1/*	$NetBSD: audiobell.c,v 1.5 2021/07/21 06:35:44 skrll 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/cdefs.h>
34__KERNEL_RCSID(0, "$NetBSD: audiobell.c,v 1.5 2021/07/21 06:35:44 skrll Exp $");
35
36#include <sys/param.h>
37#include <sys/types.h>
38#include <sys/audioio.h>
39#include <sys/conf.h>
40#include <sys/device.h>
41#include <sys/malloc.h>
42#include <sys/systm.h>
43#include <sys/uio.h>
44
45#include <dev/audio/audio_if.h>
46#include <dev/audio/audiovar.h>
47#include <dev/audio/audiodef.h>
48#include <dev/audio/audiobellvar.h>
49
50/*
51 * The hexadecagon is sufficiently close to a sine wave.
52 * Audiobell always outputs this 16 points data but changes its playback
53 * frequency.  In addition, audio layer does linear interpolation in the
54 * frequency conversion stage, so the waveform becomes smooth.
55 * When the playback frequency rises (or the device frequency is not enough
56 * high) and one wave cannot be expressed with 16 points, the data is thinned
57 * out by power of two, like 8 points -> 4 points (triangular wave)
58 * -> 2 points (rectangular wave).
59 */
60
61/* Amplitude.  Full scale amplitude is too loud. */
62#define A(x) ((x) * 0.6)
63
64/* (sin(2*pi * (x/16)) * 32767 / 100) << 16 */
65static const int32_t sinewave[] = {
66	A(        0),
67	A(  8217813),
68	A( 15184539),
69	A( 19839556),
70	A( 21474181),
71	A( 19839556),
72	A( 15184539),
73	A(  8217813),
74	A(        0),
75	A( -8217814),
76	A(-15184540),
77	A(-19839557),
78	A(-21474182),
79	A(-19839557),
80	A(-15184540),
81	A( -8217814),
82};
83#undef A
84
85/*
86 * The minimum and the maximum buffer sizes must be a multiple of 32
87 * (32 = countof(sinewave) * sizeof(uint16_t)).
88 */
89#define MINBUFSIZE	(1024)
90#define MAXBUFSIZE	(4096)
91
92/*
93 * dev is a device_t for the audio device to use.
94 * pitch is the pitch of the bell in Hz,
95 * period is the length in ms,
96 * volume is the amplitude in % of max,
97 * poll is no longer used.
98 */
99void
100audiobell(void *dev, u_int pitch, u_int period, u_int volume, int poll)
101{
102	dev_t audio;
103	int16_t *buf;
104	audio_file_t *file;
105	audio_track_t *ptrack;
106	struct uio auio;
107	struct iovec aiov;
108	u_int i;
109	u_int j;
110	u_int remaincount;
111	u_int remainbytes;
112	u_int wave1count;
113	u_int wave1bytes;
114	u_int bufbytes;
115	u_int len;
116	u_int step;
117	u_int offset;
118	u_int play_sample_rate;
119	u_int mixer_sample_rate;
120
121	KASSERT(volume <= 100);
122
123	/* Playing for 0msec does nothing. */
124	if (period == 0)
125		return;
126
127	/* The audio system isn't built for polling. */
128	if (poll)
129		return;
130
131	buf = NULL;
132	audio = AUDIO_DEVICE | device_unit((device_t)dev);
133
134	/* If not configured, we can't beep. */
135	if (audiobellopen(audio, &file) != 0)
136		return;
137
138	ptrack = file->ptrack;
139	mixer_sample_rate = ptrack->mixer->track_fmt.sample_rate;
140
141	/* Limit pitch */
142	if (pitch < 20)
143		pitch = 20;
144
145	offset = 0;
146	if (pitch <= mixer_sample_rate / 16) {
147		/* 16-point sine wave */
148		step = 1;
149	} else if (pitch <= mixer_sample_rate / 8) {
150		/* 8-point sine wave */
151		step = 2;
152	} else if (pitch <= mixer_sample_rate / 4) {
153		/* 4-point sine wave, aka, triangular wave */
154		step = 4;
155	} else {
156		/* Rectangular wave */
157		if (pitch > mixer_sample_rate / 2)
158			pitch = mixer_sample_rate / 2;
159		step = 8;
160		offset = 4;
161	}
162
163	wave1count = __arraycount(sinewave) / step;
164	play_sample_rate = pitch * wave1count;
165	audiobellsetrate(file, play_sample_rate);
166
167	/* msec to sample count */
168	remaincount = play_sample_rate * period / 1000;
169	/* Roundup to full wave */
170	remaincount = roundup(remaincount, wave1count);
171	remainbytes = remaincount * sizeof(int16_t);
172	wave1bytes = wave1count * sizeof(int16_t);
173
174	/* Based on 3*usrbuf_blksize, but not too small or too large */
175	bufbytes = ptrack->usrbuf_blksize * NBLKHW;
176	if (bufbytes < MINBUFSIZE)
177		bufbytes = MINBUFSIZE;
178	else if (bufbytes > MAXBUFSIZE)
179		bufbytes = MAXBUFSIZE;
180	else
181		bufbytes = roundup(bufbytes, wave1bytes);
182	bufbytes = uimin(bufbytes, remainbytes);
183	KASSERT(bufbytes != 0);
184	buf = malloc(bufbytes, M_TEMP, M_WAITOK);
185	if (buf == NULL)
186		goto out;
187
188	/* Generate sinewave with specified volume */
189	j = offset;
190	for (i = 0; i < bufbytes / sizeof(int16_t); i++) {
191		/* XXX audio already has track volume feature though #if 0 */
192		buf[i] = AUDIO_SCALEDOWN(sinewave[j] * (int)volume, 16);
193		j += step;
194		j %= __arraycount(sinewave);
195	}
196
197	/* Write while paused to avoid inserting silence. */
198	ptrack->is_pause = true;
199	for (; remainbytes > 0; remainbytes -= len) {
200		len = uimin(remainbytes, bufbytes);
201		aiov.iov_base = (void *)buf;
202		aiov.iov_len = len;
203		auio.uio_iov = &aiov;
204		auio.uio_iovcnt = 1;
205		auio.uio_offset = 0;
206		auio.uio_resid = len;
207		auio.uio_rw = UIO_WRITE;
208		UIO_SETUP_SYSSPACE(&auio);
209		if (audiobellwrite(file, &auio) != 0)
210			goto out;
211
212		if (ptrack->usrbuf.used >= ptrack->usrbuf_blksize * NBLKHW)
213			ptrack->is_pause = false;
214	}
215	/* Here we go! */
216	ptrack->is_pause = false;
217out:
218	if (buf != NULL)
219		free(buf, M_TEMP);
220	audiobellclose(file);
221}
222