xref: /netbsd-src/sys/dev/usb/uhid.c (revision b757af438b42b93f8c6571f026d8b8ef3eaf5fc9)
1 /*	$NetBSD: uhid.c,v 1.86 2012/03/06 03:35:29 mrg Exp $	*/
2 
3 /*
4  * Copyright (c) 1998, 2004, 2008 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 /*
34  * HID spec: http://www.usb.org/developers/devclass_docs/HID1_11.pdf
35  */
36 
37 #include <sys/cdefs.h>
38 __KERNEL_RCSID(0, "$NetBSD: uhid.c,v 1.86 2012/03/06 03:35:29 mrg Exp $");
39 
40 #include "opt_compat_netbsd.h"
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/kernel.h>
45 #include <sys/malloc.h>
46 #include <sys/signalvar.h>
47 #include <sys/device.h>
48 #include <sys/ioctl.h>
49 #include <sys/conf.h>
50 #include <sys/tty.h>
51 #include <sys/file.h>
52 #include <sys/select.h>
53 #include <sys/proc.h>
54 #include <sys/vnode.h>
55 #include <sys/poll.h>
56 #include <sys/intr.h>
57 
58 #include <dev/usb/usb.h>
59 #include <dev/usb/usbhid.h>
60 
61 #include <dev/usb/usbdevs.h>
62 #include <dev/usb/usbdi.h>
63 #include <dev/usb/usbdi_util.h>
64 #include <dev/usb/hid.h>
65 #include <dev/usb/usb_quirks.h>
66 
67 #include <dev/usb/uhidev.h>
68 
69 #ifdef UHID_DEBUG
70 #define DPRINTF(x)	if (uhiddebug) printf x
71 #define DPRINTFN(n,x)	if (uhiddebug>(n)) printf x
72 int	uhiddebug = 0;
73 #else
74 #define DPRINTF(x)
75 #define DPRINTFN(n,x)
76 #endif
77 
78 struct uhid_softc {
79 	struct uhidev sc_hdev;
80 
81 	int sc_isize;
82 	int sc_osize;
83 	int sc_fsize;
84 
85 	u_char *sc_obuf;
86 
87 	struct clist sc_q;
88 	struct selinfo sc_rsel;
89 	proc_t *sc_async;	/* process that wants SIGIO */
90 	void *sc_sih;
91 	u_char sc_state;	/* driver state */
92 #define	UHID_ASLP	0x01	/* waiting for device data */
93 #define UHID_IMMED	0x02	/* return read data immediately */
94 
95 	int sc_refcnt;
96 	u_char sc_dying;
97 };
98 
99 #define	UHIDUNIT(dev)	(minor(dev))
100 #define	UHID_CHUNK	128	/* chunk size for read */
101 #define	UHID_BSIZE	1020	/* buffer size */
102 
103 dev_type_open(uhidopen);
104 dev_type_close(uhidclose);
105 dev_type_read(uhidread);
106 dev_type_write(uhidwrite);
107 dev_type_ioctl(uhidioctl);
108 dev_type_poll(uhidpoll);
109 dev_type_kqfilter(uhidkqfilter);
110 
111 const struct cdevsw uhid_cdevsw = {
112 	uhidopen, uhidclose, uhidread, uhidwrite, uhidioctl,
113 	nostop, notty, uhidpoll, nommap, uhidkqfilter, D_OTHER,
114 };
115 
116 Static void uhid_intr(struct uhidev *, void *, u_int len);
117 Static void uhid_softintr(void *);
118 
119 Static int uhid_do_read(struct uhid_softc *, struct uio *uio, int);
120 Static int uhid_do_write(struct uhid_softc *, struct uio *uio, int);
121 Static int uhid_do_ioctl(struct uhid_softc*, u_long, void *, int, struct lwp *);
122 
123 int             uhid_match(device_t, cfdata_t, void *);
124 void            uhid_attach(device_t, device_t, void *);
125 int             uhid_detach(device_t, int);
126 int             uhid_activate(device_t, enum devact);
