xref: /openbmc/linux/drivers/net/usb/cdc_subset.c (revision a09d2831)
1 /*
2  * Simple "CDC Subset" USB Networking Links
3  * Copyright (C) 2000-2005 by David Brownell
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  */
19 
20 #include <linux/module.h>
21 #include <linux/kmod.h>
22 #include <linux/init.h>
23 #include <linux/netdevice.h>
24 #include <linux/etherdevice.h>
25 #include <linux/ethtool.h>
26 #include <linux/workqueue.h>
27 #include <linux/mii.h>
28 #include <linux/usb.h>
29 #include <linux/usb/usbnet.h>
30 
31 
32 /*
33  * This supports simple USB network links that don't require any special
34  * framing or hardware control operations.  The protocol used here is a
35  * strict subset of CDC Ethernet, with three basic differences reflecting
36  * the goal that almost any hardware should run it:
37  *
38  *  - Minimal runtime control:  one interface, no altsettings, and
39  *    no vendor or class specific control requests.  If a device is
40  *    configured, it is allowed to exchange packets with the host.
41  *    Fancier models would mean not working on some hardware.
42  *
43  *  - Minimal manufacturing control:  no IEEE "Organizationally
44  *    Unique ID" required, or an EEPROMs to store one.  Each host uses
45  *    one random "locally assigned" Ethernet address instead, which can
46  *    of course be overridden using standard tools like "ifconfig".
47  *    (With 2^46 such addresses, same-net collisions are quite rare.)
48  *
49  *  - There is no additional framing data for USB.  Packets are written
50  *    exactly as in CDC Ethernet, starting with an Ethernet header and
51  *    terminated by a short packet.  However, the host will never send a
52  *    zero length packet; some systems can't handle those robustly.
53  *
54  * Anything that can transmit and receive USB bulk packets can implement
55  * this protocol.  That includes both smart peripherals and quite a lot
56  * of "host-to-host" USB cables (which embed two devices back-to-back).
57  *
58  * Note that although Linux may use many of those host-to-host links
59  * with this "cdc_subset" framing, that doesn't mean there may not be a
60  * better approach.  Handling the "other end unplugs/replugs" scenario
61  * well tends to require chip-specific vendor requests.  Also, Windows
62  * peers at the other end of host-to-host cables may expect their own
63  * framing to be used rather than this "cdc_subset" model.
64  */
65 
66 #if defined(CONFIG_USB_EPSON2888) || defined(CONFIG_USB_ARMLINUX)
67 /* PDA style devices are always connected if present */
68 static int always_connected (struct usbnet *dev)
69 {
70 	return 0;
71 }
72 #endif
73 
74 #ifdef	CONFIG_USB_ALI_M5632
75 #define	HAVE_HARDWARE
76 
77 /*-------------------------------------------------------------------------
78  *
79  * ALi M5632 driver ... does high speed
80  *
81  * NOTE that the MS-Windows drivers for this chip use some funky and
82  * (naturally) undocumented 7-byte prefix to each packet, so this is a
83  * case where we don't currently interoperate.  Also, once you unplug
84  * one end of the cable, you need to replug the other end too ... since
85  * chip docs are unavailable, there's no way to reset the relevant state
86  * short of a power cycle.
87  *
88  *-------------------------------------------------------------------------*/
89 
90 static const struct driver_info	ali_m5632_info = {
91 	.description =	"ALi M5632",
92 };
93 
94 #endif
95 
96 
97 #ifdef	CONFIG_USB_AN2720
98 #define	HAVE_HARDWARE
99 
100 /*-------------------------------------------------------------------------
101  *
102  * AnchorChips 2720 driver ... http://www.cypress.com
103  *
104  * This doesn't seem to have a way to detect whether the peer is
105  * connected, or need any reset handshaking.  It's got pretty big
106  * internal buffers (handles most of a frame's worth of data).
107  * Chip data sheets don't describe any vendor control messages.
108  *
109  *-------------------------------------------------------------------------*/
110 
111 static const struct driver_info	an2720_info = {
112 	.description =	"AnchorChips/Cypress 2720",
113 	// no reset available!
114 	// no check_connect available!
