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 int pn_net_mtu(struct net_device *dev, int new_mtu)
265 {
266 	if ((new_mtu < PHONET_MIN_MTU) || (new_mtu > PHONET_MAX_MTU))
267 		return -EINVAL;
268 	dev->mtu = new_mtu;
269 	return 0;
270 }
271 
272 static const struct net_device_ops pn_netdev_ops = {
273 	.ndo_open	= pn_net_open,
274 	.ndo_stop	= pn_net_close,
275 	.ndo_start_xmit	= pn_net_xmit,
276 	.ndo_change_mtu	= pn_net_mtu,
277 };
278 
279 static void pn_net_setup(struct net_device *dev)
280 {
281 	dev->features		= 0;
282 	dev->type		= ARPHRD_PHONET;
283 	dev->flags		= IFF_POINTOPOINT | IFF_NOARP;
284 	dev->mtu		= PHONET_DEV_MTU;
285 	dev->hard_header_len	= 1;
286 	dev->dev_addr[0]	= PN_MEDIA_USB;
287 	dev->addr_len		= 1;
288 	dev->tx_queue_len	= 1;
289 
290 	dev->netdev_ops		= &pn_netdev_ops;
291 	dev->destructor		= free_netdev;
292 	dev->header_ops		= &phonet_header_ops;
293 }
294 
295 /*-------------------------------------------------------------------------*/
296 
297 /*
298  * Queue buffer for data from the host
299  */
300 static int
301 pn_rx_submit(struct f_phonet *fp, struct usb_request *req, gfp_t gfp_flags)
302 {
303 	struct page *page;
304 	int err;
305 
306 	page = __dev_alloc_page(gfp_flags | __GFP_NOMEMALLOC);
307 	if (!page)
308 		return -ENOMEM;
309 
310 	req->buf = page_address(page);
311 	req->length = PAGE_SIZE;
312 	req->context = page;
313 
314 	err = usb_ep_queue(fp->out_ep, req, gfp_flags);
315 	if (unlikely(err))
316 		put_page(page);
317 	return err;
318 }
319 
320 static void pn_rx_complete(struct usb_ep *ep, struct usb_request *req)
321 {
322 	struct f_phonet *fp = ep->driver_data;
323 	struct net_device *dev = fp->dev;
324 	struct page *page = req->context;
325 	struct sk_buff *skb;
326 	unsigned long flags;
327 	int status = req->status;
328 
329 	switch (status) {
330 	case 0:
331 		spin_lock_irqsave(&fp->rx.lock, flags);
332 		skb = fp->rx.skb;
333 		if (!skb)
334 			skb = fp->rx.skb = netdev_alloc_skb(dev, 12);
335 		if (req->actual < req->length) /* Last fragment */
336 			fp->rx.skb = NULL;
337 		spin_unlock_irqrestore(&fp->rx.lock, flags);
338 
339 		if (unlikely(!skb))
340 			break;
341 
342 		if (skb->len == 0) { /* First fragment */
343 			skb->protocol = htons(ETH_P_PHONET);
344 			skb_reset_mac_header(skb);
345 			/* Can't use pskb_pull() on page in IRQ */
346 			memcpy(skb_put(skb, 1), page_address(page), 1);
347 		}
348 
349 		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
350 				skb->len <= 1, req->actual, PAGE_SIZE);
351 		page = NULL;
352 
353 		if (req->actual < req->length) { /* Last fragment */
354 			skb->dev = dev;
355 			dev->stats.rx_packets++;
356 			dev->stats.rx_bytes += skb->len;
357 
358 			netif_rx(skb);
359 		}
360 		break;
361 
362 	/* Do not resubmit in these cases: */
363 	case -ESHUTDOWN: /* disconnect */
364 	case -ECONNABORTED: /* hw reset */
365 	case -ECONNRESET: /* dequeued (unlink or netif down) */
366 		req = NULL;
367 		break;
368 
369 	/* Do resubmit in these cases: */
370 	case -EOVERFLOW: /* request buffer overflow */
371 		dev->stats.rx_over_errors++;
372 	default:
373 		dev->stats.rx_errors++;
374 		break;
375 	}
376 
377 	if (page)
378 		put_page(page);
379 	if (req)
380 		pn_rx_submit(fp, req, GFP_ATOMIC);
381 }
382 
383 /*-------------------------------------------------------------------------*/
384 
385 static void __pn_reset(struct usb_function *f)
386 {
387 	struct f_phonet *fp = func_to_pn(f);
388 	struct net_device *dev = fp->dev;
