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 atomic_t notify_count;
56 bool is_open;
57
58 /* FIXME is_open needs some irq-ish locking
59 * ... possibly the same as port.ioport
60 */
61};
62
63static inline struct f_ecm *func_to_ecm(struct usb_function *f)
64{
65 return container_of(f, struct f_ecm, port.func);
66}
67
68/*-------------------------------------------------------------------------*/
69
70/*
71 * Include the status endpoint if we can, even though it's optional.
72 *
73 * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
74 * packet, to simplify cancellation; and a big transfer interval, to
75 * waste less bandwidth.
76 *
77 * Some drivers (like Linux 2.4 cdc-ether!) "need" it to exist even
78 * if they ignore the connect/disconnect notifications that real aether
79 * can provide. More advanced cdc configurations might want to support
80 * encapsulated commands (vendor-specific, using control-OUT).
81 */
82
83#define ECM_STATUS_INTERVAL_MS 32
84#define ECM_STATUS_BYTECOUNT 16 /* 8 byte header + data */
85
86
87/* interface descriptor: */
88
89static struct usb_interface_assoc_descriptor
90ecm_iad_descriptor = {
91 .bLength = sizeof ecm_iad_descriptor,
92 .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
93
94 /* .bFirstInterface = DYNAMIC, */
95 .bInterfaceCount = 2, /* control + data */
96 .bFunctionClass = USB_CLASS_COMM,
97 .bFunctionSubClass = USB_CDC_SUBCLASS_ETHERNET,
98 .bFunctionProtocol = USB_CDC_PROTO_NONE,
99 /* .iFunction = DYNAMIC */
100};
101
102
103static struct usb_interface_descriptor ecm_control_intf = {
104 .bLength = sizeof ecm_control_intf,
105 .bDescriptorType = USB_DT_INTERFACE,
106
107 /* .bInterfaceNumber = DYNAMIC */
108 /* status endpoint is optional; this could be patched later */
109 .bNumEndpoints = 1,
110 .bInterfaceClass = USB_CLASS_COMM,
111 .bInterfaceSubClass = USB_CDC_SUBCLASS_ETHERNET,
112 .bInterfaceProtocol = USB_CDC_PROTO_NONE,
113 /* .iInterface = DYNAMIC */
114};
115
116static struct usb_cdc_header_desc ecm_header_desc = {
117 .bLength = sizeof ecm_header_desc,
118 .bDescriptorType = USB_DT_CS_INTERFACE,
119 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
120
121 .bcdCDC = cpu_to_le16(0x0110),
122};
123
124static struct usb_cdc_union_desc ecm_union_desc = {
125 .bLength = sizeof(ecm_union_desc),
126 .bDescriptorType = USB_DT_CS_INTERFACE,
127 .bDescriptorSubType = USB_CDC_UNION_TYPE,
128 /* .bMasterInterface0 = DYNAMIC */
129 /* .bSlaveInterface0 = DYNAMIC */
130};
131
132static struct usb_cdc_ether_desc ecm_desc = {
133 .bLength = sizeof ecm_desc,
134 .bDescriptorType = USB_DT_CS_INTERFACE,
135 .bDescriptorSubType = USB_CDC_ETHERNET_TYPE,
136
137 /* this descriptor actually adds value, surprise! */
138 /* .iMACAddress = DYNAMIC */
139 .bmEthernetStatistics = cpu_to_le32(0), /* no statistics */
140 .wMaxSegmentSize = cpu_to_le16(ETH_FRAME_LEN),
141 .wNumberMCFilters = cpu_to_le16(0),
142 .bNumberPowerFilters = 0,
143};
144
145/* the default data interface has no endpoints ... */
146
147static struct usb_interface_descriptor ecm_data_nop_intf = {
148 .bLength = sizeof ecm_data_nop_intf,
149 .bDescriptorType = USB_DT_INTERFACE,
150
151 .bInterfaceNumber = 1,
152 .bAlternateSetting = 0,
153 .bNumEndpoints = 0,
154 .bInterfaceClass = USB_CLASS_CDC_DATA,
155 .bInterfaceSubClass = 0,
156 .bInterfaceProtocol = 0,
157 /* .iInterface = DYNAMIC */
