avoid unnecessary overhead if debugfs is disabled */
2056	if (!list_empty(&hid->debug_list))
2057		hid_dump_report(hid, type, data, size);
2058
2059	report = hid_get_report(report_enum, data);
2060
2061	if (!report) {
2062		ret = -1;
2063		goto unlock;
2064	}
2065
2066	if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
2067		ret = hdrv->raw_event(hid, report, data, size);
2068		if (ret < 0)
2069			goto unlock;
2070	}
2071
2072	ret = hid_report_raw_event(hid, type, data, size, interrupt);
2073
2074unlock:
2075	up(&hid->driver_input_lock);
2076	return ret;
2077}
2078EXPORT_SYMBOL_GPL(hid_input_report);
2079
2080bool hid_match_one_id(const struct hid_device *hdev,
2081		      const struct hid_device_id *id)
2082{
2083	return (id->bus == HID_BUS_ANY || id->bus == hdev->bus) &&
2084		(id->group == HID_GROUP_ANY || id->group == hdev->group) &&
2085		(id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&
2086		(id->product == HID_ANY_ID || id->product == hdev->product);
2087}
2088
2089const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
2090		const struct hid_device_id *id)
2091{
2092	for (; id->bus; id++)
2093		if (hid_match_one_id(hdev, id))
2094			return id;
2095
2096	return NULL;
2097}
2098EXPORT_SYMBOL_GPL(hid_match_id);
2099
2100static const struct hid_device_id hid_hiddev_list[] = {
2101	{ HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS) },
2102	{ HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS1) },
2103	{ }
2104};
2105
2106static bool hid_hiddev(struct hid_device *hdev)
2107{
2108	return !!hid_match_id(hdev, hid_hiddev_list);
2109}
2110
2111
2112static ssize_t
2113read_report_descriptor(struct file *filp, struct kobject *kobj,
2114		struct bin_attribute *attr,
2115		char *buf, loff_t off, size_t count)
2116{
2117	struct device *dev = kobj_to_dev(kobj);
2118	struct hid_device *hdev = to_hid_device(dev);
2119
2120	if (off >= hdev->rsize)
2121		return 0;
2122
2123	if (off + count > hdev->rsize)
2124		count = hdev->rsize - off;
2125
2126	memcpy(buf, hdev->rdesc + off, count);
2127
2128	return count;
2129}
2130
2131static ssize_t
2132show_country(struct device *dev, struct device_attribute *attr,
2133		char *buf)
2134{
2135	struct hid_device *hdev = to_hid_device(dev);
2136
2137	return sprintf(buf, "%02x\n", hdev->country & 0xff);
2138}
2139
2140static struct bin_attribute dev_bin_attr_report_desc = {
2141	.attr = { .name = "report_descriptor", .mode = 0444 },
2142	.read = read_report_descriptor,
2143	.size = HID_MAX_DESCRIPTOR_SIZE,
2144};
2145
2146static const struct device_attribute dev_attr_country = {
2147	.attr = { .name = "country", .mode = 0444 },
2148	.show = show_country,
2149};
2150
2151int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
2152{
2153	static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
2154		"Joystick", "Gamepad", "Keyboard", "Keypad",
2155		"Multi-Axis Controller"
2156	};
2157	const char *type, *bus;
2158	char buf[64] = "";
2159	unsigned int i;
2160	int len;
2161	int ret;
2162
 
 
 
