<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
<book id="MCAGuide">
<bookinfo>
<title>MCA Driver Programming Interface</title>
<authorgroup>
<author>
<firstname>Alan</firstname>
<surname>Cox</surname>
<affiliation>
<address>
<email>alan@lxorguk.ukuu.org.uk</email>
</address>
</affiliation>
</author>
<author>
<firstname>David</firstname>
<surname>Weinehall</surname>
</author>
<author>
<firstname>Chris</firstname>
<surname>Beauregard</surname>
</author>
</authorgroup>
<copyright>
<year>2000</year>
<holder>Alan Cox</holder>
<holder>David Weinehall</holder>
<holder>Chris Beauregard</holder>
</copyright>
<legalnotice>
<para>
This documentation is free software; you can redistribute
it and/or modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later
version.
</para>
<para>
This program is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied
warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
</para>
<para>
You should have received a copy of the GNU General Public
License along with this program; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
MA 02111-1307 USA
</para>
<para>
For more details see the file COPYING in the source
distribution of Linux.
</para>
</legalnotice>
</bookinfo>
<toc></toc>
<chapter id="intro">
<title>Introduction</title>
<para>
The MCA bus functions provide a generalised interface to find MCA
bus cards, to claim them for a driver, and to read and manipulate POS
registers without being aware of the motherboard internals or
certain deep magic specific to onboard devices.
</para>
<para>
The basic interface to the MCA bus devices is the slot. Each slot
is numbered and virtual slot numbers are assigned to the internal
devices. Using a pci_dev as other busses do does not really make
sense in the MCA context as the MCA bus resources require card
specific interpretation.
</para>
<para>
Finally the MCA bus functions provide a parallel set of DMA
functions mimicing the ISA bus DMA functions as closely as possible,
although also supporting the additional DMA functionality on the
MCA bus controllers.
</para>
</chapter>
<chapter id="bugs">
<title>Known Bugs And Assumptions</title>
<para>
None.
</para>
</chapter>
<chapter id="pubfunctions">
<title>Public Functions Provided</title>
<!-- drivers/mca/mca-legacy.c -->
<refentry id="API-mca-find-adapter">
<refentryinfo>
<title>LINUX</title>
<productname>Kernel Hackers Manual</productname>
<date>June 2011</date>
</refentryinfo>
<refmeta>
<refentrytitle><phrase>mca_find_adapter</phrase></refentrytitle>
<manvolnum>9</manvolnum>
<refmiscinfo class="version">2.6.32</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mca_find_adapter</refname>
<refpurpose>
scan for adapters
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Synopsis</title>
<funcsynopsis><funcprototype>
<funcdef>int <function>mca_find_adapter </function></funcdef>
<paramdef>int <parameter>id</parameter></paramdef>
<paramdef>int <parameter>start</parameter></paramdef>
</funcprototype></funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>id</parameter></term>
<listitem>
<para>
MCA identification to search for
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>start</parameter></term>
<listitem>
<para>
starting slot
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Search the MCA configuration for adapters matching the 16bit
ID given. The first time it should be called with start as zero
and then further calls made passing the return value of the
previous call until <constant>MCA_NOTFOUND</constant> is returned.
</para><para>
Disabled adapters are not reported.
</para>
</refsect1>
</refentry>
<refentry id="API-mca-find-unused-adapter">
<refentryinfo>
<title>LINUX</title>
<productname>Kernel Hackers Manual</productname>
<date>June 2011</date>
</refentryinfo>
<refmeta>
<refentrytitle><phrase>mca_find_unused_adapter</phrase></refentrytitle>
<manvolnum>9</manvolnum>
<refmiscinfo class="version">2.6.32</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mca_find_unused_adapter</refname>
<refpurpose>
scan for unused adapters
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Synopsis</title>
<funcsynopsis><funcprototype>
<funcdef>int <function>mca_find_unused_adapter </function></funcdef>
<paramdef>int <parameter>id</parameter></paramdef>
<paramdef>int <parameter>start</parameter></paramdef>
</funcprototype></funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>id</parameter></term>
<listitem>
<para>
MCA identification to search for
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>start</parameter></term>
<listitem>
<para>
starting slot
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Search the MCA configuration for adapters matching the 16bit
ID given. The first time it should be called with start as zero
and then further calls made passing the return value of the
previous call until <constant>MCA_NOTFOUND</constant> is returned.
