This commit adds support for URBs (USB Request/Response Blocks). These
allow for submitting multi-transfer sized buffers with USBUS handling
the individual usbdev xmits. Multiple URBs can be queued at once for a
single endpoint and USBUS will handle them in the order of submission.
OUT endpoint URBs must always consist of a whole number of full-sized
transfers (N x MaxEndpointSize). They will automatically finish after
the endpoint received a transfer less than the endpoint size.
IN endpoints can be arbitrary-sized and do not have to consist of a
whole number of full-sized transmissions. They support a flag to
indicate that the last transfer in the sequence must be less than a full
sized transfer (USBUS_URB_FLAG_AUTO_ZLP) and this adds a zero length
transfer at the end of the transmissions if the last transfer was equal
to the maximum transfer size.
URBs can be cancelled, but if the URB is already being processed it will
be cancelled after the current transmission within the URB is finished.
If it is still in the queue it will immediately be removed from the
queue.
- most were trivial
- missing group close or open
- extra space
- no doxygen comment
- name commad might open an implicit group
this hould also be implicit cosed but does not happen somtimes
- crazy: internal declared groups have to be closed internal
This API change refactors the usbdev API to supply buffers via the
usbdev_ep_xmit function. This changes from the usbdev_ep_ready call to allow
separate buffers per call. An usbdev_ep_buf_t pseudotype is available and must
be used when defining buffers used for endpoints to adhere to the DMA alignment
restrictions often required with usb peripherals.
Main advantage is that the usbdev peripherals no longer have to allocate
oversized buffers for the endpoint data, potentially saving multiple KiB
of unused buffer space. These allocations are now the responsibility of
the individual USB interfaces in the firmware
This commit changes the name of the requests over the control endpoints
to control requests instead of setup requests. This is a terminology fix
to follow the USB specification more closely as technically only the
first stage of a control request is named setup which contains a setup
packet. The whole transfer is a control transfer.
