xref: /openbmc/linux/drivers/net/usb/cdc_ncm.c (revision 9c1f8594)
1 /*
2  * cdc_ncm.c
3  *
4  * Copyright (C) ST-Ericsson 2010-2011
5  * Contact: Alexey Orishko <alexey.orishko@stericsson.com>
6  * Original author: Hans Petter Selasky <hans.petter.selasky@stericsson.com>
7  *
8  * USB Host Driver for Network Control Model (NCM)
9  * http://www.usb.org/developers/devclass_docs/NCM10.zip
10  *
11  * The NCM encoding, decoding and initialization logic
12  * derives from FreeBSD 8.x. if_cdce.c and if_cdcereg.h
13  *
14  * This software is available to you under a choice of one of two
15  * licenses. You may choose this file to be licensed under the terms
16  * of the GNU General Public License (GPL) Version 2 or the 2-clause
17  * BSD license listed below:
18  *
19  * Redistribution and use in source and binary forms, with or without
20  * modification, are permitted provided that the following conditions
21  * are met:
22  * 1. Redistributions of source code must retain the above copyright
23  *    notice, this list of conditions and the following disclaimer.
24  * 2. Redistributions in binary form must reproduce the above copyright
25  *    notice, this list of conditions and the following disclaimer in the
26  *    documentation and/or other materials provided with the distribution.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  */
40 
41 #include <linux/module.h>
42 #include <linux/init.h>
43 #include <linux/netdevice.h>
44 #include <linux/ctype.h>
45 #include <linux/ethtool.h>
46 #include <linux/workqueue.h>
47 #include <linux/mii.h>
48 #include <linux/crc32.h>
49 #include <linux/usb.h>
50 #include <linux/timer.h>
51 #include <linux/spinlock.h>
52 #include <linux/atomic.h>
53 #include <linux/usb/usbnet.h>
54 #include <linux/usb/cdc.h>
55 
56 #define	DRIVER_VERSION				"04-Aug-2011"
57 
58 /* CDC NCM subclass 3.2.1 */
59 #define USB_CDC_NCM_NDP16_LENGTH_MIN		0x10
60 
61 /* Maximum NTB length */
62 #define	CDC_NCM_NTB_MAX_SIZE_TX			16384	/* bytes */
63 #define	CDC_NCM_NTB_MAX_SIZE_RX			16384	/* bytes */
64 
65 /* Minimum value for MaxDatagramSize, ch. 6.2.9 */
66 #define	CDC_NCM_MIN_DATAGRAM_SIZE		1514	/* bytes */
67 
68 #define	CDC_NCM_MIN_TX_PKT			512	/* bytes */
69 
70 /* Default value for MaxDatagramSize */
71 #define	CDC_NCM_MAX_DATAGRAM_SIZE		2048	/* bytes */
72 
73 /*
74  * Maximum amount of datagrams in NCM Datagram Pointer Table, not counting
75  * the last NULL entry. Any additional datagrams in NTB would be discarded.
76  */
77 #define	CDC_NCM_DPT_DATAGRAMS_MAX		32
78 
79 /* Maximum amount of IN datagrams in NTB */
80 #define	CDC_NCM_DPT_DATAGRAMS_IN_MAX		0 /* unlimited */
81 
82 /* Restart the timer, if amount of datagrams is less than given value */
83 #define	CDC_NCM_RESTART_TIMER_DATAGRAM_CNT	3
84 
85 /* The following macro defines the minimum header space */
86 #define	CDC_NCM_MIN_HDR_SIZE \
87 	(sizeof(struct usb_cdc_ncm_nth16) + sizeof(struct usb_cdc_ncm_ndp16) + \
88 	(CDC_NCM_DPT_DATAGRAMS_MAX + 1) * sizeof(struct usb_cdc_ncm_dpe16))
89 
90 struct cdc_ncm_data {
91 	struct usb_cdc_ncm_nth16 nth16;
92 	struct usb_cdc_ncm_ndp16 ndp16;
93 	struct usb_cdc_ncm_dpe16 dpe16[CDC_NCM_DPT_DATAGRAMS_MAX + 1];
94 };
95 
96 struct cdc_ncm_ctx {
97 	struct cdc_ncm_data rx_ncm;
98 	struct cdc_ncm_data tx_ncm;
99 	struct usb_cdc_ncm_ntb_parameters ncm_parm;
100 	struct timer_list tx_timer;
101 
102 	const struct usb_cdc_ncm_desc *func_desc;
103 	const struct usb_cdc_header_desc *header_desc;
104 	const struct usb_cdc_union_desc *union_desc;
105 	const struct usb_cdc_ether_desc *ether_desc;
106 
107 	struct net_device *netdev;
108 	struct usb_device *udev;
109 	struct usb_host_endpoint *in_ep;
110 	struct usb_host_endpoint *out_ep;
111 	struct usb_host_endpoint *status_ep;
112 	struct usb_interface *intf;
113 	struct usb_interface *control;
114 	struct usb_interface *data;
115 
116 	struct sk_buff *tx_curr_skb;
117 	struct sk_buff *tx_rem_skb;
118 
119 	spinlock_t mtx;
120 
121 	u32 tx_timer_pending;
122 	u32 tx_curr_offset;
123 	u32 tx_curr_last_offset;
124 	u32 tx_curr_frame_num;
125 	u32 rx_speed;
126 	u32 tx_speed;
127 	u32 rx_max;
128 	u32 tx_max;
129 	u32 max_datagram_size;
130 	u16 tx_max_datagrams;
131 	u16 tx_remainder;
132 	u16 tx_modulus;
133 	u16 tx_ndp_modulus;
134 	u16 tx_seq;
135 	u16 connected;
136 };
137 
138 static void cdc_ncm_tx_timeout(unsigned long arg);
139 static const struct driver_info cdc_ncm_info;
140 static struct usb_driver cdc_ncm_driver;
141 static struct ethtool_ops cdc_ncm_ethtool_ops;
142 
143 static const struct usb_device_id cdc_devs[] = {
144 	{ USB_INTERFACE_INFO(USB_CLASS_COMM,
145 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
146 		.driver_info = (unsigned long)&cdc_ncm_info,
147 	},
148 	{
149 	},
