xref: /openbmc/linux/drivers/net/usb/cdc-phonet.c (revision 8730046c)
1 /*
2  * phonet.c -- USB CDC Phonet host driver
3  *
4  * Copyright (C) 2008-2009 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/kernel.h>
24 #include <linux/mm.h>
25 #include <linux/module.h>
26 #include <linux/gfp.h>
27 #include <linux/usb.h>
28 #include <linux/usb/cdc.h>
29 #include <linux/netdevice.h>
30 #include <linux/if_arp.h>
31 #include <linux/if_phonet.h>
32 #include <linux/phonet.h>
33 
34 #define PN_MEDIA_USB	0x1B
35 
36 static const unsigned rxq_size = 17;
37 
38 struct usbpn_dev {
39 	struct net_device	*dev;
40 
41 	struct usb_interface	*intf, *data_intf;
42 	struct usb_device	*usb;
43 	unsigned int		tx_pipe, rx_pipe;
44 	u8 active_setting;
45 	u8 disconnected;
46 
47 	unsigned		tx_queue;
48 	spinlock_t		tx_lock;
49 
50 	spinlock_t		rx_lock;
51 	struct sk_buff		*rx_skb;
52 	struct urb		*urbs[0];
53 };
54 
55 static void tx_complete(struct urb *req);
56 static void rx_complete(struct urb *req);
57 
58 /*
59  * Network device callbacks
60  */
61 static netdev_tx_t usbpn_xmit(struct sk_buff *skb, struct net_device *dev)
62 {
63 	struct usbpn_dev *pnd = netdev_priv(dev);
64 	struct urb *req = NULL;
65 	unsigned long flags;
66 	int err;
67 
68 	if (skb->protocol != htons(ETH_P_PHONET))
69 		goto drop;
70 
71 	req = usb_alloc_urb(0, GFP_ATOMIC);
72 	if (!req)
73 		goto drop;
74 	usb_fill_bulk_urb(req, pnd->usb, pnd->tx_pipe, skb->data, skb->len,
75 				tx_complete, skb);
76 	req->transfer_flags = URB_ZERO_PACKET;
77 	err = usb_submit_urb(req, GFP_ATOMIC);
78 	if (err) {
79 		usb_free_urb(req);
80 		goto drop;
81 	}
82 
83 	spin_lock_irqsave(&pnd->tx_lock, flags);
84 	pnd->tx_queue++;
85 	if (pnd->tx_queue >= dev->tx_queue_len)
86 		netif_stop_queue(dev);
87 	spin_unlock_irqrestore(&pnd->tx_lock, flags);
88 	return NETDEV_TX_OK;
89 
90 drop:
91 	dev_kfree_skb(skb);
92 	dev->stats.tx_dropped++;
93 	return NETDEV_TX_OK;
94 }
95 
96 static void tx_complete(struct urb *req)
97 {
98 	struct sk_buff *skb = req->context;
99 	struct net_device *dev = skb->dev;
100 	struct usbpn_dev *pnd = netdev_priv(dev);
101 	int status = req->status;
102 
103 	switch (status) {
104 	case 0:
105 		dev->stats.tx_bytes += skb->len;
106 		break;
107 
108 	case -ENOENT:
109 	case -ECONNRESET:
110 	case -ESHUTDOWN:
111 		dev->stats.tx_aborted_errors++;
112 	default:
113 		dev->stats.tx_errors++;
114 		dev_dbg(&dev->dev, "TX error (%d)\n", status);
115 	}
116 	dev->stats.tx_packets++;
117 
118 	spin_lock(&pnd->tx_lock);
119 	pnd->tx_queue--;
120 	netif_wake_queue(dev);
121 	spin_unlock(&pnd->tx_lock);
122 
123 	dev_kfree_skb_any(skb);
124 	usb_free_urb(req);
125 }
126 
127 static int rx_submit(struct usbpn_dev *pnd, struct urb *req, gfp_t gfp_flags)
128 {
129 	struct net_device *dev = pnd->dev;
130 	struct page *page;
131 	int err;
132 
133 	page = __dev_alloc_page(gfp_flags | __GFP_NOMEMALLOC);
