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 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
61 #define WDM_DEFAULT_BUFSIZE 256
62
63 static DEFINE_MUTEX(wdm_mutex);
64
65 /* --- method tables --- */
66
67 struct wdm_device {
68 u8 *inbuf; /* buffer for response */
69 u8 *outbuf; /* buffer for command */
70 u8 *sbuf; /* buffer for status */
71 u8 *ubuf; /* buffer for copy to user space */
72
73 struct urb *command;
74 struct urb *response;
75 struct urb *validity;
76 struct usb_interface *intf;
77 struct usb_ctrlrequest *orq;
78 struct usb_ctrlrequest *irq;
79 spinlock_t iuspin;
80
81 unsigned long flags;
82 u16 bufsize;
83 u16 wMaxCommand;
84 u16 wMaxPacketSize;
85 u16 bMaxPacketSize0;
86 __le16 inum;
87 int reslength;
88 int length;
89 int read;
90 int count;
91 dma_addr_t shandle;
92 dma_addr_t ihandle;
93 struct mutex wlock;
94 struct mutex rlock;
95 wait_queue_head_t wait;
96 struct work_struct rxwork;
97 int werr;
98 int rerr;
99 };
100
101 static struct usb_driver wdm_driver;
102
103 /* --- callbacks --- */
wdm_out_callback(struct urb * urb)104 static void wdm_out_callback(struct urb *urb)
105 {
106 struct wdm_device *desc;
107 desc = urb->context;
108 spin_lock(&desc->iuspin);
109 desc->werr = urb->status;
110 spin_unlock(&desc->iuspin);
111 clear_bit(WDM_IN_USE, &desc->flags);
112 kfree(desc->outbuf);
113 wake_up(&desc->wait);
114 }
115
wdm_in_callback(struct urb * urb)116 static void wdm_in_callback(struct urb *urb)
117 {
118 struct wdm_device *desc = urb->context;
119 int status = urb->status;
120
121 spin_lock(&desc->iuspin);
122 clear_bit(WDM_RESPONDING, &desc->flags);
123
124 if (status) {
125 switch (status) {
126 case -ENOENT:
127 dev_dbg(&desc->intf->dev,
128 "nonzero urb status received: -ENOENT");
129 goto skip_error;
130 case -ECONNRESET:
131 dev_dbg(&desc->intf->dev,
132 "nonzero urb status received: -ECONNRESET");
133 goto skip_error;
134 case -ESHUTDOWN:
135 dev_dbg(&desc->intf->dev,
136 "nonzero urb status received: -ESHUTDOWN");
137 goto skip_error;
138 case -EPIPE:
139 dev_err(&desc->intf->dev,
140 "nonzero urb status received: -EPIPE\n");
141 break;
142 default:
143 dev_err(&desc->intf->dev,
144 "Unexpected error %d\n", status);
145 break;
146 }
147 }
148
149 desc->rerr = status;
150 desc->reslength = urb->actual_length;
151 memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
152 desc->length += desc->reslength;
153 skip_error:
154 wake_up(&desc->wait);
155
156 set_bit(WDM_READ, &desc->flags);
157 spin_unlock(&desc->iuspin);
158 }
159
wdm_int_callback(struct urb * urb)160 static void wdm_int_callback(struct urb *urb)
161 {
162 int rv = 0;
163 int status = urb->status;
164 struct wdm_device *desc;
165 struct usb_ctrlrequest *req;
166 struct usb_cdc_notification *dr;
167
168 desc = urb->context;
169 req = desc->irq;
170 dr = (struct usb_cdc_notification *)desc->sbuf;
171
172 if (status) {
173 switch (status) {
174 case -ESHUTDOWN:
175 case -ENOENT:
176 case -ECONNRESET:
177 return; /* unplug */
178 case -EPIPE:
179 set_bit(WDM_INT_STALL, &desc->flags);
180 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
181 goto sw; /* halt is cleared in work */
182 default:
183 dev_err(&desc->intf->dev,
184 "nonzero urb status received: %d\n", status);
185 break;
186 }
187 }
188
