xref: /linux/drivers/hid/hid-core.c (revision 3bd6e94bec122a951d462c239b47954cf5f36e33)
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 == parser->collection_stack_size) {
132 		unsigned int *collection_stack;
133 		unsigned int new_size = parser->collection_stack_size +
134 					HID_COLLECTION_STACK_SIZE;
135 
136 		collection_stack = krealloc(parser->collection_stack,
137 					    new_size * sizeof(unsigned int),
138 					    GFP_KERNEL);
139 		if (!collection_stack)
140 			return -ENOMEM;
141 
142 		parser->collection_stack = collection_stack;
143 		parser->collection_stack_size = new_size;
144 	}
145 
146 	if (parser->device->maxcollection == parser->device->collection_size) {
147 		collection = kmalloc(
148 				array3_size(sizeof(struct hid_collection),
149 					    parser->device->collection_size,
150 					    2),
151 				GFP_KERNEL);
152 		if (collection == NULL) {
153 			hid_err(parser->device, "failed to reallocate collection array\n");
154 			return -ENOMEM;
155 		}
156 		memcpy(collection, parser->device->collection,
157 			sizeof(struct hid_collection) *
158 			parser->device->collection_size);
159 		memset(collection + parser->device->collection_size, 0,
160 			sizeof(struct hid_collection) *
161 			parser->device->collection_size);
162 		kfree(parser->device->collection);
163 		parser->device->collection = collection;
164 		parser->device->collection_size *= 2;
165 	}
166 
167 	parser->collection_stack[parser->collection_stack_ptr++] =
168 		parser->device->maxcollection;
169 
170 	collection = parser->device->collection +
171 		parser->device->maxcollection++;
172 	collection->type = type;
173 	collection->usage = usage;
174 	collection->level = parser->collection_stack_ptr - 1;
175 	collection->parent = parser->active_collection;
176 	parser->active_collection = collection;
177 
178 	if (type == HID_COLLECTION_APPLICATION)
179 		parser->device->maxapplication++;
180 
181 	return 0;
182 }
183 
184 /*
185  * Close a collection.
186  */
187 
188 static int close_collection(struct hid_parser *parser)
189 {
190 	if (!parser->collection_stack_ptr) {
191 		hid_err(parser->device, "collection stack underflow\n");
192 		return -EINVAL;
193 	}
194 	parser->collection_stack_ptr--;
195 	if (parser->active_collection)
196 		parser->active_collection = parser->active_collection->parent;
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)
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.collection_index[parser->local.usage_index] =
230 		parser->collection_stack_ptr ?
231 		parser->collection_stack[parser->collection_stack_ptr - 1] : 0;
232 	parser->local.usage_index++;
233 	return 0;
234 }
235 
236 /*
237  * Register a new field for this report.
238  */
239 
240 static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsigned flags)
241 {
242 	struct hid_report *report;
243 	struct hid_field *field;
244 	unsigned int usages;
245 	unsigned int offset;
246 	unsigned int i;
247 	unsigned int application;
248 
249 	application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
250 
251 	report = hid_register_report(parser->device, report_type,
252 				     parser->global.report_id, application);
253 	if (!report) {
254 		hid_err(parser->device, "hid_register_report failed\n");
255 		return -1;
256 	}
257 
258 	/* Handle both signed and unsigned cases properly */
259 	if ((parser->global.logical_minimum < 0 &&
260 		parser->global.logical_maximum <
261 		parser->global.logical_minimum) ||
262 		(parser->global.logical_minimum >= 0 &&
263 		(__u32)parser->global.logical_maximum <
264 		(__u32)parser->global.logical_minimum)) {
265 		dbg_hid("logical range invalid 0x%x 0x%x\n",
266 			parser->global.logical_minimum,
267 			parser->global.logical_maximum);
268 		return -1;
269 	}
270 
271 	offset = report->size;
272 	report->size += parser->global.report_size * parser->global.report_count;
273 
274 	if (!parser->local.usage_index) /* Ignore padding fields */
275 		return 0;
276 
277 	usages = max_t(unsigned, parser->local.usage_index,
278 				 parser->global.report_count);
279 
280 	field = hid_register_field(report, usages, parser->global.report_count);
281 	if (!field)
282 		return 0;
283 
284 	field->physical = hid_lookup_collection(parser, HID_COLLECTION_PHYSICAL);
285 	field->logical = hid_lookup_collection(parser, HID_COLLECTION_LOGICAL);
286 	field->application = application;
287 
288 	for (i = 0; i < usages; i++) {
289 		unsigned j = i;
290 		/* Duplicate the last usage we parsed if we have excess values */
291 		if (i >= parser->local.usage_index)
292 			j = parser->local.usage_index - 1;
293 		field->usage[i].hid = parser->local.usage[j];
294 		field->usage[i].collection_index =
295 			parser->local.collection_index[j];
296 		field->usage[i].usage_index = i;
297 		field->usage[i].resolution_multiplier = 1;
298 	}
299 
300 	field->maxusage = usages;
301 	field->flags = flags;
302 	field->report_offset = offset;
303 	field->report_type = report_type;
304 	field->report_size = parser->global.report_size;
305 	field->report_count = parser->global.report_count;
306 	field->logical_minimum = parser->global.logical_minimum;
307 	field->logical_maximum = parser->global.logical_maximum;
308 	field->physical_minimum = parser->global.physical_minimum;
309 	field->physical_maximum = parser->global.physical_maximum;
310 	field->unit_exponent = parser->global.unit_exponent;
311 	field->unit = parser->global.unit;
312 
313 	return 0;
314 }
315 
316 /*
317  * Read data value from item.
318  */
319 
320 static u32 item_udata(struct hid_item *item)
321 {
322 	switch (item->size) {
323 	case 1: return item->data.u8;
324 	case 2: return item->data.u16;
325 	case 4: return item->data.u32;
326 	}
327 	return 0;
328 }
329 
330 static s32 item_sdata(struct hid_item *item)
331 {
332 	switch (item->size) {
333 	case 1: return item->data.s8;
334 	case 2: return item->data.s16;
335 	case 4: return item->data.s32;
336 	}
337 	return 0;
338 }
339 
340 /*
341  * Process a global item.
342  */
343 
344 static int hid_parser_global(struct hid_parser *parser, struct hid_item *item)
345 {
346 	__s32 raw_value;
347 	switch (item->tag) {
348 	case HID_GLOBAL_ITEM_TAG_PUSH:
349 
350 		if (parser->global_stack_ptr == HID_GLOBAL_STACK_SIZE) {
351 			hid_err(parser->device, "global environment stack overflow\n");
352 			return -1;
353 		}
354 
355 		memcpy(parser->global_stack + parser->global_stack_ptr++,
356 			&parser->global, sizeof(struct hid_global));
357 		return 0;
358 
359 	case HID_GLOBAL_ITEM_TAG_POP:
360 
361 		if (!parser->global_stack_ptr) {
362 			hid_err(parser->device, "global environment stack underflow\n");
363 			return -1;
364 		}
365 
366 		memcpy(&parser->global, parser->global_stack +
367 			--parser->global_stack_ptr, sizeof(struct hid_global));
368 		return 0;
369 
370 	case HID_GLOBAL_ITEM_TAG_USAGE_PAGE:
371 		parser->global.usage_page = item_udata(item);
372 		return 0;
373 
374 	case HID_GLOBAL_ITEM_TAG_LOGICAL_MINIMUM:
375 		parser->global.logical_minimum = item_sdata(item);
376 		return 0;
377 
378 	case HID_GLOBAL_ITEM_TAG_LOGICAL_MAXIMUM:
379 		if (parser->global.logical_minimum < 0)
380 			parser->global.logical_maximum = item_sdata(item);
381 		else
382 			parser->global.logical_maximum = item_udata(item);
383 		return 0;
384 
385 	case HID_GLOBAL_ITEM_TAG_PHYSICAL_MINIMUM:
386 		parser->global.physical_minimum = item_sdata(item);
387 		return 0;
388 
389 	case HID_GLOBAL_ITEM_TAG_PHYSICAL_MAXIMUM:
390 		if (parser->global.physical_minimum < 0)
391 			parser->global.physical_maximum = item_sdata(item);
392 		else
393 			parser->global.physical_maximum = item_udata(item);
394 		return 0;
395 
396 	case HID_GLOBAL_ITEM_TAG_UNIT_EXPONENT:
397 		/* Many devices provide unit exponent as a two's complement
398 		 * nibble due to the common misunderstanding of HID
399 		 * specification 1.11, 6.2.2.7 Global Items. Attempt to handle
400 		 * both this and the standard encoding. */
401 		raw_value = item_sdata(item);
402 		if (!(raw_value & 0xfffffff0))
403 			parser->global.unit_exponent = hid_snto32(raw_value, 4);
404 		else
405 			parser->global.unit_exponent = raw_value;
406 		return 0;
407 
408 	case HID_GLOBAL_ITEM_TAG_UNIT:
409 		parser->global.unit = item_udata(item);
410 		return 0;
411 
412 	case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
413 		parser->global.report_size = item_udata(item);
414 		if (parser->global.report_size > 256) {
415 			hid_err(parser->device, "invalid report_size %d\n",
416 					parser->global.report_size);
417 			return -1;
418 		}
419 		return 0;
420 
421 	case HID_GLOBAL_ITEM_TAG_REPORT_COUNT:
422 		parser->global.report_count = item_udata(item);
423 		if (parser->global.report_count > HID_MAX_USAGES) {
424 			hid_err(parser->device, "invalid report_count %d\n",
425 					parser->global.report_count);
426 			return -1;
427 		}
428 		return 0;
429 
430 	case HID_GLOBAL_ITEM_TAG_REPORT_ID:
431 		parser->global.report_id = item_udata(item);
432 		if (parser->global.report_id == 0 ||
433 		    parser->global.report_id >= HID_MAX_IDS) {
434 			hid_err(parser->device, "report_id %u is invalid\n",
435 				parser->global.report_id);
436 			return -1;
437 		}
438 		return 0;
439 
440 	default:
441 		hid_err(parser->device, "unknown global tag 0x%x\n", item->tag);
442 		return -1;
443 	}
444 }
445 
446 /*
447  * Process a local item.
448  */
449 
450 static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
451 {
452 	__u32 data;
453 	unsigned n;
454 	__u32 count;
455 
456 	data = item_udata(item);
457 
458 	switch (item->tag) {
459 	case HID_LOCAL_ITEM_TAG_DELIMITER:
460 
461 		if (data) {
462 			/*
463 			 * We treat items before the first delimiter
464 			 * as global to all usage sets (branch 0).
