xref: /openbmc/linux/drivers/hid/hid-core.c (revision 1fa0a7dc)
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 #include <linux/async.h>
34 
35 #include <linux/hid.h>
36 #include <linux/hiddev.h>
37 #include <linux/hid-debug.h>
38 #include <linux/hidraw.h>
39 
40 #include "hid-ids.h"
41 
42 /*
43  * Version Information
44  */
45 
46 #define DRIVER_DESC "HID core driver"
47 
48 int hid_debug = 0;
49 module_param_named(debug, hid_debug, int, 0600);
50 MODULE_PARM_DESC(debug, "toggle HID debugging messages");
51 EXPORT_SYMBOL_GPL(hid_debug);
52 
53 static int hid_ignore_special_drivers = 0;
54 module_param_named(ignore_special_drivers, hid_ignore_special_drivers, int, 0600);
55 MODULE_PARM_DESC(ignore_special_drivers, "Ignore any special drivers and handle all devices by generic driver");
56 
57 /*
58  * Register a new report for a device.
59  */
60 
61 struct hid_report *hid_register_report(struct hid_device *device,
62 				       unsigned int type, unsigned int id,
63 				       unsigned int application)
64 {
65 	struct hid_report_enum *report_enum = device->report_enum + type;
66 	struct hid_report *report;
67 
68 	if (id >= HID_MAX_IDS)
69 		return NULL;
70 	if (report_enum->report_id_hash[id])
71 		return report_enum->report_id_hash[id];
72 
73 	report = kzalloc(sizeof(struct hid_report), GFP_KERNEL);
74 	if (!report)
75 		return NULL;
76 
77 	if (id != 0)
78 		report_enum->numbered = 1;
79 
80 	report->id = id;
81 	report->type = type;
82 	report->size = 0;
83 	report->device = device;
84 	report->application = application;
85 	report_enum->report_id_hash[id] = report;
86 
87 	list_add_tail(&report->list, &report_enum->report_list);
88 
89 	return report;
90 }
91 EXPORT_SYMBOL_GPL(hid_register_report);
92 
93 /*
94  * Register a new field for this report.
95  */
96 
97 static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages, unsigned values)
98 {
99 	struct hid_field *field;
100 
101 	if (report->maxfield == HID_MAX_FIELDS) {
102 		hid_err(report->device, "too many fields in report\n");
103 		return NULL;
104 	}
105 
106 	field = kzalloc((sizeof(struct hid_field) +
107 			 usages * sizeof(struct hid_usage) +
108 			 values * sizeof(unsigned)), GFP_KERNEL);
109 	if (!field)
110 		return NULL;
111 
112 	field->index = report->maxfield++;
113 	report->field[field->index] = field;
114 	field->usage = (struct hid_usage *)(field + 1);
115 	field->value = (s32 *)(field->usage + usages);
116 	field->report = report;
117 
118 	return field;
119 }
120 
121 /*
122  * Open a collection. The type/usage is pushed on the stack.
123  */
124 
125 static int open_collection(struct hid_parser *parser, unsigned type)
126 {
127 	struct hid_collection *collection;
128 	unsigned usage;
129 	int collection_index;
130 
131 	usage = parser->local.usage[0];
132 
133 	if (parser->collection_stack_ptr == parser->collection_stack_size) {
134 		unsigned int *collection_stack;
135 		unsigned int new_size = parser->collection_stack_size +
136 					HID_COLLECTION_STACK_SIZE;
137 
138 		collection_stack = krealloc(parser->collection_stack,
139 					    new_size * sizeof(unsigned int),
140 					    GFP_KERNEL);
141 		if (!collection_stack)
142 			return -ENOMEM;
143 
144 		parser->collection_stack = collection_stack;
145 		parser->collection_stack_size = new_size;
146 	}
147 
148 	if (parser->device->maxcollection == parser->device->collection_size) {
149 		collection = kmalloc(
150 				array3_size(sizeof(struct hid_collection),
151 					    parser->device->collection_size,
152 					    2),
153 				GFP_KERNEL);
154 		if (collection == NULL) {
155 			hid_err(parser->device, "failed to reallocate collection array\n");
156 			return -ENOMEM;
157 		}
158 		memcpy(collection, parser->device->collection,
159 			sizeof(struct hid_collection) *
160 			parser->device->collection_size);
161 		memset(collection + parser->device->collection_size, 0,
162 			sizeof(struct hid_collection) *
163 			parser->device->collection_size);
164 		kfree(parser->device->collection);
165 		parser->device->collection = collection;
166 		parser->device->collection_size *= 2;
167 	}
168 
169 	parser->collection_stack[parser->collection_stack_ptr++] =
170 		parser->device->maxcollection;
171 
172 	collection_index = parser->device->maxcollection++;
173 	collection = parser->device->collection + collection_index;
174 	collection->type = type;
175 	collection->usage = usage;
176 	collection->level = parser->collection_stack_ptr - 1;
177 	collection->parent_idx = (collection->level == 0) ? -1 :
178 		parser->collection_stack[collection->level - 1];
179 
180 	if (type == HID_COLLECTION_APPLICATION)
181 		parser->device->maxapplication++;
182 
183 	return 0;
184 }
185 
186 /*
187  * Close a collection.
188  */
189 
190 static int close_collection(struct hid_parser *parser)
191 {
192 	if (!parser->collection_stack_ptr) {
193 		hid_err(parser->device, "collection stack underflow\n");
194 		return -EINVAL;
195 	}
196 	parser->collection_stack_ptr--;
197 	return 0;
198 }
199 
200 /*
201  * Climb up the stack, search for the specified collection type
202  * and return the usage.
203  */
204 
205 static unsigned hid_lookup_collection(struct hid_parser *parser, unsigned type)
206 {
207 	struct hid_collection *collection = parser->device->collection;
208 	int n;
209 
210 	for (n = parser->collection_stack_ptr - 1; n >= 0; n--) {
211 		unsigned index = parser->collection_stack[n];
212 		if (collection[index].type == type)
213 			return collection[index].usage;
214 	}
215 	return 0; /* we know nothing about this usage type */
216 }
217 
218 /*
219  * Add a usage to the temporary parser table.
220  */
221 
222 static int hid_add_usage(struct hid_parser *parser, unsigned usage, u8 size)
223 {
224 	if (parser->local.usage_index >= HID_MAX_USAGES) {
225 		hid_err(parser->device, "usage index exceeded\n");
226 		return -1;
227 	}
228 	parser->local.usage[parser->local.usage_index] = usage;
229 	parser->local.usage_size[parser->local.usage_index] = size;
230 	parser->local.collection_index[parser->local.usage_index] =
231 		parser->collection_stack_ptr ?
232 		parser->collection_stack[parser->collection_stack_ptr - 1] : 0;
233 	parser->local.usage_index++;
234 	return 0;
235 }
236 
237 /*
238  * Register a new field for this report.
239  */
240 
241 static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsigned flags)
242 {
243 	struct hid_report *report;
244 	struct hid_field *field;
245 	unsigned int usages;
246 	unsigned int offset;
247 	unsigned int i;
248 	unsigned int application;
249 
250 	application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
251 
252 	report = hid_register_report(parser->device, report_type,
253 				     parser->global.report_id, application);
254 	if (!report) {
255 		hid_err(parser->device, "hid_register_report failed\n");
256 		return -1;
257 	}
258 
259 	/* Handle both signed and unsigned cases properly */
260 	if ((parser->global.logical_minimum < 0 &&
261 		parser->global.logical_maximum <
262 		parser->global.logical_minimum) ||
263 		(parser->global.logical_minimum >= 0 &&
264 		(__u32)parser->global.logical_maximum <
265 		(__u32)parser->global.logical_minimum)) {
266 		dbg_hid("logical range invalid 0x%x 0x%x\n",
267 			parser->global.logical_minimum,
268 			parser->global.logical_maximum);
269 		return -1;
270 	}
271 
272 	offset = report->size;
273 	report->size += parser->global.report_size * parser->global.report_count;
274 
275 	if (!parser->local.usage_index) /* Ignore padding fields */
276 		return 0;
277 
278 	usages = max_t(unsigned, parser->local.usage_index,
279 				 parser->global.report_count);
280 
281 	field = hid_register_field(report, usages, parser->global.report_count);
282 	if (!field)
283 		return 0;
284 
285 	field->physical = hid_lookup_collection(parser, HID_COLLECTION_PHYSICAL);
286 	field->logical = hid_lookup_collection(parser, HID_COLLECTION_LOGICAL);
287 	field->application = application;
288 
289 	for (i = 0; i < usages; i++) {
290 		unsigned j = i;
291 		/* Duplicate the last usage we parsed if we have excess values */
292 		if (i >= parser->local.usage_index)
293 			j = parser->local.usage_index - 1;
294 		field->usage[i].hid = parser->local.usage[j];
295 		field->usage[i].collection_index =
296 			parser->local.collection_index[j];
297 		field->usage[i].usage_index = i;
298 		field->usage[i].resolution_multiplier = 1;
299 	}
300 
301 	field->maxusage = usages;
302 	field->flags = flags;
303 	field->report_offset = offset;
304 	field->report_type = report_type;
305 	field->report_size = parser->global.report_size;
306 	field->report_count = parser->global.report_count;
307 	field->logical_minimum = parser->global.logical_minimum;
308 	field->logical_maximum = parser->global.logical_maximum;
309 	field->physical_minimum = parser->global.physical_minimum;
310 	field->physical_maximum = parser->global.physical_maximum;
311 	field->unit_exponent = parser->global.unit_exponent;
312 	field->unit = parser->global.unit;
313 
314 	return 0;
315 }
316 
317 /*
318  * Read data value from item.
319  */
320 
321 static u32 item_udata(struct hid_item *item)
322 {
323 	switch (item->size) {
324 	case 1: return item->data.u8;
325 	case 2: return item->data.u16;
326 	case 4: return item->data.u32;
327 	}
328 	return 0;
329 }
330 
331 static s32 item_sdata(struct hid_item *item)
332 {
333 	switch (item->size) {
334 	case 1: return item->data.s8;
335 	case 2: return item->data.s16;
336 	case 4: return item->data.s32;
337 	}
338 	return 0;
339 }
340 
341 /*
342  * Process a global item.
