Subject: USB: usbnet (2/9) module for simple network links

From: David Brownell <[email-masked]>
Date: Wed, 31 Aug 2005 09:52:45 -0700

This patch creates the first of several separate "minidriver" modules
for "usbnet".  This one handles only the very simplest hardware, which
can be handled almost entirely by the "usbnet" core.

    - Move device-specific bits into new "cdc_subset.c" driver,
      shrinking "usbnet" by a bunch;

    - Export the functions needed to support this minidriver
      (with EXPORT_SYMBOL_GPL);

    - Update Kconfig and kbuild accordingly.

This one handles about a dozen different device types, with the most
notable ones being Gumstix and most Linux-based PDAs (except Zaurus
running that ancient code from Sharp).

Signed-off-by: David Brownell <[email-masked]>
Signed-off-by: Greg Kroah-Hartman <[email-masked]>

---
 drivers/usb/net/Kconfig      |  123 ++++++++-------
 drivers/usb/net/Makefile     |    1 
 drivers/usb/net/cdc_subset.c |  335 +++++++++++++++++++++++++++++++++++++++++++
 drivers/usb/net/usbnet.c     |  240 +-----------------------------
 drivers/usb/net/usbnet.h     |   15 +
 5 files changed, 429 insertions(+), 285 deletions(-)

--- gregkh-2.6.orig/drivers/usb/net/Makefile	2005-09-08 14:08:20.000000000 -0700
+++ gregkh-2.6/drivers/usb/net/Makefile	2005-09-08 14:08:37.000000000 -0700
@@ -6,5 +6,6 @@ obj-$(CONFIG_USB_CATC)		+= catc.o
 obj-$(CONFIG_USB_KAWETH)	+= kaweth.o
 obj-$(CONFIG_USB_PEGASUS)	+= pegasus.o
 obj-$(CONFIG_USB_RTL8150)	+= rtl8150.o
+obj-$(CONFIG_USB_NET_CDC_SUBSET)	+= cdc_subset.o
 obj-$(CONFIG_USB_USBNET)	+= usbnet.o
 obj-$(CONFIG_USB_ZD1201)	+= zd1201.o
--- gregkh-2.6.orig/drivers/usb/net/Kconfig	2005-09-08 14:08:36.000000000 -0700
+++ gregkh-2.6/drivers/usb/net/Kconfig	2005-09-08 14:08:37.000000000 -0700
@@ -128,32 +128,6 @@ config USB_USBNET
 comment "USB Host-to-Host Cables"
 	depends on USB_USBNET
 
-config USB_ALI_M5632
-	boolean "ALi M5632 based 'USB 2.0 Data Link' cables"
-	depends on USB_USBNET
-	default y
-	help
-	  Choose this option if you're using a host-to-host cable
-	  based on this design, which supports USB 2.0 high speed.
-
-config USB_AN2720
-	boolean "AnchorChips 2720 based cables (Xircom PGUNET, ...)"
-	depends on USB_USBNET
-	default y
-	help
-	  Choose this option if you're using a host-to-host cable
-	  based on this design.  Note that AnchorChips is now a
-	  Cypress brand.
-
-config USB_BELKIN
-	boolean "eTEK based host-to-host cables (Advance, Belkin, ...)"
-	depends on USB_USBNET
-	default y
-	help
-	  Choose this option if you're using a host-to-host cable
-	  based on this design:  two NetChip 2890 chips and an Atmel
-	  microcontroller, with LEDs that indicate traffic.
-
 config USB_GENESYS
 	boolean "GeneSys GL620USB-A based cables"
 	default y
@@ -182,42 +156,9 @@ config USB_PL2301
 	  Choose this option if you're using a host-to-host cable
 	  with one of these chips.
 
