I will use the ISP1761 in a project. Some Sourcecode is available from Sourceforge. The code supports their evaluation board which has a PCI interface. In my case I cannot use this code directly because I will connect the chip directly to the Nios without PCI. I have no HW yet, so it will take some time for me to start the driver.
I found following on Nios Wiki
http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/smile.gif
Read in the nios wiki (
http://nioswiki.jot.com/wikihome/operatingsystems/%c2%b5clinux/usbhost) about USBhost,
At the bottom there is a link provided for the ISP1761,
I had no time to evaluate this yet, but it seems that it is the diff to the PCI sources.
isp 1761 (
http://dagobah.ucc.asn.au/isp1761/)