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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/* peak (theoretical) bulk transfer rate in bits-per-second */
69static inline unsigned ecm_bitrate(struct usb_gadget *g)
70{
71 if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
72 return 13 * 1024 * 8 * 1000 * 8;
73 else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
74 return 13 * 512 * 8 * 1000 * 8;
75 else
76 return 19 * 64 * 1 * 1000 * 8;
77}
78
79/*-------------------------------------------------------------------------*/
80
81/*
82 * Include the status endpoint if we can, even though it's optional.
83 *
84 * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
85 * packet, to simplify cancellation; and a big transfer interval, to
86 * waste less bandwidth.
87 *
88 * Some drivers (like Linux 2.4 cdc-ether!) "need" it to exist even
89 * if they ignore the connect/disconnect notifications that real aether
90 * can provide. More advanced cdc configurations might want to support
91 * encapsulated commands (vendor-specific, using control-OUT).
92 */
93
94#define ECM_STATUS_INTERVAL_MS 32
95#define ECM_STATUS_BYTECOUNT 16 /* 8 byte header + data */
96
97
98/* interface descriptor: */
99
100static struct usb_interface_assoc_descriptor
101ecm_iad_descriptor = {
102 .bLength = sizeof ecm_iad_descriptor,
103 .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
104
105 /* .bFirstInterface = DYNAMIC, */
106 .bInterfaceCount = 2, /* control + data */
107 .bFunctionClass = USB_CLASS_COMM,
108 .bFunctionSubClass = USB_CDC_SUBCLASS_ETHERNET,
109 .bFunctionProtocol = USB_CDC_PROTO_NONE,
110 /* .iFunction = DYNAMIC */
111};
112
113
114static struct usb_interface_descriptor ecm_control_intf = {
115 .bLength = sizeof ecm_control_intf,
116 .bDescriptorType = USB_DT_INTERFACE,
117
118 /* .bInterfaceNumber = DYNAMIC */
119 /* status endpoint is optional; this could be patched later */
120 .bNumEndpoints = 1,
121 .bInterfaceClass = USB_CLASS_COMM,
122 .bInterfaceSubClass = USB_CDC_SUBCLASS_ETHERNET,
123 .bInterfaceProtocol = USB_CDC_PROTO_NONE,
124 /* .iInterface = DYNAMIC */
125};
126
127static struct usb_cdc_header_desc ecm_header_desc = {
128 .bLength = sizeof ecm_header_desc,
129 .bDescriptorType = USB_DT_CS_INTERFACE,
130 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
131
132 .bcdCDC = cpu_to_le16(0x0110),
133};
134
135static struct usb_cdc_union_desc ecm_union_desc = {
136 .bLength = sizeof(ecm_union_desc),
137 .bDescriptorType = USB_DT_CS_INTERFACE,
138 .bDescriptorSubType = USB_CDC_UNION_TYPE,
139 /* .bMasterInterface0 = DYNAMIC */
140 /* .bSlaveInterface0 = DYNAMIC */
141};
142
143static struct usb_cdc_ether_desc ecm_desc = {
144 .bLength = sizeof ecm_desc,
145 .bDescriptorType = USB_DT_CS_INTERFACE,
146 .bDescriptorSubType = USB_CDC_ETHERNET_TYPE,
147
148 /* this descriptor actually adds value, surprise! */
149 /* .iMACAddress = DYNAMIC */
150 .bmEthernetStatistics = cpu_to_le32(0), /* no statistics */
151 .wMaxSegmentSize = cpu_to_le16(ETH_FRAME_LEN),
152 .wNumberMCFilters = cpu_to_le16(0),
153 .bNumberPowerFilters = 0,
154};
155
156/* the default data interface has no endpoints ... */
157
158static struct usb_interface_descriptor ecm_data_nop_intf = {
159 .bLength = sizeof ecm_data_nop_intf,
160 .bDescriptorType = USB_DT_INTERFACE,
161
162 .bInterfaceNumber = 1,
163 .bAlternateSetting = 0,
164 .bNumEndpoints = 0,
