xref: /linux/drivers/net/usb/cdc_ncm.c (revision 8a5617bdc111aa7ba49c81fa694fde63d3474f94)
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				"23-Apr-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 + 4) /* bytes, must be short terminated */
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 	u8 data_claimed;
138 	u8 control_claimed;
139 };
140 
141 static void cdc_ncm_tx_timeout(unsigned long arg);
142 static const struct driver_info cdc_ncm_info;
143 static struct usb_driver cdc_ncm_driver;
144 static struct ethtool_ops cdc_ncm_ethtool_ops;
145 
146 static const struct usb_device_id cdc_devs[] = {
147 	{ USB_INTERFACE_INFO(USB_CLASS_COMM,
148 		USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
149 		.driver_info = (unsigned long)&cdc_ncm_info,
150 	},
151 	{
152 	},
153 };
154 
155 MODULE_DEVICE_TABLE(usb, cdc_devs);
156 
157 static void
158 cdc_ncm_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *info)
159 {
160 	struct usbnet *dev = netdev_priv(net);
161 
162 	strncpy(info->driver, dev->driver_name, sizeof(info->driver));
163 	strncpy(info->version, DRIVER_VERSION, sizeof(info->version));
164 	strncpy(info->fw_version, dev->driver_info->description,
165 		sizeof(info->fw_version));
166 	usb_make_path(dev->udev, info->bus_info, sizeof(info->bus_info));
167 }
168 
169 static int
170 cdc_ncm_do_request(struct cdc_ncm_ctx *ctx, struct usb_cdc_notification *req,
171 		   void *data, u16 flags, u16 *actlen, u16 timeout)
172 {
173 	int err;
174 
175 	err = usb_control_msg(ctx->udev, (req->bmRequestType & USB_DIR_IN) ?
176 				usb_rcvctrlpipe(ctx->udev, 0) :
177 				usb_sndctrlpipe(ctx->udev, 0),
178 				req->bNotificationType, req->bmRequestType,
179 				req->wValue,
180 				req->wIndex, data,
181 				req->wLength, timeout);
182 
183 	if (err < 0) {
184 		if (actlen)
185 			*actlen = 0;
186 		return err;
187 	}
188 
189 	if (actlen)
190 		*actlen = err;
191 
192 	return 0;
193 }
194 
195 static u8 cdc_ncm_setup(struct cdc_ncm_ctx *ctx)
196 {
197 	struct usb_cdc_notification req;
198 	u32 val;
199 	u8 flags;
200 	u8 iface_no;
201 	int err;
202 	u16 ntb_fmt_supported;
203 
204 	iface_no = ctx->control->cur_altsetting->desc.bInterfaceNumber;
205 
206 	req.bmRequestType = USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE;
207 	req.bNotificationType = USB_CDC_GET_NTB_PARAMETERS;
208 	req.wValue = 0;
209 	req.wIndex = cpu_to_le16(iface_no);
210 	req.wLength = cpu_to_le16(sizeof(ctx->ncm_parm));
211 
212 	err = cdc_ncm_do_request(ctx, &req, &ctx->ncm_parm, 0, NULL, 1000);
213 	if (err) {
214 		pr_debug("failed GET_NTB_PARAMETERS\n");
215 		return 1;
216 	}
217 
218 	/* read correct set of parameters according to device mode */
219 	ctx->rx_max = le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize);
220 	ctx->tx_max = le32_to_cpu(ctx->ncm_parm.dwNtbOutMaxSize);
221 	ctx->tx_remainder = le16_to_cpu(ctx->ncm_parm.wNdpOutPayloadRemainder);
222 	ctx->tx_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutDivisor);
223 	ctx->tx_ndp_modulus = le16_to_cpu(ctx->ncm_parm.wNdpOutAlignment);
224 	/* devices prior to NCM Errata shall set this field to zero */
225 	ctx->tx_max_datagrams = le16_to_cpu(ctx->ncm_parm.wNtbOutMaxDatagrams);
226 	ntb_fmt_supported = le16_to_cpu(ctx->ncm_parm.bmNtbFormatsSupported);
227 
228 	if (ctx->func_desc != NULL)
229 		flags = ctx->func_desc->bmNetworkCapabilities;
230 	else
231 		flags = 0;
232 
233 	pr_debug("dwNtbInMaxSize=%u dwNtbOutMaxSize=%u "
234 		 "wNdpOutPayloadRemainder=%u wNdpOutDivisor=%u "
235 		 "wNdpOutAlignment=%u wNtbOutMaxDatagrams=%u flags=0x%x\n",
236 		 ctx->rx_max, ctx->tx_max, ctx->tx_remainder, ctx->tx_modulus,
237 		 ctx->tx_ndp_modulus, ctx->tx_max_datagrams, flags);
238 
239 	/* max count of tx datagrams */
240 	if ((ctx->tx_max_datagrams == 0) ||
241 			(ctx->tx_max_datagrams > CDC_NCM_DPT_DATAGRAMS_MAX))
242 		ctx->tx_max_datagrams = CDC_NCM_DPT_DATAGRAMS_MAX;
243 
244 	/* verify maximum size of received NTB in bytes */
245 	if (ctx->rx_max < USB_CDC_NCM_NTB_MIN_IN_SIZE) {
246 		pr_debug("Using min receive length=%d\n",
247 						USB_CDC_NCM_NTB_MIN_IN_SIZE);
248 		ctx->rx_max = USB_CDC_NCM_NTB_MIN_IN_SIZE;
249 	}
250 
251 	if (ctx->rx_max > CDC_NCM_NTB_MAX_SIZE_RX) {
252 		pr_debug("Using default maximum receive length=%d\n",
253 						CDC_NCM_NTB_MAX_SIZE_RX);
254 		ctx->rx_max = CDC_NCM_NTB_MAX_SIZE_RX;
255 	}
256 