134 	if (!page)
135 		return -ENOMEM;
136 
137 	usb_fill_bulk_urb(req, pnd->usb, pnd->rx_pipe, page_address(page),
138 				PAGE_SIZE, rx_complete, dev);
139 	req->transfer_flags = 0;
140 	err = usb_submit_urb(req, gfp_flags);
141 	if (unlikely(err)) {
142 		dev_dbg(&dev->dev, "RX submit error (%d)\n", err);
143 		put_page(page);
144 	}
145 	return err;
146 }
147 
148 static void rx_complete(struct urb *req)
149 {
150 	struct net_device *dev = req->context;
151 	struct usbpn_dev *pnd = netdev_priv(dev);
152 	struct page *page = virt_to_page(req->transfer_buffer);
153 	struct sk_buff *skb;
154 	unsigned long flags;
155 	int status = req->status;
156 
157 	switch (status) {
158 	case 0:
159 		spin_lock_irqsave(&pnd->rx_lock, flags);
160 		skb = pnd->rx_skb;
161 		if (!skb) {
162 			skb = pnd->rx_skb = netdev_alloc_skb(dev, 12);
163 			if (likely(skb)) {
164 				/* Can't use pskb_pull() on page in IRQ */
165 				memcpy(skb_put(skb, 1), page_address(page), 1);
166 				skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
167 						page, 1, req->actual_length,
168 						PAGE_SIZE);
169 				page = NULL;
170 			}
171 		} else {
172 			skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
173 					page, 0, req->actual_length,
174 					PAGE_SIZE);
175 			page = NULL;
176 		}
177 		if (req->actual_length < PAGE_SIZE)
178 			pnd->rx_skb = NULL; /* Last fragment */
179 		else
180 			skb = NULL;
181 		spin_unlock_irqrestore(&pnd->rx_lock, flags);
182 		if (skb) {
183 			skb->protocol = htons(ETH_P_PHONET);
184 			skb_reset_mac_header(skb);
185 			__skb_pull(skb, 1);
186 			skb->dev = dev;
187 			dev->stats.rx_packets++;
188 			dev->stats.rx_bytes += skb->len;
189 
190 			netif_rx(skb);
191 		}
192 		goto resubmit;
193 
194 	case -ENOENT:
195 	case -ECONNRESET:
196 	case -ESHUTDOWN:
197 		req = NULL;
198 		break;
199 
200 	case -EOVERFLOW:
201 		dev->stats.rx_over_errors++;
202 		dev_dbg(&dev->dev, "RX overflow\n");
203 		break;
204 
205 	case -EILSEQ:
206 		dev->stats.rx_crc_errors++;
207 		break;
208 	}
209 
210 	dev->stats.rx_errors++;
211 resubmit:
212 	if (page)
213 		put_page(page);
214 	if (req)
215 		rx_submit(pnd, req, GFP_ATOMIC);
216 }
217 
218 static int usbpn_close(struct net_device *dev);
219 
220 static int usbpn_open(struct net_device *dev)
221 {
222 	struct usbpn_dev *pnd = netdev_priv(dev);
223 	int err;
224 	unsigned i;
225 	unsigned num = pnd->data_intf->cur_altsetting->desc.bInterfaceNumber;
226 
227 	err = usb_set_interface(pnd->usb, num, pnd->active_setting);
228 	if (err)
229 		return err;
230 
231 	for (i = 0; i < rxq_size; i++) {
232 		struct urb *req = usb_alloc_urb(0, GFP_KERNEL);
233 
234 		if (!req || rx_submit(pnd, req, GFP_KERNEL)) {
235 			usb_free_urb(req);
236 			usbpn_close(dev);
237 			return -ENOMEM;
238 		}
239 		pnd->urbs[i] = req;
240 	}
241 
242 	netif_wake_queue(dev);
243 	return 0;
