WPF bind usercontrol's property to parent's property

I have created a usercontrol, which has 2 dependency properties. I want to bind those dependency properties to the mainViewModel's property, so that whenever something gets changed in the user-control the parent's property gets updated.

I tried, binding it normally but it didn't work. How can I bind the user-control's DP to the parent's property.

I tried this: UC:

<TextBox Name="TextBox" Text="{Binding ElementName=UCName, Path=DP1, Mode=TwoWay}"/>

MainWindow:

<UCName:UCName Width="330" CredentialName="{Binding Path=DP1, Mode=TwoWay}"></UCName:UCName>

Thanks