-config USB_KC2190
-	boolean "KT Technology KC2190 based cables (InstaNet)"
-	default y
-	depends on USB_USBNET && EXPERIMENTAL
-	help
-	  Choose this option if you're using a host-to-host cable
-	  with one of these chips.
-
 comment "Intelligent USB Devices/Gadgets"
 	depends on USB_USBNET
 
-config USB_ARMLINUX
-	boolean "Embedded ARM Linux links (iPaq, ...)"
-	depends on USB_USBNET
-	default y
-	help
-	  Choose this option to support the "usb-eth" networking driver
-	  used by most of the ARM Linux community with device controllers
-	  such as the SA-11x0 and PXA-25x UDCs, or the tftp capabilities
-	  in some PXA versions of the "blob" boot loader.
-
-	  Linux-based "Gumstix" PXA-25x based systems use this protocol
-	  to talk with other Linux systems.
-
-	  Although the ROMs shipped with Sharp Zaurus products use a
-	  different link level framing protocol, you can have them use
-	  this simpler protocol by installing a different kernel.
-
-config USB_EPSON2888
-	boolean "Epson 2888 based firmware (DEVELOPMENT)"
-	depends on USB_USBNET
-	default y
-	help
-	  Choose this option to support the usb networking links used
-	  by some sample firmware from Epson.
-
 config USB_ZAURUS
 	boolean "Sharp Zaurus (stock ROMs) and compatible"
 	depends on USB_USBNET
@@ -292,6 +233,70 @@ config USB_AX8817X
 	  This driver creates an interface named "ethX", where X depends on
 	  what other networking devices you have in use.  
 
+
+config USB_NET_CDC_SUBSET
+	tristate "Simple USB Network Links (CDC Ethernet subset)"
+	depends on USB_USBNET
+	help
+	  This driver module supports USB network devices that can work
+	  without any device-specific information.  Select it if you have
+	  one of these drivers.
+
+	  Note that while many USB host-to-host cables can work in this mode,
+	  that may mean not being able to talk to Win32 systems or more
+	  commonly not being able to handle certain events (like replugging
+	  the host on the other end) very well.  Also, these devices will
+	  not generally have permanently assigned Ethernet addresses.
+
+config USB_ALI_M5632
+	boolean "ALi M5632 based 'USB 2.0 Data Link' cables"
+	depends on USB_NET_CDC_SUBSET
+	help
+	  Choose this option if you're using a host-to-host cable
+	  based on this design, which supports USB 2.0 high speed.
+
+config USB_AN2720
+	boolean "AnchorChips 2720 based cables (Xircom PGUNET, ...)"
+	depends on USB_NET_CDC_SUBSET
+	help
+	  Choose this option if you're using a host-to-host cable
+	  based on this design.  Note that AnchorChips is now a
+	  Cypress brand.
+
+config USB_BELKIN
+	boolean "eTEK based host-to-host cables (Advance, Belkin, ...)"
+	depends on USB_NET_CDC_SUBSET
+	default y
+	help
+	  Choose this option if you're using a host-to-host cable
+	  based on this design:  two NetChip 2890 chips and an Atmel
+	  microcontroller, with LEDs that indicate traffic.
+
+config USB_ARMLINUX
+	boolean "Embedded ARM Linux links (iPaq, ...)"
+	depends on USB_NET_CDC_SUBSET
+	default y
+	help
+	  Choose this option to support the "usb-eth" networking driver
+	  used by most of the ARM Linux community with device controllers
+	  such as the SA-11x0 and PXA-25x UDCs, or the tftp capabilities
+	  in some PXA versions of the "blob" boot loader.
+
+	  Linux-based "Gumstix" PXA-25x based systems use this protocol
+	  to talk with other Linux systems.
+
+	  Although the ROMs shipped with Sharp Zaurus products use a
+	  different link level framing protocol, you can have them use
+	  this simpler protocol by installing a different kernel.
+
+config USB_EPSON2888
+	boolean "Epson 2888 based firmware (DEVELOPMENT)"
+	depends on USB_NET_CDC_SUBSET
+	help
+	  Choose this option to support the usb networking links used
+	  by some sample firmware from Epson.
+
+
 config USB_ZD1201
 	tristate "USB ZD1201 based Wireless device support"
 	depends on NET_RADIO
--- gregkh-2.6.orig/drivers/usb/net/usbnet.h	2005-09-08 14:08:36.000000000 -0700
+++ gregkh-2.6/drivers/usb/net/usbnet.h	2005-09-08 14:08:37.000000000 -0700
@@ -24,7 +24,7 @@
 #define	__USBNET_H

-/* interface from usbnet core to each USB networking device we handle */
+/* interface from usbnet core to each USB networking link we handle */
 struct usbnet {
 	/* housekeeping */
 	struct usb_device	*udev;
@@ -62,6 +62,10 @@ struct usbnet {
 #		define EVENT_LINK_RESET	4
 };
 
