Yes, HFM is a supported source for OBIEE (OBIEE 11g only, on 10 it wasn't supported).
OBIEE will use the ADM driver to get metadata structure of HFM, have a look at some additional settings required: http://docs.oracle.com/cd/E28280_01/bi.1111/e10540/datasource.htm#BIEMG1366
There is also a tutorial with step-by-step how to use it: Creating Financial Management Dashboards in Oracle BI Enterprise Edition 11g
"smartview report as data source as Excel type" : do you mean using an Excel as data source for OBIEE and the Excel is populated / refreshed using SmartView ?
Well ... yes... but ...
The Excel need to have the data in the file itself, it will not run a smartview refresh / retrieve when OBIEE need to get the data, so in the end it's just a static Excel and somebody need to refresh the Excel when required.
Very useful. Thanks Gianni.