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 * This program is distributed in the hope that it will be useful, but
 13 * WITHOUT ANY WARRANTY; without even the implied warranty of
 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 15 * General Public License for more details.
 16 *
 17 * You should have received a copy of the GNU General Public License
 18 * along with this program; if not, write to the Free Software
 19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 20 * 02110-1301 USA
 21 */
 22
 23#include <linux/mm.h>
 24#include <linux/slab.h>
 25#include <linux/kernel.h>
 26#include <linux/device.h>
 27
 28#include <linux/netdevice.h>
 29#include <linux/if_ether.h>
 30#include <linux/if_phonet.h>
 31#include <linux/if_arp.h>
 32
 33#include <linux/usb/ch9.h>
 34#include <linux/usb/cdc.h>
 35#include <linux/usb/composite.h>
 36
 37#include "u_phonet.h"
 38
 39#define PN_MEDIA_USB	0x1B
 40#define MAXPACKET	512
 41#if (PAGE_SIZE % MAXPACKET)
 42#error MAXPACKET must divide PAGE_SIZE!
 43#endif
 44
 45/*-------------------------------------------------------------------------*/
 46
 47struct phonet_port {
 48	struct f_phonet			*usb;
 49	spinlock_t			lock;
 50};
 51
 52struct f_phonet {
 53	struct usb_function		function;
 54	struct {
 55		struct sk_buff		*skb;
 56		spinlock_t		lock;
 57	} rx;
 58	struct net_device		*dev;
 59	struct usb_ep			*in_ep, *out_ep;
 60
 61	struct usb_request		*in_req;
 62	struct usb_request		*out_reqv[0];
 63};
 64
 65static int phonet_rxq_size = 17;
 66
 67static inline struct f_phonet *func_to_pn(struct usb_function *f)
 68{
 69	return container_of(f, struct f_phonet, function);
 70}
 71
 72/*-------------------------------------------------------------------------*/
 73
 74#define USB_CDC_SUBCLASS_PHONET	0xfe
 75#define USB_CDC_PHONET_TYPE	0xab
 76
 77static struct usb_interface_descriptor
 78pn_control_intf_desc = {
 79	.bLength =		sizeof pn_control_intf_desc,
 80	.bDescriptorType =	USB_DT_INTERFACE,
 81
 82	/* .bInterfaceNumber =	DYNAMIC, */
 83	.bInterfaceClass =	USB_CLASS_COMM,
 84	.bInterfaceSubClass =	USB_CDC_SUBCLASS_PHONET,
 85};
 86
 87static const struct usb_cdc_header_desc
 88pn_header_desc = {
 89	.bLength =		sizeof pn_header_desc,
 90	.bDescriptorType =	USB_DT_CS_INTERFACE,
 91	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
 92	.bcdCDC =		cpu_to_le16(0x0110),
 93};
 94
 95static const struct usb_cdc_header_desc
 96pn_phonet_desc = {
 97	.bLength =		sizeof pn_phonet_desc,
 98	.bDescriptorType =	USB_DT_CS_INTERFACE,
 99	.bDescriptorSubType =	USB_CDC_PHONET_TYPE,
100	.bcdCDC =		cpu_to_le16(0x1505), /* ??? */
101};
102
103static struct usb_cdc_union_desc
104pn_union_desc = {
105	.bLength =		sizeof pn_union_desc,
106	.bDescriptorType =	USB_DT_CS_INTERFACE,
107	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
108
109	/* .bMasterInterface0 =	DYNAMIC, */
110	/* .bSlaveInterface0 =	DYNAMIC, */
111};
112
113static struct usb_interface_descriptor
114pn_data_nop_intf_desc = {
115	.bLength =		sizeof pn_data_nop_intf_desc,
116	.bDescriptorType =	USB_DT_INTERFACE,
117
118	/* .bInterfaceNumber =	DYNAMIC, */
119	.bAlternateSetting =	0,
120	.bNumEndpoints =	0,
121	.bInterfaceClass =	USB_CLASS_CDC_DATA,
122};
123
124static struct usb_interface_descriptor
125pn_data_intf_desc = {
126	.bLength =		sizeof pn_data_intf_desc,
127	.bDescriptorType =	USB_DT_INTERFACE,
128
129	/* .bInterfaceNumber =	DYNAMIC, */
