1.\" $OpenBSD: udl.4,v 1.24 2023/05/10 22:23:25 jmc Exp $ 2.\" 3.\" Copyright (c) 2009 Marcus Glocker <mglocker@openbsd.org> 4.\" 5.\" Permission to use, copy, modify, and distribute this software for any 6.\" purpose with or without fee is hereby granted, provided that the above 7.\" copyright notice and this permission notice appear in all copies. 8.\" 9.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16.\" 17.Dd $Mdocdate: May 10 2023 $ 18.Dt UDL 4 19.Os 20.Sh NAME 21.Nm udl 22.Nd DisplayLink DL-120/DL-160 USB display devices 23.Sh SYNOPSIS 24.Cd "udl* at uhub?" 25.Cd "wsdisplay* at udl?" 26.Sh DESCRIPTION 27The 28.Nm 29driver supports USB display devices based on the DisplayLink DL-120/DL-160 30graphic chip. 31.Sh HARDWARE 32The following devices should work: 33.Pp 34.Bl -tag -width Ds -offset indent -compact 35.It Century Corp. Japan Plus One LCD-8000U 36.It Century Corp. Japan Plus One LCD-4300U 37.It DisplayLink USB to DVI 38.It ForwardVideo EasyCAP008 USB to DVI 39.It HP USB 2.0 Docking Station (FQ834) 40.It HP USB Graphics Adapter (NL571) 41.It IOGEAR USB 2.0 External DVI (GUC2020) 42.It Koenig CMP-USBVGA10 and CMP-USBVGA11 43.It Lenovo 45K5296 USB to DVI 44.It Lenovo ThinkVision LT1421 45.It Lilliput UM-70 46.It Nanovision MiMo UM-710 and UM-740 47.It Rextron VCUD60 USB to DVI 48.It Samsung LD220 49.It StarTech CONV-USB2DVI 50.It Sunweit USB to DVI 51.It Toshiba Video Dock 52.It Unitek Y-2240 USB to DVI 53.It VideoHome NBdock1920 54.El 55.Sh FILES 56The device can process compressed data (Huffman pixel difference method) 57to reduce the USB payload. 58To generate the compressed data, 59the driver needs to load a Huffman table, 60which is stored in the following binary file: 61.Pp 62.Bl -tag -width Ds -offset indent -compact 63.It Pa /etc/firmware/udl_huffman 64.El 65.Pp 66If the Huffman table can't be loaded, the driver will fall back to 67uncompressed mode. 68.Sh SEE ALSO 69.Xr intro 4 , 70.Xr usb 4 , 71.Xr wscons 4 , 72.Xr wsdisplay 4 73.Sh HISTORY 74The 75.Nm 76driver first appeared in 77.Ox 4.6 . 78.Sh AUTHORS 79.An Marcus Glocker Aq Mt mglocker@openbsd.org 80