The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/dev/sound/unit.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    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: releng/8.4/sys/dev/sound/unit.c 247542 2013-03-01 09:50:45Z des $
   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 /*
   39  * Unit magic allocator for sound driver.
   40  *
   41  * 'u' = Unit of attached soundcards
   42  * 'd' = Device type
   43  * 'c' = Channel number
   44  *
   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)
   48  *
   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
   56  * hw.snd.maxunit.
   57  */
   58 
   59 /* Default width */
   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)  */
   65 
   66 static int snd_unit_initialized = 0;
   67 
   68 #ifdef SND_DIAGNOSTIC
   69 #define SND_UNIT_ASSERT()       do {                                    \
   70         if (snd_unit_initialized == 0)                                  \
   71                 panic("%s(): Uninitialized sound unit!", __func__);     \
   72 } while (0)
   73 #else
   74 #define SND_UNIT_ASSERT()       KASSERT(snd_unit_initialized != 0,      \
   75                                 ("%s(): Uninitialized sound unit!",     \
   76                                 __func__))
   77 #endif
   78 
   79 #define MKMASK(x)       ((1 << snd_##x##_shift) - 1)
   80 
   81 int
   82 snd_max_u(void)
   83 {
   84         SND_UNIT_ASSERT();
   85 
   86         return (MKMASK(u));
   87 }
   88 
   89 int
   90 snd_max_d(void)
   91 {
   92         SND_UNIT_ASSERT();
   93 
   94         return (MKMASK(d));
   95 }
   96 
   97 int
   98 snd_max_c(void)
   99 {
  100         SND_UNIT_ASSERT();
  101 
  102         return (MKMASK(c));
  103 }
  104 
  105 int
  106 snd_unit2u(int unit)
  107 {
  108         SND_UNIT_ASSERT();
  109 
  110         return ((unit >> (snd_c_shift + snd_d_shift)) & MKMASK(u));
  111 }
  112 
  113 int
  114 snd_unit2d(int unit)
  115 {
  116         SND_UNIT_ASSERT();
  117 
  118         return ((unit >> snd_c_shift) & MKMASK(d));
  119 }
  120 
  121 int
  122 snd_unit2c(int unit)
  123 {
  124         SND_UNIT_ASSERT();
  125 
  126         return (unit & MKMASK(c));
  127 }
  128 
  129 int
  130 snd_u2unit(int u)
  131 {
  132         SND_UNIT_ASSERT();
  133 
  134         return ((u & MKMASK(u)) << (snd_c_shift + snd_d_shift));
  135 }
  136 
  137 int
  138 snd_d2unit(int d)
  139 {
  140         SND_UNIT_ASSERT();
  141 
  142         return ((d & MKMASK(d)) << snd_c_shift);
  143 }
  144 
  145 int
  146 snd_c2unit(int c)
  147 {
  148         SND_UNIT_ASSERT();
  149 
  150         return (c & MKMASK(c));
  151 }
  152 
  153 int
  154 snd_mkunit(int u, int d, int c)
  155 {
  156         SND_UNIT_ASSERT();
  157 
  158         return ((c & MKMASK(c)) | ((d & MKMASK(d)) << snd_c_shift) |
  159             ((u & MKMASK(u)) << (snd_c_shift + snd_d_shift)));
  160 }
  161 
  162 /*
  163  * This *must* be called first before any of the functions above!!!
  164  */
  165 void
  166 snd_unit_init(void)
  167 {
  168         int i;
  169 
  170         if (snd_unit_initialized != 0)
  171                 return;
  172 
  173         snd_unit_initialized = 1;
  174 
  175         if (getenv_int("hw.snd.maxunit", &i) != 0) {
  176                 if (i < SND_UNIT_UMIN)
  177                         i = SND_UNIT_UMIN;
  178                 else if (i > SND_UNIT_UMAX)
  179                         i = SND_UNIT_UMAX;
  180                 else
  181                         i = roundup2(i, 2);
  182 
  183                 for (snd_u_shift = 0; (i >> (snd_u_shift + 1)) != 0;
  184                     snd_u_shift++)
  185                         ;
  186 
  187                 /*
  188                  * Make room for channels/clones allocation unit
  189                  * to fit within 24bit MAXMINOR limit.
  190                  */
  191                 snd_c_shift = 24 - snd_u_shift - snd_d_shift;
  192         }
  193 
  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);
  198 }

Cache object: 9c2b20c4e67e57691b1c5537f00a55a7


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.