Make now is building out of the box.

Kconfig

@@ -1,13 +1,13 @@
 #
 # MCP2210
 #
-	  
+
 config MCP2210
-	tristate "MCP2210 usb to spi master"
-	depends on HID && SPI
-	help
-	  If you say yes here you get support for the Microchip
-	  MCP2210 usb to spi master.
+        tristate "MCP2210 usb to spi master"
+        depends on HID && SPI
+        help
+          If you say yes here you get support for the Microchip
+          MCP2210 usb to spi master.
 
-	  To compile this driver as a module, choose M here: the
-	  module will be called mcp2210.
+          To compile this driver as a module, choose M here: the
+          module will be called mcp2210.

Makefile

@@ -2,6 +2,35 @@
 # Makefile for mcp2210
 #
 
-mcp2210-objs := mcp2210-core.o mcp2210-spi.o
+EXTRA_CFLAGS += -Werror -Wall
 
-obj-$(CONFIG_MCP2210)		+= mcp2210.o
+# To build modules outside of the kernel tree, we run "make"
+# in the kernel source tree; the Makefile these then includes this
+# Makefile once again.
+# This conditional selects whether we are being included from the
+# kernel Makefile or not.
+ifeq ($(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 *.mod .tmp_versions modules.order Module.symvers
+
+.PHONY: modules modules_install clean
+
+else
+	# called from kernel build system: just declare what our modules are
+	CONFIG_MCP2210 ?= m
+	mcp2210-objs := mcp2210-core.o mcp2210-spi.o
+
+	obj-$(CONFIG_MCP2210) += mcp2210.o
+endif