xref: /linux/drivers/net/usb/ipheth.c (revision 87c9c16317882dd6dbbc07e349bc3223e14f3244)
1 /*
2  * ipheth.c - Apple iPhone USB Ethernet driver
3  *
4  * Copyright (c) 2009 Diego Giagio <diego@giagio.com>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of GIAGIO.COM nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * Alternatively, provided that this notice is retained in full, this
20  * software may be distributed under the terms of the GNU General
21  * Public License ("GPL") version 2, in which case the provisions of the
22  * GPL apply INSTEAD OF those given above.
23  *
24  * The provided data structures and external interfaces from this code
25  * are not restricted to be used by modules with a GPL compatible license.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
38  * DAMAGE.
39  *
40  *
41  * Attention: iPhone device must be paired, otherwise it won't respond to our
42  * driver. For more info: http://giagio.com/wiki/moin.cgi/iPhoneEthernetDriver
43  *
44  */
45 
46 #include <linux/kernel.h>
47 #include <linux/errno.h>
48 #include <linux/slab.h>
49 #include <linux/module.h>
50 #include <linux/netdevice.h>
51 #include <linux/etherdevice.h>
52 #include <linux/ethtool.h>
53 #include <linux/usb.h>
54 #include <linux/workqueue.h>
55 
56 #define USB_VENDOR_APPLE        0x05ac
57 
58 #define IPHETH_USBINTF_CLASS    255
59 #define IPHETH_USBINTF_SUBCLASS 253
60 #define IPHETH_USBINTF_PROTO    1
61 
62 #define IPHETH_BUF_SIZE         1514
63 #define IPHETH_IP_ALIGN		2	/* padding at front of URB */
64 #define IPHETH_TX_TIMEOUT       (5 * HZ)
65 
66 #define IPHETH_INTFNUM          2
67 #define IPHETH_ALT_INTFNUM      1
68 
69 #define IPHETH_CTRL_ENDP        0x00
70 #define IPHETH_CTRL_BUF_SIZE    0x40
71 #define IPHETH_CTRL_TIMEOUT     (5 * HZ)
72 
73 #define IPHETH_CMD_GET_MACADDR   0x00
74 #define IPHETH_CMD_CARRIER_CHECK 0x45
75 
76 #define IPHETH_CARRIER_CHECK_TIMEOUT round_jiffies_relative(1 * HZ)
77 #define IPHETH_CARRIER_ON       0x04
78 
79 static const struct usb_device_id ipheth_table[] = {
80 	{ USB_VENDOR_AND_INTERFACE_INFO(USB_VENDOR_APPLE, IPHETH_USBINTF_CLASS,
81 					IPHETH_USBINTF_SUBCLASS,
82 					IPHETH_USBINTF_PROTO) },
83 	{ }
84 };
85 MODULE_DEVICE_TABLE(usb, ipheth_table);
86 
87 struct ipheth_device {
88 	struct usb_device *udev;
89 	struct usb_interface *intf;
90 	struct net_device *net;
91 	struct urb *tx_urb;
92 	struct urb *rx_urb;
93 	unsigned char *tx_buf;
94 	unsigned char *rx_buf;
95 	unsigned char *ctrl_buf;
96 	u8 bulk_in;
97 	u8 bulk_out;
98 	struct delayed_work carrier_work;
99 	bool confirmed_pairing;
100 };
101 
102 static int ipheth_rx_submit(struct ipheth_device *dev, gfp_t mem_flags);
103 
104 static int ipheth_alloc_urbs(struct ipheth_device *iphone)
105 {
106 	struct urb *tx_urb = NULL;
107 	struct urb *rx_urb = NULL;
108 	u8 *tx_buf = NULL;
109 	u8 *rx_buf = NULL;
110 
111 	tx_urb = usb_alloc_urb(0, GFP_KERNEL);
112 	if (tx_urb == NULL)
113 		goto error_nomem;
114 
115 	rx_urb = usb_alloc_urb(0, GFP_KERNEL);
116 	if (rx_urb == NULL)
