Allows IRQ disable by default

Hey, you uploaded the code to your fork of the project - good.
The next step is to create a pull request. This is what I did here. This allows us to review the changes and then merge it back to the original repository.
I will underscore this (_read, _write) as this is a 'private' method (see pep8). The underscore tells the user that this method is internal - he can use it, but it's not part of the official interface.