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audiobell.c revision 1.2 
      1 /*	$NetBSD: audiobell.c,v 1.2 2019/05/08 13:40:17 isaki Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1999 Richard Earnshaw
      5  * Copyright (c) 2004 Ben Harris
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the RiscBSD team.
     18  * 4. The name of the author may not be used to endorse or promote products
     19  *    derived from this software without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #include <sys/types.h>
     34 __KERNEL_RCSID(0, "$NetBSD: audiobell.c,v 1.2 2019/05/08 13:40:17 isaki Exp $");
     35 
     36 #include <sys/audioio.h>
     37 #include <sys/conf.h>
     38 #include <sys/device.h>
     39 #include <sys/malloc.h>
     40 #include <sys/systm.h>
     41 #include <sys/uio.h>
     42 
     43 #include <dev/audio/audio_if.h>
     44 #include <dev/audio/audiovar.h>
     45 #include <dev/audio/audiodef.h>
     46 #include <dev/audio/audiobellvar.h>
     47 
     48 /* 44.1 kHz should reduce hum at higher pitches. */
     49 #define BELL_SAMPLE_RATE	44100
     50 
     51 /*
     52  * dev is a device_t for the audio device to use.
     53  * pitch is the pitch of the bell in Hz,
     54  * period is the length in ms,
     55  * volume is the amplitude in % of max,
     56  * poll is no longer used.
     57  */
     58 void
     59 audiobell(void *dev, u_int pitch, u_int period, u_int volume, int poll)
     60 {
     61 	dev_t audio;
     62 	int16_t *buf;
     63 	struct audiobell_arg bellarg;
     64 	audio_file_t *file;
     65 	audio_track_t *ptrack;
     66 	struct uio auio;
     67 	struct iovec aiov;
     68 	int i;
     69 	int remaincount;
     70 	int remainlen;
     71 	int wave1count;
     72 	int wave1len;
     73 	int len;
     74 	int16_t vol;
     75 
     76 	KASSERT(volume <= 100);
     77 
     78 	/* The audio system isn't built for polling. */
     79 	if (poll)
     80 		return;
     81 
     82 	/* Limit the pitch from 20Hz to Nyquist frequency. */
     83 	if (pitch > BELL_SAMPLE_RATE / 2)
     84 		pitch = BELL_SAMPLE_RATE;
     85 	if (pitch < 20)
     86 		pitch = 20;
     87 
     88 	buf = NULL;
     89 	audio = AUDIO_DEVICE | device_unit((device_t)dev);
     90 
     91 	memset(&bellarg, 0, sizeof(bellarg));
     92 	bellarg.encoding = AUDIO_ENCODING_SLINEAR_NE;
     93 	bellarg.precision = 16;
     94 	bellarg.channels = 1;
     95 	bellarg.sample_rate = BELL_SAMPLE_RATE;
     96 
     97 	/* If not configured, we can't beep. */
     98 	if (audiobellopen(audio, &bellarg) != 0)
     99 		return;
    100 
    101 	file = bellarg.file;
    102 	ptrack = file->ptrack;
    103 
    104 	/* msec to sample count. */
    105 	remaincount = period * BELL_SAMPLE_RATE / 1000;
    106 	remainlen = remaincount * sizeof(int16_t);
    107 
    108 	wave1count = BELL_SAMPLE_RATE / pitch;
    109 	wave1len = wave1count * sizeof(int16_t);
    110 
    111 	buf = malloc(wave1len, M_TEMP, M_WAITOK);
    112 	if (buf == NULL)
    113 		goto out;
    114 
    115 	/* Generate single square wave.  It's enough to beep. */
    116 	vol = 32767 * volume / 100;
    117 	for (i = 0; i < wave1count / 2; i++) {
    118 		buf[i] = vol;
    119 	}
    120 	vol = -vol;
    121 	for (; i < wave1count; i++) {
    122 		buf[i] = vol;
    123 	}
    124 
    125 	/* Write while paused to avoid begin inserted silence. */
    126 	ptrack->is_pause = true;
    127 	for (; remainlen > 0; remainlen -= wave1len) {
    128 		len = uimin(remainlen, wave1len);
    129 		aiov.iov_base = (void *)buf;
    130 		aiov.iov_len = len;
    131 		auio.uio_iov = &aiov;
    132 		auio.uio_iovcnt = 1;
    133 		auio.uio_offset = 0;
    134 		auio.uio_resid = len;
    135 		auio.uio_rw = UIO_WRITE;
    136 		UIO_SETUP_SYSSPACE(&auio);
    137 		if (audiobellwrite(file, &auio) != 0)
    138 			goto out;
    139 
    140 		if (ptrack->usrbuf.used >= ptrack->usrbuf_blksize * NBLKHW)
    141 			ptrack->is_pause = false;
    142 	}
    143 	/* Here we go! */
    144 	ptrack->is_pause = false;
    145 out:
    146 	if (buf != NULL)
    147 		free(buf, M_TEMP);
    148 	audiobellclose(file);
    149 }
    150