net/usb/cdc_subset.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Simple "CDC Subset" USB Networking Links
0004  * Copyright (C) 2000-2005 by David Brownell
0005  */
0006
0007 #include <linux/module.h>
0008 #include <linux/kmod.h>
0009 #include <linux/netdevice.h>
0010 #include <linux/etherdevice.h>
0011 #include <linux/ethtool.h>
0012 #include <linux/workqueue.h>
0013 #include <linux/mii.h>
0014 #include <linux/usb.h>
0015 #include <linux/usb/usbnet.h>
0016
0017
0018 /*
0019  * This supports simple USB network links that don't require any special
0020  * framing or hardware control operations.  The protocol used here is a
0021  * strict subset of CDC Ethernet, with three basic differences reflecting
0022  * the goal that almost any hardware should run it:
0023  *
0024  *  - Minimal runtime control:  one interface, no altsettings, and
0025  *    no vendor or class specific control requests.  If a device is
0026  *    configured, it is allowed to exchange packets with the host.
0027  *    Fancier models would mean not working on some hardware.
0028  *
0029  *  - Minimal manufacturing control:  no IEEE "Organizationally
0030  *    Unique ID" required, or an EEPROMs to store one.  Each host uses
0031  *    one random "locally assigned" Ethernet address instead, which can
0032  *    of course be overridden using standard tools like "ifconfig".
0033  *    (With 2^46 such addresses, same-net collisions are quite rare.)
0034  *
0035  *  - There is no additional framing data for USB.  Packets are written
0036  *    exactly as in CDC Ethernet, starting with an Ethernet header and
0037  *    terminated by a short packet.  However, the host will never send a
0038  *    zero length packet; some systems can't handle those robustly.
0039  *
0040  * Anything that can transmit and receive USB bulk packets can implement
0041  * this protocol.  That includes both smart peripherals and quite a lot
0042  * of "host-to-host" USB cables (which embed two devices back-to-back).
0043  *
0044  * Note that although Linux may use many of those host-to-host links
0045  * with this "cdc_subset" framing, that doesn't mean there may not be a
0046  * better approach.  Handling the "other end unplugs/replugs" scenario
0047  * well tends to require chip-specific vendor requests.  Also, Windows
0048  * peers at the other end of host-to-host cables may expect their own
0049  * framing to be used rather than this "cdc_subset" model.
0050  */
0051
0052 #if defined(CONFIG_USB_EPSON2888) || defined(CONFIG_USB_ARMLINUX)
0053 /* PDA style devices are always connected if present */
0054 static int always_connected (struct usbnet *dev)
0055 {
0056     return 0;
0057 }
0058 #endif
0059
0060 #ifdef  CONFIG_USB_ALI_M5632
0061 #define HAVE_HARDWARE
0062
0063 /*-------------------------------------------------------------------------
0064  *
0065  * ALi M5632 driver ... does high speed
0066  *
0067  * NOTE that the MS-Windows drivers for this chip use some funky and
0068  * (naturally) undocumented 7-byte prefix to each packet, so this is a
0069  * case where we don't currently interoperate.  Also, once you unplug
0070  * one end of the cable, you need to replug the other end too ... since
0071  * chip docs are unavailable, there's no way to reset the relevant state
0072  * short of a power cycle.
0073  *
0074  *-------------------------------------------------------------------------*/
0075
0076 static void m5632_recover(struct usbnet *dev)
0077 {
0078     struct usb_device   *udev = dev->udev;
0079     struct usb_interface    *intf = dev->intf;
0080     int r;
0081
0082     r = usb_lock_device_for_reset(udev, intf);
0083     if (r < 0)
0084         return;
0085
0086     usb_reset_device(udev);
0087     usb_unlock_device(udev);
0088 }
0089
0090 static const struct driver_info ali_m5632_info = {
0091     .description =  "ALi M5632",
0092     .flags       = FLAG_POINTTOPOINT,
0093     .recover     = m5632_recover,
0094 };
0095
0096 #endif
0097
0098 #ifdef  CONFIG_USB_AN2720
0099 #define HAVE_HARDWARE
0100
0101 /*-------------------------------------------------------------------------
0102  *
0103  * AnchorChips 2720 driver ... http://www.cypress.com
0104  *
0105  * This doesn't seem to have a way to detect whether the peer is
0106  * connected, or need any reset handshaking.  It's got pretty big
0107  * internal buffers (handles most of a frame's worth of data).
0108  * Chip data sheets don't describe any vendor control messages.
0109  *
0110  *-------------------------------------------------------------------------*/
0111
0112 static const struct driver_info an2720_info = {
0113     .description =  "AnchorChips/Cypress 2720",
0114     .flags       = FLAG_POINTTOPOINT,
0115     // no reset available!
0116     // no check_connect available!
