1 /*
2 * cdc-wdm.c
3 *
4 * This driver supports USB CDC WCM Device Management.
5 *
6 * Copyright (c) 2007-2008 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/smp_lock.h>
19 #include <linux/mutex.h>
20 #include <linux/uaccess.h>
21 #include <linux/bitops.h>
22 #include <linux/poll.h>
23 #include <linux/usb.h>
24 #include <linux/usb/cdc.h>
25 #include <asm/byteorder.h>
26 #include <asm/unaligned.h>
27
28 /*
29 * Version Information
30 */
31 #define DRIVER_VERSION "v0.03"
32 #define DRIVER_AUTHOR "Oliver Neukum"
33 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
34
35 static struct usb_device_id wdm_ids[] = {
36 {
37 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
38 USB_DEVICE_ID_MATCH_INT_SUBCLASS,
39 .bInterfaceClass = USB_CLASS_COMM,
40 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
41 },
42 { }
43 };
44
45 MODULE_DEVICE_TABLE (usb, wdm_ids);
46
47 #define WDM_MINOR_BASE 176
48
49
50 #define WDM_IN_USE 1
51 #define WDM_DISCONNECTING 2
52 #define WDM_RESULT 3
53 #define WDM_READ 4
54 #define WDM_INT_STALL 5
55 #define WDM_POLL_RUNNING 6
56
57
58 #define WDM_MAX 16
59
60
61 static DEFINE_MUTEX(wdm_mutex);
62
63 /* --- method tables --- */
64
65 struct wdm_device {
66 u8 *inbuf; /* buffer for response */
67 u8 *outbuf; /* buffer for command */
68 u8 *sbuf; /* buffer for status */
69 u8 *ubuf; /* buffer for copy to user space */
70
71 struct urb *command;
72 struct urb *response;
73 struct urb *validity;
74 struct usb_interface *intf;
75 struct usb_ctrlrequest *orq;
76 struct usb_ctrlrequest *irq;
77 spinlock_t iuspin;
78
79 unsigned long flags;
80 u16 bufsize;
81 u16 wMaxCommand;
82 u16 wMaxPacketSize;
83 u16 bMaxPacketSize0;
84 __le16 inum;
85 int reslength;
86 int length;
87 int read;
88 int count;
89 dma_addr_t shandle;
90 dma_addr_t ihandle;
91 struct mutex wlock;
92 struct mutex rlock;
93 struct mutex plock;
94 wait_queue_head_t wait;
95 struct work_struct rxwork;
96 int werr;
97 int rerr;
98 };
99
100 static struct usb_driver wdm_driver;
101
102 /* --- callbacks --- */
wdm_out_callback(struct urb * urb)103 static void wdm_out_callback(struct urb *urb)
104 {
105 struct wdm_device *desc;
106 desc = urb->context;
107 spin_lock(&desc->iuspin);
108 desc->werr = urb->status;
109 spin_unlock(&desc->iuspin);
110 clear_bit(WDM_IN_USE, &desc->flags);
111 kfree(desc->outbuf);
112 wake_up(&desc->wait);
113 }
114
wdm_in_callback(struct urb * urb)115 static void wdm_in_callback(struct urb *urb)
116 {
117 struct wdm_device *desc = urb->context;
118 int status = urb->status;
119
120 spin_lock(&desc->iuspin);
121
122 if (status) {
123 switch (status) {
124 case -ENOENT:
125 dev_dbg(&desc->intf->dev,
126 "nonzero urb status received: -ENOENT");
127 break;
128 case -ECONNRESET:
129 dev_dbg(&desc->intf->dev,
130 "nonzero urb status received: -ECONNRESET");
131 break;
132 case -ESHUTDOWN:
133 dev_dbg(&desc->intf->dev,
134 "nonzero urb status received: -ESHUTDOWN");
135 break;
136 case -EPIPE:
137 dev_err(&desc->intf->dev,
138 "nonzero urb status received: -EPIPE\n");
139 break;
140 default:
141 dev_err(&desc->intf->dev,
142 "Unexpected error %d\n", status);
143 break;
144 }
145 }
146
147 desc->rerr = status;
148 desc->reslength = urb->actual_length;
149 memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
150 desc->length += desc->reslength;
151 wake_up(&desc->wait);
152
153 set_bit(WDM_READ, &desc->flags);
154 spin_unlock(&desc->iuspin);
155 }
156
wdm_int_callback(struct urb * urb)157 static void wdm_int_callback(struct urb *urb)
158 {
159 int rv = 0;
160 int status = urb->status;
161 struct wdm_device *desc;
162 struct usb_ctrlrequest *req;
163 struct usb_cdc_notification *dr;
164
