xref: /linux/drivers/usb/gadget/function/f_phonet.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /*
2  * f_phonet.c -- USB CDC Phonet function
3  *
4  * Copyright (C) 2007-2008 Nokia Corporation. All rights reserved.
5  *
6  * Author: Rémi Denis-Courmont
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License
10  * version 2 as published by the Free Software Foundation.
11  */
12 
13 #include <linux/mm.h>
14 #include <linux/slab.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/device.h>
18 
19 #include <linux/netdevice.h>
20 #include <linux/if_ether.h>
21 #include <linux/if_phonet.h>
22 #include <linux/if_arp.h>
23 
24 #include <linux/usb/ch9.h>
25 #include <linux/usb/cdc.h>
26 #include <linux/usb/composite.h>
27 
28 #include "u_phonet.h"
29 #include "u_ether.h"
30 
31 #define PN_MEDIA_USB	0x1B
32 #define MAXPACKET	512
33 #if (PAGE_SIZE % MAXPACKET)
34 #error MAXPACKET must divide PAGE_SIZE!
35 #endif
36 
37 /*-------------------------------------------------------------------------*/
38 
39 struct phonet_port {
40 	struct f_phonet			*usb;
41 	spinlock_t			lock;
42 };
43 
44 struct f_phonet {
45 	struct usb_function		function;
46 	struct {
47 		struct sk_buff		*skb;
48 		spinlock_t		lock;
49 	} rx;
50 	struct net_device		*dev;
51 	struct usb_ep			*in_ep, *out_ep;
52 
53 	struct usb_request		*in_req;
54 	struct usb_request		*out_reqv[0];
55 };
56 
57 static int phonet_rxq_size = 17;
58 
59 static inline struct f_phonet *func_to_pn(struct usb_function *f)
60 {
61 	return container_of(f, struct f_phonet, function);
62 }
63 
64 /*-------------------------------------------------------------------------*/
65 
66 #define USB_CDC_SUBCLASS_PHONET	0xfe
67 #define USB_CDC_PHONET_TYPE	0xab
68 
69 static struct usb_interface_descriptor
70 pn_control_intf_desc = {
71 	.bLength =		sizeof pn_control_intf_desc,
72 	.bDescriptorType =	USB_DT_INTERFACE,
73 
74 	/* .bInterfaceNumber =	DYNAMIC, */
75 	.bInterfaceClass =	USB_CLASS_COMM,
76 	.bInterfaceSubClass =	USB_CDC_SUBCLASS_PHONET,
77 };
78 
79 static const struct usb_cdc_header_desc
80 pn_header_desc = {
81 	.bLength =		sizeof pn_header_desc,
82 	.bDescriptorType =	USB_DT_CS_INTERFACE,
83 	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
84 	.bcdCDC =		cpu_to_le16(0x0110),
85 };
86 
87 static const struct usb_cdc_header_desc
88 pn_phonet_desc = {
89 	.bLength =		sizeof pn_phonet_desc,
90 	.bDescriptorType =	USB_DT_CS_INTERFACE,
91 	.bDescriptorSubType =	USB_CDC_PHONET_TYPE,
92 	.bcdCDC =		cpu_to_le16(0x1505), /* ??? */
93 };
94 
95 static struct usb_cdc_union_desc
96 pn_union_desc = {
97 	.bLength =		sizeof pn_union_desc,
98 	.bDescriptorType =	USB_DT_CS_INTERFACE,
99 	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
100 
101 	/* .bMasterInterface0 =	DYNAMIC, */
102 	/* .bSlaveInterface0 =	DYNAMIC, */
103 };
104 
105 static struct usb_interface_descriptor
106 pn_data_nop_intf_desc = {
107 	.bLength =		sizeof pn_data_nop_intf_desc,
108 	.bDescriptorType =	USB_DT_INTERFACE,
109 
110 	/* .bInterfaceNumber =	DYNAMIC, */
111 	.bAlternateSetting =	0,
112 	.bNumEndpoints =	0,
113 	.bInterfaceClass =	USB_CLASS_CDC_DATA,
114 };
115 
116 static struct usb_interface_descriptor
117 pn_data_intf_desc = {
118 	.bLength =		sizeof pn_data_intf_desc,
119 	.bDescriptorType =	USB_DT_INTERFACE,
120 
121 	/* .bInterfaceNumber =	DYNAMIC, */
122 	.bAlternateSetting =	1,
123 	.bNumEndpoints =	2,