</para><para>
Adapters that have been claimed by drivers and those that
are disabled are not reported. This function thus allows a driver
to scan for further cards when some may already be driven.
</para>
</refsect1>
</refentry>
<refentry id="API-mca-read-stored-pos">
<refentryinfo>
<title>LINUX</title>
<productname>Kernel Hackers Manual</productname>
<date>June 2011</date>
</refentryinfo>
<refmeta>
<refentrytitle><phrase>mca_read_stored_pos</phrase></refentrytitle>
<manvolnum>9</manvolnum>
<refmiscinfo class="version">2.6.32</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mca_read_stored_pos</refname>
<refpurpose>
read POS register from boot data
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Synopsis</title>
<funcsynopsis><funcprototype>
<funcdef>unsigned char <function>mca_read_stored_pos </function></funcdef>
<paramdef>int <parameter>slot</parameter></paramdef>
<paramdef>int <parameter>reg</parameter></paramdef>
</funcprototype></funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>slot</parameter></term>
<listitem>
<para>
slot number to read from
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>reg</parameter></term>
<listitem>
<para>
register to read from
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Fetch a POS value that was stored at boot time by the kernel
when it scanned the MCA space. The register value is returned.
Missing or invalid registers report 0.
</para>
</refsect1>
</refentry>
<refentry id="API-mca-read-pos">
<refentryinfo>
<title>LINUX</title>
<productname>Kernel Hackers Manual</productname>
<date>June 2011</date>
</refentryinfo>
<refmeta>
<refentrytitle><phrase>mca_read_pos</phrase></refentrytitle>
<manvolnum>9</manvolnum>
<refmiscinfo class="version">2.6.32</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mca_read_pos</refname>
<refpurpose>
read POS register from card
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Synopsis</title>
<funcsynopsis><funcprototype>
<funcdef>unsigned char <function>mca_read_pos </function></funcdef>
<paramdef>int <parameter>slot</parameter></paramdef>
<paramdef>int <parameter>reg</parameter></paramdef>
</funcprototype></funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>slot</parameter></term>
<listitem>
<para>
slot number to read from
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>reg</parameter></term>
<listitem>
<para>
register to read from
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Fetch a POS value directly from the hardware to obtain the
current value. This is much slower than mca_read_stored_pos and
may not be invoked from interrupt context. It handles the
deep magic required for onboard devices transparently.
</para>
</refsect1>
</refentry>
<refentry id="API-mca-write-pos">
<refentryinfo>
<title>LINUX</title>
<productname>Kernel Hackers Manual</productname>
<date>June 2011</date>
</refentryinfo>
<refmeta>
<refentrytitle><phrase>mca_write_pos</phrase></refentrytitle>
<manvolnum>9</manvolnum>
<refmiscinfo class="version">2.6.32</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mca_write_pos</refname>
<refpurpose>
read POS register from card
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Synopsis</title>
<funcsynopsis><funcprototype>
<funcdef>void <function>mca_write_pos </function></funcdef>
<paramdef>int <parameter>slot</parameter></paramdef>
<paramdef>int <parameter>reg</parameter></paramdef>
<paramdef>unsigned char <parameter>byte</parameter></paramdef>
</funcprototype></funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>slot</parameter></term>
<listitem>
<para>
slot number to read from
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>reg</parameter></term>
<listitem>
<para>
register to read from
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>byte</parameter></term>
<listitem>
<para>
byte to write to the POS registers
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Store a POS value directly from the hardware. You should not
normally need to use this function and should have a very good
knowledge of MCA bus before you do so. Doing this wrongly can
damage the hardware.
