What is the origin of the surname Dustin?

Surname (not first name) has a English origin and background

Dustin originates from an English surname, which is derived from a Norman personal name, which is probably derived from the Old Norse Þorsteinn (Torsten). This Old Norse name is composed of elements meaning "Thor" and "stone". In ancient Germanic languages, 'Dustin" also means "brave fighter" or "valiant fighter".