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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
34static 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
44MODULE_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
61static DEFINE_MUTEX(wdm_mutex);
62
63/* --- method tables --- */
64
65struct 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
98static struct usb_driver wdm_driver;
99
100/* --- callbacks --- */
101static 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
113static 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;
150skip_error:
151 wake_up(&desc->wait);
152
153 set_bit(WDM_READ, &desc->flags);
154 spin_unlock(&desc->iuspin);
155}
156
157static 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) {
246sw:
247 rv = schedule_work(&desc->rxwork);
248 if (rv)
249 dev_err(&desc->intf->dev,
250 "Cannot schedule work\n");
251 }
252 }
253exit:
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
262static 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
270static 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
277static 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
294static 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 }
386out:
387 usb_autopm_put_interface(desc->intf);
388outnp:
389 mutex_unlock(&desc->lock);
390outnl:
391 return rv < 0 ? rv : count;
392}
393
394static 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;
408retry:
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
476err:
477 mutex_unlock(&desc->lock);
478 return rv;
479}
480
481static 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
493static 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
515desc_out:
516 return mask;
517}
518
519static 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 desc->werr = 0;
546 desc->rerr = 0;
547 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
548 if (rv < 0) {
549 desc->count--;
550 dev_err(&desc->intf->dev,
551 "Error submitting int urb - %d\n", rv);
552 }
553 } else {
554 rv = 0;
555 }
556 mutex_unlock(&desc->lock);
557 usb_autopm_put_interface(desc->intf);
558out:
559 mutex_unlock(&wdm_mutex);
560 return rv;
561}
562
563static int wdm_release(struct inode *inode, struct file *file)
564{
565 struct wdm_device *desc = file->private_data;
566
567 mutex_lock(&wdm_mutex);
568 mutex_lock(&desc->lock);
569 desc->count--;
570 mutex_unlock(&desc->lock);
571
572 if (!desc->count) {
573 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
574 kill_urbs(desc);
575 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
576 desc->intf->needs_remote_wakeup = 0;
577 }
578 mutex_unlock(&wdm_mutex);
579 return 0;
580}
581
582static const struct file_operations wdm_fops = {
583 .owner = THIS_MODULE,
584 .read = wdm_read,
585 .write = wdm_write,
586 .open = wdm_open,
587 .flush = wdm_flush,
588 .release = wdm_release,
589 .poll = wdm_poll,
590 .llseek = noop_llseek,
591};
592
593static struct usb_class_driver wdm_class = {
594 .name = "cdc-wdm%d",
595 .fops = &wdm_fops,
596 .minor_base = WDM_MINOR_BASE,
597};
598
599/* --- error handling --- */
600static void wdm_rxwork(struct work_struct *work)
601{
602 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
603 unsigned long flags;
604 int rv;
605
606 spin_lock_irqsave(&desc->iuspin, flags);
607 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
608 spin_unlock_irqrestore(&desc->iuspin, flags);
609 } else {
610 spin_unlock_irqrestore(&desc->iuspin, flags);
611 rv = usb_submit_urb(desc->response, GFP_KERNEL);
612 if (rv < 0 && rv != -EPERM) {
613 spin_lock_irqsave(&desc->iuspin, flags);
614 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
615 schedule_work(&desc->rxwork);
616 spin_unlock_irqrestore(&desc->iuspin, flags);
617 }
618 }
619}
620
621/* --- hotplug --- */
622
623static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
624{
625 int rv = -EINVAL;
626 struct usb_device *udev = interface_to_usbdev(intf);
627 struct wdm_device *desc;
628 struct usb_host_interface *iface;
629 struct usb_endpoint_descriptor *ep;
630 struct usb_cdc_dmm_desc *dmhd;
631 u8 *buffer = intf->altsetting->extra;
632 int buflen = intf->altsetting->extralen;
633 u16 maxcom = 0;
634
635 if (!buffer)
636 goto out;
637
638 while (buflen > 2) {
639 if (buffer [1] != USB_DT_CS_INTERFACE) {
640 dev_err(&intf->dev, "skipping garbage\n");
641 goto next_desc;
642 }
643
644 switch (buffer [2]) {
645 case USB_CDC_HEADER_TYPE:
646 break;
647 case USB_CDC_DMM_TYPE:
648 dmhd = (struct usb_cdc_dmm_desc *)buffer;
649 maxcom = le16_to_cpu(dmhd->wMaxCommand);
650 dev_dbg(&intf->dev,
651 "Finding maximum buffer length: %d", maxcom);
652 break;
653 default:
654 dev_err(&intf->dev,
655 "Ignoring extra header, type %d, length %d\n",
656 buffer[2], buffer[0]);
657 break;
658 }
659next_desc:
660 buflen -= buffer[0];
661 buffer += buffer[0];
662 }
663
664 rv = -ENOMEM;
665 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
666 if (!desc)
667 goto out;
668 mutex_init(&desc->lock);
669 spin_lock_init(&desc->iuspin);
670 init_waitqueue_head(&desc->wait);
671 desc->wMaxCommand = maxcom;
672 /* this will be expanded and needed in hardware endianness */
673 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
674 desc->intf = intf;
675 INIT_WORK(&desc->rxwork, wdm_rxwork);
676
677 rv = -EINVAL;
678 iface = intf->cur_altsetting;
679 if (iface->desc.bNumEndpoints != 1)
680 goto err;
681 ep = &iface->endpoint[0].desc;
682 if (!ep || !usb_endpoint_is_int_in(ep))
683 goto err;
684
685 desc->wMaxPacketSize = le16_to_cpu(ep->wMaxPacketSize);
686 desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
687
688 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
689 if (!desc->orq)
690 goto err;
691 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
692 if (!desc->irq)
693 goto err;
694
695 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
696 if (!desc->validity)
697 goto err;
698
699 desc->response = usb_alloc_urb(0, GFP_KERNEL);
700 if (!desc->response)
701 goto err;
702
703 desc->command = usb_alloc_urb(0, GFP_KERNEL);
704 if (!desc->command)
705 goto err;
706
707 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
708 if (!desc->ubuf)
709 goto err;
710
711 desc->sbuf = usb_alloc_coherent(interface_to_usbdev(intf),
712 desc->wMaxPacketSize,
713 GFP_KERNEL,
714 &desc->validity->transfer_dma);
715 if (!desc->sbuf)
716 goto err;
717
718 desc->inbuf = usb_alloc_coherent(interface_to_usbdev(intf),
719 desc->bMaxPacketSize0,
720 GFP_KERNEL,
721 &desc->response->transfer_dma);
722 if (!desc->inbuf)
723 goto err2;
724
725 usb_fill_int_urb(
726 desc->validity,
727 interface_to_usbdev(intf),
728 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
729 desc->sbuf,
730 desc->wMaxPacketSize,
731 wdm_int_callback,
732 desc,
733 ep->bInterval
734 );
735 desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
736
737 usb_set_intfdata(intf, desc);
738 rv = usb_register_dev(intf, &wdm_class);
739 if (rv < 0)
740 goto err3;
741 else
742 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
743 intf->minor - WDM_MINOR_BASE);
744out:
745 return rv;
746err3:
747 usb_set_intfdata(intf, NULL);
748 usb_free_coherent(interface_to_usbdev(desc->intf),
749 desc->bMaxPacketSize0,
750 desc->inbuf,
751 desc->response->transfer_dma);
752err2:
753 usb_free_coherent(interface_to_usbdev(desc->intf),
754 desc->wMaxPacketSize,
755 desc->sbuf,
756 desc->validity->transfer_dma);
757err:
758 free_urbs(desc);
759 kfree(desc->ubuf);
760 kfree(desc->orq);
761 kfree(desc->irq);
762 kfree(desc);
763 return rv;
764}
765
766static void wdm_disconnect(struct usb_interface *intf)
767{
768 struct wdm_device *desc;
769 unsigned long flags;
770
771 usb_deregister_dev(intf, &wdm_class);
772 mutex_lock(&wdm_mutex);
773 desc = usb_get_intfdata(intf);
774
775 /* the spinlock makes sure no new urbs are generated in the callbacks */
776 spin_lock_irqsave(&desc->iuspin, flags);
777 set_bit(WDM_DISCONNECTING, &desc->flags);
778 set_bit(WDM_READ, &desc->flags);
779 /* to terminate pending flushes */
780 clear_bit(WDM_IN_USE, &desc->flags);
781 spin_unlock_irqrestore(&desc->iuspin, flags);
782 mutex_lock(&desc->lock);
783 kill_urbs(desc);
784 cancel_work_sync(&desc->rxwork);
785 mutex_unlock(&desc->lock);
786 wake_up_all(&desc->wait);
787 if (!desc->count)
788 cleanup(desc);
789 mutex_unlock(&wdm_mutex);
790}
791
792#ifdef CONFIG_PM
793static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
794{
795 struct wdm_device *desc = usb_get_intfdata(intf);
796 int rv = 0;
797
798 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
799
800 /* if this is an autosuspend the caller does the locking */
801 if (!(message.event & PM_EVENT_AUTO))
802 mutex_lock(&desc->lock);
803 spin_lock_irq(&desc->iuspin);
804
805 if ((message.event & PM_EVENT_AUTO) &&
806 (test_bit(WDM_IN_USE, &desc->flags)
807 || test_bit(WDM_RESPONDING, &desc->flags))) {
808 spin_unlock_irq(&desc->iuspin);
809 rv = -EBUSY;
810 } else {
811
812 set_bit(WDM_SUSPENDING, &desc->flags);
813 spin_unlock_irq(&desc->iuspin);
814 /* callback submits work - order is essential */
815 kill_urbs(desc);
816 cancel_work_sync(&desc->rxwork);
817 }
818 if (!(message.event & PM_EVENT_AUTO))
819 mutex_unlock(&desc->lock);
820
821 return rv;
822}
823#endif
824
825static int recover_from_urb_loss(struct wdm_device *desc)
826{
827 int rv = 0;
828
829 if (desc->count) {
830 rv = usb_submit_urb(desc->validity, GFP_NOIO);
831 if (rv < 0)
832 dev_err(&desc->intf->dev,
833 "Error resume submitting int urb - %d\n", rv);
834 }
835 return rv;
836}
837
838#ifdef CONFIG_PM
839static int wdm_resume(struct usb_interface *intf)
