xref: /openbmc/linux/drivers/net/usb/cdc_subset.c (revision f3539c12)
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, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include <linux/module.h>
20 #include <linux/kmod.h>
21 #include <linux/netdevice.h>
22 #include <linux/etherdevice.h>
23 #include <linux/ethtool.h>
24 #include <linux/workqueue.h>
25 #include <linux/mii.h>
26 #include <linux/usb.h>
27 #include <linux/usb/usbnet.h>
28 
29 
30 /*
31  * This supports simple USB network links that don't require any special
32  * framing or hardware control operations.  The protocol used here is a
33  * strict subset of CDC Ethernet, with three basic differences reflecting
34  * the goal that almost any hardware should run it:
35  *
36  *  - Minimal runtime control:  one interface, no altsettings, and
37  *    no vendor or class specific control requests.  If a device is
38  *    configured, it is allowed to exchange packets with the host.
39  *    Fancier models would mean not working on some hardware.
40  *
41  *  - Minimal manufacturing control:  no IEEE "Organizationally
42  *    Unique ID" required, or an EEPROMs to store one.  Each host uses
43  *    one random "locally assigned" Ethernet address instead, which can
44  *    of course be overridden using standard tools like "ifconfig".
45  *    (With 2^46 such addresses, same-net collisions are quite rare.)
46  *
47  *  - There is no additional framing data for USB.  Packets are written
48  *    exactly as in CDC Ethernet, starting with an Ethernet header and
49  *    terminated by a short packet.  However, the host will never send a
50  *    zero length packet; some systems can't handle those robustly.
51  *
52  * Anything that can transmit and receive USB bulk packets can implement
53  * this protocol.  That includes both smart peripherals and quite a lot
54  * of "host-to-host" USB cables (which embed two devices back-to-back).
55  *
56  * Note that although Linux may use many of those host-to-host links
57  * with this "cdc_subset" framing, that doesn't mean there may not be a
58  * better approach.  Handling the "other end unplugs/replugs" scenario
59  * well tends to require chip-specific vendor requests.  Also, Windows
60  * peers at the other end of host-to-host cables may expect their own
61  * framing to be used rather than this "cdc_subset" model.
62  */
63 
64 #if defined(CONFIG_USB_EPSON2888) || defined(CONFIG_USB_ARMLINUX)
65 /* PDA style devices are always connected if present */
66 static int always_connected (struct usbnet *dev)
67 {
68 	return 0;
69 }
70 #endif
71 
72 #ifdef	CONFIG_USB_ALI_M5632
73 #define	HAVE_HARDWARE
74 
75 /*-------------------------------------------------------------------------
76  *
77  * ALi M5632 driver ... does high speed
78  *
79  * NOTE that the MS-Windows drivers for this chip use some funky and
80  * (naturally) undocumented 7-byte prefix to each packet, so this is a
81  * case where we don't currently interoperate.  Also, once you unplug
82  * one end of the cable, you need to replug the other end too ... since
83  * chip docs are unavailable, there's no way to reset the relevant state
84  * short of a power cycle.
85  *
86  *-------------------------------------------------------------------------*/
87 
88 static void m5632_recover(struct usbnet *dev)
89 {
90 	struct usb_device	*udev = dev->udev;
91 	struct usb_interface	*intf = dev->intf;
92 	int r;
93 
94 	r = usb_lock_device_for_reset(udev, intf);
95 	if (r < 0)
96 		return;
97 
98 	usb_reset_device(udev);
99 	usb_unlock_device(udev);
100 }
101 
102 static const struct driver_info	ali_m5632_info = {
103 	.description =	"ALi M5632",
104 	.flags       = FLAG_POINTTOPOINT,
105 	.recover     = m5632_recover,
106 };
107 
108 #endif
109 
110 #ifdef	CONFIG_USB_AN2720
111 #define	HAVE_HARDWARE
112 
113 /*-------------------------------------------------------------------------
114  *
115  * AnchorChips 2720 driver ... http://www.cypress.com
116  *
117  * This doesn't seem to have a way to detect whether the peer is
118  * connected, or need any reset handshaking.  It's got pretty big
119  * internal buffers (handles most of a frame's worth of data).
120  * Chip data sheets don't describe any vendor control messages.
121  *
122  *-------------------------------------------------------------------------*/
123 
124 static const struct driver_info	an2720_info = {
125 	.description =	"AnchorChips/Cypress 2720",
126 	.flags       = FLAG_POINTTOPOINT,
127 	// no reset available!
128 	// no check_connect available!
