xref: /openbmc/linux/drivers/net/usb/cdc_ncm.c (revision 261a9af6)
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/version.h>
51 #include <linux/timer.h>
52 #include <linux/spinlock.h>
53 #include <linux/atomic.h>
54 #include <linux/usb/usbnet.h>
55 #include <linux/usb/cdc.h>
56 
57 #define	DRIVER_VERSION				"01-June-2011"
58 
59 /* CDC NCM subclass 3.2.1 */
60 #define USB_CDC_NCM_NDP16_LENGTH_MIN		0x10
61 
62 /* Maximum NTB length */
63 #define	CDC_NCM_NTB_MAX_SIZE_TX			16384	/* bytes */
64 #define	CDC_NCM_NTB_MAX_SIZE_RX			16384	/* bytes */
65 
66 /* Minimum value for MaxDatagramSize, ch. 6.2.9 */
67 #define	CDC_NCM_MIN_DATAGRAM_SIZE		1514	/* bytes */
68 
69 #define	CDC_NCM_MIN_TX_PKT			512	/* bytes */
70 
71 /* Default value for MaxDatagramSize */
72 #define	CDC_NCM_MAX_DATAGRAM_SIZE		2048	/* bytes */
73 
74 /*
75  * Maximum amount of datagrams in NCM Datagram Pointer Table, not counting
76  * the last NULL entry. Any additional datagrams in NTB would be discarded.
77  */
78 #define	CDC_NCM_DPT_DATAGRAMS_MAX		32
79 
80 /* Maximum amount of IN datagrams in NTB */
81 #define	CDC_NCM_DPT_DATAGRAMS_IN_MAX		0 /* unlimited */
82 
83 /* Restart the timer, if amount of datagrams is less than given value */
84 #define	CDC_NCM_RESTART_TIMER_DATAGRAM_CNT	3
85 
86 /* The following macro defines the minimum header space */
87 #define	CDC_NCM_MIN_HDR_SIZE \
88 	(sizeof(struct usb_cdc_ncm_nth16) + sizeof(struct usb_cdc_ncm_ndp16) + \
89 	(CDC_NCM_DPT_DATAGRAMS_MAX + 1) * sizeof(struct usb_cdc_ncm_dpe16))
90 
91 struct cdc_ncm_data {
92 	struct usb_cdc_ncm_nth16 nth16;
93 	struct usb_cdc_ncm_ndp16 ndp16;
94 	struct usb_cdc_ncm_dpe16 dpe16[CDC_NCM_DPT_DATAGRAMS_MAX + 1];
95 };
96 
97 struct cdc_ncm_ctx {
98 	struct cdc_ncm_data rx_ncm;
99 	struct cdc_ncm_data tx_ncm;
100 	struct usb_cdc_ncm_ntb_parameters ncm_parm;
101 	struct timer_list tx_timer;
102 
103 	const struct usb_cdc_ncm_desc *func_desc;
104 	const struct usb_cdc_header_desc *header_desc;
105 	const struct usb_cdc_union_desc *union_desc;
106 	const struct usb_cdc_ether_desc *ether_desc;
107 
108 	struct net_device *netdev;
109 	struct usb_device *udev;
110 	struct usb_host_endpoint *in_ep;
111 	struct usb_host_endpoint *out_ep;
112 	struct usb_host_endpoint *status_ep;
113 	struct usb_interface *intf;
114 	struct usb_interface *control;
115 	struct usb_interface *data;
116 
117 	struct sk_buff *tx_curr_skb;
118 	struct sk_buff *tx_rem_skb;
119 
120 	spinlock_t mtx;
121 
122 	u32 tx_timer_pending;
123 	u32 tx_curr_offset;
124 	u32 tx_curr_last_offset;
125 	u32 tx_curr_frame_num;
126 	u32 rx_speed;
127 	u32 tx_speed;
128 	u32 rx_max;
129 	u32 tx_max;
130 	u32 max_datagram_size;
131 	u16 tx_max_datagrams;
132 	u16 tx_remainder;
133 	u16 tx_modulus;
134 	u16 tx_ndp_modulus;
135 	u16 tx_seq;
136 	u16 connected;
137 };
138 
139 static void cdc_ncm_tx_timeout(unsigned long arg);
140 static const struct driver_info cdc_ncm_info;
141 static struct usb_driver cdc_ncm_driver;
142 static struct ethtool_ops cdc_ncm_ethtool_ops;
143 
144 static const struct usb_device_id cdc_devs[] = {
145 	{ USB_INTERFACE_INFO(USB_CLASS_COMM,
146 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
147 		.driver_info = (unsigned long)&cdc_ncm_info,
148 	},
149 	{
150 	},
151 };
152 
153 MODULE_DEVICE_TABLE(usb, cdc_devs);
154 
155 static void
156 cdc_ncm_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *info)
157 {
158 	struct usbnet *dev = netdev_priv(net);
159 
160 	strncpy(info->driver, dev->driver_name, sizeof(info->driver));
161 	strncpy(info->version, DRIVER_VERSION, sizeof(info->version));
162 	strncpy(info->fw_version, dev->driver_info->description,
163 		sizeof(info->fw_version));
164 	usb_make_path(dev->udev, info->bus_info, sizeof(info->bus_info));
165 }
166 
167 static int
168 cdc_ncm_do_request(struct cdc_ncm_ctx *ctx, struct usb_cdc_notification *req,
169 		   void *data, u16 flags, u16 *actlen, u16 timeout)
170 {
171 	int err;
172 
173 	err = usb_control_msg(ctx->udev, (req->bmRequestType & USB_DIR_IN) ?
