summaryrefslogtreecommitdiffstats
path: root/drivers/usb/gadget/function/f_phonet.c
blob: c89e96cfa3e47b95d179d06910d528710e59d5de (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
/*
 * f_phonet.c -- USB CDC Phonet function
 *
 * Copyright (C) 2007-2008 Nokia Corporation. All rights reserved.
 *
 * Author: Rémi Denis-Courmont
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 */

#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>

#include <linux/netdevice.h>
#include <linux/if_ether.h>
#include <linux/if_phonet.h>
#include <linux/if_arp.h>

#include <linux/usb/ch9.h>
#include <linux/usb/cdc.h>
#include <linux/usb/composite.h>

#include "u_phonet.h"
#include "u_ether.h"

#define PN_MEDIA_USB	0x1B
#define MAXPACKET	512
#if (PAGE_SIZE % MAXPACKET)
#error MAXPACKET must divide PAGE_SIZE!
#endif

/*-------------------------------------------------------------------------*/

struct phonet_port {
	struct f_phonet			*usb;
	spinlock_t			lock;
};

struct f_phonet {
	struct usb_function		function;
	struct {
		struct sk_buff		*skb;
		spinlock_t		lock;
	} rx;
	struct net_device		*dev;
	struct usb_ep			*in_ep, *out_ep;

	struct usb_request		*in_req;
	struct usb_request		*out_reqv[0];
};

static int phonet_rxq_size = 17;

static inline struct f_phonet *func_to_pn(struct usb_function *f)
{
	return container_of(f, struct f_phonet, function);
}

/*-------------------------------------------------------------------------*/

#define USB_CDC_SUBCLASS_PHONET	0xfe
#define USB_CDC_PHONET_TYPE	0xab

static struct usb_interface_descriptor
pn_control_intf_desc = {
	.bLength =		sizeof pn_control_intf_desc,
	.bDescriptorType =	USB_DT_INTERFACE,

	/* .bInterfaceNumber =	DYNAMIC, */
	.bInterfaceClass =	USB_CLASS_COMM,
	.bInterfaceSubClass =	USB_CDC_SUBCLASS_PHONET,
};

static const struct usb_cdc_header_desc
pn_header_desc = {
	.bLength =		sizeof pn_header_desc,
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
	.bcdCDC =		cpu_to_le16(0x0110),
};

static const struct usb_cdc_header_desc
pn_phonet_desc = {
	.bLength =		sizeof pn_phonet_desc,
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubType =	USB_CDC_PHONET_TYPE,
	.bcdCDC =		cpu_to_le16(0x1505), /* ??? */
};

static struct usb_cdc_union_desc
pn_union_desc = {
	.bLength =		sizeof pn_union_desc,
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubType =	USB_CDC_UNION_TYPE,

	/* .bMasterInterface0 =	DYNAMIC, */
	/* .bSlaveInterface0 =	DYNAMIC, */
};

static struct usb_interface_descriptor
pn_data_nop_intf_desc = {
	.bLength =		sizeof pn_data_nop_intf_desc,
	.bDescriptorType =	USB_DT_INTERFACE,

	/* .bInterfaceNumber =	DYNAMIC, */
	.bAlternateSetting =	0,
	.bNumEndpoints =	0,
	.bInterfaceClass =	USB_CLASS_CDC_DATA,
};

static struct usb_interface_descriptor
pn_data_intf_desc = {
	.bLength =		sizeof pn_data_intf_desc,
	.bDescriptorType =	USB_DT_INTERFACE,

	/* .bInterfaceNumber =	DYNAMIC, */
	.bAlternateSetting =	1,
	.bNumEndpoints =	2,
	.bInterfaceClass =	USB_CLASS_CDC_DATA,
};

static struct usb_endpoint_descriptor
pn_fs_sink_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bEndpointAddress =	USB_DIR_OUT,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
};

static struct usb_endpoint_descriptor
pn_hs_sink_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bEndpointAddress =	USB_DIR_OUT,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =	cpu_to_le16(MAXPACKET),
};

static struct usb_endpoint_descriptor
pn_fs_source_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bEndpointAddress =	USB_DIR_IN,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
};

static struct usb_endpoint_descriptor
pn_hs_source_desc = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bEndpointAddress =	USB_DIR_IN,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =	cpu_to_le16(512),
};

