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Add linux-next specific files for 20110421
[linux-2.6/next.git] / drivers / usb / gadget / f_eem.c
blobb3c304290150028cfafca5e9f192862617971ea8
1 /*
2 * f_eem.c -- USB CDC Ethernet (EEM) link function driver
3 *
4 * Copyright (C) 2003-2005,2008 David Brownell
5 * Copyright (C) 2008 Nokia Corporation
6 * Copyright (C) 2009 EF Johnson Technologies
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 #include <linux/kernel.h>
24 #include <linux/device.h>
25 #include <linux/etherdevice.h>
26 #include <linux/crc32.h>
27 #include <linux/slab.h>
28
29 #include "u_ether.h"
30
31 #define EEM_HLEN 2
32
33 /*
34 * This function is a "CDC Ethernet Emulation Model" (CDC EEM)
35 * Ethernet link.
36 */
37
38 struct eem_ep_descs {
39 struct usb_endpoint_descriptor *in;
40 struct usb_endpoint_descriptor *out;
41 };
42
43 struct f_eem {
44 struct gether port;
45 u8 ctrl_id;
46
47 struct eem_ep_descs fs;
48 struct eem_ep_descs hs;
49 };
50
51 static inline struct f_eem *func_to_eem(struct usb_function *f)
52 {
53 return container_of(f, struct f_eem, port.func);
54 }
55
56 /*-------------------------------------------------------------------------*/
57
58 /* interface descriptor: */
59
60 static struct usb_interface_descriptor eem_intf __initdata = {
61 .bLength = sizeof eem_intf,
62 .bDescriptorType = USB_DT_INTERFACE,
63
64 /* .bInterfaceNumber = DYNAMIC */
65 .bNumEndpoints = 2,
66 .bInterfaceClass = USB_CLASS_COMM,
67 .bInterfaceSubClass = USB_CDC_SUBCLASS_EEM,
68 .bInterfaceProtocol = USB_CDC_PROTO_EEM,
69 /* .iInterface = DYNAMIC */
70 };
71
72 /* full speed support: */
73
74 static struct usb_endpoint_descriptor eem_fs_in_desc __initdata = {
75 .bLength = USB_DT_ENDPOINT_SIZE,
76 .bDescriptorType = USB_DT_ENDPOINT,
77
78 .bEndpointAddress = USB_DIR_IN,
79 .bmAttributes = USB_ENDPOINT_XFER_BULK,
80 };
81
82 static struct usb_endpoint_descriptor eem_fs_out_desc __initdata = {
83 .bLength = USB_DT_ENDPOINT_SIZE,
84 .bDescriptorType = USB_DT_ENDPOINT,
85
86 .bEndpointAddress = USB_DIR_OUT,
87 .bmAttributes = USB_ENDPOINT_XFER_BULK,
88 };
89
90 static struct usb_descriptor_header *eem_fs_function[] __initdata = {
91 /* CDC EEM control descriptors */
92 (struct usb_descriptor_header *) &eem_intf,
93 (struct usb_descriptor_header *) &eem_fs_in_desc,
94 (struct usb_descriptor_header *) &eem_fs_out_desc,
95 NULL,
96 };
97
98 /* high speed support: */
99
100 static struct usb_endpoint_descriptor eem_hs_in_desc __initdata = {
101 .bLength = USB_DT_ENDPOINT_SIZE,
102 .bDescriptorType = USB_DT_ENDPOINT,
103
104 .bEndpointAddress = USB_DIR_IN,
105 .bmAttributes = USB_ENDPOINT_XFER_BULK,
106 .wMaxPacketSize = cpu_to_le16(512),
107 };
108
109 static struct usb_endpoint_descriptor eem_hs_out_desc __initdata = {
110 .bLength = USB_DT_ENDPOINT_SIZE,
111 .bDescriptorType = USB_DT_ENDPOINT,
112
113 .bEndpointAddress = USB_DIR_OUT,
114 .bmAttributes = USB_ENDPOINT_XFER_BULK,
115 .wMaxPacketSize = cpu_to_le16(512),
116 };
117
118 static struct usb_descriptor_header *eem_hs_function[] __initdata = {
119 /* CDC EEM control descriptors */
120 (struct usb_descriptor_header *) &eem_intf,
121 (struct usb_descriptor_header *) &eem_hs_in_desc,
122 (struct usb_descriptor_header *) &eem_hs_out_desc,
123 NULL,
124 };
125
126 /* string descriptors: */
127
128 static struct usb_string eem_string_defs[] = {
129 [0].s = "CDC Ethernet Emulation Model (EEM)",
130 { } /* end of list */
131 };
132
