xref: /linux/drivers/hid/hid-core.c (revision 6419945e3313fd894af79caefca6823d4511133f)
1 /*
2  *  HID support for Linux
3  *
4  *  Copyright (c) 1999 Andreas Gal
5  *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
6  *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
7  *  Copyright (c) 2006-2012 Jiri Kosina
8  */
9 
10 /*
11  * This program is free software; you can redistribute it and/or modify it
12  * under the terms of the GNU General Public License as published by the Free
13  * Software Foundation; either version 2 of the License, or (at your option)
14  * any later version.
15  */
16 
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 
19 #include <linux/module.h>
20 #include <linux/slab.h>
21 #include <linux/init.h>
22 #include <linux/kernel.h>
23 #include <linux/list.h>
24 #include <linux/mm.h>
25 #include <linux/spinlock.h>
26 #include <asm/unaligned.h>
27 #include <asm/byteorder.h>
28 #include <linux/input.h>
29 #include <linux/wait.h>
30 #include <linux/vmalloc.h>
31 #include <linux/sched.h>
32 #include <linux/semaphore.h>
33 
34 #include <linux/hid.h>
35 #include <linux/hiddev.h>
36 #include <linux/hid-debug.h>
37 #include <linux/hidraw.h>
38 
39 #include "hid-ids.h"
40 
41 /*
42  * Version Information
43  */
44 
45 #define DRIVER_DESC "HID core driver"
46 
47 int hid_debug = 0;
48 module_param_named(debug, hid_debug, int, 0600);
49 MODULE_PARM_DESC(debug, "toggle HID debugging messages");
50 EXPORT_SYMBOL_GPL(hid_debug);
51 
52 static int hid_ignore_special_drivers = 0;
53 module_param_named(ignore_special_drivers, hid_ignore_special_drivers, int, 0600);
54 MODULE_PARM_DESC(ignore_special_drivers, "Ignore any special drivers and handle all devices by generic driver");
55 
56 /*
57  * Register a new report for a device.
58  */
59 
60 struct hid_report *hid_register_report(struct hid_device *device,
61 				       unsigned int type, unsigned int id,
62 				       unsigned int application)
63 {
64 	struct hid_report_enum *report_enum = device->report_enum + type;
65 	struct hid_report *report;
66 
67 	if (id >= HID_MAX_IDS)
68 		return NULL;
69 	if (report_enum->report_id_hash[id])
70 		return report_enum->report_id_hash[id];
71 
72 	report = kzalloc(sizeof(struct hid_report), GFP_KERNEL);
73 	if (!report)
74 		return NULL;
75 
76 	if (id != 0)
77 		report_enum->numbered = 1;
78 
79 	report->id = id;
80 	report->type = type;
81 	report->size = 0;
82 	report->device = device;
83 	report->application = application;
84 	report_enum->report_id_hash[id] = report;
85 
86 	list_add_tail(&report->list, &report_enum->report_list);
87 
88 	return report;
89 }
90 EXPORT_SYMBOL_GPL(hid_register_report);
91 
92 /*
93  * Register a new field for this report.
94  */
95 
96 static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages, unsigned values)
97 {
98 	struct hid_field *field;
99 
100 	if (report->maxfield == HID_MAX_FIELDS) {
101 		hid_err(report->device, "too many fields in report\n");
102 		return NULL;
103 	}
104 
105 	field = kzalloc((sizeof(struct hid_field) +
106 			 usages * sizeof(struct hid_usage) +
107 			 values * sizeof(unsigned)), GFP_KERNEL);
108 	if (!field)
109 		return NULL;
110 
111 	field->index = report->maxfield++;
112 	report->field[field->index] = field;
113 	field->usage = (struct hid_usage *)(field + 1);
114 	field->value = (s32 *)(field->usage + 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 
124 static int open_collection(struct hid_parser *parser, unsigned type)
125 {
126 	struct hid_collection *collection;
127 	unsigned usage;
128 
129 	usage = parser->local.usage[0];
130 
131 	if (parser->collection_stack_ptr == HID_COLLECTION_STACK_SIZE) {
132 		hid_err(parser->device, "collection stack overflow\n");
133 		return -EINVAL;
134 	}
135 
136 	if (parser->device->maxcollection == parser->device->collection_size) {
137 		collection = kmalloc(sizeof(struct hid_collection) *
138 				parser->device->collection_size * 2, GFP_KERNEL);
139 		if (collection == NULL) {
140 			hid_err(parser->device, "failed to reallocate collection array\n");
141 			return -ENOMEM;
142 		}
143 		memcpy(collection, parser->device->collection,
144 			sizeof(struct hid_collection) *
145 			parser->device->collection_size);
146 		memset(collection + parser->device->collection_size, 0,
147 			sizeof(struct hid_collection) *
148 			parser->device->collection_size);
149 		kfree(parser->device->collection);
150 		parser->device->collection = collection;
151 		parser->device->collection_size *= 2;
152 	}
153 
154 	parser->collection_stack[parser->collection_stack_ptr++] =
155 		parser->device->maxcollection;
156 
157 	collection = parser->device->collection +
158 		parser->device->maxcollection++;
159 	collection->type = type;
160 	collection->usage = usage;
161 	collection->level = parser->collection_stack_ptr - 1;
162 
163 	if (type == HID_COLLECTION_APPLICATION)
164 		parser->device->maxapplication++;
165 
166 	return 0;
167 }
168 
169 /*
170  * Close a collection.
171  */
172 
173 static int close_collection(struct hid_parser *parser)
174 {
175 	if (!parser->collection_stack_ptr) {
176 		hid_err(parser->device, "collection stack underflow\n");
177 		return -EINVAL;
178 	}
179 	parser->collection_stack_ptr--;
180 	return 0;
181 }
182 
183 /*
184  * Climb up the stack, search for the specified collection type
185  * and return the usage.
186  */
187 
188 static unsigned hid_lookup_collection(struct hid_parser *parser, unsigned type)
189 {
190 	struct hid_collection *collection = parser->device->collection;
191 	int n;
192 
193 	for (n = parser->collection_stack_ptr - 1; n >= 0; n--) {
194 		unsigned index = parser->collection_stack[n];
195 		if (collection[index].type == type)
196 			return collection[index].usage;
197 	}
198 	return 0; /* we know nothing about this usage type */
199 }
200 
201 /*
202  * Add a usage to the temporary parser table.
203  */
204 
205 static int hid_add_usage(struct hid_parser *parser, unsigned usage)
206 {
207 	if (parser->local.usage_index >= HID_MAX_USAGES) {
208 		hid_err(parser->device, "usage index exceeded\n");
209 		return -1;
210 	}
211 	parser->local.usage[parser->local.usage_index] = usage;
212 	parser->local.collection_index[parser->local.usage_index] =
213 		parser->collection_stack_ptr ?
214 		parser->collection_stack[parser->collection_stack_ptr - 1] : 0;
215 	parser->local.usage_index++;
216 	return 0;
217 }
218 
219 /*
220  * Register a new field for this report.
221  */
222 
223 static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsigned flags)
224 {
225 	struct hid_report *report;
226 	struct hid_field *field;
227 	unsigned int usages;
228 	unsigned int offset;
229 	unsigned int i;
230 	unsigned int application;
231 
232 	application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
233 
234 	report = hid_register_report(parser->device, report_type,
235 				     parser->global.report_id, application);
236 	if (!report) {
237 		hid_err(parser->device, "hid_register_report failed\n");
238 		return -1;
239 	}
240 
241 	/* Handle both signed and unsigned cases properly */
242 	if ((parser->global.logical_minimum < 0 &&
243 		parser->global.logical_maximum <
244 		parser->global.logical_minimum) ||
245 		(parser->global.logical_minimum >= 0 &&
246 		(__u32)parser->global.logical_maximum <
247 		(__u32)parser->global.logical_minimum)) {
248 		dbg_hid("logical range invalid 0x%x 0x%x\n",
249 			parser->global.logical_minimum,
250 			parser->global.logical_maximum);
251 		return -1;
252 	}
253 
254 	offset = report->size;
255 	report->size += parser->global.report_size * parser->global.report_count;
256 
257 	if (!parser->local.usage_index) /* Ignore padding fields */
258 		return 0;
259 
260 	usages = max_t(unsigned, parser->local.usage_index,
261 				 parser->global.report_count);
262 
263 	field = hid_register_field(report, usages, parser->global.report_count);
264 	if (!field)
265 		return 0;
266 
267 	field->physical = hid_lookup_collection(parser, HID_COLLECTION_PHYSICAL);
268 	field->logical = hid_lookup_collection(parser, HID_COLLECTION_LOGICAL);
269 	field->application = application;
270 
271 	for (i = 0; i < usages; i++) {
272 		unsigned j = i;
273 		/* Duplicate the last usage we parsed if we have excess values */
274 		if (i >= parser->local.usage_index)
275 			j = parser->local.usage_index - 1;
276 		field->usage[i].hid = parser->local.usage[j];
277 		field->usage[i].collection_index =
278 			parser->local.collection_index[j];
279 		field->usage[i].usage_index = i;
280 	}
281 
282 	field->maxusage = usages;
283 	field->flags = flags;
284 	field->report_offset = offset;
285 	field->report_type = report_type;
286 	field->report_size = parser->global.report_size;
287 	field->report_count = parser->global.report_count;
288 	field->logical_minimum = parser->global.logical_minimum;
289 	field->logical_maximum = parser->global.logical_maximum;
290 	field->physical_minimum = parser->global.physical_minimum;
291 	field->physical_maximum = parser->global.physical_maximum;
292 	field->unit_exponent = parser->global.unit_exponent;
293 	field->unit = parser->global.unit;
294 
295 	return 0;
296 }
297 
298 /*
299  * Read data value from item.
