xref: /openbmc/linux/drivers/net/usb/cdc_subset.c (revision 64c70b1c)
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 
30 #include "usbnet.h"
31 
32 
33 /*
34  * This supports simple USB network links that don't require any special
35  * framing or hardware control operations.  The protocol used here is a
36  * strict subset of CDC Ethernet, with three basic differences reflecting
37  * the goal that almost any hardware should run it:
38  *
39  *  - Minimal runtime control:  one interface, no altsettings, and
40  *    no vendor or class specific control requests.  If a device is
41  *    configured, it is allowed to exchange packets with the host.
42  *    Fancier models would mean not working on some hardware.
43  *
44  *  - Minimal manufacturing control:  no IEEE "Organizationally
45  *    Unique ID" required, or an EEPROMs to store one.  Each host uses
46  *    one random "locally assigned" Ethernet address instead, which can
47  *    of course be overridden using standard tools like "ifconfig".
48  *    (With 2^46 such addresses, same-net collisions are quite rare.)
49  *
50  *  - There is no additional framing data for USB.  Packets are written
51  *    exactly as in CDC Ethernet, starting with an Ethernet header and
52  *    terminated by a short packet.  However, the host will never send a
53  *    zero length packet; some systems can't handle those robustly.
54  *
55  * Anything that can transmit and receive USB bulk packets can implement
56  * this protocol.  That includes both smart peripherals and quite a lot
57  * of "host-to-host" USB cables (which embed two devices back-to-back).
58  *
59  * Note that although Linux may use many of those host-to-host links
60  * with this "cdc_subset" framing, that doesn't mean there may not be a
61  * better approach.  Handling the "other end unplugs/replugs" scenario
62  * well tends to require chip-specific vendor requests.  Also, Windows
63  * peers at the other end of host-to-host cables may expect their own
64  * framing to be used rather than this "cdc_subset" model.
65  */
66 
67 #if defined(CONFIG_USB_EPSON2888) || defined(CONFIG_USB_ARMLINUX)
68 /* PDA style devices are always connected if present */
69 static int always_connected (struct usbnet *dev)
70 {
71 	return 0;
72 }
73 #endif
74 
75 #ifdef	CONFIG_USB_ALI_M5632
76 #define	HAVE_HARDWARE
77 
78 /*-------------------------------------------------------------------------
79  *
80  * ALi M5632 driver ... does high speed
81  *
82  * NOTE that the MS-Windows drivers for this chip use some funky and
83  * (naturally) undocumented 7-byte prefix to each packet, so this is a
84  * case where we don't currently interoperate.  Also, once you unplug
85  * one end of the cable, you need to replug the other end too ... since
86  * chip docs are unavailable, there's no way to reset the relevant state
87  * short of a power cycle.
88  *
89  *-------------------------------------------------------------------------*/
90 
91 static const struct driver_info	ali_m5632_info = {
92 	.description =	"ALi M5632",
93 };
94 
95 #endif
96 
97 
98 #ifdef	CONFIG_USB_AN2720
99 #define	HAVE_HARDWARE
100 
101 /*-------------------------------------------------------------------------
102  *
103  * AnchorChips 2720 driver ... http://www.cypress.com
104  *
105  * This doesn't seem to have a way to detect whether the peer is
106  * connected, or need any reset handshaking.  It's got pretty big
107  * internal buffers (handles most of a frame's worth of data).
108  * Chip data sheets don't describe any vendor control messages.
109  *
110  *-------------------------------------------------------------------------*/
111 
112 static const struct driver_info	an2720_info = {
113 	.description =	"AnchorChips/Cypress 2720",
114 	// no reset available!
115 	// no check_connect available!
