1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * f_ncm.c -- USB CDC Network (NCM) link function driver
4  *
5  * Copyright (C) 2010 Nokia Corporation
6  * Contact: Yauheni Kaliuta <yauheni.kaliuta@nokia.com>
7  *
8  * The driver borrows from f_ecm.c which is:
9  *
10  * Copyright (C) 2003-2005,2008 David Brownell
11  * Copyright (C) 2008 Nokia Corporation
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/interrupt.h>
16 #include <linux/module.h>
17 #include <linux/device.h>
18 #include <linux/etherdevice.h>
19 #include <linux/crc32.h>
20 
21 #include <linux/usb/cdc.h>
22 
23 #include "u_ether.h"
24 #include "u_ether_configfs.h"
25 #include "u_ncm.h"
26 #include "configfs.h"
27 
28 /*
29  * This function is a "CDC Network Control Model" (CDC NCM) Ethernet link.
30  * NCM is intended to be used with high-speed network attachments.
31  *
32  * Note that NCM requires the use of "alternate settings" for its data
33  * interface.  This means that the set_alt() method has real work to do,
34  * and also means that a get_alt() method is required.
35  */
36 
37 /* to trigger crc/non-crc ndp signature */
38 
39 #define NCM_NDP_HDR_CRC		0x01000000
40 
41 enum ncm_notify_state {
42 	NCM_NOTIFY_NONE,		/* don't notify */
43 	NCM_NOTIFY_CONNECT,		/* issue CONNECT next */
44 	NCM_NOTIFY_SPEED,		/* issue SPEED_CHANGE next */
45 };
46 
47 struct f_ncm {
48 	struct gether			port;
49 	u8				ctrl_id, data_id;
50 
51 	char				ethaddr[14];
52 
53 	struct usb_ep			*notify;
54 	struct usb_request		*notify_req;
55 	u8				notify_state;
56 	atomic_t			notify_count;
57 	bool				is_open;
58 
59 	const struct ndp_parser_opts	*parser_opts;
60 	bool				is_crc;
61 	u32				ndp_sign;
62 
63 	/*
64 	 * for notification, it is accessed from both
65 	 * callback and ethernet open/close
66 	 */
67 	spinlock_t			lock;
68 
69 	struct net_device		*netdev;
70 
71 	/* For multi-frame NDP TX */
72 	struct sk_buff			*skb_tx_data;
73 	struct sk_buff			*skb_tx_ndp;
74 	u16				ndp_dgram_count;
75 	bool				timer_force_tx;
76 	struct hrtimer			task_timer;
77 	bool				timer_stopping;
78 };
79 
80 static inline struct f_ncm *func_to_ncm(struct usb_function *f)
81 {
82 	return container_of(f, struct f_ncm, port.func);
83 }
84 
85 /* peak (theoretical) bulk transfer rate in bits-per-second */
86 static inline unsigned ncm_bitrate(struct usb_gadget *g)
87 {
88 	if (gadget_is_superspeed(g) && g->speed >= USB_SPEED_SUPER_PLUS)
89 		return 4250000000U;
90 	else if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
91 		return 3750000000U;
92 	else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
93 		return 13 * 512 * 8 * 1000 * 8;
94 	else
95 		return 19 *  64 * 1 * 1000 * 8;
96 }
97 
98 /*-------------------------------------------------------------------------*/
99 
100 /*
101  * We cannot group frames so use just the minimal size which ok to put
102  * one max-size ethernet frame.
103  * If the host can group frames, allow it to do that, 16K is selected,
104  * because it's used by default by the current linux host driver
105  */
106 #define NTB_DEFAULT_IN_SIZE	16384
107 #define NTB_OUT_SIZE		16384
108 
109 /* Allocation for storing the NDP, 32 should suffice for a
110  * 16k packet. This allows a maximum of 32 * 507 Byte packets to
111  * be transmitted in a single 16kB skb, though when sending full size
112  * packets this limit will be plenty.
113  * Smaller packets are not likely to be trying to maximize the
114  * throughput and will be mstly sending smaller infrequent frames.
115  */
116 #define TX_MAX_NUM_DPE		32
117 
118 /* Delay for the transmit to wait before sending an unfilled NTB frame. */
119 #define TX_TIMEOUT_NSECS	300000
120 
121 #define FORMATS_SUPPORTED	(USB_CDC_NCM_NTB16_SUPPORTED |	\
122 				 USB_CDC_NCM_NTB32_SUPPORTED)
123 
124 static struct usb_cdc_ncm_ntb_parameters ntb_parameters = {
125 	.wLength = cpu_to_le16(sizeof(ntb_parameters)),
126 	.bmNtbFormatsSupported = cpu_to_le16(FORMATS_SUPPORTED),
127 	.dwNtbInMaxSize = cpu_to_le32(NTB_DEFAULT_IN_SIZE),
128 	.wNdpInDivisor = cpu_to_le16(4),
129 	.wNdpInPayloadRemainder = cpu_to_le16(0),
130 	.wNdpInAlignment = cpu_to_le16(4),
131 
132 	.dwNtbOutMaxSize = cpu_to_le32(NTB_OUT_SIZE),
133 	.wNdpOutDivisor = cpu_to_le16(4),
134 	.wNdpOutPayloadRemainder = cpu_to_le16(0),
135 	.wNdpOutAlignment = cpu_to_le16(4),
136 };
137 
138 /*
139  * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
140  * packet, to simplify cancellation; and a big transfer interval, to
141  * waste less bandwidth.
142  */
143 
144 #define NCM_STATUS_INTERVAL_MS		32
145 #define NCM_STATUS_BYTECOUNT		16	/* 8 byte header + data */
146 
147 static struct usb_interface_assoc_descriptor ncm_iad_desc = {
148 	.bLength =		sizeof ncm_iad_desc,
149 	.bDescriptorType =	USB_DT_INTERFACE_ASSOCIATION,
150 
151 	/* .bFirstInterface =	DYNAMIC, */
152 	.bInterfaceCount =	2,	/* control + data */
153 	.bFunctionClass =	USB_CLASS_COMM,
154 	.bFunctionSubClass =	USB_CDC_SUBCLASS_NCM,
155 	.bFunctionProtocol =	USB_CDC_PROTO_NONE,
156 	/* .iFunction =		DYNAMIC */
157 };
158 
159 /* interface descriptor: */
160 
161 static struct usb_interface_descriptor ncm_control_intf = {
162 	.bLength =		sizeof ncm_control_intf,
163 	.bDescriptorType =	USB_DT_INTERFACE,
164 
165 	/* .bInterfaceNumber = DYNAMIC */
166 	.bNumEndpoints =	1,
167 	.bInterfaceClass =	USB_CLASS_COMM,
168 	.bInterfaceSubClass =	USB_CDC_SUBCLASS_NCM,
169 	.bInterfaceProtocol =	USB_CDC_PROTO_NONE,
170 	/* .iInterface = DYNAMIC */
171 };
172 
173 static struct usb_cdc_header_desc ncm_header_desc = {
174 	.bLength =		sizeof ncm_header_desc,
175 	.bDescriptorType =	USB_DT_CS_INTERFACE,
176 	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
177 
178 	.bcdCDC =		cpu_to_le16(0x0110),
179 };
180 
181 static struct usb_cdc_union_desc ncm_union_desc = {
182 	.bLength =		sizeof(ncm_union_desc),
183 	.bDescriptorType =	USB_DT_CS_INTERFACE,
184 	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
185 	/* .bMasterInterface0 =	DYNAMIC */
186 	/* .bSlaveInterface0 =	DYNAMIC */
187 };
188 
189 static struct usb_cdc_ether_desc ecm_desc = {
190 	.bLength =		sizeof ecm_desc,
191 	.bDescriptorType =	USB_DT_CS_INTERFACE,
192 	.bDescriptorSubType =	USB_CDC_ETHERNET_TYPE,
193 
194 	/* this descriptor actually adds value, surprise! */
195 	/* .iMACAddress = DYNAMIC */
196 	.bmEthernetStatistics =	cpu_to_le32(0), /* no statistics */
197 	.wMaxSegmentSize =	cpu_to_le16(ETH_FRAME_LEN),
198 	.wNumberMCFilters =	cpu_to_le16(0),
199 	.bNumberPowerFilters =	0,
200 };
201 
202 #define NCAPS	(USB_CDC_NCM_NCAP_ETH_FILTER | USB_CDC_NCM_NCAP_CRC_MODE)
203 
204 static struct usb_cdc_ncm_desc ncm_desc = {
205 	.bLength =		sizeof ncm_desc,
206 	.bDescriptorType =	USB_DT_CS_INTERFACE,
207 	.bDescriptorSubType =	USB_CDC_NCM_TYPE,
208 
209 	.bcdNcmVersion =	cpu_to_le16(0x0100),
210 	/* can process SetEthernetPacketFilter */
211 	.bmNetworkCapabilities = NCAPS,
212 };
213 
214 /* the default data interface has no endpoints ... */
215 
216 static struct usb_interface_descriptor ncm_data_nop_intf = {
217 	.bLength =		sizeof ncm_data_nop_intf,
218 	.bDescriptorType =	USB_DT_INTERFACE,
219 
220 	.bInterfaceNumber =	1,
221 	.bAlternateSetting =	0,
222 	.bNumEndpoints =	0,
223 	.bInterfaceClass =	USB_CLASS_CDC_DATA,
224 	.bInterfaceSubClass =	0,
225 	.bInterfaceProtocol =	USB_CDC_NCM_PROTO_NTB,
226 	/* .iInterface = DYNAMIC */
227 };