+static inline struct usb_driver *driver_of(struct usb_interface *intf)
+{
+	return to_usb_driver(intf->dev.driver);
+}
 
 /* interface from the device/framing level "minidriver" to core */
 struct driver_info {
@@ -111,6 +115,15 @@ struct driver_info {
 	unsigned long	data;		/* Misc driver specific data */
 };
 
+/* Minidrivers are just drivers using the "usbnet" core as a powerful
+ * network-specific subroutine library ... that happens to do pretty
+ * much everything except custom framing and chip-specific stuff.
+ */
+extern int usbnet_probe(struct usb_interface *, const struct usb_device_id *);
+extern int usbnet_suspend (struct usb_interface *, pm_message_t );
+extern int usbnet_resume (struct usb_interface *);
+extern void usbnet_disconnect(struct usb_interface *);
+
 
 /* we record the state for each of our queued skbs */
 enum skb_state {
--- gregkh-2.6.orig/drivers/usb/net/usbnet.c	2005-09-08 14:08:36.000000000 -0700
+++ gregkh-2.6/drivers/usb/net/usbnet.c	2005-09-08 14:08:37.000000000 -0700
@@ -322,48 +322,6 @@ static void skb_return (struct usbnet *d
 }
 
 
-#ifdef	CONFIG_USB_ALI_M5632
-#define	HAVE_HARDWARE
-
-/*-------------------------------------------------------------------------
- *
- * ALi M5632 driver ... does high speed
- *
- *-------------------------------------------------------------------------*/
-
-static const struct driver_info	ali_m5632_info = {
-	.description =	"ALi M5632",
-};
-
-
-#endif
-
-
-#ifdef	CONFIG_USB_AN2720
-#define	HAVE_HARDWARE
-
-/*-------------------------------------------------------------------------
- *
- * AnchorChips 2720 driver ... http://www.cypress.com
- *
- * This doesn't seem to have a way to detect whether the peer is
- * connected, or need any reset handshaking.  It's got pretty big
- * internal buffers (handles most of a frame's worth of data).
- * Chip data sheets don't describe any vendor control messages.
- *
- *-------------------------------------------------------------------------*/
-
-static const struct driver_info	an2720_info = {
-	.description =	"AnchorChips/Cypress 2720",
-	// no reset available!
-	// no check_connect available!
-
-	.in = 2, .out = 2,		// direction distinguishes these
-};
-
-#endif	/* CONFIG_USB_AN2720 */
-
-
 #ifdef CONFIG_USB_AX8817X
 /* ASIX AX8817X based USB 2.0 Ethernet Devices */
 
@@ -1142,25 +1100,6 @@ static const struct driver_info ax88772_

 
-#ifdef	CONFIG_USB_BELKIN
-#define	HAVE_HARDWARE
-
-/*-------------------------------------------------------------------------
- *
- * Belkin F5U104 ... two NetChip 2280 devices + Atmel microcontroller
- *
- * ... also two eTEK designs, including one sold as "Advance USBNET"
- *
- *-------------------------------------------------------------------------*/
-
-static const struct driver_info	belkin_info = {
-	.description =	"Belkin, eTEK, or compatible",
-};
-
-#endif	/* CONFIG_USB_BELKIN */
-
-
-
 /*-------------------------------------------------------------------------
  *
  * Communications Device Class declarations.
@@ -1538,32 +1477,6 @@ static const struct driver_info	cdc_info

 
-#ifdef	CONFIG_USB_EPSON2888
-#define	HAVE_HARDWARE
-
-/*-------------------------------------------------------------------------
- *
- * EPSON USB clients
- *
- * This is the same idea as Linux PDAs (below) except the firmware in the
- * device might not be Tux-powered.  Epson provides reference firmware that
- * implements this interface.  Product developers can reuse or modify that
- * code, such as by using their own product and vendor codes.
- *
- * Support was from Juro Bystricky <[email-masked]>
- *
- *-------------------------------------------------------------------------*/
-
-static const struct driver_info	epson2888_info = {
-	.description =	"Epson USB Device",
-	.check_connect = always_connected,
-
-	.in = 4, .out = 3,
-};
-
-#endif	/* CONFIG_USB_EPSON2888 */
-
-
 #ifdef CONFIG_USB_GENESYS
 #define	HAVE_HARDWARE
 