150 };
151 
152 MODULE_DEVICE_TABLE(usb, cdc_devs);
153 
154 static void
155 cdc_ncm_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *info)
156 {
157 	struct usbnet *dev = netdev_priv(net);
158 
159 	strncpy(info->driver, dev->driver_name, sizeof(info->driver));
160 	strncpy(info->version, DRIVER_VERSION, sizeof(info->version));
161 	strncpy(info->fw_version, dev->driver_info->description,
162 		sizeof(info->fw_version));
163 	usb_make_path(dev->udev, info->bus_info, sizeof(info->bus_info));
164 }
165 
166 static u8 cdc_ncm_setup(struct cdc_ncm_ctx *ctx)
167 {
168 	u32 val;
169 	u8 flags;
170 	u8 iface_no;
171 	int err;
172 	u16 ntb_fmt_supported;
173 
174 	iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
175 
176 	err = usb_control_msg(ctx->udev,
177 				usb_rcvctrlpipe(ctx->udev, 0),
178 				USB_CDC_GET_NTB_PARAMETERS,
179 				USB_TYPE_CLASS | USB_DIR_IN
180 				 | USB_RECIP_INTERFACE,
181 				0, iface_no, &ctx->ncm_parm,
182 				sizeof(ctx->ncm_parm), 10000);
183 	if (err < 0) {
184 		pr_debug("failed GET_NTB_PARAMETERS\n");
185 		return 1;
186 	}
187 
188 	/* read correct set of parameters according to device mode */
189 	ctx->rx_max = le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize);
190 	ctx->tx_max = le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize);
191 	ctx->tx_remainder = le16_to_cpu(ctx->ncm_parm.wNdpOutPayloadRemainder);
192 	ctx->tx_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutDivisor);
193 	ctx->tx_ndp_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutAlignment);
194 	/* devices prior to NCM Errata shall set this field to zero */
195 	ctx->tx_max_datagrams = le16_to_cpu(ctx->ncm_parm.wNtbOutMaxDatagrams);
196 	ntb_fmt_supported = le16_to_cpu(ctx->ncm_parm.bmNtbFormatsSupported);
197 
198 	if (ctx->func_desc != NULL)
199 		flags = ctx->func_desc->bmNetworkCapabilities;
200 	else
201 		flags = 0;
202 
203 	pr_debug("dwNtbInMaxSize=%u dwNtbOutMaxSize=%u "
204 		 "wNdpOutPayloadRemainder=%u wNdpOutDivisor=%u "
205 		 "wNdpOutAlignment=%u wNtbOutMaxDatagrams=%u flags=0x%x\n",
206 		 ctx->rx_max, ctx->tx_max, ctx->tx_remainder, ctx->tx_modulus,
207 		 ctx->tx_ndp_modulus, ctx->tx_max_datagrams, flags);
208 
209 	/* max count of tx datagrams */
210 	if ((ctx->tx_max_datagrams == 0) ||
211 			(ctx->tx_max_datagrams > CDC_NCM_DPT_DATAGRAMS_MAX))
212 		ctx->tx_max_datagrams = CDC_NCM_DPT_DATAGRAMS_MAX;
213 
214 	/* verify maximum size of received NTB in bytes */
215 	if (ctx->rx_max < USB_CDC_NCM_NTB_MIN_IN_SIZE) {
216 		pr_debug("Using min receive length=%d\n",
217 						USB_CDC_NCM_NTB_MIN_IN_SIZE);
218 		ctx->rx_max = USB_CDC_NCM_NTB_MIN_IN_SIZE;
219 	}
220 
221 	if (ctx->rx_max > CDC_NCM_NTB_MAX_SIZE_RX) {
222 		pr_debug("Using default maximum receive length=%d\n",
223 						CDC_NCM_NTB_MAX_SIZE_RX);
224 		ctx->rx_max = CDC_NCM_NTB_MAX_SIZE_RX;
225 	}
226 
227 	/* inform device about NTB input size changes */
228 	if (ctx->rx_max != le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize)) {
229 
230 		if (flags & USB_CDC_NCM_NCAP_NTB_INPUT_SIZE) {
231 			struct usb_cdc_ncm_ndp_input_size *ndp_in_sz;
232 
233 			ndp_in_sz = kzalloc(sizeof(*ndp_in_sz), GFP_KERNEL);
234 			if (!ndp_in_sz) {
235 				err = -ENOMEM;
236 				goto size_err;
237 			}
238 
239 			err = usb_control_msg(ctx->udev,
240 					usb_sndctrlpipe(ctx->udev, 0),
241 					USB_CDC_SET_NTB_INPUT_SIZE,
242 					USB_TYPE_CLASS | USB_DIR_OUT
243 					 | USB_RECIP_INTERFACE,
244 					0, iface_no, ndp_in_sz, 8, 1000);
245 			kfree(ndp_in_sz);
246 		} else {
247 			__le32 *dwNtbInMaxSize;
248 			dwNtbInMaxSize = kzalloc(sizeof(*dwNtbInMaxSize),
249 					GFP_KERNEL);
250 			if (!dwNtbInMaxSize) {
251 				err = -ENOMEM;
252 				goto size_err;
253 			}
254 			*dwNtbInMaxSize = cpu_to_le32(ctx->rx_max);
255 
256 			err = usb_control_msg(ctx->udev,
257 					usb_sndctrlpipe(ctx->udev, 0),
258 					USB_CDC_SET_NTB_INPUT_SIZE,
259 					USB_TYPE_CLASS | USB_DIR_OUT
260 					 | USB_RECIP_INTERFACE,
261 					0, iface_no, dwNtbInMaxSize, 4, 1000);
262 			kfree(dwNtbInMaxSize);
263 		}
264 size_err:
265 		if (err < 0)
266 			pr_debug("Setting NTB Input Size failed\n");
267 	}
268 
269 	/* verify maximum size of transmitted NTB in bytes */
270 	if ((ctx->tx_max <
271 	    (CDC_NCM_MIN_HDR_SIZE + CDC_NCM_MIN_DATAGRAM_SIZE)) ||
272 	    (ctx->tx_max > CDC_NCM_NTB_MAX_SIZE_TX)) {
273 		pr_debug("Using default maximum transmit length=%d\n",
274 						CDC_NCM_NTB_MAX_SIZE_TX);
275 		ctx->tx_max = CDC_NCM_NTB_MAX_SIZE_TX;
276 	}
277 
278 	/*
279 	 * verify that the structure alignment is:
280 	 * - power of two
281 	 * - not greater than the maximum transmit length
282 	 * - not less than four bytes
283 	 */
284 	val = ctx->tx_ndp_modulus;
285 
