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 const 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 #define WDM_RESPONDING 7
56 #define WDM_SUSPENDING 8
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 lock;
92 wait_queue_head_t wait;
93 struct work_struct rxwork;
94 int werr;
95 int rerr;
96 };
97
98 static struct usb_driver wdm_driver;
99
100 /* --- callbacks --- */
wdm_out_callback(struct urb * urb)101 static void wdm_out_callback(struct urb *urb)
102 {
103 struct wdm_device *desc;
104 desc = urb->context;
105 spin_lock(&desc->iuspin);
106 desc->werr = urb->status;
107 spin_unlock(&desc->iuspin);
108 clear_bit(WDM_IN_USE, &desc->flags);
109 kfree(desc->outbuf);
110 wake_up(&desc->wait);
111 }
112
wdm_in_callback(struct urb * urb)113 static void wdm_in_callback(struct urb *urb)
114 {
115 struct wdm_device *desc = urb->context;
116 int status = urb->status;
117
118 spin_lock(&desc->iuspin);
119 clear_bit(WDM_RESPONDING, &desc->flags);
120
121 if (status) {
122 switch (status) {
123 case -ENOENT:
124 dev_dbg(&desc->intf->dev,
125 "nonzero urb status received: -ENOENT");
126 goto skip_error;
127 case -ECONNRESET:
128 dev_dbg(&desc->intf->dev,
129 "nonzero urb status received: -ECONNRESET");
130 goto skip_error;
131 case -ESHUTDOWN:
132 dev_dbg(&desc->intf->dev,
133 "nonzero urb status received: -ESHUTDOWN");
134 goto skip_error;
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 skip_error:
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 set_bit(WDM_RESPONDING, &desc->flags);
234 if (!test_bit(WDM_DISCONNECTING, &desc->flags)
235 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
236 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
237 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
238 __func__, rv);
239 }
240 spin_unlock(&desc->iuspin);
241 if (rv < 0) {
242 clear_bit(WDM_RESPONDING, &desc->flags);
243 if (rv == -EPERM)
244 return;
245 if (rv == -ENOMEM) {
246 sw:
247 rv = schedule_work(&desc->rxwork);
248 if (rv)
249 dev_err(&desc->intf->dev,
250 "Cannot schedule work\n");
251 }
252 }
253 exit:
254 rv = usb_submit_urb(urb, GFP_ATOMIC);
255 if (rv)
256 dev_err(&desc->intf->dev,
257 "%s - usb_submit_urb failed with result %d\n",
258 __func__, rv);
259
260 }
261
kill_urbs(struct wdm_device * desc)262 static void kill_urbs(struct wdm_device *desc)
263 {
264 /* the order here is essential */
265 usb_kill_urb(desc->command);
266 usb_kill_urb(desc->validity);
267 usb_kill_urb(desc->response);
268 }
269
free_urbs(struct wdm_device * desc)270 static void free_urbs(struct wdm_device *desc)
271 {
272 usb_free_urb(desc->validity);
273 usb_free_urb(desc->response);
274 usb_free_urb(desc->command);
275 }
276
cleanup(struct wdm_device * desc)277 static void cleanup(struct wdm_device *desc)
278 {
279 usb_free_coherent(interface_to_usbdev(desc->intf),
280 desc->wMaxPacketSize,
281 desc->sbuf,
282 desc->validity->transfer_dma);
283 usb_free_coherent(interface_to_usbdev(desc->intf),
284 desc->bMaxPacketSize0,
285 desc->inbuf,
286 desc->response->transfer_dma);
287 kfree(desc->orq);
288 kfree(desc->irq);
289 kfree(desc->ubuf);
290 free_urbs(desc);
291 kfree(desc);
292 }
293
wdm_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos)294 static ssize_t wdm_write
295 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
296 {
297 u8 *buf;
298 int rv = -EMSGSIZE, r, we;
299 struct wdm_device *desc = file->private_data;
300 struct usb_ctrlrequest *req;
301
302 if (count > desc->wMaxCommand)
303 count = desc->wMaxCommand;
304
305 spin_lock_irq(&desc->iuspin);
306 we = desc->werr;
307 desc->werr = 0;
308 spin_unlock_irq(&desc->iuspin);
309 if (we < 0)
310 return -EIO;
311
312 desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
313 if (!buf) {
314 rv = -ENOMEM;
315 goto outnl;
316 }
317
318 r = copy_from_user(buf, buffer, count);
319 if (r > 0) {
