1 /* 2 * User-space I/O driver support for HID subsystem 3 * Copyright (c) 2012 David Herrmann 4 */ 5 6 /* 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License as published by the Free 9 * Software Foundation; either version 2 of the License, or (at your option) 10 * any later version. 11 */ 12 13 #include <linux/atomic.h> 14 #include <linux/compat.h> 15 #include <linux/device.h> 16 #include <linux/fs.h> 17 #include <linux/hid.h> 18 #include <linux/input.h> 19 #include <linux/miscdevice.h> 20 #include <linux/module.h> 21 #include <linux/mutex.h> 22 #include <linux/poll.h> 23 #include <linux/sched.h> 24 #include <linux/spinlock.h> 25 #include <linux/uhid.h> 26 #include <linux/wait.h> 27 28 #define UHID_NAME "uhid" 29 #define UHID_BUFSIZE 32 30 31 struct uhid_device { 32 struct mutex devlock; 33 bool running; 34 35 __u8 *rd_data; 36 uint rd_size; 37 38 struct hid_device *hid; 39 struct uhid_event input_buf; 40 41 wait_queue_head_t waitq; 42 spinlock_t qlock; 43 __u8 head; 44 __u8 tail; 45 struct uhid_event *outq[UHID_BUFSIZE]; 46 47 /* blocking GET_REPORT support; state changes protected by qlock */ 48 struct mutex report_lock; 49 wait_queue_head_t report_wait; 50 bool report_running; 51 u32 report_id; 52 u32 report_type; 53 struct uhid_event report_buf; 54 struct work_struct worker; 55 }; 56 57 static struct miscdevice uhid_misc; 58 59 static void uhid_device_add_worker(struct work_struct *work) 60 { 61 struct uhid_device *uhid = container_of(work, struct uhid_device, worker); 62 int ret; 63 64 ret = hid_add_device(uhid->hid); 65 if (ret) { 66 hid_err(uhid->hid, "Cannot register HID device: error %d\n", ret); 67 68 hid_destroy_device(uhid->hid); 69 uhid->hid = NULL; 70 uhid->running = false; 71 } 72 } 73 74 static void uhid_queue(struct uhid_device *uhid, struct uhid_event *ev) 75 { 76 __u8 newhead; 77 78 newhead = (uhid->head + 1) % UHID_BUFSIZE; 79 80 if (newhead != uhid->tail) { 81 uhid->outq[uhid->head] = ev; 82 uhid->head = newhead; 83 wake_up_interruptible(&uhid->waitq); 84 } else { 85 hid_warn(uhid->hid, "Output queue is full\n"); 86 kfree(ev); 87 } 88 } 89 90 static int uhid_queue_event(struct uhid_device *uhid, __u32 event) 91 { 92 unsigned long flags; 93 struct uhid_event *ev; 94 95 ev = kzalloc(sizeof(*ev), GFP_KERNEL); 96 if (!ev) 97 return -ENOMEM; 98 99 ev->type = event; 100 101 spin_lock_irqsave(&uhid->qlock, flags); 102 uhid_queue(uhid, ev); 103 spin_unlock_irqrestore(&uhid->qlock, flags); 104 105 return 0; 106 } 107 108 static int uhid_hid_start(struct hid_device *hid) 109 { 110 struct uhid_device *uhid = hid->driver_data; 111 struct uhid_event *ev; 112 unsigned long flags; 113 114 ev = kzalloc(sizeof(*ev), GFP_KERNEL); 115 if (!ev) 116 return -ENOMEM; 117 118 ev->type = UHID_START; 119 120 if (hid->report_enum[HID_FEATURE_REPORT].numbered) 121 ev->u.start.dev_flags |= UHID_DEV_NUMBERED_FEATURE_REPORTS; 122 if (hid->report_enum[HID_OUTPUT_REPORT].numbered) 123 ev->u.start.dev_flags |= UHID_DEV_NUMBERED_OUTPUT_REPORTS; 124 if (hid->report_enum[HID_INPUT_REPORT].numbered) 125 ev->u.start.dev_flags |= UHID_DEV_NUMBERED_INPUT_REPORTS; 126 127 spin_lock_irqsave(&uhid->qlock, flags); 128 uhid_queue(uhid, ev); 129 spin_unlock_irqrestore(&uhid->qlock, flags); 130 131 return 0; 132 } 133 134 static void uhid_hid_stop(struct hid_device *hid) 135 { 136 struct