Get the control setup packet of a control transfer. This convenience
function is here to remind you that the control setup occupies the first
8 bytes of the transfer data buffer.
Calling this function only makes sense from a transfer callback function,
or situations where you have already allocated a suitably sized buffer at
transfer->buffer.
\param transfer a transfer
\returns a casted pointer to the start of the transfer data buffer
Get the control setup packet of a control transfer. This convenience function is here to remind you that the control setup occupies the first 8 bytes of the transfer data buffer.
Calling this function only makes sense from a transfer callback function, or situations where you have already allocated a suitably sized buffer at transfer->buffer.
\param transfer a transfer \returns a casted pointer to the start of the transfer data buffer