158};
159
160/* ... but the "real" data interface has two bulk endpoints */
161
162static struct usb_interface_descriptor ecm_data_intf = {
163 .bLength = sizeof ecm_data_intf,
164 .bDescriptorType = USB_DT_INTERFACE,
165
166 .bInterfaceNumber = 1,
167 .bAlternateSetting = 1,
168 .bNumEndpoints = 2,
169 .bInterfaceClass = USB_CLASS_CDC_DATA,
170 .bInterfaceSubClass = 0,
171 .bInterfaceProtocol = 0,
172 /* .iInterface = DYNAMIC */
173};
174
175/* full speed support: */
176
177static struct usb_endpoint_descriptor fs_ecm_notify_desc = {
178 .bLength = USB_DT_ENDPOINT_SIZE,
179 .bDescriptorType = USB_DT_ENDPOINT,
180
181 .bEndpointAddress = USB_DIR_IN,
182 .bmAttributes = USB_ENDPOINT_XFER_INT,
183 .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT),
184 .bInterval = ECM_STATUS_INTERVAL_MS,
185};
186
187static struct usb_endpoint_descriptor fs_ecm_in_desc = {
188 .bLength = USB_DT_ENDPOINT_SIZE,
189 .bDescriptorType = USB_DT_ENDPOINT,
190
191 .bEndpointAddress = USB_DIR_IN,
192 .bmAttributes = USB_ENDPOINT_XFER_BULK,
193};
194
195static struct usb_endpoint_descriptor fs_ecm_out_desc = {
196 .bLength = USB_DT_ENDPOINT_SIZE,
197 .bDescriptorType = USB_DT_ENDPOINT,
198
199 .bEndpointAddress = USB_DIR_OUT,
200 .bmAttributes = USB_ENDPOINT_XFER_BULK,
201};
202
203static struct usb_descriptor_header *ecm_fs_function[] = {
204 /* CDC ECM control descriptors */
205 (struct usb_descriptor_header *) &ecm_iad_descriptor,
206 (struct usb_descriptor_header *) &ecm_control_intf,
207 (struct usb_descriptor_header *) &ecm_header_desc,
208 (struct usb_descriptor_header *) &ecm_union_desc,
209 (struct usb_descriptor_header *) &ecm_desc,
210
211 /* NOTE: status endpoint might need to be removed */
212 (struct usb_descriptor_header *) &fs_ecm_notify_desc,
213
214 /* data interface, altsettings 0 and 1 */
215 (struct usb_descriptor_header *) &ecm_data_nop_intf,
216 (struct usb_descriptor_header *) &ecm_data_intf,
217 (struct usb_descriptor_header *) &fs_ecm_in_desc,
218 (struct usb_descriptor_header *) &fs_ecm_out_desc,
219 NULL,
220};
221
222/* high speed support: */
223
224static struct usb_endpoint_descriptor hs_ecm_notify_desc = {
225 .bLength = USB_DT_ENDPOINT_SIZE,
226 .bDescriptorType = USB_DT_ENDPOINT,
227
228 .bEndpointAddress = USB_DIR_IN,
229 .bmAttributes = USB_ENDPOINT_XFER_INT,
230 .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT),
231 .bInterval = USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
232};
233
234static struct usb_endpoint_descriptor hs_ecm_in_desc = {
235 .bLength = USB_DT_ENDPOINT_SIZE,
236 .bDescriptorType = USB_DT_ENDPOINT,
237
238 .bEndpointAddress = USB_DIR_IN,
239 .bmAttributes = USB_ENDPOINT_XFER_BULK,
240 .wMaxPacketSize = cpu_to_le16(512),
241};
242
243static struct usb_endpoint_descriptor hs_ecm_out_desc = {
244 .bLength = USB_DT_ENDPOINT_SIZE,
245 .bDescriptorType = USB_DT_ENDPOINT,
246
247 .bEndpointAddress = USB_DIR_OUT,
248 .bmAttributes = USB_ENDPOINT_XFER_BULK,
249 .wMaxPacketSize = cpu_to_le16(512),
250};
251
252static struct usb_descriptor_header *ecm_hs_function[] = {
253 /* CDC ECM control descriptors */
254 (struct usb_descriptor_header *) &ecm_iad_descriptor,
255 (struct usb_descriptor_header *) &ecm_control_intf,
256 (struct usb_descriptor_header *) &ecm_header_desc,
257 (struct usb_descriptor_header *) &ecm_union_desc,
258 (struct usb_descriptor_header *) &ecm_desc,
