1 /*
2 * f_subset.c -- "CDC Subset" Ethernet link function driver
3 *
4 * Copyright (C) 2003-2005,2008 David Brownell
5 * Copyright (C) 2008 Nokia Corporation
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22 #include <linux/kernel.h>
23 #include <linux/device.h>
24 #include <linux/etherdevice.h>
25
26 #include "u_ether.h"
27
28
29 /*
30 * This function packages a simple "CDC Subset" Ethernet port with no real
31 * control mechanisms; just raw data transfer over two bulk endpoints.
32 * The data transfer model is exactly that of CDC Ethernet, which is
33 * why we call it the "CDC Subset".
34 *
35 * Because it's not standardized, this has some interoperability issues.
36 * They mostly relate to driver binding, since the data transfer model is
37 * so simple (CDC Ethernet). The original versions of this protocol used
38 * specific product/vendor IDs: byteswapped IDs for Digital Equipment's
39 * SA-1100 "Itsy" board, which could run Linux 2.4 kernels and supported
40 * daughtercards with USB peripheral connectors. (It was used more often
41 * with other boards, using the Itsy identifiers.) Linux hosts recognized
42 * this with CONFIG_USB_ARMLINUX; these devices have only one configuration
43 * and one interface.
44 *
45 * At some point, MCCI defined a (nonconformant) CDC MDLM variant called
46 * "SAFE", which happens to have a mode which is identical to the "CDC
47 * Subset" in terms of data transfer and lack of control model. This was
48 * adopted by later Sharp Zaurus models, and by some other software which
49 * Linux hosts recognize with CONFIG_USB_NET_ZAURUS.
50 *
51 * Because Microsoft's RNDIS drivers are far from robust, we added a few
52 * descriptors to the CDC Subset code, making this code look like a SAFE
53 * implementation. This lets you use MCCI's host side MS-Windows drivers
54 * if you get fed up with RNDIS. It also makes it easier for composite
55 * drivers to work, since they can use class based binding instead of
56 * caring about specific product and vendor IDs.
57 */
58
59 struct geth_descs {
60 struct usb_endpoint_descriptor *in;
61 struct usb_endpoint_descriptor *out;
62 };
63
64 struct f_gether {
65 struct gether port;
66
67 char ethaddr[14];
68
69 struct geth_descs fs;
70 struct geth_descs hs;
71 };
72
73 static inline struct f_gether *func_to_geth(struct usb_function *f)
74 {
75 return container_of(f, struct f_gether, port.func);
76 }
77
78 /*-------------------------------------------------------------------------*/
79
80 /*
81 * "Simple" CDC-subset option is a simple vendor-neutral model that most
82 * full speed controllers can handle: one interface, two bulk endpoints.
83 * To assist host side drivers, we fancy it up a bit, and add descriptors so
84 * some host side drivers will understand it as a "SAFE" variant.
85 *
86 * "SAFE" loosely follows CDC WMC MDLM, violating the spec in various ways.
87 * Data endpoints live in the control interface, there's no data interface.
88 * And it's not used to talk to a cell phone radio.
89 */
90
91 /* interface descriptor: */
92
93 static struct usb_interface_descriptor subset_data_intf __initdata = {
94 .bLength = sizeof subset_data_intf,
95 .bDescriptorType = USB_DT_INTERFACE,
96
97 /* .bInterfaceNumber = DYNAMIC */
98 .bAlternateSetting = 0,
99 .bNumEndpoints = 2,
100 .bInterfaceClass = USB_CLASS_COMM,
101 .bInterfaceSubClass = USB_CDC_SUBCLASS_MDLM,
102 .bInterfaceProtocol = 0,
103 /* .iInterface = DYNAMIC */
104 };
105
106 static struct usb_cdc_header_desc mdlm_header_desc __initdata = {
107 .bLength = sizeof mdlm_header_desc,
108 .bDescriptorType = USB_DT_CS_INTERFACE,
109 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
110
111 .bcdCDC = cpu_to_le16(0x0110),
112 };
113
114 static struct usb_cdc_mdlm_desc mdlm_desc __initdata = {
115 .bLength = sizeof mdlm_desc,
116 .bDescriptorType = USB_DT_CS_INTERFACE,
117 .bDescriptorSubType = USB_CDC_MDLM_TYPE,
118
119 .bcdVersion = cpu_to_le16(0x0100),
120 .bGUID = {
121 0x5d, 0x34, 0xcf, 0x66, 0x11, 0x18, 0x11, 0xd6,
122 0xa2, 0x1a, 0x00, 0x01, 0x02, 0xca, 0x9a, 0x7f,
123 },
124 };
125
126 /* since "usb_cdc_mdlm_detail_desc" is a variable length structure, we
127 * can't really use its struct. All we do here is say that we're using
128 * the submode of "SAFE" which directly matches the CDC Subset.
