Solve equation perturbatively

[djymndl07]

I have this expression, $$T=2 P r-\frac{q^2}{4 \pi r^3}+\frac{1}{4 \pi r}$$. Now I want to solve this equation for $r$ perturbatively. This will give the expression $$r=\frac{T}{2 P}-\frac{1}{4 \pi T}+\frac{P \left(8 \pi P q^2-1\right)}{8 \left(\pi ^2 T^3\right)}+.......$$. I was reading an article where author did this. How can I do this in mathematica?

 

[Orodruin]

Which is your small parameter? It is unclear from your post.

 

[renormalize]

How can I do this in mathematica?