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1/*
2 * f_ecm.c -- USB CDC Ethernet (ECM) 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
13/* #define VERBOSE_DEBUG */
14
15#include <linux/slab.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/device.h>
19#include <linux/etherdevice.h>
20
21#include "u_ether.h"
22#include "u_ether_configfs.h"
23#include "u_ecm.h"
24
25
26/*
27 * This function is a "CDC Ethernet Networking Control Model" (CDC ECM)
28 * Ethernet link. The data transfer model is simple (packets sent and
29 * received over bulk endpoints using normal short packet termination),
30 * and the control model exposes various data and optional notifications.
31 *
32 * ECM is well standardized and (except for Microsoft) supported by most
33 * operating systems with USB host support. It's the preferred interop
34 * solution for Ethernet over USB, at least for firmware based solutions.
35 * (Hardware solutions tend to be more minimalist.) A newer and simpler
36 * "Ethernet Emulation Model" (CDC EEM) hasn't yet caught on.
37 *
38 * Note that ECM requires the use of "alternate settings" for its data
39 * interface. This means that the set_alt() method has real work to do,
40 * and also means that a get_alt() method is required.
41 */
42
43
44enum ecm_notify_state {
45 ECM_NOTIFY_NONE, /* don't notify */
46 ECM_NOTIFY_CONNECT, /* issue CONNECT next */
47 ECM_NOTIFY_SPEED, /* issue SPEED_CHANGE next */
48};
49
50struct f_ecm {
51 struct gether port;
52 u8 ctrl_id, data_id;
53
54 char ethaddr[14];
55
56 struct usb_ep *notify;
57 struct usb_request *notify_req;
58 u8 notify_state;
59 bool is_open;
60
61 /* FIXME is_open needs some irq-ish locking
62 * ... possibly the same as port.ioport
63 */
64};
65
66static inline struct f_ecm *func_to_ecm(struct usb_function *f)
67{
68 return container_of(f, struct f_ecm, port.func);
69}
70
71/* peak (theoretical) bulk transfer rate in bits-per-second */
72static inline unsigned ecm_bitrate(struct usb_gadget *g)
73{
74 if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
75 return 13 * 1024 * 8 * 1000 * 8;
76 else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
77 return 13 * 512 * 8 * 1000 * 8;
78 else
79 return 19 * 64 * 1 * 1000 * 8;
80}
81
82/*-------------------------------------------------------------------------*/
83
84/*
85 * Include the status endpoint if we can, even though it's optional.
86 *
87 * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
88 * packet, to simplify cancellation; and a big transfer interval, to
89 * waste less bandwidth.
90 *
91 * Some drivers (like Linux 2.4 cdc-ether!) "need" it to exist even
92 * if they ignore the connect/disconnect notifications that real aether
93 * can provide. More advanced cdc configurations might want to support
94 * encapsulated commands (vendor-specific, using control-OUT).
95 */
96
97#define ECM_STATUS_INTERVAL_MS 32
98#define ECM_STATUS_BYTECOUNT 16 /* 8 byte header + data */
99
100
101/* interface descriptor: */
102
103static struct usb_interface_assoc_descriptor
104ecm_iad_descriptor = {
105 .bLength = sizeof ecm_iad_descriptor,
106 .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
107
108 /* .bFirstInterface = DYNAMIC, */
109 .bInterfaceCount = 2, /* control + data */
110 .bFunctionClass = USB_CLASS_COMM,
111 .bFunctionSubClass = USB_CDC_SUBCLASS_ETHERNET,
112 .bFunctionProtocol = USB_CDC_PROTO_NONE,
113 /* .iFunction = DYNAMIC */
114};
115
116
117static struct usb_interface_descriptor ecm_control_intf = {
118 .bLength = sizeof ecm_control_intf,
119 .bDescriptorType = USB_DT_INTERFACE,
120
121 /* .bInterfaceNumber = DYNAMIC */
122 /* status endpoint is optional; this could be patched later */
123 .bNumEndpoints = 1,
124 .bInterfaceClass = USB_CLASS_COMM,
125 .bInterfaceSubClass = USB_CDC_SUBCLASS_ETHERNET,
126 .bInterfaceProtocol = USB_CDC_PROTO_NONE,
127 /* .iInterface = DYNAMIC */
128};
129
130static struct usb_cdc_header_desc ecm_header_desc = {
131 .bLength = sizeof ecm_header_desc,
132 .bDescriptorType = USB_DT_CS_INTERFACE,
133 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
134
135 .bcdCDC = cpu_to_le16(0x0110),
136};
137
138static struct usb_cdc_union_desc ecm_union_desc = {
139 .bLength = sizeof(ecm_union_desc),
140 .bDescriptorType = USB_DT_CS_INTERFACE,
141 .bDescriptorSubType = USB_CDC_UNION_TYPE,
142 /* .bMasterInterface0 = DYNAMIC */
143 /* .bSlaveInterface0 = DYNAMIC */
144};
145
146static struct usb_cdc_ether_desc ecm_desc = {
147 .bLength = sizeof ecm_desc,
148 .bDescriptorType = USB_DT_CS_INTERFACE,
149 .bDescriptorSubType = USB_CDC_ETHERNET_TYPE,
150
151 /* this descriptor actually adds value, surprise! */
152 /* .iMACAddress = DYNAMIC */
153 .bmEthernetStatistics = cpu_to_le32(0), /* no statistics */
154 .wMaxSegmentSize = cpu_to_le16(ETH_FRAME_LEN),
155 .wNumberMCFilters = cpu_to_le16(0),
156 .bNumberPowerFilters = 0,
157};
158
159/* the default data interface has no endpoints ... */
160
161static struct usb_interface_descriptor ecm_data_nop_intf = {
162 .bLength = sizeof ecm_data_nop_intf,
163 .bDescriptorType = USB_DT_INTERFACE,
164
165 .bInterfaceNumber = 1,
166 .bAlternateSetting = 0,
167 .bNumEndpoints = 0,
168 .bInterfaceClass = USB_CLASS_CDC_DATA,
169 .bInterfaceSubClass = 0,
170 .bInterfaceProtocol = 0,
171 /* .iInterface = DYNAMIC */
172};
173
174/* ... but the "real" data interface has two bulk endpoints */
175
176static struct usb_interface_descriptor ecm_data_intf = {
177 .bLength = sizeof ecm_data_intf,
178 .bDescriptorType = USB_DT_INTERFACE,
179
180 .bInterfaceNumber = 1,
181 .bAlternateSetting = 1,
182 .bNumEndpoints = 2,
183 .bInterfaceClass = USB_CLASS_CDC_DATA,
184 .bInterfaceSubClass = 0,
185 .bInterfaceProtocol = 0,
186 /* .iInterface = DYNAMIC */
187};
188
189/* full speed support: */
190
191static struct usb_endpoint_descriptor fs_ecm_notify_desc = {
192 .bLength = USB_DT_ENDPOINT_SIZE,
193 .bDescriptorType = USB_DT_ENDPOINT,
194
195 .bEndpointAddress = USB_DIR_IN,
196 .bmAttributes = USB_ENDPOINT_XFER_INT,
197 .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT),
198 .bInterval = ECM_STATUS_INTERVAL_MS,
199};
200
201static struct usb_endpoint_descriptor fs_ecm_in_desc = {
202 .bLength = USB_DT_ENDPOINT_SIZE,
203 .bDescriptorType = USB_DT_ENDPOINT,
204
205 .bEndpointAddress = USB_DIR_IN,
206 .bmAttributes = USB_ENDPOINT_XFER_BULK,
207};
208
209static struct usb_endpoint_descriptor fs_ecm_out_desc = {
210 .bLength = USB_DT_ENDPOINT_SIZE,
211 .bDescriptorType = USB_DT_ENDPOINT,
212
213 .bEndpointAddress = USB_DIR_OUT,
214 .bmAttributes = USB_ENDPOINT_XFER_BULK,
215};
216
217static struct usb_descriptor_header *ecm_fs_function[] = {
218 /* CDC ECM control descriptors */
219 (struct usb_descriptor_header *) &ecm_iad_descriptor,
220 (struct usb_descriptor_header *) &ecm_control_intf,
221 (struct usb_descriptor_header *) &ecm_header_desc,
222 (struct usb_descriptor_header *) &ecm_union_desc,
223 (struct usb_descriptor_header *) &ecm_desc,
224
225 /* NOTE: status endpoint might need to be removed */