300  */
301 
302 static u32 item_udata(struct hid_item *item)
303 {
304 	switch (item->size) {
305 	case 1: return item->data.u8;
306 	case 2: return item->data.u16;
307 	case 4: return item->data.u32;
308 	}
309 	return 0;
310 }
311 
312 static s32 item_sdata(struct hid_item *item)
313 {
314 	switch (item->size) {
315 	case 1: return item->data.s8;
316 	case 2: return item->data.s16;
317 	case 4: return item->data.s32;
318 	}
319 	return 0;
320 }
321 
322 /*
323  * Process a global item.
324  */
325 
326 static int hid_parser_global(struct hid_parser *parser, struct hid_item *item)
327 {
328 	__s32 raw_value;
329 	switch (item->tag) {
330 	case HID_GLOBAL_ITEM_TAG_PUSH:
331 
332 		if (parser->global_stack_ptr == HID_GLOBAL_STACK_SIZE) {
333 			hid_err(parser->device, "global environment stack overflow\n");
334 			return -1;
335 		}
336 
337 		memcpy(parser->global_stack + parser->global_stack_ptr++,
338 			&parser->global, sizeof(struct hid_global));
339 		return 0;
340 
341 	case HID_GLOBAL_ITEM_TAG_POP:
342 
343 		if (!parser->global_stack_ptr) {
344 			hid_err(parser->device, "global environment stack underflow\n");
345 			return -1;
346 		}
347 
348 		memcpy(&parser->global, parser->global_stack +
349 			--parser->global_stack_ptr, sizeof(struct hid_global));
350 		return 0;
351 
352 	case HID_GLOBAL_ITEM_TAG_USAGE_PAGE:
353 		parser->global.usage_page = item_udata(item);
354 		return 0;
355 
356 	case HID_GLOBAL_ITEM_TAG_LOGICAL_MINIMUM:
357 		parser->global.logical_minimum = item_sdata(item);
358 		return 0;
359 
360 	case HID_GLOBAL_ITEM_TAG_LOGICAL_MAXIMUM:
361 		if (parser->global.logical_minimum < 0)
362 			parser->global.logical_maximum = item_sdata(item);
363 		else
364 			parser->global.logical_maximum = item_udata(item);
365 		return 0;
366 
367 	case HID_GLOBAL_ITEM_TAG_PHYSICAL_MINIMUM:
368 		parser->global.physical_minimum = item_sdata(item);
369 		return 0;
370 
371 	case HID_GLOBAL_ITEM_TAG_PHYSICAL_MAXIMUM:
372 		if (parser->global.physical_minimum < 0)
373 			parser->global.physical_maximum = item_sdata(item);
374 		else
375 			parser->global.physical_maximum = item_udata(item);
376 		return 0;
377 
378 	case HID_GLOBAL_ITEM_TAG_UNIT_EXPONENT:
379 		/* Many devices provide unit exponent as a two's complement
380 		 * nibble due to the common misunderstanding of HID
381 		 * specification 1.11, 6.2.2.7 Global Items. Attempt to handle
382 		 * both this and the standard encoding. */
383 		raw_value = item_sdata(item);
384 		if (!(raw_value & 0xfffffff0))
385 			parser->global.unit_exponent = hid_snto32(raw_value, 4);
386 		else
387 			parser->global.unit_exponent = raw_value;
388 		return 0;
389 
390 	case HID_GLOBAL_ITEM_TAG_UNIT:
391 		parser->global.unit = item_udata(item);
392 		return 0;
393 
394 	case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
395 		parser->global.report_size = item_udata(item);
396 		if (parser->global.report_size > 128) {
397 			hid_err(parser->device, "invalid report_size %d\n",
398 					parser->global.report_size);
399 			return -1;
400 		}
401 		return 0;
402 
403 	case HID_GLOBAL_ITEM_TAG_REPORT_COUNT:
404 		parser->global.report_count = item_udata(item);
405 		if (parser->global.report_count > HID_MAX_USAGES) {
406 			hid_err(parser->device, "invalid report_count %d\n",
407 					parser->global.report_count);
408 			return -1;
409 		}
410 		return 0;
411 
412 	case HID_GLOBAL_ITEM_TAG_REPORT_ID:
413 		parser->global.report_id = item_udata(item);
414 		if (parser->global.report_id == 0 ||
415 		    parser->global.report_id >= HID_MAX_IDS) {
416 			hid_err(parser->device, "report_id %u is invalid\n",
417 				parser->global.report_id);
418 			return -1;
419 		}
420 		return 0;
421 
422 	default:
423 		hid_err(parser->device, "unknown global tag 0x%x\n", item->tag);
424 		return -1;
425 	}
426 }
427 
428 /*
429  * Process a local item.
430  */
431 
432 static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
433 {
434 	__u32 data;
435 	unsigned n;
436 	__u32 count;
437 
438 	data = item_udata(item);
439 
440 	switch (item->tag) {
441 	case HID_LOCAL_ITEM_TAG_DELIMITER:
442 
443 		if (data) {
444 			/*
445 			 * We treat items before the first delimiter
446 			 * as global to all usage sets (branch 0).
447 			 * In the moment we process only these global
448 			 * items and the first delimiter set.
449 			 */
450 			if (parser->local.delimiter_depth != 0) {
451 				hid_err(parser->device, "nested delimiters\n");
452 				return -1;
453 			}
454 			parser->local.delimiter_depth++;
455 			parser->local.delimiter_branch++;
456 		} else {
457 			if (parser->local.delimiter_depth < 1) {
458 				hid_err(parser->device, "bogus close delimiter\n");
459 				return -1;
460 			}
461 			parser->local.delimiter_depth--;
462 		}
463 		return 0;
464 
465 	case HID_LOCAL_ITEM_TAG_USAGE:
466 
467 		if (parser->local.delimiter_branch > 1) {
468 			dbg_hid("alternative usage ignored\n");
469 			return 0;
470 		}
471 
472 		if (item->size <= 2)
473 			data = (parser->global.usage_page << 16) + data;
474 
475 		return hid_add_usage(parser, data);
476 
477 	case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:
478 
479 		if (parser->local.delimiter_branch > 1) {
480 			dbg_hid("alternative usage ignored\n");
481 			return 0;
482 		}
483 
484 		if (item->size <= 2)
485 			data = (parser->global.usage_page << 16) + data;
486 
487 		parser->local.usage_minimum = data;
488 		return 0;
489 
490 	case HID_LOCAL_ITEM_TAG_USAGE_MAXIMUM:
491 
492 		if (parser->local.delimiter_branch > 1) {
493 			dbg_hid("alternative usage ignored\n");
494 			return 0;
495 		}
496 
497 		if (item->size <= 2)
498 			data = (parser->global.usage_page << 16) + data;
499 
500 		count = data - parser->local.usage_minimum;
501 		if (count + parser->local.usage_index >= HID_MAX_USAGES) {
502 			/*
503 			 * We do not warn if the name is not set, we are
504 			 * actually pre-scanning the device.
505 			 */
506 			if (dev_name(&parser->device->dev))
507 				hid_warn(parser->device,
508 					 "ignoring exceeding usage max\n");
509 			data = HID_MAX_USAGES - parser->local.usage_index +
510 				parser->local.usage_minimum - 1;
511 			if (data <= 0) {
512 				hid_err(parser->device,
513 					"no more usage index available\n");
514 				return -1;
515 			}
516 		}
517 
518 		for (n = parser->local.usage_minimum; n <= data; n++)
519 			if (hid_add_usage(parser, n)) {
520 				dbg_hid("hid_add_usage failed\n");
521 				return -1;
522 			}
523 		return 0;
524 
525 	default:
526 
527 		dbg_hid("unknown local item tag 0x%x\n", item->tag);
528 		return 0;
529 	}
530 	return 0;
531 }
532 
533 /*
534  * Process a main item.
535  */
536 
537 static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
538 {
539 	__u32 data;
540 	int ret;
541 
542 	data = item_udata(item);
543 
544 	switch (item->tag) {
545 	case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
546 		ret = open_collection(parser, data & 0xff);
547 		break;
548 	case HID_MAIN_ITEM_TAG_END_COLLECTION:
549 		ret = close_collection(parser);
550 		break;
551 	case HID_MAIN_ITEM_TAG_INPUT:
552 		ret = hid_add_field(parser, HID_INPUT_REPORT, data);
553 		break;
554 	case HID_MAIN_ITEM_TAG_OUTPUT:
555 		ret = hid_add_field(parser, HID_OUTPUT_REPORT, data);
556 		break;
557 	case HID_MAIN_ITEM_TAG_FEATURE:
558 		ret = hid_add_field(parser, HID_FEATURE_REPORT, data);
559 		break;
560 	default:
561 		hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
562 		ret = 0;
563 	}
564 
565 	memset(&parser->local, 0, sizeof(parser->local));	/* Reset the local parser environment */
566 
567 	return ret;
568 }
569 
570 /*
571  * Process a reserved item.
572  */
573 
574 static int hid_parser_reserved(struct hid_parser *parser, struct hid_item *item)
575 {
576 	dbg_hid("reserved item type, tag 0x%x\n", item->tag);
577 	return 0;
578 }
579 
580 /*
581  * Free a report and all registered fields. The field->usage and
582  * field->value table's are allocated behind the field, so we need
583  * only to free(field) itself.
584  */
585 
586 static void hid_free_report(struct hid_report *report)
587 {
588 	unsigned n;
589 
590 	for (n = 0; n < report->maxfield; n++)
591 		kfree(report->field[n]);
592 	kfree(report);
593 }
594 
595 /*
596  * Close report. This function returns the device
597  * state to the point prior to hid_open_report().
