xref: /openbmc/linux/drivers/usb/class/cdc-wdm.c (revision fd589a8f)
1 /*
2  * cdc-wdm.c
3  *
4  * This driver supports USB CDC WCM Device Management.
5  *
6  * Copyright (c) 2007-2009 Oliver Neukum
7  *
8  * Some code taken from cdc-acm.c
9  *
10  * Released under the GPLv2.
11  *
12  * Many thanks to Carl Nordbeck
13  */
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/slab.h>
17 #include <linux/module.h>
18 #include <linux/mutex.h>
19 #include <linux/uaccess.h>
20 #include <linux/bitops.h>
21 #include <linux/poll.h>
22 #include <linux/usb.h>
23 #include <linux/usb/cdc.h>
24 #include <asm/byteorder.h>
25 #include <asm/unaligned.h>
26 
27 /*
28  * Version Information
29  */
30 #define DRIVER_VERSION "v0.03"
31 #define DRIVER_AUTHOR "Oliver Neukum"
32 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
33 
34 static struct usb_device_id wdm_ids[] = {
35 	{
36 		.match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
37 				 USB_DEVICE_ID_MATCH_INT_SUBCLASS,
38 		.bInterfaceClass = USB_CLASS_COMM,
39 		.bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
40 	},
41 	{ }
42 };
43 
44 MODULE_DEVICE_TABLE (usb, wdm_ids);
45 
46 #define WDM_MINOR_BASE	176
47 
48 
49 #define WDM_IN_USE		1
50 #define WDM_DISCONNECTING	2
51 #define WDM_RESULT		3
52 #define WDM_READ		4
53 #define WDM_INT_STALL		5
54 #define WDM_POLL_RUNNING	6
55 
56 
57 #define WDM_MAX			16
58 
59 
60 static DEFINE_MUTEX(wdm_mutex);
61 
62 /* --- method tables --- */
63 
64 struct wdm_device {
65 	u8			*inbuf; /* buffer for response */
66 	u8			*outbuf; /* buffer for command */
67 	u8			*sbuf; /* buffer for status */
68 	u8			*ubuf; /* buffer for copy to user space */
69 
70 	struct urb		*command;
71 	struct urb		*response;
72 	struct urb		*validity;
73 	struct usb_interface	*intf;
74 	struct usb_ctrlrequest	*orq;
75 	struct usb_ctrlrequest	*irq;
76 	spinlock_t		iuspin;
77 
78 	unsigned long		flags;
79 	u16			bufsize;
80 	u16			wMaxCommand;
81 	u16			wMaxPacketSize;
82 	u16			bMaxPacketSize0;
83 	__le16			inum;
84 	int			reslength;
85 	int			length;
86 	int			read;
87 	int			count;
88 	dma_addr_t		shandle;
89 	dma_addr_t		ihandle;
90 	struct mutex		wlock;
91 	struct mutex		rlock;
92 	struct mutex		plock;
93 	wait_queue_head_t	wait;
94 	struct work_struct	rxwork;
95 	int			werr;
96 	int			rerr;
97 };
98 
99 static struct usb_driver wdm_driver;
100 
101 /* --- callbacks --- */
102 static void wdm_out_callback(struct urb *urb)
103 {
104 	struct wdm_device *desc;
105 	desc = urb->context;
106 	spin_lock(&desc->iuspin);
107 	desc->werr = urb->status;
108 	spin_unlock(&desc->iuspin);
109 	clear_bit(WDM_IN_USE, &desc->flags);
110 	kfree(desc->outbuf);
111 	wake_up(&desc->wait);
112 }
113 
114 static void wdm_in_callback(struct urb *urb)
115 {
116 	struct wdm_device *desc = urb->context;
117 	int status = urb->status;
118 
119 	spin_lock(&desc->iuspin);
120 
121 	if (status) {
122 		switch (status) {
123 		case -ENOENT:
124 			dev_dbg(&desc->intf->dev,
125 				"nonzero urb status received: -ENOENT");
126 			break;
127 		case -ECONNRESET:
128 			dev_dbg(&desc->intf->dev,
129 				"nonzero urb status received: -ECONNRESET");
130 			break;
131 		case -ESHUTDOWN:
132 			dev_dbg(&desc->intf->dev,
133 				"nonzero urb status received: -ESHUTDOWN");