244 }
245 
246 static int usbpn_close(struct net_device *dev)
247 {
248 	struct usbpn_dev *pnd = netdev_priv(dev);
249 	unsigned i;
250 	unsigned num = pnd->data_intf->cur_altsetting->desc.bInterfaceNumber;
251 
252 	netif_stop_queue(dev);
253 
254 	for (i = 0; i < rxq_size; i++) {
255 		struct urb *req = pnd->urbs[i];
256 
257 		if (!req)
258 			continue;
259 		usb_kill_urb(req);
260 		usb_free_urb(req);
261 		pnd->urbs[i] = NULL;
262 	}
263 
264 	return usb_set_interface(pnd->usb, num, !pnd->active_setting);
265 }
266 
267 static int usbpn_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
268 {
269 	struct if_phonet_req *req = (struct if_phonet_req *)ifr;
270 
271 	switch (cmd) {
272 	case SIOCPNGAUTOCONF:
273 		req->ifr_phonet_autoconf.device = PN_DEV_PC;
274 		return 0;
275 	}
276 	return -ENOIOCTLCMD;
277 }
278 
279 static const struct net_device_ops usbpn_ops = {
280 	.ndo_open	= usbpn_open,
281 	.ndo_stop	= usbpn_close,
282 	.ndo_start_xmit = usbpn_xmit,
283 	.ndo_do_ioctl	= usbpn_ioctl,
284 };
285 
286 static void usbpn_setup(struct net_device *dev)
287 {
288 	dev->features		= 0;
289 	dev->netdev_ops		= &usbpn_ops,
290 	dev->header_ops		= &phonet_header_ops;
291 	dev->type		= ARPHRD_PHONET;
292 	dev->flags		= IFF_POINTOPOINT | IFF_NOARP;
293 	dev->mtu		= PHONET_MAX_MTU;
294 	dev->min_mtu		= PHONET_MIN_MTU;
295 	dev->max_mtu		= PHONET_MAX_MTU;
296 	dev->hard_header_len	= 1;
297 	dev->dev_addr[0]	= PN_MEDIA_USB;
298 	dev->addr_len		= 1;
299 	dev->tx_queue_len	= 3;
300 
301 	dev->destructor		= free_netdev;
302 }
303 
304 /*
305  * USB driver callbacks
306  */
307 static struct usb_device_id usbpn_ids[] = {
308 	{
309 		.match_flags = USB_DEVICE_ID_MATCH_VENDOR
310 			| USB_DEVICE_ID_MATCH_INT_CLASS
311 			| USB_DEVICE_ID_MATCH_INT_SUBCLASS,
312 		.idVendor = 0x0421, /* Nokia */
313 		.bInterfaceClass = USB_CLASS_COMM,
314 		.bInterfaceSubClass = 0xFE,
315 	},
316 	{ },
317 };
318 
319 MODULE_DEVICE_TABLE(usb, usbpn_ids);
320 
321 static struct usb_driver usbpn_driver;
322 
323 static int usbpn_probe(struct usb_interface *intf, const struct usb_device_id *id)
324 {
325 	static const char ifname[] = "usbpn%d";
326 	const struct usb_cdc_union_desc *union_header = NULL;
327 	const struct usb_host_interface *data_desc;
328 	struct usb_interface *data_intf;
329 	struct usb_device *usbdev = interface_to_usbdev(intf);
330 	struct net_device *dev;
331 	struct usbpn_dev *pnd;
332 	u8 *data;
333 	int phonet = 0;
334 	int len, err;
335 	struct usb_cdc_parsed_header hdr;
336 
337 	data = intf->altsetting->extra;
338 	len = intf->altsetting->extralen;
339 	cdc_parse_cdc_header(&hdr, intf, data, len);
340 	union_header = hdr.usb_cdc_union_desc;
341 	phonet = hdr.phonet_magic_present;
342 
343 	if (!union_header || !phonet)
344 		return -EINVAL;
345 
346 	data_intf = usb_ifnum_to_if(usbdev, union_header->bSlaveInterface0);