165 .bInterfaceClass = USB_CLASS_CDC_DATA,
166 .bInterfaceSubClass = 0,
167 .bInterfaceProtocol = 0,
168 /* .iInterface = DYNAMIC */
169};
170
171/* ... but the "real" data interface has two bulk endpoints */
172
173static struct usb_interface_descriptor ecm_data_intf = {
174 .bLength = sizeof ecm_data_intf,
175 .bDescriptorType = USB_DT_INTERFACE,
176
177 .bInterfaceNumber = 1,
178 .bAlternateSetting = 1,
179 .bNumEndpoints = 2,
180 .bInterfaceClass = USB_CLASS_CDC_DATA,
181 .bInterfaceSubClass = 0,
182 .bInterfaceProtocol = 0,
183 /* .iInterface = DYNAMIC */
184};
185
186/* full speed support: */
187
188static struct usb_endpoint_descriptor fs_ecm_notify_desc = {
189 .bLength = USB_DT_ENDPOINT_SIZE,
190 .bDescriptorType = USB_DT_ENDPOINT,
191
192 .bEndpointAddress = USB_DIR_IN,
193 .bmAttributes = USB_ENDPOINT_XFER_INT,
194 .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT),
195 .bInterval = ECM_STATUS_INTERVAL_MS,
196};
197
198static struct usb_endpoint_descriptor fs_ecm_in_desc = {
199 .bLength = USB_DT_ENDPOINT_SIZE,
200 .bDescriptorType = USB_DT_ENDPOINT,
201
202 .bEndpointAddress = USB_DIR_IN,
203 .bmAttributes = USB_ENDPOINT_XFER_BULK,
204};
205
206static struct usb_endpoint_descriptor fs_ecm_out_desc = {
207 .bLength = USB_DT_ENDPOINT_SIZE,
208 .bDescriptorType = USB_DT_ENDPOINT,
209
210 .bEndpointAddress = USB_DIR_OUT,
211 .bmAttributes = USB_ENDPOINT_XFER_BULK,
212};
213
214static struct usb_descriptor_header *ecm_fs_function[] = {
215 /* CDC ECM control descriptors */
216 (struct usb_descriptor_header *) &ecm_iad_descriptor,
217 (struct usb_descriptor_header *) &ecm_control_intf,
218 (struct usb_descriptor_header *) &ecm_header_desc,
219 (struct usb_descriptor_header *) &ecm_union_desc,
220 (struct usb_descriptor_header *) &ecm_desc,
221
222 /* NOTE: status endpoint might need to be removed */
223 (struct usb_descriptor_header *) &fs_ecm_notify_desc,
224
225 /* data interface, altsettings 0 and 1 */
226 (struct usb_descriptor_header *) &ecm_data_nop_intf,
227 (struct usb_descriptor_header *) &ecm_data_intf,
228 (struct usb_descriptor_header *) &fs_ecm_in_desc,
229 (struct usb_descriptor_header *) &fs_ecm_out_desc,
230 NULL,
231};
232
233/* high speed support: */
234
235static struct usb_endpoint_descriptor hs_ecm_notify_desc = {
236 .bLength = USB_DT_ENDPOINT_SIZE,
237 .bDescriptorType = USB_DT_ENDPOINT,
238
239 .bEndpointAddress = USB_DIR_IN,
240 .bmAttributes = USB_ENDPOINT_XFER_INT,
241 .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT),
242 .bInterval = USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
243};
244
245static struct usb_endpoint_descriptor hs_ecm_in_desc = {
246 .bLength = USB_DT_ENDPOINT_SIZE,
247 .bDescriptorType = USB_DT_ENDPOINT,
248
249 .bEndpointAddress = USB_DIR_IN,
250 .bmAttributes = USB_ENDPOINT_XFER_BULK,
251 .wMaxPacketSize = cpu_to_le16(512),
252};
253
254static struct usb_endpoint_descriptor hs_ecm_out_desc = {
255 .bLength = USB_DT_ENDPOINT_SIZE,
256 .bDescriptorType = USB_DT_ENDPOINT,
257
258 .bEndpointAddress = USB_DIR_OUT,
259 .bmAttributes = USB_ENDPOINT_XFER_BULK,
260 .wMaxPacketSize = cpu_to_le16(512),
261};
262
263static struct usb_descriptor_header *ecm_hs_function[] = {
264 /* CDC ECM control descriptors */
265 (struct usb_descriptor_header *) &ecm_iad_descriptor,
266 (struct usb_descriptor_header *) &ecm_control_intf,
267 (struct usb_descriptor_header *) &ecm_header_desc,