174 				usb_rcvctrlpipe(ctx->udev, 0) :
175 				usb_sndctrlpipe(ctx->udev, 0),
176 				req->bNotificationType, req->bmRequestType,
177 				req->wValue,
178 				req->wIndex, data,
179 				req->wLength, timeout);
180 
181 	if (err < 0) {
182 		if (actlen)
183 			*actlen = 0;
184 		return err;
185 	}
186 
187 	if (actlen)
188 		*actlen = err;
189 
190 	return 0;
191 }
192 
193 static u8 cdc_ncm_setup(struct cdc_ncm_ctx *ctx)
194 {
195 	struct usb_cdc_notification req;
196 	u32 val;
197 	u8 flags;
198 	u8 iface_no;
199 	int err;
200 	u16 ntb_fmt_supported;
201 
202 	iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
203 
204 	req.bmRequestType = USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE;
205 	req.bNotificationType = USB_CDC_GET_NTB_PARAMETERS;
206 	req.wValue = 0;
207 	req.wIndex = cpu_to_le16(iface_no);
208 	req.wLength = cpu_to_le16(sizeof(ctx->ncm_parm));
209 
210 	err = cdc_ncm_do_request(ctx, &req, &ctx->ncm_parm, 0, NULL, 1000);
211 	if (err) {
212 		pr_debug("failed GET_NTB_PARAMETERS\n");
213 		return 1;
214 	}
215 
216 	/* read correct set of parameters according to device mode */
217 	ctx->rx_max = le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize);
218 	ctx->tx_max = le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize);
219 	ctx->tx_remainder = le16_to_cpu(ctx->ncm_parm.wNdpOutPayloadRemainder);
220 	ctx->tx_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutDivisor);
221 	ctx->tx_ndp_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutAlignment);
222 	/* devices prior to NCM Errata shall set this field to zero */
223 	ctx->tx_max_datagrams = le16_to_cpu(ctx->ncm_parm.wNtbOutMaxDatagrams);
224 	ntb_fmt_supported = le16_to_cpu(ctx->ncm_parm.bmNtbFormatsSupported);
225 
226 	if (ctx->func_desc != NULL)
227 		flags = ctx->func_desc->bmNetworkCapabilities;
228 	else
229 		flags = 0;
230 
231 	pr_debug("dwNtbInMaxSize=%u dwNtbOutMaxSize=%u "
232 		 "wNdpOutPayloadRemainder=%u wNdpOutDivisor=%u "
233 		 "wNdpOutAlignment=%u wNtbOutMaxDatagrams=%u flags=0x%x\n",
234 		 ctx->rx_max, ctx->tx_max, ctx->tx_remainder, ctx->tx_modulus,
235 		 ctx->tx_ndp_modulus, ctx->tx_max_datagrams, flags);
236 
237 	/* max count of tx datagrams */
238 	if ((ctx->tx_max_datagrams == 0) ||
239 			(ctx->tx_max_datagrams > CDC_NCM_DPT_DATAGRAMS_MAX))
240 		ctx->tx_max_datagrams = CDC_NCM_DPT_DATAGRAMS_MAX;
241 
242 	/* verify maximum size of received NTB in bytes */
243 	if (ctx->rx_max < USB_CDC_NCM_NTB_MIN_IN_SIZE) {
244 		pr_debug("Using min receive length=%d\n",
245 						USB_CDC_NCM_NTB_MIN_IN_SIZE);
246 		ctx->rx_max = USB_CDC_NCM_NTB_MIN_IN_SIZE;
247 	}
248 
249 	if (ctx->rx_max > CDC_NCM_NTB_MAX_SIZE_RX) {
250 		pr_debug("Using default maximum receive length=%d\n",
251 						CDC_NCM_NTB_MAX_SIZE_RX);
252 		ctx->rx_max = CDC_NCM_NTB_MAX_SIZE_RX;
253 	}
254 
255 	/* inform device about NTB input size changes */
256 	if (ctx->rx_max != le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize)) {
257 		req.bmRequestType = USB_TYPE_CLASS | USB_DIR_OUT |
258 							USB_RECIP_INTERFACE;
259 		req.bNotificationType = USB_CDC_SET_NTB_INPUT_SIZE;
260 		req.wValue = 0;
261 		req.wIndex = cpu_to_le16(iface_no);
262 
263 		if (flags & USB_CDC_NCM_NCAP_NTB_INPUT_SIZE) {
264 			struct usb_cdc_ncm_ndp_input_size ndp_in_sz;
265 
266 			req.wLength = 8;
267 			ndp_in_sz.dwNtbInMaxSize = cpu_to_le32(ctx->rx_max);
268 			ndp_in_sz.wNtbInMaxDatagrams =
269 					cpu_to_le16(CDC_NCM_DPT_DATAGRAMS_MAX);
270 			ndp_in_sz.wReserved = 0;
271 			err = cdc_ncm_do_request(ctx, &req, &ndp_in_sz, 0, NULL,
272 									1000);
273 		} else {
274 			__le32 dwNtbInMaxSize = cpu_to_le32(ctx->rx_max);
275 
276 			req.wLength = 4;
277 			err = cdc_ncm_do_request(ctx, &req, &dwNtbInMaxSize, 0,
278 								NULL, 1000);
279 		}
280 
281 		if (err)
282 			pr_debug("Setting NTB Input Size failed\n");
283 	}
284 
285 	/* verify maximum size of transmitted NTB in bytes */
286 	if ((ctx->tx_max <
287 	    (CDC_NCM_MIN_HDR_SIZE + CDC_NCM_MIN_DATAGRAM_SIZE)) ||
288 	    (ctx->tx_max > CDC_NCM_NTB_MAX_SIZE_TX)) {
289 		pr_debug("Using default maximum transmit length=%d\n",
290 						CDC_NCM_NTB_MAX_SIZE_TX);
291 		ctx->tx_max = CDC_NCM_NTB_MAX_SIZE_TX;
292 	}
293 
294 	/*
295 	 * verify that the structure alignment is:
296 	 * - power of two
297 	 * - not greater than the maximum transmit length
298 	 * - not less than four bytes
299 	 */
300 	val = ctx->tx_ndp_modulus;
301 
302 	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
303 	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
304 		pr_debug("Using default alignment: 4 bytes\n");
305 		ctx->tx_ndp_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
306 	}
307 