129 
130 	.in = 2, .out = 2,		// direction distinguishes these
131 };
132 
133 #endif	/* CONFIG_USB_AN2720 */
134 
135 
136 #ifdef	CONFIG_USB_BELKIN
137 #define	HAVE_HARDWARE
138 
139 /*-------------------------------------------------------------------------
140  *
141  * Belkin F5U104 ... two NetChip 2280 devices + Atmel AVR microcontroller
142  *
143  * ... also two eTEK designs, including one sold as "Advance USBNET"
144  *
145  *-------------------------------------------------------------------------*/
146 
147 static const struct driver_info	belkin_info = {
148 	.description =	"Belkin, eTEK, or compatible",
149 	.flags       = FLAG_POINTTOPOINT,
150 };
151 
152 #endif	/* CONFIG_USB_BELKIN */
153 
154 
155 
156 #ifdef	CONFIG_USB_EPSON2888
157 #define	HAVE_HARDWARE
158 
159 /*-------------------------------------------------------------------------
160  *
161  * EPSON USB clients
162  *
163  * This is the same idea as Linux PDAs (below) except the firmware in the
164  * device might not be Tux-powered.  Epson provides reference firmware that
165  * implements this interface.  Product developers can reuse or modify that
166  * code, such as by using their own product and vendor codes.
167  *
168  * Support was from Juro Bystricky <bystricky.juro@erd.epson.com>
169  *
170  *-------------------------------------------------------------------------*/
171 
172 static const struct driver_info	epson2888_info = {
173 	.description =	"Epson USB Device",
174 	.check_connect = always_connected,
175 	.flags = FLAG_POINTTOPOINT,
176 
177 	.in = 4, .out = 3,
178 };
179 
180 #endif	/* CONFIG_USB_EPSON2888 */
181 
182 
183 /*-------------------------------------------------------------------------
184  *
185  * info from Jonathan McDowell <noodles@earth.li>
186  *
187  *-------------------------------------------------------------------------*/
188 #ifdef CONFIG_USB_KC2190
189 #define HAVE_HARDWARE
190 static const struct driver_info kc2190_info = {
191 	.description =  "KC Technology KC-190",
192 	.flags = FLAG_POINTTOPOINT,
193 };
194 #endif /* CONFIG_USB_KC2190 */
195 
196 
197 #ifdef	CONFIG_USB_ARMLINUX
198 #define	HAVE_HARDWARE
199 
200 /*-------------------------------------------------------------------------
201  *
202  * Intel's SA-1100 chip integrates basic USB support, and is used
203  * in PDAs like some iPaqs, the Yopy, some Zaurus models, and more.
204  * When they run Linux, arch/arm/mach-sa1100/usb-eth.c may be used to
205  * network using minimal USB framing data.
206  *
207  * This describes the driver currently in standard ARM Linux kernels.
208  * The Zaurus uses a different driver (see later).
209  *
210  * PXA25x and PXA210 use XScale cores (ARM v5TE) with better USB support
211  * and different USB endpoint numbering than the SA1100 devices.  The
212  * mach-pxa/usb-eth.c driver re-uses the device ids from mach-sa1100
213  * so we rely on the endpoint descriptors.
214  *
215  *-------------------------------------------------------------------------*/
216 
217 static const struct driver_info	linuxdev_info = {
218 	.description =	"Linux Device",
219 	.check_connect = always_connected,
220 	.flags = FLAG_POINTTOPOINT,
221 };
222 
223 static const struct driver_info	yopy_info = {
224 	.description =	"Yopy",
225 	.check_connect = always_connected,
226 	.flags = FLAG_POINTTOPOINT,
227 };
228 
229 static const struct driver_info	blob_info = {
230 	.description =	"Boot Loader OBject",
231 	.check_connect = always_connected,
232 	.flags = FLAG_POINTTOPOINT,
233 };
234 
235 #endif	/* CONFIG_USB_ARMLINUX */
236 
237 
238 /*-------------------------------------------------------------------------*/
239 
240 #ifndef	HAVE_HARDWARE
241 #warning You need to configure some hardware for this driver
242 #endif
243 
244 /*
245  * chip vendor names won't normally be on the cables, and
246  * may not be on the device.
