[usb] Include setup packet within I/O buffer for message transfers
The USB API currently assumes that host controllers will have
immediate data buffer space available in which to store the setup
packet. This is true for xHCI, partially true for EHCI (which happens
to have 12 bytes of padding in each transfer descriptor due to
alignment requirements), and not true at all for UHCI.
Include the setup packet within the I/O buffer passed to the host
controller's message() method, thereby eliminating the requirement for
host controllers to provide immediate data buffers.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[ehci] Support USB1 devices attached via transaction translators
Support low-speed and full-speed devices attached to a USB2 hub. Such
devices use a transaction translator (TT) within the USB2 hub, which
asynchronously initiates transactions on the lower-speed bus and
returns the result via a split completion on the high-speed bus.
We make the simplifying assumption that there will never be more than
sixteen active interrupt endpoints behind a single transaction
translator; this assumption allows us to schedule all periodic start
splits in microframe 0 and all periodic split completions in
microframes 2 and 3. (We do not handle isochronous endpoints.)
Signed-off-by: Michael Brown <mcb30@ipxe.org>