226 (struct usb_descriptor_header *) &fs_ecm_notify_desc,
227
228 /* data interface, altsettings 0 and 1 */
229 (struct usb_descriptor_header *) &ecm_data_nop_intf,
230 (struct usb_descriptor_header *) &ecm_data_intf,
231 (struct usb_descriptor_header *) &fs_ecm_in_desc,
232 (struct usb_descriptor_header *) &fs_ecm_out_desc,
233 NULL,
234};
235
236/* high speed support: */
237
238static struct usb_endpoint_descriptor hs_ecm_notify_desc = {
239 .bLength = USB_DT_ENDPOINT_SIZE,
240 .bDescriptorType = USB_DT_ENDPOINT,
241
242 .bEndpointAddress = USB_DIR_IN,
243 .bmAttributes = USB_ENDPOINT_XFER_INT,
244 .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT),
245 .bInterval = USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
246};
247
248static struct usb_endpoint_descriptor hs_ecm_in_desc = {
249 .bLength = USB_DT_ENDPOINT_SIZE,
250 .bDescriptorType = USB_DT_ENDPOINT,
251
252 .bEndpointAddress = USB_DIR_IN,
253 .bmAttributes = USB_ENDPOINT_XFER_BULK,
254 .wMaxPacketSize = cpu_to_le16(512),
255};
256
257static struct usb_endpoint_descriptor hs_ecm_out_desc = {
258 .bLength = USB_DT_ENDPOINT_SIZE,
259 .bDescriptorType = USB_DT_ENDPOINT,
260
261 .bEndpointAddress = USB_DIR_OUT,
262 .bmAttributes = USB_ENDPOINT_XFER_BULK,
263 .wMaxPacketSize = cpu_to_le16(512),
264};
265
266static struct usb_descriptor_header *ecm_hs_function[] = {
267 /* CDC ECM control descriptors */
268 (struct usb_descriptor_header *) &ecm_iad_descriptor,
269 (struct usb_descriptor_header *) &ecm_control_intf,
270 (struct usb_descriptor_header *) &ecm_header_desc,
271 (struct usb_descriptor_header *) &ecm_union_desc,
272 (struct usb_descriptor_header *) &ecm_desc,
273
274 /* NOTE: status endpoint might need to be removed */
275 (struct usb_descriptor_header *) &hs_ecm_notify_desc,
276
277 /* data interface, altsettings 0 and 1 */
278 (struct usb_descriptor_header *) &ecm_data_nop_intf,
279 (struct usb_descriptor_header *) &ecm_data_intf,
280 (struct usb_descriptor_header *) &hs_ecm_in_desc,
281 (struct usb_descriptor_header *) &hs_ecm_out_desc,
282 NULL,
283};
284
285/* super speed support: */
286
287static struct usb_endpoint_descriptor ss_ecm_notify_desc = {
288 .bLength = USB_DT_ENDPOINT_SIZE,
289 .bDescriptorType = USB_DT_ENDPOINT,
290
291 .bEndpointAddress = USB_DIR_IN,
292 .bmAttributes = USB_ENDPOINT_XFER_INT,
293 .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT),
294 .bInterval = USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
295};
296
297static struct usb_ss_ep_comp_descriptor ss_ecm_intr_comp_desc = {
298 .bLength = sizeof ss_ecm_intr_comp_desc,
299 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
300
301 /* the following 3 values can be tweaked if necessary */
302 /* .bMaxBurst = 0, */
303 /* .bmAttributes = 0, */
304 .wBytesPerInterval = cpu_to_le16(ECM_STATUS_BYTECOUNT),
305};
306
307static struct usb_endpoint_descriptor ss_ecm_in_desc = {
308 .bLength = USB_DT_ENDPOINT_SIZE,
309 .bDescriptorType = USB_DT_ENDPOINT,
310
311 .bEndpointAddress = USB_DIR_IN,
312 .bmAttributes = USB_ENDPOINT_XFER_BULK,
313 .wMaxPacketSize = cpu_to_le16(1024),
314};
315
316static struct usb_endpoint_descriptor ss_ecm_out_desc = {
317 .bLength = USB_DT_ENDPOINT_SIZE,
318 .bDescriptorType = USB_DT_ENDPOINT,
319
320 .bEndpointAddress = USB_DIR_OUT,
321 .bmAttributes = USB_ENDPOINT_XFER_BULK,
322 .wMaxPacketSize = cpu_to_le16(1024),
323};
324
325static struct usb_ss_ep_comp_descriptor ss_ecm_bulk_comp_desc = {
326 .bLength = sizeof ss_ecm_bulk_comp_desc,
327 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
328
329 /* the following 2 values can be tweaked if necessary */
330 /* .bMaxBurst = 0, */
331 /* .bmAttributes = 0, */
332};
333
334static struct usb_descriptor_header *ecm_ss_function[] = {
335 /* CDC ECM control descriptors */
336 (struct usb_descriptor_header *) &ecm_iad_descriptor,
337 (struct usb_descriptor_header *) &ecm_control_intf,
338 (struct usb_descriptor_header *) &ecm_header_desc,
339 (struct usb_descriptor_header *) &ecm_union_desc,
340 (struct usb_descriptor_header *) &ecm_desc,
341
342 /* NOTE: status endpoint might need to be removed */
343 (struct usb_descriptor_header *) &ss_ecm_notify_desc,
344 (struct usb_descriptor_header *) &ss_ecm_intr_comp_desc,
345
346 /* data interface, altsettings 0 and 1 */
347 (struct usb_descriptor_header *) &ecm_data_nop_intf,
348 (struct usb_descriptor_header *) &ecm_data_intf,
349 (struct usb_descriptor_header *) &ss_ecm_in_desc,
350 (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
351 (struct usb_descriptor_header *) &ss_ecm_out_desc,
352 (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
353 NULL,
354};
355
356/* string descriptors: */
357
358static struct usb_string ecm_string_defs[] = {
359 [0].s = "CDC Ethernet Control Model (ECM)",
360 [1].s = "",
361 [2].s = "CDC Ethernet Data",
362 [3].s = "CDC ECM",
363 { } /* end of list */
364};
365
366static struct usb_gadget_strings ecm_string_table = {
367 .language = 0x0409, /* en-us */
368 .strings = ecm_string_defs,
369};
370
371static struct usb_gadget_strings *ecm_strings[] = {
372 &ecm_string_table,
373 NULL,
374};
375
376/*-------------------------------------------------------------------------*/
377
378static void ecm_do_notify(struct f_ecm *ecm)
379{
380 struct usb_request *req = ecm->notify_req;
381 struct usb_cdc_notification *event;
382 struct usb_composite_dev *cdev = ecm->port.func.config->cdev;
383 __le32 *data;
384 int status;
385
386 /* notification already in flight? */
387 if (!req)
388 return;
389
390 event = req->buf;
391 switch (ecm->notify_state) {
392 case ECM_NOTIFY_NONE:
393 return;
394
395 case ECM_NOTIFY_CONNECT:
396 event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
397 if (ecm->is_open)
398 event->wValue = cpu_to_le16(1);
399 else
400 event->wValue = cpu_to_le16(0);
401 event->wLength = 0;
402 req->length = sizeof *event;
403
404 DBG(cdev, "notify connect %s\n",
405 ecm->is_open ? "true" : "false");
406 ecm->notify_state = ECM_NOTIFY_SPEED;
407 break;
408
409 case ECM_NOTIFY_SPEED:
410 event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
411 event->wValue = cpu_to_le16(0);
412 event->wLength = cpu_to_le16(8);
413 req->length = ECM_STATUS_BYTECOUNT;
414
415 /* SPEED_CHANGE data is up/down speeds in bits/sec */
416 data = req->buf + sizeof *event;
417 data[0] = cpu_to_le32(ecm_bitrate(cdev->gadget));
418 data[1] = data[0];
419
420 DBG(cdev, "notify speed %d\n", ecm_bitrate(cdev->gadget));
421 ecm->notify_state = ECM_NOTIFY_NONE;
422 break;
423 }
424 event->bmRequestType = 0xA1;
425 event->wIndex = cpu_to_le16(ecm->ctrl_id);
426
427 ecm->notify_req = NULL;
428 status = usb_ep_queue(ecm->notify, req, GFP_ATOMIC);
429 if (status < 0) {
430 ecm->notify_req = req;
431 DBG(cdev, "notify --> %d\n", status);
432 }
433}
434
435static void ecm_notify(struct f_ecm *ecm)
436{
437 /* NOTE on most versions of Linux, host side cdc-ethernet
438 * won't listen for notifications until its netdevice opens.
439 * The first notification then sits in the FIFO for a long
440 * time, and the second one is queued.
