  For a crystalline p-adic representation of the absolute Galois group of Qp,
we define a family of Coleman maps (linear maps from the Iwasawa cohomology of
the representation to the Iwasawa algebra), using the theory of Wach modules.
Let f = sum(a_n q^n) be a normalized new modular eigenform and p an odd prime
at which f is either good ordinary or supersingular. By applying our theory to
the p-adic representation associated to f, we define two Coleman maps with
values in the Iwasawa algebra of Zp^* (after extending scalars to some
extension of Qp). Applying these maps to the Kato zeta elements gives a
decomposition of the (generally unbounded) p-adic L-functions of f into linear
combinations of two power series of bounded coefficients, generalizing works of
Pollack (in the case a_p=0) and Sprung (when f corresponds to a supersingular
elliptic curve). Using ideas of Kobayashi for elliptic curves which are
supersingular at p, we associate to each of these power series a cotorsion
Selmer group. This allows us to formulate a "main conjecture". Under some
technical conditions, we prove one inclusion of the "main conjecture" and show
that the reverse inclusion is equivalent to Kato's main conjecture.
