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freebsd/sys/dev/sound/unit.c
Pedro F. Giffuni 718cf2ccb9 sys/dev: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 14:52:40 +00:00

201 lines
4.7 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2007 Ariff Abdullah <ariff@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#ifdef HAVE_KERNEL_OPTION_HEADERS
#include "opt_snd.h"
#endif
#include <dev/sound/unit.h>
/*
* Unit magic allocator for sound driver.
*
* 'u' = Unit of attached soundcards
* 'd' = Device type
* 'c' = Channel number
*
* eg: dsp0.p1 - u=0, d=p, c=1
* dsp1.vp0 - u=1, d=vp, c=0
* dsp0.10 - u=0, d=clone, c=allocated clone (see further explanation)
*
* Maximum unit of soundcards can be tuned through "hw.snd.maxunit", which
* is between SND_UNIT_UMIN (16) and SND_UNIT_UMAX (2048). By design,
* maximum allowable allocated channel is 256, with exception for clone
* devices which doesn't have any notion of channel numbering. The use of
* channel numbering in a clone device is simply to provide uniqueness among
* allocated clones. This also means that the maximum allowable clonable
* device is largely dependant and dynamically tuned depending on
* hw.snd.maxunit.
*/
/* Default width */
static int snd_u_shift = 9; /* 0 - 0x1ff : 512 distinct soundcards */
static int snd_d_shift = 5; /* 0 - 0x1f : 32 distinct device types */
static int snd_c_shift = 10; /* 0 - 0x3ff : 1024 distinct channels
(256 limit "by design",
except for clone devices) */
static int snd_unit_initialized = 0;
#ifdef SND_DIAGNOSTIC
#define SND_UNIT_ASSERT() do { \
if (snd_unit_initialized == 0) \
panic("%s(): Uninitialized sound unit!", __func__); \
} while (0)
#else
#define SND_UNIT_ASSERT() KASSERT(snd_unit_initialized != 0, \
("%s(): Uninitialized sound unit!", \
__func__))
#endif
#define MKMASK(x) ((1 << snd_##x##_shift) - 1)
int
snd_max_u(void)
{
SND_UNIT_ASSERT();
return (MKMASK(u));
}
int
snd_max_d(void)
{
SND_UNIT_ASSERT();
return (MKMASK(d));
}
int
snd_max_c(void)
{
SND_UNIT_ASSERT();
return (MKMASK(c));
}
int
snd_unit2u(int unit)
{
SND_UNIT_ASSERT();
return ((unit >> (snd_c_shift + snd_d_shift)) & MKMASK(u));
}
int
snd_unit2d(int unit)
{
SND_UNIT_ASSERT();
return ((unit >> snd_c_shift) & MKMASK(d));
}
int
snd_unit2c(int unit)
{
SND_UNIT_ASSERT();
return (unit & MKMASK(c));
}
int
snd_u2unit(int u)
{
SND_UNIT_ASSERT();
return ((u & MKMASK(u)) << (snd_c_shift + snd_d_shift));
}
int
snd_d2unit(int d)
{
SND_UNIT_ASSERT();
return ((d & MKMASK(d)) << snd_c_shift);
}
int
snd_c2unit(int c)
{
SND_UNIT_ASSERT();
return (c & MKMASK(c));
}
int
snd_mkunit(int u, int d, int c)
{
SND_UNIT_ASSERT();
return ((c & MKMASK(c)) | ((d & MKMASK(d)) << snd_c_shift) |
((u & MKMASK(u)) << (snd_c_shift + snd_d_shift)));
}
/*
* This *must* be called first before any of the functions above!!!
*/
void
snd_unit_init(void)
{
int i;
if (snd_unit_initialized != 0)
return;
snd_unit_initialized = 1;
if (getenv_int("hw.snd.maxunit", &i) != 0) {
if (i < SND_UNIT_UMIN)
i = SND_UNIT_UMIN;
else if (i > SND_UNIT_UMAX)
i = SND_UNIT_UMAX;
else
i = roundup2(i, 2);
for (snd_u_shift = 0; (i >> (snd_u_shift + 1)) != 0;
snd_u_shift++)
;
/*
* Make room for channels/clones allocation unit
* to fit within 24bit MAXMINOR limit.
*/
snd_c_shift = 24 - snd_u_shift - snd_d_shift;
}
if (bootverbose != 0)
printf("%s() u=0x%08x [%d] d=0x%08x [%d] c=0x%08x [%d]\n",
__func__, SND_U_MASK, snd_max_u() + 1,
SND_D_MASK, snd_max_d() + 1, SND_C_MASK, snd_max_c() + 1);
}