xref: /freebsd/sys/dev/usb/usb_hid.c (revision b1f9167f94059fd55c630891d359bcff987bd7eb) 
1 /* $FreeBSD$ */
2 /*	$NetBSD: hid.c,v 1.17 2001/11/13 06:24:53 lukem Exp $	*/
3 /*-
4  * Copyright (c) 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Lennart Augustsson (lennart@augustsson.net) at
9  * Carlstedt Research & Technology.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #ifdef USB_GLOBAL_INCLUDE_FILE
34 #include USB_GLOBAL_INCLUDE_FILE
35 #else
36 #include <sys/stdint.h>
37 #include <sys/stddef.h>
38 #include <sys/param.h>
39 #include <sys/queue.h>
40 #include <sys/types.h>
41 #include <sys/systm.h>
42 #include <sys/kernel.h>
43 #include <sys/bus.h>
44 #include <sys/module.h>
45 #include <sys/lock.h>
46 #include <sys/mutex.h>
47 #include <sys/condvar.h>
48 #include <sys/sysctl.h>
49 #include <sys/sx.h>
50 #include <sys/unistd.h>
51 #include <sys/callout.h>
52 #include <sys/malloc.h>
53 #include <sys/priv.h>
54 
55 #include <dev/usb/usb.h>
56 #include <dev/usb/usbdi.h>
57 #include <dev/usb/usbdi_util.h>
58 #include <dev/usb/usbhid.h>
59 
60 #define	USB_DEBUG_VAR usb_debug
61 
62 #include <dev/usb/usb_core.h>
63 #include <dev/usb/usb_debug.h>
64 #include <dev/usb/usb_process.h>
65 #include <dev/usb/usb_device.h>
66 #include <dev/usb/usb_request.h>
67 #endif			/* USB_GLOBAL_INCLUDE_FILE */
68 
69 static void hid_clear_local(struct hid_item *);
70 static uint8_t hid_get_byte(struct hid_data *s, const uint16_t wSize);
71 
72 #define	MAXUSAGE 64
73 #define	MAXPUSH 4
74 #define	MAXID 16
75 
76 struct hid_pos_data {
77 	int32_t rid;
78 	uint32_t pos;
79 };
80 
81 struct hid_data {
82 	const uint8_t *start;
83 	const uint8_t *end;
84 	const uint8_t *p;
85 	struct hid_item cur[MAXPUSH];
86 	struct hid_pos_data last_pos[MAXID];
87 	int32_t	usages_min[MAXUSAGE];
88 	int32_t	usages_max[MAXUSAGE];
89 	int32_t usage_last;	/* last seen usage */
90 	uint32_t loc_size;	/* last seen size */
91 	uint32_t loc_count;	/* last seen count */
92 	uint8_t	kindset;	/* we have 5 kinds so 8 bits are enough */
93 	uint8_t	pushlevel;	/* current pushlevel */
94 	uint8_t	ncount;		/* end usage item count */
95 	uint8_t icount;		/* current usage item count */
96 	uint8_t	nusage;		/* end "usages_min/max" index */
97 	uint8_t	iusage;		/* current "usages_min/max" index */
98 	uint8_t ousage;		/* current "usages_min/max" offset */
99 	uint8_t	susage;		/* usage set flags */
100 };
101 
102 /*------------------------------------------------------------------------*
103  *	hid_clear_local
104  *------------------------------------------------------------------------*/
105 static void
106 hid_clear_local(struct hid_item *c)
107 {
108 
109 	c->loc.count = 0;
110 	c->loc.size = 0;
111 	c->usage = 0;
112 	c->usage_minimum = 0;
113 	c->usage_maximum = 0;
114 	c->designator_index = 0;
115 	c->designator_minimum = 0;
116 	c->designator_maximum = 0;
117 	c->string_index = 0;
118 	c->string_minimum = 0;
119 	c->string_maximum = 0;
120 	c->set_delimiter = 0;
121 }
122 
123 static void
124 hid_switch_rid(struct hid_data *s, struct hid_item *c, int32_t next_rID)
125 {
126 	uint8_t i;
127 
128 	/* check for same report ID - optimise */
129 
130 	if (c->report_ID == next_rID)
131 		return;
132 
133 	/* save current position for current rID */
134 
135 	if (c->report_ID == 0) {
136 		i = 0;
137 	} else {
138 		for (i = 1; i != MAXID; i++) {
139 			if (s->last_pos[i].rid == c->report_ID)
140 				break;
141 			if (s->last_pos[i].rid == 0)
