xref: /kernel/linux/linux-5.10/drivers/hid/hid-core.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  HID support for Linux
4 *
5 *  Copyright (c) 1999 Andreas Gal
6 *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
7 *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
8 *  Copyright (c) 2006-2012 Jiri Kosina
9 */
10
11/*
12 */
13
14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16#include <linux/module.h>
17#include <linux/slab.h>
18#include <linux/init.h>
19#include <linux/kernel.h>
20#include <linux/list.h>
21#include <linux/mm.h>
22#include <linux/spinlock.h>
23#include <asm/unaligned.h>
24#include <asm/byteorder.h>
25#include <linux/input.h>
26#include <linux/wait.h>
27#include <linux/vmalloc.h>
28#include <linux/sched.h>
29#include <linux/semaphore.h>
30
31#include <linux/hid.h>
32#include <linux/hiddev.h>
33#include <linux/hid-debug.h>
34#include <linux/hidraw.h>
35
36#include "hid-ids.h"
37
38/*
39 * Version Information
40 */
41
42#define DRIVER_DESC "HID core driver"
43
44int hid_debug = 0;
45module_param_named(debug, hid_debug, int, 0600);
46MODULE_PARM_DESC(debug, "toggle HID debugging messages");
47EXPORT_SYMBOL_GPL(hid_debug);
48
49static int hid_ignore_special_drivers = 0;
50module_param_named(ignore_special_drivers, hid_ignore_special_drivers, int, 0600);
51MODULE_PARM_DESC(ignore_special_drivers, "Ignore any special drivers and handle all devices by generic driver");
52
53/*
54 * Register a new report for a device.
55 */
56
57struct hid_report *hid_register_report(struct hid_device *device,
58				       unsigned int type, unsigned int id,
59				       unsigned int application)
60{
61	struct hid_report_enum *report_enum = device->report_enum + type;
62	struct hid_report *report;
63
64	if (id >= HID_MAX_IDS)
65		return NULL;
66	if (report_enum->report_id_hash[id])
67		return report_enum->report_id_hash[id];
68
69	report = kzalloc(sizeof(struct hid_report), GFP_KERNEL);
70	if (!report)
71		return NULL;
72
73	if (id != 0)
74		report_enum->numbered = 1;
75
76	report->id = id;
77	report->type = type;
78	report->size = 0;
79	report->device = device;
80	report->application = application;
81	report_enum->report_id_hash[id] = report;
82
83	list_add_tail(&report->list, &report_enum->report_list);
84
85	return report;
86}
87EXPORT_SYMBOL_GPL(hid_register_report);
88
89/*
90 * Register a new field for this report.
91 */
92
93static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages)
94{
95	struct hid_field *field;
96
97	if (report->maxfield == HID_MAX_FIELDS) {
98		hid_err(report->device, "too many fields in report\n");
99		return NULL;
100	}
101
102	field = kzalloc((sizeof(struct hid_field) +
103			 usages * sizeof(struct hid_usage) +
104			 usages * sizeof(unsigned)), GFP_KERNEL);
105	if (!field)
106		return NULL;
107
108	field->index = report->maxfield++;
109	report->field[field->index] = field;
110	field->usage = (struct hid_usage *)(field + 1);
111	field->value = (s32 *)(field->usage + usages);
112	field->report = report;
113
114	return field;
115}
116
117/*
118 * Open a collection. The type/usage is pushed on the stack.
119 */
120
121static int open_collection(struct hid_parser *parser, unsigned type)
122{
123	struct hid_collection *collection;
124	unsigned usage;
125	int collection_index;
126
127	usage = parser->local.usage[0];
128
129	if (parser->collection_stack_ptr == parser->collection_stack_size) {
130		unsigned int *collection_stack;
131		unsigned int new_size = parser->collection_stack_size +
132					HID_COLLECTION_STACK_SIZE;
133
134		collection_stack = krealloc(parser->collection_stack,
135					    new_size * sizeof(unsigned int),
136					    GFP_KERNEL);
137		if (!collection_stack)
138			return -ENOMEM;
139
140		parser->collection_stack = collection_stack;
141		parser->collection_stack_size = new_size;
142	}
143
144	if (parser->device->maxcollection == parser->device->collection_size) {
145		collection = kmalloc(
146				array3_size(sizeof(struct hid_collection),
147					    parser->device->collection_size,
148					    2),
149				GFP_KERNEL);
150		if (collection == NULL) {
151			hid_err(parser->device, "failed to reallocate collection array\n");
152			return -ENOMEM;
153		}
154		memcpy(collection, parser->device->collection,
155			sizeof(struct hid_collection) *
156			parser->device->collection_size);
157		memset(collection + parser->device->collection_size, 0,
158			sizeof(struct hid_collection) *
159			parser->device->collection_size);
160		kfree(parser->device->collection);
161		parser->device->collection = collection;
162		parser->device->collection_size *= 2;
163	}
164
165	parser->collection_stack[parser->collection_stack_ptr++] =
166		parser->device->maxcollection;
167
168	collection_index = parser->device->maxcollection++;
169	collection = parser->device->collection + collection_index;
170	collection->type = type;
171	collection->usage = usage;
172	collection->level = parser->collection_stack_ptr - 1;
173	collection->parent_idx = (collection->level == 0) ? -1 :
174		parser->collection_stack[collection->level - 1];
175
176	if (type == HID_COLLECTION_APPLICATION)
177		parser->device->maxapplication++;
178
179	return 0;
180}
181
182/*
183 * Close a collection.
184 */
185
186static int close_collection(struct hid_parser *parser)
187{
188	if (!parser->collection_stack_ptr) {
189		hid_err(parser->device, "collection stack underflow\n");
190		return -EINVAL;
191	}
192	parser->collection_stack_ptr--;
193	return 0;
194}
195
196/*
197 * Climb up the stack, search for the specified collection type
198 * and return the usage.
199 */
200
201static unsigned hid_lookup_collection(struct hid_parser *parser, unsigned type)
202{
203	struct hid_collection *collection = parser->device->collection;
204	int n;
205
206	for (n = parser->collection_stack_ptr - 1; n >= 0; n--) {
207		unsigned index = parser->collection_stack[n];
208		if (collection[index].type == type)
209			return collection[index].usage;
210	}
211	return 0; /* we know nothing about this usage type */
212}
213
214/*
215 * Concatenate usage which defines 16 bits or less with the
216 * currently defined usage page to form a 32 bit usage
217 */
218
219static void complete_usage(struct hid_parser *parser, unsigned int index)
220{
221	parser->local.usage[index] &= 0xFFFF;
222	parser->local.usage[index] |=
223		(parser->global.usage_page & 0xFFFF) << 16;
224}
225
226/*
227 * Add a usage to the temporary parser table.
228 */
229
230static int hid_add_usage(struct hid_parser *parser, unsigned usage, u8 size)
231{
232	if (parser->local.usage_index >= HID_MAX_USAGES) {
233		hid_err(parser->device, "usage index exceeded\n");
234		return -1;
235	}
236	parser->local.usage[parser->local.usage_index] = usage;
237
238	/*
239	 * If Usage item only includes usage id, concatenate it with
240	 * currently defined usage page
241	 */
242	if (size <= 2)
243		complete_usage(parser, parser->local.usage_index);
244
245	parser->local.usage_size[parser->local.usage_index] = size;
246	parser->local.collection_index[parser->local.usage_index] =
247		parser->collection_stack_ptr ?
248		parser->collection_stack[parser->collection_stack_ptr - 1] : 0;
249	parser->local.usage_index++;
250	return 0;
251}
252
253/*
254 * Register a new field for this report.
255 */
256
257static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsigned flags)
258{
259	struct hid_report *report;
260	struct hid_field *field;
261	unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
262	unsigned int usages;
263	unsigned int offset;
264	unsigned int i;
265	unsigned int application;
266
267	application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
268
269	report = hid_register_report(parser->device, report_type,
270				     parser->global.report_id, application);
271	if (!report) {
272		hid_err(parser->device, "hid_register_report failed\n");
273		return -1;
274	}
275
276	/* Handle both signed and unsigned cases properly */
277	if ((parser->global.logical_minimum < 0 &&
278		parser->global.logical_maximum <
279		parser->global.logical_minimum) ||
280		(parser->global.logical_minimum >= 0 &&
281		(__u32)parser->global.logical_maximum <
282		(__u32)parser->global.logical_minimum)) {
283		dbg_hid("logical range invalid 0x%x 0x%x\n",
284			parser->global.logical_minimum,
285			parser->global.logical_maximum);
286		return -1;
287	}
288
289	offset = report->size;
290	report->size += parser->global.report_size * parser->global.report_count;
291
292	if (parser->device->ll_driver->max_buffer_size)
293		max_buffer_size = parser->device->ll_driver->max_buffer_size;
294
295	/* Total size check: Allow for possible report index byte */
296	if (report->size > (max_buffer_size - 1) << 3) {
297		hid_err(parser->device, "report is too long\n");
298		return -1;
299	}
300
301	if (!parser->local.usage_index) /* Ignore padding fields */
302		return 0;
303
304	usages = max_t(unsigned, parser->local.usage_index,
305				 parser->global.report_count);
306
307	field = hid_register_field(report, usages);
308	if (!field)
309		return 0;
310
311	field->physical = hid_lookup_collection(parser, HID_COLLECTION_PHYSICAL);
312	field->logical = hid_lookup_collection(parser, HID_COLLECTION_LOGICAL);
313	field->application = application;
314
315	for (i = 0; i < usages; i++) {
316		unsigned j = i;
317		/* Duplicate the last usage we parsed if we have excess values */
318		if (i >= parser->local.usage_index)
319			j = parser->local.usage_index - 1;
320		field->usage[i].hid = parser->local.usage[j];
321		field->usage[i].collection_index =
322			parser->local.collection_index[j];
323		field->usage[i].usage_index = i;
324		field->usage[i].resolution_multiplier = 1;
325	}
326
327	field->maxusage = usages;
328	field->flags = flags;
329	field->report_offset = offset;
330	field->report_type = report_type;
331	field->report_size = parser->global.report_size;
332	field->report_count = parser->global.report_count;
333	field->logical_minimum = parser->global.logical_minimum;
334	field->logical_maximum = parser->global.logical_maximum;
335	field->physical_minimum = parser->global.physical_minimum;
336	field->physical_maximum = parser->global.physical_maximum;
337	field->unit_exponent = parser->global.unit_exponent;
338	field->unit = parser->global.unit;
339
340	return 0;
341}
342
343/*
344 * Read data value from item.
345 */
346
347static u32 item_udata(struct hid_item *item)
348{
349	switch (item->size) {
350	case 1: return item->data.u8;
351	case 2: return item->data.u16;
352	case 4: return item->data.u32;
353	}
354	return 0;
355}
356
357static s32 item_sdata(struct hid_item *item)
358{
359	switch (item->size) {
360	case 1: return item->data.s8;
361	case 2: return item->data.s16;
362	case 4: return item->data.s32;
363	}
364	return 0;
365}
366
367/*
368 * Process a global item.
