xref: /netbsd-src/sys/dev/spkr.c (revision 7d62b00eb9ad855ffcd7da46b41e23feb5476fac)
1 /*	$NetBSD: spkr.c,v 1.24 2022/09/24 23:16:37 thorpej Exp $	*/
2 
3 /*
4  * Copyright (c) 1990 Eric S. Raymond (esr@snark.thyrsus.com)
5  * Copyright (c) 1990 Andrew A. Chernov (ache@astral.msk.su)
6  * Copyright (c) 1990 Lennart Augustsson (lennart@augustsson.net)
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by Eric S. Raymond
20  * 4. The name of the author may not be used to endorse or promote products
21  *    derived from this software without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
25  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
26  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
27  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
28  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
29  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
31  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
32  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33  * POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 /*
37  * spkr.c -- device driver for console speaker on 80386
38  *
39  * v1.1 by Eric S. Raymond (esr@snark.thyrsus.com) Feb 1990
40  *      modified for 386bsd by Andrew A. Chernov <ache@astral.msk.su>
41  *      386bsd only clean version, all SYSV stuff removed
42  *      use hz value from param.c
43  */
44 
45 #include <sys/cdefs.h>
46 __KERNEL_RCSID(0, "$NetBSD: spkr.c,v 1.24 2022/09/24 23:16:37 thorpej Exp $");
47 
48 #if defined(_KERNEL_OPT)
49 #include "wsmux.h"
50 #endif
51 
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/kernel.h>
55 #include <sys/errno.h>
56 #include <sys/device.h>
57 #include <sys/kmem.h>
58 #include <sys/module.h>
59 #include <sys/uio.h>
60 #include <sys/proc.h>
61 #include <sys/ioctl.h>
62 #include <sys/conf.h>
63 
64 #include <sys/bus.h>
65 
66 #include <dev/spkrio.h>
67 #include <dev/spkrvar.h>
68 #include <dev/wscons/wsconsio.h>
69 #include <dev/wscons/wsbellvar.h>
70 #include <dev/wscons/wsbellmuxvar.h>
71 
72 #include "ioconf.h"
73 
74 dev_type_open(spkropen);
75 dev_type_close(spkrclose);
76 dev_type_write(spkrwrite);
77 dev_type_ioctl(spkrioctl);
78 
79 const struct cdevsw spkr_cdevsw = {
80 	.d_open = spkropen,
81 	.d_close = spkrclose,
82 	.d_read = noread,
83 	.d_write = spkrwrite,
84 	.d_ioctl = spkrioctl,
85 	.d_stop = nostop,
86 	.d_tty = notty,
87 	.d_poll = nopoll,
88 	.d_mmap = nommap,
89 	.d_kqfilter = nokqfilter,
90 	.d_discard = nodiscard,
91 	.d_flag = D_OTHER
92 };
93 
94 static void playinit(struct spkr_softc *);
95 static void playtone(struct spkr_softc *, int, int, int);
96 static void playstring(struct spkr_softc *, const char *, size_t);
97 
98 /**************** PLAY STRING INTERPRETER BEGINS HERE **********************
99  *
100  * Play string interpretation is modelled on IBM BASIC 2.0's PLAY statement;
101  * M[LNS] are missing and the ~ synonym and octave-tracking facility is added.
102  * String play is not interruptible except possibly at physical block
103  * boundaries.
104  */
105 
106 /*
107  * Magic number avoidance...