142 				break;
143 		}
144 	}
145 	if (i != MAXID) {
146 		s->last_pos[i].rid = c->report_ID;
147 		s->last_pos[i].pos = c->loc.pos;
148 	}
149 
150 	/* store next report ID */
151 
152 	c->report_ID = next_rID;
153 
154 	/* lookup last position for next rID */
155 
156 	if (next_rID == 0) {
157 		i = 0;
158 	} else {
159 		for (i = 1; i != MAXID; i++) {
160 			if (s->last_pos[i].rid == next_rID)
161 				break;
162 			if (s->last_pos[i].rid == 0)
163 				break;
164 		}
165 	}
166 	if (i != MAXID) {
167 		s->last_pos[i].rid = next_rID;
168 		c->loc.pos = s->last_pos[i].pos;
169 	} else {
170 		DPRINTF("Out of RID entries, position is set to zero!\n");
171 		c->loc.pos = 0;
172 	}
173 }
174 
175 /*------------------------------------------------------------------------*
176  *	hid_start_parse
177  *------------------------------------------------------------------------*/
178 struct hid_data *
179 hid_start_parse(const void *d, usb_size_t len, int kindset)
180 {
181 	struct hid_data *s;
182 
183 	if ((kindset-1) & kindset) {
184 		DPRINTFN(0, "Only one bit can be "
185 		    "set in the kindset\n");
186 		return (NULL);
187 	}
188 
189 	s = malloc(sizeof *s, M_TEMP, M_WAITOK | M_ZERO);
190 	s->start = s->p = d;
191 	s->end = ((const uint8_t *)d) + len;
192 	s->kindset = kindset;
193 	return (s);
194 }
195 
196 /*------------------------------------------------------------------------*
197  *	hid_end_parse
198  *------------------------------------------------------------------------*/
199 void
200 hid_end_parse(struct hid_data *s)
201 {
202 	if (s == NULL)
203 		return;
204 
205 	free(s, M_TEMP);
206 }
207 
208 /*------------------------------------------------------------------------*
209  *	get byte from HID descriptor
210  *------------------------------------------------------------------------*/
211 static uint8_t
212 hid_get_byte(struct hid_data *s, const uint16_t wSize)
213 {
214 	const uint8_t *ptr;
215 	uint8_t retval;
216 
217 	ptr = s->p;
218 
219 	/* check if end is reached */
220 	if (ptr == s->end)
221 		return (0);
222 
223 	/* read out a byte */
224 	retval = *ptr;
225 
226 	/* check if data pointer can be advanced by "wSize" bytes */
227 	if ((s->end - ptr) < wSize)
228 		ptr = s->end;
229 	else
230 		ptr += wSize;
231 
232 	/* update pointer */
233 	s->p = ptr;
234 
235 	return (retval);
236 }
237 
238 /*------------------------------------------------------------------------*
239  *	hid_get_item
240  *------------------------------------------------------------------------*/
241 int
242 hid_get_item(struct hid_data *s, struct hid_item *h)
243 {
244 	struct hid_item *c;
245 	unsigned int bTag, bType, bSize;
246 	uint32_t oldpos;
247 	int32_t mask;
248 	int32_t dval;
249 
250 	if (s == NULL)
251 		return (0);
252 
253 	c = &s->cur[s->pushlevel];
254 
255  top:
256 	/* check if there is an array of items */
257 	if (s->icount < s->ncount) {
258 		/* get current usage */
259 		if (s->iusage < s->nusage) {
260 			dval = s->usages_min[s->iusage] + s->ousage;
261 			c->usage = dval;
262 			s->usage_last = dval;
263 			if (dval == s->usages_max[s->iusage]) {
264 				s->iusage ++;
265 				s->ousage = 0;
266 			} else {
267 				s->ousage ++;
268 			}
269 		} else {
270 			DPRINTFN(1, "Using last usage\n");
271 			dval = s->usage_last;
272 		}
273 		s->icount ++;
274 		/*
275 		 * Only copy HID item, increment position and return
276 		 * if correct kindset!