369 */
370
371static int hid_parser_global(struct hid_parser *parser, struct hid_item *item)
372{
373	__s32 raw_value;
374	switch (item->tag) {
375	case HID_GLOBAL_ITEM_TAG_PUSH:
376
377		if (parser->global_stack_ptr == HID_GLOBAL_STACK_SIZE) {
378			hid_err(parser->device, "global environment stack overflow\n");
379			return -1;
380		}
381
382		memcpy(parser->global_stack + parser->global_stack_ptr++,
383			&parser->global, sizeof(struct hid_global));
384		return 0;
385
386	case HID_GLOBAL_ITEM_TAG_POP:
387
388		if (!parser->global_stack_ptr) {
389			hid_err(parser->device, "global environment stack underflow\n");
390			return -1;
391		}
392
393		memcpy(&parser->global, parser->global_stack +
394			--parser->global_stack_ptr, sizeof(struct hid_global));
395		return 0;
396
397	case HID_GLOBAL_ITEM_TAG_USAGE_PAGE:
398		parser->global.usage_page = item_udata(item);
399		return 0;
400
401	case HID_GLOBAL_ITEM_TAG_LOGICAL_MINIMUM:
402		parser->global.logical_minimum = item_sdata(item);
403		return 0;
404
405	case HID_GLOBAL_ITEM_TAG_LOGICAL_MAXIMUM:
406		if (parser->global.logical_minimum < 0)
407			parser->global.logical_maximum = item_sdata(item);
408		else
409			parser->global.logical_maximum = item_udata(item);
410		return 0;
411
412	case HID_GLOBAL_ITEM_TAG_PHYSICAL_MINIMUM:
413		parser->global.physical_minimum = item_sdata(item);
414		return 0;
415
416	case HID_GLOBAL_ITEM_TAG_PHYSICAL_MAXIMUM:
417		if (parser->global.physical_minimum < 0)
418			parser->global.physical_maximum = item_sdata(item);
419		else
420			parser->global.physical_maximum = item_udata(item);
421		return 0;
422
423	case HID_GLOBAL_ITEM_TAG_UNIT_EXPONENT:
424		/* Many devices provide unit exponent as a two's complement
425		 * nibble due to the common misunderstanding of HID
426		 * specification 1.11, 6.2.2.7 Global Items. Attempt to handle
427		 * both this and the standard encoding. */
428		raw_value = item_sdata(item);
429		if (!(raw_value & 0xfffffff0))
430			parser->global.unit_exponent = hid_snto32(raw_value, 4);
431		else
432			parser->global.unit_exponent = raw_value;
433		return 0;
434
435	case HID_GLOBAL_ITEM_TAG_UNIT:
436		parser->global.unit = item_udata(item);
437		return 0;
438
439	case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
440		parser->global.report_size = item_udata(item);
441		if (parser->global.report_size > 256) {
442			hid_err(parser->device, "invalid report_size %d\n",
443					parser->global.report_size);
444			return -1;
445		}
446		return 0;
447
448	case HID_GLOBAL_ITEM_TAG_REPORT_COUNT:
449		parser->global.report_count = item_udata(item);
450		if (parser->global.report_count > HID_MAX_USAGES) {
451			hid_err(parser->device, "invalid report_count %d\n",
452					parser->global.report_count);
453			return -1;
454		}
455		return 0;
456
457	case HID_GLOBAL_ITEM_TAG_REPORT_ID:
458		parser->global.report_id = item_udata(item);
459		if (parser->global.report_id == 0 ||
460		    parser->global.report_id >= HID_MAX_IDS) {
461			hid_err(parser->device, "report_id %u is invalid\n",
462				parser->global.report_id);
463			return -1;
464		}
465		return 0;
466
467	default:
468		hid_err(parser->device, "unknown global tag 0x%x\n", item->tag);
469		return -1;
470	}
471}
472
473/*
474 * Process a local item.
475 */
476
477static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
478{
479	__u32 data;
480	unsigned n;
481	__u32 count;
482
483	data = item_udata(item);
484
485	switch (item->tag) {
486	case HID_LOCAL_ITEM_TAG_DELIMITER:
487
488		if (data) {
489			/*
490			 * We treat items before the first delimiter
491			 * as global to all usage sets (branch 0).
492			 * In the moment we process only these global
493			 * items and the first delimiter set.
494			 */
495			if (parser->local.delimiter_depth != 0) {
496				hid_err(parser->device, "nested delimiters\n");
497				return -1;
498			}
499			parser->local.delimiter_depth++;
500			parser->local.delimiter_branch++;
501		} else {
502			if (parser->local.delimiter_depth < 1) {
503				hid_err(parser->device, "bogus close delimiter\n");
504				return -1;
505			}
506			parser->local.delimiter_depth--;
507		}
508		return 0;
509
510	case HID_LOCAL_ITEM_TAG_USAGE:
511
512		if (parser->local.delimiter_branch > 1) {
513			dbg_hid("alternative usage ignored\n");
514			return 0;
515		}
516
517		return hid_add_usage(parser, data, item->size);
518
519	case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:
520
521		if (parser->local.delimiter_branch > 1) {
522			dbg_hid("alternative usage ignored\n");
523			return 0;
524		}
525
526		parser->local.usage_minimum = data;
527		return 0;
528
529	case HID_LOCAL_ITEM_TAG_USAGE_MAXIMUM:
530
531		if (parser->local.delimiter_branch > 1) {
532			dbg_hid("alternative usage ignored\n");
533			return 0;
534		}
535
536		count = data - parser->local.usage_minimum;
537		if (count + parser->local.usage_index >= HID_MAX_USAGES) {
538			/*
539			 * We do not warn if the name is not set, we are
540			 * actually pre-scanning the device.
541			 */
542			if (dev_name(&parser->device->dev))
543				hid_warn(parser->device,
544					 "ignoring exceeding usage max\n");
545			data = HID_MAX_USAGES - parser->local.usage_index +
546				parser->local.usage_minimum - 1;
547			if (data <= 0) {
548				hid_err(parser->device,
549					"no more usage index available\n");
550				return -1;
551			}
552		}
553
554		for (n = parser->local.usage_minimum; n <= data; n++)
555			if (hid_add_usage(parser, n, item->size)) {
556				dbg_hid("hid_add_usage failed\n");
557				return -1;
558			}
559		return 0;
560
561	default:
562
563		dbg_hid("unknown local item tag 0x%x\n", item->tag);
564		return 0;
565	}
566	return 0;
567}
568
569/*
570 * Concatenate Usage Pages into Usages where relevant:
571 * As per specification, 6.2.2.8: "When the parser encounters a main item it
572 * concatenates the last declared Usage Page with a Usage to form a complete
573 * usage value."
574 */
575
576static void hid_concatenate_last_usage_page(struct hid_parser *parser)
577{
578	int i;
579	unsigned int usage_page;
580	unsigned int current_page;
581
582	if (!parser->local.usage_index)
583		return;
584
585	usage_page = parser->global.usage_page;
586
587	/*
588	 * Concatenate usage page again only if last declared Usage Page
589	 * has not been already used in previous usages concatenation
590	 */
591	for (i = parser->local.usage_index - 1; i >= 0; i--) {
592		if (parser->local.usage_size[i] > 2)
593			/* Ignore extended usages */
594			continue;
595
596		current_page = parser->local.usage[i] >> 16;
597		if (current_page == usage_page)
598			break;
599
600		complete_usage(parser, i);
601	}
602}
603
604/*
605 * Process a main item.
606 */
607
608static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
609{
610	__u32 data;
611	int ret;
612
613	hid_concatenate_last_usage_page(parser);
614
615	data = item_udata(item);
616
617	switch (item->tag) {
618	case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
619		ret = open_collection(parser, data & 0xff);
620		break;
621	case HID_MAIN_ITEM_TAG_END_COLLECTION:
622		ret = close_collection(parser);
623		break;
624	case HID_MAIN_ITEM_TAG_INPUT:
625		ret = hid_add_field(parser, HID_INPUT_REPORT, data);
626		break;
627	case HID_MAIN_ITEM_TAG_OUTPUT:
628		ret = hid_add_field(parser, HID_OUTPUT_REPORT, data);
629		break;
630	case HID_MAIN_ITEM_TAG_FEATURE:
631		ret = hid_add_field(parser, HID_FEATURE_REPORT, data);
632		break;
633	default:
634		hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
635		ret = 0;
636	}
637
638	memset(&parser->local, 0, sizeof(parser->local));	/* Reset the local parser environment */
639
640	return ret;
641}
642
643/*
644 * Process a reserved item.
645 */
646
647static int hid_parser_reserved(struct hid_parser *parser, struct hid_item *item)
648{
649	dbg_hid("reserved item type, tag 0x%x\n", item->tag);
650	return 0;
651}
652
653/*
654 * Free a report and all registered fields. The field->usage and
655 * field->value table's are allocated behind the field, so we need
656 * only to free(field) itself.
657 */
658
659static void hid_free_report(struct hid_report *report)
660{
661	unsigned n;
662
663	for (n = 0; n < report->maxfield; n++)
664		kfree(report->field[n]);
665	kfree(report);
666}
667
668/*
669 * Close report. This function returns the device
670 * state to the point prior to hid_open_report().
671 */
672static void hid_close_report(struct hid_device *device)
673{
674	unsigned i, j;
675
676	for (i = 0; i < HID_REPORT_TYPES; i++) {
677		struct hid_report_enum *report_enum = device->report_enum + i;
678
679		for (j = 0; j < HID_MAX_IDS; j++) {
680			struct hid_report *report = report_enum->report_id_hash[j];
681			if (report)
682				hid_free_report(report);
683		}
684		memset(report_enum, 0, sizeof(*report_enum));
685		INIT_LIST_HEAD(&report_enum->report_list);
686	}
687
688	kfree(device->rdesc);
689	device->rdesc = NULL;
690	device->rsize = 0;
691
692	kfree(device->collection);
693	device->collection = NULL;
694	device->collection_size = 0;
695	device->maxcollection = 0;
696	device->maxapplication = 0;
697
698	device->status &= ~HID_STAT_PARSED;
699}
700
701/*
702 * Free a device structure, all reports, and all fields.
703 */
704
705void hiddev_free(struct kref *ref)
706{
707	struct hid_device *hid = container_of(ref, struct hid_device, ref);
708
709	hid_close_report(hid);
710	kfree(hid->dev_rdesc);
711	kfree(hid);
712}
713
714static void hid_device_release(struct device *dev)
715{
716	struct hid_device *hid = to_hid_device(dev);
717
718	kref_put(&hid->ref, hiddev_free);
719}
720
721/*
722 * Fetch a report description item from the data stream. We support long
723 * items, though they are not used yet.
