Copyright (c) 2001 The NetBSD Foundation, Inc.
All rights reserved.
This code is derived from software contributed to The NetBSD Foundation
by Lennart Augustsson.
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.
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.
3. All advertising materials mentioning features or use of this software
must display the following acknowledgement:
This product includes software developed by the NetBSD
Foundation, Inc. and its contributors.
4. Neither the name of The NetBSD Foundation nor the names of its
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
``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 FOUNDATION OR CONTRIBUTORS
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.
.Dd November 5, 2001 .Dt EHCI 4 .Os .Sh NAME .Nm ehci .Nd USB Enhanced Host Controller driver .Sh SYNOPSIS .Cd "ehci* at cardbus? dev ? function ?" .Cd "ehci* at pci? dev ? function ?" .Cd "usb* at ehci?" .Sh DESCRIPTION The .Nm driver provides support for USB Enhanced Host Controller Interface, which is used by for USB 2.0 controllers.
p EHCI controllers are peculiar in that they can only handle the USB 2.0 protocol. This means that they normally have a companion controller (i.e., .Xr ohci 4 or .Xr uhci 4 ) handling USB 1.x devices. Consequently each USB connector is electrically connected to two USB controllers. The handling of this is totally automatic, but can be noticed since USB 1.x and USB 2.0 devices plugged in to the same connector appear to connect to different USB busses. .Sh SEE ALSO .Xr cardbus 4 , .Xr ohci 4 , .Xr pci 4 , .Xr uhci 4 , .Xr usb 4 .Sh HISTORY The .Nm driver appeared in .Nx 1.6 . .Sh BUGS The driver is not finished and is quite buggy.
p There is no support (yet) for hubs that are connected with high speed upstream and low or full speed downstream (i.e., for transaction translators).
p There is no support for interrupt or isochronous transfers.