465 			 * In the moment we process only these global
466 			 * items and the first delimiter set.
467 			 */
468 			if (parser->local.delimiter_depth != 0) {
469 				hid_err(parser->device, "nested delimiters\n");
470 				return -1;
471 			}
472 			parser->local.delimiter_depth++;
473 			parser->local.delimiter_branch++;
474 		} else {
475 			if (parser->local.delimiter_depth < 1) {
476 				hid_err(parser->device, "bogus close delimiter\n");
477 				return -1;
478 			}
479 			parser->local.delimiter_depth--;
480 		}
481 		return 0;
482 
483 	case HID_LOCAL_ITEM_TAG_USAGE:
484 
485 		if (parser->local.delimiter_branch > 1) {
486 			dbg_hid("alternative usage ignored\n");
487 			return 0;
488 		}
489 
490 		if (item->size <= 2)
491 			data = (parser->global.usage_page << 16) + data;
492 
493 		return hid_add_usage(parser, data);
494 
495 	case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:
496 
497 		if (parser->local.delimiter_branch > 1) {
498 			dbg_hid("alternative usage ignored\n");
499 			return 0;
500 		}
501 
502 		if (item->size <= 2)
503 			data = (parser->global.usage_page << 16) + data;
504 
505 		parser->local.usage_minimum = data;
506 		return 0;
507 
508 	case HID_LOCAL_ITEM_TAG_USAGE_MAXIMUM:
509 
510 		if (parser->local.delimiter_branch > 1) {
511 			dbg_hid("alternative usage ignored\n");
512 			return 0;
513 		}
514 
515 		if (item->size <= 2)
516 			data = (parser->global.usage_page << 16) + data;
517 
518 		count = data - parser->local.usage_minimum;
519 		if (count + parser->local.usage_index >= HID_MAX_USAGES) {
520 			/*
521 			 * We do not warn if the name is not set, we are
522 			 * actually pre-scanning the device.
523 			 */
524 			if (dev_name(&parser->device->dev))
525 				hid_warn(parser->device,
526 					 "ignoring exceeding usage max\n");
527 			data = HID_MAX_USAGES - parser->local.usage_index +
528 				parser->local.usage_minimum - 1;
529 			if (data <= 0) {
530 				hid_err(parser->device,
531 					"no more usage index available\n");
532 				return -1;
533 			}
534 		}
535 
536 		for (n = parser->local.usage_minimum; n <= data; n++)
537 			if (hid_add_usage(parser, n)) {
538 				dbg_hid("hid_add_usage failed\n");
539 				return -1;
540 			}
541 		return 0;
542 
543 	default:
544 
545 		dbg_hid("unknown local item tag 0x%x\n", item->tag);
546 		return 0;
547 	}
548 	return 0;
549 }
550 
551 /*
552  * Process a main item.
553  */
554 
555 static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
556 {
557 	__u32 data;
558 	int ret;
559 
560 	data = item_udata(item);
561 
562 	switch (item->tag) {
563 	case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
564 		ret = open_collection(parser, data & 0xff);
565 		break;
566 	case HID_MAIN_ITEM_TAG_END_COLLECTION:
567 		ret = close_collection(parser);
568 		break;
569 	case HID_MAIN_ITEM_TAG_INPUT:
570 		ret = hid_add_field(parser, HID_INPUT_REPORT, data);
571 		break;
572 	case HID_MAIN_ITEM_TAG_OUTPUT:
573 		ret = hid_add_field(parser, HID_OUTPUT_REPORT, data);
574 		break;
575 	case HID_MAIN_ITEM_TAG_FEATURE:
576 		ret = hid_add_field(parser, HID_FEATURE_REPORT, data);
577 		break;
578 	default:
579 		hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
580 		ret = 0;
581 	}
582 
583 	memset(&parser->local, 0, sizeof(parser->local));	/* Reset the local parser environment */
584 
585 	return ret;
586 }
587 
588 /*
589  * Process a reserved item.
590  */
591 
592 static int hid_parser_reserved(struct hid_parser *parser, struct hid_item *item)
593 {
594 	dbg_hid("reserved item type, tag 0x%x\n", item->tag);
595 	return 0;
596 }
597 
598 /*
599  * Free a report and all registered fields. The field->usage and
600  * field->value table's are allocated behind the field, so we need
601  * only to free(field) itself.
602  */
603 
604 static void hid_free_report(struct hid_report *report)
605 {
606 	unsigned n;
607 
608 	for (n = 0; n < report->maxfield; n++)
609 		kfree(report->field[n]);
610 	kfree(report);
611 }
612 
613 /*
614  * Close report. This function returns the device
615  * state to the point prior to hid_open_report().
616  */
617 static void hid_close_report(struct hid_device *device)
618 {
619 	unsigned i, j;
620 
621 	for (i = 0; i < HID_REPORT_TYPES; i++) {
622 		struct hid_report_enum *report_enum = device->report_enum + i;
623 
624 		for (j = 0; j < HID_MAX_IDS; j++) {
625 			struct hid_report *report = report_enum->report_id_hash[j];
626 			if (report)
627 				hid_free_report(report);
628 		}
629 		memset(report_enum, 0, sizeof(*report_enum));
630 		INIT_LIST_HEAD(&report_enum->report_list);
631 	}
632 
633 	kfree(device->rdesc);
634 	device->rdesc = NULL;
635 	device->rsize = 0;
636 
637 	kfree(device->collection);
638 	device->collection = NULL;
639 	device->collection_size = 0;
640 	device->maxcollection = 0;
641 	device->maxapplication = 0;
642 
643 	device->status &= ~HID_STAT_PARSED;
644 }
645 
646 /*
647  * Free a device structure, all reports, and all fields.
648  */
649 
650 static void hid_device_release(struct device *dev)
651 {
652 	struct hid_device *hid = to_hid_device(dev);
653 
654 	hid_close_report(hid);
655 	kfree(hid->dev_rdesc);
656 	kfree(hid);
657 }
658 
659 /*
660  * Fetch a report description item from the data stream. We support long
661  * items, though they are not used yet.
662  */
663 
664 static u8 *fetch_item(__u8 *start, __u8 *end, struct hid_item *item)
665 {
666 	u8 b;
667 
668 	if ((end - start) <= 0)
669 		return NULL;
670 
671 	b = *start++;
672 
673 	item->type = (b >> 2) & 3;
674 	item->tag  = (b >> 4) & 15;
675 
676 	if (item->tag == HID_ITEM_TAG_LONG) {
677 
678 		item->format = HID_ITEM_FORMAT_LONG;
679 
680 		if ((end - start) < 2)
681 			return NULL;
682 
683 		item->size = *start++;
684 		item->tag  = *start++;
685 
686 		if ((end - start) < item->size)
687 			return NULL;
688 
689 		item->data.longdata = start;
690 		start += item->size;
691 		return start;
692 	}
693 
694 	item->format = HID_ITEM_FORMAT_SHORT;
695 	item->size = b & 3;
696 
697 	switch (item->size) {
698 	case 0:
699 		return start;
700 
701 	case 1:
702 		if ((end - start) < 1)
703 			return NULL;
704 		item->data.u8 = *start++;
705 		return start;
706 
707 	case 2:
708 		if ((end - start) < 2)
709 			return NULL;
710 		item->data.u16 = get_unaligned_le16(start);
711 		start = (__u8 *)((__le16 *)start + 1);
712 		return start;
713 
714 	case 3:
715 		item->size++;
716 		if ((end - start) < 4)
717 			return NULL;
718 		item->data.u32 = get_unaligned_le32(start);
719 		start = (__u8 *)((__le32 *)start + 1);
720 		return start;
721 	}
722 
723 	return NULL;
724 }
725 
726 static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)
727 {
728 	struct hid_device *hid = parser->device;
729 
730 	if (usage == HID_DG_CONTACTID)
731 		hid->group = HID_GROUP_MULTITOUCH;
732 }
733 
734 static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
735 {
736 	if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
737 	    parser->global.report_size == 8)
738 		parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
739 }
740 
741 static void hid_scan_collection(struct hid_parser *parser, unsigned type)
742 {
743 	struct hid_device *hid = parser->device;
744 	int i;
745 
746 	if (((parser->global.usage_page << 16) == HID_UP_SENSOR) &&
747 	    type == HID_COLLECTION_PHYSICAL)
748 		hid->group = HID_GROUP_SENSOR_HUB;
749 
750 	if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
751 	    hid->product == USB_DEVICE_ID_MS_POWER_COVER &&
752 	    hid->group == HID_GROUP_MULTITOUCH)
753 		hid->group = HID_GROUP_GENERIC;
754 
755 	if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
756 		for (i = 0; i < parser->local.usage_index; i++)
757 			if (parser->local.usage[i] == HID_GD_POINTER)
758 				parser->scan_flags |= HID_SCAN_FLAG_GD_POINTER;
759 
760 	if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
761 		parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
762 }
763 
764 static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
765 {
766 	__u32 data;
767 	int i;
768 
769 	data = item_udata(item);
770 
771 	switch (item->tag) {
772 	case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
773 		hid_scan_collection(parser, data & 0xff);
774 		break;
775 	case HID_MAIN_ITEM_TAG_END_COLLECTION:
776 		break;
777 	case HID_MAIN_ITEM_TAG_INPUT:
778 		/* ignore constant inputs, they will be ignored by hid-input */
779 		if (data & HID_MAIN_ITEM_CONSTANT)
780 			break;
781 		for (i = 0; i < parser->local.usage_index; i++)
782 			hid_scan_input_usage(parser, parser->local.usage[i]);
783 		break;
784 	case HID_MAIN_ITEM_TAG_OUTPUT:
785 		break;
786 	case HID_MAIN_ITEM_TAG_FEATURE:
787 		for (i = 0; i < parser->local.usage_index; i++)
788 			hid_scan_feature_usage(parser, parser->local.usage[i]);
789 		break;
790 	}
791 
792 	/* Reset the local parser environment */
793 	memset(&parser->local, 0, sizeof(parser->local));
794 
795 	return 0;
796 }
797 
798 /*
799  * Scan a report descriptor before the device is added to the bus.
800  * Sets device groups and other properties that determine what driver
801  * to load.