724 */
725
726static u8 *fetch_item(__u8 *start, __u8 *end, struct hid_item *item)
727{
728	u8 b;
729
730	if ((end - start) <= 0)
731		return NULL;
732
733	b = *start++;
734
735	item->type = (b >> 2) & 3;
736	item->tag  = (b >> 4) & 15;
737
738	if (item->tag == HID_ITEM_TAG_LONG) {
739
740		item->format = HID_ITEM_FORMAT_LONG;
741
742		if ((end - start) < 2)
743			return NULL;
744
745		item->size = *start++;
746		item->tag  = *start++;
747
748		if ((end - start) < item->size)
749			return NULL;
750
751		item->data.longdata = start;
752		start += item->size;
753		return start;
754	}
755
756	item->format = HID_ITEM_FORMAT_SHORT;
757	item->size = b & 3;
758
759	switch (item->size) {
760	case 0:
761		return start;
762
763	case 1:
764		if ((end - start) < 1)
765			return NULL;
766		item->data.u8 = *start++;
767		return start;
768
769	case 2:
770		if ((end - start) < 2)
771			return NULL;
772		item->data.u16 = get_unaligned_le16(start);
773		start = (__u8 *)((__le16 *)start + 1);
774		return start;
775
776	case 3:
777		item->size++;
778		if ((end - start) < 4)
779			return NULL;
780		item->data.u32 = get_unaligned_le32(start);
781		start = (__u8 *)((__le32 *)start + 1);
782		return start;
783	}
784
785	return NULL;
786}
787
788static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)
789{
790	struct hid_device *hid = parser->device;
791
792	if (usage == HID_DG_CONTACTID)
793		hid->group = HID_GROUP_MULTITOUCH;
794}
795
796static void hid_scan_feature_usage(struct hid_parser *parser, u32 usage)
797{
798	if (usage == 0xff0000c5 && parser->global.report_count == 256 &&
799	    parser->global.report_size == 8)
800		parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
801
802	if (usage == 0xff0000c6 && parser->global.report_count == 1 &&
803	    parser->global.report_size == 8)
804		parser->scan_flags |= HID_SCAN_FLAG_MT_WIN_8;
805}
806
807static void hid_scan_collection(struct hid_parser *parser, unsigned type)
808{
809	struct hid_device *hid = parser->device;
810	int i;
811
812	if (((parser->global.usage_page << 16) == HID_UP_SENSOR) &&
813	    type == HID_COLLECTION_PHYSICAL)
814		hid->group = HID_GROUP_SENSOR_HUB;
815
816	if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
817	    hid->product == USB_DEVICE_ID_MS_POWER_COVER &&
818	    hid->group == HID_GROUP_MULTITOUCH)
819		hid->group = HID_GROUP_GENERIC;
820
821	if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
822		for (i = 0; i < parser->local.usage_index; i++)
823			if (parser->local.usage[i] == HID_GD_POINTER)
824				parser->scan_flags |= HID_SCAN_FLAG_GD_POINTER;
825
826	if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
827		parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
828
829	if ((parser->global.usage_page << 16) == HID_UP_GOOGLEVENDOR)
830		for (i = 0; i < parser->local.usage_index; i++)
831			if (parser->local.usage[i] ==
832					(HID_UP_GOOGLEVENDOR | 0x0001))
833				parser->device->group =
834					HID_GROUP_VIVALDI;
835}
836
837static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
838{
839	__u32 data;
840	int i;
841
842	hid_concatenate_last_usage_page(parser);
843
844	data = item_udata(item);
845
846	switch (item->tag) {
847	case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
848		hid_scan_collection(parser, data & 0xff);
849		break;
850	case HID_MAIN_ITEM_TAG_END_COLLECTION:
851		break;
852	case HID_MAIN_ITEM_TAG_INPUT:
853		/* ignore constant inputs, they will be ignored by hid-input */
854		if (data & HID_MAIN_ITEM_CONSTANT)
855			break;
856		for (i = 0; i < parser->local.usage_index; i++)
857			hid_scan_input_usage(parser, parser->local.usage[i]);
858		break;
859	case HID_MAIN_ITEM_TAG_OUTPUT:
860		break;
861	case HID_MAIN_ITEM_TAG_FEATURE:
862		for (i = 0; i < parser->local.usage_index; i++)
863			hid_scan_feature_usage(parser, parser->local.usage[i]);
864		break;
865	}
866
867	/* Reset the local parser environment */
868	memset(&parser->local, 0, sizeof(parser->local));
869
870	return 0;
871}
872
873/*
874 * Scan a report descriptor before the device is added to the bus.
875 * Sets device groups and other properties that determine what driver
876 * to load.
877 */
878static int hid_scan_report(struct hid_device *hid)
879{
880	struct hid_parser *parser;
881	struct hid_item item;
882	__u8 *start = hid->dev_rdesc;
883	__u8 *end = start + hid->dev_rsize;
884	static int (*dispatch_type[])(struct hid_parser *parser,
885				      struct hid_item *item) = {
886		hid_scan_main,
887		hid_parser_global,
888		hid_parser_local,
889		hid_parser_reserved
890	};
891
892	parser = vzalloc(sizeof(struct hid_parser));
893	if (!parser)
894		return -ENOMEM;
895
896	parser->device = hid;
897	hid->group = HID_GROUP_GENERIC;
898
899	/*
900	 * The parsing is simpler than the one in hid_open_report() as we should
901	 * be robust against hid errors. Those errors will be raised by
902	 * hid_open_report() anyway.
903	 */
904	while ((start = fetch_item(start, end, &item)) != NULL)
905		dispatch_type[item.type](parser, &item);
906
907	/*
908	 * Handle special flags set during scanning.
909	 */
910	if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
911	    (hid->group == HID_GROUP_MULTITOUCH))
912		hid->group = HID_GROUP_MULTITOUCH_WIN_8;
913
914	/*
915	 * Vendor specific handlings
916	 */
917	switch (hid->vendor) {
918	case USB_VENDOR_ID_WACOM:
919		hid->group = HID_GROUP_WACOM;
920		break;
921	case USB_VENDOR_ID_SYNAPTICS:
922		if (hid->group == HID_GROUP_GENERIC)
923			if ((parser->scan_flags & HID_SCAN_FLAG_VENDOR_SPECIFIC)
924			    && (parser->scan_flags & HID_SCAN_FLAG_GD_POINTER))
925				/*
926				 * hid-rmi should take care of them,
927				 * not hid-generic
928				 */
929				hid->group = HID_GROUP_RMI;
930		break;
931	}
932
933	kfree(parser->collection_stack);
934	vfree(parser);
935	return 0;
936}
937
938/**
939 * hid_parse_report - parse device report
940 *
941 * @hid: hid device
942 * @start: report start
943 * @size: report size
944 *
945 * Allocate the device report as read by the bus driver. This function should
946 * only be called from parse() in ll drivers.
947 */
948int hid_parse_report(struct hid_device *hid, __u8 *start, unsigned size)
949{
950	hid->dev_rdesc = kmemdup(start, size, GFP_KERNEL);
951	if (!hid->dev_rdesc)
952		return -ENOMEM;
953	hid->dev_rsize = size;
954	return 0;
955}
956EXPORT_SYMBOL_GPL(hid_parse_report);
957
958static const char * const hid_report_names[] = {
959	"HID_INPUT_REPORT",
960	"HID_OUTPUT_REPORT",
961	"HID_FEATURE_REPORT",
962};
963/**
964 * hid_validate_values - validate existing device report's value indexes
965 *
966 * @hid: hid device
967 * @type: which report type to examine
968 * @id: which report ID to examine (0 for first)
969 * @field_index: which report field to examine
970 * @report_counts: expected number of values
971 *
972 * Validate the number of values in a given field of a given report, after
973 * parsing.
974 */
975struct hid_report *hid_validate_values(struct hid_device *hid,
976				       unsigned int type, unsigned int id,
977				       unsigned int field_index,
978				       unsigned int report_counts)
979{
980	struct hid_report *report;
981
982	if (type > HID_FEATURE_REPORT) {
983		hid_err(hid, "invalid HID report type %u\n", type);
984		return NULL;
985	}
986
987	if (id >= HID_MAX_IDS) {
988		hid_err(hid, "invalid HID report id %u\n", id);
989		return NULL;
990	}
991
992	/*
993	 * Explicitly not using hid_get_report() here since it depends on
994	 * ->numbered being checked, which may not always be the case when
995	 * drivers go to access report values.
996	 */
997	if (id == 0) {
998		/*
999		 * Validating on id 0 means we should examine the first
1000		 * report in the list.
1001		 */
1002		report = list_first_entry_or_null(
1003				&hid->report_enum[type].report_list,
1004				struct hid_report, list);
1005	} else {
1006		report = hid->report_enum[type].report_id_hash[id];
1007	}
1008	if (!report) {
1009		hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
1010		return NULL;
1011	}
1012	if (report->maxfield <= field_index) {
1013		hid_err(hid, "not enough fields in %s %u\n",
1014			hid_report_names[type], id);
1015		return NULL;
1016	}
1017	if (report->field[field_index]->report_count < report_counts) {
1018		hid_err(hid, "not enough values in %s %u field %u\n",
1019			hid_report_names[type], id, field_index);
1020		return NULL;
1021	}
1022	return report;
1023}
1024EXPORT_SYMBOL_GPL(hid_validate_values);
1025
1026static int hid_calculate_multiplier(struct hid_device *hid,
1027				     struct hid_field *multiplier)
1028{
1029	int m;
1030	__s32 v = *multiplier->value;
1031	__s32 lmin = multiplier->logical_minimum;
1032	__s32 lmax = multiplier->logical_maximum;
1033	__s32 pmin = multiplier->physical_minimum;
1034	__s32 pmax = multiplier->physical_maximum;
1035
1036	/*
1037	 * "Because OS implementations will generally divide the control's
1038	 * reported count by the Effective Resolution Multiplier, designers
1039	 * should take care not to establish a potential Effective
1040	 * Resolution Multiplier of zero."
1041	 * HID Usage Table, v1.12, Section 4.3.1, p31
1042	 */
1043	if (lmax - lmin == 0)
1044		return 1;
1045	/*
1046	 * Handling the unit exponent is left as an exercise to whoever
1047	 * finds a device where that exponent is not 0.
