/*
* USB Networking Links
* Copyright (C) 2000-2005 by David Brownell
* Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
*
* 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
*/
/*
* This is a generic "USB networking" framework that works with several
* kinds of full and high speed networking devices:
*
* + USB host-to-host "network cables", used for IP-over-USB links.
* These are often used for Laplink style connectivity products.
* - AnchorChip 2720
* - Belkin, eTEK (interops with Win32 drivers)
* - GeneSys GL620USB-A
* - NetChip 1080 (interoperates with NetChip Win32 drivers)
* - Prolific PL-2301/2302 (replaces "plusb" driver)
* - KC Technology KC2190
*
* + Smart USB devices can support such links directly, using Internet
* standard protocols instead of proprietary host-to-device links.
* - Linux PDAs like iPaq, Yopy, and Zaurus
* - The BLOB boot loader (for diskless booting)
* - Linux "gadgets", perhaps using PXA-2xx or Net2280 controllers
* - Devices using EPSON's sample USB firmware
* - CDC-Ethernet class devices, such as many cable modems
*
* + Adapters to networks such as Ethernet.
* - AX8817X based USB 2.0 products
*
* Links to these devices can be bridged using Linux Ethernet bridging.
* With minor exceptions, these all use similar USB framing for network
* traffic, but need different protocols for control traffic.
*
* USB devices can implement their side of this protocol at the cost
* of two bulk endpoints; it's not restricted to "cable" applications.
* See the SA1110, Zaurus, or EPSON device/client support in this driver;
* slave/target drivers such as "usb-eth" (on most SA-1100 PDAs) or
* "g_ether" (in the Linux "gadget" framework) implement that behavior
* within devices.
*
*
* CHANGELOG:
*
* 13-sep-2000 experimental, new
* 10-oct-2000 usb_device_id table created.
* 28-oct-2000 misc fixes; mostly, discard more TTL-mangled rx packets.
* 01-nov-2000 usb_device_id table and probing api update by
* Adam J. Richter <adam@yggdrasil.com>.
* 18-dec-2000 (db) tx watchdog, "net1080" renaming to "usbnet", device_info
* and prolific support, isolate net1080-specific bits, cleanup.
* fix unlink_urbs oops in D3 PM resume code path.
*
* 02-feb-2001 (db) fix tx skb sharing, packet length, match_flags, ...
* 08-feb-2001 stubbed in "linuxdev", maybe the SA-1100 folk can use it;
* AnchorChips 2720 support (from spec) for testing;
* fix bit-ordering problem with ethernet multicast addr
* 19-feb-2001 Support for clearing halt conditions. SA1100 UDC support
* updates. Oleg Drokin (green@iXcelerator.com)
* 25-mar-2001 More SA-1100 updates, including workaround for ip problem
* expecting cleared skb->cb and framing change to match latest
* handhelds.org version (Oleg). Enable device IDs from the
* Win32 Belkin driver; other cleanups (db).
* 16-jul-2001 Bugfixes for uhci oops-on-unplug, Belkin support, various
* cleanups for problems not yet seen in the field. (db)
* 17-oct-2001 Handle "Advance USBNET" product, like Belkin/eTEK devices,
* from Ioannis Mavroukakis <i.mavroukakis@btinternet.com>;
* rx unlinks somehow weren't async; minor cleanup.
* 03-nov-2001 Merged GeneSys driver; original code from Jiun-Jie Huang
* <huangjj@genesyslogic.com.tw>, updated by Stanislav Brabec
* <utx@penguin.cz>. Made framing options (NetChip/GeneSys)
* tie mostly to (sub)driver info. Workaround some PL-2302
* chips that seem to reject SET_INTERFACE requests.
*
* 06-apr-2002 Added ethtool support, based on a patch from Brad Hards.
* Level of diagnostics is more configurable; they use device
* location (usb_device->devpath) instead of address (2.5).
* For tx_fixup, memflags can't be NOIO.
* 07-may-2002 Generalize/cleanup keventd support, handling rx stalls (mostly
* for USB 2.0 TTs) and memory shortages (potential) too. (db)
* Use "locally assigned" IEEE802 address space. (Brad Hards)
* 18-oct-2002 Support for Zaurus (Pavel Machek), related cleanup (db).
* 14-dec-2002 Remove Zaurus-private crc32 code (Pavel); 2.5 oops fix,
* cleanups and stubbed PXA-250 support (db), fix for framing
* issues on Z, net1080, and gl620a (Toby Milne)
*