129 */
130 static u8 mdlm_detail_desc[] __initdata = {
131 6,
132 USB_DT_CS_INTERFACE,
133 USB_CDC_MDLM_DETAIL_TYPE,
134
135 0, /* "SAFE" */
136 0, /* network control capabilities (none) */
137 0, /* network data capabilities ("raw" encapsulation) */
138 };
139
140 static struct usb_cdc_ether_desc ether_desc __initdata = {
141 .bLength = sizeof ether_desc,
142 .bDescriptorType = USB_DT_CS_INTERFACE,
143 .bDescriptorSubType = USB_CDC_ETHERNET_TYPE,
144
145 /* this descriptor actually adds value, surprise! */
146 /* .iMACAddress = DYNAMIC */
147 .bmEthernetStatistics = cpu_to_le32(0), /* no statistics */
148 .wMaxSegmentSize = cpu_to_le16(ETH_FRAME_LEN),
149 .wNumberMCFilters = cpu_to_le16(0),
150 .bNumberPowerFilters = 0,
151 };
152
153 /* full speed support: */
154
155 static struct usb_endpoint_descriptor fs_subset_in_desc __initdata = {
156 .bLength = USB_DT_ENDPOINT_SIZE,
157 .bDescriptorType = USB_DT_ENDPOINT,
158
159 .bEndpointAddress = USB_DIR_IN,
160 .bmAttributes = USB_ENDPOINT_XFER_BULK,
161 };
162
163 static struct usb_endpoint_descriptor fs_subset_out_desc __initdata = {
164 .bLength = USB_DT_ENDPOINT_SIZE,
165 .bDescriptorType = USB_DT_ENDPOINT,
166
167 .bEndpointAddress = USB_DIR_OUT,
168 .bmAttributes = USB_ENDPOINT_XFER_BULK,
169 };
170
171 static struct usb_descriptor_header *fs_eth_function[] __initdata = {
172 (struct usb_descriptor_header *) &subset_data_intf,
173 (struct usb_descriptor_header *) &mdlm_header_desc,
174 (struct usb_descriptor_header *) &mdlm_desc,
175 (struct usb_descriptor_header *) &mdlm_detail_desc,
176 (struct usb_descriptor_header *) ðer_desc,
177 (struct usb_descriptor_header *) &fs_subset_in_desc,
178 (struct usb_descriptor_header *) &fs_subset_out_desc,
179 NULL,
180 };
181
182 /* high speed support: */
183
184 static struct usb_endpoint_descriptor hs_subset_in_desc __initdata = {
185 .bLength = USB_DT_ENDPOINT_SIZE,
186 .bDescriptorType = USB_DT_ENDPOINT,
187
188 .bmAttributes = USB_ENDPOINT_XFER_BULK,
189 .wMaxPacketSize = cpu_to_le16(512),
190 };
191
192 static struct usb_endpoint_descriptor hs_subset_out_desc __initdata = {
193 .bLength = USB_DT_ENDPOINT_SIZE,
194 .bDescriptorType = USB_DT_ENDPOINT,
195
196 .bmAttributes = USB_ENDPOINT_XFER_BULK,
197 .wMaxPacketSize = cpu_to_le16(512),
198 };
199
200 static struct usb_descriptor_header *hs_eth_function[] __initdata = {
201 (struct usb_descriptor_header *) &subset_data_intf,
202 (struct usb_descriptor_header *) &mdlm_header_desc,
203 (struct usb_descriptor_header *) &mdlm_desc,
204 (struct usb_descriptor_header *) &mdlm_detail_desc,
205 (struct usb_descriptor_header *) ðer_desc,
206 (struct usb_descriptor_header *) &hs_subset_in_desc,
207 (struct usb_descriptor_header *) &hs_subset_out_desc,
208 NULL,
209 };
210
211 /* string descriptors: */
212
213 static struct usb_string geth_string_defs[] = {
214 [0].s = "CDC Ethernet Subset/SAFE",
215 [1].s = NULL /* DYNAMIC */,
216 { } /* end of list */
217 };
218
219 static struct usb_gadget_strings geth_string_table = {
220 .language = 0x0409, /* en-us */
221 .strings = geth_string_defs,
222 };
223
224 static struct usb_gadget_strings *geth_strings[] = {
225 &geth_string_table,