1048	 */
1049	m = ((v - lmin)/(lmax - lmin) * (pmax - pmin) + pmin);
1050	if (unlikely(multiplier->unit_exponent != 0)) {
1051		hid_warn(hid,
1052			 "unsupported Resolution Multiplier unit exponent %d\n",
1053			 multiplier->unit_exponent);
1054	}
1055
1056	/* There are no devices with an effective multiplier > 255 */
1057	if (unlikely(m == 0 || m > 255 || m < -255)) {
1058		hid_warn(hid, "unsupported Resolution Multiplier %d\n", m);
1059		m = 1;
1060	}
1061
1062	return m;
1063}
1064
1065static void hid_apply_multiplier_to_field(struct hid_device *hid,
1066					  struct hid_field *field,
1067					  struct hid_collection *multiplier_collection,
1068					  int effective_multiplier)
1069{
1070	struct hid_collection *collection;
1071	struct hid_usage *usage;
1072	int i;
1073
1074	/*
1075	 * If multiplier_collection is NULL, the multiplier applies
1076	 * to all fields in the report.
1077	 * Otherwise, it is the Logical Collection the multiplier applies to
1078	 * but our field may be in a subcollection of that collection.
1079	 */
1080	for (i = 0; i < field->maxusage; i++) {
1081		usage = &field->usage[i];
1082
1083		collection = &hid->collection[usage->collection_index];
1084		while (collection->parent_idx != -1 &&
1085		       collection != multiplier_collection)
1086			collection = &hid->collection[collection->parent_idx];
1087
1088		if (collection->parent_idx != -1 ||
1089		    multiplier_collection == NULL)
1090			usage->resolution_multiplier = effective_multiplier;
1091
1092	}
1093}
1094
1095static void hid_apply_multiplier(struct hid_device *hid,
1096				 struct hid_field *multiplier)
1097{
1098	struct hid_report_enum *rep_enum;
1099	struct hid_report *rep;
1100	struct hid_field *field;
1101	struct hid_collection *multiplier_collection;
1102	int effective_multiplier;
1103	int i;
1104
1105	/*
1106	 * "The Resolution Multiplier control must be contained in the same
1107	 * Logical Collection as the control(s) to which it is to be applied.
1108	 * If no Resolution Multiplier is defined, then the Resolution
1109	 * Multiplier defaults to 1.  If more than one control exists in a
1110	 * Logical Collection, the Resolution Multiplier is associated with
1111	 * all controls in the collection. If no Logical Collection is
1112	 * defined, the Resolution Multiplier is associated with all
1113	 * controls in the report."
1114	 * HID Usage Table, v1.12, Section 4.3.1, p30
1115	 *
1116	 * Thus, search from the current collection upwards until we find a
1117	 * logical collection. Then search all fields for that same parent
1118	 * collection. Those are the fields the multiplier applies to.
1119	 *
1120	 * If we have more than one multiplier, it will overwrite the
1121	 * applicable fields later.
1122	 */
1123	multiplier_collection = &hid->collection[multiplier->usage->collection_index];
1124	while (multiplier_collection->parent_idx != -1 &&
1125	       multiplier_collection->type != HID_COLLECTION_LOGICAL)
1126		multiplier_collection = &hid->collection[multiplier_collection->parent_idx];
1127
1128	effective_multiplier = hid_calculate_multiplier(hid, multiplier);
1129
1130	rep_enum = &hid->report_enum[HID_INPUT_REPORT];
1131	list_for_each_entry(rep, &rep_enum->report_list, list) {
1132		for (i = 0; i < rep->maxfield; i++) {
1133			field = rep->field[i];
1134			hid_apply_multiplier_to_field(hid, field,
1135						      multiplier_collection,
1136						      effective_multiplier);
1137		}
1138	}
1139}
1140
1141/*
1142 * hid_setup_resolution_multiplier - set up all resolution multipliers
1143 *
1144 * @device: hid device
1145 *
1146 * Search for all Resolution Multiplier Feature Reports and apply their
1147 * value to all matching Input items. This only updates the internal struct
1148 * fields.
1149 *
1150 * The Resolution Multiplier is applied by the hardware. If the multiplier
1151 * is anything other than 1, the hardware will send pre-multiplied events
1152 * so that the same physical interaction generates an accumulated
1153 *	accumulated_value = value * * multiplier
1154 * This may be achieved by sending
1155 * - "value * multiplier" for each event, or
1156 * - "value" but "multiplier" times as frequently, or
1157 * - a combination of the above
1158 * The only guarantee is that the same physical interaction always generates
1159 * an accumulated 'value * multiplier'.
1160 *
1161 * This function must be called before any event processing and after
1162 * any SetRequest to the Resolution Multiplier.
1163 */
1164void hid_setup_resolution_multiplier(struct hid_device *hid)
1165{
1166	struct hid_report_enum *rep_enum;
1167	struct hid_report *rep;
1168	struct hid_usage *usage;
1169	int i, j;
1170
1171	rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
1172	list_for_each_entry(rep, &rep_enum->report_list, list) {
1173		for (i = 0; i < rep->maxfield; i++) {
1174			/* Ignore if report count is out of bounds. */
1175			if (rep->field[i]->report_count < 1)
1176				continue;
1177
1178			for (j = 0; j < rep->field[i]->maxusage; j++) {
1179				usage = &rep->field[i]->usage[j];
1180				if (usage->hid == HID_GD_RESOLUTION_MULTIPLIER)
1181					hid_apply_multiplier(hid,
1182							     rep->field[i]);
1183			}
1184		}
1185	}
1186}
1187EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier);
1188
1189/**
1190 * hid_open_report - open a driver-specific device report
1191 *
1192 * @device: hid device
1193 *
1194 * Parse a report description into a hid_device structure. Reports are
1195 * enumerated, fields are attached to these reports.
1196 * 0 returned on success, otherwise nonzero error value.
1197 *
1198 * This function (or the equivalent hid_parse() macro) should only be
1199 * called from probe() in drivers, before starting the device.
1200 */
1201int hid_open_report(struct hid_device *device)
1202{
1203	struct hid_parser *parser;
1204	struct hid_item item;
1205	unsigned int size;
1206	__u8 *start;
1207	__u8 *buf;
1208	__u8 *end;
1209	__u8 *next;
1210	int ret;
1211	int i;
1212	static int (*dispatch_type[])(struct hid_parser *parser,
1213				      struct hid_item *item) = {
1214		hid_parser_main,
1215		hid_parser_global,
1216		hid_parser_local,
1217		hid_parser_reserved
1218	};
1219
1220	if (WARN_ON(device->status & HID_STAT_PARSED))
1221		return -EBUSY;
1222
1223	start = device->dev_rdesc;
1224	if (WARN_ON(!start))
1225		return -ENODEV;
1226	size = device->dev_rsize;
1227
1228	buf = kmemdup(start, size, GFP_KERNEL);
1229	if (buf == NULL)
1230		return -ENOMEM;
1231
1232	if (device->driver->report_fixup)
1233		start = device->driver->report_fixup(device, buf, &size);
1234	else
1235		start = buf;
1236
1237	start = kmemdup(start, size, GFP_KERNEL);
1238	kfree(buf);
1239	if (start == NULL)
1240		return -ENOMEM;
1241
1242	device->rdesc = start;
1243	device->rsize = size;
1244
1245	parser = vzalloc(sizeof(struct hid_parser));
1246	if (!parser) {
1247		ret = -ENOMEM;
1248		goto alloc_err;
1249	}
1250
1251	parser->device = device;
1252
1253	end = start + size;
1254
1255	device->collection = kcalloc(HID_DEFAULT_NUM_COLLECTIONS,
1256				     sizeof(struct hid_collection), GFP_KERNEL);
1257	if (!device->collection) {
1258		ret = -ENOMEM;
1259		goto err;
1260	}
1261	device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
1262	for (i = 0; i < HID_DEFAULT_NUM_COLLECTIONS; i++)
1263		device->collection[i].parent_idx = -1;
1264
1265	ret = -EINVAL;
1266	while ((next = fetch_item(start, end, &item)) != NULL) {
1267		start = next;
1268
1269		if (item.format != HID_ITEM_FORMAT_SHORT) {
1270			hid_err(device, "unexpected long global item\n");
1271			goto err;
1272		}
1273
1274		if (dispatch_type[item.type](parser, &item)) {
1275			hid_err(device, "item %u %u %u %u parsing failed\n",
1276				item.format, (unsigned)item.size,
1277				(unsigned)item.type, (unsigned)item.tag);
1278			goto err;
1279		}
1280
1281		if (start == end) {
1282			if (parser->collection_stack_ptr) {
1283				hid_err(device, "unbalanced collection at end of report description\n");
1284				goto err;
1285			}
1286			if (parser->local.delimiter_depth) {
1287				hid_err(device, "unbalanced delimiter at end of report description\n");
1288				goto err;
1289			}
1290
1291			/*
1292			 * fetch initial values in case the device's
1293			 * default multiplier isn't the recommended 1
1294			 */
1295			hid_setup_resolution_multiplier(device);
1296
1297			kfree(parser->collection_stack);
1298			vfree(parser);
1299			device->status |= HID_STAT_PARSED;
1300
1301			return 0;
1302		}
1303	}
1304
1305	hid_err(device, "item fetching failed at offset %u/%u\n",
1306		size - (unsigned int)(end - start), size);
1307err:
1308	kfree(parser->collection_stack);
1309alloc_err:
1310	vfree(parser);
1311	hid_close_report(device);
1312	return ret;
1313}
1314EXPORT_SYMBOL_GPL(hid_open_report);
1315
1316/*
1317 * Convert a signed n-bit integer to signed 32-bit integer. Common
1318 * cases are done through the compiler, the screwed things has to be
1319 * done by hand.
1320 */
1321
1322static s32 snto32(__u32 value, unsigned n)
1323{
1324	if (!value || !n)
1325		return 0;
1326
1327	if (n > 32)
1328		n = 32;
1329
1330	switch (n) {
1331	case 8:  return ((__s8)value);
1332	case 16: return ((__s16)value);
1333	case 32: return ((__s32)value);
1334	}
1335	return value & (1 << (n - 1)) ? value | (~0U << n) : value;
1336}
1337
1338s32 hid_snto32(__u32 value, unsigned n)
1339{
1340	return snto32(value, n);
1341}
1342EXPORT_SYMBOL_GPL(hid_snto32);
1343
1344/*
1345 * Convert a signed 32-bit integer to a signed n-bit integer.
1346 */
1347
1348static u32 s32ton(__s32 value, unsigned n)
1349{
1350	s32 a = value >> (n - 1);
1351	if (a && a != -1)
1352		return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
1353	return value & ((1 << n) - 1);
1354}
1355
1356/*
1357 * Extract/implement a data field from/to a little endian report (bit array).
1358 *
1359 * Code sort-of follows HID spec:
1360 *     http://www.usb.org/developers/hidpage/HID1_11.pdf
1361 *
1362 * While the USB HID spec allows unlimited length bit fields in "report
1363 * descriptors", most devices never use more than 16 bits.
1364 * One model of UPS is claimed to report "LINEV" as a 32-bit field.