124 	.bInterfaceClass =	USB_CLASS_CDC_DATA,
125 };
126 
127 static struct usb_endpoint_descriptor
128 pn_fs_sink_desc = {
129 	.bLength =		USB_DT_ENDPOINT_SIZE,
130 	.bDescriptorType =	USB_DT_ENDPOINT,
131 
132 	.bEndpointAddress =	USB_DIR_OUT,
133 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
134 };
135 
136 static struct usb_endpoint_descriptor
137 pn_hs_sink_desc = {
138 	.bLength =		USB_DT_ENDPOINT_SIZE,
139 	.bDescriptorType =	USB_DT_ENDPOINT,
140 
141 	.bEndpointAddress =	USB_DIR_OUT,
142 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
143 	.wMaxPacketSize =	cpu_to_le16(MAXPACKET),
144 };
145 
146 static struct usb_endpoint_descriptor
147 pn_fs_source_desc = {
148 	.bLength =		USB_DT_ENDPOINT_SIZE,
149 	.bDescriptorType =	USB_DT_ENDPOINT,
150 
151 	.bEndpointAddress =	USB_DIR_IN,
152 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
153 };
154 
155 static struct usb_endpoint_descriptor
156 pn_hs_source_desc = {
157 	.bLength =		USB_DT_ENDPOINT_SIZE,
158 	.bDescriptorType =	USB_DT_ENDPOINT,
159 
160 	.bEndpointAddress =	USB_DIR_IN,
161 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
162 	.wMaxPacketSize =	cpu_to_le16(512),
163 };
164 
165 static struct usb_descriptor_header *fs_pn_function[] = {
166 	(struct usb_descriptor_header *) &pn_control_intf_desc,
167 	(struct usb_descriptor_header *) &pn_header_desc,
168 	(struct usb_descriptor_header *) &pn_phonet_desc,
169 	(struct usb_descriptor_header *) &pn_union_desc,
170 	(struct usb_descriptor_header *) &pn_data_nop_intf_desc,
171 	(struct usb_descriptor_header *) &pn_data_intf_desc,
172 	(struct usb_descriptor_header *) &pn_fs_sink_desc,
173 	(struct usb_descriptor_header *) &pn_fs_source_desc,
174 	NULL,
175 };
176 
177 static struct usb_descriptor_header *hs_pn_function[] = {
178 	(struct usb_descriptor_header *) &pn_control_intf_desc,
179 	(struct usb_descriptor_header *) &pn_header_desc,
180 	(struct usb_descriptor_header *) &pn_phonet_desc,
181 	(struct usb_descriptor_header *) &pn_union_desc,
182 	(struct usb_descriptor_header *) &pn_data_nop_intf_desc,
183 	(struct usb_descriptor_header *) &pn_data_intf_desc,
184 	(struct usb_descriptor_header *) &pn_hs_sink_desc,
185 	(struct usb_descriptor_header *) &pn_hs_source_desc,
186 	NULL,
187 };
188 
189 /*-------------------------------------------------------------------------*/
190 
191 static int pn_net_open(struct net_device *dev)
192 {
193 	netif_wake_queue(dev);
194 	return 0;
195 }
196 
197 static int pn_net_close(struct net_device *dev)
198 {
199 	netif_stop_queue(dev);
200 	return 0;
201 }
202 
203 static void pn_tx_complete(struct usb_ep *ep, struct usb_request *req)
204 {
205 	struct f_phonet *fp = ep->driver_data;
206 	struct net_device *dev = fp->dev;
207 	struct sk_buff *skb = req->context;
208 
209 	switch (req->status) {
210 	case 0:
211 		dev->stats.tx_packets++;
212 		dev->stats.tx_bytes += skb->len;
213 		break;
214 
215 	case -ESHUTDOWN: /* disconnected */
216 	case -ECONNRESET: /* disabled */
217 		dev->stats.tx_aborted_errors++;
218 	default:
219 		dev->stats.tx_errors++;
220 	}
221 
222 	dev_kfree_skb_any(skb);
223 	netif_wake_queue(dev);
224 }
225 
226 static int pn_net_xmit(struct sk_buff *skb, struct net_device *dev)
227 {
228 	struct phonet_port *port = netdev_priv(dev);
229 	struct f_phonet *fp;
230 	struct usb_request *req;
231 	unsigned long flags;
232 
233 	if (skb->protocol != htons(ETH_P_PHONET))
