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
44	static int hid_ignore_special_drivers = 0;
45	module_param_named(ignore_special_drivers, hid_ignore_special_drivers, int, 0600);
46	MODULE_PARM_DESC(ignore_special_drivers, "Ignore any special drivers and handle all devices by generic driver");
47
48	/*
49	* Register a new report for a device.
50	*/
51
52	struct hid_report *hid_register_report(struct hid_device *device,
53	enum hid_report_type type, unsigned int id,
54	unsigned int application)
55	{
56	struct hid_report_enum *report_enum = device->report_enum + type;
57	struct hid_report *report;
58
59	if (id >= HID_MAX_IDS)
60	return NULL;
61	if (report_enum->report_id_hash[id])
62	return report_enum->report_id_hash[id];
63
64	report = kzalloc(size: sizeof(struct hid_report), GFP_KERNEL);
65	if (!report)
66	return NULL;
67
68	if (id != 0)
69	report_enum->numbered = 1;
70
71	report->id = id;
72	report->type = type;
73	report->size = 0;
74	report->device = device;
75	report->application = application;
76	report_enum->report_id_hash[id] = report;
77
78	list_add_tail(new: &report->list, head: &report_enum->report_list);
79	INIT_LIST_HEAD(list: &report->field_entry_list);
80
81	return report;
82	}
83	EXPORT_SYMBOL_GPL(hid_register_report);
84
85	/*
86	* Register a new field for this report.
87	*/
88
89	static struct hid_field *hid_register_field(struct hid_report *report, unsigned usages)
90	{
91	struct hid_field *field;
92
93	if (report->maxfield == HID_MAX_FIELDS) {
94	hid_err(report->device, "too many fields in report\n");
95	return NULL;
96	}
97
98	field = kzalloc(size: (sizeof(struct hid_field) +
99	usages * sizeof(struct hid_usage) +
100	3 * usages * sizeof(unsigned int)), GFP_KERNEL);
101	if (!field)
102	return NULL;
103
104	field->index = report->maxfield++;
105	report->field[field->index] = field;
106	field->usage = (struct hid_usage *)(field + 1);
107	field->value = (s32 *)(field->usage + usages);
108	field->new_value = (s32 *)(field->value + usages);
109	field->usages_priorities = (s32 *)(field->new_value + usages);
110	field->report = report;
111
112	return field;
113	}
114
115	/*
116	* Open a collection. The type/usage is pushed on the stack.
117	*/
118
119	static int open_collection(struct hid_parser *parser, unsigned type)
120	{
121	struct hid_collection *collection;
122	unsigned usage;
123	int collection_index;
124
125	usage = parser->local.usage[0];
126
127	if (parser->collection_stack_ptr == parser->collection_stack_size) {
128	unsigned int *collection_stack;
129	unsigned int new_size = parser->collection_stack_size +
130	HID_COLLECTION_STACK_SIZE;
131
132	collection_stack = krealloc(objp: parser->collection_stack,
133	new_size: new_size * sizeof(unsigned int),
134	GFP_KERNEL);
135	if (!collection_stack)
136	return -ENOMEM;
137
138	parser->collection_stack = collection_stack;
139	parser->collection_stack_size = new_size;
140	}
141
142	if (parser->device->maxcollection == parser->device->collection_size) {
143	collection = kmalloc(
144	array3_size(sizeof(struct hid_collection),
145	parser->device->collection_size,
146	2),
147	GFP_KERNEL);
148	if (collection == NULL) {
149	hid_err(parser->device, "failed to reallocate collection array\n");
150	return -ENOMEM;
151	}
152	memcpy(collection, parser->device->collection,
153	sizeof(struct hid_collection) *
154	parser->device->collection_size);
155	memset(collection + parser->device->collection_size, 0,
156	sizeof(struct hid_collection) *
157	parser->device->collection_size);
158	kfree(objp: parser->device->collection);
159	parser->device->collection = collection;
160	parser->device->collection_size *= 2;
161	}
162
163	parser->collection_stack[parser->collection_stack_ptr++] =
164	parser->device->maxcollection;
165
166	collection_index = parser->device->maxcollection++;
167	collection = parser->device->collection + collection_index;
168	collection->type = type;
169	collection->usage = usage;
170	collection->level = parser->collection_stack_ptr - 1;
171	collection->parent_idx = (collection->level == 0) ? -1 :
172	parser->collection_stack[collection->level - 1];
173
174	if (type == HID_COLLECTION_APPLICATION)
175	parser->device->maxapplication++;
176
177	return 0;
178	}
179
180	/*
181	* Close a collection.
182	*/
183
184	static int close_collection(struct hid_parser *parser)
185	{
186	if (!parser->collection_stack_ptr) {
187	hid_err(parser->device, "collection stack underflow\n");
188	return -EINVAL;
189	}
190	parser->collection_stack_ptr--;
191	return 0;
192	}
193
194	/*
195	* Climb up the stack, search for the specified collection type
196	* and return the usage.
197	*/
198
199	static unsigned hid_lookup_collection(struct hid_parser *parser, unsigned type)
200	{
201	struct hid_collection *collection = parser->device->collection;
202	int n;
203
204	for (n = parser->collection_stack_ptr - 1; n >= 0; n--) {
205	unsigned index = parser->collection_stack[n];
206	if (collection[index].type == type)
207	return collection[index].usage;
208	}
209	return 0; /* we know nothing about this usage type */
210	}
211
212	/*
213	* Concatenate usage which defines 16 bits or less with the
214	* currently defined usage page to form a 32 bit usage
215	*/
216
217	static void complete_usage(struct hid_parser *parser, unsigned int index)
218	{
219	parser->local.usage[index] &= 0xFFFF;
220	parser->local.usage[index] |=
221	(parser->global.usage_page & 0xFFFF) << 16;
222	}
223
224	/*
225	* Add a usage to the temporary parser table.
226	*/
227
228	static int hid_add_usage(struct hid_parser *parser, unsigned usage, u8 size)
229	{
230	if (parser->local.usage_index >= HID_MAX_USAGES) {
231	hid_err(parser->device, "usage index exceeded\n");
232	return -1;
233	}
234	parser->local.usage[parser->local.usage_index] = usage;
235
236	/*
237	* If Usage item only includes usage id, concatenate it with
238	* currently defined usage page
239	*/
240	if (size <= 2)
241	complete_usage(parser, index: parser->local.usage_index);
242
243	parser->local.usage_size[parser->local.usage_index] = size;
244	parser->local.collection_index[parser->local.usage_index] =
245	parser->collection_stack_ptr ?
246	parser->collection_stack[parser->collection_stack_ptr - 1] : 0;
247	parser->local.usage_index++;
248	return 0;
249	}
250
251	/*
252	* Register a new field for this report.
253	*/
254
255	static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsigned flags)
256	{
257	struct hid_report *report;
258	struct hid_field *field;
259	unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
260	unsigned int usages;
261	unsigned int offset;
262	unsigned int i;
263	unsigned int application;
264
265	application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
266
267	report = hid_register_report(parser->device, report_type,
268	parser->global.report_id, application);
269	if (!report) {
270	hid_err(parser->device, "hid_register_report failed\n");
271	return -1;
272	}
273
274	/* Handle both signed and unsigned cases properly */
275	if ((parser->global.logical_minimum < 0 &&
276	parser->global.logical_maximum <
277	parser->global.logical_minimum) ||
278	(parser->global.logical_minimum >= 0 &&
279	(__u32)parser->global.logical_maximum <
280	(__u32)parser->global.logical_minimum)) {
281	dbg_hid("logical range invalid 0x%x 0x%x\n",
282	parser->global.logical_minimum,
283	parser->global.logical_maximum);
284	return -1;
285	}
286
287	offset = report->size;
288	report->size += parser->global.report_size * parser->global.report_count;
289
290	if (parser->device->ll_driver->max_buffer_size)
291	max_buffer_size = parser->device->ll_driver->max_buffer_size;
292
293	/* Total size check: Allow for possible report index byte */
294	if (report->size > (max_buffer_size - 1) << 3) {
295	hid_err(parser->device, "report is too long\n");
296	return -1;
297	}
298
299	if (!parser->local.usage_index) /* Ignore padding fields */
300	return 0;
301
302	usages = max_t(unsigned, parser->local.usage_index,
303	parser->global.report_count);
304
305	field = hid_register_field(report, usages);
306	if (!field)
307	return 0;
308
309	field->physical = hid_lookup_collection(parser, HID_COLLECTION_PHYSICAL);
310	field->logical = hid_lookup_collection(parser, HID_COLLECTION_LOGICAL);
311	field->application = application;
312
313	for (i = 0; i < usages; i++) {
314	unsigned j = i;
315	/* Duplicate the last usage we parsed if we have excess values */
316	if (i >= parser->local.usage_index)
317	j = parser->local.usage_index - 1;
318	field->usage[i].hid = parser->local.usage[j];
319	field->usage[i].collection_index =
320	parser->local.collection_index[j];
321	field->usage[i].usage_index = i;
322	field->usage[i].resolution_multiplier = 1;
323	}
324
325	field->maxusage = usages;
326	field->flags = flags;
327	field->report_offset = offset;
328	field->report_type = report_type;
329	field->report_size = parser->global.report_size;
330	field->report_count = parser->global.report_count;
331	field->logical_minimum = parser->global.logical_minimum;
332	field->logical_maximum = parser->global.logical_maximum;
333	field->physical_minimum = parser->global.physical_minimum;
334	field->physical_maximum = parser->global.physical_maximum;
335	field->unit_exponent = parser->global.unit_exponent;
336	field->unit = parser->global.unit;
337
338	return 0;
339	}
340
341	/*
342	* Read data value from item.
343	*/
344
345	static u32 item_udata(struct hid_item *item)
346	{
347	switch (item->size) {
348	case 1: return item->data.u8;
349	case 2: return item->data.u16;
350	case 4: return item->data.u32;
351	}
352	return 0;
353	}
354
355	static s32 item_sdata(struct hid_item *item)
356	{
357	switch (item->size) {
358	case 1: return item->data.s8;
359	case 2: return item->data.s16;
360	case 4: return item->data.s32;
361	}
362	return 0;
363	}
364
365	/*
366	* Process a global item.
367	*/
368
369	static int hid_parser_global(struct hid_parser *parser, struct hid_item *item)
370	{
371	__s32 raw_value;
372	switch (item->tag) {
373	case HID_GLOBAL_ITEM_TAG_PUSH:
374
375	if (parser->global_stack_ptr == HID_GLOBAL_STACK_SIZE) {
376	hid_err(parser->device, "global environment stack overflow\n");
377	return -1;
378	}
379
380	memcpy(parser->global_stack + parser->global_stack_ptr++,
381	&parser->global, sizeof(struct hid_global));
382	return 0;
383
384	case HID_GLOBAL_ITEM_TAG_POP:
385
386	if (!parser->global_stack_ptr) {
387	hid_err(parser->device, "global environment stack underflow\n");
388	return -1;
389	}
390
391	memcpy(&parser->global, parser->global_stack +
392	--parser->global_stack_ptr, sizeof(struct hid_global));
393	return 0;
394
395	case HID_GLOBAL_ITEM_TAG_USAGE_PAGE:
396	parser->global.usage_page = item_udata(item);
397	return 0;
398
399	case HID_GLOBAL_ITEM_TAG_LOGICAL_MINIMUM:
400	parser->global.logical_minimum = item_sdata(item);
401	return 0;
402
403	case HID_GLOBAL_ITEM_TAG_LOGICAL_MAXIMUM:
404	if (parser->global.logical_minimum < 0)
405	parser->global.logical_maximum = item_sdata(item);
406	else
407	parser->global.logical_maximum = item_udata(item);
408	return 0;
409
410	case HID_GLOBAL_ITEM_TAG_PHYSICAL_MINIMUM:
411	parser->global.physical_minimum = item_sdata(item);
412	return 0;
413
414	case HID_GLOBAL_ITEM_TAG_PHYSICAL_MAXIMUM:
415	if (parser->global.physical_minimum < 0)
416	parser->global.physical_maximum = item_sdata(item);
417	else
418	parser->global.physical_maximum = item_udata(item);
419	return 0;
420
421	case HID_GLOBAL_ITEM_TAG_UNIT_EXPONENT:
422	/* Many devices provide unit exponent as a two's complement
423	* nibble due to the common misunderstanding of HID
424	* specification 1.11, 6.2.2.7 Global Items. Attempt to handle
425	* both this and the standard encoding. */
426	raw_value = item_sdata(item);
427	if (!(raw_value & 0xfffffff0))
428	parser->global.unit_exponent = hid_snto32(value: raw_value, n: 4);
429	else
430	parser->global.unit_exponent = raw_value;
431	return 0;
432
433	case HID_GLOBAL_ITEM_TAG_UNIT:
434	parser->global.unit = item_udata(item);
435	return 0;
436
437	case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
438	parser->global.report_size = item_udata(item);
439	if (parser->global.report_size > 256) {
440	hid_err(parser->device, "invalid report_size %d\n",
441	parser->global.report_size);
442	return -1;
443	}
444	return 0;
445
446	case HID_GLOBAL_ITEM_TAG_REPORT_COUNT:
447	parser->global.report_count = item_udata(item);
448	if (parser->global.report_count > HID_MAX_USAGES) {
449	hid_err(parser->device, "invalid report_count %d\n",
450	parser->global.report_count);
451	return -1;
452	}
453	return 0;
454
455	case HID_GLOBAL_ITEM_TAG_REPORT_ID:
456	parser->global.report_id = item_udata(item);
457	if (parser->global.report_id == 0 ||
458	parser->global.report_id >= HID_MAX_IDS) {
459	hid_err(parser->device, "report_id %u is invalid\n",
460	parser->global.report_id);
461	return -1;
462	}
463	return 0;
464
465	default:
466	hid_err(parser->device, "unknown global tag 0x%x\n", item->tag);
467	return -1;
468	}
469	}
470
471	/*
472	* Process a local item.
