  In this paper, we revisit the scenario that an internal gradual magnetic
dissipation takes place within the wind from a newborn millisecond magnetar can
be responsible for gamma-ray burst production. We show that a combination of
two emission components in this model, i.e., the photospheric emission from the
wind and the synchrotron radiation within the magnetic reconnection region, can
give a reasonable fit to the observed spectrum of the prompt emission phase of
GRB 160804A. We obtain the physical parameters through a Monte Carlo procedure
and deduce the initial spin period and magnetic field of the central magnetar.
Furthermore, the independent afterglow fitting analysis gives a consistent
result, adding great credibility to this scenario. In addition, we predict a
subclass of GRBs called bursts from such a Magnetar wind Internal Gradual
MAgnetic Dissipation (abbreviated as "MIGMAD bursts") that have several
distinctive properties.
