  One of the most direct preparations of a Gottesman-Kitaev-Preskill qubit in
an oscillator uses a tunable photon-pressure (also called optomechanical)
coupling of the form $g \hat{q} a^{\dagger} a$, enabling to imprint the modular
value of the position $\hat{q}$ of one oscillator onto the state of an ancilla
oscillator. We analyze the practical feasibility of executing such modular
quadrature measurements in a parametric circuit-QED realization of this
coupling. We provide estimates for the expected GKP squeezing induced by the
protocol and discuss the effect of photon loss and other errors on the
resulting squeezing.