286 	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
287 	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
288 		pr_debug("Using default alignment: 4 bytes\n");
289 		ctx->tx_ndp_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
290 	}
291 
292 	/*
293 	 * verify that the payload alignment is:
294 	 * - power of two
295 	 * - not greater than the maximum transmit length
296 	 * - not less than four bytes
297 	 */
298 	val = ctx->tx_modulus;
299 
300 	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
301 	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
302 		pr_debug("Using default transmit modulus: 4 bytes\n");
303 		ctx->tx_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
304 	}
305 
306 	/* verify the payload remainder */
307 	if (ctx->tx_remainder >= ctx->tx_modulus) {
308 		pr_debug("Using default transmit remainder: 0 bytes\n");
309 		ctx->tx_remainder = 0;
310 	}
311 
312 	/* adjust TX-remainder according to NCM specification. */
313 	ctx->tx_remainder = ((ctx->tx_remainder - ETH_HLEN) &
314 						(ctx->tx_modulus - 1));
315 
316 	/* additional configuration */
317 
318 	/* set CRC Mode */
319 	if (flags & USB_CDC_NCM_NCAP_CRC_MODE) {
320 		err = usb_control_msg(ctx->udev, usb_sndctrlpipe(ctx->udev, 0),
321 				USB_CDC_SET_CRC_MODE,
322 				USB_TYPE_CLASS | USB_DIR_OUT
323 				 | USB_RECIP_INTERFACE,
324 				USB_CDC_NCM_CRC_NOT_APPENDED,
325 				iface_no, NULL, 0, 1000);
326 		if (err < 0)
327 			pr_debug("Setting CRC mode off failed\n");
328 	}
329 
330 	/* set NTB format, if both formats are supported */
331 	if (ntb_fmt_supported & USB_CDC_NCM_NTH32_SIGN) {
332 		err = usb_control_msg(ctx->udev, usb_sndctrlpipe(ctx->udev, 0),
333 				USB_CDC_SET_NTB_FORMAT, USB_TYPE_CLASS
334 				 | USB_DIR_OUT | USB_RECIP_INTERFACE,
335 				USB_CDC_NCM_NTB16_FORMAT,
336 				iface_no, NULL, 0, 1000);
337 		if (err < 0)
338 			pr_debug("Setting NTB format to 16-bit failed\n");
339 	}
340 
341 	ctx->max_datagram_size = CDC_NCM_MIN_DATAGRAM_SIZE;
342 
343 	/* set Max Datagram Size (MTU) */
344 	if (flags & USB_CDC_NCM_NCAP_MAX_DATAGRAM_SIZE) {
345 		__le16 *max_datagram_size;
346 		u16 eth_max_sz = le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);
347 
348 		max_datagram_size = kzalloc(sizeof(*max_datagram_size),
349 				GFP_KERNEL);
350 		if (!max_datagram_size) {
351 			err = -ENOMEM;
352 			goto max_dgram_err;
353 		}
354 
355 		err = usb_control_msg(ctx->udev, usb_rcvctrlpipe(ctx->udev, 0),
356 				USB_CDC_GET_MAX_DATAGRAM_SIZE,
357 				USB_TYPE_CLASS | USB_DIR_IN
358 				 | USB_RECIP_INTERFACE,
359 				0, iface_no, max_datagram_size,
360 				2, 1000);
361 		if (err < 0) {
362 			pr_debug("GET_MAX_DATAGRAM_SIZE failed, use size=%u\n",
363 						CDC_NCM_MIN_DATAGRAM_SIZE);
364 			kfree(max_datagram_size);
365 		} else {
366 			ctx->max_datagram_size =
367 				le16_to_cpu(*max_datagram_size);
368 			/* Check Eth descriptor value */
369 			if (eth_max_sz < CDC_NCM_MAX_DATAGRAM_SIZE) {
370 				if (ctx->max_datagram_size > eth_max_sz)
371 					ctx->max_datagram_size = eth_max_sz;
372 			} else {
373 				if (ctx->max_datagram_size >
374 						CDC_NCM_MAX_DATAGRAM_SIZE)
375 					ctx->max_datagram_size =
376 						CDC_NCM_MAX_DATAGRAM_SIZE;
377 			}
378 
379 			if (ctx->max_datagram_size < CDC_NCM_MIN_DATAGRAM_SIZE)
380 				ctx->max_datagram_size =
381 					CDC_NCM_MIN_DATAGRAM_SIZE;
382 
383 			/* if value changed, update device */
384 			err = usb_control_msg(ctx->udev,
385 						usb_sndctrlpipe(ctx->udev, 0),
386 						USB_CDC_SET_MAX_DATAGRAM_SIZE,
387 						USB_TYPE_CLASS | USB_DIR_OUT
388 						 | USB_RECIP_INTERFACE,
389 						0,
390 						iface_no, max_datagram_size,
391 						2, 1000);
392 			kfree(max_datagram_size);
393 max_dgram_err:
394 			if (err < 0)
395 				pr_debug("SET_MAX_DATAGRAM_SIZE failed\n");
396 		}
397 
398 	}
399 
400 	if (ctx->netdev->mtu != (ctx->max_datagram_size - ETH_HLEN))
401 		ctx->netdev->mtu = ctx->max_datagram_size - ETH_HLEN;
402 
403 	return 0;
404 }
405 
406 static void
407 cdc_ncm_find_endpoints(struct cdc_ncm_ctx *ctx, struct usb_interface *intf)
408 {
409 	struct usb_host_endpoint *e;
410 	u8 ep;
411 
412 	for (ep = 0; ep < intf->cur_altsetting->desc.bNumEndpoints; ep++) {
413 
414 		e = intf->cur_altsetting->endpoint + ep;
415 		switch (e->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
416 		case USB_ENDPOINT_XFER_INT:
417 			if (usb_endpoint_dir_in(&e->desc)) {
418 				if (ctx->status_ep == NULL)
419 					ctx->status_ep = e;
420 			}
421 			break;
422 
423 		case USB_ENDPOINT_XFER_BULK:
424 			if (usb_endpoint_dir_in(&e->desc)) {
425 				if (ctx->in_ep == NULL)
426 					ctx->in_ep = e;
427 			} else {
428 				if (ctx->out_ep == NULL)
429 					ctx->out_ep = e;
430 			}
431 			break;
432 