598  */
599 static void hid_close_report(struct hid_device *device)
600 {
601 	unsigned i, j;
602 
603 	for (i = 0; i < HID_REPORT_TYPES; i++) {
604 		struct hid_report_enum *report_enum = device->report_enum + i;
605 
606 		for (j = 0; j < HID_MAX_IDS; j++) {
607 			struct hid_report *report = report_enum->report_id_hash[j];
608 			if (report)
609 				hid_free_report(report);
610 		}
611 		memset(report_enum, 0, sizeof(*report_enum));
612 		INIT_LIST_HEAD(&report_enum->report_list);
613 	}
614 
615 	kfree(device->rdesc);
616 	device->rdesc = NULL;
617 	device->rsize = 0;
618 
619 	kfree(device->collection);
620 	device->collection = NULL;
621 	device->collection_size = 0;
622 	device->maxcollection = 0;
623 	device->maxapplication = 0;
624 
625 	device->status &= ~HID_STAT_PARSED;
626 }
627 
628 /*
629  * Free a device structure, all reports, and all fields.
630  */
631 
632 static void hid_device_release(struct device *dev)
633 {
634 	struct hid_device *hid = to_hid_device(dev);
635 
636 	hid_close_report(hid);
637 	kfree(hid->dev_rdesc);
638 	kfree(hid);
639 }
640 
641 /*
642  * Fetch a report description item from the data stream. We support long
643  * items, though they are not used yet.
644  */
645 
646 static u8 *fetch_item(__u8 *start, __u8 *end, struct hid_item *item)
647 {
648 	u8 b;
649 
650 	if ((end - start) <= 0)
651 		return NULL;
652 
653 	b = *start++;
654 
655 	item->type = (b >> 2) & 3;
656 	item->tag  = (b >> 4) & 15;
657 
658 	if (item->tag == HID_ITEM_TAG_LONG) {
659 
660 		item->format = HID_ITEM_FORMAT_LONG;
661 
662 		if ((end - start) < 2)
663 			return NULL;
664 
665 		item->size = *start++;
666 		item->tag  = *start++;
667 
668 		if ((end - start) < item->size)
669 			return NULL;
670 
671 		item->data.longdata = start;
672 		start += item->size;
673 		return start;
674 	}
675 
676 	item->format = HID_ITEM_FORMAT_SHORT;
677 	item->size = b & 3;
678 
679 	switch (item->size) {
680 	case 0:
681 		return start;
682 
683 	case 1:
684 		if ((end - start) < 1)
685 			return NULL;
686 		item->data.u8 = *start++;
687 		return start;
688 
689 	case 2:
690 		if ((end - start) < 2)
691 			return NULL;
692 		item->data.u16 = get_unaligned_le16(start);
693 		start = (__u8 *)((__le16 *)start + 1);
694 		return start;
695 
696 	case 3:
697 		item->size++;
698 		if ((end - start) < 4)
699 			return NULL;
700 		item->data.u32 = get_unaligned_le32(start);
701 		start = (__u8 *)((__le32 *)start + 1);
702 		return start;
703 	}
704 
705 	return NULL;
706 }
707 
708 static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)
709 {
710 	struct hid_device *hid = parser->device;
711 
712 	if (usage == HID_DG_CONTACTID)
713 		hid->group = HID_GROUP_MULTITOUCH;
714 }
715 
716 static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
717 {
718 	if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
719 	    parser->global.report_size == 8)
720 		parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
721 }
722 
723 static void hid_scan_collection(struct hid_parser *parser, unsigned type)
724 {
725 	struct hid_device *hid = parser->device;
726 	int i;
727 
728 	if (((parser->global.usage_page << 16) == HID_UP_SENSOR) &&
729 	    type == HID_COLLECTION_PHYSICAL)
730 		hid->group = HID_GROUP_SENSOR_HUB;
731 
732 	if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
733 	    hid->product == USB_DEVICE_ID_MS_POWER_COVER &&
734 	    hid->group == HID_GROUP_MULTITOUCH)
735 		hid->group = HID_GROUP_GENERIC;
736 
737 	if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
738 		for (i = 0; i < parser->local.usage_index; i++)
739 			if (parser->local.usage[i] == HID_GD_POINTER)
740 				parser->scan_flags |= HID_SCAN_FLAG_GD_POINTER;
741 
742 	if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
743 		parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
744 }
745 
746 static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
747 {
748 	__u32 data;
749 	int i;
750 
751 	data = item_udata(item);
752 
753 	switch (item->tag) {
754 	case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
755 		hid_scan_collection(parser, data & 0xff);
756 		break;
757 	case HID_MAIN_ITEM_TAG_END_COLLECTION:
758 		break;
759 	case HID_MAIN_ITEM_TAG_INPUT:
760 		/* ignore constant inputs, they will be ignored by hid-input */
761 		if (data & HID_MAIN_ITEM_CONSTANT)
762 			break;
763 		for (i = 0; i < parser->local.usage_index; i++)
764 			hid_scan_input_usage(parser, parser->local.usage[i]);
765 		break;
766 	case HID_MAIN_ITEM_TAG_OUTPUT:
767 		break;
768 	case HID_MAIN_ITEM_TAG_FEATURE:
769 		for (i = 0; i < parser->local.usage_index; i++)
770 			hid_scan_feature_usage(parser, parser->local.usage[i]);
771 		break;
772 	}
773 
774 	/* Reset the local parser environment */
775 	memset(&parser->local, 0, sizeof(parser->local));
776 
777 	return 0;
778 }
779 
780 /*
781  * Scan a report descriptor before the device is added to the bus.
782  * Sets device groups and other properties that determine what driver
783  * to load.
784  */
785 static int hid_scan_report(struct hid_device *hid)
786 {
787 	struct hid_parser *parser;
788 	struct hid_item item;
789 	__u8 *start = hid->dev_rdesc;
790 	__u8 *end = start + hid->dev_rsize;
791 	static int (*dispatch_type[])(struct hid_parser *parser,
792 				      struct hid_item *item) = {
793 		hid_scan_main,
794 		hid_parser_global,
795 		hid_parser_local,
796 		hid_parser_reserved
797 	};
798 
799 	parser = vzalloc(sizeof(struct hid_parser));
800 	if (!parser)
801 		return -ENOMEM;
802 
803 	parser->device = hid;
804 	hid->group = HID_GROUP_GENERIC;
805 
806 	/*
807 	 * The parsing is simpler than the one in hid_open_report() as we should
808 	 * be robust against hid errors. Those errors will be raised by
809 	 * hid_open_report() anyway.
810 	 */
811 	while ((start = fetch_item(start, end, &item)) != NULL)
812 		dispatch_type[item.type](parser, &item);
813 
814 	/*
815 	 * Handle special flags set during scanning.
816 	 */
817 	if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
818 	    (hid->group == HID_GROUP_MULTITOUCH))
819 		hid->group = HID_GROUP_MULTITOUCH_WIN_8;
820 
821 	/*
822 	 * Vendor specific handlings
823 	 */
824 	switch (hid->vendor) {
825 	case USB_VENDOR_ID_WACOM:
826 		hid->group = HID_GROUP_WACOM;
827 		break;
828 	case USB_VENDOR_ID_SYNAPTICS:
829 		if (hid->group == HID_GROUP_GENERIC)
830 			if ((parser->scan_flags & HID_SCAN_FLAG_VENDOR_SPECIFIC)
831 			    && (parser->scan_flags & HID_SCAN_FLAG_GD_POINTER))
832 				/*
833 				 * hid-rmi should take care of them,
834 				 * not hid-generic
835 				 */
836 				hid->group = HID_GROUP_RMI;
837 		break;
838 	}
839 
840 	vfree(parser);
841 	return 0;
842 }
843 
844 /**
845  * hid_parse_report - parse device report
846  *
847  * @device: hid device
848  * @start: report start
849  * @size: report size
850  *
851  * Allocate the device report as read by the bus driver. This function should
852  * only be called from parse() in ll drivers.
853  */
854 int hid_parse_report(struct hid_device *hid, __u8 *start, unsigned size)
855 {
856 	hid->dev_rdesc = kmemdup(start, size, GFP_KERNEL);
857 	if (!hid->dev_rdesc)
858 		return -ENOMEM;
859 	hid->dev_rsize = size;
860 	return 0;
861 }
862 EXPORT_SYMBOL_GPL(hid_parse_report);
863 
864 static const char * const hid_report_names[] = {
865 	"HID_INPUT_REPORT",
866 	"HID_OUTPUT_REPORT",
867 	"HID_FEATURE_REPORT",
868 };
869 /**
870  * hid_validate_values - validate existing device report's value indexes
871  *
872  * @device: hid device
873  * @type: which report type to examine
874  * @id: which report ID to examine (0 for first)
875  * @field_index: which report field to examine
876  * @report_counts: expected number of values
877  *
878  * Validate the number of values in a given field of a given report, after
879  * parsing.
880  */
881 struct hid_report *hid_validate_values(struct hid_device *hid,
882 				       unsigned int type, unsigned int id,
883 				       unsigned int field_index,
884 				       unsigned int report_counts)
885 {
886 	struct hid_report *report;
887 
888 	if (type > HID_FEATURE_REPORT) {
889 		hid_err(hid, "invalid HID report type %u\n", type);
890 		return NULL;
891 	}
892 
893 	if (id >= HID_MAX_IDS) {
894 		hid_err(hid, "invalid HID report id %u\n", id);
895 		return NULL;
896 	}
897 
898 	/*
899 	 * Explicitly not using hid_get_report() here since it depends on
900 	 * ->numbered being checked, which may not always be the case when
901 	 * drivers go to access report values.
902 	 */
903 	if (id == 0) {
904 		/*
905 		 * Validating on id 0 means we should examine the first
906 		 * report in the list.
907 		 */
908 		report = list_entry(
909 				hid->report_enum[type].report_list.next,
910 				struct hid_report, list);
911 	} else {
912 		report = hid->report_enum[type].report_id_hash[id];
913 	}
914 	if (!report) {
915 		hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
916 		return NULL;
917 	}
918 	if (report->maxfield <= field_index) {
919 		hid_err(hid, "not enough fields in %s %u\n",
920 			hid_report_names[type], id);
921 		return NULL;
922 	}
923 	if (report->field[field_index]->report_count < report_counts) {
924 		hid_err(hid, "not enough values in %s %u field %u\n",
925 			hid_report_names[type], id, field_index);
926 		return NULL;
927 	}
928 	return report;
929 }
930 EXPORT_SYMBOL_GPL(hid_validate_values);
931 
932 /**
933  * hid_open_report - open a driver-specific device report
934  *
935  * @device: hid device
936  *
937  * Parse a report description into a hid_device structure. Reports are
938  * enumerated, fields are attached to these reports.