 
2163	if (hdev->quirks & HID_QUIRK_HIDDEV_FORCE)
2164		connect_mask |= (HID_CONNECT_HIDDEV_FORCE | HID_CONNECT_HIDDEV);
2165	if (hdev->quirks & HID_QUIRK_HIDINPUT_FORCE)
2166		connect_mask |= HID_CONNECT_HIDINPUT_FORCE;
2167	if (hdev->bus != BUS_USB)
2168		connect_mask &= ~HID_CONNECT_HIDDEV;
2169	if (hid_hiddev(hdev))
2170		connect_mask |= HID_CONNECT_HIDDEV_FORCE;
2171
2172	if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,
2173				connect_mask & HID_CONNECT_HIDINPUT_FORCE))
2174		hdev->claimed |= HID_CLAIMED_INPUT;
2175
2176	if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect &&
2177			!hdev->hiddev_connect(hdev,
2178				connect_mask & HID_CONNECT_HIDDEV_FORCE))
2179		hdev->claimed |= HID_CLAIMED_HIDDEV;
2180	if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))
2181		hdev->claimed |= HID_CLAIMED_HIDRAW;
2182
2183	if (connect_mask & HID_CONNECT_DRIVER)
2184		hdev->claimed |= HID_CLAIMED_DRIVER;
2185
2186	/* Drivers with the ->raw_event callback set are not required to connect
2187	 * to any other listener. */
2188	if (!hdev->claimed && !hdev->driver->raw_event) {
2189		hid_err(hdev, "device has no listeners, quitting\n");
2190		return -ENODEV;
2191	}
2192
2193	hid_process_ordering(hdev);
2194
2195	if ((hdev->claimed & HID_CLAIMED_INPUT) &&
2196			(connect_mask & HID_CONNECT_FF) && hdev->ff_init)
2197		hdev->ff_init(hdev);
2198
2199	len = 0;
2200	if (hdev->claimed & HID_CLAIMED_INPUT)
2201		len += sprintf(buf + len, "input");
2202	if (hdev->claimed & HID_CLAIMED_HIDDEV)
2203		len += sprintf(buf + len, "%shiddev%d", len ? "," : "",
2204				((struct hiddev *)hdev->hiddev)->minor);
2205	if (hdev->claimed & HID_CLAIMED_HIDRAW)
2206		len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
2207				((struct hidraw *)hdev->hidraw)->minor);
2208
2209	type = "Device";
2210	for (i = 0; i < hdev->maxcollection; i++) {
2211		struct hid_collection *col = &hdev->collection[i];
2212		if (col->type == HID_COLLECTION_APPLICATION &&
2213		   (col->usage & HID_USAGE_PAGE) == HID_UP_GENDESK &&
2214		   (col->usage & 0xffff) < ARRAY_SIZE(types)) {
2215			type = types[col->usage & 0xffff];
2216			break;
2217		}
2218	}
2219
2220	switch (hdev->bus) {
2221	case BUS_USB:
2222		bus = "USB";
2223		break;
2224	case BUS_BLUETOOTH:
2225		bus = "BLUETOOTH";
2226		break;
2227	case BUS_I2C:
2228		bus = "I2C";
2229		break;
2230	case BUS_VIRTUAL:
2231		bus = "VIRTUAL";
2232		break;
2233	case BUS_INTEL_ISHTP:
2234	case BUS_AMD_SFH:
2235		bus = "SENSOR HUB";
2236		break;
2237	default:
2238		bus = "<UNKNOWN>";
2239	}
2240
2241	ret = device_create_file(&hdev->dev, &dev_attr_country);
2242	if (ret)
2243		hid_warn(hdev,
2244			 "can't create sysfs country code attribute err: %d\n", ret);
2245
2246	hid_info(hdev, "%s: %s HID v%x.%02x %s [%s] on %s\n",
2247		 buf, bus, hdev->version >> 8, hdev->version & 0xff,
2248		 type, hdev->name, hdev->phys);
2249
2250	return 0;
2251}
2252EXPORT_SYMBOL_GPL(hid_connect);
2253
2254void hid_disconnect(struct hid_device *hdev)
2255{
2256	device_remove_file(&hdev->dev, &dev_attr_country);
2257	if (hdev->claimed & HID_CLAIMED_INPUT)
2258		hidinput_disconnect(hdev);
2259	if (hdev->claimed & HID_CLAIMED_HIDDEV)
2260		hdev->hiddev_disconnect(hdev);
2261	if (hdev->claimed & HID_CLAIMED_HIDRAW)
2262		hidraw_disconnect(hdev);
2263	hdev->claimed = 0;
 