433 		default:
434 			break;
435 		}
436 	}
437 }
438 
439 static void cdc_ncm_free(struct cdc_ncm_ctx *ctx)
440 {
441 	if (ctx == NULL)
442 		return;
443 
444 	del_timer_sync(&ctx->tx_timer);
445 
446 	if (ctx->tx_rem_skb != NULL) {
447 		dev_kfree_skb_any(ctx->tx_rem_skb);
448 		ctx->tx_rem_skb = NULL;
449 	}
450 
451 	if (ctx->tx_curr_skb != NULL) {
452 		dev_kfree_skb_any(ctx->tx_curr_skb);
453 		ctx->tx_curr_skb = NULL;
454 	}
455 
456 	kfree(ctx);
457 }
458 
459 static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
460 {
461 	struct cdc_ncm_ctx *ctx;
462 	struct usb_driver *driver;
463 	u8 *buf;
464 	int len;
465 	int temp;
466 	u8 iface_no;
467 
468 	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
469 	if (ctx == NULL)
470 		return -ENODEV;
471 
472 	memset(ctx, 0, sizeof(*ctx));
473 
474 	init_timer(&ctx->tx_timer);
475 	spin_lock_init(&ctx->mtx);
476 	ctx->netdev = dev->net;
477 
478 	/* store ctx pointer in device data field */
479 	dev->data[0] = (unsigned long)ctx;
480 
481 	/* get some pointers */
482 	driver = driver_of(intf);
483 	buf = intf->cur_altsetting->extra;
484 	len = intf->cur_altsetting->extralen;
485 
486 	ctx->udev = dev->udev;
487 	ctx->intf = intf;
488 
489 	/* parse through descriptors associated with control interface */
490 	while ((len > 0) && (buf[0] > 2) && (buf[0] <= len)) {
491 
492 		if (buf[1] != USB_DT_CS_INTERFACE)
493 			goto advance;
494 
495 		switch (buf[2]) {
496 		case USB_CDC_UNION_TYPE:
497 			if (buf[0] < sizeof(*(ctx->union_desc)))
498 				break;
499 
500 			ctx->union_desc =
501 					(const struct usb_cdc_union_desc *)buf;
502 
503 			ctx->control = usb_ifnum_to_if(dev->udev,
504 					ctx->union_desc->bMasterInterface0);
505 			ctx->data = usb_ifnum_to_if(dev->udev,
506 					ctx->union_desc->bSlaveInterface0);
507 			break;
508 
509 		case USB_CDC_ETHERNET_TYPE:
510 			if (buf[0] < sizeof(*(ctx->ether_desc)))
511 				break;
512 
513 			ctx->ether_desc =
514 					(const struct usb_cdc_ether_desc *)buf;
515 			dev->hard_mtu =
516 				le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);
517 
518 			if (dev->hard_mtu < CDC_NCM_MIN_DATAGRAM_SIZE)
519 				dev->hard_mtu =	CDC_NCM_MIN_DATAGRAM_SIZE;
520 			else if (dev->hard_mtu > CDC_NCM_MAX_DATAGRAM_SIZE)
521 				dev->hard_mtu =	CDC_NCM_MAX_DATAGRAM_SIZE;
522 			break;
523 
524 		case USB_CDC_NCM_TYPE:
525 			if (buf[0] < sizeof(*(ctx->func_desc)))
526 				break;
527 
528 			ctx->func_desc = (const struct usb_cdc_ncm_desc *)buf;
529 			break;
530 
531 		default:
532 			break;
533 		}
534 advance:
535 		/* advance to next descriptor */
536 		temp = buf[0];
537 		buf += temp;
538 		len -= temp;
539 	}
540 
541 	/* check if we got everything */
542 	if ((ctx->control == NULL) || (ctx->data == NULL) ||
543 	    (ctx->ether_desc == NULL) || (ctx->control != intf))
544 		goto error;
545 
546 	/* claim interfaces, if any */
547 	temp = usb_driver_claim_interface(driver, ctx->data, dev);
548 	if (temp)
549 		goto error;
550 
551 	iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
552 
553 	/* reset data interface */
554 	temp = usb_set_interface(dev->udev, iface_no, 0);
555 	if (temp)
556 		goto error2;
557 
558 	/* initialize data interface */
559 	if (cdc_ncm_setup(ctx))
560 		goto error2;
561 
562 	/* configure data interface */
563 	temp = usb_set_interface(dev->udev, iface_no, 1);
564 	if (temp)
565 		goto error2;
566 
567 	cdc_ncm_find_endpoints(ctx, ctx->data);
568 	cdc_ncm_find_endpoints(ctx, ctx->control);
569 
570 	if ((ctx->in_ep == NULL) || (ctx->out_ep == NULL) ||
571 	    (ctx->status_ep == NULL))
572 		goto error2;
573 
574 	dev->net->ethtool_ops = &cdc_ncm_ethtool_ops;
575 
576 	usb_set_intfdata(ctx->data, dev);
577 	usb_set_intfdata(ctx->control, dev);
578 	usb_set_intfdata(ctx->intf, dev);
579 
580 	temp = usbnet_get_ethernet_addr(dev, ctx->ether_desc->iMACAddress);
581 	if (temp)
582 		goto error2;
583 
584 	dev_info(&dev->udev->dev, "MAC-Address: "
585 				"0x%02x:0x%02x:0x%02x:0x%02x:0x%02x:0x%02x\n",
586 				dev->net->dev_addr[0], dev->net->dev_addr[1],
587 				dev->net->dev_addr[2], dev->net->dev_addr[3],
588 				dev->net->dev_addr[4], dev->net->dev_addr[5]);
589 
590 	dev->in = usb_rcvbulkpipe(dev->udev,
591 		ctx->in_ep->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
592 	dev->out = usb_sndbulkpipe(dev->udev,
593 		ctx->out_ep->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
594 	dev->status = ctx->status_ep;
595 	dev->rx_urb_size = ctx->rx_max;
596 
597 	/*
598 	 * We should get an event when network connection is "connected" or
599 	 * "disconnected". Set network connection in "disconnected" state
600 	 * (carrier is OFF) during attach, so the IP network stack does not
601 	 * start IPv6 negotiation and more.