257 	/* inform device about NTB input size changes */
258 	if (ctx->rx_max != le32_to_cpu(ctx->ncm_parm.dwNtbInMaxSize)) {
259 		req.bmRequestType = USB_TYPE_CLASS | USB_DIR_OUT |
260 							USB_RECIP_INTERFACE;
261 		req.bNotificationType = USB_CDC_SET_NTB_INPUT_SIZE;
262 		req.wValue = 0;
263 		req.wIndex = cpu_to_le16(iface_no);
264 
265 		if (flags & USB_CDC_NCM_NCAP_NTB_INPUT_SIZE) {
266 			struct usb_cdc_ncm_ndp_input_size ndp_in_sz;
267 
268 			req.wLength = 8;
269 			ndp_in_sz.dwNtbInMaxSize = cpu_to_le32(ctx->rx_max);
270 			ndp_in_sz.wNtbInMaxDatagrams =
271 					cpu_to_le16(CDC_NCM_DPT_DATAGRAMS_MAX);
272 			ndp_in_sz.wReserved = 0;
273 			err = cdc_ncm_do_request(ctx, &req, &ndp_in_sz, 0, NULL,
274 									1000);
275 		} else {
276 			__le32 dwNtbInMaxSize = cpu_to_le32(ctx->rx_max);
277 
278 			req.wLength = 4;
279 			err = cdc_ncm_do_request(ctx, &req, &dwNtbInMaxSize, 0,
280 								NULL, 1000);
281 		}
282 
283 		if (err)
284 			pr_debug("Setting NTB Input Size failed\n");
285 	}
286 
287 	/* verify maximum size of transmitted NTB in bytes */
288 	if ((ctx->tx_max <
289 	    (CDC_NCM_MIN_HDR_SIZE + CDC_NCM_MIN_DATAGRAM_SIZE)) ||
290 	    (ctx->tx_max > CDC_NCM_NTB_MAX_SIZE_TX)) {
291 		pr_debug("Using default maximum transmit length=%d\n",
292 						CDC_NCM_NTB_MAX_SIZE_TX);
293 		ctx->tx_max = CDC_NCM_NTB_MAX_SIZE_TX;
294 	}
295 
296 	/*
297 	 * verify that the structure alignment is:
298 	 * - power of two
299 	 * - not greater than the maximum transmit length
300 	 * - not less than four bytes
301 	 */
302 	val = ctx->tx_ndp_modulus;
303 
304 	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
305 	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
306 		pr_debug("Using default alignment: 4 bytes\n");
307 		ctx->tx_ndp_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
308 	}
309 
310 	/*
311 	 * verify that the payload alignment is:
312 	 * - power of two
313 	 * - not greater than the maximum transmit length
314 	 * - not less than four bytes
315 	 */
316 	val = ctx->tx_modulus;
317 
318 	if ((val < USB_CDC_NCM_NDP_ALIGN_MIN_SIZE) ||
319 	    (val != ((-val) & val)) || (val >= ctx->tx_max)) {
320 		pr_debug("Using default transmit modulus: 4 bytes\n");
321 		ctx->tx_modulus = USB_CDC_NCM_NDP_ALIGN_MIN_SIZE;
322 	}
323 
324 	/* verify the payload remainder */
325 	if (ctx->tx_remainder >= ctx->tx_modulus) {
326 		pr_debug("Using default transmit remainder: 0 bytes\n");
327 		ctx->tx_remainder = 0;
328 	}
329 
330 	/* adjust TX-remainder according to NCM specification. */
331 	ctx->tx_remainder = ((ctx->tx_remainder - ETH_HLEN) &
332 						(ctx->tx_modulus - 1));
333 
334 	/* additional configuration */
335 
336 	/* set CRC Mode */
337 	if (flags & USB_CDC_NCM_NCAP_CRC_MODE) {
338 		req.bmRequestType = USB_TYPE_CLASS | USB_DIR_OUT |
339 							USB_RECIP_INTERFACE;
340 		req.bNotificationType = USB_CDC_SET_CRC_MODE;
341 		req.wValue = cpu_to_le16(USB_CDC_NCM_CRC_NOT_APPENDED);
342 		req.wIndex = cpu_to_le16(iface_no);
343 		req.wLength = 0;
344 
345 		err = cdc_ncm_do_request(ctx, &req, NULL, 0, NULL, 1000);
346 		if (err)
347 			pr_debug("Setting CRC mode off failed\n");
348 	}
349 
350 	/* set NTB format, if both formats are supported */
351 	if (ntb_fmt_supported & USB_CDC_NCM_NTH32_SIGN) {
352 		req.bmRequestType = USB_TYPE_CLASS | USB_DIR_OUT |
353 							USB_RECIP_INTERFACE;
354 		req.bNotificationType = USB_CDC_SET_NTB_FORMAT;
355 		req.wValue = cpu_to_le16(USB_CDC_NCM_NTB16_FORMAT);
356 		req.wIndex = cpu_to_le16(iface_no);
357 		req.wLength = 0;
358 
359 		err = cdc_ncm_do_request(ctx, &req, NULL, 0, NULL, 1000);
360 		if (err)
361 			pr_debug("Setting NTB format to 16-bit failed\n");
362 	}
363 
364 	ctx->max_datagram_size = CDC_NCM_MIN_DATAGRAM_SIZE;
365 
366 	/* set Max Datagram Size (MTU) */
367 	if (flags & USB_CDC_NCM_NCAP_MAX_DATAGRAM_SIZE) {
368 		__le16 max_datagram_size;
369 		u16 eth_max_sz = le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);
370 
371 		req.bmRequestType = USB_TYPE_CLASS | USB_DIR_IN |
372 							USB_RECIP_INTERFACE;
373 		req.bNotificationType = USB_CDC_GET_MAX_DATAGRAM_SIZE;
374 		req.wValue = 0;
375 		req.wIndex = cpu_to_le16(iface_no);
376 		req.wLength = cpu_to_le16(2);
377 
378 		err = cdc_ncm_do_request(ctx, &req, &max_datagram_size, 0, NULL,
379 									1000);
380 		if (err) {
381 			pr_debug("GET_MAX_DATAGRAM_SIZE failed, use size=%u\n",
382 						CDC_NCM_MIN_DATAGRAM_SIZE);