234 		goto out;
235 
236 	spin_lock_irqsave(&port->lock, flags);
237 	fp = port->usb;
238 	if (unlikely(!fp)) /* race with carrier loss */
239 		goto out_unlock;
240 
241 	req = fp->in_req;
242 	req->buf = skb->data;
243 	req->length = skb->len;
244 	req->complete = pn_tx_complete;
245 	req->zero = 1;
246 	req->context = skb;
247 
248 	if (unlikely(usb_ep_queue(fp->in_ep, req, GFP_ATOMIC)))
249 		goto out_unlock;
250 
251 	netif_stop_queue(dev);
252 	skb = NULL;
253 
254 out_unlock:
255 	spin_unlock_irqrestore(&port->lock, flags);
256 out:
257 	if (unlikely(skb)) {
258 		dev_kfree_skb(skb);
259 		dev->stats.tx_dropped++;
260 	}
261 	return NETDEV_TX_OK;
262 }
263 
264 static const struct net_device_ops pn_netdev_ops = {
265 	.ndo_open	= pn_net_open,
266 	.ndo_stop	= pn_net_close,
267 	.ndo_start_xmit	= pn_net_xmit,
268 };
269 
270 static void pn_net_setup(struct net_device *dev)
271 {
272 	dev->features		= 0;
273 	dev->type		= ARPHRD_PHONET;
274 	dev->flags		= IFF_POINTOPOINT | IFF_NOARP;
275 	dev->mtu		= PHONET_DEV_MTU;
276 	dev->min_mtu		= PHONET_MIN_MTU;
277 	dev->max_mtu		= PHONET_MAX_MTU;
278 	dev->hard_header_len	= 1;
279 	dev->dev_addr[0]	= PN_MEDIA_USB;
280 	dev->addr_len		= 1;
281 	dev->tx_queue_len	= 1;
282 
283 	dev->netdev_ops		= &pn_netdev_ops;
284 	dev->destructor		= free_netdev;
285 	dev->header_ops		= &phonet_header_ops;
286 }
287 
288 /*-------------------------------------------------------------------------*/
289 
290 /*
291  * Queue buffer for data from the host
292  */
293 static int
294 pn_rx_submit(struct f_phonet *fp, struct usb_request *req, gfp_t gfp_flags)
295 {
296 	struct page *page;
297 	int err;
298 
299 	page = __dev_alloc_page(gfp_flags | __GFP_NOMEMALLOC);
300 	if (!page)
301 		return -ENOMEM;
302 
303 	req->buf = page_address(page);
304 	req->length = PAGE_SIZE;
305 	req->context = page;
306 
307 	err = usb_ep_queue(fp->out_ep, req, gfp_flags);
308 	if (unlikely(err))
309 		put_page(page);
310 	return err;
311 }
312 
313 static void pn_rx_complete(struct usb_ep *ep, struct usb_request *req)
314 {
315 	struct f_phonet *fp = ep->driver_data;
316 	struct net_device *dev = fp->dev;
317 	struct page *page = req->context;
318 	struct sk_buff *skb;
319 	unsigned long flags;
320 	int status = req->status;
321 
322 	switch (status) {
323 	case 0:
324 		spin_lock_irqsave(&fp->rx.lock, flags);
325 		skb = fp->rx.skb;
326 		if (!skb)
327 			skb = fp->rx.skb = netdev_alloc_skb(dev, 12);
328 		if (req->actual < req->length) /* Last fragment */
329 			fp->rx.skb = NULL;
330 		spin_unlock_irqrestore(&fp->rx.lock, flags);
331 
332 		if (unlikely(!skb))
333 			break;
334 
335 		if (skb->len == 0) { /* First fragment */
336 			skb->protocol = htons(ETH_P_PHONET);
337 			skb_reset_mac_header(skb);
338 			/* Can't use pskb_pull() on page in IRQ */
339 			memcpy(skb_put(skb, 1), page_address(page), 1);
340 		}
341 
342 		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
343 				skb->len <= 1, req->actual, PAGE_SIZE);
344 		page = NULL;
345 
346 		if (req->actual < req->length) { /* Last fragment */
347 			skb->dev = dev;
348 			dev->stats.rx_packets++;
349 			dev->stats.rx_bytes += skb->len;
350 
351 			netif_rx(skb);
352 		}
353 		break;
354 
355 	/* Do not resubmit in these cases: */
356 	case -ESHUTDOWN: /* disconnect */
357 	case -ECONNABORTED: /* hw reset */
358 	case -ECONNRESET: /* dequeued (unlink or netif down) */