 
2264}
2265EXPORT_SYMBOL_GPL(hid_disconnect);
2266
2267/**
2268 * hid_hw_start - start underlying HW
2269 * @hdev: hid device
2270 * @connect_mask: which outputs to connect, see HID_CONNECT_*
2271 *
2272 * Call this in probe function *after* hid_parse. This will setup HW
2273 * buffers and start the device (if not defeirred to device open).
2274 * hid_hw_stop must be called if this was successful.
2275 */
2276int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask)
2277{
2278	int error;
2279
2280	error = hdev->ll_driver->start(hdev);
2281	if (error)
2282		return error;
2283
2284	if (connect_mask) {
2285		error = hid_connect(hdev, connect_mask);
2286		if (error) {
2287			hdev->ll_driver->stop(hdev);
2288			return error;
2289		}
2290	}
2291
2292	return 0;
2293}
2294EXPORT_SYMBOL_GPL(hid_hw_start);
2295
2296/**
2297 * hid_hw_stop - stop underlying HW
2298 * @hdev: hid device
2299 *
2300 * This is usually called from remove function or from probe when something
2301 * failed and hid_hw_start was called already.
2302 */
2303void hid_hw_stop(struct hid_device *hdev)
2304{
2305	hid_disconnect(hdev);
2306	hdev->ll_driver->stop(hdev);
2307}
2308EXPORT_SYMBOL_GPL(hid_hw_stop);
2309
2310/**
2311 * hid_hw_open - signal underlying HW to start delivering events
2312 * @hdev: hid device
2313 *
2314 * Tell underlying HW to start delivering events from the device.
2315 * This function should be called sometime after successful call
2316 * to hid_hw_start().
2317 */
2318int hid_hw_open(struct hid_device *hdev)
2319{
2320	int ret;
2321
2322	ret = mutex_lock_killable(&hdev->ll_open_lock);
2323	if (ret)
2324		return ret;
2325
2326	if (!hdev->ll_open_count++) {
2327		ret = hdev->ll_driver->open(hdev);
2328		if (ret)
2329			hdev->ll_open_count--;
2330	}
2331
2332	mutex_unlock(&hdev->ll_open_lock);
2333	return ret;
2334}
2335EXPORT_SYMBOL_GPL(hid_hw_open);
2336
2337/**
2338 * hid_hw_close - signal underlaying HW to stop delivering events
2339 *
2340 * @hdev: hid device
2341 *
2342 * This function indicates that we are not interested in the events
2343 * from this device anymore. Delivery of events may or may not stop,
2344 * depending on the number of users still outstanding.
2345 */
2346void hid_hw_close(struct hid_device *hdev)
2347{
2348	mutex_lock(&hdev->ll_open_lock);
2349	if (!--hdev->ll_open_count)
2350		hdev->ll_driver->close(hdev);
2351	mutex_unlock(&hdev->ll_open_lock);
2352}
2353EXPORT_SYMBOL_GPL(hid_hw_close);
2354
2355/**
2356 * hid_hw_request - send report request to device
2357 *
2358 * @hdev: hid device
2359 * @report: report to send
2360 * @reqtype: hid request type
2361 */
2362void hid_hw_request(struct hid_device *hdev,
2363		    struct hid_report *report, enum hid_class_request reqtype)
2364{
2365	if (hdev->ll_driver->request)
2366		return hdev->ll_driver->request(hdev, report, reqtype);
2367
2368	__hid_request(hdev, report, reqtype);
2369}
2370EXPORT_SYMBOL_GPL(hid_hw_request);
2371
2372/**
2373 * hid_hw_raw_request - send report request to device
2374 *
2375 * @hdev: hid device
2376 * @reportnum: report ID
2377 * @buf: in/out data to transfer
2378 * @len: length of buf
2379 * @rtype: HID report type
2380 * @reqtype: HID_REQ_GET_REPORT or HID_REQ_SET_REPORT
2381 *
2382 * Return: count of data transferred, negative if error
2383 *
2384 * Same behavior as hid_hw_request, but with raw buffers instead.
2385 */
2386int hid_hw_raw_request(struct hid_device *hdev,
2387		       unsigned char reportnum, __u8 *buf,
2388		       size_t len, enum hid_report_type rtype, enum hid_class_request reqtype)
2389{
2390	if (len < 1 || len > HID_MAX_BUFFER_SIZE || !buf)
 