343  */
344 
345 static int hid_parser_global(struct hid_parser *parser, struct hid_item *item)
346 {
347 	__s32 raw_value;
348 	switch (item->tag) {
349 	case HID_GLOBAL_ITEM_TAG_PUSH:
350 
351 		if (parser->global_stack_ptr == HID_GLOBAL_STACK_SIZE) {
352 			hid_err(parser->device, "global environment stack overflow\n");
353 			return -1;
354 		}
355 
356 		memcpy(parser->global_stack + parser->global_stack_ptr++,
357 			&parser->global, sizeof(struct hid_global));
358 		return 0;
359 
360 	case HID_GLOBAL_ITEM_TAG_POP:
361 
362 		if (!parser->global_stack_ptr) {
363 			hid_err(parser->device, "global environment stack underflow\n");
364 			return -1;
365 		}
366 
367 		memcpy(&parser->global, parser->global_stack +
368 			--parser->global_stack_ptr, sizeof(struct hid_global));
369 		return 0;
370 
371 	case HID_GLOBAL_ITEM_TAG_USAGE_PAGE:
372 		parser->global.usage_page = item_udata(item);
373 		return 0;
374 
375 	case HID_GLOBAL_ITEM_TAG_LOGICAL_MINIMUM:
376 		parser->global.logical_minimum = item_sdata(item);
377 		return 0;
378 
379 	case HID_GLOBAL_ITEM_TAG_LOGICAL_MAXIMUM:
380 		if (parser->global.logical_minimum < 0)
381 			parser->global.logical_maximum = item_sdata(item);
382 		else
383 			parser->global.logical_maximum = item_udata(item);
384 		return 0;
385 
386 	case HID_GLOBAL_ITEM_TAG_PHYSICAL_MINIMUM:
387 		parser->global.physical_minimum = item_sdata(item);
388 		return 0;
389 
390 	case HID_GLOBAL_ITEM_TAG_PHYSICAL_MAXIMUM:
391 		if (parser->global.physical_minimum < 0)
392 			parser->global.physical_maximum = item_sdata(item);
393 		else
394 			parser->global.physical_maximum = item_udata(item);
395 		return 0;
396 
397 	case HID_GLOBAL_ITEM_TAG_UNIT_EXPONENT:
398 		/* Many devices provide unit exponent as a two's complement
399 		 * nibble due to the common misunderstanding of HID
400 		 * specification 1.11, 6.2.2.7 Global Items. Attempt to handle
401 		 * both this and the standard encoding. */
402 		raw_value = item_sdata(item);
403 		if (!(raw_value & 0xfffffff0))
404 			parser->global.unit_exponent = hid_snto32(raw_value, 4);
405 		else
406 			parser->global.unit_exponent = raw_value;
407 		return 0;
408 
409 	case HID_GLOBAL_ITEM_TAG_UNIT:
410 		parser->global.unit = item_udata(item);
411 		return 0;
412 
413 	case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
414 		parser->global.report_size = item_udata(item);
415 		if (parser->global.report_size > 256) {
416 			hid_err(parser->device, "invalid report_size %d\n",
417 					parser->global.report_size);
418 			return -1;
419 		}
420 		return 0;
421 
422 	case HID_GLOBAL_ITEM_TAG_REPORT_COUNT:
423 		parser->global.report_count = item_udata(item);
424 		if (parser->global.report_count > HID_MAX_USAGES) {
425 			hid_err(parser->device, "invalid report_count %d\n",
426 					parser->global.report_count);
427 			return -1;
428 		}
429 		return 0;
430 
431 	case HID_GLOBAL_ITEM_TAG_REPORT_ID:
432 		parser->global.report_id = item_udata(item);
433 		if (parser->global.report_id == 0 ||
434 		    parser->global.report_id >= HID_MAX_IDS) {
435 			hid_err(parser->device, "report_id %u is invalid\n",
436 				parser->global.report_id);
437 			return -1;
438 		}
439 		return 0;
440 
441 	default:
442 		hid_err(parser->device, "unknown global tag 0x%x\n", item->tag);
443 		return -1;
444 	}
445 }
446 
447 /*
448  * Process a local item.
449  */
450 
451 static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
452 {
453 	__u32 data;
454 	unsigned n;
455 	__u32 count;
456 
457 	data = item_udata(item);
458 
459 	switch (item->tag) {
460 	case HID_LOCAL_ITEM_TAG_DELIMITER:
461 
462 		if (data) {
463 			/*
464 			 * We treat items before the first delimiter
465 			 * as global to all usage sets (branch 0).
466 			 * In the moment we process only these global
467 			 * items and the first delimiter set.
468 			 */
469 			if (parser->local.delimiter_depth != 0) {
470 				hid_err(parser->device, "nested delimiters\n");
471 				return -1;
472 			}
473 			parser->local.delimiter_depth++;
474 			parser->local.delimiter_branch++;
475 		} else {
476 			if (parser->local.delimiter_depth < 1) {
477 				hid_err(parser->device, "bogus close delimiter\n");
478 				return -1;
479 			}
480 			parser->local.delimiter_depth--;
481 		}
482 		return 0;
483 
484 	case HID_LOCAL_ITEM_TAG_USAGE:
485 
486 		if (parser->local.delimiter_branch > 1) {
487 			dbg_hid("alternative usage ignored\n");
488 			return 0;
489 		}
490 
491 		return hid_add_usage(parser, data, item->size);
492 
493 	case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:
494 
495 		if (parser->local.delimiter_branch > 1) {
496 			dbg_hid("alternative usage ignored\n");
497 			return 0;
498 		}
499 
500 		parser->local.usage_minimum = data;
501 		return 0;
502 
503 	case HID_LOCAL_ITEM_TAG_USAGE_MAXIMUM:
504 
505 		if (parser->local.delimiter_branch > 1) {
506 			dbg_hid("alternative usage ignored\n");
507 			return 0;
508 		}
509 
510 		count = data - parser->local.usage_minimum;
511 		if (count + parser->local.usage_index >= HID_MAX_USAGES) {
512 			/*
513 			 * We do not warn if the name is not set, we are
514 			 * actually pre-scanning the device.
515 			 */
516 			if (dev_name(&parser->device->dev))
517 				hid_warn(parser->device,
518 					 "ignoring exceeding usage max\n");
519 			data = HID_MAX_USAGES - parser->local.usage_index +
520 				parser->local.usage_minimum - 1;
521 			if (data <= 0) {
522 				hid_err(parser->device,
523 					"no more usage index available\n");
524 				return -1;
525 			}
526 		}
527 
528 		for (n = parser->local.usage_minimum; n <= data; n++)
529 			if (hid_add_usage(parser, n, item->size)) {
530 				dbg_hid("hid_add_usage failed\n");
531 				return -1;
532 			}
533 		return 0;
534 
535 	default:
536 
537 		dbg_hid("unknown local item tag 0x%x\n", item->tag);
538 		return 0;
539 	}
540 	return 0;
541 }
542 
543 /*
544  * Concatenate Usage Pages into Usages where relevant:
545  * As per specification, 6.2.2.8: "When the parser encounters a main item it
546  * concatenates the last declared Usage Page with a Usage to form a complete
547  * usage value."
548  */
549 
550 static void hid_concatenate_usage_page(struct hid_parser *parser)
551 {
552 	int i;
553 
554 	for (i = 0; i < parser->local.usage_index; i++)
555 		if (parser->local.usage_size[i] <= 2)
556 			parser->local.usage[i] += parser->global.usage_page << 16;
557 }
558 
559 /*
560  * Process a main item.
561  */
562 
563 static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
564 {
565 	__u32 data;
566 	int ret;
567 
568 	hid_concatenate_usage_page(parser);
569 
570 	data = item_udata(item);
571 
572 	switch (item->tag) {
573 	case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
574 		ret = open_collection(parser, data & 0xff);
575 		break;
576 	case HID_MAIN_ITEM_TAG_END_COLLECTION:
577 		ret = close_collection(parser);
578 		break;
579 	case HID_MAIN_ITEM_TAG_INPUT:
580 		ret = hid_add_field(parser, HID_INPUT_REPORT, data);
581 		break;
582 	case HID_MAIN_ITEM_TAG_OUTPUT:
583 		ret = hid_add_field(parser, HID_OUTPUT_REPORT, data);
584 		break;
585 	case HID_MAIN_ITEM_TAG_FEATURE:
586 		ret = hid_add_field(parser, HID_FEATURE_REPORT, data);
587 		break;
588 	default:
589 		hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
590 		ret = 0;
591 	}
592 
593 	memset(&parser->local, 0, sizeof(parser->local));	/* Reset the local parser environment */
594 
595 	return ret;
596 }
597 
598 /*
599  * Process a reserved item.
600  */
601 
602 static int hid_parser_reserved(struct hid_parser *parser, struct hid_item *item)
603 {
604 	dbg_hid("reserved item type, tag 0x%x\n", item->tag);
605 	return 0;
606 }
607 
608 /*
609  * Free a report and all registered fields. The field->usage and
610  * field->value table's are allocated behind the field, so we need
611  * only to free(field) itself.
612  */
613 
614 static void hid_free_report(struct hid_report *report)
615 {
616 	unsigned n;
617 
618 	for (n = 0; n < report->maxfield; n++)
619 		kfree(report->field[n]);
620 	kfree(report);
621 }
622 
623 /*
624  * Close report. This function returns the device
625  * state to the point prior to hid_open_report().
626  */
627 static void hid_close_report(struct hid_device *device)
628 {
629 	unsigned i, j;
630 
631 	for (i = 0; i < HID_REPORT_TYPES; i++) {
632 		struct hid_report_enum *report_enum = device->report_enum + i;
633 
634 		for (j = 0; j < HID_MAX_IDS; j++) {
635 			struct hid_report *report = report_enum->report_id_hash[j];
636 			if (report)
637 				hid_free_report(report);
638 		}
639 		memset(report_enum, 0, sizeof(*report_enum));
640 		INIT_LIST_HEAD(&report_enum->report_list);
641 	}
642 
643 	kfree(device->rdesc);
644 	device->rdesc = NULL;
645 	device->rsize = 0;
646 
647 	kfree(device->collection);
648 	device->collection = NULL;
649 	device->collection_size = 0;
650 	device->maxcollection = 0;
651 	device->maxapplication = 0;
652 
653 	device->status &= ~HID_STAT_PARSED;
654 }
655 
656 /*
657  * Free a device structure, all reports, and all fields.
658  */
659 
660 static void hid_device_release(struct device *dev)
661 {
662 	struct hid_device *hid = to_hid_device(dev);
663 
664 	hid_close_report(hid);
665 	kfree(hid->dev_rdesc);
666 	kfree(hid);
667 }
668 
669 /*
670  * Fetch a report description item from the data stream. We support long
671  * items, though they are not used yet.