441 */
442 ecm->notify_state = ECM_NOTIFY_CONNECT;
443 ecm_do_notify(ecm);
444}
445
446static void ecm_notify_complete(struct usb_ep *ep, struct usb_request *req)
447{
448 struct f_ecm *ecm = req->context;
449 struct usb_composite_dev *cdev = ecm->port.func.config->cdev;
450 struct usb_cdc_notification *event = req->buf;
451
452 switch (req->status) {
453 case 0:
454 /* no fault */
455 break;
456 case -ECONNRESET:
457 case -ESHUTDOWN:
458 ecm->notify_state = ECM_NOTIFY_NONE;
459 break;
460 default:
461 DBG(cdev, "event %02x --> %d\n",
462 event->bNotificationType, req->status);
463 break;
464 }
465 ecm->notify_req = req;
466 ecm_do_notify(ecm);
467}
468
469static int ecm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
470{
471 struct f_ecm *ecm = func_to_ecm(f);
472 struct usb_composite_dev *cdev = f->config->cdev;
473 struct usb_request *req = cdev->req;
474 int value = -EOPNOTSUPP;
475 u16 w_index = le16_to_cpu(ctrl->wIndex);
476 u16 w_value = le16_to_cpu(ctrl->wValue);
477 u16 w_length = le16_to_cpu(ctrl->wLength);
478
479 /* composite driver infrastructure handles everything except
480 * CDC class messages; interface activation uses set_alt().
481 */
482 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
483 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
484 | USB_CDC_SET_ETHERNET_PACKET_FILTER:
485 /* see 6.2.30: no data, wIndex = interface,
486 * wValue = packet filter bitmap
487 */
488 if (w_length != 0 || w_index != ecm->ctrl_id)
489 goto invalid;
490 DBG(cdev, "packet filter %02x\n", w_value);
491 /* REVISIT locking of cdc_filter. This assumes the UDC
492 * driver won't have a concurrent packet TX irq running on
493 * another CPU; or that if it does, this write is atomic...
494 */
495 ecm->port.cdc_filter = w_value;
496 value = 0;
497 break;
498
499 /* and optionally:
500 * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
501 * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
502 * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
503 * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
504 * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
505 * case USB_CDC_GET_ETHERNET_STATISTIC:
506 */
507
508 default:
509invalid:
510 DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
511 ctrl->bRequestType, ctrl->bRequest,
512 w_value, w_index, w_length);
513 }
514
515 /* respond with data transfer or status phase? */
516 if (value >= 0) {
517 DBG(cdev, "ecm req%02x.%02x v%04x i%04x l%d\n",
518 ctrl->bRequestType, ctrl->bRequest,
519 w_value, w_index, w_length);
520 req->zero = 0;
521 req->length = value;
522 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
523 if (value < 0)
524 ERROR(cdev, "ecm req %02x.%02x response err %d\n",
525 ctrl->bRequestType, ctrl->bRequest,
526 value);
527 }
528
529 /* device either stalls (value < 0) or reports success */
530 return value;
531}
532
533
534static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
535{
536 struct f_ecm *ecm = func_to_ecm(f);
537 struct usb_composite_dev *cdev = f->config->cdev;
538
539 /* Control interface has only altsetting 0 */
540 if (intf == ecm->ctrl_id) {
541 if (alt != 0)
542 goto fail;
543
544 VDBG(cdev, "reset ecm control %d\n", intf);
545 usb_ep_disable(ecm->notify);
546 if (!(ecm->notify->desc)) {
547 VDBG(cdev, "init ecm ctrl %d\n", intf);
548 if (config_ep_by_speed(cdev->gadget, f, ecm->notify))
549 goto fail;
550 }
551 usb_ep_enable(ecm->notify);
552
553 /* Data interface has two altsettings, 0 and 1 */
554 } else if (intf == ecm->data_id) {
555 if (alt > 1)
556 goto fail;
557
558 if (ecm->port.in_ep->enabled) {
559 DBG(cdev, "reset ecm\n");
560 gether_disconnect(&ecm->port);
561 }
562
563 if (!ecm->port.in_ep->desc ||
564 !ecm->port.out_ep->desc) {
565 DBG(cdev, "init ecm\n");
566 if (config_ep_by_speed(cdev->gadget, f,
567 ecm->port.in_ep) ||
568 config_ep_by_speed(cdev->gadget, f,
569 ecm->port.out_ep)) {
570 ecm->port.in_ep->desc = NULL;
571 ecm->port.out_ep->desc = NULL;
572 goto fail;
573 }
574 }
575
576 /* CDC Ethernet only sends data in non-default altsettings.
577 * Changing altsettings resets filters, statistics, etc.
578 */
579 if (alt == 1) {
580 struct net_device *net;
581
582 /* Enable zlps by default for ECM conformance;
583 * override for musb_hdrc (avoids txdma ovhead).
584 */
585 ecm->port.is_zlp_ok =
586 gadget_is_zlp_supported(cdev->gadget);
587 ecm->port.cdc_filter = DEFAULT_FILTER;
588 DBG(cdev, "activate ecm\n");
589 net = gether_connect(&ecm->port);
590 if (IS_ERR(net))
591 return PTR_ERR(net);
592 }
593
594 /* NOTE this can be a minor disagreement with the ECM spec,
595 * which says speed notifications will "always" follow
596 * connection notifications. But we allow one connect to
597 * follow another (if the first is in flight), and instead
598 * just guarantee that a speed notification is always sent.
599 */
600 ecm_notify(ecm);
601 } else
602 goto fail;
603
604 return 0;
605fail:
606 return -EINVAL;
607}
608
609/* Because the data interface supports multiple altsettings,
610 * this ECM function *MUST* implement a get_alt() method.
611 */
612static int ecm_get_alt(struct usb_function *f, unsigned intf)
613{
614 struct f_ecm *ecm = func_to_ecm(f);
615
616 if (intf == ecm->ctrl_id)
617 return 0;
618 return ecm->port.in_ep->enabled ? 1 : 0;
619}
620
621static void ecm_disable(struct usb_function *f)
622{
623 struct f_ecm *ecm = func_to_ecm(f);
624 struct usb_composite_dev *cdev = f->config->cdev;
625
626 DBG(cdev, "ecm deactivated\n");
627
628 if (ecm->port.in_ep->enabled)
629 gether_disconnect(&ecm->port);
630
631 usb_ep_disable(ecm->notify);
632 ecm->notify->desc = NULL;
633}
634
635/*-------------------------------------------------------------------------*/
636
637/*
638 * Callbacks let us notify the host about connect/disconnect when the
639 * net device is opened or closed.
640 *
641 * For testing, note that link states on this side include both opened
642 * and closed variants of:
643 *
644 * - disconnected/unconfigured
645 * - configured but inactive (data alt 0)
646 * - configured and active (data alt 1)
647 *
648 * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
649 * SET_INTERFACE (altsetting). Remember also that "configured" doesn't
650 * imply the host is actually polling the notification endpoint, and
651 * likewise that "active" doesn't imply it's actually using the data
652 * endpoints for traffic.