308 	/*
309 	 * verify that the payload alignment is:
310 	 * - power of two
311 	 * - not greater than the maximum transmit length
312 	 * - not less than four bytes
313 	 */
314 	val = ctx->tx_modulus;
315 
316 	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
317 	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
318 		pr_debug("Using default transmit modulus: 4 bytes\n");
319 		ctx->tx_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
320 	}
321 
322 	/* verify the payload remainder */
323 	if (ctx->tx_remainder >= ctx->tx_modulus) {
324 		pr_debug("Using default transmit remainder: 0 bytes\n");
325 		ctx->tx_remainder = 0;
326 	}
327 
328 	/* adjust TX-remainder according to NCM specification. */
329 	ctx->tx_remainder = ((ctx->tx_remainder - ETH_HLEN) &
330 						(ctx->tx_modulus - 1));
331 
332 	/* additional configuration */
333 
334 	/* set CRC Mode */
335 	if (flags & USB_CDC_NCM_NCAP_CRC_MODE) {
336 		req.bmRequestType = USB_TYPE_CLASS | USB_DIR_OUT |
337 							USB_RECIP_INTERFACE;
338 		req.bNotificationType = USB_CDC_SET_CRC_MODE;
339 		req.wValue = cpu_to_le16(USB_CDC_NCM_CRC_NOT_APPENDED);
340 		req.wIndex = cpu_to_le16(iface_no);
341 		req.wLength = 0;
342 
343 		err = cdc_ncm_do_request(ctx, &req, NULL, 0, NULL, 1000);
344 		if (err)
345 			pr_debug("Setting CRC mode off failed\n");
346 	}
347 
348 	/* set NTB format, if both formats are supported */
349 	if (ntb_fmt_supported & USB_CDC_NCM_NTH32_SIGN) {
350 		req.bmRequestType = USB_TYPE_CLASS | USB_DIR_OUT |
351 							USB_RECIP_INTERFACE;
352 		req.bNotificationType = USB_CDC_SET_NTB_FORMAT;
353 		req.wValue = cpu_to_le16(USB_CDC_NCM_NTB16_FORMAT);
354 		req.wIndex = cpu_to_le16(iface_no);
355 		req.wLength = 0;
356 
357 		err = cdc_ncm_do_request(ctx, &req, NULL, 0, NULL, 1000);
358 		if (err)
359 			pr_debug("Setting NTB format to 16-bit failed\n");
360 	}
361 
362 	ctx->max_datagram_size = CDC_NCM_MIN_DATAGRAM_SIZE;
363 
364 	/* set Max Datagram Size (MTU) */
365 	if (flags & USB_CDC_NCM_NCAP_MAX_DATAGRAM_SIZE) {
366 		__le16 max_datagram_size;
367 		u16 eth_max_sz = le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);
368 
369 		req.bmRequestType = USB_TYPE_CLASS | USB_DIR_IN |
370 							USB_RECIP_INTERFACE;
371 		req.bNotificationType = USB_CDC_GET_MAX_DATAGRAM_SIZE;
372 		req.wValue = 0;
373 		req.wIndex = cpu_to_le16(iface_no);
374 		req.wLength = cpu_to_le16(2);
375 
376 		err = cdc_ncm_do_request(ctx, &req, &max_datagram_size, 0, NULL,
377 									1000);
378 		if (err) {
379 			pr_debug("GET_MAX_DATAGRAM_SIZE failed, use size=%u\n",
380 						CDC_NCM_MIN_DATAGRAM_SIZE);
381 		} else {
382 			ctx->max_datagram_size = le16_to_cpu(max_datagram_size);
383 			/* Check Eth descriptor value */
384 			if (eth_max_sz < CDC_NCM_MAX_DATAGRAM_SIZE) {
385 				if (ctx->max_datagram_size > eth_max_sz)
386 					ctx->max_datagram_size = eth_max_sz;
387 			} else {
388 				if (ctx->max_datagram_size >
389 						CDC_NCM_MAX_DATAGRAM_SIZE)
390 					ctx->max_datagram_size =
391 						CDC_NCM_MAX_DATAGRAM_SIZE;
392 			}
393 
394 			if (ctx->max_datagram_size < CDC_NCM_MIN_DATAGRAM_SIZE)
395 				ctx->max_datagram_size =
396 					CDC_NCM_MIN_DATAGRAM_SIZE;
397 
398 			/* if value changed, update device */
399 			req.bmRequestType = USB_TYPE_CLASS | USB_DIR_OUT |
400 							USB_RECIP_INTERFACE;
401 			req.bNotificationType = USB_CDC_SET_MAX_DATAGRAM_SIZE;
402 			req.wValue = 0;
403 			req.wIndex = cpu_to_le16(iface_no);
404 			req.wLength = 2;
405 			max_datagram_size = cpu_to_le16(ctx->max_datagram_size);
406 
407 			err = cdc_ncm_do_request(ctx, &req, &max_datagram_size,
408 								0, NULL, 1000);
409 			if (err)
410 				pr_debug("SET_MAX_DATAGRAM_SIZE failed\n");
411 		}
412 
413 	}
414 
415 	if (ctx->netdev->mtu != (ctx->max_datagram_size - ETH_HLEN))
416 		ctx->netdev->mtu = ctx->max_datagram_size - ETH_HLEN;
417 
418 	return 0;
419 }
420 
421 static void
422 cdc_ncm_find_endpoints(struct cdc_ncm_ctx *ctx, struct usb_interface *intf)
423 {
424 	struct usb_host_endpoint *e;
425 	u8 ep;
426 
427 	for (ep = 0; ep < intf->cur_altsetting->desc.bNumEndpoints; ep++) {
428 
429 		e = intf->cur_altsetting->endpoint + ep;
430 		switch (e->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
431 		case USB_ENDPOINT_XFER_INT:
432 			if (usb_endpoint_dir_in(&e->desc)) {
433 				if (ctx->status_ep == NULL)
434 					ctx->status_ep = e;
435 			}
436 			break;
437 
438 		case USB_ENDPOINT_XFER_BULK:
439 			if (usb_endpoint_dir_in(&e->desc)) {
440 				if (ctx->in_ep == NULL)
441 					ctx->in_ep = e;
442 			} else {
443 				if (ctx->out_ep == NULL)
444 					ctx->out_ep = e;
445 			}
446 			break;
447 
448 		default:
449 			break;
450 		}
451 	}
452 }