127 extern struct cfdriver uhid_cd;
128 CFATTACH_DECL_NEW(uhid, sizeof(struct uhid_softc), uhid_match, uhid_attach, uhid_detach, uhid_activate);
129 
130 int
131 uhid_match(device_t parent, cfdata_t match, void *aux)
132 {
133 #ifdef UHID_DEBUG
134 	struct uhidev_attach_arg *uha = aux;
135 #endif
136 
137 	DPRINTF(("uhid_match: report=%d\n", uha->reportid));
138 
139 	if (match->cf_flags & 1)
140 		return (UMATCH_HIGHEST);
141 	else
142 		return (UMATCH_IFACECLASS_GENERIC);
143 }
144 
145 void
146 uhid_attach(device_t parent, device_t self, void *aux)
147 {
148 	struct uhid_softc *sc = device_private(self);
149 	struct uhidev_attach_arg *uha = aux;
150 	int size, repid;
151 	void *desc;
152 
153 	sc->sc_hdev.sc_dev = self;
154 	selinit(&sc->sc_rsel);
155 	sc->sc_hdev.sc_intr = uhid_intr;
156 	sc->sc_hdev.sc_parent = uha->parent;
157 	sc->sc_hdev.sc_report_id = uha->reportid;
158 	sc->sc_sih = softint_establish(SOFTINT_MPSAFE | SOFTINT_CLOCK,
159 	    uhid_softintr, sc);
160 
161 	uhidev_get_report_desc(uha->parent, &desc, &size);
162 	repid = uha->reportid;
163 	sc->sc_isize = hid_report_size(desc, size, hid_input,   repid);
164 	sc->sc_osize = hid_report_size(desc, size, hid_output,  repid);
165 	sc->sc_fsize = hid_report_size(desc, size, hid_feature, repid);
166 
167 	aprint_naive("\n");
168 	aprint_normal(": input=%d, output=%d, feature=%d\n",
169 	       sc->sc_isize, sc->sc_osize, sc->sc_fsize);
170 
171 	if (!pmf_device_register(self, NULL, NULL))
172 		aprint_error_dev(self, "couldn't establish power handler\n");
173 
174 	return;
175 }
176 
177 int
178 uhid_activate(device_t self, enum devact act)
179 {
180 	struct uhid_softc *sc = device_private(self);
181 
182 	switch (act) {
183 	case DVACT_DEACTIVATE:
184 		sc->sc_dying = 1;
185 		return 0;
186 	default:
187 		return EOPNOTSUPP;
188 	}
189 }
190 
191 int
192 uhid_detach(device_t self, int flags)
193 {
194 	struct uhid_softc *sc = device_private(self);
195 	int s;
196 	int maj, mn;
197 
198 	DPRINTF(("uhid_detach: sc=%p flags=%d\n", sc, flags));
199 
200 	sc->sc_dying = 1;
201 
202 	if (sc->sc_hdev.sc_state & UHIDEV_OPEN) {
203 		s = splusb();
204 		if (--sc->sc_refcnt >= 0) {
205 			/* Wake everyone */
206 			wakeup(&sc->sc_q);
207 			/* Wait for processes to go away. */
208 			usb_detach_waitold(sc->sc_hdev.sc_dev);
209 		}
210 		splx(s);
211 	}
212 
213 	/* locate the major number */
214 	maj = cdevsw_lookup_major(&uhid_cdevsw);
215 
216 	/* Nuke the vnodes for any open instances (calls close). */
217 	mn = device_unit(self);
218 	vdevgone(maj, mn, mn, VCHR);
219 
220 #if 0
221 	usbd_add_drv_event(USB_EVENT_DRIVER_DETACH,
222 			   sc->sc_hdev.sc_parent->sc_udev,
223 			   sc->sc_hdev.sc_dev);
224 #endif
225 	seldestroy(&sc->sc_rsel);
226 	softint_disestablish(sc->sc_sih);
227 
228 	return (0);
229 }
230 
231 void
232 uhid_intr(struct uhidev *addr, void *data, u_int len)
