drivers/thunderbolt/Makefile - linux - Git at Google

 obj-${CONFIG_THUNDERBOLT} := thunderbolt.o
 thunderbolt-objs := nhi.o ctl.o tb.o switch.o cap.o path.o tunnel_pci.o eeprom.o
 thunderbolt-objs += domain.o dma_port.o icm.o property.o xdomain.o
	obj-${CONFIG_THUNDERBOLT} := thunderbolt.o
	thunderbolt-objs := nhi.o ctl.o tb.o switch.o cap.o path.o tunnel_pci.o eeprom.o
	thunderbolt-objs += domain.o dma_port.o icm.o property.o xdomain.o