259
260 /* NOTE: status endpoint might need to be removed */
261 (struct usb_descriptor_header *) &hs_ecm_notify_desc,
262
263 /* data interface, altsettings 0 and 1 */
264 (struct usb_descriptor_header *) &ecm_data_nop_intf,
265 (struct usb_descriptor_header *) &ecm_data_intf,
266 (struct usb_descriptor_header *) &hs_ecm_in_desc,
267 (struct usb_descriptor_header *) &hs_ecm_out_desc,
268 NULL,
269};
270
271/* super speed support: */
272
273static struct usb_endpoint_descriptor ss_ecm_notify_desc = {
274 .bLength = USB_DT_ENDPOINT_SIZE,
275 .bDescriptorType = USB_DT_ENDPOINT,
276
277 .bEndpointAddress = USB_DIR_IN,
278 .bmAttributes = USB_ENDPOINT_XFER_INT,
279 .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT),
280 .bInterval = USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
281};
282
283static struct usb_ss_ep_comp_descriptor ss_ecm_intr_comp_desc = {
284 .bLength = sizeof ss_ecm_intr_comp_desc,
285 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
286
287 /* the following 3 values can be tweaked if necessary */
288 /* .bMaxBurst = 0, */
289 /* .bmAttributes = 0, */
290 .wBytesPerInterval = cpu_to_le16(ECM_STATUS_BYTECOUNT),
291};
292
293static struct usb_endpoint_descriptor ss_ecm_in_desc = {
294 .bLength = USB_DT_ENDPOINT_SIZE,
295 .bDescriptorType = USB_DT_ENDPOINT,
296
297 .bEndpointAddress = USB_DIR_IN,
298 .bmAttributes = USB_ENDPOINT_XFER_BULK,
299 .wMaxPacketSize = cpu_to_le16(1024),
300};
301
302static struct usb_endpoint_descriptor ss_ecm_out_desc = {
303 .bLength = USB_DT_ENDPOINT_SIZE,
304 .bDescriptorType = USB_DT_ENDPOINT,
305
306 .bEndpointAddress = USB_DIR_OUT,
307 .bmAttributes = USB_ENDPOINT_XFER_BULK,
308 .wMaxPacketSize = cpu_to_le16(1024),
309};
310
311static struct usb_ss_ep_comp_descriptor ss_ecm_bulk_comp_desc = {
312 .bLength = sizeof ss_ecm_bulk_comp_desc,
313 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
314
315 /* the following 2 values can be tweaked if necessary */
316 /* .bMaxBurst = 0, */
317 /* .bmAttributes = 0, */
318};
319
320static struct usb_descriptor_header *ecm_ss_function[] = {
321 /* CDC ECM control descriptors */
322 (struct usb_descriptor_header *) &ecm_iad_descriptor,
323 (struct usb_descriptor_header *) &ecm_control_intf,
324 (struct usb_descriptor_header *) &ecm_header_desc,
325 (struct usb_descriptor_header *) &ecm_union_desc,
326 (struct usb_descriptor_header *) &ecm_desc,
327
328 /* NOTE: status endpoint might need to be removed */
329 (struct usb_descriptor_header *) &ss_ecm_notify_desc,
330 (struct usb_descriptor_header *) &ss_ecm_intr_comp_desc,
331
332 /* data interface, altsettings 0 and 1 */
333 (struct usb_descriptor_header *) &ecm_data_nop_intf,
334 (struct usb_descriptor_header *) &ecm_data_intf,
335 (struct usb_descriptor_header *) &ss_ecm_in_desc,
336 (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
337 (struct usb_descriptor_header *) &ss_ecm_out_desc,
338 (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
339 NULL,
340};
341
342/* string descriptors: */
343
344static struct usb_string ecm_string_defs[] = {
345 [0].s = "CDC Ethernet Control Model (ECM)",
346 [1].s = "",
347 [2].s = "CDC Ethernet Data",
348 [3].s = "CDC ECM",
349 { } /* end of list */
350};
351
352static struct usb_gadget_strings ecm_string_table = {
353 .language = 0x0409, /* en-us */
354 .strings = ecm_string_defs,
355};
356