453 
454 static void cdc_ncm_free(struct cdc_ncm_ctx *ctx)
455 {
456 	if (ctx == NULL)
457 		return;
458 
459 	del_timer_sync(&ctx->tx_timer);
460 
461 	if (ctx->tx_rem_skb != NULL) {
462 		dev_kfree_skb_any(ctx->tx_rem_skb);
463 		ctx->tx_rem_skb = NULL;
464 	}
465 
466 	if (ctx->tx_curr_skb != NULL) {
467 		dev_kfree_skb_any(ctx->tx_curr_skb);
468 		ctx->tx_curr_skb = NULL;
469 	}
470 
471 	kfree(ctx);
472 }
473 
474 static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
475 {
476 	struct cdc_ncm_ctx *ctx;
477 	struct usb_driver *driver;
478 	u8 *buf;
479 	int len;
480 	int temp;
481 	u8 iface_no;
482 
483 	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
484 	if (ctx == NULL)
485 		return -ENODEV;
486 
487 	memset(ctx, 0, sizeof(*ctx));
488 
489 	init_timer(&ctx->tx_timer);
490 	spin_lock_init(&ctx->mtx);
491 	ctx->netdev = dev->net;
492 
493 	/* store ctx pointer in device data field */
494 	dev->data[0] = (unsigned long)ctx;
495 
496 	/* get some pointers */
497 	driver = driver_of(intf);
498 	buf = intf->cur_altsetting->extra;
499 	len = intf->cur_altsetting->extralen;
500 
501 	ctx->udev = dev->udev;
502 	ctx->intf = intf;
503 
504 	/* parse through descriptors associated with control interface */
505 	while ((len > 0) && (buf[0] > 2) && (buf[0] <= len)) {
506 
507 		if (buf[1] != USB_DT_CS_INTERFACE)
508 			goto advance;
509 
510 		switch (buf[2]) {
511 		case USB_CDC_UNION_TYPE:
512 			if (buf[0] < sizeof(*(ctx->union_desc)))
513 				break;
514 
515 			ctx->union_desc =
516 					(const struct usb_cdc_union_desc *)buf;
517 
518 			ctx->control = usb_ifnum_to_if(dev->udev,
519 					ctx->union_desc->bMasterInterface0);
520 			ctx->data = usb_ifnum_to_if(dev->udev,
521 					ctx->union_desc->bSlaveInterface0);
522 			break;
523 
524 		case USB_CDC_ETHERNET_TYPE:
525 			if (buf[0] < sizeof(*(ctx->ether_desc)))
526 				break;
527 
528 			ctx->ether_desc =
529 					(const struct usb_cdc_ether_desc *)buf;
530 			dev->hard_mtu =
531 				le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);
532 
533 			if (dev->hard_mtu < CDC_NCM_MIN_DATAGRAM_SIZE)
534 				dev->hard_mtu =	CDC_NCM_MIN_DATAGRAM_SIZE;
535 			else if (dev->hard_mtu > CDC_NCM_MAX_DATAGRAM_SIZE)
536 				dev->hard_mtu =	CDC_NCM_MAX_DATAGRAM_SIZE;
537 			break;
538 
539 		case USB_CDC_NCM_TYPE:
540 			if (buf[0] < sizeof(*(ctx->func_desc)))
541 				break;
542 
543 			ctx->func_desc = (const struct usb_cdc_ncm_desc *)buf;
544 			break;
545 
546 		default:
547 			break;
548 		}
549 advance:
550 		/* advance to next descriptor */
551 		temp = buf[0];
552 		buf += temp;
553 		len -= temp;
554 	}
555 
556 	/* check if we got everything */
557 	if ((ctx->control == NULL) || (ctx->data == NULL) ||
558 	    (ctx->ether_desc == NULL) || (ctx->control != intf))
559 		goto error;
560 
561 	/* claim interfaces, if any */
562 	temp = usb_driver_claim_interface(driver, ctx->data, dev);
563 	if (temp)
564 		goto error;
565 
566 	iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
567 
568 	/* reset data interface */
569 	temp = usb_set_interface(dev->udev, iface_no, 0);
570 	if (temp)
571 		goto error2;
572 
573 	/* initialize data interface */
574 	if (cdc_ncm_setup(ctx))
575 		goto error2;
576 
577 	/* configure data interface */
578 	temp = usb_set_interface(dev->udev, iface_no, 1);
579 	if (temp)
580 		goto error2;
581 
582 	cdc_ncm_find_endpoints(ctx, ctx->data);
583 	cdc_ncm_find_endpoints(ctx, ctx->control);
584 
585 	if ((ctx->in_ep == NULL) || (ctx->out_ep == NULL) ||
586 	    (ctx->status_ep == NULL))
587 		goto error2;
588 
589 	dev->net->ethtool_ops = &cdc_ncm_ethtool_ops;
590 
591 	usb_set_intfdata(ctx->data, dev);
592 	usb_set_intfdata(ctx->control, dev);
593 	usb_set_intfdata(ctx->intf, dev);
594 
595 	temp = usbnet_get_ethernet_addr(dev, ctx->ether_desc->iMACAddress);
596 	if (temp)
597 		goto error2;
598 
599 	dev_info(&dev->udev->dev, "MAC-Address: "
600 				"0x%02x:0x%02x:0x%02x:0x%02x:0x%02x:0x%02x\n",
601 				dev->net->dev_addr[0], dev->net->dev_addr[1],
602 				dev->net->dev_addr[2], dev->net->dev_addr[3],
603 				dev->net->dev_addr[4], dev->net->dev_addr[5]);
604 
605 	dev->in = usb_rcvbulkpipe(dev->udev,
606 		ctx->in_ep->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
607 	dev->out = usb_sndbulkpipe(dev->udev,
608 		ctx->out_ep->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
609 	dev->status = ctx->status_ep;
610 	dev->rx_urb_size = ctx->rx_max;
611 
612 	/*
613 	 * We should get an event when network connection is "connected" or
614 	 * "disconnected". Set network connection in "disconnected" state
615 	 * (carrier is OFF) during attach, so the IP network stack does not
616 	 * start IPv6 negotiation and more.
