The driver source does not do anything more than push raw chunks of data to/from the chipset. Apparently, the data is in "MEIF" format - a proprietary Nokia protocol. It doesn't seem the driver is particularly interesting or helpful in doing something useful with the BCM4751.
www spinics net lists linux-i2c msg03690.html
No details of the format are provided, only a document relating to licensing information from Nokia.
www forum nokia com info sw.nokia.com id b265d3aa-8198-4eb0-a0e3-077748ccea40 MEIF_Specification_License.pdf.html
The following talks a bit about MEIF, or the ME interface, describing it is "a de facto standard for GPS/GNSS chip manufacturers." Several related names seem to be "MEIF", "ME interface", and "ME-PE".
books google com books?id=stTSHdFhrFUC&pg=PA280&lpg=PA280&dq=meif+a gps&source=bl&ots=z6QfZFkbPl&sig=pAsP8i1RWIhtF1Yeb n3t1JApc4U&hl=en&ei=q8GcTK-BKcGB8gb67ZWVDw&sa=X&oi=book_result&ct=result&resn um=2&ved=0CBMQ6AEwAQ#v=onepage&q&f=false
It seems a common enough format in the industry, but no specifications were immediately forthcoming. Perhaps the Nexus has a more complete open source tree and includes something relating to MEIF?