347 	if (data_intf == NULL)
348 		return -ENODEV;
349 	/* Data interface has one inactive and one active setting */
350 	if (data_intf->num_altsetting != 2)
351 		return -EINVAL;
352 	if (data_intf->altsetting[0].desc.bNumEndpoints == 0 &&
353 	    data_intf->altsetting[1].desc.bNumEndpoints == 2)
354 		data_desc = data_intf->altsetting + 1;
355 	else
356 	if (data_intf->altsetting[0].desc.bNumEndpoints == 2 &&
357 	    data_intf->altsetting[1].desc.bNumEndpoints == 0)
358 		data_desc = data_intf->altsetting;
359 	else
360 		return -EINVAL;
361 
362 	dev = alloc_netdev(sizeof(*pnd) + sizeof(pnd->urbs[0]) * rxq_size,
363 			   ifname, NET_NAME_UNKNOWN, usbpn_setup);
364 	if (!dev)
365 		return -ENOMEM;
366 
367 	pnd = netdev_priv(dev);
368 	SET_NETDEV_DEV(dev, &intf->dev);
369 
370 	pnd->dev = dev;
371 	pnd->usb = usbdev;
372 	pnd->intf = intf;
373 	pnd->data_intf = data_intf;
374 	spin_lock_init(&pnd->tx_lock);
375 	spin_lock_init(&pnd->rx_lock);
376 	/* Endpoints */
377 	if (usb_pipein(data_desc->endpoint[0].desc.bEndpointAddress)) {
378 		pnd->rx_pipe = usb_rcvbulkpipe(usbdev,
379 			data_desc->endpoint[0].desc.bEndpointAddress);
380 		pnd->tx_pipe = usb_sndbulkpipe(usbdev,
381 			data_desc->endpoint[1].desc.bEndpointAddress);
382 	} else {
383 		pnd->rx_pipe = usb_rcvbulkpipe(usbdev,
384 			data_desc->endpoint[1].desc.bEndpointAddress);
385 		pnd->tx_pipe = usb_sndbulkpipe(usbdev,
386 			data_desc->endpoint[0].desc.bEndpointAddress);
387 	}
388 	pnd->active_setting = data_desc - data_intf->altsetting;
389 
390 	err = usb_driver_claim_interface(&usbpn_driver, data_intf, pnd);
391 	if (err)
392 		goto out;
393 
394 	/* Force inactive mode until the network device is brought UP */
395 	usb_set_interface(usbdev, union_header->bSlaveInterface0,
396 				!pnd->active_setting);
397 	usb_set_intfdata(intf, pnd);
398 
399 	err = register_netdev(dev);
400 	if (err) {
401 		usb_driver_release_interface(&usbpn_driver, data_intf);
402 		goto out;
403 	}
404 
405 	dev_dbg(&dev->dev, "USB CDC Phonet device found\n");
406 	return 0;
407 
408 out:
409 	usb_set_intfdata(intf, NULL);
410 	free_netdev(dev);
411 	return err;
412 }
413 
414 static void usbpn_disconnect(struct usb_interface *intf)
415 {
416 	struct usbpn_dev *pnd = usb_get_intfdata(intf);
417 
418 	if (pnd->disconnected)
419 		return;
420 
421 	pnd->disconnected = 1;
422 	usb_driver_release_interface(&usbpn_driver,
423 			(pnd->intf == intf) ? pnd->data_intf : pnd->intf);
424 	unregister_netdev(pnd->dev);
425 }
426 
427 static struct usb_driver usbpn_driver = {
428 	.name =		"cdc_phonet",
429 	.probe =	usbpn_probe,
430 	.disconnect =	usbpn_disconnect,
431 	.id_table =	usbpn_ids,
432 	.disable_hub_initiated_lpm = 1,
433 };
434 
435 module_usb_driver(usbpn_driver);
436 
437 MODULE_AUTHOR("Remi Denis-Courmont");
438 MODULE_DESCRIPTION("USB CDC Phonet host interface");
439 MODULE_LICENSE("GPL");
440