115 
116 	.in = 2, .out = 2,		// direction distinguishes these
117 };
118 
119 #endif	/* CONFIG_USB_AN2720 */
120 
121 
122 #ifdef	CONFIG_USB_BELKIN
123 #define	HAVE_HARDWARE
124 
125 /*-------------------------------------------------------------------------
126  *
127  * Belkin F5U104 ... two NetChip 2280 devices + Atmel AVR microcontroller
128  *
129  * ... also two eTEK designs, including one sold as "Advance USBNET"
130  *
131  *-------------------------------------------------------------------------*/
132 
133 static const struct driver_info	belkin_info = {
134 	.description =	"Belkin, eTEK, or compatible",
135 };
136 
137 #endif	/* CONFIG_USB_BELKIN */
138 
139 
140 
141 #ifdef	CONFIG_USB_EPSON2888
142 #define	HAVE_HARDWARE
143 
144 /*-------------------------------------------------------------------------
145  *
146  * EPSON USB clients
147  *
148  * This is the same idea as Linux PDAs (below) except the firmware in the
149  * device might not be Tux-powered.  Epson provides reference firmware that
150  * implements this interface.  Product developers can reuse or modify that
151  * code, such as by using their own product and vendor codes.
152  *
153  * Support was from Juro Bystricky <bystricky.juro@erd.epson.com>
154  *
155  *-------------------------------------------------------------------------*/
156 
157 static const struct driver_info	epson2888_info = {
158 	.description =	"Epson USB Device",
159 	.check_connect = always_connected,
160 
161 	.in = 4, .out = 3,
162 };
163 
164 #endif	/* CONFIG_USB_EPSON2888 */
165 
166 
167 /*-------------------------------------------------------------------------
168  *
169  * info from Jonathan McDowell <noodles@earth.li>
170  *
171  *-------------------------------------------------------------------------*/
172 #ifdef CONFIG_USB_KC2190
173 #define HAVE_HARDWARE
174 static const struct driver_info kc2190_info = {
175 	.description =  "KC Technology KC-190",
176 };
177 #endif /* CONFIG_USB_KC2190 */
178 
179 
180 #ifdef	CONFIG_USB_ARMLINUX
181 #define	HAVE_HARDWARE
182 
183 /*-------------------------------------------------------------------------
184  *
185  * Intel's SA-1100 chip integrates basic USB support, and is used
186  * in PDAs like some iPaqs, the Yopy, some Zaurus models, and more.
187  * When they run Linux, arch/arm/mach-sa1100/usb-eth.c may be used to
188  * network using minimal USB framing data.
189  *
190  * This describes the driver currently in standard ARM Linux kernels.
191  * The Zaurus uses a different driver (see later).
192  *
193  * PXA25x and PXA210 use XScale cores (ARM v5TE) with better USB support
194  * and different USB endpoint numbering than the SA1100 devices.  The
195  * mach-pxa/usb-eth.c driver re-uses the device ids from mach-sa1100
196  * so we rely on the endpoint descriptors.
197  *
198  *-------------------------------------------------------------------------*/
199 
200 static const struct driver_info	linuxdev_info = {
201 	.description =	"Linux Device",
202 	.check_connect = always_connected,
203 };
204 
205 static const struct driver_info	yopy_info = {
206 	.description =	"Yopy",
207 	.check_connect = always_connected,
208 };
209 
210 static const struct driver_info	blob_info = {
211 	.description =	"Boot Loader OBject",
212 	.check_connect = always_connected,
213 };
214 
215 #endif	/* CONFIG_USB_ARMLINUX */
216 
217 
218 /*-------------------------------------------------------------------------*/
219 
220 #ifndef	HAVE_HARDWARE
221 #warning You need to configure some hardware for this driver
222 #endif
223 
224 /*
225  * chip vendor names won't normally be on the cables, and
226  * may not be on the device.