165 desc = urb->context;
166 req = desc->irq;
167 dr = (struct usb_cdc_notification *)desc->sbuf;
168
169 if (status) {
170 switch (status) {
171 case -ESHUTDOWN:
172 case -ENOENT:
173 case -ECONNRESET:
174 return; /* unplug */
175 case -EPIPE:
176 set_bit(WDM_INT_STALL, &desc->flags);
177 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
178 goto sw; /* halt is cleared in work */
179 default:
180 dev_err(&desc->intf->dev,
181 "nonzero urb status received: %d\n", status);
182 break;
183 }
184 }
185
186 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
187 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
188 urb->actual_length);
189 goto exit;
190 }
191
192 switch (dr->bNotificationType) {
193 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
194 dev_dbg(&desc->intf->dev,
195 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
196 dr->wIndex, dr->wLength);
197 break;
198
199 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
200
201 dev_dbg(&desc->intf->dev,
202 "NOTIFY_NETWORK_CONNECTION %s network",
203 dr->wValue ? "connected to" : "disconnected from");
204 goto exit;
205 default:
206 clear_bit(WDM_POLL_RUNNING, &desc->flags);
207 dev_err(&desc->intf->dev,
208 "unknown notification %d received: index %d len %d\n",
209 dr->bNotificationType, dr->wIndex, dr->wLength);
210 goto exit;
211 }
212
213 req->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
214 req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
215 req->wValue = 0;
216 req->wIndex = desc->inum;
217 req->wLength = cpu_to_le16(desc->wMaxCommand);
218
219 usb_fill_control_urb(
220 desc->response,
221 interface_to_usbdev(desc->intf),
222 /* using common endpoint 0 */
223 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
224 (unsigned char *)req,
225 desc->inbuf,
226 desc->wMaxCommand,
227 wdm_in_callback,
228 desc
229 );
230 desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
231 spin_lock(&desc->iuspin);
232 clear_bit(WDM_READ, &desc->flags);
233 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
234 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
235 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
236 __func__, rv);
237 }
238 spin_unlock(&desc->iuspin);
239 if (rv < 0) {
240 if (rv == -EPERM)
241 return;
242 if (rv == -ENOMEM) {
243 sw:
244 rv = schedule_work(&desc->rxwork);
245 if (rv)
246 dev_err(&desc->intf->dev,
247 "Cannot schedule work\n");
248 }
249 }
250 exit:
251 rv = usb_submit_urb(urb, GFP_ATOMIC);
252 if (rv)
253 dev_err(&desc->intf->dev,
254 "%s - usb_submit_urb failed with result %d\n",
255 __func__, rv);
256
257 }
258
kill_urbs(struct wdm_device * desc)259 static void kill_urbs(struct wdm_device *desc)
260 {
261 /* the order here is essential */
262 usb_kill_urb(desc->command);
263 usb_kill_urb(desc->validity);
264 usb_kill_urb(desc->response);
265 }
266
free_urbs(struct wdm_device * desc)267 static void free_urbs(struct wdm_device *desc)
268 {
269 usb_free_urb(desc->validity);
270 usb_free_urb(desc->response);
271 usb_free_urb(desc->command);
272 }
273
cleanup(struct wdm_device * desc)274 static void cleanup(struct wdm_device *desc)
275 {
276 usb_buffer_free(interface_to_usbdev(desc->intf),
277 desc->wMaxPacketSize,
278 desc->sbuf,
279 desc->validity->transfer_dma);
280 usb_buffer_free(interface_to_usbdev(desc->intf),
281 desc->wMaxCommand,
282 desc->inbuf,
283 desc->response->transfer_dma);
284 kfree(desc->orq);
285 kfree(desc->irq);
286 kfree(desc->ubuf);
287 free_urbs(desc);
288 kfree(desc);
289 }
290
wdm_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos)291 static ssize_t wdm_write
292 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
293 {
294 u8 *buf;