357static struct usb_gadget_strings *ecm_strings[] = {
358 &ecm_string_table,
359 NULL,
360};
361
362/*-------------------------------------------------------------------------*/
363
364static void ecm_do_notify(struct f_ecm *ecm)
365{
366 struct usb_request *req = ecm->notify_req;
367 struct usb_cdc_notification *event;
368 struct usb_composite_dev *cdev = ecm->port.func.config->cdev;
369 __le32 *data;
370 int status;
371
372 /* notification already in flight? */
373 if (atomic_read(v: &ecm->notify_count))
374 return;
375
376 event = req->buf;
377 switch (ecm->notify_state) {
378 case ECM_NOTIFY_NONE:
379 return;
380
381 case ECM_NOTIFY_CONNECT:
382 event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
383 if (ecm->is_open)
384 event->wValue = cpu_to_le16(1);
385 else
386 event->wValue = cpu_to_le16(0);
387 event->wLength = 0;
388 req->length = sizeof *event;
389
390 DBG(cdev, "notify connect %s\n",
391 ecm->is_open ? "true" : "false");
392 ecm->notify_state = ECM_NOTIFY_SPEED;
393 break;
394
395 case ECM_NOTIFY_SPEED:
396 event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
397 event->wValue = cpu_to_le16(0);
398 event->wLength = cpu_to_le16(8);
399 req->length = ECM_STATUS_BYTECOUNT;
400
401 /* SPEED_CHANGE data is up/down speeds in bits/sec */
402 data = req->buf + sizeof *event;
403 data[0] = cpu_to_le32(gether_bitrate(cdev->gadget));
404 data[1] = data[0];
405
406 DBG(cdev, "notify speed %d\n", gether_bitrate(cdev->gadget));
407 ecm->notify_state = ECM_NOTIFY_NONE;
408 break;
409 }
410 event->bmRequestType = 0xA1;
411 event->wIndex = cpu_to_le16(ecm->ctrl_id);
412
413 atomic_inc(v: &ecm->notify_count);
414 status = usb_ep_queue(ep: ecm->notify, req, GFP_ATOMIC);
415 if (status < 0) {
416 atomic_dec(v: &ecm->notify_count);
417 DBG(cdev, "notify --> %d\n", status);
418 }
419}
420
421static void ecm_notify(struct f_ecm *ecm)
422{
423 /* NOTE on most versions of Linux, host side cdc-ethernet
424 * won't listen for notifications until its netdevice opens.
425 * The first notification then sits in the FIFO for a long
426 * time, and the second one is queued.
427 */
428 ecm->notify_state = ECM_NOTIFY_CONNECT;
429 ecm_do_notify(ecm);
430}
431
432static void ecm_notify_complete(struct usb_ep *ep, struct usb_request *req)
433{
434 struct f_ecm *ecm = req->context;
435 struct usb_composite_dev *cdev = ecm->port.func.config->cdev;
436 struct usb_cdc_notification *event = req->buf;
437
438 switch (req->status) {
439 case 0:
440 /* no fault */
441 atomic_dec(v: &ecm->notify_count);
442 break;
443 case -ECONNRESET:
444 case -ESHUTDOWN:
445 atomic_set(v: &ecm->notify_count, i: 0);
446 ecm->notify_state = ECM_NOTIFY_NONE;
447 break;
448 default:
449 DBG(cdev, "event %02x --> %d\n",
450 event->bNotificationType, req->status);
451 atomic_dec(v: &ecm->notify_count);
452 break;
453 }
454 ecm_do_notify(ecm);
455}
456
457static int ecm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
458{
459 struct f_ecm *ecm = func_to_ecm(f);
460 struct usb_composite_dev *cdev = f->config->cdev;
461 struct usb_request *req = cdev->req;
462 int value = -EOPNOTSUPP;
463 u16 w_index = le16_to_cpu(ctrl->wIndex);
464 u16 w_value = le16_to_cpu(ctrl->wValue);
465 u16 w_length = le16_to_cpu(ctrl->wLength);
466
467 /* composite driver infrastructure handles everything except
468 * CDC class messages; interface activation uses set_alt().