 
 
 
 
2391		return -EINVAL;
2392
2393	return hdev->ll_driver->raw_request(hdev, reportnum, buf, len,
2394					    rtype, reqtype);
2395}
2396EXPORT_SYMBOL_GPL(hid_hw_raw_request);
2397
2398/**
2399 * hid_hw_output_report - send output report to device
2400 *
2401 * @hdev: hid device
2402 * @buf: raw data to transfer
2403 * @len: length of buf
2404 *
2405 * Return: count of data transferred, negative if error
2406 */
2407int hid_hw_output_report(struct hid_device *hdev, __u8 *buf, size_t len)
2408{
2409	if (len < 1 || len > HID_MAX_BUFFER_SIZE || !buf)
 
 
 
 
 
2410		return -EINVAL;
2411
2412	if (hdev->ll_driver->output_report)
2413		return hdev->ll_driver->output_report(hdev, buf, len);
2414
2415	return -ENOSYS;
2416}
2417EXPORT_SYMBOL_GPL(hid_hw_output_report);
2418
2419#ifdef CONFIG_PM
2420int hid_driver_suspend(struct hid_device *hdev, pm_message_t state)
2421{
2422	if (hdev->driver && hdev->driver->suspend)
2423		return hdev->driver->suspend(hdev, state);
2424
2425	return 0;
2426}
2427EXPORT_SYMBOL_GPL(hid_driver_suspend);
2428
2429int hid_driver_reset_resume(struct hid_device *hdev)
2430{
2431	if (hdev->driver && hdev->driver->reset_resume)
2432		return hdev->driver->reset_resume(hdev);
2433
2434	return 0;
2435}
2436EXPORT_SYMBOL_GPL(hid_driver_reset_resume);
2437
2438int hid_driver_resume(struct hid_device *hdev)
2439{
2440	if (hdev->driver && hdev->driver->resume)
2441		return hdev->driver->resume(hdev);
2442
2443	return 0;
2444}
2445EXPORT_SYMBOL_GPL(hid_driver_resume);
2446#endif /* CONFIG_PM */
2447
2448struct hid_dynid {
2449	struct list_head list;
2450	struct hid_device_id id;
2451};
2452
2453/**
2454 * new_id_store - add a new HID device ID to this driver and re-probe devices
2455 * @drv: target device driver
2456 * @buf: buffer for scanning device ID data
2457 * @count: input size
2458 *
2459 * Adds a new dynamic hid device ID to this driver,
2460 * and causes the driver to probe for all devices again.
2461 */
2462static ssize_t new_id_store(struct device_driver *drv, const char *buf,
2463		size_t count)
2464{
2465	struct hid_driver *hdrv = to_hid_driver(drv);
2466	struct hid_dynid *dynid;
2467	__u32 bus, vendor, product;
2468	unsigned long driver_data = 0;
2469	int ret;
2470
2471	ret = sscanf(buf, "%x %x %x %lx",
2472			&bus, &vendor, &product, &driver_data);
2473	if (ret < 3)
2474		return -EINVAL;
2475
2476	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
2477	if (!dynid)
2478		return -ENOMEM;
2479
2480	dynid->id.bus = bus;
2481	dynid->id.group = HID_GROUP_ANY;
2482	dynid->id.vendor = vendor;
2483	dynid->id.product = product;
2484	dynid->id.driver_data = driver_data;
2485
2486	spin_lock(&hdrv->dyn_lock);
2487	list_add_tail(&dynid->list, &hdrv->dyn_list);
2488	spin_unlock(&hdrv->dyn_lock);
2489
2490	ret = driver_attach(&hdrv->driver);
2491
2492	return ret ? : count;
2493}
2494static DRIVER_ATTR_WO(new_id);
2495
2496static struct attribute *hid_drv_attrs[] = {
2497	&driver_attr_new_id.attr,
2498	NULL,
2499};
2500ATTRIBUTE_GROUPS(hid_drv);
2501
2502static void hid_free_dynids(struct hid_driver *hdrv)
2503{
2504	struct hid_dynid *dynid, *n;
2505
2506	spin_lock(&hdrv->dyn_lock);
2507	list_for_each_entry_safe(dynid, n, &hdrv->dyn_list, list) {
2508		list_del(&dynid->list);
2509		kfree(dynid);
2510	}
2511	spin_unlock(&hdrv->dyn_lock);
2512}
2513
2514const struct hid_device_id *hid_match_device(struct hid_device *hdev,
2515					     struct hid_driver *hdrv)
2516{
2517	struct hid_dynid *dynid;
2518
2519	spin_lock(&hdrv->dyn_lock);
2520	list_for_each_entry(dynid, &hdrv->dyn_list, list) {
2521		if (hid_match_one_id(hdev, &dynid->id)) {
2522			spin_unlock(&hdrv->dyn_lock);
2523			return &dynid->id;
2524		}
2525	}
2526	spin_unlock(&hdrv->dyn_lock);
2527
2528	return hid_match_id(hdev, hdrv->id_table);
2529}
2530EXPORT_SYMBOL_GPL(hid_match_device);
2531
2532static int hid_bus_match(struct device *dev, struct device_driver *drv)
2533{
2534	struct hid_driver *hdrv = to_hid_driver(drv);
2535	struct hid_device *hdev = to_hid_device(dev);
2536
2537	return hid_match_device(hdev, hdrv) != NULL;
2538}
2539
2540/**
2541 * hid_compare_device_paths - check if both devices share the same path
2542 * @hdev_a: hid device
2543 * @hdev_b: hid device
2544 * @separator: char to use as separator
2545 *
2546 * Check if two devices share the same path up to the last occurrence of
2547 * the separator char. Both paths must exist (i.e., zero-length paths
2548 * don't match).
2549 */
2550bool hid_compare_device_paths(struct hid_device *hdev_a,
2551			      struct hid_device *hdev_b, char separator)
2552{
2553	int n1 = strrchr(hdev_a->phys, separator) - hdev_a->phys;
2554	int n2 = strrchr(hdev_b->phys, separator) - hdev_b->phys;
2555
2556	if (n1 != n2 || n1 <= 0 || n2 <= 0)
2557		return false;
2558
2559	return !strncmp(hdev_a->phys, hdev_b->phys, n1);
2560}
2561EXPORT_SYMBOL_GPL(hid_compare_device_paths);
2562
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2563static int hid_device_probe(struct device *dev)
2564{
 