1365 * Search linux-kernel and linux-usb-devel archives for "hid-core extract".
1366 */
1367
1368static u32 __extract(u8 *report, unsigned offset, int n)
1369{
1370	unsigned int idx = offset / 8;
1371	unsigned int bit_nr = 0;
1372	unsigned int bit_shift = offset % 8;
1373	int bits_to_copy = 8 - bit_shift;
1374	u32 value = 0;
1375	u32 mask = n < 32 ? (1U << n) - 1 : ~0U;
1376
1377	while (n > 0) {
1378		value |= ((u32)report[idx] >> bit_shift) << bit_nr;
1379		n -= bits_to_copy;
1380		bit_nr += bits_to_copy;
1381		bits_to_copy = 8;
1382		bit_shift = 0;
1383		idx++;
1384	}
1385
1386	return value & mask;
1387}
1388
1389u32 hid_field_extract(const struct hid_device *hid, u8 *report,
1390			unsigned offset, unsigned n)
1391{
1392	if (n > 32) {
1393		hid_warn_once(hid, "%s() called with n (%d) > 32! (%s)\n",
1394			      __func__, n, current->comm);
1395		n = 32;
1396	}
1397
1398	return __extract(report, offset, n);
1399}
1400EXPORT_SYMBOL_GPL(hid_field_extract);
1401
1402/*
1403 * "implement" : set bits in a little endian bit stream.
1404 * Same concepts as "extract" (see comments above).
1405 * The data mangled in the bit stream remains in little endian
1406 * order the whole time. It make more sense to talk about
1407 * endianness of register values by considering a register
1408 * a "cached" copy of the little endian bit stream.
1409 */
1410
1411static void __implement(u8 *report, unsigned offset, int n, u32 value)
1412{
1413	unsigned int idx = offset / 8;
1414	unsigned int bit_shift = offset % 8;
1415	int bits_to_set = 8 - bit_shift;
1416
1417	while (n - bits_to_set >= 0) {
1418		report[idx] &= ~(0xff << bit_shift);
1419		report[idx] |= value << bit_shift;
1420		value >>= bits_to_set;
1421		n -= bits_to_set;
1422		bits_to_set = 8;
1423		bit_shift = 0;
1424		idx++;
1425	}
1426
1427	/* last nibble */
1428	if (n) {
1429		u8 bit_mask = ((1U << n) - 1);
1430		report[idx] &= ~(bit_mask << bit_shift);
1431		report[idx] |= value << bit_shift;
1432	}
1433}
1434
1435static void implement(const struct hid_device *hid, u8 *report,
1436		      unsigned offset, unsigned n, u32 value)
1437{
1438	if (unlikely(n > 32)) {
1439		hid_warn(hid, "%s() called with n (%d) > 32! (%s)\n",
1440			 __func__, n, current->comm);
1441		n = 32;
1442	} else if (n < 32) {
1443		u32 m = (1U << n) - 1;
1444
1445		if (unlikely(value > m)) {
1446			hid_warn(hid,
1447				 "%s() called with too large value %d (n: %d)! (%s)\n",
1448				 __func__, value, n, current->comm);
1449			value &= m;
1450		}
1451	}
1452
1453	__implement(report, offset, n, value);
1454}
1455
1456/*
1457 * Search an array for a value.
1458 */
1459
1460static int search(__s32 *array, __s32 value, unsigned n)
1461{
1462	while (n--) {
1463		if (*array++ == value)
1464			return 0;
1465	}
1466	return -1;
1467}
1468
1469/**
1470 * hid_match_report - check if driver's raw_event should be called
1471 *
1472 * @hid: hid device
1473 * @report: hid report to match against
1474 *
1475 * compare hid->driver->report_table->report_type to report->type
1476 */
1477static int hid_match_report(struct hid_device *hid, struct hid_report *report)
1478{
1479	const struct hid_report_id *id = hid->driver->report_table;
1480
1481	if (!id) /* NULL means all */
1482		return 1;
1483
1484	for (; id->report_type != HID_TERMINATOR; id++)
1485		if (id->report_type == HID_ANY_ID ||
1486				id->report_type == report->type)
1487			return 1;
1488	return 0;
1489}
1490
1491/**
1492 * hid_match_usage - check if driver's event should be called
1493 *
1494 * @hid: hid device
1495 * @usage: usage to match against
1496 *
1497 * compare hid->driver->usage_table->usage_{type,code} to
1498 * usage->usage_{type,code}
1499 */
1500static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage)
1501{
1502	const struct hid_usage_id *id = hid->driver->usage_table;
1503
1504	if (!id) /* NULL means all */
1505		return 1;
1506
1507	for (; id->usage_type != HID_ANY_ID - 1; id++)
1508		if ((id->usage_hid == HID_ANY_ID ||
1509				id->usage_hid == usage->hid) &&
1510				(id->usage_type == HID_ANY_ID ||
1511				id->usage_type == usage->type) &&
1512				(id->usage_code == HID_ANY_ID ||
1513				 id->usage_code == usage->code))
1514			return 1;
1515	return 0;
1516}
1517
1518static void hid_process_event(struct hid_device *hid, struct hid_field *field,
1519		struct hid_usage *usage, __s32 value, int interrupt)
1520{
1521	struct hid_driver *hdrv = hid->driver;
1522	int ret;
1523
1524	if (!list_empty(&hid->debug_list))
1525		hid_dump_input(hid, usage, value);
1526
1527	if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
1528		ret = hdrv->event(hid, field, usage, value);
1529		if (ret != 0) {
1530			if (ret < 0)
1531				hid_err(hid, "%s's event failed with %d\n",
1532						hdrv->name, ret);
1533			return;
1534		}
1535	}
1536
1537	if (hid->claimed & HID_CLAIMED_INPUT)
1538		hidinput_hid_event(hid, field, usage, value);
1539	if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
1540		hid->hiddev_hid_event(hid, field, usage, value);
1541}
1542
1543/*
1544 * Analyse a received field, and fetch the data from it. The field
1545 * content is stored for next report processing (we do differential
1546 * reporting to the layer).
1547 */
1548
1549static void hid_input_field(struct hid_device *hid, struct hid_field *field,
1550			    __u8 *data, int interrupt)
1551{
1552	unsigned n;
1553	unsigned count = field->report_count;
1554	unsigned offset = field->report_offset;
1555	unsigned size = field->report_size;
1556	__s32 min = field->logical_minimum;
1557	__s32 max = field->logical_maximum;
1558	__s32 *value;
1559
1560	value = kmalloc_array(count, sizeof(__s32), GFP_ATOMIC);
1561	if (!value)
1562		return;
1563
1564	for (n = 0; n < count; n++) {
1565
1566		value[n] = min < 0 ?
1567			snto32(hid_field_extract(hid, data, offset + n * size,
1568			       size), size) :
1569			hid_field_extract(hid, data, offset + n * size, size);
1570
1571		/* Ignore report if ErrorRollOver */
1572		if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
1573		    value[n] >= min && value[n] <= max &&
1574		    value[n] - min < field->maxusage &&
1575		    field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1)
1576			goto exit;
1577	}
1578
1579	for (n = 0; n < count; n++) {
1580
1581		if (HID_MAIN_ITEM_VARIABLE & field->flags) {
1582			hid_process_event(hid, field, &field->usage[n], value[n], interrupt);
1583			continue;
1584		}
1585
1586		if (field->value[n] >= min && field->value[n] <= max
1587			&& field->value[n] - min < field->maxusage
1588			&& field->usage[field->value[n] - min].hid
1589			&& search(value, field->value[n], count))
1590				hid_process_event(hid, field, &field->usage[field->value[n] - min], 0, interrupt);
1591
1592		if (value[n] >= min && value[n] <= max
1593			&& value[n] - min < field->maxusage
1594			&& field->usage[value[n] - min].hid
1595			&& search(field->value, value[n], count))
1596				hid_process_event(hid, field, &field->usage[value[n] - min], 1, interrupt);
1597	}
1598
1599	memcpy(field->value, value, count * sizeof(__s32));
1600exit:
1601	kfree(value);
1602}
1603
1604/*
1605 * Output the field into the report.
1606 */
1607
1608static void hid_output_field(const struct hid_device *hid,
1609			     struct hid_field *field, __u8 *data)
1610{
1611	unsigned count = field->report_count;
1612	unsigned offset = field->report_offset;
1613	unsigned size = field->report_size;
1614	unsigned n;
1615
1616	for (n = 0; n < count; n++) {
1617		if (field->logical_minimum < 0)	/* signed values */
1618			implement(hid, data, offset + n * size, size,
1619				  s32ton(field->value[n], size));
1620		else				/* unsigned values */
1621			implement(hid, data, offset + n * size, size,
1622				  field->value[n]);
1623	}
1624}
1625
1626/*
1627 * Compute the size of a report.
1628 */
1629static size_t hid_compute_report_size(struct hid_report *report)
1630{
1631	if (report->size)
1632		return ((report->size - 1) >> 3) + 1;
1633
1634	return 0;
1635}
1636
1637/*
1638 * Create a report. 'data' has to be allocated using
1639 * hid_alloc_report_buf() so that it has proper size.
1640 */
1641
1642void hid_output_report(struct hid_report *report, __u8 *data)
1643{
1644	unsigned n;
1645
1646	if (report->id > 0)
1647		*data++ = report->id;
1648
1649	memset(data, 0, hid_compute_report_size(report));
1650	for (n = 0; n < report->maxfield; n++)
1651		hid_output_field(report->device, report->field[n], data);
1652}
1653EXPORT_SYMBOL_GPL(hid_output_report);
1654
1655/*
1656 * Allocator for buffer that is going to be passed to hid_output_report()
1657 */
1658u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
1659{
1660	/*
1661	 * 7 extra bytes are necessary to achieve proper functionality
1662	 * of implement() working on 8 byte chunks
1663	 */
1664
1665	u32 len = hid_report_len(report) + 7;
1666
1667	return kmalloc(len, flags);
1668}
1669EXPORT_SYMBOL_GPL(hid_alloc_report_buf);
1670
1671/*
1672 * Set a field value. The report this field belongs to has to be
1673 * created and transferred to the device, to set this value in the
1674 * device.