228 
229 /* ... but the "real" data interface has two bulk endpoints */
230 
231 static struct usb_interface_descriptor ncm_data_intf = {
232 	.bLength =		sizeof ncm_data_intf,
233 	.bDescriptorType =	USB_DT_INTERFACE,
234 
235 	.bInterfaceNumber =	1,
236 	.bAlternateSetting =	1,
237 	.bNumEndpoints =	2,
238 	.bInterfaceClass =	USB_CLASS_CDC_DATA,
239 	.bInterfaceSubClass =	0,
240 	.bInterfaceProtocol =	USB_CDC_NCM_PROTO_NTB,
241 	/* .iInterface = DYNAMIC */
242 };
243 
244 /* full speed support: */
245 
246 static struct usb_endpoint_descriptor fs_ncm_notify_desc = {
247 	.bLength =		USB_DT_ENDPOINT_SIZE,
248 	.bDescriptorType =	USB_DT_ENDPOINT,
249 
250 	.bEndpointAddress =	USB_DIR_IN,
251 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
252 	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
253 	.bInterval =		NCM_STATUS_INTERVAL_MS,
254 };
255 
256 static struct usb_endpoint_descriptor fs_ncm_in_desc = {
257 	.bLength =		USB_DT_ENDPOINT_SIZE,
258 	.bDescriptorType =	USB_DT_ENDPOINT,
259 
260 	.bEndpointAddress =	USB_DIR_IN,
261 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
262 };
263 
264 static struct usb_endpoint_descriptor fs_ncm_out_desc = {
265 	.bLength =		USB_DT_ENDPOINT_SIZE,
266 	.bDescriptorType =	USB_DT_ENDPOINT,
267 
268 	.bEndpointAddress =	USB_DIR_OUT,
269 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
270 };
271 
272 static struct usb_descriptor_header *ncm_fs_function[] = {
273 	(struct usb_descriptor_header *) &ncm_iad_desc,
274 	/* CDC NCM control descriptors */
275 	(struct usb_descriptor_header *) &ncm_control_intf,
276 	(struct usb_descriptor_header *) &ncm_header_desc,
277 	(struct usb_descriptor_header *) &ncm_union_desc,
278 	(struct usb_descriptor_header *) &ecm_desc,
279 	(struct usb_descriptor_header *) &ncm_desc,
280 	(struct usb_descriptor_header *) &fs_ncm_notify_desc,
281 	/* data interface, altsettings 0 and 1 */
282 	(struct usb_descriptor_header *) &ncm_data_nop_intf,
283 	(struct usb_descriptor_header *) &ncm_data_intf,
284 	(struct usb_descriptor_header *) &fs_ncm_in_desc,
285 	(struct usb_descriptor_header *) &fs_ncm_out_desc,
286 	NULL,
287 };
288 
289 /* high speed support: */
290 
291 static struct usb_endpoint_descriptor hs_ncm_notify_desc = {
292 	.bLength =		USB_DT_ENDPOINT_SIZE,
293 	.bDescriptorType =	USB_DT_ENDPOINT,
294 
295 	.bEndpointAddress =	USB_DIR_IN,
296 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
297 	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
298 	.bInterval =		USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS),
299 };
300 static struct usb_endpoint_descriptor hs_ncm_in_desc = {
301 	.bLength =		USB_DT_ENDPOINT_SIZE,
302 	.bDescriptorType =	USB_DT_ENDPOINT,
303 
304 	.bEndpointAddress =	USB_DIR_IN,
305 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
306 	.wMaxPacketSize =	cpu_to_le16(512),
307 };
308 
309 static struct usb_endpoint_descriptor hs_ncm_out_desc = {
310 	.bLength =		USB_DT_ENDPOINT_SIZE,
311 	.bDescriptorType =	USB_DT_ENDPOINT,
312 
313 	.bEndpointAddress =	USB_DIR_OUT,
314 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
315 	.wMaxPacketSize =	cpu_to_le16(512),
316 };
317 
318 static struct usb_descriptor_header *ncm_hs_function[] = {
319 	(struct usb_descriptor_header *) &ncm_iad_desc,
320 	/* CDC NCM control descriptors */
321 	(struct usb_descriptor_header *) &ncm_control_intf,
322 	(struct usb_descriptor_header *) &ncm_header_desc,
323 	(struct usb_descriptor_header *) &ncm_union_desc,
324 	(struct usb_descriptor_header *) &ecm_desc,
325 	(struct usb_descriptor_header *) &ncm_desc,
326 	(struct usb_descriptor_header *) &hs_ncm_notify_desc,
327 	/* data interface, altsettings 0 and 1 */
328 	(struct usb_descriptor_header *) &ncm_data_nop_intf,
329 	(struct usb_descriptor_header *) &ncm_data_intf,
330 	(struct usb_descriptor_header *) &hs_ncm_in_desc,
331 	(struct usb_descriptor_header *) &hs_ncm_out_desc,
332 	NULL,
333 };
334 
335 
336 /* super speed support: */
337 
338 static struct usb_endpoint_descriptor ss_ncm_notify_desc = {
339 	.bLength =		USB_DT_ENDPOINT_SIZE,
340 	.bDescriptorType =	USB_DT_ENDPOINT,
341 
342 	.bEndpointAddress =	USB_DIR_IN,
343 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
344 	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
345 	.bInterval =		USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS)
346 };
347 
348 static struct usb_ss_ep_comp_descriptor ss_ncm_notify_comp_desc = {
349 	.bLength =		sizeof(ss_ncm_notify_comp_desc),
350 	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
351 
352 	/* the following 3 values can be tweaked if necessary */
353 	/* .bMaxBurst =		0, */
354 	/* .bmAttributes =	0, */
355 	.wBytesPerInterval =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
356 };
357 
358 static struct usb_endpoint_descriptor ss_ncm_in_desc = {
359 	.bLength =		USB_DT_ENDPOINT_SIZE,
360 	.bDescriptorType =	USB_DT_ENDPOINT,
361 
362 	.bEndpointAddress =	USB_DIR_IN,
363 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
364 	.wMaxPacketSize =	cpu_to_le16(1024),
365 };
366 
367 static struct usb_endpoint_descriptor ss_ncm_out_desc = {
368 	.bLength =		USB_DT_ENDPOINT_SIZE,
369 	.bDescriptorType =	USB_DT_ENDPOINT,
370 
371 	.bEndpointAddress =	USB_DIR_OUT,
372 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
373 	.wMaxPacketSize =	cpu_to_le16(1024),
374 };
375 
376 static struct usb_ss_ep_comp_descriptor ss_ncm_bulk_comp_desc = {
377 	.bLength =		sizeof(ss_ncm_bulk_comp_desc),
378 	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
379 
380 	/* the following 2 values can be tweaked if necessary */
381 	.bMaxBurst =		15,
382 	/* .bmAttributes =	0, */
383 };
384 
385 static struct usb_descriptor_header *ncm_ss_function[] = {
386 	(struct usb_descriptor_header *) &ncm_iad_desc,
387 	/* CDC NCM control descriptors */
388 	(struct usb_descriptor_header *) &ncm_control_intf,
389 	(struct usb_descriptor_header *) &ncm_header_desc,
390 	(struct usb_descriptor_header *) &ncm_union_desc,
391 	(struct usb_descriptor_header *) &ecm_desc,
392 	(struct usb_descriptor_header *) &ncm_desc,
393 	(struct usb_descriptor_header *) &ss_ncm_notify_desc,
394 	(struct usb_descriptor_header *) &ss_ncm_notify_comp_desc,
395 	/* data interface, altsettings 0 and 1 */
396 	(struct usb_descriptor_header *) &ncm_data_nop_intf,
397 	(struct usb_descriptor_header *) &ncm_data_intf,
398 	(struct usb_descriptor_header *) &ss_ncm_in_desc,
399 	(struct usb_descriptor_header *) &ss_ncm_bulk_comp_desc,
400 	(struct usb_descriptor_header *) &ss_ncm_out_desc,
401 	(struct usb_descriptor_header *) &ss_ncm_bulk_comp_desc,
402 	NULL,
403 };
404 
405 /* string descriptors: */
406 
407 #define STRING_CTRL_IDX	0
408 #define STRING_MAC_IDX	1
409 #define STRING_DATA_IDX	2
410 #define STRING_IAD_IDX	3
411 
412 static struct usb_string ncm_string_defs[] = {
413 	[STRING_CTRL_IDX].s = "CDC Network Control Model (NCM)",
414 	[STRING_MAC_IDX].s = "",
415 	[STRING_DATA_IDX].s = "CDC Network Data",
416 	[STRING_IAD_IDX].s = "CDC NCM",
417 	{  } /* end of list */
418 };
419 
420 static struct usb_gadget_strings ncm_string_table = {
421 	.language =		0x0409,	/* en-us */
422 	.strings =		ncm_string_defs,
423 };
424 
425 static struct usb_gadget_strings *ncm_strings[] = {
426 	&ncm_string_table,
427 	NULL,
428 };
429 
430 /*
431  * Here are options for NCM Datagram Pointer table (NDP) parser.
