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1/*
2 * ether.c -- Ethernet gadget driver, with CDC and non-CDC options
3 *
4 * Copyright (C) 2003-2005,2008 David Brownell
5 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
6 * Copyright (C) 2008 Nokia Corporation
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23/* #define VERBOSE_DEBUG */
24
25#include <linux/kernel.h>
26#include <linux/utsname.h>
27
28
29#if defined USB_ETH_RNDIS
30# undef USB_ETH_RNDIS
31#endif
32#ifdef CONFIG_USB_ETH_RNDIS
33# define USB_ETH_RNDIS y
34#endif
35
36#include "u_ether.h"
37
38
39/*
40 * Ethernet gadget driver -- with CDC and non-CDC options
41 * Builds on hardware support for a full duplex link.
42 *
43 * CDC Ethernet is the standard USB solution for sending Ethernet frames
44 * using USB. Real hardware tends to use the same framing protocol but look
45 * different for control features. This driver strongly prefers to use
46 * this USB-IF standard as its open-systems interoperability solution;
47 * most host side USB stacks (except from Microsoft) support it.
48 *
49 * This is sometimes called "CDC ECM" (Ethernet Control Model) to support
50 * TLA-soup. "CDC ACM" (Abstract Control Model) is for modems, and a new
51 * "CDC EEM" (Ethernet Emulation Model) is starting to spread.
52 *
53 * There's some hardware that can't talk CDC ECM. We make that hardware
54 * implement a "minimalist" vendor-agnostic CDC core: same framing, but
55 * link-level setup only requires activating the configuration. Only the
56 * endpoint descriptors, and product/vendor IDs, are relevant; no control
57 * operations are available. Linux supports it, but other host operating
58 * systems may not. (This is a subset of CDC Ethernet.)
59 *
60 * It turns out that if you add a few descriptors to that "CDC Subset",
61 * (Windows) host side drivers from MCCI can treat it as one submode of
62 * a proprietary scheme called "SAFE" ... without needing to know about
63 * specific product/vendor IDs. So we do that, making it easier to use
64 * those MS-Windows drivers. Those added descriptors make it resemble a
65 * CDC MDLM device, but they don't change device behavior at all. (See
66 * MCCI Engineering report 950198 "SAFE Networking Functions".)
67 *
68 * A third option is also in use. Rather than CDC Ethernet, or something
69 * simpler, Microsoft pushes their own approach: RNDIS. The published
70 * RNDIS specs are ambiguous and appear to be incomplete, and are also
71 * needlessly complex. They borrow more from CDC ACM than CDC ECM.
72 */
73
74#define DRIVER_DESC "Ethernet Gadget"
75#define DRIVER_VERSION "Memorial Day 2008"
76
77#ifdef USB_ETH_RNDIS
78#define PREFIX "RNDIS/"
79#else
80#define PREFIX ""
81#endif
82
83/*
84 * This driver aims for interoperability by using CDC ECM unless
85 *
86 * can_support_ecm()
87 *
88 * returns false, in which case it supports the CDC Subset. By default,
89 * that returns true; most hardware has no problems with CDC ECM, that's
90 * a good default. Previous versions of this driver had no default; this
91 * version changes that, removing overhead for new controller support.
92 *
93 * IF YOUR HARDWARE CAN'T SUPPORT CDC ECM, UPDATE THAT ROUTINE!
94 */
95
96static inline bool has_rndis(void)
97{
98#ifdef USB_ETH_RNDIS
99 return true;
100#else
101 return false;
102#endif
103}
104
105/*-------------------------------------------------------------------------*/
106
107/*
108 * Kbuild is not very cooperative with respect to linking separately
109 * compiled library objects into one module. So for now we won't use
110 * separate compilation ... ensuring init/exit sections work to shrink
111 * the runtime footprint, and giving us at least some parts of what
112 * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
113 */
114#include "composite.c"
115#include "usbstring.c"
116#include "config.c"
117#include "epautoconf.c"
118
119#include "f_ecm.c"
120#include "f_subset.c"
121#ifdef USB_ETH_RNDIS
122#include "f_rndis.c"
123#include "rndis.c"
124#endif
125#include "f_eem.c"
126#include "u_ether.c"
127
128/*-------------------------------------------------------------------------*/
129
130/* DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!!
131 * Instead: allocate your own, using normal USB-IF procedures.
132 */
133
134/* Thanks to NetChip Technologies for donating this product ID.
135 * It's for devices with only CDC Ethernet configurations.
136 */
137#define CDC_VENDOR_NUM 0x0525 /* NetChip */
138#define CDC_PRODUCT_NUM 0xa4a1 /* Linux-USB Ethernet Gadget */
139
140/* For hardware that can't talk CDC, we use the same vendor ID that
141 * ARM Linux has used for ethernet-over-usb, both with sa1100 and
142 * with pxa250. We're protocol-compatible, if the host-side drivers
143 * use the endpoint descriptors. bcdDevice (version) is nonzero, so
144 * drivers that need to hard-wire endpoint numbers have a hook.