473	*/
474
475	static int hid_parser_local(struct hid_parser *parser, struct hid_item *item)
476	{
477	__u32 data;
478	unsigned n;
479	__u32 count;
480
481	data = item_udata(item);
482
483	switch (item->tag) {
484	case HID_LOCAL_ITEM_TAG_DELIMITER:
485
486	if (data) {
487	/*
488	* We treat items before the first delimiter
489	* as global to all usage sets (branch 0).
490	* In the moment we process only these global
491	* items and the first delimiter set.
492	*/
493	if (parser->local.delimiter_depth != 0) {
494	hid_err(parser->device, "nested delimiters\n");
495	return -1;
496	}
497	parser->local.delimiter_depth++;
498	parser->local.delimiter_branch++;
499	} else {
500	if (parser->local.delimiter_depth < 1) {
501	hid_err(parser->device, "bogus close delimiter\n");
502	return -1;
503	}
504	parser->local.delimiter_depth--;
505	}
506	return 0;
507
508	case HID_LOCAL_ITEM_TAG_USAGE:
509
510	if (parser->local.delimiter_branch > 1) {
511	dbg_hid("alternative usage ignored\n");
512	return 0;
513	}
514
515	return hid_add_usage(parser, usage: data, size: item->size);
516
517	case HID_LOCAL_ITEM_TAG_USAGE_MINIMUM:
518
519	if (parser->local.delimiter_branch > 1) {
520	dbg_hid("alternative usage ignored\n");
521	return 0;
522	}
523
524	parser->local.usage_minimum = data;
525	return 0;
526
527	case HID_LOCAL_ITEM_TAG_USAGE_MAXIMUM:
528
529	if (parser->local.delimiter_branch > 1) {
530	dbg_hid("alternative usage ignored\n");
531	return 0;
532	}
533
534	count = data - parser->local.usage_minimum;
535	if (count + parser->local.usage_index >= HID_MAX_USAGES) {
536	/*
537	* We do not warn if the name is not set, we are
538	* actually pre-scanning the device.
539	*/
540	if (dev_name(dev: &parser->device->dev))
541	hid_warn(parser->device,
542	"ignoring exceeding usage max\n");
543	data = HID_MAX_USAGES - parser->local.usage_index +
544	parser->local.usage_minimum - 1;
545	if (data <= 0) {
546	hid_err(parser->device,
547	"no more usage index available\n");
548	return -1;
549	}
550	}
551
552	for (n = parser->local.usage_minimum; n <= data; n++)
553	if (hid_add_usage(parser, usage: n, size: item->size)) {
554	dbg_hid("hid_add_usage failed\n");
555	return -1;
556	}
557	return 0;
558
559	default:
560
561	dbg_hid("unknown local item tag 0x%x\n", item->tag);
562	return 0;
563	}
564	return 0;
565	}
566
567	/*
568	* Concatenate Usage Pages into Usages where relevant:
569	* As per specification, 6.2.2.8: "When the parser encounters a main item it
570	* concatenates the last declared Usage Page with a Usage to form a complete
571	* usage value."
572	*/
573
574	static void hid_concatenate_last_usage_page(struct hid_parser *parser)
575	{
576	int i;
577	unsigned int usage_page;
578	unsigned int current_page;
579
580	if (!parser->local.usage_index)
581	return;
582
583	usage_page = parser->global.usage_page;
584
585	/*
586	* Concatenate usage page again only if last declared Usage Page
587	* has not been already used in previous usages concatenation
588	*/
589	for (i = parser->local.usage_index - 1; i >= 0; i--) {
590	if (parser->local.usage_size[i] > 2)
591	/* Ignore extended usages */
592	continue;
593
594	current_page = parser->local.usage[i] >> 16;
595	if (current_page == usage_page)
596	break;
597
598	complete_usage(parser, index: i);
599	}
600	}
601
602	/*
603	* Process a main item.
604	*/
605
606	static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
607	{
608	__u32 data;
609	int ret;
610
611	hid_concatenate_last_usage_page(parser);
612
613	data = item_udata(item);
614
615	switch (item->tag) {
616	case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
617	ret = open_collection(parser, type: data & 0xff);
618	break;
619	case HID_MAIN_ITEM_TAG_END_COLLECTION:
620	ret = close_collection(parser);
621	break;
622	case HID_MAIN_ITEM_TAG_INPUT:
623	ret = hid_add_field(parser, report_type: HID_INPUT_REPORT, flags: data);
624	break;
625	case HID_MAIN_ITEM_TAG_OUTPUT:
626	ret = hid_add_field(parser, report_type: HID_OUTPUT_REPORT, flags: data);
627	break;
628	case HID_MAIN_ITEM_TAG_FEATURE:
629	ret = hid_add_field(parser, report_type: HID_FEATURE_REPORT, flags: data);
630	break;
631	default:
632	hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
633	ret = 0;
634	}
635
636	memset(&parser->local, 0, sizeof(parser->local)); /* Reset the local parser environment */
637
638	return ret;
639	}
640
641	/*
642	* Process a reserved item.
643	*/
644
645	static int hid_parser_reserved(struct hid_parser *parser, struct hid_item *item)
646	{
647	dbg_hid("reserved item type, tag 0x%x\n", item->tag);
648	return 0;
649	}
650
651	/*
652	* Free a report and all registered fields. The field->usage and
653	* field->value table's are allocated behind the field, so we need
654	* only to free(field) itself.
655	*/
656
657	static void hid_free_report(struct hid_report *report)
658	{
659	unsigned n;
660
661	kfree(objp: report->field_entries);
662
663	for (n = 0; n < report->maxfield; n++)
664	kfree(objp: report->field[n]);
665	kfree(objp: report);
666	}
667
668	/*
669	* Close report. This function returns the device
670	* state to the point prior to hid_open_report().
671	*/
672	static 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(list: &report_enum->report_list);
686	}
687
688	kfree(objp: device->rdesc);
689	device->rdesc = NULL;
690	device->rsize = 0;
691
692	kfree(objp: 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
705	void hiddev_free(struct kref *ref)
706	{
707	struct hid_device *hid = container_of(ref, struct hid_device, ref);
708
709	hid_close_report(device: hid);
710	kfree(objp: hid->dev_rdesc);
711	kfree(objp: hid);
712	}
713
714	static void hid_device_release(struct device *dev)
715	{
716	struct hid_device *hid = to_hid_device(dev);
717
718	kref_put(kref: &hid->ref, release: 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
726	static 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(p: 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(p: start);
781	start = (__u8 *)((__le32 *)start + 1);
782	return start;
783	}
784
785	return NULL;
786	}
787
788	static 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
796	static 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
807	static void hid_scan_collection(struct hid_parser *parser, unsigned type)
808	{
809	struct hid_device *hid = parser->device;
810	int i;
811
812	if (((parser->global.usage_page << 16) == HID_UP_SENSOR) &&
813	(type == HID_COLLECTION_PHYSICAL ||
814	type == HID_COLLECTION_APPLICATION))
815	hid->group = HID_GROUP_SENSOR_HUB;
816
817	if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
818	hid->product == USB_DEVICE_ID_MS_POWER_COVER &&
819	hid->group == HID_GROUP_MULTITOUCH)
820	hid->group = HID_GROUP_GENERIC;
821
822	if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
823	for (i = 0; i < parser->local.usage_index; i++)
824	if (parser->local.usage[i] == HID_GD_POINTER)
825	parser->scan_flags |= HID_SCAN_FLAG_GD_POINTER;
826
827	if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
828	parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
829
830	if ((parser->global.usage_page << 16) == HID_UP_GOOGLEVENDOR)
831	for (i = 0; i < parser->local.usage_index; i++)
832	if (parser->local.usage[i] ==
833	(HID_UP_GOOGLEVENDOR | 0x0001))
834	parser->device->group =
835	HID_GROUP_VIVALDI;
836	}
837
838	static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
839	{
840	__u32 data;
841	int i;
842
843	hid_concatenate_last_usage_page(parser);
844
845	data = item_udata(item);
846
847	switch (item->tag) {
848	case HID_MAIN_ITEM_TAG_BEGIN_COLLECTION:
849	hid_scan_collection(parser, type: data & 0xff);
850	break;
851	case HID_MAIN_ITEM_TAG_END_COLLECTION:
852	break;
853	case HID_MAIN_ITEM_TAG_INPUT:
854	/* ignore constant inputs, they will be ignored by hid-input */
855	if (data & HID_MAIN_ITEM_CONSTANT)
856	break;
857	for (i = 0; i < parser->local.usage_index; i++)
858	hid_scan_input_usage(parser, usage: parser->local.usage[i]);
859	break;
860	case HID_MAIN_ITEM_TAG_OUTPUT:
861	break;
862	case HID_MAIN_ITEM_TAG_FEATURE:
863	for (i = 0; i < parser->local.usage_index; i++)
864	hid_scan_feature_usage(parser, usage: parser->local.usage[i]);
865	break;
866	}
867
868	/* Reset the local parser environment */
869	memset(&parser->local, 0, sizeof(parser->local));
870
871	return 0;
872	}
873
874	/*
875	* Scan a report descriptor before the device is added to the bus.
876	* Sets device groups and other properties that determine what driver
877	* to load.
878	*/
879	static int hid_scan_report(struct hid_device *hid)
880	{
881	struct hid_parser *parser;
882	struct hid_item item;
883	__u8 *start = hid->dev_rdesc;
884	__u8 *end = start + hid->dev_rsize;
885	static int (*dispatch_type[])(struct hid_parser *parser,
886	struct hid_item *item) = {
887	hid_scan_main,
888	hid_parser_global,
889	hid_parser_local,
890	hid_parser_reserved
891	};
892
893	parser = vzalloc(size: sizeof(struct hid_parser));
894	if (!parser)
895	return -ENOMEM;
896
897	parser->device = hid;
898	hid->group = HID_GROUP_GENERIC;
899
900	/*
901	* The parsing is simpler than the one in hid_open_report() as we should
902	* be robust against hid errors. Those errors will be raised by
903	* hid_open_report() anyway.
904	*/
905	while ((start = fetch_item(start, end, item: &item)) != NULL)
906	dispatch_type[item.type](parser, &item);
907
908	/*
909	* Handle special flags set during scanning.