189 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
190 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
191 urb->actual_length);
192 goto exit;
193 }
194
195 switch (dr->bNotificationType) {
196 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
197 dev_dbg(&desc->intf->dev,
198 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
199 dr->wIndex, dr->wLength);
200 break;
201
202 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
203
204 dev_dbg(&desc->intf->dev,
205 "NOTIFY_NETWORK_CONNECTION %s network",
206 dr->wValue ? "connected to" : "disconnected from");
207 goto exit;
208 default:
209 clear_bit(WDM_POLL_RUNNING, &desc->flags);
210 dev_err(&desc->intf->dev,
211 "unknown notification %d received: index %d len %d\n",
212 dr->bNotificationType, dr->wIndex, dr->wLength);
213 goto exit;
214 }
215
216 req->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
217 req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
218 req->wValue = 0;
219 req->wIndex = desc->inum;
220 req->wLength = cpu_to_le16(desc->wMaxCommand);
221
222 usb_fill_control_urb(
223 desc->response,
224 interface_to_usbdev(desc->intf),
225 /* using common endpoint 0 */
226 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
227 (unsigned char *)req,
228 desc->inbuf,
229 desc->wMaxCommand,
230 wdm_in_callback,
231 desc
232 );
233 desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
234 spin_lock(&desc->iuspin);
235 clear_bit(WDM_READ, &desc->flags);
236 set_bit(WDM_RESPONDING, &desc->flags);
237 if (!test_bit(WDM_DISCONNECTING, &desc->flags)
238 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
239 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
240 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
241 __func__, rv);
242 }
243 spin_unlock(&desc->iuspin);
244 if (rv < 0) {
245 clear_bit(WDM_RESPONDING, &desc->flags);
246 if (rv == -EPERM)
247 return;
248 if (rv == -ENOMEM) {
249 sw:
250 rv = schedule_work(&desc->rxwork);
251 if (rv)
252 dev_err(&desc->intf->dev,
253 "Cannot schedule work\n");
254 }
255 }
256 exit:
257 rv = usb_submit_urb(urb, GFP_ATOMIC);
258 if (rv)
259 dev_err(&desc->intf->dev,
260 "%s - usb_submit_urb failed with result %d\n",
261 __func__, rv);
262
263 }
264
kill_urbs(struct wdm_device * desc)265 static void kill_urbs(struct wdm_device *desc)
266 {
267 /* the order here is essential */
268 usb_kill_urb(desc->command);
269 usb_kill_urb(desc->validity);
270 usb_kill_urb(desc->response);
271 }
272
free_urbs(struct wdm_device * desc)273 static void free_urbs(struct wdm_device *desc)
274 {
275 usb_free_urb(desc->validity);
276 usb_free_urb(desc->response);
277 usb_free_urb(desc->command);
278 }
279
cleanup(struct wdm_device * desc)280 static void cleanup(struct wdm_device *desc)
281 {
282 usb_free_coherent(interface_to_usbdev(desc->intf),
283 desc->wMaxPacketSize,
284 desc->sbuf,
285 desc->validity->transfer_dma);
286 usb_free_coherent(interface_to_usbdev(desc->intf),
287 desc->bMaxPacketSize0,
288 desc->inbuf,
289 desc->response->transfer_dma);
290 kfree(desc->orq);
291 kfree(desc->irq);
292 kfree(desc->ubuf);
293 free_urbs(desc);
294 kfree(desc);
295 }
296
wdm_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos)297 static ssize_t wdm_write
298 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
