xref: /netbsd-src/sys/dev/usb/uhid.c (revision b5677b36047b601b9addaaa494a58ceae82c2a6c)
1 /*	$NetBSD: uhid.c,v 1.82 2008/05/24 16:40:58 cube 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 1.82 2008/05/24 16:40:58 cube 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) logprintf x
71 #define DPRINTFN(n,x)	if (uhiddebug>(n)) logprintf 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 	usb_proc_ptr 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 USB_DECLARE_DRIVER(uhid);
124 
125 int
126 uhid_match(device_t parent, cfdata_t match, void *aux)
127 {
128 #ifdef UHID_DEBUG
129 	struct uhidev_attach_arg *uha = aux;
130 #endif
131 
132 	DPRINTF(("uhid_match: report=%d\n", uha->reportid));
133 
134 	if (match->cf_flags & 1)
135 		return (UMATCH_HIGHEST);
136 	else
137 		return (UMATCH_IFACECLASS_GENERIC);
138 }
139 
140 void
141 uhid_attach(device_t parent, device_t self, void *aux)
142 {
143 	struct uhid_softc *sc = device_private(self);
144 	struct uhidev_attach_arg *uha = aux;
145 	int size, repid;
146 	void *desc;
147 
148 	sc->sc_hdev.sc_dev = self;
149 	selinit(&sc->sc_rsel);
150 	sc->sc_hdev.sc_intr = uhid_intr;
151 	sc->sc_hdev.sc_parent = uha->parent;
152 	sc->sc_hdev.sc_report_id = uha->reportid;
153 	sc->sc_sih = softint_establish(SOFTINT_MPSAFE | SOFTINT_CLOCK,
154 	    uhid_softintr, sc);
155 
156 	uhidev_get_report_desc(uha->parent, &desc, &size);
157 	repid = uha->reportid;
158 	sc->sc_isize = hid_report_size(desc, size, hid_input,   repid);
159 	sc->sc_osize = hid_report_size(desc, size, hid_output,  repid);
160 	sc->sc_fsize = hid_report_size(desc, size, hid_feature, repid);
161 
162 	aprint_naive("\n");
163 	aprint_normal(": input=%d, output=%d, feature=%d\n",
164 	       sc->sc_isize, sc->sc_osize, sc->sc_fsize);
165 
166 	if (!pmf_device_register(self, NULL, NULL))
167 		aprint_error_dev(self, "couldn't establish power handler\n");
168 
169 	USB_ATTACH_SUCCESS_RETURN;
170 }
171 
172 int
173 uhid_activate(device_ptr_t self, enum devact act)
174 {
175 	struct uhid_softc *sc = device_private(self);
176 
177 	switch (act) {
178 	case DVACT_ACTIVATE:
179 		return (EOPNOTSUPP);
180 
181 	case DVACT_DEACTIVATE:
182 		sc->sc_dying = 1;
183 		break;
184 	}
185 	return (0);
186 }
187 
188 int
189 uhid_detach(device_t self, int flags)
190 {
191 	struct uhid_softc *sc = device_private(self);
192 	int s;
193 	int maj, mn;
194 
195 	DPRINTF(("uhid_detach: sc=%p flags=%d\n", sc, flags));
196 
197 	sc->sc_dying = 1;
198 
199 	if (sc->sc_hdev.sc_state & UHIDEV_OPEN) {
200 		s = splusb();
201 		if (--sc->sc_refcnt >= 0) {
202 			/* Wake everyone */
203 			wakeup(&sc->sc_q);
204 			/* Wait for processes to go away. */
205 			usb_detach_wait(USBDEV(sc->sc_hdev.sc_dev));
206 		}
207 		splx(s);
208 	}
209 
210 	/* locate the major number */
211 #if defined(__NetBSD__)
212 	maj = cdevsw_lookup_major(&uhid_cdevsw);
213 #elif defined(__OpenBSD__)
214 	for (maj = 0; maj < nchrdev; maj++)
215 		if (cdevsw[maj].d_open == uhidopen)
