udav_csr_read
err = udav_csr_read(un, UDAV_PAR, un->un_eaddr, ETHER_ADDR_LEN);
return udav_csr_read(un, offset, &val, 1) ? 0 : val;
udav_csr_read(un, UDAV_EPDRL, data, 2);
static int udav_csr_read(struct usbnet *, int, void *, int);