Linux Audio

Check our new training course

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