469 */
470 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
471 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
472 | USB_CDC_SET_ETHERNET_PACKET_FILTER:
473 /* see 6.2.30: no data, wIndex = interface,
474 * wValue = packet filter bitmap
475 */
476 if (w_length != 0 || w_index != ecm->ctrl_id)
477 goto invalid;
478 DBG(cdev, "packet filter %02x\n", w_value);
479 /* REVISIT locking of cdc_filter. This assumes the UDC
480 * driver won't have a concurrent packet TX irq running on
481 * another CPU; or that if it does, this write is atomic...
482 */
483 ecm->port.cdc_filter = w_value;
484 value = 0;
485 break;
486
487 /* and optionally:
488 * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
489 * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
490 * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
491 * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
492 * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
493 * case USB_CDC_GET_ETHERNET_STATISTIC:
494 */
495
496 default:
497invalid:
498 DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
499 ctrl->bRequestType, ctrl->bRequest,
500 w_value, w_index, w_length);
501 }
502
503 /* respond with data transfer or status phase? */
504 if (value >= 0) {
505 DBG(cdev, "ecm req%02x.%02x v%04x i%04x l%d\n",
506 ctrl->bRequestType, ctrl->bRequest,
507 w_value, w_index, w_length);
508 req->zero = 0;
509 req->length = value;
510 value = usb_ep_queue(ep: cdev->gadget->ep0, req, GFP_ATOMIC);
511 if (value < 0)
512 ERROR(cdev, "ecm req %02x.%02x response err %d\n",
513 ctrl->bRequestType, ctrl->bRequest,
514 value);
515 }
516
517 /* device either stalls (value < 0) or reports success */
518 return value;
519}
520
521
522static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
523{
524 struct f_ecm *ecm = func_to_ecm(f);
525 struct usb_composite_dev *cdev = f->config->cdev;
526
527 /* Control interface has only altsetting 0 */
528 if (intf == ecm->ctrl_id) {
529 if (alt != 0)
530 goto fail;
531
532 VDBG(cdev, "reset ecm control %d\n", intf);
533 usb_ep_disable(ep: ecm->notify);
534 if (!(ecm->notify->desc)) {
535 VDBG(cdev, "init ecm ctrl %d\n", intf);
536 if (config_ep_by_speed(g: cdev->gadget, f, ep: ecm->notify))
537 goto fail;
538 }
539 usb_ep_enable(ep: ecm->notify);
540
541 /* Data interface has two altsettings, 0 and 1 */
542 } else if (intf == ecm->data_id) {
543 if (alt > 1)
544 goto fail;
545
546 if (ecm->port.in_ep->enabled) {
547 DBG(cdev, "reset ecm\n");
548 gether_disconnect(&ecm->port);
549 }
550
551 if (!ecm->port.in_ep->desc ||
552 !ecm->port.out_ep->desc) {
553 DBG(cdev, "init ecm\n");
554 if (config_ep_by_speed(g: cdev->gadget, f,
555 ep: ecm->port.in_ep) ||
556 config_ep_by_speed(g: cdev->gadget, f,
557 ep: ecm->port.out_ep)) {
558 ecm->port.in_ep->desc = NULL;
559 ecm->port.out_ep->desc = NULL;
560 goto fail;
561 }
562 }
563
564 /* CDC Ethernet only sends data in non-default altsettings.
565 * Changing altsettings resets filters, statistics, etc.
566 */
567 if (alt == 1) {
568 struct net_device *net;
569
570 /* Enable zlps by default for ECM conformance;
571 * override for musb_hdrc (avoids txdma ovhead).
572 */
573 ecm->port.is_zlp_ok =
574 gadget_is_zlp_supported(g: cdev->gadget);
575 ecm->port.cdc_filter = DEFAULT_FILTER;
576 DBG(cdev, "activate ecm\n");
577 net = gether_connect(&ecm->port);
578 if (IS_ERR(ptr: net))
579 return PTR_ERR(ptr: net);
580 }
581
582 /* NOTE this can be a minor disagreement with the ECM spec,
583 * which says speed notifications will "always" follow
584 * connection notifications. But we allow one connect to
585 * follow another (if the first is in flight), and instead
586 * just guarantee that a speed notification is always sent.
587 */
588 ecm_notify(ecm);
589 } else
590 goto fail;
591
592 return 0;
593fail:
594 return -EINVAL;
595}
596
597/* Because the data interface supports multiple altsettings,
598 * this ECM function *MUST* implement a get_alt() method.