116 
117 	.in = 2, .out = 2,		// direction distinguishes these
118 };
119 
120 #endif	/* CONFIG_USB_AN2720 */
121 
122 
123 #ifdef	CONFIG_USB_BELKIN
124 #define	HAVE_HARDWARE
125 
126 /*-------------------------------------------------------------------------
127  *
128  * Belkin F5U104 ... two NetChip 2280 devices + Atmel AVR microcontroller
129  *
130  * ... also two eTEK designs, including one sold as "Advance USBNET"
131  *
132  *-------------------------------------------------------------------------*/
133 
134 static const struct driver_info	belkin_info = {
135 	.description =	"Belkin, eTEK, or compatible",
136 };
137 
138 #endif	/* CONFIG_USB_BELKIN */
139 
140 
141 
142 #ifdef	CONFIG_USB_EPSON2888
143 #define	HAVE_HARDWARE
144 
145 /*-------------------------------------------------------------------------
146  *
147  * EPSON USB clients
148  *
149  * This is the same idea as Linux PDAs (below) except the firmware in the
150  * device might not be Tux-powered.  Epson provides reference firmware that
151  * implements this interface.  Product developers can reuse or modify that
152  * code, such as by using their own product and vendor codes.
153  *
154  * Support was from Juro Bystricky <bystricky.juro@erd.epson.com>
155  *
156  *-------------------------------------------------------------------------*/
157 
158 static const struct driver_info	epson2888_info = {
159 	.description =	"Epson USB Device",
160 	.check_connect = always_connected,
161 
162 	.in = 4, .out = 3,
163 };
164 
165 #endif	/* CONFIG_USB_EPSON2888 */
166 
167 
168 /*-------------------------------------------------------------------------
169  *
170  * info from Jonathan McDowell <noodles@earth.li>
171  *
172  *-------------------------------------------------------------------------*/
173 #ifdef CONFIG_USB_KC2190
174 #define HAVE_HARDWARE
175 static const struct driver_info kc2190_info = {
176 	.description =  "KC Technology KC-190",
177 };
178 #endif /* CONFIG_USB_KC2190 */
179 
180 
181 #ifdef	CONFIG_USB_ARMLINUX
182 #define	HAVE_HARDWARE
183 
184 /*-------------------------------------------------------------------------
185  *
186  * Intel's SA-1100 chip integrates basic USB support, and is used
187  * in PDAs like some iPaqs, the Yopy, some Zaurus models, and more.
188  * When they run Linux, arch/arm/mach-sa1100/usb-eth.c may be used to
189  * network using minimal USB framing data.
190  *
191  * This describes the driver currently in standard ARM Linux kernels.
192  * The Zaurus uses a different driver (see later).
193  *
194  * PXA25x and PXA210 use XScale cores (ARM v5TE) with better USB support
195  * and different USB endpoint numbering than the SA1100 devices.  The
196  * mach-pxa/usb-eth.c driver re-uses the device ids from mach-sa1100
197  * so we rely on the endpoint descriptors.
198  *
199  *-------------------------------------------------------------------------*/
200 
201 static const struct driver_info	linuxdev_info = {
202 	.description =	"Linux Device",
203 	.check_connect = always_connected,
204 };
205 
206 static const struct driver_info	yopy_info = {
207 	.description =	"Yopy",
208 	.check_connect = always_connected,
209 };
210 
211 static const struct driver_info	blob_info = {
212 	.description =	"Boot Loader OBject",
213 	.check_connect = always_connected,
214 };
215 
216 #endif	/* CONFIG_USB_ARMLINUX */
217 
218 
219 /*-------------------------------------------------------------------------*/
220 
221 #ifndef	HAVE_HARDWARE
222 #error You need to configure some hardware for this driver
223 #endif
224 
225 /*
226  * chip vendor names won't normally be on the cables, and
227  * may not be on the device.