840{
841 struct wdm_device *desc = usb_get_intfdata(intf);
842 int rv;
843
844 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
845
846 clear_bit(WDM_SUSPENDING, &desc->flags);
847 rv = recover_from_urb_loss(desc);
848
849 return rv;
850}
851#endif
852
853static int wdm_pre_reset(struct usb_interface *intf)
854{
855 struct wdm_device *desc = usb_get_intfdata(intf);
856
857 mutex_lock(&desc->lock);
858 kill_urbs(desc);
859
860 /*
861 * we notify everybody using poll of
862 * an exceptional situation
863 * must be done before recovery lest a spontaneous
864 * message from the device is lost
865 */
866 spin_lock_irq(&desc->iuspin);
867 desc->rerr = -EINTR;
868 spin_unlock_irq(&desc->iuspin);
869 wake_up_all(&desc->wait);
870 return 0;
871}
872
873static int wdm_post_reset(struct usb_interface *intf)
874{
875 struct wdm_device *desc = usb_get_intfdata(intf);
876 int rv;
877
878 rv = recover_from_urb_loss(desc);
879 mutex_unlock(&desc->lock);
880 return 0;
881}
882
883static struct usb_driver wdm_driver = {
884 .name = "cdc_wdm",
885 .probe = wdm_probe,
886 .disconnect = wdm_disconnect,
887#ifdef CONFIG_PM
888 .suspend = wdm_suspend,
889 .resume = wdm_resume,
890 .reset_resume = wdm_resume,
891#endif
892 .pre_reset = wdm_pre_reset,
893 .post_reset = wdm_post_reset,
894 .id_table = wdm_ids,
895 .supports_autosuspend = 1,
896};
897
898/* --- low level module stuff --- */
899
900static int __init wdm_init(void)
901{
902 int rv;
903
904 rv = usb_register(&wdm_driver);
905
906 return rv;
907}
908
909static void __exit wdm_exit(void)
910{
911 usb_deregister(&wdm_driver);
912}
913
914module_init(wdm_init);
915module_exit(wdm_exit);
916
917MODULE_AUTHOR(DRIVER_AUTHOR);
918MODULE_DESCRIPTION(DRIVER_DESC);
919MODULE_LICENSE("GPL");
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#include <linux/usb/cdc-wdm.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#define HUAWEI_VENDOR_ID 0x12D1
36
37static const struct usb_device_id wdm_ids[] = {
38 {
39 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
40 USB_DEVICE_ID_MATCH_INT_SUBCLASS,
41 .bInterfaceClass = USB_CLASS_COMM,
42 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
43 },
44 {
45 /*
46 * Huawei E392, E398 and possibly other Qualcomm based modems
47 * embed the Qualcomm QMI protocol inside CDC on CDC ECM like
48 * control interfaces. Userspace access to this is required
49 * to configure the accompanying data interface
50 */
51 .match_flags = USB_DEVICE_ID_MATCH_VENDOR |
52 USB_DEVICE_ID_MATCH_INT_INFO,
53 .idVendor = HUAWEI_VENDOR_ID,
54 .bInterfaceClass = USB_CLASS_VENDOR_SPEC,
55 .bInterfaceSubClass = 1,
56 .bInterfaceProtocol = 9, /* NOTE: CDC ECM control interface! */
57 },
58 {
59 /* Vodafone/Huawei K5005 (12d1:14c8) and similar modems */
60 .match_flags = USB_DEVICE_ID_MATCH_VENDOR |
61 USB_DEVICE_ID_MATCH_INT_INFO,
62 .idVendor = HUAWEI_VENDOR_ID,
63 .bInterfaceClass = USB_CLASS_VENDOR_SPEC,
64 .bInterfaceSubClass = 1,
65 .bInterfaceProtocol = 57, /* NOTE: CDC ECM control interface! */
66 },
67 { }
68};
69
70MODULE_DEVICE_TABLE (usb, wdm_ids);
71
72#define WDM_MINOR_BASE 176
73
74
75#define WDM_IN_USE 1
76#define WDM_DISCONNECTING 2
77#define WDM_RESULT 3
78#define WDM_READ 4
79#define WDM_INT_STALL 5
80#define WDM_POLL_RUNNING 6
81#define WDM_RESPONDING 7
82#define WDM_SUSPENDING 8
83#define WDM_RESETTING 9
84
85#define WDM_MAX 16
86
87/* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
88#define WDM_DEFAULT_BUFSIZE 256
89
90static DEFINE_MUTEX(wdm_mutex);
91static DEFINE_SPINLOCK(wdm_device_list_lock);
92static LIST_HEAD(wdm_device_list);
93
94/* --- method tables --- */
95
96struct wdm_device {
97 u8 *inbuf; /* buffer for response */
98 u8 *outbuf; /* buffer for command */
99 u8 *sbuf; /* buffer for status */
100 u8 *ubuf; /* buffer for copy to user space */
101
102 struct urb *command;
103 struct urb *response;
104 struct urb *validity;
105 struct usb_interface *intf;
106 struct usb_ctrlrequest *orq;
107 struct usb_ctrlrequest *irq;
108 spinlock_t iuspin;
109
110 unsigned long flags;
111 u16 bufsize;
112 u16 wMaxCommand;
113 u16 wMaxPacketSize;
114 __le16 inum;
115 int reslength;
116 int length;
117 int read;
118 int count;
119 dma_addr_t shandle;
120 dma_addr_t ihandle;
121 struct mutex wlock;
122 struct mutex rlock;
123 wait_queue_head_t wait;
124 struct work_struct rxwork;
125 int werr;
126 int rerr;
127
128 struct list_head device_list;
129 int (*manage_power)(struct usb_interface *, int);
130};
131
132static struct usb_driver wdm_driver;
133
134/* return intfdata if we own the interface, else look up intf in the list */
135static struct wdm_device *wdm_find_device(struct usb_interface *intf)
136{
137 struct wdm_device *desc;
138
139 spin_lock(&wdm_device_list_lock);