static struct usb_descriptor_header *fs_pn_function[] = {
	(struct usb_descriptor_header *) &pn_control_intf_desc,
	(struct usb_descriptor_header *) &pn_header_desc,
	(struct usb_descriptor_header *) &pn_phonet_desc,
	(struct usb_descriptor_header *) &pn_union_desc,
	(struct usb_descriptor_header *) &pn_data_nop_intf_desc,
	(struct usb_descriptor_header *) &pn_data_intf_desc,
	(struct usb_descriptor_header *) &pn_fs_sink_desc,
	(struct usb_descriptor_header *) &pn_fs_source_desc,
	NULL,
};

static struct usb_descriptor_header *hs_pn_function[] = {
	(struct usb_descriptor_header *) &pn_control_intf_desc,
	(struct usb_descriptor_header *) &pn_header_desc,
	(struct usb_descriptor_header *) &pn_phonet_desc,
	(struct usb_descriptor_header *) &pn_union_desc,
	(struct usb_descriptor_header *) &pn_data_nop_intf_desc,
	(struct usb_descriptor_header *) &pn_data_intf_desc,
	(struct usb_descriptor_header *) &pn_hs_sink_desc,
	(struct usb_descriptor_header *) &pn_hs_source_desc,
	NULL,
};

/*-------------------------------------------------------------------------*/

static int pn_net_open(struct net_device *dev)
{
	netif_wake_queue(dev);
	return 0;
}

static int pn_net_close(struct net_device *dev)
{
	netif_stop_queue(dev);
	return 0;
}

static void pn_tx_complete(struct usb_ep *ep, struct usb_request *req)
{
	struct f_phonet *fp = ep->driver_data;
	struct net_device *dev = fp->dev;
	struct sk_buff *skb = req->context;

	switch (req->status) {
	case 0:
		dev->stats.tx_packets++;
		dev->stats.tx_bytes += skb->len;
		break;

	case -ESHUTDOWN: /* disconnected */
	case -ECONNRESET: /* disabled */
		dev->stats.tx_aborted_errors++;
	default:
		dev->stats.tx_errors++;
	}

	dev_kfree_skb_any(skb);
	netif_wake_queue(dev);
}

static int pn_net_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct phonet_port *port = netdev_priv(dev);
	struct f_phonet *fp;
	struct usb_request *req;
	unsigned long flags;

	if (skb->protocol != htons(ETH_P_PHONET))
		goto out;

	spin_lock_irqsave(&port->lock, flags);
	fp = port->usb;
	if (unlikely(!fp)) /* race with carrier loss */
		goto out_unlock;

	req = fp->in_req;
	req->buf = skb->data;
	req->length = skb->len;
	req->complete = pn_tx_complete;
	req->zero = 1;
	req->context = skb;

	if (unlikely(usb_ep_queue(fp->in_ep, req, GFP_ATOMIC)))
		goto out_unlock;

	netif_stop_queue(dev);
	skb = NULL;

out_unlock:
	spin_unlock_irqrestore(&port->lock, flags);
out:
	if (unlikely(skb)) {
		dev_kfree_skb(skb);
		dev->stats.tx_dropped++;
	}
	return NETDEV_TX_OK;
}

static int pn_net_mtu(struct net_device *dev, int new_mtu)
{
	if ((new_mtu < PHONET_MIN_MTU) || (new_mtu > PHONET_MAX_MTU))
		return -EINVAL;
	dev->mtu = new_mtu;
	return 0;
}

static const struct net_device_ops pn_netdev_ops = {
	.ndo_open	= pn_net_open,
	.ndo_stop	= pn_net_close,
	.ndo_start_xmit	= pn_net_xmit,
	.ndo_change_mtu	= pn_net_mtu,
};

static void pn_net_setup(struct net_device *dev)
{
	dev->features		= 0;
	dev->type		= ARPHRD_PHONET;
	dev->flags		= IFF_POINTOPOINT | IFF_NOARP;
	dev->mtu		= PHONET_DEV_MTU;
	dev->hard_header_len	= 1;
	dev->dev_addr[0]	= PN_MEDIA_USB;
	dev->addr_len		= 1;
	dev->tx_queue_len	= 1;

	dev->netdev_ops		= &pn_netdev_ops;
	dev->destructor		= free_netdev;
	dev->header_ops		= &phonet_header_ops;
}

