spi device from handle

kernel 2.6.33

relevant section of dts has:
spi@7000 {
 	fpga0: fpga@0 {
 		#address-cells = <1>;
 		#size-cells = <0>;
 		compatible = "fsl, espi-fpga";
 		reg = <0>;
 		linux,modalias = "spidev";
 		spi-max-frequency = <1572864>;
 	};
}


I have another device driver that needs to talk to this fpga device, but 
for the life of me I can't figure out the appropriate hooks to get there. 
The device can be talked to from userland via /dev/spixyx.k, but how do I 
get to the device from another driver?

Any little hints would be appreciated.  Upgrading kernel is not an option 
(sorry).

thanks

mike