140 list_for_each_entry(desc, &wdm_device_list, device_list)
141 if (desc->intf == intf)
142 goto found;
143 desc = NULL;
144found:
145 spin_unlock(&wdm_device_list_lock);
146
147 return desc;
148}
149
150static struct wdm_device *wdm_find_device_by_minor(int minor)
151{
152 struct wdm_device *desc;
153
154 spin_lock(&wdm_device_list_lock);
155 list_for_each_entry(desc, &wdm_device_list, device_list)
156 if (desc->intf->minor == minor)
157 goto found;
158 desc = NULL;
159found:
160 spin_unlock(&wdm_device_list_lock);
161
162 return desc;
163}
164
165/* --- callbacks --- */
166static void wdm_out_callback(struct urb *urb)
167{
168 struct wdm_device *desc;
169 desc = urb->context;
170 spin_lock(&desc->iuspin);
171 desc->werr = urb->status;
172 spin_unlock(&desc->iuspin);
173 kfree(desc->outbuf);
174 desc->outbuf = NULL;
175 clear_bit(WDM_IN_USE, &desc->flags);
176 wake_up(&desc->wait);
177}
178
179static void wdm_in_callback(struct urb *urb)
180{
181 struct wdm_device *desc = urb->context;
182 int status = urb->status;
183
184 spin_lock(&desc->iuspin);
185 clear_bit(WDM_RESPONDING, &desc->flags);
186
187 if (status) {
188 switch (status) {
189 case -ENOENT:
190 dev_dbg(&desc->intf->dev,
191 "nonzero urb status received: -ENOENT");
192 goto skip_error;
193 case -ECONNRESET:
194 dev_dbg(&desc->intf->dev,
195 "nonzero urb status received: -ECONNRESET");
196 goto skip_error;
197 case -ESHUTDOWN:
198 dev_dbg(&desc->intf->dev,
199 "nonzero urb status received: -ESHUTDOWN");
200 goto skip_error;
201 case -EPIPE:
202 dev_err(&desc->intf->dev,
203 "nonzero urb status received: -EPIPE\n");
204 break;
205 default:
206 dev_err(&desc->intf->dev,
207 "Unexpected error %d\n", status);
208 break;
209 }
210 }
211
212 desc->rerr = status;
213 desc->reslength = urb->actual_length;
214 memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
215 desc->length += desc->reslength;
216skip_error:
217 wake_up(&desc->wait);
218
219 set_bit(WDM_READ, &desc->flags);
220 spin_unlock(&desc->iuspin);
221}
222
223static void wdm_int_callback(struct urb *urb)
224{
225 int rv = 0;
226 int status = urb->status;
227 struct wdm_device *desc;
228 struct usb_cdc_notification *dr;
229
230 desc = urb->context;
231 dr = (struct usb_cdc_notification *)desc->sbuf;
232
233 if (status) {
234 switch (status) {
235 case -ESHUTDOWN:
236 case -ENOENT:
237 case -ECONNRESET:
238 return; /* unplug */
239 case -EPIPE:
240 set_bit(WDM_INT_STALL, &desc->flags);
241 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
242 goto sw; /* halt is cleared in work */
243 default:
244 dev_err(&desc->intf->dev,
245 "nonzero urb status received: %d\n", status);
246 break;
247 }
248 }
249
250 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
251 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
252 urb->actual_length);
253 goto exit;
254 }
255
256 switch (dr->bNotificationType) {
257 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
258 dev_dbg(&desc->intf->dev,
259 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
260 dr->wIndex, dr->wLength);
261 break;
262
263 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
264
265 dev_dbg(&desc->intf->dev,
266 "NOTIFY_NETWORK_CONNECTION %s network",
267 dr->wValue ? "connected to" : "disconnected from");
268 goto exit;
269 default:
270 clear_bit(WDM_POLL_RUNNING, &desc->flags);
271 dev_err(&desc->intf->dev,
272 "unknown notification %d received: index %d len %d\n",
273 dr->bNotificationType, dr->wIndex, dr->wLength);
274 goto exit;
275 }
276
277 spin_lock(&desc->iuspin);
278 clear_bit(WDM_READ, &desc->flags);
279 set_bit(WDM_RESPONDING, &desc->flags);
280 if (!test_bit(WDM_DISCONNECTING, &desc->flags)
281 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
282 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
283 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
284 __func__, rv);
285 }
286 spin_unlock(&desc->iuspin);
287 if (rv < 0) {
288 clear_bit(WDM_RESPONDING, &desc->flags);
289 if (rv == -EPERM)
290 return;
291 if (rv == -ENOMEM) {
292sw:
293 rv = schedule_work(&desc->rxwork);
294 if (rv)
295 dev_err(&desc->intf->dev,
296 "Cannot schedule work\n");
297 }
298 }
299exit:
300 rv = usb_submit_urb(urb, GFP_ATOMIC);
301 if (rv)
302 dev_err(&desc->intf->dev,
303 "%s - usb_submit_urb failed with result %d\n",
304 __func__, rv);
305
306}
307
308static void kill_urbs(struct wdm_device *desc)
309{
310 /* the order here is essential */
311 usb_kill_urb(desc->command);
312 usb_kill_urb(desc->validity);
313 usb_kill_urb(desc->response);
314}
315
316static void free_urbs(struct wdm_device *desc)
317{
318 usb_free_urb(desc->validity);
319 usb_free_urb(desc->response);
320 usb_free_urb(desc->command);
321}
322
323static void cleanup(struct wdm_device *desc)
324{
325 kfree(desc->sbuf);
326 kfree(desc->inbuf);
