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