226 NULL,
227 };
228
229 /*-------------------------------------------------------------------------*/
230
231 static int geth_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
232 {
233 struct f_gether *geth = func_to_geth(f);
234 struct usb_composite_dev *cdev = f->config->cdev;
235 struct net_device *net;
236
237 /* we know alt == 0, so this is an activation or a reset */
238
239 if (geth->port.in_ep->driver_data) {
240 DBG(cdev, "reset cdc subset\n");
241 gether_disconnect(&geth->port);
242 }
243
244 DBG(cdev, "init + activate cdc subset\n");
245 geth->port.in = ep_choose(cdev->gadget,
246 geth->hs.in, geth->fs.in);
247 geth->port.out = ep_choose(cdev->gadget,
248 geth->hs.out, geth->fs.out);
249
250 net = gether_connect(&geth->port);
251 return IS_ERR(net) ? PTR_ERR(net) : 0;
252 }
253
254 static void geth_disable(struct usb_function *f)
255 {
256 struct f_gether *geth = func_to_geth(f);
257 struct usb_composite_dev *cdev = f->config->cdev;
258
259 DBG(cdev, "net deactivated\n");
260 gether_disconnect(&geth->port);
261 }
262
263 /*-------------------------------------------------------------------------*/
264
265 /* serial function driver setup/binding */
266
267 static int __init
268 geth_bind(struct usb_configuration *c, struct usb_function *f)
269 {
270 struct usb_composite_dev *cdev = c->cdev;
271 struct f_gether *geth = func_to_geth(f);
272 int status;
273 struct usb_ep *ep;
274
275 /* allocate instance-specific interface IDs */
276 status = usb_interface_id(c, f);
277 if (status < 0)
278 goto fail;
279 subset_data_intf.bInterfaceNumber = status;
280
281 status = -ENODEV;
282
283 /* allocate instance-specific endpoints */
284 ep = usb_ep_autoconfig(cdev->gadget, &fs_subset_in_desc);
285 if (!ep)
286 goto fail;
287 geth->port.in_ep = ep;
288 ep->driver_data = cdev; /* claim */
289
290 ep = usb_ep_autoconfig(cdev->gadget, &fs_subset_out_desc);
291 if (!ep)
292 goto fail;
293 geth->port.out_ep = ep;
294 ep->driver_data = cdev; /* claim */
295
296 /* copy descriptors, and track endpoint copies */
297 f->descriptors = usb_copy_descriptors(fs_eth_function);
298
299 geth->fs.in = usb_find_endpoint(fs_eth_function,
300 f->descriptors, &fs_subset_in_desc);
301 geth->fs.out = usb_find_endpoint(fs_eth_function,
302 f->descriptors, &fs_subset_out_desc);
303
304
305 /* support all relevant hardware speeds... we expect that when
306 * hardware is dual speed, all bulk-capable endpoints work at
307 * both speeds
308 */
309 if (gadget_is_dualspeed(c->cdev->gadget)) {
310 hs_subset_in_desc.bEndpointAddress =
311 fs_subset_in_desc.bEndpointAddress;
312 hs_subset_out_desc.bEndpointAddress =
313 fs_subset_out_desc.bEndpointAddress;
314
315 /* copy descriptors, and track endpoint copies */
316 f->hs_descriptors = usb_copy_descriptors(hs_eth_function);
317
318 geth->hs.in = usb_find_endpoint(hs_eth_function,
319 f->hs_descriptors, &hs_subset_in_desc);
320 geth->hs.out = usb_find_endpoint(hs_eth_function,
321 f->hs_descriptors, &hs_subset_out_desc);
322 }
323
324 /* NOTE: all that is done without knowing or caring about
325 * the network link ... which is unavailable to this code
326 * until we're activated via set_alt().
