xref: /netbsd-src/sys/dev/usb/uhid.c (revision c2f76ff004a2cb67efe5b12d97bd3ef7fe89e18d)
1 /*	$NetBSD: uhid.c,v 1.84 2010/11/03 22:34:24 dyoung 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 1.84 2010/11/03 22:34:24 dyoung 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_wait(sc->sc_hdev.sc_dev);
209 		}
210 		splx(s);
211 	}
212 
213 	/* locate the major number */
214 #if defined(__NetBSD__)
215 	maj = cdevsw_lookup_major(&uhid_cdevsw);
216 #elif defined(__OpenBSD__)
217 	for (maj = 0; maj < nchrdev; maj++)
218 		if (cdevsw[maj].d_open == uhidopen)
219 			break;
220 #endif
221 
222 	/* Nuke the vnodes for any open instances (calls close). */
223 	mn = device_unit(self);
224 	vdevgone(maj, mn, mn, VCHR);
225 
226 #if 0
227 	usbd_add_drv_event(USB_EVENT_DRIVER_DETACH,
228 			   sc->sc_hdev.sc_parent->sc_udev,
229 			   sc->sc_hdev.sc_dev);
230 #endif
231 	seldestroy(&sc->sc_rsel);
232 	softint_disestablish(sc->sc_sih);
233 
234 	return (0);
235 }
236 
237 void
238 uhid_intr(struct uhidev *addr, void *data, u_int len)
239 {
240 	struct uhid_softc *sc = (struct uhid_softc *)addr;
241 
242 #ifdef UHID_DEBUG
243 	if (uhiddebug > 5) {
244 		u_int32_t i;
245 
246 		DPRINTF(("uhid_intr: data ="));
247 		for (i = 0; i < len; i++)
248 			DPRINTF((" %02x", ((u_char *)data)[i]));
249 		DPRINTF(("\n"));
250 	}
251 #endif
252 
253 	(void)b_to_q(data, len, &sc->sc_q);
254 
255 	if (sc->sc_state & UHID_ASLP) {
256 		sc->sc_state &= ~UHID_ASLP;
257 		DPRINTFN(5, ("uhid_intr: waking %p\n", &sc->sc_q));
258 		wakeup(&sc->sc_q);
259 	}
260 	selnotify(&sc->sc_rsel, 0, 0);
261 	if (sc->sc_async != NULL) {
262 		DPRINTFN(3, ("uhid_intr: sending SIGIO %p\n", sc->sc_async));
263 		softint_schedule(sc->sc_sih);
264 	}
265 }
266 
267 void
268 uhid_softintr(void *cookie)
269 {
270 	struct uhid_softc *sc;
271 
272 	sc = cookie;
273 
274 	mutex_enter(proc_lock);
275 	if (sc->sc_async != NULL)
276 		 psignal(sc->sc_async, SIGIO);
277 	mutex_exit(proc_lock);
278 }
279 
280 int
281 uhidopen(dev_t dev, int flag, int mode,
282     struct lwp *l)
283 {
284 	struct uhid_softc *sc;
285 	int error;
286 
287 	sc = device_lookup_private(&uhid_cd, UHIDUNIT(dev));
288 	if (sc == NULL)
289 		return ENXIO;
290 
291 	DPRINTF(("uhidopen: sc=%p\n", sc));
292 
293 	if (sc->sc_dying)
294 		return (ENXIO);
295 
296 	error = uhidev_open(&sc->sc_hdev);
297 	if (error)
298 		return (error);
299 
300 	if (clalloc(&sc->sc_q, UHID_BSIZE, 0) == -1) {
301 		uhidev_close(&sc->sc_hdev);
302 		return (ENOMEM);
303 	}
304 	sc->sc_obuf = malloc(sc->sc_osize, M_USBDEV, M_WAITOK);
305 	sc->sc_state &= ~UHID_IMMED;
306 	mutex_enter(proc_lock);
307 	sc->sc_async = NULL;
308 	mutex_exit(proc_lock);
309 
310 	return (0);
311 }
312 
313 int
314 uhidclose(dev_t dev, int flag, int mode,
315     struct lwp *l)
316 {
317 	struct uhid_softc *sc;
318 
319 	sc = device_lookup_private(&uhid_cd, UHIDUNIT(dev));
320 
321 	DPRINTF(("uhidclose: sc=%p\n", sc));
322 
323 	clfree(&sc->sc_q);
324 	free(sc->sc_obuf, M_USBDEV);
325 	mutex_enter(proc_lock);
326 	sc->sc_async = NULL;
327 	mutex_exit(proc_lock);
328 	uhidev_close(&sc->sc_hdev);
329 
330 	return (0);
331 }
