。
He went and showed up while I was still asleep.
Literal
I [subject-が] still sleeping-am time [in-に] he [by-に] come-ended-up.
Intricate passive-like construction: 来られてしまった is the 'suffering passive' of 来る + ~てしまう. The 'suffering passive' expresses that someone's action inconvenienced the speaker — literally 'was come to' but with the nuance 'his coming was a problem for me.' A distinctly Japanese grammatical feature with no direct English equivalent.