— USB Enhanced Host Controller
driver provides support for the USB Enhanced Host
Controller Interface, which is used by USB 2.0 controllers.
EHCI controllers are peculiar in that they can only handle the USB 2.0 protocol.
This means that they normally have one or more companion controllers (i.e.,
) 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.
device driver first appeared in
The driver is not finished and is quite buggy.
There is currently no support for isochronous transfers.