383 		} else {
384 			ctx->max_datagram_size = le16_to_cpu(max_datagram_size);
385 			/* Check Eth descriptor value */
386 			if (eth_max_sz < CDC_NCM_MAX_DATAGRAM_SIZE) {
387 				if (ctx->max_datagram_size > eth_max_sz)
388 					ctx->max_datagram_size = eth_max_sz;
389 			} else {
390 				if (ctx->max_datagram_size >
391 						CDC_NCM_MAX_DATAGRAM_SIZE)
392 					ctx->max_datagram_size =
393 						CDC_NCM_MAX_DATAGRAM_SIZE;
394 			}
395 
396 			if (ctx->max_datagram_size < CDC_NCM_MIN_DATAGRAM_SIZE)
397 				ctx->max_datagram_size =
398 					CDC_NCM_MIN_DATAGRAM_SIZE;
399 
400 			/* if value changed, update device */
401 			req.bmRequestType = USB_TYPE_CLASS | USB_DIR_OUT |
402 							USB_RECIP_INTERFACE;
403 			req.bNotificationType = USB_CDC_SET_MAX_DATAGRAM_SIZE;
404 			req.wValue = 0;
405 			req.wIndex = cpu_to_le16(iface_no);
406 			req.wLength = 2;
407 			max_datagram_size = cpu_to_le16(ctx->max_datagram_size);
408 
409 			err = cdc_ncm_do_request(ctx, &req, &max_datagram_size,
410 								0, NULL, 1000);
411 			if (err)
412 				pr_debug("SET_MAX_DATAGRAM_SIZE failed\n");
413 		}
414 
415 	}
416 
417 	if (ctx->netdev->mtu != (ctx->max_datagram_size - ETH_HLEN))
418 		ctx->netdev->mtu = ctx->max_datagram_size - ETH_HLEN;
419 
420 	return 0;
421 }
422 
423 static void
424 cdc_ncm_find_endpoints(struct cdc_ncm_ctx *ctx, struct usb_interface *intf)
425 {
426 	struct usb_host_endpoint *e;
427 	u8 ep;
428 
429 	for (ep = 0; ep < intf->cur_altsetting->desc.bNumEndpoints; ep++) {
430 
431 		e = intf->cur_altsetting->endpoint + ep;
432 		switch (e->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
433 		case USB_ENDPOINT_XFER_INT:
434 			if (usb_endpoint_dir_in(&e->desc)) {
435 				if (ctx->status_ep == NULL)
436 					ctx->status_ep = e;
437 			}
438 			break;
439 
440 		case USB_ENDPOINT_XFER_BULK:
441 			if (usb_endpoint_dir_in(&e->desc)) {
442 				if (ctx->in_ep == NULL)
443 					ctx->in_ep = e;
444 			} else {
445 				if (ctx->out_ep == NULL)
446 					ctx->out_ep = e;
447 			}
448 			break;
449 
450 		default:
451 			break;
452 		}
453 	}
454 }
455 
456 static void cdc_ncm_free(struct cdc_ncm_ctx *ctx)
457 {
458 	if (ctx == NULL)
459 		return;
460 
461 	del_timer_sync(&ctx->tx_timer);
462 
463 	if (ctx->data_claimed) {
464 		usb_set_intfdata(ctx->data, NULL);
465 		usb_driver_release_interface(driver_of(ctx->intf), ctx->data);
466 	}
467 
468 	if (ctx->control_claimed) {
469 		usb_set_intfdata(ctx->control, NULL);
470 		usb_driver_release_interface(driver_of(ctx->intf),
471 								ctx->control);
472 	}
473 
474 	if (ctx->tx_rem_skb != NULL) {
475 		dev_kfree_skb_any(ctx->tx_rem_skb);
476 		ctx->tx_rem_skb = NULL;
477 	}
478 
479 	if (ctx->tx_curr_skb != NULL) {
480 		dev_kfree_skb_any(ctx->tx_curr_skb);
481 		ctx->tx_curr_skb = NULL;
482 	}
483 
484 	kfree(ctx);
485 }
486 
487 static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
488 {
489 	struct cdc_ncm_ctx *ctx;
490 	struct usb_driver *driver;
491 	u8 *buf;
492 	int len;
493 	int temp;
494 	u8 iface_no;
495 
496 	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
497 	if (ctx == NULL)
498 		goto error;
499 
500 	memset(ctx, 0, sizeof(*ctx));
501 
502 	init_timer(&ctx->tx_timer);
503 	spin_lock_init(&ctx->mtx);
504 	ctx->netdev = dev->net;
505 
506 	/* store ctx pointer in device data field */
507 	dev->data[0] = (unsigned long)ctx;
508 
509 	/* get some pointers */
510 	driver = driver_of(intf);
511 	buf = intf->cur_altsetting->extra;
512 	len = intf->cur_altsetting->extralen;
513 
514 	ctx->udev = dev->udev;
515 	ctx->intf = intf;
516 
517 	/* parse through descriptors associated with control interface */
518 	while ((len > 0) && (buf[0] > 2) && (buf[0] <= len)) {
519 
520 		if (buf[1] != USB_DT_CS_INTERFACE)
521 			goto advance;
522 
523 		switch (buf[2]) {
524 		case USB_CDC_UNION_TYPE:
525 			if (buf[0] < sizeof(*(ctx->union_desc)))
526 				break;
527 
528 			ctx->union_desc =
529 					(const struct usb_cdc_union_desc *)buf;
530 
531 			ctx->control = usb_ifnum_to_if(dev->udev,
532 					ctx->union_desc->bMasterInterface0);
533 			ctx->data = usb_ifnum_to_if(dev->udev,
534 					ctx->union_desc->bSlaveInterface0);
535 			break;
536 
537 		case USB_CDC_ETHERNET_TYPE:
538 			if (buf[0] < sizeof(*(ctx->ether_desc)))
539 				break;
540 
541 			ctx->ether_desc =
542 					(const struct usb_cdc_ether_desc *)buf;
543 			dev->hard_mtu =
