diff options
author | msmith <msmith@FreeBSD.org> | 1998-01-02 09:31:18 +0000 |
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committer | msmith <msmith@FreeBSD.org> | 1998-01-02 09:31:18 +0000 |
commit | 91062cd50c53e88752af20485b4d4250302134b6 (patch) | |
tree | 7ca4caa47e5b175ea5d74ee9d150314151342202 | |
parent | 6fb547d5b33df78f1a839ee2371eb369b39905a8 (diff) | |
download | FreeBSD-src-91062cd50c53e88752af20485b4d4250302134b6.zip FreeBSD-src-91062cd50c53e88752af20485b4d4250302134b6.tar.gz |
Add a manpage for the 'ppi' device, detailing its use and feeding.
-rw-r--r-- | share/man/man4/Makefile | 2 | ||||
-rw-r--r-- | share/man/man4/ppi.4 | 108 |
2 files changed, 109 insertions, 1 deletions
diff --git a/share/man/man4/Makefile b/share/man/man4/Makefile index f0c52d1..4e737e3 100644 --- a/share/man/man4/Makefile +++ b/share/man/man4/Makefile @@ -3,7 +3,7 @@ MAN4= bpf.4 ccd.4 cd.4 ch.4 ddb.4 divert.4 drum.4 fd.4 fpa.4 \ icmp.4 ifmib.4 inet.4 intro.4 ip.4 ipfirewall.4 \ lkm.4 lo.4 netintro.4 \ - null.4 od.4 ppp.4 pt.4 pty.4 route.4 \ + null.4 od.4 ppi.4 ppp.4 pt.4 pty.4 route.4 \ scsi.4 sd.4 sl.4 smp.4 snp.4 sppp.4 ssc.4 st.4 su.4 tcp.4 \ ttcp.4 termios.4 tty.4 tun.4 udp.4 uk.4 update.4 unix.4 vn.4 \ worm.4 yp.4 zero.4 diff --git a/share/man/man4/ppi.4 b/share/man/man4/ppi.4 new file mode 100644 index 0000000..d3d7e28 --- /dev/null +++ b/share/man/man4/ppi.4 @@ -0,0 +1,108 @@ +.\" Copyright (c) 1997 +.\" Michael Smith +.\" +.\" 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 as +.\" the first lines of this file unmodified. +.\" 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 ``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 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. +.\" +.\" $Id$ +.\" +.Dd January 2, 1998 +.Dt PPI 4 +.Os FreeBSD +.Sh NAME +.Nm ppi +.Nd +user-space interface to ppbus parallel 'geek' port +.Sh SYNOPSIS +.Cd "device ppi0 at ppbus? +.sp +Minor numbering: Unit numbers correspond directly to ppbus numbers. +.Sh DESCRIPTION +The +.Nm +driver provides a convenient means for user applications to manipulate the +state of the parallel port, enabling easy low-speed I/O operations without +the security problems inherent with the use of the +.Pa /dev/io +interface. +.Sh PROGRAMMING INTERFACE +.Pp +.Fd #include </sys/dev/ppbus/ppi.h> +.Fd #include </sys/dev/ppbus/ppbconf.h> +.Pp +All I/O on the +.Nm +interface is performed using +.Fn ioctl +calls. Each command takes a single +.Ty u_int8_t +argument, transferring one byte of data. The following commands are +available: +.Bl -tag -width 10 +.It PPIGDATA, PPISDATA +Get and set the contents of the data register. +.It PPIGSTATUS, PPISSTATUS +Get and set the contents of the status register. +.It PPIGCTRL, PPISCTRL +Get and set the contents of the control register. +The following defines correspond to bits in this register. Setting +a bit in the control register drives the corresponding output low. +.Bl -tag -width 10 -compact +.It STROBE +.It AUTOFEED +.It nINIT +.It SELECTIN +.It PCD +.El +.It PPIGEPP, PPISEPP +Get and set the contents of the EPP control register. +.It PPIGECR, PPISECR +Get and set the contents of the ECP control register. +.It PPIGFIFO, PPISFIFO +Read and write the ECP FIFO (8-bit operations only). +.El +.Sh EXAMPLES +To present the value 0x5a to the data port, drive STROBE low and then high +again, the following code fragment can be used: +.Bd -literal -compact + + int fd; + u_int8_t val; + + val = 0x5a; + ioctl(fd, PPISDATA, &val); + ioctl(fd, PPIGCTRL, &val); + val |= STROBE; + ioctl(fd, PPISCTRL, &val); + val &= ~STROBE; + ioctl(fd, PPISCTRL, &val); + +.Ed +.Sh BUGS +The inverse sense of signals is confusing. +.Pp +The +.Fn ioctl +interface is slow, and there is no way (yet) to chain multiple operations together. +.Pp +The headers required for user applications are not installed as part of the +standard system. |