233 {
234 	struct uhid_softc *sc = (struct uhid_softc *)addr;
235 
236 #ifdef UHID_DEBUG
237 	if (uhiddebug > 5) {
238 		u_int32_t i;
239 
240 		DPRINTF(("uhid_intr: data ="));
241 		for (i = 0; i < len; i++)
242 			DPRINTF((" %02x", ((u_char *)data)[i]));
243 		DPRINTF(("\n"));
244 	}
245 #endif
246 
247 	(void)b_to_q(data, len, &sc->sc_q);
248 
249 	if (sc->sc_state & UHID_ASLP) {
250 		sc->sc_state &= ~UHID_ASLP;
251 		DPRINTFN(5, ("uhid_intr: waking %p\n", &sc->sc_q));
252 		wakeup(&sc->sc_q);
253 	}
254 	selnotify(&sc->sc_rsel, 0, 0);
255 	if (sc->sc_async != NULL) {
256 		DPRINTFN(3, ("uhid_intr: sending SIGIO %p\n", sc->sc_async));
257 		softint_schedule(sc->sc_sih);
258 	}
259 }
260 
261 void
262 uhid_softintr(void *cookie)
263 {
264 	struct uhid_softc *sc;
265 
266 	sc = cookie;
267 
268 	mutex_enter(proc_lock);
269 	if (sc->sc_async != NULL)
270 		 psignal(sc->sc_async, SIGIO);
271 	mutex_exit(proc_lock);
272 }
273 
274 int
275 uhidopen(dev_t dev, int flag, int mode,
276     struct lwp *l)
277 {
278 	struct uhid_softc *sc;
279 	int error;
280 
281 	sc = device_lookup_private(&uhid_cd, UHIDUNIT(dev));
282 	if (sc == NULL)
283 		return ENXIO;
284 
285 	DPRINTF(("uhidopen: sc=%p\n", sc));
286 
287 	if (sc->sc_dying)
288 		return (ENXIO);
289 
290 	error = uhidev_open(&sc->sc_hdev);
291 	if (error)
292 		return (error);
293 
294 	if (clalloc(&sc->sc_q, UHID_BSIZE, 0) == -1) {
295 		uhidev_close(&sc->sc_hdev);
296 		return (ENOMEM);
297 	}
298 	sc->sc_obuf = malloc(sc->sc_osize, M_USBDEV, M_WAITOK);
299 	sc->sc_state &= ~UHID_IMMED;
300 	mutex_enter(proc_lock);
301 	sc->sc_async = NULL;
302 	mutex_exit(proc_lock);
303 
304 	return (0);
305 }
306 
307 int
308 uhidclose(dev_t dev, int flag, int mode,
309     struct lwp *l)
310 {
311 	struct uhid_softc *sc;
312 
313 	sc = device_lookup_private(&uhid_cd, UHIDUNIT(dev));
314 
315 	DPRINTF(("uhidclose: sc=%p\n", sc));
316 
317 	clfree(&sc->sc_q);
318 	free(sc->sc_obuf, M_USBDEV);
319 	mutex_enter(proc_lock);
320 	sc->sc_async = NULL;
321 	mutex_exit(proc_lock);
322 	uhidev_close(&sc->sc_hdev);
323 
324 	return (0);
325 }
326 
327 int
328 uhid_do_read(struct uhid_softc *sc, struct uio *uio, int flag)
329 {
330 	int s;
331 	int error = 0;
332 	int extra;
333 	size_t length;
334 	u_char buffer[UHID_CHUNK];
335 	usbd_status err;
336 
337 	DPRINTFN(1, ("uhidread\n"));
338 	if (sc->sc_state & UHID_IMMED) {
339 		DPRINTFN(1, ("uhidread immed\n"));
340 		extra = sc->sc_hdev.sc_report_id != 0;
341 		err = uhidev_get_report(&sc->sc_hdev, UHID_INPUT_REPORT,
342 					buffer, sc->sc_isize + extra);
343 		if (err)
344 			return (EIO);
345 		return (uiomove(buffer+extra, sc->sc_isize, uio));
346 	}
347 
348 	s = splusb();
349 	while (sc->sc_q.c_cc == 0) {
350 		if (flag & IO_NDELAY) {
351 			splx(s);
352 			return (EWOULDBLOCK);
353 		}
354 		sc->sc_state |= UHID_ASLP;
355 		DPRINTFN(5, ("uhidread: sleep on %p\n", &sc->sc_q));