910	*/
911	if ((parser->scan_flags & HID_SCAN_FLAG_MT_WIN_8) &&
912	(hid->group == HID_GROUP_MULTITOUCH))
913	hid->group = HID_GROUP_MULTITOUCH_WIN_8;
914
915	/*
916	* Vendor specific handlings
917	*/
918	switch (hid->vendor) {
919	case USB_VENDOR_ID_WACOM:
920	hid->group = HID_GROUP_WACOM;
921	break;
922	case USB_VENDOR_ID_SYNAPTICS:
923	if (hid->group == HID_GROUP_GENERIC)
924	if ((parser->scan_flags & HID_SCAN_FLAG_VENDOR_SPECIFIC)
925	&& (parser->scan_flags & HID_SCAN_FLAG_GD_POINTER))
926	/*
927	* hid-rmi should take care of them,
928	* not hid-generic
929	*/
930	hid->group = HID_GROUP_RMI;
931	break;
932	}
933
934	kfree(objp: parser->collection_stack);
935	vfree(addr: parser);
936	return 0;
937	}
938
939	/**
940	* hid_parse_report - parse device report
941	*
942	* @hid: hid device
943	* @start: report start
944	* @size: report size
945	*
946	* Allocate the device report as read by the bus driver. This function should
947	* only be called from parse() in ll drivers.
948	*/
949	int hid_parse_report(struct hid_device *hid, __u8 *start, unsigned size)
950	{
951	hid->dev_rdesc = kmemdup(p: start, size, GFP_KERNEL);
952	if (!hid->dev_rdesc)
953	return -ENOMEM;
954	hid->dev_rsize = size;
955	return 0;
956	}
957	EXPORT_SYMBOL_GPL(hid_parse_report);
958
959	static const char * const hid_report_names[] = {
960	"HID_INPUT_REPORT",
961	"HID_OUTPUT_REPORT",
962	"HID_FEATURE_REPORT",
963	};
964	/**
965	* hid_validate_values - validate existing device report's value indexes
966	*
967	* @hid: hid device
968	* @type: which report type to examine
969	* @id: which report ID to examine (0 for first)
970	* @field_index: which report field to examine
971	* @report_counts: expected number of values
972	*
973	* Validate the number of values in a given field of a given report, after
974	* parsing.
975	*/
976	struct hid_report *hid_validate_values(struct hid_device *hid,
977	enum hid_report_type type, unsigned int id,
978	unsigned int field_index,
979	unsigned int report_counts)
980	{
981	struct hid_report *report;
982
983	if (type > HID_FEATURE_REPORT) {
984	hid_err(hid, "invalid HID report type %u\n", type);
985	return NULL;
986	}
987
988	if (id >= HID_MAX_IDS) {
989	hid_err(hid, "invalid HID report id %u\n", id);
990	return NULL;
991	}
992
993	/*
994	* Explicitly not using hid_get_report() here since it depends on
995	* ->numbered being checked, which may not always be the case when
996	* drivers go to access report values.
997	*/
998	if (id == 0) {
999	/*
1000	* Validating on id 0 means we should examine the first
1001	* report in the list.
1002	*/
1003	report = list_first_entry_or_null(
1004	&hid->report_enum[type].report_list,
1005	struct hid_report, list);
1006	} else {
1007	report = hid->report_enum[type].report_id_hash[id];
1008	}
1009	if (!report) {
1010	hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
1011	return NULL;
1012	}
1013	if (report->maxfield <= field_index) {
1014	hid_err(hid, "not enough fields in %s %u\n",
1015	hid_report_names[type], id);
1016	return NULL;
1017	}
1018	if (report->field[field_index]->report_count < report_counts) {
1019	hid_err(hid, "not enough values in %s %u field %u\n",
1020	hid_report_names[type], id, field_index);
1021	return NULL;
1022	}
1023	return report;
1024	}
1025	EXPORT_SYMBOL_GPL(hid_validate_values);
1026
1027	static int hid_calculate_multiplier(struct hid_device *hid,
1028	struct hid_field *multiplier)
1029	{
1030	int m;
1031	__s32 v = *multiplier->value;
1032	__s32 lmin = multiplier->logical_minimum;
1033	__s32 lmax = multiplier->logical_maximum;
1034	__s32 pmin = multiplier->physical_minimum;
1035	__s32 pmax = multiplier->physical_maximum;
1036
1037	/*
1038	* "Because OS implementations will generally divide the control's
1039	* reported count by the Effective Resolution Multiplier, designers
1040	* should take care not to establish a potential Effective
1041	* Resolution Multiplier of zero."
1042	* HID Usage Table, v1.12, Section 4.3.1, p31
1043	*/
1044	if (lmax - lmin == 0)
1045	return 1;
1046	/*
1047	* Handling the unit exponent is left as an exercise to whoever
1048	* finds a device where that exponent is not 0.
1049	*/
1050	m = ((v - lmin)/(lmax - lmin) * (pmax - pmin) + pmin);
1051	if (unlikely(multiplier->unit_exponent != 0)) {
1052	hid_warn(hid,
1053	"unsupported Resolution Multiplier unit exponent %d\n",
1054	multiplier->unit_exponent);
1055	}
1056
1057	/* There are no devices with an effective multiplier > 255 */
1058	if (unlikely(m == 0 || m > 255 || m < -255)) {
1059	hid_warn(hid, "unsupported Resolution Multiplier %d\n", m);
1060	m = 1;
1061	}
1062
1063	return m;
1064	}
1065
1066	static void hid_apply_multiplier_to_field(struct hid_device *hid,
1067	struct hid_field *field,
1068	struct hid_collection *multiplier_collection,
1069	int effective_multiplier)
1070	{
1071	struct hid_collection *collection;
1072	struct hid_usage *usage;
1073	int i;
1074
1075	/*
1076	* If multiplier_collection is NULL, the multiplier applies
1077	* to all fields in the report.
1078	* Otherwise, it is the Logical Collection the multiplier applies to
1079	* but our field may be in a subcollection of that collection.
1080	*/
1081	for (i = 0; i < field->maxusage; i++) {
1082	usage = &field->usage[i];
1083
1084	collection = &hid->collection[usage->collection_index];
1085	while (collection->parent_idx != -1 &&
1086	collection != multiplier_collection)
1087	collection = &hid->collection[collection->parent_idx];
1088
1089	if (collection->parent_idx != -1 ||
1090	multiplier_collection == NULL)
1091	usage->resolution_multiplier = effective_multiplier;
1092
1093	}
1094	}
1095
1096	static void hid_apply_multiplier(struct hid_device *hid,
1097	struct hid_field *multiplier)
1098	{
1099	struct hid_report_enum *rep_enum;
1100	struct hid_report *rep;
1101	struct hid_field *field;
1102	struct hid_collection *multiplier_collection;
1103	int effective_multiplier;
1104	int i;
1105
1106	/*
1107	* "The Resolution Multiplier control must be contained in the same
1108	* Logical Collection as the control(s) to which it is to be applied.
1109	* If no Resolution Multiplier is defined, then the Resolution
1110	* Multiplier defaults to 1. If more than one control exists in a
1111	* Logical Collection, the Resolution Multiplier is associated with
1112	* all controls in the collection. If no Logical Collection is
1113	* defined, the Resolution Multiplier is associated with all
1114	* controls in the report."
1115	* HID Usage Table, v1.12, Section 4.3.1, p30
1116	*
1117	* Thus, search from the current collection upwards until we find a
1118	* logical collection. Then search all fields for that same parent
1119	* collection. Those are the fields the multiplier applies to.
1120	*
1121	* If we have more than one multiplier, it will overwrite the
1122	* applicable fields later.
1123	*/
1124	multiplier_collection = &hid->collection[multiplier->usage->collection_index];
1125	while (multiplier_collection->parent_idx != -1 &&
1126	multiplier_collection->type != HID_COLLECTION_LOGICAL)
1127	multiplier_collection = &hid->collection[multiplier_collection->parent_idx];
1128
1129	effective_multiplier = hid_calculate_multiplier(hid, multiplier);
1130
1131	rep_enum = &hid->report_enum[HID_INPUT_REPORT];
1132	list_for_each_entry(rep, &rep_enum->report_list, list) {
1133	for (i = 0; i < rep->maxfield; i++) {
1134	field = rep->field[i];
1135	hid_apply_multiplier_to_field(hid, field,
1136	multiplier_collection,
1137	effective_multiplier);
1138	}
1139	}
1140	}
1141
1142	/*
1143	* hid_setup_resolution_multiplier - set up all resolution multipliers
1144	*
1145	* @device: hid device
1146	*
1147	* Search for all Resolution Multiplier Feature Reports and apply their
1148	* value to all matching Input items. This only updates the internal struct
1149	* fields.
1150	*
1151	* The Resolution Multiplier is applied by the hardware. If the multiplier
1152	* is anything other than 1, the hardware will send pre-multiplied events
1153	* so that the same physical interaction generates an accumulated
1154	* accumulated_value = value * * multiplier
1155	* This may be achieved by sending
1156	* - "value * multiplier" for each event, or
1157	* - "value" but "multiplier" times as frequently, or
1158	* - a combination of the above
1159	* The only guarantee is that the same physical interaction always generates
1160	* an accumulated 'value * multiplier'.
1161	*
1162	* This function must be called before any event processing and after
1163	* any SetRequest to the Resolution Multiplier.
1164	*/
1165	void hid_setup_resolution_multiplier(struct hid_device *hid)
1166	{
1167	struct hid_report_enum *rep_enum;
1168	struct hid_report *rep;
1169	struct hid_usage *usage;
1170	int i, j;
1171
1172	rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
1173	list_for_each_entry(rep, &rep_enum->report_list, list) {
1174	for (i = 0; i < rep->maxfield; i++) {
1175	/* Ignore if report count is out of bounds. */
1176	if (rep->field[i]->report_count < 1)
1177	continue;
1178
1179	for (j = 0; j < rep->field[i]->maxusage; j++) {
1180	usage = &rep->field[i]->usage[j];
1181	if (usage->hid == HID_GD_RESOLUTION_MULTIPLIER)
1182	hid_apply_multiplier(hid,
1183	multiplier: rep->field[i]);
1184	}
1185	}
1186	}
1187	}
1188	EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier);
1189
1190	/**
1191	* hid_open_report - open a driver-specific device report
1192	*
1193	* @device: hid device
1194	*
1195	* Parse a report description into a hid_device structure. Reports are
1196	* enumerated, fields are attached to these reports.
1197	* 0 returned on success, otherwise nonzero error value.
1198	*
1199	* This function (or the equivalent hid_parse() macro) should only be
1200	* called from probe() in drivers, before starting the device.