672  */
673 
674 static u8 *fetch_item(__u8 *start, __u8 *end, struct hid_item *item)
675 {
676 	u8 b;
677 
678 	if ((end - start) <= 0)
679 		return NULL;
680 
681 	b = *start++;
682 
683 	item->type = (b >> 2) & 3;
684 	item->tag  = (b >> 4) & 15;
685 
686 	if (item->tag == HID_ITEM_TAG_LONG) {
687 
688 		item->format = HID_ITEM_FORMAT_LONG;
689 
690 		if ((end - start) < 2)
691 			return NULL;
692 
693 		item->size = *start++;
694 		item->tag  = *start++;
695 
696 		if ((end - start) < item->size)
697 			return NULL;
698 
699 		item->data.longdata = start;
700 		start += item->size;
701 		return start;
702 	}
703 
704 	item->format = HID_ITEM_FORMAT_SHORT;
705 	item->size = b & 3;
706 
707 	switch (item->size) {
708 	case 0:
709 		return start;
710 
711 	case 1:
712 		if ((end - start) < 1)
713 			return NULL;
714 		item->data.u8 = *start++;
715 		return start;
716 
717 	case 2:
718 		if ((end - start) < 2)
719 			return NULL;
720 		item->data.u16 = get_unaligned_le16(start);
721 		start = (__u8 *)((__le16 *)start + 1);
722 		return start;
723 
724 	case 3:
725 		item->size++;
726 		if ((end - start) < 4)
727 			return NULL;
728 		item->data.u32 = get_unaligned_le32(start);
729 		start = (__u8 *)((__le32 *)start + 1);
730 		return start;
731 	}
732 
733 	return NULL;
734 }
735 
736 static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)
737 {
738 	struct hid_device *hid = parser->device;
739 
740 	if (usage == HID_DG_CONTACTID)
741 		hid->group = HID_GROUP_MULTITOUCH;
742 }
743 
744 static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
745 {
746 	if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
747 	    parser->global.report_size == 8)
748 		parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
749 }
750 
751 static void hid_scan_collection(struct hid_parser *parser, unsigned type)
752 {
753 	struct hid_device *hid = parser->device;
754 	int i;
755 
756 	if (((parser->global.usage_page << 16) == HID_UP_SENSOR) &&
757 	    type == HID_COLLECTION_PHYSICAL)
758 		hid->group = HID_GROUP_SENSOR_HUB;
759 
760 	if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
761 	    hid->product == USB_DEVICE_ID_MS_POWER_COVER &&
762 	    hid->group == HID_GROUP_MULTITOUCH)
763 		hid->group = HID_GROUP_GENERIC;
764 
765 	if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
766 		for (i = 0; i < parser->local.usage_index; i++)
767 			if (parser->local.usage[i] == HID_GD_POINTER)
768 				parser->scan_flags |= HID_SCAN_FLAG_GD_POINTER;
769 
770 	if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
771 		parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
772 }
773 
774 static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
775 {
776 	__u32 data;
777 	int i;
778 
779 	hid_concatenate_usage_page(parser);
780 
781 	data = item_udata(item);
782 
783 	switch (item->tag) {
784 	case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
785 		hid_scan_collection(parser, data & 0xff);
786 		break;
787 	case HID_MAIN_ITEM_TAG_END_COLLECTION:
788 		break;
789 	case HID_MAIN_ITEM_TAG_INPUT:
790 		/* ignore constant inputs, they will be ignored by hid-input */
791 		if (data & HID_MAIN_ITEM_CONSTANT)
792 			break;
793 		for (i = 0; i < parser->local.usage_index; i++)
794 			hid_scan_input_usage(parser, parser->local.usage[i]);
795 		break;
796 	case HID_MAIN_ITEM_TAG_OUTPUT:
797 		break;
798 	case HID_MAIN_ITEM_TAG_FEATURE:
799 		for (i = 0; i < parser->local.usage_index; i++)
800 			hid_scan_feature_usage(parser, parser->local.usage[i]);
801 		break;
802 	}
803 
804 	/* Reset the local parser environment */
805 	memset(&parser->local, 0, sizeof(parser->local));
806 
807 	return 0;
808 }
809 
810 /*
811  * Scan a report descriptor before the device is added to the bus.
812  * Sets device groups and other properties that determine what driver
813  * to load.
814  */
815 static int hid_scan_report(struct hid_device *hid)
816 {
817 	struct hid_parser *parser;
818 	struct hid_item item;
819 	__u8 *start = hid->dev_rdesc;
820 	__u8 *end = start + hid->dev_rsize;
821 	static int (*dispatch_type[])(struct hid_parser *parser,
822 				      struct hid_item *item) = {
823 		hid_scan_main,
824 		hid_parser_global,
825 		hid_parser_local,
826 		hid_parser_reserved
827 	};
828 
829 	parser = vzalloc(sizeof(struct hid_parser));
830 	if (!parser)
831 		return -ENOMEM;
832 
833 	parser->device = hid;
834 	hid->group = HID_GROUP_GENERIC;
835 
836 	/*
837 	 * The parsing is simpler than the one in hid_open_report() as we should
838 	 * be robust against hid errors. Those errors will be raised by
839 	 * hid_open_report() anyway.
840 	 */
841 	while ((start = fetch_item(start, end, &item)) != NULL)
842 		dispatch_type[item.type](parser, &item);
843 
844 	/*
845 	 * Handle special flags set during scanning.
846 	 */
847 	if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
848 	    (hid->group == HID_GROUP_MULTITOUCH))
849 		hid->group = HID_GROUP_MULTITOUCH_WIN_8;
850 
851 	/*
852 	 * Vendor specific handlings
853 	 */
854 	switch (hid->vendor) {
855 	case USB_VENDOR_ID_WACOM:
856 		hid->group = HID_GROUP_WACOM;
857 		break;
858 	case USB_VENDOR_ID_SYNAPTICS:
859 		if (hid->group == HID_GROUP_GENERIC)
860 			if ((parser->scan_flags & HID_SCAN_FLAG_VENDOR_SPECIFIC)
861 			    && (parser->scan_flags & HID_SCAN_FLAG_GD_POINTER))
862 				/*
863 				 * hid-rmi should take care of them,
864 				 * not hid-generic
865 				 */
866 				hid->group = HID_GROUP_RMI;
867 		break;
868 	}
869 
870 	kfree(parser->collection_stack);
871 	vfree(parser);
872 	return 0;
873 }
874 
875 /**
876  * hid_parse_report - parse device report
877  *
878  * @device: hid device
879  * @start: report start
880  * @size: report size
881  *
882  * Allocate the device report as read by the bus driver. This function should
883  * only be called from parse() in ll drivers.
884  */
885 int hid_parse_report(struct hid_device *hid, __u8 *start, unsigned size)
886 {
887 	hid->dev_rdesc = kmemdup(start, size, GFP_KERNEL);
888 	if (!hid->dev_rdesc)
889 		return -ENOMEM;
890 	hid->dev_rsize = size;
891 	return 0;
892 }
893 EXPORT_SYMBOL_GPL(hid_parse_report);
894 
895 static const char * const hid_report_names[] = {
896 	"HID_INPUT_REPORT",
897 	"HID_OUTPUT_REPORT",
898 	"HID_FEATURE_REPORT",
899 };
900 /**
901  * hid_validate_values - validate existing device report's value indexes
902  *
903  * @device: hid device
904  * @type: which report type to examine
905  * @id: which report ID to examine (0 for first)
906  * @field_index: which report field to examine
907  * @report_counts: expected number of values
908  *
909  * Validate the number of values in a given field of a given report, after
910  * parsing.
911  */
912 struct hid_report *hid_validate_values(struct hid_device *hid,
913 				       unsigned int type, unsigned int id,
914 				       unsigned int field_index,
915 				       unsigned int report_counts)
916 {
917 	struct hid_report *report;
918 
919 	if (type > HID_FEATURE_REPORT) {
920 		hid_err(hid, "invalid HID report type %u\n", type);
921 		return NULL;
922 	}
923 
924 	if (id >= HID_MAX_IDS) {
925 		hid_err(hid, "invalid HID report id %u\n", id);
926 		return NULL;
927 	}
928 
929 	/*
930 	 * Explicitly not using hid_get_report() here since it depends on
931 	 * ->numbered being checked, which may not always be the case when
932 	 * drivers go to access report values.
933 	 */
934 	if (id == 0) {
935 		/*
936 		 * Validating on id 0 means we should examine the first
937 		 * report in the list.
938 		 */
939 		report = list_entry(
940 				hid->report_enum[type].report_list.next,
941 				struct hid_report, list);
942 	} else {
943 		report = hid->report_enum[type].report_id_hash[id];
944 	}
945 	if (!report) {
946 		hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
947 		return NULL;
948 	}
949 	if (report->maxfield <= field_index) {
950 		hid_err(hid, "not enough fields in %s %u\n",
951 			hid_report_names[type], id);
952 		return NULL;
953 	}
954 	if (report->field[field_index]->report_count < report_counts) {
955 		hid_err(hid, "not enough values in %s %u field %u\n",
956 			hid_report_names[type], id, field_index);
957 		return NULL;
958 	}
959 	return report;
960 }
961 EXPORT_SYMBOL_GPL(hid_validate_values);
962 
963 static int hid_calculate_multiplier(struct hid_device *hid,
964 				     struct hid_field *multiplier)
965 {
966 	int m;
967 	__s32 v = *multiplier->value;
968 	__s32 lmin = multiplier->logical_minimum;
969 	__s32 lmax = multiplier->logical_maximum;
970 	__s32 pmin = multiplier->physical_minimum;
971 	__s32 pmax = multiplier->physical_maximum;
972 
973 	/*
974 	 * "Because OS implementations will generally divide the control's
975 	 * reported count by the Effective Resolution Multiplier, designers
976 	 * should take care not to establish a potential Effective
977 	 * Resolution Multiplier of zero."
978 	 * HID Usage Table, v1.12, Section 4.3.1, p31
979 	 */
980 	if (lmax - lmin == 0)
981 		return 1;
982 	/*
983 	 * Handling the unit exponent is left as an exercise to whoever
984 	 * finds a device where that exponent is not 0.
985 	 */
986 	m = ((v - lmin)/(lmax - lmin) * (pmax - pmin) + pmin);
987 	if (unlikely(multiplier->unit_exponent != 0)) {
988 		hid_warn(hid,
989 			 "unsupported Resolution Multiplier unit exponent %d\n",
990 			 multiplier->unit_exponent);
991 	}
992 
993 	/* There are no devices with an effective multiplier > 255 */
994 	if (unlikely(m == 0 || m > 255 || m < -255)) {
995 		hid_warn(hid, "unsupported Resolution Multiplier %d\n", m);
996 		m = 1;
997 	}
998 
999 	return m;
1000 }
1001 
1002 static void hid_apply_multiplier_to_field(struct hid_device *hid,
1003 					  struct hid_field *field,
1004 					  struct hid_collection *multiplier_collection,
1005 					  int effective_multiplier)
1006 {
1007 	struct hid_collection *collection;
1008 	struct hid_usage *usage;
1009 	int i;
1010 
1011 	/*
1012 	 * If multiplier_collection is NULL, the multiplier applies
1013 	 * to all fields in the report.
1014 	 * Otherwise, it is the Logical Collection the multiplier applies to
1015 	 * but our field may be in a subcollection of that collection.
1016 	 */
1017 	for (i = 0; i < field->maxusage; i++) {
1018 		usage = &field->usage[i];
1019 
1020 		collection = &hid->collection[usage->collection_index];
1021 		while (collection->parent_idx != -1 &&
1022 		       collection != multiplier_collection)
1023 			collection = &hid->collection[collection->parent_idx];
1024 
1025 		if (collection->parent_idx != -1 ||
1026 		    multiplier_collection == NULL)
1027 			usage->resolution_multiplier = effective_multiplier;
1028 
1029 	}
1030 }
1031 
1032 static void hid_apply_multiplier(struct hid_device *hid,
1033 				 struct hid_field *multiplier)
1034 {
1035 	struct hid_report_enum *rep_enum;
1036 	struct hid_report *rep;
1037 	struct hid_field *field;
1038 	struct hid_collection *multiplier_collection;
1039 	int effective_multiplier;
1040 	int i;
1041 
1042 	/*
1043 	 * "The Resolution Multiplier control must be contained in the same
1044 	 * Logical Collection as the control(s) to which it is to be applied.