802  */
803 static int hid_scan_report(struct hid_device *hid)
804 {
805 	struct hid_parser *parser;
806 	struct hid_item item;
807 	__u8 *start = hid->dev_rdesc;
808 	__u8 *end = start + hid->dev_rsize;
809 	static int (*dispatch_type[])(struct hid_parser *parser,
810 				      struct hid_item *item) = {
811 		hid_scan_main,
812 		hid_parser_global,
813 		hid_parser_local,
814 		hid_parser_reserved
815 	};
816 
817 	parser = vzalloc(sizeof(struct hid_parser));
818 	if (!parser)
819 		return -ENOMEM;
820 
821 	parser->device = hid;
822 	hid->group = HID_GROUP_GENERIC;
823 
824 	/*
825 	 * The parsing is simpler than the one in hid_open_report() as we should
826 	 * be robust against hid errors. Those errors will be raised by
827 	 * hid_open_report() anyway.
828 	 */
829 	while ((start = fetch_item(start, end, &item)) != NULL)
830 		dispatch_type[item.type](parser, &item);
831 
832 	/*
833 	 * Handle special flags set during scanning.
834 	 */
835 	if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
836 	    (hid->group == HID_GROUP_MULTITOUCH))
837 		hid->group = HID_GROUP_MULTITOUCH_WIN_8;
838 
839 	/*
840 	 * Vendor specific handlings
841 	 */
842 	switch (hid->vendor) {
843 	case USB_VENDOR_ID_WACOM:
844 		hid->group = HID_GROUP_WACOM;
845 		break;
846 	case USB_VENDOR_ID_SYNAPTICS:
847 		if (hid->group == HID_GROUP_GENERIC)
848 			if ((parser->scan_flags & HID_SCAN_FLAG_VENDOR_SPECIFIC)
849 			    && (parser->scan_flags & HID_SCAN_FLAG_GD_POINTER))
850 				/*
851 				 * hid-rmi should take care of them,
852 				 * not hid-generic
853 				 */
854 				hid->group = HID_GROUP_RMI;
855 		break;
856 	}
857 
858 	kfree(parser->collection_stack);
859 	vfree(parser);
860 	return 0;
861 }
862 
863 /**
864  * hid_parse_report - parse device report
865  *
866  * @device: hid device
867  * @start: report start
868  * @size: report size
869  *
870  * Allocate the device report as read by the bus driver. This function should
871  * only be called from parse() in ll drivers.
872  */
873 int hid_parse_report(struct hid_device *hid, __u8 *start, unsigned size)
874 {
875 	hid->dev_rdesc = kmemdup(start, size, GFP_KERNEL);
876 	if (!hid->dev_rdesc)
877 		return -ENOMEM;
878 	hid->dev_rsize = size;
879 	return 0;
880 }
881 EXPORT_SYMBOL_GPL(hid_parse_report);
882 
883 static const char * const hid_report_names[] = {
884 	"HID_INPUT_REPORT",
885 	"HID_OUTPUT_REPORT",
886 	"HID_FEATURE_REPORT",
887 };
888 /**
889  * hid_validate_values - validate existing device report's value indexes
890  *
891  * @device: hid device
892  * @type: which report type to examine
893  * @id: which report ID to examine (0 for first)
894  * @field_index: which report field to examine
895  * @report_counts: expected number of values
896  *
897  * Validate the number of values in a given field of a given report, after
898  * parsing.
899  */
900 struct hid_report *hid_validate_values(struct hid_device *hid,
901 				       unsigned int type, unsigned int id,
902 				       unsigned int field_index,
903 				       unsigned int report_counts)
904 {
905 	struct hid_report *report;
906 
907 	if (type > HID_FEATURE_REPORT) {
908 		hid_err(hid, "invalid HID report type %u\n", type);
909 		return NULL;
910 	}
911 
912 	if (id >= HID_MAX_IDS) {
913 		hid_err(hid, "invalid HID report id %u\n", id);
914 		return NULL;
915 	}
916 
917 	/*
918 	 * Explicitly not using hid_get_report() here since it depends on
919 	 * ->numbered being checked, which may not always be the case when
920 	 * drivers go to access report values.
921 	 */
922 	if (id == 0) {
923 		/*
924 		 * Validating on id 0 means we should examine the first
925 		 * report in the list.
926 		 */
927 		report = list_entry(
928 				hid->report_enum[type].report_list.next,
929 				struct hid_report, list);
930 	} else {
931 		report = hid->report_enum[type].report_id_hash[id];
932 	}
933 	if (!report) {
934 		hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
935 		return NULL;
936 	}
937 	if (report->maxfield <= field_index) {
938 		hid_err(hid, "not enough fields in %s %u\n",
939 			hid_report_names[type], id);
940 		return NULL;
941 	}
942 	if (report->field[field_index]->report_count < report_counts) {
943 		hid_err(hid, "not enough values in %s %u field %u\n",
944 			hid_report_names[type], id, field_index);
945 		return NULL;
946 	}
947 	return report;
948 }
949 EXPORT_SYMBOL_GPL(hid_validate_values);
950 
951 static int hid_calculate_multiplier(struct hid_device *hid,
952 				     struct hid_field *multiplier)
953 {
954 	int m;
955 	__s32 v = *multiplier->value;
956 	__s32 lmin = multiplier->logical_minimum;
957 	__s32 lmax = multiplier->logical_maximum;
958 	__s32 pmin = multiplier->physical_minimum;
959 	__s32 pmax = multiplier->physical_maximum;
960 
961 	/*
962 	 * "Because OS implementations will generally divide the control's
963 	 * reported count by the Effective Resolution Multiplier, designers
964 	 * should take care not to establish a potential Effective
965 	 * Resolution Multiplier of zero."
966 	 * HID Usage Table, v1.12, Section 4.3.1, p31
967 	 */
968 	if (lmax - lmin == 0)
969 		return 1;
970 	/*
971 	 * Handling the unit exponent is left as an exercise to whoever
972 	 * finds a device where that exponent is not 0.
973 	 */
974 	m = ((v - lmin)/(lmax - lmin) * (pmax - pmin) + pmin);
975 	if (unlikely(multiplier->unit_exponent != 0)) {
976 		hid_warn(hid,
977 			 "unsupported Resolution Multiplier unit exponent %d\n",
978 			 multiplier->unit_exponent);
979 	}
980 
981 	/* There are no devices with an effective multiplier > 255 */
982 	if (unlikely(m == 0 || m > 255 || m < -255)) {
983 		hid_warn(hid, "unsupported Resolution Multiplier %d\n", m);
984 		m = 1;
985 	}
986 
987 	return m;
988 }
989 
990 static void hid_apply_multiplier_to_field(struct hid_device *hid,
991 					  struct hid_field *field,
992 					  struct hid_collection *multiplier_collection,
993 					  int effective_multiplier)
994 {
995 	struct hid_collection *collection;
996 	struct hid_usage *usage;
997 	int i;
998 
999 	/*
1000 	 * If multiplier_collection is NULL, the multiplier applies
1001 	 * to all fields in the report.
1002 	 * Otherwise, it is the Logical Collection the multiplier applies to
1003 	 * but our field may be in a subcollection of that collection.
1004 	 */
1005 	for (i = 0; i < field->maxusage; i++) {
1006 		usage = &field->usage[i];
1007 
1008 		collection = &hid->collection[usage->collection_index];
1009 		while (collection && collection != multiplier_collection)
1010 			collection = collection->parent;
1011 
1012 		if (collection || multiplier_collection == NULL)
1013 			usage->resolution_multiplier = effective_multiplier;
1014 
1015 	}
1016 }
1017 
1018 static void hid_apply_multiplier(struct hid_device *hid,
1019 				 struct hid_field *multiplier)
1020 {
1021 	struct hid_report_enum *rep_enum;
1022 	struct hid_report *rep;
1023 	struct hid_field *field;
1024 	struct hid_collection *multiplier_collection;
1025 	int effective_multiplier;
1026 	int i;
1027 
1028 	/*
1029 	 * "The Resolution Multiplier control must be contained in the same
1030 	 * Logical Collection as the control(s) to which it is to be applied.
1031 	 * If no Resolution Multiplier is defined, then the Resolution
1032 	 * Multiplier defaults to 1.  If more than one control exists in a
1033 	 * Logical Collection, the Resolution Multiplier is associated with
1034 	 * all controls in the collection. If no Logical Collection is
1035 	 * defined, the Resolution Multiplier is associated with all
1036 	 * controls in the report."
1037 	 * HID Usage Table, v1.12, Section 4.3.1, p30
1038 	 *
1039 	 * Thus, search from the current collection upwards until we find a
1040 	 * logical collection. Then search all fields for that same parent
1041 	 * collection. Those are the fields the multiplier applies to.
1042 	 *
1043 	 * If we have more than one multiplier, it will overwrite the
1044 	 * applicable fields later.
1045 	 */
1046 	multiplier_collection = &hid->collection[multiplier->usage->collection_index];
1047 	while (multiplier_collection &&
1048 	       multiplier_collection->type != HID_COLLECTION_LOGICAL)
1049 		multiplier_collection = multiplier_collection->parent;
1050 
1051 	effective_multiplier = hid_calculate_multiplier(hid, multiplier);
1052 
1053 	rep_enum = &hid->report_enum[HID_INPUT_REPORT];
1054 	list_for_each_entry(rep, &rep_enum->report_list, list) {
1055 		for (i = 0; i < rep->maxfield; i++) {
1056 			field = rep->field[i];
1057 			hid_apply_multiplier_to_field(hid, field,
1058 						      multiplier_collection,
1059 						      effective_multiplier);
1060 		}
1061 	}
1062 }
1063 
1064 /*
1065  * hid_setup_resolution_multiplier - set up all resolution multipliers
1066  *
1067  * @device: hid device
1068  *
1069  * Search for all Resolution Multiplier Feature Reports and apply their
1070  * value to all matching Input items. This only updates the internal struct
1071  * fields.
1072  *
1073  * The Resolution Multiplier is applied by the hardware. If the multiplier
1074  * is anything other than 1, the hardware will send pre-multiplied events
1075  * so that the same physical interaction generates an accumulated
1076  *	accumulated_value = value * * multiplier
1077  * This may be achieved by sending
1078  * - "value * multiplier" for each event, or
1079  * - "value" but "multiplier" times as frequently, or
1080  * - a combination of the above
1081  * The only guarantee is that the same physical interaction always generates
1082  * an accumulated 'value * multiplier'.
