  In the presence of a circularly polarized mid-infrared radiation graphene
develops dynamical band gaps in its quasi-energy band structure and becomes a
Floquet insulator. Here we analyze how topologically protected edge states
arise inside these gaps in the presence of an edge. Our results show that the
gap appearing at $\hbar\Omega/2$, where $\hbar \Omega$ is the photon energy, is
bridged by two chiral edge states whose propagation direction is set by the
direction of the polarization of the radiation field. Therefore, both the
propagation direction and the energy window where the states appear can be
controlled externally. We present both analytical and numerical calculations
that fully characterize these states. This is complemented by simple
topological arguments that account for them and by numerical calculations for
the case of semi-infinite sample, thereby eliminating finite size effects.