432  * There are 2 different formats: NDP16 and NDP32 in the spec (ch. 3),
433  * in NDP16 offsets and sizes fields are 1 16bit word wide,
434  * in NDP32 -- 2 16bit words wide. Also signatures are different.
435  * To make the parser code the same, put the differences in the structure,
436  * and switch pointers to the structures when the format is changed.
437  */
438 
439 struct ndp_parser_opts {
440 	u32		nth_sign;
441 	u32		ndp_sign;
442 	unsigned	nth_size;
443 	unsigned	ndp_size;
444 	unsigned	dpe_size;
445 	unsigned	ndplen_align;
446 	/* sizes in u16 units */
447 	unsigned	dgram_item_len; /* index or length */
448 	unsigned	block_length;
449 	unsigned	ndp_index;
450 	unsigned	reserved1;
451 	unsigned	reserved2;
452 	unsigned	next_ndp_index;
453 };
454 
455 #define INIT_NDP16_OPTS {					\
456 		.nth_sign = USB_CDC_NCM_NTH16_SIGN,		\
457 		.ndp_sign = USB_CDC_NCM_NDP16_NOCRC_SIGN,	\
458 		.nth_size = sizeof(struct usb_cdc_ncm_nth16),	\
459 		.ndp_size = sizeof(struct usb_cdc_ncm_ndp16),	\
460 		.dpe_size = sizeof(struct usb_cdc_ncm_dpe16),	\
461 		.ndplen_align = 4,				\
462 		.dgram_item_len = 1,				\
463 		.block_length = 1,				\
464 		.ndp_index = 1,					\
465 		.reserved1 = 0,					\
466 		.reserved2 = 0,					\
467 		.next_ndp_index = 1,				\
468 	}
469 
470 
471 #define INIT_NDP32_OPTS {					\
472 		.nth_sign = USB_CDC_NCM_NTH32_SIGN,		\
473 		.ndp_sign = USB_CDC_NCM_NDP32_NOCRC_SIGN,	\
474 		.nth_size = sizeof(struct usb_cdc_ncm_nth32),	\
475 		.ndp_size = sizeof(struct usb_cdc_ncm_ndp32),	\
476 		.dpe_size = sizeof(struct usb_cdc_ncm_dpe32),	\
477 		.ndplen_align = 8,				\
478 		.dgram_item_len = 2,				\
479 		.block_length = 2,				\
480 		.ndp_index = 2,					\
481 		.reserved1 = 1,					\
482 		.reserved2 = 2,					\
483 		.next_ndp_index = 2,				\
484 	}
485 
486 static const struct ndp_parser_opts ndp16_opts = INIT_NDP16_OPTS;
487 static const struct ndp_parser_opts ndp32_opts = INIT_NDP32_OPTS;
488 
489 static inline void put_ncm(__le16 **p, unsigned size, unsigned val)
490 {
491 	switch (size) {
492 	case 1:
493 		put_unaligned_le16((u16)val, *p);
494 		break;
495 	case 2:
496 		put_unaligned_le32((u32)val, *p);
497 
498 		break;
499 	default:
500 		BUG();
501 	}
502 
503 	*p += size;
504 }
505 
506 static inline unsigned get_ncm(__le16 **p, unsigned size)
507 {
508 	unsigned tmp;
509 
510 	switch (size) {
511 	case 1:
512 		tmp = get_unaligned_le16(*p);
513 		break;
514 	case 2:
515 		tmp = get_unaligned_le32(*p);
516 		break;
517 	default:
518 		BUG();
519 	}
520 
521 	*p += size;
522 	return tmp;
523 }
524 
525 /*-------------------------------------------------------------------------*/
526 
527 static inline void ncm_reset_values(struct f_ncm *ncm)
528 {
529 	ncm->parser_opts = &ndp16_opts;
530 	ncm->is_crc = false;
531 	ncm->ndp_sign = ncm->parser_opts->ndp_sign;
532 	ncm->port.cdc_filter = DEFAULT_FILTER;
533 
534 	/* doesn't make sense for ncm, fixed size used */
535 	ncm->port.header_len = 0;
536 
537 	ncm->port.fixed_out_len = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
538 	ncm->port.fixed_in_len = NTB_DEFAULT_IN_SIZE;
539 }
540 
541 /*
542  * Context: ncm->lock held
543  */
544 static void ncm_do_notify(struct f_ncm *ncm)
545 {
546 	struct usb_request		*req = ncm->notify_req;
547 	struct usb_cdc_notification	*event;
548 	struct usb_composite_dev	*cdev = ncm->port.func.config->cdev;
549 	__le32				*data;
550 	int				status;
551 
552 	/* notification already in flight? */
553 	if (atomic_read(&ncm->notify_count))
554 		return;
555 
556 	event = req->buf;
557 	switch (ncm->notify_state) {
558 	case NCM_NOTIFY_NONE:
559 		return;
560 
561 	case NCM_NOTIFY_CONNECT:
562 		event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
563 		if (ncm->is_open)
564 			event->wValue = cpu_to_le16(1);
565 		else
566 			event->wValue = cpu_to_le16(0);
567 		event->wLength = 0;
568 		req->length = sizeof *event;
569 
570 		DBG(cdev, "notify connect %s\n",
571 				ncm->is_open ? "true" : "false");
572 		ncm->notify_state = NCM_NOTIFY_NONE;
573 		break;
574 
575 	case NCM_NOTIFY_SPEED:
576 		event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
577 		event->wValue = cpu_to_le16(0);
578 		event->wLength = cpu_to_le16(8);
579 		req->length = NCM_STATUS_BYTECOUNT;
580 
581 		/* SPEED_CHANGE data is up/down speeds in bits/sec */
582 		data = req->buf + sizeof *event;
583 		data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));
584 		data[1] = data[0];
585 
586 		DBG(cdev, "notify speed %d\n", ncm_bitrate(cdev->gadget));
587 		ncm->notify_state = NCM_NOTIFY_CONNECT;
588 		break;
589 	}
590 	event->bmRequestType = 0xA1;
591 	event->wIndex = cpu_to_le16(ncm->ctrl_id);
592 
593 	atomic_inc(&ncm->notify_count);
594 
595 	/*
596 	 * In double buffering if there is a space in FIFO,
597 	 * completion callback can be called right after the call,
598 	 * so unlocking
599 	 */
600 	spin_unlock(&ncm->lock);
601 	status = usb_ep_queue(ncm->notify, req, GFP_ATOMIC);
602 	spin_lock(&ncm->lock);
603 	if (status < 0) {
604 		atomic_dec(&ncm->notify_count);
605 		DBG(cdev, "notify --> %d\n", status);
606 	}
607 }
608 
609 /*
610  * Context: ncm->lock held
611  */
612 static void ncm_notify(struct f_ncm *ncm)
613 {
614 	/*
615 	 * NOTE on most versions of Linux, host side cdc-ethernet
616 	 * won't listen for notifications until its netdevice opens.
617 	 * The first notification then sits in the FIFO for a long
618 	 * time, and the second one is queued.