359 		req = NULL;
360 		break;
361 
362 	/* Do resubmit in these cases: */
363 	case -EOVERFLOW: /* request buffer overflow */
364 		dev->stats.rx_over_errors++;
365 	default:
366 		dev->stats.rx_errors++;
367 		break;
368 	}
369 
370 	if (page)
371 		put_page(page);
372 	if (req)
373 		pn_rx_submit(fp, req, GFP_ATOMIC);
374 }
375 
376 /*-------------------------------------------------------------------------*/
377 
378 static void __pn_reset(struct usb_function *f)
379 {
380 	struct f_phonet *fp = func_to_pn(f);
381 	struct net_device *dev = fp->dev;
382 	struct phonet_port *port = netdev_priv(dev);
383 
384 	netif_carrier_off(dev);
385 	port->usb = NULL;
386 
387 	usb_ep_disable(fp->out_ep);
388 	usb_ep_disable(fp->in_ep);
389 	if (fp->rx.skb) {
390 		dev_kfree_skb_irq(fp->rx.skb);
391 		fp->rx.skb = NULL;
392 	}
393 }
394 
395 static int pn_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
396 {
397 	struct f_phonet *fp = func_to_pn(f);
398 	struct usb_gadget *gadget = fp->function.config->cdev->gadget;
399 
400 	if (intf == pn_control_intf_desc.bInterfaceNumber)
401 		/* control interface, no altsetting */
402 		return (alt > 0) ? -EINVAL : 0;
403 
404 	if (intf == pn_data_intf_desc.bInterfaceNumber) {
405 		struct net_device *dev = fp->dev;
406 		struct phonet_port *port = netdev_priv(dev);
407 
408 		/* data intf (0: inactive, 1: active) */
409 		if (alt > 1)
410 			return -EINVAL;
411 
412 		spin_lock(&port->lock);
413 
414 		if (fp->in_ep->enabled)
415 			__pn_reset(f);
416 
417 		if (alt == 1) {
418 			int i;
419 
420 			if (config_ep_by_speed(gadget, f, fp->in_ep) ||
421 			    config_ep_by_speed(gadget, f, fp->out_ep)) {
422 				fp->in_ep->desc = NULL;
423 				fp->out_ep->desc = NULL;
424 				spin_unlock(&port->lock);
425 				return -EINVAL;
426 			}
427 			usb_ep_enable(fp->out_ep);
428 			usb_ep_enable(fp->in_ep);
429 
430 			port->usb = fp;
431 			fp->out_ep->driver_data = fp;
432 			fp->in_ep->driver_data = fp;
433 
434 			netif_carrier_on(dev);
435 			for (i = 0; i < phonet_rxq_size; i++)
436 				pn_rx_submit(fp, fp->out_reqv[i], GFP_ATOMIC);
437 		}
438 		spin_unlock(&port->lock);
439 		return 0;
440 	}
441 
442 	return -EINVAL;
443 }
444 
445 static int pn_get_alt(struct usb_function *f, unsigned intf)
446 {
447 	struct f_phonet *fp = func_to_pn(f);
448 
449 	if (intf == pn_control_intf_desc.bInterfaceNumber)
450 		return 0;
451 
452 	if (intf == pn_data_intf_desc.bInterfaceNumber) {
453 		struct phonet_port *port = netdev_priv(fp->dev);
454 		u8 alt;
455 
456 		spin_lock(&port->lock);
457 		alt = port->usb != NULL;
458 		spin_unlock(&port->lock);
459 		return alt;
460 	}
461 
462 	return -EINVAL;
463 }
464 
465 static void pn_disconnect(struct usb_function *f)
466 {
467 	struct f_phonet *fp = func_to_pn(f);
468 	struct phonet_port *port = netdev_priv(fp->dev);
469 	unsigned long flags;
470 
471 	/* remain disabled until set_alt */
472 	spin_lock_irqsave(&port->lock, flags);
473 	__pn_reset(f);
474 	spin_unlock_irqrestore(&port->lock, flags);
475 }
476 
477 /*-------------------------------------------------------------------------*/
478 
479 static int pn_bind(struct usb_configuration *c, struct usb_function *f)
480 {
481 	struct usb_composite_dev *cdev = c->cdev;
482 	struct usb_gadget *gadget = cdev->gadget;
483 	struct f_phonet *fp = func_to_pn(f);
484 	struct usb_ep *ep;
485 	int status, i;
486 
487 	struct f_phonet_opts *phonet_opts;
