XL_W4_PHY_MGMT
CSR_WRITE_2(sc, XL_W4_PHY_MGMT, \
CSR_READ_2(sc, XL_W4_PHY_MGMT) | (x))
CSR_WRITE_2(sc, XL_W4_PHY_MGMT, \
CSR_READ_2(sc, XL_W4_PHY_MGMT) & ~(x))
CSR_WRITE_2(sc, XL_W4_PHY_MGMT, 0);
ack = CSR_READ_2(sc, XL_W4_PHY_MGMT) & XL_MII_DATA;
if (CSR_READ_2(sc, XL_W4_PHY_MGMT) & XL_MII_DATA)