356 		error = tsleep(&sc->sc_q, PZERO | PCATCH, "uhidrea", 0);
357 		DPRINTFN(5, ("uhidread: woke, error=%d\n", error));
358 		if (sc->sc_dying)
359 			error = EIO;
360 		if (error) {
361 			sc->sc_state &= ~UHID_ASLP;
362 			break;
363 		}
364 	}
365 	splx(s);
366 
367 	/* Transfer as many chunks as possible. */
368 	while (sc->sc_q.c_cc > 0 && uio->uio_resid > 0 && !error) {
369 		length = min(sc->sc_q.c_cc, uio->uio_resid);
370 		if (length > sizeof(buffer))
371 			length = sizeof(buffer);
372 
373 		/* Remove a small chunk from the input queue. */
374 		(void) q_to_b(&sc->sc_q, buffer, length);
375 		DPRINTFN(5, ("uhidread: got %lu chars\n", (u_long)length));
376 
377 		/* Copy the data to the user process. */
378 		if ((error = uiomove(buffer, length, uio)) != 0)
379 			break;
380 	}
381 
382 	return (error);
383 }
384 
385 int
386 uhidread(dev_t dev, struct uio *uio, int flag)
387 {
388 	struct uhid_softc *sc;
389 	int error;
390 
391 	sc = device_lookup_private(&uhid_cd, UHIDUNIT(dev));
392 
393 	sc->sc_refcnt++;
394 	error = uhid_do_read(sc, uio, flag);
395 	if (--sc->sc_refcnt < 0)
396 		usb_detach_wakeupold(sc->sc_hdev.sc_dev);
397 	return (error);
398 }
399 
400 int
401 uhid_do_write(struct uhid_softc *sc, struct uio *uio, int flag)
402 {
403 	int error;
404 	int size;
405 	usbd_status err;
406 
407 	DPRINTFN(1, ("uhidwrite\n"));
408 
409 	if (sc->sc_dying)
410 		return (EIO);
411 
412 	size = sc->sc_osize;
413 	error = 0;
414 	if (uio->uio_resid != size)
415 		return (EINVAL);
416 	error = uiomove(sc->sc_obuf, size, uio);
417 	if (!error) {
418 		err = uhidev_set_report(&sc->sc_hdev, UHID_OUTPUT_REPORT,
419 					sc->sc_obuf, size);
420 		if (err)
421 			error = EIO;
422 	}
423 
424 	return (error);
425 }
426 
427 int
428 uhidwrite(dev_t dev, struct uio *uio, int flag)
429 {
430 	struct uhid_softc *sc;
431 	int error;
432 
433 	sc = device_lookup_private(&uhid_cd, UHIDUNIT(dev));
434 
435 	sc->sc_refcnt++;
436 	error = uhid_do_write(sc, uio, flag);
437 	if (--sc->sc_refcnt < 0)
438 		usb_detach_wakeupold(sc->sc_hdev.sc_dev);
439 	return (error);
440 }
441 
442 int
443 uhid_do_ioctl(struct uhid_softc *sc, u_long cmd, void *addr,
444     int flag, struct lwp *l)
445 {
446 	struct usb_ctl_report_desc *rd;
447 	struct usb_ctl_report *re;
448 	u_char buffer[UHID_CHUNK];
449 	int size, extra;
450 	usbd_status err;
451 	void *desc;
452 
453 	DPRINTFN(2, ("uhidioctl: cmd=%lx\n", cmd));
454 
455 	if (sc->sc_dying)
456 		return (EIO);
457 
458 	switch (cmd) {
459 	case FIONBIO:
460 		/* All handled in the upper FS layer. */
461 		break;
462 
463 	case FIOASYNC:
464 		mutex_enter(proc_lock);
465 		if (*(int *)addr) {
466 			if (sc->sc_async != NULL)
467 				return (EBUSY);
468 			sc->sc_async = l->l_proc;
469 			DPRINTF(("uhid_do_ioctl: FIOASYNC %p\n", l->l_proc));
470 		} else
471 			sc->sc_async = NULL;
