Erro ao salvar usuario _ com Hibernate

package catalogo.modelo;

import java.io.Serializable;
import javax.persistence.Basic;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Table;

@Entity
@Table(name = "usuario", schema = "catalogo")
@NamedQueries({
    @NamedQuery(name = "Usuario.findAll", query = "SELECT u FROM Usuario u")})
public class Usuario implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "codigo", nullable = false)
    private Integer codigo;

    @Basic(optional = false)
    @Column(name = "login", nullable = false, length = 45)
    private String login;

    @Basic(optional = false)
    @Column(name = "senha", nullable = false, length = 45)
    private String senha;

    @Column(name = "nome", length = 45)
    private String nome;

    //@JoinColumn(name = "tipo_usuario_codigo", referencedColumnName = "codigo", nullable = true)
    //@ManyToOne(optional = false)
    //private TipoUsuario tipoUsuarioCodigo;

    public Usuario() {
    }

    public Usuario(Integer codigo) {
        this.codigo = codigo;
    }

    public Usuario(Integer codigo, String login, String senha) {
        this.codigo = codigo;
        this.login = login;
        this.senha = senha;
    }

    public Integer getCodigo() {
        return codigo;
    }

    public void setCodigo(Integer codigo) {
        this.codigo = codigo;
    }

    public String getLogin() {
        return login;
    }

    public void setLogin(String login) {
        this.login = login;
    }

    public String getSenha() {
        return senha;
    }

    public void setSenha(String senha) {
        this.senha = senha;
    }

    public String getNome() {
        return nome;
    }

    public void setNome(String nome) {
        this.nome = nome;
    }

   /* public TipoUsuario getTipoUsuarioCodigo() {
        return tipoUsuarioCodigo;
    }

    public void setTipoUsuarioCodigo(TipoUsuario tipoUsuarioCodigo) {
        this.tipoUsuarioCodigo = tipoUsuarioCodigo;
    }*/

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (codigo != null ? codigo.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof Usuario)) {
            return false;
        }
        Usuario other = (Usuario) object;
        if ((this.codigo == null && other.codigo != null) || (this.codigo != null && !this.codigo.equals(other.codigo))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "catalogo.modelo.Usuario[codigo=" + codigo + "]";
    }

}

package catalogo.modelo;

import java.io.Serializable;
import java.util.Collection;
import javax.persistence.Basic;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.OneToMany;
import javax.persistence.Table;

@Entity
@Table(name = "tipo_usuario", schema = "catalogo")
@NamedQueries({
    @NamedQuery(name = "TipoUsuario.findAll", query = "SELECT t FROM TipoUsuario t")})
public class TipoUsuario implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @Column(name = "codigo", nullable = false)
    private Integer codigo;
    @Basic(optional = false)
    @Column(name = "tipo", nullable = true, length = 45)//nullable false depois
    private String tipo;
    @OneToMany(cascade = CascadeType.ALL, mappedBy = "tipoUsuarioCodigo")
    private Collection<Usuario> usuarioCollection;

    public TipoUsuario() {
    }

    public TipoUsuario(Integer codigo) {
        this.codigo = codigo;
    }

    public TipoUsuario(Integer codigo, String tipo) {
        this.codigo = codigo;
        this.tipo = tipo;
    }

    public Integer getCodigo() {
        return codigo;
    }

    public void setCodigo(Integer codigo) {
        this.codigo = codigo;
    }

    public String getTipo() {
        return tipo;
    }

    public void setTipo(String tipo) {
        this.tipo = tipo;
    }

    public Collection<Usuario> getUsuarioCollection() {
        return usuarioCollection;
    }

    public void setUsuarioCollection(Collection<Usuario> usuarioCollection) {
        this.usuarioCollection = usuarioCollection;
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (codigo != null ? codigo.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof TipoUsuario)) {
            return false;
        }
        TipoUsuario other = (TipoUsuario) object;
        if ((this.codigo == null && other.codigo != null) || (this.codigo != null && !this.codigo.equals(other.codigo))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "catalogo.modelo.TipoUsuario[codigo=" + codigo + "]";
    }

}