What is the test for a waiver of the Fifth Amendment privilege?

"The Constitution does not require that a criminal suspect know and understand every possible consequence of a waiver of the Fifth Amendment privilege. [Citations.]" (Colorado v. Spring (1987) 479 U.S. 564, 574.) "[A] valid waiver does not require that an individual be informed of all information 'useful' in making his decision or all information that 'might . . . affec[t] his decision to confess.' [Citation.] '[W]e have never read the Constitution to require that the police supply a suspect with a flow of information to help him calibrate his self-interest in deciding whether to speak or stand by his rights.' [Citation.]" (Id. at pp. 576-577, fn. omitted; see People v. Tate (2010) 49 Cal.4th 635, 683.)