130	.bAlternateSetting =	1,
131	.bNumEndpoints =	2,
132	.bInterfaceClass =	USB_CLASS_CDC_DATA,
133};
134
135static struct usb_endpoint_descriptor
136pn_fs_sink_desc = {
137	.bLength =		USB_DT_ENDPOINT_SIZE,
138	.bDescriptorType =	USB_DT_ENDPOINT,
139
140	.bEndpointAddress =	USB_DIR_OUT,
141	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
142};
143
144static struct usb_endpoint_descriptor
145pn_hs_sink_desc = {
146	.bLength =		USB_DT_ENDPOINT_SIZE,
147	.bDescriptorType =	USB_DT_ENDPOINT,
148
149	.bEndpointAddress =	USB_DIR_OUT,
150	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
151	.wMaxPacketSize =	cpu_to_le16(MAXPACKET),
152};
153
154static struct usb_endpoint_descriptor
155pn_fs_source_desc = {
156	.bLength =		USB_DT_ENDPOINT_SIZE,
157	.bDescriptorType =	USB_DT_ENDPOINT,
158
159	.bEndpointAddress =	USB_DIR_IN,
160	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
161};
162
163static struct usb_endpoint_descriptor
164pn_hs_source_desc = {
165	.bLength =		USB_DT_ENDPOINT_SIZE,
166	.bDescriptorType =	USB_DT_ENDPOINT,
167
168	.bEndpointAddress =	USB_DIR_IN,
169	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
170	.wMaxPacketSize =	cpu_to_le16(512),
171};
172
173static struct usb_descriptor_header *fs_pn_function[] = {
174	(struct usb_descriptor_header *) &pn_control_intf_desc,
175	(struct usb_descriptor_header *) &pn_header_desc,
176	(struct usb_descriptor_header *) &pn_phonet_desc,
177	(struct usb_descriptor_header *) &pn_union_desc,
178	(struct usb_descriptor_header *) &pn_data_nop_intf_desc,
179	(struct usb_descriptor_header *) &pn_data_intf_desc,
180	(struct usb_descriptor_header *) &pn_fs_sink_desc,
181	(struct usb_descriptor_header *) &pn_fs_source_desc,
182	NULL,
183};
184
185static struct usb_descriptor_header *hs_pn_function[] = {
186	(struct usb_descriptor_header *) &pn_control_intf_desc,
187	(struct usb_descriptor_header *) &pn_header_desc,
188	(struct usb_descriptor_header *) &pn_phonet_desc,
189	(struct usb_descriptor_header *) &pn_union_desc,
190	(struct usb_descriptor_header *) &pn_data_nop_intf_desc,
191	(struct usb_descriptor_header *) &pn_data_intf_desc,
192	(struct usb_descriptor_header *) &pn_hs_sink_desc,
193	(struct usb_descriptor_header *) &pn_hs_source_desc,
194	NULL,
195};
196
197/*-------------------------------------------------------------------------*/
198
199static int pn_net_open(struct net_device *dev)
200{
201	netif_wake_queue(dev);
202	return 0;
203}
204
205static int pn_net_close(struct net_device *dev)
206{
207	netif_stop_queue(dev);
208	return 0;
209}
210
211static void pn_tx_complete(struct usb_ep *ep, struct usb_request *req)
212{
213	struct f_phonet *fp = ep->driver_data;
214	struct net_device *dev = fp->dev;
215	struct sk_buff *skb = req->context;
216
217	switch (req->status) {
218	case 0:
219		dev->stats.tx_packets++;
220		dev->stats.tx_bytes += skb->len;
221		break;
222
223	case -ESHUTDOWN: /* disconnected */
224	case -ECONNRESET: /* disabled */
225		dev->stats.tx_aborted_errors++;
226	default:
227		dev->stats.tx_errors++;
228	}
229
230	dev_kfree_skb_any(skb);
231	netif_wake_queue(dev);
232}
233
234static int pn_net_xmit(struct sk_buff *skb, struct net_device *dev)
235{
236	struct phonet_port *port = netdev_priv(dev);
237	struct f_phonet *fp;
238	struct usb_request *req;
239	unsigned long flags;
240
241	if (skb->protocol != htons(ETH_P_PHONET))
242		goto out;
243
244	spin_lock_irqsave(&port->lock, flags);
