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path: root/drivers/usb/gadget/f_eem.c
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Diffstat (limited to 'drivers/usb/gadget/f_eem.c')
-rw-r--r--drivers/usb/gadget/f_eem.c562
1 files changed, 562 insertions, 0 deletions
diff --git a/drivers/usb/gadget/f_eem.c b/drivers/usb/gadget/f_eem.c
new file mode 100644
index 000000000000..0a577d5694fd
--- /dev/null
+++ b/drivers/usb/gadget/f_eem.c
@@ -0,0 +1,562 @@
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
28#include "u_ether.h"
29
30#define EEM_HLEN 2
31
32/*
33 * This function is a "CDC Ethernet Emulation Model" (CDC EEM)
34 * Ethernet link.
35 */
36
37struct eem_ep_descs {
38 struct usb_endpoint_descriptor *in;
39 struct usb_endpoint_descriptor *out;
40};
41
42struct f_eem {
43 struct gether port;
44 u8 ctrl_id;
45
46 struct eem_ep_descs fs;
47 struct eem_ep_descs hs;
48};
49
50static inline struct f_eem *func_to_eem(struct usb_function *f)
51{
52 return container_of(f, struct f_eem, port.func);
53}
54
55/*-------------------------------------------------------------------------*/
56
57/* interface descriptor: */
58
59static struct usb_interface_descriptor eem_intf __initdata = {
60 .bLength = sizeof eem_intf,
61 .bDescriptorType = USB_DT_INTERFACE,
62
63 /* .bInterfaceNumber = DYNAMIC */
64 .bNumEndpoints = 2,
65 .bInterfaceClass = USB_CLASS_COMM,
66 .bInterfaceSubClass = USB_CDC_SUBCLASS_EEM,
67 .bInterfaceProtocol = USB_CDC_PROTO_EEM,
68 /* .iInterface = DYNAMIC */
69};
70
71/* full speed support: */
72
73static struct usb_endpoint_descriptor eem_fs_in_desc __initdata = {
74 .bLength = USB_DT_ENDPOINT_SIZE,
75 .bDescriptorType = USB_DT_ENDPOINT,
76
77 .bEndpointAddress = USB_DIR_IN,
78 .bmAttributes = USB_ENDPOINT_XFER_BULK,
79};
80
81static struct usb_endpoint_descriptor eem_fs_out_desc __initdata = {
82 .bLength = USB_DT_ENDPOINT_SIZE,
83 .bDescriptorType = USB_DT_ENDPOINT,
84
85 .bEndpointAddress = USB_DIR_OUT,
86 .bmAttributes = USB_ENDPOINT_XFER_BULK,
87};
88
89static struct usb_descriptor_header *eem_fs_function[] __initdata = {
90 /* CDC EEM control descriptors */
91 (struct usb_descriptor_header *) &eem_intf,
92 (struct usb_descriptor_header *) &eem_fs_in_desc,
93 (struct usb_descriptor_header *) &eem_fs_out_desc,
94 NULL,
95};
96
97/* high speed support: */
98
99static struct usb_endpoint_descriptor eem_hs_in_desc __initdata = {
100 .bLength = USB_DT_ENDPOINT_SIZE,
101 .bDescriptorType = USB_DT_ENDPOINT,
102
103 .bEndpointAddress = USB_DIR_IN,
104 .bmAttributes = USB_ENDPOINT_XFER_BULK,
105 .wMaxPacketSize = cpu_to_le16(512),
106};
107
108static struct usb_endpoint_descriptor eem_hs_out_desc __initdata = {
109 .bLength = USB_DT_ENDPOINT_SIZE,
110 .bDescriptorType = USB_DT_ENDPOINT,
111
112 .bEndpointAddress = USB_DIR_OUT,
113 .bmAttributes = USB_ENDPOINT_XFER_BULK,
114 .wMaxPacketSize = cpu_to_le16(512),
115};
116
117static struct usb_descriptor_header *eem_hs_function[] __initdata = {
118 /* CDC EEM control descriptors */
119 (struct usb_descriptor_header *) &eem_intf,
120 (struct usb_descriptor_header *) &eem_hs_in_desc,
121 (struct usb_descriptor_header *) &eem_hs_out_desc,
122 NULL,
123};
124
125/* string descriptors: */
126
127static struct usb_string eem_string_defs[] = {
128 [0].s = "CDC Ethernet Emulation Model (EEM)",
129 { } /* end of list */
130};
131
132static struct usb_gadget_strings eem_string_table = {
133 .language = 0x0409, /* en-us */
134 .strings = eem_string_defs,
135};
136
137static struct usb_gadget_strings *eem_strings[] = {
138 &eem_string_table,
139 NULL,
140};
141
142/*-------------------------------------------------------------------------*/
143
144static int eem_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
145{
146 struct usb_composite_dev *cdev = f->config->cdev;
147 int value = -EOPNOTSUPP;
148 u16 w_index = le16_to_cpu(ctrl->wIndex);
149 u16 w_value = le16_to_cpu(ctrl->wValue);
150 u16 w_length = le16_to_cpu(ctrl->wLength);
151
152 DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
153 ctrl->bRequestType, ctrl->bRequest,
154 w_value, w_index, w_length);
155
156 /* device either stalls (value < 0) or reports success */
157 return value;
158}
159
160
161static int eem_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
162{
163 struct f_eem *eem = func_to_eem(f);