268 (struct usb_descriptor_header *) &ecm_union_desc,
269 (struct usb_descriptor_header *) &ecm_desc,
270
271 /* NOTE: status endpoint might need to be removed */
272 (struct usb_descriptor_header *) &hs_ecm_notify_desc,
273
274 /* data interface, altsettings 0 and 1 */
275 (struct usb_descriptor_header *) &ecm_data_nop_intf,
276 (struct usb_descriptor_header *) &ecm_data_intf,
277 (struct usb_descriptor_header *) &hs_ecm_in_desc,
278 (struct usb_descriptor_header *) &hs_ecm_out_desc,
279 NULL,
280};
281
282/* super speed support: */
283
284static struct usb_endpoint_descriptor ss_ecm_notify_desc = {
285 .bLength = USB_DT_ENDPOINT_SIZE,
286 .bDescriptorType = USB_DT_ENDPOINT,
287
288 .bEndpointAddress = USB_DIR_IN,
289 .bmAttributes = USB_ENDPOINT_XFER_INT,
290 .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT),
291 .bInterval = USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
292};
293
294static struct usb_ss_ep_comp_descriptor ss_ecm_intr_comp_desc = {
295 .bLength = sizeof ss_ecm_intr_comp_desc,
296 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
297
298 /* the following 3 values can be tweaked if necessary */
299 /* .bMaxBurst = 0, */
300 /* .bmAttributes = 0, */
301 .wBytesPerInterval = cpu_to_le16(ECM_STATUS_BYTECOUNT),
302};
303
304static struct usb_endpoint_descriptor ss_ecm_in_desc = {
305 .bLength = USB_DT_ENDPOINT_SIZE,
306 .bDescriptorType = USB_DT_ENDPOINT,
307
308 .bEndpointAddress = USB_DIR_IN,
309 .bmAttributes = USB_ENDPOINT_XFER_BULK,
310 .wMaxPacketSize = cpu_to_le16(1024),
311};
312
313static struct usb_endpoint_descriptor ss_ecm_out_desc = {
314 .bLength = USB_DT_ENDPOINT_SIZE,
315 .bDescriptorType = USB_DT_ENDPOINT,
316
317 .bEndpointAddress = USB_DIR_OUT,
318 .bmAttributes = USB_ENDPOINT_XFER_BULK,
319 .wMaxPacketSize = cpu_to_le16(1024),
320};
321
322static struct usb_ss_ep_comp_descriptor ss_ecm_bulk_comp_desc = {
323 .bLength = sizeof ss_ecm_bulk_comp_desc,
324 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
325
326 /* the following 2 values can be tweaked if necessary */
327 /* .bMaxBurst = 0, */
328 /* .bmAttributes = 0, */
329};
330
331static struct usb_descriptor_header *ecm_ss_function[] = {
332 /* CDC ECM control descriptors */
333 (struct usb_descriptor_header *) &ecm_iad_descriptor,
334 (struct usb_descriptor_header *) &ecm_control_intf,
335 (struct usb_descriptor_header *) &ecm_header_desc,
336 (struct usb_descriptor_header *) &ecm_union_desc,
337 (struct usb_descriptor_header *) &ecm_desc,
338
339 /* NOTE: status endpoint might need to be removed */
340 (struct usb_descriptor_header *) &ss_ecm_notify_desc,
341 (struct usb_descriptor_header *) &ss_ecm_intr_comp_desc,
342
343 /* data interface, altsettings 0 and 1 */
344 (struct usb_descriptor_header *) &ecm_data_nop_intf,
345 (struct usb_descriptor_header *) &ecm_data_intf,
346 (struct usb_descriptor_header *) &ss_ecm_in_desc,
347 (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
348 (struct usb_descriptor_header *) &ss_ecm_out_desc,
349 (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc,
350 NULL,
351};
352
353/* string descriptors: */
354
355static struct usb_string ecm_string_defs[] = {
356 [0].s = "CDC Ethernet Control Model (ECM)",
357 [1].s = "",
358 [2].s = "CDC Ethernet Data",
359 [3].s = "CDC ECM",
360 { } /* end of list */
361};
362
363static struct usb_gadget_strings ecm_string_table = {
364 .language = 0x0409, /* en-us */