602 	 */
603 	netif_carrier_off(dev->net);
604 	ctx->tx_speed = ctx->rx_speed = 0;
605 	return 0;
606 
607 error2:
608 	usb_set_intfdata(ctx->control, NULL);
609 	usb_set_intfdata(ctx->data, NULL);
610 	usb_driver_release_interface(driver, ctx->data);
611 error:
612 	cdc_ncm_free((struct cdc_ncm_ctx *)dev->data[0]);
613 	dev->data[0] = 0;
614 	dev_info(&dev->udev->dev, "bind() failure\n");
615 	return -ENODEV;
616 }
617 
618 static void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
619 {
620 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
621 	struct usb_driver *driver = driver_of(intf);
622 
623 	if (ctx == NULL)
624 		return;		/* no setup */
625 
626 	/* disconnect master --> disconnect slave */
627 	if (intf == ctx->control && ctx->data) {
628 		usb_set_intfdata(ctx->data, NULL);
629 		usb_driver_release_interface(driver, ctx->data);
630 		ctx->data = NULL;
631 
632 	} else if (intf == ctx->data && ctx->control) {
633 		usb_set_intfdata(ctx->control, NULL);
634 		usb_driver_release_interface(driver, ctx->control);
635 		ctx->control = NULL;
636 	}
637 
638 	usb_set_intfdata(ctx->intf, NULL);
639 	cdc_ncm_free(ctx);
640 }
641 
642 static void cdc_ncm_zero_fill(u8 *ptr, u32 first, u32 end, u32 max)
643 {
644 	if (first >= max)
645 		return;
646 	if (first >= end)
647 		return;
648 	if (end > max)
649 		end = max;
650 	memset(ptr + first, 0, end - first);
651 }
652 
653 static struct sk_buff *
654 cdc_ncm_fill_tx_frame(struct cdc_ncm_ctx *ctx, struct sk_buff *skb)
655 {
656 	struct sk_buff *skb_out;
657 	u32 rem;
658 	u32 offset;
659 	u32 last_offset;
660 	u16 n = 0, index;
661 	u8 ready2send = 0;
662 
663 	/* if there is a remaining skb, it gets priority */
664 	if (skb != NULL)
665 		swap(skb, ctx->tx_rem_skb);
666 	else
667 		ready2send = 1;
668 
669 	/*
670 	 * +----------------+
671 	 * | skb_out        |
672 	 * +----------------+
673 	 *           ^ offset
674 	 *        ^ last_offset
675 	 */
676 
677 	/* check if we are resuming an OUT skb */
678 	if (ctx->tx_curr_skb != NULL) {
679 		/* pop variables */
680 		skb_out = ctx->tx_curr_skb;
681 		offset = ctx->tx_curr_offset;
682 		last_offset = ctx->tx_curr_last_offset;
683 		n = ctx->tx_curr_frame_num;
684 
685 	} else {
686 		/* reset variables */
687 		skb_out = alloc_skb((ctx->tx_max + 1), GFP_ATOMIC);
688 		if (skb_out == NULL) {
689 			if (skb != NULL) {
690 				dev_kfree_skb_any(skb);
691 				ctx->netdev->stats.tx_dropped++;
692 			}
693 			goto exit_no_skb;
694 		}
695 
696 		/* make room for NTH and NDP */
697 		offset = ALIGN(sizeof(struct usb_cdc_ncm_nth16),
698 					ctx->tx_ndp_modulus) +
699 					sizeof(struct usb_cdc_ncm_ndp16) +
700 					(ctx->tx_max_datagrams + 1) *
701 					sizeof(struct usb_cdc_ncm_dpe16);
702 
703 		/* store last valid offset before alignment */
704 		last_offset = offset;
705 		/* align first Datagram offset correctly */
706 		offset = ALIGN(offset, ctx->tx_modulus) + ctx->tx_remainder;
707 		/* zero buffer till the first IP datagram */
708 		cdc_ncm_zero_fill(skb_out->data, 0, offset, offset);
709 		n = 0;
710 		ctx->tx_curr_frame_num = 0;
711 	}
712 
713 	for (; n < ctx->tx_max_datagrams; n++) {
714 		/* check if end of transmit buffer is reached */
715 		if (offset >= ctx->tx_max) {
716 			ready2send = 1;
717 			break;
718 		}
719 		/* compute maximum buffer size */
720 		rem = ctx->tx_max - offset;
721 
722 		if (skb == NULL) {
723 			skb = ctx->tx_rem_skb;
724 			ctx->tx_rem_skb = NULL;
725 
726 			/* check for end of skb */
727 			if (skb == NULL)
728 				break;
729 		}
730 
731 		if (skb->len > rem) {
732 			if (n == 0) {
733 				/* won't fit, MTU problem? */
734 				dev_kfree_skb_any(skb);
735 				skb = NULL;
736 				ctx->netdev->stats.tx_dropped++;
737 			} else {
738 				/* no room for skb - store for later */
739 				if (ctx->tx_rem_skb != NULL) {
740 					dev_kfree_skb_any(ctx->tx_rem_skb);
741 					ctx->netdev->stats.tx_dropped++;
742 				}
743 				ctx->tx_rem_skb = skb;
744 				skb = NULL;
745 				ready2send = 1;
746 			}
747 			break;
748 		}
749 
750 		memcpy(((u8 *)skb_out->data) + offset, skb->data, skb->len);
751 
752 		ctx->tx_ncm.dpe16[n].wDatagramLength = cpu_to_le16(skb->len);
753 		ctx->tx_ncm.dpe16[n].wDatagramIndex = cpu_to_le16(offset);
754 
755 		/* update offset */
756 		offset += skb->len;
757 
758 		/* store last valid offset before alignment */
759 		last_offset = offset;
760 
761 		/* align offset correctly */
762 		offset = ALIGN(offset, ctx->tx_modulus) + ctx->tx_remainder;
763 
764 		/* zero padding */
765 		cdc_ncm_zero_fill(skb_out->data, last_offset, offset,
766 								ctx->tx_max);
767 		dev_kfree_skb_any(skb);
768 		skb = NULL;
769 	}
770 
771 	/* free up any dangling skb */
772 	if (skb != NULL) {
773 		dev_kfree_skb_any(skb);
774 		skb = NULL;
775 		ctx->netdev->stats.tx_dropped++;
776 	}
777 
778 	ctx->tx_curr_frame_num = n;
779 
780 	if (n == 0) {
781 		/* wait for more frames */
782 		/* push variables */
783 		ctx->tx_curr_skb = skb_out;
784 		ctx->tx_curr_offset = offset;
785 		ctx->tx_curr_last_offset = last_offset;
786 		goto exit_no_skb;
787 
788 	} else if ((n < ctx->tx_max_datagrams) && (ready2send == 0)) {
789 		/* wait for more frames */
790 		/* push variables */
791 		ctx->tx_curr_skb = skb_out;
792 		ctx->tx_curr_offset = offset;
793 		ctx->tx_curr_last_offset = last_offset;
794 		/* set the pending count */
795 		if (n < CDC_NCM_RESTART_TIMER_DATAGRAM_CNT)
796 			ctx->tx_timer_pending = 2;
797 		goto exit_no_skb;
798 
799 	} else {
800 		/* frame goes out */
801 		/* variables will be reset at next call */
802 	}
803 
804 	/* check for overflow */
805 	if (last_offset > ctx->tx_max)
806 		last_offset = ctx->tx_max;
807 
808 	/* revert offset */
809 	offset = last_offset;
810 
811 	/*
812 	 * If collected data size is less or equal CDC_NCM_MIN_TX_PKT bytes,
813 	 * we send buffers as it is. If we get more data, it would be more
814 	 * efficient for USB HS mobile device with DMA engine to receive a full
815 	 * size NTB, than canceling DMA transfer and receiving a short packet.