117 		goto free_tx_urb;
118 
119 	tx_buf = usb_alloc_coherent(iphone->udev, IPHETH_BUF_SIZE,
120 				    GFP_KERNEL, &tx_urb->transfer_dma);
121 	if (tx_buf == NULL)
122 		goto free_rx_urb;
123 
124 	rx_buf = usb_alloc_coherent(iphone->udev, IPHETH_BUF_SIZE,
125 				    GFP_KERNEL, &rx_urb->transfer_dma);
126 	if (rx_buf == NULL)
127 		goto free_tx_buf;
128 
129 
130 	iphone->tx_urb = tx_urb;
131 	iphone->rx_urb = rx_urb;
132 	iphone->tx_buf = tx_buf;
133 	iphone->rx_buf = rx_buf;
134 	return 0;
135 
136 free_tx_buf:
137 	usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE, tx_buf,
138 			  tx_urb->transfer_dma);
139 free_rx_urb:
140 	usb_free_urb(rx_urb);
141 free_tx_urb:
142 	usb_free_urb(tx_urb);
143 error_nomem:
144 	return -ENOMEM;
145 }
146 
147 static void ipheth_free_urbs(struct ipheth_device *iphone)
148 {
149 	usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE, iphone->rx_buf,
150 			  iphone->rx_urb->transfer_dma);
151 	usb_free_coherent(iphone->udev, IPHETH_BUF_SIZE, iphone->tx_buf,
152 			  iphone->tx_urb->transfer_dma);
153 	usb_free_urb(iphone->rx_urb);
154 	usb_free_urb(iphone->tx_urb);
155 }
156 
157 static void ipheth_kill_urbs(struct ipheth_device *dev)
158 {
159 	usb_kill_urb(dev->tx_urb);
160 	usb_kill_urb(dev->rx_urb);
161 }
162 
163 static void ipheth_rcvbulk_callback(struct urb *urb)
164 {
165 	struct ipheth_device *dev;
166 	struct sk_buff *skb;
167 	int status;
168 	char *buf;
169 	int len;
170 
171 	dev = urb->context;
172 	if (dev == NULL)
173 		return;
174 
175 	status = urb->status;
176 	switch (status) {
177 	case -ENOENT:
178 	case -ECONNRESET:
179 	case -ESHUTDOWN:
180 	case -EPROTO:
181 		return;
182 	case 0:
183 		break;
184 	default:
185 		dev_err(&dev->intf->dev, "%s: urb status: %d\n",
186 			__func__, status);
187 		return;
188 	}
189 
190 	if (urb->actual_length <= IPHETH_IP_ALIGN) {
191 		dev->net->stats.rx_length_errors++;
192 		return;
193 	}
194 	len = urb->actual_length - IPHETH_IP_ALIGN;
195 	buf = urb->transfer_buffer + IPHETH_IP_ALIGN;
196 
197 	skb = dev_alloc_skb(len);
198 	if (!skb) {
199 		dev_err(&dev->intf->dev, "%s: dev_alloc_skb: -ENOMEM\n",
200 			__func__);
201 		dev->net->stats.rx_dropped++;
202 		return;
203 	}
204 
205 	skb_put_data(skb, buf, len);
206 	skb->dev = dev->net;
207 	skb->protocol = eth_type_trans(skb, dev->net);
208 
209 	dev->net->stats.rx_packets++;
210 	dev->net->stats.rx_bytes += len;
211 	dev->confirmed_pairing = true;
212 	netif_rx(skb);
213 	ipheth_rx_submit(dev, GFP_ATOMIC);
214 }
215 
216 static void ipheth_sndbulk_callback(struct urb *urb)
217 {
218 	struct ipheth_device *dev;
219 	int status = urb->status;
220 
221 	dev = urb->context;
222 	if (dev == NULL)
223 		return;
224 
225 	if (status != 0 &&
226 	    status != -ENOENT &&
227 	    status != -ECONNRESET &&
228 	    status != -ESHUTDOWN)
229 		dev_err(&dev->intf->dev, "%s: urb status: %d\n",
230 		__func__, status);
231 
232 	if (status == 0)
233 		netif_wake_queue(dev->net);
234 	else
235 		// on URB error, trigger immediate poll
