midisynvar.h revision 1.9.14.14 1 /* $NetBSD: midisynvar.h,v 1.9.14.14 2006/06/08 04:55:23 chap Exp $ */
2
3 /*
4 * Copyright (c) 1998 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Lennart Augustsson (augustss (at) NetBSD.org).
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the NetBSD
21 * Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39 #ifndef _SYS_DEV_MIDISYNVAR_H_
40 #define _SYS_DEV_MIDISYNVAR_H_
41
42 #include "midictl.h"
43
44 typedef struct midisyn midisyn;
45
46 /*
47 * Important: any synth driver that uses midisyn must set up its methods
48 * structure in a way that refers to members /by name/ and zeroes the rest
49 * (as is the effect of C99 initializers with designators). This discipline
50 * will allow the structure to evolve methods for newly implemented
51 * functionality or to exploit capabilities of new drivers with a minimal
52 * versioning burden. Because midisyn is at present a very rudimentary and
53 * partial implementation, change should be expected in this set of methods.
54 * Do not hesitate to add one in the course of implementing new stuff, as
55 * long as it will be generally useful and there is some reasonable fallback
56 * for drivers without it.
57 */
58 struct midisyn_methods {
59 int (*open) (midisyn *, int /* flags */);
60 void (*close) (midisyn *);
61 int (*ioctl) (midisyn *, u_long, caddr_t, int, struct lwp *);
62 /*
63 * allocv(midisyn *ms, uint_fast8_t chan, uint_fast8_t key);
64 * Allocate one of the devices actual voices (stealing one if
65 * necessary) to play note number 'key' (the MIDI note number, not
66 * a frequency) associated with MIDI channel chan. An implementation
67 * might want to choose a voice already last used on chan, to save
68 * shuffling of patches.
69 * One day a variant of this method will probably be needed, with an
70 * extra argument indicating whether a melodic or percussive voice is
71 * wanted.
72 */
73 int (*allocv) (midisyn *, uint_fast8_t, uint_fast8_t);
74 void (*noteon) (midisyn *, uint32_t, uint32_t, uint32_t);
75 void (*noteoff) (midisyn *, uint32_t, uint32_t, uint32_t);
76 void (*pgmchg) (midisyn *, uint32_t, uint32_t);
77 };
78
79 struct voice {
80 u_int chan_note; /* channel and note */
81 #define MS_CHANNOTE(chan, note) ((chan) * 256 + (note))
82 #define MS_GETCHAN(v) ((v)->chan_note >> 8)
83 u_int seqno; /* allocation index (increases with time) */
84 u_char inuse;
85 };
86
87 #define MIDI_MAX_CHANS 16
88
89 struct midisyn {
90 /* Filled by synth driver */
91 struct midisyn_methods *mets;
92 char name[32];
93 int nvoice;
94 int flags;
95 #define MS_DOALLOC 1 /* obsolescent: implied if driver has no allocv */
96 #define MS_FREQXLATE 2
97 void *data;
98
99 /* Set up by midisyn but available to synth driver for reading ctls */
100 /*
101 * Note - there is currently no locking on this structure; if the synth
102 * driver interacts with midictl it should do so synchronously, when
103 * processing a call from midisyn, and not at other times such as upon
104 * an interrupt. (may revisit locking if problems crop up.)
105 */
106 midictl ctl;
107
108 /* Used by midisyn driver */
109 struct voice *voices;
110 u_int seqno;
111 u_int16_t pgms[MIDI_MAX_CHANS]; /* ref'd if driver uses MS_GETPGM */
112 };
113
114 #define MS_GETPGM(ms, vno) ((ms)->pgms[MS_GETCHAN(&(ms)->voices[vno])])
115
116 struct midi_softc;
117
118 extern const struct midi_hw_if midisyn_hw_if;
119
120 void midisyn_attach (struct midi_softc *, midisyn *);
121
122 /*
123 * Convert a 14-bit volume or expression controller value to centibels using
124 * the General MIDI formula. The maximum controller value translates to 0 cB
125 * (no attenuation), a half-range controller to -119 cB (level cut by 11.9 dB)
126 * and a zero controller to INT16_MIN. If you are converting a 7-bit value
127 * just shift it 7 bits left first.
128 */
129 extern int16_t midisyn_vol2cB(uint_fast16_t);
130
131 /*
132 * MIDI RP-012 constitutes a MIDI Tuning Specification. The units are
133 * fractional-MIDIkeys, that is, the key number 00 - 7f left shifted
134 * 14 bits to provide a 14-bit fraction that divides each semitone. The
135 * whole thing is just a 21-bit number that is bent and tuned simply by
136 * adding and subtracting--the same offset is the same pitch change anywhere
137 * on the scale. One downside is that a cent is 163.84 of these units, so
138 * you can't expect a lengthy integer sum of cents to come out in tune; if you
139 * do anything in cents it is best to use them only for local adjustment of
140 * a pitch.
141 *
142 * This function converts a pitch in MIDItune units to Hz left-shifted 18 bits.
143 * That should leave you enough to shift down to whatever precision the hardware
144 * supports. You can generate a float representation in Hz (where float is
145 * supported) with scalbn(midisyn_mt2hz18(mt),-18).
146 */
147 extern uint32_t midisyn_mt2hz18(uint32_t);
148
149 #define MIDISYN_HZ18_TO_HZ(f) ((f) >> 18)
150 #define MIDISYN_KEY_TO_MT(k) ((k)<<14)
151 #define MIDISYN_MT_TO_KEY(m) (((m)+(1<<13))>>14)
152
153 #define MIDISYN_FREQ_TO_HZ(f) ((f) >> 16) /* deprecated; going away RSN */
154
155 #endif /* _SYS_DEV_MIDISYNVAR_H_ */
156