1045 	 * If no Resolution Multiplier is defined, then the Resolution
1046 	 * Multiplier defaults to 1.  If more than one control exists in a
1047 	 * Logical Collection, the Resolution Multiplier is associated with
1048 	 * all controls in the collection. If no Logical Collection is
1049 	 * defined, the Resolution Multiplier is associated with all
1050 	 * controls in the report."
1051 	 * HID Usage Table, v1.12, Section 4.3.1, p30
1052 	 *
1053 	 * Thus, search from the current collection upwards until we find a
1054 	 * logical collection. Then search all fields for that same parent
1055 	 * collection. Those are the fields the multiplier applies to.
1056 	 *
1057 	 * If we have more than one multiplier, it will overwrite the
1058 	 * applicable fields later.
1059 	 */
1060 	multiplier_collection = &hid->collection[multiplier->usage->collection_index];
1061 	while (multiplier_collection->parent_idx != -1 &&
1062 	       multiplier_collection->type != HID_COLLECTION_LOGICAL)
1063 		multiplier_collection = &hid->collection[multiplier_collection->parent_idx];
1064 
1065 	effective_multiplier = hid_calculate_multiplier(hid, multiplier);
1066 
1067 	rep_enum = &hid->report_enum[HID_INPUT_REPORT];
1068 	list_for_each_entry(rep, &rep_enum->report_list, list) {
1069 		for (i = 0; i < rep->maxfield; i++) {
1070 			field = rep->field[i];
1071 			hid_apply_multiplier_to_field(hid, field,
1072 						      multiplier_collection,
1073 						      effective_multiplier);
1074 		}
1075 	}
1076 }
1077 
1078 /*
1079  * hid_setup_resolution_multiplier - set up all resolution multipliers
1080  *
1081  * @device: hid device
1082  *
1083  * Search for all Resolution Multiplier Feature Reports and apply their
1084  * value to all matching Input items. This only updates the internal struct
1085  * fields.
1086  *
1087  * The Resolution Multiplier is applied by the hardware. If the multiplier
1088  * is anything other than 1, the hardware will send pre-multiplied events
1089  * so that the same physical interaction generates an accumulated
1090  *	accumulated_value = value * * multiplier
1091  * This may be achieved by sending
1092  * - "value * multiplier" for each event, or
1093  * - "value" but "multiplier" times as frequently, or
1094  * - a combination of the above
1095  * The only guarantee is that the same physical interaction always generates
1096  * an accumulated 'value * multiplier'.
1097  *
1098  * This function must be called before any event processing and after
1099  * any SetRequest to the Resolution Multiplier.
1100  */
1101 void hid_setup_resolution_multiplier(struct hid_device *hid)
1102 {
1103 	struct hid_report_enum *rep_enum;
1104 	struct hid_report *rep;
1105 	struct hid_usage *usage;
1106 	int i, j;
1107 
1108 	rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
1109 	list_for_each_entry(rep, &rep_enum->report_list, list) {
1110 		for (i = 0; i < rep->maxfield; i++) {
1111 			/* Ignore if report count is out of bounds. */
1112 			if (rep->field[i]->report_count < 1)
1113 				continue;
1114 
1115 			for (j = 0; j < rep->field[i]->maxusage; j++) {
1116 				usage = &rep->field[i]->usage[j];
1117 				if (usage->hid == HID_GD_RESOLUTION_MULTIPLIER)
1118 					hid_apply_multiplier(hid,
1119 							     rep->field[i]);
1120 			}
1121 		}
1122 	}
1123 }
1124 EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier);
1125 
1126 /**
1127  * hid_open_report - open a driver-specific device report
1128  *
1129  * @device: hid device
1130  *
1131  * Parse a report description into a hid_device structure. Reports are
1132  * enumerated, fields are attached to these reports.
1133  * 0 returned on success, otherwise nonzero error value.
1134  *
1135  * This function (or the equivalent hid_parse() macro) should only be
1136  * called from probe() in drivers, before starting the device.
1137  */
1138 int hid_open_report(struct hid_device *device)
1139 {
1140 	struct hid_parser *parser;
1141 	struct hid_item item;
1142 	unsigned int size;
1143 	__u8 *start;
1144 	__u8 *buf;
1145 	__u8 *end;
1146 	int ret;
1147 	static int (*dispatch_type[])(struct hid_parser *parser,
1148 				      struct hid_item *item) = {
1149 		hid_parser_main,
1150 		hid_parser_global,
1151 		hid_parser_local,
1152 		hid_parser_reserved
1153 	};
1154 
1155 	if (WARN_ON(device->status & HID_STAT_PARSED))
1156 		return -EBUSY;
1157 
1158 	start = device->dev_rdesc;
1159 	if (WARN_ON(!start))
1160 		return -ENODEV;
1161 	size = device->dev_rsize;
1162 
1163 	buf = kmemdup(start, size, GFP_KERNEL);
1164 	if (buf == NULL)
1165 		return -ENOMEM;
1166 
1167 	if (device->driver->report_fixup)
1168 		start = device->driver->report_fixup(device, buf, &size);
1169 	else
1170 		start = buf;
1171 
1172 	start = kmemdup(start, size, GFP_KERNEL);
1173 	kfree(buf);
1174 	if (start == NULL)
1175 		return -ENOMEM;
1176 
1177 	device->rdesc = start;
1178 	device->rsize = size;
1179 
1180 	parser = vzalloc(sizeof(struct hid_parser));
1181 	if (!parser) {
1182 		ret = -ENOMEM;
1183 		goto alloc_err;
1184 	}
1185 
1186 	parser->device = device;
1187 
1188 	end = start + size;
1189 
1190 	device->collection = kcalloc(HID_DEFAULT_NUM_COLLECTIONS,
1191 				     sizeof(struct hid_collection), GFP_KERNEL);
1192 	if (!device->collection) {
1193 		ret = -ENOMEM;
1194 		goto err;
1195 	}
1196 	device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
1197 
1198 	ret = -EINVAL;
1199 	while ((start = fetch_item(start, end, &item)) != NULL) {
1200 
1201 		if (item.format != HID_ITEM_FORMAT_SHORT) {
1202 			hid_err(device, "unexpected long global item\n");
1203 			goto err;
1204 		}
1205 
1206 		if (dispatch_type[item.type](parser, &item)) {
1207 			hid_err(device, "item %u %u %u %u parsing failed\n",
1208 				item.format, (unsigned)item.size,
1209 				(unsigned)item.type, (unsigned)item.tag);
1210 			goto err;
1211 		}
1212 
1213 		if (start == end) {
1214 			if (parser->collection_stack_ptr) {
1215 				hid_err(device, "unbalanced collection at end of report description\n");
1216 				goto err;
1217 			}
1218 			if (parser->local.delimiter_depth) {
1219 				hid_err(device, "unbalanced delimiter at end of report description\n");
1220 				goto err;
1221 			}
1222 
1223 			/*
1224 			 * fetch initial values in case the device's
1225 			 * default multiplier isn't the recommended 1
1226 			 */
1227 			hid_setup_resolution_multiplier(device);
1228 
1229 			kfree(parser->collection_stack);
1230 			vfree(parser);
1231 			device->status |= HID_STAT_PARSED;
1232 
1233 			return 0;
1234 		}
1235 	}
1236 
1237 	hid_err(device, "item fetching failed at offset %d\n", (int)(end - start));
1238 err:
1239 	kfree(parser->collection_stack);
1240 alloc_err:
1241 	vfree(parser);
1242 	hid_close_report(device);
1243 	return ret;
1244 }
1245 EXPORT_SYMBOL_GPL(hid_open_report);
1246 
1247 /*
1248  * Convert a signed n-bit integer to signed 32-bit integer. Common
1249  * cases are done through the compiler, the screwed things has to be
1250  * done by hand.
1251  */
1252 
1253 static s32 snto32(__u32 value, unsigned n)
1254 {
1255 	switch (n) {
1256 	case 8:  return ((__s8)value);
1257 	case 16: return ((__s16)value);
1258 	case 32: return ((__s32)value);
1259 	}
1260 	return value & (1 << (n - 1)) ? value | (~0U << n) : value;
1261 }
1262 
1263 s32 hid_snto32(__u32 value, unsigned n)
1264 {
1265 	return snto32(value, n);
1266 }
1267 EXPORT_SYMBOL_GPL(hid_snto32);
1268 
1269 /*
1270  * Convert a signed 32-bit integer to a signed n-bit integer.
1271  */
1272 
1273 static u32 s32ton(__s32 value, unsigned n)
1274 {
1275 	s32 a = value >> (n - 1);
1276 	if (a && a != -1)
1277 		return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
1278 	return value & ((1 << n) - 1);
1279 }
1280 
1281 /*
1282  * Extract/implement a data field from/to a little endian report (bit array).
1283  *
1284  * Code sort-of follows HID spec:
1285  *     http://www.usb.org/developers/hidpage/HID1_11.pdf
1286  *
1287  * While the USB HID spec allows unlimited length bit fields in "report
1288  * descriptors", most devices never use more than 16 bits.
1289  * One model of UPS is claimed to report "LINEV" as a 32-bit field.
1290  * Search linux-kernel and linux-usb-devel archives for "hid-core extract".
1291  */
1292 
1293 static u32 __extract(u8 *report, unsigned offset, int n)
1294 {
1295 	unsigned int idx = offset / 8;
1296 	unsigned int bit_nr = 0;
1297 	unsigned int bit_shift = offset % 8;
1298 	int bits_to_copy = 8 - bit_shift;
1299 	u32 value = 0;
1300 	u32 mask = n < 32 ? (1U << n) - 1 : ~0U;
1301 
1302 	while (n > 0) {
1303 		value |= ((u32)report[idx] >> bit_shift) << bit_nr;
1304 		n -= bits_to_copy;
1305 		bit_nr += bits_to_copy;
1306 		bits_to_copy = 8;
1307 		bit_shift = 0;
1308 		idx++;
1309 	}
1310 
1311 	return value & mask;
1312 }
1313 
1314 u32 hid_field_extract(const struct hid_device *hid, u8 *report,
1315 			unsigned offset, unsigned n)
1316 {
1317 	if (n > 256) {
1318 		hid_warn(hid, "hid_field_extract() called with n (%d) > 256! (%s)\n",
1319 			 n, current->comm);
1320 		n = 256;
1321 	}
1322 
1323 	return __extract(report, offset, n);
1324 }
1325 EXPORT_SYMBOL_GPL(hid_field_extract);
1326 
1327 /*
1328  * "implement" : set bits in a little endian bit stream.
1329  * Same concepts as "extract" (see comments above).
1330  * The data mangled in the bit stream remains in little endian
1331  * order the whole time. It make more sense to talk about
1332  * endianness of register values by considering a register
1333  * a "cached" copy of the little endian bit stream.