1675 */
1676
1677int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
1678{
1679	unsigned size;
1680
1681	if (!field)
1682		return -1;
1683
1684	size = field->report_size;
1685
1686	hid_dump_input(field->report->device, field->usage + offset, value);
1687
1688	if (offset >= field->report_count) {
1689		hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n",
1690				offset, field->report_count);
1691		return -1;
1692	}
1693	if (field->logical_minimum < 0) {
1694		if (value != snto32(s32ton(value, size), size)) {
1695			hid_err(field->report->device, "value %d is out of range\n", value);
1696			return -1;
1697		}
1698	}
1699	field->value[offset] = value;
1700	return 0;
1701}
1702EXPORT_SYMBOL_GPL(hid_set_field);
1703
1704static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
1705		const u8 *data)
1706{
1707	struct hid_report *report;
1708	unsigned int n = 0;	/* Normally report number is 0 */
1709
1710	/* Device uses numbered reports, data[0] is report number */
1711	if (report_enum->numbered)
1712		n = *data;
1713
1714	report = report_enum->report_id_hash[n];
1715	if (report == NULL)
1716		dbg_hid("undefined report_id %u received\n", n);
1717
1718	return report;
1719}
1720
1721/*
1722 * Implement a generic .request() callback, using .raw_request()
1723 * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
1724 */
1725int __hid_request(struct hid_device *hid, struct hid_report *report,
1726		int reqtype)
1727{
1728	char *buf;
1729	int ret;
1730	u32 len;
1731
1732	buf = hid_alloc_report_buf(report, GFP_KERNEL);
1733	if (!buf)
1734		return -ENOMEM;
1735
1736	len = hid_report_len(report);
1737
1738	if (reqtype == HID_REQ_SET_REPORT)
1739		hid_output_report(report, buf);
1740
1741	ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
1742					  report->type, reqtype);
1743	if (ret < 0) {
1744		dbg_hid("unable to complete request: %d\n", ret);
1745		goto out;
1746	}
1747
1748	if (reqtype == HID_REQ_GET_REPORT)
1749		hid_input_report(hid, report->type, buf, ret, 0);
1750
1751	ret = 0;
1752
1753out:
1754	kfree(buf);
1755	return ret;
1756}
1757EXPORT_SYMBOL_GPL(__hid_request);
1758
1759int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, u32 size,
1760		int interrupt)
1761{
1762	struct hid_report_enum *report_enum = hid->report_enum + type;
1763	struct hid_report *report;
1764	struct hid_driver *hdrv;
1765	int max_buffer_size = HID_MAX_BUFFER_SIZE;
1766	unsigned int a;
1767	u32 rsize, csize = size;
1768	u8 *cdata = data;
1769	int ret = 0;
1770
1771	report = hid_get_report(report_enum, data);
1772	if (!report)
1773		goto out;
1774
1775	if (report_enum->numbered) {
1776		cdata++;
1777		csize--;
1778	}
1779
1780	rsize = hid_compute_report_size(report);
1781
1782	if (hid->ll_driver->max_buffer_size)
1783		max_buffer_size = hid->ll_driver->max_buffer_size;
1784
1785	if (report_enum->numbered && rsize >= max_buffer_size)
1786		rsize = max_buffer_size - 1;
1787	else if (rsize > max_buffer_size)
1788		rsize = max_buffer_size;
1789
1790	if (csize < rsize) {
1791		dbg_hid("report %d is too short, (%d < %d)\n", report->id,
1792				csize, rsize);
1793		memset(cdata + csize, 0, rsize - csize);
1794	}
1795
1796	if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
1797		hid->hiddev_report_event(hid, report);
1798	if (hid->claimed & HID_CLAIMED_HIDRAW) {
1799		ret = hidraw_report_event(hid, data, size);
1800		if (ret)
1801			goto out;
1802	}
1803
1804	if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
1805		for (a = 0; a < report->maxfield; a++)
1806			hid_input_field(hid, report->field[a], cdata, interrupt);
1807		hdrv = hid->driver;
1808		if (hdrv && hdrv->report)
1809			hdrv->report(hid, report);
1810	}
1811
1812	if (hid->claimed & HID_CLAIMED_INPUT)
1813		hidinput_report_event(hid, report);
1814out:
1815	return ret;
1816}
1817EXPORT_SYMBOL_GPL(hid_report_raw_event);
1818
1819/**
1820 * hid_input_report - report data from lower layer (usb, bt...)
1821 *
1822 * @hid: hid device
1823 * @type: HID report type (HID_*_REPORT)
1824 * @data: report contents
1825 * @size: size of data parameter
1826 * @interrupt: distinguish between interrupt and control transfers
1827 *
1828 * This is data entry for lower layers.
1829 */
1830int hid_input_report(struct hid_device *hid, int type, u8 *data, u32 size, int interrupt)
1831{
1832	struct hid_report_enum *report_enum;
1833	struct hid_driver *hdrv;
1834	struct hid_report *report;
1835	int ret = 0;
1836
1837	if (!hid)
1838		return -ENODEV;
1839
1840	if (down_trylock(&hid->driver_input_lock))
1841		return -EBUSY;
1842
1843	if (!hid->driver) {
1844		ret = -ENODEV;
1845		goto unlock;
1846	}
1847	report_enum = hid->report_enum + type;
1848	hdrv = hid->driver;
1849
1850	if (!size) {
1851		dbg_hid("empty report\n");
1852		ret = -1;
1853		goto unlock;
1854	}
1855
1856	/* Avoid unnecessary overhead if debugfs is disabled */
1857	if (!list_empty(&hid->debug_list))
1858		hid_dump_report(hid, type, data, size);
1859
1860	report = hid_get_report(report_enum, data);
1861
1862	if (!report) {
1863		ret = -1;
1864		goto unlock;
1865	}
1866
1867	if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
1868		ret = hdrv->raw_event(hid, report, data, size);
1869		if (ret < 0)
1870			goto unlock;
1871	}
1872
1873	ret = hid_report_raw_event(hid, type, data, size, interrupt);
1874
1875unlock:
1876	up(&hid->driver_input_lock);
1877	return ret;
1878}
1879EXPORT_SYMBOL_GPL(hid_input_report);
1880
1881bool hid_match_one_id(const struct hid_device *hdev,
1882		      const struct hid_device_id *id)
1883{
1884	return (id->bus == HID_BUS_ANY || id->bus == hdev->bus) &&
1885		(id->group == HID_GROUP_ANY || id->group == hdev->group) &&
1886		(id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&
1887		(id->product == HID_ANY_ID || id->product == hdev->product);
1888}
1889
1890const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
1891		const struct hid_device_id *id)
1892{
1893	for (; id->bus; id++)
1894		if (hid_match_one_id(hdev, id))
1895			return id;
1896
1897	return NULL;
1898}
1899
1900static const struct hid_device_id hid_hiddev_list[] = {
1901	{ HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS) },
1902	{ HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS1) },
1903	{ }
1904};
1905
1906static bool hid_hiddev(struct hid_device *hdev)
1907{
1908	return !!hid_match_id(hdev, hid_hiddev_list);
1909}
1910
1911
1912static ssize_t
1913read_report_descriptor(struct file *filp, struct kobject *kobj,
1914		struct bin_attribute *attr,
1915		char *buf, loff_t off, size_t count)
1916{
1917	struct device *dev = kobj_to_dev(kobj);
1918	struct hid_device *hdev = to_hid_device(dev);
1919
1920	if (off >= hdev->rsize)
1921		return 0;
1922
1923	if (off + count > hdev->rsize)
1924		count = hdev->rsize - off;
1925
1926	memcpy(buf, hdev->rdesc + off, count);
1927
1928	return count;
1929}
1930
1931static ssize_t
1932show_country(struct device *dev, struct device_attribute *attr,
1933		char *buf)
1934{
1935	struct hid_device *hdev = to_hid_device(dev);
1936
1937	return sprintf(buf, "%02x\n", hdev->country & 0xff);
1938}
1939
1940static struct bin_attribute dev_bin_attr_report_desc = {
1941	.attr = { .name = "report_descriptor", .mode = 0444 },
1942	.read = read_report_descriptor,
1943	.size = HID_MAX_DESCRIPTOR_SIZE,
1944};
1945
1946static const struct device_attribute dev_attr_country = {
1947	.attr = { .name = "country", .mode = 0444 },
1948	.show = show_country,
1949};
1950
1951int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
1952{
1953	static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
1954		"Joystick", "Gamepad", "Keyboard", "Keypad",
1955		"Multi-Axis Controller"
1956	};
1957	const char *type, *bus;
1958	char buf[64] = "";
1959	unsigned int i;
1960	int len;
1961	int ret;
1962
1963	if (hdev->quirks & HID_QUIRK_HIDDEV_FORCE)
1964		connect_mask |= (HID_CONNECT_HIDDEV_FORCE | HID_CONNECT_HIDDEV);
1965	if (hdev->quirks & HID_QUIRK_HIDINPUT_FORCE)
1966		connect_mask |= HID_CONNECT_HIDINPUT_FORCE;
1967	if (hdev->bus != BUS_USB)
1968		connect_mask &= ~HID_CONNECT_HIDDEV;
1969	if (hid_hiddev(hdev))
1970		connect_mask |= HID_CONNECT_HIDDEV_FORCE;
1971
1972	if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,
1973				connect_mask & HID_CONNECT_HIDINPUT_FORCE))
1974		hdev->claimed |= HID_CLAIMED_INPUT;
1975
1976	if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect &&
1977			!hdev->hiddev_connect(hdev,
1978				connect_mask & HID_CONNECT_HIDDEV_FORCE))
1979		hdev->claimed |= HID_CLAIMED_HIDDEV;
1980	if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))
1981		hdev->claimed |= HID_CLAIMED_HIDRAW;
1982
1983	if (connect_mask & HID_CONNECT_DRIVER)
1984		hdev->claimed |= HID_CLAIMED_DRIVER;
1985
1986	/* Drivers with the ->raw_event callback set are not required to connect
1987	 * to any other listener. */
1988	if (!hdev->claimed && !hdev->driver->raw_event) {
1989		hid_err(hdev, "device has no listeners, quitting\n");
1990		return -ENODEV;
1991	}
1992
1993	if ((hdev->claimed & HID_CLAIMED_INPUT) &&
1994			(connect_mask & HID_CONNECT_FF) && hdev->ff_init)
1995		hdev->ff_init(hdev);
1996
1997	len = 0;
1998	if (hdev->claimed & HID_CLAIMED_INPUT)
1999		len += sprintf(buf + len, "input");
2000	if (hdev->claimed & HID_CLAIMED_HIDDEV)
2001		len += sprintf(buf + len, "%shiddev%d", len ? "," : "",
2002				((struct hiddev *)hdev->hiddev)->minor);
2003	if (hdev->claimed & HID_CLAIMED_HIDRAW)
2004		len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
2005				((struct hidraw *)hdev->hidraw)->minor);
2006
2007	type = "Device";
2008	for (i = 0; i < hdev->maxcollection; i++) {
2009		struct hid_collection *col = &hdev->collection[i];
2010		if (col->type == HID_COLLECTION_APPLICATION &&
2011		   (col->usage & HID_USAGE_PAGE) == HID_UP_GENDESK &&
2012		   (col->usage & 0xffff) < ARRAY_SIZE(types)) {
2013			type = types[col->usage & 0xffff];
2014			break;
2015		}
2016	}
2017
2018	switch (hdev->bus) {
2019	case BUS_USB:
2020		bus = "USB";
2021		break;
2022	case BUS_BLUETOOTH:
2023		bus = "BLUETOOTH";
2024		break;
2025	case BUS_I2C:
2026		bus = "I2C";
2027		break;
2028	case BUS_VIRTUAL:
2029		bus = "VIRTUAL";
2030		break;
2031	default:
2032		bus = "<UNKNOWN>";
2033	}
2034
2035	ret = device_create_file(&hdev->dev, &dev_attr_country);
2036	if (ret)
2037		hid_warn(hdev,
2038			 "can't create sysfs country code attribute err: %d\n", ret);
2039
2040	hid_info(hdev, "%s: %s HID v%x.%02x %s [%s] on %s\n",
2041		 buf, bus, hdev->version >> 8, hdev->version & 0xff,
2042		 type, hdev->name, hdev->phys);
2043
2044	return 0;
2045}
2046EXPORT_SYMBOL_GPL(hid_connect);
2047
2048void hid_disconnect(struct hid_device *hdev)
2049{
2050	device_remove_file(&hdev->dev, &dev_attr_country);
2051	if (hdev->claimed & HID_CLAIMED_INPUT)
2052		hidinput_disconnect(hdev);
2053	if (hdev->claimed & HID_CLAIMED_HIDDEV)
2054		hdev->hiddev_disconnect(hdev);
2055	if (hdev->claimed & HID_CLAIMED_HIDRAW)
2056		hidraw_disconnect(hdev);
2057	hdev->claimed = 0;
2058}
2059EXPORT_SYMBOL_GPL(hid_disconnect);
2060
2061/**
2062 * hid_hw_start - start underlying HW
2063 * @hdev: hid device
2064 * @connect_mask: which outputs to connect, see HID_CONNECT_*
2065 *
2066 * Call this in probe function *after* hid_parse. This will setup HW
2067 * buffers and start the device (if not defeirred to device open).