389 	struct phonet_port *port = netdev_priv(dev);
390 
391 	netif_carrier_off(dev);
392 	port->usb = NULL;
393 
394 	usb_ep_disable(fp->out_ep);
395 	usb_ep_disable(fp->in_ep);
396 	if (fp->rx.skb) {
397 		dev_kfree_skb_irq(fp->rx.skb);
398 		fp->rx.skb = NULL;
399 	}
400 }
401 
402 static int pn_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
403 {
404 	struct f_phonet *fp = func_to_pn(f);
405 	struct usb_gadget *gadget = fp->function.config->cdev->gadget;
406 
407 	if (intf == pn_control_intf_desc.bInterfaceNumber)
408 		/* control interface, no altsetting */
409 		return (alt > 0) ? -EINVAL : 0;
410 
411 	if (intf == pn_data_intf_desc.bInterfaceNumber) {
412 		struct net_device *dev = fp->dev;
413 		struct phonet_port *port = netdev_priv(dev);
414 
415 		/* data intf (0: inactive, 1: active) */
416 		if (alt > 1)
417 			return -EINVAL;
418 
419 		spin_lock(&port->lock);
420 
421 		if (fp->in_ep->driver_data)
422 			__pn_reset(f);
423 
424 		if (alt == 1) {
425 			int i;
426 
427 			if (config_ep_by_speed(gadget, f, fp->in_ep) ||
428 			    config_ep_by_speed(gadget, f, fp->out_ep)) {
429 				fp->in_ep->desc = NULL;
430 				fp->out_ep->desc = NULL;
431 				spin_unlock(&port->lock);
432 				return -EINVAL;
433 			}
434 			usb_ep_enable(fp->out_ep);
435 			usb_ep_enable(fp->in_ep);
436 
437 			port->usb = fp;
438 			fp->out_ep->driver_data = fp;
439 			fp->in_ep->driver_data = fp;
440 
441 			netif_carrier_on(dev);
442 			for (i = 0; i < phonet_rxq_size; i++)
443 				pn_rx_submit(fp, fp->out_reqv[i], GFP_ATOMIC);
444 		}
445 		spin_unlock(&port->lock);
446 		return 0;
447 	}
448 
449 	return -EINVAL;
450 }
451 
452 static int pn_get_alt(struct usb_function *f, unsigned intf)
453 {
454 	struct f_phonet *fp = func_to_pn(f);
455 
456 	if (intf == pn_control_intf_desc.bInterfaceNumber)
457 		return 0;
458 
459 	if (intf == pn_data_intf_desc.bInterfaceNumber) {
460 		struct phonet_port *port = netdev_priv(fp->dev);
461 		u8 alt;
462 
463 		spin_lock(&port->lock);
464 		alt = port->usb != NULL;
465 		spin_unlock(&port->lock);
466 		return alt;
467 	}
468 
469 	return -EINVAL;
470 }
471 
472 static void pn_disconnect(struct usb_function *f)
473 {
474 	struct f_phonet *fp = func_to_pn(f);
475 	struct phonet_port *port = netdev_priv(fp->dev);
476 	unsigned long flags;
477 
478 	/* remain disabled until set_alt */
479 	spin_lock_irqsave(&port->lock, flags);
480 	__pn_reset(f);
481 	spin_unlock_irqrestore(&port->lock, flags);
482 }
483 
484 /*-------------------------------------------------------------------------*/
485 
486 static int pn_bind(struct usb_configuration *c, struct usb_function *f)
487 {
488 	struct usb_composite_dev *cdev = c->cdev;
489 	struct usb_gadget *gadget = cdev->gadget;
490 	struct f_phonet *fp = func_to_pn(f);
491 	struct usb_ep *ep;
492 	int status, i;
493 
494 	struct f_phonet_opts *phonet_opts;
495 
496 	phonet_opts = container_of(f->fi, struct f_phonet_opts, func_inst);
497 
498 	/*
499 	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
500 	 * configurations are bound in sequence with list_for_each_entry,
501 	 * in each configuration its functions are bound in sequence
502 	 * with list_for_each_entry, so we assume no race condition
503 	 * with regard to phonet_opts->bound access
504 	 */
505 	if (!phonet_opts->bound) {
506 		gphonet_set_gadget(phonet_opts->net, gadget);
507 		status = gphonet_register_netdev(phonet_opts->net);
508 		if (status)
509 			return status;