320 kfree(buf);
321 rv = -EFAULT;
322 goto outnl;
323 }
324
325 /* concurrent writes and disconnect */
326 r = mutex_lock_interruptible(&desc->lock);
327 rv = -ERESTARTSYS;
328 if (r) {
329 kfree(buf);
330 goto outnl;
331 }
332
333 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
334 kfree(buf);
335 rv = -ENODEV;
336 goto outnp;
337 }
338
339 r = usb_autopm_get_interface(desc->intf);
340 if (r < 0) {
341 kfree(buf);
342 goto outnp;
343 }
344
345 if (!(file->f_flags & O_NONBLOCK))
346 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
347 &desc->flags));
348 else
349 if (test_bit(WDM_IN_USE, &desc->flags))
350 r = -EAGAIN;
351 if (r < 0) {
352 kfree(buf);
353 goto out;
354 }
355
356 req = desc->orq;
357 usb_fill_control_urb(
358 desc->command,
359 interface_to_usbdev(desc->intf),
360 /* using common endpoint 0 */
361 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
362 (unsigned char *)req,
363 buf,
364 count,
365 wdm_out_callback,
366 desc
367 );
368
369 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
370 USB_RECIP_INTERFACE);
371 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
372 req->wValue = 0;
373 req->wIndex = desc->inum;
374 req->wLength = cpu_to_le16(count);
375 set_bit(WDM_IN_USE, &desc->flags);
376
377 rv = usb_submit_urb(desc->command, GFP_KERNEL);
378 if (rv < 0) {
379 kfree(buf);
380 clear_bit(WDM_IN_USE, &desc->flags);
381 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
382 } else {
383 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
384 req->wIndex);
385 }
386 out:
387 usb_autopm_put_interface(desc->intf);
388 outnp:
389 mutex_unlock(&desc->lock);
390 outnl:
391 return rv < 0 ? rv : count;
392 }
393
wdm_read(struct file * file,char __user * buffer,size_t count,loff_t * ppos)394 static ssize_t wdm_read
395 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
396 {
397 int rv, cntr = 0;
398 int i = 0;
399 struct wdm_device *desc = file->private_data;
400
401
402 rv = mutex_lock_interruptible(&desc->lock); /*concurrent reads */
403 if (rv < 0)
404 return -ERESTARTSYS;
405
406 if (desc->length == 0) {
407 desc->read = 0;
408 retry:
409 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
410 rv = -ENODEV;
411 goto err;
412 }
413 i++;
414 if (file->f_flags & O_NONBLOCK) {
415 if (!test_bit(WDM_READ, &desc->flags)) {
416 rv = cntr ? cntr : -EAGAIN;
417 goto err;
418 }
419 rv = 0;
420 } else {
421 rv = wait_event_interruptible(desc->wait,
422 test_bit(WDM_READ, &desc->flags));
423 }
424
425 /* may have happened while we slept */
426 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
427 rv = -ENODEV;
428 goto err;
429 }
430 usb_mark_last_busy(interface_to_usbdev(desc->intf));
431 if (rv < 0) {
432 rv = -ERESTARTSYS;
433 goto err;
434 }
435
436 spin_lock_irq(&desc->iuspin);
437
438 if (desc->rerr) { /* read completed, error happened */
439 desc->rerr = 0;
440 spin_unlock_irq(&desc->iuspin);
441 rv = -EIO;
442 goto err;
443 }
444 /*
445 * recheck whether we've lost the race
446 * against the completion handler
447 */
448 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
449 spin_unlock_irq(&desc->iuspin);
450 goto retry;
451 }
452 if (!desc->reslength) { /* zero length read */
453 spin_unlock_irq(&desc->iuspin);
454 goto retry;
455 }
456 clear_bit(WDM_READ, &desc->flags);
457 spin_unlock_irq(&desc->iuspin);
458 }
459
460 cntr = count > desc->length ? desc->length : count;
461 rv = copy_to_user(buffer, desc->ubuf, cntr);
462 if (rv > 0) {
463 rv = -EFAULT;
464 goto err;
465 }
466
467 for (i = 0; i < desc->length - cntr; i++)
468 desc->ubuf[i] = desc->ubuf[i + cntr];
469
470 desc->length -= cntr;
471 /* in case we had outstanding data */
472 if (!desc->length)
473 clear_bit(WDM_READ, &desc->flags);
474 rv = cntr;
475
476 err:
477 mutex_unlock(&desc->lock);
478 return rv;
479 }
480
