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.TH "PARPORT_POLL_PERIPHERAL" "" "06 October 2005" "" ""

.SH NAME
parport_poll_peripheral \- poll status lines
.SH SYNOPSIS
"SYNOPSIS"
.sp
\fB
.sp
int parport_poll_peripheral  (struct parport * \fIport\fB, unsigned char \fImask\fB, unsigned char \fIresult\fB, int \fIusec\fB);
\fR
.SH "ARGUMENTS"
.TP
\fB\fIport\fB\fR
port to watch
.TP
\fB\fImask\fB\fR
status lines to watch
.TP
\fB\fIresult\fB\fR
desired values of chosen status lines
.TP
\fB\fIusec\fB\fR
timeout
.SH "DESCRIPTION"
.PP
This function busy-waits until the masked status lines have
the desired values, or until the timeout period elapses.  The
\fImask\fR and \fIresult\fR parameters are bitmasks, with the bits
defined by the constants in parport.h: PARPORT_STATUS_BUSY,
and so on.
.PP
This function does not call \fBschedule\fR; instead it busy-waits
using \fBudelay\fR\&.  It currently has a resolution of 5usec.
.PP
If the status lines take on the desired values before the
timeout period elapses, \fBparport_poll_peripheral\fR returns zero
immediately.  A zero return value greater than zero indicates
a timeout.  An error code (less than zero) indicates an error,
most likely a signal that arrived, and the caller should
finish what it is doing as soon as possible.