1201	*/
1202	int hid_open_report(struct hid_device *device)
1203	{
1204	struct hid_parser *parser;
1205	struct hid_item item;
1206	unsigned int size;
1207	__u8 *start;
1208	__u8 *buf;
1209	__u8 *end;
1210	__u8 *next;
1211	int ret;
1212	int i;
1213	static int (*dispatch_type[])(struct hid_parser *parser,
1214	struct hid_item *item) = {
1215	hid_parser_main,
1216	hid_parser_global,
1217	hid_parser_local,
1218	hid_parser_reserved
1219	};
1220
1221	if (WARN_ON(device->status & HID_STAT_PARSED))
1222	return -EBUSY;
1223
1224	start = device->dev_rdesc;
1225	if (WARN_ON(!start))
1226	return -ENODEV;
1227	size = device->dev_rsize;
1228
1229	/* call_hid_bpf_rdesc_fixup() ensures we work on a copy of rdesc */
1230	buf = call_hid_bpf_rdesc_fixup(hdev: device, rdesc: start, size: &size);
1231	if (buf == NULL)
1232	return -ENOMEM;
1233
1234	if (device->driver->report_fixup)
1235	start = device->driver->report_fixup(device, buf, &size);
1236	else
1237	start = buf;
1238
1239	start = kmemdup(p: start, size, GFP_KERNEL);
1240	kfree(objp: buf);
1241	if (start == NULL)
1242	return -ENOMEM;
1243
1244	device->rdesc = start;
1245	device->rsize = size;
1246
1247	parser = vzalloc(size: sizeof(struct hid_parser));
1248	if (!parser) {
1249	ret = -ENOMEM;
1250	goto alloc_err;
1251	}
1252
1253	parser->device = device;
1254
1255	end = start + size;
1256
1257	device->collection = kcalloc(HID_DEFAULT_NUM_COLLECTIONS,
1258	size: sizeof(struct hid_collection), GFP_KERNEL);
1259	if (!device->collection) {
1260	ret = -ENOMEM;
1261	goto err;
1262	}
1263	device->collection_size = HID_DEFAULT_NUM_COLLECTIONS;
1264	for (i = 0; i < HID_DEFAULT_NUM_COLLECTIONS; i++)
1265	device->collection[i].parent_idx = -1;
1266
1267	ret = -EINVAL;
1268	while ((next = fetch_item(start, end, item: &item)) != NULL) {
1269	start = next;
1270
1271	if (item.format != HID_ITEM_FORMAT_SHORT) {
1272	hid_err(device, "unexpected long global item\n");
1273	goto err;
1274	}
1275
1276	if (dispatch_type[item.type](parser, &item)) {
1277	hid_err(device, "item %u %u %u %u parsing failed\n",
1278	item.format, (unsigned)item.size,
1279	(unsigned)item.type, (unsigned)item.tag);
1280	goto err;
1281	}
1282
1283	if (start == end) {
1284	if (parser->collection_stack_ptr) {
1285	hid_err(device, "unbalanced collection at end of report description\n");
1286	goto err;
1287	}
1288	if (parser->local.delimiter_depth) {
1289	hid_err(device, "unbalanced delimiter at end of report description\n");
1290	goto err;
1291	}
1292
1293	/*
1294	* fetch initial values in case the device's
1295	* default multiplier isn't the recommended 1
1296	*/
1297	hid_setup_resolution_multiplier(device);
1298
1299	kfree(objp: parser->collection_stack);
1300	vfree(addr: parser);
1301	device->status |= HID_STAT_PARSED;
1302
1303	return 0;
1304	}
1305	}
1306
1307	hid_err(device, "item fetching failed at offset %u/%u\n",
1308	size - (unsigned int)(end - start), size);
1309	err:
1310	kfree(objp: parser->collection_stack);
1311	alloc_err:
1312	vfree(addr: parser);
1313	hid_close_report(device);
1314	return ret;
1315	}
1316	EXPORT_SYMBOL_GPL(hid_open_report);
1317
1318	/*
1319	* Convert a signed n-bit integer to signed 32-bit integer. Common
1320	* cases are done through the compiler, the screwed things has to be
1321	* done by hand.
1322	*/
1323
1324	static s32 snto32(__u32 value, unsigned n)
1325	{
1326	if (!value || !n)
1327	return 0;
1328
1329	if (n > 32)
1330	n = 32;
1331
1332	switch (n) {
1333	case 8: return ((__s8)value);
1334	case 16: return ((__s16)value);
1335	case 32: return ((__s32)value);
1336	}
1337	return value & (1 << (n - 1)) ? value | (~0U << n) : value;
1338	}
1339
1340	s32 hid_snto32(__u32 value, unsigned n)
1341	{
1342	return snto32(value, n);
1343	}
1344	EXPORT_SYMBOL_GPL(hid_snto32);
1345
1346	/*
1347	* Convert a signed 32-bit integer to a signed n-bit integer.
1348	*/
1349
1350	static u32 s32ton(__s32 value, unsigned n)
1351	{
1352	s32 a = value >> (n - 1);
1353	if (a && a != -1)
1354	return value < 0 ? 1 << (n - 1) : (1 << (n - 1)) - 1;
1355	return value & ((1 << n) - 1);
1356	}
1357
1358	/*
1359	* Extract/implement a data field from/to a little endian report (bit array).
1360	*
1361	* Code sort-of follows HID spec:
1362	* http://www.usb.org/developers/hidpage/HID1_11.pdf
1363	*
1364	* While the USB HID spec allows unlimited length bit fields in "report
1365	* descriptors", most devices never use more than 16 bits.
1366	* One model of UPS is claimed to report "LINEV" as a 32-bit field.
1367	* Search linux-kernel and linux-usb-devel archives for "hid-core extract".
1368	*/
1369
1370	static u32 __extract(u8 *report, unsigned offset, int n)
1371	{
1372	unsigned int idx = offset / 8;
1373	unsigned int bit_nr = 0;
1374	unsigned int bit_shift = offset % 8;
1375	int bits_to_copy = 8 - bit_shift;
1376	u32 value = 0;
1377	u32 mask = n < 32 ? (1U << n) - 1 : ~0U;
1378
1379	while (n > 0) {
1380	value |= ((u32)report[idx] >> bit_shift) << bit_nr;
1381	n -= bits_to_copy;
1382	bit_nr += bits_to_copy;
1383	bits_to_copy = 8;
1384	bit_shift = 0;
1385	idx++;
1386	}
1387
1388	return value & mask;
1389	}
1390
1391	u32 hid_field_extract(const struct hid_device *hid, u8 *report,
1392	unsigned offset, unsigned n)
1393	{
1394	if (n > 32) {
1395	hid_warn_once(hid, "%s() called with n (%d) > 32! (%s)\n",
1396	__func__, n, current->comm);
1397	n = 32;
1398	}
1399
1400	return __extract(report, offset, n);
1401	}
1402	EXPORT_SYMBOL_GPL(hid_field_extract);
1403
1404	/*
1405	* "implement" : set bits in a little endian bit stream.
1406	* Same concepts as "extract" (see comments above).
1407	* The data mangled in the bit stream remains in little endian
1408	* order the whole time. It make more sense to talk about
1409	* endianness of register values by considering a register
1410	* a "cached" copy of the little endian bit stream.
1411	*/
1412
1413	static void __implement(u8 *report, unsigned offset, int n, u32 value)
1414	{
1415	unsigned int idx = offset / 8;
1416	unsigned int bit_shift = offset % 8;
1417	int bits_to_set = 8 - bit_shift;
1418
1419	while (n - bits_to_set >= 0) {
1420	report[idx] &= ~(0xff << bit_shift);
1421	report[idx] |= value << bit_shift;
1422	value >>= bits_to_set;
1423	n -= bits_to_set;
1424	bits_to_set = 8;
1425	bit_shift = 0;
1426	idx++;
1427	}
1428
1429	/* last nibble */
1430	if (n) {
1431	u8 bit_mask = ((1U << n) - 1);
1432	report[idx] &= ~(bit_mask << bit_shift);
1433	report[idx] |= value << bit_shift;
1434	}
1435	}
1436
1437	static void implement(const struct hid_device *hid, u8 *report,
1438	unsigned offset, unsigned n, u32 value)
1439	{
1440	if (unlikely(n > 32)) {
1441	hid_warn(hid, "%s() called with n (%d) > 32! (%s)\n",
1442	__func__, n, current->comm);
1443	n = 32;
1444	} else if (n < 32) {
1445	u32 m = (1U << n) - 1;
1446
1447	if (unlikely(value > m)) {
1448	hid_warn(hid,
1449	"%s() called with too large value %d (n: %d)! (%s)\n",
1450	__func__, value, n, current->comm);
1451	WARN_ON(1);
1452	value &= m;
1453	}
1454	}
1455
1456	__implement(report, offset, n, value);
1457	}
1458
1459	/*
1460	* Search an array for a value.
1461	*/
1462
1463	static int search(__s32 *array, __s32 value, unsigned n)
1464	{
1465	while (n--) {
1466	if (*array++ == value)
1467	return 0;
1468	}
1469	return -1;
1470	}
1471
1472	/**
1473	* hid_match_report - check if driver's raw_event should be called
1474	*
1475	* @hid: hid device
1476	* @report: hid report to match against
1477	*
1478	* compare hid->driver->report_table->report_type to report->type
1479	*/
1480	static int hid_match_report(struct hid_device *hid, struct hid_report *report)
1481	{
1482	const struct hid_report_id *id = hid->driver->report_table;
1483
1484	if (!id) /* NULL means all */
1485	return 1;
1486
1487	for (; id->report_type != HID_TERMINATOR; id++)
1488	if (id->report_type == HID_ANY_ID ||
1489	id->report_type == report->type)
1490	return 1;
1491	return 0;
1492	}
1493
1494	/**
1495	* hid_match_usage - check if driver's event should be called
1496	*
1497	* @hid: hid device
1498	* @usage: usage to match against
1499	*
1500	* compare hid->driver->usage_table->usage_{type,code} to
1501	* usage->usage_{type,code}
1502	*/
1503	static int hid_match_usage(struct hid_device *hid, struct hid_usage *usage)
1504	{
1505	const struct hid_usage_id *id = hid->driver->usage_table;
1506
1507	if (!id) /* NULL means all */
1508	return 1;
1509
1510	for (; id->usage_type != HID_ANY_ID - 1; id++)
1511	if ((id->usage_hid == HID_ANY_ID ||
1512	id->usage_hid == usage->hid) &&
1513	(id->usage_type == HID_ANY_ID ||
1514	id->usage_type == usage->type) &&
1515	(id->usage_code == HID_ANY_ID ||
1516	id->usage_code == usage->code))
1517	return 1;
1518	return 0;
1519	}
1520
1521	static void hid_process_event(struct hid_device *hid, struct hid_field *field,
1522	struct hid_usage *usage, __s32 value, int interrupt)
1523	{
1524	struct hid_driver *hdrv = hid->driver;
1525	int ret;
1526
1527	if (!list_empty(head: &hid->debug_list))
1528	hid_dump_input(hid, usage, value);
1529
1530	if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
1531	ret = hdrv->event(hid, field, usage, value);
1532	if (ret != 0) {
1533	if (ret < 0)
1534	hid_err(hid, "%s's event failed with %d\n",
1535	hdrv->name, ret);
1536	return;
1537	}
1538	}
1539
1540	if (hid->claimed & HID_CLAIMED_INPUT)
1541	hidinput_hid_event(hid, field, usage, value);
1542	if (hid->claimed & HID_CLAIMED_HIDDEV && interrupt && hid->hiddev_hid_event)
1543	hid->hiddev_hid_event(hid, field, usage, value);
1544	}
1545
1546	/*
1547	* Checks if the given value is valid within this field
1548	*/
1549	static inline int hid_array_value_is_valid(struct hid_field *field,
1550	__s32 value)
1551	{
1552	__s32 min = field->logical_minimum;
1553
1554	/*
1555	* Value needs to be between logical min and max, and
1556	* (value - min) is used as an index in the usage array.
1557	* This array is of size field->maxusage
1558	*/
1559	return value >= min &&
1560	value <= field->logical_maximum &&
1561	value - min < field->maxusage;
1562	}
1563
1564	/*
1565	* Fetch the field from the data. The field content is stored for next
1566	* report processing (we do differential reporting to the layer).
1567	*/
1568	static void hid_input_fetch_field(struct hid_device *hid,
1569	struct hid_field *field,
1570	__u8 *data)
1571	{
1572	unsigned n;
1573	unsigned count = field->report_count;
1574	unsigned offset = field->report_offset;
1575	unsigned size = field->report_size;
1576	__s32 min = field->logical_minimum;
1577	__s32 *value;
1578
1579	value = field->new_value;
1580	memset(value, 0, count * sizeof(__s32));
1581	field->ignored = false;
1582
1583	for (n = 0; n < count; n++) {
1584
1585	value[n] = min < 0 ?
1586	snto32(value: hid_field_extract(hid, data, offset + n * size,
1587	size), n: size) :
1588	hid_field_extract(hid, data, offset + n * size, size);
1589
1590	/* Ignore report if ErrorRollOver */
1591	if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
1592	hid_array_value_is_valid(field, value: value[n]) &&
1593	field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1) {
1594	field->ignored = true;
1595	return;
1596	}
1597	}
1598	}
1599
1600	/*
1601	* Process a received variable field.
1602	*/
1603
1604	static void hid_input_var_field(struct hid_device *hid,
1605	struct hid_field *field,
1606	int interrupt)
1607	{
1608	unsigned int count = field->report_count;
1609	__s32 *value = field->new_value;
1610	unsigned int n;
1611
1612	for (n = 0; n < count; n++)
1613	hid_process_event(hid,
1614	field,
1615	usage: &field->usage[n],
1616	value: value[n],
1617	interrupt);
1618
1619	memcpy(field->value, value, count * sizeof(__s32));
1620	}
1621
1622	/*
1623	* Process a received array field. The field content is stored for
1624	* next report processing (we do differential reporting to the layer).