1334  */
1335 
1336 static void __implement(u8 *report, unsigned offset, int n, u32 value)
1337 {
1338 	unsigned int idx = offset / 8;
1339 	unsigned int bit_shift = offset % 8;
1340 	int bits_to_set = 8 - bit_shift;
1341 
1342 	while (n - bits_to_set >= 0) {
1343 		report[idx] &= ~(0xff << bit_shift);
1344 		report[idx] |= value << bit_shift;
1345 		value >>= bits_to_set;
1346 		n -= bits_to_set;
1347 		bits_to_set = 8;
1348 		bit_shift = 0;
1349 		idx++;
1350 	}
1351 
1352 	/* last nibble */
1353 	if (n) {
1354 		u8 bit_mask = ((1U << n) - 1);
1355 		report[idx] &= ~(bit_mask << bit_shift);
1356 		report[idx] |= value << bit_shift;
1357 	}
1358 }
1359 
1360 static void implement(const struct hid_device *hid, u8 *report,
1361 		      unsigned offset, unsigned n, u32 value)
1362 {
1363 	if (unlikely(n > 32)) {
1364 		hid_warn(hid, "%s() called with n (%d) > 32! (%s)\n",
1365 			 __func__, n, current->comm);
1366 		n = 32;
1367 	} else if (n < 32) {
1368 		u32 m = (1U << n) - 1;
1369 
1370 		if (unlikely(value > m)) {
1371 			hid_warn(hid,
1372 				 "%s() called with too large value %d (n: %d)! (%s)\n",
1373 				 __func__, value, n, current->comm);
1374 			WARN_ON(1);
1375 			value &= m;
1376 		}
1377 	}
1378 
1379 	__implement(report, offset, n, value);
1380 }
1381 
1382 /*
1383  * Search an array for a value.
1384  */
1385 
1386 static int search(__s32 *array, __s32 value, unsigned n)
1387 {
1388 	while (n--) {
1389 		if (*array++ == value)
1390 			return 0;
1391 	}
1392 	return -1;
1393 }
1394 
1395 /**
1396  * hid_match_report - check if driver's raw_event should be called
1397  *
1398  * @hid: hid device
1399  * @report_type: type to match against
1400  *
1401  * compare hid->driver->report_table->report_type to report->type
1402  */
1403 static int hid_match_report(struct hid_device *hid, struct hid_report *report)
1404 {
1405 	const struct hid_report_id *id = hid->driver->report_table;
1406 
1407 	if (!id) /* NULL means all */
1408 		return 1;
1409 
1410 	for (; id->report_type != HID_TERMINATOR; id++)
1411 		if (id->report_type == HID_ANY_ID ||
1412 				id->report_type == report->type)
1413 			return 1;
1414 	return 0;
1415 }
1416 
1417 /**
1418  * hid_match_usage - check if driver's event should be called
1419  *
1420  * @hid: hid device
1421  * @usage: usage to match against
1422  *
1423  * compare hid->driver->usage_table->usage_{type,code} to
1424  * usage->usage_{type,code}
1425  */
1426 static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage)
1427 {
1428 	const struct hid_usage_id *id = hid->driver->usage_table;
1429 
1430 	if (!id) /* NULL means all */
1431 		return 1;
1432 
1433 	for (; id->usage_type != HID_ANY_ID - 1; id++)
1434 		if ((id->usage_hid == HID_ANY_ID ||
1435 				id->usage_hid == usage->hid) &&
1436 				(id->usage_type == HID_ANY_ID ||
1437 				id->usage_type == usage->type) &&
1438 				(id->usage_code == HID_ANY_ID ||
1439 				 id->usage_code == usage->code))
1440 			return 1;
1441 	return 0;
1442 }
1443 
1444 static void hid_process_event(struct hid_device *hid, struct hid_field *field,
1445 		struct hid_usage *usage, __s32 value, int interrupt)
1446 {
1447 	struct hid_driver *hdrv = hid->driver;
1448 	int ret;
1449 
1450 	if (!list_empty(&hid->debug_list))
1451 		hid_dump_input(hid, usage, value);
1452 
1453 	if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
1454 		ret = hdrv->event(hid, field, usage, value);
1455 		if (ret != 0) {
1456 			if (ret < 0)
1457 				hid_err(hid, "%s's event failed with %d\n",
1458 						hdrv->name, ret);
1459 			return;
1460 		}
1461 	}
1462 
1463 	if (hid->claimed & HID_CLAIMED_INPUT)
1464 		hidinput_hid_event(hid, field, usage, value);
1465 	if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
1466 		hid->hiddev_hid_event(hid, field, usage, value);
1467 }
1468 
1469 /*
1470  * Analyse a received field, and fetch the data from it. The field
1471  * content is stored for next report processing (we do differential
1472  * reporting to the layer).
1473  */
1474 
1475 static void hid_input_field(struct hid_device *hid, struct hid_field *field,
1476 			    __u8 *data, int interrupt)
1477 {
1478 	unsigned n;
1479 	unsigned count = field->report_count;
1480 	unsigned offset = field->report_offset;
1481 	unsigned size = field->report_size;
1482 	__s32 min = field->logical_minimum;
1483 	__s32 max = field->logical_maximum;
1484 	__s32 *value;
1485 
1486 	value = kmalloc_array(count, sizeof(__s32), GFP_ATOMIC);
1487 	if (!value)
1488 		return;
1489 
1490 	for (n = 0; n < count; n++) {
1491 
1492 		value[n] = min < 0 ?
1493 			snto32(hid_field_extract(hid, data, offset + n * size,
1494 			       size), size) :
1495 			hid_field_extract(hid, data, offset + n * size, size);
1496 
1497 		/* Ignore report if ErrorRollOver */
1498 		if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
1499 		    value[n] >= min && value[n] <= max &&
1500 		    value[n] - min < field->maxusage &&
1501 		    field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1)
1502 			goto exit;
1503 	}
1504 
1505 	for (n = 0; n < count; n++) {
1506 
1507 		if (HID_MAIN_ITEM_VARIABLE & field->flags) {
1508 			hid_process_event(hid, field, &field->usage[n], value[n], interrupt);
1509 			continue;
1510 		}
1511 
1512 		if (field->value[n] >= min && field->value[n] <= max
1513 			&& field->value[n] - min < field->maxusage
1514 			&& field->usage[field->value[n] - min].hid
1515 			&& search(value, field->value[n], count))
1516 				hid_process_event(hid, field, &field->usage[field->value[n] - min], 0, interrupt);
1517 
1518 		if (value[n] >= min && value[n] <= max
1519 			&& value[n] - min < field->maxusage
1520 			&& field->usage[value[n] - min].hid
1521 			&& search(field->value, value[n], count))
1522 				hid_process_event(hid, field, &field->usage[value[n] - min], 1, interrupt);
1523 	}
1524 
1525 	memcpy(field->value, value, count * sizeof(__s32));
1526 exit:
1527 	kfree(value);
1528 }
1529 
1530 /*
1531  * Output the field into the report.
1532  */
1533 
1534 static void hid_output_field(const struct hid_device *hid,
1535 			     struct hid_field *field, __u8 *data)
1536 {
1537 	unsigned count = field->report_count;
1538 	unsigned offset = field->report_offset;
1539 	unsigned size = field->report_size;
1540 	unsigned n;
1541 
1542 	for (n = 0; n < count; n++) {
1543 		if (field->logical_minimum < 0)	/* signed values */
1544 			implement(hid, data, offset + n * size, size,
1545 				  s32ton(field->value[n], size));
1546 		else				/* unsigned values */
1547 			implement(hid, data, offset + n * size, size,
1548 				  field->value[n]);
1549 	}
1550 }
1551 
1552 /*
1553  * Create a report. 'data' has to be allocated using
1554  * hid_alloc_report_buf() so that it has proper size.
1555  */
1556 
1557 void hid_output_report(struct hid_report *report, __u8 *data)
1558 {
1559 	unsigned n;
1560 
1561 	if (report->id > 0)
1562 		*data++ = report->id;
1563 
1564 	memset(data, 0, ((report->size - 1) >> 3) + 1);
1565 	for (n = 0; n < report->maxfield; n++)
1566 		hid_output_field(report->device, report->field[n], data);
1567 }
1568 EXPORT_SYMBOL_GPL(hid_output_report);
1569 
1570 /*
1571  * Allocator for buffer that is going to be passed to hid_output_report()
1572  */
1573 u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
1574 {
1575 	/*
1576 	 * 7 extra bytes are necessary to achieve proper functionality
1577 	 * of implement() working on 8 byte chunks
1578 	 */
1579 
1580 	u32 len = hid_report_len(report) + 7;
1581 
1582 	return kmalloc(len, flags);
1583 }
1584 EXPORT_SYMBOL_GPL(hid_alloc_report_buf);
1585 
1586 /*
1587  * Set a field value. The report this field belongs to has to be
1588  * created and transferred to the device, to set this value in the
1589  * device.