472 		mutex_exit(proc_lock);
473 		break;
474 
475 	/* XXX this is not the most general solution. */
476 	case TIOCSPGRP:
477 		mutex_enter(proc_lock);
478 		if (sc->sc_async == NULL) {
479 			mutex_exit(proc_lock);
480 			return (EINVAL);
481 		}
482 		if (*(int *)addr != sc->sc_async->p_pgid) {
483 			mutex_exit(proc_lock);
484 			return (EPERM);
485 		}
486 		mutex_exit(proc_lock);
487 		break;
488 
489 	case FIOSETOWN:
490 		mutex_enter(proc_lock);
491 		if (sc->sc_async == NULL) {
492 			mutex_exit(proc_lock);
493 			return (EINVAL);
494 		}
495 		if (-*(int *)addr != sc->sc_async->p_pgid
496 		    && *(int *)addr != sc->sc_async->p_pid) {
497 			mutex_exit(proc_lock);
498 			return (EPERM);
499 		}
500 		mutex_exit(proc_lock);
501 		break;
502 
503 	case USB_GET_REPORT_DESC:
504 		uhidev_get_report_desc(sc->sc_hdev.sc_parent, &desc, &size);
505 		rd = (struct usb_ctl_report_desc *)addr;
506 		size = min(size, sizeof rd->ucrd_data);
507 		rd->ucrd_size = size;
508 		memcpy(rd->ucrd_data, desc, size);
509 		break;
510 
511 	case USB_SET_IMMED:
512 		if (*(int *)addr) {
513 			extra = sc->sc_hdev.sc_report_id != 0;
514 			err = uhidev_get_report(&sc->sc_hdev, UHID_INPUT_REPORT,
515 						buffer, sc->sc_isize + extra);
516 			if (err)
517 				return (EOPNOTSUPP);
518 
519 			sc->sc_state |=  UHID_IMMED;
520 		} else
521 			sc->sc_state &= ~UHID_IMMED;
522 		break;
523 
524 	case USB_GET_REPORT:
525 		re = (struct usb_ctl_report *)addr;
526 		switch (re->ucr_report) {
527 		case UHID_INPUT_REPORT:
528 			size = sc->sc_isize;
529 			break;
530 		case UHID_OUTPUT_REPORT:
531 			size = sc->sc_osize;
532 			break;
533 		case UHID_FEATURE_REPORT:
534 			size = sc->sc_fsize;
535 			break;
536 		default:
537 			return (EINVAL);
538 		}
539 		extra = sc->sc_hdev.sc_report_id != 0;
540 		err = uhidev_get_report(&sc->sc_hdev, re->ucr_report,
541 		    re->ucr_data, size + extra);
542 		if (extra)
543 			memcpy(re->ucr_data, re->ucr_data+1, size);
544 		if (err)
545 			return (EIO);
546 		break;
547 
548 	case USB_SET_REPORT:
549 		re = (struct usb_ctl_report *)addr;
550 		switch (re->ucr_report) {
551 		case UHID_INPUT_REPORT:
552 			size = sc->sc_isize;
553 			break;
554 		case UHID_OUTPUT_REPORT:
555 			size = sc->sc_osize;
556 			break;
557 		case UHID_FEATURE_REPORT:
558 			size = sc->sc_fsize;
559 			break;
560 		default:
561 			return (EINVAL);
562 		}
563 		err = uhidev_set_report(&sc->sc_hdev, re->ucr_report,
564 		    re->ucr_data, size);
565 		if (err)
566 			return (EIO);
567 		break;
568 
569 	case USB_GET_REPORT_ID:
570 		*(int *)addr = sc->sc_hdev.sc_report_id;
571 		break;
572 
573 	case USB_GET_DEVICEINFO:
574 		usbd_fill_deviceinfo(sc->sc_hdev.sc_parent->sc_udev,
575 			             (struct usb_device_info *)addr, 0);
576 		break;
577 #ifdef COMPAT_30
578 	case USB_GET_DEVICEINFO_OLD:
579 		usbd_fill_deviceinfo_old(sc->sc_hdev.sc_parent->sc_udev,