544 				le16_to_cpu(ctx->ether_desc->wMaxSegmentSize);
545 
546 			if (dev->hard_mtu < CDC_NCM_MIN_DATAGRAM_SIZE)
547 				dev->hard_mtu =	CDC_NCM_MIN_DATAGRAM_SIZE;
548 			else if (dev->hard_mtu > CDC_NCM_MAX_DATAGRAM_SIZE)
549 				dev->hard_mtu =	CDC_NCM_MAX_DATAGRAM_SIZE;
550 			break;
551 
552 		case USB_CDC_NCM_TYPE:
553 			if (buf[0] < sizeof(*(ctx->func_desc)))
554 				break;
555 
556 			ctx->func_desc = (const struct usb_cdc_ncm_desc *)buf;
557 			break;
558 
559 		default:
560 			break;
561 		}
562 advance:
563 		/* advance to next descriptor */
564 		temp = buf[0];
565 		buf += temp;
566 		len -= temp;
567 	}
568 
569 	/* check if we got everything */
570 	if ((ctx->control == NULL) || (ctx->data == NULL) ||
571 	    (ctx->ether_desc == NULL))
572 		goto error;
573 
574 	/* claim interfaces, if any */
575 	if (ctx->data != intf) {
576 		temp = usb_driver_claim_interface(driver, ctx->data, dev);
577 		if (temp)
578 			goto error;
579 		ctx->data_claimed = 1;
580 	}
581 
582 	if (ctx->control != intf) {
583 		temp = usb_driver_claim_interface(driver, ctx->control, dev);
584 		if (temp)
585 			goto error;
586 		ctx->control_claimed = 1;
587 	}
588 
589 	iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
590 
591 	/* reset data interface */
592 	temp = usb_set_interface(dev->udev, iface_no, 0);
593 	if (temp)
594 		goto error;
595 
596 	/* initialize data interface */
597 	if (cdc_ncm_setup(ctx))
598 		goto error;
599 
600 	/* configure data interface */
601 	temp = usb_set_interface(dev->udev, iface_no, 1);
602 	if (temp)
603 		goto error;
604 
605 	cdc_ncm_find_endpoints(ctx, ctx->data);
606 	cdc_ncm_find_endpoints(ctx, ctx->control);
607 
608 	if ((ctx->in_ep == NULL) || (ctx->out_ep == NULL) ||
609 	    (ctx->status_ep == NULL))
610 		goto error;
611 
612 	dev->net->ethtool_ops = &cdc_ncm_ethtool_ops;
613 
614 	usb_set_intfdata(ctx->data, dev);
615 	usb_set_intfdata(ctx->control, dev);
616 	usb_set_intfdata(ctx->intf, dev);
617 
618 	temp = usbnet_get_ethernet_addr(dev, ctx->ether_desc->iMACAddress);
619 	if (temp)
620 		goto error;
621 
622 	dev_info(&dev->udev->dev, "MAC-Address: "
623 				"0x%02x:0x%02x:0x%02x:0x%02x:0x%02x:0x%02x\n",
624 				dev->net->dev_addr[0], dev->net->dev_addr[1],
625 				dev->net->dev_addr[2], dev->net->dev_addr[3],
626 				dev->net->dev_addr[4], dev->net->dev_addr[5]);
627 
628 	dev->in = usb_rcvbulkpipe(dev->udev,
629 		ctx->in_ep->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
630 	dev->out = usb_sndbulkpipe(dev->udev,
631 		ctx->out_ep->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
632 	dev->status = ctx->status_ep;
633 	dev->rx_urb_size = ctx->rx_max;
634 
635 	/*
636 	 * We should get an event when network connection is "connected" or
637 	 * "disconnected". Set network connection in "disconnected" state
638 	 * (carrier is OFF) during attach, so the IP network stack does not
639 	 * start IPv6 negotiation and more.
640 	 */
641 	netif_carrier_off(dev->net);
642 	ctx->tx_speed = ctx->rx_speed = 0;
643 	return 0;
644 
645 error:
646 	cdc_ncm_free((struct cdc_ncm_ctx *)dev->data[0]);
647 	dev->data[0] = 0;
648 	dev_info(&dev->udev->dev, "Descriptor failure\n");
649 	return -ENODEV;
650 }
651 
652 static void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
653 {
654 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
655 	struct usb_driver *driver;
656 
657 	if (ctx == NULL)
658 		return;		/* no setup */
659 
660 	driver = driver_of(intf);
661 
662 	usb_set_intfdata(ctx->data, NULL);
663 	usb_set_intfdata(ctx->control, NULL);
664 	usb_set_intfdata(ctx->intf, NULL);
665 
666 	/* release interfaces, if any */
667 	if (ctx->data_claimed) {
668 		usb_driver_release_interface(driver, ctx->data);
669 		ctx->data_claimed = 0;
670 	}
671 
672 	if (ctx->control_claimed) {
673 		usb_driver_release_interface(driver, ctx->control);
674 		ctx->control_claimed = 0;
675 	}
676 
677 	cdc_ncm_free(ctx);
678 }
679 
680 static void cdc_ncm_zero_fill(u8 *ptr, u32 first, u32 end, u32 max)
681 {
682 	if (first >= max)
683 		return;
684 	if (first >= end)
685 		return;
686 	if (end > max)
687 		end = max;
688 	memset(ptr + first, 0, end - first);
689 }
690 
691 static struct sk_buff *
692 cdc_ncm_fill_tx_frame(struct cdc_ncm_ctx *ctx, struct sk_buff *skb)
693 {
694 	struct sk_buff *skb_out;
695 	u32 rem;
696 	u32 offset;
697 	u32 last_offset;
698 	u16 n = 0;
699 	u8 ready2send = 0;
700 