277 		 */
278 		if (s->kindset & (1 << c->kind)) {
279 			*h = *c;
280 			DPRINTFN(1, "%u,%u,%u\n", h->loc.pos,
281 			    h->loc.size, h->loc.count);
282 			c->loc.pos += c->loc.size * c->loc.count;
283 			return (1);
284 		}
285 	}
286 
287 	/* reset state variables */
288 	s->icount = 0;
289 	s->ncount = 0;
290 	s->iusage = 0;
291 	s->nusage = 0;
292 	s->susage = 0;
293 	s->ousage = 0;
294 	hid_clear_local(c);
295 
296 	/* get next item */
297 	while (s->p != s->end) {
298 
299 		bSize = hid_get_byte(s, 1);
300 		if (bSize == 0xfe) {
301 			/* long item */
302 			bSize = hid_get_byte(s, 1);
303 			bSize |= hid_get_byte(s, 1) << 8;
304 			bTag = hid_get_byte(s, 1);
305 			bType = 0xff;	/* XXX what should it be */
306 		} else {
307 			/* short item */
308 			bTag = bSize >> 4;
309 			bType = (bSize >> 2) & 3;
310 			bSize &= 3;
311 			if (bSize == 3)
312 				bSize = 4;
313 		}
314 		switch (bSize) {
315 		case 0:
316 			dval = 0;
317 			mask = 0;
318 			break;
319 		case 1:
320 			dval = (int8_t)hid_get_byte(s, 1);
321 			mask = 0xFF;
322 			break;
323 		case 2:
324 			dval = hid_get_byte(s, 1);
325 			dval |= hid_get_byte(s, 1) << 8;
326 			dval = (int16_t)dval;
327 			mask = 0xFFFF;
328 			break;
329 		case 4:
330 			dval = hid_get_byte(s, 1);
331 			dval |= hid_get_byte(s, 1) << 8;
332 			dval |= hid_get_byte(s, 1) << 16;
333 			dval |= hid_get_byte(s, 1) << 24;
334 			mask = 0xFFFFFFFF;
335 			break;
336 		default:
337 			dval = hid_get_byte(s, bSize);
338 			DPRINTFN(0, "bad length %u (data=0x%02x)\n",
339 			    bSize, dval);
340 			continue;
341 		}
342 
343 		switch (bType) {
344 		case 0:		/* Main */
345 			switch (bTag) {
346 			case 8:	/* Input */
347 				c->kind = hid_input;
348 				c->flags = dval;
349 		ret:
350 				c->loc.count = s->loc_count;
351 				c->loc.size = s->loc_size;
352 
353 				if (c->flags & HIO_VARIABLE) {
354 					/* range check usage count */
355 					if (c->loc.count > 255) {
356 						DPRINTFN(0, "Number of "
357 						    "items truncated to 255\n");
358 						s->ncount = 255;
359 					} else
360 						s->ncount = c->loc.count;
361 
362 					/*
363 					 * The "top" loop will return
364 					 * one and one item:
365 					 */
366 					c->loc.count = 1;
367 				} else {
368 					s->ncount = 1;
369 				}
370 				goto top;
371 
372 			case 9:	/* Output */
373 				c->kind = hid_output;
374 				c->flags = dval;
375 				goto ret;
376 			case 10:	/* Collection */
377 				c->kind = hid_collection;
378 				c->collection = dval;
379 				c->collevel++;
380 				c->usage = s->usage_last;
381 				*h = *c;
382 				return (1);
383 			case 11:	/* Feature */
384 				c->kind = hid_feature;
385 				c->flags = dval;
386 				goto ret;
387 			case 12:	/* End collection */
388 				c->kind = hid_endcollection;
389 				if (c->collevel == 0) {
390 					DPRINTFN(0, "invalid end collection\n");
391 					return (0);
392 				}
393 				c->collevel--;
394 				*h = *c;
395 				return (1);
396 			default:
397 				DPRINTFN(0, "Main bTag=%d\n", bTag);
398 				break;
399 			}
400 			break;
401 		case 1:		/* Global */
402 			switch (bTag) {
403 			case 0:
404 				c->_usage_page = dval << 16;
405 				break;
406 			case 1:
407 				c->logical_minimum = dval;
408 				break;
409 			case 2:
410 				c->logical_maximum = dval;
411 				break;
412 			case 3:
413 				c->physical_minimum = dval;
414 				break;
415 			case 4:
416 				c->physical_maximum = dval;