@@ -2495,52 +2408,6 @@ static const struct driver_info	prolific
 #endif /* CONFIG_USB_PL2301 */
 
 
-#ifdef CONFIG_USB_KC2190
-#define HAVE_HARDWARE
-static const struct driver_info kc2190_info = {
-	.description =  "KC Technology KC-190",
-};
-#endif /* CONFIG_USB_KC2190 */
-
-
-#ifdef	CONFIG_USB_ARMLINUX
-#define	HAVE_HARDWARE
-
-/*-------------------------------------------------------------------------
- *
- * Intel's SA-1100 chip integrates basic USB support, and is used
- * in PDAs like some iPaqs, the Yopy, some Zaurus models, and more.
- * When they run Linux, arch/arm/mach-sa1100/usb-eth.c may be used to
- * network using minimal USB framing data.
- *
- * This describes the driver currently in standard ARM Linux kernels.
- * The Zaurus uses a different driver (see later).
- *
- * PXA25x and PXA210 use XScale cores (ARM v5TE) with better USB support
- * and different USB endpoint numbering than the SA1100 devices.  The
- * mach-pxa/usb-eth.c driver re-uses the device ids from mach-sa1100
- * so we rely on the endpoint descriptors.
- *
- *-------------------------------------------------------------------------*/
-
-static const struct driver_info	linuxdev_info = {
-	.description =	"Linux Device",
-	.check_connect = always_connected,
-};
-
-static const struct driver_info	yopy_info = {
-	.description =	"Yopy",
-	.check_connect = always_connected,
-};
-
-static const struct driver_info	blob_info = {
-	.description =	"Boot Loader OBject",
-	.check_connect = always_connected,
-};
-
-#endif	/* CONFIG_USB_ARMLINUX */
-
-
 #ifdef CONFIG_USB_ZAURUS
 #define	HAVE_HARDWARE
 
@@ -3575,7 +3442,7 @@ static void usbnet_bh (unsigned long par
  
 // precondition: never called in_interrupt
 
-static void usbnet_disconnect (struct usb_interface *intf)
+void usbnet_disconnect (struct usb_interface *intf)
 {
 	struct usbnet		*dev;
 	struct usb_device	*xdev;
@@ -3589,7 +3456,8 @@ static void usbnet_disconnect (struct us
 	xdev = interface_to_usbdev (intf);
 
 	if (netif_msg_probe (dev))
-		devinfo (dev, "unregister usbnet usb-%s-%s, %s",
+		devinfo (dev, "unregister '%s' usb-%s-%s, %s",
+			intf->dev.driver->name,
 			xdev->bus->bus_name, xdev->devpath,
 			dev->driver_info->description);
 	
@@ -3605,6 +3473,7 @@ static void usbnet_disconnect (struct us
 	free_netdev(net);
 	usb_put_dev (xdev);
 }
+EXPORT_SYMBOL_GPL(usbnet_disconnect);

 /*-------------------------------------------------------------------------*/
@@ -3613,7 +3482,7 @@ static struct ethtool_ops usbnet_ethtool
 
 // precondition: never called in_interrupt
 
-static int
+int
 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
 {
 	struct usbnet			*dev;
@@ -3719,8 +3588,9 @@ usbnet_probe (struct usb_interface *udev
 	if (status)
 		goto out3;
 	if (netif_msg_probe (dev))
-		devinfo (dev, "register usbnet at usb-%s-%s, %s, "
+		devinfo (dev, "register '%s' at usb-%s-%s, %s, "
 				"%02x:%02x:%02x:%02x:%02x:%02x",
+			udev->dev.driver->name,
 			xdev->bus->bus_name, xdev->devpath,
 			dev->driver_info->description,
 			net->dev_addr [0], net->dev_addr [1],
@@ -3744,12 +3614,15 @@ out:
 	usb_put_dev(xdev);
 	return status;
 }
+EXPORT_SYMBOL_GPL(usbnet_probe);
 
 /*-------------------------------------------------------------------------*/
 
-#ifdef	CONFIG_PM
+/* FIXME these suspend/resume methods assume non-CDC style
+ * devices, with only one interface.
+ */
 