580 					 (struct usb_device_info_old *)addr, 0);
581 
582 		break;
583 #endif
584         case USB_GET_STRING_DESC:
585 	    {
586                 struct usb_string_desc *si = (struct usb_string_desc *)addr;
587                 err = usbd_get_string_desc(sc->sc_hdev.sc_parent->sc_udev,
588 			si->usd_string_index,
589                 	si->usd_language_id, &si->usd_desc, &size);
590                 if (err)
591                         return (EINVAL);
592                 break;
593 	    }
594 
595 	default:
596 		return (EINVAL);
597 	}
598 	return (0);
599 }
600 
601 int
602 uhidioctl(dev_t dev, u_long cmd, void *addr, int flag, struct lwp *l)
603 {
604 	struct uhid_softc *sc;
605 	int error;
606 
607 	sc = device_lookup_private(&uhid_cd, UHIDUNIT(dev));
608 
609 	sc->sc_refcnt++;
610 	error = uhid_do_ioctl(sc, cmd, addr, flag, l);
611 	if (--sc->sc_refcnt < 0)
612 		usb_detach_wakeupold(sc->sc_hdev.sc_dev);
613 	return (error);
614 }
615 
616 int
617 uhidpoll(dev_t dev, int events, struct lwp *l)
618 {
619 	struct uhid_softc *sc;
620 	int revents = 0;
621 	int s;
622 
623 	sc = device_lookup_private(&uhid_cd, UHIDUNIT(dev));
624 
625 	if (sc->sc_dying)
626 		return (POLLHUP);
627 
628 	s = splusb();
629 	if (events & (POLLOUT | POLLWRNORM))
630 		revents |= events & (POLLOUT | POLLWRNORM);
631 	if (events & (POLLIN | POLLRDNORM)) {
632 		if (sc->sc_q.c_cc > 0)
633 			revents |= events & (POLLIN | POLLRDNORM);
634 		else
635 			selrecord(l, &sc->sc_rsel);
636 	}
637 
638 	splx(s);
639 	return (revents);
640 }
641 
642 static void
643 filt_uhidrdetach(struct knote *kn)
644 {
645 	struct uhid_softc *sc = kn->kn_hook;
646 	int s;
647 
648 	s = splusb();
649 	SLIST_REMOVE(&sc->sc_rsel.sel_klist, kn, knote, kn_selnext);
650 	splx(s);
651 }
652 
653 static int
654 filt_uhidread(struct knote *kn, long hint)
655 {
656 	struct uhid_softc *sc = kn->kn_hook;
657 
658 	kn->kn_data = sc->sc_q.c_cc;
659 	return (kn->kn_data > 0);
660 }
661 
662 static const struct filterops uhidread_filtops =
663 	{ 1, NULL, filt_uhidrdetach, filt_uhidread };
664 
665 static const struct filterops uhid_seltrue_filtops =
666 	{ 1, NULL, filt_uhidrdetach, filt_seltrue };
667 
668 int
669 uhidkqfilter(dev_t dev, struct knote *kn)
670 {
671 	struct uhid_softc *sc;
672 	struct klist *klist;
673 	int s;
674 
675 	sc = device_lookup_private(&uhid_cd, UHIDUNIT(dev));
676 
677 	if (sc->sc_dying)
678 		return (ENXIO);
679 
680 	switch (kn->kn_filter) {
681 	case EVFILT_READ:
682 		klist = &sc->sc_rsel.sel_klist;
683 		kn->kn_fop = &uhidread_filtops;
684 		break;
685 
686 	case EVFILT_WRITE:
687 		klist = &sc->sc_rsel.sel_klist;
688 		kn->kn_fop = &uhid_seltrue_filtops;
689 		break;
690 
691 	default:
692 		return (EINVAL);
693 	}
694 
695 	kn->kn_hook = sc;
696 
697 	s = splusb();
698 	SLIST_INSERT_HEAD(klist, kn, kn_selnext);
699 	splx(s);
700 
701 	return (0);
702 }
703