247  */
248 
249 static const struct usb_device_id	products [] = {
250 
251 #ifdef	CONFIG_USB_ALI_M5632
252 {
253 	USB_DEVICE (0x0402, 0x5632),	// ALi defaults
254 	.driver_info =	(unsigned long) &ali_m5632_info,
255 },
256 {
257 	USB_DEVICE (0x182d,0x207c),	// SiteCom CN-124
258 	.driver_info =	(unsigned long) &ali_m5632_info,
259 },
260 #endif
261 
262 #ifdef	CONFIG_USB_AN2720
263 {
264 	USB_DEVICE (0x0547, 0x2720),	// AnchorChips defaults
265 	.driver_info =	(unsigned long) &an2720_info,
266 }, {
267 	USB_DEVICE (0x0547, 0x2727),	// Xircom PGUNET
268 	.driver_info =	(unsigned long) &an2720_info,
269 },
270 #endif
271 
272 #ifdef	CONFIG_USB_BELKIN
273 {
274 	USB_DEVICE (0x050d, 0x0004),	// Belkin
275 	.driver_info =	(unsigned long) &belkin_info,
276 }, {
277 	USB_DEVICE (0x056c, 0x8100),	// eTEK
278 	.driver_info =	(unsigned long) &belkin_info,
279 }, {
280 	USB_DEVICE (0x0525, 0x9901),	// Advance USBNET (eTEK)
281 	.driver_info =	(unsigned long) &belkin_info,
282 },
283 #endif
284 
285 #ifdef	CONFIG_USB_EPSON2888
286 {
287 	USB_DEVICE (0x0525, 0x2888),	// EPSON USB client
288 	.driver_info	= (unsigned long) &epson2888_info,
289 },
290 #endif
291 
292 #ifdef CONFIG_USB_KC2190
293 {
294 	USB_DEVICE (0x050f, 0x0190),	// KC-190
295 	.driver_info =	(unsigned long) &kc2190_info,
296 },
297 #endif
298 
299 #ifdef	CONFIG_USB_ARMLINUX
300 /*
301  * SA-1100 using standard ARM Linux kernels, or compatible.
302  * Often used when talking to Linux PDAs (iPaq, Yopy, etc).
303  * The sa-1100 "usb-eth" driver handles the basic framing.
304  *
305  * PXA25x or PXA210 ...  these use a "usb-eth" driver much like
306  * the sa1100 one, but hardware uses different endpoint numbers.
307  *
308  * Or the Linux "Ethernet" gadget on hardware that can't talk
309  * CDC Ethernet (e.g., no altsettings), in either of two modes:
310  *  - acting just like the old "usb-eth" firmware, though
311  *    the implementation is different
312  *  - supporting RNDIS as the first/default configuration for
313  *    MS-Windows interop; Linux needs to use the other config
314  */
315 {
316 	// 1183 = 0x049F, both used as hex values?
317 	// Compaq "Itsy" vendor/product id
318 	USB_DEVICE (0x049F, 0x505A),	// usb-eth, or compatible
319 	.driver_info =	(unsigned long) &linuxdev_info,
320 }, {
321 	USB_DEVICE (0x0E7E, 0x1001),	// G.Mate "Yopy"
322 	.driver_info =	(unsigned long) &yopy_info,
323 }, {
324 	USB_DEVICE (0x8086, 0x07d3),	// "blob" bootloader
325 	.driver_info =	(unsigned long) &blob_info,
326 }, {
327 	USB_DEVICE (0x1286, 0x8001),    // "blob" bootloader
328 	.driver_info =  (unsigned long) &blob_info,
329 }, {
330 	// Linux Ethernet/RNDIS gadget, mostly on PXA, second config
331 	// e.g. Gumstix, current OpenZaurus, ... or anything else
332 	// that just enables this gadget option.
333 	USB_DEVICE (0x0525, 0xa4a2),
334 	.driver_info =	(unsigned long) &linuxdev_info,
335 },
336 #endif
337 
338 	{ },		// END
339 };
340 MODULE_DEVICE_TABLE(usb, products);
341 
342 /*-------------------------------------------------------------------------*/
343 static int dummy_prereset(struct usb_interface *intf)
344 {
345         return 0;
346 }
347 
348 static int dummy_postreset(struct usb_interface *intf)
349 {
350         return 0;
351 }
352 
353 static struct usb_driver cdc_subset_driver = {
354 	.name =		"cdc_subset",
355 	.probe =	usbnet_probe,
356 	.suspend =	usbnet_suspend,
357 	.resume =	usbnet_resume,
358 	.pre_reset =	dummy_prereset,
359 	.post_reset =	dummy_postreset,
360 	.disconnect =	usbnet_disconnect,
361 	.id_table =	products,
362 	.disable_hub_initiated_lpm = 1,
363 };
364 
365 module_usb_driver(cdc_subset_driver);
366 
367 MODULE_AUTHOR("David Brownell");
368 MODULE_DESCRIPTION("Simple 'CDC Subset' USB networking links");
369 MODULE_LICENSE("GPL");
370