701 	/* if there is a remaining skb, it gets priority */
702 	if (skb != NULL)
703 		swap(skb, ctx->tx_rem_skb);
704 	else
705 		ready2send = 1;
706 
707 	/*
708 	 * +----------------+
709 	 * | skb_out        |
710 	 * +----------------+
711 	 *           ^ offset
712 	 *        ^ last_offset
713 	 */
714 
715 	/* check if we are resuming an OUT skb */
716 	if (ctx->tx_curr_skb != NULL) {
717 		/* pop variables */
718 		skb_out = ctx->tx_curr_skb;
719 		offset = ctx->tx_curr_offset;
720 		last_offset = ctx->tx_curr_last_offset;
721 		n = ctx->tx_curr_frame_num;
722 
723 	} else {
724 		/* reset variables */
725 		skb_out = alloc_skb(ctx->tx_max, GFP_ATOMIC);
726 		if (skb_out == NULL) {
727 			if (skb != NULL) {
728 				dev_kfree_skb_any(skb);
729 				ctx->netdev->stats.tx_dropped++;
730 			}
731 			goto exit_no_skb;
732 		}
733 
734 		/* make room for NTH and NDP */
735 		offset = ALIGN(sizeof(struct usb_cdc_ncm_nth16),
736 					ctx->tx_ndp_modulus) +
737 					sizeof(struct usb_cdc_ncm_ndp16) +
738 					(ctx->tx_max_datagrams + 1) *
739 					sizeof(struct usb_cdc_ncm_dpe16);
740 
741 		/* store last valid offset before alignment */
742 		last_offset = offset;
743 		/* align first Datagram offset correctly */
744 		offset = ALIGN(offset, ctx->tx_modulus) + ctx->tx_remainder;
745 		/* zero buffer till the first IP datagram */
746 		cdc_ncm_zero_fill(skb_out->data, 0, offset, offset);
747 		n = 0;
748 		ctx->tx_curr_frame_num = 0;
749 	}
750 
751 	for (; n < ctx->tx_max_datagrams; n++) {
752 		/* check if end of transmit buffer is reached */
753 		if (offset >= ctx->tx_max) {
754 			ready2send = 1;
755 			break;
756 		}
757 		/* compute maximum buffer size */
758 		rem = ctx->tx_max - offset;
759 
760 		if (skb == NULL) {
761 			skb = ctx->tx_rem_skb;
762 			ctx->tx_rem_skb = NULL;
763 
764 			/* check for end of skb */
765 			if (skb == NULL)
766 				break;
767 		}
768 
769 		if (skb->len > rem) {
770 			if (n == 0) {
771 				/* won't fit, MTU problem? */
772 				dev_kfree_skb_any(skb);
773 				skb = NULL;
774 				ctx->netdev->stats.tx_dropped++;
775 			} else {
776 				/* no room for skb - store for later */
777 				if (ctx->tx_rem_skb != NULL) {
778 					dev_kfree_skb_any(ctx->tx_rem_skb);
779 					ctx->netdev->stats.tx_dropped++;
780 				}
781 				ctx->tx_rem_skb = skb;
782 				skb = NULL;
783 				ready2send = 1;
784 			}
785 			break;
786 		}
787 
788 		memcpy(((u8 *)skb_out->data) + offset, skb->data, skb->len);
789 
790 		ctx->tx_ncm.dpe16[n].wDatagramLength = cpu_to_le16(skb->len);
791 		ctx->tx_ncm.dpe16[n].wDatagramIndex = cpu_to_le16(offset);
792 
793 		/* update offset */
794 		offset += skb->len;
795 
796 		/* store last valid offset before alignment */
797 		last_offset = offset;
798 
799 		/* align offset correctly */
800 		offset = ALIGN(offset, ctx->tx_modulus) + ctx->tx_remainder;
801 
802 		/* zero padding */
803 		cdc_ncm_zero_fill(skb_out->data, last_offset, offset,
804 								ctx->tx_max);
805 		dev_kfree_skb_any(skb);
806 		skb = NULL;
807 	}
808 
809 	/* free up any dangling skb */
810 	if (skb != NULL) {
811 		dev_kfree_skb_any(skb);
812 		skb = NULL;
813 		ctx->netdev->stats.tx_dropped++;
814 	}
815 
816 	ctx->tx_curr_frame_num = n;
817 
818 	if (n == 0) {
819 		/* wait for more frames */
820 		/* push variables */
821 		ctx->tx_curr_skb = skb_out;
822 		ctx->tx_curr_offset = offset;
823 		ctx->tx_curr_last_offset = last_offset;
824 		goto exit_no_skb;
825 
826 	} else if ((n < ctx->tx_max_datagrams) && (ready2send == 0)) {
827 		/* wait for more frames */
828 		/* push variables */
829 		ctx->tx_curr_skb = skb_out;
830 		ctx->tx_curr_offset = offset;
831 		ctx->tx_curr_last_offset = last_offset;
832 		/* set the pending count */
833 		if (n < CDC_NCM_RESTART_TIMER_DATAGRAM_CNT)
834 			ctx->tx_timer_pending = 2;
835 		goto exit_no_skb;
836 
837 	} else {
838 		/* frame goes out */
839 		/* variables will be reset at next call */
840 	}
841 
842 	/* check for overflow */
843 	if (last_offset > ctx->tx_max)
844 		last_offset = ctx->tx_max;
845 
846 	/* revert offset */
847 	offset = last_offset;
848 
849 	/*
850 	 * If collected data size is less or equal CDC_NCM_MIN_TX_PKT bytes,
851 	 * we send buffers as it is. If we get more data, it would be more
852 	 * efficient for USB HS mobile device with DMA engine to receive a full
853 	 * size NTB, than canceling DMA transfer and receiving a short packet.