299 {
300 u8 *buf;
301 int rv = -EMSGSIZE, r, we;
302 struct wdm_device *desc = file->private_data;
303 struct usb_ctrlrequest *req;
304
305 if (count > desc->wMaxCommand)
306 count = desc->wMaxCommand;
307
308 spin_lock_irq(&desc->iuspin);
309 we = desc->werr;
310 desc->werr = 0;
311 spin_unlock_irq(&desc->iuspin);
312 if (we < 0)
313 return -EIO;
314
315 desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
316 if (!buf) {
317 rv = -ENOMEM;
318 goto outnl;
319 }
320
321 r = copy_from_user(buf, buffer, count);
322 if (r > 0) {
323 kfree(buf);
324 rv = -EFAULT;
325 goto outnl;
326 }
327
328 /* concurrent writes and disconnect */
329 r = mutex_lock_interruptible(&desc->wlock);
330 rv = -ERESTARTSYS;
331 if (r) {
332 kfree(buf);
333 goto outnl;
334 }
335
336 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
337 kfree(buf);
338 rv = -ENODEV;
339 goto outnp;
340 }
341
342 r = usb_autopm_get_interface(desc->intf);
343 if (r < 0) {
344 kfree(buf);
345 goto outnp;
346 }
347
348 if (!(file->f_flags & O_NONBLOCK))
349 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
350 &desc->flags));
351 else
352 if (test_bit(WDM_IN_USE, &desc->flags))
353 r = -EAGAIN;
354 if (r < 0) {
355 kfree(buf);
356 goto out;
357 }
358
359 req = desc->orq;
360 usb_fill_control_urb(
361 desc->command,
362 interface_to_usbdev(desc->intf),
363 /* using common endpoint 0 */
364 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
365 (unsigned char *)req,
366 buf,
367 count,
368 wdm_out_callback,
369 desc
370 );
371
372 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
373 USB_RECIP_INTERFACE);
374 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
375 req->wValue = 0;
376 req->wIndex = desc->inum;
377 req->wLength = cpu_to_le16(count);
378 set_bit(WDM_IN_USE, &desc->flags);
379
380 rv = usb_submit_urb(desc->command, GFP_KERNEL);
381 if (rv < 0) {
382 kfree(buf);
383 clear_bit(WDM_IN_USE, &desc->flags);
384 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
385 } else {
386 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
387 req->wIndex);
388 }
389 out:
390 usb_autopm_put_interface(desc->intf);
391 outnp:
392 mutex_unlock(&desc->wlock);
393 outnl:
394 return rv < 0 ? rv : count;
395 }
396
wdm_read(struct file * file,char __user * buffer,size_t count,loff_t * ppos)397 static ssize_t wdm_read
398 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
399 {
400 int rv, cntr = 0;
401 int i = 0;
402 struct wdm_device *desc = file->private_data;
403
404
405 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
406 if (rv < 0)
407 return -ERESTARTSYS;
408
409 if (desc->length == 0) {
410 desc->read = 0;
411 retry:
412 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
413 rv = -ENODEV;
414 goto err;
415 }
416 i++;
417 if (file->f_flags & O_NONBLOCK) {
418 if (!test_bit(WDM_READ, &desc->flags)) {
419 rv = cntr ? cntr : -EAGAIN;
420 goto err;
421 }
422 rv = 0;
423 } else {
424 rv = wait_event_interruptible(desc->wait,
425 test_bit(WDM_READ, &desc->flags));
426 }
427
428 /* may have happened while we slept */
429 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
430 rv = -ENODEV;
431 goto err;
432 }
433 usb_mark_last_busy(interface_to_usbdev(desc->intf));
434 if (rv < 0) {
435 rv = -ERESTARTSYS;
436 goto err;