0117
0118     .in = 2, .out = 2,      // direction distinguishes these
0119 };
0120
0121 #endif  /* CONFIG_USB_AN2720 */
0122
0123
0124 #ifdef  CONFIG_USB_BELKIN
0125 #define HAVE_HARDWARE
0126
0127 /*-------------------------------------------------------------------------
0128  *
0129  * Belkin F5U104 ... two NetChip 2280 devices + Atmel AVR microcontroller
0130  *
0131  * ... also two eTEK designs, including one sold as "Advance USBNET"
0132  *
0133  *-------------------------------------------------------------------------*/
0134
0135 static const struct driver_info belkin_info = {
0136     .description =  "Belkin, eTEK, or compatible",
0137     .flags       = FLAG_POINTTOPOINT,
0138 };
0139
0140 #endif  /* CONFIG_USB_BELKIN */
0141
0142
0143
0144 #ifdef  CONFIG_USB_EPSON2888
0145 #define HAVE_HARDWARE
0146
0147 /*-------------------------------------------------------------------------
0148  *
0149  * EPSON USB clients
0150  *
0151  * This is the same idea as Linux PDAs (below) except the firmware in the
0152  * device might not be Tux-powered.  Epson provides reference firmware that
0153  * implements this interface.  Product developers can reuse or modify that
0154  * code, such as by using their own product and vendor codes.
0155  *
0156  * Support was from Juro Bystricky <bystricky.juro@erd.epson.com>
0157  *
0158  *-------------------------------------------------------------------------*/
0159
0160 static const struct driver_info epson2888_info = {
0161     .description =  "Epson USB Device",
0162     .check_connect = always_connected,
0163     .flags = FLAG_POINTTOPOINT,
0164
0165     .in = 4, .out = 3,
0166 };
0167
0168 #endif  /* CONFIG_USB_EPSON2888 */
0169
0170
0171 /*-------------------------------------------------------------------------
0172  *
0173  * info from Jonathan McDowell <noodles@earth.li>
0174  *
0175  *-------------------------------------------------------------------------*/
0176 #ifdef CONFIG_USB_KC2190
0177 #define HAVE_HARDWARE
0178 static const struct driver_info kc2190_info = {
0179     .description =  "KC Technology KC-190",
0180     .flags = FLAG_POINTTOPOINT,
0181 };
0182 #endif /* CONFIG_USB_KC2190 */
0183
0184
0185 #ifdef  CONFIG_USB_ARMLINUX
0186 #define HAVE_HARDWARE
0187
0188 /*-------------------------------------------------------------------------
0189  *
0190  * Intel's SA-1100 chip integrates basic USB support, and is used
0191  * in PDAs like some iPaqs, the Yopy, some Zaurus models, and more.
0192  * When they run Linux, arch/arm/mach-sa1100/usb-eth.c may be used to
0193  * network using minimal USB framing data.
0194  *
0195  * This describes the driver currently in standard ARM Linux kernels.
0196  * The Zaurus uses a different driver (see later).
0197  *
0198  * PXA25x and PXA210 use XScale cores (ARM v5TE) with better USB support
0199  * and different USB endpoint numbering than the SA1100 devices.  The
0200  * mach-pxa/usb-eth.c driver re-uses the device ids from mach-sa1100
0201  * so we rely on the endpoint descriptors.
0202  *
0203  *-------------------------------------------------------------------------*/
0204
0205 static const struct driver_info linuxdev_info = {
0206     .description =  "Linux Device",
0207     .check_connect = always_connected,
0208     .flags = FLAG_POINTTOPOINT,
0209 };
0210
0211 static const struct driver_info yopy_info = {
0212     .description =  "Yopy",
0213     .check_connect = always_connected,
0214     .flags = FLAG_POINTTOPOINT,
0215 };
0216
0217 static const struct driver_info blob_info = {
0218     .description =  "Boot Loader OBject",
0219     .check_connect = always_connected,
0220     .flags = FLAG_POINTTOPOINT,
0221 };
0222
0223 #endif  /* CONFIG_USB_ARMLINUX */
0224
0225
0226 /*-------------------------------------------------------------------------*/
0227
0228 #ifndef HAVE_HARDWARE
0229 #warning You need to configure some hardware for this driver
0230 #endif
0231
0232 /*
0233  * chip vendor names won't normally be on the cables, and
0234  * may not be on the device.
