  We obtain observational constraints on Randall--Sundrum type II braneworld
inflation using a compilation of data including WMAP, the 2dF and latest SDSS
galaxy redshift surveys. We place constraints on three classes of inflation
models (large-field, small-field and hybrid models) in the high-energy regime,
which exhibit different behaviour compared to the low-energy case. The quartic
potential is outside the $2\sigma$ observational contour bound for a number of
$e$-folds less than 60, and steep inflation driven by an exponential potential
is excluded because of its high tensor-to-scalar ratio. It is more difficult to
strongly constrain small-field and hybrid models due to additional freedoms
associated with the potentials, but we obtain upper bounds for the energy scale
of inflation and the model parameters in certain cases. We also discuss
possible ways to break the degeneracy of consistency relations and inflationary
observables.