437 }
438
439 spin_lock_irq(&desc->iuspin);
440
441 if (desc->rerr) { /* read completed, error happened */
442 desc->rerr = 0;
443 spin_unlock_irq(&desc->iuspin);
444 rv = -EIO;
445 goto err;
446 }
447 /*
448 * recheck whether we've lost the race
449 * against the completion handler
450 */
451 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
452 spin_unlock_irq(&desc->iuspin);
453 goto retry;
454 }
455 if (!desc->reslength) { /* zero length read */
456 spin_unlock_irq(&desc->iuspin);
457 goto retry;
458 }
459 clear_bit(WDM_READ, &desc->flags);
460 spin_unlock_irq(&desc->iuspin);
461 }
462
463 cntr = count > desc->length ? desc->length : count;
464 rv = copy_to_user(buffer, desc->ubuf, cntr);
465 if (rv > 0) {
466 rv = -EFAULT;
467 goto err;
468 }
469
470 for (i = 0; i < desc->length - cntr; i++)
471 desc->ubuf[i] = desc->ubuf[i + cntr];
472
473 spin_lock_irq(&desc->iuspin);
474 desc->length -= cntr;
475 spin_unlock_irq(&desc->iuspin);
476 /* in case we had outstanding data */
477 if (!desc->length)
478 clear_bit(WDM_READ, &desc->flags);
479 rv = cntr;
480
481 err:
482 mutex_unlock(&desc->rlock);
483 return rv;
484 }
485
wdm_flush(struct file * file,fl_owner_t id)486 static int wdm_flush(struct file *file, fl_owner_t id)
487 {
488 struct wdm_device *desc = file->private_data;
489
490 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
491 if (desc->werr < 0)
492 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
493 desc->werr);
494
495 return desc->werr;
496 }
497
wdm_poll(struct file * file,struct poll_table_struct * wait)498 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
499 {
500 struct wdm_device *desc = file->private_data;
501 unsigned long flags;
502 unsigned int mask = 0;
503
504 spin_lock_irqsave(&desc->iuspin, flags);
505 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
506 mask = POLLERR;
507 spin_unlock_irqrestore(&desc->iuspin, flags);
508 goto desc_out;
509 }
510 if (test_bit(WDM_READ, &desc->flags))
511 mask = POLLIN | POLLRDNORM;
512 if (desc->rerr || desc->werr)
513 mask |= POLLERR;
514 if (!test_bit(WDM_IN_USE, &desc->flags))
515 mask |= POLLOUT | POLLWRNORM;
516 spin_unlock_irqrestore(&desc->iuspin, flags);
517
518 poll_wait(file, &desc->wait, wait);
519
520 desc_out:
521 return mask;
522 }
523
wdm_open(struct inode * inode,struct file * file)524 static int wdm_open(struct inode *inode, struct file *file)
525 {
526 int minor = iminor(inode);
527 int rv = -ENODEV;
528 struct usb_interface *intf;
529 struct wdm_device *desc;
530
531 mutex_lock(&wdm_mutex);
532 intf = usb_find_interface(&wdm_driver, minor);
533 if (!intf)
534 goto out;
535
536 desc = usb_get_intfdata(intf);
537 if (test_bit(WDM_DISCONNECTING, &desc->flags))
538 goto out;
539 file->private_data = desc;
540
541 rv = usb_autopm_get_interface(desc->intf);
542 if (rv < 0) {
543 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
544 goto out;
545 }
546 intf->needs_remote_wakeup = 1;
547
548 /* using write lock to protect desc->count */
549 mutex_lock(&desc->wlock);
550 if (!desc->count++) {
551 desc->werr = 0;
552 desc->rerr = 0;
553 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
554 if (rv < 0) {
555 desc->count--;
556 dev_err(&desc->intf->dev,
557 "Error submitting int urb - %d\n", rv);
558 }
559 } else {