</para><para>
This function may not be used from interrupt context.
</para><para>
Note that this a technically a Bad Thing, as IBM tech stuff says
you should only set POS values through their utilities.
However, some devices such as the 3c523 recommend that you write
back some data to make sure the configuration is consistent.
I'd say that IBM is right, but I like my drivers to work.
</para><para>
This function can't do checks to see if multiple devices end up
with the same resources, so you might see magic smoke if someone
screws up.
</para>
</refsect1>
</refentry>
<refentry id="API-mca-set-adapter-name">
<refentryinfo>
<title>LINUX</title>
<productname>Kernel Hackers Manual</productname>
<date>June 2011</date>
</refentryinfo>
<refmeta>
<refentrytitle><phrase>mca_set_adapter_name</phrase></refentrytitle>
<manvolnum>9</manvolnum>
<refmiscinfo class="version">2.6.32</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mca_set_adapter_name</refname>
<refpurpose>
Set the description of the card
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Synopsis</title>
<funcsynopsis><funcprototype>
<funcdef>void <function>mca_set_adapter_name </function></funcdef>
<paramdef>int <parameter>slot</parameter></paramdef>
<paramdef>char * <parameter>name</parameter></paramdef>
</funcprototype></funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>slot</parameter></term>
<listitem>
<para>
slot to name
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>name</parameter></term>
<listitem>
<para>
text string for the namen
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
This function sets the name reported via /proc for this
adapter slot. This is for user information only. Setting a
name deletes any previous name.
</para>
</refsect1>
</refentry>
<refentry id="API-mca-mark-as-used">
<refentryinfo>
<title>LINUX</title>
<productname>Kernel Hackers Manual</productname>
<date>June 2011</date>
</refentryinfo>
<refmeta>
<refentrytitle><phrase>mca_mark_as_used</phrase></refentrytitle>
<manvolnum>9</manvolnum>
<refmiscinfo class="version">2.6.32</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mca_mark_as_used</refname>
<refpurpose>
claim an MCA device
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Synopsis</title>
<funcsynopsis><funcprototype>
<funcdef>int <function>mca_mark_as_used </function></funcdef>
<paramdef>int <parameter>slot</parameter></paramdef>
</funcprototype></funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>slot</parameter></term>
<listitem>
<para>
slot to claim
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>FIXME</title>
<para>
should we make this threadsafe
</para><para>
Claim an MCA slot for a device driver. If the
slot is already taken the function returns 1,
if it is not taken it is claimed and 0 is
returned.
</para>
</refsect1>
</refentry>
<refentry id="API-mca-mark-as-unused">
<refentryinfo>
<title>LINUX</title>
<productname>Kernel Hackers Manual</productname>
<date>June 2011</date>
</refentryinfo>
<refmeta>
<refentrytitle><phrase>mca_mark_as_unused</phrase></refentrytitle>
<manvolnum>9</manvolnum>
<refmiscinfo class="version">2.6.32</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mca_mark_as_unused</refname>
<refpurpose>
release an MCA device
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Synopsis</title>
<funcsynopsis><funcprototype>
<funcdef>void <function>mca_mark_as_unused </function></funcdef>
<paramdef>int <parameter>slot</parameter></paramdef>
</funcprototype></funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>slot</parameter></term>
<listitem>
<para>
slot to claim
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Release the slot for other drives to use.
</para>
</refsect1>
</refentry>
</chapter>
<chapter id="dmafunctions">
<title>DMA Functions Provided</title>
<!-- arch/x86/include/asm/mca_dma.h -->
<refentry id="API-mca-enable-dma">
<refentryinfo>
<title>LINUX</title>
<productname>Kernel Hackers Manual</productname>
<date>June 2011</date>
</refentryinfo>
<refmeta>
<refentrytitle><phrase>mca_enable_dma</phrase></refentrytitle>
<manvolnum>9</manvolnum>
<refmiscinfo class="version">2.6.32</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mca_enable_dma</refname>
<refpurpose>
channel to enable DMA on
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Synopsis</title>
<funcsynopsis><funcprototype>
<funcdef>void <function>mca_enable_dma </function></funcdef>
<paramdef>unsigned int <parameter>dmanr</parameter></paramdef>
</funcprototype></funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>dmanr</parameter></term>
<listitem>
<para>
DMA channel
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Enable the MCA bus DMA on a channel. This can be called from
IRQ context.
