REG_LINK_CTRL
AT_READ_REG(hw, REG_LINK_CTRL, p++);
AT_READ_REG(hw, REG_LINK_CTRL, &data);
AT_WRITE_REG(hw, REG_LINK_CTRL, data);
AT_READ_REG(hw, REG_LINK_CTRL, &link_ctrl_data);