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diff --git a/share/man/man4/ppi.4 b/share/man/man4/ppi.4 new file mode 100644 index 000000000000..a4084ad63648 --- /dev/null +++ b/share/man/man4/ppi.4 @@ -0,0 +1,107 @@ +.\" 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. +.\" +.\" $FreeBSD$ +.\" +.Dd January 2, 1998 +.Dt PPI 4 +.Os +.Sh NAME +.Nm ppi +.Nd "user-space interface to ppbus parallel 'geek' port" +.Sh SYNOPSIS +.Cd "device ppi" +.Pp +Minor numbering: unit numbers correspond directly to ppbus numbers. +.Pp +.In dev/ppbus/ppi.h +.In dev/ppbus/ppbconf.h +.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 +All I/O on the +.Nm +interface is performed using +.Fn ioctl +calls. +Each command takes a single +.Ft uint8_t +argument, transferring one byte of data. +The following commands are available: +.Bl -tag -width indent +.It Dv PPIGDATA , PPISDATA +Get and set the contents of the data register. +.It Dv PPIGSTATUS , PPISSTATUS +Get and set the contents of the status register. +.It Dv 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 indent -compact +.It Dv STROBE +.It Dv AUTOFEED +.It Dv nINIT +.It Dv SELECTIN +.It Dv PCD +.El +.It Dv PPIGEPP , PPISEPP +Get and set the contents of the EPP control register. +.It Dv PPIGECR , PPISECR +Get and set the contents of the ECP control register. +.It Dv 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; + uint8_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. |