365 .strings = ecm_string_defs,
366};
367
368static struct usb_gadget_strings *ecm_strings[] = {
369 &ecm_string_table,
370 NULL,
371};
372
373/*-------------------------------------------------------------------------*/
374
375static void ecm_do_notify(struct f_ecm *ecm)
376{
377 struct usb_request *req = ecm->notify_req;
378 struct usb_cdc_notification *event;
379 struct usb_composite_dev *cdev = ecm->port.func.config->cdev;
380 __le32 *data;
381 int status;
382
383 /* notification already in flight? */
384 if (atomic_read(&ecm->notify_count))
385 return;
386
387 event = req->buf;
388 switch (ecm->notify_state) {
389 case ECM_NOTIFY_NONE:
390 return;
391
392 case ECM_NOTIFY_CONNECT:
393 event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
394 if (ecm->is_open)
395 event->wValue = cpu_to_le16(1);
396 else
397 event->wValue = cpu_to_le16(0);
398 event->wLength = 0;
399 req->length = sizeof *event;
400
401 DBG(cdev, "notify connect %s\n",
402 ecm->is_open ? "true" : "false");
403 ecm->notify_state = ECM_NOTIFY_SPEED;
404 break;
405
406 case ECM_NOTIFY_SPEED:
407 event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
408 event->wValue = cpu_to_le16(0);
409 event->wLength = cpu_to_le16(8);
410 req->length = ECM_STATUS_BYTECOUNT;
411
412 /* SPEED_CHANGE data is up/down speeds in bits/sec */
413 data = req->buf + sizeof *event;
414 data[0] = cpu_to_le32(ecm_bitrate(cdev->gadget));
415 data[1] = data[0];
416
417 DBG(cdev, "notify speed %d\n", ecm_bitrate(cdev->gadget));
418 ecm->notify_state = ECM_NOTIFY_NONE;
419 break;
420 }
421 event->bmRequestType = 0xA1;
422 event->wIndex = cpu_to_le16(ecm->ctrl_id);
423
424 atomic_inc(&ecm->notify_count);
425 status = usb_ep_queue(ecm->notify, req, GFP_ATOMIC);
426 if (status < 0) {
427 atomic_dec(&ecm->notify_count);
428 DBG(cdev, "notify --> %d\n", status);
429 }
430}
431
432static void ecm_notify(struct f_ecm *ecm)
433{
434 /* NOTE on most versions of Linux, host side cdc-ethernet
435 * won't listen for notifications until its netdevice opens.
436 * The first notification then sits in the FIFO for a long
437 * time, and the second one is queued.
438 */
439 ecm->notify_state = ECM_NOTIFY_CONNECT;
440 ecm_do_notify(ecm);
441}
442
443static void ecm_notify_complete(struct usb_ep *ep, struct usb_request *req)
444{
445 struct f_ecm *ecm = req->context;
446 struct usb_composite_dev *cdev = ecm->port.func.config->cdev;
447 struct usb_cdc_notification *event = req->buf;
448
449 switch (req->status) {
450 case 0:
451 /* no fault */
452 atomic_dec(&ecm->notify_count);
453 break;
454 case -ECONNRESET:
455 case -ESHUTDOWN:
456 atomic_set(&ecm->notify_count, 0);
457 ecm->notify_state = ECM_NOTIFY_NONE;
458 break;
459 default:
460 DBG(cdev, "event %02x --> %d\n",
461 event->bNotificationType, req->status);
462 atomic_dec(&ecm->notify_count);
463 break;
464 }
465 ecm_do_notify(ecm);
466}
467
468static int ecm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
469{
470 struct f_ecm *ecm = func_to_ecm(f);
471 struct usb_composite_dev *cdev = f->config->cdev;
472 struct usb_request *req = cdev->req;
473 int value = -EOPNOTSUPP;
474 u16 w_index = le16_to_cpu(ctrl->wIndex);
475 u16 w_value = le16_to_cpu(ctrl->wValue);
476 u16 w_length = le16_to_cpu(ctrl->wLength);
477
478 /* composite driver infrastructure handles everything except
479 * CDC class messages; interface activation uses set_alt().