599 */
600static int ecm_get_alt(struct usb_function *f, unsigned intf)
601{
602 struct f_ecm *ecm = func_to_ecm(f);
603
604 if (intf == ecm->ctrl_id)
605 return 0;
606 return ecm->port.in_ep->enabled ? 1 : 0;
607}
608
609static void ecm_disable(struct usb_function *f)
610{
611 struct f_ecm *ecm = func_to_ecm(f);
612 struct usb_composite_dev *cdev = f->config->cdev;
613
614 DBG(cdev, "ecm deactivated\n");
615
616 if (ecm->port.in_ep->enabled) {
617 gether_disconnect(&ecm->port);
618 } else {
619 ecm->port.in_ep->desc = NULL;
620 ecm->port.out_ep->desc = NULL;
621 }
622
623 usb_ep_disable(ep: ecm->notify);
624 ecm->notify->desc = NULL;
625}
626
627/*-------------------------------------------------------------------------*/
628
629/*
630 * Callbacks let us notify the host about connect/disconnect when the
631 * net device is opened or closed.
632 *
633 * For testing, note that link states on this side include both opened
634 * and closed variants of:
635 *
636 * - disconnected/unconfigured
637 * - configured but inactive (data alt 0)
638 * - configured and active (data alt 1)
639 *
640 * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
641 * SET_INTERFACE (altsetting). Remember also that "configured" doesn't
642 * imply the host is actually polling the notification endpoint, and
643 * likewise that "active" doesn't imply it's actually using the data
644 * endpoints for traffic.
645 */
646
647static void ecm_open(struct gether *geth)
648{
649 struct f_ecm *ecm = func_to_ecm(f: &geth->func);
650
651 DBG(ecm->port.func.config->cdev, "%s\n", __func__);
652
653 ecm->is_open = true;
654 ecm_notify(ecm);
655}
656
657static void ecm_close(struct gether *geth)
658{
659 struct f_ecm *ecm = func_to_ecm(f: &geth->func);
660
661 DBG(ecm->port.func.config->cdev, "%s\n", __func__);
662
663 ecm->is_open = false;
664 ecm_notify(ecm);
665}
666
667/*-------------------------------------------------------------------------*/
668
669/* ethernet function driver setup/binding */
670
671static int
672ecm_bind(struct usb_configuration *c, struct usb_function *f)
673{
674 struct usb_composite_dev *cdev = c->cdev;
675 struct f_ecm *ecm = func_to_ecm(f);
676 struct usb_string *us;
677 int status = 0;
678 struct usb_ep *ep;
679
680 struct f_ecm_opts *ecm_opts;
681
682 if (!can_support_ecm(gadget: cdev->gadget))
683 return -EINVAL;
684
685 ecm_opts = container_of(f->fi, struct f_ecm_opts, func_inst);
686
687 mutex_lock(&ecm_opts->lock);
688
689 gether_set_gadget(net: ecm_opts->net, g: cdev->gadget);
690
691 if (!ecm_opts->bound) {
692 status = gether_register_netdev(net: ecm_opts->net);
693 ecm_opts->bound = true;
694 }
695
696 mutex_unlock(lock: &ecm_opts->lock);
697 if (status)
698 return status;
699
700 ecm_string_defs[1].s = ecm->ethaddr;
701
702 us = usb_gstrings_attach(cdev, sp: ecm_strings,
703 ARRAY_SIZE(ecm_string_defs));
704 if (IS_ERR(ptr: us))
705 return PTR_ERR(ptr: us);
706 ecm_control_intf.iInterface = us[0].id;
707 ecm_data_intf.iInterface = us[2].id;
708 ecm_desc.iMACAddress = us[1].id;
709 ecm_iad_descriptor.iFunction = us[3].id;
710
711 /* allocate instance-specific interface IDs */
712 status = usb_interface_id(c, f);
713 if (status < 0)
714 goto fail;
715 ecm->ctrl_id = status;
716 ecm_iad_descriptor.bFirstInterface = status;
717
718 ecm_control_intf.bInterfaceNumber = status;
719 ecm_union_desc.bMasterInterface0 = status;
720
721 status = usb_interface_id(c, f);
722 if (status < 0)
723 goto fail;
724 ecm->data_id = status;
725
726 ecm_data_nop_intf.bInterfaceNumber = status;
727 ecm_data_intf.bInterfaceNumber = status;
728 ecm_union_desc.bSlaveInterface0 = status;
729
730 status = -ENODEV;
731
732 /* allocate instance-specific endpoints */
733 ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_in_desc);
734 if (!ep)
735 goto fail;
736 ecm->port.in_ep = ep;
737
738 ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_out_desc);
739 if (!ep)
740 goto fail;
741 ecm->port.out_ep = ep;
742
743 /* NOTE: a status/notification endpoint is *OPTIONAL* but we
744 * don't treat it that way. It's simpler, and some newer CDC
745 * profiles (wireless handsets) no longer treat it as optional.
