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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/slab.h>
23#include <linux/kernel.h>
24#include <linux/device.h>
25#include <linux/etherdevice.h>
26
27#include "u_ether.h"
28
29
30/*
31 * This function packages a simple "CDC Subset" Ethernet port with no real
32 * control mechanisms; just raw data transfer over two bulk endpoints.
33 * The data transfer model is exactly that of CDC Ethernet, which is
34 * why we call it the "CDC Subset".
35 *
36 * Because it's not standardized, this has some interoperability issues.
37 * They mostly relate to driver binding, since the data transfer model is
38 * so simple (CDC Ethernet). The original versions of this protocol used
39 * specific product/vendor IDs: byteswapped IDs for Digital Equipment's
40 * SA-1100 "Itsy" board, which could run Linux 2.4 kernels and supported
41 * daughtercards with USB peripheral connectors. (It was used more often
42 * with other boards, using the Itsy identifiers.) Linux hosts recognized
43 * this with CONFIG_USB_ARMLINUX; these devices have only one configuration
44 * and one interface.
45 *
46 * At some point, MCCI defined a (nonconformant) CDC MDLM variant called
47 * "SAFE", which happens to have a mode which is identical to the "CDC
48 * Subset" in terms of data transfer and lack of control model. This was
49 * adopted by later Sharp Zaurus models, and by some other software which
50 * Linux hosts recognize with CONFIG_USB_NET_ZAURUS.
51 *
52 * Because Microsoft's RNDIS drivers are far from robust, we added a few
53 * descriptors to the CDC Subset code, making this code look like a SAFE
54 * implementation. This lets you use MCCI's host side MS-Windows drivers
55 * if you get fed up with RNDIS. It also makes it easier for composite
56 * drivers to work, since they can use class based binding instead of
57 * caring about specific product and vendor IDs.
58 */
59
60struct f_gether {
61 struct gether port;
62
63 char ethaddr[14];
64};
65
66static inline struct f_gether *func_to_geth(struct usb_function *f)
67{
68 return container_of(f, struct f_gether, port.func);
69}
70
71/*-------------------------------------------------------------------------*/
72
73/*
74 * "Simple" CDC-subset option is a simple vendor-neutral model that most
75 * full speed controllers can handle: one interface, two bulk endpoints.
76 * To assist host side drivers, we fancy it up a bit, and add descriptors so
77 * some host side drivers will understand it as a "SAFE" variant.
78 *
79 * "SAFE" loosely follows CDC WMC MDLM, violating the spec in various ways.
80 * Data endpoints live in the control interface, there's no data interface.
81 * And it's not used to talk to a cell phone radio.
82 */
83
84/* interface descriptor: */
85
86static struct usb_interface_descriptor subset_data_intf __initdata = {
87 .bLength = sizeof subset_data_intf,
88 .bDescriptorType = USB_DT_INTERFACE,
89
90 /* .bInterfaceNumber = DYNAMIC */
91 .bAlternateSetting = 0,
92 .bNumEndpoints = 2,
93 .bInterfaceClass = USB_CLASS_COMM,
94 .bInterfaceSubClass = USB_CDC_SUBCLASS_MDLM,
95 .bInterfaceProtocol = 0,
96 /* .iInterface = DYNAMIC */
97};
98
99static struct usb_cdc_header_desc mdlm_header_desc __initdata = {
100 .bLength = sizeof mdlm_header_desc,
101 .bDescriptorType = USB_DT_CS_INTERFACE,
102 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
103
104 .bcdCDC = cpu_to_le16(0x0110),
105};
106
107static struct usb_cdc_mdlm_desc mdlm_desc __initdata = {
108 .bLength = sizeof mdlm_desc,
109 .bDescriptorType = USB_DT_CS_INTERFACE,
110 .bDescriptorSubType = USB_CDC_MDLM_TYPE,
111
112 .bcdVersion = cpu_to_le16(0x0100),
113 .bGUID = {
114 0x5d, 0x34, 0xcf, 0x66, 0x11, 0x18, 0x11, 0xd6,
115 0xa2, 0x1a, 0x00, 0x01, 0x02, 0xca, 0x9a, 0x7f,
116 },
117};
118
119/* since "usb_cdc_mdlm_detail_desc" is a variable length structure, we
120 * can't really use its struct. All we do here is say that we're using
121 * the submode of "SAFE" which directly matches the CDC Subset.