327 kfree(desc->orq);
328 kfree(desc->irq);
329 kfree(desc->ubuf);
330 free_urbs(desc);
331 kfree(desc);
332}
333
334static ssize_t wdm_write
335(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
336{
337 u8 *buf;
338 int rv = -EMSGSIZE, r, we;
339 struct wdm_device *desc = file->private_data;
340 struct usb_ctrlrequest *req;
341
342 if (count > desc->wMaxCommand)
343 count = desc->wMaxCommand;
344
345 spin_lock_irq(&desc->iuspin);
346 we = desc->werr;
347 desc->werr = 0;
348 spin_unlock_irq(&desc->iuspin);
349 if (we < 0)
350 return -EIO;
351
352 buf = kmalloc(count, GFP_KERNEL);
353 if (!buf) {
354 rv = -ENOMEM;
355 goto outnl;
356 }
357
358 r = copy_from_user(buf, buffer, count);
359 if (r > 0) {
360 kfree(buf);
361 rv = -EFAULT;
362 goto outnl;
363 }
364
365 /* concurrent writes and disconnect */
366 r = mutex_lock_interruptible(&desc->wlock);
367 rv = -ERESTARTSYS;
368 if (r) {
369 kfree(buf);
370 goto outnl;
371 }
372
373 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
374 kfree(buf);
375 rv = -ENODEV;
376 goto outnp;
377 }
378
379 r = usb_autopm_get_interface(desc->intf);
380 if (r < 0) {
381 kfree(buf);
382 rv = usb_translate_errors(r);
383 goto outnp;
384 }
385
386 if (!(file->f_flags & O_NONBLOCK))
387 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
388 &desc->flags));
389 else
390 if (test_bit(WDM_IN_USE, &desc->flags))
391 r = -EAGAIN;
392
393 if (test_bit(WDM_RESETTING, &desc->flags))
394 r = -EIO;
395
396 if (r < 0) {
397 kfree(buf);
398 rv = r;
399 goto out;
400 }
401
402 req = desc->orq;
403 usb_fill_control_urb(
404 desc->command,
405 interface_to_usbdev(desc->intf),
406 /* using common endpoint 0 */
407 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
408 (unsigned char *)req,
409 buf,
410 count,
411 wdm_out_callback,
412 desc
413 );
414
415 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
416 USB_RECIP_INTERFACE);
417 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
418 req->wValue = 0;
419 req->wIndex = desc->inum;
420 req->wLength = cpu_to_le16(count);
421 set_bit(WDM_IN_USE, &desc->flags);
422 desc->outbuf = buf;
423
424 rv = usb_submit_urb(desc->command, GFP_KERNEL);
425 if (rv < 0) {
426 kfree(buf);
427 desc->outbuf = NULL;
428 clear_bit(WDM_IN_USE, &desc->flags);
429 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
430 rv = usb_translate_errors(rv);
431 } else {
432 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
433 req->wIndex);
434 }
435out:
436 usb_autopm_put_interface(desc->intf);
437outnp:
438 mutex_unlock(&desc->wlock);
439outnl:
440 return rv < 0 ? rv : count;
441}
442
443static ssize_t wdm_read
444(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
445{
446 int rv, cntr;
447 int i = 0;
448 struct wdm_device *desc = file->private_data;
449
450
451 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
452 if (rv < 0)
453 return -ERESTARTSYS;
454
455 cntr = ACCESS_ONCE(desc->length);
456 if (cntr == 0) {
457 desc->read = 0;
458retry:
459 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
460 rv = -ENODEV;
461 goto err;
462 }
463 i++;
464 if (file->f_flags & O_NONBLOCK) {
465 if (!test_bit(WDM_READ, &desc->flags)) {
466 rv = cntr ? cntr : -EAGAIN;
467 goto err;
468 }
469 rv = 0;
470 } else {
471 rv = wait_event_interruptible(desc->wait,
472 test_bit(WDM_READ, &desc->flags));
473 }
474
475 /* may have happened while we slept */
476 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
477 rv = -ENODEV;
478 goto err;
479 }
480 if (test_bit(WDM_RESETTING, &desc->flags)) {
481 rv = -EIO;
482 goto err;
483 }
484 usb_mark_last_busy(interface_to_usbdev(desc->intf));
485 if (rv < 0) {
486 rv = -ERESTARTSYS;
487 goto err;
488 }
489
490 spin_lock_irq(&desc->iuspin);
491
492 if (desc->rerr) { /* read completed, error happened */
493 desc->rerr = 0;
494 spin_unlock_irq(&desc->iuspin);
495 rv = -EIO;
496 goto err;
497 }
498 /*
499 * recheck whether we've lost the race
500 * against the completion handler
501 */
502 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
503 spin_unlock_irq(&desc->iuspin);
504 goto retry;
505 }
506 if (!desc->reslength) { /* zero length read */
507 dev_dbg(&desc->intf->dev, "%s: zero length - clearing WDM_READ\n", __func__);
508 clear_bit(WDM_READ, &desc->flags);
509 spin_unlock_irq(&desc->iuspin);
510 goto retry;
511 }
512 cntr = desc->length;
513 spin_unlock_irq(&desc->iuspin);
514 }
515
516 if (cntr > count)
517 cntr = count;
518 rv = copy_to_user(buffer, desc->ubuf, cntr);
519 if (rv > 0) {
520 rv = -EFAULT;
521 goto err;
522 }
523
524 spin_lock_irq(&desc->iuspin);
525
526 for (i = 0; i < desc->length - cntr; i++)
527 desc->ubuf[i] = desc->ubuf[i + cntr];
528
529 desc->length -= cntr;
530 /* in case we had outstanding data */
531 if (!desc->length)
532 clear_bit(WDM_READ, &desc->flags);