617 	 */
618 	netif_carrier_off(dev->net);
619 	ctx->tx_speed = ctx->rx_speed = 0;
620 	return 0;
621 
622 error2:
623 	usb_set_intfdata(ctx->control, NULL);
624 	usb_set_intfdata(ctx->data, NULL);
625 	usb_driver_release_interface(driver, ctx->data);
626 error:
627 	cdc_ncm_free((struct cdc_ncm_ctx *)dev->data[0]);
628 	dev->data[0] = 0;
629 	dev_info(&dev->udev->dev, "bind() failure\n");
630 	return -ENODEV;
631 }
632 
633 static void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
634 {
635 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
636 	struct usb_driver *driver = driver_of(intf);
637 
638 	if (ctx == NULL)
639 		return;		/* no setup */
640 
641 	/* disconnect master --> disconnect slave */
642 	if (intf == ctx->control && ctx->data) {
643 		usb_set_intfdata(ctx->data, NULL);
644 		usb_driver_release_interface(driver, ctx->data);
645 		ctx->data = NULL;
646 
647 	} else if (intf == ctx->data && ctx->control) {
648 		usb_set_intfdata(ctx->control, NULL);
649 		usb_driver_release_interface(driver, ctx->control);
650 		ctx->control = NULL;
651 	}
652 
653 	usb_set_intfdata(ctx->intf, NULL);
654 	cdc_ncm_free(ctx);
655 }
656 
657 static void cdc_ncm_zero_fill(u8 *ptr, u32 first, u32 end, u32 max)
658 {
659 	if (first >= max)
660 		return;
661 	if (first >= end)
662 		return;
663 	if (end > max)
664 		end = max;
665 	memset(ptr + first, 0, end - first);
666 }
667 
668 static struct sk_buff *
669 cdc_ncm_fill_tx_frame(struct cdc_ncm_ctx *ctx, struct sk_buff *skb)
670 {
671 	struct sk_buff *skb_out;
672 	u32 rem;
673 	u32 offset;
674 	u32 last_offset;
675 	u16 n = 0;
676 	u8 ready2send = 0;
677 
678 	/* if there is a remaining skb, it gets priority */
679 	if (skb != NULL)
680 		swap(skb, ctx->tx_rem_skb);
681 	else
682 		ready2send = 1;
683 
684 	/*
685 	 * +----------------+
686 	 * | skb_out        |
687 	 * +----------------+
688 	 *           ^ offset
689 	 *        ^ last_offset
690 	 */
691 
692 	/* check if we are resuming an OUT skb */
693 	if (ctx->tx_curr_skb != NULL) {
694 		/* pop variables */
695 		skb_out = ctx->tx_curr_skb;
696 		offset = ctx->tx_curr_offset;
697 		last_offset = ctx->tx_curr_last_offset;
698 		n = ctx->tx_curr_frame_num;
699 
700 	} else {
701 		/* reset variables */
702 		skb_out = alloc_skb((ctx->tx_max + 1), GFP_ATOMIC);
703 		if (skb_out == NULL) {
704 			if (skb != NULL) {
705 				dev_kfree_skb_any(skb);
706 				ctx->netdev->stats.tx_dropped++;
707 			}
708 			goto exit_no_skb;
709 		}
710 
711 		/* make room for NTH and NDP */
712 		offset = ALIGN(sizeof(struct usb_cdc_ncm_nth16),
713 					ctx->tx_ndp_modulus) +
714 					sizeof(struct usb_cdc_ncm_ndp16) +
715 					(ctx->tx_max_datagrams + 1) *
716 					sizeof(struct usb_cdc_ncm_dpe16);
717 
718 		/* store last valid offset before alignment */
719 		last_offset = offset;
720 		/* align first Datagram offset correctly */
721 		offset = ALIGN(offset, ctx->tx_modulus) + ctx->tx_remainder;
722 		/* zero buffer till the first IP datagram */
723 		cdc_ncm_zero_fill(skb_out->data, 0, offset, offset);
724 		n = 0;
725 		ctx->tx_curr_frame_num = 0;
726 	}
727 
728 	for (; n < ctx->tx_max_datagrams; n++) {
729 		/* check if end of transmit buffer is reached */
730 		if (offset >= ctx->tx_max) {
731 			ready2send = 1;
732 			break;
733 		}
734 		/* compute maximum buffer size */
735 		rem = ctx->tx_max - offset;
736 
737 		if (skb == NULL) {
738 			skb = ctx->tx_rem_skb;
739 			ctx->tx_rem_skb = NULL;
740 
741 			/* check for end of skb */
742 			if (skb == NULL)
743 				break;
744 		}
745 
746 		if (skb->len > rem) {
747 			if (n == 0) {
748 				/* won't fit, MTU problem? */
749 				dev_kfree_skb_any(skb);
750 				skb = NULL;
751 				ctx->netdev->stats.tx_dropped++;
752 			} else {
753 				/* no room for skb - store for later */
754 				if (ctx->tx_rem_skb != NULL) {
755 					dev_kfree_skb_any(ctx->tx_rem_skb);
756 					ctx->netdev->stats.tx_dropped++;
757 				}
758 				ctx->tx_rem_skb = skb;
759 				skb = NULL;
760 				ready2send = 1;
761 			}
762 			break;
763 		}
764 
765 		memcpy(((u8 *)skb_out->data) + offset, skb->data, skb->len);
766 
767 		ctx->tx_ncm.dpe16[n].wDatagramLength = cpu_to_le16(skb->len);
768 		ctx->tx_ncm.dpe16[n].wDatagramIndex = cpu_to_le16(offset);
769 
770 		/* update offset */
771 		offset += skb->len;
772 
773 		/* store last valid offset before alignment */
774 		last_offset = offset;
775 
776 		/* align offset correctly */
777 		offset = ALIGN(offset, ctx->tx_modulus) + ctx->tx_remainder;
778 
779 		/* zero padding */
780 		cdc_ncm_zero_fill(skb_out->data, last_offset, offset,
781 								ctx->tx_max);
782 		dev_kfree_skb_any(skb);
783 		skb = NULL;
784 	}
785 
786 	/* free up any dangling skb */
787 	if (skb != NULL) {
788 		dev_kfree_skb_any(skb);
789 		skb = NULL;
790 		ctx->netdev->stats.tx_dropped++;
791 	}
792 
793 	ctx->tx_curr_frame_num = n;
794 
795 	if (n == 0) {
796 		/* wait for more frames */
797 		/* push variables */
798 		ctx->tx_curr_skb = skb_out;
799 		ctx->tx_curr_offset = offset;
800 		ctx->tx_curr_last_offset = last_offset;
801 		goto exit_no_skb;
802 
803 	} else if ((n < ctx->tx_max_datagrams) && (ready2send == 0)) {
804 		/* wait for more frames */
805 		/* push variables */
806 		ctx->tx_curr_skb = skb_out;
807 		ctx->tx_curr_offset = offset;
808 		ctx->tx_curr_last_offset = last_offset;
809 		/* set the pending count */
810 		if (n < CDC_NCM_RESTART_TIMER_DATAGRAM_CNT)
811 			ctx->tx_timer_pending = 2;
812 		goto exit_no_skb;
813 
814 	} else {
815 		/* frame goes out */
816 		/* variables will be reset at next call */
817 	}
818 
819 	/* check for overflow */
820 	if (last_offset > ctx->tx_max)
821 		last_offset = ctx->tx_max;
822 
823 	/* revert offset */
824 	offset = last_offset;
825 
826 	/*
827 	 * If collected data size is less or equal CDC_NCM_MIN_TX_PKT bytes,
828 	 * we send buffers as it is. If we get more data, it would be more
829 	 * efficient for USB HS mobile device with DMA engine to receive a full
830 	 * size NTB, than canceling DMA transfer and receiving a short packet.
