sys/dev/usb/usb_hid.c

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