295 int rv = -EMSGSIZE, r, we;
296 struct wdm_device *desc = file->private_data;
297 struct usb_ctrlrequest *req;
298
299 if (count > desc->wMaxCommand)
300 count = desc->wMaxCommand;
301
302 spin_lock_irq(&desc->iuspin);
303 we = desc->werr;
304 desc->werr = 0;
305 spin_unlock_irq(&desc->iuspin);
306 if (we < 0)
307 return -EIO;
308
309 r = mutex_lock_interruptible(&desc->wlock); /* concurrent writes */
310 rv = -ERESTARTSYS;
311 if (r)
312 goto outnl;
313
314 r = usb_autopm_get_interface(desc->intf);
315 if (r < 0)
316 goto outnp;
317 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
318 &desc->flags));
319 if (r < 0)
320 goto out;
321
322 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
323 rv = -ENODEV;
324 goto out;
325 }
326
327 desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
328 if (!buf) {
329 rv = -ENOMEM;
330 goto out;
331 }
332
333 r = copy_from_user(buf, buffer, count);
334 if (r > 0) {
335 kfree(buf);
336 rv = -EFAULT;
337 goto out;
338 }
339
340 req = desc->orq;
341 usb_fill_control_urb(
342 desc->command,
343 interface_to_usbdev(desc->intf),
344 /* using common endpoint 0 */
345 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
346 (unsigned char *)req,
347 buf,
348 count,
349 wdm_out_callback,
350 desc
351 );
352
353 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
354 USB_RECIP_INTERFACE);
355 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
356 req->wValue = 0;
357 req->wIndex = desc->inum;
358 req->wLength = cpu_to_le16(count);
359 set_bit(WDM_IN_USE, &desc->flags);
360
361 rv = usb_submit_urb(desc->command, GFP_KERNEL);
362 if (rv < 0) {
363 kfree(buf);
364 clear_bit(WDM_IN_USE, &desc->flags);
365 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
366 } else {
367 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
368 req->wIndex);
369 }
370 out:
371 usb_autopm_put_interface(desc->intf);
372 outnp:
373 mutex_unlock(&desc->wlock);
374 outnl:
375 return rv < 0 ? rv : count;
376 }
377
wdm_read(struct file * file,char __user * buffer,size_t count,loff_t * ppos)378 static ssize_t wdm_read
379 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
380 {
381 int rv, cntr;
382 int i = 0;
383 struct wdm_device *desc = file->private_data;
384
385
386 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
387 if (rv < 0)
388 return -ERESTARTSYS;
389
390 if (desc->length == 0) {
391 desc->read = 0;
392 retry:
393 i++;
394 rv = wait_event_interruptible(desc->wait,
395 test_bit(WDM_READ, &desc->flags));
396
397 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
398 rv = -ENODEV;
399 goto err;
400 }
401 usb_mark_last_busy(interface_to_usbdev(desc->intf));
402 if (rv < 0) {
403 rv = -ERESTARTSYS;
404 goto err;
405 }
406
407 spin_lock_irq(&desc->iuspin);
408
409 if (desc->rerr) { /* read completed, error happened */
410 int t = desc->rerr;
411 desc->rerr = 0;
412 spin_unlock_irq(&desc->iuspin);
413 dev_err(&desc->intf->dev,
414 "reading had resulted in %d\n", t);
415 rv = -EIO;
416 goto err;
417 }
418 /*
419 * recheck whether we've lost the race
420 * against the completion handler
421 */
422 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
423 spin_unlock_irq(&desc->iuspin);
424 goto retry;
425 }
426 if (!desc->reslength) { /* zero length read */
427 spin_unlock_irq(&desc->iuspin);
428 goto retry;
429 }
430 clear_bit(WDM_READ, &desc->flags);
431 spin_unlock_irq(&desc->iuspin);
432 }
433
434 cntr = count > desc->length ? desc->length : count;
435 rv = copy_to_user(buffer, desc->ubuf, cntr);
436 if (rv > 0) {
437 rv = -EFAULT;
438 goto err;
439 }
440
441 for (i = 0; i < desc->length - cntr; i++)
442 desc->ubuf[i] = desc->ubuf[i + cntr];
443
444 desc->length -= cntr;