332 
333 int
334 uhid_do_read(struct uhid_softc *sc, struct uio *uio, int flag)
335 {
336 	int s;
337 	int error = 0;
338 	int extra;
339 	size_t length;
340 	u_char buffer[UHID_CHUNK];
341 	usbd_status err;
342 
343 	DPRINTFN(1, ("uhidread\n"));
344 	if (sc->sc_state & UHID_IMMED) {
345 		DPRINTFN(1, ("uhidread immed\n"));
346 		extra = sc->sc_hdev.sc_report_id != 0;
347 		err = uhidev_get_report(&sc->sc_hdev, UHID_INPUT_REPORT,
348 					buffer, sc->sc_isize + extra);
349 		if (err)
350 			return (EIO);
351 		return (uiomove(buffer+extra, sc->sc_isize, uio));
352 	}
353 
354 	s = splusb();
355 	while (sc->sc_q.c_cc == 0) {
356 		if (flag & IO_NDELAY) {
357 			splx(s);
358 			return (EWOULDBLOCK);
359 		}
360 		sc->sc_state |= UHID_ASLP;
361 		DPRINTFN(5, ("uhidread: sleep on %p\n", &sc->sc_q));
362 		error = tsleep(&sc->sc_q, PZERO | PCATCH, "uhidrea", 0);
363 		DPRINTFN(5, ("uhidread: woke, error=%d\n", error));
364 		if (sc->sc_dying)
365 			error = EIO;
366 		if (error) {
367 			sc->sc_state &= ~UHID_ASLP;
368 			break;
369 		}
370 	}
371 	splx(s);
372 
373 	/* Transfer as many chunks as possible. */
374 	while (sc->sc_q.c_cc > 0 && uio->uio_resid > 0 && !error) {
375 		length = min(sc->sc_q.c_cc, uio->uio_resid);
376 		if (length > sizeof(buffer))
377 			length = sizeof(buffer);
378 
379 		/* Remove a small chunk from the input queue. */
380 		(void) q_to_b(&sc->sc_q, buffer, length);
381 		DPRINTFN(5, ("uhidread: got %lu chars\n", (u_long)length));
382 
383 		/* Copy the data to the user process. */
384 		if ((error = uiomove(buffer, length, uio)) != 0)
385 			break;
386 	}
387 
388 	return (error);
389 }
390 
391 int
392 uhidread(dev_t dev, struct uio *uio, int flag)
393 {
394 	struct uhid_softc *sc;
395 	int error;
396 
397 	sc = device_lookup_private(&uhid_cd, UHIDUNIT(dev));
398 
399 	sc->sc_refcnt++;
400 	error = uhid_do_read(sc, uio, flag);
401 	if (--sc->sc_refcnt < 0)
402 		usb_detach_wakeup(sc->sc_hdev.sc_dev);
403 	return (error);
404 }
405 
406 int
407 uhid_do_write(struct uhid_softc *sc, struct uio *uio, int flag)
408 {
409 	int error;
410 	int size;
411 	usbd_status err;
412 
413 	DPRINTFN(1, ("uhidwrite\n"));
414 
415 	if (sc->sc_dying)
416 		return (EIO);
417 
418 	size = sc->sc_osize;
419 	error = 0;
420 	if (uio->uio_resid != size)
421 		return (EINVAL);
422 	error = uiomove(sc->sc_obuf, size, uio);
423 	if (!error) {
424 		err = uhidev_set_report(&sc->sc_hdev, UHID_OUTPUT_REPORT,
425 					sc->sc_obuf, size);
426 		if (err)
427 			error = EIO;
428 	}
429 
430 	return (error);
431 }
432 
433 int
434 uhidwrite(dev_t dev, struct uio *uio, int flag)
435 {
436 	struct uhid_softc *sc;
437 	int error;
438 
439 	sc = device_lookup_private(&uhid_cd, UHIDUNIT(dev));
440 
441 	sc->sc_refcnt++;
442 	error = uhid_do_write(sc, uio, flag);
443 	if (--sc->sc_refcnt < 0)
444 		usb_detach_wakeup(sc->sc_hdev.sc_dev);
445 	return (error);
446 }
447 
448 int
449 uhid_do_ioctl(struct uhid_softc *sc, u_long cmd, void *addr,
450     int flag, struct lwp *l)
451 {
452 	struct usb_ctl_report_desc *rd;
453 	struct usb_ctl_report *re;
454 	u_char buffer[UHID_CHUNK];
455 	int size, extra;