1083  *
1084  * This function must be called before any event processing and after
1085  * any SetRequest to the Resolution Multiplier.
1086  */
1087 void hid_setup_resolution_multiplier(struct hid_device *hid)
1088 {
1089 	struct hid_report_enum *rep_enum;
1090 	struct hid_report *rep;
1091 	struct hid_usage *usage;
1092 	int i, j;
1093 
1094 	rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
1095 	list_for_each_entry(rep, &rep_enum->report_list, list) {
1096 		for (i = 0; i < rep->maxfield; i++) {
1097 			/* Ignore if report count is out of bounds. */
1098 			if (rep->field[i]->report_count < 1)
1099 				continue;
1100 
1101 			for (j = 0; j < rep->field[i]->maxusage; j++) {
1102 				usage = &rep->field[i]->usage[j];
1103 				if (usage->hid == HID_GD_RESOLUTION_MULTIPLIER)
1104 					hid_apply_multiplier(hid,
1105 							     rep->field[i]);
1106 			}
1107 		}
1108 	}
1109 }
1110 EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier);
1111 
1112 /**
1113  * hid_open_report - open a driver-specific device report
1114  *
1115  * @device: hid device
1116  *
1117  * Parse a report description into a hid_device structure. Reports are
1118  * enumerated, fields are attached to these reports.
1119  * 0 returned on success, otherwise nonzero error value.
1120  *
1121  * This function (or the equivalent hid_parse() macro) should only be
1122  * called from probe() in drivers, before starting the device.
1123  */
1124 int hid_open_report(struct hid_device *device)
1125 {
1126 	struct hid_parser *parser;
1127 	struct hid_item item;
1128 	unsigned int size;
1129 	__u8 *start;
1130 	__u8 *buf;
1131 	__u8 *end;
1132 	int ret;
1133 	static int (*dispatch_type[])(struct hid_parser *parser,
1134 				      struct hid_item *item) = {
1135 		hid_parser_main,
1136 		hid_parser_global,
1137 		hid_parser_local,
1138 		hid_parser_reserved
1139 	};
1140 
1141 	if (WARN_ON(device->status & HID_STAT_PARSED))
1142 		return -EBUSY;
1143 
1144 	start = device->dev_rdesc;
1145 	if (WARN_ON(!start))
1146 		return -ENODEV;
1147 	size = device->dev_rsize;
1148 
1149 	buf = kmemdup(start, size, GFP_KERNEL);
1150 	if (buf == NULL)
1151 		return -ENOMEM;
1152 
1153 	if (device->driver->report_fixup)
1154 		start = device->driver->report_fixup(device, buf, &size);
1155 	else
1156 		start = buf;
1157 
1158 	start = kmemdup(start, size, GFP_KERNEL);
1159 	kfree(buf);
1160 	if (start == NULL)
1161 		return -ENOMEM;
1162 
1163 	device->rdesc = start;
1164 	device->rsize = size;
1165 
1166 	parser = vzalloc(sizeof(struct hid_parser));
1167 	if (!parser) {
1168 		ret = -ENOMEM;
1169 		goto alloc_err;
1170 	}
1171 
1172 	parser->device = device;
1173 
1174 	end = start + size;
1175 
1176 	device->collection = kcalloc(HID_DEFAULT_NUM_COLLECTIONS,
1177 				     sizeof(struct hid_collection), GFP_KERNEL);
1178 	if (!device->collection) {
1179 		ret = -ENOMEM;
1180 		goto err;
1181 	}
1182 	device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
1183 
1184 	ret = -EINVAL;
1185 	while ((start = fetch_item(start, end, &item)) != NULL) {
1186 
1187 		if (item.format != HID_ITEM_FORMAT_SHORT) {
1188 			hid_err(device, "unexpected long global item\n");
1189 			goto err;
1190 		}
1191 
1192 		if (dispatch_type[item.type](parser, &item)) {
1193 			hid_err(device, "item %u %u %u %u parsing failed\n",
1194 				item.format, (unsigned)item.size,
1195 				(unsigned)item.type, (unsigned)item.tag);
1196 			goto err;
1197 		}
1198 
1199 		if (start == end) {
1200 			if (parser->collection_stack_ptr) {
1201 				hid_err(device, "unbalanced collection at end of report description\n");
1202 				goto err;
1203 			}
1204 			if (parser->local.delimiter_depth) {
1205 				hid_err(device, "unbalanced delimiter at end of report description\n");
1206 				goto err;
1207 			}
1208 
1209 			/*
1210 			 * fetch initial values in case the device's
1211 			 * default multiplier isn't the recommended 1
1212 			 */
1213 			hid_setup_resolution_multiplier(device);
1214 
1215 			kfree(parser->collection_stack);
1216 			vfree(parser);
1217 			device->status |= HID_STAT_PARSED;
1218 
1219 			return 0;
1220 		}
1221 	}
1222 
1223 	hid_err(device, "item fetching failed at offset %d\n", (int)(end - start));
1224 err:
1225 	kfree(parser->collection_stack);
1226 alloc_err:
1227 	vfree(parser);
1228 	hid_close_report(device);
1229 	return ret;
1230 }
1231 EXPORT_SYMBOL_GPL(hid_open_report);
1232 
1233 /*
1234  * Convert a signed n-bit integer to signed 32-bit integer. Common
1235  * cases are done through the compiler, the screwed things has to be
1236  * done by hand.
1237  */
1238 
1239 static s32 snto32(__u32 value, unsigned n)
1240 {
1241 	switch (n) {
1242 	case 8:  return ((__s8)value);
1243 	case 16: return ((__s16)value);
1244 	case 32: return ((__s32)value);
1245 	}
1246 	return value & (1 << (n - 1)) ? value | (~0U << n) : value;
1247 }
1248 
1249 s32 hid_snto32(__u32 value, unsigned n)
1250 {
1251 	return snto32(value, n);
1252 }
1253 EXPORT_SYMBOL_GPL(hid_snto32);
1254 
1255 /*
1256  * Convert a signed 32-bit integer to a signed n-bit integer.
1257  */
1258 
1259 static u32 s32ton(__s32 value, unsigned n)
1260 {
1261 	s32 a = value >> (n - 1);
1262 	if (a && a != -1)
1263 		return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
1264 	return value & ((1 << n) - 1);
1265 }
1266 
1267 /*
1268  * Extract/implement a data field from/to a little endian report (bit array).
1269  *
1270  * Code sort-of follows HID spec:
1271  *     http://www.usb.org/developers/hidpage/HID1_11.pdf
1272  *
1273  * While the USB HID spec allows unlimited length bit fields in "report
1274  * descriptors", most devices never use more than 16 bits.
1275  * One model of UPS is claimed to report "LINEV" as a 32-bit field.
1276  * Search linux-kernel and linux-usb-devel archives for "hid-core extract".
1277  */
1278 
1279 static u32 __extract(u8 *report, unsigned offset, int n)
1280 {
1281 	unsigned int idx = offset / 8;
1282 	unsigned int bit_nr = 0;
1283 	unsigned int bit_shift = offset % 8;
1284 	int bits_to_copy = 8 - bit_shift;
1285 	u32 value = 0;
1286 	u32 mask = n < 32 ? (1U << n) - 1 : ~0U;
1287 
1288 	while (n > 0) {
1289 		value |= ((u32)report[idx] >> bit_shift) << bit_nr;
1290 		n -= bits_to_copy;
1291 		bit_nr += bits_to_copy;
1292 		bits_to_copy = 8;
1293 		bit_shift = 0;
1294 		idx++;
1295 	}
1296 
1297 	return value & mask;
1298 }
1299 
1300 u32 hid_field_extract(const struct hid_device *hid, u8 *report,
1301 			unsigned offset, unsigned n)
1302 {
1303 	if (n > 32) {
1304 		hid_warn(hid, "hid_field_extract() called with n (%d) > 32! (%s)\n",
1305 			 n, current->comm);
1306 		n = 32;
1307 	}
1308 
1309 	return __extract(report, offset, n);
1310 }
1311 EXPORT_SYMBOL_GPL(hid_field_extract);
1312 
1313 /*
1314  * "implement" : set bits in a little endian bit stream.
1315  * Same concepts as "extract" (see comments above).
1316  * The data mangled in the bit stream remains in little endian
1317  * order the whole time. It make more sense to talk about
1318  * endianness of register values by considering a register
1319  * a "cached" copy of the little endian bit stream.
1320  */
1321 
1322 static void __implement(u8 *report, unsigned offset, int n, u32 value)
1323 {
1324 	unsigned int idx = offset / 8;
1325 	unsigned int bit_shift = offset % 8;
1326 	int bits_to_set = 8 - bit_shift;
1327 
1328 	while (n - bits_to_set >= 0) {
1329 		report[idx] &= ~(0xff << bit_shift);
1330 		report[idx] |= value << bit_shift;
1331 		value >>= bits_to_set;
1332 		n -= bits_to_set;
1333 		bits_to_set = 8;
1334 		bit_shift = 0;
1335 		idx++;
1336 	}
1337 
1338 	/* last nibble */
1339 	if (n) {
1340 		u8 bit_mask = ((1U << n) - 1);
1341 		report[idx] &= ~(bit_mask << bit_shift);
1342 		report[idx] |= value << bit_shift;
1343 	}
1344 }
1345 
1346 static void implement(const struct hid_device *hid, u8 *report,
1347 		      unsigned offset, unsigned n, u32 value)
1348 {
1349 	if (unlikely(n > 32)) {
1350 		hid_warn(hid, "%s() called with n (%d) > 32! (%s)\n",
1351 			 __func__, n, current->comm);
1352 		n = 32;
1353 	} else if (n < 32) {
1354 		u32 m = (1U << n) - 1;
1355 
1356 		if (unlikely(value > m)) {
1357 			hid_warn(hid,
1358 				 "%s() called with too large value %d (n: %d)! (%s)\n",
1359 				 __func__, value, n, current->comm);
1360 			WARN_ON(1);
1361 			value &= m;
1362 		}
1363 	}
1364 
1365 	__implement(report, offset, n, value);
1366 }
1367 
1368 /*
1369  * Search an array for a value.
