RCANFD_F_RFOFFSET
#define RCANFD_F_RFID(gpriv, x) (RCANFD_F_RFOFFSET(gpriv) + (0x80 * (x)))
#define RCANFD_F_RFPTR(gpriv, x) (RCANFD_F_RFOFFSET(gpriv) + 0x04 + (0x80 * (x)))
#define RCANFD_F_RFFDSTS(gpriv, x) (RCANFD_F_RFOFFSET(gpriv) + 0x08 + (0x80 * (x)))
(RCANFD_F_RFOFFSET(gpriv) + 0x0c + (0x80 * (x)) + (0x04 * (df)))