445 /* in case we had outstanding data */
446 if (!desc->length)
447 clear_bit(WDM_READ, &desc->flags);
448 rv = cntr;
449
450 err:
451 mutex_unlock(&desc->rlock);
452 if (rv < 0)
453 dev_err(&desc->intf->dev, "wdm_read: exit error\n");
454 return rv;
455 }
456
wdm_flush(struct file * file,fl_owner_t id)457 static int wdm_flush(struct file *file, fl_owner_t id)
458 {
459 struct wdm_device *desc = file->private_data;
460
461 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
462 if (desc->werr < 0)
463 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
464 desc->werr);
465
466 return desc->werr;
467 }
468
wdm_poll(struct file * file,struct poll_table_struct * wait)469 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
470 {
471 struct wdm_device *desc = file->private_data;
472 unsigned long flags;
473 unsigned int mask = 0;
474
475 spin_lock_irqsave(&desc->iuspin, flags);
476 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
477 mask = POLLERR;
478 spin_unlock_irqrestore(&desc->iuspin, flags);
479 goto desc_out;
480 }
481 if (test_bit(WDM_READ, &desc->flags))
482 mask = POLLIN | POLLRDNORM;
483 if (desc->rerr || desc->werr)
484 mask |= POLLERR;
485 if (!test_bit(WDM_IN_USE, &desc->flags))
486 mask |= POLLOUT | POLLWRNORM;
487 spin_unlock_irqrestore(&desc->iuspin, flags);
488
489 poll_wait(file, &desc->wait, wait);
490
491 desc_out:
492 return mask;
493 }
494
wdm_open(struct inode * inode,struct file * file)495 static int wdm_open(struct inode *inode, struct file *file)
496 {
497 int minor = iminor(inode);
498 int rv = -ENODEV;
499 struct usb_interface *intf;
500 struct wdm_device *desc;
501
502 mutex_lock(&wdm_mutex);
503 intf = usb_find_interface(&wdm_driver, minor);
504 if (!intf)
505 goto out;
506
507 desc = usb_get_intfdata(intf);
508 if (test_bit(WDM_DISCONNECTING, &desc->flags))
509 goto out;
510
511 ;
512 file->private_data = desc;
513
514 rv = usb_autopm_get_interface(desc->intf);
515 if (rv < 0) {
516 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
517 goto out;
518 }
519 intf->needs_remote_wakeup = 1;
520
521 mutex_lock(&desc->plock);
522 if (!desc->count++) {
523 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
524 if (rv < 0) {
525 desc->count--;
526 dev_err(&desc->intf->dev,
527 "Error submitting int urb - %d\n", rv);
528 }
529 } else {
530 rv = 0;
531 }
532 mutex_unlock(&desc->plock);
533 usb_autopm_put_interface(desc->intf);
534 out:
535 mutex_unlock(&wdm_mutex);
536 return rv;
537 }
538
wdm_release(struct inode * inode,struct file * file)539 static int wdm_release(struct inode *inode, struct file *file)
540 {
541 struct wdm_device *desc = file->private_data;
542
543 mutex_lock(&wdm_mutex);
544 mutex_lock(&desc->plock);
545 desc->count--;
546 mutex_unlock(&desc->plock);
547
548 if (!desc->count) {
549 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
550 kill_urbs(desc);
551 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
552 desc->intf->needs_remote_wakeup = 0;
553 }
554 mutex_unlock(&wdm_mutex);
555 return 0;
556 }
557
558 static const struct file_operations wdm_fops = {
559 .owner = THIS_MODULE,
560 .read = wdm_read,
561 .write = wdm_write,
562 .open = wdm_open,
563 .flush = wdm_flush,
564 .release = wdm_release,
565 .poll = wdm_poll
566 };
567
568 static struct usb_class_driver wdm_class = {
569 .name = "cdc-wdm%d",
570 .fops = &wdm_fops,
571 .minor_base = WDM_MINOR_BASE,
572 };
573
574 /* --- error handling --- */
wdm_rxwork(struct work_struct * work)575 static void wdm_rxwork(struct work_struct *work)
576 {
577 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
578 unsigned long flags;
579 int rv;
580
581 spin_lock_irqsave(&desc->iuspin, flags);
