1 /*-
2 * Copyright (c) 2007 Ariff Abdullah <ariff@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: head/sys/dev/sound/unit.c 193640 2009-06-07 19:12:08Z ariff $
27 */
28
29 #include <sys/param.h>
30 #include <sys/systm.h>
31
32 #ifdef HAVE_KERNEL_OPTION_HEADERS
33 #include "opt_snd.h"
34 #endif
35
36 #include <dev/sound/unit.h>
37
38 #if 0
39
40 /*
41 * Unit magic allocator for sound driver.
42 *
43 * 'u' = Unit of attached soundcards
44 * 'd' = Device type
45 * 'c' = Channel number
46 *
47 * eg: dsp0.p1 - u=0, d=p, c=1
48 * dsp1.vp0 - u=1, d=vp, c=0
49 * dsp0.10 - u=0, d=clone, c=allocated clone (see further explanation)
50 *
51 * Maximum unit of soundcards can be tuned through "hw.snd.maxunit", which
52 * is between SND_UNIT_UMIN (16) and SND_UNIT_UMAX (2048). By design,
53 * maximum allowable allocated channel is 256, with exception for clone
54 * devices which doesn't have any notion of channel numbering. The use of
55 * channel numbering in a clone device is simply to provide uniqueness among
56 * allocated clones. This also means that the maximum allowable clonable
57 * device is largely dependant and dynamically tuned depending on
58 * hw.snd.maxunit.
59 */
60
61 /* Default width */
62 static int snd_u_shift = 9; /* 0 - 0x1ff : 512 distinct soundcards */
63 static int snd_d_shift = 5; /* 0 - 0x1f : 32 distinct device types */
64 static int snd_c_shift = 10; /* 0 - 0x3ff : 1024 distinct channels
65 (256 limit "by design",
66 except for clone devices) */
67
68 static int snd_unit_initialized = 0;
69
70 #ifdef SND_DIAGNOSTIC
71 #define SND_UNIT_ASSERT() do { \
72 if (snd_unit_initialized == 0) \
73 panic("%s(): Uninitialized sound unit!", __func__); \
74 } while (0)
75 #else
76 #define SND_UNIT_ASSERT() KASSERT(snd_unit_initialized != 0, \
77 ("%s(): Uninitialized sound unit!", \
78 __func__))
79 #endif
80
81 #define MKMASK(x) ((1 << snd_##x##_shift) - 1)
82
83 int
84 snd_max_u(void)
85 {
86 SND_UNIT_ASSERT();
87
88 return (MKMASK(u));
89 }
90
91 int
92 snd_max_d(void)
93 {
94 SND_UNIT_ASSERT();
95
96 return (MKMASK(d));
97 }
98
99 int
100 snd_max_c(void)
101 {
102 SND_UNIT_ASSERT();
103
104 return (MKMASK(c));
105 }
106
107 int
108 snd_unit2u(int unit)
109 {
110 SND_UNIT_ASSERT();
111
112 return ((unit >> (snd_c_shift + snd_d_shift)) & MKMASK(u));
113 }
114
115 int
116 snd_unit2d(int unit)
117 {
118 SND_UNIT_ASSERT();
119
120 return ((unit >> snd_c_shift) & MKMASK(d));
121 }
122
123 int
124 snd_unit2c(int unit)
125 {
126 SND_UNIT_ASSERT();
127
128 return (unit & MKMASK(c));
129 }
130
131 int
132 snd_u2unit(int u)
133 {
134 SND_UNIT_ASSERT();
135
136 return ((u & MKMASK(u)) << (snd_c_shift + snd_d_shift));
137 }
138
139 int
140 snd_d2unit(int d)
141 {
142 SND_UNIT_ASSERT();
143
144 return ((d & MKMASK(d)) << snd_c_shift);
145 }
146
147 int
148 snd_c2unit(int c)
149 {
150 SND_UNIT_ASSERT();
151
152 return (c & MKMASK(c));
153 }
154
155 int
156 snd_mkunit(int u, int d, int c)
157 {
158 SND_UNIT_ASSERT();
159
160 return ((c & MKMASK(c)) | ((d & MKMASK(d)) << snd_c_shift) |
161 ((u & MKMASK(u)) << (snd_c_shift + snd_d_shift)));
162 }
163
164 /*
165 * This *must* be called first before any of the functions above!!!
166 */
167 void
168 snd_unit_init(void)
169 {
170 int i;
171
172 if (snd_unit_initialized != 0)
173 return;
174
175 snd_unit_initialized = 1;
176
177 if (kgetenv_int("hw.snd.maxunit", &i) != 0) {
178 if (i < SND_UNIT_UMIN)
179 i = SND_UNIT_UMIN;
180 else if (i > SND_UNIT_UMAX)
181 i = SND_UNIT_UMAX;
182 else
183 i = roundup2(i, 2);
184
185 for (snd_u_shift = 0; (i >> (snd_u_shift + 1)) != 0;
186 snd_u_shift++)
187 ;
188
189 /*
190 * Make room for channels/clones allocation unit
191 * to fit within 24bit MAXMINOR limit.
192 */
193 snd_c_shift = 24 - snd_u_shift - snd_d_shift;
194 }
195
196 if (bootverbose != 0)
197 kprintf("%s() u=0x%08x [%d] d=0x%08x [%d] c=0x%08x [%d]\n",
198 __func__, SND_U_MASK, snd_max_u() + 1,
199 SND_D_MASK, snd_max_d() + 1, SND_C_MASK, snd_max_c() + 1);
200 }
201 #endif
202
203 void
snd_unit_init(void)204 snd_unit_init(void)
205 {
206 }
207