rtl2832-entropyd
Use an rtl2832 USB dongle to generate random data for the linux kernel
... already has a module to use the rtl2832 for its intended purpose, listening to radio, so if you want to use it to generate entropy, you will have to blacklist that module, so it doesn't load. If it is loaded, this program will not be able to acquire the rtl2832 device, and won't run. Create the file /etc/modprobe.d/blacklist-dvb_usb_rtl28xxu.conf with the line blacklist dvb_usb_rtl28xxu in it.
The project website is an html version of the man page, so you can find more complete information there.