327 */
328
329 DBG(cdev, "CDC Subset: %s speed IN/%s OUT/%s\n",
330 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
331 geth->port.in_ep->name, geth->port.out_ep->name);
332 return 0;
333
334 fail:
335 /* we might as well release our claims on endpoints */
336 if (geth->port.out)
337 geth->port.out_ep->driver_data = NULL;
338 if (geth->port.in)
339 geth->port.in_ep->driver_data = NULL;
340
341 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
342
343 return status;
344 }
345
346 static void
347 geth_unbind(struct usb_configuration *c, struct usb_function *f)
348 {
349 if (gadget_is_dualspeed(c->cdev->gadget))
350 usb_free_descriptors(f->hs_descriptors);
351 usb_free_descriptors(f->descriptors);
352 geth_string_defs[1].s = NULL;
353 kfree(func_to_geth(f));
354 }
355
356 /**
357 * geth_bind_config - add CDC Subset network link to a configuration
358 * @c: the configuration to support the network link
359 * @ethaddr: a buffer in which the ethernet address of the host side
360 * side of the link was recorded
361 * Context: single threaded during gadget setup
362 *
363 * Returns zero on success, else negative errno.
364 *
365 * Caller must have called @gether_setup(). Caller is also responsible
366 * for calling @gether_cleanup() before module unload.
367 */
368 int __init geth_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN])
369 {
370 struct f_gether *geth;
371 int status;
372
373 if (!ethaddr)
374 return -EINVAL;
375
376 /* maybe allocate device-global string IDs */
377 if (geth_string_defs[0].id == 0) {
378
379 /* interface label */
380 status = usb_string_id(c->cdev);
381 if (status < 0)
382 return status;
383 geth_string_defs[0].id = status;
384 subset_data_intf.iInterface = status;
385
386 /* MAC address */
387 status = usb_string_id(c->cdev);
388 if (status < 0)
389 return status;
390 geth_string_defs[1].id = status;
391 ether_desc.iMACAddress = status;
392 }
393
394 /* allocate and initialize one new instance */
395 geth = kzalloc(sizeof *geth, GFP_KERNEL);
396 if (!geth)
397 return -ENOMEM;
398
399 /* export host's Ethernet address in CDC format */
400 snprintf(geth->ethaddr, sizeof geth->ethaddr,
401 "%02X%02X%02X%02X%02X%02X",
402 ethaddr[0], ethaddr[1], ethaddr[2],
403 ethaddr[3], ethaddr[4], ethaddr[5]);
404 geth_string_defs[1].s = geth->ethaddr;
405
406 geth->port.cdc_filter = DEFAULT_FILTER;
407
408 geth->port.func.name = "cdc_subset";
409 geth->port.func.strings = geth_strings;
410 geth->port.func.bind = geth_bind;
411 geth->port.func.unbind = geth_unbind;
412 geth->port.func.set_alt = geth_set_alt;
413 geth->port.func.disable = geth_disable;
414
415 status = usb_add_function(c, &geth->port.func);
416 if (status) {
417 geth_string_defs[1].s = NULL;
418 kfree(geth);
419 }
420 return status;
421 }
422
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