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");