939  * 0 returned on success, otherwise nonzero error value.
940  *
941  * This function (or the equivalent hid_parse() macro) should only be
942  * called from probe() in drivers, before starting the device.
943  */
944 int hid_open_report(struct hid_device *device)
945 {
946 	struct hid_parser *parser;
947 	struct hid_item item;
948 	unsigned int size;
949 	__u8 *start;
950 	__u8 *buf;
951 	__u8 *end;
952 	int ret;
953 	static int (*dispatch_type[])(struct hid_parser *parser,
954 				      struct hid_item *item) = {
955 		hid_parser_main,
956 		hid_parser_global,
957 		hid_parser_local,
958 		hid_parser_reserved
959 	};
960 
961 	if (WARN_ON(device->status & HID_STAT_PARSED))
962 		return -EBUSY;
963 
964 	start = device->dev_rdesc;
965 	if (WARN_ON(!start))
966 		return -ENODEV;
967 	size = device->dev_rsize;
968 
969 	buf = kmemdup(start, size, GFP_KERNEL);
970 	if (buf == NULL)
971 		return -ENOMEM;
972 
973 	if (device->driver->report_fixup)
974 		start = device->driver->report_fixup(device, buf, &size);
975 	else
976 		start = buf;
977 
978 	start = kmemdup(start, size, GFP_KERNEL);
979 	kfree(buf);
980 	if (start == NULL)
981 		return -ENOMEM;
982 
983 	device->rdesc = start;
984 	device->rsize = size;
985 
986 	parser = vzalloc(sizeof(struct hid_parser));
987 	if (!parser) {
988 		ret = -ENOMEM;
989 		goto err;
990 	}
991 
992 	parser->device = device;
993 
994 	end = start + size;
995 
996 	device->collection = kcalloc(HID_DEFAULT_NUM_COLLECTIONS,
997 				     sizeof(struct hid_collection), GFP_KERNEL);
998 	if (!device->collection) {
999 		ret = -ENOMEM;
1000 		goto err;
1001 	}
1002 	device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
1003 
1004 	ret = -EINVAL;
1005 	while ((start = fetch_item(start, end, &item)) != NULL) {
1006 
1007 		if (item.format != HID_ITEM_FORMAT_SHORT) {
1008 			hid_err(device, "unexpected long global item\n");
1009 			goto err;
1010 		}
1011 
1012 		if (dispatch_type[item.type](parser, &item)) {
1013 			hid_err(device, "item %u %u %u %u parsing failed\n",
1014 				item.format, (unsigned)item.size,
1015 				(unsigned)item.type, (unsigned)item.tag);
1016 			goto err;
1017 		}
1018 
1019 		if (start == end) {
1020 			if (parser->collection_stack_ptr) {
1021 				hid_err(device, "unbalanced collection at end of report description\n");
1022 				goto err;
1023 			}
1024 			if (parser->local.delimiter_depth) {
1025 				hid_err(device, "unbalanced delimiter at end of report description\n");
1026 				goto err;
1027 			}
1028 			vfree(parser);
1029 			device->status |= HID_STAT_PARSED;
1030 			return 0;
1031 		}
1032 	}
1033 
1034 	hid_err(device, "item fetching failed at offset %d\n", (int)(end - start));
1035 err:
1036 	vfree(parser);
1037 	hid_close_report(device);
1038 	return ret;
1039 }
1040 EXPORT_SYMBOL_GPL(hid_open_report);
1041 
1042 /*
1043  * Convert a signed n-bit integer to signed 32-bit integer. Common
1044  * cases are done through the compiler, the screwed things has to be
1045  * done by hand.
1046  */
1047 
1048 static s32 snto32(__u32 value, unsigned n)
1049 {
1050 	switch (n) {
1051 	case 8:  return ((__s8)value);
1052 	case 16: return ((__s16)value);
1053 	case 32: return ((__s32)value);
1054 	}
1055 	return value & (1 << (n - 1)) ? value | (~0U << n) : value;
1056 }
1057 
1058 s32 hid_snto32(__u32 value, unsigned n)
1059 {
1060 	return snto32(value, n);
1061 }
1062 EXPORT_SYMBOL_GPL(hid_snto32);
1063 
1064 /*
1065  * Convert a signed 32-bit integer to a signed n-bit integer.
1066  */
1067 
1068 static u32 s32ton(__s32 value, unsigned n)
1069 {
1070 	s32 a = value >> (n - 1);
1071 	if (a && a != -1)
1072 		return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
1073 	return value & ((1 << n) - 1);
1074 }
1075 
1076 /*
1077  * Extract/implement a data field from/to a little endian report (bit array).
1078  *
1079  * Code sort-of follows HID spec:
1080  *     http://www.usb.org/developers/hidpage/HID1_11.pdf
1081  *
1082  * While the USB HID spec allows unlimited length bit fields in "report
1083  * descriptors", most devices never use more than 16 bits.
1084  * One model of UPS is claimed to report "LINEV" as a 32-bit field.
1085  * Search linux-kernel and linux-usb-devel archives for "hid-core extract".
1086  */
1087 
1088 static u32 __extract(u8 *report, unsigned offset, int n)
1089 {
1090 	unsigned int idx = offset / 8;
1091 	unsigned int bit_nr = 0;
1092 	unsigned int bit_shift = offset % 8;
1093 	int bits_to_copy = 8 - bit_shift;
1094 	u32 value = 0;
1095 	u32 mask = n < 32 ? (1U << n) - 1 : ~0U;
1096 
1097 	while (n > 0) {
1098 		value |= ((u32)report[idx] >> bit_shift) << bit_nr;
1099 		n -= bits_to_copy;
1100 		bit_nr += bits_to_copy;
1101 		bits_to_copy = 8;
1102 		bit_shift = 0;
1103 		idx++;
1104 	}
1105 
1106 	return value & mask;
1107 }
1108 
1109 u32 hid_field_extract(const struct hid_device *hid, u8 *report,
1110 			unsigned offset, unsigned n)
1111 {
1112 	if (n > 32) {
1113 		hid_warn(hid, "hid_field_extract() called with n (%d) > 32! (%s)\n",
1114 			 n, current->comm);
1115 		n = 32;
1116 	}
1117 
1118 	return __extract(report, offset, n);
1119 }
1120 EXPORT_SYMBOL_GPL(hid_field_extract);
1121 
1122 /*
1123  * "implement" : set bits in a little endian bit stream.
1124  * Same concepts as "extract" (see comments above).
1125  * The data mangled in the bit stream remains in little endian
1126  * order the whole time. It make more sense to talk about
1127  * endianness of register values by considering a register
1128  * a "cached" copy of the little endian bit stream.
1129  */
1130 
1131 static void __implement(u8 *report, unsigned offset, int n, u32 value)
1132 {
1133 	unsigned int idx = offset / 8;
1134 	unsigned int bit_shift = offset % 8;
1135 	int bits_to_set = 8 - bit_shift;
1136 
1137 	while (n - bits_to_set >= 0) {
1138 		report[idx] &= ~(0xff << bit_shift);
1139 		report[idx] |= value << bit_shift;
1140 		value >>= bits_to_set;
1141 		n -= bits_to_set;
1142 		bits_to_set = 8;
1143 		bit_shift = 0;
1144 		idx++;
1145 	}
1146 
1147 	/* last nibble */
1148 	if (n) {
1149 		u8 bit_mask = ((1U << n) - 1);
1150 		report[idx] &= ~(bit_mask << bit_shift);
1151 		report[idx] |= value << bit_shift;
1152 	}
1153 }
1154 
1155 static void implement(const struct hid_device *hid, u8 *report,
1156 		      unsigned offset, unsigned n, u32 value)
1157 {
1158 	if (unlikely(n > 32)) {
1159 		hid_warn(hid, "%s() called with n (%d) > 32! (%s)\n",
1160 			 __func__, n, current->comm);
1161 		n = 32;
1162 	} else if (n < 32) {
1163 		u32 m = (1U << n) - 1;
1164 
1165 		if (unlikely(value > m)) {
1166 			hid_warn(hid,
1167 				 "%s() called with too large value %d (n: %d)! (%s)\n",
1168 				 __func__, value, n, current->comm);
1169 			WARN_ON(1);
1170 			value &= m;
1171 		}
1172 	}
1173 
1174 	__implement(report, offset, n, value);
1175 }
1176 
1177 /*
1178  * Search an array for a value.