145 *
146 * The protocol is a minimal subset of CDC Ether, which works on any bulk
147 * hardware that's not deeply broken ... even on hardware that can't talk
148 * RNDIS (like SA-1100, with no interrupt endpoint, or anything that
149 * doesn't handle control-OUT).
150 */
151#define SIMPLE_VENDOR_NUM 0x049f
152#define SIMPLE_PRODUCT_NUM 0x505a
153
154/* For hardware that can talk RNDIS and either of the above protocols,
155 * use this ID ... the windows INF files will know it. Unless it's
156 * used with CDC Ethernet, Linux 2.4 hosts will need updates to choose
157 * the non-RNDIS configuration.
158 */
159#define RNDIS_VENDOR_NUM 0x0525 /* NetChip */
160#define RNDIS_PRODUCT_NUM 0xa4a2 /* Ethernet/RNDIS Gadget */
161
162/* For EEM gadgets */
163#define EEM_VENDOR_NUM 0x1d6b /* Linux Foundation */
164#define EEM_PRODUCT_NUM 0x0102 /* EEM Gadget */
165
166/*-------------------------------------------------------------------------*/
167
168static struct usb_device_descriptor device_desc = {
169 .bLength = sizeof device_desc,
170 .bDescriptorType = USB_DT_DEVICE,
171
172 .bcdUSB = cpu_to_le16 (0x0200),
173
174 .bDeviceClass = USB_CLASS_COMM,
175 .bDeviceSubClass = 0,
176 .bDeviceProtocol = 0,
177 /* .bMaxPacketSize0 = f(hardware) */
178
179 /* Vendor and product id defaults change according to what configs
180 * we support. (As does bNumConfigurations.) These values can
181 * also be overridden by module parameters.
182 */
183 .idVendor = cpu_to_le16 (CDC_VENDOR_NUM),
184 .idProduct = cpu_to_le16 (CDC_PRODUCT_NUM),
185 /* .bcdDevice = f(hardware) */
186 /* .iManufacturer = DYNAMIC */
187 /* .iProduct = DYNAMIC */
188 /* NO SERIAL NUMBER */
189 .bNumConfigurations = 1,
190};
191
192static struct usb_otg_descriptor otg_descriptor = {
193 .bLength = sizeof otg_descriptor,
194 .bDescriptorType = USB_DT_OTG,
195
196 /* REVISIT SRP-only hardware is possible, although
197 * it would not be called "OTG" ...
198 */
199 .bmAttributes = USB_OTG_SRP | USB_OTG_HNP,
200};
201
202static const struct usb_descriptor_header *otg_desc[] = {
203 (struct usb_descriptor_header *) &otg_descriptor,
204 NULL,
205};
206
207
208/* string IDs are assigned dynamically */
209
210#define STRING_MANUFACTURER_IDX 0
211#define STRING_PRODUCT_IDX 1
212
213static char manufacturer[50];
214
215static struct usb_string strings_dev[] = {
216 [STRING_MANUFACTURER_IDX].s = manufacturer,
217 [STRING_PRODUCT_IDX].s = PREFIX DRIVER_DESC,
218 { } /* end of list */
219};
220
221static struct usb_gadget_strings stringtab_dev = {
222 .language = 0x0409, /* en-us */
223 .strings = strings_dev,
224};
225
226static struct usb_gadget_strings *dev_strings[] = {
227 &stringtab_dev,
228 NULL,
229};
230
231static u8 hostaddr[ETH_ALEN];
232
233/*-------------------------------------------------------------------------*/
234
235/*
236 * We may not have an RNDIS configuration, but if we do it needs to be
237 * the first one present. That's to make Microsoft's drivers happy,
238 * and to follow DOCSIS 1.0 (cable modem standard).
239 */
240static int __init rndis_do_config(struct usb_configuration *c)
241{
242 /* FIXME alloc iConfiguration string, set it in c->strings */
243
244 if (gadget_is_otg(c->cdev->gadget)) {
245 c->descriptors = otg_desc;
246 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
247 }
248
249 return rndis_bind_config(c, hostaddr);
250}
251
252static struct usb_configuration rndis_config_driver = {
253 .label = "RNDIS",
254 .bConfigurationValue = 2,
255 /* .iConfiguration = DYNAMIC */
256 .bmAttributes = USB_CONFIG_ATT_SELFPOWER,
257};
258
259/*-------------------------------------------------------------------------*/
260
261#ifdef CONFIG_USB_ETH_EEM
262static int use_eem = 1;
263#else
264static int use_eem;
265#endif
266module_param(use_eem, bool, 0);
267MODULE_PARM_DESC(use_eem, "use CDC EEM mode");
268
269/*
270 * We _always_ have an ECM, CDC Subset, or EEM configuration.