653 */
654
655static void ecm_open(struct gether *geth)
656{
657 struct f_ecm *ecm = func_to_ecm(&geth->func);
658
659 DBG(ecm->port.func.config->cdev, "%s\n", __func__);
660
661 ecm->is_open = true;
662 ecm_notify(ecm);
663}
664
665static void ecm_close(struct gether *geth)
666{
667 struct f_ecm *ecm = func_to_ecm(&geth->func);
668
669 DBG(ecm->port.func.config->cdev, "%s\n", __func__);
670
671 ecm->is_open = false;
672 ecm_notify(ecm);
673}
674
675/*-------------------------------------------------------------------------*/
676
677/* ethernet function driver setup/binding */
678
679static int
680ecm_bind(struct usb_configuration *c, struct usb_function *f)
681{
682 struct usb_composite_dev *cdev = c->cdev;
683 struct f_ecm *ecm = func_to_ecm(f);
684 struct usb_string *us;
685 int status;
686 struct usb_ep *ep;
687
688 struct f_ecm_opts *ecm_opts;
689
690 if (!can_support_ecm(cdev->gadget))
691 return -EINVAL;
692
693 ecm_opts = container_of(f->fi, struct f_ecm_opts, func_inst);
694
695 /*
696 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
697 * configurations are bound in sequence with list_for_each_entry,
698 * in each configuration its functions are bound in sequence
699 * with list_for_each_entry, so we assume no race condition
700 * with regard to ecm_opts->bound access
701 */
702 if (!ecm_opts->bound) {
703 mutex_lock(&ecm_opts->lock);
704 gether_set_gadget(ecm_opts->net, cdev->gadget);
705 status = gether_register_netdev(ecm_opts->net);
706 mutex_unlock(&ecm_opts->lock);
707 if (status)
708 return status;
709 ecm_opts->bound = true;
710 }
711
712 us = usb_gstrings_attach(cdev, ecm_strings,
713 ARRAY_SIZE(ecm_string_defs));
714 if (IS_ERR(us))
715 return PTR_ERR(us);
716 ecm_control_intf.iInterface = us[0].id;
717 ecm_data_intf.iInterface = us[2].id;
718 ecm_desc.iMACAddress = us[1].id;
719 ecm_iad_descriptor.iFunction = us[3].id;
720
721 /* allocate instance-specific interface IDs */
722 status = usb_interface_id(c, f);
723 if (status < 0)
724 goto fail;
725 ecm->ctrl_id = status;
726 ecm_iad_descriptor.bFirstInterface = status;
727
728 ecm_control_intf.bInterfaceNumber = status;
729 ecm_union_desc.bMasterInterface0 = status;
730
731 status = usb_interface_id(c, f);
732 if (status < 0)
733 goto fail;
734 ecm->data_id = status;
735
736 ecm_data_nop_intf.bInterfaceNumber = status;
737 ecm_data_intf.bInterfaceNumber = status;
738 ecm_union_desc.bSlaveInterface0 = status;
739
740 status = -ENODEV;
741
742 /* allocate instance-specific endpoints */
743 ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_in_desc);
744 if (!ep)
745 goto fail;
746 ecm->port.in_ep = ep;
747
748 ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_out_desc);
749 if (!ep)
750 goto fail;
751 ecm->port.out_ep = ep;
752
753 /* NOTE: a status/notification endpoint is *OPTIONAL* but we
754 * don't treat it that way. It's simpler, and some newer CDC
755 * profiles (wireless handsets) no longer treat it as optional.
756 */
757 ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_notify_desc);
758 if (!ep)
759 goto fail;
760 ecm->notify = ep;
761
762 status = -ENOMEM;
763
764 /* allocate notification request and buffer */
765 ecm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
766 if (!ecm->notify_req)
767 goto fail;
768 ecm->notify_req->buf = kmalloc(ECM_STATUS_BYTECOUNT, GFP_KERNEL);
769 if (!ecm->notify_req->buf)
770 goto fail;
771 ecm->notify_req->context = ecm;
772 ecm->notify_req->complete = ecm_notify_complete;
773
774 /* support all relevant hardware speeds... we expect that when
775 * hardware is dual speed, all bulk-capable endpoints work at
776 * both speeds
777 */
778 hs_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
779 hs_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
780 hs_ecm_notify_desc.bEndpointAddress =
781 fs_ecm_notify_desc.bEndpointAddress;
782
783 ss_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
784 ss_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
785 ss_ecm_notify_desc.bEndpointAddress =
786 fs_ecm_notify_desc.bEndpointAddress;
787
788 status = usb_assign_descriptors(f, ecm_fs_function, ecm_hs_function,
789 ecm_ss_function, NULL);
790 if (status)
791 goto fail;
792
793 /* NOTE: all that is done without knowing or caring about
794 * the network link ... which is unavailable to this code
795 * until we're activated via set_alt().
796 */
797
798 ecm->port.open = ecm_open;
799 ecm->port.close = ecm_close;
800
801 DBG(cdev, "CDC Ethernet: %s speed IN/%s OUT/%s NOTIFY/%s\n",
802 gadget_is_superspeed(c->cdev->gadget) ? "super" :
803 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
804 ecm->port.in_ep->name, ecm->port.out_ep->name,
805 ecm->notify->name);
806 return 0;
807
808fail:
809 if (ecm->notify_req) {
810 kfree(ecm->notify_req->buf);
811 usb_ep_free_request(ecm->notify, ecm->notify_req);
812 }
813
814 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
815
816 return status;
817}
818
819static inline struct f_ecm_opts *to_f_ecm_opts(struct config_item *item)
820{
821 return container_of(to_config_group(item), struct f_ecm_opts,
822 func_inst.group);
823}
824
825/* f_ecm_item_ops */
826USB_ETHERNET_CONFIGFS_ITEM(ecm);
827
828/* f_ecm_opts_dev_addr */
829USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ecm);
830
831/* f_ecm_opts_host_addr */
832USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ecm);
833
834/* f_ecm_opts_qmult */
835USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ecm);
836
837/* f_ecm_opts_ifname */
838USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ecm);
839
840static struct configfs_attribute *ecm_attrs[] = {
841 &ecm_opts_attr_dev_addr,
842 &ecm_opts_attr_host_addr,
843 &ecm_opts_attr_qmult,
844 &ecm_opts_attr_ifname,
845 NULL,
846};
847
848static struct config_item_type ecm_func_type = {
849 .ct_item_ops = &ecm_item_ops,
850 .ct_attrs = ecm_attrs,
851 .ct_owner = THIS_MODULE,
852};
853
854static void ecm_free_inst(struct usb_function_instance *f)
855{
856 struct f_ecm_opts *opts;
857
858 opts = container_of(f, struct f_ecm_opts, func_inst);
859 if (opts->bound)
860 gether_cleanup(netdev_priv(opts->net));
861 else
862 free_netdev(opts->net);
863 kfree(opts);
864}
865
866static struct usb_function_instance *ecm_alloc_inst(void)
867{
868 struct f_ecm_opts *opts;
869
870 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
871 if (!opts)
872 return ERR_PTR(-ENOMEM);
873 mutex_init(&opts->lock);
874 opts->func_inst.free_func_inst = ecm_free_inst;
875 opts->net = gether_setup_default();
876 if (IS_ERR(opts->net)) {
877 struct net_device *net = opts->net;
878 kfree(opts);
879 return ERR_CAST(net);
880 }
881
882 config_group_init_type_name(&opts->func_inst.group, "", &ecm_func_type);
883
884 return &opts->func_inst;
885}
886
887static void ecm_free(struct usb_function *f)
888{
889 struct f_ecm *ecm;
890 struct f_ecm_opts *opts;
891
892 ecm = func_to_ecm(f);
893 opts = container_of(f->fi, struct f_ecm_opts, func_inst);
894 kfree(ecm);
895 mutex_lock(&opts->lock);
896 opts->refcnt--;
897 mutex_unlock(&opts->lock);
898}
899
900static void ecm_unbind(struct usb_configuration *c, struct usb_function *f)
901{
902 struct f_ecm *ecm = func_to_ecm(f);
903
904 DBG(c->cdev, "ecm unbind\n");
905
906 usb_free_all_descriptors(f);
907
908 kfree(ecm->notify_req->buf);
909 usb_ep_free_request(ecm->notify, ecm->notify_req);
910}
911
912static struct usb_function *ecm_alloc(struct usb_function_instance *fi)
913{
914 struct f_ecm *ecm;
915 struct f_ecm_opts *opts;
916 int status;
917
918 /* allocate and initialize one new instance */
919 ecm = kzalloc(sizeof(*ecm), GFP_KERNEL);
920 if (!ecm)
921 return ERR_PTR(-ENOMEM);
922
923 opts = container_of(fi, struct f_ecm_opts, func_inst);
924 mutex_lock(&opts->lock);
925 opts->refcnt++;
926
927 /* export host's Ethernet address in CDC format */
928 status = gether_get_host_addr_cdc(opts->net, ecm->ethaddr,
929 sizeof(ecm->ethaddr));
930 if (status < 12) {
931 kfree(ecm);
932 mutex_unlock(&opts->lock);
933 return ERR_PTR(-EINVAL);
934 }
935 ecm_string_defs[1].s = ecm->ethaddr;
936
937 ecm->port.ioport = netdev_priv(opts->net);
938 mutex_unlock(&opts->lock);
939 ecm->port.cdc_filter = DEFAULT_FILTER;
940
941 ecm->port.func.name = "cdc_ethernet";
942 /* descriptors are per-instance copies */
943 ecm->port.func.bind = ecm_bind;
944 ecm->port.func.unbind = ecm_unbind;
945 ecm->port.func.set_alt = ecm_set_alt;
946 ecm->port.func.get_alt = ecm_get_alt;
947 ecm->port.func.setup = ecm_setup;
948 ecm->port.func.disable = ecm_disable;
949 ecm->port.func.free_func = ecm_free;
950
951 return &ecm->port.func;
952}
953
954DECLARE_USB_FUNCTION_INIT(ecm, ecm_alloc_inst, ecm_alloc);
955MODULE_LICENSE("GPL");
956MODULE_AUTHOR("David Brownell");
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * f_ecm.c -- USB CDC Ethernet (ECM) link function driver
4 *
5 * Copyright (C) 2003-2005,2008 David Brownell
6 * Copyright (C) 2008 Nokia Corporation
7 */
8
9/* #define VERBOSE_DEBUG */
10
11#include <linux/slab.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/device.h>
15#include <linux/etherdevice.h>
16
17#include "u_ether.h"
18#include "u_ether_configfs.h"
19#include "u_ecm.h"
20
21
22/*
23 * This function is a "CDC Ethernet Networking Control Model" (CDC ECM)
24 * Ethernet link. The data transfer model is simple (packets sent and
25 * received over bulk endpoints using normal short packet termination),
26 * and the control model exposes various data and optional notifications.