1625	*/
1626
1627	static void hid_input_array_field(struct hid_device *hid,
1628	struct hid_field *field,
1629	int interrupt)
1630	{
1631	unsigned int n;
1632	unsigned int count = field->report_count;
1633	__s32 min = field->logical_minimum;
1634	__s32 *value;
1635
1636	value = field->new_value;
1637
1638	/* ErrorRollOver */
1639	if (field->ignored)
1640	return;
1641
1642	for (n = 0; n < count; n++) {
1643	if (hid_array_value_is_valid(field, value: field->value[n]) &&
1644	search(array: value, value: field->value[n], n: count))
1645	hid_process_event(hid,
1646	field,
1647	usage: &field->usage[field->value[n] - min],
1648	value: 0,
1649	interrupt);
1650
1651	if (hid_array_value_is_valid(field, value: value[n]) &&
1652	search(array: field->value, value: value[n], n: count))
1653	hid_process_event(hid,
1654	field,
1655	usage: &field->usage[value[n] - min],
1656	value: 1,
1657	interrupt);
1658	}
1659
1660	memcpy(field->value, value, count * sizeof(__s32));
1661	}
1662
1663	/*
1664	* Analyse a received report, and fetch the data from it. The field
1665	* content is stored for next report processing (we do differential
1666	* reporting to the layer).
1667	*/
1668	static void hid_process_report(struct hid_device *hid,
1669	struct hid_report *report,
1670	__u8 *data,
1671	int interrupt)
1672	{
1673	unsigned int a;
1674	struct hid_field_entry *entry;
1675	struct hid_field *field;
1676
1677	/* first retrieve all incoming values in data */
1678	for (a = 0; a < report->maxfield; a++)
1679	hid_input_fetch_field(hid, field: report->field[a], data);
1680
1681	if (!list_empty(head: &report->field_entry_list)) {
1682	/* INPUT_REPORT, we have a priority list of fields */
1683	list_for_each_entry(entry,
1684	&report->field_entry_list,
1685	list) {
1686	field = entry->field;
1687
1688	if (field->flags & HID_MAIN_ITEM_VARIABLE)
1689	hid_process_event(hid,
1690	field,
1691	usage: &field->usage[entry->index],
1692	value: field->new_value[entry->index],
1693	interrupt);
1694	else
1695	hid_input_array_field(hid, field, interrupt);
1696	}
1697
1698	/* we need to do the memcpy at the end for var items */
1699	for (a = 0; a < report->maxfield; a++) {
1700	field = report->field[a];
1701
1702	if (field->flags & HID_MAIN_ITEM_VARIABLE)
1703	memcpy(field->value, field->new_value,
1704	field->report_count * sizeof(__s32));
1705	}
1706	} else {
1707	/* FEATURE_REPORT, regular processing */
1708	for (a = 0; a < report->maxfield; a++) {
1709	field = report->field[a];
1710
1711	if (field->flags & HID_MAIN_ITEM_VARIABLE)
1712	hid_input_var_field(hid, field, interrupt);
1713	else
1714	hid_input_array_field(hid, field, interrupt);
1715	}
1716	}
1717	}
1718
1719	/*
1720	* Insert a given usage_index in a field in the list
1721	* of processed usages in the report.
1722	*
1723	* The elements of lower priority score are processed
1724	* first.
1725	*/
1726	static void __hid_insert_field_entry(struct hid_device *hid,
1727	struct hid_report *report,
1728	struct hid_field_entry *entry,
1729	struct hid_field *field,
1730	unsigned int usage_index)
1731	{
1732	struct hid_field_entry *next;
1733
1734	entry->field = field;
1735	entry->index = usage_index;
1736	entry->priority = field->usages_priorities[usage_index];
1737
1738	/* insert the element at the correct position */
1739	list_for_each_entry(next,
1740	&report->field_entry_list,
1741	list) {
1742	/*
1743	* the priority of our element is strictly higher
1744	* than the next one, insert it before
1745	*/
1746	if (entry->priority > next->priority) {
1747	list_add_tail(new: &entry->list, head: &next->list);
1748	return;
1749	}
1750	}
1751
1752	/* lowest priority score: insert at the end */
1753	list_add_tail(new: &entry->list, head: &report->field_entry_list);
1754	}
1755
1756	static void hid_report_process_ordering(struct hid_device *hid,
1757	struct hid_report *report)
1758	{
1759	struct hid_field *field;
1760	struct hid_field_entry *entries;
1761	unsigned int a, u, usages;
1762	unsigned int count = 0;
1763
1764	/* count the number of individual fields in the report */
1765	for (a = 0; a < report->maxfield; a++) {
1766	field = report->field[a];
1767
1768	if (field->flags & HID_MAIN_ITEM_VARIABLE)
1769	count += field->report_count;
1770	else
1771	count++;
1772	}
1773
1774	/* allocate the memory to process the fields */
1775	entries = kcalloc(n: count, size: sizeof(*entries), GFP_KERNEL);
1776	if (!entries)
1777	return;
1778
1779	report->field_entries = entries;
1780
1781	/*
1782	* walk through all fields in the report and
1783	* store them by priority order in report->field_entry_list
1784	*
1785	* - Var elements are individualized (field + usage_index)
1786	* - Arrays are taken as one, we can not chose an order for them
1787	*/
1788	usages = 0;
1789	for (a = 0; a < report->maxfield; a++) {
1790	field = report->field[a];
1791
1792	if (field->flags & HID_MAIN_ITEM_VARIABLE) {
1793	for (u = 0; u < field->report_count; u++) {
1794	__hid_insert_field_entry(hid, report,
1795	entry: &entries[usages],
1796	field, usage_index: u);
1797	usages++;
1798	}
1799	} else {
1800	__hid_insert_field_entry(hid, report, entry: &entries[usages],
1801	field, usage_index: 0);
1802	usages++;
1803	}
1804	}
1805	}
1806
1807	static void hid_process_ordering(struct hid_device *hid)
1808	{
1809	struct hid_report *report;
1810	struct hid_report_enum *report_enum = &hid->report_enum[HID_INPUT_REPORT];
1811
1812	list_for_each_entry(report, &report_enum->report_list, list)
1813	hid_report_process_ordering(hid, report);
1814	}
1815
1816	/*
1817	* Output the field into the report.
1818	*/
1819
1820	static void hid_output_field(const struct hid_device *hid,
1821	struct hid_field *field, __u8 *data)
1822	{
1823	unsigned count = field->report_count;
1824	unsigned offset = field->report_offset;
1825	unsigned size = field->report_size;
1826	unsigned n;
1827
1828	for (n = 0; n < count; n++) {
1829	if (field->logical_minimum < 0) /* signed values */
1830	implement(hid, report: data, offset: offset + n * size, n: size,
1831	value: s32ton(value: field->value[n], n: size));
1832	else /* unsigned values */
1833	implement(hid, report: data, offset: offset + n * size, n: size,
1834	value: field->value[n]);
1835	}
1836	}
1837
1838	/*
1839	* Compute the size of a report.
1840	*/
1841	static size_t hid_compute_report_size(struct hid_report *report)
1842	{
1843	if (report->size)
1844	return ((report->size - 1) >> 3) + 1;
1845
1846	return 0;
1847	}
1848
1849	/*
1850	* Create a report. 'data' has to be allocated using
1851	* hid_alloc_report_buf() so that it has proper size.
1852	*/
1853
1854	void hid_output_report(struct hid_report *report, __u8 *data)
1855	{
1856	unsigned n;
1857
1858	if (report->id > 0)
1859	*data++ = report->id;
1860
1861	memset(data, 0, hid_compute_report_size(report));
1862	for (n = 0; n < report->maxfield; n++)
1863	hid_output_field(hid: report->device, field: report->field[n], data);
1864	}
1865	EXPORT_SYMBOL_GPL(hid_output_report);
1866
1867	/*
1868	* Allocator for buffer that is going to be passed to hid_output_report()
1869	*/
1870	u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags)
1871	{
1872	/*
1873	* 7 extra bytes are necessary to achieve proper functionality
1874	* of implement() working on 8 byte chunks
1875	*/
1876
1877	u32 len = hid_report_len(report) + 7;
1878
1879	return kmalloc(size: len, flags);
1880	}
1881	EXPORT_SYMBOL_GPL(hid_alloc_report_buf);
1882
1883	/*
1884	* Set a field value. The report this field belongs to has to be
1885	* created and transferred to the device, to set this value in the
1886	* device.
1887	*/
1888
1889	int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
1890	{
1891	unsigned size;
1892
1893	if (!field)
1894	return -1;
1895
1896	size = field->report_size;
1897
1898	hid_dump_input(field->report->device, field->usage + offset, value);
1899
1900	if (offset >= field->report_count) {
1901	hid_err(field->report->device, "offset (%d) exceeds report_count (%d)\n",
1902	offset, field->report_count);
1903	return -1;
1904	}
1905	if (field->logical_minimum < 0) {
1906	if (value != snto32(value: s32ton(value, n: size), n: size)) {
1907	hid_err(field->report->device, "value %d is out of range\n", value);
1908	return -1;
1909	}
1910	}
1911	field->value[offset] = value;
1912	return 0;
1913	}
1914	EXPORT_SYMBOL_GPL(hid_set_field);
1915
1916	static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
1917	const u8 *data)
1918	{
1919	struct hid_report *report;
1920	unsigned int n = 0; /* Normally report number is 0 */
1921
1922	/* Device uses numbered reports, data[0] is report number */
1923	if (report_enum->numbered)
1924	n = *data;
1925
1926	report = report_enum->report_id_hash[n];
1927	if (report == NULL)
1928	dbg_hid("undefined report_id %u received\n", n);
1929
1930	return report;
1931	}
1932
1933	/*
1934	* Implement a generic .request() callback, using .raw_request()
1935	* DO NOT USE in hid drivers directly, but through hid_hw_request instead.
1936	*/
1937	int __hid_request(struct hid_device *hid, struct hid_report *report,
1938	enum hid_class_request reqtype)
1939	{
1940	char *buf;
1941	int ret;
1942	u32 len;
1943
1944	buf = hid_alloc_report_buf(report, GFP_KERNEL);
1945	if (!buf)
1946	return -ENOMEM;
1947
1948	len = hid_report_len(report);
1949
1950	if (reqtype == HID_REQ_SET_REPORT)
1951	hid_output_report(report, buf);
1952
1953	ret = hid->ll_driver->raw_request(hid, report->id, buf, len,
1954	report->type, reqtype);
1955	if (ret < 0) {
1956	dbg_hid("unable to complete request: %d\n", ret);
1957	goto out;
1958	}
1959
1960	if (reqtype == HID_REQ_GET_REPORT)
1961	hid_input_report(hid, type: report->type, data: buf, size: ret, interrupt: 0);
1962
1963	ret = 0;
1964
1965	out:
1966	kfree(objp: buf);
1967	return ret;
1968	}
1969	EXPORT_SYMBOL_GPL(__hid_request);
1970
1971	int hid_report_raw_event(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
1972	int interrupt)
1973	{
1974	struct hid_report_enum *report_enum = hid->report_enum + type;
1975	struct hid_report *report;
1976	struct hid_driver *hdrv;
1977	int max_buffer_size = HID_MAX_BUFFER_SIZE;
1978	u32 rsize, csize = size;
1979	u8 *cdata = data;
1980	int ret = 0;
1981
1982	report = hid_get_report(report_enum, data);
1983	if (!report)
1984	goto out;
1985
1986	if (report_enum->numbered) {
1987	cdata++;
1988	csize--;
1989	}
1990
1991	rsize = hid_compute_report_size(report);
1992
1993	if (hid->ll_driver->max_buffer_size)
1994	max_buffer_size = hid->ll_driver->max_buffer_size;
1995
1996	if (report_enum->numbered && rsize >= max_buffer_size)
1997	rsize = max_buffer_size - 1;
1998	else if (rsize > max_buffer_size)
1999	rsize = max_buffer_size;
2000
2001	if (csize < rsize) {
2002	dbg_hid("report %d is too short, (%d < %d)\n", report->id,
2003	csize, rsize);
2004	memset(cdata + csize, 0, rsize - csize);
2005	}
2006
2007	if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_report_event)
2008	hid->hiddev_report_event(hid, report);
2009	if (hid->claimed & HID_CLAIMED_HIDRAW) {
2010	ret = hidraw_report_event(hid, data, size);
2011	if (ret)
2012	goto out;
2013	}
2014
2015	if (hid->claimed != HID_CLAIMED_HIDRAW && report->maxfield) {
2016	hid_process_report(hid, report, data: cdata, interrupt);
2017	hdrv = hid->driver;
2018	if (hdrv && hdrv->report)
2019	hdrv->report(hid, report);
2020	}
2021
2022	if (hid->claimed & HID_CLAIMED_INPUT)
2023	hidinput_report_event(hid, report);
2024	out:
2025	return ret;
2026	}
2027	EXPORT_SYMBOL_GPL(hid_report_raw_event);
2028
2029	/**
2030	* hid_input_report - report data from lower layer (usb, bt...)