216 			break;
217 #endif
218 
219 	/* Nuke the vnodes for any open instances (calls close). */
220 	mn = device_unit(self);
221 	vdevgone(maj, mn, mn, VCHR);
222 
223 #if 0
224 	usbd_add_drv_event(USB_EVENT_DRIVER_DETACH,
225 			   sc->sc_hdev.sc_parent->sc_udev,
226 			   USBDEV(sc->sc_hdev.sc_dev));
227 #endif
228 	seldestroy(&sc->sc_rsel);
229 	softint_disestablish(sc->sc_sih);
230 
231 	return (0);
232 }
233 
234 void
235 uhid_intr(struct uhidev *addr, void *data, u_int len)
236 {
237 	struct uhid_softc *sc = (struct uhid_softc *)addr;
238 
239 #ifdef UHID_DEBUG
240 	if (uhiddebug > 5) {
241 		u_int32_t i;
242 
243 		DPRINTF(("uhid_intr: data ="));
244 		for (i = 0; i < len; i++)
245 			DPRINTF((" %02x", ((u_char *)data)[i]));
246 		DPRINTF(("\n"));
247 	}
248 #endif
249 
250 	(void)b_to_q(data, len, &sc->sc_q);
251 
252 	if (sc->sc_state & UHID_ASLP) {
253 		sc->sc_state &= ~UHID_ASLP;
254 		DPRINTFN(5, ("uhid_intr: waking %p\n", &sc->sc_q));
255 		wakeup(&sc->sc_q);
256 	}
257 	selnotify(&sc->sc_rsel, 0, 0);
258 	if (sc->sc_async != NULL) {
259 		DPRINTFN(3, ("uhid_intr: sending SIGIO %p\n", sc->sc_async));
260 		softint_schedule(sc->sc_sih);
261 	}
262 }
263 
264 void
265 uhid_softintr(void *cookie)
266 {
267 	struct uhid_softc *sc;
268 
269 	sc = cookie;
270 
271 	mutex_enter(proc_lock);
272 	if (sc->sc_async != NULL)
273 		 psignal(sc->sc_async, SIGIO);
274 	mutex_exit(proc_lock);
275 }
276 
277 int
278 uhidopen(dev_t dev, int flag, int mode,
279     struct lwp *l)
280 {
281 	struct uhid_softc *sc;
282 	int error;
283 
284 	USB_GET_SC_OPEN(uhid, UHIDUNIT(dev), sc);
285 
286 	DPRINTF(("uhidopen: sc=%p\n", sc));
287 
288 	if (sc->sc_dying)
289 		return (ENXIO);
290 
291 	error = uhidev_open(&sc->sc_hdev);
292 	if (error)
293 		return (error);
294 
295 	if (clalloc(&sc->sc_q, UHID_BSIZE, 0) == -1) {
296 		uhidev_close(&sc->sc_hdev);
297 		return (ENOMEM);
298 	}
299 	sc->sc_obuf = malloc(sc->sc_osize, M_USBDEV, M_WAITOK);
300 	sc->sc_state &= ~UHID_IMMED;
301 	mutex_enter(proc_lock);
302 	sc->sc_async = NULL;
303 	mutex_exit(proc_lock);
304 
305 	return (0);
306 }
307 
308 int
309 uhidclose(dev_t dev, int flag, int mode,
310     struct lwp *l)
311 {
312 	struct uhid_softc *sc;
313 
314 	USB_GET_SC(uhid, UHIDUNIT(dev), sc);
315 
316 	DPRINTF(("uhidclose: sc=%p\n", sc));
317 
318 	clfree(&sc->sc_q);
319 	free(sc->sc_obuf, M_USBDEV);
320 	mutex_enter(proc_lock);
321 	sc->sc_async = NULL;
322 	mutex_exit(proc_lock);
323 	uhidev_close(&sc->sc_hdev);
324 
325 	return (0);
326 }
327 
328 int
329 uhid_do_read(struct uhid_softc *sc, struct uio *uio, int flag)
330 {
331 	int s;
332 	int error = 0;
333 	int extra;
334 	size_t length;
335 	u_char buffer[UHID_CHUNK];
336 	usbd_status err;
337 
338 	DPRINTFN(1, ("uhidread\n"));
339 	if (sc->sc_state & UHID_IMMED) {
340 		DPRINTFN(1, ("uhidread immed\n"));
341 		extra = sc->sc_hdev.sc_report_id != 0;
342 		err = uhidev_get_report(&sc->sc_hdev, UHID_INPUT_REPORT,