133 static struct usb_gadget_strings eem_string_table = {
134 .language = 0x0409, /* en-us */
135 .strings = eem_string_defs,
136 };
137
138 static struct usb_gadget_strings *eem_strings[] = {
139 &eem_string_table,
140 NULL,
141 };
142
143 /*-------------------------------------------------------------------------*/
144
145 static int eem_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
146 {
147 struct usb_composite_dev *cdev = f->config->cdev;
148 int value = -EOPNOTSUPP;
149 u16 w_index = le16_to_cpu(ctrl->wIndex);
150 u16 w_value = le16_to_cpu(ctrl->wValue);
151 u16 w_length = le16_to_cpu(ctrl->wLength);
152
153 DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
154 ctrl->bRequestType, ctrl->bRequest,
155 w_value, w_index, w_length);
156
157 /* device either stalls (value < 0) or reports success */
158 return value;
159 }
160
161
162 static int eem_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
163 {
164 struct f_eem *eem = func_to_eem(f);
165 struct usb_composite_dev *cdev = f->config->cdev;
166 struct net_device *net;
167
168 /* we know alt == 0, so this is an activation or a reset */
169 if (alt != 0)
170 goto fail;
171
172 if (intf == eem->ctrl_id) {
173
174 if (eem->port.in_ep->driver_data) {
175 DBG(cdev, "reset eem\n");
176 gether_disconnect(&eem->port);
177 }
178
179 if (!eem->port.in) {
180 DBG(cdev, "init eem\n");
181 eem->port.in = ep_choose(cdev->gadget,
182 eem->hs.in, eem->fs.in);
183 eem->port.out = ep_choose(cdev->gadget,
184 eem->hs.out, eem->fs.out);
185 }
186
187 /* zlps should not occur because zero-length EEM packets
188 * will be inserted in those cases where they would occur
189 */
190 eem->port.is_zlp_ok = 1;
191 eem->port.cdc_filter = DEFAULT_FILTER;
192 DBG(cdev, "activate eem\n");
193 net = gether_connect(&eem->port);
194 if (IS_ERR(net))
195 return PTR_ERR(net);
196 } else
197 goto fail;
198
199 return 0;
200 fail:
201 return -EINVAL;
202 }
203
204 static void eem_disable(struct usb_function *f)
205 {
206 struct f_eem *eem = func_to_eem(f);
207 struct usb_composite_dev *cdev = f->config->cdev;
208
209 DBG(cdev, "eem deactivated\n");
210
211 if (eem->port.in_ep->driver_data)
212 gether_disconnect(&eem->port);
213 }
214
215 /*-------------------------------------------------------------------------*/
216
217 /* EEM function driver setup/binding */
218
219 static int __init
220 eem_bind(struct usb_configuration *c, struct usb_function *f)
221 {
222 struct usb_composite_dev *cdev = c->cdev;
223 struct f_eem *eem = func_to_eem(f);
224 int status;
225 struct usb_ep *ep;
226
227 /* allocate instance-specific interface IDs */
228 status = usb_interface_id(c, f);
229 if (status < 0)
230 goto fail;
231 eem->ctrl_id = status;
232 eem_intf.bInterfaceNumber = status;
233
234 status = -ENODEV;
235
236 /* allocate instance-specific endpoints */
237 ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_in_desc);
238 if (!ep)
239 goto fail;
240 eem->port.in_ep = ep;
241 ep->driver_data = cdev; /* claim */
242
243 ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_out_desc);
244 if (!ep)
245 goto fail;
246 eem->port.out_ep = ep;
247 ep->driver_data = cdev; /* claim */
248
249 status = -ENOMEM;
250
251 /* copy descriptors, and track endpoint copies */
252 f->descriptors = usb_copy_descriptors(eem_fs_function);
253 if (!f->descriptors)
254 goto fail;
255
256 eem->fs.in = usb_find_endpoint(eem_fs_function,
257 f->descriptors, &eem_fs_in_desc);