417 				break;
418 			case 5:
419 				c->unit_exponent = dval;
420 				break;
421 			case 6:
422 				c->unit = dval;
423 				break;
424 			case 7:
425 				/* mask because value is unsigned */
426 				s->loc_size = dval & mask;
427 				break;
428 			case 8:
429 				hid_switch_rid(s, c, dval & mask);
430 				break;
431 			case 9:
432 				/* mask because value is unsigned */
433 				s->loc_count = dval & mask;
434 				break;
435 			case 10:	/* Push */
436 				s->pushlevel ++;
437 				if (s->pushlevel < MAXPUSH) {
438 					s->cur[s->pushlevel] = *c;
439 					/* store size and count */
440 					c->loc.size = s->loc_size;
441 					c->loc.count = s->loc_count;
442 					/* update current item pointer */
443 					c = &s->cur[s->pushlevel];
444 				} else {
445 					DPRINTFN(0, "Cannot push "
446 					    "item @ %d\n", s->pushlevel);
447 				}
448 				break;
449 			case 11:	/* Pop */
450 				s->pushlevel --;
451 				if (s->pushlevel < MAXPUSH) {
452 					/* preserve position */
453 					oldpos = c->loc.pos;
454 					c = &s->cur[s->pushlevel];
455 					/* restore size and count */
456 					s->loc_size = c->loc.size;
457 					s->loc_count = c->loc.count;
458 					/* set default item location */
459 					c->loc.pos = oldpos;
460 					c->loc.size = 0;
461 					c->loc.count = 0;
462 				} else {
463 					DPRINTFN(0, "Cannot pop "
464 					    "item @ %d\n", s->pushlevel);
465 				}
466 				break;
467 			default:
468 				DPRINTFN(0, "Global bTag=%d\n", bTag);
469 				break;
470 			}
471 			break;
472 		case 2:		/* Local */
473 			switch (bTag) {
474 			case 0:
475 				if (bSize != 4)
476 					dval = (dval & mask) | c->_usage_page;
477 
478 				/* set last usage, in case of a collection */
479 				s->usage_last = dval;
480 
481 				if (s->nusage < MAXUSAGE) {
482 					s->usages_min[s->nusage] = dval;
483 					s->usages_max[s->nusage] = dval;
484 					s->nusage ++;
485 				} else {
486 					DPRINTFN(0, "max usage reached\n");
487 				}
488 
489 				/* clear any pending usage sets */
490 				s->susage = 0;
491 				break;
492 			case 1:
493 				s->susage |= 1;
494 
495 				if (bSize != 4)
496 					dval = (dval & mask) | c->_usage_page;
497 				c->usage_minimum = dval;
498 
499 				goto check_set;
500 			case 2:
501 				s->susage |= 2;
502 
503 				if (bSize != 4)
504 					dval = (dval & mask) | c->_usage_page;
505 				c->usage_maximum = dval;
506 
507 			check_set:
508 				if (s->susage != 3)
509 					break;
510 
511 				/* sanity check */
512 				if ((s->nusage < MAXUSAGE) &&
513 				    (c->usage_minimum <= c->usage_maximum)) {
514 					/* add usage range */
515 					s->usages_min[s->nusage] =
516 					    c->usage_minimum;
517 					s->usages_max[s->nusage] =
518 					    c->usage_maximum;
519 					s->nusage ++;
520 				} else {
521 					DPRINTFN(0, "Usage set dropped\n");
522 				}
523 				s->susage = 0;
524 				break;
525 			case 3:
526 				c->designator_index = dval;
527 				break;
528 			case 4:
529 				c->designator_minimum = dval;
530 				break;
531 			case 5:
532 				c->designator_maximum = dval;
533 				break;
534 			case 7:
535 				c->string_index = dval;
536 				break;
537 			case 8:
538 				c->string_minimum = dval;
539 				break;
540 			case 9:
541 				c->string_maximum = dval;
542 				break;
543 			case 10:
544 				c->set_delimiter = dval;
545 				break;
546 			default:
547 				DPRINTFN(0, "Local bTag=%d\n", bTag);
548 				break;
549 			}
550 			break;