746 */
747 ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_notify_desc);
748 if (!ep)
749 goto fail;
750 ecm->notify = ep;
751
752 status = -ENOMEM;
753
754 /* allocate notification request and buffer */
755 ecm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
756 if (!ecm->notify_req)
757 goto fail;
758 ecm->notify_req->buf = kmalloc(ECM_STATUS_BYTECOUNT, GFP_KERNEL);
759 if (!ecm->notify_req->buf)
760 goto fail;
761 ecm->notify_req->context = ecm;
762 ecm->notify_req->complete = ecm_notify_complete;
763
764 /* support all relevant hardware speeds... we expect that when
765 * hardware is dual speed, all bulk-capable endpoints work at
766 * both speeds
767 */
768 hs_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
769 hs_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
770 hs_ecm_notify_desc.bEndpointAddress =
771 fs_ecm_notify_desc.bEndpointAddress;
772
773 ss_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
774 ss_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
775 ss_ecm_notify_desc.bEndpointAddress =
776 fs_ecm_notify_desc.bEndpointAddress;
777
778 status = usb_assign_descriptors(f, fs: ecm_fs_function, hs: ecm_hs_function,
779 ss: ecm_ss_function, ssp: ecm_ss_function);
780 if (status)
781 goto fail;
782
783 /* NOTE: all that is done without knowing or caring about
784 * the network link ... which is unavailable to this code
785 * until we're activated via set_alt().
786 */
787
788 ecm->port.open = ecm_open;
789 ecm->port.close = ecm_close;
790
791 DBG(cdev, "CDC Ethernet: IN/%s OUT/%s NOTIFY/%s\n",
792 ecm->port.in_ep->name, ecm->port.out_ep->name,
793 ecm->notify->name);
794 return 0;
795
796fail:
797 if (ecm->notify_req) {
798 kfree(objp: ecm->notify_req->buf);
799 usb_ep_free_request(ep: ecm->notify, req: ecm->notify_req);
800 }
801
802 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
803
804 return status;
805}
806
807static inline struct f_ecm_opts *to_f_ecm_opts(struct config_item *item)
808{
809 return container_of(to_config_group(item), struct f_ecm_opts,
810 func_inst.group);
811}
812
813/* f_ecm_item_ops */
814USB_ETHERNET_CONFIGFS_ITEM(ecm);
815
816/* f_ecm_opts_dev_addr */
817USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ecm);
818
819/* f_ecm_opts_host_addr */
820USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ecm);
821
822/* f_ecm_opts_qmult */
823USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ecm);
824
825/* f_ecm_opts_ifname */
826USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ecm);
827
828static struct configfs_attribute *ecm_attrs[] = {
829 &ecm_opts_attr_dev_addr,
830 &ecm_opts_attr_host_addr,
831 &ecm_opts_attr_qmult,
832 &ecm_opts_attr_ifname,
833 NULL,
834};
835
836static const struct config_item_type ecm_func_type = {
837 .ct_item_ops = &ecm_item_ops,
838 .ct_attrs = ecm_attrs,
839 .ct_owner = THIS_MODULE,
840};
841
842static void ecm_free_inst(struct usb_function_instance *f)
843{
844 struct f_ecm_opts *opts;
845
846 opts = container_of(f, struct f_ecm_opts, func_inst);
847 if (opts->bound)
848 gether_cleanup(dev: netdev_priv(dev: opts->net));
849 else
850 free_netdev(dev: opts->net);
851 kfree(objp: opts);
852}
853
854static struct usb_function_instance *ecm_alloc_inst(void)
855{
856 struct f_ecm_opts *opts;
857
858 opts = kzalloc(size: sizeof(*opts), GFP_KERNEL);