1590  */
1591 
1592 int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
1593 {
1594 	unsigned size;
1595 
1596 	if (!field)
1597 		return -1;
1598 
1599 	size = field->report_size;
1600 
1601 	hid_dump_input(field->report->device, field->usage + offset, value);
1602 
1603 	if (offset >= field->report_count) {
1604 		hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n",
1605 				offset, field->report_count);
1606 		return -1;
1607 	}
1608 	if (field->logical_minimum < 0) {
1609 		if (value != snto32(s32ton(value, size), size)) {
1610 			hid_err(field->report->device, "value %d is out of range\n", value);
1611 			return -1;
1612 		}
1613 	}
1614 	field->value[offset] = value;
1615 	return 0;
1616 }
1617 EXPORT_SYMBOL_GPL(hid_set_field);
1618 
1619 static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
1620 		const u8 *data)
1621 {
1622 	struct hid_report *report;
1623 	unsigned int n = 0;	/* Normally report number is 0 */
1624 
1625 	/* Device uses numbered reports, data[0] is report number */
1626 	if (report_enum->numbered)
1627 		n = *data;
1628 
1629 	report = report_enum->report_id_hash[n];
1630 	if (report == NULL)
1631 		dbg_hid("undefined report_id %u received\n", n);
1632 
1633 	return report;
1634 }
1635 
1636 /*
1637  * Implement a generic .request() callback, using .raw_request()
1638  * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
1639  */
1640 int __hid_request(struct hid_device *hid, struct hid_report *report,
1641 		int reqtype)
1642 {
1643 	char *buf;
1644 	int ret;
1645 	u32 len;
1646 
1647 	buf = hid_alloc_report_buf(report, GFP_KERNEL);
1648 	if (!buf)
1649 		return -ENOMEM;
1650 
1651 	len = hid_report_len(report);
1652 
1653 	if (reqtype == HID_REQ_SET_REPORT)
1654 		hid_output_report(report, buf);
1655 
1656 	ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
1657 					  report->type, reqtype);
1658 	if (ret < 0) {
1659 		dbg_hid("unable to complete request: %d\n", ret);
1660 		goto out;
1661 	}
1662 
1663 	if (reqtype == HID_REQ_GET_REPORT)
1664 		hid_input_report(hid, report->type, buf, ret, 0);
1665 
1666 	ret = 0;
1667 
1668 out:
1669 	kfree(buf);
1670 	return ret;
1671 }
1672 EXPORT_SYMBOL_GPL(__hid_request);
1673 
1674 int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, u32 size,
1675 		int interrupt)
1676 {
1677 	struct hid_report_enum *report_enum = hid->report_enum + type;
1678 	struct hid_report *report;
1679 	struct hid_driver *hdrv;
1680 	unsigned int a;
1681 	u32 rsize, csize = size;
1682 	u8 *cdata = data;
1683 	int ret = 0;
1684 
1685 	report = hid_get_report(report_enum, data);
1686 	if (!report)
1687 		goto out;
1688 
1689 	if (report_enum->numbered) {
1690 		cdata++;
1691 		csize--;
1692 	}
1693 
1694 	rsize = ((report->size - 1) >> 3) + 1;
1695 
1696 	if (rsize > HID_MAX_BUFFER_SIZE)
1697 		rsize = HID_MAX_BUFFER_SIZE;
1698 
1699 	if (csize < rsize) {
1700 		dbg_hid("report %d is too short, (%d < %d)\n", report->id,
1701 				csize, rsize);
1702 		memset(cdata + csize, 0, rsize - csize);
1703 	}
1704 
1705 	if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
1706 		hid->hiddev_report_event(hid, report);
1707 	if (hid->claimed & HID_CLAIMED_HIDRAW) {
1708 		ret = hidraw_report_event(hid, data, size);
1709 		if (ret)
1710 			goto out;
1711 	}
1712 
1713 	if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
1714 		for (a = 0; a < report->maxfield; a++)
1715 			hid_input_field(hid, report->field[a], cdata, interrupt);
1716 		hdrv = hid->driver;
1717 		if (hdrv && hdrv->report)
1718 			hdrv->report(hid, report);
1719 	}
1720 
1721 	if (hid->claimed & HID_CLAIMED_INPUT)
1722 		hidinput_report_event(hid, report);
1723 out:
1724 	return ret;
1725 }
1726 EXPORT_SYMBOL_GPL(hid_report_raw_event);
1727 
1728 /**
1729  * hid_input_report - report data from lower layer (usb, bt...)
1730  *
1731  * @hid: hid device
1732  * @type: HID report type (HID_*_REPORT)
1733  * @data: report contents
1734  * @size: size of data parameter
1735  * @interrupt: distinguish between interrupt and control transfers
1736  *
1737  * This is data entry for lower layers.
1738  */
1739 int hid_input_report(struct hid_device *hid, int type, u8 *data, u32 size, int interrupt)
1740 {
1741 	struct hid_report_enum *report_enum;
1742 	struct hid_driver *hdrv;
1743 	struct hid_report *report;
1744 	int ret = 0;
1745 
1746 	if (!hid)
1747 		return -ENODEV;
1748 
1749 	if (down_trylock(&hid->driver_input_lock))
1750 		return -EBUSY;
1751 
1752 	if (!hid->driver) {
1753 		ret = -ENODEV;
1754 		goto unlock;
1755 	}
1756 	report_enum = hid->report_enum + type;
1757 	hdrv = hid->driver;
1758 
1759 	if (!size) {
1760 		dbg_hid("empty report\n");
1761 		ret = -1;
1762 		goto unlock;
1763 	}
1764 
1765 	/* Avoid unnecessary overhead if debugfs is disabled */
1766 	if (!list_empty(&hid->debug_list))
1767 		hid_dump_report(hid, type, data, size);
1768 
1769 	report = hid_get_report(report_enum, data);
1770 
1771 	if (!report) {
1772 		ret = -1;
1773 		goto unlock;
1774 	}
1775 
1776 	if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
1777 		ret = hdrv->raw_event(hid, report, data, size);
1778 		if (ret < 0)
1779 			goto unlock;
1780 	}
1781 
1782 	ret = hid_report_raw_event(hid, type, data, size, interrupt);
1783 
1784 unlock:
1785 	up(&hid->driver_input_lock);
1786 	return ret;
1787 }
1788 EXPORT_SYMBOL_GPL(hid_input_report);
1789 
1790 bool hid_match_one_id(const struct hid_device *hdev,
1791 		      const struct hid_device_id *id)
1792 {
1793 	return (id->bus == HID_BUS_ANY || id->bus == hdev->bus) &&
1794 		(id->group == HID_GROUP_ANY || id->group == hdev->group) &&
1795 		(id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&
1796 		(id->product == HID_ANY_ID || id->product == hdev->product);
1797 }
1798 
1799 const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
1800 		const struct hid_device_id *id)
1801 {
1802 	for (; id->bus; id++)
1803 		if (hid_match_one_id(hdev, id))
1804 			return id;
1805 
1806 	return NULL;
1807 }
1808 
1809 static const struct hid_device_id hid_hiddev_list[] = {
1810 	{ HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS) },
1811 	{ HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS1) },
1812 	{ }
1813 };
1814 
1815 static bool hid_hiddev(struct hid_device *hdev)
1816 {
1817 	return !!hid_match_id(hdev, hid_hiddev_list);
1818 }
1819 
1820 
1821 static ssize_t
1822 read_report_descriptor(struct file *filp, struct kobject *kobj,
1823 		struct bin_attribute *attr,
1824 		char *buf, loff_t off, size_t count)
1825 {
1826 	struct device *dev = kobj_to_dev(kobj);
1827 	struct hid_device *hdev = to_hid_device(dev);
1828 
1829 	if (off >= hdev->rsize)
1830 		return 0;
1831 
1832 	if (off + count > hdev->rsize)
1833 		count = hdev->rsize - off;
1834 
1835 	memcpy(buf, hdev->rdesc + off, count);
1836 
1837 	return count;
1838 }
1839 
1840 static ssize_t
1841 show_country(struct device *dev, struct device_attribute *attr,
1842 		char *buf)
1843 {
1844 	struct hid_device *hdev = to_hid_device(dev);
1845 
1846 	return sprintf(buf, "%02x\n", hdev->country & 0xff);
1847 }
1848 
1849 static struct bin_attribute dev_bin_attr_report_desc = {
1850 	.attr = { .name = "report_descriptor", .mode = 0444 },
1851 	.read = read_report_descriptor,
1852 	.size = HID_MAX_DESCRIPTOR_SIZE,
1853 };
1854 
1855 static const struct device_attribute dev_attr_country = {
1856 	.attr = { .name = "country", .mode = 0444 },
1857 	.show = show_country,
1858 };
1859 
1860 int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
1861 {
1862 	static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
1863 		"Joystick", "Gamepad", "Keyboard", "Keypad",
1864 		"Multi-Axis Controller"
1865 	};
1866 	const char *type, *bus;
1867 	char buf[64] = "";
1868 	unsigned int i;
1869 	int len;
1870 	int ret;
1871 
1872 	if (hdev->quirks & HID_QUIRK_HIDDEV_FORCE)
1873 		connect_mask |= (HID_CONNECT_HIDDEV_FORCE | HID_CONNECT_HIDDEV);
1874 	if (hdev->quirks & HID_QUIRK_HIDINPUT_FORCE)
1875 		connect_mask |= HID_CONNECT_HIDINPUT_FORCE;
1876 	if (hdev->bus != BUS_USB)
1877 		connect_mask &= ~HID_CONNECT_HIDDEV;
1878 	if (hid_hiddev(hdev))
1879 		connect_mask |= HID_CONNECT_HIDDEV_FORCE;
1880 
1881 	if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,
1882 				connect_mask & HID_CONNECT_HIDINPUT_FORCE))
1883 		hdev->claimed |= HID_CLAIMED_INPUT;
1884 
1885 	if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect &&
1886 			!hdev->hiddev_connect(hdev,
1887 				connect_mask & HID_CONNECT_HIDDEV_FORCE))
1888 		hdev->claimed |= HID_CLAIMED_HIDDEV;
1889 	if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))
1890 		hdev->claimed |= HID_CLAIMED_HIDRAW;
1891 
1892 	if (connect_mask & HID_CONNECT_DRIVER)
1893 		hdev->claimed |= HID_CLAIMED_DRIVER;
1894 
1895 	/* Drivers with the ->raw_event callback set are not required to connect
1896 	 * to any other listener. */
1897 	if (!hdev->claimed && !hdev->driver->raw_event) {
1898 		hid_err(hdev, "device has no listeners, quitting\n");
1899 		return -ENODEV;
1900 	}
1901 
1902 	if ((hdev->claimed & HID_CLAIMED_INPUT) &&
1903 			(connect_mask & HID_CONNECT_FF) && hdev->ff_init)
1904 		hdev->ff_init(hdev);
1905 
1906 	len = 0;
1907 	if (hdev->claimed & HID_CLAIMED_INPUT)
1908 		len += sprintf(buf + len, "input");
1909 	if (hdev->claimed & HID_CLAIMED_HIDDEV)
1910 		len += sprintf(buf + len, "%shiddev%d", len ? "," : "",
1911 				((struct hiddev *)hdev->hiddev)->minor);
1912 	if (hdev->claimed & HID_CLAIMED_HIDRAW)
1913 		len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
1914 				((struct hidraw *)hdev->hidraw)->minor);
1915 
1916 	type = "Device";
1917 	for (i = 0; i < hdev->maxcollection; i++) {
1918 		struct hid_collection *col = &hdev->collection[i];
1919 		if (col->type == HID_COLLECTION_APPLICATION &&
1920 		   (col->usage & HID_USAGE_PAGE) == HID_UP_GENDESK &&
1921 		   (col->usage & 0xffff) < ARRAY_SIZE(types)) {
1922 			type = types[col->usage & 0xffff];
1923 			break;
1924 		}
1925 	}
1926 
1927 	switch (hdev->bus) {
1928 	case BUS_USB:
1929 		bus = "USB";
1930 		break;
1931 	case BUS_BLUETOOTH:
1932 		bus = "BLUETOOTH";
1933 		break;
1934 	case BUS_I2C:
1935 		bus = "I2C";
1936 		break;
1937 	default:
1938 		bus = "<UNKNOWN>";
1939 	}
1940 
1941 	ret = device_create_file(&hdev->dev, &dev_attr_country);
1942 	if (ret)
1943 		hid_warn(hdev,
1944 			 "can't create sysfs country code attribute err: %d\n", ret);
1945 
1946 	hid_info(hdev, "%s: %s HID v%x.%02x %s [%s] on %s\n",
1947 		 buf, bus, hdev->version >> 8, hdev->version & 0xff,
1948 		 type, hdev->name, hdev->phys);
1949 
1950 	return 0;
1951 }
1952 EXPORT_SYMBOL_GPL(hid_connect);
1953 
1954 void hid_disconnect(struct hid_device *hdev)
1955 {
1956 	device_remove_file(&hdev->dev, &dev_attr_country);
1957 	if (hdev->claimed & HID_CLAIMED_INPUT)
1958 		hidinput_disconnect(hdev);
1959 	if (hdev->claimed & HID_CLAIMED_HIDDEV)
1960 		hdev->hiddev_disconnect(hdev);
1961 	if (hdev->claimed & HID_CLAIMED_HIDRAW)
1962 		hidraw_disconnect(hdev);
1963 	hdev->claimed = 0;
1964 }
1965 EXPORT_SYMBOL_GPL(hid_disconnect);
1966 
1967 /**
1968  * hid_hw_start - start underlying HW
1969  * @hdev: hid device
1970  * @connect_mask: which outputs to connect, see HID_CONNECT_*
1971  *
1972  * Call this in probe function *after* hid_parse. This will setup HW
1973  * buffers and start the device (if not defeirred to device open).