134 			break;
135 		case -EPIPE:
136 			dev_err(&desc->intf->dev,
137 				"nonzero urb status received: -EPIPE\n");
138 			break;
139 		default:
140 			dev_err(&desc->intf->dev,
141 				"Unexpected error %d\n", status);
142 			break;
143 		}
144 	}
145 
146 	desc->rerr = status;
147 	desc->reslength = urb->actual_length;
148 	memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
149 	desc->length += desc->reslength;
150 	wake_up(&desc->wait);
151 
152 	set_bit(WDM_READ, &desc->flags);
153 	spin_unlock(&desc->iuspin);
154 }
155 
156 static void wdm_int_callback(struct urb *urb)
157 {
158 	int rv = 0;
159 	int status = urb->status;
160 	struct wdm_device *desc;
161 	struct usb_ctrlrequest *req;
162 	struct usb_cdc_notification *dr;
163 
164 	desc = urb->context;
165 	req = desc->irq;
166 	dr = (struct usb_cdc_notification *)desc->sbuf;
167 
168 	if (status) {
169 		switch (status) {
170 		case -ESHUTDOWN:
171 		case -ENOENT:
172 		case -ECONNRESET:
173 			return; /* unplug */
174 		case -EPIPE:
175 			set_bit(WDM_INT_STALL, &desc->flags);
176 			dev_err(&desc->intf->dev, "Stall on int endpoint\n");
177 			goto sw; /* halt is cleared in work */
178 		default:
179 			dev_err(&desc->intf->dev,
180 				"nonzero urb status received: %d\n", status);
181 			break;
182 		}
183 	}
184 
185 	if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
186 		dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
187 			urb->actual_length);
188 		goto exit;
189 	}
190 
191 	switch (dr->bNotificationType) {
192 	case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
193 		dev_dbg(&desc->intf->dev,
194 			"NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
195 			dr->wIndex, dr->wLength);
196 		break;
197 
198 	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
199 
200 		dev_dbg(&desc->intf->dev,
201 			"NOTIFY_NETWORK_CONNECTION %s network",
202 			dr->wValue ? "connected to" : "disconnected from");
203 		goto exit;
204 	default:
205 		clear_bit(WDM_POLL_RUNNING, &desc->flags);
206 		dev_err(&desc->intf->dev,
207 			"unknown notification %d received: index %d len %d\n",
208 			dr->bNotificationType, dr->wIndex, dr->wLength);
209 		goto exit;
210 	}
211 
212 	req->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
213 	req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
214 	req->wValue = 0;
215 	req->wIndex = desc->inum;
216 	req->wLength = cpu_to_le16(desc->wMaxCommand);
217 
218 	usb_fill_control_urb(
219 		desc->response,
220 		interface_to_usbdev(desc->intf),
221 		/* using common endpoint 0 */
222 		usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
223 		(unsigned char *)req,
224 		desc->inbuf,
225 		desc->wMaxCommand,
226 		wdm_in_callback,
227 		desc
228 	);
229 	desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
230 	spin_lock(&desc->iuspin);
231 	clear_bit(WDM_READ, &desc->flags);
232 	if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
233 		rv = usb_submit_urb(desc->response, GFP_ATOMIC);
234 		dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
235 			__func__, rv);
236 	}
237 	spin_unlock(&desc->iuspin);
238 	if (rv < 0) {
239 		if (rv == -EPERM)
240 			return;
241 		if (rv == -ENOMEM) {
242 sw:
243 			rv = schedule_work(&desc->rxwork);
244 			if (rv)
245 				dev_err(&desc->intf->dev,
