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;
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	/*
699	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
700	 * configurations are bound in sequence with list_for_each_entry,
701	 * in each configuration its functions are bound in sequence
702	 * with list_for_each_entry, so we assume no race condition
703	 * with regard to ecm_opts->bound access
704	 */
705	if (!ecm_opts->bound) {
706		mutex_lock(&ecm_opts->lock);
707		gether_set_gadget(ecm_opts->net, cdev->gadget);
708		status = gether_register_netdev(ecm_opts->net);
709		mutex_unlock(&ecm_opts->lock);
710		if (status)
711			return status;
712		ecm_opts->bound = true;
713	}
 
 
 
 
714
715	ecm_string_defs[1].s = ecm->ethaddr;
716
717	us = usb_gstrings_attach(cdev, ecm_strings,
718				 ARRAY_SIZE(ecm_string_defs));
719	if (IS_ERR(us))
720		return PTR_ERR(us);
721	ecm_control_intf.iInterface = us[0].id;
722	ecm_data_intf.iInterface = us[2].id;
723	ecm_desc.iMACAddress = us[1].id;
724	ecm_iad_descriptor.iFunction = us[3].id;
725
726	/* allocate instance-specific interface IDs */
727	status = usb_interface_id(c, f);
728	if (status < 0)
729		goto fail;
730	ecm->ctrl_id = status;
731	ecm_iad_descriptor.bFirstInterface = status;
732
733	ecm_control_intf.bInterfaceNumber = status;
734	ecm_union_desc.bMasterInterface0 = status;
735
736	status = usb_interface_id(c, f);
737	if (status < 0)
738		goto fail;
739	ecm->data_id = status;
740
741	ecm_data_nop_intf.bInterfaceNumber = status;
742	ecm_data_intf.bInterfaceNumber = status;
743	ecm_union_desc.bSlaveInterface0 = status;
744
745	status = -ENODEV;
746
747	/* allocate instance-specific endpoints */
748	ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_in_desc);
749	if (!ep)
750		goto fail;
751	ecm->port.in_ep = ep;
752
753	ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_out_desc);
754	if (!ep)
755		goto fail;
756	ecm->port.out_ep = ep;
757
758	/* NOTE:  a status/notification endpoint is *OPTIONAL* but we
759	 * don't treat it that way.  It's simpler, and some newer CDC
760	 * profiles (wireless handsets) no longer treat it as optional.
761	 */
762	ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_notify_desc);
763	if (!ep)
764		goto fail;
765	ecm->notify = ep;
766
767	status = -ENOMEM;
768
769	/* allocate notification request and buffer */
770	ecm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
771	if (!ecm->notify_req)
772		goto fail;
773	ecm->notify_req->buf = kmalloc(ECM_STATUS_BYTECOUNT, GFP_KERNEL);
774	if (!ecm->notify_req->buf)
775		goto fail;
776	ecm->notify_req->context = ecm;
777	ecm->notify_req->complete = ecm_notify_complete;
778
779	/* support all relevant hardware speeds... we expect that when
780	 * hardware is dual speed, all bulk-capable endpoints work at
781	 * both speeds
782	 */
783	hs_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
784	hs_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
785	hs_ecm_notify_desc.bEndpointAddress =
786		fs_ecm_notify_desc.bEndpointAddress;
787
788	ss_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress;
789	ss_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress;
790	ss_ecm_notify_desc.bEndpointAddress =
791		fs_ecm_notify_desc.bEndpointAddress;
792
793	status = usb_assign_descriptors(f, ecm_fs_function, ecm_hs_function,
794			ecm_ss_function, ecm_ss_function);
795	if (status)
796		goto fail;
797
798	/* NOTE:  all that is done without knowing or caring about
799	 * the network link ... which is unavailable to this code
800	 * until we're activated via set_alt().