2565	struct hid_driver *hdrv = to_hid_driver(dev->driver);
2566	struct hid_device *hdev = to_hid_device(dev);
2567	const struct hid_device_id *id;
2568	int ret = 0;
2569
2570	if (down_interruptible(&hdev->driver_input_lock)) {
2571		ret = -EINTR;
2572		goto end;
2573	}
2574	hdev->io_started = false;
2575
2576	clear_bit(ffs(HID_STAT_REPROBED), &hdev->status);
2577
2578	if (!hdev->driver) {
2579		id = hid_match_device(hdev, hdrv);
2580		if (id == NULL) {
2581			ret = -ENODEV;
2582			goto unlock;
2583		}
2584
2585		if (hdrv->match) {
2586			if (!hdrv->match(hdev, hid_ignore_special_drivers)) {
2587				ret = -ENODEV;
2588				goto unlock;
2589			}
2590		} else {
2591			/*
2592			 * hid-generic implements .match(), so if
2593			 * hid_ignore_special_drivers is set, we can safely
2594			 * return.
2595			 */
2596			if (hid_ignore_special_drivers) {
2597				ret = -ENODEV;
2598				goto unlock;
2599			}
2600		}
2601
2602		/* reset the quirks that has been previously set */
2603		hdev->quirks = hid_lookup_quirk(hdev);
2604		hdev->driver = hdrv;
2605		if (hdrv->probe) {
2606			ret = hdrv->probe(hdev, id);
2607		} else { /* default probe */
2608			ret = hid_open_report(hdev);
2609			if (!ret)
2610				ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
2611		}
2612		if (ret) {
2613			hid_close_report(hdev);
2614			hdev->driver = NULL;
2615		}
2616	}
2617unlock:
2618	if (!hdev->io_started)
2619		up(&hdev->driver_input_lock);
2620end:
2621	return ret;
2622}
2623
2624static void hid_device_remove(struct device *dev)
2625{
2626	struct hid_device *hdev = to_hid_device(dev);
2627	struct hid_driver *hdrv;
2628
2629	down(&hdev->driver_input_lock);
2630	hdev->io_started = false;
2631
2632	hdrv = hdev->driver;
2633	if (hdrv) {
2634		if (hdrv->remove)
2635			hdrv->remove(hdev);
2636		else /* default remove */
2637			hid_hw_stop(hdev);
 
