Splitting a house

I live in Illinois. My (50's m) mother just passed and so my brother (50's m) and I just inherited her house equally. I have my own house. He has been living with her for the past 15 years and not paying rent. Going forward, we had planned on each of us paying half the mortgage and he would cover utilities since he will continue to live there. I'm hoping for some advice regarding any rent payment. We'll both be paying towards the mortgage, but since he's benefiting from living there, should rent be paid or how can we balance this so it's fair? Thanks for any advice!