560 rv = 0;
561 }
562 mutex_unlock(&desc->wlock);
563 usb_autopm_put_interface(desc->intf);
564 out:
565 mutex_unlock(&wdm_mutex);
566 return rv;
567 }
568
wdm_release(struct inode * inode,struct file * file)569 static int wdm_release(struct inode *inode, struct file *file)
570 {
571 struct wdm_device *desc = file->private_data;
572
573 mutex_lock(&wdm_mutex);
574
575 /* using write lock to protect desc->count */
576 mutex_lock(&desc->wlock);
577 desc->count--;
578 mutex_unlock(&desc->wlock);
579
580 if (!desc->count) {
581 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
582 kill_urbs(desc);
583 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
584 desc->intf->needs_remote_wakeup = 0;
585 }
586 mutex_unlock(&wdm_mutex);
587 return 0;
588 }
589
590 static const struct file_operations wdm_fops = {
591 .owner = THIS_MODULE,
592 .read = wdm_read,
593 .write = wdm_write,
594 .open = wdm_open,
595 .flush = wdm_flush,
596 .release = wdm_release,
597 .poll = wdm_poll,
598 .llseek = noop_llseek,
599 };
600
601 static struct usb_class_driver wdm_class = {
602 .name = "cdc-wdm%d",
603 .fops = &wdm_fops,
604 .minor_base = WDM_MINOR_BASE,
605 };
606
607 /* --- error handling --- */
wdm_rxwork(struct work_struct * work)608 static void wdm_rxwork(struct work_struct *work)
609 {
610 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
611 unsigned long flags;
612 int rv;
613
614 spin_lock_irqsave(&desc->iuspin, flags);
615 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
616 spin_unlock_irqrestore(&desc->iuspin, flags);
617 } else {
618 spin_unlock_irqrestore(&desc->iuspin, flags);
619 rv = usb_submit_urb(desc->response, GFP_KERNEL);
620 if (rv < 0 && rv != -EPERM) {
621 spin_lock_irqsave(&desc->iuspin, flags);
622 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
623 schedule_work(&desc->rxwork);
624 spin_unlock_irqrestore(&desc->iuspin, flags);
625 }
626 }
627 }
628
629 /* --- hotplug --- */
630
wdm_probe(struct usb_interface * intf,const struct usb_device_id * id)631 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
632 {
633 int rv = -EINVAL;
634 struct usb_device *udev = interface_to_usbdev(intf);
635 struct wdm_device *desc;
636 struct usb_host_interface *iface;
637 struct usb_endpoint_descriptor *ep;
638 struct usb_cdc_dmm_desc *dmhd;
639 u8 *buffer = intf->altsetting->extra;
640 int buflen = intf->altsetting->extralen;
641 u16 maxcom = WDM_DEFAULT_BUFSIZE;
642
643 if (!buffer)
644 goto out;
645
646 while (buflen > 2) {
647 if (buffer [1] != USB_DT_CS_INTERFACE) {
648 dev_err(&intf->dev, "skipping garbage\n");
649 goto next_desc;
650 }
651
652 switch (buffer [2]) {
653 case USB_CDC_HEADER_TYPE:
654 break;
655 case USB_CDC_DMM_TYPE:
656 dmhd = (struct usb_cdc_dmm_desc *)buffer;
657 maxcom = le16_to_cpu(dmhd->wMaxCommand);
658 dev_dbg(&intf->dev,
659 "Finding maximum buffer length: %d", maxcom);
660 break;
661 default:
662 dev_err(&intf->dev,
663 "Ignoring extra header, type %d, length %d\n",
664 buffer[2], buffer[0]);
665 break;
666 }
667 next_desc:
668 buflen -= buffer[0];
669 buffer += buffer[0];
670 }
671
672 rv = -ENOMEM;
673 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
674 if (!desc)
675 goto out;
676 mutex_init(&desc->rlock);
677 mutex_init(&desc->wlock);
678 spin_lock_init(&desc->iuspin);