/*-------------------------------------------------------------------------*/

/*
 * Queue buffer for data from the host
 */
static int
pn_rx_submit(struct f_phonet *fp, struct usb_request *req, gfp_t gfp_flags)
{
	struct page *page;
	int err;

	page = __dev_alloc_page(gfp_flags | __GFP_NOMEMALLOC);
	if (!page)
		return -ENOMEM;

	req->buf = page_address(page);
	req->length = PAGE_SIZE;
	req->context = page;

	err = usb_ep_queue(fp->out_ep, req, gfp_flags);
	if (unlikely(err))
		put_page(page);
	return err;
}

static void pn_rx_complete(struct usb_ep *ep, struct usb_request *req)
{
	struct f_phonet *fp = ep->driver_data;
	struct net_device *dev = fp->dev;
	struct page *page = req->context;
	struct sk_buff *skb;
	unsigned long flags;
	int status = req->status;

	switch (status) {
	case 0:
		spin_lock_irqsave(&fp->rx.lock, flags);
		skb = fp->rx.skb;
		if (!skb)
			skb = fp->rx.skb = netdev_alloc_skb(dev, 12);
		if (req->actual < req->length) /* Last fragment */
			fp->rx.skb = NULL;
		spin_unlock_irqrestore(&fp->rx.lock, flags);

		if (unlikely(!skb))
			break;

		if (skb->len == 0) { /* First fragment */
			skb->protocol = htons(ETH_P_PHONET);
			skb_reset_mac_header(skb);
			/* Can't use pskb_pull() on page in IRQ */
			memcpy(skb_put(skb, 1), page_address(page), 1);
		}

		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
				skb->len <= 1, req->actual, PAGE_SIZE);
		page = NULL;

		if (req->actual < req->length) { /* Last fragment */
			skb->dev = dev;
			dev->stats.rx_packets++;
			dev->stats.rx_bytes += skb->len;

			netif_rx(skb);
		}
		break;

	/* Do not resubmit in these cases: */
	case -ESHUTDOWN: /* disconnect */
	case -ECONNABORTED: /* hw reset */
	case -ECONNRESET: /* dequeued (unlink or netif down) */
		req = NULL;
		break;

	/* Do resubmit in these cases: */
	case -EOVERFLOW: /* request buffer overflow */
		dev->stats.rx_over_errors++;
	default:
		dev->stats.rx_errors++;
		break;
	}

	if (page)
		put_page(page);
	if (req)
		pn_rx_submit(fp, req, GFP_ATOMIC);
}

/*-------------------------------------------------------------------------*/

static void __pn_reset(struct usb_function *f)
{
	struct f_phonet *fp = func_to_pn(f);
	struct net_device *dev = fp->dev;
	struct phonet_port *port = netdev_priv(dev);

	netif_carrier_off(dev);
	port->usb = NULL;

	usb_ep_disable(fp->out_ep);
	usb_ep_disable(fp->in_ep);
	if (fp->rx.skb) {
		dev_kfree_skb_irq(fp->rx.skb);
		fp->rx.skb = NULL;
	}
}

static int pn_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
{
	struct f_phonet *fp = func_to_pn(f);
	struct usb_gadget *gadget = fp->function.config->cdev->gadget;

	if (intf == pn_control_intf_desc.bInterfaceNumber)
		/* control interface, no altsetting */
		return (alt > 0) ? -EINVAL : 0;

	if (intf == pn_data_intf_desc.bInterfaceNumber) {
		struct net_device *dev = fp->dev;
		struct phonet_port *port = netdev_priv(dev);

		/* data intf (0: inactive, 1: active) */
		if (alt > 1)
			return -EINVAL;

		spin_lock(&port->lock);
		__pn_reset(f);
		if (alt == 1) {
			int i;

			if (config_ep_by_speed(gadget, f, fp->in_ep) ||
			    config_ep_by_speed(gadget, f, fp->out_ep)) {
				fp->in_ep->desc = NULL;
				fp->out_ep->desc = NULL;
				spin_unlock(&port->lock);
				return -EINVAL;
			}
			usb_ep_enable(fp->out_ep);
			usb_ep_enable(fp->in_ep);

			port->usb = fp;
			fp->out_ep->driver_data = fp;
			fp->in_ep->driver_data = fp;

			netif_carrier_on(dev);
			for (i = 0; i < phonet_rxq_size; i++)
				pn_rx_submit(fp, fp->out_reqv[i], GFP_ATOMIC);
		}
		spin_unlock(&port->lock);
		return 0;
	}

	return -EINVAL;
}

static int pn_get_alt(struct usb_function *f, unsigned intf)
{
	struct f_phonet *fp = func_to_pn(f);

	if (intf == pn_control_intf_desc.bInterfaceNumber)
		return 0;

	if (intf == pn_data_intf_desc.bInterfaceNumber) {
		struct phonet_port *port = netdev_priv(fp->dev);
		u8 alt;

		spin_lock(&port->lock);
		alt = port->usb != NULL;
		spin_unlock(&port->lock);
		return alt;
	}

	return -EINVAL;
}

static void pn_disconnect(struct usb_function *f)
{
	struct f_phonet *fp = func_to_pn(f);
	struct phonet_port *port = netdev_priv(fp->dev);
	unsigned long flags;