122 */
123static u8 mdlm_detail_desc[] __initdata = {
124 6,
125 USB_DT_CS_INTERFACE,
126 USB_CDC_MDLM_DETAIL_TYPE,
127
128 0, /* "SAFE" */
129 0, /* network control capabilities (none) */
130 0, /* network data capabilities ("raw" encapsulation) */
131};
132
133static struct usb_cdc_ether_desc ether_desc __initdata = {
134 .bLength = sizeof ether_desc,
135 .bDescriptorType = USB_DT_CS_INTERFACE,
136 .bDescriptorSubType = USB_CDC_ETHERNET_TYPE,
137
138 /* this descriptor actually adds value, surprise! */
139 /* .iMACAddress = DYNAMIC */
140 .bmEthernetStatistics = cpu_to_le32(0), /* no statistics */
141 .wMaxSegmentSize = cpu_to_le16(ETH_FRAME_LEN),
142 .wNumberMCFilters = cpu_to_le16(0),
143 .bNumberPowerFilters = 0,
144};
145
146/* full speed support: */
147
148static struct usb_endpoint_descriptor fs_subset_in_desc __initdata = {
149 .bLength = USB_DT_ENDPOINT_SIZE,
150 .bDescriptorType = USB_DT_ENDPOINT,
151
152 .bEndpointAddress = USB_DIR_IN,
153 .bmAttributes = USB_ENDPOINT_XFER_BULK,
154};
155
156static struct usb_endpoint_descriptor fs_subset_out_desc __initdata = {
157 .bLength = USB_DT_ENDPOINT_SIZE,
158 .bDescriptorType = USB_DT_ENDPOINT,
159
160 .bEndpointAddress = USB_DIR_OUT,
161 .bmAttributes = USB_ENDPOINT_XFER_BULK,
162};
163
164static struct usb_descriptor_header *fs_eth_function[] __initdata = {
165 (struct usb_descriptor_header *) &subset_data_intf,
166 (struct usb_descriptor_header *) &mdlm_header_desc,
167 (struct usb_descriptor_header *) &mdlm_desc,
168 (struct usb_descriptor_header *) &mdlm_detail_desc,
169 (struct usb_descriptor_header *) ðer_desc,
170 (struct usb_descriptor_header *) &fs_subset_in_desc,
171 (struct usb_descriptor_header *) &fs_subset_out_desc,
172 NULL,
173};
174
175/* high speed support: */
176
177static struct usb_endpoint_descriptor hs_subset_in_desc __initdata = {
178 .bLength = USB_DT_ENDPOINT_SIZE,
179 .bDescriptorType = USB_DT_ENDPOINT,
180
181 .bmAttributes = USB_ENDPOINT_XFER_BULK,
182 .wMaxPacketSize = cpu_to_le16(512),
183};
184
185static struct usb_endpoint_descriptor hs_subset_out_desc __initdata = {
186 .bLength = USB_DT_ENDPOINT_SIZE,
187 .bDescriptorType = USB_DT_ENDPOINT,
188
189 .bmAttributes = USB_ENDPOINT_XFER_BULK,
190 .wMaxPacketSize = cpu_to_le16(512),
191};
192
193static struct usb_descriptor_header *hs_eth_function[] __initdata = {
194 (struct usb_descriptor_header *) &subset_data_intf,
195 (struct usb_descriptor_header *) &mdlm_header_desc,
196 (struct usb_descriptor_header *) &mdlm_desc,
197 (struct usb_descriptor_header *) &mdlm_detail_desc,
198 (struct usb_descriptor_header *) ðer_desc,
199 (struct usb_descriptor_header *) &hs_subset_in_desc,
200 (struct usb_descriptor_header *) &hs_subset_out_desc,
201 NULL,
202};
203
204/* super speed support: */
205
206static struct usb_endpoint_descriptor ss_subset_in_desc __initdata = {
207 .bLength = USB_DT_ENDPOINT_SIZE,
208 .bDescriptorType = USB_DT_ENDPOINT,
209
210 .bmAttributes = USB_ENDPOINT_XFER_BULK,
211 .wMaxPacketSize = cpu_to_le16(1024),
212};
213
214static struct usb_endpoint_descriptor ss_subset_out_desc __initdata = {
215 .bLength = USB_DT_ENDPOINT_SIZE,
216 .bDescriptorType = USB_DT_ENDPOINT,
217
218 .bmAttributes = USB_ENDPOINT_XFER_BULK,
219 .wMaxPacketSize = cpu_to_le16(1024),
220};
221
222static struct usb_ss_ep_comp_descriptor ss_subset_bulk_comp_desc __initdata = {
223 .bLength = sizeof ss_subset_bulk_comp_desc,
224 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
225
226 /* the following 2 values can be tweaked if necessary */
227 /* .bMaxBurst = 0, */
228 /* .bmAttributes = 0, */
229};
230
231static struct usb_descriptor_header *ss_eth_function[] __initdata = {
232 (struct usb_descriptor_header *) &subset_data_intf,
233 (struct usb_descriptor_header *) &mdlm_header_desc,
234 (struct usb_descriptor_header *) &mdlm_desc,
235 (struct usb_descriptor_header *) &mdlm_detail_desc,
236 (struct usb_descriptor_header *) ðer_desc,