1179  */
1180 
1181 static int search(__s32 *array, __s32 value, unsigned n)
1182 {
1183 	while (n--) {
1184 		if (*array++ == value)
1185 			return 0;
1186 	}
1187 	return -1;
1188 }
1189 
1190 /**
1191  * hid_match_report - check if driver's raw_event should be called
1192  *
1193  * @hid: hid device
1194  * @report_type: type to match against
1195  *
1196  * compare hid->driver->report_table->report_type to report->type
1197  */
1198 static int hid_match_report(struct hid_device *hid, struct hid_report *report)
1199 {
1200 	const struct hid_report_id *id = hid->driver->report_table;
1201 
1202 	if (!id) /* NULL means all */
1203 		return 1;
1204 
1205 	for (; id->report_type != HID_TERMINATOR; id++)
1206 		if (id->report_type == HID_ANY_ID ||
1207 				id->report_type == report->type)
1208 			return 1;
1209 	return 0;
1210 }
1211 
1212 /**
1213  * hid_match_usage - check if driver's event should be called
1214  *
1215  * @hid: hid device
1216  * @usage: usage to match against
1217  *
1218  * compare hid->driver->usage_table->usage_{type,code} to
1219  * usage->usage_{type,code}
1220  */
1221 static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage)
1222 {
1223 	const struct hid_usage_id *id = hid->driver->usage_table;
1224 
1225 	if (!id) /* NULL means all */
1226 		return 1;
1227 
1228 	for (; id->usage_type != HID_ANY_ID - 1; id++)
1229 		if ((id->usage_hid == HID_ANY_ID ||
1230 				id->usage_hid == usage->hid) &&
1231 				(id->usage_type == HID_ANY_ID ||
1232 				id->usage_type == usage->type) &&
1233 				(id->usage_code == HID_ANY_ID ||
1234 				 id->usage_code == usage->code))
1235 			return 1;
1236 	return 0;
1237 }
1238 
1239 static void hid_process_event(struct hid_device *hid, struct hid_field *field,
1240 		struct hid_usage *usage, __s32 value, int interrupt)
1241 {
1242 	struct hid_driver *hdrv = hid->driver;
1243 	int ret;
1244 
1245 	if (!list_empty(&hid->debug_list))
1246 		hid_dump_input(hid, usage, value);
1247 
1248 	if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
1249 		ret = hdrv->event(hid, field, usage, value);
1250 		if (ret != 0) {
1251 			if (ret < 0)
1252 				hid_err(hid, "%s's event failed with %d\n",
1253 						hdrv->name, ret);
1254 			return;
1255 		}
1256 	}
1257 
1258 	if (hid->claimed & HID_CLAIMED_INPUT)
1259 		hidinput_hid_event(hid, field, usage, value);
1260 	if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
1261 		hid->hiddev_hid_event(hid, field, usage, value);
1262 }
1263 
1264 /*
1265  * Analyse a received field, and fetch the data from it. The field
1266  * content is stored for next report processing (we do differential
1267  * reporting to the layer).
1268  */
1269 
1270 static void hid_input_field(struct hid_device *hid, struct hid_field *field,
1271 			    __u8 *data, int interrupt)
1272 {
1273 	unsigned n;
1274 	unsigned count = field->report_count;
1275 	unsigned offset = field->report_offset;
1276 	unsigned size = field->report_size;
1277 	__s32 min = field->logical_minimum;
1278 	__s32 max = field->logical_maximum;
1279 	__s32 *value;
1280 
1281 	value = kmalloc(sizeof(__s32) * count, GFP_ATOMIC);
1282 	if (!value)
1283 		return;
1284 
1285 	for (n = 0; n < count; n++) {
1286 
1287 		value[n] = min < 0 ?
1288 			snto32(hid_field_extract(hid, data, offset + n * size,
1289 			       size), size) :
1290 			hid_field_extract(hid, data, offset + n * size, size);
1291 
1292 		/* Ignore report if ErrorRollOver */
1293 		if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
1294 		    value[n] >= min && value[n] <= max &&
1295 		    value[n] - min < field->maxusage &&
1296 		    field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1)
1297 			goto exit;
1298 	}
1299 
1300 	for (n = 0; n < count; n++) {
1301 
1302 		if (HID_MAIN_ITEM_VARIABLE & field->flags) {
1303 			hid_process_event(hid, field, &field->usage[n], value[n], interrupt);
1304 			continue;
1305 		}
1306 
1307 		if (field->value[n] >= min && field->value[n] <= max
1308 			&& field->value[n] - min < field->maxusage
1309 			&& field->usage[field->value[n] - min].hid
1310 			&& search(value, field->value[n], count))
1311 				hid_process_event(hid, field, &field->usage[field->value[n] - min], 0, interrupt);
1312 
1313 		if (value[n] >= min && value[n] <= max
1314 			&& value[n] - min < field->maxusage
1315 			&& field->usage[value[n] - min].hid
1316 			&& search(field->value, value[n], count))
1317 				hid_process_event(hid, field, &field->usage[value[n] - min], 1, interrupt);
1318 	}
1319 
1320 	memcpy(field->value, value, count * sizeof(__s32));
1321 exit:
1322 	kfree(value);
1323 }
1324 
1325 /*
1326  * Output the field into the report.
1327  */
1328 
1329 static void hid_output_field(const struct hid_device *hid,
1330 			     struct hid_field *field, __u8 *data)
1331 {
1332 	unsigned count = field->report_count;
1333 	unsigned offset = field->report_offset;
1334 	unsigned size = field->report_size;
1335 	unsigned n;
1336 
1337 	for (n = 0; n < count; n++) {
1338 		if (field->logical_minimum < 0)	/* signed values */
1339 			implement(hid, data, offset + n * size, size,
1340 				  s32ton(field->value[n], size));
1341 		else				/* unsigned values */
1342 			implement(hid, data, offset + n * size, size,
1343 				  field->value[n]);
1344 	}
1345 }
1346 
1347 /*
1348  * Create a report. 'data' has to be allocated using
1349  * hid_alloc_report_buf() so that it has proper size.
1350  */
1351 
1352 void hid_output_report(struct hid_report *report, __u8 *data)
1353 {
1354 	unsigned n;
1355 
1356 	if (report->id > 0)
1357 		*data++ = report->id;
1358 
1359 	memset(data, 0, ((report->size - 1) >> 3) + 1);
1360 	for (n = 0; n < report->maxfield; n++)
1361 		hid_output_field(report->device, report->field[n], data);
1362 }
1363 EXPORT_SYMBOL_GPL(hid_output_report);
1364 
1365 /*
1366  * Allocator for buffer that is going to be passed to hid_output_report()
1367  */
1368 u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
1369 {
1370 	/*
1371 	 * 7 extra bytes are necessary to achieve proper functionality
1372 	 * of implement() working on 8 byte chunks
1373 	 */
1374 
1375 	u32 len = hid_report_len(report) + 7;
1376 
1377 	return kmalloc(len, flags);
1378 }
1379 EXPORT_SYMBOL_GPL(hid_alloc_report_buf);
1380 
1381 /*
1382  * Set a field value. The report this field belongs to has to be
1383  * created and transferred to the device, to set this value in the
1384  * device.
1385  */
1386 
1387 int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
1388 {
1389 	unsigned size;
1390 
1391 	if (!field)
1392 		return -1;
1393 
1394 	size = field->report_size;
1395 
1396 	hid_dump_input(field->report->device, field->usage + offset, value);
1397 
1398 	if (offset >= field->report_count) {
1399 		hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n",
1400 				offset, field->report_count);
1401 		return -1;
1402 	}
1403 	if (field->logical_minimum < 0) {
1404 		if (value != snto32(s32ton(value, size), size)) {
1405 			hid_err(field->report->device, "value %d is out of range\n", value);
1406 			return -1;
1407 		}
1408 	}
1409 	field->value[offset] = value;
1410 	return 0;
1411 }
1412 EXPORT_SYMBOL_GPL(hid_set_field);
1413 
1414 static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
1415 		const u8 *data)
1416 {
1417 	struct hid_report *report;
1418 	unsigned int n = 0;	/* Normally report number is 0 */
1419 
1420 	/* Device uses numbered reports, data[0] is report number */
1421 	if (report_enum->numbered)
1422 		n = *data;
1423 
1424 	report = report_enum->report_id_hash[n];
1425 	if (report == NULL)
1426 		dbg_hid("undefined report_id %u received\n", n);
1427 
1428 	return report;
1429 }
1430 
1431 /*
1432  * Implement a generic .request() callback, using .raw_request()
1433  * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
1434  */
1435 void __hid_request(struct hid_device *hid, struct hid_report *report,
1436 		int reqtype)
1437 {
1438 	char *buf;
1439 	int ret;
1440 	u32 len;
1441 
1442 	buf = hid_alloc_report_buf(report, GFP_KERNEL);
1443 	if (!buf)
1444 		return;
1445 
1446 	len = hid_report_len(report);
1447 
1448 	if (reqtype == HID_REQ_SET_REPORT)
1449 		hid_output_report(report, buf);
1450 
1451 	ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
1452 					  report->type, reqtype);
1453 	if (ret < 0) {
1454 		dbg_hid("unable to complete request: %d\n", ret);
1455 		goto out;
1456 	}
1457 
1458 	if (reqtype == HID_REQ_GET_REPORT)
1459 		hid_input_report(hid, report->type, buf, ret, 0);
1460 
1461 out:
1462 	kfree(buf);
1463 }
1464 EXPORT_SYMBOL_GPL(__hid_request);
1465 
1466 int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, u32 size,
1467 		int interrupt)
1468 {
1469 	struct hid_report_enum *report_enum = hid->report_enum + type;
1470 	struct hid_report *report;
1471 	struct hid_driver *hdrv;
1472 	unsigned int a;
1473 	u32 rsize, csize = size;
1474 	u8 *cdata = data;
1475 	int ret = 0;
1476 
1477 	report = hid_get_report(report_enum, data);
1478 	if (!report)
1479 		goto out;
1480 
1481 	if (report_enum->numbered) {
1482 		cdata++;
1483 		csize--;
1484 	}
1485 
1486 	rsize = ((report->size - 1) >> 3) + 1;
1487 
1488 	if (rsize > HID_MAX_BUFFER_SIZE)
1489 		rsize = HID_MAX_BUFFER_SIZE;
1490 
1491 	if (csize < rsize) {
1492 		dbg_hid("report %d is too short, (%d < %d)\n", report->id,
1493 				csize, rsize);
1494 		memset(cdata + csize, 0, rsize - csize);
1495 	}
1496 
1497 	if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
1498 		hid->hiddev_report_event(hid, report);
1499 	if (hid->claimed & HID_CLAIMED_HIDRAW) {
1500 		ret = hidraw_report_event(hid, data, size);
1501 		if (ret)
1502 			goto out;
1503 	}
1504 
1505 	if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
1506 		for (a = 0; a < report->maxfield; a++)
1507 			hid_input_field(hid, report->field[a], cdata, interrupt);
1508 		hdrv = hid->driver;
1509 		if (hdrv && hdrv->report)
1510 			hdrv->report(hid, report);
1511 	}
1512 
1513 	if (hid->claimed & HID_CLAIMED_INPUT)
1514 		hidinput_report_event(hid, report);
1515 out:
1516 	return ret;
1517 }
1518 EXPORT_SYMBOL_GPL(hid_report_raw_event);
1519 
1520 /**
1521  * hid_input_report - report data from lower layer (usb, bt...)