164 struct usb_composite_dev *cdev = f->config->cdev;
165 struct net_device *net;
166
167 /* we know alt == 0, so this is an activation or a reset */
168 if (alt != 0)
169 goto fail;
170
171 if (intf == eem->ctrl_id) {
172
173 if (eem->port.in_ep->driver_data) {
174 DBG(cdev, "reset eem\n");
175 gether_disconnect(&eem->port);
176 }
177
178 if (!eem->port.in) {
179 DBG(cdev, "init eem\n");
180 eem->port.in = ep_choose(cdev->gadget,
181 eem->hs.in, eem->fs.in);
182 eem->port.out = ep_choose(cdev->gadget,
183 eem->hs.out, eem->fs.out);
184 }
185
186 /* zlps should not occur because zero-length EEM packets
187 * will be inserted in those cases where they would occur
188 */
189 eem->port.is_zlp_ok = 1;
190 eem->port.cdc_filter = DEFAULT_FILTER;
191 DBG(cdev, "activate eem\n");
192 net = gether_connect(&eem->port);
193 if (IS_ERR(net))
194 return PTR_ERR(net);
195 } else
196 goto fail;
197
198 return 0;
199fail:
200 return -EINVAL;
201}
202
203static void eem_disable(struct usb_function *f)
204{
205 struct f_eem *eem = func_to_eem(f);
206 struct usb_composite_dev *cdev = f->config->cdev;
207
208 DBG(cdev, "eem deactivated\n");
209
210 if (eem->port.in_ep->driver_data)
211 gether_disconnect(&eem->port);
212}
213
214/*-------------------------------------------------------------------------*/
215
216/* EEM function driver setup/binding */
217
218static int __init
219eem_bind(struct usb_configuration *c, struct usb_function *f)
220{
221 struct usb_composite_dev *cdev = c->cdev;
222 struct f_eem *eem = func_to_eem(f);
223 int status;
224 struct usb_ep *ep;
225
226 /* allocate instance-specific interface IDs */
227 status = usb_interface_id(c, f);
228 if (status < 0)
229 goto fail;
230 eem->ctrl_id = status;
231 eem_intf.bInterfaceNumber = status;
232
233 status = -ENODEV;
234
235 /* allocate instance-specific endpoints */
236 ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_in_desc);
237 if (!ep)
238 goto fail;
239 eem->port.in_ep = ep;
240 ep->driver_data = cdev; /* claim */
241
242 ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_out_desc);
243 if (!ep)
244 goto fail;
245 eem->port.out_ep = ep;
246 ep->driver_data = cdev; /* claim */
247
248 status = -ENOMEM;
249
250 /* copy descriptors, and track endpoint copies */
251 f->descriptors = usb_copy_descriptors(eem_fs_function);
252 if (!f->descriptors)
253 goto fail;
254
255 eem->fs.in = usb_find_endpoint(eem_fs_function,
256 f->descriptors, &eem_fs_in_desc);
257 eem->fs.out = usb_find_endpoint(eem_fs_function,
258 f->descriptors, &eem_fs_out_desc);
259
260 /* support all relevant hardware speeds... we expect that when
261 * hardware is dual speed, all bulk-capable endpoints work at
262 * both speeds
263 */
264 if (gadget_is_dualspeed(c->cdev->gadget)) {
265 eem_hs_in_desc.bEndpointAddress =
266 eem_fs_in_desc.bEndpointAddress;
267 eem_hs_out_desc.bEndpointAddress =
268 eem_fs_out_desc.bEndpointAddress;
269
270 /* copy descriptors, and track endpoint copies */
271 f->hs_descriptors = usb_copy_descriptors(eem_hs_function);
272 if (!f->hs_descriptors)
273 goto fail;
274
275 eem->hs.in = usb_find_endpoint(eem_hs_function,
276 f->hs_descriptors, &eem_hs_in_desc);
277 eem->hs.out = usb_find_endpoint(eem_hs_function,
278 f->hs_descriptors, &eem_hs_out_desc);
279 }
280
281 DBG(cdev, "CDC Ethernet (EEM): %s speed IN/%s OUT/%s\n",
282 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
283 eem->port.in_ep->name, eem->port.out_ep->name);
284 return 0;
285
286fail:
287 if (f->descriptors)
288 usb_free_descriptors(f->descriptors);
289
290 /* we might as well release our claims on endpoints */
291 if (eem->port.out)
292 eem->port.out_ep->driver_data = NULL;
293 if (eem->port.in)
294 eem->port.in_ep->driver_data = NULL;
295
296 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
297
298 return status;
299}
300
301static void
302eem_unbind(struct usb_configuration *c, struct usb_function *f)
303{
304 struct f_eem *eem = func_to_eem(f);
305
306 DBG(c->cdev, "eem unbind\n");
307
308 if (gadget_is_dualspeed(c->cdev->gadget))
309 usb_free_descriptors(f->hs_descriptors);
310 usb_free_descriptors(f->descriptors);
311 kfree(eem);
312}
313
314static void eem_cmd_complete(struct usb_ep *ep, struct usb_request *req)
315{
316}
317
318/*
319 * Add the EEM header and ethernet checksum.