801	 */
802
803	ecm->port.open = ecm_open;
804	ecm->port.close = ecm_close;
805
806	DBG(cdev, "CDC Ethernet: %s speed IN/%s OUT/%s NOTIFY/%s\n",
807			gadget_is_superspeed(c->cdev->gadget) ? "super" :
808			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
809			ecm->port.in_ep->name, ecm->port.out_ep->name,
810			ecm->notify->name);
811	return 0;
812
813fail:
814	if (ecm->notify_req) {
815		kfree(ecm->notify_req->buf);
816		usb_ep_free_request(ecm->notify, ecm->notify_req);
817	}
818
819	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
820
821	return status;
822}
823
824static inline struct f_ecm_opts *to_f_ecm_opts(struct config_item *item)
825{
826	return container_of(to_config_group(item), struct f_ecm_opts,
827			    func_inst.group);
828}
829
830/* f_ecm_item_ops */
831USB_ETHERNET_CONFIGFS_ITEM(ecm);
832
833/* f_ecm_opts_dev_addr */
834USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ecm);
835
836/* f_ecm_opts_host_addr */
837USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ecm);
838
839/* f_ecm_opts_qmult */
840USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ecm);
841
842/* f_ecm_opts_ifname */
843USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ecm);
844
845static struct configfs_attribute *ecm_attrs[] = {
846	&ecm_opts_attr_dev_addr,
847	&ecm_opts_attr_host_addr,
848	&ecm_opts_attr_qmult,
849	&ecm_opts_attr_ifname,
850	NULL,
851};
852
853static const struct config_item_type ecm_func_type = {
854	.ct_item_ops	= &ecm_item_ops,
855	.ct_attrs	= ecm_attrs,
856	.ct_owner	= THIS_MODULE,
857};
858
859static void ecm_free_inst(struct usb_function_instance *f)
860{
861	struct f_ecm_opts *opts;
862
863	opts = container_of(f, struct f_ecm_opts, func_inst);
864	if (opts->bound)
865		gether_cleanup(netdev_priv(opts->net));
866	else
867		free_netdev(opts->net);
868	kfree(opts);
869}
870
871static struct usb_function_instance *ecm_alloc_inst(void)
872{
873	struct f_ecm_opts *opts;
874
875	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
876	if (!opts)
877		return ERR_PTR(-ENOMEM);
878	mutex_init(&opts->lock);
879	opts->func_inst.free_func_inst = ecm_free_inst;
880	opts->net = gether_setup_default();
881	if (IS_ERR(opts->net)) {
882		struct net_device *net = opts->net;
883		kfree(opts);
884		return ERR_CAST(net);
885	}
886
887	config_group_init_type_name(&opts->func_inst.group, "", &ecm_func_type);
888
889	return &opts->func_inst;
890}
891
892static void ecm_free(struct usb_function *f)
893{
894	struct f_ecm *ecm;
895	struct f_ecm_opts *opts;
896
897	ecm = func_to_ecm(f);
898	opts = container_of(f->fi, struct f_ecm_opts, func_inst);
899	kfree(ecm);
900	mutex_lock(&opts->lock);
901	opts->refcnt--;
902	mutex_unlock(&opts->lock);
903}
904
905static void ecm_unbind(struct usb_configuration *c, struct usb_function *f)
906{
907	struct f_ecm		*ecm = func_to_ecm(f);
908
909	DBG(c->cdev, "ecm unbind\n");
910
911	usb_free_all_descriptors(f);
912
913	if (atomic_read(&ecm->notify_count)) {
914		usb_ep_dequeue(ecm->notify, ecm->notify_req);
915		atomic_set(&ecm->notify_count, 0);
916	}
917
918	kfree(ecm->notify_req->buf);
919	usb_ep_free_request(ecm->notify, ecm->notify_req);
920}
921
922static struct usb_function *ecm_alloc(struct usb_function_instance *fi)
923{
924	struct f_ecm	*ecm;
925	struct f_ecm_opts *opts;
926	int status;
927
928	/* allocate and initialize one new instance */
929	ecm = kzalloc(sizeof(*ecm), GFP_KERNEL);
930	if (!ecm)
931		return ERR_PTR(-ENOMEM);
932
933	opts = container_of(fi, struct f_ecm_opts, func_inst);
934	mutex_lock(&opts->lock);
935	opts->refcnt++;
936
937	/* export host's Ethernet address in CDC format */
938	status = gether_get_host_addr_cdc(opts->net, ecm->ethaddr,
939					  sizeof(ecm->ethaddr));
940	if (status < 12) {
941		kfree(ecm);
942		mutex_unlock(&opts->lock);
943		return ERR_PTR(-EINVAL);
944	}
945
946	ecm->port.ioport = netdev_priv(opts->net);
947	mutex_unlock(&opts->lock);
948	ecm->port.cdc_filter = DEFAULT_FILTER;
949
950	ecm->port.func.name = "cdc_ethernet";
951	/* descriptors are per-instance copies */
952	ecm->port.func.bind = ecm_bind;
953	ecm->port.func.unbind = ecm_unbind;
954	ecm->port.func.set_alt = ecm_set_alt;
955	ecm->port.func.get_alt = ecm_get_alt;
956	ecm->port.func.setup = ecm_setup;
957	ecm->port.func.disable = ecm_disable;
958	ecm->port.func.free_func = ecm_free;
959
960	return &ecm->port.func;
961}
962
963DECLARE_USB_FUNCTION_INIT(ecm, ecm_alloc_inst, ecm_alloc);
964MODULE_LICENSE("GPL");
965MODULE_AUTHOR("David Brownell");