679 init_waitqueue_head(&desc->wait);
680 desc->wMaxCommand = maxcom;
681 /* this will be expanded and needed in hardware endianness */
682 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
683 desc->intf = intf;
684 INIT_WORK(&desc->rxwork, wdm_rxwork);
685
686 rv = -EINVAL;
687 iface = intf->cur_altsetting;
688 if (iface->desc.bNumEndpoints != 1)
689 goto err;
690 ep = &iface->endpoint[0].desc;
691 if (!ep || !usb_endpoint_is_int_in(ep))
692 goto err;
693
694 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
695 desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
696
697 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
698 if (!desc->orq)
699 goto err;
700 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
701 if (!desc->irq)
702 goto err;
703
704 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
705 if (!desc->validity)
706 goto err;
707
708 desc->response = usb_alloc_urb(0, GFP_KERNEL);
709 if (!desc->response)
710 goto err;
711
712 desc->command = usb_alloc_urb(0, GFP_KERNEL);
713 if (!desc->command)
714 goto err;
715
716 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
717 if (!desc->ubuf)
718 goto err;
719
720 desc->sbuf = usb_alloc_coherent(interface_to_usbdev(intf),
721 desc->wMaxPacketSize,
722 GFP_KERNEL,
723 &desc->validity->transfer_dma);
724 if (!desc->sbuf)
725 goto err;
726
727 desc->inbuf = usb_alloc_coherent(interface_to_usbdev(intf),
728 desc->wMaxCommand,
729 GFP_KERNEL,
730 &desc->response->transfer_dma);
731 if (!desc->inbuf)
732 goto err2;
733
734 usb_fill_int_urb(
735 desc->validity,
736 interface_to_usbdev(intf),
737 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
738 desc->sbuf,
739 desc->wMaxPacketSize,
740 wdm_int_callback,
741 desc,
742 ep->bInterval
743 );
744 desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
745
746 usb_set_intfdata(intf, desc);
747 rv = usb_register_dev(intf, &wdm_class);
748 if (rv < 0)
749 goto err3;
750 else
751 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
752 intf->minor - WDM_MINOR_BASE);
753 out:
754 return rv;
755 err3:
756 usb_set_intfdata(intf, NULL);
757 usb_free_coherent(interface_to_usbdev(desc->intf),
758 desc->bMaxPacketSize0,
759 desc->inbuf,
760 desc->response->transfer_dma);
761 err2:
762 usb_free_coherent(interface_to_usbdev(desc->intf),
763 desc->wMaxPacketSize,
764 desc->sbuf,
765 desc->validity->transfer_dma);
766 err:
767 free_urbs(desc);
768 kfree(desc->ubuf);
769 kfree(desc->orq);
770 kfree(desc->irq);
771 kfree(desc);
772 return rv;
773 }
774
wdm_disconnect(struct usb_interface * intf)775 static void wdm_disconnect(struct usb_interface *intf)
776 {
777 struct wdm_device *desc;
778 unsigned long flags;
779
780 usb_deregister_dev(intf, &wdm_class);
781 mutex_lock(&wdm_mutex);
782 desc = usb_get_intfdata(intf);
783
784 /* the spinlock makes sure no new urbs are generated in the callbacks */
785 spin_lock_irqsave(&desc->iuspin, flags);
786 set_bit(WDM_DISCONNECTING, &desc->flags);
787 set_bit(WDM_READ, &desc->flags);
788 /* to terminate pending flushes */
789 clear_bit(WDM_IN_USE, &desc->flags);
790 spin_unlock_irqrestore(&desc->iuspin, flags);
791 wake_up_all(&desc->wait);
792 mutex_lock(&desc->rlock);
793 mutex_lock(&desc->wlock);
794 kill_urbs(desc);
795 cancel_work_sync(&desc->rxwork);