245	fp = port->usb;
246	if (unlikely(!fp)) /* race with carrier loss */
247		goto out_unlock;
248
249	req = fp->in_req;
250	req->buf = skb->data;
251	req->length = skb->len;
252	req->complete = pn_tx_complete;
253	req->zero = 1;
254	req->context = skb;
255
256	if (unlikely(usb_ep_queue(fp->in_ep, req, GFP_ATOMIC)))
257		goto out_unlock;
258
259	netif_stop_queue(dev);
260	skb = NULL;
261
262out_unlock:
263	spin_unlock_irqrestore(&port->lock, flags);
264out:
265	if (unlikely(skb)) {
266		dev_kfree_skb(skb);
267		dev->stats.tx_dropped++;
268	}
269	return NETDEV_TX_OK;
270}
271
272static int pn_net_mtu(struct net_device *dev, int new_mtu)
273{
274	if ((new_mtu < PHONET_MIN_MTU) || (new_mtu > PHONET_MAX_MTU))
275		return -EINVAL;
276	dev->mtu = new_mtu;
277	return 0;
278}
279
280static const struct net_device_ops pn_netdev_ops = {
281	.ndo_open	= pn_net_open,
282	.ndo_stop	= pn_net_close,
283	.ndo_start_xmit	= pn_net_xmit,
284	.ndo_change_mtu	= pn_net_mtu,
285};
286
287static void pn_net_setup(struct net_device *dev)
288{
289	dev->features		= 0;
290	dev->type		= ARPHRD_PHONET;
291	dev->flags		= IFF_POINTOPOINT | IFF_NOARP;
292	dev->mtu		= PHONET_DEV_MTU;
293	dev->hard_header_len	= 1;
294	dev->dev_addr[0]	= PN_MEDIA_USB;
295	dev->addr_len		= 1;
296	dev->tx_queue_len	= 1;
297
298	dev->netdev_ops		= &pn_netdev_ops;
299	dev->destructor		= free_netdev;
300	dev->header_ops		= &phonet_header_ops;
301}
302
303/*-------------------------------------------------------------------------*/
304
305/*
306 * Queue buffer for data from the host
307 */
308static int
309pn_rx_submit(struct f_phonet *fp, struct usb_request *req, gfp_t gfp_flags)
310{
311	struct net_device *dev = fp->dev;
312	struct page *page;
313	int err;
314
315	page = __netdev_alloc_page(dev, gfp_flags);
316	if (!page)
317		return -ENOMEM;
318
319	req->buf = page_address(page);
320	req->length = PAGE_SIZE;
321	req->context = page;
322
323	err = usb_ep_queue(fp->out_ep, req, gfp_flags);
324	if (unlikely(err))
325		netdev_free_page(dev, page);
326	return err;
327}
328
329static void pn_rx_complete(struct usb_ep *ep, struct usb_request *req)
330{
331	struct f_phonet *fp = ep->driver_data;
332	struct net_device *dev = fp->dev;
333	struct page *page = req->context;
334	struct sk_buff *skb;
335	unsigned long flags;
336	int status = req->status;
337
338	switch (status) {
339	case 0:
340		spin_lock_irqsave(&fp->rx.lock, flags);
341		skb = fp->rx.skb;
342		if (!skb)
343			skb = fp->rx.skb = netdev_alloc_skb(dev, 12);
344		if (req->actual < req->length) /* Last fragment */
345			fp->rx.skb = NULL;
346		spin_unlock_irqrestore(&fp->rx.lock, flags);
347
348		if (unlikely(!skb))
349			break;
350
351		if (skb->len == 0) { /* First fragment */
352			skb->protocol = htons(ETH_P_PHONET);
353			skb_reset_mac_header(skb);
354			/* Can't use pskb_pull() on page in IRQ */
355			memcpy(skb_put(skb, 1), page_address(page), 1);
356		}
357
358		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
359				skb->len == 0, req->actual);
360		page = NULL;
361
362		if (req->actual < req->length) { /* Last fragment */
363			skb->dev = dev;
364			dev->stats.rx_packets++;
365			dev->stats.rx_bytes += skb->len;
366
367			netif_rx(skb);
368		}
369		break;
370
371	/* Do not resubmit in these cases: */
372	case -ESHUTDOWN: /* disconnect */
373	case -ECONNABORTED: /* hw reset */
374	case -ECONNRESET: /* dequeued (unlink or netif down) */
