You can iterate over functions (or anything else) using
@@ command modifier.
In your case, after you analyze the binary to get functions, you can run:
pdf @@ fcn*
This command will print the disassembly of every function iterating over function's flags starting with fcn. You can use any other wildcard you want.
You might also want to check out
pdr.) command, which prints disassembly recursively across the function graph (form current basic block)