 
 
 
2638		hid_close_report(hdev);
2639		hdev->driver = NULL;
2640	}
2641
2642	if (!hdev->io_started)
2643		up(&hdev->driver_input_lock);
2644}
2645
2646static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
2647			     char *buf)
2648{
2649	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
2650
2651	return scnprintf(buf, PAGE_SIZE, "hid:b%04Xg%04Xv%08Xp%08X\n",
2652			 hdev->bus, hdev->group, hdev->vendor, hdev->product);
2653}
2654static DEVICE_ATTR_RO(modalias);
2655
2656static struct attribute *hid_dev_attrs[] = {
2657	&dev_attr_modalias.attr,
2658	NULL,
2659};
2660static struct bin_attribute *hid_dev_bin_attrs[] = {
2661	&dev_bin_attr_report_desc,
2662	NULL
2663};
2664static const struct attribute_group hid_dev_group = {
2665	.attrs = hid_dev_attrs,
2666	.bin_attrs = hid_dev_bin_attrs,
2667};
2668__ATTRIBUTE_GROUPS(hid_dev);
2669
2670static int hid_uevent(struct device *dev, struct kobj_uevent_env *env)
2671{
2672	struct hid_device *hdev = to_hid_device(dev);
2673
2674	if (add_uevent_var(env, "HID_ID=%04X:%08X:%08X",
2675			hdev->bus, hdev->vendor, hdev->product))
2676		return -ENOMEM;
2677
2678	if (add_uevent_var(env, "HID_NAME=%s", hdev->name))
2679		return -ENOMEM;
2680
2681	if (add_uevent_var(env, "HID_PHYS=%s", hdev->phys))
2682		return -ENOMEM;
2683
2684	if (add_uevent_var(env, "HID_UNIQ=%s", hdev->uniq))
2685		return -ENOMEM;
2686
2687	if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",
2688			   hdev->bus, hdev->group, hdev->vendor, hdev->product))
2689		return -ENOMEM;
2690
2691	return 0;
2692}
2693
2694struct bus_type hid_bus_type = {
2695	.name		= "hid",
2696	.dev_groups	= hid_dev_groups,
2697	.drv_groups	= hid_drv_groups,
2698	.match		= hid_bus_match,
2699	.probe		= hid_device_probe,
2700	.remove		= hid_device_remove,
2701	.uevent		= hid_uevent,
2702};
2703EXPORT_SYMBOL(hid_bus_type);
2704
2705int hid_add_device(struct hid_device *hdev)
2706{
2707	static atomic_t id = ATOMIC_INIT(0);
2708	int ret;
2709
2710	if (WARN_ON(hdev->status & HID_STAT_ADDED))
2711		return -EBUSY;
2712
2713	hdev->quirks = hid_lookup_quirk(hdev);
2714
2715	/* we need to kill them here, otherwise they will stay allocated to
2716	 * wait for coming driver */
2717	if (hid_ignore(hdev))
2718		return -ENODEV;
2719
2720	/*
2721	 * Check for the mandatory transport channel.
2722	 */
2723	 if (!hdev->ll_driver->raw_request) {
2724		hid_err(hdev, "transport driver missing .raw_request()\n");
2725		return -EINVAL;
2726	 }
2727
2728	/*
2729	 * Read the device report descriptor once and use as template
2730	 * for the driver-specific modifications.
2731	 */
2732	ret = hdev->ll_driver->parse(hdev);
