If you dream about someone who died does it mean his soul came to your dreams?

No, not necessarily. It is quite normal to dream about someone shortly after their death or while you are mourning their loss. Usually this only means that your own mind is struggling to accept the reality and finality of the person's passing. However, there are some dreams that give you an opportunity to say goodbye or that represent the bonds of love and caring that extend beyond the limits of physical existance. In those cases, the memory of the dream encounter with the loved one is as real and valid as encounters that occur before death. See the link below for further discussion on seeing deceased persons in dreams.