551 		default:
552 			DPRINTFN(0, "default bType=%d\n", bType);
553 			break;
554 		}
555 	}
556 	return (0);
557 }
558 
559 /*------------------------------------------------------------------------*
560  *	hid_report_size
561  *------------------------------------------------------------------------*/
562 int
563 hid_report_size(const void *buf, usb_size_t len, enum hid_kind k, uint8_t *id)
564 {
565 	struct hid_data *d;
566 	struct hid_item h;
567 	uint32_t temp;
568 	uint32_t hpos;
569 	uint32_t lpos;
570 	uint8_t any_id;
571 
572 	any_id = 0;
573 	hpos = 0;
574 	lpos = 0xFFFFFFFF;
575 
576 	for (d = hid_start_parse(buf, len, 1 << k); hid_get_item(d, &h);) {
577 		if (h.kind == k) {
578 			/* check for ID-byte presense */
579 			if ((h.report_ID != 0) && !any_id) {
580 				if (id != NULL)
581 					*id = h.report_ID;
582 				any_id = 1;
583 			}
584 			/* compute minimum */
585 			if (lpos > h.loc.pos)
586 				lpos = h.loc.pos;
587 			/* compute end position */
588 			temp = h.loc.pos + (h.loc.size * h.loc.count);
589 			/* compute maximum */
590 			if (hpos < temp)
591 				hpos = temp;
592 		}
593 	}
594 	hid_end_parse(d);
595 
596 	/* safety check - can happen in case of currupt descriptors */
597 	if (lpos > hpos)
598 		temp = 0;
599 	else
600 		temp = hpos - lpos;
601 
602 	/* check for ID byte */
603 	if (any_id)
604 		temp += 8;
605 	else if (id != NULL)
606 		*id = 0;
607 
608 	/* return length in bytes rounded up */
609 	return ((temp + 7) / 8);
610 }
611 
612 /*------------------------------------------------------------------------*
613  *	hid_locate
614  *------------------------------------------------------------------------*/
615 int
616 hid_locate(const void *desc, usb_size_t size, int32_t u, enum hid_kind k,
617     uint8_t index, struct hid_location *loc, uint32_t *flags, uint8_t *id)
618 {
619 	struct hid_data *d;
620 	struct hid_item h;
621 
622 	for (d = hid_start_parse(desc, size, 1 << k); hid_get_item(d, &h);) {
623 		if (h.kind == k && !(h.flags & HIO_CONST) && h.usage == u) {
624 			if (index--)
625 				continue;
626 			if (loc != NULL)
627 				*loc = h.loc;
628 			if (flags != NULL)
629 				*flags = h.flags;
630 			if (id != NULL)
631 				*id = h.report_ID;
632 			hid_end_parse(d);
633 			return (1);
634 		}
635 	}
636 	if (loc != NULL)
637 		loc->size = 0;
638 	if (flags != NULL)
639 		*flags = 0;
640 	if (id != NULL)
641 		*id = 0;
642 	hid_end_parse(d);
643 	return (0);
644 }
645 
646 /*------------------------------------------------------------------------*
647  *	hid_get_data
648  *------------------------------------------------------------------------*/
649 static uint32_t
650 hid_get_data_sub(const uint8_t *buf, usb_size_t len, struct hid_location *loc,
651     int is_signed)
652 {
653 	uint32_t hpos = loc->pos;
654 	uint32_t hsize = loc->size;
655 	uint32_t data;
656 	uint32_t rpos;
657 	uint8_t n;
658 
659 	DPRINTFN(11, "hid_get_data: loc %d/%d\n", hpos, hsize);
660 
661 	/* Range check and limit */
662 	if (hsize == 0)
663 		return (0);
664 	if (hsize > 32)
665 		hsize = 32;
666 
667 	/* Get data in a safe way */
668 	data = 0;
669 	rpos = (hpos / 8);
670 	n = (hsize + 7) / 8;
671 	rpos += n;
672 	while (n--) {
673 		rpos--;
674 		if (rpos < len)
675 			data |= buf[rpos] << (8 * n);
676 	}
677 
678 	/* Correctly shift down data */
679 	data = (data >> (hpos % 8));
680 	n = 32 - hsize;
681 
682 	/* Mask and sign extend in one */
