1.\" 2.\" Copyright (c) 1993 Christopher G. Demetriou 3.\" Copyright (c) 1994 Geoffrey M. Rehmet 4.\" Copyright (c) 1999 Nicolas Souchu 5.\" All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" $FreeBSD$ 29.\" 30.Dd February 14, 1999 31.Dt LPT 4 32.Os 33.Sh NAME 34.Nm lpt 35.Nd generic printer device driver 36.Sh SYNOPSIS 37.Cd "device ppbus" 38.Cd "device lpt" 39.Pp 40.Cd "device ppc0 at isa? port IO_LPT1 irq 7" 41.Cd "device ppc1 at isa? port IO_LPT2 irq 7" 42.Cd "device ppc2 at isa? port IO_LPT3 irq 7" 43.Pp 44For BIOS-probed ports: 45.Cd "device ppc0 at isa? port? irq 7" 46.Pp 47For polled ports: 48.Cd "device ppc0 at isa? port?" 49.Cd "device ppc1 at isa? port IO_LPT2" 50.Pp 51For DMA capable parallel port: 52.Cd "device ppc0 at isa? port? irq 7 drq 1" 53.Sh DESCRIPTION 54The current 55.Em lpt 56driver is the port of the original lpt driver to the 57.Xr ppbus 4 58system. 59.Pp 60One purpose of this port was to allow parallel port sharing with other 61parallel devices. 62Secondly, inb()/outb() calls have been replaced by ppbus 63function calls. 64lpt is now arch-independent thanks to the ppbus interface. 65See 66.Xr ppbus 4 67for more info about the ppbus system. 68.Pp 69The parallel port bus is allocated by lpt when the printer device is opened 70and released only when the transfer is completed: either when the device 71is closed or when the entire buffer is sent in interrupt driven mode. 72.Pp 73The driver can be configured to be either interrupt-driven, or 74to poll the printer. Ports that are configured to be 75interrupt-driven can be switched to polled mode by using the 76.Xr lptcontrol 8 77command. 78.Pp 79Depending on your hardware, extended capabilities may be configured with the 80.Xr lptcontrol 8 81command. 82With an ECP/ISA port, you can take advantage 83of FIFO and DMA. 84.Pp 85In order to retrieve printer info from /dev/lpt0, just apply the 86.Nm cat 87command to the device. 88If the printer supports IEEE1284 nibble mode and has 89data to send to the host, you'll get it. 90.Sh SEE ALSO 91.Xr ppbus 4 , 92.Xr lptcontrol 8 93.Sh HISTORY 94This driver replaces the functionality of the lpa 95driver, which is now defunct. 96.Sh FILES 97.Bl -tag -width Pa -compact 98.It Pa /dev/lpt0 99first parallel port driver 100.El 101.Sh BUGS 102There are lots of them, especially in cheap parallel port implementations. 103.Pp 104It is only possible to open a lpt port when a printer is connected and 105on-line, making it impossible to run 106.Xr lptcontrol 8 107when there is no printer connected. 108.Pp 109This driver could still stand a rewrite. 110