108  */
109 #define SECS_PER_MIN	60	/* seconds per minute */
110 #define WHOLE_NOTE	4	/* quarter notes per whole note */
111 #define MIN_VALUE	64	/* the most we can divide a note by */
112 #define DFLT_VALUE	4	/* default value (quarter-note) */
113 #define FILLTIME	8	/* for articulation, break note in parts */
114 #define STACCATO	6	/* 6/8 = 3/4 of note is filled */
115 #define NORMAL		7	/* 7/8ths of note interval is filled */
116 #define LEGATO		8	/* all of note interval is filled */
117 #define DFLT_OCTAVE	4	/* default octave */
118 #define MIN_TEMPO	32	/* minimum tempo */
119 #define DFLT_TEMPO	120	/* default tempo */
120 #define MAX_TEMPO	255	/* max tempo */
121 #define NUM_MULT	3	/* numerator of dot multiplier */
122 #define DENOM_MULT	2	/* denominator of dot multiplier */
123 
124 /* letter to half-tone:         A   B  C  D  E  F  G */
125 static const int notetab[8] = { 9, 11, 0, 2, 4, 5, 7 };
126 
127 /*
128  * This is the American Standard A440 Equal-Tempered scale with frequencies
129  * rounded to nearest integer. Thank Goddess for the good ol' CRC Handbook...
130  * our octave 0 is standard octave 2.
131  */
132 #define OCTAVE_NOTES	12	/* semitones per octave */
133 static const int pitchtab[] =
134 {
135 /*        C     C#    D     D#    E     F     F#    G     G#    A     A#    B*/
136 /* 0 */   65,   69,   73,   78,   82,   87,   93,   98,  103,  110,  117,  123,
137 /* 1 */  131,  139,  147,  156,  165,  175,  185,  196,  208,  220,  233,  247,
138 /* 2 */  262,  277,  294,  311,  330,  349,  370,  392,  415,  440,  466,  494,
139 /* 3 */  523,  554,  587,  622,  659,  698,  740,  784,  831,  880,  932,  988,
140 /* 4 */ 1047, 1109, 1175, 1245, 1319, 1397, 1480, 1568, 1661, 1760, 1865, 1975,
141 /* 5 */ 2093, 2217, 2349, 2489, 2637, 2794, 2960, 3136, 3322, 3520, 3729, 3951,
142 /* 6 */ 4186, 4435, 4698, 4978, 5274, 5588, 5920, 6272, 6644, 7040, 7459, 7902,
143 };
144 #define NOCTAVES (int)(__arraycount(pitchtab) / OCTAVE_NOTES)
145 
146 static void
147 playinit(struct spkr_softc *sc)
148 {
149 	sc->sc_octave = DFLT_OCTAVE;
150 	sc->sc_whole = (hz * SECS_PER_MIN * WHOLE_NOTE) / DFLT_TEMPO;
151 	sc->sc_fill = NORMAL;
152 	sc->sc_value = DFLT_VALUE;
153 	sc->sc_octtrack = false;
154 	sc->sc_octprefix = true;/* act as though there was an initial O(n) */
155 }
156 
157 #define SPKRPRI (PZERO - 1)
158 
159 /* Rest for given number of ticks */
160 static void
161 rest(struct spkr_softc *sc, int ticks)
162 {
163 
164 #ifdef SPKRDEBUG
165 	device_printf(sc->sc_dev, "%s: rest for %d ticks\n", __func__, ticks);
166 #endif /* SPKRDEBUG */
167 	KASSERT(ticks > 0);
168 
169 	tsleep(sc->sc_dev, SPKRPRI | PCATCH, device_xname(sc->sc_dev), ticks);
170 }
171 
172 /*
173  * Play tone of proper duration for current rhythm signature.
174  * note indicates "O0C" = 0, "O0C#" = 1, "O0D" = 2, ... , and
175  * -1 indiacates a rest.
176  * val indicates the length, "L4" = 4, "L8" = 8.
177  * sustain indicates the number of subsequent dots that extend the sound
178  * by one a half.
179  */
180 static void
181 playtone(struct spkr_softc *sc, int note, int val, int sustain)
182 {
183 	int whole;
184 	int total;
185 	int sound;
186 	int silence;
187 
188 	/* this weirdness avoids floating-point arithmetic */
189 	whole = sc->sc_whole;
190 	for (; sustain; sustain--) {
191 		whole *= NUM_MULT;
192 		val *= DENOM_MULT;
193 	}
194 
195 	/* Total length in tick */
196 	total = whole / val;
197 
198 	if (note == -1) {
199 #ifdef SPKRDEBUG
200 		device_printf(sc->sc_dev, "%s: rest for %d ticks\n",
201 		    __func__, total);
202 #endif /* SPKRDEBUG */
203 		if (total != 0)
204 			rest(sc, total);
205 		return;
206 	}
207 
208 	/*
209 	 * Rest 1/8 (if NORMAL) or 3/8 (if STACCATO) in tick.