</para>
</refsect1>
</refentry>
<refentry id="API-mca-disable-dma">
<refentryinfo>
<title>LINUX</title>
<productname>Kernel Hackers Manual</productname>
<date>June 2011</date>
</refentryinfo>
<refmeta>
<refentrytitle><phrase>mca_disable_dma</phrase></refentrytitle>
<manvolnum>9</manvolnum>
<refmiscinfo class="version">2.6.32</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mca_disable_dma</refname>
<refpurpose>
channel to disable DMA on
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Synopsis</title>
<funcsynopsis><funcprototype>
<funcdef>void <function>mca_disable_dma </function></funcdef>
<paramdef>unsigned int <parameter>dmanr</parameter></paramdef>
</funcprototype></funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>dmanr</parameter></term>
<listitem>
<para>
DMA channel
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Enable the MCA bus DMA on a channel. This can be called from
IRQ context.
</para>
</refsect1>
</refentry>
<refentry id="API-mca-set-dma-addr">
<refentryinfo>
<title>LINUX</title>
<productname>Kernel Hackers Manual</productname>
<date>June 2011</date>
</refentryinfo>
<refmeta>
<refentrytitle><phrase>mca_set_dma_addr</phrase></refentrytitle>
<manvolnum>9</manvolnum>
<refmiscinfo class="version">2.6.32</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mca_set_dma_addr</refname>
<refpurpose>
load a 24bit DMA address
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Synopsis</title>
<funcsynopsis><funcprototype>
<funcdef>void <function>mca_set_dma_addr </function></funcdef>
<paramdef>unsigned int <parameter>dmanr</parameter></paramdef>
<paramdef>unsigned int <parameter>a</parameter></paramdef>
</funcprototype></funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>dmanr</parameter></term>
<listitem>
<para>
DMA channel
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>a</parameter></term>
<listitem>
<para>
24bit bus address
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Load the address register in the DMA controller. This has a 24bit
limitation (16Mb).
</para>
</refsect1>
</refentry>
<refentry id="API-mca-get-dma-addr">
<refentryinfo>
<title>LINUX</title>
<productname>Kernel Hackers Manual</productname>
<date>June 2011</date>
</refentryinfo>
<refmeta>
<refentrytitle><phrase>mca_get_dma_addr</phrase></refentrytitle>
<manvolnum>9</manvolnum>
<refmiscinfo class="version">2.6.32</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mca_get_dma_addr</refname>
<refpurpose>
load a 24bit DMA address
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Synopsis</title>
<funcsynopsis><funcprototype>
<funcdef>unsigned int <function>mca_get_dma_addr </function></funcdef>
<paramdef>unsigned int <parameter>dmanr</parameter></paramdef>
</funcprototype></funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>dmanr</parameter></term>
<listitem>
<para>
DMA channel
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Read the address register in the DMA controller. This has a 24bit
limitation (16Mb). The return is a bus address.
</para>
</refsect1>
</refentry>
<refentry id="API-mca-set-dma-count">
<refentryinfo>
<title>LINUX</title>
<productname>Kernel Hackers Manual</productname>
<date>June 2011</date>
</refentryinfo>
<refmeta>
<refentrytitle><phrase>mca_set_dma_count</phrase></refentrytitle>
<manvolnum>9</manvolnum>
<refmiscinfo class="version">2.6.32</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mca_set_dma_count</refname>
<refpurpose>
load a 16bit transfer count
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Synopsis</title>
<funcsynopsis><funcprototype>
<funcdef>void <function>mca_set_dma_count </function></funcdef>
<paramdef>unsigned int <parameter>dmanr</parameter></paramdef>
<paramdef>unsigned int <parameter>count</parameter></paramdef>
</funcprototype></funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>dmanr</parameter></term>
<listitem>
<para>
DMA channel
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>count</parameter></term>
<listitem>
<para>
count
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Set the DMA count for this channel. This can be up to 64Kbytes.