619 	 *
620 	 * If ncm_notify() is called before the second (CONNECT)
621 	 * notification is sent, then it will reset to send the SPEED
622 	 * notificaion again (and again, and again), but it's not a problem
623 	 */
624 	ncm->notify_state = NCM_NOTIFY_SPEED;
625 	ncm_do_notify(ncm);
626 }
627 
628 static void ncm_notify_complete(struct usb_ep *ep, struct usb_request *req)
629 {
630 	struct f_ncm			*ncm = req->context;
631 	struct usb_composite_dev	*cdev = ncm->port.func.config->cdev;
632 	struct usb_cdc_notification	*event = req->buf;
633 
634 	spin_lock(&ncm->lock);
635 	switch (req->status) {
636 	case 0:
637 		VDBG(cdev, "Notification %02x sent\n",
638 		     event->bNotificationType);
639 		atomic_dec(&ncm->notify_count);
640 		break;
641 	case -ECONNRESET:
642 	case -ESHUTDOWN:
643 		atomic_set(&ncm->notify_count, 0);
644 		ncm->notify_state = NCM_NOTIFY_NONE;
645 		break;
646 	default:
647 		DBG(cdev, "event %02x --> %d\n",
648 			event->bNotificationType, req->status);
649 		atomic_dec(&ncm->notify_count);
650 		break;
651 	}
652 	ncm_do_notify(ncm);
653 	spin_unlock(&ncm->lock);
654 }
655 
656 static void ncm_ep0out_complete(struct usb_ep *ep, struct usb_request *req)
657 {
658 	/* now for SET_NTB_INPUT_SIZE only */
659 	unsigned		in_size;
660 	struct usb_function	*f = req->context;
661 	struct f_ncm		*ncm = func_to_ncm(f);
662 	struct usb_composite_dev *cdev = f->config->cdev;
663 
664 	req->context = NULL;
665 	if (req->status || req->actual != req->length) {
666 		DBG(cdev, "Bad control-OUT transfer\n");
667 		goto invalid;
668 	}
669 
670 	in_size = get_unaligned_le32(req->buf);
671 	if (in_size < USB_CDC_NCM_NTB_MIN_IN_SIZE ||
672 	    in_size > le32_to_cpu(ntb_parameters.dwNtbInMaxSize)) {
673 		DBG(cdev, "Got wrong INPUT SIZE (%d) from host\n", in_size);
674 		goto invalid;
675 	}
676 
677 	ncm->port.fixed_in_len = in_size;
678 	VDBG(cdev, "Set NTB INPUT SIZE %d\n", in_size);
679 	return;
680 
681 invalid:
682 	usb_ep_set_halt(ep);
683 	return;
684 }
685 
686 static int ncm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
687 {
688 	struct f_ncm		*ncm = func_to_ncm(f);
689 	struct usb_composite_dev *cdev = f->config->cdev;
690 	struct usb_request	*req = cdev->req;
691 	int			value = -EOPNOTSUPP;
692 	u16			w_index = le16_to_cpu(ctrl->wIndex);
693 	u16			w_value = le16_to_cpu(ctrl->wValue);
694 	u16			w_length = le16_to_cpu(ctrl->wLength);
695 
696 	/*
697 	 * composite driver infrastructure handles everything except
698 	 * CDC class messages; interface activation uses set_alt().
699 	 */
700 	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
701 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
702 			| USB_CDC_SET_ETHERNET_PACKET_FILTER:
703 		/*
704 		 * see 6.2.30: no data, wIndex = interface,
705 		 * wValue = packet filter bitmap
706 		 */
707 		if (w_length != 0 || w_index != ncm->ctrl_id)
708 			goto invalid;
709 		DBG(cdev, "packet filter %02x\n", w_value);
710 		/*
711 		 * REVISIT locking of cdc_filter.  This assumes the UDC
712 		 * driver won't have a concurrent packet TX irq running on
713 		 * another CPU; or that if it does, this write is atomic...
714 		 */
715 		ncm->port.cdc_filter = w_value;
716 		value = 0;
717 		break;
718 	/*
719 	 * and optionally:
720 	 * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
721 	 * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
722 	 * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
723 	 * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
724 	 * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
725 	 * case USB_CDC_GET_ETHERNET_STATISTIC:
726 	 */
727 
728 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
729 		| USB_CDC_GET_NTB_PARAMETERS:
730 
731 		if (w_length == 0 || w_value != 0 || w_index != ncm->ctrl_id)
732 			goto invalid;
733 		value = w_length > sizeof ntb_parameters ?
734 			sizeof ntb_parameters : w_length;
735 		memcpy(req->buf, &ntb_parameters, value);
736 		VDBG(cdev, "Host asked NTB parameters\n");
737 		break;
738 
739 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
740 		| USB_CDC_GET_NTB_INPUT_SIZE:
741 
742 		if (w_length < 4 || w_value != 0 || w_index != ncm->ctrl_id)
743 			goto invalid;
744 		put_unaligned_le32(ncm->port.fixed_in_len, req->buf);
745 		value = 4;
746 		VDBG(cdev, "Host asked INPUT SIZE, sending %d\n",
747 		     ncm->port.fixed_in_len);
748 		break;
749 
750 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
751 		| USB_CDC_SET_NTB_INPUT_SIZE:
752 	{
753 		if (w_length != 4 || w_value != 0 || w_index != ncm->ctrl_id)
754 			goto invalid;
755 		req->complete = ncm_ep0out_complete;
756 		req->length = w_length;
757 		req->context = f;
758 
759 		value = req->length;
760 		break;
761 	}
762 
763 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
764 		| USB_CDC_GET_NTB_FORMAT:
765 	{
766 		uint16_t format;
767 
768 		if (w_length < 2 || w_value != 0 || w_index != ncm->ctrl_id)
769 			goto invalid;
770 		format = (ncm->parser_opts == &ndp16_opts) ? 0x0000 : 0x0001;
771 		put_unaligned_le16(format, req->buf);
772 		value = 2;
773 		VDBG(cdev, "Host asked NTB FORMAT, sending %d\n", format);
774 		break;
775 	}
776 
777 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
778 		| USB_CDC_SET_NTB_FORMAT:
779 	{
780 		if (w_length != 0 || w_index != ncm->ctrl_id)
781 			goto invalid;
782 		switch (w_value) {
783 		case 0x0000:
784 			ncm->parser_opts = &ndp16_opts;
785 			DBG(cdev, "NCM16 selected\n");
786 			break;
787 		case 0x0001:
788 			ncm->parser_opts = &ndp32_opts;
789 			DBG(cdev, "NCM32 selected\n");
790 			break;
791 		default:
792 			goto invalid;
793 		}
794 		value = 0;
795 		break;
796 	}
797 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
798 		| USB_CDC_GET_CRC_MODE:
799 	{
800 		uint16_t is_crc;
801 
802 		if (w_length < 2 || w_value != 0 || w_index != ncm->ctrl_id)
803 			goto invalid;
804 		is_crc = ncm->is_crc ? 0x0001 : 0x0000;
805 		put_unaligned_le16(is_crc, req->buf);
806 		value = 2;
807 		VDBG(cdev, "Host asked CRC MODE, sending %d\n", is_crc);
808 		break;
809 	}
810 
811 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
812 		| USB_CDC_SET_CRC_MODE:
813 	{
814 		if (w_length != 0 || w_index != ncm->ctrl_id)
815 			goto invalid;
816 		switch (w_value) {
817 		case 0x0000:
818 			ncm->is_crc = false;
819 			DBG(cdev, "non-CRC mode selected\n");
820 			break;
821 		case 0x0001:
822 			ncm->is_crc = true;
823 			DBG(cdev, "CRC mode selected\n");
824 			break;
825 		default:
826 			goto invalid;
827 		}
828 		value = 0;
829 		break;
830 	}
831 
832 	/* and disabled in ncm descriptor: */
833 	/* case USB_CDC_GET_NET_ADDRESS: */
834 	/* case USB_CDC_SET_NET_ADDRESS: */
835 	/* case USB_CDC_GET_MAX_DATAGRAM_SIZE: */
836 	/* case USB_CDC_SET_MAX_DATAGRAM_SIZE: */
837 
838 	default:
839 invalid:
840 		DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
841 			ctrl->bRequestType, ctrl->bRequest,
842 			w_value, w_index, w_length);
843 	}
844 	ncm->ndp_sign = ncm->parser_opts->ndp_sign |
845 		(ncm->is_crc ? NCM_NDP_HDR_CRC : 0);
846 
847 	/* respond with data transfer or status phase? */
848 	if (value >= 0) {
849 		DBG(cdev, "ncm req%02x.%02x v%04x i%04x l%d\n",
850 			ctrl->bRequestType, ctrl->bRequest,
851 			w_value, w_index, w_length);
852 		req->zero = 0;
853 		req->length = value;
854 		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
855 		if (value < 0)
856 			ERROR(cdev, "ncm req %02x.%02x response err %d\n",
857 					ctrl->bRequestType, ctrl->bRequest,
858 					value);
859 	}
860 
861 	/* device either stalls (value < 0) or reports success */
862 	return value;
863 }
864 
865 
866 static int ncm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
867 {
868 	struct f_ncm		*ncm = func_to_ncm(f);
869 	struct usb_composite_dev *cdev = f->config->cdev;
870 
871 	/* Control interface has only altsetting 0 */
872 	if (intf == ncm->ctrl_id) {
873 		if (alt != 0)
874 			goto fail;
875 
876 		DBG(cdev, "reset ncm control %d\n", intf);
877 		usb_ep_disable(ncm->notify);
878 
879 		if (!(ncm->notify->desc)) {
880 			DBG(cdev, "init ncm ctrl %d\n", intf);
881 			if (config_ep_by_speed(cdev->gadget, f, ncm->notify))
882 				goto fail;
883 		}
884 		usb_ep_enable(ncm->notify);
885 
886 	/* Data interface has two altsettings, 0 and 1 */
887 	} else if (intf == ncm->data_id) {
888 		if (alt > 1)
889 			goto fail;
890 
891 		if (ncm->port.in_ep->enabled) {
892 			DBG(cdev, "reset ncm\n");
893 			ncm->timer_stopping = true;
894 			ncm->netdev = NULL;
895 			gether_disconnect(&ncm->port);
896 			ncm_reset_values(ncm);
897 		}
898 
899 		/*
900 		 * CDC Network only sends data in non-default altsettings.