27 *
28 * ECM is well standardized and (except for Microsoft) supported by most
29 * operating systems with USB host support. It's the preferred interop
30 * solution for Ethernet over USB, at least for firmware based solutions.
31 * (Hardware solutions tend to be more minimalist.) A newer and simpler
32 * "Ethernet Emulation Model" (CDC EEM) hasn't yet caught on.
33 *
34 * Note that ECM requires the use of "alternate settings" for its data
35 * interface. This means that the set_alt() method has real work to do,
36 * and also means that a get_alt() method is required.
37 */
38
39
40enum ecm_notify_state {
41 ECM_NOTIFY_NONE, /* don't notify */
42 ECM_NOTIFY_CONNECT, /* issue CONNECT next */
43 ECM_NOTIFY_SPEED, /* issue SPEED_CHANGE next */
44};
45
46struct f_ecm {
47 struct gether port;
48 u8 ctrl_id, data_id;
49
50 char ethaddr[14];
51
52 struct usb_ep *notify;
53 struct usb_request *notify_req;
54 u8 notify_state;
55 bool is_open;
56
57 /* FIXME is_open needs some irq-ish locking
58 * ... possibly the same as port.ioport
59 */
60};
61
62static inline struct f_ecm *func_to_ecm(struct usb_function *f)
63{
64 return container_of(f, struct f_ecm, port.func);
65}
66
67/* peak (theoretical) bulk transfer rate in bits-per-second */
68static inline unsigned ecm_bitrate(struct usb_gadget *g)
69{
70 if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
71 return 13 * 1024 * 8 * 1000 * 8;
72 else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
73 return 13 * 512 * 8 * 1000 * 8;
74 else
75 return 19 * 64 * 1 * 1000 * 8;
76}
77
78/*-------------------------------------------------------------------------*/
79
80/*
81 * Include the status endpoint if we can, even though it's optional.
82 *
83 * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
84 * packet, to simplify cancellation; and a big transfer interval, to
85 * waste less bandwidth.
86 *
87 * Some drivers (like Linux 2.4 cdc-ether!) "need" it to exist even
88 * if they ignore the connect/disconnect notifications that real aether
89 * can provide. More advanced cdc configurations might want to support
90 * encapsulated commands (vendor-specific, using control-OUT).
91 */
92
93#define ECM_STATUS_INTERVAL_MS 32
94#define ECM_STATUS_BYTECOUNT 16 /* 8 byte header + data */
95
96
97/* interface descriptor: */
98
99static struct usb_interface_assoc_descriptor
100ecm_iad_descriptor = {
101 .bLength = sizeof ecm_iad_descriptor,
102 .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
103
104 /* .bFirstInterface = DYNAMIC, */
105 .bInterfaceCount = 2, /* control + data */
106 .bFunctionClass = USB_CLASS_COMM,
107 .bFunctionSubClass = USB_CDC_SUBCLASS_ETHERNET,
108 .bFunctionProtocol = USB_CDC_PROTO_NONE,
109 /* .iFunction = DYNAMIC */
110};
111
112
113static struct usb_interface_descriptor ecm_control_intf = {
114 .bLength = sizeof ecm_control_intf,
115 .bDescriptorType = USB_DT_INTERFACE,
116
117 /* .bInterfaceNumber = DYNAMIC */
118 /* status endpoint is optional; this could be patched later */
119 .bNumEndpoints = 1,
120 .bInterfaceClass = USB_CLASS_COMM,
121 .bInterfaceSubClass = USB_CDC_SUBCLASS_ETHERNET,
122 .bInterfaceProtocol = USB_CDC_PROTO_NONE,
123 /* .iInterface = DYNAMIC */
124};
125
126static struct usb_cdc_header_desc ecm_header_desc = {
127 .bLength = sizeof ecm_header_desc,
128 .bDescriptorType = USB_DT_CS_INTERFACE,
129 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
130
131 .bcdCDC = cpu_to_le16(0x0110),
132};
133
134static struct usb_cdc_union_desc ecm_union_desc = {
135 .bLength = sizeof(ecm_union_desc),
136 .bDescriptorType = USB_DT_CS_INTERFACE,
137 .bDescriptorSubType = USB_CDC_UNION_TYPE,
138 /* .bMasterInterface0 = DYNAMIC */
139 /* .bSlaveInterface0 = DYNAMIC */
140};
141
142static struct usb_cdc_ether_desc ecm_desc = {
143 .bLength = sizeof ecm_desc,
144 .bDescriptorType = USB_DT_CS_INTERFACE,
145 .bDescriptorSubType = USB_CDC_ETHERNET_TYPE,
146
147 /* this descriptor actually adds value, surprise! */
148 /* .iMACAddress = DYNAMIC */
149 .bmEthernetStatistics = cpu_to_le32(0), /* no statistics */
150 .wMaxSegmentSize = cpu_to_le16(ETH_FRAME_LEN),
151 .wNumberMCFilters = cpu_to_le16(0),
152 .bNumberPowerFilters = 0,
153};
154
155/* the default data interface has no endpoints ... */
156
157static struct usb_interface_descriptor ecm_data_nop_intf = {
158 .bLength = sizeof ecm_data_nop_intf,
159 .bDescriptorType = USB_DT_INTERFACE,
160
161 .bInterfaceNumber = 1,
162 .bAlternateSetting = 0,
163 .bNumEndpoints = 0,
164 .bInterfaceClass = USB_CLASS_CDC_DATA,
165 .bInterfaceSubClass = 0,
166 .bInterfaceProtocol = 0,
167 /* .iInterface = DYNAMIC */
168};
169
170/* ... but the "real" data interface has two bulk endpoints */
171
172static struct usb_interface_descriptor ecm_data_intf = {
173 .bLength = sizeof ecm_data_intf,
174 .bDescriptorType = USB_DT_INTERFACE,
175
176 .bInterfaceNumber = 1,
177 .bAlternateSetting = 1,
178 .bNumEndpoints = 2,
179 .bInterfaceClass = USB_CLASS_CDC_DATA,
180 .bInterfaceSubClass = 0,
181 .bInterfaceProtocol = 0,
182 /* .iInterface = DYNAMIC */
183};
184
185/* full speed support: */
186
187static struct usb_endpoint_descriptor fs_ecm_notify_desc = {
188 .bLength = USB_DT_ENDPOINT_SIZE,
189 .bDescriptorType = USB_DT_ENDPOINT,
190
191 .bEndpointAddress = USB_DIR_IN,
192 .bmAttributes = USB_ENDPOINT_XFER_INT,
193 .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT),
194 .bInterval = ECM_STATUS_INTERVAL_MS,
195};
196
197static struct usb_endpoint_descriptor fs_ecm_in_desc = {
198 .bLength = USB_DT_ENDPOINT_SIZE,
199 .bDescriptorType = USB_DT_ENDPOINT,
200
201 .bEndpointAddress = USB_DIR_IN,
202 .bmAttributes = USB_ENDPOINT_XFER_BULK,
203};
204
205static struct usb_endpoint_descriptor fs_ecm_out_desc = {
206 .bLength = USB_DT_ENDPOINT_SIZE,
207 .bDescriptorType = USB_DT_ENDPOINT,
208
209 .bEndpointAddress = USB_DIR_OUT,
210 .bmAttributes = USB_ENDPOINT_XFER_BULK,
211};
212
213static struct usb_descriptor_header *ecm_fs_function[] = {
214 /* CDC ECM control descriptors */
215 (struct usb_descriptor_header *) &ecm_iad_descriptor,
216 (struct usb_descriptor_header *) &ecm_control_intf,
217 (struct usb_descriptor_header *) &ecm_header_desc,
218 (struct usb_descriptor_header *) &ecm_union_desc,
219 (struct usb_descriptor_header *) &ecm_desc,
220
221 /* NOTE: status endpoint might need to be removed */
222 (struct usb_descriptor_header *) &fs_ecm_notify_desc,
223
224 /* data interface, altsettings 0 and 1 */
225 (struct usb_descriptor_header *) &ecm_data_nop_intf,
226 (struct usb_descriptor_header *) &ecm_data_intf,
227 (struct usb_descriptor_header *) &fs_ecm_in_desc,
228 (struct usb_descriptor_header *) &fs_ecm_out_desc,
229 NULL,
230};
231
232/* high speed support: */