0235  */
0236
0237 static const struct usb_device_id   products [] = {
0238
0239 #ifdef  CONFIG_USB_ALI_M5632
0240 {
0241     USB_DEVICE (0x0402, 0x5632),    // ALi defaults
0242     .driver_info =  (unsigned long) &ali_m5632_info,
0243 },
0244 {
0245     USB_DEVICE (0x182d,0x207c), // SiteCom CN-124
0246     .driver_info =  (unsigned long) &ali_m5632_info,
0247 },
0248 #endif
0249
0250 #ifdef  CONFIG_USB_AN2720
0251 {
0252     USB_DEVICE (0x0547, 0x2720),    // AnchorChips defaults
0253     .driver_info =  (unsigned long) &an2720_info,
0254 }, {
0255     USB_DEVICE (0x0547, 0x2727),    // Xircom PGUNET
0256     .driver_info =  (unsigned long) &an2720_info,
0257 },
0258 #endif
0259
0260 #ifdef  CONFIG_USB_BELKIN
0261 {
0262     USB_DEVICE (0x050d, 0x0004),    // Belkin
0263     .driver_info =  (unsigned long) &belkin_info,
0264 }, {
0265     USB_DEVICE (0x056c, 0x8100),    // eTEK
0266     .driver_info =  (unsigned long) &belkin_info,
0267 }, {
0268     USB_DEVICE (0x0525, 0x9901),    // Advance USBNET (eTEK)
0269     .driver_info =  (unsigned long) &belkin_info,
0270 },
0271 #endif
0272
0273 #ifdef  CONFIG_USB_EPSON2888
0274 {
0275     USB_DEVICE (0x0525, 0x2888),    // EPSON USB client
0276     .driver_info    = (unsigned long) &epson2888_info,
0277 },
0278 #endif
0279
0280 #ifdef CONFIG_USB_KC2190
0281 {
0282     USB_DEVICE (0x050f, 0x0190),    // KC-190
0283     .driver_info =  (unsigned long) &kc2190_info,
0284 },
0285 #endif
0286
0287 #ifdef  CONFIG_USB_ARMLINUX
0288 /*
0289  * SA-1100 using standard ARM Linux kernels, or compatible.
0290  * Often used when talking to Linux PDAs (iPaq, Yopy, etc).
0291  * The sa-1100 "usb-eth" driver handles the basic framing.
0292  *
0293  * PXA25x or PXA210 ...  these use a "usb-eth" driver much like
0294  * the sa1100 one, but hardware uses different endpoint numbers.
0295  *
0296  * Or the Linux "Ethernet" gadget on hardware that can't talk
0297  * CDC Ethernet (e.g., no altsettings), in either of two modes:
0298  *  - acting just like the old "usb-eth" firmware, though
0299  *    the implementation is different
0300  *  - supporting RNDIS as the first/default configuration for
0301  *    MS-Windows interop; Linux needs to use the other config
0302  */
0303 {
0304     // 1183 = 0x049F, both used as hex values?
0305     // Compaq "Itsy" vendor/product id
0306     USB_DEVICE (0x049F, 0x505A),    // usb-eth, or compatible
0307     .driver_info =  (unsigned long) &linuxdev_info,
0308 }, {
0309     USB_DEVICE (0x0E7E, 0x1001),    // G.Mate "Yopy"
0310     .driver_info =  (unsigned long) &yopy_info,
0311 }, {
0312     USB_DEVICE (0x8086, 0x07d3),    // "blob" bootloader
0313     .driver_info =  (unsigned long) &blob_info,
0314 }, {
0315     USB_DEVICE (0x1286, 0x8001),    // "blob" bootloader
0316     .driver_info =  (unsigned long) &blob_info,
0317 }, {
0318     // Linux Ethernet/RNDIS gadget, mostly on PXA, second config
0319     // e.g. Gumstix, current OpenZaurus, ... or anything else
0320     // that just enables this gadget option.
0321     USB_DEVICE (0x0525, 0xa4a2),
0322     .driver_info =  (unsigned long) &linuxdev_info,
0323 },
0324 #endif
0325
0326     { },        // END
0327 };
0328 MODULE_DEVICE_TABLE(usb, products);
0329
0330 /*-------------------------------------------------------------------------*/
0331 static int dummy_prereset(struct usb_interface *intf)
0332 {
0333         return 0;
0334 }
0335
0336 static int dummy_postreset(struct usb_interface *intf)
0337 {
0338         return 0;
0339 }
0340
0341 static struct usb_driver cdc_subset_driver = {
0342     .name =     "cdc_subset",
0343     .probe =    usbnet_probe,
0344     .suspend =  usbnet_suspend,
0345     .resume =   usbnet_resume,
0346     .pre_reset =    dummy_prereset,
0347     .post_reset =   dummy_postreset,
0348     .disconnect =   usbnet_disconnect,
0349     .id_table = products,
0350     .disable_hub_initiated_lpm = 1,
0351 };
0352
0353 module_usb_driver(cdc_subset_driver);
0354
0355 MODULE_AUTHOR("David Brownell");
0356 MODULE_DESCRIPTION("Simple 'CDC Subset' USB networking links");
0357 MODULE_LICENSE("GPL");