343 					buffer, sc->sc_isize + extra);
344 		if (err)
345 			return (EIO);
346 		return (uiomove(buffer+extra, sc->sc_isize, uio));
347 	}
348 
349 	s = splusb();
350 	while (sc->sc_q.c_cc == 0) {
351 		if (flag & IO_NDELAY) {
352 			splx(s);
353 			return (EWOULDBLOCK);
354 		}
355 		sc->sc_state |= UHID_ASLP;
356 		DPRINTFN(5, ("uhidread: sleep on %p\n", &sc->sc_q));
357 		error = tsleep(&sc->sc_q, PZERO | PCATCH, "uhidrea", 0);
358 		DPRINTFN(5, ("uhidread: woke, error=%d\n", error));
359 		if (sc->sc_dying)
360 			error = EIO;
361 		if (error) {
362 			sc->sc_state &= ~UHID_ASLP;
363 			break;
364 		}
365 	}
366 	splx(s);
367 
368 	/* Transfer as many chunks as possible. */
369 	while (sc->sc_q.c_cc > 0 && uio->uio_resid > 0 && !error) {
370 		length = min(sc->sc_q.c_cc, uio->uio_resid);
371 		if (length > sizeof(buffer))
372 			length = sizeof(buffer);
373 
374 		/* Remove a small chunk from the input queue. */
375 		(void) q_to_b(&sc->sc_q, buffer, length);
376 		DPRINTFN(5, ("uhidread: got %lu chars\n", (u_long)length));
377 
378 		/* Copy the data to the user process. */
379 		if ((error = uiomove(buffer, length, uio)) != 0)
380 			break;
381 	}
382 
383 	return (error);
384 }
385 
386 int
387 uhidread(dev_t dev, struct uio *uio, int flag)
388 {
389 	struct uhid_softc *sc;
390 	int error;
391 
392 	USB_GET_SC(uhid, UHIDUNIT(dev), sc);
393 
394 	sc->sc_refcnt++;
395 	error = uhid_do_read(sc, uio, flag);
396 	if (--sc->sc_refcnt < 0)
397 		usb_detach_wakeup(USBDEV(sc->sc_hdev.sc_dev));
398 	return (error);
399 }
400 
401 int
402 uhid_do_write(struct uhid_softc *sc, struct uio *uio, int flag)
403 {
404 	int error;
405 	int size;
406 	usbd_status err;
407 
408 	DPRINTFN(1, ("uhidwrite\n"));
409 
410 	if (sc->sc_dying)
411 		return (EIO);
412 
413 	size = sc->sc_osize;
414 	error = 0;
415 	if (uio->uio_resid != size)
416 		return (EINVAL);
417 	error = uiomove(sc->sc_obuf, size, uio);
418 	if (!error) {
419 		err = uhidev_set_report(&sc->sc_hdev, UHID_OUTPUT_REPORT,
420 					sc->sc_obuf, size);
421 		if (err)
422 			error = EIO;
423 	}
424 
425 	return (error);
426 }
427 
428 int
429 uhidwrite(dev_t dev, struct uio *uio, int flag)
430 {
431 	struct uhid_softc *sc;
432 	int error;
433 
434 	USB_GET_SC(uhid, UHIDUNIT(dev), sc);
435 
436 	sc->sc_refcnt++;
437 	error = uhid_do_write(sc, uio, flag);
438 	if (--sc->sc_refcnt < 0)
439 		usb_detach_wakeup(USBDEV(sc->sc_hdev.sc_dev));
440 	return (error);
441 }
442 
443 int
444 uhid_do_ioctl(struct uhid_softc *sc, u_long cmd, void *addr,
445     int flag, struct lwp *l)
446 {
447 	struct usb_ctl_report_desc *rd;
448 	struct usb_ctl_report *re;
449 	u_char buffer[UHID_CHUNK];
450 	int size, extra;
451 	usbd_status err;
452 	void *desc;
453 
454 	DPRINTFN(2, ("uhidioctl: cmd=%lx\n", cmd));
455 
456 	if (sc->sc_dying)
457 		return (EIO);
458 
459 	switch (cmd) {
460 	case FIONBIO:
461 		/* All handled in the upper FS layer. */
462 		break;
463 
464 	case FIOASYNC:
465 		mutex_enter(proc_lock);