831 	 */
832 	if (offset > CDC_NCM_MIN_TX_PKT)
833 		offset = ctx->tx_max;
834 
835 	/* final zero padding */
836 	cdc_ncm_zero_fill(skb_out->data, last_offset, offset, ctx->tx_max);
837 
838 	/* store last offset */
839 	last_offset = offset;
840 
841 	if (((last_offset < ctx->tx_max) && ((last_offset %
842 			le16_to_cpu(ctx->out_ep->desc.wMaxPacketSize)) == 0)) ||
843 	    (((last_offset == ctx->tx_max) && ((ctx->tx_max %
844 		le16_to_cpu(ctx->out_ep->desc.wMaxPacketSize)) == 0)) &&
845 		(ctx->tx_max < le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize)))) {
846 		/* force short packet */
847 		*(((u8 *)skb_out->data) + last_offset) = 0;
848 		last_offset++;
849 	}
850 
851 	/* zero the rest of the DPEs plus the last NULL entry */
852 	for (; n <= CDC_NCM_DPT_DATAGRAMS_MAX; n++) {
853 		ctx->tx_ncm.dpe16[n].wDatagramLength = 0;
854 		ctx->tx_ncm.dpe16[n].wDatagramIndex = 0;
855 	}
856 
857 	/* fill out 16-bit NTB header */
858 	ctx->tx_ncm.nth16.dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN);
859 	ctx->tx_ncm.nth16.wHeaderLength =
860 					cpu_to_le16(sizeof(ctx->tx_ncm.nth16));
861 	ctx->tx_ncm.nth16.wSequence = cpu_to_le16(ctx->tx_seq);
862 	ctx->tx_ncm.nth16.wBlockLength = cpu_to_le16(last_offset);
863 	ctx->tx_ncm.nth16.wNdpIndex = ALIGN(sizeof(struct usb_cdc_ncm_nth16),
864 							ctx->tx_ndp_modulus);
865 
866 	memcpy(skb_out->data, &(ctx->tx_ncm.nth16), sizeof(ctx->tx_ncm.nth16));
867 	ctx->tx_seq++;
868 
869 	/* fill out 16-bit NDP table */
870 	ctx->tx_ncm.ndp16.dwSignature =
871 				cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN);
872 	rem = sizeof(ctx->tx_ncm.ndp16) + ((ctx->tx_curr_frame_num + 1) *
873 					sizeof(struct usb_cdc_ncm_dpe16));
874 	ctx->tx_ncm.ndp16.wLength = cpu_to_le16(rem);
875 	ctx->tx_ncm.ndp16.wNextNdpIndex = 0; /* reserved */
876 
877 	memcpy(((u8 *)skb_out->data) + ctx->tx_ncm.nth16.wNdpIndex,
878 						&(ctx->tx_ncm.ndp16),
879 						sizeof(ctx->tx_ncm.ndp16));
880 
881 	memcpy(((u8 *)skb_out->data) + ctx->tx_ncm.nth16.wNdpIndex +
882 					sizeof(ctx->tx_ncm.ndp16),
883 					&(ctx->tx_ncm.dpe16),
884 					(ctx->tx_curr_frame_num + 1) *
885 					sizeof(struct usb_cdc_ncm_dpe16));
886 
887 	/* set frame length */
888 	skb_put(skb_out, last_offset);
889 
890 	/* return skb */
891 	ctx->tx_curr_skb = NULL;
892 	return skb_out;
893 
894 exit_no_skb:
895 	return NULL;
896 }
897 
898 static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx)
899 {
900 	/* start timer, if not already started */
901 	if (timer_pending(&ctx->tx_timer) == 0) {
902 		ctx->tx_timer.function = &cdc_ncm_tx_timeout;
903 		ctx->tx_timer.data = (unsigned long)ctx;
904 		ctx->tx_timer.expires = jiffies + ((HZ + 999) / 1000);
905 		add_timer(&ctx->tx_timer);
906 	}
907 }
908 
909 static void cdc_ncm_tx_timeout(unsigned long arg)
910 {
911 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)arg;
912 	u8 restart;
913 
914 	spin_lock(&ctx->mtx);
915 	if (ctx->tx_timer_pending != 0) {
916 		ctx->tx_timer_pending--;
917 		restart = 1;
918 	} else {
919 		restart = 0;
920 	}
921 
922 	spin_unlock(&ctx->mtx);
923 
924 	if (restart) {
925 		spin_lock(&ctx->mtx);
926 		cdc_ncm_tx_timeout_start(ctx);
927 		spin_unlock(&ctx->mtx);
928 	} else if (ctx->netdev != NULL) {
929 		usbnet_start_xmit(NULL, ctx->netdev);
930 	}
931 }
932 
933 static struct sk_buff *
934 cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
935 {
936 	struct sk_buff *skb_out;
937 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
938 	u8 need_timer = 0;
939 
940 	/*
941 	 * The Ethernet API we are using does not support transmitting
942 	 * multiple Ethernet frames in a single call. This driver will
943 	 * accumulate multiple Ethernet frames and send out a larger
944 	 * USB frame when the USB buffer is full or when a single jiffies
945 	 * timeout happens.