237 (struct usb_descriptor_header *) &ss_subset_in_desc,
238 (struct usb_descriptor_header *) &ss_subset_bulk_comp_desc,
239 (struct usb_descriptor_header *) &ss_subset_out_desc,
240 (struct usb_descriptor_header *) &ss_subset_bulk_comp_desc,
241 NULL,
242};
243
244/* string descriptors: */
245
246static struct usb_string geth_string_defs[] = {
247 [0].s = "CDC Ethernet Subset/SAFE",
248 [1].s = NULL /* DYNAMIC */,
249 { } /* end of list */
250};
251
252static struct usb_gadget_strings geth_string_table = {
253 .language = 0x0409, /* en-us */
254 .strings = geth_string_defs,
255};
256
257static struct usb_gadget_strings *geth_strings[] = {
258 &geth_string_table,
259 NULL,
260};
261
262/*-------------------------------------------------------------------------*/
263
264static int geth_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
265{
266 struct f_gether *geth = func_to_geth(f);
267 struct usb_composite_dev *cdev = f->config->cdev;
268 struct net_device *net;
269
270 /* we know alt == 0, so this is an activation or a reset */
271
272 if (geth->port.in_ep->driver_data) {
273 DBG(cdev, "reset cdc subset\n");
274 gether_disconnect(&geth->port);
275 }
276
277 DBG(cdev, "init + activate cdc subset\n");
278 if (config_ep_by_speed(cdev->gadget, f, geth->port.in_ep) ||
279 config_ep_by_speed(cdev->gadget, f, geth->port.out_ep)) {
280 geth->port.in_ep->desc = NULL;
281 geth->port.out_ep->desc = NULL;
282 return -EINVAL;
283 }
284
285 net = gether_connect(&geth->port);
286 return IS_ERR(net) ? PTR_ERR(net) : 0;
287}
288
289static void geth_disable(struct usb_function *f)
290{
291 struct f_gether *geth = func_to_geth(f);
292 struct usb_composite_dev *cdev = f->config->cdev;
293
294 DBG(cdev, "net deactivated\n");
295 gether_disconnect(&geth->port);
296}
297
298/*-------------------------------------------------------------------------*/
299
300/* serial function driver setup/binding */
301
302static int __init
303geth_bind(struct usb_configuration *c, struct usb_function *f)
304{
305 struct usb_composite_dev *cdev = c->cdev;
306 struct f_gether *geth = func_to_geth(f);
307 int status;
308 struct usb_ep *ep;
309
310 /* allocate instance-specific interface IDs */
311 status = usb_interface_id(c, f);
312 if (status < 0)
313 goto fail;
314 subset_data_intf.bInterfaceNumber = status;
315
316 status = -ENODEV;
317
318 /* allocate instance-specific endpoints */
319 ep = usb_ep_autoconfig(cdev->gadget, &fs_subset_in_desc);
320 if (!ep)
321 goto fail;
322 geth->port.in_ep = ep;
323 ep->driver_data = cdev; /* claim */
324
325 ep = usb_ep_autoconfig(cdev->gadget, &fs_subset_out_desc);
326 if (!ep)
327 goto fail;
328 geth->port.out_ep = ep;
329 ep->driver_data = cdev; /* claim */
330
331 /* copy descriptors, and track endpoint copies */
332 f->descriptors = usb_copy_descriptors(fs_eth_function);
333 if (!f->descriptors)
334 goto fail;
335
336 /* support all relevant hardware speeds... we expect that when
337 * hardware is dual speed, all bulk-capable endpoints work at
338 * both speeds
339 */
340 if (gadget_is_dualspeed(c->cdev->gadget)) {
341 hs_subset_in_desc.bEndpointAddress =
342 fs_subset_in_desc.bEndpointAddress;
343 hs_subset_out_desc.bEndpointAddress =
344 fs_subset_out_desc.bEndpointAddress;
345
346 /* copy descriptors, and track endpoint copies */
347 f->hs_descriptors = usb_copy_descriptors(hs_eth_function);
348 if (!f->hs_descriptors)
349 goto fail;
350 }
351
352 if (gadget_is_superspeed(c->cdev->gadget)) {
353 ss_subset_in_desc.bEndpointAddress =
354 fs_subset_in_desc.bEndpointAddress;
355 ss_subset_out_desc.bEndpointAddress =
356 fs_subset_out_desc.bEndpointAddress;
357
358 /* copy descriptors, and track endpoint copies */
359 f->ss_descriptors = usb_copy_descriptors(ss_eth_function);
360 if (!f->ss_descriptors)
361 goto fail;
362 }
363
364 /* NOTE: all that is done without knowing or caring about
365 * the network link ... which is unavailable to this code
366 * until we're activated via set_alt().