510 		phonet_opts->bound = true;
511 	}
512 
513 	/* Reserve interface IDs */
514 	status = usb_interface_id(c, f);
515 	if (status < 0)
516 		goto err;
517 	pn_control_intf_desc.bInterfaceNumber = status;
518 	pn_union_desc.bMasterInterface0 = status;
519 
520 	status = usb_interface_id(c, f);
521 	if (status < 0)
522 		goto err;
523 	pn_data_nop_intf_desc.bInterfaceNumber = status;
524 	pn_data_intf_desc.bInterfaceNumber = status;
525 	pn_union_desc.bSlaveInterface0 = status;
526 
527 	/* Reserve endpoints */
528 	status = -ENODEV;
529 	ep = usb_ep_autoconfig(gadget, &pn_fs_sink_desc);
530 	if (!ep)
531 		goto err;
532 	fp->out_ep = ep;
533 	ep->driver_data = fp; /* Claim */
534 
535 	ep = usb_ep_autoconfig(gadget, &pn_fs_source_desc);
536 	if (!ep)
537 		goto err;
538 	fp->in_ep = ep;
539 	ep->driver_data = fp; /* Claim */
540 
541 	pn_hs_sink_desc.bEndpointAddress = pn_fs_sink_desc.bEndpointAddress;
542 	pn_hs_source_desc.bEndpointAddress = pn_fs_source_desc.bEndpointAddress;
543 
544 	/* Do not try to bind Phonet twice... */
545 	status = usb_assign_descriptors(f, fs_pn_function, hs_pn_function,
546 			NULL);
547 	if (status)
548 		goto err;
549 
550 	/* Incoming USB requests */
551 	status = -ENOMEM;
552 	for (i = 0; i < phonet_rxq_size; i++) {
553 		struct usb_request *req;
554 
555 		req = usb_ep_alloc_request(fp->out_ep, GFP_KERNEL);
556 		if (!req)
557 			goto err_req;
558 
559 		req->complete = pn_rx_complete;
560 		fp->out_reqv[i] = req;
561 	}
562 
563 	/* Outgoing USB requests */
564 	fp->in_req = usb_ep_alloc_request(fp->in_ep, GFP_KERNEL);
565 	if (!fp->in_req)
566 		goto err_req;
567 
568 	INFO(cdev, "USB CDC Phonet function\n");
569 	INFO(cdev, "using %s, OUT %s, IN %s\n", cdev->gadget->name,
570 		fp->out_ep->name, fp->in_ep->name);
571 	return 0;
572 
573 err_req:
574 	for (i = 0; i < phonet_rxq_size && fp->out_reqv[i]; i++)
575 		usb_ep_free_request(fp->out_ep, fp->out_reqv[i]);
576 	usb_free_all_descriptors(f);
577 err:
578 	if (fp->out_ep)
579 		fp->out_ep->driver_data = NULL;
580 	if (fp->in_ep)
581 		fp->in_ep->driver_data = NULL;
582 	ERROR(cdev, "USB CDC Phonet: cannot autoconfigure\n");
583 	return status;
584 }
585 
586 static inline struct f_phonet_opts *to_f_phonet_opts(struct config_item *item)
587 {
588 	return container_of(to_config_group(item), struct f_phonet_opts,
589 			func_inst.group);
590 }
591 
592 CONFIGFS_ATTR_STRUCT(f_phonet_opts);
593 static ssize_t f_phonet_attr_show(struct config_item *item,
594 				struct configfs_attribute *attr,
595 				char *page)
596 {
597 	struct f_phonet_opts *opts = to_f_phonet_opts(item);
598 	struct f_phonet_opts_attribute *f_phonet_opts_attr =
599 		container_of(attr, struct f_phonet_opts_attribute, attr);
600 	ssize_t ret = 0;
601 
602 	if (f_phonet_opts_attr->show)
603 		ret = f_phonet_opts_attr->show(opts, page);
604 	return ret;
605 }
606 
607 static void phonet_attr_release(struct config_item *item)
608 {
609 	struct f_phonet_opts *opts = to_f_phonet_opts(item);
610 
611 	usb_put_function_instance(&opts->func_inst);
612 }
613 
614 static struct configfs_item_operations phonet_item_ops = {
615 	.release		= phonet_attr_release,
616 	.show_attribute		= f_phonet_attr_show,
617 };
618 
619 static ssize_t f_phonet_ifname_show(struct f_phonet_opts *opts, char *page)
620 {
621 	return gether_get_ifname(opts->net, page, PAGE_SIZE);
622 }
623 
624 static struct f_phonet_opts_attribute f_phonet_ifname =
625 	__CONFIGFS_ATTR_RO(ifname, f_phonet_ifname_show);
626 