946 	 */
947 	if (ctx == NULL)
948 		goto error;
949 
950 	spin_lock(&ctx->mtx);
951 	skb_out = cdc_ncm_fill_tx_frame(ctx, skb);
952 	if (ctx->tx_curr_skb != NULL)
953 		need_timer = 1;
954 
955 	/* Start timer, if there is a remaining skb */
956 	if (need_timer)
957 		cdc_ncm_tx_timeout_start(ctx);
958 
959 	if (skb_out)
960 		dev->net->stats.tx_packets += ctx->tx_curr_frame_num;
961 
962 	spin_unlock(&ctx->mtx);
963 	return skb_out;
964 
965 error:
966 	if (skb != NULL)
967 		dev_kfree_skb_any(skb);
968 
969 	return NULL;
970 }
971 
972 static int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
973 {
974 	struct sk_buff *skb;
975 	struct cdc_ncm_ctx *ctx;
976 	int sumlen;
977 	int actlen;
978 	int temp;
979 	int nframes;
980 	int x;
981 	int offset;
982 
983 	ctx = (struct cdc_ncm_ctx *)dev->data[0];
984 	if (ctx == NULL)
985 		goto error;
986 
987 	actlen = skb_in->len;
988 	sumlen = CDC_NCM_NTB_MAX_SIZE_RX;
989 
990 	if (actlen < (sizeof(ctx->rx_ncm.nth16) + sizeof(ctx->rx_ncm.ndp16))) {
991 		pr_debug("frame too short\n");
992 		goto error;
993 	}
994 
995 	memcpy(&(ctx->rx_ncm.nth16), ((u8 *)skb_in->data),
996 						sizeof(ctx->rx_ncm.nth16));
997 
998 	if (le32_to_cpu(ctx->rx_ncm.nth16.dwSignature) !=
999 	    USB_CDC_NCM_NTH16_SIGN) {
1000 		pr_debug("invalid NTH16 signature <%u>\n",
1001 			 le32_to_cpu(ctx->rx_ncm.nth16.dwSignature));
1002 		goto error;
1003 	}
1004 
1005 	temp = le16_to_cpu(ctx->rx_ncm.nth16.wBlockLength);
1006 	if (temp > sumlen) {
1007 		pr_debug("unsupported NTB block length %u/%u\n", temp, sumlen);
1008 		goto error;
1009 	}
1010 
1011 	temp = le16_to_cpu(ctx->rx_ncm.nth16.wNdpIndex);
1012 	if ((temp + sizeof(ctx->rx_ncm.ndp16)) > actlen) {
1013 		pr_debug("invalid DPT16 index\n");
1014 		goto error;
1015 	}
1016 
1017 	memcpy(&(ctx->rx_ncm.ndp16), ((u8 *)skb_in->data) + temp,
1018 						sizeof(ctx->rx_ncm.ndp16));
1019 
1020 	if (le32_to_cpu(ctx->rx_ncm.ndp16.dwSignature) !=
1021 	    USB_CDC_NCM_NDP16_NOCRC_SIGN) {
1022 		pr_debug("invalid DPT16 signature <%u>\n",
1023 			 le32_to_cpu(ctx->rx_ncm.ndp16.dwSignature));
1024 		goto error;
1025 	}
1026 
1027 	if (le16_to_cpu(ctx->rx_ncm.ndp16.wLength) <
1028 	    USB_CDC_NCM_NDP16_LENGTH_MIN) {
1029 		pr_debug("invalid DPT16 length <%u>\n",
1030 			 le32_to_cpu(ctx->rx_ncm.ndp16.dwSignature));
1031 		goto error;
1032 	}
1033 
1034 	nframes = ((le16_to_cpu(ctx->rx_ncm.ndp16.wLength) -
1035 					sizeof(struct usb_cdc_ncm_ndp16)) /
1036 					sizeof(struct usb_cdc_ncm_dpe16));
1037 	nframes--; /* we process NDP entries except for the last one */
1038 
1039 	pr_debug("nframes = %u\n", nframes);
1040 
1041 	temp += sizeof(ctx->rx_ncm.ndp16);
1042 
1043 	if ((temp + nframes * (sizeof(struct usb_cdc_ncm_dpe16))) > actlen) {
1044 		pr_debug("Invalid nframes = %d\n", nframes);
1045 		goto error;
1046 	}
1047 
1048 	if (nframes > CDC_NCM_DPT_DATAGRAMS_MAX) {
1049 		pr_debug("Truncating number of frames from %u to %u\n",
1050 					nframes, CDC_NCM_DPT_DATAGRAMS_MAX);
1051 		nframes = CDC_NCM_DPT_DATAGRAMS_MAX;
1052 	}
1053 
1054 	memcpy(&(ctx->rx_ncm.dpe16), ((u8 *)skb_in->data) + temp,
1055 				nframes * (sizeof(struct usb_cdc_ncm_dpe16)));
1056 
1057 	for (x = 0; x < nframes; x++) {
1058 		offset = le16_to_cpu(ctx->rx_ncm.dpe16[x].wDatagramIndex);
1059 		temp = le16_to_cpu(ctx->rx_ncm.dpe16[x].wDatagramLength);
1060 
1061 		/*
1062 		 * CDC NCM ch. 3.7
1063 		 * All entries after first NULL entry are to be ignored
1064 		 */
1065 		if ((offset == 0) || (temp == 0)) {
1066 			if (!x)
1067 				goto error; /* empty NTB */
1068 			break;
1069 		}
1070 
1071 		/* sanity checking */
1072 		if (((offset + temp) > actlen) ||
1073 		    (temp > CDC_NCM_MAX_DATAGRAM_SIZE) || (temp < ETH_HLEN)) {
1074 			pr_debug("invalid frame detected (ignored)"
1075 					"offset[%u]=%u, length=%u, skb=%p\n",
1076 					x, offset, temp, skb_in);
1077 			if (!x)
1078 				goto error;
1079 			break;
1080 
1081 		} else {
1082 			skb = skb_clone(skb_in, GFP_ATOMIC);
1083 			if (!skb)
1084 				goto error;
1085 			skb->len = temp;
1086 			skb->data = ((u8 *)skb_in->data) + offset;
1087 			skb_set_tail_pointer(skb, temp);
1088 			usbnet_skb_return(dev, skb);
1089 		}
1090 	}
1091 	return 1;
1092 error:
1093 	return 0;
1094 }
1095 
1096 static void
1097 cdc_ncm_speed_change(struct cdc_ncm_ctx *ctx,
1098 		     struct usb_cdc_speed_change *data)
1099 {
1100 	uint32_t rx_speed = le32_to_cpu(data->DLBitRRate);
1101 	uint32_t tx_speed = le32_to_cpu(data->ULBitRate);
1102 
1103 	/*
1104 	 * Currently the USB-NET API does not support reporting the actual
1105 	 * device speed. Do print it instead.