816 	 */
817 	if (offset > CDC_NCM_MIN_TX_PKT)
818 		offset = ctx->tx_max;
819 
820 	/* final zero padding */
821 	cdc_ncm_zero_fill(skb_out->data, last_offset, offset, ctx->tx_max);
822 
823 	/* store last offset */
824 	last_offset = offset;
825 
826 	if (((last_offset < ctx->tx_max) && ((last_offset %
827 			le16_to_cpu(ctx->out_ep->desc.wMaxPacketSize)) == 0)) ||
828 	    (((last_offset == ctx->tx_max) && ((ctx->tx_max %
829 		le16_to_cpu(ctx->out_ep->desc.wMaxPacketSize)) == 0)) &&
830 		(ctx->tx_max < le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize)))) {
831 		/* force short packet */
832 		*(((u8 *)skb_out->data) + last_offset) = 0;
833 		last_offset++;
834 	}
835 
836 	/* zero the rest of the DPEs plus the last NULL entry */
837 	for (; n <= CDC_NCM_DPT_DATAGRAMS_MAX; n++) {
838 		ctx->tx_ncm.dpe16[n].wDatagramLength = 0;
839 		ctx->tx_ncm.dpe16[n].wDatagramIndex = 0;
840 	}
841 
842 	/* fill out 16-bit NTB header */
843 	ctx->tx_ncm.nth16.dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN);
844 	ctx->tx_ncm.nth16.wHeaderLength =
845 					cpu_to_le16(sizeof(ctx->tx_ncm.nth16));
846 	ctx->tx_ncm.nth16.wSequence = cpu_to_le16(ctx->tx_seq);
847 	ctx->tx_ncm.nth16.wBlockLength = cpu_to_le16(last_offset);
848 	index = ALIGN(sizeof(struct usb_cdc_ncm_nth16), ctx->tx_ndp_modulus);
849 	ctx->tx_ncm.nth16.wNdpIndex = cpu_to_le16(index);
850 
851 	memcpy(skb_out->data, &(ctx->tx_ncm.nth16), sizeof(ctx->tx_ncm.nth16));
852 	ctx->tx_seq++;
853 
854 	/* fill out 16-bit NDP table */
855 	ctx->tx_ncm.ndp16.dwSignature =
856 				cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN);
857 	rem = sizeof(ctx->tx_ncm.ndp16) + ((ctx->tx_curr_frame_num + 1) *
858 					sizeof(struct usb_cdc_ncm_dpe16));
859 	ctx->tx_ncm.ndp16.wLength = cpu_to_le16(rem);
860 	ctx->tx_ncm.ndp16.wNextNdpIndex = 0; /* reserved */
861 
862 	memcpy(((u8 *)skb_out->data) + index,
863 						&(ctx->tx_ncm.ndp16),
864 						sizeof(ctx->tx_ncm.ndp16));
865 
866 	memcpy(((u8 *)skb_out->data) + index + sizeof(ctx->tx_ncm.ndp16),
867 					&(ctx->tx_ncm.dpe16),
868 					(ctx->tx_curr_frame_num + 1) *
869 					sizeof(struct usb_cdc_ncm_dpe16));
870 
871 	/* set frame length */
872 	skb_put(skb_out, last_offset);
873 
874 	/* return skb */
875 	ctx->tx_curr_skb = NULL;
876 	return skb_out;
877 
878 exit_no_skb:
879 	return NULL;
880 }
881 
882 static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx)
883 {
884 	/* start timer, if not already started */
885 	if (timer_pending(&ctx->tx_timer) == 0) {
886 		ctx->tx_timer.function = &cdc_ncm_tx_timeout;
887 		ctx->tx_timer.data = (unsigned long)ctx;
888 		ctx->tx_timer.expires = jiffies + ((HZ + 999) / 1000);
889 		add_timer(&ctx->tx_timer);
890 	}
891 }
892 
893 static void cdc_ncm_tx_timeout(unsigned long arg)
894 {
895 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)arg;
896 	u8 restart;
897 
898 	spin_lock(&ctx->mtx);
899 	if (ctx->tx_timer_pending != 0) {
900 		ctx->tx_timer_pending--;
901 		restart = 1;
902 	} else {
903 		restart = 0;
904 	}
905 
906 	spin_unlock(&ctx->mtx);
907 
908 	if (restart) {
909 		spin_lock(&ctx->mtx);
910 		cdc_ncm_tx_timeout_start(ctx);
911 		spin_unlock(&ctx->mtx);
912 	} else if (ctx->netdev != NULL) {
913 		usbnet_start_xmit(NULL, ctx->netdev);
914 	}
915 }
916 
917 static struct sk_buff *
918 cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
919 {
920 	struct sk_buff *skb_out;
921 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
922 	u8 need_timer = 0;
923 
924 	/*
925 	 * The Ethernet API we are using does not support transmitting
926 	 * multiple Ethernet frames in a single call. This driver will
927 	 * accumulate multiple Ethernet frames and send out a larger
928 	 * USB frame when the USB buffer is full or when a single jiffies
929 	 * timeout happens.