236 		schedule_delayed_work(&dev->carrier_work, 0);
237 }
238 
239 static int ipheth_carrier_set(struct ipheth_device *dev)
240 {
241 	struct usb_device *udev;
242 	int retval;
243 
244 	if (!dev->confirmed_pairing)
245 		return 0;
246 
247 	udev = dev->udev;
248 	retval = usb_control_msg(udev,
249 			usb_rcvctrlpipe(udev, IPHETH_CTRL_ENDP),
250 			IPHETH_CMD_CARRIER_CHECK, /* request */
251 			0xc0, /* request type */
252 			0x00, /* value */
253 			0x02, /* index */
254 			dev->ctrl_buf, IPHETH_CTRL_BUF_SIZE,
255 			IPHETH_CTRL_TIMEOUT);
256 	if (retval < 0) {
257 		dev_err(&dev->intf->dev, "%s: usb_control_msg: %d\n",
258 			__func__, retval);
259 		return retval;
260 	}
261 
262 	if (dev->ctrl_buf[0] == IPHETH_CARRIER_ON) {
263 		netif_carrier_on(dev->net);
264 		if (dev->tx_urb->status != -EINPROGRESS)
265 			netif_wake_queue(dev->net);
266 	} else {
267 		netif_carrier_off(dev->net);
268 		netif_stop_queue(dev->net);
269 	}
270 	return 0;
271 }
272 
273 static void ipheth_carrier_check_work(struct work_struct *work)
274 {
275 	struct ipheth_device *dev = container_of(work, struct ipheth_device,
276 						 carrier_work.work);
277 
278 	ipheth_carrier_set(dev);
279 	schedule_delayed_work(&dev->carrier_work, IPHETH_CARRIER_CHECK_TIMEOUT);
280 }
281 
282 static int ipheth_get_macaddr(struct ipheth_device *dev)
283 {
284 	struct usb_device *udev = dev->udev;
285 	struct net_device *net = dev->net;
286 	int retval;
287 
288 	retval = usb_control_msg(udev,
289 				 usb_rcvctrlpipe(udev, IPHETH_CTRL_ENDP),
290 				 IPHETH_CMD_GET_MACADDR, /* request */
291 				 0xc0, /* request type */
292 				 0x00, /* value */
293 				 0x02, /* index */
294 				 dev->ctrl_buf,
295 				 IPHETH_CTRL_BUF_SIZE,
296 				 IPHETH_CTRL_TIMEOUT);
297 	if (retval < 0) {
298 		dev_err(&dev->intf->dev, "%s: usb_control_msg: %d\n",
299 			__func__, retval);
300 	} else if (retval < ETH_ALEN) {
301 		dev_err(&dev->intf->dev,
302 			"%s: usb_control_msg: short packet: %d bytes\n",
303 			__func__, retval);
304 		retval = -EINVAL;
305 	} else {
306 		memcpy(net->dev_addr, dev->ctrl_buf, ETH_ALEN);
307 		retval = 0;
308 	}
309 
310 	return retval;
311 }
312 
313 static int ipheth_rx_submit(struct ipheth_device *dev, gfp_t mem_flags)
314 {
315 	struct usb_device *udev = dev->udev;
316 	int retval;
317 
318 	usb_fill_bulk_urb(dev->rx_urb, udev,
319 			  usb_rcvbulkpipe(udev, dev->bulk_in),
320 			  dev->rx_buf, IPHETH_BUF_SIZE,
321 			  ipheth_rcvbulk_callback,
322 			  dev);
323 	dev->rx_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
324 
325 	retval = usb_submit_urb(dev->rx_urb, mem_flags);
326 	if (retval)
327 		dev_err(&dev->intf->dev, "%s: usb_submit_urb: %d\n",
328 			__func__, retval);
329 	return retval;
330 }
331 
332 static int ipheth_open(struct net_device *net)
333 {
334 	struct ipheth_device *dev = netdev_priv(net);
335 	struct usb_device *udev = dev->udev;
336 	int retval = 0;
337 
338 	usb_set_interface(udev, IPHETH_INTFNUM, IPHETH_ALT_INTFNUM);
339 
340 	retval = ipheth_carrier_set(dev);