	/* remain disabled until set_alt */
	spin_lock_irqsave(&port->lock, flags);
	__pn_reset(f);
	spin_unlock_irqrestore(&port->lock, flags);
}

/*-------------------------------------------------------------------------*/

static int pn_bind(struct usb_configuration *c, struct usb_function *f)
{
	struct usb_composite_dev *cdev = c->cdev;
	struct usb_gadget *gadget = cdev->gadget;
	struct f_phonet *fp = func_to_pn(f);
	struct usb_ep *ep;
	int status, i;

	struct f_phonet_opts *phonet_opts;

	phonet_opts = container_of(f->fi, struct f_phonet_opts, func_inst);

	/*
	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
	 * configurations are bound in sequence with list_for_each_entry,
	 * in each configuration its functions are bound in sequence
	 * with list_for_each_entry, so we assume no race condition
	 * with regard to phonet_opts->bound access
	 */
	if (!phonet_opts->bound) {
		gphonet_set_gadget(phonet_opts->net, gadget);
		status = gphonet_register_netdev(phonet_opts->net);
		if (status)
			return status;
		phonet_opts->bound = true;
	}

	/* Reserve interface IDs */
	status = usb_interface_id(c, f);
	if (status < 0)
		goto err;
	pn_control_intf_desc.bInterfaceNumber = status;
	pn_union_desc.bMasterInterface0 = status;

	status = usb_interface_id(c, f);
	if (status < 0)
		goto err;
	pn_data_nop_intf_desc.bInterfaceNumber = status;
	pn_data_intf_desc.bInterfaceNumber = status;
	pn_union_desc.bSlaveInterface0 = status;

	/* Reserve endpoints */
	status = -ENODEV;
	ep = usb_ep_autoconfig(gadget, &pn_fs_sink_desc);
	if (!ep)
		goto err;
	fp->out_ep = ep;
	ep->driver_data = fp; /* Claim */

	ep = usb_ep_autoconfig(gadget, &pn_fs_source_desc);
	if (!ep)
		goto err;
	fp->in_ep = ep;
	ep->driver_data = fp; /* Claim */

	pn_hs_sink_desc.bEndpointAddress = pn_fs_sink_desc.bEndpointAddress;
	pn_hs_source_desc.bEndpointAddress = pn_fs_source_desc.bEndpointAddress;

	/* Do not try to bind Phonet twice... */
	status = usb_assign_descriptors(f, fs_pn_function, hs_pn_function,
			NULL);
	if (status)
		goto err;

	/* Incoming USB requests */
	status = -ENOMEM;
	for (i = 0; i < phonet_rxq_size; i++) {
		struct usb_request *req;

		req = usb_ep_alloc_request(fp->out_ep, GFP_KERNEL);
		if (!req)
			goto err_req;

		req->complete = pn_rx_complete;
		fp->out_reqv[i] = req;
	}

	/* Outgoing USB requests */
	fp->in_req = usb_ep_alloc_request(fp->in_ep, GFP_KERNEL);
	if (!fp->in_req)
		goto err_req;

	INFO(cdev, "USB CDC Phonet function\n");
	INFO(cdev, "using %s, OUT %s, IN %s\n", cdev->gadget->name,
		fp->out_ep->name, fp->in_ep->name);
	return 0;

err_req:
	for (i = 0; i < phonet_rxq_size && fp->out_reqv[i]; i++)
		usb_ep_free_request(fp->out_ep, fp->out_reqv[i]);
	usb_free_all_descriptors(f);
err:
	if (fp->out_ep)
		fp->out_ep->driver_data = NULL;
	if (fp->in_ep)
		fp->in_ep->driver_data = NULL;
	ERROR(cdev, "USB CDC Phonet: cannot autoconfigure\n");
	return status;
}

static inline struct f_phonet_opts *to_f_phonet_opts(struct config_item *item)
{
	return container_of(to_config_group(item), struct f_phonet_opts,
			func_inst.group);
}