533
534 spin_unlock_irq(&desc->iuspin);
535
536 rv = cntr;
537
538err:
539 mutex_unlock(&desc->rlock);
540 return rv;
541}
542
543static int wdm_flush(struct file *file, fl_owner_t id)
544{
545 struct wdm_device *desc = file->private_data;
546
547 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
548
549 /* cannot dereference desc->intf if WDM_DISCONNECTING */
550 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags))
551 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
552 desc->werr);
553
554 return usb_translate_errors(desc->werr);
555}
556
557static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
558{
559 struct wdm_device *desc = file->private_data;
560 unsigned long flags;
561 unsigned int mask = 0;
562
563 spin_lock_irqsave(&desc->iuspin, flags);
564 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
565 mask = POLLHUP | POLLERR;
566 spin_unlock_irqrestore(&desc->iuspin, flags);
567 goto desc_out;
568 }
569 if (test_bit(WDM_READ, &desc->flags))
570 mask = POLLIN | POLLRDNORM;
571 if (desc->rerr || desc->werr)
572 mask |= POLLERR;
573 if (!test_bit(WDM_IN_USE, &desc->flags))
574 mask |= POLLOUT | POLLWRNORM;
575 spin_unlock_irqrestore(&desc->iuspin, flags);
576
577 poll_wait(file, &desc->wait, wait);
578
579desc_out:
580 return mask;
581}
582
583static int wdm_open(struct inode *inode, struct file *file)
584{
585 int minor = iminor(inode);
586 int rv = -ENODEV;
587 struct usb_interface *intf;
588 struct wdm_device *desc;
589
590 mutex_lock(&wdm_mutex);
591 desc = wdm_find_device_by_minor(minor);
592 if (!desc)
593 goto out;
594
595 intf = desc->intf;
596 if (test_bit(WDM_DISCONNECTING, &desc->flags))
597 goto out;
598 file->private_data = desc;
599
600 rv = usb_autopm_get_interface(desc->intf);
601 if (rv < 0) {
602 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
603 goto out;
604 }
605
606 /* using write lock to protect desc->count */
607 mutex_lock(&desc->wlock);
608 if (!desc->count++) {
609 desc->werr = 0;
610 desc->rerr = 0;
611 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
612 if (rv < 0) {
613 desc->count--;
614 dev_err(&desc->intf->dev,
615 "Error submitting int urb - %d\n", rv);
616 rv = usb_translate_errors(rv);
617 }
618 } else {
619 rv = 0;
620 }
621 mutex_unlock(&desc->wlock);
622 if (desc->count == 1)
623 desc->manage_power(intf, 1);
624 usb_autopm_put_interface(desc->intf);
625out:
626 mutex_unlock(&wdm_mutex);
627 return rv;
628}
629
630static int wdm_release(struct inode *inode, struct file *file)
631{
632 struct wdm_device *desc = file->private_data;
633
634 mutex_lock(&wdm_mutex);
635
636 /* using write lock to protect desc->count */
637 mutex_lock(&desc->wlock);
638 desc->count--;
639 mutex_unlock(&desc->wlock);
640
641 if (!desc->count) {
642 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
643 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
644 kill_urbs(desc);
645 desc->manage_power(desc->intf, 0);
646 } else {
647 /* must avoid dev_printk here as desc->intf is invalid */
648 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
649 cleanup(desc);
650 }
651 }
652 mutex_unlock(&wdm_mutex);
653 return 0;
654}
655
656static const struct file_operations wdm_fops = {
657 .owner = THIS_MODULE,
658 .read = wdm_read,
659 .write = wdm_write,
660 .open = wdm_open,
661 .flush = wdm_flush,
662 .release = wdm_release,
663 .poll = wdm_poll,
664 .llseek = noop_llseek,
665};
666
667static struct usb_class_driver wdm_class = {
668 .name = "cdc-wdm%d",
669 .fops = &wdm_fops,
670 .minor_base = WDM_MINOR_BASE,
671};
672
673/* --- error handling --- */
674static void wdm_rxwork(struct work_struct *work)
675{
676 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
677 unsigned long flags;
678 int rv;
679
680 spin_lock_irqsave(&desc->iuspin, flags);
681 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
682 spin_unlock_irqrestore(&desc->iuspin, flags);
683 } else {
684 spin_unlock_irqrestore(&desc->iuspin, flags);
685 rv = usb_submit_urb(desc->response, GFP_KERNEL);
686 if (rv < 0 && rv != -EPERM) {
687 spin_lock_irqsave(&desc->iuspin, flags);
688 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
689 schedule_work(&desc->rxwork);
690 spin_unlock_irqrestore(&desc->iuspin, flags);
691 }
692 }
693}
694
695/* --- hotplug --- */
696
697static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
698 u16 bufsize, int (*manage_power)(struct usb_interface *, int))
699{
700 int rv = -ENOMEM;
701 struct wdm_device *desc;
702
703 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
704 if (!desc)
705 goto out;
706 INIT_LIST_HEAD(&desc->device_list);
707 mutex_init(&desc->rlock);
708 mutex_init(&desc->wlock);
709 spin_lock_init(&desc->iuspin);
710 init_waitqueue_head(&desc->wait);
711 desc->wMaxCommand = bufsize;
