xref: /freebsd/share/man/man4/ehci.4 (revision f728775b2140566cd8b9706885a8da8e8f971f22)
18e13d96bSTom Rhodes.\" $NetBSD: ehci.4,v 1.8 2001/11/21 17:22:56 augustss Exp $
28e13d96bSTom Rhodes.\"
38e13d96bSTom Rhodes.\" Copyright (c) 2001 The NetBSD Foundation, Inc.
48e13d96bSTom Rhodes.\" All rights reserved.
58e13d96bSTom Rhodes.\"
68e13d96bSTom Rhodes.\" This code is derived from software contributed to The NetBSD Foundation
78e13d96bSTom Rhodes.\" by Lennart Augustsson.
88e13d96bSTom Rhodes.\"
98e13d96bSTom Rhodes.\" Redistribution and use in source and binary forms, with or without
108e13d96bSTom Rhodes.\" modification, are permitted provided that the following conditions
118e13d96bSTom Rhodes.\" are met:
128e13d96bSTom Rhodes.\" 1. Redistributions of source code must retain the above copyright
138e13d96bSTom Rhodes.\"    notice, this list of conditions and the following disclaimer.
148e13d96bSTom Rhodes.\" 2. Redistributions in binary form must reproduce the above copyright
158e13d96bSTom Rhodes.\"    notice, this list of conditions and the following disclaimer in the
168e13d96bSTom Rhodes.\"    documentation and/or other materials provided with the distribution.
178e13d96bSTom Rhodes.\"
188e13d96bSTom Rhodes.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
198e13d96bSTom Rhodes.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
208e13d96bSTom Rhodes.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
218e13d96bSTom Rhodes.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
228e13d96bSTom Rhodes.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
238e13d96bSTom Rhodes.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
248e13d96bSTom Rhodes.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
258e13d96bSTom Rhodes.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
268e13d96bSTom Rhodes.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
278e13d96bSTom Rhodes.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
288e13d96bSTom Rhodes.\" POSSIBILITY OF SUCH DAMAGE.
298e13d96bSTom Rhodes.\"
308e13d96bSTom Rhodes.\" $FreeBSD$
318e13d96bSTom Rhodes.\"
32*f728775bSHans Petter Selasky.Dd February 24, 2011
338e13d96bSTom Rhodes.Dt EHCI 4
348e13d96bSTom Rhodes.Os
358e13d96bSTom Rhodes.Sh NAME
368e13d96bSTom Rhodes.Nm ehci
378e13d96bSTom Rhodes.Nd USB Enhanced Host Controller driver
388e13d96bSTom Rhodes.Sh SYNOPSIS
398e13d96bSTom Rhodes.Cd "device ehci"
408e13d96bSTom Rhodes.Sh DESCRIPTION
418e13d96bSTom RhodesThe
428e13d96bSTom Rhodes.Nm
438e13d96bSTom Rhodesdriver provides support for the
448e13d96bSTom Rhodes.Tn USB
458e13d96bSTom RhodesEnhanced Host Controller Interface,
468e13d96bSTom Rhodeswhich is used by
478e13d96bSTom Rhodes.Tn USB
488e13d96bSTom Rhodes2.0 controllers.
498e13d96bSTom Rhodes.Pp
508e13d96bSTom Rhodes.Tn EHCI
518e13d96bSTom Rhodescontrollers are peculiar in that they can only handle the
528e13d96bSTom Rhodes.Tn USB
538e13d96bSTom Rhodes2.0 protocol.
548e13d96bSTom RhodesThis means that they normally have one or more companion controllers
558e13d96bSTom Rhodes(i.e.,
568e13d96bSTom Rhodes.Xr ohci 4
578e13d96bSTom Rhodesor
588e13d96bSTom Rhodes.Xr uhci 4 )
598e13d96bSTom Rhodeshandling USB 1.x devices.
608e13d96bSTom RhodesConsequently each
618e13d96bSTom Rhodes.Tn USB
628e13d96bSTom Rhodesconnector is electrically connected to two
638e13d96bSTom Rhodes.Tn USB
648e13d96bSTom Rhodescontrollers.
658e13d96bSTom RhodesThe handling of this is totally automatic,
668e13d96bSTom Rhodesbut can be noticed since
678e13d96bSTom Rhodes.Tn USB
688e13d96bSTom Rhodes1.x and
698e13d96bSTom Rhodes.Tn USB
708e13d96bSTom Rhodes2.0 devices plugged in to the same
718e13d96bSTom Rhodesconnector appear to connect to different USB busses.
728e13d96bSTom Rhodes.Sh SEE ALSO
73*f728775bSHans Petter Selasky.Xr xhci 4 ,
748e13d96bSTom Rhodes.Xr ohci 4 ,
758e13d96bSTom Rhodes.Xr uhci 4 ,
768e13d96bSTom Rhodes.Xr usb 4
778e13d96bSTom Rhodes.Sh HISTORY
788e13d96bSTom RhodesThe
798e13d96bSTom Rhodes.Nm
808e13d96bSTom Rhodesdevice driver first appeared in
818e13d96bSTom Rhodes.Fx 5.1 .
82*f728775bSHans Petter Selasky.Sh LOADER TUNABLES
83*f728775bSHans Petter SelaskyTunables can be set at the
84*f728775bSHans Petter Selasky.Xr loader 8
85*f728775bSHans Petter Selaskyprompt before booting the kernel or stored in
86*f728775bSHans Petter Selasky.Xr loader.conf 5 .
87*f728775bSHans Petter Selasky.Bl -tag -width "xxxxxx"
88*f728775bSHans Petter Selasky.It Va hw.usb.ehci.lostintrbug
89*f728775bSHans Petter SelaskyThis tunable enables the lost interrupt quirk.
90*f728775bSHans Petter SelaskyThe default value is 0 (off).
91*f728775bSHans Petter Selasky.It Va hw.usb.ehci.iaadbug
92*f728775bSHans Petter SelaskyThis tunable enables the EHCI doorbell quirk.
93*f728775bSHans Petter SelaskyThe default value is 0 (off).
94*f728775bSHans Petter Selasky.It Va hw.usb.ehci.no_hs
95*f728775bSHans Petter SelaskyThis tunable disables USB devices to attach like HIGH-speed ones and will force all attached devices to attach to the FULL- or LOW-speed companion controller.
96*f728775bSHans Petter SelaskyThe default value is 0 (off).
97*f728775bSHans Petter Selasky.El
98