-static int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
+int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
 {
 	struct usbnet		*dev = usb_get_intfdata(intf);
 	
@@ -3762,8 +3635,9 @@ static int usbnet_suspend (struct usb_in
 	intf->dev.power.power_state = PMSG_SUSPEND;
 	return 0;
 }
+EXPORT_SYMBOL_GPL(usbnet_suspend);
 
-static int usbnet_resume (struct usb_interface *intf)
+int usbnet_resume (struct usb_interface *intf)
 {
 	struct usbnet		*dev = usb_get_intfdata(intf);
 
@@ -3772,13 +3646,8 @@ static int usbnet_resume (struct usb_int
 	tasklet_schedule (&dev->bh);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(usbnet_resume);
 
-#else	/* !CONFIG_PM */
-
-#define	usbnet_suspend	NULL
-#define	usbnet_resume	NULL
-
-#endif	/* CONFIG_PM */
 
 /*-------------------------------------------------------------------------*/
 
@@ -3793,36 +3662,6 @@ static int usbnet_resume (struct usb_int
 
 static const struct usb_device_id	products [] = {
 
-#ifdef	CONFIG_USB_ALI_M5632
-{
-	USB_DEVICE (0x0402, 0x5632),	// ALi defaults
-	.driver_info =	(unsigned long) &ali_m5632_info,
-},
-#endif
-
-#ifdef	CONFIG_USB_AN2720
-{
-	USB_DEVICE (0x0547, 0x2720),	// AnchorChips defaults
-	.driver_info =	(unsigned long) &an2720_info,
-}, {
-	USB_DEVICE (0x0547, 0x2727),	// Xircom PGUNET
-	.driver_info =	(unsigned long) &an2720_info,
-},
-#endif
-
-#ifdef	CONFIG_USB_BELKIN
-{
-	USB_DEVICE (0x050d, 0x0004),	// Belkin
-	.driver_info =	(unsigned long) &belkin_info,
-}, {
-	USB_DEVICE (0x056c, 0x8100),	// eTEK
-	.driver_info =	(unsigned long) &belkin_info,
-}, {
-	USB_DEVICE (0x0525, 0x9901),	// Advance USBNET (eTEK)
-	.driver_info =	(unsigned long) &belkin_info,
-},
-#endif
-
 #ifdef CONFIG_USB_AX8817X
 {
 	// Linksys USB200M
@@ -3879,13 +3718,6 @@ static const struct usb_device_id	produc
 },
 #endif
 
-#ifdef	CONFIG_USB_EPSON2888
-{
-	USB_DEVICE (0x0525, 0x2888),	// EPSON USB client
-	.driver_info	= (unsigned long) &epson2888_info,
-},
-#endif
-
 #ifdef	CONFIG_USB_GENESYS
 {
 	USB_DEVICE (0x05e3, 0x0502),	// GL620USB-A
@@ -3916,13 +3748,6 @@ static const struct usb_device_id	produc
 },
 #endif
 
-#ifdef CONFIG_USB_KC2190
-{
-	USB_DEVICE (0x050f, 0x0190),	// KC-190
-	.driver_info =	(unsigned long) &kc2190_info,
-},
-#endif
-
 #ifdef	CONFIG_USB_RNDIS
 {
 	/* RNDIS is MSFT's un-official variant of CDC ACM */
@@ -3931,41 +3756,6 @@ static const struct usb_device_id	produc
 },
 #endif
 