210 	 * silence should be rounded down.
211 	 */
212 	silence = total * (FILLTIME - sc->sc_fill) / FILLTIME;
213 	sound = total - silence;
214 
215 #ifdef SPKRDEBUG
216 	device_printf(sc->sc_dev,
217 	    "%s: note %d for %d ticks, rest for %d ticks\n", __func__,
218 	    note, sound, silence);
219 #endif /* SPKRDEBUG */
220 
221 	if (sound != 0)
222 		(*sc->sc_tone)(sc->sc_dev, pitchtab[note], sound);
223 	if (silence != 0)
224 		rest(sc, silence);
225 }
226 
227 /* interpret and play an item from a notation string */
228 static void
229 playstring(struct spkr_softc *sc, const char *cp, size_t slen)
230 {
231 	int pitch;
232 	int lastpitch = OCTAVE_NOTES * DFLT_OCTAVE;
233 
234 #define GETNUM(cp, v)	\
235 	for (v = 0; slen > 0 && isdigit((unsigned char)cp[1]); ) { \
236 		v = v * 10 + (*++cp - '0'); \
237 		slen--; \
238 	}
239 
240 	for (; slen--; cp++) {
241 		int sustain, timeval, tempo;
242 		char c = toupper((unsigned char)*cp);
243 
244 #ifdef SPKRDEBUG
245 		if (0x20 <= c && c < 0x7f) {
246 			device_printf(sc->sc_dev, "%s: '%c'\n", __func__, c);
247 		} else {
248 			device_printf(sc->sc_dev, "%s: (0x%x)\n", __func__, c);
249 		}
250 #endif /* SPKRDEBUG */
251 
252 		switch (c) {
253 		case 'A': case 'B': case 'C': case 'D':
254 		case 'E': case 'F': case 'G':
255 			/* compute pitch */
256 			pitch = notetab[c - 'A'] + sc->sc_octave * OCTAVE_NOTES;
257 
258 			/* this may be followed by an accidental sign */
259 			if (slen > 0 && (cp[1] == '#' || cp[1] == '+')) {
260 				++pitch;
261 				++cp;
262 				slen--;
263 			} else if (slen > 0 && cp[1] == '-') {
264 				--pitch;
265 				++cp;
266 				slen--;
267 			}
268 
269 			/*
270 			 * If octave-tracking mode is on, and there has been no
271 			 * octave- setting prefix, find the version of the
272 			 * current letter note * closest to the last
273 			 * regardless of octave.
