svn commit: r53370 - head/en_US.ISO8859-1/books/arch-handbook/sound
Benedict Reuschling
bcr at FreeBSD.org
Thu Sep 5 16:59:09 UTC 2019
Author: bcr
Date: Thu Sep 5 16:59:08 2019
New Revision: 53370
URL: https://svnweb.freebsd.org/changeset/doc/53370
Log:
Clean up some errors from textproc/igor
by wrapping long lines.
Event: vBSDcon Hackathon
Modified:
head/en_US.ISO8859-1/books/arch-handbook/sound/chapter.xml
Modified: head/en_US.ISO8859-1/books/arch-handbook/sound/chapter.xml
==============================================================================
--- head/en_US.ISO8859-1/books/arch-handbook/sound/chapter.xml Thu Sep 5 15:28:22 2019 (r53369)
+++ head/en_US.ISO8859-1/books/arch-handbook/sound/chapter.xml Thu Sep 5 16:59:08 2019 (r53370)
@@ -4,16 +4,23 @@
$FreeBSD$
-->
-<chapter xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" version="5.0" xml:id="oss">
- <info><title>Sound Subsystem</title>
+<chapter xmlns="http://docbook.org/ns/docbook"
+ xmlns:xlink="http://www.w3.org/1999/xlink" version="5.0"
+ xml:id="oss">
+ <info>
+ <title>Sound Subsystem</title>
+
<authorgroup>
- <author><personname><firstname>Jean-Francois</firstname><surname>Dockes</surname></personname><contrib>Contributed by </contrib></author>
+ <author>
+ <personname>
+ <firstname>Jean-Francois</firstname>
+ <surname>Dockes</surname>
+ </personname>
+ <contrib>Contributed by </contrib>
+ </author>
</authorgroup>
-
</info>
-
-
<sect1 xml:id="oss-intro">
<title>Introduction</title>
@@ -96,7 +103,9 @@
<title>Probing, Attaching, etc.</title>
<para>Sound drivers probe and attach in almost the same way as any
- hardware driver module. You might want to look at the <link linkend="isa-driver"> ISA</link> or <link linkend="pci">PCI</link> specific sections of the handbook for
+ hardware driver module. You might want to look at the <link
+ linkend="isa-driver">ISA</link> or <link
+ linkend="pci">PCI</link> specific sections of the handbook for
more information.</para>
<para>However, sound drivers differ in some ways:</para>
@@ -104,9 +113,9 @@
<itemizedlist>
<listitem>
<para>They declare themselves as <filename>pcm</filename>
- class devices, with a
- <varname remap="structname">struct snddev_info</varname> device private
- structure:</para>
+ class devices, with a <varname
+ remap="structname">struct snddev_info</varname> device
+ private structure:</para>
<programlisting> static driver_t xxx_driver = {
"pcm",
@@ -117,8 +126,11 @@
DRIVER_MODULE(snd_xxxpci, pci, xxx_driver, pcm_devclass, 0, 0);
MODULE_DEPEND(snd_xxxpci, snd_pcm, PCM_MINVER, PCM_PREFVER,PCM_MAXVER);</programlisting>
- <para>Most sound drivers<indexterm><primary>device
- drivers</primary><secondary>sound</secondary></indexterm>
+ <para>Most sound drivers
+ <indexterm>
+ <primary>device drivers</primary>
+ <secondary>sound</secondary>
+ </indexterm>
need to store additional private information about their
device. A private data structure is usually allocated in
the attach routine. Its address is passed to
@@ -134,7 +146,8 @@
<para>The sound driver attach routine should declare its MIXER
or AC97 interface to <filename>pcm</filename> by calling
<function>mixer_init()</function>. For a MIXER interface,
- this causes in turn a call to <link linkend="xxxmixer-init"><function>xxxmixer_init()</function></link>.</para>
+ this causes in turn a call to <link
+ linkend="xxxmixer-init"><function>xxxmixer_init()</function></link>.</para>
</listitem>
<listitem>
@@ -196,7 +209,8 @@
<title>Interfaces</title>
<para>The interface between the <filename>pcm</filename> core
- and the sound drivers is defined in terms of <link linkend="kernel-objects">kernel objects</link>.</para>
+ and the sound drivers is defined in terms of <link
+ linkend="kernel-objects">kernel objects</link>.</para>
<para>There are two main interfaces that a sound driver will
usually provide: <emphasis>CHANNEL</emphasis> and either
@@ -235,11 +249,12 @@
<para>For sound data transfers, the
<filename>pcm</filename> core and the sound drivers
communicate through a shared memory area, described by a
- <varname remap="structname">struct snd_dbuf</varname>.</para>
+ <varname remap="structname">struct
+ snd_dbuf</varname>.</para>
- <para><varname remap="structname">struct snd_dbuf</varname> is private to
- <filename>pcm</filename>, and sound drivers obtain
- values of interest by calls to accessor functions
+ <para><varname remap="structname">struct snd_dbuf</varname> is
+ private to <filename>pcm</filename>, and sound drivers
+ obtain values of interest by calls to accessor functions
(<function>sndbuf_getxxx()</function>).</para>
<para>The shared memory area has a size of
@@ -253,7 +268,8 @@
<itemizedlist>
<listitem>
<para><filename>pcm</filename> initially fills up the
- buffer, then calls the sound driver's <link linkend="channel-trigger">
+ buffer, then calls the sound driver's <link
+ linkend="channel-trigger">
<function>xxxchannel_trigger()</function></link>
function with a parameter of PCMTRIG_START.</para>
</listitem>
@@ -273,8 +289,9 @@
<listitem>
<para><function>chn_intr()</function> arranges to copy new
data to the area that was transferred to the device (now
- free), and make appropriate updates to the
- <varname remap="structname">snd_dbuf</varname> structure.</para>
+ free), and make appropriate updates to the <varname
+ remap="structname">snd_dbuf</varname>
+ structure.</para>
</listitem>
</itemizedlist>
</sect3>
@@ -301,8 +318,8 @@
<calloutlist>
<callout arearefs="co-chinit-params">
<para><varname>b</varname> is the address for the channel
- <varname remap="structname">struct snd_dbuf</varname>. It should be
- initialized in the function by calling
+ <varname remap="structname">struct snd_dbuf</varname>.
+ It should be initialized in the function by calling
<function>sndbuf_alloc()</function>. The buffer size to
use is normally a small multiple of the 'typical' unit
transfer size for your device.</para>
@@ -491,10 +508,10 @@
<callout arearefs="co-chgetcaps-return">
<para>The routine returns a pointer to a (usually
- statically-defined)
- <varname remap="structname">pcmchan_caps</varname> structure (defined
- in <filename>sound/pcm/channel.h</filename>. The
- structure holds the minimum and maximum sampling
+ statically-defined) <varname
+ remap="structname">pcmchan_caps</varname> structure
+ (defined in <filename>sound/pcm/channel.h</filename>.
+ The structure holds the minimum and maximum sampling
frequencies, and the accepted sound formats. Look at
any sound driver for an example.</para>
</callout>
@@ -626,7 +643,7 @@
<para><function>xxxmixer_uninit()</function> should ensure
that all sound is muted and if possible mixer hardware
- should be powered down </para>
+ should be powered down.</para>
<para><function>xxxmixer_reinit()</function> should ensure
that the mixer hardware is powered up and any settings not
More information about the svn-doc-head
mailing list