320 * We currently do not attempt to put multiple ethernet frames
321 * into a single USB transfer
322 */
323static struct sk_buff *eem_wrap(struct gether *port, struct sk_buff *skb)
324{
325 struct sk_buff *skb2 = NULL;
326 struct usb_ep *in = port->in_ep;
327 int padlen = 0;
328 u16 len = skb->len;
329
330 if (!skb_cloned(skb)) {
331 int headroom = skb_headroom(skb);
332 int tailroom = skb_tailroom(skb);
333
334 /* When (len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) is 0,
335 * stick two bytes of zero-length EEM packet on the end.
336 */
337 if (((len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) == 0)
338 padlen += 2;
339
340 if ((tailroom >= (ETH_FCS_LEN + padlen)) &&
341 (headroom >= EEM_HLEN))
342 goto done;
343 }
344
345 skb2 = skb_copy_expand(skb, EEM_HLEN, ETH_FCS_LEN + padlen, GFP_ATOMIC);
346 dev_kfree_skb_any(skb);
347 skb = skb2;
348 if (!skb)
349 return skb;
350
351done:
352 /* use the "no CRC" option */
353 put_unaligned_be32(0xdeadbeef, skb_put(skb, 4));
354
355 /* EEM packet header format:
356 * b0..13: length of ethernet frame
357 * b14: bmCRC (0 == sentinel CRC)
358 * b15: bmType (0 == data)
359 */
360 len = skb->len;
361 put_unaligned_le16((len & 0x3FFF) | BIT(14), skb_push(skb, 2));
362
363 /* add a zero-length EEM packet, if needed */
364 if (padlen)
365 put_unaligned_le16(0, skb_put(skb, 2));
366
367 return skb;
368}
369
370/*
371 * Remove the EEM header. Note that there can be many EEM packets in a single
372 * USB transfer, so we need to break them out and handle them independently.
373 */
374static int eem_unwrap(struct gether *port,
375 struct sk_buff *skb,
376 struct sk_buff_head *list)
377{
378 struct usb_composite_dev *cdev = port->func.config->cdev;
379 int status = 0;
380
381 do {
382 struct sk_buff *skb2;
383 u16 header;
384 u16 len = 0;
385
386 if (skb->len < EEM_HLEN) {
387 status = -EINVAL;
388 DBG(cdev, "invalid EEM header\n");
389 goto error;
390 }
391
392 /* remove the EEM header */
393 header = get_unaligned_le16(skb->data);
394 skb_pull(skb, EEM_HLEN);
395
396 /* EEM packet header format:
397 * b0..14: EEM type dependent (data or command)
398 * b15: bmType (0 == data, 1 == command)
399 */
400 if (header & BIT(15)) {
401 struct usb_request *req = cdev->req;
402 u16 bmEEMCmd;
403
404 /* EEM command packet format:
405 * b0..10: bmEEMCmdParam
406 * b11..13: bmEEMCmd
407 * b14: reserved (must be zero)
408 * b15: bmType (1 == command)
409 */
410 if (header & BIT(14))
411 continue;
412
413 bmEEMCmd = (header >> 11) & 0x7;
414 switch (bmEEMCmd) {
415 case 0: /* echo */
416 len = header & 0x7FF;
417 if (skb->len < len) {
418 status = -EOVERFLOW;
419 goto error;
420 }
421
422 skb2 = skb_clone(skb, GFP_ATOMIC);
423 if (unlikely(!skb2)) {
424 DBG(cdev, "EEM echo response error\n");
425 goto next;
426 }
427 skb_trim(skb2, len);
428 put_unaligned_le16(BIT(15) | BIT(11) | len,
429 skb_push(skb2, 2));
430 skb_copy_bits(skb, 0, req->buf, skb->len);
431 req->length = skb->len;
432 req->complete = eem_cmd_complete;
433 req->zero = 1;
434 if (usb_ep_queue(port->in_ep, req, GFP_ATOMIC))
435 DBG(cdev, "echo response queue fail\n");
436 break;
437
438 case 1: /* echo response */
439 case 2: /* suspend hint */
