Suppose that the driver snd-xyz have several source files. They are located in the new subdirectory, pci/xyz.
	Add a new directory (xyz) in
	alsa-driver/pci/Makefile as below
      
  obj-$(CONFIG_SND) += xyz/
        
	Under the directory xyz, create a Makefile
      
Example 15.1. Sample Makefile for a driver xyz
  ifndef SND_TOPDIR
  SND_TOPDIR=../..
  endif
  include $(SND_TOPDIR)/toplevel.config
  include $(SND_TOPDIR)/Makefile.conf
  snd-xyz-objs := xyz.o abc.o def.o
  obj-$(CONFIG_SND_XYZ) += snd-xyz.o
  include $(SND_TOPDIR)/Rules.make
        
	
Create the Kconfig entry
This procedure is as same as in the last section.
Run cvscompile script to re-generate the configure script and build the whole stuff again.