2031	*
2032	* @hid: hid device
2033	* @type: HID report type (HID_*_REPORT)
2034	* @data: report contents
2035	* @size: size of data parameter
2036	* @interrupt: distinguish between interrupt and control transfers
2037	*
2038	* This is data entry for lower layers.
2039	*/
2040	int hid_input_report(struct hid_device *hid, enum hid_report_type type, u8 *data, u32 size,
2041	int interrupt)
2042	{
2043	struct hid_report_enum *report_enum;
2044	struct hid_driver *hdrv;
2045	struct hid_report *report;
2046	int ret = 0;
2047
2048	if (!hid)
2049	return -ENODEV;
2050
2051	if (down_trylock(sem: &hid->driver_input_lock))
2052	return -EBUSY;
2053
2054	if (!hid->driver) {
2055	ret = -ENODEV;
2056	goto unlock;
2057	}
2058	report_enum = hid->report_enum + type;
2059	hdrv = hid->driver;
2060
2061	data = dispatch_hid_bpf_device_event(hid, type, data, size: &size, interrupt);
2062	if (IS_ERR(ptr: data)) {
2063	ret = PTR_ERR(ptr: data);
2064	goto unlock;
2065	}
2066
2067	if (!size) {
2068	dbg_hid("empty report\n");
2069	ret = -1;
2070	goto unlock;
2071	}
2072
2073	/* Avoid unnecessary overhead if debugfs is disabled */
2074	if (!list_empty(head: &hid->debug_list))
2075	hid_dump_report(hid, type, data, size);
2076
2077	report = hid_get_report(report_enum, data);
2078
2079	if (!report) {
2080	ret = -1;
2081	goto unlock;
2082	}
2083
2084	if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
2085	ret = hdrv->raw_event(hid, report, data, size);
2086	if (ret < 0)
2087	goto unlock;
2088	}
2089
2090	ret = hid_report_raw_event(hid, type, data, size, interrupt);
2091
2092	unlock:
2093	up(sem: &hid->driver_input_lock);
2094	return ret;
2095	}
2096	EXPORT_SYMBOL_GPL(hid_input_report);
2097
2098	bool hid_match_one_id(const struct hid_device *hdev,
2099	const struct hid_device_id *id)
2100	{
2101	return (id->bus == HID_BUS_ANY || id->bus == hdev->bus) &&
2102	(id->group == HID_GROUP_ANY || id->group == hdev->group) &&
2103	(id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&
2104	(id->product == HID_ANY_ID || id->product == hdev->product);
2105	}
2106
2107	const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
2108	const struct hid_device_id *id)
2109	{
2110	for (; id->bus; id++)
2111	if (hid_match_one_id(hdev, id))
2112	return id;
2113
2114	return NULL;
2115	}
2116	EXPORT_SYMBOL_GPL(hid_match_id);
2117
2118	static const struct hid_device_id hid_hiddev_list[] = {
2119	{ HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS) },
2120	{ HID_USB_DEVICE(USB_VENDOR_ID_MGE, USB_DEVICE_ID_MGE_UPS1) },
2121	{ }
2122	};
2123
2124	static bool hid_hiddev(struct hid_device *hdev)
2125	{
2126	return !!hid_match_id(hdev, hid_hiddev_list);
2127	}
2128
2129
2130	static ssize_t
2131	read_report_descriptor(struct file *filp, struct kobject *kobj,
2132	struct bin_attribute *attr,
2133	char *buf, loff_t off, size_t count)
2134	{
2135	struct device *dev = kobj_to_dev(kobj);
2136	struct hid_device *hdev = to_hid_device(dev);
2137
2138	if (off >= hdev->rsize)
2139	return 0;
2140
2141	if (off + count > hdev->rsize)
2142	count = hdev->rsize - off;
2143
2144	memcpy(buf, hdev->rdesc + off, count);
2145
2146	return count;
2147	}
2148
2149	static ssize_t
2150	show_country(struct device *dev, struct device_attribute *attr,
2151	char *buf)
2152	{
2153	struct hid_device *hdev = to_hid_device(dev);
2154
2155	return sprintf(buf, fmt: "%02x\n", hdev->country & 0xff);
2156	}
2157
2158	static struct bin_attribute dev_bin_attr_report_desc = {
2159	.attr = { .name = "report_descriptor", .mode = 0444 },
2160	.read = read_report_descriptor,
2161	.size = HID_MAX_DESCRIPTOR_SIZE,
2162	};
2163
2164	static const struct device_attribute dev_attr_country = {
2165	.attr = { .name = "country", .mode = 0444 },
2166	.show = show_country,
2167	};
2168
2169	int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
2170	{
2171	static const char *types[] = { "Device", "Pointer", "Mouse", "Device",
2172	"Joystick", "Gamepad", "Keyboard", "Keypad",
2173	"Multi-Axis Controller"
2174	};
2175	const char *type, *bus;
2176	char buf[64] = "";
2177	unsigned int i;
2178	int len;
2179	int ret;
2180
2181	ret = hid_bpf_connect_device(hdev);
2182	if (ret)
2183	return ret;
2184
2185	if (hdev->quirks & HID_QUIRK_HIDDEV_FORCE)
2186	connect_mask |= (HID_CONNECT_HIDDEV_FORCE | HID_CONNECT_HIDDEV);
2187	if (hdev->quirks & HID_QUIRK_HIDINPUT_FORCE)
2188	connect_mask |= HID_CONNECT_HIDINPUT_FORCE;
2189	if (hdev->bus != BUS_USB)
2190	connect_mask &= ~HID_CONNECT_HIDDEV;
2191	if (hid_hiddev(hdev))
2192	connect_mask |= HID_CONNECT_HIDDEV_FORCE;
2193
2194	if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hid: hdev,
2195	force: connect_mask & HID_CONNECT_HIDINPUT_FORCE))
2196	hdev->claimed |= HID_CLAIMED_INPUT;
2197
2198	if ((connect_mask & HID_CONNECT_HIDDEV) && hdev->hiddev_connect &&
2199	!hdev->hiddev_connect(hdev,
2200	connect_mask & HID_CONNECT_HIDDEV_FORCE))
2201	hdev->claimed |= HID_CLAIMED_HIDDEV;
2202	if ((connect_mask & HID_CONNECT_HIDRAW) && !hidraw_connect(hdev))
2203	hdev->claimed |= HID_CLAIMED_HIDRAW;
2204
2205	if (connect_mask & HID_CONNECT_DRIVER)
2206	hdev->claimed |= HID_CLAIMED_DRIVER;
2207
2208	/* Drivers with the ->raw_event callback set are not required to connect
2209	* to any other listener. */
2210	if (!hdev->claimed && !hdev->driver->raw_event) {
2211	hid_err(hdev, "device has no listeners, quitting\n");
2212	return -ENODEV;
2213	}
2214
2215	hid_process_ordering(hid: hdev);
2216
2217	if ((hdev->claimed & HID_CLAIMED_INPUT) &&
2218	(connect_mask & HID_CONNECT_FF) && hdev->ff_init)
2219	hdev->ff_init(hdev);
2220
2221	len = 0;
2222	if (hdev->claimed & HID_CLAIMED_INPUT)
2223	len += sprintf(buf: buf + len, fmt: "input");
2224	if (hdev->claimed & HID_CLAIMED_HIDDEV)
2225	len += sprintf(buf: buf + len, fmt: "%shiddev%d", len ? "," : "",
2226	((struct hiddev *)hdev->hiddev)->minor);
2227	if (hdev->claimed & HID_CLAIMED_HIDRAW)
2228	len += sprintf(buf: buf + len, fmt: "%shidraw%d", len ? "," : "",
2229	((struct hidraw *)hdev->hidraw)->minor);
2230
2231	type = "Device";
2232	for (i = 0; i < hdev->maxcollection; i++) {
2233	struct hid_collection *col = &hdev->collection[i];
2234	if (col->type == HID_COLLECTION_APPLICATION &&
2235	(col->usage & HID_USAGE_PAGE) == HID_UP_GENDESK &&
2236	(col->usage & 0xffff) < ARRAY_SIZE(types)) {
2237	type = types[col->usage & 0xffff];
2238	break;
2239	}
2240	}
2241
2242	switch (hdev->bus) {
2243	case BUS_USB:
2244	bus = "USB";
2245	break;
2246	case BUS_BLUETOOTH:
2247	bus = "BLUETOOTH";
2248	break;
2249	case BUS_I2C:
2250	bus = "I2C";
2251	break;
2252	case BUS_VIRTUAL:
2253	bus = "VIRTUAL";
2254	break;
2255	case BUS_INTEL_ISHTP:
2256	case BUS_AMD_SFH:
2257	bus = "SENSOR HUB";
2258	break;
2259	default:
2260	bus = "<UNKNOWN>";
2261	}
2262
2263	ret = device_create_file(device: &hdev->dev, entry: &dev_attr_country);
2264	if (ret)
2265	hid_warn(hdev,
2266	"can't create sysfs country code attribute err: %d\n", ret);
2267
2268	hid_info(hdev, "%s: %s HID v%x.%02x %s [%s] on %s\n",
2269	buf, bus, hdev->version >> 8, hdev->version & 0xff,
2270	type, hdev->name, hdev->phys);
2271
2272	return 0;
2273	}
2274	EXPORT_SYMBOL_GPL(hid_connect);
2275
2276	void hid_disconnect(struct hid_device *hdev)
2277	{
2278	device_remove_file(dev: &hdev->dev, attr: &dev_attr_country);
2279	if (hdev->claimed & HID_CLAIMED_INPUT)
2280	hidinput_disconnect(hdev);
2281	if (hdev->claimed & HID_CLAIMED_HIDDEV)
2282	hdev->hiddev_disconnect(hdev);
2283	if (hdev->claimed & HID_CLAIMED_HIDRAW)
2284	hidraw_disconnect(hdev);
2285	hdev->claimed = 0;
2286
2287	hid_bpf_disconnect_device(hdev);
2288	}
2289	EXPORT_SYMBOL_GPL(hid_disconnect);
2290
2291	/**
2292	* hid_hw_start - start underlying HW
2293	* @hdev: hid device
2294	* @connect_mask: which outputs to connect, see HID_CONNECT_*
2295	*
2296	* Call this in probe function *after* hid_parse. This will setup HW
2297	* buffers and start the device (if not defeirred to device open).
2298	* hid_hw_stop must be called if this was successful.
2299	*/
2300	int hid_hw_start(struct hid_device *hdev, unsigned int connect_mask)
2301	{
2302	int error;
2303
2304	error = hdev->ll_driver->start(hdev);
2305	if (error)
2306	return error;
2307
2308	if (connect_mask) {
2309	error = hid_connect(hdev, connect_mask);
2310	if (error) {
2311	hdev->ll_driver->stop(hdev);
2312	return error;
2313	}
2314	}
2315
2316	return 0;
2317	}
2318	EXPORT_SYMBOL_GPL(hid_hw_start);
2319
2320	/**
2321	* hid_hw_stop - stop underlying HW
2322	* @hdev: hid device
2323	*
2324	* This is usually called from remove function or from probe when something
2325	* failed and hid_hw_start was called already.
2326	*/
2327	void hid_hw_stop(struct hid_device *hdev)
2328	{
2329	hid_disconnect(hdev);
2330	hdev->ll_driver->stop(hdev);
2331	}
2332	EXPORT_SYMBOL_GPL(hid_hw_stop);
2333
2334	/**
2335	* hid_hw_open - signal underlying HW to start delivering events
2336	* @hdev: hid device
2337	*
2338	* Tell underlying HW to start delivering events from the device.
2339	* This function should be called sometime after successful call
2340	* to hid_hw_start().