367 */
368
369 DBG(cdev, "CDC Subset: %s speed IN/%s OUT/%s\n",
370 gadget_is_superspeed(c->cdev->gadget) ? "super" :
371 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
372 geth->port.in_ep->name, geth->port.out_ep->name);
373 return 0;
374
375fail:
376 if (f->descriptors)
377 usb_free_descriptors(f->descriptors);
378 if (f->hs_descriptors)
379 usb_free_descriptors(f->hs_descriptors);
380
381 /* we might as well release our claims on endpoints */
382 if (geth->port.out_ep->desc)
383 geth->port.out_ep->driver_data = NULL;
384 if (geth->port.in_ep->desc)
385 geth->port.in_ep->driver_data = NULL;
386
387 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
388
389 return status;
390}
391
392static void
393geth_unbind(struct usb_configuration *c, struct usb_function *f)
394{
395 if (gadget_is_superspeed(c->cdev->gadget))
396 usb_free_descriptors(f->ss_descriptors);
397 if (gadget_is_dualspeed(c->cdev->gadget))
398 usb_free_descriptors(f->hs_descriptors);
399 usb_free_descriptors(f->descriptors);
400 geth_string_defs[1].s = NULL;
401 kfree(func_to_geth(f));
402}
403
404/**
405 * geth_bind_config - add CDC Subset network link to a configuration
406 * @c: the configuration to support the network link
407 * @ethaddr: a buffer in which the ethernet address of the host side
408 * side of the link was recorded
409 * Context: single threaded during gadget setup
410 *
411 * Returns zero on success, else negative errno.
412 *
413 * Caller must have called @gether_setup(). Caller is also responsible
414 * for calling @gether_cleanup() before module unload.
415 */
416int __init geth_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN])
417{
418 struct f_gether *geth;
419 int status;
420
421 if (!ethaddr)
422 return -EINVAL;
423
424 /* maybe allocate device-global string IDs */
425 if (geth_string_defs[0].id == 0) {
426
427 /* interface label */
428 status = usb_string_id(c->cdev);
429 if (status < 0)
430 return status;
431 geth_string_defs[0].id = status;
432 subset_data_intf.iInterface = status;
433
434 /* MAC address */
435 status = usb_string_id(c->cdev);
436 if (status < 0)
437 return status;
438 geth_string_defs[1].id = status;
439 ether_desc.iMACAddress = status;
440 }
441
442 /* allocate and initialize one new instance */
443 geth = kzalloc(sizeof *geth, GFP_KERNEL);
444 if (!geth)
445 return -ENOMEM;
446
447 /* export host's Ethernet address in CDC format */
448 snprintf(geth->ethaddr, sizeof geth->ethaddr,
449 "%02X%02X%02X%02X%02X%02X",
450 ethaddr[0], ethaddr[1], ethaddr[2],
451 ethaddr[3], ethaddr[4], ethaddr[5]);
452 geth_string_defs[1].s = geth->ethaddr;
453
454 geth->port.cdc_filter = DEFAULT_FILTER;
455
456 geth->port.func.name = "cdc_subset";
457 geth->port.func.strings = geth_strings;
458 geth->port.func.bind = geth_bind;
459 geth->port.func.unbind = geth_unbind;
460 geth->port.func.set_alt = geth_set_alt;
461 geth->port.func.disable = geth_disable;
462
463 status = usb_add_function(c, &geth->port.func);
464 if (status) {
465 geth_string_defs[1].s = NULL;
466 kfree(geth);
467 }
468 return status;
469}