-#ifdef	CONFIG_USB_ARMLINUX
-/*
- * SA-1100 using standard ARM Linux kernels, or compatible.
- * Often used when talking to Linux PDAs (iPaq, Yopy, etc).
- * The sa-1100 "usb-eth" driver handles the basic framing.
- *
- * PXA25x or PXA210 ...  these use a "usb-eth" driver much like
- * the sa1100 one, but hardware uses different endpoint numbers.
- *
- * Or the Linux "Ethernet" gadget on hardware that can't talk
- * CDC Ethernet (e.g., no altsettings), in either of two modes:
- *  - acting just like the old "usb-eth" firmware, though
- *    the implementation is different 
- *  - supporting RNDIS as the first/default configuration for
- *    MS-Windows interop; Linux needs to use the other config
- */
-{
-	// 1183 = 0x049F, both used as hex values?
-	// Compaq "Itsy" vendor/product id
-	USB_DEVICE (0x049F, 0x505A),	// usb-eth, or compatible
-	.driver_info =	(unsigned long) &linuxdev_info,
-}, {
-	USB_DEVICE (0x0E7E, 0x1001),	// G.Mate "Yopy"
-	.driver_info =	(unsigned long) &yopy_info,
-}, {
-	USB_DEVICE (0x8086, 0x07d3),	// "blob" bootloader
-	.driver_info =	(unsigned long) &blob_info,
-}, {
-	// Linux Ethernet/RNDIS gadget on pxa210/25x/26x
-	// e.g. Gumstix, current OpenZaurus, ...
-	USB_DEVICE_VER (0x0525, 0xa4a2, 0x0203, 0x0203),
-	.driver_info =	(unsigned long) &linuxdev_info,
-}, 
-#endif
-
 #if	defined(CONFIG_USB_ZAURUS) || defined(CONFIG_USB_CDCETHER)
 /*
  * SA-1100 based Sharp Zaurus ("collie"), or compatible.
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ gregkh-2.6/drivers/usb/net/cdc_subset.c	2005-09-08 14:08:37.000000000 -0700
@@ -0,0 +1,335 @@
+/*
+ * Simple "CDC Subset" USB Networking Links
+ * Copyright (C) 2000-2005 by David Brownell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/config.h>
+#ifdef	CONFIG_USB_DEBUG
+#   define DEBUG
+#endif
+#include <linux/module.h>
+#include <linux/kmod.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/workqueue.h>
+#include <linux/mii.h>
+#include <linux/usb.h>
+
+#include "usbnet.h"
+
+
+/*
+ * This supports simple USB network links that don't require any special
+ * framing or hardware control operations.  The protocol used here is a
+ * strict subset of CDC Ethernet, with three basic differences reflecting
+ * the goal that almost any hardware should run it:
+ *
+ *  - Minimal runtime control:  one interface, no altsettings, and
+ *    no vendor or class specific control requests.  If a device is
+ *    configured, it is allowed to exchange packets with the host.
+ *    Fancier models would mean not working on some hardware.
+ *
+ *  - Minimal manufacturing control:  no IEEE "Organizationally
+ *    Unique ID" required, or an EEPROMs to store one.  Each host uses
+ *    one random "locally assigned" Ethernet address instead, which can
+ *    of course be overridden using standard tools like "ifconfig".
+ *    (With 2^46 such addresses, same-net collisions are quite rare.)
+ *
+ *  - There is no additional framing data for USB.  Packets are written
+ *    exactly as in CDC Ethernet, starting with an Ethernet header and
+ *    terminated by a short packet.  However, the host will never send a
+ *    zero length packet; some systems can't handle those robustly.
+ *
+ * Anything that can transmit and receive USB bulk packets can implement
+ * this protocol.  That includes both smart peripherals and quite a lot
+ * of "host-to-host" USB cables (which embed two devices back-to-back).
+ *
+ * Note that although Linux may use many of those host-to-host links
+ * with this "cdc_subset" framing, that doesn't mean there may not be a
+ * better approach.  Handling the "other end unplugs/replugs" scenario
+ * well tends to require chip-specific vendor requests.  Also, Windows
+ * peers at the other end of host-to-host cables may expect their own