1106 	 */
1107 	if ((tx_speed != ctx->tx_speed) || (rx_speed != ctx->rx_speed)) {
1108 		ctx->tx_speed = tx_speed;
1109 		ctx->rx_speed = rx_speed;
1110 
1111 		if ((tx_speed > 1000000) && (rx_speed > 1000000)) {
1112 			printk(KERN_INFO KBUILD_MODNAME
1113 				": %s: %u mbit/s downlink "
1114 				"%u mbit/s uplink\n",
1115 				ctx->netdev->name,
1116 				(unsigned int)(rx_speed / 1000000U),
1117 				(unsigned int)(tx_speed / 1000000U));
1118 		} else {
1119 			printk(KERN_INFO KBUILD_MODNAME
1120 				": %s: %u kbit/s downlink "
1121 				"%u kbit/s uplink\n",
1122 				ctx->netdev->name,
1123 				(unsigned int)(rx_speed / 1000U),
1124 				(unsigned int)(tx_speed / 1000U));
1125 		}
1126 	}
1127 }
1128 
1129 static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
1130 {
1131 	struct cdc_ncm_ctx *ctx;
1132 	struct usb_cdc_notification *event;
1133 
1134 	ctx = (struct cdc_ncm_ctx *)dev->data[0];
1135 
1136 	if (urb->actual_length < sizeof(*event))
1137 		return;
1138 
1139 	/* test for split data in 8-byte chunks */
1140 	if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
1141 		cdc_ncm_speed_change(ctx,
1142 		      (struct usb_cdc_speed_change *)urb->transfer_buffer);
1143 		return;
1144 	}
1145 
1146 	event = urb->transfer_buffer;
1147 
1148 	switch (event->bNotificationType) {
1149 	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
1150 		/*
1151 		 * According to the CDC NCM specification ch.7.1
1152 		 * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be
1153 		 * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE.
1154 		 */
1155 		ctx->connected = event->wValue;
1156 
1157 		printk(KERN_INFO KBUILD_MODNAME ": %s: network connection:"
1158 			" %sconnected\n",
1159 			ctx->netdev->name, ctx->connected ? "" : "dis");
1160 
1161 		if (ctx->connected)
1162 			netif_carrier_on(dev->net);
1163 		else {
1164 			netif_carrier_off(dev->net);
1165 			ctx->tx_speed = ctx->rx_speed = 0;
1166 		}
1167 		break;
1168 
1169 	case USB_CDC_NOTIFY_SPEED_CHANGE:
1170 		if (urb->actual_length < (sizeof(*event) +
1171 					sizeof(struct usb_cdc_speed_change)))
1172 			set_bit(EVENT_STS_SPLIT, &dev->flags);
1173 		else
1174 			cdc_ncm_speed_change(ctx,
1175 				(struct usb_cdc_speed_change *) &event[1]);
1176 		break;
1177 
1178 	default:
1179 		dev_err(&dev->udev->dev, "NCM: unexpected "
1180 			"notification 0x%02x!\n", event->bNotificationType);
1181 		break;
1182 	}
1183 }
1184 
1185 static int cdc_ncm_check_connect(struct usbnet *dev)
1186 {
1187 	struct cdc_ncm_ctx *ctx;
1188 
1189 	ctx = (struct cdc_ncm_ctx *)dev->data[0];
1190 	if (ctx == NULL)
1191 		return 1;	/* disconnected */
1192 
1193 	return !ctx->connected;
1194 }
1195 
1196 static int
1197 cdc_ncm_probe(struct usb_interface *udev, const struct usb_device_id *prod)
1198 {
1199 	return usbnet_probe(udev, prod);
1200 }
1201 
1202 static void cdc_ncm_disconnect(struct usb_interface *intf)
1203 {
1204 	struct usbnet *dev = usb_get_intfdata(intf);
1205 
1206 	if (dev == NULL)
1207 		return;		/* already disconnected */
1208 
1209 	usbnet_disconnect(intf);
1210 }
1211 
1212 static int cdc_ncm_manage_power(struct usbnet *dev, int status)
1213 {
1214 	dev->intf->needs_remote_wakeup = status;
1215 	return 0;
1216 }
1217 
1218 static const struct driver_info cdc_ncm_info = {
1219 	.description = "CDC NCM",
1220 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET,
1221 	.bind = cdc_ncm_bind,
1222 	.unbind = cdc_ncm_unbind,
1223 	.check_connect = cdc_ncm_check_connect,
1224 	.manage_power = cdc_ncm_manage_power,
1225 	.status = cdc_ncm_status,
1226 	.rx_fixup = cdc_ncm_rx_fixup,
1227 	.tx_fixup = cdc_ncm_tx_fixup,
1228 };
1229 
1230 static struct usb_driver cdc_ncm_driver = {
1231 	.name = "cdc_ncm",
1232 	.id_table = cdc_devs,
1233 	.probe = cdc_ncm_probe,
1234 	.disconnect = cdc_ncm_disconnect,
1235 	.suspend = usbnet_suspend,
1236 	.resume = usbnet_resume,
1237 	.reset_resume =	usbnet_resume,
1238 	.supports_autosuspend = 1,
1239 };
1240 
1241 static struct ethtool_ops cdc_ncm_ethtool_ops = {
1242 	.get_drvinfo = cdc_ncm_get_drvinfo,
1243 	.get_link = usbnet_get_link,
1244 	.get_msglevel = usbnet_get_msglevel,
1245 	.set_msglevel = usbnet_set_msglevel,
1246 	.get_settings = usbnet_get_settings,
1247 	.set_settings = usbnet_set_settings,
1248 	.nway_reset = usbnet_nway_reset,
1249 };
1250 
1251 static int __init cdc_ncm_init(void)
1252 {
1253 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION "\n");
1254 	return usb_register(&cdc_ncm_driver);
1255 }
1256 
1257 module_init(cdc_ncm_init);
1258 
1259 static void __exit cdc_ncm_exit(void)
1260 {
1261 	usb_deregister(&cdc_ncm_driver);
1262 }
1263 
1264 module_exit(cdc_ncm_exit);
1265 
1266 MODULE_AUTHOR("Hans Petter Selasky");
1267 MODULE_DESCRIPTION("USB CDC NCM host driver");
1268 MODULE_LICENSE("Dual BSD/GPL");
1269