341 	if (retval)
342 		return retval;
343 
344 	retval = ipheth_rx_submit(dev, GFP_KERNEL);
345 	if (retval)
346 		return retval;
347 
348 	schedule_delayed_work(&dev->carrier_work, IPHETH_CARRIER_CHECK_TIMEOUT);
349 	return retval;
350 }
351 
352 static int ipheth_close(struct net_device *net)
353 {
354 	struct ipheth_device *dev = netdev_priv(net);
355 
356 	cancel_delayed_work_sync(&dev->carrier_work);
357 	netif_stop_queue(net);
358 	return 0;
359 }
360 
361 static netdev_tx_t ipheth_tx(struct sk_buff *skb, struct net_device *net)
362 {
363 	struct ipheth_device *dev = netdev_priv(net);
364 	struct usb_device *udev = dev->udev;
365 	int retval;
366 
367 	/* Paranoid */
368 	if (skb->len > IPHETH_BUF_SIZE) {
369 		WARN(1, "%s: skb too large: %d bytes\n", __func__, skb->len);
370 		dev->net->stats.tx_dropped++;
371 		dev_kfree_skb_any(skb);
372 		return NETDEV_TX_OK;
373 	}
374 
375 	memcpy(dev->tx_buf, skb->data, skb->len);
376 	if (skb->len < IPHETH_BUF_SIZE)
377 		memset(dev->tx_buf + skb->len, 0, IPHETH_BUF_SIZE - skb->len);
378 
379 	usb_fill_bulk_urb(dev->tx_urb, udev,
380 			  usb_sndbulkpipe(udev, dev->bulk_out),
381 			  dev->tx_buf, IPHETH_BUF_SIZE,
382 			  ipheth_sndbulk_callback,
383 			  dev);
384 	dev->tx_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
385 
386 	netif_stop_queue(net);
387 	retval = usb_submit_urb(dev->tx_urb, GFP_ATOMIC);
388 	if (retval) {
389 		dev_err(&dev->intf->dev, "%s: usb_submit_urb: %d\n",
390 			__func__, retval);
391 		dev->net->stats.tx_errors++;
392 		dev_kfree_skb_any(skb);
393 		netif_wake_queue(net);
394 	} else {
395 		dev->net->stats.tx_packets++;
396 		dev->net->stats.tx_bytes += skb->len;
397 		dev_consume_skb_any(skb);
398 	}
399 
400 	return NETDEV_TX_OK;
401 }
402 
403 static void ipheth_tx_timeout(struct net_device *net, unsigned int txqueue)
404 {
405 	struct ipheth_device *dev = netdev_priv(net);
406 
407 	dev_err(&dev->intf->dev, "%s: TX timeout\n", __func__);
408 	dev->net->stats.tx_errors++;
409 	usb_unlink_urb(dev->tx_urb);
410 }
411 
412 static u32 ipheth_ethtool_op_get_link(struct net_device *net)
413 {
414 	struct ipheth_device *dev = netdev_priv(net);
415 	return netif_carrier_ok(dev->net);
416 }
417 
418 static const struct ethtool_ops ops = {
419 	.get_link = ipheth_ethtool_op_get_link
420 };
421 
422 static const struct net_device_ops ipheth_netdev_ops = {
423 	.ndo_open = ipheth_open,
424 	.ndo_stop = ipheth_close,
425 	.ndo_start_xmit = ipheth_tx,
426 	.ndo_tx_timeout = ipheth_tx_timeout,
427 };
428 
429 static int ipheth_probe(struct usb_interface *intf,
430 			const struct usb_device_id *id)
431 {
432 	struct usb_device *udev = interface_to_usbdev(intf);
433 	struct usb_host_interface *hintf;
434 	struct usb_endpoint_descriptor *endp;
435 	struct ipheth_device *dev;
436 	struct net_device *netdev;
437 	int i;
438 	int retval;
439 
440 	netdev = alloc_etherdev(sizeof(struct ipheth_device));
441 	if (!netdev)
442 		return -ENOMEM;
443 
444 	netdev->netdev_ops = &ipheth_netdev_ops;