246 					"Cannot schedule work\n");
247 		}
248 	}
249 exit:
250 	rv = usb_submit_urb(urb, GFP_ATOMIC);
251 	if (rv)
252 		dev_err(&desc->intf->dev,
253 			"%s - usb_submit_urb failed with result %d\n",
254 			__func__, rv);
255 
256 }
257 
258 static void kill_urbs(struct wdm_device *desc)
259 {
260 	/* the order here is essential */
261 	usb_kill_urb(desc->command);
262 	usb_kill_urb(desc->validity);
263 	usb_kill_urb(desc->response);
264 }
265 
266 static void free_urbs(struct wdm_device *desc)
267 {
268 	usb_free_urb(desc->validity);
269 	usb_free_urb(desc->response);
270 	usb_free_urb(desc->command);
271 }
272 
273 static void cleanup(struct wdm_device *desc)
274 {
275 	usb_buffer_free(interface_to_usbdev(desc->intf),
276 			desc->wMaxPacketSize,
277 			desc->sbuf,
278 			desc->validity->transfer_dma);
279 	usb_buffer_free(interface_to_usbdev(desc->intf),
280 			desc->wMaxCommand,
281 			desc->inbuf,
282 			desc->response->transfer_dma);
283 	kfree(desc->orq);
284 	kfree(desc->irq);
285 	kfree(desc->ubuf);
286 	free_urbs(desc);
287 	kfree(desc);
288 }
289 
290 static ssize_t wdm_write
291 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
292 {
293 	u8 *buf;
294 	int rv = -EMSGSIZE, r, we;
295 	struct wdm_device *desc = file->private_data;
296 	struct usb_ctrlrequest *req;
297 
298 	if (count > desc->wMaxCommand)
299 		count = desc->wMaxCommand;
300 
301 	spin_lock_irq(&desc->iuspin);
302 	we = desc->werr;
303 	desc->werr = 0;
304 	spin_unlock_irq(&desc->iuspin);
305 	if (we < 0)
306 		return -EIO;
307 
308 	r = mutex_lock_interruptible(&desc->wlock); /* concurrent writes */
309 	rv = -ERESTARTSYS;
310 	if (r)
311 		goto outnl;
312 
313 	r = usb_autopm_get_interface(desc->intf);
314 	if (r < 0)
315 		goto outnp;
316 	r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
317 							   &desc->flags));
318 	if (r < 0)
319 		goto out;
320 
321 	if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
322 		rv = -ENODEV;
323 		goto out;
324 	}
325 
326 	desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
327 	if (!buf) {
328 		rv = -ENOMEM;
329 		goto out;
330 	}
331 
332 	r = copy_from_user(buf, buffer, count);
333 	if (r > 0) {
334 		kfree(buf);
335 		rv = -EFAULT;
336 		goto out;
337 	}
338 
339 	req = desc->orq;
340 	usb_fill_control_urb(
341 		desc->command,
342 		interface_to_usbdev(desc->intf),
343 		/* using common endpoint 0 */
344 		usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
345 		(unsigned char *)req,
346 		buf,
347 		count,
348 		wdm_out_callback,
349 		desc
350 	);
351 
352 	req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
353 			     USB_RECIP_INTERFACE);
354 	req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
355 	req->wValue = 0;
356 	req->wIndex = desc->inum;
357 	req->wLength = cpu_to_le16(count);
358 	set_bit(WDM_IN_USE, &desc->flags);
359 
360 	rv = usb_submit_urb(desc->command, GFP_KERNEL);
361 	if (rv < 0) {
362 		kfree(buf);
363 		clear_bit(WDM_IN_USE, &desc->flags);
364 		dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
365 	} else {
366 		dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
367 			req->wIndex);
368 	}
369 out:
370 	usb_autopm_put_interface(desc->intf);
371 outnp:
372 	mutex_unlock(&desc->wlock);
373 outnl:
374 	return rv < 0 ? rv : count;
375 }
376 
377 static ssize_t wdm_read
378 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
379 {
380 	int rv, cntr;
381 	int i = 0;
382 	struct wdm_device *desc = file->private_data;
383 
384 
385 	rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
386 	if (rv < 0)
387 		return -ERESTARTSYS;
388 
389 	if (desc->length == 0) {
390 		desc->read = 0;
391 retry:
392 		i++;
393 		rv = wait_event_interruptible(desc->wait,
394 					      test_bit(WDM_READ, &desc->flags));
395 
396 		if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
397 			rv = -ENODEV;
398 			goto err;
399 		}
400 		usb_mark_last_busy(interface_to_usbdev(desc->intf));
401 		if (rv < 0) {
402 			rv = -ERESTARTSYS;
403 			goto err;
404 		}
405 
406 		spin_lock_irq(&desc->iuspin);
407 
408 		if (desc->rerr) { /* read completed, error happened */
409 			int t = desc->rerr;
410 			desc->rerr = 0;
411 			spin_unlock_irq(&desc->iuspin);
412 			dev_err(&desc->intf->dev,
413 				"reading had resulted in %d\n", t);
414 			rv = -EIO;
415 			goto err;
416 		}
417 		/*
418 		 * recheck whether we've lost the race
419 		 * against the completion handler
420 		 */
421 		if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
422 			spin_unlock_irq(&desc->iuspin);
423 			goto retry;
424 		}
425 		if (!desc->reslength) { /* zero length read */
426 			spin_unlock_irq(&desc->iuspin);
427 			goto retry;
428 		}
429 		clear_bit(WDM_READ, &desc->flags);
430 		spin_unlock_irq(&desc->iuspin);
431 	}
432 
433 	cntr = count > desc->length ? desc->length : count;
434 	rv = copy_to_user(buffer, desc->ubuf, cntr);
435 	if (rv > 0) {
436 		rv = -EFAULT;
437 		goto err;
438 	}
439 
440 	for (i = 0; i < desc->length - cntr; i++)
441 		desc->ubuf[i] = desc->ubuf[i + cntr];
442 
443 	desc->length -= cntr;
444 	/* in case we had outstanding data */
445 	if (!desc->length)
446 		clear_bit(WDM_READ, &desc->flags);
447 	rv = cntr;
448 
449 err:
450 	mutex_unlock(&desc->rlock);
451 	if (rv < 0)
452 		dev_err(&desc->intf->dev, "wdm_read: exit error\n");
453 	return rv;
454 }
455 
456 static int wdm_flush(struct file *file, fl_owner_t id)
457 {
458 	struct wdm_device *desc = file->private_data;
459 
460 	wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
461 	if (desc->werr < 0)
462 		dev_err(&desc->intf->dev, "Error in flush path: %d\n",
463 			desc->werr);
464 
465 	return desc->werr;
466 }
467 
468 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
469 {
470 	struct wdm_device *desc = file->private_data;
471 	unsigned long flags;
472 	unsigned int mask = 0;
473 
474 	spin_lock_irqsave(&desc->iuspin, flags);
475 	if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
476 		mask = POLLERR;
477 		spin_unlock_irqrestore(&desc->iuspin, flags);
478 		goto desc_out;
479 	}
480 	if (test_bit(WDM_READ, &desc->flags))
481 		mask = POLLIN | POLLRDNORM;
482 	if (desc->rerr || desc->werr)
483 		mask |= POLLERR;
484 	if (!test_bit(WDM_IN_USE, &desc->flags))
485 		mask |= POLLOUT | POLLWRNORM;
486 	spin_unlock_irqrestore(&desc->iuspin, flags);
487 
488 	poll_wait(file, &desc->wait, wait);
489 
490 desc_out:
491 	return mask;
492 }
493 
494 static int wdm_open(struct inode *inode, struct file *file)
495 {
496 	int minor = iminor(inode);
497 	int rv = -ENODEV;