2341	*/
2342	int hid_hw_open(struct hid_device *hdev)
2343	{
2344	int ret;
2345
2346	ret = mutex_lock_killable(&hdev->ll_open_lock);
2347	if (ret)
2348	return ret;
2349
2350	if (!hdev->ll_open_count++) {
2351	ret = hdev->ll_driver->open(hdev);
2352	if (ret)
2353	hdev->ll_open_count--;
2354	}
2355
2356	mutex_unlock(lock: &hdev->ll_open_lock);
2357	return ret;
2358	}
2359	EXPORT_SYMBOL_GPL(hid_hw_open);
2360
2361	/**
2362	* hid_hw_close - signal underlaying HW to stop delivering events
2363	*
2364	* @hdev: hid device
2365	*
2366	* This function indicates that we are not interested in the events
2367	* from this device anymore. Delivery of events may or may not stop,
2368	* depending on the number of users still outstanding.
2369	*/
2370	void hid_hw_close(struct hid_device *hdev)
2371	{
2372	mutex_lock(&hdev->ll_open_lock);
2373	if (!--hdev->ll_open_count)
2374	hdev->ll_driver->close(hdev);
2375	mutex_unlock(lock: &hdev->ll_open_lock);
2376	}
2377	EXPORT_SYMBOL_GPL(hid_hw_close);
2378
2379	/**
2380	* hid_hw_request - send report request to device
2381	*
2382	* @hdev: hid device
2383	* @report: report to send
2384	* @reqtype: hid request type
2385	*/
2386	void hid_hw_request(struct hid_device *hdev,
2387	struct hid_report *report, enum hid_class_request reqtype)
2388	{
2389	if (hdev->ll_driver->request)
2390	return hdev->ll_driver->request(hdev, report, reqtype);
2391
2392	__hid_request(hdev, report, reqtype);
2393	}
2394	EXPORT_SYMBOL_GPL(hid_hw_request);
2395
2396	/**
2397	* hid_hw_raw_request - send report request to device
2398	*
2399	* @hdev: hid device
2400	* @reportnum: report ID
2401	* @buf: in/out data to transfer
2402	* @len: length of buf
2403	* @rtype: HID report type
2404	* @reqtype: HID_REQ_GET_REPORT or HID_REQ_SET_REPORT
2405	*
2406	* Return: count of data transferred, negative if error
2407	*
2408	* Same behavior as hid_hw_request, but with raw buffers instead.
2409	*/
2410	int hid_hw_raw_request(struct hid_device *hdev,
2411	unsigned char reportnum, __u8 *buf,
2412	size_t len, enum hid_report_type rtype, enum hid_class_request reqtype)
2413	{
2414	unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
2415
2416	if (hdev->ll_driver->max_buffer_size)
2417	max_buffer_size = hdev->ll_driver->max_buffer_size;
2418
2419	if (len < 1 || len > max_buffer_size || !buf)
2420	return -EINVAL;
2421
2422	return hdev->ll_driver->raw_request(hdev, reportnum, buf, len,
2423	rtype, reqtype);
2424	}
2425	EXPORT_SYMBOL_GPL(hid_hw_raw_request);
2426
2427	/**
2428	* hid_hw_output_report - send output report to device
2429	*
2430	* @hdev: hid device
2431	* @buf: raw data to transfer
2432	* @len: length of buf
2433	*
2434	* Return: count of data transferred, negative if error
2435	*/
2436	int hid_hw_output_report(struct hid_device *hdev, __u8 *buf, size_t len)
2437	{
2438	unsigned int max_buffer_size = HID_MAX_BUFFER_SIZE;
2439
2440	if (hdev->ll_driver->max_buffer_size)
2441	max_buffer_size = hdev->ll_driver->max_buffer_size;
2442
2443	if (len < 1 || len > max_buffer_size || !buf)
2444	return -EINVAL;
2445
2446	if (hdev->ll_driver->output_report)
2447	return hdev->ll_driver->output_report(hdev, buf, len);
2448
2449	return -ENOSYS;
2450	}
2451	EXPORT_SYMBOL_GPL(hid_hw_output_report);
2452
2453	#ifdef CONFIG_PM
2454	int hid_driver_suspend(struct hid_device *hdev, pm_message_t state)
2455	{
2456	if (hdev->driver && hdev->driver->suspend)
2457	return hdev->driver->suspend(hdev, state);
2458
2459	return 0;
2460	}
2461	EXPORT_SYMBOL_GPL(hid_driver_suspend);
2462
2463	int hid_driver_reset_resume(struct hid_device *hdev)
2464	{
2465	if (hdev->driver && hdev->driver->reset_resume)
2466	return hdev->driver->reset_resume(hdev);
2467
2468	return 0;
2469	}
2470	EXPORT_SYMBOL_GPL(hid_driver_reset_resume);
2471
2472	int hid_driver_resume(struct hid_device *hdev)
2473	{
2474	if (hdev->driver && hdev->driver->resume)
2475	return hdev->driver->resume(hdev);
2476
2477	return 0;
2478	}
2479	EXPORT_SYMBOL_GPL(hid_driver_resume);
2480	#endif /* CONFIG_PM */
2481
2482	struct hid_dynid {
2483	struct list_head list;
2484	struct hid_device_id id;
2485	};
2486
2487	/**
2488	* new_id_store - add a new HID device ID to this driver and re-probe devices
2489	* @drv: target device driver
2490	* @buf: buffer for scanning device ID data
2491	* @count: input size
2492	*
2493	* Adds a new dynamic hid device ID to this driver,
2494	* and causes the driver to probe for all devices again.
2495	*/
2496	static ssize_t new_id_store(struct device_driver *drv, const char *buf,
2497	size_t count)
2498	{
2499	struct hid_driver *hdrv = to_hid_driver(drv);
2500	struct hid_dynid *dynid;
2501	__u32 bus, vendor, product;
2502	unsigned long driver_data = 0;
2503	int ret;
2504
2505	ret = sscanf(buf, "%x %x %x %lx",
2506	&bus, &vendor, &product, &driver_data);
2507	if (ret < 3)
2508	return -EINVAL;
2509
2510	dynid = kzalloc(size: sizeof(*dynid), GFP_KERNEL);
2511	if (!dynid)
2512	return -ENOMEM;
2513
2514	dynid->id.bus = bus;
2515	dynid->id.group = HID_GROUP_ANY;
2516	dynid->id.vendor = vendor;
2517	dynid->id.product = product;
2518	dynid->id.driver_data = driver_data;
2519
2520	spin_lock(lock: &hdrv->dyn_lock);
2521	list_add_tail(new: &dynid->list, head: &hdrv->dyn_list);
2522	spin_unlock(lock: &hdrv->dyn_lock);
2523
2524	ret = driver_attach(drv: &hdrv->driver);
2525
2526	return ret ? : count;
2527	}
2528	static DRIVER_ATTR_WO(new_id);
2529
2530	static struct attribute *hid_drv_attrs[] = {
2531	&driver_attr_new_id.attr,
2532	NULL,
2533	};
2534	ATTRIBUTE_GROUPS(hid_drv);
2535
2536	static void hid_free_dynids(struct hid_driver *hdrv)
2537	{
2538	struct hid_dynid *dynid, *n;
2539
2540	spin_lock(lock: &hdrv->dyn_lock);
2541	list_for_each_entry_safe(dynid, n, &hdrv->dyn_list, list) {
2542	list_del(entry: &dynid->list);
2543	kfree(objp: dynid);
2544	}
2545	spin_unlock(lock: &hdrv->dyn_lock);
2546	}
2547
2548	const struct hid_device_id *hid_match_device(struct hid_device *hdev,
2549	struct hid_driver *hdrv)
2550	{
2551	struct hid_dynid *dynid;
2552
2553	spin_lock(lock: &hdrv->dyn_lock);
2554	list_for_each_entry(dynid, &hdrv->dyn_list, list) {
2555	if (hid_match_one_id(hdev, id: &dynid->id)) {
2556	spin_unlock(lock: &hdrv->dyn_lock);
2557	return &dynid->id;
2558	}
2559	}
2560	spin_unlock(lock: &hdrv->dyn_lock);
2561
2562	return hid_match_id(hdev, hdrv->id_table);
2563	}
2564	EXPORT_SYMBOL_GPL(hid_match_device);
2565
2566	static int hid_bus_match(struct device *dev, struct device_driver *drv)
2567	{
2568	struct hid_driver *hdrv = to_hid_driver(drv);
2569	struct hid_device *hdev = to_hid_device(dev);
2570
2571	return hid_match_device(hdev, hdrv) != NULL;
2572	}
2573
2574	/**
2575	* hid_compare_device_paths - check if both devices share the same path
2576	* @hdev_a: hid device
2577	* @hdev_b: hid device
2578	* @separator: char to use as separator
2579	*
2580	* Check if two devices share the same path up to the last occurrence of
2581	* the separator char. Both paths must exist (i.e., zero-length paths
2582	* don't match).
2583	*/
2584	bool hid_compare_device_paths(struct hid_device *hdev_a,
2585	struct hid_device *hdev_b, char separator)
2586	{
2587	int n1 = strrchr(hdev_a->phys, separator) - hdev_a->phys;
2588	int n2 = strrchr(hdev_b->phys, separator) - hdev_b->phys;
2589
2590	if (n1 != n2 || n1 <= 0 || n2 <= 0)
2591	return false;
2592
2593	return !strncmp(hdev_a->phys, hdev_b->phys, n1);
2594	}
2595	EXPORT_SYMBOL_GPL(hid_compare_device_paths);
2596
2597	static bool hid_check_device_match(struct hid_device *hdev,
2598	struct hid_driver *hdrv,
2599	const struct hid_device_id **id)
2600	{
2601	*id = hid_match_device(hdev, hdrv);
2602	if (!*id)
2603	return false;
2604
2605	if (hdrv->match)
2606	return hdrv->match(hdev, hid_ignore_special_drivers);
2607
2608	/*
2609	* hid-generic implements .match(), so we must be dealing with a
2610	* different HID driver here, and can simply check if
2611	* hid_ignore_special_drivers is set or not.
2612	*/
2613	return !hid_ignore_special_drivers;
2614	}
2615
2616	static int __hid_device_probe(struct hid_device *hdev, struct hid_driver *hdrv)
2617	{
2618	const struct hid_device_id *id;
2619	int ret;
2620
2621	if (!hid_check_device_match(hdev, hdrv, id: &id))
2622	return -ENODEV;
2623
2624	hdev->devres_group_id = devres_open_group(dev: &hdev->dev, NULL, GFP_KERNEL);
2625	if (!hdev->devres_group_id)
2626	return -ENOMEM;
2627
2628	/* reset the quirks that has been previously set */
2629	hdev->quirks = hid_lookup_quirk(hdev);
2630	hdev->driver = hdrv;
2631
2632	if (hdrv->probe) {
2633	ret = hdrv->probe(hdev, id);
2634	} else { /* default probe */
2635	ret = hid_open_report(hdev);
2636	if (!ret)
2637	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
2638	}
2639
2640	/*
2641	* Note that we are not closing the devres group opened above so
2642	* even resources that were attached to the device after probe is
2643	* run are released when hid_device_remove() is executed. This is
2644	* needed as some drivers would allocate additional resources,
2645	* for example when updating firmware.
