[knc1]

A rather limited selection of USB serial, but its there:
Ref: https://www.kernel.org/pub/linux/ker...2.4.37.tar.bz2

#
# Makefile for the USB serial device drivers.
#

O_TARGET    := usb-serial.o

# Object file lists.

obj-$(CONFIG_USB_SERIAL)                        += usbserial.o
obj-$(CONFIG_USB_SERIAL_VISOR)            += visor.o
obj-$(CONFIG_USB_SERIAL_IPAQ)            += ipaq.o
obj-$(CONFIG_USB_SERIAL_WHITEHEAT)        += whiteheat.o
obj-$(CONFIG_USB_SERIAL_FTDI_SIO)        += ftdi_sio.o
obj-$(CONFIG_USB_SERIAL_KEYSPAN_PDA)        += keyspan_pda.o
obj-$(CONFIG_USB_SERIAL_XIRCOM)            += keyspan_pda.o
obj-$(CONFIG_USB_SERIAL_KEYSPAN)        += keyspan.o
obj-$(CONFIG_USB_SERIAL_OMNINET)        += omninet.o
obj-$(CONFIG_USB_SERIAL_DIGI_ACCELEPORT)    += digi_acceleport.o
obj-$(CONFIG_USB_SERIAL_BELKIN)            += belkin_sa.o
obj-$(CONFIG_USB_SERIAL_EMPEG)            += empeg.o
obj-$(CONFIG_USB_SERIAL_MCT_U232)        += mct_u232.o
obj-$(CONFIG_USB_SERIAL_EDGEPORT)        += io_edgeport.o
obj-$(CONFIG_USB_SERIAL_EDGEPORT_TI)        += io_ti.o
obj-$(CONFIG_USB_SERIAL_PL2303)            += pl2303.o
obj-$(CONFIG_USB_SERIAL_CYBERJACK)        += cyberjack.o
obj-$(CONFIG_USB_SERIAL_IR)            += ir-usb.o
obj-$(CONFIG_USB_SERIAL_KLSI)            += kl5kusb105.o
obj-$(CONFIG_USB_SERIAL_KOBIL_SCT)        += kobil_sct.o

# Objects that export symbols.
export-objs    := usbserial.o

include $(TOPDIR)/Rules.make