683 	if (is_signed != 0)
684 		data = (int32_t)((int32_t)data << n) >> n;
685 	else
686 		data = (uint32_t)((uint32_t)data << n) >> n;
687 
688 	DPRINTFN(11, "hid_get_data: loc %d/%d = %lu\n",
689 	    loc->pos, loc->size, (long)data);
690 	return (data);
691 }
692 
693 int32_t
694 hid_get_data(const uint8_t *buf, usb_size_t len, struct hid_location *loc)
695 {
696 	return (hid_get_data_sub(buf, len, loc, 1));
697 }
698 
699 uint32_t
700 hid_get_data_unsigned(const uint8_t *buf, usb_size_t len, struct hid_location *loc)
701 {
702         return (hid_get_data_sub(buf, len, loc, 0));
703 }
704 
705 /*------------------------------------------------------------------------*
706  *	hid_put_data
707  *------------------------------------------------------------------------*/
708 void
709 hid_put_data_unsigned(uint8_t *buf, usb_size_t len,
710     struct hid_location *loc, unsigned int value)
711 {
712 	uint32_t hpos = loc->pos;
713 	uint32_t hsize = loc->size;
714 	uint64_t data;
715 	uint64_t mask;
716 	uint32_t rpos;
717 	uint8_t n;
718 
719 	DPRINTFN(11, "hid_put_data: loc %d/%d = %u\n", hpos, hsize, value);
720 
721 	/* Range check and limit */
722 	if (hsize == 0)
723 		return;
724 	if (hsize > 32)
725 		hsize = 32;
726 
727 	/* Put data in a safe way */
728 	rpos = (hpos / 8);
729 	n = (hsize + 7) / 8;
730 	data = ((uint64_t)value) << (hpos % 8);
731 	mask = ((1ULL << hsize) - 1ULL) << (hpos % 8);
732 	rpos += n;
733 	while (n--) {
734 		rpos--;
735 		if (rpos < len) {
736 			buf[rpos] &= ~(mask >> (8 * n));
737 			buf[rpos] |= (data >> (8 * n));
738 		}
739 	}
740 }
741 
742 /*------------------------------------------------------------------------*
743  *	hid_is_collection
744  *------------------------------------------------------------------------*/
745 int
746 hid_is_collection(const void *desc, usb_size_t size, int32_t usage)
747 {
748 	struct hid_data *hd;
749 	struct hid_item hi;
750 	int err;
751 
752 	hd = hid_start_parse(desc, size, hid_input);
753 	if (hd == NULL)
754 		return (0);
755 
756 	while ((err = hid_get_item(hd, &hi))) {
757 		 if (hi.kind == hid_collection &&
758 		     hi.usage == usage)
759 			break;
760 	}
761 	hid_end_parse(hd);
762 	return (err);
763 }
764 
765 /*------------------------------------------------------------------------*
766  *	hid_get_descriptor_from_usb
767  *
768  * This function will search for a HID descriptor between two USB
769  * interface descriptors.
770  *
771  * Return values:
772  * NULL: No more HID descriptors.
773  * Else: Pointer to HID descriptor.
774  *------------------------------------------------------------------------*/
775 struct usb_hid_descriptor *
776 hid_get_descriptor_from_usb(struct usb_config_descriptor *cd,
777     struct usb_interface_descriptor *id)
778 {
779 	struct usb_descriptor *desc = (void *)id;
780 
781 	if (desc == NULL) {
782 		return (NULL);
783 	}
784 	while ((desc = usb_desc_foreach(cd, desc))) {
785 		if ((desc->bDescriptorType == UDESC_HID) &&
786 		    (desc->bLength >= USB_HID_DESCRIPTOR_SIZE(0))) {
787 			return (void *)desc;
788 		}
789 		if (desc->bDescriptorType == UDESC_INTERFACE) {
790 			break;
791 		}
792 	}
793 	return (NULL);
794 }
795 
796 /*------------------------------------------------------------------------*
797  *	usbd_req_get_hid_desc
798  *
799  * This function will read out an USB report descriptor from the USB
800  * device.