227  */
228 
229 static const struct usb_device_id	products [] = {
230 
231 #ifdef	CONFIG_USB_ALI_M5632
232 {
233 	USB_DEVICE (0x0402, 0x5632),	// ALi defaults
234 	.driver_info =	(unsigned long) &ali_m5632_info,
235 },
236 {
237 	USB_DEVICE (0x182d,0x207c),	// SiteCom CN-124
238 	.driver_info =	(unsigned long) &ali_m5632_info,
239 },
240 #endif
241 
242 #ifdef	CONFIG_USB_AN2720
243 {
244 	USB_DEVICE (0x0547, 0x2720),	// AnchorChips defaults
245 	.driver_info =	(unsigned long) &an2720_info,
246 }, {
247 	USB_DEVICE (0x0547, 0x2727),	// Xircom PGUNET
248 	.driver_info =	(unsigned long) &an2720_info,
249 },
250 #endif
251 
252 #ifdef	CONFIG_USB_BELKIN
253 {
254 	USB_DEVICE (0x050d, 0x0004),	// Belkin
255 	.driver_info =	(unsigned long) &belkin_info,
256 }, {
257 	USB_DEVICE (0x056c, 0x8100),	// eTEK
258 	.driver_info =	(unsigned long) &belkin_info,
259 }, {
260 	USB_DEVICE (0x0525, 0x9901),	// Advance USBNET (eTEK)
261 	.driver_info =	(unsigned long) &belkin_info,
262 },
263 #endif
264 
265 #ifdef	CONFIG_USB_EPSON2888
266 {
267 	USB_DEVICE (0x0525, 0x2888),	// EPSON USB client
268 	.driver_info	= (unsigned long) &epson2888_info,
269 },
270 #endif
271 
272 #ifdef CONFIG_USB_KC2190
273 {
274 	USB_DEVICE (0x050f, 0x0190),	// KC-190
275 	.driver_info =	(unsigned long) &kc2190_info,
276 },
277 #endif
278 
279 #ifdef	CONFIG_USB_ARMLINUX
280 /*
281  * SA-1100 using standard ARM Linux kernels, or compatible.
282  * Often used when talking to Linux PDAs (iPaq, Yopy, etc).
283  * The sa-1100 "usb-eth" driver handles the basic framing.
284  *
285  * PXA25x or PXA210 ...  these use a "usb-eth" driver much like
286  * the sa1100 one, but hardware uses different endpoint numbers.
287  *
288  * Or the Linux "Ethernet" gadget on hardware that can't talk
289  * CDC Ethernet (e.g., no altsettings), in either of two modes:
290  *  - acting just like the old "usb-eth" firmware, though
291  *    the implementation is different
292  *  - supporting RNDIS as the first/default configuration for
293  *    MS-Windows interop; Linux needs to use the other config
294  */
295 {
296 	// 1183 = 0x049F, both used as hex values?
297 	// Compaq "Itsy" vendor/product id
298 	USB_DEVICE (0x049F, 0x505A),	// usb-eth, or compatible
299 	.driver_info =	(unsigned long) &linuxdev_info,
300 }, {
301 	USB_DEVICE (0x0E7E, 0x1001),	// G.Mate "Yopy"
302 	.driver_info =	(unsigned long) &yopy_info,
303 }, {
304 	USB_DEVICE (0x8086, 0x07d3),	// "blob" bootloader
305 	.driver_info =	(unsigned long) &blob_info,
306 }, {
307 	USB_DEVICE (0x1286, 0x8001),    // "blob" bootloader
308 	.driver_info =  (unsigned long) &blob_info,
309 }, {
310 	// Linux Ethernet/RNDIS gadget, mostly on PXA, second config
311 	// e.g. Gumstix, current OpenZaurus, ... or anything else
312 	// that just enables this gadget option.
313 	USB_DEVICE (0x0525, 0xa4a2),
314 	.driver_info =	(unsigned long) &linuxdev_info,
315 },
316 #endif
317 
318 	{ },		// END
319 };
320 MODULE_DEVICE_TABLE(usb, products);
321 
322 /*-------------------------------------------------------------------------*/
323 
324 static struct usb_driver cdc_subset_driver = {
325 	.name =		"cdc_subset",
326 	.probe =	usbnet_probe,
327 	.suspend =	usbnet_suspend,
328 	.resume =	usbnet_resume,
329 	.disconnect =	usbnet_disconnect,
330 	.id_table =	products,
331 };
332 
333 static int __init cdc_subset_init(void)
334 {
335 	return usb_register(&cdc_subset_driver);
336 }
337 module_init(cdc_subset_init);
338 
339 static void __exit cdc_subset_exit(void)
340 {
341 	usb_deregister(&cdc_subset_driver);
342 }
343 module_exit(cdc_subset_exit);
344 
345 MODULE_AUTHOR("David Brownell");
346 MODULE_DESCRIPTION("Simple 'CDC Subset' USB networking links");
347 MODULE_LICENSE("GPL");
348