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 } 207