|
Packit |
d36e9b |
.\" Title: ieee1284_data
|
|
Packit |
d36e9b |
.\" Author: Tim Waugh <twaugh@redhat.com>
|
|
Packit |
d36e9b |
.\" Generator: DocBook XSL Stylesheets v1.72.0 <http://docbook.sf.net/>
|
|
Packit |
d36e9b |
.\" Date: 09/18/2007
|
|
Packit |
d36e9b |
.\" Manual: Functions
|
|
Packit |
d36e9b |
.\" Source:
|
|
Packit |
d36e9b |
.\"
|
|
Packit |
d36e9b |
.TH "IEEE1284_DATA" "3" "09/18/2007" "" "Functions"
|
|
Packit |
d36e9b |
.\" disable hyphenation
|
|
Packit |
d36e9b |
.nh
|
|
Packit |
d36e9b |
.\" disable justification (adjust text to left margin only)
|
|
Packit |
d36e9b |
.ad l
|
|
Packit |
d36e9b |
.SH "NAME"
|
|
Packit |
d36e9b |
ieee1284_read_data, ieee1284_write_data, ieee1284_data_dir, ieee1284_wait_data \- control the data lines
|
|
Packit |
d36e9b |
.SH "SYNOPSIS"
|
|
Packit |
d36e9b |
.sp
|
|
Packit |
d36e9b |
.ft B
|
|
Packit |
d36e9b |
.nf
|
|
Packit |
d36e9b |
#include <ieee1284.h>
|
|
Packit |
d36e9b |
.fi
|
|
Packit |
d36e9b |
.ft
|
|
Packit |
d36e9b |
.HP 23
|
|
Packit |
d36e9b |
.BI "int ieee1284_read_data(struct\ parport\ *" "port" ");"
|
|
Packit |
d36e9b |
.HP 25
|
|
Packit |
d36e9b |
.BI "void ieee1284_write_data(struct\ parport\ *" "port" ", unsigned\ char\ " "dt" ");"
|
|
Packit |
d36e9b |
.HP 22
|
|
Packit |
d36e9b |
.BI "int ieee1284_data_dir(struct\ parport\ *" "port" ", int\ " "reverse" ");"
|
|
Packit |
d36e9b |
.HP 23
|
|
Packit |
d36e9b |
.BI "int ieee1284_wait_data(struct\ parport\ *" "port" ", unsigned\ char\ " "mask" ", unsigned\ char\ " "val" ", struct\ timeval\ *" "timeout" ");"
|
|
Packit |
d36e9b |
.SH "DESCRIPTION"
|
|
Packit |
d36e9b |
.PP
|
|
Packit |
d36e9b |
These functions manipulate the data lines of the parallel port associated with
|
|
Packit |
d36e9b |
\fIport\fR
|
|
Packit |
d36e9b |
(which must have been claimed using
|
|
Packit |
d36e9b |
\fBieee1284_claim\fR(3)). The lines are represented by an 8\-bit number (one line per bit) and a direction. The data lines are driven as a group; they may be all host\-driven (forward
|
|
Packit |
d36e9b |
direction) or not (reverse
|
|
Packit |
d36e9b |
direction). When the peripheral is driving them the host must not.
|
|
Packit |
d36e9b |
.PP
|
|
Packit |
d36e9b |
For
|
|
Packit |
d36e9b |
\fBieee1284_data_dir\fR
|
|
Packit |
d36e9b |
the
|
|
Packit |
d36e9b |
\fIreverse\fR
|
|
Packit |
d36e9b |
parameter should be zero to turn the data line drivers on and non\-zero to turn them off. Some port types may be unable to switch off the data line drivers.
|
|
Packit |
d36e9b |
.PP
|
|
Packit |
d36e9b |
Setting the data lines may have side effects on some port types (for example, some Amiga ports pulse nStrobe).
|
|
Packit |
d36e9b |
.PP
|
|
Packit |
d36e9b |
\fBieee1284_wait_data\fR
|
|
Packit |
d36e9b |
waits, up until the
|
|
Packit |
d36e9b |
\fItimeout\fR, for the data bits specified in
|
|
Packit |
d36e9b |
\fImask\fR
|
|
Packit |
d36e9b |
to have the corresponding values in
|
|
Packit |
d36e9b |
\fIval\fR.
|
|
Packit |
d36e9b |
.SH "RETURN VALUE"
|
|
Packit |
d36e9b |
.PP
|
|
Packit |
d36e9b |
\fBieee1284_read_data\fR
|
|
Packit |
d36e9b |
returns the 8\-bit number representing the data lines unless it is not possible to return such a value with this port type, in which case it returns an error code. Possible error codes:
|
|
Packit |
d36e9b |
.PP
|
|
Packit |
d36e9b |
\fBE1284_NOTAVAIL\fR
|
|
Packit |
d36e9b |
.RS 4
|
|
Packit |
d36e9b |
Bi\-directional data lines are not available on this system.
|
|
Packit |
d36e9b |
.RE
|
|
Packit |
d36e9b |
.PP
|
|
Packit |
d36e9b |
\fBE1284_INVALIDPORT\fR
|
|
Packit |
d36e9b |
.RS 4
|
|
Packit |
d36e9b |
The
|
|
Packit |
d36e9b |
\fIport\fR
|
|
Packit |
d36e9b |
parameter is invalid (perhaps it has not been claimed, for instance).
|
|
Packit |
d36e9b |
.RE
|
|
Packit |
d36e9b |
.PP
|
|
Packit |
d36e9b |
\fBE1284_SYS\fR
|
|
Packit |
d36e9b |
.RS 4
|
|
Packit |
d36e9b |
There was an error at the operating system level, and
|
|
Packit |
d36e9b |
\fIerrno\fR
|
|
Packit |
d36e9b |
has been set accordingly.
|
|
Packit |
d36e9b |
.RE
|
|
Packit |
d36e9b |
.PP
|
|
Packit |
d36e9b |
\fBE1284_TIMEDOUT\fR
|
|
Packit |
d36e9b |
.RS 4
|
|
Packit |
d36e9b |
The
|
|
Packit |
d36e9b |
\fItimeout\fR
|
|
Packit |
d36e9b |
has elapsed.
|
|
Packit |
d36e9b |
.RE
|
|
Packit |
d36e9b |
.PP
|
|
Packit |
d36e9b |
Whereas
|
|
Packit |
d36e9b |
\fBieee1284_read_data\fR
|
|
Packit |
d36e9b |
may return
|
|
Packit |
d36e9b |
\fBE1284_NOTAVAIL\fR
|
|
Packit |
d36e9b |
on its first invocation on the port, if it does not do so then it cannot until
|
|
Packit |
d36e9b |
\fBieee1284_close\fR
|
|
Packit |
d36e9b |
is called for that port.
|
|
Packit |
d36e9b |
.SH "AUTHOR"
|
|
Packit |
d36e9b |
.PP
|
|
Packit |
d36e9b |
\fBTim Waugh\fR <\&twaugh@redhat.com\&>
|
|
Packit |
d36e9b |
.sp -1n
|
|
Packit |
d36e9b |
.IP "" 4
|
|
Packit |
d36e9b |
Author.
|
|
Packit |
d36e9b |
.SH "COPYRIGHT"
|
|
Packit |
d36e9b |
Copyright \(co 2001\-2003 Tim Waugh
|
|
Packit |
d36e9b |
.br
|
|
Packit |
d36e9b |
|