xref: /freebsd/share/examples/sound/ossmidi.h (revision 535af610)
1 /*
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2022 Goran Mekić
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <stdlib.h>
29 #include <stdio.h>
30 #include <fcntl.h>
31 
32 #define CMD_MASK 0xF0
33 #define NOTE_ON 0x90
34 #define NOTE_OFF 0x80
35 #define CHANNEL_MASK 0xF
36 #define CONTROLER_ON 0xB0
37 
38 typedef struct midi_event {
39 	unsigned char type;
40 	unsigned char channel;
41 	union {
42 		unsigned char note;
43 		unsigned controller;
44 	};
45 	union {
46 		unsigned char velocity;
47 		unsigned char value;
48 	};
49 } midi_event_t;
50 
51 typedef struct midi_config {
52 	char   *device;
53 	int	fd;
54 } midi_config_t;
55 
56 void
57 oss_midi_init(midi_config_t *config)
58 {
59 	if ((config->fd = open(config->device, O_RDWR)) == -1) {
60 		perror("Error opening MIDI device");
61 		exit(1);
62 	}
63 }
64