What is the test for prior drug use in drug possession cases?

We begin with the limited admissibility of prior drug use in narcotics prosecutions. "The crime of possession of methamphetamine consists of four elements: (1) defendant exercised control over or the right to control an amount of methamphetamine; (2) defendant knew of its presence; (3) defendant knew of its nature as a controlled substance; and (4) the substance was in an amount usable for consumption. [Citations.]" (People v. Tripp (2007) 151 Cal.App.4th 951, 956 (Tripp), italics in original.)