2646	*/
2647
2648	if (ret) {
2649	devres_release_group(dev: &hdev->dev, id: hdev->devres_group_id);
2650	hid_close_report(device: hdev);
2651	hdev->driver = NULL;
2652	}
2653
2654	return ret;
2655	}
2656
2657	static int hid_device_probe(struct device *dev)
2658	{
2659	struct hid_device *hdev = to_hid_device(dev);
2660	struct hid_driver *hdrv = to_hid_driver(dev->driver);
2661	int ret = 0;
2662
2663	if (down_interruptible(sem: &hdev->driver_input_lock))
2664	return -EINTR;
2665
2666	hdev->io_started = false;
2667	clear_bit(ffs(HID_STAT_REPROBED), addr: &hdev->status);
2668
2669	if (!hdev->driver)
2670	ret = __hid_device_probe(hdev, hdrv);
2671
2672	if (!hdev->io_started)
2673	up(sem: &hdev->driver_input_lock);
2674
2675	return ret;
2676	}
2677
2678	static void hid_device_remove(struct device *dev)
2679	{
2680	struct hid_device *hdev = to_hid_device(dev);
2681	struct hid_driver *hdrv;
2682
2683	down(sem: &hdev->driver_input_lock);
2684	hdev->io_started = false;
2685
2686	hdrv = hdev->driver;
2687	if (hdrv) {
2688	if (hdrv->remove)
2689	hdrv->remove(hdev);
2690	else /* default remove */
2691	hid_hw_stop(hdev);
2692
2693	/* Release all devres resources allocated by the driver */
2694	devres_release_group(dev: &hdev->dev, id: hdev->devres_group_id);
2695
2696	hid_close_report(device: hdev);
2697	hdev->driver = NULL;
2698	}
2699
2700	if (!hdev->io_started)
2701	up(sem: &hdev->driver_input_lock);
2702	}
2703
2704	static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
2705	char *buf)
2706	{
2707	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
2708
2709	return scnprintf(buf, PAGE_SIZE, fmt: "hid:b%04Xg%04Xv%08Xp%08X\n",
2710	hdev->bus, hdev->group, hdev->vendor, hdev->product);
2711	}
2712	static DEVICE_ATTR_RO(modalias);
2713
2714	static struct attribute *hid_dev_attrs[] = {
2715	&dev_attr_modalias.attr,
2716	NULL,
2717	};
2718	static struct bin_attribute *hid_dev_bin_attrs[] = {
2719	&dev_bin_attr_report_desc,
2720	NULL
2721	};
2722	static const struct attribute_group hid_dev_group = {
2723	.attrs = hid_dev_attrs,
2724	.bin_attrs = hid_dev_bin_attrs,
2725	};
2726	__ATTRIBUTE_GROUPS(hid_dev);
2727
2728	static int hid_uevent(const struct device *dev, struct kobj_uevent_env *env)
2729	{
2730	const struct hid_device *hdev = to_hid_device(dev);
2731
2732	if (add_uevent_var(env, format: "HID_ID=%04X:%08X:%08X",
2733	hdev->bus, hdev->vendor, hdev->product))
2734	return -ENOMEM;
2735
2736	if (add_uevent_var(env, format: "HID_NAME=%s", hdev->name))
2737	return -ENOMEM;
2738
2739	if (add_uevent_var(env, format: "HID_PHYS=%s", hdev->phys))
2740	return -ENOMEM;
2741
2742	if (add_uevent_var(env, format: "HID_UNIQ=%s", hdev->uniq))
2743	return -ENOMEM;
2744
2745	if (add_uevent_var(env, format: "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",
2746	hdev->bus, hdev->group, hdev->vendor, hdev->product))
2747	return -ENOMEM;
2748
2749	return 0;
2750	}
2751
2752	const struct bus_type hid_bus_type = {
2753	.name = "hid",
2754	.dev_groups = hid_dev_groups,
2755	.drv_groups = hid_drv_groups,
2756	.match = hid_bus_match,
2757	.probe = hid_device_probe,
2758	.remove = hid_device_remove,
2759	.uevent = hid_uevent,
2760	};
2761	EXPORT_SYMBOL(hid_bus_type);
2762
2763	int hid_add_device(struct hid_device *hdev)
2764	{
2765	static atomic_t id = ATOMIC_INIT(0);
2766	int ret;
2767
2768	if (WARN_ON(hdev->status & HID_STAT_ADDED))
2769	return -EBUSY;
2770
2771	hdev->quirks = hid_lookup_quirk(hdev);
2772
2773	/* we need to kill them here, otherwise they will stay allocated to
2774	* wait for coming driver */
2775	if (hid_ignore(hdev))
2776	return -ENODEV;
2777
2778	/*
2779	* Check for the mandatory transport channel.
2780	*/
2781	if (!hdev->ll_driver->raw_request) {
2782	hid_err(hdev, "transport driver missing .raw_request()\n");
2783	return -EINVAL;
2784	}
2785
2786	/*
2787	* Read the device report descriptor once and use as template
2788	* for the driver-specific modifications.
2789	*/
2790	ret = hdev->ll_driver->parse(hdev);
2791	if (ret)
2792	return ret;
2793	if (!hdev->dev_rdesc)
2794	return -ENODEV;
2795
2796	/*
2797	* Scan generic devices for group information
2798	*/
2799	if (hid_ignore_special_drivers) {
2800	hdev->group = HID_GROUP_GENERIC;
2801	} else if (!hdev->group &&
2802	!(hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)) {
2803	ret = hid_scan_report(hid: hdev);
2804	if (ret)
2805	hid_warn(hdev, "bad device descriptor (%d)\n", ret);
2806	}
2807
2808	hdev->id = atomic_inc_return(v: &id);
2809
2810	/* XXX hack, any other cleaner solution after the driver core
2811	* is converted to allow more than 20 bytes as the device name? */
2812	dev_set_name(dev: &hdev->dev, name: "%04X:%04X:%04X.%04X", hdev->bus,
2813	hdev->vendor, hdev->product, hdev->id);
2814
2815	hid_debug_register(hdev, dev_name(dev: &hdev->dev));
2816	ret = device_add(dev: &hdev->dev);
2817	if (!ret)
2818	hdev->status |= HID_STAT_ADDED;
2819	else
2820	hid_debug_unregister(hdev);
2821
2822	return ret;
2823	}
2824	EXPORT_SYMBOL_GPL(hid_add_device);
2825
2826	/**
2827	* hid_allocate_device - allocate new hid device descriptor
2828	*
2829	* Allocate and initialize hid device, so that hid_destroy_device might be
2830	* used to free it.
2831	*
2832	* New hid_device pointer is returned on success, otherwise ERR_PTR encoded
2833	* error value.
2834	*/
2835	struct hid_device *hid_allocate_device(void)
2836	{
2837	struct hid_device *hdev;
2838	int ret = -ENOMEM;
2839
2840	hdev = kzalloc(size: sizeof(*hdev), GFP_KERNEL);
2841	if (hdev == NULL)
2842	return ERR_PTR(error: ret);
2843
2844	device_initialize(dev: &hdev->dev);
2845	hdev->dev.release = hid_device_release;
2846	hdev->dev.bus = &hid_bus_type;
2847	device_enable_async_suspend(dev: &hdev->dev);
2848
2849	hid_close_report(device: hdev);
2850
2851	init_waitqueue_head(&hdev->debug_wait);
2852	INIT_LIST_HEAD(list: &hdev->debug_list);
2853	spin_lock_init(&hdev->debug_list_lock);
2854	sema_init(sem: &hdev->driver_input_lock, val: 1);
2855	mutex_init(&hdev->ll_open_lock);
2856	kref_init(kref: &hdev->ref);
2857
2858	hid_bpf_device_init(hid: hdev);
2859
2860	return hdev;
2861	}
2862	EXPORT_SYMBOL_GPL(hid_allocate_device);
2863
2864	static void hid_remove_device(struct hid_device *hdev)
2865	{
2866	if (hdev->status & HID_STAT_ADDED) {
2867	device_del(dev: &hdev->dev);
2868	hid_debug_unregister(hdev);
2869	hdev->status &= ~HID_STAT_ADDED;
2870	}
2871	kfree(objp: hdev->dev_rdesc);
2872	hdev->dev_rdesc = NULL;
2873	hdev->dev_rsize = 0;
2874	}
2875
2876	/**
2877	* hid_destroy_device - free previously allocated device
2878	*
2879	* @hdev: hid device
2880	*
2881	* If you allocate hid_device through hid_allocate_device, you should ever
2882	* free by this function.
2883	*/
2884	void hid_destroy_device(struct hid_device *hdev)
2885	{
2886	hid_bpf_destroy_device(hid: hdev);
2887	hid_remove_device(hdev);
2888	put_device(dev: &hdev->dev);
2889	}
2890	EXPORT_SYMBOL_GPL(hid_destroy_device);
2891
2892
2893	static int __hid_bus_reprobe_drivers(struct device *dev, void *data)
2894	{
2895	struct hid_driver *hdrv = data;
2896	struct hid_device *hdev = to_hid_device(dev);
2897
2898	if (hdev->driver == hdrv &&
2899	!hdrv->match(hdev, hid_ignore_special_drivers) &&
2900	!test_and_set_bit(ffs(HID_STAT_REPROBED), addr: &hdev->status))
2901	return device_reprobe(dev);
2902
2903	return 0;
2904	}
2905
2906	static int __hid_bus_driver_added(struct device_driver *drv, void *data)
2907	{
2908	struct hid_driver *hdrv = to_hid_driver(drv);
2909
2910	if (hdrv->match) {
2911	bus_for_each_dev(bus: &hid_bus_type, NULL, data: hdrv,
2912	fn: __hid_bus_reprobe_drivers);
2913	}
2914
2915	return 0;
2916	}
2917
2918	static int __bus_removed_driver(struct device_driver *drv, void *data)
2919	{
2920	return bus_rescan_devices(bus: &hid_bus_type);
2921	}
2922
2923	int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
2924	const char *mod_name)
2925	{
2926	int ret;
2927
2928	hdrv->driver.name = hdrv->name;
2929	hdrv->driver.bus = &hid_bus_type;
2930	hdrv->driver.owner = owner;
2931	hdrv->driver.mod_name = mod_name;
2932
2933	INIT_LIST_HEAD(list: &hdrv->dyn_list);
2934	spin_lock_init(&hdrv->dyn_lock);
2935
2936	ret = driver_register(drv: &hdrv->driver);
2937
2938	if (ret == 0)
2939	bus_for_each_drv(bus: &hid_bus_type, NULL, NULL,
2940	fn: __hid_bus_driver_added);
2941
2942	return ret;
2943	}
2944	EXPORT_SYMBOL_GPL(__hid_register_driver);
2945
2946	void hid_unregister_driver(struct hid_driver *hdrv)
2947	{
2948	driver_unregister(drv: &hdrv->driver);
2949	hid_free_dynids(hdrv);
2950
2951	bus_for_each_drv(bus: &hid_bus_type, NULL, data: hdrv, fn: __bus_removed_driver);
2952	}
2953	EXPORT_SYMBOL_GPL(hid_unregister_driver);
2954
2955	int hid_check_keys_pressed(struct hid_device *hid)
2956	{
2957	struct hid_input *hidinput;
2958	int i;
2959
2960	if (!(hid->claimed & HID_CLAIMED_INPUT))
2961	return 0;
2962
2963	list_for_each_entry(hidinput, &hid->inputs, list) {
2964	for (i = 0; i < BITS_TO_LONGS(KEY_MAX); i++)
2965	if (hidinput->input->key[i])
2966	return 1;
2967	}
2968
2969	return 0;
2970	}
2971	EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
2972
2973	#ifdef CONFIG_HID_BPF
2974	static struct hid_bpf_ops hid_ops = {
2975	.hid_get_report = hid_get_report,
2976	.hid_hw_raw_request = hid_hw_raw_request,
2977	.owner = THIS_MODULE,
2978	.bus_type = &hid_bus_type,
2979	};
2980	#endif
2981
2982	static int __init hid_init(void)
2983	{
2984	int ret;
2985
2986	ret = bus_register(bus: &hid_bus_type);
2987	if (ret) {
2988	pr_err("can't register hid bus\n");
2989	goto err;
2990	}
2991
2992	#ifdef CONFIG_HID_BPF
2993	hid_bpf_ops = &hid_ops;
2994	#endif
2995
2996	ret = hidraw_init();
2997	if (ret)
2998	goto err_bus;
2999
3000	hid_debug_init();
3001
3002	return 0;
3003	err_bus:
3004	bus_unregister(bus: &hid_bus_type);
3005	err:
3006	return ret;
3007	}
3008
3009	static void __exit hid_exit(void)
3010	{
3011	#ifdef CONFIG_HID_BPF
3012	hid_bpf_ops = NULL;
3013	#endif
3014	hid_debug_exit();
3015	hidraw_exit();
3016	bus_unregister(bus: &hid_bus_type);
3017	hid_quirks_exit(HID_BUS_ANY);
3018	}
3019
3020	module_init(hid_init);
3021	module_exit(hid_exit);
3022
3023	MODULE_AUTHOR("Andreas Gal");
3024	MODULE_AUTHOR("Vojtech Pavlik");
3025	MODULE_AUTHOR("Jiri Kosina");
3026	MODULE_LICENSE("GPL");
3027