Systems and methods for controlling access to a computing device. The methods include: detecting, by a computing device in a first state, two or more user actions of tactile input applied to only one or more physical volume control buttons of a housing of the computing device; determining that the detected two or more user actions of the tactile input are valid based on a code sequence; and changing the first state of the computing device to a second state to enable use of at least one functionality of the computing device, in response to determining that the detected two or more user actions of the tactile input are valid.