uhid_device *uhid = hid->driver_data; 137 138 hid->claimed = 0; 139 uhid_queue_event(uhid, UHID_STOP); 140 } 141 142 static int uhid_hid_open(struct hid_device *hid) 143 { 144 struct uhid_device *uhid = hid->driver_data; 145 146 return uhid_queue_event(uhid, UHID_OPEN); 147 } 148 149 static void uhid_hid_close(struct hid_device *hid) 150 { 151 struct uhid_device *uhid = hid->driver_data; 152 153 uhid_queue_event(uhid, UHID_CLOSE); 154 } 155 156 static int uhid_hid_parse(struct hid_device *hid) 157 { 158 struct uhid_device *uhid = hid->driver_data; 159 160 return hid_parse_report(hid, uhid->rd_data, uhid->rd_size); 161 } 162 163 /* must be called with report_lock held */ 164 static int __uhid_report_queue_and_wait(struct uhid_device *uhid, 165 struct uhid_event *ev, 166 __u32 *report_id) 167 { 168 unsigned long flags; 169 int ret; 170 171 spin_lock_irqsave(&uhid->qlock, flags); 172 *report_id = ++uhid->report_id; 173 uhid->report_type = ev->type + 1; 174 uhid->report_running = true; 175 uhid_queue(uhid, ev); 176 spin_unlock_irqrestore(&uhid->qlock, flags); 177 178 ret = wait_event_interruptible_timeout(uhid->report_wait, 179 !uhid->report_running || !uhid->running, 180 5 * HZ); 181 if (!ret || !uhid->running || uhid->report_running) 182 ret = -EIO; 183 else if (ret < 0) 184 ret = -ERESTARTSYS; 185 else 186 ret = 0; 187 188 uhid->report_running = false; 189 190 return ret; 191 } 192 193 static void uhid_report_wake_up(struct uhid_device *uhid, u32 id, 194 const struct uhid_event *ev) 195 { 196 unsigned long flags; 197 198 spin_lock_irqsave(&uhid->qlock, flags); 199 200 /* id for old report; drop it silently */ 201 if (uhid->report_type != ev->type || uhid->report_id != id) 202 goto unlock; 203 if (!uhid->report_running) 204 goto unlock; 205 206 memcpy(&uhid->report_buf, ev, sizeof(*ev)); 207 uhid->report_running = false; 208 wake_up_interruptible(&uhid->report_wait); 209 210 unlock: 211 spin_unlock_irqrestore(&uhid->qlock, flags); 212 } 213 214 static int uhid_hid_get_report(struct hid_device *hid, unsigned char rnum, 215 u8 *buf, size_t count, u8 rtype) 216 { 217 struct uhid_device *uhid = hid->driver_data; 218 struct uhid_get_report_reply_req *req; 219 struct uhid_event *ev; 220 int ret; 221 222 if (!uhid->running) 223 return -EIO; 224 225 ev = kzalloc(sizeof(*ev), GFP_KERNEL); 226 if (!ev) 227 return -ENOMEM; 228 229 ev->type = UHID_GET_REPORT; 230 ev->u.get_report.rnum = rnum; 231 ev->u.get_report.rtype = rtype; 232 233 ret = mutex_lock_interruptible(&uhid->report_lock); 234 if (ret) { 235 kfree(ev); 236 return ret; 237 } 238 239 /* this _always_ takes ownership of @ev */ 240 ret = __uhid_report_queue_and_wait(uhid, ev, &ev->u.get_report.id); 241 if (ret) 242 goto unlock; 243 244 req = &uhid->report_buf.u.get_report_reply; 245 if (req->err) { 246 ret = -EIO; 247 } else { 248 ret = min3(count, (size_t)req->size, (size_t)UHID_DATA_MAX); 249 memcpy(buf, req->data, ret); 250 } 251 252 unlock: 253 mutex_unlock(&uhid->report_lock); 254 return ret; 255 } 256 257 static int uhid_hid_set_report(struct hid_device *hid, unsigned char rnum, 258 const u8 *buf, size_t count, u8 rtype) 259 { 260 struct uhid_device *uhid = hid->driver_data; 261 struct uhid_event *ev; 262 int ret; 263 264 if (!uhid->running || count > UHID_DATA_MAX) 265 return -EIO; 266 267 ev = kzalloc(sizeof(*ev), GFP_KERNEL); 