The problem of regulating a time-varying or uncertain discrete-time linear system with state and control constraints to the origin is addressed. Based on an interpolation technique, and by minimizing an appropriate objective function, one can archive feasibility and a robustly asymptotically stable closed-loop behavior. Moreover, we show that the control is a piecewise affine and continuous function of the state. The relation to Model Predictive Control is discussed. Several simulation examples demonstrate the performance.