Setting a count of zero will not do what you expect.
</para>
</refsect1>
</refentry>
<refentry id="API-mca-get-dma-residue">
<refentryinfo>
<title>LINUX</title>
<productname>Kernel Hackers Manual</productname>
<date>June 2011</date>
</refentryinfo>
<refmeta>
<refentrytitle><phrase>mca_get_dma_residue</phrase></refentrytitle>
<manvolnum>9</manvolnum>
<refmiscinfo class="version">2.6.32</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mca_get_dma_residue</refname>
<refpurpose>
get the remaining bytes to transfer
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Synopsis</title>
<funcsynopsis><funcprototype>
<funcdef>unsigned int <function>mca_get_dma_residue </function></funcdef>
<paramdef>unsigned int <parameter>dmanr</parameter></paramdef>
</funcprototype></funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>dmanr</parameter></term>
<listitem>
<para>
DMA channel
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
This function returns the number of bytes left to transfer
on this DMA channel.
</para>
</refsect1>
</refentry>
<refentry id="API-mca-set-dma-io">
<refentryinfo>
<title>LINUX</title>
<productname>Kernel Hackers Manual</productname>
<date>June 2011</date>
</refentryinfo>
<refmeta>
<refentrytitle><phrase>mca_set_dma_io</phrase></refentrytitle>
<manvolnum>9</manvolnum>
<refmiscinfo class="version">2.6.32</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mca_set_dma_io</refname>
<refpurpose>
set the port for an I/O transfer
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Synopsis</title>
<funcsynopsis><funcprototype>
<funcdef>void <function>mca_set_dma_io </function></funcdef>
<paramdef>unsigned int <parameter>dmanr</parameter></paramdef>
<paramdef>unsigned int <parameter>io_addr</parameter></paramdef>
</funcprototype></funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>dmanr</parameter></term>
<listitem>
<para>
DMA channel
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>io_addr</parameter></term>
<listitem>
<para>
an I/O port number
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
Unlike the ISA bus DMA controllers the DMA on MCA bus can transfer
with an I/O port target.
</para>
</refsect1>
</refentry>
<refentry id="API-mca-set-dma-mode">
<refentryinfo>
<title>LINUX</title>
<productname>Kernel Hackers Manual</productname>
<date>June 2011</date>
</refentryinfo>
<refmeta>
<refentrytitle><phrase>mca_set_dma_mode</phrase></refentrytitle>
<manvolnum>9</manvolnum>
<refmiscinfo class="version">2.6.32</refmiscinfo>
</refmeta>
<refnamediv>
<refname>mca_set_dma_mode</refname>
<refpurpose>
set the DMA mode
</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Synopsis</title>
<funcsynopsis><funcprototype>
<funcdef>void <function>mca_set_dma_mode </function></funcdef>
<paramdef>unsigned int <parameter>dmanr</parameter></paramdef>
<paramdef>unsigned int <parameter>mode</parameter></paramdef>
</funcprototype></funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>dmanr</parameter></term>
<listitem>
<para>
DMA channel
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>mode</parameter></term>
<listitem>
<para>
mode to set
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>
The DMA controller supports several modes. The mode values you can
set are-
</para><para>
<constant>MCA_DMA_MODE_READ</constant> when reading from the DMA device.
</para><para>
<constant>MCA_DMA_MODE_WRITE</constant> to writing to the DMA device.
</para><para>
<constant>MCA_DMA_MODE_IO</constant> to do DMA to or from an I/O port.
</para><para>
<constant>MCA_DMA_MODE_16</constant> to do 16bit transfers.
</para>
</refsect1>
</refentry>
</chapter>
</book>