480 */
481 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
482 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
483 | USB_CDC_SET_ETHERNET_PACKET_FILTER:
484 /* see 6.2.30: no data, wIndex = interface,
485 * wValue = packet filter bitmap
486 */
487 if (w_length != 0 || w_index != ecm->ctrl_id)
488 goto invalid;
489 DBG(cdev, "packet filter %02x\n", w_value);
490 /* REVISIT locking of cdc_filter. This assumes the UDC
491 * driver won't have a concurrent packet TX irq running on
492 * another CPU; or that if it does, this write is atomic...
493 */
494 ecm->port.cdc_filter = w_value;
495 value = 0;
496 break;
497
498 /* and optionally:
499 * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
500 * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
501 * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
502 * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
503 * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
504 * case USB_CDC_GET_ETHERNET_STATISTIC:
505 */
506
507 default:
508invalid:
509 DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
510 ctrl->bRequestType, ctrl->bRequest,
511 w_value, w_index, w_length);
512 }
513
514 /* respond with data transfer or status phase? */
515 if (value >= 0) {
516 DBG(cdev, "ecm req%02x.%02x v%04x i%04x l%d\n",
517 ctrl->bRequestType, ctrl->bRequest,
518 w_value, w_index, w_length);
519 req->zero = 0;
520 req->length = value;
521 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
522 if (value < 0)
523 ERROR(cdev, "ecm req %02x.%02x response err %d\n",
524 ctrl->bRequestType, ctrl->bRequest,
525 value);
526 }
527
528 /* device either stalls (value < 0) or reports success */
529 return value;
530}
531
532
533static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
534{
535 struct f_ecm *ecm = func_to_ecm(f);
536 struct usb_composite_dev *cdev = f->config->cdev;
537
538 /* Control interface has only altsetting 0 */
539 if (intf == ecm->ctrl_id) {
540 if (alt != 0)
541 goto fail;
542
543 VDBG(cdev, "reset ecm control %d\n", intf);
544 usb_ep_disable(ecm->notify);
545 if (!(ecm->notify->desc)) {
546 VDBG(cdev, "init ecm ctrl %d\n", intf);
547 if (config_ep_by_speed(cdev->gadget, f, ecm->notify))
548 goto fail;
549 }
550 usb_ep_enable(ecm->notify);
551
552 /* Data interface has two altsettings, 0 and 1 */
553 } else if (intf == ecm->data_id) {
554 if (alt > 1)
555 goto fail;
556
557 if (ecm->port.in_ep->enabled) {
558 DBG(cdev, "reset ecm\n");
559 gether_disconnect(&ecm->port);
560 }
561
562 if (!ecm->port.in_ep->desc ||
563 !ecm->port.out_ep->desc) {
564 DBG(cdev, "init ecm\n");
565 if (config_ep_by_speed(cdev->gadget, f,
566 ecm->port.in_ep) ||
567 config_ep_by_speed(cdev->gadget, f,
568 ecm->port.out_ep)) {
569 ecm->port.in_ep->desc = NULL;
570 ecm->port.out_ep->desc = NULL;
571 goto fail;
572 }
573 }
574
575 /* CDC Ethernet only sends data in non-default altsettings.
576 * Changing altsettings resets filters, statistics, etc.
577 */
578 if (alt == 1) {
579 struct net_device *net;
580
581 /* Enable zlps by default for ECM conformance;
582 * override for musb_hdrc (avoids txdma ovhead).