+ * framing to be used rather than this "cdc_subset" model.
+ */
+
+#if defined(CONFIG_USB_EPSON2888) || defined(CONFIG_USB_ARMLINUX)
+/* PDA style devices are always connected if present */
+static int always_connected (struct usbnet *dev)
+{
+	return 0;
+}
+#endif
+
+#ifdef	CONFIG_USB_ALI_M5632
+#define	HAVE_HARDWARE
+
+/*-------------------------------------------------------------------------
+ *
+ * ALi M5632 driver ... does high speed
+ *
+ *-------------------------------------------------------------------------*/
+
+static const struct driver_info	ali_m5632_info = {
+	.description =	"ALi M5632",
+};
+
+
+#endif
+
+
+#ifdef	CONFIG_USB_AN2720
+#define	HAVE_HARDWARE
+
+/*-------------------------------------------------------------------------
+ *
+ * AnchorChips 2720 driver ... http://www.cypress.com
+ *
+ * This doesn't seem to have a way to detect whether the peer is
+ * connected, or need any reset handshaking.  It's got pretty big
+ * internal buffers (handles most of a frame's worth of data).
+ * Chip data sheets don't describe any vendor control messages.
+ *
+ *-------------------------------------------------------------------------*/
+
+static const struct driver_info	an2720_info = {
+	.description =	"AnchorChips/Cypress 2720",
+	// no reset available!
+	// no check_connect available!
+
+	.in = 2, .out = 2,		// direction distinguishes these
+};
+
+#endif	/* CONFIG_USB_AN2720 */
+
+
+#ifdef	CONFIG_USB_BELKIN
+#define	HAVE_HARDWARE
+
+/*-------------------------------------------------------------------------
+ *
+ * Belkin F5U104 ... two NetChip 2280 devices + Atmel AVR microcontroller
+ *
+ * ... also two eTEK designs, including one sold as "Advance USBNET"
+ *
+ *-------------------------------------------------------------------------*/
+
+static const struct driver_info	belkin_info = {
+	.description =	"Belkin, eTEK, or compatible",
+};
+
+#endif	/* CONFIG_USB_BELKIN */
+
+
+
+#ifdef	CONFIG_USB_EPSON2888
+#define	HAVE_HARDWARE
+
+/*-------------------------------------------------------------------------
+ *
+ * EPSON USB clients
+ *
+ * This is the same idea as Linux PDAs (below) except the firmware in the
+ * device might not be Tux-powered.  Epson provides reference firmware that
+ * implements this interface.  Product developers can reuse or modify that
+ * code, such as by using their own product and vendor codes.
+ *
+ * Support was from Juro Bystricky <[email-masked]>
+ *
+ *-------------------------------------------------------------------------*/
+
+static const struct driver_info	epson2888_info = {
+	.description =	"Epson USB Device",
+	.check_connect = always_connected,
+
+	.in = 4, .out = 3,
+};
+
+#endif	/* CONFIG_USB_EPSON2888 */
+
+
+#ifdef CONFIG_USB_KC2190
+#define HAVE_HARDWARE
+static const struct driver_info kc2190_info = {
+	.description =  "KC Technology KC-190",
+};
+#endif /* CONFIG_USB_KC2190 */
+
+
+#ifdef	CONFIG_USB_ARMLINUX
+#define	HAVE_HARDWARE
+
+/*-------------------------------------------------------------------------
+ *
+ * Intel's SA-1100 chip integrates basic USB support, and is used
+ * in PDAs like some iPaqs, the Yopy, some Zaurus models, and more.
+ * When they run Linux, arch/arm/mach-sa1100/usb-eth.c may be used to
+ * network using minimal USB framing data.
+ *
+ * This describes the driver currently in standard ARM Linux kernels.
+ * The Zaurus uses a different driver (see later).
+ *
+ * PXA25x and PXA210 use XScale cores (ARM v5TE) with better USB support
+ * and different USB endpoint numbering than the SA1100 devices.  The
+ * mach-pxa/usb-eth.c driver re-uses the device ids from mach-sa1100
+ * so we rely on the endpoint descriptors.
+ *
+ *-------------------------------------------------------------------------*/
+
+static const struct driver_info	linuxdev_info = {
