An input device for performing control functions of a machine having a work tool may include a left-hand joystick mounted on a left armrest of an operator's seat, and a right-hand joystick mounted on a right armrest of an operator's seat. Each of the left-hand and right-hand joysticks may include a base portion configured to conform to and least partially cradle an operator's hand, a handle extending from the base portion with a proximal end of the handle being connected to the base portion, and a distal end of the handle supporting a head portion of the joystick. The head portion of the joystick may include a front surface including a configurable face plate. The configurable face plate may include one of a pair of upshift and downshift buttons or a roller configured to perform one of discrete or continuously variable shifting, respectively, of a transmission of the machine. The handle may include a thumb rest area at the distal end of the handle transitioning into the head portion of the joystick.