228  */
229 
230 static const struct usb_device_id	products [] = {
231 
232 #ifdef	CONFIG_USB_ALI_M5632
233 {
234 	USB_DEVICE (0x0402, 0x5632),	// ALi defaults
235 	.driver_info =	(unsigned long) &ali_m5632_info,
236 },
237 {
238 	USB_DEVICE (0x182d,0x207c),	// SiteCom CN-124
239 	.driver_info =	(unsigned long) &ali_m5632_info,
240 },
241 #endif
242 
243 #ifdef	CONFIG_USB_AN2720
244 {
245 	USB_DEVICE (0x0547, 0x2720),	// AnchorChips defaults
246 	.driver_info =	(unsigned long) &an2720_info,
247 }, {
248 	USB_DEVICE (0x0547, 0x2727),	// Xircom PGUNET
249 	.driver_info =	(unsigned long) &an2720_info,
250 },
251 #endif
252 
253 #ifdef	CONFIG_USB_BELKIN
254 {
255 	USB_DEVICE (0x050d, 0x0004),	// Belkin
256 	.driver_info =	(unsigned long) &belkin_info,
257 }, {
258 	USB_DEVICE (0x056c, 0x8100),	// eTEK
259 	.driver_info =	(unsigned long) &belkin_info,
260 }, {
261 	USB_DEVICE (0x0525, 0x9901),	// Advance USBNET (eTEK)
262 	.driver_info =	(unsigned long) &belkin_info,
263 },
264 #endif
265 
266 #ifdef	CONFIG_USB_EPSON2888
267 {
268 	USB_DEVICE (0x0525, 0x2888),	// EPSON USB client
269 	.driver_info	= (unsigned long) &epson2888_info,
270 },
271 #endif
272 
273 #ifdef CONFIG_USB_KC2190
274 {
275 	USB_DEVICE (0x050f, 0x0190),	// KC-190
276 	.driver_info =	(unsigned long) &kc2190_info,
277 },
278 #endif
279 
280 #ifdef	CONFIG_USB_ARMLINUX
281 /*
282  * SA-1100 using standard ARM Linux kernels, or compatible.
283  * Often used when talking to Linux PDAs (iPaq, Yopy, etc).
284  * The sa-1100 "usb-eth" driver handles the basic framing.
285  *
286  * PXA25x or PXA210 ...  these use a "usb-eth" driver much like
287  * the sa1100 one, but hardware uses different endpoint numbers.
288  *
289  * Or the Linux "Ethernet" gadget on hardware that can't talk
290  * CDC Ethernet (e.g., no altsettings), in either of two modes:
291  *  - acting just like the old "usb-eth" firmware, though
292  *    the implementation is different
293  *  - supporting RNDIS as the first/default configuration for
294  *    MS-Windows interop; Linux needs to use the other config
295  */
296 {
297 	// 1183 = 0x049F, both used as hex values?
298 	// Compaq "Itsy" vendor/product id
299 	USB_DEVICE (0x049F, 0x505A),	// usb-eth, or compatible
300 	.driver_info =	(unsigned long) &linuxdev_info,
301 }, {
302 	USB_DEVICE (0x0E7E, 0x1001),	// G.Mate "Yopy"
303 	.driver_info =	(unsigned long) &yopy_info,
304 }, {
305 	USB_DEVICE (0x8086, 0x07d3),	// "blob" bootloader
306 	.driver_info =	(unsigned long) &blob_info,
307 }, {
308 	// Linux Ethernet/RNDIS gadget on pxa210/25x/26x, second config
309 	// e.g. Gumstix, current OpenZaurus, ...
310 	USB_DEVICE_VER (0x0525, 0xa4a2, 0x0203, 0x0203),
311 	.driver_info =	(unsigned long) &linuxdev_info,
312 },
313 #endif
314 
315 	{ },		// END
316 };
317 MODULE_DEVICE_TABLE(usb, products);
318 
319 /*-------------------------------------------------------------------------*/
320 
321 static struct usb_driver cdc_subset_driver = {
322 	.name =		"cdc_subset",
323 	.probe =	usbnet_probe,
324 	.suspend =	usbnet_suspend,
325 	.resume =	usbnet_resume,
326 	.disconnect =	usbnet_disconnect,
327 	.id_table =	products,
328 };
329 
330 static int __init cdc_subset_init(void)
331 {
332 	return usb_register(&cdc_subset_driver);
333 }
334 module_init(cdc_subset_init);
335 
336 static void __exit cdc_subset_exit(void)
337 {
338 	usb_deregister(&cdc_subset_driver);
339 }
340 module_exit(cdc_subset_exit);
341 
342 MODULE_AUTHOR("David Brownell");
343 MODULE_DESCRIPTION("Simple 'CDC Subset' USB networking links");
344 MODULE_LICENSE("GPL");
345