901 		 * Changing altsettings resets filters, statistics, etc.
902 		 */
903 		if (alt == 1) {
904 			struct net_device	*net;
905 
906 			if (!ncm->port.in_ep->desc ||
907 			    !ncm->port.out_ep->desc) {
908 				DBG(cdev, "init ncm\n");
909 				if (config_ep_by_speed(cdev->gadget, f,
910 						       ncm->port.in_ep) ||
911 				    config_ep_by_speed(cdev->gadget, f,
912 						       ncm->port.out_ep)) {
913 					ncm->port.in_ep->desc = NULL;
914 					ncm->port.out_ep->desc = NULL;
915 					goto fail;
916 				}
917 			}
918 
919 			/* TODO */
920 			/* Enable zlps by default for NCM conformance;
921 			 * override for musb_hdrc (avoids txdma ovhead)
922 			 */
923 			ncm->port.is_zlp_ok =
924 				gadget_is_zlp_supported(cdev->gadget);
925 			ncm->port.cdc_filter = DEFAULT_FILTER;
926 			DBG(cdev, "activate ncm\n");
927 			net = gether_connect(&ncm->port);
928 			if (IS_ERR(net))
929 				return PTR_ERR(net);
930 			ncm->netdev = net;
931 			ncm->timer_stopping = false;
932 		}
933 
934 		spin_lock(&ncm->lock);
935 		ncm_notify(ncm);
936 		spin_unlock(&ncm->lock);
937 	} else
938 		goto fail;
939 
940 	return 0;
941 fail:
942 	return -EINVAL;
943 }
944 
945 /*
946  * Because the data interface supports multiple altsettings,
947  * this NCM function *MUST* implement a get_alt() method.
948  */
949 static int ncm_get_alt(struct usb_function *f, unsigned intf)
950 {
951 	struct f_ncm		*ncm = func_to_ncm(f);
952 
953 	if (intf == ncm->ctrl_id)
954 		return 0;
955 	return ncm->port.in_ep->enabled ? 1 : 0;
956 }
957 
958 static struct sk_buff *package_for_tx(struct f_ncm *ncm)
959 {
960 	__le16		*ntb_iter;
961 	struct sk_buff	*skb2 = NULL;
962 	unsigned	ndp_pad;
963 	unsigned	ndp_index;
964 	unsigned	new_len;
965 
966 	const struct ndp_parser_opts *opts = ncm->parser_opts;
967 	const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
968 	const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
969 
970 	/* Stop the timer */
971 	hrtimer_try_to_cancel(&ncm->task_timer);
972 
973 	ndp_pad = ALIGN(ncm->skb_tx_data->len, ndp_align) -
974 			ncm->skb_tx_data->len;
975 	ndp_index = ncm->skb_tx_data->len + ndp_pad;
976 	new_len = ndp_index + dgram_idx_len + ncm->skb_tx_ndp->len;
977 
978 	/* Set the final BlockLength and wNdpIndex */
979 	ntb_iter = (void *) ncm->skb_tx_data->data;
980 	/* Increment pointer to BlockLength */
981 	ntb_iter += 2 + 1 + 1;
982 	put_ncm(&ntb_iter, opts->block_length, new_len);
983 	put_ncm(&ntb_iter, opts->ndp_index, ndp_index);
984 
985 	/* Set the final NDP wLength */
986 	new_len = opts->ndp_size +
987 			(ncm->ndp_dgram_count * dgram_idx_len);
988 	ncm->ndp_dgram_count = 0;
989 	/* Increment from start to wLength */
990 	ntb_iter = (void *) ncm->skb_tx_ndp->data;
991 	ntb_iter += 2;
992 	put_unaligned_le16(new_len, ntb_iter);
993 
994 	/* Merge the skbs */
995 	swap(skb2, ncm->skb_tx_data);
996 	if (ncm->skb_tx_data) {
997 		dev_consume_skb_any(ncm->skb_tx_data);
998 		ncm->skb_tx_data = NULL;
999 	}
1000 
1001 	/* Insert NDP alignment. */
1002 	skb_put_zero(skb2, ndp_pad);
1003 
1004 	/* Copy NTB across. */
1005 	skb_put_data(skb2, ncm->skb_tx_ndp->data, ncm->skb_tx_ndp->len);
1006 	dev_consume_skb_any(ncm->skb_tx_ndp);
1007 	ncm->skb_tx_ndp = NULL;
1008 
1009 	/* Insert zero'd datagram. */
1010 	skb_put_zero(skb2, dgram_idx_len);
1011 
1012 	return skb2;
1013 }
1014 
1015 static struct sk_buff *ncm_wrap_ntb(struct gether *port,
1016 				    struct sk_buff *skb)
1017 {
1018 	struct f_ncm	*ncm = func_to_ncm(&port->func);
1019 	struct sk_buff	*skb2 = NULL;
1020 	int		ncb_len = 0;
1021 	__le16		*ntb_data;
1022 	__le16		*ntb_ndp;
1023 	int		dgram_pad;
1024 
1025 	unsigned	max_size = ncm->port.fixed_in_len;
1026 	const struct ndp_parser_opts *opts = ncm->parser_opts;
1027 	const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
1028 	const int div = le16_to_cpu(ntb_parameters.wNdpInDivisor);
1029 	const int rem = le16_to_cpu(ntb_parameters.wNdpInPayloadRemainder);
1030 	const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
1031 
1032 	if (!skb && !ncm->skb_tx_data)
1033 		return NULL;
1034 
1035 	if (skb) {
1036 		/* Add the CRC if required up front */
1037 		if (ncm->is_crc) {
1038 			uint32_t	crc;
1039 			__le16		*crc_pos;
1040 
1041 			crc = ~crc32_le(~0,
1042 					skb->data,
1043 					skb->len);
1044 			crc_pos = skb_put(skb, sizeof(uint32_t));
1045 			put_unaligned_le32(crc, crc_pos);
1046 		}
1047 
1048 		/* If the new skb is too big for the current NCM NTB then
1049 		 * set the current stored skb to be sent now and clear it
1050 		 * ready for new data.
1051 		 * NOTE: Assume maximum align for speed of calculation.
1052 		 */
1053 		if (ncm->skb_tx_data
1054 		    && (ncm->ndp_dgram_count >= TX_MAX_NUM_DPE
1055 		    || (ncm->skb_tx_data->len +
1056 		    div + rem + skb->len +
1057 		    ncm->skb_tx_ndp->len + ndp_align + (2 * dgram_idx_len))
1058 		    > max_size)) {
1059 			skb2 = package_for_tx(ncm);
1060 			if (!skb2)
1061 				goto err;
1062 		}
1063 
1064 		if (!ncm->skb_tx_data) {
1065 			ncb_len = opts->nth_size;
1066 			dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
1067 			ncb_len += dgram_pad;
1068 
1069 			/* Create a new skb for the NTH and datagrams. */
1070 			ncm->skb_tx_data = alloc_skb(max_size, GFP_ATOMIC);
1071 			if (!ncm->skb_tx_data)
1072 				goto err;
1073 
1074 			ncm->skb_tx_data->dev = ncm->netdev;
1075 			ntb_data = skb_put_zero(ncm->skb_tx_data, ncb_len);
1076 			/* dwSignature */
1077 			put_unaligned_le32(opts->nth_sign, ntb_data);
1078 			ntb_data += 2;
1079 			/* wHeaderLength */
1080 			put_unaligned_le16(opts->nth_size, ntb_data++);
1081 
1082 			/* Allocate an skb for storing the NDP,
1083 			 * TX_MAX_NUM_DPE should easily suffice for a
1084 			 * 16k packet.
