A camshaft phaser, including: a stator arranged to receive torque; a rotor arranged to be non-rotatably connected to a camshaft; first and second wedge plates radially disposed between the rotor and the stator; and a displacement assembly arranged to for an advance mode, displace the first wedge plate in a first axial direction so that the rotor is rotatable with respect to the stator in a first circumferential direction. For a retard mode, the displacement assembly is arranged to displace the second wedge plate in a second axial direction, opposite first axial direction, so that the rotor is rotatable with respect to the stator in a second circumferential direction, opposite the first circumferential direction.