930 	 */
931 	if (ctx == NULL)
932 		goto error;
933 
934 	spin_lock(&ctx->mtx);
935 	skb_out = cdc_ncm_fill_tx_frame(ctx, skb);
936 	if (ctx->tx_curr_skb != NULL)
937 		need_timer = 1;
938 
939 	/* Start timer, if there is a remaining skb */
940 	if (need_timer)
941 		cdc_ncm_tx_timeout_start(ctx);
942 
943 	if (skb_out)
944 		dev->net->stats.tx_packets += ctx->tx_curr_frame_num;
945 
946 	spin_unlock(&ctx->mtx);
947 	return skb_out;
948 
949 error:
950 	if (skb != NULL)
951 		dev_kfree_skb_any(skb);
952 
953 	return NULL;
954 }
955 
956 static int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
957 {
958 	struct sk_buff *skb;
959 	struct cdc_ncm_ctx *ctx;
960 	int sumlen;
961 	int actlen;
962 	int temp;
963 	int nframes;
964 	int x;
965 	int offset;
966 
967 	ctx = (struct cdc_ncm_ctx *)dev->data[0];
968 	if (ctx == NULL)
969 		goto error;
970 
971 	actlen = skb_in->len;
972 	sumlen = CDC_NCM_NTB_MAX_SIZE_RX;
973 
974 	if (actlen < (sizeof(ctx->rx_ncm.nth16) + sizeof(ctx->rx_ncm.ndp16))) {
975 		pr_debug("frame too short\n");
976 		goto error;
977 	}
978 
979 	memcpy(&(ctx->rx_ncm.nth16), ((u8 *)skb_in->data),
980 						sizeof(ctx->rx_ncm.nth16));
981 
982 	if (le32_to_cpu(ctx->rx_ncm.nth16.dwSignature) !=
983 	    USB_CDC_NCM_NTH16_SIGN) {
984 		pr_debug("invalid NTH16 signature <%u>\n",
985 			 le32_to_cpu(ctx->rx_ncm.nth16.dwSignature));
986 		goto error;
987 	}
988 
989 	temp = le16_to_cpu(ctx->rx_ncm.nth16.wBlockLength);
990 	if (temp > sumlen) {
991 		pr_debug("unsupported NTB block length %u/%u\n", temp, sumlen);
992 		goto error;
993 	}
994 
995 	temp = le16_to_cpu(ctx->rx_ncm.nth16.wNdpIndex);
996 	if ((temp + sizeof(ctx->rx_ncm.ndp16)) > actlen) {
997 		pr_debug("invalid DPT16 index\n");
998 		goto error;
999 	}
1000 
1001 	memcpy(&(ctx->rx_ncm.ndp16), ((u8 *)skb_in->data) + temp,
1002 						sizeof(ctx->rx_ncm.ndp16));
1003 
1004 	if (le32_to_cpu(ctx->rx_ncm.ndp16.dwSignature) !=
1005 	    USB_CDC_NCM_NDP16_NOCRC_SIGN) {
1006 		pr_debug("invalid DPT16 signature <%u>\n",
1007 			 le32_to_cpu(ctx->rx_ncm.ndp16.dwSignature));
1008 		goto error;
1009 	}
1010 
1011 	if (le16_to_cpu(ctx->rx_ncm.ndp16.wLength) <
1012 	    USB_CDC_NCM_NDP16_LENGTH_MIN) {
1013 		pr_debug("invalid DPT16 length <%u>\n",
1014 			 le32_to_cpu(ctx->rx_ncm.ndp16.dwSignature));
1015 		goto error;
1016 	}
1017 
1018 	nframes = ((le16_to_cpu(ctx->rx_ncm.ndp16.wLength) -
1019 					sizeof(struct usb_cdc_ncm_ndp16)) /
1020 					sizeof(struct usb_cdc_ncm_dpe16));
1021 	nframes--; /* we process NDP entries except for the last one */
1022 
1023 	pr_debug("nframes = %u\n", nframes);
1024 
1025 	temp += sizeof(ctx->rx_ncm.ndp16);
1026 
1027 	if ((temp + nframes * (sizeof(struct usb_cdc_ncm_dpe16))) > actlen) {
1028 		pr_debug("Invalid nframes = %d\n", nframes);
1029 		goto error;
1030 	}
1031 
1032 	if (nframes > CDC_NCM_DPT_DATAGRAMS_MAX) {
1033 		pr_debug("Truncating number of frames from %u to %u\n",
1034 					nframes, CDC_NCM_DPT_DATAGRAMS_MAX);
1035 		nframes = CDC_NCM_DPT_DATAGRAMS_MAX;
1036 	}
1037 
1038 	memcpy(&(ctx->rx_ncm.dpe16), ((u8 *)skb_in->data) + temp,
1039 				nframes * (sizeof(struct usb_cdc_ncm_dpe16)));
1040 
1041 	for (x = 0; x < nframes; x++) {
1042 		offset = le16_to_cpu(ctx->rx_ncm.dpe16[x].wDatagramIndex);
1043 		temp = le16_to_cpu(ctx->rx_ncm.dpe16[x].wDatagramLength);
1044 
1045 		/*
1046 		 * CDC NCM ch. 3.7
1047 		 * All entries after first NULL entry are to be ignored
1048 		 */
1049 		if ((offset == 0) || (temp == 0)) {
1050 			if (!x)
1051 				goto error; /* empty NTB */
1052 			break;
1053 		}
1054 
1055 		/* sanity checking */
1056 		if (((offset + temp) > actlen) ||
1057 		    (temp > CDC_NCM_MAX_DATAGRAM_SIZE) || (temp < ETH_HLEN)) {
1058 			pr_debug("invalid frame detected (ignored)"
1059 					"offset[%u]=%u, length=%u, skb=%p\n",
1060 					x, offset, temp, skb_in);
1061 			if (!x)
1062 				goto error;
1063 			break;
1064 
1065 		} else {
1066 			skb = skb_clone(skb_in, GFP_ATOMIC);
1067 			if (!skb)
1068 				goto error;
1069 			skb->len = temp;
1070 			skb->data = ((u8 *)skb_in->data) + offset;
1071 			skb_set_tail_pointer(skb, temp);
1072 			usbnet_skb_return(dev, skb);
1073 		}
1074 	}
1075 	return 1;
1076 error:
1077 	return 0;
1078 }
1079 
1080 static void
1081 cdc_ncm_speed_change(struct cdc_ncm_ctx *ctx,
1082 		     struct usb_cdc_speed_change *data)
1083 {
1084 	uint32_t rx_speed = le32_to_cpu(data->DLBitRRate);
1085 	uint32_t tx_speed = le32_to_cpu(data->ULBitRate);
1086 
1087 	/*
1088 	 * Currently the USB-NET API does not support reporting the actual
1089 	 * device speed. Do print it instead.