wdm_flush(struct file * file,fl_owner_t id)481 static int wdm_flush(struct file *file, fl_owner_t id)
482 {
483 struct wdm_device *desc = file->private_data;
484
485 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
486 if (desc->werr < 0)
487 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
488 desc->werr);
489
490 return desc->werr;
491 }
492
wdm_poll(struct file * file,struct poll_table_struct * wait)493 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
494 {
495 struct wdm_device *desc = file->private_data;
496 unsigned long flags;
497 unsigned int mask = 0;
498
499 spin_lock_irqsave(&desc->iuspin, flags);
500 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
501 mask = POLLERR;
502 spin_unlock_irqrestore(&desc->iuspin, flags);
503 goto desc_out;
504 }
505 if (test_bit(WDM_READ, &desc->flags))
506 mask = POLLIN | POLLRDNORM;
507 if (desc->rerr || desc->werr)
508 mask |= POLLERR;
509 if (!test_bit(WDM_IN_USE, &desc->flags))
510 mask |= POLLOUT | POLLWRNORM;
511 spin_unlock_irqrestore(&desc->iuspin, flags);
512
513 poll_wait(file, &desc->wait, wait);
514
515 desc_out:
516 return mask;
517 }
518
wdm_open(struct inode * inode,struct file * file)519 static int wdm_open(struct inode *inode, struct file *file)
520 {
521 int minor = iminor(inode);
522 int rv = -ENODEV;
523 struct usb_interface *intf;
524 struct wdm_device *desc;
525
526 mutex_lock(&wdm_mutex);
527 intf = usb_find_interface(&wdm_driver, minor);
528 if (!intf)
529 goto out;
530
531 desc = usb_get_intfdata(intf);
532 if (test_bit(WDM_DISCONNECTING, &desc->flags))
533 goto out;
534 file->private_data = desc;
535
536 rv = usb_autopm_get_interface(desc->intf);
537 if (rv < 0) {
538 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
539 goto out;
540 }
541 intf->needs_remote_wakeup = 1;
542
543 mutex_lock(&desc->lock);
544 if (!desc->count++) {
545 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
546 if (rv < 0) {
547 desc->count--;
548 dev_err(&desc->intf->dev,
549 "Error submitting int urb - %d\n", rv);
550 }
551 } else {
552 rv = 0;
553 }
554 mutex_unlock(&desc->lock);
555 usb_autopm_put_interface(desc->intf);
556 out:
557 mutex_unlock(&wdm_mutex);
558 return rv;
559 }
560
wdm_release(struct inode * inode,struct file * file)561 static int wdm_release(struct inode *inode, struct file *file)
562 {
563 struct wdm_device *desc = file->private_data;
564
565 mutex_lock(&wdm_mutex);
566 mutex_lock(&desc->lock);
567 desc->count--;
568 mutex_unlock(&desc->lock);
569
570 if (!desc->count) {
571 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
572 kill_urbs(desc);
573 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
574 desc->intf->needs_remote_wakeup = 0;
575 }
576 mutex_unlock(&wdm_mutex);
577 return 0;
578 }
579
580 static const struct file_operations wdm_fops = {
581 .owner = THIS_MODULE,
582 .read = wdm_read,
583 .write = wdm_write,
584 .open = wdm_open,
585 .flush = wdm_flush,
586 .release = wdm_release,
587 .poll = wdm_poll,
588 .llseek = noop_llseek,
589 };
590
591 static struct usb_class_driver wdm_class = {
592 .name = "cdc-wdm%d",
593 .fops = &wdm_fops,
594 .minor_base = WDM_MINOR_BASE,
595 };
596
597 /* --- error handling --- */
wdm_rxwork(struct work_struct * work)598 static void wdm_rxwork(struct work_struct *work)
599 {
600 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
601 unsigned long flags;
602 int rv;
603
604 spin_lock_irqsave(&desc->iuspin, flags);
605 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
606 spin_unlock_irqrestore(&desc->iuspin, flags);
607 } else {
608 spin_unlock_irqrestore(&desc->iuspin, flags);
609 rv = usb_submit_urb(desc->response, GFP_KERNEL);
610 if (rv < 0 && rv != -EPERM) {
611 spin_lock_irqsave(&desc->iuspin, flags);
612 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
613 schedule_work(&desc->rxwork);
614 spin_unlock_irqrestore(&desc->iuspin, flags);
615 }
616 }