488 
489 	phonet_opts = container_of(f->fi, struct f_phonet_opts, func_inst);
490 
491 	/*
492 	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
493 	 * configurations are bound in sequence with list_for_each_entry,
494 	 * in each configuration its functions are bound in sequence
495 	 * with list_for_each_entry, so we assume no race condition
496 	 * with regard to phonet_opts->bound access
497 	 */
498 	if (!phonet_opts->bound) {
499 		gphonet_set_gadget(phonet_opts->net, gadget);
500 		status = gphonet_register_netdev(phonet_opts->net);
501 		if (status)
502 			return status;
503 		phonet_opts->bound = true;
504 	}
505 
506 	/* Reserve interface IDs */
507 	status = usb_interface_id(c, f);
508 	if (status < 0)
509 		goto err;
510 	pn_control_intf_desc.bInterfaceNumber = status;
511 	pn_union_desc.bMasterInterface0 = status;
512 
513 	status = usb_interface_id(c, f);
514 	if (status < 0)
515 		goto err;
516 	pn_data_nop_intf_desc.bInterfaceNumber = status;
517 	pn_data_intf_desc.bInterfaceNumber = status;
518 	pn_union_desc.bSlaveInterface0 = status;
519 
520 	/* Reserve endpoints */
521 	status = -ENODEV;
522 	ep = usb_ep_autoconfig(gadget, &pn_fs_sink_desc);
523 	if (!ep)
524 		goto err;
525 	fp->out_ep = ep;
526 
527 	ep = usb_ep_autoconfig(gadget, &pn_fs_source_desc);
528 	if (!ep)
529 		goto err;
530 	fp->in_ep = ep;
531 
532 	pn_hs_sink_desc.bEndpointAddress = pn_fs_sink_desc.bEndpointAddress;
533 	pn_hs_source_desc.bEndpointAddress = pn_fs_source_desc.bEndpointAddress;
534 
535 	/* Do not try to bind Phonet twice... */
536 	status = usb_assign_descriptors(f, fs_pn_function, hs_pn_function,
537 			NULL, NULL);
538 	if (status)
539 		goto err;
540 
541 	/* Incoming USB requests */
542 	status = -ENOMEM;
543 	for (i = 0; i < phonet_rxq_size; i++) {
544 		struct usb_request *req;
545 
546 		req = usb_ep_alloc_request(fp->out_ep, GFP_KERNEL);
547 		if (!req)
548 			goto err_req;
549 
550 		req->complete = pn_rx_complete;
551 		fp->out_reqv[i] = req;
552 	}
553 
554 	/* Outgoing USB requests */
555 	fp->in_req = usb_ep_alloc_request(fp->in_ep, GFP_KERNEL);
556 	if (!fp->in_req)
557 		goto err_req;
558 
559 	INFO(cdev, "USB CDC Phonet function\n");
560 	INFO(cdev, "using %s, OUT %s, IN %s\n", cdev->gadget->name,
561 		fp->out_ep->name, fp->in_ep->name);
562 	return 0;
563 
564 err_req:
565 	for (i = 0; i < phonet_rxq_size && fp->out_reqv[i]; i++)
566 		usb_ep_free_request(fp->out_ep, fp->out_reqv[i]);
567 	usb_free_all_descriptors(f);
568 err:
569 	ERROR(cdev, "USB CDC Phonet: cannot autoconfigure\n");
570 	return status;
571 }
572 
573 static inline struct f_phonet_opts *to_f_phonet_opts(struct config_item *item)
574 {
575 	return container_of(to_config_group(item), struct f_phonet_opts,
576 			func_inst.group);
577 }
578 
579 static void phonet_attr_release(struct config_item *item)
580 {
581 	struct f_phonet_opts *opts = to_f_phonet_opts(item);
582 
583 	usb_put_function_instance(&opts->func_inst);
584 }
585 
586 static struct configfs_item_operations phonet_item_ops = {
587 	.release		= phonet_attr_release,
588 };
589 
590 static ssize_t f_phonet_ifname_show(struct config_item *item, char *page)
591 {
592 	return gether_get_ifname(to_f_phonet_opts(item)->net, page, PAGE_SIZE);
593 }
594 
595 CONFIGFS_ATTR_RO(f_phonet_, ifname);
596 
597 static struct configfs_attribute *phonet_attrs[] = {
598 	&f_phonet_attr_ifname,