796 mutex_unlock(&desc->wlock);
797 mutex_unlock(&desc->rlock);
798 if (!desc->count)
799 cleanup(desc);
800 mutex_unlock(&wdm_mutex);
801 }
802
803 #ifdef CONFIG_PM
wdm_suspend(struct usb_interface * intf,pm_message_t message)804 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
805 {
806 struct wdm_device *desc = usb_get_intfdata(intf);
807 int rv = 0;
808
809 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
810
811 /* if this is an autosuspend the caller does the locking */
812 if (!PMSG_IS_AUTO(message)) {
813 mutex_lock(&desc->rlock);
814 mutex_lock(&desc->wlock);
815 }
816 spin_lock_irq(&desc->iuspin);
817
818 if (PMSG_IS_AUTO(message) &&
819 (test_bit(WDM_IN_USE, &desc->flags)
820 || test_bit(WDM_RESPONDING, &desc->flags))) {
821 spin_unlock_irq(&desc->iuspin);
822 rv = -EBUSY;
823 } else {
824
825 set_bit(WDM_SUSPENDING, &desc->flags);
826 spin_unlock_irq(&desc->iuspin);
827 /* callback submits work - order is essential */
828 kill_urbs(desc);
829 cancel_work_sync(&desc->rxwork);
830 }
831 if (!PMSG_IS_AUTO(message)) {
832 mutex_unlock(&desc->wlock);
833 mutex_unlock(&desc->rlock);
834 }
835
836 return rv;
837 }
838 #endif
839
recover_from_urb_loss(struct wdm_device * desc)840 static int recover_from_urb_loss(struct wdm_device *desc)
841 {
842 int rv = 0;
843
844 if (desc->count) {
845 rv = usb_submit_urb(desc->validity, GFP_NOIO);
846 if (rv < 0)
847 dev_err(&desc->intf->dev,
848 "Error resume submitting int urb - %d\n", rv);
849 }
850 return rv;
851 }
852
853 #ifdef CONFIG_PM
wdm_resume(struct usb_interface * intf)854 static int wdm_resume(struct usb_interface *intf)
855 {
856 struct wdm_device *desc = usb_get_intfdata(intf);
857 int rv;
858
859 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
860
861 clear_bit(WDM_SUSPENDING, &desc->flags);
862 rv = recover_from_urb_loss(desc);
863
864 return rv;
865 }
866 #endif
867
wdm_pre_reset(struct usb_interface * intf)868 static int wdm_pre_reset(struct usb_interface *intf)
869 {
870 struct wdm_device *desc = usb_get_intfdata(intf);
871
872 mutex_lock(&desc->rlock);
873 mutex_lock(&desc->wlock);
874 kill_urbs(desc);
875
876 /*
877 * we notify everybody using poll of
878 * an exceptional situation
879 * must be done before recovery lest a spontaneous
880 * message from the device is lost
881 */
882 spin_lock_irq(&desc->iuspin);
883 desc->rerr = -EINTR;
884 spin_unlock_irq(&desc->iuspin);
885 wake_up_all(&desc->wait);
886 return 0;
887 }
888
wdm_post_reset(struct usb_interface * intf)889 static int wdm_post_reset(struct usb_interface *intf)
890 {
891 struct wdm_device *desc = usb_get_intfdata(intf);
892 int rv;
893
894 rv = recover_from_urb_loss(desc);
895 mutex_unlock(&desc->wlock);
896 mutex_unlock(&desc->rlock);
897 return 0;
898 }
899
900 static struct usb_driver wdm_driver = {
901 .name = "cdc_wdm",
902 .probe = wdm_probe,
903 .disconnect = wdm_disconnect,
904 #ifdef CONFIG_PM
905 .suspend = wdm_suspend,
906 .resume = wdm_resume,
907 .reset_resume = wdm_resume,
908 #endif
909 .pre_reset = wdm_pre_reset,
910 .post_reset = wdm_post_reset,
911 .id_table = wdm_ids,
912 .supports_autosuspend = 1,
913 };
914
915 module_usb_driver(wdm_driver);
916
917 MODULE_AUTHOR(DRIVER_AUTHOR);
918 MODULE_DESCRIPTION(DRIVER_DESC);
919 MODULE_LICENSE("GPL");
920