Was Venus born of Jupiter castrating Saturn, or Saturn castrating Caelus?

A god took revenge on his father by castrating him and then threw his genitalia in the sea. The sea foam gathered, and thanks to the great fertility of the gods, Venus was born. I want to know if Jupiter castrated Saturn for swallowing Saturn's children and Jupiter's siblings or if Saturn castrated Caelus for hiding his children in Tartarus, deep within the Earth, hurting his wife and Saturn's mother, Terra.