801  *
802  * Return values:
803  * NULL: Failure.
804  * Else: Success. The pointer should eventually be passed to free().
805  *------------------------------------------------------------------------*/
806 usb_error_t
807 usbd_req_get_hid_desc(struct usb_device *udev, struct mtx *mtx,
808     void **descp, uint16_t *sizep,
809     struct malloc_type *mem, uint8_t iface_index)
810 {
811 	struct usb_interface *iface = usbd_get_iface(udev, iface_index);
812 	struct usb_hid_descriptor *hid;
813 	usb_error_t err;
814 
815 	if ((iface == NULL) || (iface->idesc == NULL)) {
816 		return (USB_ERR_INVAL);
817 	}
818 	hid = hid_get_descriptor_from_usb
819 	    (usbd_get_config_descriptor(udev), iface->idesc);
820 
821 	if (hid == NULL) {
822 		return (USB_ERR_IOERROR);
823 	}
824 	*sizep = UGETW(hid->descrs[0].wDescriptorLength);
825 	if (*sizep == 0) {
826 		return (USB_ERR_IOERROR);
827 	}
828 	if (mtx)
829 		mtx_unlock(mtx);
830 
831 	*descp = malloc(*sizep, mem, M_ZERO | M_WAITOK);
832 
833 	if (mtx)
834 		mtx_lock(mtx);
835 
836 	if (*descp == NULL) {
837 		return (USB_ERR_NOMEM);
838 	}
839 	err = usbd_req_get_report_descriptor
840 	    (udev, mtx, *descp, *sizep, iface_index);
841 
842 	if (err) {
843 		free(*descp, mem);
844 		*descp = NULL;
845 		return (err);
846 	}
847 	return (USB_ERR_NORMAL_COMPLETION);
848 }
849 
850 /*------------------------------------------------------------------------*
851  *	hid_is_mouse
852  *
853  * This function will decide if a USB descriptor belongs to a USB mouse.
854  *
855  * Return values:
856  * Zero: Not a USB mouse.
857  * Else: Is a USB mouse.
858  *------------------------------------------------------------------------*/
859 int
860 hid_is_mouse(const void *d_ptr, uint16_t d_len)
861 {
862 	struct hid_data *hd;
863 	struct hid_item hi;
864 	int mdepth;
865 	int found;
866 
867 	hd = hid_start_parse(d_ptr, d_len, 1 << hid_input);
868 	if (hd == NULL)
869 		return (0);
870 
871 	mdepth = 0;
872 	found = 0;
873 
874 	while (hid_get_item(hd, &hi)) {
875 		switch (hi.kind) {
876 		case hid_collection:
877 			if (mdepth != 0)
878 				mdepth++;
879 			else if (hi.collection == 1 &&
880 			     hi.usage ==
881 			      HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_MOUSE))
882 				mdepth++;
883 			break;
884 		case hid_endcollection:
885 			if (mdepth != 0)
886 				mdepth--;
887 			break;
888 		case hid_input:
889 			if (mdepth == 0)
890 				break;
891 			if (hi.usage ==
892 			     HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_X) &&
893 			    (hi.flags & (HIO_CONST|HIO_RELATIVE)) == HIO_RELATIVE)
894 				found++;
895 			if (hi.usage ==
896 			     HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_Y) &&
897 			    (hi.flags & (HIO_CONST|HIO_RELATIVE)) == HIO_RELATIVE)
898 				found++;
899 			break;
900 		default:
901 			break;
902 		}
903 	}
904 	hid_end_parse(hd);
905 	return (found);
906 }
907 
908 /*------------------------------------------------------------------------*
909  *	hid_is_keyboard
910  *
911  * This function will decide if a USB descriptor belongs to a USB keyboard.
912  *
913  * Return values:
914  * Zero: Not a USB keyboard.
915  * Else: Is a USB keyboard.
916  *------------------------------------------------------------------------*/
917 int
918 hid_is_keyboard(const void *d_ptr, uint16_t d_len)
919 {
920 	if (hid_is_collection(d_ptr, d_len,
921 	    HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_KEYBOARD)))
922 		return (1);
923 	return (0);
924 }
925