498 	struct usb_interface *intf;
499 	struct wdm_device *desc;
500 
501 	mutex_lock(&wdm_mutex);
502 	intf = usb_find_interface(&wdm_driver, minor);
503 	if (!intf)
504 		goto out;
505 
506 	desc = usb_get_intfdata(intf);
507 	if (test_bit(WDM_DISCONNECTING, &desc->flags))
508 		goto out;
509 
510 	;
511 	file->private_data = desc;
512 
513 	rv = usb_autopm_get_interface(desc->intf);
514 	if (rv < 0) {
515 		dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
516 		goto out;
517 	}
518 	intf->needs_remote_wakeup = 1;
519 
520 	mutex_lock(&desc->plock);
521 	if (!desc->count++) {
522 		rv = usb_submit_urb(desc->validity, GFP_KERNEL);
523 		if (rv < 0) {
524 			desc->count--;
525 			dev_err(&desc->intf->dev,
526 				"Error submitting int urb - %d\n", rv);
527 		}
528 	} else {
529 		rv = 0;
530 	}
531 	mutex_unlock(&desc->plock);
532 	usb_autopm_put_interface(desc->intf);
533 out:
534 	mutex_unlock(&wdm_mutex);
535 	return rv;
536 }
537 
538 static int wdm_release(struct inode *inode, struct file *file)
539 {
540 	struct wdm_device *desc = file->private_data;
541 
542 	mutex_lock(&wdm_mutex);
543 	mutex_lock(&desc->plock);
544 	desc->count--;
545 	mutex_unlock(&desc->plock);
546 
547 	if (!desc->count) {
548 		dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
549 		kill_urbs(desc);
550 		if (!test_bit(WDM_DISCONNECTING, &desc->flags))
551 			desc->intf->needs_remote_wakeup = 0;
552 	}
553 	mutex_unlock(&wdm_mutex);
554 	return 0;
555 }
556 
557 static const struct file_operations wdm_fops = {
558 	.owner =	THIS_MODULE,
559 	.read =		wdm_read,
560 	.write =	wdm_write,
561 	.open =		wdm_open,
562 	.flush =	wdm_flush,
563 	.release =	wdm_release,
564 	.poll =		wdm_poll
565 };
566 
567 static struct usb_class_driver wdm_class = {
568 	.name =		"cdc-wdm%d",
569 	.fops =		&wdm_fops,
570 	.minor_base =	WDM_MINOR_BASE,
571 };
572 
573 /* --- error handling --- */
574 static void wdm_rxwork(struct work_struct *work)
575 {
576 	struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
577 	unsigned long flags;
578 	int rv;
579 
580 	spin_lock_irqsave(&desc->iuspin, flags);
581 	if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
582 		spin_unlock_irqrestore(&desc->iuspin, flags);
583 	} else {
584 		spin_unlock_irqrestore(&desc->iuspin, flags);
585 		rv = usb_submit_urb(desc->response, GFP_KERNEL);
586 		if (rv < 0 && rv != -EPERM) {
587 			spin_lock_irqsave(&desc->iuspin, flags);
588 			if (!test_bit(WDM_DISCONNECTING, &desc->flags))
589 				schedule_work(&desc->rxwork);
590 			spin_unlock_irqrestore(&desc->iuspin, flags);
591 		}
592 	}
593 }
594 
595 /* --- hotplug --- */
596 
597 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
598 {
599 	int rv = -EINVAL;
600 	struct usb_device *udev = interface_to_usbdev(intf);
601 	struct wdm_device *desc;
602 	struct usb_host_interface *iface;
603 	struct usb_endpoint_descriptor *ep;
604 	struct usb_cdc_dmm_desc *dmhd;
605 	u8 *buffer = intf->altsetting->extra;
606 	int buflen = intf->altsetting->extralen;
607 	u16 maxcom = 0;
608 
609 	if (!buffer)
610 		goto out;
611 
612 	while (buflen > 2) {
613 		if (buffer [1] != USB_DT_CS_INTERFACE) {
614 			dev_err(&intf->dev, "skipping garbage\n");
615 			goto next_desc;
616 		}
617 
618 		switch (buffer [2]) {