582 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
583 spin_unlock_irqrestore(&desc->iuspin, flags);
584 } else {
585 spin_unlock_irqrestore(&desc->iuspin, flags);
586 rv = usb_submit_urb(desc->response, GFP_KERNEL);
587 if (rv < 0 && rv != -EPERM) {
588 spin_lock_irqsave(&desc->iuspin, flags);
589 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
590 schedule_work(&desc->rxwork);
591 spin_unlock_irqrestore(&desc->iuspin, flags);
592 }
593 }
594 }
595
596 /* --- hotplug --- */
597
wdm_probe(struct usb_interface * intf,const struct usb_device_id * id)598 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
599 {
600 int rv = -EINVAL;
601 struct usb_device *udev = interface_to_usbdev(intf);
602 struct wdm_device *desc;
603 struct usb_host_interface *iface;
604 struct usb_endpoint_descriptor *ep;
605 struct usb_cdc_dmm_desc *dmhd;
606 u8 *buffer = intf->altsetting->extra;
607 int buflen = intf->altsetting->extralen;
608 u16 maxcom = 0;
609
610 if (!buffer)
611 goto out;
612
613 while (buflen > 0) {
614 if (buffer [1] != USB_DT_CS_INTERFACE) {
615 dev_err(&intf->dev, "skipping garbage\n");
616 goto next_desc;
617 }
618
619 switch (buffer [2]) {
620 case USB_CDC_HEADER_TYPE:
621 break;
622 case USB_CDC_DMM_TYPE:
623 dmhd = (struct usb_cdc_dmm_desc *)buffer;
624 maxcom = le16_to_cpu(dmhd->wMaxCommand);
625 dev_dbg(&intf->dev,
626 "Finding maximum buffer length: %d", maxcom);
627 break;
628 default:
629 dev_err(&intf->dev,
630 "Ignoring extra header, type %d, length %d\n",
631 buffer[2], buffer[0]);
632 break;
633 }
634 next_desc:
635 buflen -= buffer[0];
636 buffer += buffer[0];
637 }
638
639 rv = -ENOMEM;
640 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
641 if (!desc)
642 goto out;
643 mutex_init(&desc->wlock);
644 mutex_init(&desc->rlock);
645 mutex_init(&desc->plock);
646 spin_lock_init(&desc->iuspin);
647 init_waitqueue_head(&desc->wait);
648 desc->wMaxCommand = maxcom;
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 iface = &intf->altsetting[0];
654 ep = &iface->endpoint[0].desc;
655 if (!usb_endpoint_is_int_in(ep)) {
656 rv = -EINVAL;
657 goto err;
658 }
659
660 desc->wMaxPacketSize = le16_to_cpu(ep->wMaxPacketSize);
661 desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
662
663 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
664 if (!desc->orq)
665 goto err;
666 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
667 if (!desc->irq)
668 goto err;
669
670 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
671 if (!desc->validity)
672 goto err;
673
674 desc->response = usb_alloc_urb(0, GFP_KERNEL);
675 if (!desc->response)
676 goto err;
677
678 desc->command = usb_alloc_urb(0, GFP_KERNEL);
679 if (!desc->command)
680 goto err;
681
682 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
683 if (!desc->ubuf)
684 goto err;
685
686 desc->sbuf = usb_buffer_alloc(interface_to_usbdev(intf),
687 desc->wMaxPacketSize,
688 GFP_KERNEL,
689 &desc->validity->transfer_dma);
690 if (!desc->sbuf)
691 goto err;
692
693 desc->inbuf = usb_buffer_alloc(interface_to_usbdev(intf),
694 desc->bMaxPacketSize0,
695 GFP_KERNEL,
696 &desc->response->transfer_dma);
697 if (!desc->inbuf)
698 goto err2;
699
700 usb_fill_int_urb(
701 desc->validity,
702 interface_to_usbdev(intf),
703 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
704 desc->sbuf,
705 desc->wMaxPacketSize,
706 wdm_int_callback,
707 desc,
708 ep->bInterval
709 );
710 desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
711
712 usb_set_intfdata(intf, desc);
713 rv = usb_register_dev(intf, &wdm_class);
714 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
715 intf->minor - WDM_MINOR_BASE);
