sys/dev/sound/unit.c

   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
 204 snd_unit_init(void)
 205 {
 206 }