1090 	 */
1091 	if ((tx_speed != ctx->tx_speed) || (rx_speed != ctx->rx_speed)) {
1092 		ctx->tx_speed = tx_speed;
1093 		ctx->rx_speed = rx_speed;
1094 
1095 		if ((tx_speed > 1000000) && (rx_speed > 1000000)) {
1096 			printk(KERN_INFO KBUILD_MODNAME
1097 				": %s: %u mbit/s downlink "
1098 				"%u mbit/s uplink\n",
1099 				ctx->netdev->name,
1100 				(unsigned int)(rx_speed / 1000000U),
1101 				(unsigned int)(tx_speed / 1000000U));
1102 		} else {
1103 			printk(KERN_INFO KBUILD_MODNAME
1104 				": %s: %u kbit/s downlink "
1105 				"%u kbit/s uplink\n",
1106 				ctx->netdev->name,
1107 				(unsigned int)(rx_speed / 1000U),
1108 				(unsigned int)(tx_speed / 1000U));
1109 		}
1110 	}
1111 }
1112 
1113 static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
1114 {
1115 	struct cdc_ncm_ctx *ctx;
1116 	struct usb_cdc_notification *event;
1117 
1118 	ctx = (struct cdc_ncm_ctx *)dev->data[0];
1119 
1120 	if (urb->actual_length < sizeof(*event))
1121 		return;
1122 
1123 	/* test for split data in 8-byte chunks */
1124 	if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
1125 		cdc_ncm_speed_change(ctx,
1126 		      (struct usb_cdc_speed_change *)urb->transfer_buffer);
1127 		return;
1128 	}
1129 
1130 	event = urb->transfer_buffer;
1131 
1132 	switch (event->bNotificationType) {
1133 	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
1134 		/*
1135 		 * According to the CDC NCM specification ch.7.1
1136 		 * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be
1137 		 * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE.
1138 		 */
1139 		ctx->connected = event->wValue;
1140 
1141 		printk(KERN_INFO KBUILD_MODNAME ": %s: network connection:"
1142 			" %sconnected\n",
1143 			ctx->netdev->name, ctx->connected ? "" : "dis");
1144 
1145 		if (ctx->connected)
1146 			netif_carrier_on(dev->net);
1147 		else {
1148 			netif_carrier_off(dev->net);
1149 			ctx->tx_speed = ctx->rx_speed = 0;
1150 		}
1151 		break;
1152 
1153 	case USB_CDC_NOTIFY_SPEED_CHANGE:
1154 		if (urb->actual_length < (sizeof(*event) +
1155 					sizeof(struct usb_cdc_speed_change)))
1156 			set_bit(EVENT_STS_SPLIT, &dev->flags);
1157 		else
1158 			cdc_ncm_speed_change(ctx,
1159 				(struct usb_cdc_speed_change *) &event[1]);
1160 		break;
1161 
1162 	default:
1163 		dev_err(&dev->udev->dev, "NCM: unexpected "
1164 			"notification 0x%02x!\n", event->bNotificationType);
1165 		break;
1166 	}
1167 }
1168 
1169 static int cdc_ncm_check_connect(struct usbnet *dev)
1170 {
1171 	struct cdc_ncm_ctx *ctx;
1172 
1173 	ctx = (struct cdc_ncm_ctx *)dev->data[0];
1174 	if (ctx == NULL)
1175 		return 1;	/* disconnected */
1176 
1177 	return !ctx->connected;
1178 }
1179 
1180 static int
1181 cdc_ncm_probe(struct usb_interface *udev, const struct usb_device_id *prod)
1182 {
1183 	return usbnet_probe(udev, prod);
1184 }
1185 
1186 static void cdc_ncm_disconnect(struct usb_interface *intf)
1187 {
1188 	struct usbnet *dev = usb_get_intfdata(intf);
1189 
1190 	if (dev == NULL)
1191 		return;		/* already disconnected */
1192 
1193 	usbnet_disconnect(intf);
1194 }
1195 
1196 static int cdc_ncm_manage_power(struct usbnet *dev, int status)
1197 {
1198 	dev->intf->needs_remote_wakeup = status;
1199 	return 0;
1200 }
1201 
1202 static const struct driver_info cdc_ncm_info = {
1203 	.description = "CDC NCM",
1204 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET,
1205 	.bind = cdc_ncm_bind,
1206 	.unbind = cdc_ncm_unbind,
1207 	.check_connect = cdc_ncm_check_connect,
1208 	.manage_power = cdc_ncm_manage_power,
1209 	.status = cdc_ncm_status,
1210 	.rx_fixup = cdc_ncm_rx_fixup,
1211 	.tx_fixup = cdc_ncm_tx_fixup,
1212 };
1213 
1214 static struct usb_driver cdc_ncm_driver = {
1215 	.name = "cdc_ncm",
1216 	.id_table = cdc_devs,
1217 	.probe = cdc_ncm_probe,
1218 	.disconnect = cdc_ncm_disconnect,
1219 	.suspend = usbnet_suspend,
1220 	.resume = usbnet_resume,
1221 	.reset_resume =	usbnet_resume,
1222 	.supports_autosuspend = 1,
1223 };
1224 
1225 static struct ethtool_ops cdc_ncm_ethtool_ops = {
1226 	.get_drvinfo = cdc_ncm_get_drvinfo,
1227 	.get_link = usbnet_get_link,
1228 	.get_msglevel = usbnet_get_msglevel,
1229 	.set_msglevel = usbnet_set_msglevel,
1230 	.get_settings = usbnet_get_settings,
1231 	.set_settings = usbnet_set_settings,
1232 	.nway_reset = usbnet_nway_reset,
1233 };
1234 
1235 static int __init cdc_ncm_init(void)
1236 {
1237 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION "\n");
1238 	return usb_register(&cdc_ncm_driver);
1239 }
1240 
1241 module_init(cdc_ncm_init);
1242 
1243 static void __exit cdc_ncm_exit(void)
1244 {
1245 	usb_deregister(&cdc_ncm_driver);
1246 }
1247 
1248 module_exit(cdc_ncm_exit);
1249 
1250 MODULE_AUTHOR("Hans Petter Selasky");
1251 MODULE_DESCRIPTION("USB CDC NCM host driver");
1252 MODULE_LICENSE("Dual BSD/GPL");
1253