CAN interface enable
CONFIG_GRCAN_ENABLE
  Say Y here to enable GRCAN core.

CAN interrupt
CONFIG_GRCANIRQ
  Defines which interrupt number the CAN core will generate.

CAN interrupt
CONFIG_GRCANSINGLE
  Say Y here to assign one   interrupt  (common).
  Say N here to assign three interrupts (common, txsync, rxsync).