2733	if (ret)
2734		return ret;
2735	if (!hdev->dev_rdesc)
2736		return -ENODEV;
2737
2738	/*
2739	 * Scan generic devices for group information
2740	 */
2741	if (hid_ignore_special_drivers) {
2742		hdev->group = HID_GROUP_GENERIC;
2743	} else if (!hdev->group &&
2744		   !(hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)) {
2745		ret = hid_scan_report(hdev);
2746		if (ret)
2747			hid_warn(hdev, "bad device descriptor (%d)\n", ret);
2748	}
2749
2750	hdev->id = atomic_inc_return(&id);
2751
2752	/* XXX hack, any other cleaner solution after the driver core
2753	 * is converted to allow more than 20 bytes as the device name? */
2754	dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
2755		     hdev->vendor, hdev->product, hdev->id);
2756
2757	hid_debug_register(hdev, dev_name(&hdev->dev));
2758	ret = device_add(&hdev->dev);
2759	if (!ret)
2760		hdev->status |= HID_STAT_ADDED;
2761	else
2762		hid_debug_unregister(hdev);
2763
2764	return ret;
2765}
2766EXPORT_SYMBOL_GPL(hid_add_device);
2767
2768/**
2769 * hid_allocate_device - allocate new hid device descriptor
2770 *
2771 * Allocate and initialize hid device, so that hid_destroy_device might be
2772 * used to free it.
2773 *
2774 * New hid_device pointer is returned on success, otherwise ERR_PTR encoded
2775 * error value.
2776 */
2777struct hid_device *hid_allocate_device(void)
2778{
2779	struct hid_device *hdev;
2780	int ret = -ENOMEM;
2781
2782	hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
2783	if (hdev == NULL)
2784		return ERR_PTR(ret);
2785
2786	device_initialize(&hdev->dev);
2787	hdev->dev.release = hid_device_release;
2788	hdev->dev.bus = &hid_bus_type;
2789	device_enable_async_suspend(&hdev->dev);
2790
2791	hid_close_report(hdev);
2792
2793	init_waitqueue_head(&hdev->debug_wait);
2794	INIT_LIST_HEAD(&hdev->debug_list);
2795	spin_lock_init(&hdev->debug_list_lock);
2796	sema_init(&hdev->driver_input_lock, 1);
2797	mutex_init(&hdev->ll_open_lock);
 
 
 
2798
2799	return hdev;
2800}
2801EXPORT_SYMBOL_GPL(hid_allocate_device);
2802
2803static void hid_remove_device(struct hid_device *hdev)
2804{
2805	if (hdev->status & HID_STAT_ADDED) {
2806		device_del(&hdev->dev);
2807		hid_debug_unregister(hdev);
2808		hdev->status &= ~HID_STAT_ADDED;
2809	}
2810	kfree(hdev->dev_rdesc);
2811	hdev->dev_rdesc = NULL;
2812	hdev->dev_rsize = 0;
2813}
2814
2815/**
2816 * hid_destroy_device - free previously allocated device
2817 *
2818 * @hdev: hid device
2819 *
2820 * If you allocate hid_device through hid_allocate_device, you should ever
2821 * free by this function.
2822 */
2823void hid_destroy_device(struct hid_device *hdev)
2824{
 