456 	usbd_status err;
457 	void *desc;
458 
459 	DPRINTFN(2, ("uhidioctl: cmd=%lx\n", cmd));
460 
461 	if (sc->sc_dying)
462 		return (EIO);
463 
464 	switch (cmd) {
465 	case FIONBIO:
466 		/* All handled in the upper FS layer. */
467 		break;
468 
469 	case FIOASYNC:
470 		mutex_enter(proc_lock);
471 		if (*(int *)addr) {
472 			if (sc->sc_async != NULL)
473 				return (EBUSY);
474 			sc->sc_async = l->l_proc;
475 			DPRINTF(("uhid_do_ioctl: FIOASYNC %p\n", l->l_proc));
476 		} else
477 			sc->sc_async = NULL;
478 		mutex_exit(proc_lock);
479 		break;
480 
481 	/* XXX this is not the most general solution. */
482 	case TIOCSPGRP:
483 		mutex_enter(proc_lock);
484 		if (sc->sc_async == NULL) {
485 			mutex_exit(proc_lock);
486 			return (EINVAL);
487 		}
488 		if (*(int *)addr != sc->sc_async->p_pgid) {
489 			mutex_exit(proc_lock);
490 			return (EPERM);
491 		}
492 		mutex_exit(proc_lock);
493 		break;
494 
495 	case FIOSETOWN:
496 		mutex_enter(proc_lock);
497 		if (sc->sc_async == NULL) {
498 			mutex_exit(proc_lock);
499 			return (EINVAL);
500 		}
501 		if (-*(int *)addr != sc->sc_async->p_pgid
502 		    && *(int *)addr != sc->sc_async->p_pid) {
503 			mutex_exit(proc_lock);
504 			return (EPERM);
505 		}
506 		mutex_exit(proc_lock);
507 		break;
508 
509 	case USB_GET_REPORT_DESC:
510 		uhidev_get_report_desc(sc->sc_hdev.sc_parent, &desc, &size);
511 		rd = (struct usb_ctl_report_desc *)addr;
512 		size = min(size, sizeof rd->ucrd_data);
513 		rd->ucrd_size = size;
514 		memcpy(rd->ucrd_data, desc, size);
515 		break;
516 
517 	case USB_SET_IMMED:
518 		if (*(int *)addr) {
519 			extra = sc->sc_hdev.sc_report_id != 0;
520 			err = uhidev_get_report(&sc->sc_hdev, UHID_INPUT_REPORT,
521 						buffer, sc->sc_isize + extra);
522 			if (err)
523 				return (EOPNOTSUPP);
524 
525 			sc->sc_state |=  UHID_IMMED;
526 		} else
527 			sc->sc_state &= ~UHID_IMMED;
528 		break;
529 
530 	case USB_GET_REPORT:
531 		re = (struct usb_ctl_report *)addr;
532 		switch (re->ucr_report) {
533 		case UHID_INPUT_REPORT:
534 			size = sc->sc_isize;
535 			break;
536 		case UHID_OUTPUT_REPORT:
537 			size = sc->sc_osize;
538 			break;
539 		case UHID_FEATURE_REPORT:
540 			size = sc->sc_fsize;
541 			break;
542 		default:
543 			return (EINVAL);
544 		}
545 		extra = sc->sc_hdev.sc_report_id != 0;
546 		err = uhidev_get_report(&sc->sc_hdev, re->ucr_report,
547 		    re->ucr_data, size + extra);
548 		if (extra)
549 			memcpy(re->ucr_data, re->ucr_data+1, size);
550 		if (err)
551 			return (EIO);
552 		break;
553 
554 	case USB_SET_REPORT:
555 		re = (struct usb_ctl_report *)addr;
556 		switch (re->ucr_report) {
557 		case UHID_INPUT_REPORT:
558 			size = sc->sc_isize;
559 			break;
560 		case UHID_OUTPUT_REPORT:
561 			size = sc->sc_osize;
562 			break;
563 		case UHID_FEATURE_REPORT:
564 			size = sc->sc_fsize;
565 			break;
566 		default:
567 			return (EINVAL);
568 		}
569 		err = uhidev_set_report(&sc->sc_hdev, re->ucr_report,
570 		    re->ucr_data, size);
571 		if (err)
572 			return (EIO);
573 		break;
574 
575 	case USB_GET_REPORT_ID:
576 		*(int *)addr = sc->sc_hdev.sc_report_id;
577 		break;
578 