268 if (!ev) 269 return -ENOMEM; 270 271 ev->type = UHID_SET_REPORT; 272 ev->u.set_report.rnum = rnum; 273 ev->u.set_report.rtype = rtype; 274 ev->u.set_report.size = count; 275 memcpy(ev->u.set_report.data, buf, count); 276 277 ret = mutex_lock_interruptible(&uhid->report_lock); 278 if (ret) { 279 kfree(ev); 280 return ret; 281 } 282 283 /* this _always_ takes ownership of @ev */ 284 ret = __uhid_report_queue_and_wait(uhid, ev, &ev->u.set_report.id); 285 if (ret) 286 goto unlock; 287 288 if (uhid->report_buf.u.set_report_reply.err) 289 ret = -EIO; 290 else 291 ret = count; 292 293 unlock: 294 mutex_unlock(&uhid->report_lock); 295 return ret; 296 } 297 298 static int uhid_hid_raw_request(struct hid_device *hid, unsigned char reportnum, 299 __u8 *buf, size_t len, unsigned char rtype, 300 int reqtype) 301 { 302 u8 u_rtype; 303 304 switch (rtype) { 305 case HID_FEATURE_REPORT: 306 u_rtype = UHID_FEATURE_REPORT; 307 break; 308 case HID_OUTPUT_REPORT: 309 u_rtype = UHID_OUTPUT_REPORT; 310 break; 311 case HID_INPUT_REPORT: 312 u_rtype = UHID_INPUT_REPORT; 313 break; 314 default: 315 return -EINVAL; 316 } 317 318 switch (reqtype) { 319 case HID_REQ_GET_REPORT: 320 return uhid_hid_get_report(hid, reportnum, buf, len, u_rtype); 321 case HID_REQ_SET_REPORT: 322 return uhid_hid_set_report(hid, reportnum, buf, len, u_rtype); 323 default: 324 return -EIO; 325 } 326 } 327 328 static int uhid_hid_output_raw(struct hid_device *hid, __u8 *buf, size_t count, 329 unsigned char report_type) 330 { 331 struct uhid_device *uhid = hid->driver_data; 332 __u8 rtype; 333 unsigned long flags; 334 struct uhid_event *ev; 335 336 switch (report_type) { 337 case HID_FEATURE_REPORT: 338 rtype = UHID_FEATURE_REPORT; 339 break; 340 case HID_OUTPUT_REPORT: 341 rtype = UHID_OUTPUT_REPORT; 342 break; 343 default: 344 return -EINVAL; 345 } 346 347 if (count < 1 || count > UHID_DATA_MAX) 348 return -EINVAL; 349 350 ev = kzalloc(sizeof(*ev), GFP_KERNEL); 351 if (!ev) 352 return -ENOMEM; 353 354 ev->type = UHID_OUTPUT; 355 ev->u.output.size = count; 356 ev->u.output.rtype = rtype; 357 memcpy(ev->u.output.data, buf, count); 358 359 spin_lock_irqsave(&uhid->qlock, flags); 360 uhid_queue(uhid, ev); 361 spin_unlock_irqrestore(&uhid->qlock, flags); 362 363 return count; 364 } 365 366 static int uhid_hid_output_report(struct hid_device *hid, __u8 *buf, 367 size_t count) 368 { 369 return uhid_hid_output_raw(hid, buf, count, HID_OUTPUT_REPORT); 370 } 371 372 struct hid_ll_driver uhid_hid_driver = { 373 .start = uhid_hid_start, 374 .stop = uhid_hid_stop, 375 .open = uhid_hid_open, 376 .close = uhid_hid_close, 377 .parse = uhid_hid_parse, 378 .raw_request = uhid_hid_raw_request, 379 .output_report = uhid_hid_output_report, 380 }; 381 EXPORT_SYMBOL_GPL(uhid_hid_driver); 382 383 #ifdef CONFIG_COMPAT 384 385 /* Apparently we haven't stepped on these rakes enough times yet. */ 386 struct uhid_create_req_compat { 387 __u8 name[128]; 388 __u8 phys[64]; 389 __u8 uniq[64]; 390 391 compat_uptr_t rd_data; 392 __u16 rd_size; 393 394 __u16 bus; 395 __u32 vendor; 396 __u32 product; 397 __u32 version; 398 __u32 country; 399 } __attribute__((__packed__)); 400 401 static int uhid_event_from_user(const char __user *buffer, size_t len, 402 struct uhid_event *event) 403 { 404 if (in_compat_syscall()) { 405 u32 type; 406 407 if (get_user(type, buffer)) 408 return -EFAULT; 409 410 if (type == UHID_CREATE) { 411 /* 412 * This is our messed up request with compat pointer. 