712 /* this will be expanded and needed in hardware endianness */
713 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
714 desc->intf = intf;
715 INIT_WORK(&desc->rxwork, wdm_rxwork);
716
717 rv = -EINVAL;
718 if (!usb_endpoint_is_int_in(ep))
719 goto err;
720
721 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
722
723 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
724 if (!desc->orq)
725 goto err;
726 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
727 if (!desc->irq)
728 goto err;
729
730 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
731 if (!desc->validity)
732 goto err;
733
734 desc->response = usb_alloc_urb(0, GFP_KERNEL);
735 if (!desc->response)
736 goto err;
737
738 desc->command = usb_alloc_urb(0, GFP_KERNEL);
739 if (!desc->command)
740 goto err;
741
742 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
743 if (!desc->ubuf)
744 goto err;
745
746 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
747 if (!desc->sbuf)
748 goto err;
749
750 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
751 if (!desc->inbuf)
752 goto err;
753
754 usb_fill_int_urb(
755 desc->validity,
756 interface_to_usbdev(intf),
757 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
758 desc->sbuf,
759 desc->wMaxPacketSize,
760 wdm_int_callback,
761 desc,
762 ep->bInterval
763 );
764
765 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
766 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
767 desc->irq->wValue = 0;
768 desc->irq->wIndex = desc->inum;
769 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
770
771 usb_fill_control_urb(
772 desc->response,
773 interface_to_usbdev(intf),
774 /* using common endpoint 0 */
775 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
776 (unsigned char *)desc->irq,
777 desc->inbuf,
778 desc->wMaxCommand,
779 wdm_in_callback,
780 desc
781 );
782
783 desc->manage_power = manage_power;
784
785 spin_lock(&wdm_device_list_lock);
786 list_add(&desc->device_list, &wdm_device_list);
787 spin_unlock(&wdm_device_list_lock);
788
789 rv = usb_register_dev(intf, &wdm_class);
790 if (rv < 0)
791 goto err;
792 else
793 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
794out:
795 return rv;
796err:
797 spin_lock(&wdm_device_list_lock);
798 list_del(&desc->device_list);
799 spin_unlock(&wdm_device_list_lock);
800 cleanup(desc);
801 return rv;
802}
803
804static int wdm_manage_power(struct usb_interface *intf, int on)
805{
806 /* need autopm_get/put here to ensure the usbcore sees the new value */
807 int rv = usb_autopm_get_interface(intf);
808 if (rv < 0)
809 goto err;
810
811 intf->needs_remote_wakeup = on;
812 usb_autopm_put_interface(intf);
813err:
814 return rv;
815}
816
817static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
818{
819 int rv = -EINVAL;
820 struct usb_host_interface *iface;
821 struct usb_endpoint_descriptor *ep;
822 struct usb_cdc_dmm_desc *dmhd;
823 u8 *buffer = intf->altsetting->extra;
824 int buflen = intf->altsetting->extralen;
825 u16 maxcom = WDM_DEFAULT_BUFSIZE;
826
827 if (!buffer)
828 goto err;
829 while (buflen > 2) {
830 if (buffer[1] != USB_DT_CS_INTERFACE) {
831 dev_err(&intf->dev, "skipping garbage\n");
832 goto next_desc;
833 }
834
835 switch (buffer[2]) {
836 case USB_CDC_HEADER_TYPE:
837 break;
838 case USB_CDC_DMM_TYPE:
839 dmhd = (struct usb_cdc_dmm_desc *)buffer;
840 maxcom = le16_to_cpu(dmhd->wMaxCommand);
841 dev_dbg(&intf->dev,
842 "Finding maximum buffer length: %d", maxcom);
843 break;
844 default:
845 dev_err(&intf->dev,
846 "Ignoring extra header, type %d, length %d\n",
847 buffer[2], buffer[0]);
848 break;
849 }
850next_desc:
851 buflen -= buffer[0];
852 buffer += buffer[0];
853 }
854
855 iface = intf->cur_altsetting;
856 if (iface->desc.bNumEndpoints != 1)
857 goto err;
858 ep = &iface->endpoint[0].desc;
859
860 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
861
862err:
863 return rv;
864}
865
866/**
867 * usb_cdc_wdm_register - register a WDM subdriver
868 * @intf: usb interface the subdriver will associate with
869 * @ep: interrupt endpoint to monitor for notifications
870 * @bufsize: maximum message size to support for read/write
871 *
872 * Create WDM usb class character device and associate it with intf
873 * without binding, allowing another driver to manage the interface.
874 *
875 * The subdriver will manage the given interrupt endpoint exclusively
876 * and will issue control requests referring to the given intf. It
877 * will otherwise avoid interferring, and in particular not do
878 * usb_set_intfdata/usb_get_intfdata on intf.
879 *
880 * The return value is a pointer to the subdriver's struct usb_driver.
881 * The registering driver is responsible for calling this subdriver's
882 * disconnect, suspend, resume, pre_reset and post_reset methods from
883 * its own.