579 	case USB_GET_DEVICEINFO:
580 		usbd_fill_deviceinfo(sc->sc_hdev.sc_parent->sc_udev,
581 			             (struct usb_device_info *)addr, 0);
582 		break;
583 #ifdef COMPAT_30
584 	case USB_GET_DEVICEINFO_OLD:
585 		usbd_fill_deviceinfo_old(sc->sc_hdev.sc_parent->sc_udev,
586 					 (struct usb_device_info_old *)addr, 0);
587 
588 		break;
589 #endif
590         case USB_GET_STRING_DESC:
591 	    {
592                 struct usb_string_desc *si = (struct usb_string_desc *)addr;
593                 err = usbd_get_string_desc(sc->sc_hdev.sc_parent->sc_udev,
594 			si->usd_string_index,
595                 	si->usd_language_id, &si->usd_desc, &size);
596                 if (err)
597                         return (EINVAL);
598                 break;
599 	    }
600 
601 	default:
602 		return (EINVAL);
603 	}
604 	return (0);
605 }
606 
607 int
608 uhidioctl(dev_t dev, u_long cmd, void *addr, int flag, struct lwp *l)
609 {
610 	struct uhid_softc *sc;
611 	int error;
612 
613 	sc = device_lookup_private(&uhid_cd, UHIDUNIT(dev));
614 
615 	sc->sc_refcnt++;
616 	error = uhid_do_ioctl(sc, cmd, addr, flag, l);
617 	if (--sc->sc_refcnt < 0)
618 		usb_detach_wakeup(sc->sc_hdev.sc_dev);
619 	return (error);
620 }
621 
622 int
623 uhidpoll(dev_t dev, int events, struct lwp *l)
624 {
625 	struct uhid_softc *sc;
626 	int revents = 0;
627 	int s;
628 
629 	sc = device_lookup_private(&uhid_cd, UHIDUNIT(dev));
630 
631 	if (sc->sc_dying)
632 		return (POLLHUP);
633 
634 	s = splusb();
635 	if (events & (POLLOUT | POLLWRNORM))
636 		revents |= events & (POLLOUT | POLLWRNORM);
637 	if (events & (POLLIN | POLLRDNORM)) {
638 		if (sc->sc_q.c_cc > 0)
639 			revents |= events & (POLLIN | POLLRDNORM);
640 		else
641 			selrecord(l, &sc->sc_rsel);
642 	}
643 
644 	splx(s);
645 	return (revents);
646 }
647 
648 static void
649 filt_uhidrdetach(struct knote *kn)
650 {
651 	struct uhid_softc *sc = kn->kn_hook;
652 	int s;
653 
654 	s = splusb();
655 	SLIST_REMOVE(&sc->sc_rsel.sel_klist, kn, knote, kn_selnext);
656 	splx(s);
657 }
658 
659 static int
660 filt_uhidread(struct knote *kn, long hint)
661 {
662 	struct uhid_softc *sc = kn->kn_hook;
663 
664 	kn->kn_data = sc->sc_q.c_cc;
665 	return (kn->kn_data > 0);
666 }
667 
668 static const struct filterops uhidread_filtops =
669 	{ 1, NULL, filt_uhidrdetach, filt_uhidread };
670 
671 static const struct filterops uhid_seltrue_filtops =
672 	{ 1, NULL, filt_uhidrdetach, filt_seltrue };
673 
674 int
675 uhidkqfilter(dev_t dev, struct knote *kn)
676 {
677 	struct uhid_softc *sc;
678 	struct klist *klist;
679 	int s;
680 
681 	sc = device_lookup_private(&uhid_cd, UHIDUNIT(dev));
682 
683 	if (sc->sc_dying)
684 		return (ENXIO);
685 
686 	switch (kn->kn_filter) {
687 	case EVFILT_READ:
688 		klist = &sc->sc_rsel.sel_klist;
689 		kn->kn_fop = &uhidread_filtops;
690 		break;
691 
692 	case EVFILT_WRITE:
693 		klist = &sc->sc_rsel.sel_klist;
694 		kn->kn_fop = &uhid_seltrue_filtops;
695 		break;
696 
697 	default:
698 		return (EINVAL);
699 	}
700 
701 	kn->kn_hook = sc;
702 
703 	s = splusb();
704 	SLIST_INSERT_HEAD(klist, kn, kn_selnext);
705 	splx(s);
706 
707 	return (0);
708 }
709