1085 			 */
1086 			ncm->skb_tx_ndp = alloc_skb((int)(opts->ndp_size
1087 						    + opts->dpe_size
1088 						    * TX_MAX_NUM_DPE),
1089 						    GFP_ATOMIC);
1090 			if (!ncm->skb_tx_ndp)
1091 				goto err;
1092 
1093 			ncm->skb_tx_ndp->dev = ncm->netdev;
1094 			ntb_ndp = skb_put(ncm->skb_tx_ndp, opts->ndp_size);
1095 			memset(ntb_ndp, 0, ncb_len);
1096 			/* dwSignature */
1097 			put_unaligned_le32(ncm->ndp_sign, ntb_ndp);
1098 			ntb_ndp += 2;
1099 
1100 			/* There is always a zeroed entry */
1101 			ncm->ndp_dgram_count = 1;
1102 
1103 			/* Note: we skip opts->next_ndp_index */
1104 		}
1105 
1106 		/* Delay the timer. */
1107 		hrtimer_start(&ncm->task_timer, TX_TIMEOUT_NSECS,
1108 			      HRTIMER_MODE_REL_SOFT);
1109 
1110 		/* Add the datagram position entries */
1111 		ntb_ndp = skb_put_zero(ncm->skb_tx_ndp, dgram_idx_len);
1112 
1113 		ncb_len = ncm->skb_tx_data->len;
1114 		dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
1115 		ncb_len += dgram_pad;
1116 
1117 		/* (d)wDatagramIndex */
1118 		put_ncm(&ntb_ndp, opts->dgram_item_len, ncb_len);
1119 		/* (d)wDatagramLength */
1120 		put_ncm(&ntb_ndp, opts->dgram_item_len, skb->len);
1121 		ncm->ndp_dgram_count++;
1122 
1123 		/* Add the new data to the skb */
1124 		skb_put_zero(ncm->skb_tx_data, dgram_pad);
1125 		skb_put_data(ncm->skb_tx_data, skb->data, skb->len);
1126 		dev_consume_skb_any(skb);
1127 		skb = NULL;
1128 
1129 	} else if (ncm->skb_tx_data && ncm->timer_force_tx) {
1130 		/* If the tx was requested because of a timeout then send */
1131 		skb2 = package_for_tx(ncm);
1132 		if (!skb2)
1133 			goto err;
1134 	}
1135 
1136 	return skb2;
1137 
1138 err:
1139 	ncm->netdev->stats.tx_dropped++;
1140 
1141 	if (skb)
1142 		dev_kfree_skb_any(skb);
1143 	if (ncm->skb_tx_data)
1144 		dev_kfree_skb_any(ncm->skb_tx_data);
1145 	if (ncm->skb_tx_ndp)
1146 		dev_kfree_skb_any(ncm->skb_tx_ndp);
1147 
1148 	return NULL;
1149 }
1150 
1151 /*
1152  * The transmit should only be run if no skb data has been sent
1153  * for a certain duration.
1154  */
1155 static enum hrtimer_restart ncm_tx_timeout(struct hrtimer *data)
1156 {
1157 	struct f_ncm *ncm = container_of(data, struct f_ncm, task_timer);
1158 
1159 	/* Only send if data is available. */
1160 	if (!ncm->timer_stopping && ncm->skb_tx_data) {
1161 		ncm->timer_force_tx = true;
1162 
1163 		/* XXX This allowance of a NULL skb argument to ndo_start_xmit
1164 		 * XXX is not sane.  The gadget layer should be redesigned so
1165 		 * XXX that the dev->wrap() invocations to build SKBs is transparent
1166 		 * XXX and performed in some way outside of the ndo_start_xmit
1167 		 * XXX interface.
1168 		 */
1169 		ncm->netdev->netdev_ops->ndo_start_xmit(NULL, ncm->netdev);
1170 
1171 		ncm->timer_force_tx = false;
1172 	}
1173 	return HRTIMER_NORESTART;
1174 }
1175 
1176 static int ncm_unwrap_ntb(struct gether *port,
1177 			  struct sk_buff *skb,
1178 			  struct sk_buff_head *list)
1179 {
1180 	struct f_ncm	*ncm = func_to_ncm(&port->func);
1181 	__le16		*tmp = (void *) skb->data;
1182 	unsigned	index, index2;
1183 	int		ndp_index;
1184 	unsigned	dg_len, dg_len2;
1185 	unsigned	ndp_len;
1186 	unsigned	block_len;
1187 	struct sk_buff	*skb2;
1188 	int		ret = -EINVAL;
1189 	unsigned	ntb_max = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
1190 	unsigned	frame_max = le16_to_cpu(ecm_desc.wMaxSegmentSize);
1191 	const struct ndp_parser_opts *opts = ncm->parser_opts;
1192 	unsigned	crc_len = ncm->is_crc ? sizeof(uint32_t) : 0;
1193 	int		dgram_counter;
1194 
1195 	/* dwSignature */
1196 	if (get_unaligned_le32(tmp) != opts->nth_sign) {
1197 		INFO(port->func.config->cdev, "Wrong NTH SIGN, skblen %d\n",
1198 			skb->len);
1199 		print_hex_dump(KERN_INFO, "HEAD:", DUMP_PREFIX_ADDRESS, 32, 1,
1200 			       skb->data, 32, false);
1201 
1202 		goto err;
1203 	}
1204 	tmp += 2;
1205 	/* wHeaderLength */
1206 	if (get_unaligned_le16(tmp++) != opts->nth_size) {
1207 		INFO(port->func.config->cdev, "Wrong NTB headersize\n");
1208 		goto err;
1209 	}
1210 	tmp++; /* skip wSequence */
1211 
1212 	block_len = get_ncm(&tmp, opts->block_length);
1213 	/* (d)wBlockLength */
1214 	if (block_len > ntb_max) {
1215 		INFO(port->func.config->cdev, "OUT size exceeded\n");
1216 		goto err;
1217 	}
1218 
1219 	ndp_index = get_ncm(&tmp, opts->ndp_index);
1220 
1221 	/* Run through all the NDP's in the NTB */
1222 	do {
1223 		/*
1224 		 * NCM 3.2
1225 		 * dwNdpIndex
1226 		 */
1227 		if (((ndp_index % 4) != 0) ||
1228 				(ndp_index < opts->nth_size) ||
1229 				(ndp_index > (block_len -
1230 					      opts->ndp_size))) {
1231 			INFO(port->func.config->cdev, "Bad index: %#X\n",
1232 			     ndp_index);
1233 			goto err;
1234 		}
1235 
1236 		/*
1237 		 * walk through NDP
1238 		 * dwSignature
1239 		 */
1240 		tmp = (void *)(skb->data + ndp_index);
1241 		if (get_unaligned_le32(tmp) != ncm->ndp_sign) {
1242 			INFO(port->func.config->cdev, "Wrong NDP SIGN\n");
1243 			goto err;
1244 		}
1245 		tmp += 2;
1246 
1247 		ndp_len = get_unaligned_le16(tmp++);
1248 		/*
1249 		 * NCM 3.3.1
1250 		 * wLength
1251 		 * entry is 2 items
1252 		 * item size is 16/32 bits, opts->dgram_item_len * 2 bytes
1253 		 * minimal: struct usb_cdc_ncm_ndpX + normal entry + zero entry
1254 		 * Each entry is a dgram index and a dgram length.
1255 		 */
1256 		if ((ndp_len < opts->ndp_size
1257 				+ 2 * 2 * (opts->dgram_item_len * 2)) ||
1258 				(ndp_len % opts->ndplen_align != 0)) {
1259 			INFO(port->func.config->cdev, "Bad NDP length: %#X\n",
1260 			     ndp_len);
1261 			goto err;
1262 		}
1263 		tmp += opts->reserved1;
1264 		/* Check for another NDP (d)wNextNdpIndex */
1265 		ndp_index = get_ncm(&tmp, opts->next_ndp_index);
1266 		tmp += opts->reserved2;
1267 
1268 		ndp_len -= opts->ndp_size;
1269 		index2 = get_ncm(&tmp, opts->dgram_item_len);
1270 		dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
1271 		dgram_counter = 0;
1272 
1273 		do {
1274 			index = index2;
1275 			/* wDatagramIndex[0] */
1276 			if ((index < opts->nth_size) ||
1277 					(index > block_len - opts->dpe_size)) {
1278 				INFO(port->func.config->cdev,
1279 				     "Bad index: %#X\n", index);
1280 				goto err;
1281 			}
1282 
1283 			dg_len = dg_len2;
1284 			/*
1285 			 * wDatagramLength[0]
1286 			 * ethernet hdr + crc or larger than max frame size
1287 			 */
1288 			if ((dg_len < 14 + crc_len) ||
1289 					(dg_len > frame_max)) {
1290 				INFO(port->func.config->cdev,
1291 				     "Bad dgram length: %#X\n", dg_len);
1292 				goto err;
1293 			}
1294 			if (ncm->is_crc) {
1295 				uint32_t crc, crc2;
1296 
1297 				crc = get_unaligned_le32(skb->data +
1298 							 index + dg_len -
1299 							 crc_len);
1300 				crc2 = ~crc32_le(~0,
1301 						 skb->data + index,
1302 						 dg_len - crc_len);
1303 				if (crc != crc2) {
1304 					INFO(port->func.config->cdev,
1305 					     "Bad CRC\n");
1306 					goto err;
1307 				}
1308 			}
1309 
1310 			index2 = get_ncm(&tmp, opts->dgram_item_len);
1311 			dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
1312 
1313 			/* wDatagramIndex[1] */
1314 			if (index2 > block_len - opts->dpe_size) {
1315 				INFO(port->func.config->cdev,
1316 				     "Bad index: %#X\n", index2);
1317 				goto err;
1318 			}
1319 
1320 			/*
1321 			 * Copy the data into a new skb.