274 			 */
275 			if (sc->sc_octtrack && !sc->sc_octprefix) {
276 				int d = abs(pitch - lastpitch);
277 				if (d > abs(pitch + OCTAVE_NOTES - lastpitch)) {
278 					if (sc->sc_octave < NOCTAVES - 1) {
279 						++sc->sc_octave;
280 						pitch += OCTAVE_NOTES;
281 					}
282 				}
283 
284 				if (d > abs(pitch - OCTAVE_NOTES - lastpitch)) {
285 					if (sc->sc_octave > 0) {
286 						--sc->sc_octave;
287 						pitch -= OCTAVE_NOTES;
288 					}
289 				}
290 			}
291 			sc->sc_octprefix = false;
292 			lastpitch = pitch;
293 
294 			/*
295 			 * ...which may in turn be followed by an override
296 			 * time value
297 			 */
298 			GETNUM(cp, timeval);
299 			if (timeval <= 0 || timeval > MIN_VALUE)
300 				timeval = sc->sc_value;
301 
302 			/* ...and/or sustain dots */
303 			for (sustain = 0; slen > 0 && cp[1] == '.'; cp++) {
304 				slen--;
305 				sustain++;
306 			}
307 
308 			/* time to emit the actual tone */
309 			playtone(sc, pitch, timeval, sustain);
310 			break;
311 
312 		case 'O':
313 			if (slen > 0 && (cp[1] == 'N' || cp[1] == 'n')) {
314 				sc->sc_octprefix = sc->sc_octtrack = false;
315 				++cp;
316 				slen--;
317 			} else if (slen > 0 && (cp[1] == 'L' || cp[1] == 'l')) {
318 				sc->sc_octtrack = true;
319 				++cp;
320 				slen--;
321 			} else {
322 				GETNUM(cp, sc->sc_octave);
323 				if (sc->sc_octave >= NOCTAVES)
324 					sc->sc_octave = DFLT_OCTAVE;
325 				sc->sc_octprefix = true;
326 			}
327 			break;
328 
329 		case '>':
330 			if (sc->sc_octave < NOCTAVES - 1)
331 				sc->sc_octave++;
332 			sc->sc_octprefix = true;
333 			break;
334 
335 		case '<':
336 			if (sc->sc_octave > 0)
337 				sc->sc_octave--;
338 			sc->sc_octprefix = true;
339 			break;
340 
341 		case 'N':
342 			GETNUM(cp, pitch);
343 			for (sustain = 0; slen > 0 && cp[1] == '.'; cp++) {
344 				slen--;
345 				sustain++;
346 			}
347 			playtone(sc, pitch - 1, sc->sc_value, sustain);
348 			break;
349 
350 		case 'L':
351 			GETNUM(cp, sc->sc_value);
352 			if (sc->sc_value <= 0 || sc->sc_value > MIN_VALUE)
353 				sc->sc_value = DFLT_VALUE;
354 			break;
355 
356 		case 'P':
357 		case '~':
358 			/* this may be followed by an override time value */
359 			GETNUM(cp, timeval);
360 			if (timeval <= 0 || timeval > MIN_VALUE)
361 				timeval = sc->sc_value;
362 			for (sustain = 0; slen > 0 && cp[1] == '.'; cp++) {
363 				slen--;
364 				sustain++;
365 			}
366 			playtone(sc, -1, timeval, sustain);
367 			break;
368 
369 		case 'T':
370 			GETNUM(cp, tempo);
371 			if (tempo < MIN_TEMPO || tempo > MAX_TEMPO)
372 				tempo = DFLT_TEMPO;
373 			sc->sc_whole = (hz * SECS_PER_MIN * WHOLE_NOTE) / tempo;
374 			break;
375 
376 		case 'M':
377 			if (slen > 0 && (cp[1] == 'N' || cp[1] == 'n')) {
378 				sc->sc_fill = NORMAL;
379 				++cp;
380 				slen--;
381 			} else if (slen > 0 && (cp[1] == 'L' || cp[1] == 'l')) {
382 				sc->sc_fill = LEGATO;
383 				++cp;
384 				slen--;
385 			} else if (slen > 0 && (cp[1] == 'S' || cp[1] == 's')) {
386 				sc->sc_fill = STACCATO;
387 				++cp;
388 				slen--;
389 			}
390 			break;
391 		}
392 	}
393 }
394 
395 /******************* UNIX DRIVER HOOKS BEGIN HERE **************************/
396 #define spkrenter(d)	device_lookup_private(&spkr_cd, d)
397 
398 /*
399  * Attaches spkr.  Specify tone function with the following specification:
400  *
401  * void
402  * tone(device_t self, u_int pitch, u_int tick)
403  *	plays a beep with specified parameters.
404  *	The argument 'pitch' specifies the pitch of a beep in Hz.  The argument
405  *	'tick' specifies the period of a beep in tick(9).  This function waits
406  *	to finish playing the beep and then halts it.
407  *	If the pitch is zero, it halts all sound if any (for compatibility
408  *	with the past confused specifications, but there should be no sound at
409  *	this point).  And it returns immediately, without waiting ticks.  So
410  *	you cannot use this as a rest.
