Makefile

# ----------------------------------------------------------------------------- 
# Web source:
# http://www.cs.fsu.edu/~baker/devices/lxr/http/source/ldd-examples/misc-modules/Makefile
# ----------------------------------------------------------------------------- 
# To build modules outside of the kernel tree, we run "make"
# in the kernel source tree; the Makefile these then includes this
# Makefile once again.
# This conditional selects whether we are being included from the
# kernel Makefile or not.

# ----------------------------------------------------------------------------- 
# export these for cross compiling
# export ARCH=arm 
# export CROSS_COMPILE=arm-linux-eabi-
# export KERNELDIR=[path to kernel source]
# ----------------------------------------------------------------------------- 

ifeq ($(KERNELRELEASE),)

    # Assume the source tree is where the running kernel was built
    # You should set KERNELDIR in the environment if it's elsewhere
    KERNELDIR ?= /lib/modules/$(shell uname -r)/build
    # The current directory is passed to sub-makes as argument
    PWD := $(shell pwd)

modules:
	$(MAKE) -C $(KERNELDIR) M=$(PWD) modules

modules_install:
	$(MAKE) -C $(KERNELDIR) M=$(PWD) modules_install

clean:
	rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions
	rm -rf modules.order Module.symvers

.PHONY: modules modules_install clean

else
    fpc1020-objs := fpc1020_main.o fpc1020_common.o fpc1020_input.o fpc1020_capture.o fpc1020_regulator.o

    # called from kernel build system: just declare what our modules are
    obj-m := fpc1020.o
endif