"je n'en ai que faire" & "il en est tout autant" ... meaning?

I often accross phrases, where I think I know roughly what is meant, but can not quite understand the grammar behind them.

The two phrases I’d like to understand come from a poem called “La Montre et le Cadran Solaire“:

...

“J’attends", répondit-il, "que le soleil m’éclaire... “

“Attends-le donc, moi, je n’en ai que faire“,

Dit la montre; “sans lui, je vais toujours mon train“.

...

“Écoute, voilà l’heure; elle sonne à l’instant:

Une, deux, trois, quatre. Il en est tout autant“,

Dit-elle ...

(je vais toujours mon train“ is also a strange phrase, I guess it means something like “I always go by my mechanism“? But gramatically, again I don’t know, is it ok? Or poetic licence?)

kb