1522  *
1523  * @hid: hid device
1524  * @type: HID report type (HID_*_REPORT)
1525  * @data: report contents
1526  * @size: size of data parameter
1527  * @interrupt: distinguish between interrupt and control transfers
1528  *
1529  * This is data entry for lower layers.
1530  */
1531 int hid_input_report(struct hid_device *hid, int type, u8 *data, u32 size, int interrupt)
1532 {
1533 	struct hid_report_enum *report_enum;
1534 	struct hid_driver *hdrv;
1535 	struct hid_report *report;
1536 	int ret = 0;
1537 
1538 	if (!hid)
1539 		return -ENODEV;
1540 
1541 	if (down_trylock(&hid->driver_input_lock))
1542 		return -EBUSY;
1543 
1544 	if (!hid->driver) {
1545 		ret = -ENODEV;
1546 		goto unlock;
1547 	}
1548 	report_enum = hid->report_enum + type;
1549 	hdrv = hid->driver;
1550 
1551 	if (!size) {
1552 		dbg_hid("empty report\n");
1553 		ret = -1;
1554 		goto unlock;
1555 	}
1556 
1557 	/* Avoid unnecessary overhead if debugfs is disabled */
1558 	if (!list_empty(&hid->debug_list))
1559 		hid_dump_report(hid, type, data, size);
1560 
1561 	report = hid_get_report(report_enum, data);
1562 
1563 	if (!report) {
1564 		ret = -1;
1565 		goto unlock;
1566 	}
1567 
1568 	if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
1569 		ret = hdrv->raw_event(hid, report, data, size);
1570 		if (ret < 0)
1571 			goto unlock;
1572 	}
1573 
1574 	ret = hid_report_raw_event(hid, type, data, size, interrupt);
1575 
1576 unlock:
1577 	up(&hid->driver_input_lock);
1578 	return ret;
1579 }
1580 EXPORT_SYMBOL_GPL(hid_input_report);
1581 
1582 bool hid_match_one_id(const struct hid_device *hdev,
1583 		      const struct hid_device_id *id)
1584 {
1585 	return (id->bus == HID_BUS_ANY || id->bus == hdev->bus) &&
1586 		(id->group == HID_GROUP_ANY || id->group == hdev->group) &&
1587 		(id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&
1588 		(id->product == HID_ANY_ID || id->product == hdev->product);
1589 }
1590 
1591 const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
1592 		const struct hid_device_id *id)
1593 {
1594 	for (; id->bus; id++)
1595 		if (hid_match_one_id(hdev, id))
1596 			return id;
1597 
1598 	return NULL;
1599 }
1600 
1601 static const struct hid_device_id hid_hiddev_list[] = {
1602 	{ HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS) },
1603 	{ HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS1) },
1604 	{ }
1605 };
1606 
1607 static bool hid_hiddev(struct hid_device *hdev)
1608 {
1609 	return !!hid_match_id(hdev, hid_hiddev_list);
1610 }
1611 
1612 
1613 static ssize_t
1614 read_report_descriptor(struct file *filp, struct kobject *kobj,
1615 		struct bin_attribute *attr,
1616 		char *buf, loff_t off, size_t count)
1617 {
1618 	struct device *dev = kobj_to_dev(kobj);
1619 	struct hid_device *hdev = to_hid_device(dev);
1620 
1621 	if (off >= hdev->rsize)
1622 		return 0;
1623 
1624 	if (off + count > hdev->rsize)
1625 		count = hdev->rsize - off;
1626 
1627 	memcpy(buf, hdev->rdesc + off, count);
1628 
1629 	return count;
1630 }
1631 
1632 static ssize_t
1633 show_country(struct device *dev, struct device_attribute *attr,
1634 		char *buf)
1635 {
1636 	struct hid_device *hdev = to_hid_device(dev);
1637 
1638 	return sprintf(buf, "%02x\n", hdev->country & 0xff);
1639 }
1640 
1641 static struct bin_attribute dev_bin_attr_report_desc = {
1642 	.attr = { .name = "report_descriptor", .mode = 0444 },
1643 	.read = read_report_descriptor,
1644 	.size = HID_MAX_DESCRIPTOR_SIZE,
1645 };
1646 
1647 static const struct device_attribute dev_attr_country = {
1648 	.attr = { .name = "country", .mode = 0444 },
1649 	.show = show_country,
1650 };
1651 
1652 int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
1653 {
1654 	static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
1655 		"Joystick", "Gamepad", "Keyboard", "Keypad",
1656 		"Multi-Axis Controller"
1657 	};
1658 	const char *type, *bus;
1659 	char buf[64] = "";
1660 	unsigned int i;
1661 	int len;
1662 	int ret;
1663 
1664 	if (hdev->quirks & HID_QUIRK_HIDDEV_FORCE)
1665 		connect_mask |= (HID_CONNECT_HIDDEV_FORCE | HID_CONNECT_HIDDEV);
1666 	if (hdev->quirks & HID_QUIRK_HIDINPUT_FORCE)
1667 		connect_mask |= HID_CONNECT_HIDINPUT_FORCE;
1668 	if (hdev->bus != BUS_USB)
1669 		connect_mask &= ~HID_CONNECT_HIDDEV;
1670 	if (hid_hiddev(hdev))
1671 		connect_mask |= HID_CONNECT_HIDDEV_FORCE;
1672 
1673 	if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,
1674 				connect_mask & HID_CONNECT_HIDINPUT_FORCE))
1675 		hdev->claimed |= HID_CLAIMED_INPUT;
1676 
1677 	if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect &&
1678 			!hdev->hiddev_connect(hdev,
1679 				connect_mask & HID_CONNECT_HIDDEV_FORCE))
1680 		hdev->claimed |= HID_CLAIMED_HIDDEV;
1681 	if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))
1682 		hdev->claimed |= HID_CLAIMED_HIDRAW;
1683 
1684 	if (connect_mask & HID_CONNECT_DRIVER)
1685 		hdev->claimed |= HID_CLAIMED_DRIVER;
1686 
1687 	/* Drivers with the ->raw_event callback set are not required to connect
1688 	 * to any other listener. */
1689 	if (!hdev->claimed && !hdev->driver->raw_event) {
1690 		hid_err(hdev, "device has no listeners, quitting\n");
1691 		return -ENODEV;
1692 	}
1693 
1694 	if ((hdev->claimed & HID_CLAIMED_INPUT) &&
1695 			(connect_mask & HID_CONNECT_FF) && hdev->ff_init)
1696 		hdev->ff_init(hdev);
1697 
1698 	len = 0;
1699 	if (hdev->claimed & HID_CLAIMED_INPUT)
1700 		len += sprintf(buf + len, "input");
1701 	if (hdev->claimed & HID_CLAIMED_HIDDEV)
1702 		len += sprintf(buf + len, "%shiddev%d", len ? "," : "",
1703 				((struct hiddev *)hdev->hiddev)->minor);
1704 	if (hdev->claimed & HID_CLAIMED_HIDRAW)
1705 		len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
1706 				((struct hidraw *)hdev->hidraw)->minor);
1707 
1708 	type = "Device";
1709 	for (i = 0; i < hdev->maxcollection; i++) {
1710 		struct hid_collection *col = &hdev->collection[i];
1711 		if (col->type == HID_COLLECTION_APPLICATION &&
1712 		   (col->usage & HID_USAGE_PAGE) == HID_UP_GENDESK &&
1713 		   (col->usage & 0xffff) < ARRAY_SIZE(types)) {
1714 			type = types[col->usage & 0xffff];
1715 			break;
1716 		}
1717 	}
1718 
1719 	switch (hdev->bus) {
1720 	case BUS_USB:
1721 		bus = "USB";
1722 		break;
1723 	case BUS_BLUETOOTH:
1724 		bus = "BLUETOOTH";
1725 		break;
1726 	case BUS_I2C:
1727 		bus = "I2C";
1728 		break;
1729 	default:
1730 		bus = "<UNKNOWN>";
1731 	}
1732 
1733 	ret = device_create_file(&hdev->dev, &dev_attr_country);
1734 	if (ret)
1735 		hid_warn(hdev,
1736 			 "can't create sysfs country code attribute err: %d\n", ret);
1737 
1738 	hid_info(hdev, "%s: %s HID v%x.%02x %s [%s] on %s\n",
1739 		 buf, bus, hdev->version >> 8, hdev->version & 0xff,
1740 		 type, hdev->name, hdev->phys);
1741 
1742 	return 0;
1743 }
1744 EXPORT_SYMBOL_GPL(hid_connect);
1745 
1746 void hid_disconnect(struct hid_device *hdev)
1747 {
1748 	device_remove_file(&hdev->dev, &dev_attr_country);
1749 	if (hdev->claimed & HID_CLAIMED_INPUT)
1750 		hidinput_disconnect(hdev);
1751 	if (hdev->claimed & HID_CLAIMED_HIDDEV)
1752 		hdev->hiddev_disconnect(hdev);
1753 	if (hdev->claimed & HID_CLAIMED_HIDRAW)
1754 		hidraw_disconnect(hdev);
1755 	hdev->claimed = 0;
1756 }
1757 EXPORT_SYMBOL_GPL(hid_disconnect);
1758 
1759 /**
1760  * hid_hw_start - start underlying HW
1761  * @hdev: hid device
1762  * @connect_mask: which outputs to connect, see HID_CONNECT_*
1763  *
1764  * Call this in probe function *after* hid_parse. This will setup HW
1765  * buffers and start the device (if not defeirred to device open).
1766  * hid_hw_stop must be called if this was successful.