466 		if (*(int *)addr) {
467 			if (sc->sc_async != NULL)
468 				return (EBUSY);
469 			sc->sc_async = l->l_proc;
470 			DPRINTF(("uhid_do_ioctl: FIOASYNC %p\n", l->l_proc));
471 		} else
472 			sc->sc_async = NULL;
473 		mutex_exit(proc_lock);
474 		break;
475 
476 	/* XXX this is not the most general solution. */
477 	case TIOCSPGRP:
478 		mutex_enter(proc_lock);
479 		if (sc->sc_async == NULL) {
480 			mutex_exit(proc_lock);
481 			return (EINVAL);
482 		}
483 		if (*(int *)addr != sc->sc_async->p_pgid) {
484 			mutex_exit(proc_lock);
485 			return (EPERM);
486 		}
487 		mutex_exit(proc_lock);
488 		break;
489 
490 	case FIOSETOWN:
491 		mutex_enter(proc_lock);
492 		if (sc->sc_async == NULL) {
493 			mutex_exit(proc_lock);
494 			return (EINVAL);
495 		}
496 		if (-*(int *)addr != sc->sc_async->p_pgid
497 		    && *(int *)addr != sc->sc_async->p_pid) {
498 			mutex_exit(proc_lock);
499 			return (EPERM);
500 		}
501 		mutex_exit(proc_lock);
502 		break;
503 
504 	case USB_GET_REPORT_DESC:
505 		uhidev_get_report_desc(sc->sc_hdev.sc_parent, &desc, &size);
506 		rd = (struct usb_ctl_report_desc *)addr;
507 		size = min(size, sizeof rd->ucrd_data);
508 		rd->ucrd_size = size;
509 		memcpy(rd->ucrd_data, desc, size);
510 		break;
511 
512 	case USB_SET_IMMED:
513 		if (*(int *)addr) {
514 			extra = sc->sc_hdev.sc_report_id != 0;
515 			err = uhidev_get_report(&sc->sc_hdev, UHID_INPUT_REPORT,
516 						buffer, sc->sc_isize + extra);
517 			if (err)
518 				return (EOPNOTSUPP);
519 
520 			sc->sc_state |=  UHID_IMMED;
521 		} else
522 			sc->sc_state &= ~UHID_IMMED;
523 		break;
524 
525 	case USB_GET_REPORT:
526 		re = (struct usb_ctl_report *)addr;
527 		switch (re->ucr_report) {
528 		case UHID_INPUT_REPORT:
529 			size = sc->sc_isize;
530 			break;
531 		case UHID_OUTPUT_REPORT:
532 			size = sc->sc_osize;
533 			break;
534 		case UHID_FEATURE_REPORT:
535 			size = sc->sc_fsize;
536 			break;
537 		default:
538 			return (EINVAL);
539 		}
540 		extra = sc->sc_hdev.sc_report_id != 0;
541 		err = uhidev_get_report(&sc->sc_hdev, re->ucr_report,
542 		    re->ucr_data, size + extra);
543 		if (extra)
544 			memcpy(re->ucr_data, re->ucr_data+1, size);
545 		if (err)
546 			return (EIO);
547 		break;
548 
549 	case USB_SET_REPORT:
550 		re = (struct usb_ctl_report *)addr;
551 		switch (re->ucr_report) {
552 		case UHID_INPUT_REPORT:
553 			size = sc->sc_isize;
554 			break;
555 		case UHID_OUTPUT_REPORT:
556 			size = sc->sc_osize;
557 			break;
558 		case UHID_FEATURE_REPORT:
559 			size = sc->sc_fsize;
560 			break;
561 		default:
562 			return (EINVAL);
563 		}
564 		err = uhidev_set_report(&sc->sc_hdev, re->ucr_report,
565 		    re->ucr_data, size);
566 		if (err)
567 			return (EIO);
568 		break;
569 
570 	case USB_GET_REPORT_ID:
571 		*(int *)addr = sc->sc_hdev.sc_report_id;
572 		break;
573 
574 	case USB_GET_DEVICEINFO:
575 		usbd_fill_deviceinfo(sc->sc_hdev.sc_parent->sc_udev,
576 			             (struct usb_device_info *)addr, 0);