233
234static struct usb_endpoint_descriptor hs_ecm_notify_desc = {
235 .bLength = USB_DT_ENDPOINT_SIZE,
236 .bDescriptorType = USB_DT_ENDPOINT,
237
238 .bEndpointAddress = USB_DIR_IN,
239 .bmAttributes = USB_ENDPOINT_XFER_INT,
240 .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT),
241 .bInterval = USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
242};
243
244static struct usb_endpoint_descriptor hs_ecm_in_desc = {
245 .bLength = USB_DT_ENDPOINT_SIZE,
246 .bDescriptorType = USB_DT_ENDPOINT,
247
248 .bEndpointAddress = USB_DIR_IN,
249 .bmAttributes = USB_ENDPOINT_XFER_BULK,
250 .wMaxPacketSize = cpu_to_le16(512),
251};
252
253static struct usb_endpoint_descriptor hs_ecm_out_desc = {
254 .bLength = USB_DT_ENDPOINT_SIZE,
255 .bDescriptorType = USB_DT_ENDPOINT,
256
257 .bEndpointAddress = USB_DIR_OUT,
258 .bmAttributes = USB_ENDPOINT_XFER_BULK,
259 .wMaxPacketSize = cpu_to_le16(512),
260};
261
262static struct usb_descriptor_header *ecm_hs_function[] = {
263 /* CDC ECM control descriptors */
264 (struct usb_descriptor_header *) &ecm_iad_descriptor,
265 (struct usb_descriptor_header *) &ecm_control_intf,
266 (struct usb_descriptor_header *) &ecm_header_desc,
267 (struct usb_descriptor_header *) &ecm_union_desc,
268 (struct usb_descriptor_header *) &ecm_desc,
269
270 /* NOTE: status endpoint might need to be removed */
271 (struct usb_descriptor_header *) &hs_ecm_notify_desc,
272
273 /* data interface, altsettings 0 and 1 */
274 (struct usb_descriptor_header *) &ecm_data_nop_intf,
275 (struct usb_descriptor_header *) &ecm_data_intf,
276 (struct usb_descriptor_header *) &hs_ecm_in_desc,
277 (struct usb_descriptor_header *) &hs_ecm_out_desc,
278 NULL,
279};
280
281/* super speed support: */
282
283static struct usb_endpoint_descriptor ss_ecm_notify_desc = {
284 .bLength = USB_DT_ENDPOINT_SIZE,
285 .bDescriptorType = USB_DT_ENDPOINT,
286
287 .bEndpointAddress = USB_DIR_IN,
288 .bmAttributes = USB_ENDPOINT_XFER_INT,
289 .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT),
290 .bInterval = USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
291};
292
293static struct usb_ss_ep_comp_descriptor ss_ecm_intr_comp_desc = {
294 .bLength = sizeof ss_ecm_intr_comp_desc,
295 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
296
297 /* the following 3 values can be tweaked if necessary */
298 /* .bMaxBurst = 0, */
299 /* .bmAttributes = 0, */
300 .wBytesPerInterval = cpu_to_le16(ECM_STATUS_BYTECOUNT),
301};
302
303static struct usb_endpoint_descriptor ss_ecm_in_desc = {
304 .bLength = USB_DT_ENDPOINT_SIZE,
305 .bDescriptorType = USB_DT_ENDPOINT,
306
307 .bEndpointAddress = USB_DIR_IN,
308 .bmAttributes = USB_ENDPOINT_XFER_BULK,
309 .wMaxPacketSize = cpu_to_le16(1024),
310};
311
312static struct usb_endpoint_descriptor ss_ecm_out_desc = {
313 .bLength = USB_DT_ENDPOINT_SIZE,
314 .bDescriptorType = USB_DT_ENDPOINT,
315
316 .bEndpointAddress = USB_DIR_OUT,
317 .bmAttributes = USB_ENDPOINT_XFER_BULK,
318 .wMaxPacketSize = cpu_to_le16(1024),
319};
320
321static struct usb_ss_ep_comp_descriptor ss_ecm_bulk_comp_desc = {
322 .bLength = sizeof ss_ecm_bulk_comp_desc,
323 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
324
325 /* the following 2 values can be tweaked if necessary */
326 /* .bMaxBurst = 0, */
327 /* .bmAttributes = 0, */
328};
329
330static struct usb_descriptor_header *ecm_ss_function[] = {
331 /* CDC ECM control descriptors */
332 (struct usb_descriptor_header *) &ecm_iad_descriptor,
333 (struct usb_descriptor_header *) &ecm_control_intf,
334 (struct usb_descriptor_header *) &ecm_header_desc,
335 (struct usb_descriptor_header *) &ecm_union_desc,
336 (struct usb_descriptor_header *) &ecm_desc,
337
338 /* NOTE: status endpoint might need to be removed */
339 (struct usb_descriptor_header *) &ss_ecm_notify_desc,
340 (struct usb_descriptor_header *) &ss_ecm_intr_comp_desc,
341
342 /* data interface, altsettings 0 and 1 */
343 (struct usb_descriptor_header *) &ecm_data_nop_intf,
344 (struct usb_descriptor_header *) &ecm_data_intf,
345 (struct usb_descriptor_header *) &ss_ecm_in_desc,
346 (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
347 (struct usb_descriptor_header *) &ss_ecm_out_desc,
348 (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
349 NULL,
350};
351
352/* string descriptors: */
353
354static struct usb_string ecm_string_defs[] = {
355 [0].s = "CDC Ethernet Control Model (ECM)",
356 [1].s = "",
357 [2].s = "CDC Ethernet Data",
358 [3].s = "CDC ECM",
359 { } /* end of list */
360};
361
362static struct usb_gadget_strings ecm_string_table = {
363 .language = 0x0409, /* en-us */
364 .strings = ecm_string_defs,
365};
366
367static struct usb_gadget_strings *ecm_strings[] = {
368 &ecm_string_table,
369 NULL,
370};
371
372/*-------------------------------------------------------------------------*/
373
374static void ecm_do_notify(struct f_ecm *ecm)
375{
376 struct usb_request *req = ecm->notify_req;
377 struct usb_cdc_notification *event;
378 struct usb_composite_dev *cdev = ecm->port.func.config->cdev;
379 __le32 *data;
380 int status;
381
382 /* notification already in flight? */
383 if (!req)
384 return;
385
386 event = req->buf;
387 switch (ecm->notify_state) {
388 case ECM_NOTIFY_NONE:
389 return;
390
391 case ECM_NOTIFY_CONNECT:
392 event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
393 if (ecm->is_open)
394 event->wValue = cpu_to_le16(1);
395 else
396 event->wValue = cpu_to_le16(0);
397 event->wLength = 0;
398 req->length = sizeof *event;
399
400 DBG(cdev, "notify connect %s\n",
401 ecm->is_open ? "true" : "false");
402 ecm->notify_state = ECM_NOTIFY_SPEED;
403 break;
404
405 case ECM_NOTIFY_SPEED:
406 event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
407 event->wValue = cpu_to_le16(0);
408 event->wLength = cpu_to_le16(8);
409 req->length = ECM_STATUS_BYTECOUNT;
410
411 /* SPEED_CHANGE data is up/down speeds in bits/sec */
412 data = req->buf + sizeof *event;
413 data[0] = cpu_to_le32(ecm_bitrate(cdev->gadget));
414 data[1] = data[0];
415
416 DBG(cdev, "notify speed %d\n", ecm_bitrate(cdev->gadget));
417 ecm->notify_state = ECM_NOTIFY_NONE;
418 break;
419 }
420 event->bmRequestType = 0xA1;
421 event->wIndex = cpu_to_le16(ecm->ctrl_id);
422
423 ecm->notify_req = NULL;
424 status = usb_ep_queue(ecm->notify, req, GFP_ATOMIC);
425 if (status < 0) {
426 ecm->notify_req = req;
427 DBG(cdev, "notify --> %d\n", status);
428 }
429}
430
431static void ecm_notify(struct f_ecm *ecm)
432{
433 /* NOTE on most versions of Linux, host side cdc-ethernet
434 * won't listen for notifications until its netdevice opens.
435 * The first notification then sits in the FIFO for a long
436 * time, and the second one is queued.