413 * It is largish (more than 256 bytes) so we better 414 * allocate it from the heap. 415 */ 416 struct uhid_create_req_compat *compat; 417 418 compat = kzalloc(sizeof(*compat), GFP_KERNEL); 419 if (!compat) 420 return -ENOMEM; 421 422 buffer += sizeof(type); 423 len -= sizeof(type); 424 if (copy_from_user(compat, buffer, 425 min(len, sizeof(*compat)))) { 426 kfree(compat); 427 return -EFAULT; 428 } 429 430 /* Shuffle the data over to proper structure */ 431 event->type = type; 432 433 memcpy(event->u.create.name, compat->name, 434 sizeof(compat->name)); 435 memcpy(event->u.create.phys, compat->phys, 436 sizeof(compat->phys)); 437 memcpy(event->u.create.uniq, compat->uniq, 438 sizeof(compat->uniq)); 439 440 event->u.create.rd_data = compat_ptr(compat->rd_data); 441 event->u.create.rd_size = compat->rd_size; 442 443 event->u.create.bus = compat->bus; 444 event->u.create.vendor = compat->vendor; 445 event->u.create.product = compat->product; 446 event->u.create.version = compat->version; 447 event->u.create.country = compat->country; 448 449 kfree(compat); 450 return 0; 451 } 452 /* All others can be copied directly */ 453 } 454 455 if (copy_from_user(event, buffer, min(len, sizeof(*event)))) 456 return -EFAULT; 457 458 return 0; 459 } 460 #else 461 static int uhid_event_from_user(const char __user *buffer, size_t len, 462 struct uhid_event *event) 463 { 464 if (copy_from_user(event, buffer, min(len, sizeof(*event)))) 465 return -EFAULT; 466 467 return 0; 468 } 469 #endif 470 471 static int uhid_dev_create2(struct uhid_device *uhid, 472 const struct uhid_event *ev) 473 { 474 struct hid_device *hid; 475 size_t rd_size, len; 476 void *rd_data; 477 int ret; 478 479 if (uhid->running) 480 return -EALREADY; 481 482 rd_size = ev->u.create2.rd_size; 483 if (rd_size <= 0 || rd_size > HID_MAX_DESCRIPTOR_SIZE) 484 return -EINVAL; 485 486 rd_data = kmemdup(ev->u.create2.rd_data, rd_size, GFP_KERNEL); 487 if (!rd_data) 488 return -ENOMEM; 489 490 uhid->rd_size = rd_size; 491 uhid->rd_data = rd_data; 492 493 hid = hid_allocate_device(); 494 if (IS_ERR(hid)) { 495 ret = PTR_ERR(hid); 496 goto err_free; 497 } 498 499 len = min(sizeof(hid->name), sizeof(ev->u.create2.name)); 500 strlcpy(hid->name, ev->u.create2.name, len); 501 len = min(sizeof(hid->phys), sizeof(ev->u.create2.phys)); 502 strlcpy(hid->phys, ev->u.create2.phys, len); 503 len = min(sizeof(hid->uniq), sizeof(ev->u.create2.uniq)); 504 strlcpy(hid->uniq, ev->u.create2.uniq, len); 505 506 hid->ll_driver = &uhid_hid_driver; 507 hid->bus = ev->u.create2.bus; 508 hid->vendor = ev->u.create2.vendor; 509 hid->product = ev->u.create2.product; 510 hid->version = ev->u.create2.version; 511 hid->country = ev->u.create2.country; 512 hid->driver_data = uhid; 513 hid->dev.parent = uhid_misc.this_device; 514 515 uhid->hid = hid; 516 uhid->running = true; 517 518 /* Adding of a HID device is done through a worker, to allow HID drivers 519 * which use feature requests during .probe to work, without they would 520 * be blocked on devlock, which is held by uhid_char_write. 