1370  */
1371 
1372 static int search(__s32 *array, __s32 value, unsigned n)
1373 {
1374 	while (n--) {
1375 		if (*array++ == value)
1376 			return 0;
1377 	}
1378 	return -1;
1379 }
1380 
1381 /**
1382  * hid_match_report - check if driver's raw_event should be called
1383  *
1384  * @hid: hid device
1385  * @report_type: type to match against
1386  *
1387  * compare hid->driver->report_table->report_type to report->type
1388  */
1389 static int hid_match_report(struct hid_device *hid, struct hid_report *report)
1390 {
1391 	const struct hid_report_id *id = hid->driver->report_table;
1392 
1393 	if (!id) /* NULL means all */
1394 		return 1;
1395 
1396 	for (; id->report_type != HID_TERMINATOR; id++)
1397 		if (id->report_type == HID_ANY_ID ||
1398 				id->report_type == report->type)
1399 			return 1;
1400 	return 0;
1401 }
1402 
1403 /**
1404  * hid_match_usage - check if driver's event should be called
1405  *
1406  * @hid: hid device
1407  * @usage: usage to match against
1408  *
1409  * compare hid->driver->usage_table->usage_{type,code} to
1410  * usage->usage_{type,code}
1411  */
1412 static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage)
1413 {
1414 	const struct hid_usage_id *id = hid->driver->usage_table;
1415 
1416 	if (!id) /* NULL means all */
1417 		return 1;
1418 
1419 	for (; id->usage_type != HID_ANY_ID - 1; id++)
1420 		if ((id->usage_hid == HID_ANY_ID ||
1421 				id->usage_hid == usage->hid) &&
1422 				(id->usage_type == HID_ANY_ID ||
1423 				id->usage_type == usage->type) &&
1424 				(id->usage_code == HID_ANY_ID ||
1425 				 id->usage_code == usage->code))
1426 			return 1;
1427 	return 0;
1428 }
1429 
1430 static void hid_process_event(struct hid_device *hid, struct hid_field *field,
1431 		struct hid_usage *usage, __s32 value, int interrupt)
1432 {
1433 	struct hid_driver *hdrv = hid->driver;
1434 	int ret;
1435 
1436 	if (!list_empty(&hid->debug_list))
1437 		hid_dump_input(hid, usage, value);
1438 
1439 	if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
1440 		ret = hdrv->event(hid, field, usage, value);
1441 		if (ret != 0) {
1442 			if (ret < 0)
1443 				hid_err(hid, "%s's event failed with %d\n",
1444 						hdrv->name, ret);
1445 			return;
1446 		}
1447 	}
1448 
1449 	if (hid->claimed & HID_CLAIMED_INPUT)
1450 		hidinput_hid_event(hid, field, usage, value);
1451 	if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
1452 		hid->hiddev_hid_event(hid, field, usage, value);
1453 }
1454 
1455 /*
1456  * Analyse a received field, and fetch the data from it. The field
1457  * content is stored for next report processing (we do differential
1458  * reporting to the layer).
1459  */
1460 
1461 static void hid_input_field(struct hid_device *hid, struct hid_field *field,
1462 			    __u8 *data, int interrupt)
1463 {
1464 	unsigned n;
1465 	unsigned count = field->report_count;
1466 	unsigned offset = field->report_offset;
1467 	unsigned size = field->report_size;
1468 	__s32 min = field->logical_minimum;
1469 	__s32 max = field->logical_maximum;
1470 	__s32 *value;
1471 
1472 	value = kmalloc_array(count, sizeof(__s32), GFP_ATOMIC);
1473 	if (!value)
1474 		return;
1475 
1476 	for (n = 0; n < count; n++) {
1477 
1478 		value[n] = min < 0 ?
1479 			snto32(hid_field_extract(hid, data, offset + n * size,
1480 			       size), size) :
1481 			hid_field_extract(hid, data, offset + n * size, size);
1482 
1483 		/* Ignore report if ErrorRollOver */
1484 		if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
1485 		    value[n] >= min && value[n] <= max &&
1486 		    value[n] - min < field->maxusage &&
1487 		    field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1)
1488 			goto exit;
1489 	}
1490 
1491 	for (n = 0; n < count; n++) {
1492 
1493 		if (HID_MAIN_ITEM_VARIABLE & field->flags) {
1494 			hid_process_event(hid, field, &field->usage[n], value[n], interrupt);
1495 			continue;
1496 		}
1497 
1498 		if (field->value[n] >= min && field->value[n] <= max
1499 			&& field->value[n] - min < field->maxusage
1500 			&& field->usage[field->value[n] - min].hid
1501 			&& search(value, field->value[n], count))
1502 				hid_process_event(hid, field, &field->usage[field->value[n] - min], 0, interrupt);
1503 
1504 		if (value[n] >= min && value[n] <= max
1505 			&& value[n] - min < field->maxusage
1506 			&& field->usage[value[n] - min].hid
1507 			&& search(field->value, value[n], count))
1508 				hid_process_event(hid, field, &field->usage[value[n] - min], 1, interrupt);
1509 	}
1510 
1511 	memcpy(field->value, value, count * sizeof(__s32));
1512 exit:
1513 	kfree(value);
1514 }
1515 
1516 /*
1517  * Output the field into the report.
1518  */
1519 
1520 static void hid_output_field(const struct hid_device *hid,
1521 			     struct hid_field *field, __u8 *data)
1522 {
1523 	unsigned count = field->report_count;
1524 	unsigned offset = field->report_offset;
1525 	unsigned size = field->report_size;
1526 	unsigned n;
1527 
1528 	for (n = 0; n < count; n++) {
1529 		if (field->logical_minimum < 0)	/* signed values */
1530 			implement(hid, data, offset + n * size, size,
1531 				  s32ton(field->value[n], size));
1532 		else				/* unsigned values */
1533 			implement(hid, data, offset + n * size, size,
1534 				  field->value[n]);
1535 	}
1536 }
1537 
1538 /*
1539  * Create a report. 'data' has to be allocated using
1540  * hid_alloc_report_buf() so that it has proper size.
1541  */
1542 
1543 void hid_output_report(struct hid_report *report, __u8 *data)
1544 {
1545 	unsigned n;
1546 
1547 	if (report->id > 0)
1548 		*data++ = report->id;
1549 
1550 	memset(data, 0, ((report->size - 1) >> 3) + 1);
1551 	for (n = 0; n < report->maxfield; n++)
1552 		hid_output_field(report->device, report->field[n], data);
1553 }
1554 EXPORT_SYMBOL_GPL(hid_output_report);
1555 
1556 /*
1557  * Allocator for buffer that is going to be passed to hid_output_report()
1558  */
1559 u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
1560 {
1561 	/*
1562 	 * 7 extra bytes are necessary to achieve proper functionality
1563 	 * of implement() working on 8 byte chunks
1564 	 */
1565 
1566 	u32 len = hid_report_len(report) + 7;
1567 
1568 	return kmalloc(len, flags);
1569 }
1570 EXPORT_SYMBOL_GPL(hid_alloc_report_buf);
1571 
1572 /*
1573  * Set a field value. The report this field belongs to has to be
1574  * created and transferred to the device, to set this value in the
1575  * device.
1576  */
1577 
1578 int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
1579 {
1580 	unsigned size;
1581 
1582 	if (!field)
1583 		return -1;
1584 
1585 	size = field->report_size;
1586 
1587 	hid_dump_input(field->report->device, field->usage + offset, value);
1588 
1589 	if (offset >= field->report_count) {
1590 		hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n",
1591 				offset, field->report_count);
1592 		return -1;
1593 	}
1594 	if (field->logical_minimum < 0) {
1595 		if (value != snto32(s32ton(value, size), size)) {
1596 			hid_err(field->report->device, "value %d is out of range\n", value);
1597 			return -1;
1598 		}
1599 	}
1600 	field->value[offset] = value;
1601 	return 0;
1602 }
1603 EXPORT_SYMBOL_GPL(hid_set_field);
1604 
1605 static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
1606 		const u8 *data)
1607 {
1608 	struct hid_report *report;
1609 	unsigned int n = 0;	/* Normally report number is 0 */
1610 
1611 	/* Device uses numbered reports, data[0] is report number */
1612 	if (report_enum->numbered)
1613 		n = *data;
1614 
1615 	report = report_enum->report_id_hash[n];
1616 	if (report == NULL)
1617 		dbg_hid("undefined report_id %u received\n", n);
1618 
1619 	return report;
1620 }
1621 
1622 /*
1623  * Implement a generic .request() callback, using .raw_request()
1624  * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
1625  */
1626 void __hid_request(struct hid_device *hid, struct hid_report *report,
1627 		int reqtype)
1628 {
1629 	char *buf;
1630 	int ret;
1631 	u32 len;
1632 
1633 	buf = hid_alloc_report_buf(report, GFP_KERNEL);
1634 	if (!buf)
1635 		return;
1636 
1637 	len = hid_report_len(report);
1638 
1639 	if (reqtype == HID_REQ_SET_REPORT)
1640 		hid_output_report(report, buf);
1641 
1642 	ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
1643 					  report->type, reqtype);
1644 	if (ret < 0) {
1645 		dbg_hid("unable to complete request: %d\n", ret);
1646 		goto out;
1647 	}
1648 
1649 	if (reqtype == HID_REQ_GET_REPORT)
1650 		hid_input_report(hid, report->type, buf, ret, 0);
1651 
1652 out:
1653 	kfree(buf);
1654 }
1655 EXPORT_SYMBOL_GPL(__hid_request);
1656 
1657 int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, u32 size,
1658 		int interrupt)
1659 {
1660 	struct hid_report_enum *report_enum = hid->report_enum + type;
1661 	struct hid_report *report;
1662 	struct hid_driver *hdrv;
1663 	unsigned int a;
1664 	u32 rsize, csize = size;
1665 	u8 *cdata = data;
1666 	int ret = 0;
1667 
1668 	report = hid_get_report(report_enum, data);
1669 	if (!report)
1670 		goto out;
1671 
1672 	if (report_enum->numbered) {
1673 		cdata++;
1674 		csize--;
1675 	}
1676 
1677 	rsize = ((report->size - 1) >> 3) + 1;
1678 
1679 	if (rsize > HID_MAX_BUFFER_SIZE)
1680 		rsize = HID_MAX_BUFFER_SIZE;
1681 
1682 	if (csize < rsize) {
1683 		dbg_hid("report %d is too short, (%d < %d)\n", report->id,
1684 				csize, rsize);
1685 		memset(cdata + csize, 0, rsize - csize);
1686 	}
1687 
1688 	if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
1689 		hid->hiddev_report_event(hid, report);
1690 	if (hid->claimed & HID_CLAIMED_HIDRAW) {
1691 		ret = hidraw_report_event(hid, data, size);
1692 		if (ret)
1693 			goto out;
1694 	}
1695 
1696 	if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
1697 		for (a = 0; a < report->maxfield; a++)
1698 			hid_input_field(hid, report->field[a], cdata, interrupt);
1699 		hdrv = hid->driver;
1700 		if (hdrv && hdrv->report)
1701 			hdrv->report(hid, report);
1702 	}
1703 
1704 	if (hid->claimed & HID_CLAIMED_INPUT)
1705 		hidinput_report_event(hid, report);
1706 out:
1707 	return ret;
1708 }
1709 EXPORT_SYMBOL_GPL(hid_report_raw_event);
1710 
1711 /**
1712  * hid_input_report - report data from lower layer (usb, bt...)