619 		case USB_CDC_HEADER_TYPE:
620 			break;
621 		case USB_CDC_DMM_TYPE:
622 			dmhd = (struct usb_cdc_dmm_desc *)buffer;
623 			maxcom = le16_to_cpu(dmhd->wMaxCommand);
624 			dev_dbg(&intf->dev,
625 				"Finding maximum buffer length: %d", maxcom);
626 			break;
627 		default:
628 			dev_err(&intf->dev,
629 				"Ignoring extra header, type %d, length %d\n",
630 				buffer[2], buffer[0]);
631 			break;
632 		}
633 next_desc:
634 		buflen -= buffer[0];
635 		buffer += buffer[0];
636 	}
637 
638 	rv = -ENOMEM;
639 	desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
640 	if (!desc)
641 		goto out;
642 	mutex_init(&desc->wlock);
643 	mutex_init(&desc->rlock);
644 	mutex_init(&desc->plock);
645 	spin_lock_init(&desc->iuspin);
646 	init_waitqueue_head(&desc->wait);
647 	desc->wMaxCommand = maxcom;
648 	/* this will be expanded and needed in hardware endianness */
649 	desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
650 	desc->intf = intf;
651 	INIT_WORK(&desc->rxwork, wdm_rxwork);
652 
653 	rv = -EINVAL;
654 	iface = intf->cur_altsetting;
655 	if (iface->desc.bNumEndpoints != 1)
656 		goto err;
657 	ep = &iface->endpoint[0].desc;
658 	if (!ep || !usb_endpoint_is_int_in(ep))
659 		goto err;
660 
661 	desc->wMaxPacketSize = le16_to_cpu(ep->wMaxPacketSize);
662 	desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
663 
664 	desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
665 	if (!desc->orq)
666 		goto err;
667 	desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
668 	if (!desc->irq)
669 		goto err;
670 
671 	desc->validity = usb_alloc_urb(0, GFP_KERNEL);
672 	if (!desc->validity)
673 		goto err;
674 
675 	desc->response = usb_alloc_urb(0, GFP_KERNEL);
676 	if (!desc->response)
677 		goto err;
678 
679 	desc->command = usb_alloc_urb(0, GFP_KERNEL);
680 	if (!desc->command)
681 		goto err;
682 
683 	desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
684 	if (!desc->ubuf)
685 		goto err;
686 
687 	desc->sbuf = usb_buffer_alloc(interface_to_usbdev(intf),
688 					desc->wMaxPacketSize,
689 					GFP_KERNEL,
690 					&desc->validity->transfer_dma);
691 	if (!desc->sbuf)
692 		goto err;
693 
694 	desc->inbuf = usb_buffer_alloc(interface_to_usbdev(intf),
695 					desc->bMaxPacketSize0,
696 					GFP_KERNEL,
697 					&desc->response->transfer_dma);
698 	if (!desc->inbuf)
699 		goto err2;
700 
701 	usb_fill_int_urb(
702 		desc->validity,
703 		interface_to_usbdev(intf),
704 		usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
705 		desc->sbuf,
706 		desc->wMaxPacketSize,
707 		wdm_int_callback,
708 		desc,
709 		ep->bInterval
710 	);
711 	desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
712 
713 	usb_set_intfdata(intf, desc);
714 	rv = usb_register_dev(intf, &wdm_class);
715 	if (rv < 0)
716 		goto err3;
717 	else
718 		dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
719 			intf->minor - WDM_MINOR_BASE);
720 out:
721 	return rv;
722 err3:
723 	usb_set_intfdata(intf, NULL);
724 	usb_buffer_free(interface_to_usbdev(desc->intf),
725 			desc->bMaxPacketSize0,
726 			desc->inbuf,
727 			desc->response->transfer_dma);
728 err2:
729 	usb_buffer_free(interface_to_usbdev(desc->intf),
730 			desc->wMaxPacketSize,
731 			desc->sbuf,
732 			desc->validity->transfer_dma);
733 err:
734 	free_urbs(desc);
735 	kfree(desc->ubuf);
736 	kfree(desc->orq);
737 	kfree(desc->irq);
738 	kfree(desc);
739 	return rv;
740 }
741 
742 static void wdm_disconnect(struct usb_interface *intf)
743 {
744 	struct wdm_device *desc;
745 	unsigned long flags;
746 
747 	usb_deregister_dev(intf, &wdm_class);
748 	mutex_lock(&wdm_mutex);
749 	desc = usb_get_intfdata(intf);
750 
751 	/* the spinlock makes sure no new urbs are generated in the callbacks */
752 	spin_lock_irqsave(&desc->iuspin, flags);
753 	set_bit(WDM_DISCONNECTING, &desc->flags);
754 	set_bit(WDM_READ, &desc->flags);
755 	/* to terminate pending flushes */
756 	clear_bit(WDM_IN_USE, &desc->flags);
757 	spin_unlock_irqrestore(&desc->iuspin, flags);
758 	cancel_work_sync(&desc->rxwork);
759 	kill_urbs(desc);
760 	wake_up_all(&desc->wait);
761 	if (!desc->count)
762 		cleanup(desc);
763 	mutex_unlock(&wdm_mutex);
764 }
765 
766 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
767 {
768 	struct wdm_device *desc = usb_get_intfdata(intf);
769 	int rv = 0;
770 
771 	dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
772 
773 	mutex_lock(&desc->plock);
774 #ifdef CONFIG_PM
775 	if ((message.event & PM_EVENT_AUTO) &&
776 			test_bit(WDM_IN_USE, &desc->flags)) {
777 		rv = -EBUSY;
778 	} else {
779 #endif
780 		cancel_work_sync(&desc->rxwork);
781 		kill_urbs(desc);
782 #ifdef CONFIG_PM
783 	}
784 #endif
785 	mutex_unlock(&desc->plock);
786 
787 	return rv;
788 }
789 
790 static int recover_from_urb_loss(struct wdm_device *desc)
791 {
792 	int rv = 0;
793 
794 	if (desc->count) {
795 		rv = usb_submit_urb(desc->validity, GFP_NOIO);
796 		if (rv < 0)
797 			dev_err(&desc->intf->dev,
798 				"Error resume submitting int urb - %d\n", rv);
799 	}
800 	return rv;
801 }
802 static int wdm_resume(struct usb_interface *intf)
803 {
804 	struct wdm_device *desc = usb_get_intfdata(intf);
805 	int rv;
806 
807 	dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
808 	mutex_lock(&desc->plock);
809 	rv = recover_from_urb_loss(desc);
810 	mutex_unlock(&desc->plock);
811 	return rv;
812 }
813 
814 static int wdm_pre_reset(struct usb_interface *intf)
815 {
816 	struct wdm_device *desc = usb_get_intfdata(intf);
817 
818 	mutex_lock(&desc->plock);
819 	return 0;
820 }
821 
822 static int wdm_post_reset(struct usb_interface *intf)
823 {
824 	struct wdm_device *desc = usb_get_intfdata(intf);
825 	int rv;
826 
827 	rv = recover_from_urb_loss(desc);
828 	mutex_unlock(&desc->plock);
829 	return 0;
830 }
831 
832 static struct usb_driver wdm_driver = {
833 	.name =		"cdc_wdm",
834 	.probe =	wdm_probe,
835 	.disconnect =	wdm_disconnect,
836 	.suspend =	wdm_suspend,
837 	.resume =	wdm_resume,
838 	.reset_resume =	wdm_resume,
839 	.pre_reset =	wdm_pre_reset,
840 	.post_reset =	wdm_post_reset,
841 	.id_table =	wdm_ids,
842 	.supports_autosuspend = 1,
843 };
844 
845 /* --- low level module stuff --- */
846 
847 static int __init wdm_init(void)
848 {
849 	int rv;
850 
851 	rv = usb_register(&wdm_driver);
852 
853 	return rv;
854 }
855 
856 static void __exit wdm_exit(void)
857 {
858 	usb_deregister(&wdm_driver);
859 }
860 
861 module_init(wdm_init);
862 module_exit(wdm_exit);
863 
864 MODULE_AUTHOR(DRIVER_AUTHOR);
865 MODULE_DESCRIPTION(DRIVER_DESC);
866 MODULE_LICENSE("GPL");
867