Does the sentence below require a comma before "who's," or is sentence two correct? Are both correct depending on the context and meaning of the speaker? I would appreciate an explanation of the grammar. And thanks for the help.
1. I am an Iowa native who's come home to help on the farm.
2. I am an Iowa native, who's come home to help on the farm.
1. I am an Iowa native who's come home to help on the farm.
2. I am an Iowa native, who's come home to help on the farm.