617 }
618
619 /* --- hotplug --- */
620
wdm_probe(struct usb_interface * intf,const struct usb_device_id * id)621 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
622 {
623 int rv = -EINVAL;
624 struct usb_device *udev = interface_to_usbdev(intf);
625 struct wdm_device *desc;
626 struct usb_host_interface *iface;
627 struct usb_endpoint_descriptor *ep;
628 struct usb_cdc_dmm_desc *dmhd;
629 u8 *buffer = intf->altsetting->extra;
630 int buflen = intf->altsetting->extralen;
631 u16 maxcom = 0;
632
633 if (!buffer)
634 goto out;
635
636 while (buflen > 2) {
637 if (buffer [1] != USB_DT_CS_INTERFACE) {
638 dev_err(&intf->dev, "skipping garbage\n");
639 goto next_desc;
640 }
641
642 switch (buffer [2]) {
643 case USB_CDC_HEADER_TYPE:
644 break;
645 case USB_CDC_DMM_TYPE:
646 dmhd = (struct usb_cdc_dmm_desc *)buffer;
647 maxcom = le16_to_cpu(dmhd->wMaxCommand);
648 dev_dbg(&intf->dev,
649 "Finding maximum buffer length: %d", maxcom);
650 break;
651 default:
652 dev_err(&intf->dev,
653 "Ignoring extra header, type %d, length %d\n",
654 buffer[2], buffer[0]);
655 break;
656 }
657 next_desc:
658 buflen -= buffer[0];
659 buffer += buffer[0];
660 }
661
662 rv = -ENOMEM;
663 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
664 if (!desc)
665 goto out;
666 mutex_init(&desc->lock);
667 spin_lock_init(&desc->iuspin);
668 init_waitqueue_head(&desc->wait);
669 desc->wMaxCommand = maxcom;
670 /* this will be expanded and needed in hardware endianness */
671 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
672 desc->intf = intf;
673 INIT_WORK(&desc->rxwork, wdm_rxwork);
674
675 rv = -EINVAL;
676 iface = intf->cur_altsetting;
677 if (iface->desc.bNumEndpoints != 1)
678 goto err;
679 ep = &iface->endpoint[0].desc;
680 if (!ep || !usb_endpoint_is_int_in(ep))
681 goto err;
682
683 desc->wMaxPacketSize = le16_to_cpu(ep->wMaxPacketSize);
684 desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
685
686 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
687 if (!desc->orq)
688 goto err;
689 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
690 if (!desc->irq)
691 goto err;
692
693 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
694 if (!desc->validity)
695 goto err;
696
697 desc->response = usb_alloc_urb(0, GFP_KERNEL);
698 if (!desc->response)
699 goto err;
700
701 desc->command = usb_alloc_urb(0, GFP_KERNEL);
702 if (!desc->command)
703 goto err;
704
705 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
706 if (!desc->ubuf)
707 goto err;
708
709 desc->sbuf = usb_alloc_coherent(interface_to_usbdev(intf),
710 desc->wMaxPacketSize,
711 GFP_KERNEL,
712 &desc->validity->transfer_dma);
713 if (!desc->sbuf)
714 goto err;
715
716 desc->inbuf = usb_alloc_coherent(interface_to_usbdev(intf),
717 desc->bMaxPacketSize0,
718 GFP_KERNEL,
719 &desc->response->transfer_dma);
720 if (!desc->inbuf)
721 goto err2;
722
723 usb_fill_int_urb(
724 desc->validity,
725 interface_to_usbdev(intf),
726 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
727 desc->sbuf,
728 desc->wMaxPacketSize,
729 wdm_int_callback,
730 desc,
731 ep->bInterval
732 );
733 desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
734
735 usb_set_intfdata(intf, desc);
736 rv = usb_register_dev(intf, &wdm_class);
737 if (rv < 0)
738 goto err3;
739 else
740 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
741 intf->minor - WDM_MINOR_BASE);
742 out:
743 return rv;
744 err3:
745 usb_set_intfdata(intf, NULL);
746 usb_free_coherent(interface_to_usbdev(desc->intf),
747 desc->bMaxPacketSize0,
748 desc->inbuf,
749 desc->response->transfer_dma);
750 err2:
751 usb_free_coherent(interface_to_usbdev(desc->intf),
752 desc->wMaxPacketSize,
753 desc->sbuf,
754 desc->validity->transfer_dma);
755 err:
756 free_urbs(desc);
757 kfree(desc->ubuf);
758 kfree(desc->orq);
759 kfree(desc->irq);
760 kfree(desc);
761 return rv;