1974  * hid_hw_stop must be called if this was successful.
1975  */
1976 int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask)
1977 {
1978 	int error;
1979 
1980 	error = hdev->ll_driver->start(hdev);
1981 	if (error)
1982 		return error;
1983 
1984 	if (connect_mask) {
1985 		error = hid_connect(hdev, connect_mask);
1986 		if (error) {
1987 			hdev->ll_driver->stop(hdev);
1988 			return error;
1989 		}
1990 	}
1991 
1992 	return 0;
1993 }
1994 EXPORT_SYMBOL_GPL(hid_hw_start);
1995 
1996 /**
1997  * hid_hw_stop - stop underlying HW
1998  * @hdev: hid device
1999  *
2000  * This is usually called from remove function or from probe when something
2001  * failed and hid_hw_start was called already.
2002  */
2003 void hid_hw_stop(struct hid_device *hdev)
2004 {
2005 	hid_disconnect(hdev);
2006 	hdev->ll_driver->stop(hdev);
2007 }
2008 EXPORT_SYMBOL_GPL(hid_hw_stop);
2009 
2010 /**
2011  * hid_hw_open - signal underlying HW to start delivering events
2012  * @hdev: hid device
2013  *
2014  * Tell underlying HW to start delivering events from the device.
2015  * This function should be called sometime after successful call
2016  * to hid_hw_start().
2017  */
2018 int hid_hw_open(struct hid_device *hdev)
2019 {
2020 	int ret;
2021 
2022 	ret = mutex_lock_killable(&hdev->ll_open_lock);
2023 	if (ret)
2024 		return ret;
2025 
2026 	if (!hdev->ll_open_count++) {
2027 		ret = hdev->ll_driver->open(hdev);
2028 		if (ret)
2029 			hdev->ll_open_count--;
2030 	}
2031 
2032 	mutex_unlock(&hdev->ll_open_lock);
2033 	return ret;
2034 }
2035 EXPORT_SYMBOL_GPL(hid_hw_open);
2036 
2037 /**
2038  * hid_hw_close - signal underlaying HW to stop delivering events
2039  *
2040  * @hdev: hid device
2041  *
2042  * This function indicates that we are not interested in the events
2043  * from this device anymore. Delivery of events may or may not stop,
2044  * depending on the number of users still outstanding.
2045  */
2046 void hid_hw_close(struct hid_device *hdev)
2047 {
2048 	mutex_lock(&hdev->ll_open_lock);
2049 	if (!--hdev->ll_open_count)
2050 		hdev->ll_driver->close(hdev);
2051 	mutex_unlock(&hdev->ll_open_lock);
2052 }
2053 EXPORT_SYMBOL_GPL(hid_hw_close);
2054 
2055 struct hid_dynid {
2056 	struct list_head list;
2057 	struct hid_device_id id;
2058 };
2059 
2060 /**
2061  * store_new_id - add a new HID device ID to this driver and re-probe devices
2062  * @driver: target device driver
2063  * @buf: buffer for scanning device ID data
2064  * @count: input size
2065  *
2066  * Adds a new dynamic hid device ID to this driver,
2067  * and causes the driver to probe for all devices again.
2068  */
2069 static ssize_t new_id_store(struct device_driver *drv, const char *buf,
2070 		size_t count)
2071 {
2072 	struct hid_driver *hdrv = to_hid_driver(drv);
2073 	struct hid_dynid *dynid;
2074 	__u32 bus, vendor, product;
2075 	unsigned long driver_data = 0;
2076 	int ret;
2077 
2078 	ret = sscanf(buf, "%x %x %x %lx",
2079 			&bus, &vendor, &product, &driver_data);
2080 	if (ret < 3)
2081 		return -EINVAL;
2082 
2083 	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
2084 	if (!dynid)
2085 		return -ENOMEM;
2086 
2087 	dynid->id.bus = bus;
2088 	dynid->id.group = HID_GROUP_ANY;
2089 	dynid->id.vendor = vendor;
2090 	dynid->id.product = product;
2091 	dynid->id.driver_data = driver_data;
2092 
2093 	spin_lock(&hdrv->dyn_lock);
2094 	list_add_tail(&dynid->list, &hdrv->dyn_list);
2095 	spin_unlock(&hdrv->dyn_lock);
2096 
2097 	ret = driver_attach(&hdrv->driver);
2098 
2099 	return ret ? : count;
2100 }
2101 static DRIVER_ATTR_WO(new_id);
2102 
2103 static struct attribute *hid_drv_attrs[] = {
2104 	&driver_attr_new_id.attr,
2105 	NULL,
2106 };
2107 ATTRIBUTE_GROUPS(hid_drv);
2108 
2109 static void hid_free_dynids(struct hid_driver *hdrv)
2110 {
2111 	struct hid_dynid *dynid, *n;
2112 
2113 	spin_lock(&hdrv->dyn_lock);
2114 	list_for_each_entry_safe(dynid, n, &hdrv->dyn_list, list) {
2115 		list_del(&dynid->list);
2116 		kfree(dynid);
2117 	}
2118 	spin_unlock(&hdrv->dyn_lock);
2119 }
2120 
2121 const struct hid_device_id *hid_match_device(struct hid_device *hdev,
2122 					     struct hid_driver *hdrv)
2123 {
2124 	struct hid_dynid *dynid;
2125 
2126 	spin_lock(&hdrv->dyn_lock);
2127 	list_for_each_entry(dynid, &hdrv->dyn_list, list) {
2128 		if (hid_match_one_id(hdev, &dynid->id)) {
2129 			spin_unlock(&hdrv->dyn_lock);
2130 			return &dynid->id;
2131 		}
2132 	}
2133 	spin_unlock(&hdrv->dyn_lock);
2134 
2135 	return hid_match_id(hdev, hdrv->id_table);
2136 }
2137 EXPORT_SYMBOL_GPL(hid_match_device);
2138 
2139 static int hid_bus_match(struct device *dev, struct device_driver *drv)
2140 {
2141 	struct hid_driver *hdrv = to_hid_driver(drv);
2142 	struct hid_device *hdev = to_hid_device(dev);
2143 
2144 	return hid_match_device(hdev, hdrv) != NULL;
2145 }
2146 
2147 /**
2148  * hid_compare_device_paths - check if both devices share the same path
2149  * @hdev_a: hid device
2150  * @hdev_b: hid device
2151  * @separator: char to use as separator
2152  *
2153  * Check if two devices share the same path up to the last occurrence of
2154  * the separator char. Both paths must exist (i.e., zero-length paths
2155  * don't match).
2156  */
2157 bool hid_compare_device_paths(struct hid_device *hdev_a,
2158 			      struct hid_device *hdev_b, char separator)
2159 {
2160 	int n1 = strrchr(hdev_a->phys, separator) - hdev_a->phys;
2161 	int n2 = strrchr(hdev_b->phys, separator) - hdev_b->phys;
2162 
2163 	if (n1 != n2 || n1 <= 0 || n2 <= 0)
2164 		return false;
2165 
2166 	return !strncmp(hdev_a->phys, hdev_b->phys, n1);
2167 }
2168 EXPORT_SYMBOL_GPL(hid_compare_device_paths);
2169 
2170 static int hid_device_probe(struct device *dev)
2171 {
2172 	struct hid_driver *hdrv = to_hid_driver(dev->driver);
2173 	struct hid_device *hdev = to_hid_device(dev);
2174 	const struct hid_device_id *id;
2175 	int ret = 0;
2176 
2177 	if (down_interruptible(&hdev->driver_input_lock)) {
2178 		ret = -EINTR;
2179 		goto end;
2180 	}
2181 	hdev->io_started = false;
2182 
2183 	clear_bit(ffs(HID_STAT_REPROBED), &hdev->status);
2184 
2185 	if (!hdev->driver) {
2186 		id = hid_match_device(hdev, hdrv);
2187 		if (id == NULL) {
2188 			ret = -ENODEV;
2189 			goto unlock;
2190 		}
2191 
2192 		if (hdrv->match) {
2193 			if (!hdrv->match(hdev, hid_ignore_special_drivers)) {
2194 				ret = -ENODEV;
2195 				goto unlock;
2196 			}
2197 		} else {
2198 			/*
2199 			 * hid-generic implements .match(), so if
2200 			 * hid_ignore_special_drivers is set, we can safely
2201 			 * return.