859 if (!opts)
860 return ERR_PTR(error: -ENOMEM);
861 mutex_init(&opts->lock);
862 opts->func_inst.free_func_inst = ecm_free_inst;
863 opts->net = gether_setup_default();
864 if (IS_ERR(ptr: opts->net)) {
865 struct net_device *net = opts->net;
866 kfree(objp: opts);
867 return ERR_CAST(ptr: net);
868 }
869
870 config_group_init_type_name(group: &opts->func_inst.group, name: "", type: &ecm_func_type);
871
872 return &opts->func_inst;
873}
874
875static void ecm_suspend(struct usb_function *f)
876{
877 struct f_ecm *ecm = func_to_ecm(f);
878 struct usb_composite_dev *cdev = ecm->port.func.config->cdev;
879
880 DBG(cdev, "ECM Suspend\n");
881
882 gether_suspend(link: &ecm->port);
883}
884
885static void ecm_resume(struct usb_function *f)
886{
887 struct f_ecm *ecm = func_to_ecm(f);
888 struct usb_composite_dev *cdev = ecm->port.func.config->cdev;
889
890 DBG(cdev, "ECM Resume\n");
891
892 gether_resume(link: &ecm->port);
893}
894
895static void ecm_free(struct usb_function *f)
896{
897 struct f_ecm *ecm;
898 struct f_ecm_opts *opts;
899
900 ecm = func_to_ecm(f);
901 opts = container_of(f->fi, struct f_ecm_opts, func_inst);
902 kfree(objp: ecm);
903 mutex_lock(&opts->lock);
904 opts->refcnt--;
905 mutex_unlock(lock: &opts->lock);
906}
907
908static void ecm_unbind(struct usb_configuration *c, struct usb_function *f)
909{
910 struct f_ecm *ecm = func_to_ecm(f);
911
912 DBG(c->cdev, "ecm unbind\n");
913
914 usb_free_all_descriptors(f);
915
916 if (atomic_read(v: &ecm->notify_count)) {
917 usb_ep_dequeue(ep: ecm->notify, req: ecm->notify_req);
918 atomic_set(v: &ecm->notify_count, i: 0);
919 }
920
921 kfree(objp: ecm->notify_req->buf);
922 usb_ep_free_request(ep: ecm->notify, req: ecm->notify_req);
923}
924
925static struct usb_function *ecm_alloc(struct usb_function_instance *fi)
926{
927 struct f_ecm *ecm;
928 struct f_ecm_opts *opts;
929 int status;
930
931 /* allocate and initialize one new instance */
932 ecm = kzalloc(size: sizeof(*ecm), GFP_KERNEL);
933 if (!ecm)
934 return ERR_PTR(error: -ENOMEM);
935
936 opts = container_of(fi, struct f_ecm_opts, func_inst);
937 mutex_lock(&opts->lock);
938 opts->refcnt++;
939
940 /* export host's Ethernet address in CDC format */
941 status = gether_get_host_addr_cdc(net: opts->net, host_addr: ecm->ethaddr,
942 len: sizeof(ecm->ethaddr));
943 if (status < 12) {
944 kfree(objp: ecm);
945 mutex_unlock(lock: &opts->lock);
946 return ERR_PTR(error: -EINVAL);
947 }
948
949 ecm->port.ioport = netdev_priv(dev: opts->net);
950 mutex_unlock(lock: &opts->lock);
951 ecm->port.cdc_filter = DEFAULT_FILTER;
952
953 ecm->port.func.name = "cdc_ethernet";
954 /* descriptors are per-instance copies */
955 ecm->port.func.bind = ecm_bind;
956 ecm->port.func.unbind = ecm_unbind;
957 ecm->port.func.set_alt = ecm_set_alt;
958 ecm->port.func.get_alt = ecm_get_alt;
959 ecm->port.func.setup = ecm_setup;
960 ecm->port.func.disable = ecm_disable;
961 ecm->port.func.free_func = ecm_free;
962 ecm->port.func.suspend = ecm_suspend;
963 ecm->port.func.resume = ecm_resume;
964
965 return &ecm->port.func;
966}
967
968DECLARE_USB_FUNCTION_INIT(ecm, ecm_alloc_inst, ecm_alloc);
969MODULE_LICENSE("GPL");
970MODULE_AUTHOR("David Brownell");
971

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source code of linux/drivers/usb/gadget/function/f_ecm.c