2 * Copyright (c) 2007 Ariff Abdullah <ariff@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
29 #include <sys/param.h>
30 #include <sys/systm.h>
32 #ifdef HAVE_KERNEL_OPTION_HEADERS
36 #include <dev/sound/unit.h>
39 * Unit magic allocator for sound driver.
41 * 'u' = Unit of attached soundcards
43 * 'c' = Channel number
45 * eg: dsp0.p1 - u=0, d=p, c=1
46 * dsp1.vp0 - u=1, d=vp, c=0
47 * dsp0.10 - u=0, d=clone, c=allocated clone (see further explanation)
49 * Maximum unit of soundcards can be tuned through "hw.snd.maxunit", which
50 * is between SND_UNIT_UMIN (16) and SND_UNIT_UMAX (2048). By design,
51 * maximum allowable allocated channel is 256, with exception for clone
52 * devices which doesn't have any notion of channel numbering. The use of
53 * channel numbering in a clone device is simply to provide uniqueness among
54 * allocated clones. This also means that the maximum allowable clonable
55 * device is largely dependant and dynamically tuned depending on
60 static int snd_u_shift = 9; /* 0 - 0x1ff : 512 distinct soundcards */
61 static int snd_d_shift = 5; /* 0 - 0x1f : 32 distinct device types */
62 static int snd_c_shift = 10; /* 0 - 0x3ff : 1024 distinct channels
63 (256 limit "by design",
64 except for clone devices) */
66 static int snd_unit_initialized = 0;
69 #define SND_UNIT_ASSERT() do { \
70 if (snd_unit_initialized == 0) \
71 panic("%s(): Uninitialized sound unit!", __func__); \
74 #define SND_UNIT_ASSERT() KASSERT(snd_unit_initialized != 0, \
75 ("%s(): Uninitialized sound unit!", \
79 #define MKMASK(x) ((1 << snd_##x##_shift) - 1)
110 return ((unit >> (snd_c_shift + snd_d_shift)) & MKMASK(u));
118 return ((unit >> snd_c_shift) & MKMASK(d));
126 return (unit & MKMASK(c));
134 return ((u & MKMASK(u)) << (snd_c_shift + snd_d_shift));
142 return ((d & MKMASK(d)) << snd_c_shift);
150 return (c & MKMASK(c));
154 snd_mkunit(int u, int d, int c)
158 return ((c & MKMASK(c)) | ((d & MKMASK(d)) << snd_c_shift) |
159 ((u & MKMASK(u)) << (snd_c_shift + snd_d_shift)));
163 * This *must* be called first before any of the functions above!!!
170 if (snd_unit_initialized != 0)
173 snd_unit_initialized = 1;
175 if (getenv_int("hw.snd.maxunit", &i) != 0) {
176 if (i < SND_UNIT_UMIN)
178 else if (i > SND_UNIT_UMAX)
183 for (snd_u_shift = 0; (i >> (snd_u_shift + 1)) != 0;
188 * Make room for channels/clones allocation unit
189 * to fit within 24bit MAXMINOR limit.
191 snd_c_shift = 24 - snd_u_shift - snd_d_shift;
194 if (bootverbose != 0)
195 printf("%s() u=0x%08x [%d] d=0x%08x [%d] c=0x%08x [%d]\n",
196 __func__, SND_U_MASK, snd_max_u() + 1,
197 SND_D_MASK, snd_max_d() + 1, SND_C_MASK, snd_max_c() + 1);