1713  *
1714  * @hid: hid device
1715  * @type: HID report type (HID_*_REPORT)
1716  * @data: report contents
1717  * @size: size of data parameter
1718  * @interrupt: distinguish between interrupt and control transfers
1719  *
1720  * This is data entry for lower layers.
1721  */
1722 int hid_input_report(struct hid_device *hid, int type, u8 *data, u32 size, int interrupt)
1723 {
1724 	struct hid_report_enum *report_enum;
1725 	struct hid_driver *hdrv;
1726 	struct hid_report *report;
1727 	int ret = 0;
1728 
1729 	if (!hid)
1730 		return -ENODEV;
1731 
1732 	if (down_trylock(&hid->driver_input_lock))
1733 		return -EBUSY;
1734 
1735 	if (!hid->driver) {
1736 		ret = -ENODEV;
1737 		goto unlock;
1738 	}
1739 	report_enum = hid->report_enum + type;
1740 	hdrv = hid->driver;
1741 
1742 	if (!size) {
1743 		dbg_hid("empty report\n");
1744 		ret = -1;
1745 		goto unlock;
1746 	}
1747 
1748 	/* Avoid unnecessary overhead if debugfs is disabled */
1749 	if (!list_empty(&hid->debug_list))
1750 		hid_dump_report(hid, type, data, size);
1751 
1752 	report = hid_get_report(report_enum, data);
1753 
1754 	if (!report) {
1755 		ret = -1;
1756 		goto unlock;
1757 	}
1758 
1759 	if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
1760 		ret = hdrv->raw_event(hid, report, data, size);
1761 		if (ret < 0)
1762 			goto unlock;
1763 	}
1764 
1765 	ret = hid_report_raw_event(hid, type, data, size, interrupt);
1766 
1767 unlock:
1768 	up(&hid->driver_input_lock);
1769 	return ret;
1770 }
1771 EXPORT_SYMBOL_GPL(hid_input_report);
1772 
1773 bool hid_match_one_id(const struct hid_device *hdev,
1774 		      const struct hid_device_id *id)
1775 {
1776 	return (id->bus == HID_BUS_ANY || id->bus == hdev->bus) &&
1777 		(id->group == HID_GROUP_ANY || id->group == hdev->group) &&
1778 		(id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&
1779 		(id->product == HID_ANY_ID || id->product == hdev->product);
1780 }
1781 
1782 const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
1783 		const struct hid_device_id *id)
1784 {
1785 	for (; id->bus; id++)
1786 		if (hid_match_one_id(hdev, id))
1787 			return id;
1788 
1789 	return NULL;
1790 }
1791 
1792 static const struct hid_device_id hid_hiddev_list[] = {
1793 	{ HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS) },
1794 	{ HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS1) },
1795 	{ }
1796 };
1797 
1798 static bool hid_hiddev(struct hid_device *hdev)
1799 {
1800 	return !!hid_match_id(hdev, hid_hiddev_list);
1801 }
1802 
1803 
1804 static ssize_t
1805 read_report_descriptor(struct file *filp, struct kobject *kobj,
1806 		struct bin_attribute *attr,
1807 		char *buf, loff_t off, size_t count)
1808 {
1809 	struct device *dev = kobj_to_dev(kobj);
1810 	struct hid_device *hdev = to_hid_device(dev);
1811 
1812 	if (off >= hdev->rsize)
1813 		return 0;
1814 
1815 	if (off + count > hdev->rsize)
1816 		count = hdev->rsize - off;
1817 
1818 	memcpy(buf, hdev->rdesc + off, count);
1819 
1820 	return count;
1821 }
1822 
1823 static ssize_t
1824 show_country(struct device *dev, struct device_attribute *attr,
1825 		char *buf)
1826 {
1827 	struct hid_device *hdev = to_hid_device(dev);
1828 
1829 	return sprintf(buf, "%02x\n", hdev->country & 0xff);
1830 }
1831 
1832 static struct bin_attribute dev_bin_attr_report_desc = {
1833 	.attr = { .name = "report_descriptor", .mode = 0444 },
1834 	.read = read_report_descriptor,
1835 	.size = HID_MAX_DESCRIPTOR_SIZE,
1836 };
1837 
1838 static const struct device_attribute dev_attr_country = {
1839 	.attr = { .name = "country", .mode = 0444 },
1840 	.show = show_country,
1841 };
1842 
1843 int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
1844 {
1845 	static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
1846 		"Joystick", "Gamepad", "Keyboard", "Keypad",
1847 		"Multi-Axis Controller"
1848 	};
1849 	const char *type, *bus;
1850 	char buf[64] = "";
1851 	unsigned int i;
1852 	int len;
1853 	int ret;
1854 
1855 	if (hdev->quirks & HID_QUIRK_HIDDEV_FORCE)
1856 		connect_mask |= (HID_CONNECT_HIDDEV_FORCE | HID_CONNECT_HIDDEV);
1857 	if (hdev->quirks & HID_QUIRK_HIDINPUT_FORCE)
1858 		connect_mask |= HID_CONNECT_HIDINPUT_FORCE;
1859 	if (hdev->bus != BUS_USB)
1860 		connect_mask &= ~HID_CONNECT_HIDDEV;
1861 	if (hid_hiddev(hdev))
1862 		connect_mask |= HID_CONNECT_HIDDEV_FORCE;
1863 
1864 	if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,
1865 				connect_mask & HID_CONNECT_HIDINPUT_FORCE))
1866 		hdev->claimed |= HID_CLAIMED_INPUT;
1867 
1868 	if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect &&
1869 			!hdev->hiddev_connect(hdev,
1870 				connect_mask & HID_CONNECT_HIDDEV_FORCE))
1871 		hdev->claimed |= HID_CLAIMED_HIDDEV;
1872 	if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))
1873 		hdev->claimed |= HID_CLAIMED_HIDRAW;
1874 
1875 	if (connect_mask & HID_CONNECT_DRIVER)
1876 		hdev->claimed |= HID_CLAIMED_DRIVER;
1877 
1878 	/* Drivers with the ->raw_event callback set are not required to connect
1879 	 * to any other listener. */
1880 	if (!hdev->claimed && !hdev->driver->raw_event) {
1881 		hid_err(hdev, "device has no listeners, quitting\n");
1882 		return -ENODEV;
1883 	}
1884 
1885 	if ((hdev->claimed & HID_CLAIMED_INPUT) &&
1886 			(connect_mask & HID_CONNECT_FF) && hdev->ff_init)
1887 		hdev->ff_init(hdev);
1888 
1889 	len = 0;
1890 	if (hdev->claimed & HID_CLAIMED_INPUT)
1891 		len += sprintf(buf + len, "input");
1892 	if (hdev->claimed & HID_CLAIMED_HIDDEV)
1893 		len += sprintf(buf + len, "%shiddev%d", len ? "," : "",
1894 				((struct hiddev *)hdev->hiddev)->minor);
1895 	if (hdev->claimed & HID_CLAIMED_HIDRAW)
1896 		len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
1897 				((struct hidraw *)hdev->hidraw)->minor);
1898 
1899 	type = "Device";
1900 	for (i = 0; i < hdev->maxcollection; i++) {
1901 		struct hid_collection *col = &hdev->collection[i];
1902 		if (col->type == HID_COLLECTION_APPLICATION &&
1903 		   (col->usage & HID_USAGE_PAGE) == HID_UP_GENDESK &&
1904 		   (col->usage & 0xffff) < ARRAY_SIZE(types)) {
1905 			type = types[col->usage & 0xffff];
1906 			break;
1907 		}
1908 	}
1909 
1910 	switch (hdev->bus) {
1911 	case BUS_USB:
1912 		bus = "USB";
1913 		break;
1914 	case BUS_BLUETOOTH:
1915 		bus = "BLUETOOTH";
1916 		break;
1917 	case BUS_I2C:
1918 		bus = "I2C";
1919 		break;
1920 	default:
1921 		bus = "<UNKNOWN>";
1922 	}
1923 
1924 	ret = device_create_file(&hdev->dev, &dev_attr_country);
1925 	if (ret)
1926 		hid_warn(hdev,
1927 			 "can't create sysfs country code attribute err: %d\n", ret);
1928 
1929 	hid_info(hdev, "%s: %s HID v%x.%02x %s [%s] on %s\n",
1930 		 buf, bus, hdev->version >> 8, hdev->version & 0xff,
1931 		 type, hdev->name, hdev->phys);
1932 
1933 	return 0;
1934 }
1935 EXPORT_SYMBOL_GPL(hid_connect);
1936 
1937 void hid_disconnect(struct hid_device *hdev)
1938 {
1939 	device_remove_file(&hdev->dev, &dev_attr_country);
1940 	if (hdev->claimed & HID_CLAIMED_INPUT)
1941 		hidinput_disconnect(hdev);
1942 	if (hdev->claimed & HID_CLAIMED_HIDDEV)
1943 		hdev->hiddev_disconnect(hdev);
1944 	if (hdev->claimed & HID_CLAIMED_HIDRAW)
1945 		hidraw_disconnect(hdev);
1946 	hdev->claimed = 0;
1947 }
1948 EXPORT_SYMBOL_GPL(hid_disconnect);
1949 
1950 /**
1951  * hid_hw_start - start underlying HW
1952  * @hdev: hid device
1953  * @connect_mask: which outputs to connect, see HID_CONNECT_*
1954  *
1955  * Call this in probe function *after* hid_parse. This will setup HW
1956  * buffers and start the device (if not defeirred to device open).
1957  * hid_hw_stop must be called if this was successful.