+	.description =	"Linux Device",
+	.check_connect = always_connected,
+};
+
+static const struct driver_info	yopy_info = {
+	.description =	"Yopy",
+	.check_connect = always_connected,
+};
+
+static const struct driver_info	blob_info = {
+	.description =	"Boot Loader OBject",
+	.check_connect = always_connected,
+};
+
+#endif	/* CONFIG_USB_ARMLINUX */
+
+
+/*-------------------------------------------------------------------------*/
+
+#ifndef	HAVE_HARDWARE
+#error You need to configure some hardware for this driver
+#endif
+
+/*
+ * chip vendor names won't normally be on the cables, and
+ * may not be on the device.
+ */
+
+static const struct usb_device_id	products [] = {
+
+#ifdef	CONFIG_USB_ALI_M5632
+{
+	USB_DEVICE (0x0402, 0x5632),	// ALi defaults
+	.driver_info =	(unsigned long) &ali_m5632_info,
+},
+#endif
+
+#ifdef	CONFIG_USB_AN2720
+{
+	USB_DEVICE (0x0547, 0x2720),	// AnchorChips defaults
+	.driver_info =	(unsigned long) &an2720_info,
+}, {
+	USB_DEVICE (0x0547, 0x2727),	// Xircom PGUNET
+	.driver_info =	(unsigned long) &an2720_info,
+},
+#endif
+
+#ifdef	CONFIG_USB_BELKIN
+{
+	USB_DEVICE (0x050d, 0x0004),	// Belkin
+	.driver_info =	(unsigned long) &belkin_info,
+}, {
+	USB_DEVICE (0x056c, 0x8100),	// eTEK
+	.driver_info =	(unsigned long) &belkin_info,
+}, {
+	USB_DEVICE (0x0525, 0x9901),	// Advance USBNET (eTEK)
+	.driver_info =	(unsigned long) &belkin_info,
+},
+#endif
+
+#ifdef	CONFIG_USB_EPSON2888
+{
+	USB_DEVICE (0x0525, 0x2888),	// EPSON USB client
+	.driver_info	= (unsigned long) &epson2888_info,
+},
+#endif
+
+#ifdef CONFIG_USB_KC2190
+{
+	USB_DEVICE (0x050f, 0x0190),	// KC-190
+	.driver_info =	(unsigned long) &kc2190_info,
+},
+#endif
+
+#ifdef	CONFIG_USB_ARMLINUX
+/*
+ * SA-1100 using standard ARM Linux kernels, or compatible.
+ * Often used when talking to Linux PDAs (iPaq, Yopy, etc).
+ * The sa-1100 "usb-eth" driver handles the basic framing.
+ *
+ * PXA25x or PXA210 ...  these use a "usb-eth" driver much like
+ * the sa1100 one, but hardware uses different endpoint numbers.
+ *
+ * Or the Linux "Ethernet" gadget on hardware that can't talk
+ * CDC Ethernet (e.g., no altsettings), in either of two modes:
+ *  - acting just like the old "usb-eth" firmware, though
+ *    the implementation is different
+ *  - supporting RNDIS as the first/default configuration for
+ *    MS-Windows interop; Linux needs to use the other config
+ */
+{
+	// 1183 = 0x049F, both used as hex values?
+	// Compaq "Itsy" vendor/product id
+	USB_DEVICE (0x049F, 0x505A),	// usb-eth, or compatible
+	.driver_info =	(unsigned long) &linuxdev_info,
+}, {
+	USB_DEVICE (0x0E7E, 0x1001),	// G.Mate "Yopy"
+	.driver_info =	(unsigned long) &yopy_info,
+}, {
+	USB_DEVICE (0x8086, 0x07d3),	// "blob" bootloader
+	.driver_info =	(unsigned long) &blob_info,
+}, {
+	// Linux Ethernet/RNDIS gadget on pxa210/25x/26x, second config
+	// e.g. Gumstix, current OpenZaurus, ...
+	USB_DEVICE_VER (0x0525, 0xa4a2, 0x0203, 0x0203),
+	.driver_info =	(unsigned long) &linuxdev_info,
+},
+#endif
+
+	{ },		// END
+};
+MODULE_DEVICE_TABLE(usb, products);
+
+/*-------------------------------------------------------------------------*/
+
+static struct usb_driver cdc_subset_driver = {
+	.owner =	THIS_MODULE,
+	.name =		"cdc_subset",
+	.probe =	usbnet_probe,
+	.suspend =	usbnet_suspend,
+	.resume =	usbnet_resume,
+	.disconnect =	usbnet_disconnect,
+	.id_table =	products,
+};
+
+static int __init cdc_subset_init(void)
+{
+ 	return usb_register(&cdc_subset_driver);
+}
+module_init(cdc_subset_init);
+
+static void __exit cdc_subset_exit(void)
+{
+ 	usb_deregister(&cdc_subset_driver);
+}
+module_exit(cdc_subset_exit);
+
+MODULE_AUTHOR("David Brownell");
+MODULE_DESCRIPTION("Simple 'CDC Subset' USB networking links");
+MODULE_LICENSE("GPL");