375		req = NULL;
376		break;
377
378	/* Do resubmit in these cases: */
379	case -EOVERFLOW: /* request buffer overflow */
380		dev->stats.rx_over_errors++;
381	default:
382		dev->stats.rx_errors++;
383		break;
384	}
385
386	if (page)
387		netdev_free_page(dev, page);
388	if (req)
389		pn_rx_submit(fp, req, GFP_ATOMIC);
390}
391
392/*-------------------------------------------------------------------------*/
393
394static void __pn_reset(struct usb_function *f)
395{
396	struct f_phonet *fp = func_to_pn(f);
397	struct net_device *dev = fp->dev;
398	struct phonet_port *port = netdev_priv(dev);
399
400	netif_carrier_off(dev);
401	port->usb = NULL;
402
403	usb_ep_disable(fp->out_ep);
404	usb_ep_disable(fp->in_ep);
405	if (fp->rx.skb) {
406		dev_kfree_skb_irq(fp->rx.skb);
407		fp->rx.skb = NULL;
408	}
409}
410
411static int pn_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
412{
413	struct f_phonet *fp = func_to_pn(f);
414	struct usb_gadget *gadget = fp->function.config->cdev->gadget;
415
416	if (intf == pn_control_intf_desc.bInterfaceNumber)
417		/* control interface, no altsetting */
418		return (alt > 0) ? -EINVAL : 0;
419
420	if (intf == pn_data_intf_desc.bInterfaceNumber) {
421		struct net_device *dev = fp->dev;
422		struct phonet_port *port = netdev_priv(dev);
423
424		/* data intf (0: inactive, 1: active) */
425		if (alt > 1)
426			return -EINVAL;
427
428		spin_lock(&port->lock);
429		__pn_reset(f);
430		if (alt == 1) {
431			int i;
432
433			if (config_ep_by_speed(gadget, f, fp->in_ep) ||
434			    config_ep_by_speed(gadget, f, fp->out_ep)) {
435				fp->in_ep->desc = NULL;
436				fp->out_ep->desc = NULL;
437				spin_unlock(&port->lock);
438				return -EINVAL;
439			}
440			usb_ep_enable(fp->out_ep);
441			usb_ep_enable(fp->in_ep);
442
443			port->usb = fp;
444			fp->out_ep->driver_data = fp;
445			fp->in_ep->driver_data = fp;
446
447			netif_carrier_on(dev);
448			for (i = 0; i < phonet_rxq_size; i++)
449				pn_rx_submit(fp, fp->out_reqv[i], GFP_ATOMIC);
450		}
451		spin_unlock(&port->lock);
452		return 0;
453	}
454
455	return -EINVAL;
456}
457
458static int pn_get_alt(struct usb_function *f, unsigned intf)
459{
460	struct f_phonet *fp = func_to_pn(f);
461
462	if (intf == pn_control_intf_desc.bInterfaceNumber)
463		return 0;
464
465	if (intf == pn_data_intf_desc.bInterfaceNumber) {
466		struct phonet_port *port = netdev_priv(fp->dev);
467		u8 alt;
468
469		spin_lock(&port->lock);
470		alt = port->usb != NULL;
471		spin_unlock(&port->lock);
472		return alt;
473	}
474
475	return -EINVAL;
476}
477
478static void pn_disconnect(struct usb_function *f)
479{
480	struct f_phonet *fp = func_to_pn(f);
481	struct phonet_port *port = netdev_priv(fp->dev);
482	unsigned long flags;
483
484	/* remain disabled until set_alt */
485	spin_lock_irqsave(&port->lock, flags);
486	__pn_reset(f);
487	spin_unlock_irqrestore(&port->lock, flags);
488}
489
490/*-------------------------------------------------------------------------*/
491
492static __init
493int pn_bind(struct usb_configuration *c, struct usb_function *f)
494{
495	struct usb_composite_dev *cdev = c->cdev;
496	struct usb_gadget *gadget = cdev->gadget;
497	struct f_phonet *fp = func_to_pn(f);
498	struct usb_ep *ep;
499	int status, i;
500
501	/* Reserve interface IDs */
502	status = usb_interface_id(c, f);
503	if (status < 0)
504		goto err;
505	pn_control_intf_desc.bInterfaceNumber = status;
506	pn_union_desc.bMasterInterface0 = status;