884 */
885struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
886 struct usb_endpoint_descriptor *ep,
887 int bufsize,
888 int (*manage_power)(struct usb_interface *, int))
889{
890 int rv = -EINVAL;
891
892 rv = wdm_create(intf, ep, bufsize, manage_power);
893 if (rv < 0)
894 goto err;
895
896 return &wdm_driver;
897err:
898 return ERR_PTR(rv);
899}
900EXPORT_SYMBOL(usb_cdc_wdm_register);
901
902static void wdm_disconnect(struct usb_interface *intf)
903{
904 struct wdm_device *desc;
905 unsigned long flags;
906
907 usb_deregister_dev(intf, &wdm_class);
908 desc = wdm_find_device(intf);
909 mutex_lock(&wdm_mutex);
910
911 /* the spinlock makes sure no new urbs are generated in the callbacks */
912 spin_lock_irqsave(&desc->iuspin, flags);
913 set_bit(WDM_DISCONNECTING, &desc->flags);
914 set_bit(WDM_READ, &desc->flags);
915 /* to terminate pending flushes */
916 clear_bit(WDM_IN_USE, &desc->flags);
917 spin_unlock_irqrestore(&desc->iuspin, flags);
918 wake_up_all(&desc->wait);
919 mutex_lock(&desc->rlock);
920 mutex_lock(&desc->wlock);
921 kill_urbs(desc);
922 cancel_work_sync(&desc->rxwork);
923 mutex_unlock(&desc->wlock);
924 mutex_unlock(&desc->rlock);
925
926 /* the desc->intf pointer used as list key is now invalid */
927 spin_lock(&wdm_device_list_lock);
928 list_del(&desc->device_list);
929 spin_unlock(&wdm_device_list_lock);
930
931 if (!desc->count)
932 cleanup(desc);
933 else
934 dev_dbg(&intf->dev, "%s: %d open files - postponing cleanup\n", __func__, desc->count);
935 mutex_unlock(&wdm_mutex);
936}
937
938#ifdef CONFIG_PM
939static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
940{
941 struct wdm_device *desc = wdm_find_device(intf);
942 int rv = 0;
943
944 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
945
946 /* if this is an autosuspend the caller does the locking */
947 if (!PMSG_IS_AUTO(message)) {
948 mutex_lock(&desc->rlock);
949 mutex_lock(&desc->wlock);
950 }
951 spin_lock_irq(&desc->iuspin);
952
953 if (PMSG_IS_AUTO(message) &&
954 (test_bit(WDM_IN_USE, &desc->flags)
955 || test_bit(WDM_RESPONDING, &desc->flags))) {
956 spin_unlock_irq(&desc->iuspin);
957 rv = -EBUSY;
958 } else {
959
960 set_bit(WDM_SUSPENDING, &desc->flags);
961 spin_unlock_irq(&desc->iuspin);
962 /* callback submits work - order is essential */
963 kill_urbs(desc);
964 cancel_work_sync(&desc->rxwork);
965 }
966 if (!PMSG_IS_AUTO(message)) {
967 mutex_unlock(&desc->wlock);
968 mutex_unlock(&desc->rlock);
969 }
970
971 return rv;
972}
973#endif
974
975static int recover_from_urb_loss(struct wdm_device *desc)
976{
977 int rv = 0;
978
979 if (desc->count) {
980 rv = usb_submit_urb(desc->validity, GFP_NOIO);
981 if (rv < 0)
982 dev_err(&desc->intf->dev,
983 "Error resume submitting int urb - %d\n", rv);
984 }
985 return rv;
986}
987
988#ifdef CONFIG_PM
989static int wdm_resume(struct usb_interface *intf)
990{
991 struct wdm_device *desc = wdm_find_device(intf);
992 int rv;
993
994 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
995
996 clear_bit(WDM_SUSPENDING, &desc->flags);
997 rv = recover_from_urb_loss(desc);
998
999 return rv;
1000}
1001#endif
1002
1003static int wdm_pre_reset(struct usb_interface *intf)
1004{
1005 struct wdm_device *desc = wdm_find_device(intf);
1006
1007 /*
1008 * we notify everybody using poll of
1009 * an exceptional situation
1010 * must be done before recovery lest a spontaneous
1011 * message from the device is lost
1012 */
1013 spin_lock_irq(&desc->iuspin);
1014 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */
1015 set_bit(WDM_READ, &desc->flags); /* unblock read */
1016 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */
1017 desc->rerr = -EINTR;
1018 spin_unlock_irq(&desc->iuspin);
1019 wake_up_all(&desc->wait);
1020 mutex_lock(&desc->rlock);
1021 mutex_lock(&desc->wlock);
1022 kill_urbs(desc);
1023 cancel_work_sync(&desc->rxwork);
1024 return 0;
1025}
1026
1027static int wdm_post_reset(struct usb_interface *intf)
1028{
1029 struct wdm_device *desc = wdm_find_device(intf);
1030 int rv;
1031
1032 clear_bit(WDM_RESETTING, &desc->flags);
1033 rv = recover_from_urb_loss(desc);
1034 mutex_unlock(&desc->wlock);
1035 mutex_unlock(&desc->rlock);
1036 return 0;
1037}
1038
1039static struct usb_driver wdm_driver = {
1040 .name = "cdc_wdm",
1041 .probe = wdm_probe,
1042 .disconnect = wdm_disconnect,
1043#ifdef CONFIG_PM
1044 .suspend = wdm_suspend,
1045 .resume = wdm_resume,
1046 .reset_resume = wdm_resume,
1047#endif
1048 .pre_reset = wdm_pre_reset,
1049 .post_reset = wdm_post_reset,
1050 .id_table = wdm_ids,
1051 .supports_autosuspend = 1,
1052 .disable_hub_initiated_lpm = 1,
1053};
1054
1055module_usb_driver(wdm_driver);
1056
1057MODULE_AUTHOR(DRIVER_AUTHOR);
1058MODULE_DESCRIPTION(DRIVER_DESC);
1059MODULE_LICENSE("GPL");