445 	netdev->watchdog_timeo = IPHETH_TX_TIMEOUT;
446 	strcpy(netdev->name, "eth%d");
447 
448 	dev = netdev_priv(netdev);
449 	dev->udev = udev;
450 	dev->net = netdev;
451 	dev->intf = intf;
452 	dev->confirmed_pairing = false;
453 	/* Set up endpoints */
454 	hintf = usb_altnum_to_altsetting(intf, IPHETH_ALT_INTFNUM);
455 	if (hintf == NULL) {
456 		retval = -ENODEV;
457 		dev_err(&intf->dev, "Unable to find alternate settings interface\n");
458 		goto err_endpoints;
459 	}
460 
461 	for (i = 0; i < hintf->desc.bNumEndpoints; i++) {
462 		endp = &hintf->endpoint[i].desc;
463 		if (usb_endpoint_is_bulk_in(endp))
464 			dev->bulk_in = endp->bEndpointAddress;
465 		else if (usb_endpoint_is_bulk_out(endp))
466 			dev->bulk_out = endp->bEndpointAddress;
467 	}
468 	if (!(dev->bulk_in && dev->bulk_out)) {
469 		retval = -ENODEV;
470 		dev_err(&intf->dev, "Unable to find endpoints\n");
471 		goto err_endpoints;
472 	}
473 
474 	dev->ctrl_buf = kmalloc(IPHETH_CTRL_BUF_SIZE, GFP_KERNEL);
475 	if (dev->ctrl_buf == NULL) {
476 		retval = -ENOMEM;
477 		goto err_alloc_ctrl_buf;
478 	}
479 
480 	retval = ipheth_get_macaddr(dev);
481 	if (retval)
482 		goto err_get_macaddr;
483 
484 	INIT_DELAYED_WORK(&dev->carrier_work, ipheth_carrier_check_work);
485 
486 	retval = ipheth_alloc_urbs(dev);
487 	if (retval) {
488 		dev_err(&intf->dev, "error allocating urbs: %d\n", retval);
489 		goto err_alloc_urbs;
490 	}
491 
492 	usb_set_intfdata(intf, dev);
493 
494 	SET_NETDEV_DEV(netdev, &intf->dev);
495 	netdev->ethtool_ops = &ops;
496 
497 	retval = register_netdev(netdev);
498 	if (retval) {
499 		dev_err(&intf->dev, "error registering netdev: %d\n", retval);
500 		retval = -EIO;
501 		goto err_register_netdev;
502 	}
503 	// carrier down and transmit queues stopped until packet from device
504 	netif_carrier_off(netdev);
505 	netif_tx_stop_all_queues(netdev);
506 	dev_info(&intf->dev, "Apple iPhone USB Ethernet device attached\n");
507 	return 0;
508 
509 err_register_netdev:
510 	ipheth_free_urbs(dev);
511 err_alloc_urbs:
512 err_get_macaddr:
513 err_alloc_ctrl_buf:
514 	kfree(dev->ctrl_buf);
515 err_endpoints:
516 	free_netdev(netdev);
517 	return retval;
518 }
519 
520 static void ipheth_disconnect(struct usb_interface *intf)
521 {
522 	struct ipheth_device *dev;
523 
524 	dev = usb_get_intfdata(intf);
525 	if (dev != NULL) {
526 		unregister_netdev(dev->net);
527 		ipheth_kill_urbs(dev);
528 		ipheth_free_urbs(dev);
529 		kfree(dev->ctrl_buf);
530 		free_netdev(dev->net);
531 	}
532 	usb_set_intfdata(intf, NULL);
533 	dev_info(&intf->dev, "Apple iPhone USB Ethernet now disconnected\n");
534 }
535 
536 static struct usb_driver ipheth_driver = {
537 	.name =		"ipheth",
538 	.probe =	ipheth_probe,
539 	.disconnect =	ipheth_disconnect,
540 	.id_table =	ipheth_table,
541 	.disable_hub_initiated_lpm = 1,
542 };
543 
544 module_usb_driver(ipheth_driver);
545 
546 MODULE_AUTHOR("Diego Giagio <diego@giagio.com>");
547 MODULE_DESCRIPTION("Apple iPhone USB Ethernet driver");
548 MODULE_LICENSE("Dual BSD/GPL");
549