577 		break;
578 #ifdef COMPAT_30
579 	case USB_GET_DEVICEINFO_OLD:
580 		usbd_fill_deviceinfo_old(sc->sc_hdev.sc_parent->sc_udev,
581 					 (struct usb_device_info_old *)addr, 0);
582 
583 		break;
584 #endif
585         case USB_GET_STRING_DESC:
586 	    {
587                 struct usb_string_desc *si = (struct usb_string_desc *)addr;
588                 err = usbd_get_string_desc(sc->sc_hdev.sc_parent->sc_udev,
589 			si->usd_string_index,
590                 	si->usd_language_id, &si->usd_desc, &size);
591                 if (err)
592                         return (EINVAL);
593                 break;
594 	    }
595 
596 	default:
597 		return (EINVAL);
598 	}
599 	return (0);
600 }
601 
602 int
603 uhidioctl(dev_t dev, u_long cmd, void *addr, int flag, struct lwp *l)
604 {
605 	struct uhid_softc *sc;
606 	int error;
607 
608 	USB_GET_SC(uhid, UHIDUNIT(dev), sc);
609 
610 	sc->sc_refcnt++;
611 	error = uhid_do_ioctl(sc, cmd, addr, flag, l);
612 	if (--sc->sc_refcnt < 0)
613 		usb_detach_wakeup(USBDEV(sc->sc_hdev.sc_dev));
614 	return (error);
615 }
616 
617 int
618 uhidpoll(dev_t dev, int events, struct lwp *l)
619 {
620 	struct uhid_softc *sc;
621 	int revents = 0;
622 	int s;
623 
624 	USB_GET_SC(uhid, UHIDUNIT(dev), sc);
625 
626 	if (sc->sc_dying)
627 		return (POLLHUP);
628 
629 	s = splusb();
630 	if (events & (POLLOUT | POLLWRNORM))
631 		revents |= events & (POLLOUT | POLLWRNORM);
632 	if (events & (POLLIN | POLLRDNORM)) {
633 		if (sc->sc_q.c_cc > 0)
634 			revents |= events & (POLLIN | POLLRDNORM);
635 		else
636 			selrecord(l, &sc->sc_rsel);
637 	}
638 
639 	splx(s);
640 	return (revents);
641 }
642 
643 static void
644 filt_uhidrdetach(struct knote *kn)
645 {
646 	struct uhid_softc *sc = kn->kn_hook;
647 	int s;
648 
649 	s = splusb();
650 	SLIST_REMOVE(&sc->sc_rsel.sel_klist, kn, knote, kn_selnext);
651 	splx(s);
652 }
653 
654 static int
655 filt_uhidread(struct knote *kn, long hint)
656 {
657 	struct uhid_softc *sc = kn->kn_hook;
658 
659 	kn->kn_data = sc->sc_q.c_cc;
660 	return (kn->kn_data > 0);
661 }
662 
663 static const struct filterops uhidread_filtops =
664 	{ 1, NULL, filt_uhidrdetach, filt_uhidread };
665 
666 static const struct filterops uhid_seltrue_filtops =
667 	{ 1, NULL, filt_uhidrdetach, filt_seltrue };
668 
669 int
670 uhidkqfilter(dev_t dev, struct knote *kn)
671 {
672 	struct uhid_softc *sc;
673 	struct klist *klist;
674 	int s;
675 
676 	USB_GET_SC(uhid, UHIDUNIT(dev), sc);
677 
678 	if (sc->sc_dying)
679 		return (ENXIO);
680 
681 	switch (kn->kn_filter) {
682 	case EVFILT_READ:
683 		klist = &sc->sc_rsel.sel_klist;
684 		kn->kn_fop = &uhidread_filtops;
685 		break;
686 
687 	case EVFILT_WRITE:
688 		klist = &sc->sc_rsel.sel_klist;
689 		kn->kn_fop = &uhid_seltrue_filtops;
690 		break;
691 
692 	default:
693 		return (EINVAL);
694 	}
695 
696 	kn->kn_hook = sc;
697 
698 	s = splusb();
699 	SLIST_INSERT_HEAD(klist, kn, kn_selnext);
700 	splx(s);
701 
702 	return (0);
703 }
704