437 */
438 ecm->notify_state = ECM_NOTIFY_CONNECT;
439 ecm_do_notify(ecm);
440}
441
442static void ecm_notify_complete(struct usb_ep *ep, struct usb_request *req)
443{
444 struct f_ecm *ecm = req->context;
445 struct usb_composite_dev *cdev = ecm->port.func.config->cdev;
446 struct usb_cdc_notification *event = req->buf;
447
448 switch (req->status) {
449 case 0:
450 /* no fault */
451 break;
452 case -ECONNRESET:
453 case -ESHUTDOWN:
454 ecm->notify_state = ECM_NOTIFY_NONE;
455 break;
456 default:
457 DBG(cdev, "event %02x --> %d\n",
458 event->bNotificationType, req->status);
459 break;
460 }
461 ecm->notify_req = req;
462 ecm_do_notify(ecm);
463}
464
465static int ecm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
466{
467 struct f_ecm *ecm = func_to_ecm(f);
468 struct usb_composite_dev *cdev = f->config->cdev;
469 struct usb_request *req = cdev->req;
470 int value = -EOPNOTSUPP;
471 u16 w_index = le16_to_cpu(ctrl->wIndex);
472 u16 w_value = le16_to_cpu(ctrl->wValue);
473 u16 w_length = le16_to_cpu(ctrl->wLength);
474
475 /* composite driver infrastructure handles everything except
476 * CDC class messages; interface activation uses set_alt().
477 */
478 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
479 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
480 | USB_CDC_SET_ETHERNET_PACKET_FILTER:
481 /* see 6.2.30: no data, wIndex = interface,
482 * wValue = packet filter bitmap
483 */
484 if (w_length != 0 || w_index != ecm->ctrl_id)
485 goto invalid;
486 DBG(cdev, "packet filter %02x\n", w_value);
487 /* REVISIT locking of cdc_filter. This assumes the UDC
488 * driver won't have a concurrent packet TX irq running on
489 * another CPU; or that if it does, this write is atomic...
490 */
491 ecm->port.cdc_filter = w_value;
492 value = 0;
493 break;
494
495 /* and optionally:
496 * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
497 * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
498 * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
499 * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
500 * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
501 * case USB_CDC_GET_ETHERNET_STATISTIC:
502 */
503
504 default:
505invalid:
506 DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
507 ctrl->bRequestType, ctrl->bRequest,
508 w_value, w_index, w_length);
509 }
510
511 /* respond with data transfer or status phase? */
512 if (value >= 0) {
513 DBG(cdev, "ecm req%02x.%02x v%04x i%04x l%d\n",
514 ctrl->bRequestType, ctrl->bRequest,
515 w_value, w_index, w_length);
516 req->zero = 0;
517 req->length = value;
518 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
519 if (value < 0)
520 ERROR(cdev, "ecm req %02x.%02x response err %d\n",
521 ctrl->bRequestType, ctrl->bRequest,
522 value);
523 }
524
525 /* device either stalls (value < 0) or reports success */
526 return value;
527}
528
529
530static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
531{
532 struct f_ecm *ecm = func_to_ecm(f);
533 struct usb_composite_dev *cdev = f->config->cdev;
534
535 /* Control interface has only altsetting 0 */
536 if (intf == ecm->ctrl_id) {
537 if (alt != 0)
538 goto fail;
539
540 VDBG(cdev, "reset ecm control %d\n", intf);
541 usb_ep_disable(ecm->notify);
542 if (!(ecm->notify->desc)) {
543 VDBG(cdev, "init ecm ctrl %d\n", intf);
544 if (config_ep_by_speed(cdev->gadget, f, ecm->notify))
545 goto fail;
546 }
547 usb_ep_enable(ecm->notify);
548
549 /* Data interface has two altsettings, 0 and 1 */
550 } else if (intf == ecm->data_id) {
551 if (alt > 1)
552 goto fail;
553
554 if (ecm->port.in_ep->enabled) {
555 DBG(cdev, "reset ecm\n");
556 gether_disconnect(&ecm->port);
557 }
558
559 if (!ecm->port.in_ep->desc ||
560 !ecm->port.out_ep->desc) {
561 DBG(cdev, "init ecm\n");
562 if (config_ep_by_speed(cdev->gadget, f,
563 ecm->port.in_ep) ||
564 config_ep_by_speed(cdev->gadget, f,
565 ecm->port.out_ep)) {
566 ecm->port.in_ep->desc = NULL;
567 ecm->port.out_ep->desc = NULL;
568 goto fail;
569 }
570 }
571
572 /* CDC Ethernet only sends data in non-default altsettings.
573 * Changing altsettings resets filters, statistics, etc.
574 */
575 if (alt == 1) {
576 struct net_device *net;
577
578 /* Enable zlps by default for ECM conformance;
579 * override for musb_hdrc (avoids txdma ovhead).
580 */
581 ecm->port.is_zlp_ok =
582 gadget_is_zlp_supported(cdev->gadget);
583 ecm->port.cdc_filter = DEFAULT_FILTER;
584 DBG(cdev, "activate ecm\n");
585 net = gether_connect(&ecm->port);
586 if (IS_ERR(net))
587 return PTR_ERR(net);
588 }
589
590 /* NOTE this can be a minor disagreement with the ECM spec,
591 * which says speed notifications will "always" follow
592 * connection notifications. But we allow one connect to
593 * follow another (if the first is in flight), and instead
594 * just guarantee that a speed notification is always sent.
595 */
596 ecm_notify(ecm);
597 } else
598 goto fail;
599
600 return 0;
601fail:
602 return -EINVAL;
603}
604
605/* Because the data interface supports multiple altsettings,
606 * this ECM function *MUST* implement a get_alt() method.
607 */
608static int ecm_get_alt(struct usb_function *f, unsigned intf)
609{
610 struct f_ecm *ecm = func_to_ecm(f);
611
612 if (intf == ecm->ctrl_id)
613 return 0;
614 return ecm->port.in_ep->enabled ? 1 : 0;
615}
616
617static void ecm_disable(struct usb_function *f)
618{
619 struct f_ecm *ecm = func_to_ecm(f);
620 struct usb_composite_dev *cdev = f->config->cdev;
621
622 DBG(cdev, "ecm deactivated\n");
623
624 if (ecm->port.in_ep->enabled)
625 gether_disconnect(&ecm->port);
626
627 usb_ep_disable(ecm->notify);
628 ecm->notify->desc = NULL;
629}
630
631/*-------------------------------------------------------------------------*/
632
633/*
634 * Callbacks let us notify the host about connect/disconnect when the
635 * net device is opened or closed.
636 *
637 * For testing, note that link states on this side include both opened
638 * and closed variants of:
639 *
640 * - disconnected/unconfigured
641 * - configured but inactive (data alt 0)
642 * - configured and active (data alt 1)
643 *
644 * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
645 * SET_INTERFACE (altsetting). Remember also that "configured" doesn't
646 * imply the host is actually polling the notification endpoint, and
647 * likewise that "active" doesn't imply it's actually using the data
648 * endpoints for traffic.