1767  */
1768 int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask)
1769 {
1770 	int error;
1771 
1772 	error = hdev->ll_driver->start(hdev);
1773 	if (error)
1774 		return error;
1775 
1776 	if (connect_mask) {
1777 		error = hid_connect(hdev, connect_mask);
1778 		if (error) {
1779 			hdev->ll_driver->stop(hdev);
1780 			return error;
1781 		}
1782 	}
1783 
1784 	return 0;
1785 }
1786 EXPORT_SYMBOL_GPL(hid_hw_start);
1787 
1788 /**
1789  * hid_hw_stop - stop underlying HW
1790  * @hdev: hid device
1791  *
1792  * This is usually called from remove function or from probe when something
1793  * failed and hid_hw_start was called already.
1794  */
1795 void hid_hw_stop(struct hid_device *hdev)
1796 {
1797 	hid_disconnect(hdev);
1798 	hdev->ll_driver->stop(hdev);
1799 }
1800 EXPORT_SYMBOL_GPL(hid_hw_stop);
1801 
1802 /**
1803  * hid_hw_open - signal underlying HW to start delivering events
1804  * @hdev: hid device
1805  *
1806  * Tell underlying HW to start delivering events from the device.
1807  * This function should be called sometime after successful call
1808  * to hid_hw_start().
1809  */
1810 int hid_hw_open(struct hid_device *hdev)
1811 {
1812 	int ret;
1813 
1814 	ret = mutex_lock_killable(&hdev->ll_open_lock);
1815 	if (ret)
1816 		return ret;
1817 
1818 	if (!hdev->ll_open_count++) {
1819 		ret = hdev->ll_driver->open(hdev);
1820 		if (ret)
1821 			hdev->ll_open_count--;
1822 	}
1823 
1824 	mutex_unlock(&hdev->ll_open_lock);
1825 	return ret;
1826 }
1827 EXPORT_SYMBOL_GPL(hid_hw_open);
1828 
1829 /**
1830  * hid_hw_close - signal underlaying HW to stop delivering events
1831  *
1832  * @hdev: hid device
1833  *
1834  * This function indicates that we are not interested in the events
1835  * from this device anymore. Delivery of events may or may not stop,
1836  * depending on the number of users still outstanding.
1837  */
1838 void hid_hw_close(struct hid_device *hdev)
1839 {
1840 	mutex_lock(&hdev->ll_open_lock);
1841 	if (!--hdev->ll_open_count)
1842 		hdev->ll_driver->close(hdev);
1843 	mutex_unlock(&hdev->ll_open_lock);
1844 }
1845 EXPORT_SYMBOL_GPL(hid_hw_close);
1846 
1847 struct hid_dynid {
1848 	struct list_head list;
1849 	struct hid_device_id id;
1850 };
1851 
1852 /**
1853  * store_new_id - add a new HID device ID to this driver and re-probe devices
1854  * @driver: target device driver
1855  * @buf: buffer for scanning device ID data
1856  * @count: input size
1857  *
1858  * Adds a new dynamic hid device ID to this driver,
1859  * and causes the driver to probe for all devices again.
1860  */
1861 static ssize_t new_id_store(struct device_driver *drv, const char *buf,
1862 		size_t count)
1863 {
1864 	struct hid_driver *hdrv = to_hid_driver(drv);
1865 	struct hid_dynid *dynid;
1866 	__u32 bus, vendor, product;
1867 	unsigned long driver_data = 0;
1868 	int ret;
1869 
1870 	ret = sscanf(buf, "%x %x %x %lx",
1871 			&bus, &vendor, &product, &driver_data);
1872 	if (ret < 3)
1873 		return -EINVAL;
1874 
1875 	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
1876 	if (!dynid)
1877 		return -ENOMEM;
1878 
1879 	dynid->id.bus = bus;
1880 	dynid->id.group = HID_GROUP_ANY;
1881 	dynid->id.vendor = vendor;
1882 	dynid->id.product = product;
1883 	dynid->id.driver_data = driver_data;
1884 
1885 	spin_lock(&hdrv->dyn_lock);
1886 	list_add_tail(&dynid->list, &hdrv->dyn_list);
1887 	spin_unlock(&hdrv->dyn_lock);
1888 
1889 	ret = driver_attach(&hdrv->driver);
1890 
1891 	return ret ? : count;
1892 }
1893 static DRIVER_ATTR_WO(new_id);
1894 
1895 static struct attribute *hid_drv_attrs[] = {
1896 	&driver_attr_new_id.attr,
1897 	NULL,
1898 };
1899 ATTRIBUTE_GROUPS(hid_drv);
1900 
1901 static void hid_free_dynids(struct hid_driver *hdrv)
1902 {
1903 	struct hid_dynid *dynid, *n;
1904 
1905 	spin_lock(&hdrv->dyn_lock);
1906 	list_for_each_entry_safe(dynid, n, &hdrv->dyn_list, list) {
1907 		list_del(&dynid->list);
1908 		kfree(dynid);
1909 	}
1910 	spin_unlock(&hdrv->dyn_lock);
1911 }
1912 
1913 const struct hid_device_id *hid_match_device(struct hid_device *hdev,
1914 					     struct hid_driver *hdrv)
1915 {
1916 	struct hid_dynid *dynid;
1917 
1918 	spin_lock(&hdrv->dyn_lock);
1919 	list_for_each_entry(dynid, &hdrv->dyn_list, list) {
1920 		if (hid_match_one_id(hdev, &dynid->id)) {
1921 			spin_unlock(&hdrv->dyn_lock);
1922 			return &dynid->id;
1923 		}
1924 	}
1925 	spin_unlock(&hdrv->dyn_lock);
1926 
1927 	return hid_match_id(hdev, hdrv->id_table);
1928 }
1929 EXPORT_SYMBOL_GPL(hid_match_device);
1930 
1931 static int hid_bus_match(struct device *dev, struct device_driver *drv)
1932 {
1933 	struct hid_driver *hdrv = to_hid_driver(drv);
1934 	struct hid_device *hdev = to_hid_device(dev);
1935 
1936 	return hid_match_device(hdev, hdrv) != NULL;
1937 }
1938 
1939 static int hid_device_probe(struct device *dev)
1940 {
1941 	struct hid_driver *hdrv = to_hid_driver(dev->driver);
1942 	struct hid_device *hdev = to_hid_device(dev);
1943 	const struct hid_device_id *id;
1944 	int ret = 0;
1945 
1946 	if (down_interruptible(&hdev->driver_input_lock)) {
1947 		ret = -EINTR;
1948 		goto end;
1949 	}
1950 	hdev->io_started = false;
1951 
1952 	if (!hdev->driver) {
1953 		id = hid_match_device(hdev, hdrv);
1954 		if (id == NULL) {
1955 			ret = -ENODEV;
1956 			goto unlock;
1957 		}
1958 
1959 		if (hdrv->match) {
1960 			if (!hdrv->match(hdev, hid_ignore_special_drivers)) {
1961 				ret = -ENODEV;
1962 				goto unlock;
1963 			}
1964 		} else {
1965 			/*
1966 			 * hid-generic implements .match(), so if
1967 			 * hid_ignore_special_drivers is set, we can safely
1968 			 * return.
1969 			 */
1970 			if (hid_ignore_special_drivers) {
1971 				ret = -ENODEV;
1972 				goto unlock;
1973 			}
1974 		}
1975 
1976 		/* reset the quirks that has been previously set */
1977 		hdev->quirks = hid_lookup_quirk(hdev);
1978 		hdev->driver = hdrv;
1979 		if (hdrv->probe) {
1980 			ret = hdrv->probe(hdev, id);
1981 		} else { /* default probe */
1982 			ret = hid_open_report(hdev);
1983 			if (!ret)
1984 				ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
1985 		}
1986 		if (ret) {
1987 			hid_close_report(hdev);
1988 			hdev->driver = NULL;
1989 		}
1990 	}
1991 unlock:
1992 	if (!hdev->io_started)
1993 		up(&hdev->driver_input_lock);
1994 end:
1995 	return ret;
1996 }
1997 
1998 static int hid_device_remove(struct device *dev)
1999 {
2000 	struct hid_device *hdev = to_hid_device(dev);
2001 	struct hid_driver *hdrv;
2002 	int ret = 0;
2003 
2004 	if (down_interruptible(&hdev->driver_input_lock)) {
2005 		ret = -EINTR;
2006 		goto end;
2007 	}
2008 	hdev->io_started = false;
2009 
2010 	hdrv = hdev->driver;
2011 	if (hdrv) {
2012 		if (hdrv->remove)
2013 			hdrv->remove(hdev);
2014 		else /* default remove */
2015 			hid_hw_stop(hdev);
2016 		hid_close_report(hdev);
2017 		hdev->driver = NULL;
2018 	}
2019 
2020 	if (!hdev->io_started)
2021 		up(&hdev->driver_input_lock);
2022 end:
2023 	return ret;
2024 }
2025 
2026 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
2027 			     char *buf)
2028 {
2029 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
2030 
2031 	return scnprintf(buf, PAGE_SIZE, "hid:b%04Xg%04Xv%08Xp%08X\n",
2032 			 hdev->bus, hdev->group, hdev->vendor, hdev->product);
2033 }
2034 static DEVICE_ATTR_RO(modalias);
2035 
2036 static struct attribute *hid_dev_attrs[] = {
2037 	&dev_attr_modalias.attr,
2038 	NULL,
2039 };
2040 static struct bin_attribute *hid_dev_bin_attrs[] = {
2041 	&dev_bin_attr_report_desc,
2042 	NULL
2043 };
2044 static const struct attribute_group hid_dev_group = {
2045 	.attrs = hid_dev_attrs,
2046 	.bin_attrs = hid_dev_bin_attrs,
2047 };
2048 __ATTRIBUTE_GROUPS(hid_dev);
2049 
2050 static int hid_uevent(struct device *dev, struct kobj_uevent_env *env)
2051 {
2052 	struct hid_device *hdev = to_hid_device(dev);
2053 
2054 	if (add_uevent_var(env, "HID_ID=%04X:%08X:%08X",
2055 			hdev->bus, hdev->vendor, hdev->product))
2056 		return -ENOMEM;
2057 
2058 	if (add_uevent_var(env, "HID_NAME=%s", hdev->name))
2059 		return -ENOMEM;
2060 
2061 	if (add_uevent_var(env, "HID_PHYS=%s", hdev->phys))
2062 		return -ENOMEM;
2063 
2064 	if (add_uevent_var(env, "HID_UNIQ=%s", hdev->uniq))
2065 		return -ENOMEM;
2066 
2067 	if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",
2068 			   hdev->bus, hdev->group, hdev->vendor, hdev->product))
2069 		return -ENOMEM;
2070 
2071 	return 0;
2072 }
2073 
2074 struct bus_type hid_bus_type = {
2075 	.name		= "hid",
2076 	.dev_groups	= hid_dev_groups,
2077 	.drv_groups	= hid_drv_groups,
2078 	.match		= hid_bus_match,
2079 	.probe		= hid_device_probe,
2080 	.remove		= hid_device_remove,
2081 	.uevent		= hid_uevent,
2082 };
2083 EXPORT_SYMBOL(hid_bus_type);
2084 
2085 int hid_add_device(struct hid_device *hdev)
2086 {
2087 	static atomic_t id = ATOMIC_INIT(0);
2088 	int ret;
2089 
2090 	if (WARN_ON(hdev->status & HID_STAT_ADDED))
2091 		return -EBUSY;
2092 
2093 	hdev->quirks = hid_lookup_quirk(hdev);
2094 
2095 	/* we need to kill them here, otherwise they will stay allocated to
2096 	 * wait for coming driver */
2097 	if (hid_ignore(hdev))
2098 		return -ENODEV;
2099 
2100 	/*
2101 	 * Check for the mandatory transport channel.