762 }
763
wdm_disconnect(struct usb_interface * intf)764 static void wdm_disconnect(struct usb_interface *intf)
765 {
766 struct wdm_device *desc;
767 unsigned long flags;
768
769 usb_deregister_dev(intf, &wdm_class);
770 mutex_lock(&wdm_mutex);
771 desc = usb_get_intfdata(intf);
772
773 /* the spinlock makes sure no new urbs are generated in the callbacks */
774 spin_lock_irqsave(&desc->iuspin, flags);
775 set_bit(WDM_DISCONNECTING, &desc->flags);
776 set_bit(WDM_READ, &desc->flags);
777 /* to terminate pending flushes */
778 clear_bit(WDM_IN_USE, &desc->flags);
779 spin_unlock_irqrestore(&desc->iuspin, flags);
780 mutex_lock(&desc->lock);
781 kill_urbs(desc);
782 cancel_work_sync(&desc->rxwork);
783 mutex_unlock(&desc->lock);
784 wake_up_all(&desc->wait);
785 if (!desc->count)
786 cleanup(desc);
787 mutex_unlock(&wdm_mutex);
788 }
789
790 #ifdef CONFIG_PM
wdm_suspend(struct usb_interface * intf,pm_message_t message)791 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
792 {
793 struct wdm_device *desc = usb_get_intfdata(intf);
794 int rv = 0;
795
796 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
797
798 /* if this is an autosuspend the caller does the locking */
799 if (!(message.event & PM_EVENT_AUTO))
800 mutex_lock(&desc->lock);
801 spin_lock_irq(&desc->iuspin);
802
803 if ((message.event & PM_EVENT_AUTO) &&
804 (test_bit(WDM_IN_USE, &desc->flags)
805 || test_bit(WDM_RESPONDING, &desc->flags))) {
806 spin_unlock_irq(&desc->iuspin);
807 rv = -EBUSY;
808 } else {
809
810 set_bit(WDM_SUSPENDING, &desc->flags);
811 spin_unlock_irq(&desc->iuspin);
812 /* callback submits work - order is essential */
813 kill_urbs(desc);
814 cancel_work_sync(&desc->rxwork);
815 }
816 if (!(message.event & PM_EVENT_AUTO))
817 mutex_unlock(&desc->lock);
818
819 return rv;
820 }
821 #endif
822
recover_from_urb_loss(struct wdm_device * desc)823 static int recover_from_urb_loss(struct wdm_device *desc)
824 {
825 int rv = 0;
826
827 if (desc->count) {
828 rv = usb_submit_urb(desc->validity, GFP_NOIO);
829 if (rv < 0)
830 dev_err(&desc->intf->dev,
831 "Error resume submitting int urb - %d\n", rv);
832 }
833 return rv;
834 }
835
836 #ifdef CONFIG_PM
wdm_resume(struct usb_interface * intf)837 static int wdm_resume(struct usb_interface *intf)
838 {
839 struct wdm_device *desc = usb_get_intfdata(intf);
840 int rv;
841
842 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
843
844 clear_bit(WDM_SUSPENDING, &desc->flags);
845 rv = recover_from_urb_loss(desc);
846
847 return rv;
848 }
849 #endif
850
wdm_pre_reset(struct usb_interface * intf)851 static int wdm_pre_reset(struct usb_interface *intf)
852 {
853 struct wdm_device *desc = usb_get_intfdata(intf);
854
855 mutex_lock(&desc->lock);
856 return 0;
857 }
858
wdm_post_reset(struct usb_interface * intf)859 static int wdm_post_reset(struct usb_interface *intf)
860 {
861 struct wdm_device *desc = usb_get_intfdata(intf);
862 int rv;
863
864 rv = recover_from_urb_loss(desc);
865 mutex_unlock(&desc->lock);
866 return 0;
867 }
868
869 static struct usb_driver wdm_driver = {
870 .name = "cdc_wdm",
871 .probe = wdm_probe,
872 .disconnect = wdm_disconnect,
873 #ifdef CONFIG_PM
874 .suspend = wdm_suspend,
875 .resume = wdm_resume,
876 .reset_resume = wdm_resume,
877 #endif
878 .pre_reset = wdm_pre_reset,
879 .post_reset = wdm_post_reset,
880 .id_table = wdm_ids,
881 .supports_autosuspend = 1,
882 };
883
884 /* --- low level module stuff --- */
885
wdm_init(void)886 static int __init wdm_init(void)
887 {
888 int rv;
889
890 rv = usb_register(&wdm_driver);
891
892 return rv;
893 }
894
wdm_exit(void)895 static void __exit wdm_exit(void)
896 {
897 usb_deregister(&wdm_driver);
898 }
899
900 module_init(wdm_init);
901 module_exit(wdm_exit);
902
903 MODULE_AUTHOR(DRIVER_AUTHOR);
904 MODULE_DESCRIPTION(DRIVER_DESC);
905 MODULE_LICENSE("GPL");
906