Manually bind to parent view or controller

How can you manually (in the .js file, not .hbs) connect bindings from a component to the parent view's controller?

Per the documentation, it seems you should be able to bind a component property to the parent view's controller property. I know that the method I am about to describe used to work (around Ember v1.5).

var binding = Ember.Binding.from('inputValue').to('parentView.controller.outputValue');
binding.connect(this);

But now, parentView and controller don't exist. They seem to have been renamed to _parentView and _controller which suggests to me that it is not a "blessed" way of binding values from a component to it's parent controller.

So does anyone know if there is a way to do that, other than gumming up your .hbs helpers with tons of ugly code?

{{component-helper ComponentVar1=ContollerVar1 ComponentVar2=ContollerVar2 ComponentVar3=ContollerVar3}}

// vs.

{{component-helper}}

Personally, I only need values to go one way (as shown when I try to hook things up manually using Ember.Binding). So doing it through the helper in an .hbs file is not only uglier, but also unnecessarily creates two-way bindings (I think).