1958  */
1959 int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask)
1960 {
1961 	int error;
1962 
1963 	error = hdev->ll_driver->start(hdev);
1964 	if (error)
1965 		return error;
1966 
1967 	if (connect_mask) {
1968 		error = hid_connect(hdev, connect_mask);
1969 		if (error) {
1970 			hdev->ll_driver->stop(hdev);
1971 			return error;
1972 		}
1973 	}
1974 
1975 	return 0;
1976 }
1977 EXPORT_SYMBOL_GPL(hid_hw_start);
1978 
1979 /**
1980  * hid_hw_stop - stop underlying HW
1981  * @hdev: hid device
1982  *
1983  * This is usually called from remove function or from probe when something
1984  * failed and hid_hw_start was called already.
1985  */
1986 void hid_hw_stop(struct hid_device *hdev)
1987 {
1988 	hid_disconnect(hdev);
1989 	hdev->ll_driver->stop(hdev);
1990 }
1991 EXPORT_SYMBOL_GPL(hid_hw_stop);
1992 
1993 /**
1994  * hid_hw_open - signal underlying HW to start delivering events
1995  * @hdev: hid device
1996  *
1997  * Tell underlying HW to start delivering events from the device.
1998  * This function should be called sometime after successful call
1999  * to hid_hw_start().
2000  */
2001 int hid_hw_open(struct hid_device *hdev)
2002 {
2003 	int ret;
2004 
2005 	ret = mutex_lock_killable(&hdev->ll_open_lock);
2006 	if (ret)
2007 		return ret;
2008 
2009 	if (!hdev->ll_open_count++) {
2010 		ret = hdev->ll_driver->open(hdev);
2011 		if (ret)
2012 			hdev->ll_open_count--;
2013 	}
2014 
2015 	mutex_unlock(&hdev->ll_open_lock);
2016 	return ret;
2017 }
2018 EXPORT_SYMBOL_GPL(hid_hw_open);
2019 
2020 /**
2021  * hid_hw_close - signal underlaying HW to stop delivering events
2022  *
2023  * @hdev: hid device
2024  *
2025  * This function indicates that we are not interested in the events
2026  * from this device anymore. Delivery of events may or may not stop,
2027  * depending on the number of users still outstanding.
2028  */
2029 void hid_hw_close(struct hid_device *hdev)
2030 {
2031 	mutex_lock(&hdev->ll_open_lock);
2032 	if (!--hdev->ll_open_count)
2033 		hdev->ll_driver->close(hdev);
2034 	mutex_unlock(&hdev->ll_open_lock);
2035 }
2036 EXPORT_SYMBOL_GPL(hid_hw_close);
2037 
2038 struct hid_dynid {
2039 	struct list_head list;
2040 	struct hid_device_id id;
2041 };
2042 
2043 /**
2044  * store_new_id - add a new HID device ID to this driver and re-probe devices
2045  * @driver: target device driver
2046  * @buf: buffer for scanning device ID data
2047  * @count: input size
2048  *
2049  * Adds a new dynamic hid device ID to this driver,
2050  * and causes the driver to probe for all devices again.
2051  */
2052 static ssize_t new_id_store(struct device_driver *drv, const char *buf,
2053 		size_t count)
2054 {
2055 	struct hid_driver *hdrv = to_hid_driver(drv);
2056 	struct hid_dynid *dynid;
2057 	__u32 bus, vendor, product;
2058 	unsigned long driver_data = 0;
2059 	int ret;
2060 
2061 	ret = sscanf(buf, "%x %x %x %lx",
2062 			&bus, &vendor, &product, &driver_data);
2063 	if (ret < 3)
2064 		return -EINVAL;
2065 
2066 	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
2067 	if (!dynid)
2068 		return -ENOMEM;
2069 
2070 	dynid->id.bus = bus;
2071 	dynid->id.group = HID_GROUP_ANY;
2072 	dynid->id.vendor = vendor;
2073 	dynid->id.product = product;
2074 	dynid->id.driver_data = driver_data;
2075 
2076 	spin_lock(&hdrv->dyn_lock);
2077 	list_add_tail(&dynid->list, &hdrv->dyn_list);
2078 	spin_unlock(&hdrv->dyn_lock);
2079 
2080 	ret = driver_attach(&hdrv->driver);
2081 
2082 	return ret ? : count;
2083 }
2084 static DRIVER_ATTR_WO(new_id);
2085 
2086 static struct attribute *hid_drv_attrs[] = {
2087 	&driver_attr_new_id.attr,
2088 	NULL,
2089 };
2090 ATTRIBUTE_GROUPS(hid_drv);
2091 
2092 static void hid_free_dynids(struct hid_driver *hdrv)
2093 {
2094 	struct hid_dynid *dynid, *n;
2095 
2096 	spin_lock(&hdrv->dyn_lock);
2097 	list_for_each_entry_safe(dynid, n, &hdrv->dyn_list, list) {
2098 		list_del(&dynid->list);
2099 		kfree(dynid);
2100 	}
2101 	spin_unlock(&hdrv->dyn_lock);
2102 }
2103 
2104 const struct hid_device_id *hid_match_device(struct hid_device *hdev,
2105 					     struct hid_driver *hdrv)
2106 {
2107 	struct hid_dynid *dynid;
2108 
2109 	spin_lock(&hdrv->dyn_lock);
2110 	list_for_each_entry(dynid, &hdrv->dyn_list, list) {
2111 		if (hid_match_one_id(hdev, &dynid->id)) {
2112 			spin_unlock(&hdrv->dyn_lock);
2113 			return &dynid->id;
2114 		}
2115 	}
2116 	spin_unlock(&hdrv->dyn_lock);
2117 
2118 	return hid_match_id(hdev, hdrv->id_table);
2119 }
2120 EXPORT_SYMBOL_GPL(hid_match_device);
2121 
2122 static int hid_bus_match(struct device *dev, struct device_driver *drv)
2123 {
2124 	struct hid_driver *hdrv = to_hid_driver(drv);
2125 	struct hid_device *hdev = to_hid_device(dev);
2126 
2127 	return hid_match_device(hdev, hdrv) != NULL;
2128 }
2129 
2130 /**
2131  * hid_compare_device_paths - check if both devices share the same path
2132  * @hdev_a: hid device
2133  * @hdev_b: hid device
2134  * @separator: char to use as separator
2135  *
2136  * Check if two devices share the same path up to the last occurrence of
2137  * the separator char. Both paths must exist (i.e., zero-length paths
2138  * don't match).
2139  */
2140 bool hid_compare_device_paths(struct hid_device *hdev_a,
2141 			      struct hid_device *hdev_b, char separator)
2142 {
2143 	int n1 = strrchr(hdev_a->phys, separator) - hdev_a->phys;
2144 	int n2 = strrchr(hdev_b->phys, separator) - hdev_b->phys;
2145 
2146 	if (n1 != n2 || n1 <= 0 || n2 <= 0)
2147 		return false;
2148 
2149 	return !strncmp(hdev_a->phys, hdev_b->phys, n1);
2150 }
2151 EXPORT_SYMBOL_GPL(hid_compare_device_paths);
2152 
2153 static int hid_device_probe(struct device *dev)
2154 {
2155 	struct hid_driver *hdrv = to_hid_driver(dev->driver);
2156 	struct hid_device *hdev = to_hid_device(dev);
2157 	const struct hid_device_id *id;
2158 	int ret = 0;
2159 
2160 	if (down_interruptible(&hdev->driver_input_lock)) {
2161 		ret = -EINTR;
2162 		goto end;
2163 	}
2164 	hdev->io_started = false;
2165 
2166 	clear_bit(ffs(HID_STAT_REPROBED), &hdev->status);
2167 
2168 	if (!hdev->driver) {
2169 		id = hid_match_device(hdev, hdrv);
2170 		if (id == NULL) {
2171 			ret = -ENODEV;
2172 			goto unlock;
2173 		}
2174 
2175 		if (hdrv->match) {
2176 			if (!hdrv->match(hdev, hid_ignore_special_drivers)) {
2177 				ret = -ENODEV;
2178 				goto unlock;
2179 			}
2180 		} else {
2181 			/*
2182 			 * hid-generic implements .match(), so if
2183 			 * hid_ignore_special_drivers is set, we can safely
2184 			 * return.
