There isn't a campsite with direct access to the ski resort. The nearest campsite is situated about half way up the mountain, so you would need to drive up to the resort to ski.
There is an aire of sorts in the top car park, no electric or fresh water but there is toilets which are open when the ski pass office is open. There is a grey and black dump, but the twice we have been there is was either covered over in ice and snow or shut off.
Good skiing though when the weather's is right. Avoid the weekends and Spanish holidays, as it gets crazy busy.