2068 * hid_hw_stop must be called if this was successful.
2069 */
2070int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask)
2071{
2072	int error;
2073
2074	error = hdev->ll_driver->start(hdev);
2075	if (error)
2076		return error;
2077
2078	if (connect_mask) {
2079		error = hid_connect(hdev, connect_mask);
2080		if (error) {
2081			hdev->ll_driver->stop(hdev);
2082			return error;
2083		}
2084	}
2085
2086	return 0;
2087}
2088EXPORT_SYMBOL_GPL(hid_hw_start);
2089
2090/**
2091 * hid_hw_stop - stop underlying HW
2092 * @hdev: hid device
2093 *
2094 * This is usually called from remove function or from probe when something
2095 * failed and hid_hw_start was called already.
2096 */
2097void hid_hw_stop(struct hid_device *hdev)
2098{
2099	hid_disconnect(hdev);
2100	hdev->ll_driver->stop(hdev);
2101}
2102EXPORT_SYMBOL_GPL(hid_hw_stop);
2103
2104/**
2105 * hid_hw_open - signal underlying HW to start delivering events
2106 * @hdev: hid device
2107 *
2108 * Tell underlying HW to start delivering events from the device.
2109 * This function should be called sometime after successful call
2110 * to hid_hw_start().
2111 */
2112int hid_hw_open(struct hid_device *hdev)
2113{
2114	int ret;
2115
2116	ret = mutex_lock_killable(&hdev->ll_open_lock);
2117	if (ret)
2118		return ret;
2119
2120	if (!hdev->ll_open_count++) {
2121		ret = hdev->ll_driver->open(hdev);
2122		if (ret)
2123			hdev->ll_open_count--;
2124	}
2125
2126	mutex_unlock(&hdev->ll_open_lock);
2127	return ret;
2128}
2129EXPORT_SYMBOL_GPL(hid_hw_open);
2130
2131/**
2132 * hid_hw_close - signal underlaying HW to stop delivering events
2133 *
2134 * @hdev: hid device
2135 *
2136 * This function indicates that we are not interested in the events
2137 * from this device anymore. Delivery of events may or may not stop,
2138 * depending on the number of users still outstanding.
2139 */
2140void hid_hw_close(struct hid_device *hdev)
2141{
2142	mutex_lock(&hdev->ll_open_lock);
2143	if (!--hdev->ll_open_count)
2144		hdev->ll_driver->close(hdev);
2145	mutex_unlock(&hdev->ll_open_lock);
2146}
2147EXPORT_SYMBOL_GPL(hid_hw_close);
2148
2149struct hid_dynid {
2150	struct list_head list;
2151	struct hid_device_id id;
2152};
2153
2154/**
2155 * store_new_id - add a new HID device ID to this driver and re-probe devices
2156 * @drv: target device driver
2157 * @buf: buffer for scanning device ID data
2158 * @count: input size
2159 *
2160 * Adds a new dynamic hid device ID to this driver,
2161 * and causes the driver to probe for all devices again.
2162 */
2163static ssize_t new_id_store(struct device_driver *drv, const char *buf,
2164		size_t count)
2165{
2166	struct hid_driver *hdrv = to_hid_driver(drv);
2167	struct hid_dynid *dynid;
2168	__u32 bus, vendor, product;
2169	unsigned long driver_data = 0;
2170	int ret;
2171
2172	ret = sscanf(buf, "%x %x %x %lx",
2173			&bus, &vendor, &product, &driver_data);
2174	if (ret < 3)
2175		return -EINVAL;
2176
2177	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
2178	if (!dynid)
2179		return -ENOMEM;
2180
2181	dynid->id.bus = bus;
2182	dynid->id.group = HID_GROUP_ANY;
2183	dynid->id.vendor = vendor;
2184	dynid->id.product = product;
2185	dynid->id.driver_data = driver_data;
2186
2187	spin_lock(&hdrv->dyn_lock);
2188	list_add_tail(&dynid->list, &hdrv->dyn_list);
2189	spin_unlock(&hdrv->dyn_lock);
2190
2191	ret = driver_attach(&hdrv->driver);
2192
2193	return ret ? : count;
2194}
2195static DRIVER_ATTR_WO(new_id);
2196
2197static struct attribute *hid_drv_attrs[] = {
2198	&driver_attr_new_id.attr,
2199	NULL,
2200};
2201ATTRIBUTE_GROUPS(hid_drv);
2202
2203static void hid_free_dynids(struct hid_driver *hdrv)
2204{
2205	struct hid_dynid *dynid, *n;
2206
2207	spin_lock(&hdrv->dyn_lock);
2208	list_for_each_entry_safe(dynid, n, &hdrv->dyn_list, list) {
2209		list_del(&dynid->list);
2210		kfree(dynid);
2211	}
2212	spin_unlock(&hdrv->dyn_lock);
2213}
2214
2215const struct hid_device_id *hid_match_device(struct hid_device *hdev,
2216					     struct hid_driver *hdrv)
2217{
2218	struct hid_dynid *dynid;
2219
2220	spin_lock(&hdrv->dyn_lock);
2221	list_for_each_entry(dynid, &hdrv->dyn_list, list) {
2222		if (hid_match_one_id(hdev, &dynid->id)) {
2223			spin_unlock(&hdrv->dyn_lock);
2224			return &dynid->id;
2225		}
2226	}
2227	spin_unlock(&hdrv->dyn_lock);
2228
2229	return hid_match_id(hdev, hdrv->id_table);
2230}
2231EXPORT_SYMBOL_GPL(hid_match_device);
2232
2233static int hid_bus_match(struct device *dev, struct device_driver *drv)
2234{
2235	struct hid_driver *hdrv = to_hid_driver(drv);
2236	struct hid_device *hdev = to_hid_device(dev);
2237
2238	return hid_match_device(hdev, hdrv) != NULL;
2239}
2240
2241/**
2242 * hid_compare_device_paths - check if both devices share the same path
2243 * @hdev_a: hid device
2244 * @hdev_b: hid device
2245 * @separator: char to use as separator
2246 *
2247 * Check if two devices share the same path up to the last occurrence of
2248 * the separator char. Both paths must exist (i.e., zero-length paths
2249 * don't match).
2250 */
2251bool hid_compare_device_paths(struct hid_device *hdev_a,
2252			      struct hid_device *hdev_b, char separator)
2253{
2254	int n1 = strrchr(hdev_a->phys, separator) - hdev_a->phys;
2255	int n2 = strrchr(hdev_b->phys, separator) - hdev_b->phys;
2256
2257	if (n1 != n2 || n1 <= 0 || n2 <= 0)
2258		return false;
2259
2260	return !strncmp(hdev_a->phys, hdev_b->phys, n1);
2261}
2262EXPORT_SYMBOL_GPL(hid_compare_device_paths);
2263
2264static int hid_device_probe(struct device *dev)
2265{
2266	struct hid_driver *hdrv = to_hid_driver(dev->driver);
2267	struct hid_device *hdev = to_hid_device(dev);
2268	const struct hid_device_id *id;
2269	int ret = 0;
2270
2271	if (down_interruptible(&hdev->driver_input_lock)) {
2272		ret = -EINTR;
2273		goto end;
2274	}
2275	hdev->io_started = false;
2276
2277	clear_bit(ffs(HID_STAT_REPROBED), &hdev->status);
2278
2279	if (!hdev->driver) {
2280		id = hid_match_device(hdev, hdrv);
2281		if (id == NULL) {
2282			ret = -ENODEV;
2283			goto unlock;
2284		}
2285
2286		if (hdrv->match) {
2287			if (!hdrv->match(hdev, hid_ignore_special_drivers)) {
2288				ret = -ENODEV;
2289				goto unlock;
2290			}
2291		} else {
2292			/*
2293			 * hid-generic implements .match(), so if
2294			 * hid_ignore_special_drivers is set, we can safely
2295			 * return.