411  *	If the tick is zero, it returns immediately.
412  */
413 void
414 spkr_attach(device_t self, void (*tone)(device_t, u_int, u_int))
415 {
416 	struct spkr_softc *sc = device_private(self);
417 
418 #ifdef SPKRDEBUG
419 	aprint_debug("%s: entering for unit %d\n", __func__,
420 	    device_unit(self));
421 #endif /* SPKRDEBUG */
422 	sc->sc_dev = self;
423 	sc->sc_tone = tone;
424 	sc->sc_inbuf = NULL;
425 	sc->sc_wsbelldev = NULL;
426 
427 	spkr_rescan(self, NULL, NULL);
428 }
429 
430 int
431 spkr_detach(device_t self, int flags)
432 {
433 	struct spkr_softc *sc = device_private(self);
434 	int rc;
435 
436 #ifdef SPKRDEBUG
437 	aprint_debug("%s: entering for unit %d\n", __func__,
438 	    device_unit(self));
439 #endif /* SPKRDEBUG */
440 	if (sc == NULL)
441 		return ENXIO;
442 
443 	/* XXXNS If speaker never closes, we cannot complete the detach. */
444 	while ((flags & DETACH_FORCE) != 0 && sc->sc_inbuf != NULL)
445 		kpause("spkrwait", TRUE, 1, NULL);
446 	if (sc->sc_inbuf != NULL)
447 		return EBUSY;
448 
449 	rc = config_detach_children(self, flags);
450 
451 	return rc;
452 }
453 
454 /* ARGSUSED */
455 int
456 spkr_rescan(device_t self, const char *iattr, const int *locators)
457 {
458 #if NWSMUX > 0
459 	struct spkr_softc *sc = device_private(self);
460 	struct wsbelldev_attach_args a;
461 
462 	if (sc->sc_wsbelldev == NULL) {
463 		a.accesscookie = sc;
464 		sc->sc_wsbelldev = config_found(self, &a, wsbelldevprint,
465 		    CFARGS_NONE);
466 	}
467 #endif
468 	return 0;
469 }
470 
471 int
472 spkr_childdet(device_t self, device_t child)
473 {
474 	struct spkr_softc *sc = device_private(self);
475 
476 	if (sc->sc_wsbelldev == child)
477 		sc->sc_wsbelldev = NULL;
478 
479 	return 0;
480 }
481 
482 int
483 spkropen(dev_t dev, int	flags, int mode, struct lwp *l)
484 {
485 	struct spkr_softc *sc = spkrenter(minor(dev));
486 
487 #ifdef SPKRDEBUG
488 	device_printf(sc->sc_dev, "%s: entering\n", __func__);
489 #endif /* SPKRDEBUG */
490 	if (sc == NULL)
491 		return ENXIO;
492 	if (sc->sc_inbuf != NULL)
493 		return EBUSY;
494 
495 	sc->sc_inbuf = kmem_alloc(DEV_BSIZE, KM_SLEEP);
496 	playinit(sc);
497 	return 0;
498 }
499 
500 int
501 spkrwrite(dev_t dev, struct uio *uio, int flags)
502 {
503 	struct spkr_softc *sc = spkrenter(minor(dev));
504 
505 #ifdef SPKRDEBUG
506 	device_printf(sc->sc_dev, "%s: entering with length = %zu\n",
507 	    __func__, uio->uio_resid);
508 #endif /* SPKRDEBUG */
509 	if (sc == NULL)
510 		return ENXIO;
511 	if (sc->sc_inbuf == NULL)
512 		return EINVAL;
513 
514 	size_t n = uimin(DEV_BSIZE, uio->uio_resid);
515 	int error = uiomove(sc->sc_inbuf, n, uio);
516 	if (error)
517 		return error;
518 	playstring(sc, sc->sc_inbuf, n);
519 	return 0;
520 }
521 
522 int
523 spkrclose(dev_t dev, int flags, int mode, struct lwp *l)
524 {
525 	struct spkr_softc *sc = spkrenter(minor(dev));
526 
527 #ifdef SPKRDEBUG
528 	device_printf(sc->sc_dev, "%s: entering\n", __func__);
529 #endif /* SPKRDEBUG */
530 	if (sc == NULL)
531 		return ENXIO;
532 	if (sc->sc_inbuf == NULL)
533 		return EINVAL;
534 
535 	sc->sc_tone(sc->sc_dev, 0, 0);
536 	kmem_free(sc->sc_inbuf, DEV_BSIZE);
537 	sc->sc_inbuf = NULL;
538 
539 	return 0;
540 }
541 
542 /*
543  * Play tone specified by tp.