440 case 3: /* response hint */
441 case 4: /* response complete hint */
442 case 5: /* tickle */
443 default: /* reserved */
444 continue;
445 }
446 } else {
447 u32 crc, crc2;
448 struct sk_buff *skb3;
449
450 /* check for zero-length EEM packet */
451 if (header == 0)
452 continue;
453
454 /* EEM data packet format:
455 * b0..13: length of ethernet frame
456 * b14: bmCRC (0 == sentinel, 1 == calculated)
457 * b15: bmType (0 == data)
458 */
459 len = header & 0x3FFF;
460 if ((skb->len < len)
461 || (len < (ETH_HLEN + ETH_FCS_LEN))) {
462 status = -EINVAL;
463 goto error;
464 }
465
466 /* validate CRC */
467 crc = get_unaligned_le32(skb->data + len - ETH_FCS_LEN);
468 if (header & BIT(14)) {
469 crc = get_unaligned_le32(skb->data + len
470 - ETH_FCS_LEN);
471 crc2 = ~crc32_le(~0,
472 skb->data,
473 skb->len - ETH_FCS_LEN);
474 } else {
475 crc = get_unaligned_be32(skb->data + len
476 - ETH_FCS_LEN);
477 crc2 = 0xdeadbeef;
478 }
479 if (crc != crc2) {
480 DBG(cdev, "invalid EEM CRC\n");
481 goto next;
482 }
483
484 skb2 = skb_clone(skb, GFP_ATOMIC);
485 if (unlikely(!skb2)) {
486 DBG(cdev, "unable to unframe EEM packet\n");
487 continue;
488 }
489 skb_trim(skb2, len - ETH_FCS_LEN);
490
491 skb3 = skb_copy_expand(skb2,
492 NET_IP_ALIGN,
493 0,
494 GFP_ATOMIC);
495 if (unlikely(!skb3)) {
496 DBG(cdev, "unable to realign EEM packet\n");
497 dev_kfree_skb_any(skb2);
498 continue;
499 }
500 dev_kfree_skb_any(skb2);
501 skb_queue_tail(list, skb3);
502 }
503next:
504 skb_pull(skb, len);
505 } while (skb->len);
506
507error:
508 dev_kfree_skb_any(skb);
509 return status;
510}
511
512/**
513 * eem_bind_config - add CDC Ethernet (EEM) network link to a configuration
514 * @c: the configuration to support the network link
515 * Context: single threaded during gadget setup
516 *
517 * Returns zero on success, else negative errno.
518 *
519 * Caller must have called @gether_setup(). Caller is also responsible
520 * for calling @gether_cleanup() before module unload.
521 */
522int __init eem_bind_config(struct usb_configuration *c)
523{
524 struct f_eem *eem;
525 int status;
526
527 /* maybe allocate device-global string IDs */
528 if (eem_string_defs[0].id == 0) {
529
530 /* control interface label */
531 status = usb_string_id(c->cdev);
532 if (status < 0)
533 return status;
534 eem_string_defs[0].id = status;
535 eem_intf.iInterface = status;
536 }
537
538 /* allocate and initialize one new instance */
539 eem = kzalloc(sizeof *eem, GFP_KERNEL);
540 if (!eem)
541 return -ENOMEM;
542
543 eem->port.cdc_filter = DEFAULT_FILTER;
544
545 eem->port.func.name = "cdc_eem";
546 eem->port.func.strings = eem_strings;
547 /* descriptors are per-instance copies */
548 eem->port.func.bind = eem_bind;
549 eem->port.func.unbind = eem_unbind;
550 eem->port.func.set_alt = eem_set_alt;
551 eem->port.func.setup = eem_setup;
552 eem->port.func.disable = eem_disable;
553 eem->port.wrap = eem_wrap;
554 eem->port.unwrap = eem_unwrap;
555 eem->port.header_len = EEM_HLEN;
556
557 status = usb_add_function(c, &eem->port.func);
558 if (status)
559 kfree(eem);
560 return status;
561}
562
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-23 16:33:09 -0500