In order to port can4linux to the BananaPi, the CAN module description is needed from the A20 hardware manual. can4linux is a character-driver-based Linux driver used already on desktop PCs and embedded platforms like Freescale FlexCAN (the i.MX series of micro controllers) or Xiliny Zynq.
There is a more detailed document about CAN on the A20 at 
can4linux was succesful ported to the BananaPi. To use it, an external transceiver is required. Take care of the 3.3 V IO pins. Best to use a 3.3 V Transceiver like the TI SN65HVD230. The driver sould also work on the Banana Pro.