583 */
584 ecm->port.is_zlp_ok =
585 gadget_is_zlp_supported(cdev->gadget);
586 ecm->port.cdc_filter = DEFAULT_FILTER;
587 DBG(cdev, "activate ecm\n");
588 net = gether_connect(&ecm->port);
589 if (IS_ERR(net))
590 return PTR_ERR(net);
591 }
592
593 /* NOTE this can be a minor disagreement with the ECM spec,
594 * which says speed notifications will "always" follow
595 * connection notifications. But we allow one connect to
596 * follow another (if the first is in flight), and instead
597 * just guarantee that a speed notification is always sent.
598 */
599 ecm_notify(ecm);
600 } else
601 goto fail;
602
603 return 0;
604fail:
605 return -EINVAL;
606}
607
608/* Because the data interface supports multiple altsettings,
609 * this ECM function *MUST* implement a get_alt() method.
610 */
611static int ecm_get_alt(struct usb_function *f, unsigned intf)
612{
613 struct f_ecm *ecm = func_to_ecm(f);
614
615 if (intf == ecm->ctrl_id)
616 return 0;
617 return ecm->port.in_ep->enabled ? 1 : 0;
618}
619
620static void ecm_disable(struct usb_function *f)
621{
622 struct f_ecm *ecm = func_to_ecm(f);
623 struct usb_composite_dev *cdev = f->config->cdev;
624
625 DBG(cdev, "ecm deactivated\n");
626
627 if (ecm->port.in_ep->enabled) {
628 gether_disconnect(&ecm->port);
629 } else {
630 ecm->port.in_ep->desc = NULL;
631 ecm->port.out_ep->desc = NULL;
632 }
633
634 usb_ep_disable(ecm->notify);
635 ecm->notify->desc = NULL;
636}
637
638/*-------------------------------------------------------------------------*/
639
640/*
641 * Callbacks let us notify the host about connect/disconnect when the
642 * net device is opened or closed.
643 *
644 * For testing, note that link states on this side include both opened
645 * and closed variants of:
646 *
647 * - disconnected/unconfigured
648 * - configured but inactive (data alt 0)
649 * - configured and active (data alt 1)
650 *
651 * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
652 * SET_INTERFACE (altsetting). Remember also that "configured" doesn't
653 * imply the host is actually polling the notification endpoint, and
654 * likewise that "active" doesn't imply it's actually using the data
655 * endpoints for traffic.
656 */
657
658static void ecm_open(struct gether *geth)
659{
660 struct f_ecm *ecm = func_to_ecm(&geth->func);
661
662 DBG(ecm->port.func.config->cdev, "%s\n", __func__);
663
664 ecm->is_open = true;
665 ecm_notify(ecm);
666}
667
668static void ecm_close(struct gether *geth)
669{
670 struct f_ecm *ecm = func_to_ecm(&geth->func);
671
672 DBG(ecm->port.func.config->cdev, "%s\n", __func__);
673
674 ecm->is_open = false;
675 ecm_notify(ecm);
676}
677
678/*-------------------------------------------------------------------------*/
679
680/* ethernet function driver setup/binding */
681
682static int
683ecm_bind(struct usb_configuration *c, struct usb_function *f)
684{
685 struct usb_composite_dev *cdev = c->cdev;
686 struct f_ecm *ecm = func_to_ecm(f);
687 struct usb_string *us;
688 int status = 0;
689 struct usb_ep *ep;
690
691 struct f_ecm_opts *ecm_opts;
692
693 if (!can_support_ecm(cdev->gadget))
694 return -EINVAL;
695
696 ecm_opts = container_of(f->fi, struct f_ecm_opts, func_inst);
697
698 mutex_lock(&ecm_opts->lock);
699
700 gether_set_gadget(ecm_opts->net, cdev->gadget);
701
702 if (!ecm_opts->bound) {
703 status = gether_register_netdev(ecm_opts->net);
704 ecm_opts->bound = true;
705 }
706
707 mutex_unlock(&ecm_opts->lock);
708 if (status)
709 return status;
710
711 ecm_string_defs[1].s = ecm->ethaddr;
712
713 us = usb_gstrings_attach(cdev, ecm_strings,