599 	NULL,
600 };
601 
602 static struct config_item_type phonet_func_type = {
603 	.ct_item_ops	= &phonet_item_ops,
604 	.ct_attrs	= phonet_attrs,
605 	.ct_owner	= THIS_MODULE,
606 };
607 
608 static void phonet_free_inst(struct usb_function_instance *f)
609 {
610 	struct f_phonet_opts *opts;
611 
612 	opts = container_of(f, struct f_phonet_opts, func_inst);
613 	if (opts->bound)
614 		gphonet_cleanup(opts->net);
615 	else
616 		free_netdev(opts->net);
617 	kfree(opts);
618 }
619 
620 static struct usb_function_instance *phonet_alloc_inst(void)
621 {
622 	struct f_phonet_opts *opts;
623 
624 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
625 	if (!opts)
626 		return ERR_PTR(-ENOMEM);
627 
628 	opts->func_inst.free_func_inst = phonet_free_inst;
629 	opts->net = gphonet_setup_default();
630 	if (IS_ERR(opts->net)) {
631 		struct net_device *net = opts->net;
632 		kfree(opts);
633 		return ERR_CAST(net);
634 	}
635 
636 	config_group_init_type_name(&opts->func_inst.group, "",
637 			&phonet_func_type);
638 
639 	return &opts->func_inst;
640 }
641 
642 static void phonet_free(struct usb_function *f)
643 {
644 	struct f_phonet *phonet;
645 
646 	phonet = func_to_pn(f);
647 	kfree(phonet);
648 }
649 
650 static void pn_unbind(struct usb_configuration *c, struct usb_function *f)
651 {
652 	struct f_phonet *fp = func_to_pn(f);
653 	int i;
654 
655 	/* We are already disconnected */
656 	if (fp->in_req)
657 		usb_ep_free_request(fp->in_ep, fp->in_req);
658 	for (i = 0; i < phonet_rxq_size; i++)
659 		if (fp->out_reqv[i])
660 			usb_ep_free_request(fp->out_ep, fp->out_reqv[i]);
661 
662 	usb_free_all_descriptors(f);
663 }
664 
665 static struct usb_function *phonet_alloc(struct usb_function_instance *fi)
666 {
667 	struct f_phonet *fp;
668 	struct f_phonet_opts *opts;
669 	int size;
670 
671 	size = sizeof(*fp) + (phonet_rxq_size * sizeof(struct usb_request *));
672 	fp = kzalloc(size, GFP_KERNEL);
673 	if (!fp)
674 		return ERR_PTR(-ENOMEM);
675 
676 	opts = container_of(fi, struct f_phonet_opts, func_inst);
677 
678 	fp->dev = opts->net;
679 	fp->function.name = "phonet";
680 	fp->function.bind = pn_bind;
681 	fp->function.unbind = pn_unbind;
682 	fp->function.set_alt = pn_set_alt;
683 	fp->function.get_alt = pn_get_alt;
684 	fp->function.disable = pn_disconnect;
685 	fp->function.free_func = phonet_free;
686 	spin_lock_init(&fp->rx.lock);
687 
688 	return &fp->function;
689 }
690 
691 struct net_device *gphonet_setup_default(void)
692 {
693 	struct net_device *dev;
694 	struct phonet_port *port;
695 
696 	/* Create net device */
697 	dev = alloc_netdev(sizeof(*port), "upnlink%d", NET_NAME_UNKNOWN,
698 			   pn_net_setup);
699 	if (!dev)
700 		return ERR_PTR(-ENOMEM);
701 
702 	port = netdev_priv(dev);
703 	spin_lock_init(&port->lock);
704 	netif_carrier_off(dev);
705 
706 	return dev;
707 }
708 
709 void gphonet_set_gadget(struct net_device *net, struct usb_gadget *g)
710 {
711 	SET_NETDEV_DEV(net, &g->dev);
712 }
713 
714 int gphonet_register_netdev(struct net_device *net)
715 {
716 	int status;
717 
718 	status = register_netdev(net);
719 	if (status)
720 		free_netdev(net);
721 
722 	return status;
723 }
724 
725 void gphonet_cleanup(struct net_device *dev)
726 {
727 	unregister_netdev(dev);
728 }
729 
730 DECLARE_USB_FUNCTION_INIT(phonet, phonet_alloc_inst, phonet_alloc);
731 MODULE_AUTHOR("Rémi Denis-Courmont");
732 MODULE_LICENSE("GPL");
733