IGC_MMDAC
ret_val = hw->phy.ops.write_reg(hw, IGC_MMDAC, dev_addr);
ret_val = hw->phy.ops.write_reg(hw, IGC_MMDAC, IGC_MMDAC_FUNC_DATA |
ret_val = hw->phy.ops.write_reg(hw, IGC_MMDAC, 0);