CONFIGFS_ATTR_STRUCT(f_phonet_opts);
static ssize_t f_phonet_attr_show(struct config_item *item,
				struct configfs_attribute *attr,
				char *page)
{
	struct f_phonet_opts *opts = to_f_phonet_opts(item);
	struct f_phonet_opts_attribute *f_phonet_opts_attr =
		container_of(attr, struct f_phonet_opts_attribute, attr);
	ssize_t ret = 0;

	if (f_phonet_opts_attr->show)
		ret = f_phonet_opts_attr->show(opts, page);
	return ret;
}

static void phonet_attr_release(struct config_item *item)
{
	struct f_phonet_opts *opts = to_f_phonet_opts(item);

	usb_put_function_instance(&opts->func_inst);
}

static struct configfs_item_operations phonet_item_ops = {
	.release		= phonet_attr_release,
	.show_attribute		= f_phonet_attr_show,
};

static ssize_t f_phonet_ifname_show(struct f_phonet_opts *opts, char *page)
{
	return gether_get_ifname(opts->net, page, PAGE_SIZE);
}

static struct f_phonet_opts_attribute f_phonet_ifname =
	__CONFIGFS_ATTR_RO(ifname, f_phonet_ifname_show);

static struct configfs_attribute *phonet_attrs[] = {
	&f_phonet_ifname.attr,
	NULL,
};

static struct config_item_type phonet_func_type = {
	.ct_item_ops	= &phonet_item_ops,
	.ct_attrs	= phonet_attrs,
	.ct_owner	= THIS_MODULE,
};

static void phonet_free_inst(struct usb_function_instance *f)
{
	struct f_phonet_opts *opts;

	opts = container_of(f, struct f_phonet_opts, func_inst);
	if (opts->bound)
		gphonet_cleanup(opts->net);
	else
		free_netdev(opts->net);
	kfree(opts);
}

static struct usb_function_instance *phonet_alloc_inst(void)
{
	struct f_phonet_opts *opts;

	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
	if (!opts)
		return ERR_PTR(-ENOMEM);

	opts->func_inst.free_func_inst = phonet_free_inst;
	opts->net = gphonet_setup_default();
	if (IS_ERR(opts->net)) {
		struct net_device *net = opts->net;
		kfree(opts);
		return ERR_CAST(net);
	}

	config_group_init_type_name(&opts->func_inst.group, "",
			&phonet_func_type);

	return &opts->func_inst;
}

static void phonet_free(struct usb_function *f)
{
	struct f_phonet *phonet;

	phonet = func_to_pn(f);
	kfree(phonet);
}

static void pn_unbind(struct usb_configuration *c, struct usb_function *f)
{
	struct f_phonet *fp = func_to_pn(f);
	int i;

	/* We are already disconnected */
	if (fp->in_req)
		usb_ep_free_request(fp->in_ep, fp->in_req);
	for (i = 0; i < phonet_rxq_size; i++)
		if (fp->out_reqv[i])
			usb_ep_free_request(fp->out_ep, fp->out_reqv[i]);

	usb_free_all_descriptors(f);
}

static struct usb_function *phonet_alloc(struct usb_function_instance *fi)
{
	struct f_phonet *fp;
	struct f_phonet_opts *opts;
	int size;

	size = sizeof(*fp) + (phonet_rxq_size * sizeof(struct usb_request *));
	fp = kzalloc(size, GFP_KERNEL);
	if (!fp)
		return ERR_PTR(-ENOMEM);

	opts = container_of(fi, struct f_phonet_opts, func_inst);

	fp->dev = opts->net;
	fp->function.name = "phonet";
	fp->function.bind = pn_bind;
	fp->function.unbind = pn_unbind;
	fp->function.set_alt = pn_set_alt;
	fp->function.get_alt = pn_get_alt;
	fp->function.disable = pn_disconnect;
	fp->function.free_func = phonet_free;
	spin_lock_init(&fp->rx.lock);

	return &fp->function;
}

struct net_device *gphonet_setup_default(void)
{
	struct net_device *dev;
	struct phonet_port *port;

	/* Create net device */
	dev = alloc_netdev(sizeof(*port), "upnlink%d", NET_NAME_UNKNOWN,
			   pn_net_setup);
	if (!dev)
		return ERR_PTR(-ENOMEM);

	port = netdev_priv(dev);
	spin_lock_init(&port->lock);
	netif_carrier_off(dev);

	return dev;
}

void gphonet_set_gadget(struct net_device *net, struct usb_gadget *g)
{
	SET_NETDEV_DEV(net, &g->dev);
}

int gphonet_register_netdev(struct net_device *net)
{
	int status;

	status = register_netdev(net);
	if (status)
		free_netdev(net);

	return status;
}

void gphonet_cleanup(struct net_device *dev)
{
	unregister_netdev(dev);
}

DECLARE_USB_FUNCTION_INIT(phonet, phonet_alloc_inst, phonet_alloc);
MODULE_AUTHOR("Rémi Denis-Courmont");
MODULE_LICENSE("GPL");