649 */
650
651static void ecm_open(struct gether *geth)
652{
653 struct f_ecm *ecm = func_to_ecm(&geth->func);
654
655 DBG(ecm->port.func.config->cdev, "%s\n", __func__);
656
657 ecm->is_open = true;
658 ecm_notify(ecm);
659}
660
661static void ecm_close(struct gether *geth)
662{
663 struct f_ecm *ecm = func_to_ecm(&geth->func);
664
665 DBG(ecm->port.func.config->cdev, "%s\n", __func__);
666
667 ecm->is_open = false;
668 ecm_notify(ecm);
669}
670
671/*-------------------------------------------------------------------------*/
672
673/* ethernet function driver setup/binding */
674
675static int
676ecm_bind(struct usb_configuration *c, struct usb_function *f)
677{
678 struct usb_composite_dev *cdev = c->cdev;
679 struct f_ecm *ecm = func_to_ecm(f);
680 struct usb_string *us;
681 int status;
682 struct usb_ep *ep;
683
684 struct f_ecm_opts *ecm_opts;
685
686 if (!can_support_ecm(cdev->gadget))
687 return -EINVAL;
688
689 ecm_opts = container_of(f->fi, struct f_ecm_opts, func_inst);
690
691 /*
692 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
693 * configurations are bound in sequence with list_for_each_entry,
694 * in each configuration its functions are bound in sequence
695 * with list_for_each_entry, so we assume no race condition
696 * with regard to ecm_opts->bound access
697 */
698 if (!ecm_opts->bound) {
699 mutex_lock(&ecm_opts->lock);
700 gether_set_gadget(ecm_opts->net, cdev->gadget);
701 status = gether_register_netdev(ecm_opts->net);
702 mutex_unlock(&ecm_opts->lock);
703 if (status)
704 return status;
705 ecm_opts->bound = true;
706 }
707
708 us = usb_gstrings_attach(cdev, ecm_strings,
709 ARRAY_SIZE(ecm_string_defs));
710 if (IS_ERR(us))
711 return PTR_ERR(us);
712 ecm_control_intf.iInterface = us[0].id;
713 ecm_data_intf.iInterface = us[2].id;
714 ecm_desc.iMACAddress = us[1].id;
715 ecm_iad_descriptor.iFunction = us[3].id;
716
717 /* allocate instance-specific interface IDs */
718 status = usb_interface_id(c, f);
719 if (status < 0)
720 goto fail;
721 ecm->ctrl_id = status;
722 ecm_iad_descriptor.bFirstInterface = status;
723
724 ecm_control_intf.bInterfaceNumber = status;
725 ecm_union_desc.bMasterInterface0 = status;
726
727 status = usb_interface_id(c, f);
728 if (status < 0)
729 goto fail;
730 ecm->data_id = status;
731
732 ecm_data_nop_intf.bInterfaceNumber = status;
733 ecm_data_intf.bInterfaceNumber = status;
734 ecm_union_desc.bSlaveInterface0 = status;
735
736 status = -ENODEV;
737
738 /* allocate instance-specific endpoints */
739 ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_in_desc);
740 if (!ep)
741 goto fail;
742 ecm->port.in_ep = ep;
743
744 ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_out_desc);
745 if (!ep)
746 goto fail;
747 ecm->port.out_ep = ep;
748
749 /* NOTE: a status/notification endpoint is *OPTIONAL* but we
750 * don't treat it that way. It's simpler, and some newer CDC
751 * profiles (wireless handsets) no longer treat it as optional.
752 */
753 ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_notify_desc);
754 if (!ep)
755 goto fail;
756 ecm->notify = ep;
757
758 status = -ENOMEM;
759
760 /* allocate notification request and buffer */
761 ecm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
762 if (!ecm->notify_req)
763 goto fail;
764 ecm->notify_req->buf = kmalloc(ECM_STATUS_BYTECOUNT, GFP_KERNEL);
765 if (!ecm->notify_req->buf)
766 goto fail;
767 ecm->notify_req->context = ecm;
768 ecm->notify_req->complete = ecm_notify_complete;
769
770 /* support all relevant hardware speeds... we expect that when
771 * hardware is dual speed, all bulk-capable endpoints work at
772 * both speeds
773 */
774 hs_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
775 hs_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
776 hs_ecm_notify_desc.bEndpointAddress =
777 fs_ecm_notify_desc.bEndpointAddress;
778
779 ss_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
780 ss_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
781 ss_ecm_notify_desc.bEndpointAddress =
782 fs_ecm_notify_desc.bEndpointAddress;
783
784 status = usb_assign_descriptors(f, ecm_fs_function, ecm_hs_function,
785 ecm_ss_function, NULL);
786 if (status)
787 goto fail;
788
789 /* NOTE: all that is done without knowing or caring about
790 * the network link ... which is unavailable to this code
791 * until we're activated via set_alt().
792 */
793
794 ecm->port.open = ecm_open;
795 ecm->port.close = ecm_close;
796
797 DBG(cdev, "CDC Ethernet: %s speed IN/%s OUT/%s NOTIFY/%s\n",
798 gadget_is_superspeed(c->cdev->gadget) ? "super" :
799 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
800 ecm->port.in_ep->name, ecm->port.out_ep->name,
801 ecm->notify->name);
802 return 0;
803
804fail:
805 if (ecm->notify_req) {
806 kfree(ecm->notify_req->buf);
807 usb_ep_free_request(ecm->notify, ecm->notify_req);
808 }
809
810 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
811
812 return status;
813}
814
815static inline struct f_ecm_opts *to_f_ecm_opts(struct config_item *item)
816{
817 return container_of(to_config_group(item), struct f_ecm_opts,
818 func_inst.group);
819}
820
821/* f_ecm_item_ops */
822USB_ETHERNET_CONFIGFS_ITEM(ecm);
823
824/* f_ecm_opts_dev_addr */
825USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ecm);
826
827/* f_ecm_opts_host_addr */
828USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ecm);
829
830/* f_ecm_opts_qmult */
831USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ecm);
832
833/* f_ecm_opts_ifname */
834USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ecm);
835
836static struct configfs_attribute *ecm_attrs[] = {
837 &ecm_opts_attr_dev_addr,
838 &ecm_opts_attr_host_addr,
839 &ecm_opts_attr_qmult,
840 &ecm_opts_attr_ifname,
841 NULL,
842};
843
844static const struct config_item_type ecm_func_type = {
845 .ct_item_ops = &ecm_item_ops,
846 .ct_attrs = ecm_attrs,
847 .ct_owner = THIS_MODULE,
848};
849
850static void ecm_free_inst(struct usb_function_instance *f)
851{
852 struct f_ecm_opts *opts;
853
854 opts = container_of(f, struct f_ecm_opts, func_inst);
855 if (opts->bound)
856 gether_cleanup(netdev_priv(opts->net));
857 else
858 free_netdev(opts->net);
859 kfree(opts);
860}
861
862static struct usb_function_instance *ecm_alloc_inst(void)
863{
864 struct f_ecm_opts *opts;
865
866 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
867 if (!opts)
868 return ERR_PTR(-ENOMEM);
869 mutex_init(&opts->lock);
870 opts->func_inst.free_func_inst = ecm_free_inst;
871 opts->net = gether_setup_default();
872 if (IS_ERR(opts->net)) {
873 struct net_device *net = opts->net;
874 kfree(opts);
875 return ERR_CAST(net);
876 }
877
878 config_group_init_type_name(&opts->func_inst.group, "", &ecm_func_type);
879
880 return &opts->func_inst;
881}
882
883static void ecm_free(struct usb_function *f)
884{
885 struct f_ecm *ecm;
886 struct f_ecm_opts *opts;
887
888 ecm = func_to_ecm(f);
889 opts = container_of(f->fi, struct f_ecm_opts, func_inst);
890 kfree(ecm);
891 mutex_lock(&opts->lock);
892 opts->refcnt--;
893 mutex_unlock(&opts->lock);
894}
895
896static void ecm_unbind(struct usb_configuration *c, struct usb_function *f)
897{
898 struct f_ecm *ecm = func_to_ecm(f);
899
900 DBG(c->cdev, "ecm unbind\n");
901
902 usb_free_all_descriptors(f);
903
904 kfree(ecm->notify_req->buf);
905 usb_ep_free_request(ecm->notify, ecm->notify_req);
906}
907
908static struct usb_function *ecm_alloc(struct usb_function_instance *fi)
909{
910 struct f_ecm *ecm;
911 struct f_ecm_opts *opts;
912 int status;
913
914 /* allocate and initialize one new instance */
915 ecm = kzalloc(sizeof(*ecm), GFP_KERNEL);
916 if (!ecm)
917 return ERR_PTR(-ENOMEM);
918
919 opts = container_of(fi, struct f_ecm_opts, func_inst);
920 mutex_lock(&opts->lock);
921 opts->refcnt++;
922
923 /* export host's Ethernet address in CDC format */
924 status = gether_get_host_addr_cdc(opts->net, ecm->ethaddr,
925 sizeof(ecm->ethaddr));
926 if (status < 12) {
927 kfree(ecm);
928 mutex_unlock(&opts->lock);
929 return ERR_PTR(-EINVAL);
930 }
931 ecm_string_defs[1].s = ecm->ethaddr;
932
933 ecm->port.ioport = netdev_priv(opts->net);
934 mutex_unlock(&opts->lock);
935 ecm->port.cdc_filter = DEFAULT_FILTER;
936
937 ecm->port.func.name = "cdc_ethernet";
938 /* descriptors are per-instance copies */
939 ecm->port.func.bind = ecm_bind;
940 ecm->port.func.unbind = ecm_unbind;
941 ecm->port.func.set_alt = ecm_set_alt;
942 ecm->port.func.get_alt = ecm_get_alt;
943 ecm->port.func.setup = ecm_setup;
944 ecm->port.func.disable = ecm_disable;
945 ecm->port.func.free_func = ecm_free;
946
947 return &ecm->port.func;
948}
949
950DECLARE_USB_FUNCTION_INIT(ecm, ecm_alloc_inst, ecm_alloc);
951MODULE_LICENSE("GPL");
952MODULE_AUTHOR("David Brownell");