2202 			 */
2203 			if (hid_ignore_special_drivers) {
2204 				ret = -ENODEV;
2205 				goto unlock;
2206 			}
2207 		}
2208 
2209 		/* reset the quirks that has been previously set */
2210 		hdev->quirks = hid_lookup_quirk(hdev);
2211 		hdev->driver = hdrv;
2212 		if (hdrv->probe) {
2213 			ret = hdrv->probe(hdev, id);
2214 		} else { /* default probe */
2215 			ret = hid_open_report(hdev);
2216 			if (!ret)
2217 				ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
2218 		}
2219 		if (ret) {
2220 			hid_close_report(hdev);
2221 			hdev->driver = NULL;
2222 		}
2223 	}
2224 unlock:
2225 	if (!hdev->io_started)
2226 		up(&hdev->driver_input_lock);
2227 end:
2228 	return ret;
2229 }
2230 
2231 static int hid_device_remove(struct device *dev)
2232 {
2233 	struct hid_device *hdev = to_hid_device(dev);
2234 	struct hid_driver *hdrv;
2235 	int ret = 0;
2236 
2237 	if (down_interruptible(&hdev->driver_input_lock)) {
2238 		ret = -EINTR;
2239 		goto end;
2240 	}
2241 	hdev->io_started = false;
2242 
2243 	hdrv = hdev->driver;
2244 	if (hdrv) {
2245 		if (hdrv->remove)
2246 			hdrv->remove(hdev);
2247 		else /* default remove */
2248 			hid_hw_stop(hdev);
2249 		hid_close_report(hdev);
2250 		hdev->driver = NULL;
2251 	}
2252 
2253 	if (!hdev->io_started)
2254 		up(&hdev->driver_input_lock);
2255 end:
2256 	return ret;
2257 }
2258 
2259 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
2260 			     char *buf)
2261 {
2262 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
2263 
2264 	return scnprintf(buf, PAGE_SIZE, "hid:b%04Xg%04Xv%08Xp%08X\n",
2265 			 hdev->bus, hdev->group, hdev->vendor, hdev->product);
2266 }
2267 static DEVICE_ATTR_RO(modalias);
2268 
2269 static struct attribute *hid_dev_attrs[] = {
2270 	&dev_attr_modalias.attr,
2271 	NULL,
2272 };
2273 static struct bin_attribute *hid_dev_bin_attrs[] = {
2274 	&dev_bin_attr_report_desc,
2275 	NULL
2276 };
2277 static const struct attribute_group hid_dev_group = {
2278 	.attrs = hid_dev_attrs,
2279 	.bin_attrs = hid_dev_bin_attrs,
2280 };
2281 __ATTRIBUTE_GROUPS(hid_dev);
2282 
2283 static int hid_uevent(struct device *dev, struct kobj_uevent_env *env)
2284 {
2285 	struct hid_device *hdev = to_hid_device(dev);
2286 
2287 	if (add_uevent_var(env, "HID_ID=%04X:%08X:%08X",
2288 			hdev->bus, hdev->vendor, hdev->product))
2289 		return -ENOMEM;
2290 
2291 	if (add_uevent_var(env, "HID_NAME=%s", hdev->name))
2292 		return -ENOMEM;
2293 
2294 	if (add_uevent_var(env, "HID_PHYS=%s", hdev->phys))
2295 		return -ENOMEM;
2296 
2297 	if (add_uevent_var(env, "HID_UNIQ=%s", hdev->uniq))
2298 		return -ENOMEM;
2299 
2300 	if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",
2301 			   hdev->bus, hdev->group, hdev->vendor, hdev->product))
2302 		return -ENOMEM;
2303 
2304 	return 0;
2305 }
2306 
2307 struct bus_type hid_bus_type = {
2308 	.name		= "hid",
2309 	.dev_groups	= hid_dev_groups,
2310 	.drv_groups	= hid_drv_groups,
2311 	.match		= hid_bus_match,
2312 	.probe		= hid_device_probe,
2313 	.remove		= hid_device_remove,
2314 	.uevent		= hid_uevent,
2315 };
2316 EXPORT_SYMBOL(hid_bus_type);
2317 
2318 int hid_add_device(struct hid_device *hdev)
2319 {
2320 	static atomic_t id = ATOMIC_INIT(0);
2321 	int ret;
2322 
2323 	if (WARN_ON(hdev->status & HID_STAT_ADDED))
2324 		return -EBUSY;
2325 
2326 	hdev->quirks = hid_lookup_quirk(hdev);
2327 
2328 	/* we need to kill them here, otherwise they will stay allocated to
2329 	 * wait for coming driver */
2330 	if (hid_ignore(hdev))
2331 		return -ENODEV;
2332 
2333 	/*
2334 	 * Check for the mandatory transport channel.
2335 	 */
2336 	 if (!hdev->ll_driver->raw_request) {
2337 		hid_err(hdev, "transport driver missing .raw_request()\n");
2338 		return -EINVAL;
2339 	 }
2340 
2341 	/*
2342 	 * Read the device report descriptor once and use as template
2343 	 * for the driver-specific modifications.
2344 	 */
2345 	ret = hdev->ll_driver->parse(hdev);
2346 	if (ret)
2347 		return ret;
2348 	if (!hdev->dev_rdesc)
2349 		return -ENODEV;
2350 
2351 	/*
2352 	 * Scan generic devices for group information
2353 	 */
2354 	if (hid_ignore_special_drivers) {
2355 		hdev->group = HID_GROUP_GENERIC;
2356 	} else if (!hdev->group &&
2357 		   !(hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)) {
2358 		ret = hid_scan_report(hdev);
2359 		if (ret)
2360 			hid_warn(hdev, "bad device descriptor (%d)\n", ret);
2361 	}
2362 
2363 	/* XXX hack, any other cleaner solution after the driver core
2364 	 * is converted to allow more than 20 bytes as the device name? */
2365 	dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
2366 		     hdev->vendor, hdev->product, atomic_inc_return(&id));
2367 
2368 	/*
2369 	 * Try loading the module for the device before the add, so that we do
2370 	 * not first have hid-generic binding only to have it replaced
2371 	 * immediately afterwards with a specialized driver.
2372 	 */
2373 	if (!current_is_async())
2374 		request_module("hid:b%04Xg%04Xv%08Xp%08X", hdev->bus,
2375 			       hdev->group, hdev->vendor, hdev->product);
2376 
2377 	hid_debug_register(hdev, dev_name(&hdev->dev));
2378 	ret = device_add(&hdev->dev);
2379 	if (!ret)
2380 		hdev->status |= HID_STAT_ADDED;
2381 	else
2382 		hid_debug_unregister(hdev);
2383 
2384 	return ret;
2385 }
2386 EXPORT_SYMBOL_GPL(hid_add_device);
2387 
2388 /**
2389  * hid_allocate_device - allocate new hid device descriptor
2390  *
2391  * Allocate and initialize hid device, so that hid_destroy_device might be
2392  * used to free it.
2393  *
2394  * New hid_device pointer is returned on success, otherwise ERR_PTR encoded
2395  * error value.
2396  */
2397 struct hid_device *hid_allocate_device(void)
2398 {
2399 	struct hid_device *hdev;
2400 	int ret = -ENOMEM;
2401 
2402 	hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
2403 	if (hdev == NULL)
2404 		return ERR_PTR(ret);
2405 
2406 	device_initialize(&hdev->dev);
2407 	hdev->dev.release = hid_device_release;
2408 	hdev->dev.bus = &hid_bus_type;
2409 	device_enable_async_suspend(&hdev->dev);
2410 
2411 	hid_close_report(hdev);
2412 
2413 	init_waitqueue_head(&hdev->debug_wait);
2414 	INIT_LIST_HEAD(&hdev->debug_list);
2415 	spin_lock_init(&hdev->debug_list_lock);
2416 	sema_init(&hdev->driver_input_lock, 1);
2417 	mutex_init(&hdev->ll_open_lock);
2418 
2419 	return hdev;
2420 }
2421 EXPORT_SYMBOL_GPL(hid_allocate_device);
2422 
2423 static void hid_remove_device(struct hid_device *hdev)
2424 {
2425 	if (hdev->status & HID_STAT_ADDED) {
2426 		device_del(&hdev->dev);
2427 		hid_debug_unregister(hdev);
2428 		hdev->status &= ~HID_STAT_ADDED;
2429 	}
2430 	kfree(hdev->dev_rdesc);
2431 	hdev->dev_rdesc = NULL;
2432 	hdev->dev_rsize = 0;
2433 }
2434 
2435 /**
2436  * hid_destroy_device - free previously allocated device
2437  *
2438  * @hdev: hid device
2439  *
2440  * If you allocate hid_device through hid_allocate_device, you should ever
2441  * free by this function.
2442  */
2443 void hid_destroy_device(struct hid_device *hdev)
2444 {
2445 	hid_remove_device(hdev);
2446 	put_device(&hdev->dev);
2447 }
2448 EXPORT_SYMBOL_GPL(hid_destroy_device);
2449 
2450 
2451 static int __hid_bus_reprobe_drivers(struct device *dev, void *data)
2452 {
2453 	struct hid_driver *hdrv = data;
2454 	struct hid_device *hdev = to_hid_device(dev);
2455 
2456 	if (hdev->driver == hdrv &&
2457 	    !hdrv->match(hdev, hid_ignore_special_drivers) &&
2458 	    !test_and_set_bit(ffs(HID_STAT_REPROBED), &hdev->status))
2459 		return device_reprobe(dev);
2460 
2461 	return 0;
2462 }
2463 
2464 static int __hid_bus_driver_added(struct device_driver *drv, void *data)
2465 {
2466 	struct hid_driver *hdrv = to_hid_driver(drv);
2467 
2468 	if (hdrv->match) {
2469 		bus_for_each_dev(&hid_bus_type, NULL, hdrv,
2470 				 __hid_bus_reprobe_drivers);
2471 	}
2472 
2473 	return 0;
2474 }
2475 
2476 static int __bus_removed_driver(struct device_driver *drv, void *data)
2477 {
2478 	return bus_rescan_devices(&hid_bus_type);
2479 }
2480 
2481 int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
2482 		const char *mod_name)
2483 {
2484 	int ret;
2485 
2486 	hdrv->driver.name = hdrv->name;
2487 	hdrv->driver.bus = &hid_bus_type;
2488 	hdrv->driver.owner = owner;
2489 	hdrv->driver.mod_name = mod_name;
2490 
2491 	INIT_LIST_HEAD(&hdrv->dyn_list);
2492 	spin_lock_init(&hdrv->dyn_lock);
2493 
2494 	ret = driver_register(&hdrv->driver);
2495 
2496 	if (ret == 0)
2497 		bus_for_each_drv(&hid_bus_type, NULL, NULL,
2498 				 __hid_bus_driver_added);
2499 
2500 	return ret;
2501 }
2502 EXPORT_SYMBOL_GPL(__hid_register_driver);
2503 
2504 void hid_unregister_driver(struct hid_driver *hdrv)
2505 {
2506 	driver_unregister(&hdrv->driver);
2507 	hid_free_dynids(hdrv);
2508 
2509 	bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver);
2510 }
2511 EXPORT_SYMBOL_GPL(hid_unregister_driver);
2512 
2513 int hid_check_keys_pressed(struct hid_device *hid)
2514 {
2515 	struct hid_input *hidinput;
2516 	int i;
2517 
2518 	if (!(hid->claimed & HID_CLAIMED_INPUT))
2519 		return 0;
2520 
2521 	list_for_each_entry(hidinput, &hid->inputs, list) {
2522 		for (i = 0; i < BITS_TO_LONGS(KEY_MAX); i++)
2523 			if (hidinput->input->key[i])
2524 				return 1;
2525 	}
2526 
2527 	return 0;
2528 }
2529 
2530 EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
2531 
2532 static int __init hid_init(void)
2533 {
2534 	int ret;
2535 
2536 	if (hid_debug)
2537 		pr_warn("hid_debug is now used solely for parser and driver debugging.\n"
2538 			"debugfs is now used for inspecting the device (report descriptor, reports)\n");
2539 
2540 	ret = bus_register(&hid_bus_type);
2541 	if (ret) {
2542 		pr_err("can't register hid bus\n");
2543 		goto err;
2544 	}
2545 
2546 	ret = hidraw_init();
2547 	if (ret)
2548 		goto err_bus;
2549 
2550 	hid_debug_init();
2551 
2552 	return 0;
2553 err_bus:
2554 	bus_unregister(&hid_bus_type);
2555 err:
2556 	return ret;
2557 }
2558 
2559 static void __exit hid_exit(void)
2560 {
2561 	hid_debug_exit();
2562 	hidraw_exit();
2563 	bus_unregister(&hid_bus_type);
2564 	hid_quirks_exit(HID_BUS_ANY);
2565 }
2566 
2567 module_init(hid_init);
2568 module_exit(hid_exit);
2569 
2570 MODULE_AUTHOR("Andreas Gal");
2571 MODULE_AUTHOR("Vojtech Pavlik");
2572 MODULE_AUTHOR("Jiri Kosina");
2573 MODULE_LICENSE("GPL");
2574