USB: driver for mcs7830 (aka DeLOCK) USB ethernet adapter

This driver adds support for the DeLOCK USB ethernet adapter
and potentially others based on the MosChip MCS7830 chip.

It is based on the usbnet and asix drivers as well as the
original device driver provided by MosChip, which in turn
was based on the usbnet driver.

It has been tested successfully on an OHCI, but interestingly
there seems to be a problem with the mcs7830 when connected to
the ICH6/EHCI in my thinkpad: it keeps receiving lots of
broken packets in the RX interrupt. The problem goes away when
I'm using an active USB hub, so I assume it's not related to
the device driver, but rather to the hardware.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/net/Kconfig

@@ -207,6 +207,14 @@ config USB_NET_PLUSB
 	  Choose this option if you're using a host-to-host cable
 	  with one of these chips.
 
+config USB_NET_MCS7830
+	tristate "MosChip MCS7830 based Ethernet adapters"
+	depends on USB_USBNET
+	help
+	  Choose this option if you're using a 10/100 Ethernet USB2
+	  adapter based on the MosChip 7830 controller. This includes
+	  adapters marketed under the DeLOCK brand.
+
 config USB_NET_RNDIS_HOST
 	tristate "Host for RNDIS devices (EXPERIMENTAL)"
 	depends on USB_USBNET && EXPERIMENTAL

drivers/usb/net/Makefile

@@ -14,6 +14,7 @@ obj-$(CONFIG_USB_NET_PLUSB)	+= plusb.o
 obj-$(CONFIG_USB_NET_RNDIS_HOST)	+= rndis_host.o
 obj-$(CONFIG_USB_NET_CDC_SUBSET)	+= cdc_subset.o
 obj-$(CONFIG_USB_NET_ZAURUS)	+= zaurus.o
+obj-$(CONFIG_USB_NET_MCS7830)	+= mcs7830.o
 obj-$(CONFIG_USB_USBNET)	+= usbnet.o
 
 ifeq ($(CONFIG_USB_DEBUG),y)