716 if (rv < 0)
717 goto err;
718 out:
719 return rv;
720 err2:
721 usb_buffer_free(interface_to_usbdev(desc->intf),
722 desc->wMaxPacketSize,
723 desc->sbuf,
724 desc->validity->transfer_dma);
725 err:
726 free_urbs(desc);
727 kfree(desc->ubuf);
728 kfree(desc->orq);
729 kfree(desc->irq);
730 kfree(desc);
731 return rv;
732 }
733
wdm_disconnect(struct usb_interface * intf)734 static void wdm_disconnect(struct usb_interface *intf)
735 {
736 struct wdm_device *desc;
737 unsigned long flags;
738
739 usb_deregister_dev(intf, &wdm_class);
740 mutex_lock(&wdm_mutex);
741 desc = usb_get_intfdata(intf);
742
743 /* the spinlock makes sure no new urbs are generated in the callbacks */
744 spin_lock_irqsave(&desc->iuspin, flags);
745 set_bit(WDM_DISCONNECTING, &desc->flags);
746 set_bit(WDM_READ, &desc->flags);
747 /* to terminate pending flushes */
748 clear_bit(WDM_IN_USE, &desc->flags);
749 spin_unlock_irqrestore(&desc->iuspin, flags);
750 cancel_work_sync(&desc->rxwork);
751 kill_urbs(desc);
752 wake_up_all(&desc->wait);
753 if (!desc->count)
754 cleanup(desc);
755 mutex_unlock(&wdm_mutex);
756 }
757
wdm_suspend(struct usb_interface * intf,pm_message_t message)758 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
759 {
760 struct wdm_device *desc = usb_get_intfdata(intf);
761 int rv = 0;
762
763 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
764
765 mutex_lock(&desc->plock);
766 #ifdef CONFIG_PM
767 if ((message.event & PM_EVENT_AUTO) &&
768 test_bit(WDM_IN_USE, &desc->flags)) {
769 rv = -EBUSY;
770 } else {
771 #endif
772 cancel_work_sync(&desc->rxwork);
773 kill_urbs(desc);
774 #ifdef CONFIG_PM
775 }
776 #endif
777 mutex_unlock(&desc->plock);
778
779 return rv;
780 }
781
recover_from_urb_loss(struct wdm_device * desc)782 static int recover_from_urb_loss(struct wdm_device *desc)
783 {
784 int rv = 0;
785
786 if (desc->count) {
787 rv = usb_submit_urb(desc->validity, GFP_NOIO);
788 if (rv < 0)
789 dev_err(&desc->intf->dev,
790 "Error resume submitting int urb - %d\n", rv);
791 }
792 return rv;
793 }
wdm_resume(struct usb_interface * intf)794 static int wdm_resume(struct usb_interface *intf)
795 {
796 struct wdm_device *desc = usb_get_intfdata(intf);
797 int rv;
798
799 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
800 mutex_lock(&desc->plock);
801 rv = recover_from_urb_loss(desc);
802 mutex_unlock(&desc->plock);
803 return rv;
804 }
805
wdm_pre_reset(struct usb_interface * intf)806 static int wdm_pre_reset(struct usb_interface *intf)
807 {
808 struct wdm_device *desc = usb_get_intfdata(intf);
809
810 mutex_lock(&desc->plock);
811 return 0;
812 }
813
wdm_post_reset(struct usb_interface * intf)814 static int wdm_post_reset(struct usb_interface *intf)
815 {
816 struct wdm_device *desc = usb_get_intfdata(intf);
817 int rv;
818
819 rv = recover_from_urb_loss(desc);
820 mutex_unlock(&desc->plock);
821 return 0;
822 }
823
824 static struct usb_driver wdm_driver = {
825 .name = "cdc_wdm",
826 .probe = wdm_probe,
827 .disconnect = wdm_disconnect,
828 .suspend = wdm_suspend,
829 .resume = wdm_resume,
830 .reset_resume = wdm_resume,
831 .pre_reset = wdm_pre_reset,
832 .post_reset = wdm_post_reset,
833 .id_table = wdm_ids,
834 .supports_autosuspend = 1,
835 };
836
837 /* --- low level module stuff --- */
838
wdm_init(void)839 static int __init wdm_init(void)
840 {
841 int rv;
842
843 rv = usb_register(&wdm_driver);
844
845 return rv;
846 }
847
wdm_exit(void)848 static void __exit wdm_exit(void)
849 {
850 usb_deregister(&wdm_driver);
851 }
852
853 module_init(wdm_init);
854 module_exit(wdm_exit);
855
856 MODULE_AUTHOR(DRIVER_AUTHOR);
857 MODULE_DESCRIPTION(DRIVER_DESC);
858 MODULE_LICENSE("GPL");
859