544  * tp->frequency is the frequency (0 means a rest).
545  * tp->duration is the length in tick (returns immediately if 0).
546  */
547 static void
548 playonetone(struct spkr_softc *sc, tone_t *tp)
549 {
550 	if (tp->duration <= 0)
551 		return;
552 
553 	if (tp->frequency == 0)
554 		rest(sc, tp->duration);
555 	else
556 		(*sc->sc_tone)(sc->sc_dev, tp->frequency, tp->duration);
557 }
558 
559 int
560 spkrioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
561 {
562 	struct spkr_softc *sc = spkrenter(minor(dev));
563 	tone_t *tp;
564 	tone_t ttp;
565 	int error;
566 
567 #ifdef SPKRDEBUG
568 	device_printf(sc->sc_dev, "%s: entering with cmd = %lx\n",
569 	    __func__, cmd);
570 #endif /* SPKRDEBUG */
571 	if (sc == NULL)
572 		return ENXIO;
573 	if (sc->sc_inbuf == NULL)
574 		return EINVAL;
575 
576 	switch (cmd) {
577 	case SPKRTONE:
578 		playonetone(sc, data);
579 		return 0;
580 	case SPKRTUNE:
581 		for (tp = *(void **)data;; tp++) {
582 			error = copyin(tp, &ttp, sizeof(tone_t));
583 			if (error)
584 				return(error);
585 			if (ttp.duration == 0)
586 				break;
587 			playonetone(sc, &ttp);
588 		}
589 		return 0;
590 	case SPKRGETVOL:
591 		if (data != NULL)
592 			*(u_int *)data = sc->sc_vol;
593 		return 0;
594 	case SPKRSETVOL:
595 		if (data != NULL && *(u_int *)data <= 100)
596 			sc->sc_vol = *(u_int *)data;
597 		return 0;
598 	default:
599 		return ENOTTY;
600 	}
601 }
602 
603 #ifdef _MODULE
604 #include "ioconf.c"
605 #endif
606 
607 MODULE(MODULE_CLASS_DRIVER, spkr, "audio" /* and/or pcppi */ );
608 
609 int
610 spkr_modcmd(modcmd_t cmd, void *arg)
611 {
612 	int error = 0;
613 #ifdef _MODULE
614 	devmajor_t bmajor, cmajor;
615 #endif
616 
617 	switch(cmd) {
618 	case MODULE_CMD_INIT:
619 #ifdef _MODULE
620 		bmajor = cmajor = -1;
621 		error = devsw_attach(spkr_cd.cd_name, NULL, &bmajor,
622 		    &spkr_cdevsw, &cmajor);
623 		if (error)
624 			break;
625 
626 		error = config_init_component(cfdriver_ioconf_spkr,
627 		    cfattach_ioconf_spkr, cfdata_ioconf_spkr);
628 		if (error) {
629 			devsw_detach(NULL, &spkr_cdevsw);
630 		}
631 #endif
632 		break;
633 
634 	case MODULE_CMD_FINI:
635 #ifdef _MODULE
636 		error = config_fini_component(cfdriver_ioconf_spkr,
637 		    cfattach_ioconf_spkr, cfdata_ioconf_spkr);
638 		if (error == 0)
639 			devsw_detach(NULL, &spkr_cdevsw);
640 #endif
641 		break;
642 
643 	default:
644 		error = ENOTTY;
645 		break;
646 	}
647 
648 	return error;
649 }
650