854 	 */
855 	if (offset > CDC_NCM_MIN_TX_PKT)
856 		offset = ctx->tx_max;
857 
858 	/* final zero padding */
859 	cdc_ncm_zero_fill(skb_out->data, last_offset, offset, ctx->tx_max);
860 
861 	/* store last offset */
862 	last_offset = offset;
863 
864 	if ((last_offset < ctx->tx_max) && ((last_offset %
865 			le16_to_cpu(ctx->out_ep->desc.wMaxPacketSize)) == 0)) {
866 		/* force short packet */
867 		*(((u8 *)skb_out->data) + last_offset) = 0;
868 		last_offset++;
869 	}
870 
871 	/* zero the rest of the DPEs plus the last NULL entry */
872 	for (; n <= CDC_NCM_DPT_DATAGRAMS_MAX; n++) {
873 		ctx->tx_ncm.dpe16[n].wDatagramLength = 0;
874 		ctx->tx_ncm.dpe16[n].wDatagramIndex = 0;
875 	}
876 
877 	/* fill out 16-bit NTB header */
878 	ctx->tx_ncm.nth16.dwSignature = cpu_to_le32(USB_CDC_NCM_NTH16_SIGN);
879 	ctx->tx_ncm.nth16.wHeaderLength =
880 					cpu_to_le16(sizeof(ctx->tx_ncm.nth16));
881 	ctx->tx_ncm.nth16.wSequence = cpu_to_le16(ctx->tx_seq);
882 	ctx->tx_ncm.nth16.wBlockLength = cpu_to_le16(last_offset);
883 	ctx->tx_ncm.nth16.wNdpIndex = ALIGN(sizeof(struct usb_cdc_ncm_nth16),
884 							ctx->tx_ndp_modulus);
885 
886 	memcpy(skb_out->data, &(ctx->tx_ncm.nth16), sizeof(ctx->tx_ncm.nth16));
887 	ctx->tx_seq++;
888 
889 	/* fill out 16-bit NDP table */
890 	ctx->tx_ncm.ndp16.dwSignature =
891 				cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN);
892 	rem = sizeof(ctx->tx_ncm.ndp16) + ((ctx->tx_curr_frame_num + 1) *
893 					sizeof(struct usb_cdc_ncm_dpe16));
894 	ctx->tx_ncm.ndp16.wLength = cpu_to_le16(rem);
895 	ctx->tx_ncm.ndp16.wNextNdpIndex = 0; /* reserved */
896 
897 	memcpy(((u8 *)skb_out->data) + ctx->tx_ncm.nth16.wNdpIndex,
898 						&(ctx->tx_ncm.ndp16),
899 						sizeof(ctx->tx_ncm.ndp16));
900 
901 	memcpy(((u8 *)skb_out->data) + ctx->tx_ncm.nth16.wNdpIndex +
902 					sizeof(ctx->tx_ncm.ndp16),
903 					&(ctx->tx_ncm.dpe16),
904 					(ctx->tx_curr_frame_num + 1) *
905 					sizeof(struct usb_cdc_ncm_dpe16));
906 
907 	/* set frame length */
908 	skb_put(skb_out, last_offset);
909 
910 	/* return skb */
911 	ctx->tx_curr_skb = NULL;
912 	return skb_out;
913 
914 exit_no_skb:
915 	return NULL;
916 }
917 
918 static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx)
919 {
920 	/* start timer, if not already started */
921 	if (timer_pending(&ctx->tx_timer) == 0) {
922 		ctx->tx_timer.function = &cdc_ncm_tx_timeout;
923 		ctx->tx_timer.data = (unsigned long)ctx;
924 		ctx->tx_timer.expires = jiffies + ((HZ + 999) / 1000);
925 		add_timer(&ctx->tx_timer);
926 	}
927 }
928 
929 static void cdc_ncm_tx_timeout(unsigned long arg)
930 {
931 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)arg;
932 	u8 restart;
933 
934 	spin_lock(&ctx->mtx);
935 	if (ctx->tx_timer_pending != 0) {
936 		ctx->tx_timer_pending--;
937 		restart = 1;
938 	} else {
939 		restart = 0;
940 	}
941 
942 	spin_unlock(&ctx->mtx);
943 
944 	if (restart) {
945 		spin_lock(&ctx->mtx);
946 		cdc_ncm_tx_timeout_start(ctx);
947 		spin_unlock(&ctx->mtx);
948 	} else if (ctx->netdev != NULL) {
949 		usbnet_start_xmit(NULL, ctx->netdev);
950 	}
951 }
952 
953 static struct sk_buff *
954 cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
955 {
956 	struct sk_buff *skb_out;
957 	struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
958 	u8 need_timer = 0;
959 
960 	/*
961 	 * The Ethernet API we are using does not support transmitting
962 	 * multiple Ethernet frames in a single call. This driver will
963 	 * accumulate multiple Ethernet frames and send out a larger
964 	 * USB frame when the USB buffer is full or when a single jiffies
965 	 * timeout happens.
