summaryrefslogtreecommitdiff
path: root/sys/dev/audiobell.c
blob: 9edca719370a57554f3c63ed0ed40e126fe57cf9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
/*	$NetBSD: audiobell.c,v 1.8 2009/05/12 10:22:31 cegger Exp $	*/

/*
 * Copyright (c) 1999 Richard Earnshaw
 * Copyright (c) 2004 Ben Harris
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the RiscBSD team.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/types.h>
__KERNEL_RCSID(0, "$NetBSD: audiobell.c,v 1.8 2009/05/12 10:22:31 cegger Exp $");

#include <sys/audioio.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/fcntl.h>
#include <sys/malloc.h>
#include <sys/null.h>
#include <sys/systm.h>
#include <sys/uio.h>

#include <dev/audio_if.h>
#include <dev/audiobellvar.h>

extern dev_type_open(audioopen);
extern dev_type_write(audiowrite);
extern dev_type_close(audioclose);

/* Convert a %age volume to an amount to add to u-law values */
/* XXX Probably highly inaccurate -- should be regenerated */
static const uint8_t volmap[] = {
	0x7f, 0x67, 0x5b, 0x53, 0x49, 0x45, 0x41, 0x3e, 0x3a, 0x38,
	0x36, 0x32, 0x30, 0x2f, 0x2e, 0x2c, 0x2b, 0x2a, 0x28, 0x27,
	0x26, 0x25, 0x23, 0x22, 0x21, 0x1f, 0x1f, 0x1e, 0x1e, 0x1d,
	0x1c, 0x1c, 0x1b, 0x1a, 0x1a, 0x19, 0x18, 0x18, 0x17, 0x17,
	0x16, 0x15, 0x15, 0x14, 0x13, 0x13, 0x12, 0x11, 0x11, 0x10,
	0x0f, 0x0f, 0x0f, 0x0f, 0x0e, 0x0e, 0x0e, 0x0d, 0x0d, 0x0d,
	0x0c, 0x0c, 0x0c, 0x0b, 0x0b, 0x0b, 0x0a, 0x0a, 0x0a, 0x09,
	0x09, 0x09, 0x08, 0x08, 0x08, 0x07, 0x07, 0x07, 0x07, 0x06,
	0x06, 0x06, 0x05, 0x05, 0x05, 0x04, 0x04, 0x04,	0x03, 0x03,
	0x03, 0x02, 0x02, 0x02, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00,
	0x00
};

/* 1/4 cycle sine wave in u-law */
/* XXX Probably highly inaccurate -- should be regenerated */
static const uint8_t sinewave[] = {
	0xff, 0xd3, 0xc5, 0xbc, 0xb6, 0xb0, 0xad, 0xaa,
	0xa7, 0xa3, 0xa0, 0x9e, 0x9d, 0x9b, 0x9a, 0x98,
	0x97, 0x96, 0x94, 0x93, 0x91, 0x90, 0x8f, 0x8e,
	0x8e, 0x8d, 0x8c, 0x8c, 0x8b, 0x8b, 0x8a, 0x89,
	0x89, 0x88, 0x88, 0x87, 0x87, 0x86, 0x86, 0x85,
	0x85, 0x84, 0x84, 0x84, 0x83, 0x83, 0x83, 0x82,
	0x82, 0x82, 0x81, 0x81, 0x81, 0x81, 0x80, 0x80,
	0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
	0x80,
};

static inline uint8_t
audiobell_ulawscale(uint8_t val, uint8_t vol)
{
	uint8_t result;

	result = val + vol;
	/* Spot underflow and just return silence */
	if ((result ^ val) & 0x80)
		return 0x7f;
	return result;
}

static inline void
audiobell_expandwave(uint8_t *buf, int volume)
{
	u_int i;
	int uvol;

	KASSERT(volume >= 0 && volume <= 100);
	uvol = volmap[volume];
	for (i = 0; i < 65; i++)
		buf[i] = audiobell_ulawscale(sinewave[i], uvol);
	for (i = 65; i < 128; i++)
		 buf[i] = buf[128 - i];
	for (i = 128; i < 256; i++)
		buf[i] = buf[i - 128] ^ 0x80;
}

/*
 * The algorithm here is based on that described in the RISC OS Programmer's
 * Reference Manual (pp1624--1628).
 */
static inline int
audiobell_synthesize(uint8_t *buf, u_int pitch, u_int period, u_int volume)
{
	uint8_t *wave;
	uint16_t phase;

	wave = malloc(256, M_TEMP, M_WAITOK);
	if (wave == NULL) return -1;
	audiobell_expandwave(wave, volume);
	pitch = pitch * 65536 / 8000;
	period = period * 8; /* 8000 / 1000 */
	phase = 0;

	for (; period != 0; period--) {
		*buf++ = wave[phase >> 8];
		phase += pitch;
	}

	free(wave, M_TEMP);
	return 0;
}

void
audiobell(void *arg, u_int pitch, u_int period, u_int volume, int poll)
{
	device_t audio = arg;
	uint8_t *buf;
	struct uio auio;
	struct iovec aiov;

	/* The audio system isn't built for polling. */
	if (poll) return;

	/* If not configured, we can't beep. */
	if (audioopen(AUDIO_DEVICE | device_unit(audio), FWRITE, 0, NULL) != 0)
		return;

	buf = malloc(period * 8, M_TEMP, M_WAITOK);
	if (buf == NULL) goto out;
	if (audiobell_synthesize(buf, pitch, period, volume) != 0) goto out;

	aiov.iov_base = (void *)buf;
	aiov.iov_len = period * 8;
	auio.uio_iov = &aiov;
	auio.uio_iovcnt = 1;
	auio.uio_offset = 0;
	auio.uio_resid = period * 8;
	auio.uio_rw = UIO_WRITE;
	UIO_SETUP_SYSSPACE(&auio);

	audiowrite(AUDIO_DEVICE | device_unit(audio), &auio, 0);

out:
	if (buf != NULL) free(buf, M_TEMP);
	audioclose(AUDIO_DEVICE | device_unit(audio), FWRITE, 0, NULL);
}