507
508	status = usb_interface_id(c, f);
509	if (status < 0)
510		goto err;
511	pn_data_nop_intf_desc.bInterfaceNumber = status;
512	pn_data_intf_desc.bInterfaceNumber = status;
513	pn_union_desc.bSlaveInterface0 = status;
514
515	/* Reserve endpoints */
516	status = -ENODEV;
517	ep = usb_ep_autoconfig(gadget, &pn_fs_sink_desc);
518	if (!ep)
519		goto err;
520	fp->out_ep = ep;
521	ep->driver_data = fp; /* Claim */
522
523	ep = usb_ep_autoconfig(gadget, &pn_fs_source_desc);
524	if (!ep)
525		goto err;
526	fp->in_ep = ep;
527	ep->driver_data = fp; /* Claim */
528
529	pn_hs_sink_desc.bEndpointAddress =
530		pn_fs_sink_desc.bEndpointAddress;
531	pn_hs_source_desc.bEndpointAddress =
532		pn_fs_source_desc.bEndpointAddress;
533
534	/* Do not try to bind Phonet twice... */
535	fp->function.descriptors = fs_pn_function;
536	fp->function.hs_descriptors = hs_pn_function;
537
538	/* Incoming USB requests */
539	status = -ENOMEM;
540	for (i = 0; i < phonet_rxq_size; i++) {
541		struct usb_request *req;
542
543		req = usb_ep_alloc_request(fp->out_ep, GFP_KERNEL);
544		if (!req)
545			goto err;
546
547		req->complete = pn_rx_complete;
548		fp->out_reqv[i] = req;
549	}
550
551	/* Outgoing USB requests */
552	fp->in_req = usb_ep_alloc_request(fp->in_ep, GFP_KERNEL);
553	if (!fp->in_req)
554		goto err;
555
556	INFO(cdev, "USB CDC Phonet function\n");
557	INFO(cdev, "using %s, OUT %s, IN %s\n", cdev->gadget->name,
558		fp->out_ep->name, fp->in_ep->name);
559	return 0;
560
561err:
562	if (fp->out_ep)
563		fp->out_ep->driver_data = NULL;
564	if (fp->in_ep)
565		fp->in_ep->driver_data = NULL;
566	ERROR(cdev, "USB CDC Phonet: cannot autoconfigure\n");
567	return status;
568}
569
570static void
571pn_unbind(struct usb_configuration *c, struct usb_function *f)
572{
573	struct f_phonet *fp = func_to_pn(f);
574	int i;
575
576	/* We are already disconnected */
577	if (fp->in_req)
578		usb_ep_free_request(fp->in_ep, fp->in_req);
579	for (i = 0; i < phonet_rxq_size; i++)
580		if (fp->out_reqv[i])
581			usb_ep_free_request(fp->out_ep, fp->out_reqv[i]);
582
583	kfree(fp);
584}
585
586/*-------------------------------------------------------------------------*/
587
588static struct net_device *dev;
589
590int __init phonet_bind_config(struct usb_configuration *c)
591{
592	struct f_phonet *fp;
593	int err, size;
594
595	size = sizeof(*fp) + (phonet_rxq_size * sizeof(struct usb_request *));
596	fp = kzalloc(size, GFP_KERNEL);
597	if (!fp)
598		return -ENOMEM;
599
600	fp->dev = dev;
601	fp->function.name = "phonet";
602	fp->function.bind = pn_bind;
603	fp->function.unbind = pn_unbind;
604	fp->function.set_alt = pn_set_alt;
605	fp->function.get_alt = pn_get_alt;
606	fp->function.disable = pn_disconnect;
607	spin_lock_init(&fp->rx.lock);
608
609	err = usb_add_function(c, &fp->function);
610	if (err)
611		kfree(fp);
612	return err;
613}
614
615int __init gphonet_setup(struct usb_gadget *gadget)
616{
617	struct phonet_port *port;
618	int err;
619
620	/* Create net device */
621	BUG_ON(dev);
622	dev = alloc_netdev(sizeof(*port), "upnlink%d", pn_net_setup);
623	if (!dev)
624		return -ENOMEM;
625
626	port = netdev_priv(dev);
627	spin_lock_init(&port->lock);
628	netif_carrier_off(dev);
629	SET_NETDEV_DEV(dev, &gadget->dev);
630
631	err = register_netdev(dev);
632	if (err)
633		free_netdev(dev);
634	return err;
635}
636
637void gphonet_cleanup(void)
638{
639	unregister_netdev(dev);
640}