627 static struct configfs_attribute *phonet_attrs[] = {
628 	&f_phonet_ifname.attr,
629 	NULL,
630 };
631 
632 static struct config_item_type phonet_func_type = {
633 	.ct_item_ops	= &phonet_item_ops,
634 	.ct_attrs	= phonet_attrs,
635 	.ct_owner	= THIS_MODULE,
636 };
637 
638 static void phonet_free_inst(struct usb_function_instance *f)
639 {
640 	struct f_phonet_opts *opts;
641 
642 	opts = container_of(f, struct f_phonet_opts, func_inst);
643 	if (opts->bound)
644 		gphonet_cleanup(opts->net);
645 	else
646 		free_netdev(opts->net);
647 	kfree(opts);
648 }
649 
650 static struct usb_function_instance *phonet_alloc_inst(void)
651 {
652 	struct f_phonet_opts *opts;
653 
654 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
655 	if (!opts)
656 		return ERR_PTR(-ENOMEM);
657 
658 	opts->func_inst.free_func_inst = phonet_free_inst;
659 	opts->net = gphonet_setup_default();
660 	if (IS_ERR(opts->net)) {
661 		struct net_device *net = opts->net;
662 		kfree(opts);
663 		return ERR_CAST(net);
664 	}
665 
666 	config_group_init_type_name(&opts->func_inst.group, "",
667 			&phonet_func_type);
668 
669 	return &opts->func_inst;
670 }
671 
672 static void phonet_free(struct usb_function *f)
673 {
674 	struct f_phonet *phonet;
675 
676 	phonet = func_to_pn(f);
677 	kfree(phonet);
678 }
679 
680 static void pn_unbind(struct usb_configuration *c, struct usb_function *f)
681 {
682 	struct f_phonet *fp = func_to_pn(f);
683 	int i;
684 
685 	/* We are already disconnected */
686 	if (fp->in_req)
687 		usb_ep_free_request(fp->in_ep, fp->in_req);
688 	for (i = 0; i < phonet_rxq_size; i++)
689 		if (fp->out_reqv[i])
690 			usb_ep_free_request(fp->out_ep, fp->out_reqv[i]);
691 
692 	usb_free_all_descriptors(f);
693 }
694 
695 static struct usb_function *phonet_alloc(struct usb_function_instance *fi)
696 {
697 	struct f_phonet *fp;
698 	struct f_phonet_opts *opts;
699 	int size;
700 
701 	size = sizeof(*fp) + (phonet_rxq_size * sizeof(struct usb_request *));
702 	fp = kzalloc(size, GFP_KERNEL);
703 	if (!fp)
704 		return ERR_PTR(-ENOMEM);
705 
706 	opts = container_of(fi, struct f_phonet_opts, func_inst);
707 
708 	fp->dev = opts->net;
709 	fp->function.name = "phonet";
710 	fp->function.bind = pn_bind;
711 	fp->function.unbind = pn_unbind;
712 	fp->function.set_alt = pn_set_alt;
713 	fp->function.get_alt = pn_get_alt;
714 	fp->function.disable = pn_disconnect;
715 	fp->function.free_func = phonet_free;
716 	spin_lock_init(&fp->rx.lock);
717 
718 	return &fp->function;
719 }
720 
721 struct net_device *gphonet_setup_default(void)
722 {
723 	struct net_device *dev;
724 	struct phonet_port *port;
725 
726 	/* Create net device */
727 	dev = alloc_netdev(sizeof(*port), "upnlink%d", NET_NAME_UNKNOWN,
728 			   pn_net_setup);
729 	if (!dev)
730 		return ERR_PTR(-ENOMEM);
731 
732 	port = netdev_priv(dev);
733 	spin_lock_init(&port->lock);
734 	netif_carrier_off(dev);
735 
736 	return dev;
737 }
738 
739 void gphonet_set_gadget(struct net_device *net, struct usb_gadget *g)
740 {
741 	SET_NETDEV_DEV(net, &g->dev);
742 }
743 
744 int gphonet_register_netdev(struct net_device *net)
745 {
746 	int status;
747 
748 	status = register_netdev(net);
749 	if (status)
750 		free_netdev(net);
751 
752 	return status;
753 }
754 
755 void gphonet_cleanup(struct net_device *dev)
756 {
757 	unregister_netdev(dev);
758 }
759 
760 DECLARE_USB_FUNCTION_INIT(phonet, phonet_alloc_inst, phonet_alloc);
761 MODULE_AUTHOR("Rémi Denis-Courmont");
762 MODULE_LICENSE("GPL");
763