FMC (FPGA Mezzanine Carrier) is a mechanical and electrical
standard for mezzanine cards that plug into a carrier board.
This kernel subsystem supports the matching between carrier
and mezzanine based on identifiers stored in the internal I2C
EEPROM, as well as having carrier-independent drivers.

The framework was born outside of the kernel and at this time
the off-tree code base is more complete. Code and documentation
is at git://ohwr.org/fmc-projects/fmc-bus.git .

source code:

drivers/fmc/