2296			 */
2297			if (hid_ignore_special_drivers) {
2298				ret = -ENODEV;
2299				goto unlock;
2300			}
2301		}
2302
2303		/* reset the quirks that has been previously set */
2304		hdev->quirks = hid_lookup_quirk(hdev);
2305		hdev->driver = hdrv;
2306		if (hdrv->probe) {
2307			ret = hdrv->probe(hdev, id);
2308		} else { /* default probe */
2309			ret = hid_open_report(hdev);
2310			if (!ret)
2311				ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
2312		}
2313		if (ret) {
2314			hid_close_report(hdev);
2315			hdev->driver = NULL;
2316		}
2317	}
2318unlock:
2319	if (!hdev->io_started)
2320		up(&hdev->driver_input_lock);
2321end:
2322	return ret;
2323}
2324
2325static int hid_device_remove(struct device *dev)
2326{
2327	struct hid_device *hdev = to_hid_device(dev);
2328	struct hid_driver *hdrv;
2329
2330	down(&hdev->driver_input_lock);
2331	hdev->io_started = false;
2332
2333	hdrv = hdev->driver;
2334	if (hdrv) {
2335		if (hdrv->remove)
2336			hdrv->remove(hdev);
2337		else /* default remove */
2338			hid_hw_stop(hdev);
2339		hid_close_report(hdev);
2340		hdev->driver = NULL;
2341	}
2342
2343	if (!hdev->io_started)
2344		up(&hdev->driver_input_lock);
2345
2346	return 0;
2347}
2348
2349static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
2350			     char *buf)
2351{
2352	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
2353
2354	return scnprintf(buf, PAGE_SIZE, "hid:b%04Xg%04Xv%08Xp%08X\n",
2355			 hdev->bus, hdev->group, hdev->vendor, hdev->product);
2356}
2357static DEVICE_ATTR_RO(modalias);
2358
2359static struct attribute *hid_dev_attrs[] = {
2360	&dev_attr_modalias.attr,
2361	NULL,
2362};
2363static struct bin_attribute *hid_dev_bin_attrs[] = {
2364	&dev_bin_attr_report_desc,
2365	NULL
2366};
2367static const struct attribute_group hid_dev_group = {
2368	.attrs = hid_dev_attrs,
2369	.bin_attrs = hid_dev_bin_attrs,
2370};
2371__ATTRIBUTE_GROUPS(hid_dev);
2372
2373static int hid_uevent(struct device *dev, struct kobj_uevent_env *env)
2374{
2375	struct hid_device *hdev = to_hid_device(dev);
2376
2377	if (add_uevent_var(env, "HID_ID=%04X:%08X:%08X",
2378			hdev->bus, hdev->vendor, hdev->product))
2379		return -ENOMEM;
2380
2381	if (add_uevent_var(env, "HID_NAME=%s", hdev->name))
2382		return -ENOMEM;
2383
2384	if (add_uevent_var(env, "HID_PHYS=%s", hdev->phys))
2385		return -ENOMEM;
2386
2387	if (add_uevent_var(env, "HID_UNIQ=%s", hdev->uniq))
2388		return -ENOMEM;
2389
2390	if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",
2391			   hdev->bus, hdev->group, hdev->vendor, hdev->product))
2392		return -ENOMEM;
2393
2394	return 0;
2395}
2396
2397struct bus_type hid_bus_type = {
2398	.name		= "hid",
2399	.dev_groups	= hid_dev_groups,
2400	.drv_groups	= hid_drv_groups,
2401	.match		= hid_bus_match,
2402	.probe		= hid_device_probe,
2403	.remove		= hid_device_remove,
2404	.uevent		= hid_uevent,
2405};
2406EXPORT_SYMBOL(hid_bus_type);
2407
2408int hid_add_device(struct hid_device *hdev)
2409{
2410	static atomic_t id = ATOMIC_INIT(0);
2411	int ret;
2412
2413	if (WARN_ON(hdev->status & HID_STAT_ADDED))
2414		return -EBUSY;
2415
2416	hdev->quirks = hid_lookup_quirk(hdev);
2417
2418	/* we need to kill them here, otherwise they will stay allocated to
2419	 * wait for coming driver */
2420	if (hid_ignore(hdev))
2421		return -ENODEV;
2422
2423	/*
2424	 * Check for the mandatory transport channel.
2425	 */
2426	 if (!hdev->ll_driver->raw_request) {
2427		hid_err(hdev, "transport driver missing .raw_request()\n");
2428		return -EINVAL;
2429	 }
2430
2431	/*
2432	 * Read the device report descriptor once and use as template
2433	 * for the driver-specific modifications.
2434	 */
2435	ret = hdev->ll_driver->parse(hdev);
2436	if (ret)
2437		return ret;
2438	if (!hdev->dev_rdesc)
2439		return -ENODEV;
2440
2441	/*
2442	 * Scan generic devices for group information
2443	 */
2444	if (hid_ignore_special_drivers) {
2445		hdev->group = HID_GROUP_GENERIC;
2446	} else if (!hdev->group &&
2447		   !(hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)) {
2448		ret = hid_scan_report(hdev);
2449		if (ret)
2450			hid_warn(hdev, "bad device descriptor (%d)\n", ret);
2451	}
2452
2453	hdev->id = atomic_inc_return(&id);
2454
2455	/* XXX hack, any other cleaner solution after the driver core
2456	 * is converted to allow more than 20 bytes as the device name? */
2457	dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
2458		     hdev->vendor, hdev->product, hdev->id);
2459
2460	hid_debug_register(hdev, dev_name(&hdev->dev));
2461	ret = device_add(&hdev->dev);
2462	if (!ret)
2463		hdev->status |= HID_STAT_ADDED;
2464	else
2465		hid_debug_unregister(hdev);
2466
2467	return ret;
2468}
2469EXPORT_SYMBOL_GPL(hid_add_device);
2470
2471/**
2472 * hid_allocate_device - allocate new hid device descriptor
2473 *
2474 * Allocate and initialize hid device, so that hid_destroy_device might be
2475 * used to free it.
2476 *
2477 * New hid_device pointer is returned on success, otherwise ERR_PTR encoded
2478 * error value.
2479 */
2480struct hid_device *hid_allocate_device(void)
2481{
2482	struct hid_device *hdev;
2483	int ret = -ENOMEM;
2484
2485	hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
2486	if (hdev == NULL)
2487		return ERR_PTR(ret);
2488
2489	device_initialize(&hdev->dev);
2490	hdev->dev.release = hid_device_release;
2491	hdev->dev.bus = &hid_bus_type;
2492	device_enable_async_suspend(&hdev->dev);
2493
2494	hid_close_report(hdev);
2495
2496	init_waitqueue_head(&hdev->debug_wait);
2497	INIT_LIST_HEAD(&hdev->debug_list);
2498	spin_lock_init(&hdev->debug_list_lock);
2499	sema_init(&hdev->driver_input_lock, 1);
2500	mutex_init(&hdev->ll_open_lock);
2501	kref_init(&hdev->ref);
2502
2503	return hdev;
2504}
2505EXPORT_SYMBOL_GPL(hid_allocate_device);
2506
2507static void hid_remove_device(struct hid_device *hdev)
2508{
2509	if (hdev->status & HID_STAT_ADDED) {
2510		device_del(&hdev->dev);
2511		hid_debug_unregister(hdev);
2512		hdev->status &= ~HID_STAT_ADDED;
2513	}
2514	kfree(hdev->dev_rdesc);
2515	hdev->dev_rdesc = NULL;
2516	hdev->dev_rsize = 0;
2517}
2518
2519/**
2520 * hid_destroy_device - free previously allocated device
2521 *
2522 * @hdev: hid device
2523 *
2524 * If you allocate hid_device through hid_allocate_device, you should ever
2525 * free by this function.
2526 */
2527void hid_destroy_device(struct hid_device *hdev)
2528{
2529	hid_remove_device(hdev);
2530	put_device(&hdev->dev);
2531}
2532EXPORT_SYMBOL_GPL(hid_destroy_device);
2533
2534
2535static int __hid_bus_reprobe_drivers(struct device *dev, void *data)
2536{
2537	struct hid_driver *hdrv = data;
2538	struct hid_device *hdev = to_hid_device(dev);
2539
2540	if (hdev->driver == hdrv &&
2541	    !hdrv->match(hdev, hid_ignore_special_drivers) &&
2542	    !test_and_set_bit(ffs(HID_STAT_REPROBED), &hdev->status))
2543		return device_reprobe(dev);
2544
2545	return 0;
2546}
2547
2548static int __hid_bus_driver_added(struct device_driver *drv, void *data)
2549{
2550	struct hid_driver *hdrv = to_hid_driver(drv);
2551
2552	if (hdrv->match) {
2553		bus_for_each_dev(&hid_bus_type, NULL, hdrv,
2554				 __hid_bus_reprobe_drivers);
2555	}
2556
2557	return 0;
2558}
2559
2560static int __bus_removed_driver(struct device_driver *drv, void *data)
2561{
2562	return bus_rescan_devices(&hid_bus_type);
2563}
2564
2565int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
2566		const char *mod_name)
2567{
2568	int ret;
2569
2570	hdrv->driver.name = hdrv->name;
2571	hdrv->driver.bus = &hid_bus_type;
2572	hdrv->driver.owner = owner;
2573	hdrv->driver.mod_name = mod_name;
2574
2575	INIT_LIST_HEAD(&hdrv->dyn_list);
2576	spin_lock_init(&hdrv->dyn_lock);
2577
2578	ret = driver_register(&hdrv->driver);
2579
2580	if (ret == 0)
2581		bus_for_each_drv(&hid_bus_type, NULL, NULL,
2582				 __hid_bus_driver_added);
2583
2584	return ret;
2585}
2586EXPORT_SYMBOL_GPL(__hid_register_driver);
2587
2588void hid_unregister_driver(struct hid_driver *hdrv)
2589{
2590	driver_unregister(&hdrv->driver);
2591	hid_free_dynids(hdrv);
2592
2593	bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver);
2594}
2595EXPORT_SYMBOL_GPL(hid_unregister_driver);
2596
2597int hid_check_keys_pressed(struct hid_device *hid)
2598{
2599	struct hid_input *hidinput;
2600	int i;
2601
2602	if (!(hid->claimed & HID_CLAIMED_INPUT))
2603		return 0;
2604
2605	list_for_each_entry(hidinput, &hid->inputs, list) {
2606		for (i = 0; i < BITS_TO_LONGS(KEY_MAX); i++)
2607			if (hidinput->input->key[i])
2608				return 1;
2609	}
2610
2611	return 0;
2612}
2613
2614EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
2615
2616static int __init hid_init(void)
2617{
2618	int ret;
2619
2620	if (hid_debug)
2621		pr_warn("hid_debug is now used solely for parser and driver debugging.\n"
2622			"debugfs is now used for inspecting the device (report descriptor, reports)\n");
2623
2624	ret = bus_register(&hid_bus_type);
2625	if (ret) {
2626		pr_err("can't register hid bus\n");
2627		goto err;
2628	}
2629
2630	ret = hidraw_init();
2631	if (ret)
2632		goto err_bus;
2633
2634	hid_debug_init();
2635
2636	return 0;
2637err_bus:
2638	bus_unregister(&hid_bus_type);
2639err:
2640	return ret;
2641}
2642
2643static void __exit hid_exit(void)
2644{
2645	hid_debug_exit();
2646	hidraw_exit();
2647	bus_unregister(&hid_bus_type);
2648	hid_quirks_exit(HID_BUS_ANY);
2649}
2650
2651module_init(hid_init);
2652module_exit(hid_exit);
2653
2654MODULE_AUTHOR("Andreas Gal");
2655MODULE_AUTHOR("Vojtech Pavlik");
2656MODULE_AUTHOR("Jiri Kosina");
2657MODULE_LICENSE("GPL");
2658