1322 			 * This ensures the truesize is correct
1323 			 */
1324 			skb2 = netdev_alloc_skb_ip_align(ncm->netdev,
1325 							 dg_len - crc_len);
1326 			if (skb2 == NULL)
1327 				goto err;
1328 			skb_put_data(skb2, skb->data + index,
1329 				     dg_len - crc_len);
1330 
1331 			skb_queue_tail(list, skb2);
1332 
1333 			ndp_len -= 2 * (opts->dgram_item_len * 2);
1334 
1335 			dgram_counter++;
1336 			if (index2 == 0 || dg_len2 == 0)
1337 				break;
1338 		} while (ndp_len > 2 * (opts->dgram_item_len * 2));
1339 	} while (ndp_index);
1340 
1341 	dev_consume_skb_any(skb);
1342 
1343 	VDBG(port->func.config->cdev,
1344 	     "Parsed NTB with %d frames\n", dgram_counter);
1345 	return 0;
1346 err:
1347 	skb_queue_purge(list);
1348 	dev_kfree_skb_any(skb);
1349 	return ret;
1350 }
1351 
1352 static void ncm_disable(struct usb_function *f)
1353 {
1354 	struct f_ncm		*ncm = func_to_ncm(f);
1355 	struct usb_composite_dev *cdev = f->config->cdev;
1356 
1357 	DBG(cdev, "ncm deactivated\n");
1358 
1359 	if (ncm->port.in_ep->enabled) {
1360 		ncm->timer_stopping = true;
1361 		ncm->netdev = NULL;
1362 		gether_disconnect(&ncm->port);
1363 	}
1364 
1365 	if (ncm->notify->enabled) {
1366 		usb_ep_disable(ncm->notify);
1367 		ncm->notify->desc = NULL;
1368 	}
1369 }
1370 
1371 /*-------------------------------------------------------------------------*/
1372 
1373 /*
1374  * Callbacks let us notify the host about connect/disconnect when the
1375  * net device is opened or closed.
1376  *
1377  * For testing, note that link states on this side include both opened
1378  * and closed variants of:
1379  *
1380  *   - disconnected/unconfigured
1381  *   - configured but inactive (data alt 0)
1382  *   - configured and active (data alt 1)
1383  *
1384  * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
1385  * SET_INTERFACE (altsetting).  Remember also that "configured" doesn't
1386  * imply the host is actually polling the notification endpoint, and
1387  * likewise that "active" doesn't imply it's actually using the data
1388  * endpoints for traffic.
1389  */
1390 
1391 static void ncm_open(struct gether *geth)
1392 {
1393 	struct f_ncm		*ncm = func_to_ncm(&geth->func);
1394 
1395 	DBG(ncm->port.func.config->cdev, "%s\n", __func__);
1396 
1397 	spin_lock(&ncm->lock);
1398 	ncm->is_open = true;
1399 	ncm_notify(ncm);
1400 	spin_unlock(&ncm->lock);
1401 }
1402 
1403 static void ncm_close(struct gether *geth)
1404 {
1405 	struct f_ncm		*ncm = func_to_ncm(&geth->func);
1406 
1407 	DBG(ncm->port.func.config->cdev, "%s\n", __func__);
1408 
1409 	spin_lock(&ncm->lock);
1410 	ncm->is_open = false;
1411 	ncm_notify(ncm);
1412 	spin_unlock(&ncm->lock);
1413 }
1414 
1415 /*-------------------------------------------------------------------------*/
1416 
1417 /* ethernet function driver setup/binding */
1418 
1419 static int ncm_bind(struct usb_configuration *c, struct usb_function *f)
1420 {
1421 	struct usb_composite_dev *cdev = c->cdev;
1422 	struct f_ncm		*ncm = func_to_ncm(f);
1423 	struct usb_string	*us;
1424 	int			status;
1425 	struct usb_ep		*ep;
1426 	struct f_ncm_opts	*ncm_opts;
1427 
1428 	if (!can_support_ecm(cdev->gadget))
1429 		return -EINVAL;
1430 
1431 	ncm_opts = container_of(f->fi, struct f_ncm_opts, func_inst);
1432 
1433 	if (cdev->use_os_string) {
1434 		f->os_desc_table = kzalloc(sizeof(*f->os_desc_table),
1435 					   GFP_KERNEL);
1436 		if (!f->os_desc_table)
1437 			return -ENOMEM;
1438 		f->os_desc_n = 1;
1439 		f->os_desc_table[0].os_desc = &ncm_opts->ncm_os_desc;
1440 	}
1441 
1442 	/*
1443 	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
1444 	 * configurations are bound in sequence with list_for_each_entry,
1445 	 * in each configuration its functions are bound in sequence
1446 	 * with list_for_each_entry, so we assume no race condition
1447 	 * with regard to ncm_opts->bound access
1448 	 */
1449 	if (!ncm_opts->bound) {
1450 		mutex_lock(&ncm_opts->lock);
1451 		gether_set_gadget(ncm_opts->net, cdev->gadget);
1452 		status = gether_register_netdev(ncm_opts->net);
1453 		mutex_unlock(&ncm_opts->lock);
1454 		if (status)
1455 			goto fail;
1456 		ncm_opts->bound = true;
1457 	}
1458 	us = usb_gstrings_attach(cdev, ncm_strings,
1459 				 ARRAY_SIZE(ncm_string_defs));
1460 	if (IS_ERR(us)) {
1461 		status = PTR_ERR(us);
1462 		goto fail;
1463 	}
1464 	ncm_control_intf.iInterface = us[STRING_CTRL_IDX].id;
1465 	ncm_data_nop_intf.iInterface = us[STRING_DATA_IDX].id;
1466 	ncm_data_intf.iInterface = us[STRING_DATA_IDX].id;
1467 	ecm_desc.iMACAddress = us[STRING_MAC_IDX].id;
1468 	ncm_iad_desc.iFunction = us[STRING_IAD_IDX].id;
1469 
1470 	/* allocate instance-specific interface IDs */
1471 	status = usb_interface_id(c, f);
1472 	if (status < 0)
1473 		goto fail;
1474 	ncm->ctrl_id = status;
1475 	ncm_iad_desc.bFirstInterface = status;
1476 
1477 	ncm_control_intf.bInterfaceNumber = status;
1478 	ncm_union_desc.bMasterInterface0 = status;
1479 
1480 	if (cdev->use_os_string)
1481 		f->os_desc_table[0].if_id =
1482 			ncm_iad_desc.bFirstInterface;
1483 
1484 	status = usb_interface_id(c, f);
1485 	if (status < 0)
1486 		goto fail;
1487 	ncm->data_id = status;
1488 
1489 	ncm_data_nop_intf.bInterfaceNumber = status;
1490 	ncm_data_intf.bInterfaceNumber = status;
1491 	ncm_union_desc.bSlaveInterface0 = status;
1492 
1493 	status = -ENODEV;
1494 
1495 	/* allocate instance-specific endpoints */
1496 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_in_desc);
1497 	if (!ep)
1498 		goto fail;
1499 	ncm->port.in_ep = ep;
1500 
1501 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_out_desc);
1502 	if (!ep)
1503 		goto fail;
1504 	ncm->port.out_ep = ep;
1505 
1506 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_notify_desc);
1507 	if (!ep)
1508 		goto fail;
1509 	ncm->notify = ep;
1510 
1511 	status = -ENOMEM;
1512 
1513 	/* allocate notification request and buffer */
1514 	ncm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
1515 	if (!ncm->notify_req)
1516 		goto fail;
1517 	ncm->notify_req->buf = kmalloc(NCM_STATUS_BYTECOUNT, GFP_KERNEL);
1518 	if (!ncm->notify_req->buf)
1519 		goto fail;
1520 	ncm->notify_req->context = ncm;
1521 	ncm->notify_req->complete = ncm_notify_complete;
1522 
1523 	/*
1524 	 * support all relevant hardware speeds... we expect that when
1525 	 * hardware is dual speed, all bulk-capable endpoints work at
1526 	 * both speeds
1527 	 */
1528 	hs_ncm_in_desc.bEndpointAddress = fs_ncm_in_desc.bEndpointAddress;
1529 	hs_ncm_out_desc.bEndpointAddress = fs_ncm_out_desc.bEndpointAddress;
1530 	hs_ncm_notify_desc.bEndpointAddress =
1531 		fs_ncm_notify_desc.bEndpointAddress;
1532 
1533 	ss_ncm_in_desc.bEndpointAddress = fs_ncm_in_desc.bEndpointAddress;
1534 	ss_ncm_out_desc.bEndpointAddress = fs_ncm_out_desc.bEndpointAddress;
1535 	ss_ncm_notify_desc.bEndpointAddress =
1536 		fs_ncm_notify_desc.bEndpointAddress;
1537 
1538 	status = usb_assign_descriptors(f, ncm_fs_function, ncm_hs_function,
1539 			ncm_ss_function, ncm_ss_function);
1540 	if (status)
1541 		goto fail;
1542 
1543 	/*
1544 	 * NOTE:  all that is done without knowing or caring about
1545 	 * the network link ... which is unavailable to this code
1546 	 * until we're activated via set_alt().