271 */
272static int __init eth_do_config(struct usb_configuration *c)
273{
274 /* FIXME alloc iConfiguration string, set it in c->strings */
275
276 if (gadget_is_otg(c->cdev->gadget)) {
277 c->descriptors = otg_desc;
278 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
279 }
280
281 if (use_eem)
282 return eem_bind_config(c);
283 else if (can_support_ecm(c->cdev->gadget))
284 return ecm_bind_config(c, hostaddr);
285 else
286 return geth_bind_config(c, hostaddr);
287}
288
289static struct usb_configuration eth_config_driver = {
290 /* .label = f(hardware) */
291 .bConfigurationValue = 1,
292 /* .iConfiguration = DYNAMIC */
293 .bmAttributes = USB_CONFIG_ATT_SELFPOWER,
294};
295
296/*-------------------------------------------------------------------------*/
297
298static int __init eth_bind(struct usb_composite_dev *cdev)
299{
300 int gcnum;
301 struct usb_gadget *gadget = cdev->gadget;
302 int status;
303
304 /* set up network link layer */
305 status = gether_setup(cdev->gadget, hostaddr);
306 if (status < 0)
307 return status;
308
309 /* set up main config label and device descriptor */
310 if (use_eem) {
311 /* EEM */
312 eth_config_driver.label = "CDC Ethernet (EEM)";
313 device_desc.idVendor = cpu_to_le16(EEM_VENDOR_NUM);
314 device_desc.idProduct = cpu_to_le16(EEM_PRODUCT_NUM);
315 } else if (can_support_ecm(cdev->gadget)) {
316 /* ECM */
317 eth_config_driver.label = "CDC Ethernet (ECM)";
318 } else {
319 /* CDC Subset */
320 eth_config_driver.label = "CDC Subset/SAFE";
321
322 device_desc.idVendor = cpu_to_le16(SIMPLE_VENDOR_NUM);
323 device_desc.idProduct = cpu_to_le16(SIMPLE_PRODUCT_NUM);
324 if (!has_rndis())
325 device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
326 }
327
328 if (has_rndis()) {
329 /* RNDIS plus ECM-or-Subset */
330 device_desc.idVendor = cpu_to_le16(RNDIS_VENDOR_NUM);
331 device_desc.idProduct = cpu_to_le16(RNDIS_PRODUCT_NUM);
332 device_desc.bNumConfigurations = 2;
333 }
334
335 gcnum = usb_gadget_controller_number(gadget);
336 if (gcnum >= 0)
337 device_desc.bcdDevice = cpu_to_le16(0x0300 | gcnum);
338 else {
339 /* We assume that can_support_ecm() tells the truth;
340 * but if the controller isn't recognized at all then
341 * that assumption is a bit more likely to be wrong.
342 */
343 dev_warn(&gadget->dev,
344 "controller '%s' not recognized; trying %s\n",
345 gadget->name,
346 eth_config_driver.label);
347 device_desc.bcdDevice =
348 cpu_to_le16(0x0300 | 0x0099);
349 }
350
351
352 /* Allocate string descriptor numbers ... note that string
353 * contents can be overridden by the composite_dev glue.
354 */
355
356 /* device descriptor strings: manufacturer, product */
357 snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
358 init_utsname()->sysname, init_utsname()->release,
359 gadget->name);
360 status = usb_string_id(cdev);
361 if (status < 0)
362 goto fail;
363 strings_dev[STRING_MANUFACTURER_IDX].id = status;
364 device_desc.iManufacturer = status;
365
366 status = usb_string_id(cdev);
367 if (status < 0)
368 goto fail;
369 strings_dev[STRING_PRODUCT_IDX].id = status;
370 device_desc.iProduct = status;
371
372 /* register our configuration(s); RNDIS first, if it's used */
373 if (has_rndis()) {
374 status = usb_add_config(cdev, &rndis_config_driver,
375 rndis_do_config);
376 if (status < 0)
377 goto fail;
378 }
379
380 status = usb_add_config(cdev, ð_config_driver, eth_do_config);
381 if (status < 0)
382 goto fail;
383
384 dev_info(&gadget->dev, "%s, version: " DRIVER_VERSION "\n",
385 DRIVER_DESC);
386
387 return 0;
388
389fail:
390 gether_cleanup();
391 return status;
392}
393
394static int __exit eth_unbind(struct usb_composite_dev *cdev)
395{
396 gether_cleanup();
397 return 0;
398}
399
400static struct usb_composite_driver eth_driver = {
401 .name = "g_ether",
402 .dev = &device_desc,
403 .strings = dev_strings,
404 .max_speed = USB_SPEED_SUPER,
405 .unbind = __exit_p(eth_unbind),
406};
407
408MODULE_DESCRIPTION(PREFIX DRIVER_DESC);
409MODULE_AUTHOR("David Brownell, Benedikt Spanger");
410MODULE_LICENSE("GPL");
411
412static int __init init(void)
413{
414 return usb_composite_probe(ð_driver, eth_bind);
415}
416module_init(init);
417
418static void __exit cleanup(void)
419{
420 usb_composite_unregister(ð_driver);
421}
422module_exit(cleanup);