258 eem->fs.out = usb_find_endpoint(eem_fs_function,
259 f->descriptors, &eem_fs_out_desc);
260
261 /* support all relevant hardware speeds... we expect that when
262 * hardware is dual speed, all bulk-capable endpoints work at
263 * both speeds
264 */
265 if (gadget_is_dualspeed(c->cdev->gadget)) {
266 eem_hs_in_desc.bEndpointAddress =
267 eem_fs_in_desc.bEndpointAddress;
268 eem_hs_out_desc.bEndpointAddress =
269 eem_fs_out_desc.bEndpointAddress;
270
271 /* copy descriptors, and track endpoint copies */
272 f->hs_descriptors = usb_copy_descriptors(eem_hs_function);
273 if (!f->hs_descriptors)
274 goto fail;
275
276 eem->hs.in = usb_find_endpoint(eem_hs_function,
277 f->hs_descriptors, &eem_hs_in_desc);
278 eem->hs.out = usb_find_endpoint(eem_hs_function,
279 f->hs_descriptors, &eem_hs_out_desc);
280 }
281
282 DBG(cdev, "CDC Ethernet (EEM): %s speed IN/%s OUT/%s\n",
283 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
284 eem->port.in_ep->name, eem->port.out_ep->name);
285 return 0;
286
287 fail:
288 if (f->descriptors)
289 usb_free_descriptors(f->descriptors);
290
291 /* we might as well release our claims on endpoints */
292 if (eem->port.out)
293 eem->port.out_ep->driver_data = NULL;
294 if (eem->port.in)
295 eem->port.in_ep->driver_data = NULL;
296
297 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
298
299 return status;
300 }
301
302 static void
303 eem_unbind(struct usb_configuration *c, struct usb_function *f)
304 {
305 struct f_eem *eem = func_to_eem(f);
306
307 DBG(c->cdev, "eem unbind\n");
308
309 if (gadget_is_dualspeed(c->cdev->gadget))
310 usb_free_descriptors(f->hs_descriptors);
311 usb_free_descriptors(f->descriptors);
312 kfree(eem);
313 }
314
315 static void eem_cmd_complete(struct usb_ep *ep, struct usb_request *req)
316 {
317 struct sk_buff *skb = (struct sk_buff *)req->context;
318
319 dev_kfree_skb_any(skb);
320 }
321
322 /*
323 * Add the EEM header and ethernet checksum.
324 * We currently do not attempt to put multiple ethernet frames
325 * into a single USB transfer
326 */
327 static struct sk_buff *eem_wrap(struct gether *port, struct sk_buff *skb)
328 {
329 struct sk_buff *skb2 = NULL;
330 struct usb_ep *in = port->in_ep;
331 int padlen = 0;
332 u16 len = skb->len;
333
334 if (!skb_cloned(skb)) {
335 int headroom = skb_headroom(skb);
336 int tailroom = skb_tailroom(skb);
337
338 /* When (len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) is 0,
339 * stick two bytes of zero-length EEM packet on the end.
340 */
341 if (((len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) == 0)
342 padlen += 2;
343
344 if ((tailroom >= (ETH_FCS_LEN + padlen)) &&
345 (headroom >= EEM_HLEN))
346 goto done;
347 }
348
349 skb2 = skb_copy_expand(skb, EEM_HLEN, ETH_FCS_LEN + padlen, GFP_ATOMIC);
350 dev_kfree_skb_any(skb);
351 skb = skb2;
352 if (!skb)
353 return skb;
354
355 done:
356 /* use the "no CRC" option */
357 put_unaligned_be32(0xdeadbeef, skb_put(skb, 4));
358
359 /* EEM packet header format:
360 * b0..13: length of ethernet frame
361 * b14: bmCRC (0 == sentinel CRC)
362 * b15: bmType (0 == data)
363 */
364 len = skb->len;
365 put_unaligned_le16(len & 0x3FFF, skb_push(skb, 2));
366
367 /* add a zero-length EEM packet, if needed */
368 if (padlen)
369 put_unaligned_le16(0, skb_put(skb, 2));
370
371 return skb;
372 }
373
374 /*
375 * Remove the EEM header. Note that there can be many EEM packets in a single
376 * USB transfer, so we need to break them out and handle them independently.