714 ARRAY_SIZE(ecm_string_defs));
715 if (IS_ERR(us))
716 return PTR_ERR(us);
717 ecm_control_intf.iInterface = us[0].id;
718 ecm_data_intf.iInterface = us[2].id;
719 ecm_desc.iMACAddress = us[1].id;
720 ecm_iad_descriptor.iFunction = us[3].id;
721
722 /* allocate instance-specific interface IDs */
723 status = usb_interface_id(c, f);
724 if (status < 0)
725 goto fail;
726 ecm->ctrl_id = status;
727 ecm_iad_descriptor.bFirstInterface = status;
728
729 ecm_control_intf.bInterfaceNumber = status;
730 ecm_union_desc.bMasterInterface0 = status;
731
732 status = usb_interface_id(c, f);
733 if (status < 0)
734 goto fail;
735 ecm->data_id = status;
736
737 ecm_data_nop_intf.bInterfaceNumber = status;
738 ecm_data_intf.bInterfaceNumber = status;
739 ecm_union_desc.bSlaveInterface0 = status;
740
741 status = -ENODEV;
742
743 /* allocate instance-specific endpoints */
744 ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_in_desc);
745 if (!ep)
746 goto fail;
747 ecm->port.in_ep = ep;
748
749 ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_out_desc);
750 if (!ep)
751 goto fail;
752 ecm->port.out_ep = ep;
753
754 /* NOTE: a status/notification endpoint is *OPTIONAL* but we
755 * don't treat it that way. It's simpler, and some newer CDC
756 * profiles (wireless handsets) no longer treat it as optional.
757 */
758 ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_notify_desc);
759 if (!ep)
760 goto fail;
761 ecm->notify = ep;
762
763 status = -ENOMEM;
764
765 /* allocate notification request and buffer */
766 ecm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
767 if (!ecm->notify_req)
768 goto fail;
769 ecm->notify_req->buf = kmalloc(ECM_STATUS_BYTECOUNT, GFP_KERNEL);
770 if (!ecm->notify_req->buf)
771 goto fail;
772 ecm->notify_req->context = ecm;
773 ecm->notify_req->complete = ecm_notify_complete;
774
775 /* support all relevant hardware speeds... we expect that when
776 * hardware is dual speed, all bulk-capable endpoints work at
777 * both speeds
778 */
779 hs_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
780 hs_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
781 hs_ecm_notify_desc.bEndpointAddress =
782 fs_ecm_notify_desc.bEndpointAddress;
783
784 ss_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
785 ss_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
786 ss_ecm_notify_desc.bEndpointAddress =
787 fs_ecm_notify_desc.bEndpointAddress;
788
789 status = usb_assign_descriptors(f, ecm_fs_function, ecm_hs_function,
790 ecm_ss_function, ecm_ss_function);
791 if (status)
792 goto fail;
793
794 /* NOTE: all that is done without knowing or caring about
795 * the network link ... which is unavailable to this code
796 * until we're activated via set_alt().
797 */
798
799 ecm->port.open = ecm_open;
800 ecm->port.close = ecm_close;
801
802 DBG(cdev, "CDC Ethernet: %s speed IN/%s OUT/%s NOTIFY/%s\n",
803 gadget_is_superspeed(c->cdev->gadget) ? "super" :
804 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
805 ecm->port.in_ep->name, ecm->port.out_ep->name,
806 ecm->notify->name);
807 return 0;
808
809fail:
810 if (ecm->notify_req) {
811 kfree(ecm->notify_req->buf);
812 usb_ep_free_request(ecm->notify, ecm->notify_req);
813 }
814
815 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
816
817 return status;
818}
819
820static inline struct f_ecm_opts *to_f_ecm_opts(struct config_item *item)
821{
822 return container_of(to_config_group(item), struct f_ecm_opts,
823 func_inst.group);
824}
825
826/* f_ecm_item_ops */
827USB_ETHERNET_CONFIGFS_ITEM(ecm);
828
829/* f_ecm_opts_dev_addr */
830USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ecm);
831
832/* f_ecm_opts_host_addr */
833USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ecm);
834
835/* f_ecm_opts_qmult */
836USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ecm);
837
838/* f_ecm_opts_ifname */
839USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ecm);
840
841static struct configfs_attribute *ecm_attrs[] = {
842 &ecm_opts_attr_dev_addr,
843 &ecm_opts_attr_host_addr,
844 &ecm_opts_attr_qmult,
845 &ecm_opts_attr_ifname,
846 NULL,
847};
848
849static const struct config_item_type ecm_func_type = {
850 .ct_item_ops = &ecm_item_ops,
851 .ct_attrs = ecm_attrs,
852 .ct_owner = THIS_MODULE,
853};
854
855static void ecm_free_inst(struct usb_function_instance *f)
856{
857 struct f_ecm_opts *opts;
858
859 opts = container_of(f, struct f_ecm_opts, func_inst);
860 if (opts->bound)
861 gether_cleanup(netdev_priv(opts->net));
862 else
863 free_netdev(opts->net);
864 kfree(opts);
865}
866
867static struct usb_function_instance *ecm_alloc_inst(void)
868{
869 struct f_ecm_opts *opts;
870
871 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
872 if (!opts)
873 return ERR_PTR(-ENOMEM);
874 mutex_init(&opts->lock);
875 opts->func_inst.free_func_inst = ecm_free_inst;
876 opts->net = gether_setup_default();
877 if (IS_ERR(opts->net)) {
878 struct net_device *net = opts->net;
879 kfree(opts);
880 return ERR_CAST(net);
881 }
882
883 config_group_init_type_name(&opts->func_inst.group, "", &ecm_func_type);
884
885 return &opts->func_inst;
886}
887
888static void ecm_free(struct usb_function *f)
889{
890 struct f_ecm *ecm;
891 struct f_ecm_opts *opts;
892
893 ecm = func_to_ecm(f);
894 opts = container_of(f->fi, struct f_ecm_opts, func_inst);
895 kfree(ecm);
896 mutex_lock(&opts->lock);
897 opts->refcnt--;
898 mutex_unlock(&opts->lock);
899}
900
901static void ecm_unbind(struct usb_configuration *c, struct usb_function *f)
902{
903 struct f_ecm *ecm = func_to_ecm(f);
904
905 DBG(c->cdev, "ecm unbind\n");
906
907 usb_free_all_descriptors(f);
908
909 if (atomic_read(&ecm->notify_count)) {
910 usb_ep_dequeue(ecm->notify, ecm->notify_req);
911 atomic_set(&ecm->notify_count, 0);
912 }
913
914 kfree(ecm->notify_req->buf);
915 usb_ep_free_request(ecm->notify, ecm->notify_req);
916}
917
918static struct usb_function *ecm_alloc(struct usb_function_instance *fi)
919{
920 struct f_ecm *ecm;
921 struct f_ecm_opts *opts;
922 int status;
923
924 /* allocate and initialize one new instance */
925 ecm = kzalloc(sizeof(*ecm), GFP_KERNEL);
926 if (!ecm)
927 return ERR_PTR(-ENOMEM);
928
929 opts = container_of(fi, struct f_ecm_opts, func_inst);
930 mutex_lock(&opts->lock);
931 opts->refcnt++;
932
933 /* export host's Ethernet address in CDC format */
934 status = gether_get_host_addr_cdc(opts->net, ecm->ethaddr,
935 sizeof(ecm->ethaddr));
936 if (status < 12) {
937 kfree(ecm);
938 mutex_unlock(&opts->lock);
939 return ERR_PTR(-EINVAL);
940 }
941
942 ecm->port.ioport = netdev_priv(opts->net);
943 mutex_unlock(&opts->lock);
944 ecm->port.cdc_filter = DEFAULT_FILTER;
945
946 ecm->port.func.name = "cdc_ethernet";
947 /* descriptors are per-instance copies */
948 ecm->port.func.bind = ecm_bind;
949 ecm->port.func.unbind = ecm_unbind;
950 ecm->port.func.set_alt = ecm_set_alt;
951 ecm->port.func.get_alt = ecm_get_alt;
952 ecm->port.func.setup = ecm_setup;
953 ecm->port.func.disable = ecm_disable;
954 ecm->port.func.free_func = ecm_free;
955
956 return &ecm->port.func;
957}
958
959DECLARE_USB_FUNCTION_INIT(ecm, ecm_alloc_inst, ecm_alloc);
960MODULE_LICENSE("GPL");
961MODULE_AUTHOR("David Brownell");