2102 	 */
2103 	 if (!hdev->ll_driver->raw_request) {
2104 		hid_err(hdev, "transport driver missing .raw_request()\n");
2105 		return -EINVAL;
2106 	 }
2107 
2108 	/*
2109 	 * Read the device report descriptor once and use as template
2110 	 * for the driver-specific modifications.
2111 	 */
2112 	ret = hdev->ll_driver->parse(hdev);
2113 	if (ret)
2114 		return ret;
2115 	if (!hdev->dev_rdesc)
2116 		return -ENODEV;
2117 
2118 	/*
2119 	 * Scan generic devices for group information
2120 	 */
2121 	if (hid_ignore_special_drivers) {
2122 		hdev->group = HID_GROUP_GENERIC;
2123 	} else if (!hdev->group &&
2124 		   !(hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)) {
2125 		ret = hid_scan_report(hdev);
2126 		if (ret)
2127 			hid_warn(hdev, "bad device descriptor (%d)\n", ret);
2128 	}
2129 
2130 	/* XXX hack, any other cleaner solution after the driver core
2131 	 * is converted to allow more than 20 bytes as the device name? */
2132 	dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
2133 		     hdev->vendor, hdev->product, atomic_inc_return(&id));
2134 
2135 	hid_debug_register(hdev, dev_name(&hdev->dev));
2136 	ret = device_add(&hdev->dev);
2137 	if (!ret)
2138 		hdev->status |= HID_STAT_ADDED;
2139 	else
2140 		hid_debug_unregister(hdev);
2141 
2142 	return ret;
2143 }
2144 EXPORT_SYMBOL_GPL(hid_add_device);
2145 
2146 /**
2147  * hid_allocate_device - allocate new hid device descriptor
2148  *
2149  * Allocate and initialize hid device, so that hid_destroy_device might be
2150  * used to free it.
2151  *
2152  * New hid_device pointer is returned on success, otherwise ERR_PTR encoded
2153  * error value.
2154  */
2155 struct hid_device *hid_allocate_device(void)
2156 {
2157 	struct hid_device *hdev;
2158 	int ret = -ENOMEM;
2159 
2160 	hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
2161 	if (hdev == NULL)
2162 		return ERR_PTR(ret);
2163 
2164 	device_initialize(&hdev->dev);
2165 	hdev->dev.release = hid_device_release;
2166 	hdev->dev.bus = &hid_bus_type;
2167 	device_enable_async_suspend(&hdev->dev);
2168 
2169 	hid_close_report(hdev);
2170 
2171 	init_waitqueue_head(&hdev->debug_wait);
2172 	INIT_LIST_HEAD(&hdev->debug_list);
2173 	spin_lock_init(&hdev->debug_list_lock);
2174 	sema_init(&hdev->driver_input_lock, 1);
2175 	mutex_init(&hdev->ll_open_lock);
2176 
2177 	return hdev;
2178 }
2179 EXPORT_SYMBOL_GPL(hid_allocate_device);
2180 
2181 static void hid_remove_device(struct hid_device *hdev)
2182 {
2183 	if (hdev->status & HID_STAT_ADDED) {
2184 		device_del(&hdev->dev);
2185 		hid_debug_unregister(hdev);
2186 		hdev->status &= ~HID_STAT_ADDED;
2187 	}
2188 	kfree(hdev->dev_rdesc);
2189 	hdev->dev_rdesc = NULL;
2190 	hdev->dev_rsize = 0;
2191 }
2192 
2193 /**
2194  * hid_destroy_device - free previously allocated device
2195  *
2196  * @hdev: hid device
2197  *
2198  * If you allocate hid_device through hid_allocate_device, you should ever
2199  * free by this function.
2200  */
2201 void hid_destroy_device(struct hid_device *hdev)
2202 {
2203 	hid_remove_device(hdev);
2204 	put_device(&hdev->dev);
2205 }
2206 EXPORT_SYMBOL_GPL(hid_destroy_device);
2207 
2208 
2209 static int __hid_bus_reprobe_drivers(struct device *dev, void *data)
2210 {
2211 	struct hid_driver *hdrv = data;
2212 	struct hid_device *hdev = to_hid_device(dev);
2213 
2214 	if (hdev->driver == hdrv &&
2215 	    !hdrv->match(hdev, hid_ignore_special_drivers))
2216 		return device_reprobe(dev);
2217 
2218 	return 0;
2219 }
2220 
2221 static int __hid_bus_driver_added(struct device_driver *drv, void *data)
2222 {
2223 	struct hid_driver *hdrv = to_hid_driver(drv);
2224 
2225 	if (hdrv->match) {
2226 		bus_for_each_dev(&hid_bus_type, NULL, hdrv,
2227 				 __hid_bus_reprobe_drivers);
2228 	}
2229 
2230 	return 0;
2231 }
2232 
2233 static int __bus_removed_driver(struct device_driver *drv, void *data)
2234 {
2235 	return bus_rescan_devices(&hid_bus_type);
2236 }
2237 
2238 int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
2239 		const char *mod_name)
2240 {
2241 	int ret;
2242 
2243 	hdrv->driver.name = hdrv->name;
2244 	hdrv->driver.bus = &hid_bus_type;
2245 	hdrv->driver.owner = owner;
2246 	hdrv->driver.mod_name = mod_name;
2247 
2248 	INIT_LIST_HEAD(&hdrv->dyn_list);
2249 	spin_lock_init(&hdrv->dyn_lock);
2250 
2251 	ret = driver_register(&hdrv->driver);
2252 
2253 	if (ret == 0)
2254 		bus_for_each_drv(&hid_bus_type, NULL, NULL,
2255 				 __hid_bus_driver_added);
2256 
2257 	return ret;
2258 }
2259 EXPORT_SYMBOL_GPL(__hid_register_driver);
2260 
2261 void hid_unregister_driver(struct hid_driver *hdrv)
2262 {
2263 	driver_unregister(&hdrv->driver);
2264 	hid_free_dynids(hdrv);
2265 
2266 	bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver);
2267 }
2268 EXPORT_SYMBOL_GPL(hid_unregister_driver);
2269 
2270 int hid_check_keys_pressed(struct hid_device *hid)
2271 {
2272 	struct hid_input *hidinput;
2273 	int i;
2274 
2275 	if (!(hid->claimed & HID_CLAIMED_INPUT))
2276 		return 0;
2277 
2278 	list_for_each_entry(hidinput, &hid->inputs, list) {
2279 		for (i = 0; i < BITS_TO_LONGS(KEY_MAX); i++)
2280 			if (hidinput->input->key[i])
2281 				return 1;
2282 	}
2283 
2284 	return 0;
2285 }
2286 
2287 EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
2288 
2289 static int __init hid_init(void)
2290 {
2291 	int ret;
2292 
2293 	if (hid_debug)
2294 		pr_warn("hid_debug is now used solely for parser and driver debugging.\n"
2295 			"debugfs is now used for inspecting the device (report descriptor, reports)\n");
2296 
2297 	ret = bus_register(&hid_bus_type);
2298 	if (ret) {
2299 		pr_err("can't register hid bus\n");
2300 		goto err;
2301 	}
2302 
2303 	ret = hidraw_init();
2304 	if (ret)
2305 		goto err_bus;
2306 
2307 	hid_debug_init();
2308 
2309 	return 0;
2310 err_bus:
2311 	bus_unregister(&hid_bus_type);
2312 err:
2313 	return ret;
2314 }
2315 
2316 static void __exit hid_exit(void)
2317 {
2318 	hid_debug_exit();
2319 	hidraw_exit();
2320 	bus_unregister(&hid_bus_type);
2321 	hid_quirks_exit(HID_BUS_ANY);
2322 }
2323 
2324 module_init(hid_init);
2325 module_exit(hid_exit);
2326 
2327 MODULE_AUTHOR("Andreas Gal");
2328 MODULE_AUTHOR("Vojtech Pavlik");
2329 MODULE_AUTHOR("Jiri Kosina");
2330 MODULE_LICENSE("GPL");
2331