377 */
378 static int eem_unwrap(struct gether *port,
379 struct sk_buff *skb,
380 struct sk_buff_head *list)
381 {
382 struct usb_composite_dev *cdev = port->func.config->cdev;
383 int status = 0;
384
385 do {
386 struct sk_buff *skb2;
387 u16 header;
388 u16 len = 0;
389
390 if (skb->len < EEM_HLEN) {
391 status = -EINVAL;
392 DBG(cdev, "invalid EEM header\n");
393 goto error;
394 }
395
396 /* remove the EEM header */
397 header = get_unaligned_le16(skb->data);
398 skb_pull(skb, EEM_HLEN);
399
400 /* EEM packet header format:
401 * b0..14: EEM type dependent (data or command)
402 * b15: bmType (0 == data, 1 == command)
403 */
404 if (header & BIT(15)) {
405 struct usb_request *req = cdev->req;
406 u16 bmEEMCmd;
407
408 /* EEM command packet format:
409 * b0..10: bmEEMCmdParam
410 * b11..13: bmEEMCmd
411 * b14: reserved (must be zero)
412 * b15: bmType (1 == command)
413 */
414 if (header & BIT(14))
415 continue;
416
417 bmEEMCmd = (header >> 11) & 0x7;
418 switch (bmEEMCmd) {
419 case 0: /* echo */
420 len = header & 0x7FF;
421 if (skb->len < len) {
422 status = -EOVERFLOW;
423 goto error;
424 }
425
426 skb2 = skb_clone(skb, GFP_ATOMIC);
427 if (unlikely(!skb2)) {
428 DBG(cdev, "EEM echo response error\n");
429 goto next;
430 }
431 skb_trim(skb2, len);
432 put_unaligned_le16(BIT(15) | BIT(11) | len,
433 skb_push(skb2, 2));
434 skb_copy_bits(skb2, 0, req->buf, skb2->len);
435 req->length = skb2->len;
436 req->complete = eem_cmd_complete;
437 req->zero = 1;
438 req->context = skb2;
439 if (usb_ep_queue(port->in_ep, req, GFP_ATOMIC))
440 DBG(cdev, "echo response queue fail\n");
441 break;
442
443 case 1: /* echo response */
444 case 2: /* suspend hint */
445 case 3: /* response hint */
446 case 4: /* response complete hint */
447 case 5: /* tickle */
448 default: /* reserved */
449 continue;
450 }
451 } else {
452 u32 crc, crc2;
453 struct sk_buff *skb3;
454
455 /* check for zero-length EEM packet */
456 if (header == 0)
457 continue;
458
459 /* EEM data packet format:
460 * b0..13: length of ethernet frame
461 * b14: bmCRC (0 == sentinel, 1 == calculated)
462 * b15: bmType (0 == data)
463 */
464 len = header & 0x3FFF;
465 if ((skb->len < len)
466 || (len < (ETH_HLEN + ETH_FCS_LEN))) {
467 status = -EINVAL;
468 goto error;
469 }
470
471 /* validate CRC */
472 if (header & BIT(14)) {
473 crc = get_unaligned_le32(skb->data + len
474 - ETH_FCS_LEN);
475 crc2 = ~crc32_le(~0,
476 skb->data, len - ETH_FCS_LEN);
477 } else {
478 crc = get_unaligned_be32(skb->data + len
479 - ETH_FCS_LEN);
480 crc2 = 0xdeadbeef;
481 }
482 if (crc != crc2) {
483 DBG(cdev, "invalid EEM CRC\n");
484 goto next;
485 }
486
487 skb2 = skb_clone(skb, GFP_ATOMIC);
488 if (unlikely(!skb2)) {
489 DBG(cdev, "unable to unframe EEM packet\n");
490 continue;
491 }
492 skb_trim(skb2, len - ETH_FCS_LEN);
493
494 skb3 = skb_copy_expand(skb2,
495 NET_IP_ALIGN,
496 0,
497 GFP_ATOMIC);
498 if (unlikely(!skb3)) {
499 DBG(cdev, "unable to realign EEM packet\n");
500 dev_kfree_skb_any(skb2);
501 continue;
502 }
503 dev_kfree_skb_any(skb2);
504 skb_queue_tail(list, skb3);
505 }
506 next:
507 skb_pull(skb, len);
508 } while (skb->len);
509
510 error:
511 dev_kfree_skb_any(skb);
512 return status;
513 }
514
515 /**
516 * eem_bind_config - add CDC Ethernet (EEM) network link to a configuration
517 * @c: the configuration to support the network link
518 * Context: single threaded during gadget setup
519 *
520 * Returns zero on success, else negative errno.
521 *
522 * Caller must have called @gether_setup(). Caller is also responsible
523 * for calling @gether_cleanup() before module unload.
524 */
525 int __init eem_bind_config(struct usb_configuration *c)
526 {
527 struct f_eem *eem;
528 int status;
529
530 /* maybe allocate device-global string IDs */
531 if (eem_string_defs[0].id == 0) {
532
533 /* control interface label */
534 status = usb_string_id(c->cdev);
535 if (status < 0)
536 return status;
537 eem_string_defs[0].id = status;
538 eem_intf.iInterface = status;
539 }
540
541 /* allocate and initialize one new instance */
542 eem = kzalloc(sizeof *eem, GFP_KERNEL);
543 if (!eem)
544 return -ENOMEM;
545
546 eem->port.cdc_filter = DEFAULT_FILTER;
547
548 eem->port.func.name = "cdc_eem";
549 eem->port.func.strings = eem_strings;
550 /* descriptors are per-instance copies */
551 eem->port.func.bind = eem_bind;
552 eem->port.func.unbind = eem_unbind;
553 eem->port.func.set_alt = eem_set_alt;
554 eem->port.func.setup = eem_setup;
555 eem->port.func.disable = eem_disable;
556 eem->port.wrap = eem_wrap;
557 eem->port.unwrap = eem_unwrap;
558 eem->port.header_len = EEM_HLEN;
559
560 status = usb_add_function(c, &eem->port.func);
561 if (status)
562 kfree(eem);
563 return status;
564 }
565
linux-next