966 	 */
967 	if (ctx == NULL)
968 		goto error;
969 
970 	spin_lock(&ctx->mtx);
971 	skb_out = cdc_ncm_fill_tx_frame(ctx, skb);
972 	if (ctx->tx_curr_skb != NULL)
973 		need_timer = 1;
974 
975 	/* Start timer, if there is a remaining skb */
976 	if (need_timer)
977 		cdc_ncm_tx_timeout_start(ctx);
978 
979 	if (skb_out)
980 		dev->net->stats.tx_packets += ctx->tx_curr_frame_num;
981 
982 	spin_unlock(&ctx->mtx);
983 	return skb_out;
984 
985 error:
986 	if (skb != NULL)
987 		dev_kfree_skb_any(skb);
988 
989 	return NULL;
990 }
991 
992 static int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
993 {
994 	struct sk_buff *skb;
995 	struct cdc_ncm_ctx *ctx;
996 	int sumlen;
997 	int actlen;
998 	int temp;
999 	int nframes;
1000 	int x;
1001 	int offset;
1002 
1003 	ctx = (struct cdc_ncm_ctx *)dev->data[0];
1004 	if (ctx == NULL)
1005 		goto error;
1006 
1007 	actlen = skb_in->len;
1008 	sumlen = CDC_NCM_NTB_MAX_SIZE_RX;
1009 
1010 	if (actlen < (sizeof(ctx->rx_ncm.nth16) + sizeof(ctx->rx_ncm.ndp16))) {
1011 		pr_debug("frame too short\n");
1012 		goto error;
1013 	}
1014 
1015 	memcpy(&(ctx->rx_ncm.nth16), ((u8 *)skb_in->data),
1016 						sizeof(ctx->rx_ncm.nth16));
1017 
1018 	if (le32_to_cpu(ctx->rx_ncm.nth16.dwSignature) !=
1019 	    USB_CDC_NCM_NTH16_SIGN) {
1020 		pr_debug("invalid NTH16 signature <%u>\n",
1021 			 le32_to_cpu(ctx->rx_ncm.nth16.dwSignature));
1022 		goto error;
1023 	}
1024 
1025 	temp = le16_to_cpu(ctx->rx_ncm.nth16.wBlockLength);
1026 	if (temp > sumlen) {
1027 		pr_debug("unsupported NTB block length %u/%u\n", temp, sumlen);
1028 		goto error;
1029 	}
1030 
1031 	temp = le16_to_cpu(ctx->rx_ncm.nth16.wNdpIndex);
1032 	if ((temp + sizeof(ctx->rx_ncm.ndp16)) > actlen) {
1033 		pr_debug("invalid DPT16 index\n");
1034 		goto error;
1035 	}
1036 
1037 	memcpy(&(ctx->rx_ncm.ndp16), ((u8 *)skb_in->data) + temp,
1038 						sizeof(ctx->rx_ncm.ndp16));
1039 
1040 	if (le32_to_cpu(ctx->rx_ncm.ndp16.dwSignature) !=
1041 	    USB_CDC_NCM_NDP16_NOCRC_SIGN) {
1042 		pr_debug("invalid DPT16 signature <%u>\n",
1043 			 le32_to_cpu(ctx->rx_ncm.ndp16.dwSignature));
1044 		goto error;
1045 	}
1046 
1047 	if (le16_to_cpu(ctx->rx_ncm.ndp16.wLength) <
1048 	    USB_CDC_NCM_NDP16_LENGTH_MIN) {
1049 		pr_debug("invalid DPT16 length <%u>\n",
1050 			 le32_to_cpu(ctx->rx_ncm.ndp16.dwSignature));
1051 		goto error;
1052 	}
1053 
1054 	nframes = ((le16_to_cpu(ctx->rx_ncm.ndp16.wLength) -
1055 					sizeof(struct usb_cdc_ncm_ndp16)) /
1056 					sizeof(struct usb_cdc_ncm_dpe16));
1057 	nframes--; /* we process NDP entries except for the last one */
1058 
1059 	pr_debug("nframes = %u\n", nframes);
1060 
1061 	temp += sizeof(ctx->rx_ncm.ndp16);
1062 
1063 	if ((temp + nframes * (sizeof(struct usb_cdc_ncm_dpe16))) > actlen) {
1064 		pr_debug("Invalid nframes = %d\n", nframes);
1065 		goto error;
1066 	}
1067 
1068 	if (nframes > CDC_NCM_DPT_DATAGRAMS_MAX) {
1069 		pr_debug("Truncating number of frames from %u to %u\n",
1070 					nframes, CDC_NCM_DPT_DATAGRAMS_MAX);
1071 		nframes = CDC_NCM_DPT_DATAGRAMS_MAX;
1072 	}
1073 
1074 	memcpy(&(ctx->rx_ncm.dpe16), ((u8 *)skb_in->data) + temp,
1075 				nframes * (sizeof(struct usb_cdc_ncm_dpe16)));
1076 
1077 	for (x = 0; x < nframes; x++) {
1078 		offset = le16_to_cpu(ctx->rx_ncm.dpe16[x].wDatagramIndex);
1079 		temp = le16_to_cpu(ctx->rx_ncm.dpe16[x].wDatagramLength);
1080 
1081 		/*
1082 		 * CDC NCM ch. 3.7
1083 		 * All entries after first NULL entry are to be ignored
1084 		 */
1085 		if ((offset == 0) || (temp == 0)) {
1086 			if (!x)
1087 				goto error; /* empty NTB */
1088 			break;
1089 		}
1090 
1091 		/* sanity checking */
1092 		if (((offset + temp) > actlen) ||
1093 		    (temp > CDC_NCM_MAX_DATAGRAM_SIZE) || (temp < ETH_HLEN)) {
1094 			pr_debug("invalid frame detected (ignored)"
1095 					"offset[%u]=%u, length=%u, skb=%p\n",
1096 					x, offset, temp, skb_in);
1097 			if (!x)
1098 				goto error;
1099 			break;
1100 
1101 		} else {
1102 			skb = skb_clone(skb_in, GFP_ATOMIC);
1103 			if (!skb)
1104 				goto error;
1105 			skb->len = temp;
1106 			skb->data = ((u8 *)skb_in->data) + offset;
1107 			skb_set_tail_pointer(skb, temp);
1108 			usbnet_skb_return(dev, skb);
1109 		}
1110 	}
1111 	return 1;
1112 error:
1113 	return 0;
1114 }
1115 
1116 static void
1117 cdc_ncm_speed_change(struct cdc_ncm_ctx *ctx,
1118 		     struct usb_cdc_speed_change *data)
1119 {
1120 	uint32_t rx_speed = le32_to_cpu(data->DLBitRRate);
1121 	uint32_t tx_speed = le32_to_cpu(data->ULBitRate);
1122 
1123 	/*
1124 	 * Currently the USB-NET API does not support reporting the actual
1125 	 * device speed. Do print it instead.