2825	hid_remove_device(hdev);
2826	put_device(&hdev->dev);
2827}
2828EXPORT_SYMBOL_GPL(hid_destroy_device);
2829
2830
2831static int __hid_bus_reprobe_drivers(struct device *dev, void *data)
2832{
2833	struct hid_driver *hdrv = data;
2834	struct hid_device *hdev = to_hid_device(dev);
2835
2836	if (hdev->driver == hdrv &&
2837	    !hdrv->match(hdev, hid_ignore_special_drivers) &&
2838	    !test_and_set_bit(ffs(HID_STAT_REPROBED), &hdev->status))
2839		return device_reprobe(dev);
2840
2841	return 0;
2842}
2843
2844static int __hid_bus_driver_added(struct device_driver *drv, void *data)
2845{
2846	struct hid_driver *hdrv = to_hid_driver(drv);
2847
2848	if (hdrv->match) {
2849		bus_for_each_dev(&hid_bus_type, NULL, hdrv,
2850				 __hid_bus_reprobe_drivers);
2851	}
2852
2853	return 0;
2854}
2855
2856static int __bus_removed_driver(struct device_driver *drv, void *data)
2857{
2858	return bus_rescan_devices(&hid_bus_type);
2859}
2860
2861int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
2862		const char *mod_name)
2863{
2864	int ret;
2865
2866	hdrv->driver.name = hdrv->name;
2867	hdrv->driver.bus = &hid_bus_type;
2868	hdrv->driver.owner = owner;
2869	hdrv->driver.mod_name = mod_name;
2870
2871	INIT_LIST_HEAD(&hdrv->dyn_list);
2872	spin_lock_init(&hdrv->dyn_lock);
2873
2874	ret = driver_register(&hdrv->driver);
2875
2876	if (ret == 0)
2877		bus_for_each_drv(&hid_bus_type, NULL, NULL,
2878				 __hid_bus_driver_added);
2879
2880	return ret;
2881}
2882EXPORT_SYMBOL_GPL(__hid_register_driver);
2883
2884void hid_unregister_driver(struct hid_driver *hdrv)
2885{
2886	driver_unregister(&hdrv->driver);
2887	hid_free_dynids(hdrv);
2888
2889	bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver);
2890}
2891EXPORT_SYMBOL_GPL(hid_unregister_driver);
2892
2893int hid_check_keys_pressed(struct hid_device *hid)
2894{
2895	struct hid_input *hidinput;
2896	int i;
2897
2898	if (!(hid->claimed & HID_CLAIMED_INPUT))
2899		return 0;
2900
2901	list_for_each_entry(hidinput, &hid->inputs, list) {
2902		for (i = 0; i < BITS_TO_LONGS(KEY_MAX); i++)
2903			if (hidinput->input->key[i])
2904				return 1;
2905	}
2906
2907	return 0;
2908}
2909EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
2910
 
 
 
 
 
 
 
 
 
2911static int __init hid_init(void)
2912{
2913	int ret;
2914
2915	if (hid_debug)
2916		pr_warn("hid_debug is now used solely for parser and driver debugging.\n"
2917			"debugfs is now used for inspecting the device (report descriptor, reports)\n");
2918
2919	ret = bus_register(&hid_bus_type);
2920	if (ret) {
2921		pr_err("can't register hid bus\n");
2922		goto err;
2923	}
2924
 
 
 
 
2925	ret = hidraw_init();
2926	if (ret)
2927		goto err_bus;
2928
2929	hid_debug_init();
2930
2931	return 0;
2932err_bus:
2933	bus_unregister(&hid_bus_type);
2934err:
2935	return ret;
2936}
2937
2938static void __exit hid_exit(void)
2939{
 
 
 
2940	hid_debug_exit();
2941	hidraw_exit();
2942	bus_unregister(&hid_bus_type);
2943	hid_quirks_exit(HID_BUS_ANY);
2944}
2945
2946module_init(hid_init);
2947module_exit(hid_exit);
2948
2949MODULE_AUTHOR("Andreas Gal");
2950MODULE_AUTHOR("Vojtech Pavlik");
2951MODULE_AUTHOR("Jiri Kosina");
2952MODULE_LICENSE("GPL");