521 */ 522 schedule_work(&uhid->worker); 523 524 return 0; 525 526 err_free: 527 kfree(uhid->rd_data); 528 uhid->rd_data = NULL; 529 uhid->rd_size = 0; 530 return ret; 531 } 532 533 static int uhid_dev_create(struct uhid_device *uhid, 534 struct uhid_event *ev) 535 { 536 struct uhid_create_req orig; 537 538 orig = ev->u.create; 539 540 if (orig.rd_size <= 0 || orig.rd_size > HID_MAX_DESCRIPTOR_SIZE) 541 return -EINVAL; 542 if (copy_from_user(&ev->u.create2.rd_data, orig.rd_data, orig.rd_size)) 543 return -EFAULT; 544 545 memcpy(ev->u.create2.name, orig.name, sizeof(orig.name)); 546 memcpy(ev->u.create2.phys, orig.phys, sizeof(orig.phys)); 547 memcpy(ev->u.create2.uniq, orig.uniq, sizeof(orig.uniq)); 548 ev->u.create2.rd_size = orig.rd_size; 549 ev->u.create2.bus = orig.bus; 550 ev->u.create2.vendor = orig.vendor; 551 ev->u.create2.product = orig.product; 552 ev->u.create2.version = orig.version; 553 ev->u.create2.country = orig.country; 554 555 return uhid_dev_create2(uhid, ev); 556 } 557 558 static int uhid_dev_destroy(struct uhid_device *uhid) 559 { 560 if (!uhid->running) 561 return -EINVAL; 562 563 uhid->running = false; 564 wake_up_interruptible(&uhid->report_wait); 565 566 cancel_work_sync(&uhid->worker); 567 568 hid_destroy_device(uhid->hid); 569 kfree(uhid->rd_data); 570 571 return 0; 572 } 573 574 static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev) 575 { 576 if (!uhid->running) 577 return -EINVAL; 578 579 hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input.data, 580 min_t(size_t, ev->u.input.size, UHID_DATA_MAX), 0); 581 582 return 0; 583 } 584 585 static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev) 586 { 587 if (!uhid->running) 588 return -EINVAL; 589 590 hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input2.data, 591 min_t(size_t, ev->u.input2.size, UHID_DATA_MAX), 0); 592 593 return 0; 594 } 595 596 static int uhid_dev_get_report_reply(struct uhid_device *uhid, 597 struct uhid_event *ev) 598 { 599 if (!uhid->running) 600 return -EINVAL; 601 602 uhid_report_wake_up(uhid, ev->u.get_report_reply.id, ev); 603 return 0; 604 } 605 606 static int uhid_dev_set_report_reply(struct uhid_device *uhid, 607 struct uhid_event *ev) 608 { 609 if (!uhid->running) 610 return -EINVAL; 611 612 uhid_report_wake_up(uhid, ev->u.set_report_reply.id, ev); 613 return 0; 614 } 615 616 static int uhid_char_open(struct inode *inode, struct file *file) 617 { 618 struct uhid_device *uhid; 619 620 uhid = kzalloc(sizeof(*uhid), GFP_KERNEL); 621 if (!uhid) 622 return -ENOMEM; 623 624 mutex_init(&uhid->devlock); 625 mutex_init(&uhid->report_lock); 626 spin_lock_init(&uhid->qlock); 627 init_waitqueue_head(&uhid->waitq); 628 init_waitqueue_head(&uhid->report_wait); 629 uhid->running = false; 630 INIT_WORK(&uhid->worker, uhid_device_add_worker); 631 632 file->private_data = uhid; 633 nonseekable_open(inode, file); 634 635 return 0; 636 } 637 638 static int uhid_char_release(struct inode *inode, struct file *file) 639 { 640 struct uhid_device *uhid = file->private_data; 641 unsigned int i; 642 643 uhid_dev_destroy(uhid); 644 645 for (i = 0; i < UHID_BUFSIZE; ++i) 646 kfree(uhid->outq[i]); 647 648 kfree(uhid); 649 650 return 0; 651 } 652 653 static ssize_t uhid_char_read(struct file *file, char __user *buffer, 654 size_t count, loff_t *ppos) 655 { 656 struct uhid_device *uhid = file->private_data; 657 int ret; 658 unsigned long flags; 659 size_t len; 660 661 /* they need at least the "type" member of