2185 			 */
2186 			if (hid_ignore_special_drivers) {
2187 				ret = -ENODEV;
2188 				goto unlock;
2189 			}
2190 		}
2191 
2192 		/* reset the quirks that has been previously set */
2193 		hdev->quirks = hid_lookup_quirk(hdev);
2194 		hdev->driver = hdrv;
2195 		if (hdrv->probe) {
2196 			ret = hdrv->probe(hdev, id);
2197 		} else { /* default probe */
2198 			ret = hid_open_report(hdev);
2199 			if (!ret)
2200 				ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
2201 		}
2202 		if (ret) {
2203 			hid_close_report(hdev);
2204 			hdev->driver = NULL;
2205 		}
2206 	}
2207 unlock:
2208 	if (!hdev->io_started)
2209 		up(&hdev->driver_input_lock);
2210 end:
2211 	return ret;
2212 }
2213 
2214 static int hid_device_remove(struct device *dev)
2215 {
2216 	struct hid_device *hdev = to_hid_device(dev);
2217 	struct hid_driver *hdrv;
2218 	int ret = 0;
2219 
2220 	if (down_interruptible(&hdev->driver_input_lock)) {
2221 		ret = -EINTR;
2222 		goto end;
2223 	}
2224 	hdev->io_started = false;
2225 
2226 	hdrv = hdev->driver;
2227 	if (hdrv) {
2228 		if (hdrv->remove)
2229 			hdrv->remove(hdev);
2230 		else /* default remove */
2231 			hid_hw_stop(hdev);
2232 		hid_close_report(hdev);
2233 		hdev->driver = NULL;
2234 	}
2235 
2236 	if (!hdev->io_started)
2237 		up(&hdev->driver_input_lock);
2238 end:
2239 	return ret;
2240 }
2241 
2242 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
2243 			     char *buf)
2244 {
2245 	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
2246 
2247 	return scnprintf(buf, PAGE_SIZE, "hid:b%04Xg%04Xv%08Xp%08X\n",
2248 			 hdev->bus, hdev->group, hdev->vendor, hdev->product);
2249 }
2250 static DEVICE_ATTR_RO(modalias);
2251 
2252 static struct attribute *hid_dev_attrs[] = {
2253 	&dev_attr_modalias.attr,
2254 	NULL,
2255 };
2256 static struct bin_attribute *hid_dev_bin_attrs[] = {
2257 	&dev_bin_attr_report_desc,
2258 	NULL
2259 };
2260 static const struct attribute_group hid_dev_group = {
2261 	.attrs = hid_dev_attrs,
2262 	.bin_attrs = hid_dev_bin_attrs,
2263 };
2264 __ATTRIBUTE_GROUPS(hid_dev);
2265 
2266 static int hid_uevent(struct device *dev, struct kobj_uevent_env *env)
2267 {
2268 	struct hid_device *hdev = to_hid_device(dev);
2269 
2270 	if (add_uevent_var(env, "HID_ID=%04X:%08X:%08X",
2271 			hdev->bus, hdev->vendor, hdev->product))
2272 		return -ENOMEM;
2273 
2274 	if (add_uevent_var(env, "HID_NAME=%s", hdev->name))
2275 		return -ENOMEM;
2276 
2277 	if (add_uevent_var(env, "HID_PHYS=%s", hdev->phys))
2278 		return -ENOMEM;
2279 
2280 	if (add_uevent_var(env, "HID_UNIQ=%s", hdev->uniq))
2281 		return -ENOMEM;
2282 
2283 	if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",
2284 			   hdev->bus, hdev->group, hdev->vendor, hdev->product))
2285 		return -ENOMEM;
2286 
2287 	return 0;
2288 }
2289 
2290 struct bus_type hid_bus_type = {
2291 	.name		= "hid",
2292 	.dev_groups	= hid_dev_groups,
2293 	.drv_groups	= hid_drv_groups,
2294 	.match		= hid_bus_match,
2295 	.probe		= hid_device_probe,
2296 	.remove		= hid_device_remove,
2297 	.uevent		= hid_uevent,
2298 };
2299 EXPORT_SYMBOL(hid_bus_type);
2300 
2301 int hid_add_device(struct hid_device *hdev)
2302 {
2303 	static atomic_t id = ATOMIC_INIT(0);
2304 	int ret;
2305 
2306 	if (WARN_ON(hdev->status & HID_STAT_ADDED))
2307 		return -EBUSY;
2308 
2309 	hdev->quirks = hid_lookup_quirk(hdev);
2310 
2311 	/* we need to kill them here, otherwise they will stay allocated to
2312 	 * wait for coming driver */
2313 	if (hid_ignore(hdev))
2314 		return -ENODEV;
2315 
2316 	/*
2317 	 * Check for the mandatory transport channel.
2318 	 */
2319 	 if (!hdev->ll_driver->raw_request) {
2320 		hid_err(hdev, "transport driver missing .raw_request()\n");
2321 		return -EINVAL;
2322 	 }
2323 
2324 	/*
2325 	 * Read the device report descriptor once and use as template
2326 	 * for the driver-specific modifications.
2327 	 */
2328 	ret = hdev->ll_driver->parse(hdev);
2329 	if (ret)
2330 		return ret;
2331 	if (!hdev->dev_rdesc)
2332 		return -ENODEV;
2333 
2334 	/*
2335 	 * Scan generic devices for group information
2336 	 */
2337 	if (hid_ignore_special_drivers) {
2338 		hdev->group = HID_GROUP_GENERIC;
2339 	} else if (!hdev->group &&
2340 		   !(hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)) {
2341 		ret = hid_scan_report(hdev);
2342 		if (ret)
2343 			hid_warn(hdev, "bad device descriptor (%d)\n", ret);
2344 	}
2345 
2346 	/* XXX hack, any other cleaner solution after the driver core
2347 	 * is converted to allow more than 20 bytes as the device name? */
2348 	dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
2349 		     hdev->vendor, hdev->product, atomic_inc_return(&id));
2350 
2351 	hid_debug_register(hdev, dev_name(&hdev->dev));
2352 	ret = device_add(&hdev->dev);
2353 	if (!ret)
2354 		hdev->status |= HID_STAT_ADDED;
2355 	else
2356 		hid_debug_unregister(hdev);
2357 
2358 	return ret;
2359 }
2360 EXPORT_SYMBOL_GPL(hid_add_device);
2361 
2362 /**
2363  * hid_allocate_device - allocate new hid device descriptor
2364  *
2365  * Allocate and initialize hid device, so that hid_destroy_device might be
2366  * used to free it.
2367  *
2368  * New hid_device pointer is returned on success, otherwise ERR_PTR encoded
2369  * error value.
2370  */
2371 struct hid_device *hid_allocate_device(void)
2372 {
2373 	struct hid_device *hdev;
2374 	int ret = -ENOMEM;
2375 
2376 	hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
2377 	if (hdev == NULL)
2378 		return ERR_PTR(ret);
2379 
2380 	device_initialize(&hdev->dev);
2381 	hdev->dev.release = hid_device_release;
2382 	hdev->dev.bus = &hid_bus_type;
2383 	device_enable_async_suspend(&hdev->dev);
2384 
2385 	hid_close_report(hdev);
2386 
2387 	init_waitqueue_head(&hdev->debug_wait);
2388 	INIT_LIST_HEAD(&hdev->debug_list);
2389 	spin_lock_init(&hdev->debug_list_lock);
2390 	sema_init(&hdev->driver_input_lock, 1);
2391 	mutex_init(&hdev->ll_open_lock);
2392 
2393 	return hdev;
2394 }
2395 EXPORT_SYMBOL_GPL(hid_allocate_device);
2396 
2397 static void hid_remove_device(struct hid_device *hdev)
2398 {
2399 	if (hdev->status & HID_STAT_ADDED) {
2400 		device_del(&hdev->dev);
2401 		hid_debug_unregister(hdev);
2402 		hdev->status &= ~HID_STAT_ADDED;
2403 	}
2404 	kfree(hdev->dev_rdesc);
2405 	hdev->dev_rdesc = NULL;
2406 	hdev->dev_rsize = 0;
2407 }
2408 
2409 /**
2410  * hid_destroy_device - free previously allocated device
2411  *
2412  * @hdev: hid device
2413  *
2414  * If you allocate hid_device through hid_allocate_device, you should ever
2415  * free by this function.
2416  */
2417 void hid_destroy_device(struct hid_device *hdev)
2418 {
2419 	hid_remove_device(hdev);
2420 	put_device(&hdev->dev);
2421 }
2422 EXPORT_SYMBOL_GPL(hid_destroy_device);
2423 
2424 
2425 static int __hid_bus_reprobe_drivers(struct device *dev, void *data)
2426 {
2427 	struct hid_driver *hdrv = data;
2428 	struct hid_device *hdev = to_hid_device(dev);
2429 
2430 	if (hdev->driver == hdrv &&
2431 	    !hdrv->match(hdev, hid_ignore_special_drivers) &&
2432 	    !test_and_set_bit(ffs(HID_STAT_REPROBED), &hdev->status))
2433 		return device_reprobe(dev);
2434 
2435 	return 0;
2436 }
2437 
2438 static int __hid_bus_driver_added(struct device_driver *drv, void *data)
2439 {
2440 	struct hid_driver *hdrv = to_hid_driver(drv);
2441 
2442 	if (hdrv->match) {
2443 		bus_for_each_dev(&hid_bus_type, NULL, hdrv,
2444 				 __hid_bus_reprobe_drivers);
2445 	}
2446 
2447 	return 0;
2448 }
2449 
2450 static int __bus_removed_driver(struct device_driver *drv, void *data)
2451 {
2452 	return bus_rescan_devices(&hid_bus_type);
2453 }
2454 
2455 int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
2456 		const char *mod_name)
2457 {
2458 	int ret;
2459 
2460 	hdrv->driver.name = hdrv->name;
2461 	hdrv->driver.bus = &hid_bus_type;
2462 	hdrv->driver.owner = owner;
2463 	hdrv->driver.mod_name = mod_name;
2464 
2465 	INIT_LIST_HEAD(&hdrv->dyn_list);
2466 	spin_lock_init(&hdrv->dyn_lock);
2467 
2468 	ret = driver_register(&hdrv->driver);
2469 
2470 	if (ret == 0)
2471 		bus_for_each_drv(&hid_bus_type, NULL, NULL,
2472 				 __hid_bus_driver_added);
2473 
2474 	return ret;
2475 }
2476 EXPORT_SYMBOL_GPL(__hid_register_driver);
2477 
2478 void hid_unregister_driver(struct hid_driver *hdrv)
2479 {
2480 	driver_unregister(&hdrv->driver);
2481 	hid_free_dynids(hdrv);
2482 
2483 	bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver);
2484 }
2485 EXPORT_SYMBOL_GPL(hid_unregister_driver);
2486 
2487 int hid_check_keys_pressed(struct hid_device *hid)
2488 {
2489 	struct hid_input *hidinput;
2490 	int i;
2491 
2492 	if (!(hid->claimed & HID_CLAIMED_INPUT))
2493 		return 0;
2494 
2495 	list_for_each_entry(hidinput, &hid->inputs, list) {
2496 		for (i = 0; i < BITS_TO_LONGS(KEY_MAX); i++)
2497 			if (hidinput->input->key[i])
2498 				return 1;
2499 	}
2500 
2501 	return 0;
2502 }
2503 
2504 EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
2505 
2506 static int __init hid_init(void)
2507 {
2508 	int ret;
2509 
2510 	if (hid_debug)
2511 		pr_warn("hid_debug is now used solely for parser and driver debugging.\n"
2512 			"debugfs is now used for inspecting the device (report descriptor, reports)\n");
2513 
2514 	ret = bus_register(&hid_bus_type);
2515 	if (ret) {
2516 		pr_err("can't register hid bus\n");
2517 		goto err;
2518 	}
2519 
2520 	ret = hidraw_init();
2521 	if (ret)
2522 		goto err_bus;
2523 
2524 	hid_debug_init();
2525 
2526 	return 0;
2527 err_bus:
2528 	bus_unregister(&hid_bus_type);
2529 err:
2530 	return ret;
2531 }
2532 
2533 static void __exit hid_exit(void)
2534 {
2535 	hid_debug_exit();
2536 	hidraw_exit();
2537 	bus_unregister(&hid_bus_type);
2538 	hid_quirks_exit(HID_BUS_ANY);
2539 }
2540 
2541 module_init(hid_init);
2542 module_exit(hid_exit);
2543 
2544 MODULE_AUTHOR("Andreas Gal");
2545 MODULE_AUTHOR("Vojtech Pavlik");
2546 MODULE_AUTHOR("Jiri Kosina");
2547 MODULE_LICENSE("GPL");
2548