1547 	 */
1548 
1549 	ncm->port.open = ncm_open;
1550 	ncm->port.close = ncm_close;
1551 
1552 	hrtimer_init(&ncm->task_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
1553 	ncm->task_timer.function = ncm_tx_timeout;
1554 
1555 	DBG(cdev, "CDC Network: %s speed IN/%s OUT/%s NOTIFY/%s\n",
1556 			gadget_is_superspeed(c->cdev->gadget) ? "super" :
1557 			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
1558 			ncm->port.in_ep->name, ncm->port.out_ep->name,
1559 			ncm->notify->name);
1560 	return 0;
1561 
1562 fail:
1563 	kfree(f->os_desc_table);
1564 	f->os_desc_n = 0;
1565 
1566 	if (ncm->notify_req) {
1567 		kfree(ncm->notify_req->buf);
1568 		usb_ep_free_request(ncm->notify, ncm->notify_req);
1569 	}
1570 
1571 	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
1572 
1573 	return status;
1574 }
1575 
1576 static inline struct f_ncm_opts *to_f_ncm_opts(struct config_item *item)
1577 {
1578 	return container_of(to_config_group(item), struct f_ncm_opts,
1579 			    func_inst.group);
1580 }
1581 
1582 /* f_ncm_item_ops */
1583 USB_ETHERNET_CONFIGFS_ITEM(ncm);
1584 
1585 /* f_ncm_opts_dev_addr */
1586 USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ncm);
1587 
1588 /* f_ncm_opts_host_addr */
1589 USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ncm);
1590 
1591 /* f_ncm_opts_qmult */
1592 USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ncm);
1593 
1594 /* f_ncm_opts_ifname */
1595 USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ncm);
1596 
1597 static struct configfs_attribute *ncm_attrs[] = {
1598 	&ncm_opts_attr_dev_addr,
1599 	&ncm_opts_attr_host_addr,
1600 	&ncm_opts_attr_qmult,
1601 	&ncm_opts_attr_ifname,
1602 	NULL,
1603 };
1604 
1605 static const struct config_item_type ncm_func_type = {
1606 	.ct_item_ops	= &ncm_item_ops,
1607 	.ct_attrs	= ncm_attrs,
1608 	.ct_owner	= THIS_MODULE,
1609 };
1610 
1611 static void ncm_free_inst(struct usb_function_instance *f)
1612 {
1613 	struct f_ncm_opts *opts;
1614 
1615 	opts = container_of(f, struct f_ncm_opts, func_inst);
1616 	if (opts->bound)
1617 		gether_cleanup(netdev_priv(opts->net));
1618 	else
1619 		free_netdev(opts->net);
1620 	kfree(opts->ncm_interf_group);
1621 	kfree(opts);
1622 }
1623 
1624 static struct usb_function_instance *ncm_alloc_inst(void)
1625 {
1626 	struct f_ncm_opts *opts;
1627 	struct usb_os_desc *descs[1];
1628 	char *names[1];
1629 	struct config_group *ncm_interf_group;
1630 
1631 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1632 	if (!opts)
1633 		return ERR_PTR(-ENOMEM);
1634 	opts->ncm_os_desc.ext_compat_id = opts->ncm_ext_compat_id;
1635 
1636 	mutex_init(&opts->lock);
1637 	opts->func_inst.free_func_inst = ncm_free_inst;
1638 	opts->net = gether_setup_default();
1639 	if (IS_ERR(opts->net)) {
1640 		struct net_device *net = opts->net;
1641 		kfree(opts);
1642 		return ERR_CAST(net);
1643 	}
1644 	INIT_LIST_HEAD(&opts->ncm_os_desc.ext_prop);
1645 
1646 	descs[0] = &opts->ncm_os_desc;
1647 	names[0] = "ncm";
1648 
1649 	config_group_init_type_name(&opts->func_inst.group, "", &ncm_func_type);
1650 	ncm_interf_group =
1651 		usb_os_desc_prepare_interf_dir(&opts->func_inst.group, 1, descs,
1652 					       names, THIS_MODULE);
1653 	if (IS_ERR(ncm_interf_group)) {
1654 		ncm_free_inst(&opts->func_inst);
1655 		return ERR_CAST(ncm_interf_group);
1656 	}
1657 	opts->ncm_interf_group = ncm_interf_group;
1658 
1659 	return &opts->func_inst;
1660 }
1661 
1662 static void ncm_free(struct usb_function *f)
1663 {
1664 	struct f_ncm *ncm;
1665 	struct f_ncm_opts *opts;
1666 
1667 	ncm = func_to_ncm(f);
1668 	opts = container_of(f->fi, struct f_ncm_opts, func_inst);
1669 	kfree(ncm);
1670 	mutex_lock(&opts->lock);
1671 	opts->refcnt--;
1672 	mutex_unlock(&opts->lock);
1673 }
1674 
1675 static void ncm_unbind(struct usb_configuration *c, struct usb_function *f)
1676 {
1677 	struct f_ncm *ncm = func_to_ncm(f);
1678 
1679 	DBG(c->cdev, "ncm unbind\n");
1680 
1681 	hrtimer_cancel(&ncm->task_timer);
1682 
1683 	kfree(f->os_desc_table);
1684 	f->os_desc_n = 0;
1685 
1686 	ncm_string_defs[0].id = 0;
1687 	usb_free_all_descriptors(f);
1688 
1689 	if (atomic_read(&ncm->notify_count)) {
1690 		usb_ep_dequeue(ncm->notify, ncm->notify_req);
1691 		atomic_set(&ncm->notify_count, 0);
1692 	}
1693 
1694 	kfree(ncm->notify_req->buf);
1695 	usb_ep_free_request(ncm->notify, ncm->notify_req);
1696 }
1697 
1698 static struct usb_function *ncm_alloc(struct usb_function_instance *fi)
1699 {
1700 	struct f_ncm		*ncm;
1701 	struct f_ncm_opts	*opts;
1702 	int status;
1703 
1704 	/* allocate and initialize one new instance */
1705 	ncm = kzalloc(sizeof(*ncm), GFP_KERNEL);
1706 	if (!ncm)
1707 		return ERR_PTR(-ENOMEM);
1708 
1709 	opts = container_of(fi, struct f_ncm_opts, func_inst);
1710 	mutex_lock(&opts->lock);
1711 	opts->refcnt++;
1712 
1713 	/* export host's Ethernet address in CDC format */
1714 	status = gether_get_host_addr_cdc(opts->net, ncm->ethaddr,
1715 				      sizeof(ncm->ethaddr));
1716 	if (status < 12) { /* strlen("01234567890a") */
1717 		kfree(ncm);
1718 		mutex_unlock(&opts->lock);
1719 		return ERR_PTR(-EINVAL);
1720 	}
1721 	ncm_string_defs[STRING_MAC_IDX].s = ncm->ethaddr;
1722 
1723 	spin_lock_init(&ncm->lock);
1724 	ncm_reset_values(ncm);
1725 	ncm->port.ioport = netdev_priv(opts->net);
1726 	mutex_unlock(&opts->lock);
1727 	ncm->port.is_fixed = true;
1728 	ncm->port.supports_multi_frame = true;
1729 
1730 	ncm->port.func.name = "cdc_network";
1731 	/* descriptors are per-instance copies */
1732 	ncm->port.func.bind = ncm_bind;
1733 	ncm->port.func.unbind = ncm_unbind;
1734 	ncm->port.func.set_alt = ncm_set_alt;
1735 	ncm->port.func.get_alt = ncm_get_alt;
1736 	ncm->port.func.setup = ncm_setup;
1737 	ncm->port.func.disable = ncm_disable;
1738 	ncm->port.func.free_func = ncm_free;
1739 
1740 	ncm->port.wrap = ncm_wrap_ntb;
1741 	ncm->port.unwrap = ncm_unwrap_ntb;
1742 
1743 	return &ncm->port.func;
1744 }
1745 
1746 DECLARE_USB_FUNCTION_INIT(ncm, ncm_alloc_inst, ncm_alloc);
1747 MODULE_LICENSE("GPL");
1748 MODULE_AUTHOR("Yauheni Kaliuta");
1749