uhid_event */ 662 if (count < sizeof(__u32)) 663 return -EINVAL; 664 665 try_again: 666 if (file->f_flags & O_NONBLOCK) { 667 if (uhid->head == uhid->tail) 668 return -EAGAIN; 669 } else { 670 ret = wait_event_interruptible(uhid->waitq, 671 uhid->head != uhid->tail); 672 if (ret) 673 return ret; 674 } 675 676 ret = mutex_lock_interruptible(&uhid->devlock); 677 if (ret) 678 return ret; 679 680 if (uhid->head == uhid->tail) { 681 mutex_unlock(&uhid->devlock); 682 goto try_again; 683 } else { 684 len = min(count, sizeof(**uhid->outq)); 685 if (copy_to_user(buffer, uhid->outq[uhid->tail], len)) { 686 ret = -EFAULT; 687 } else { 688 kfree(uhid->outq[uhid->tail]); 689 uhid->outq[uhid->tail] = NULL; 690 691 spin_lock_irqsave(&uhid->qlock, flags); 692 uhid->tail = (uhid->tail + 1) % UHID_BUFSIZE; 693 spin_unlock_irqrestore(&uhid->qlock, flags); 694 } 695 } 696 697 mutex_unlock(&uhid->devlock); 698 return ret ? ret : len; 699 } 700 701 static ssize_t uhid_char_write(struct file *file, const char __user *buffer, 702 size_t count, loff_t *ppos) 703 { 704 struct uhid_device *uhid = file->private_data; 705 int ret; 706 size_t len; 707 708 /* we need at least the "type" member of uhid_event */ 709 if (count < sizeof(__u32)) 710 return -EINVAL; 711 712 ret = mutex_lock_interruptible(&uhid->devlock); 713 if (ret) 714 return ret; 715 716 memset(&uhid->input_buf, 0, sizeof(uhid->input_buf)); 717 len = min(count, sizeof(uhid->input_buf)); 718 719 ret = uhid_event_from_user(buffer, len, &uhid->input_buf); 720 if (ret) 721 goto unlock; 722 723 switch (uhid->input_buf.type) { 724 case UHID_CREATE: 725 ret = uhid_dev_create(uhid, &uhid->input_buf); 726 break; 727 case UHID_CREATE2: 728 ret = uhid_dev_create2(uhid, &uhid->input_buf); 729 break; 730 case UHID_DESTROY: 731 ret = uhid_dev_destroy(uhid); 732 break; 733 case UHID_INPUT: 734 ret = uhid_dev_input(uhid, &uhid->input_buf); 735 break; 736 case UHID_INPUT2: 737 ret = uhid_dev_input2(uhid, &uhid->input_buf); 738 break; 739 case UHID_GET_REPORT_REPLY: 740 ret = uhid_dev_get_report_reply(uhid, &uhid->input_buf); 741 break; 742 case UHID_SET_REPORT_REPLY: 743 ret = uhid_dev_set_report_reply(uhid, &uhid->input_buf); 744 break; 745 default: 746 ret = -EOPNOTSUPP; 747 } 748 749 unlock: 750 mutex_unlock(&uhid->devlock); 751 752 /* return "count" not "len" to not confuse the caller */ 753 return ret ? ret : count; 754 } 755 756 static __poll_t uhid_char_poll(struct file *file, poll_table *wait) 757 { 758 struct uhid_device *uhid = file->private_data; 759 760 poll_wait(file, &uhid->waitq, wait); 761 762 if (uhid->head != uhid->tail) 763 return EPOLLIN | EPOLLRDNORM; 764 765 return 0; 766 } 767 768 static const struct file_operations uhid_fops = { 769 .owner = THIS_MODULE, 770 .open = uhid_char_open, 771 .release = uhid_char_release, 772 .read = uhid_char_read, 773 .write = uhid_char_write, 774 .poll = uhid_char_poll, 775 .llseek = no_llseek, 776 }; 777 778 static struct miscdevice uhid_misc = { 779 .fops = &uhid_fops, 780 .minor = UHID_MINOR, 781 .name = UHID_NAME, 782 }; 783 module_misc_device(uhid_misc); 784 785 MODULE_LICENSE("GPL"); 786 MODULE_AUTHOR("David Herrmann <dh.herrmann@gmail.com>"); 787 MODULE_DESCRIPTION("User-space I/O driver support for HID subsystem"); 788 MODULE_ALIAS_MISCDEV(UHID_MINOR); 789 MODULE_ALIAS("devname:" UHID_NAME); 790