1126 	 */
1127 	if ((tx_speed != ctx->tx_speed) || (rx_speed != ctx->rx_speed)) {
1128 		ctx->tx_speed = tx_speed;
1129 		ctx->rx_speed = rx_speed;
1130 
1131 		if ((tx_speed > 1000000) && (rx_speed > 1000000)) {
1132 			printk(KERN_INFO KBUILD_MODNAME
1133 				": %s: %u mbit/s downlink "
1134 				"%u mbit/s uplink\n",
1135 				ctx->netdev->name,
1136 				(unsigned int)(rx_speed / 1000000U),
1137 				(unsigned int)(tx_speed / 1000000U));
1138 		} else {
1139 			printk(KERN_INFO KBUILD_MODNAME
1140 				": %s: %u kbit/s downlink "
1141 				"%u kbit/s uplink\n",
1142 				ctx->netdev->name,
1143 				(unsigned int)(rx_speed / 1000U),
1144 				(unsigned int)(tx_speed / 1000U));
1145 		}
1146 	}
1147 }
1148 
1149 static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
1150 {
1151 	struct cdc_ncm_ctx *ctx;
1152 	struct usb_cdc_notification *event;
1153 
1154 	ctx = (struct cdc_ncm_ctx *)dev->data[0];
1155 
1156 	if (urb->actual_length < sizeof(*event))
1157 		return;
1158 
1159 	/* test for split data in 8-byte chunks */
1160 	if (test_and_clear_bit(EVENT_STS_SPLIT, &dev->flags)) {
1161 		cdc_ncm_speed_change(ctx,
1162 		      (struct usb_cdc_speed_change *)urb->transfer_buffer);
1163 		return;
1164 	}
1165 
1166 	event = urb->transfer_buffer;
1167 
1168 	switch (event->bNotificationType) {
1169 	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
1170 		/*
1171 		 * According to the CDC NCM specification ch.7.1
1172 		 * USB_CDC_NOTIFY_NETWORK_CONNECTION notification shall be
1173 		 * sent by device after USB_CDC_NOTIFY_SPEED_CHANGE.
1174 		 */
1175 		ctx->connected = event->wValue;
1176 
1177 		printk(KERN_INFO KBUILD_MODNAME ": %s: network connection:"
1178 			" %sconnected\n",
1179 			ctx->netdev->name, ctx->connected ? "" : "dis");
1180 
1181 		if (ctx->connected)
1182 			netif_carrier_on(dev->net);
1183 		else {
1184 			netif_carrier_off(dev->net);
1185 			ctx->tx_speed = ctx->rx_speed = 0;
1186 		}
1187 		break;
1188 
1189 	case USB_CDC_NOTIFY_SPEED_CHANGE:
1190 		if (urb->actual_length < (sizeof(*event) +
1191 					sizeof(struct usb_cdc_speed_change)))
1192 			set_bit(EVENT_STS_SPLIT, &dev->flags);
1193 		else
1194 			cdc_ncm_speed_change(ctx,
1195 				(struct usb_cdc_speed_change *) &event[1]);
1196 		break;
1197 
1198 	default:
1199 		dev_err(&dev->udev->dev, "NCM: unexpected "
1200 			"notification 0x%02x!\n", event->bNotificationType);
1201 		break;
1202 	}
1203 }
1204 
1205 static int cdc_ncm_check_connect(struct usbnet *dev)
1206 {
1207 	struct cdc_ncm_ctx *ctx;
1208 
1209 	ctx = (struct cdc_ncm_ctx *)dev->data[0];
1210 	if (ctx == NULL)
1211 		return 1;	/* disconnected */
1212 
1213 	return !ctx->connected;
1214 }
1215 
1216 static int
1217 cdc_ncm_probe(struct usb_interface *udev, const struct usb_device_id *prod)
1218 {
1219 	return usbnet_probe(udev, prod);
1220 }
1221 
1222 static void cdc_ncm_disconnect(struct usb_interface *intf)
1223 {
1224 	struct usbnet *dev = usb_get_intfdata(intf);
1225 
1226 	if (dev == NULL)
1227 		return;		/* already disconnected */
1228 
1229 	usbnet_disconnect(intf);
1230 }
1231 
1232 static int cdc_ncm_manage_power(struct usbnet *dev, int status)
1233 {
1234 	dev->intf->needs_remote_wakeup = status;
1235 	return 0;
1236 }
1237 
1238 static const struct driver_info cdc_ncm_info = {
1239 	.description = "CDC NCM",
1240 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET,
1241 	.bind = cdc_ncm_bind,
1242 	.unbind = cdc_ncm_unbind,
1243 	.check_connect = cdc_ncm_check_connect,
1244 	.manage_power = cdc_ncm_manage_power,
1245 	.status = cdc_ncm_status,
1246 	.rx_fixup = cdc_ncm_rx_fixup,
1247 	.tx_fixup = cdc_ncm_tx_fixup,
1248 };
1249 
1250 static struct usb_driver cdc_ncm_driver = {
1251 	.name = "cdc_ncm",
1252 	.id_table = cdc_devs,
1253 	.probe = cdc_ncm_probe,
1254 	.disconnect = cdc_ncm_disconnect,
1255 	.suspend = usbnet_suspend,
1256 	.resume = usbnet_resume,
1257 	.supports_autosuspend = 1,
1258 };
1259 
1260 static struct ethtool_ops cdc_ncm_ethtool_ops = {
1261 	.get_drvinfo = cdc_ncm_get_drvinfo,
1262 	.get_link = usbnet_get_link,
1263 	.get_msglevel = usbnet_get_msglevel,
1264 	.set_msglevel = usbnet_set_msglevel,
1265 	.get_settings = usbnet_get_settings,
1266 	.set_settings = usbnet_set_settings,
1267 	.nway_reset = usbnet_nway_reset,
1268 };
1269 
1270 static int __init cdc_ncm_init(void)
1271 {
1272 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION "\n");
1273 	return usb_register(&cdc_ncm_driver);
1274 }
1275 
1276 module_init(cdc_ncm_init);
1277 
1278 static void __exit cdc_ncm_exit(void)
1279 {
1280 	usb_deregister(&cdc_ncm_driver);
1281 }
1282 
1283 module_exit(cdc_ncm_exit);
1284 
1285 MODULE_AUTHOR("Hans Petter Selasky");
1286 MODULE_DESCRIPTION("USB CDC NCM host driver");
1287 MODULE_LICENSE("Dual BSD/GPL");
1288