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s390/ftrace: enforce DYNAMIC_FTRACE if FUNCTION_TRACER is selected
[linux-2.6/btrfs-unstable.git] / drivers / usb / class / cdc-wdm.c
bloba051a7a2b1bd534a93fd459da7c553e0a5af4dfa
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/ioctl.h>
17 #include <linux/slab.h>
18 #include <linux/module.h>
19 #include <linux/mutex.h>
20 #include <linux/uaccess.h>
21 #include <linux/bitops.h>
22 #include <linux/poll.h>
23 #include <linux/usb.h>
24 #include <linux/usb/cdc.h>
25 #include <asm/byteorder.h>
26 #include <asm/unaligned.h>
27 #include <linux/usb/cdc-wdm.h>
28
29 /*
30 * Version Information
31 */
32 #define DRIVER_VERSION "v0.03"
33 #define DRIVER_AUTHOR "Oliver Neukum"
34 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
35
36 static const struct usb_device_id wdm_ids[] = {
37 {
38 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
39 USB_DEVICE_ID_MATCH_INT_SUBCLASS,
40 .bInterfaceClass = USB_CLASS_COMM,
41 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
42 },
43 { }
44 };
45
46 MODULE_DEVICE_TABLE (usb, wdm_ids);
47
48 #define WDM_MINOR_BASE 176
49
50
51 #define WDM_IN_USE 1
52 #define WDM_DISCONNECTING 2
53 #define WDM_RESULT 3
54 #define WDM_READ 4
55 #define WDM_INT_STALL 5
56 #define WDM_POLL_RUNNING 6
57 #define WDM_RESPONDING 7
58 #define WDM_SUSPENDING 8
59 #define WDM_RESETTING 9
60 #define WDM_OVERFLOW 10
61
62 #define WDM_MAX 16
63
64 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
65 #define WDM_DEFAULT_BUFSIZE 256
66
67 static DEFINE_MUTEX(wdm_mutex);
68 static DEFINE_SPINLOCK(wdm_device_list_lock);
69 static LIST_HEAD(wdm_device_list);
70
71 /* --- method tables --- */
72
73 struct wdm_device {
74 u8 *inbuf; /* buffer for response */
75 u8 *outbuf; /* buffer for command */
76 u8 *sbuf; /* buffer for status */
77 u8 *ubuf; /* buffer for copy to user space */
78
79 struct urb *command;
80 struct urb *response;
81 struct urb *validity;
82 struct usb_interface *intf;
83 struct usb_ctrlrequest *orq;
84 struct usb_ctrlrequest *irq;
85 spinlock_t iuspin;
86
87 unsigned long flags;
88 u16 bufsize;
89 u16 wMaxCommand;
90 u16 wMaxPacketSize;
91 __le16 inum;
92 int reslength;
93 int length;
94 int read;
95 int count;
96 dma_addr_t shandle;
97 dma_addr_t ihandle;
98 struct mutex wlock;
99 struct mutex rlock;
100 wait_queue_head_t wait;
101 struct work_struct rxwork;
102 int werr;
103 int rerr;
104 int resp_count;
105
106 struct list_head device_list;
107 int (*manage_power)(struct usb_interface *, int);
108 };
109
110 static struct usb_driver wdm_driver;
111
112 /* return intfdata if we own the interface, else look up intf in the list */
113 static struct wdm_device *wdm_find_device(struct usb_interface *intf)
114 {
115 struct wdm_device *desc;
116
117 spin_lock(&wdm_device_list_lock);
118 list_for_each_entry(desc, &wdm_device_list, device_list)
119 if (desc->intf == intf)
120 goto found;
121 desc = NULL;
122 found:
123 spin_unlock(&wdm_device_list_lock);
124
125 return desc;
126 }
127
128 static struct wdm_device *wdm_find_device_by_minor(int minor)
129 {
130 struct wdm_device *desc;
131
132 spin_lock(&wdm_device_list_lock);
133 list_for_each_entry(desc, &wdm_device_list, device_list)
134 if (desc->intf->minor == minor)
135 goto found;
136 desc = NULL;
137 found:
138 spin_unlock(&wdm_device_list_lock);
139
140 return desc;
141 }
142
143 /* --- callbacks --- */
144 static void wdm_out_callback(struct urb *urb)
145 {
146 struct wdm_device *desc;
147 desc = urb->context;
148 spin_lock(&desc->iuspin);
149 desc->werr = urb->status;
150 spin_unlock(&desc->iuspin);
151 kfree(desc->outbuf);
152 desc->outbuf = NULL;
153 clear_bit(WDM_IN_USE, &desc->flags);
154 wake_up(&desc->wait);
155 }
156
157 static void wdm_in_callback(struct urb *urb)
158 {
159 struct wdm_device *desc = urb->context;
160 int status = urb->status;
161 int length = urb->actual_length;
162
163 spin_lock(&desc->iuspin);
164 clear_bit(WDM_RESPONDING, &desc->flags);
165
166 if (status) {
167 switch (status) {
168 case -ENOENT:
169 dev_dbg(&desc->intf->dev,
170 "nonzero urb status received: -ENOENT");
171 goto skip_error;
172 case -ECONNRESET:
173 dev_dbg(&desc->intf->dev,
174 "nonzero urb status received: -ECONNRESET");
175 goto skip_error;
176 case -ESHUTDOWN:
177 dev_dbg(&desc->intf->dev,
178 "nonzero urb status received: -ESHUTDOWN");
179 goto skip_error;
180 case -EPIPE:
181 dev_err(&desc->intf->dev,
182 "nonzero urb status received: -EPIPE\n");
183 break;
184 default:
185 dev_err(&desc->intf->dev,
186 "Unexpected error %d\n", status);
187 break;
188 }
189 }
190
191 desc->rerr = status;
192 if (length + desc->length > desc->wMaxCommand) {
193 /* The buffer would overflow */
194 set_bit(WDM_OVERFLOW, &desc->flags);
195 } else {
196 /* we may already be in overflow */
197 if (!test_bit(WDM_OVERFLOW, &desc->flags)) {
198 memmove(desc->ubuf + desc->length, desc->inbuf, length);
199 desc->length += length;
200 desc->reslength = length;
201 }
202 }
203 skip_error:
204 wake_up(&desc->wait);
205
206 set_bit(WDM_READ, &desc->flags);
207 spin_unlock(&desc->iuspin);
208 }
209
210 static void wdm_int_callback(struct urb *urb)
211 {
212 int rv = 0;
213 int responding;
214 int status = urb->status;
215 struct wdm_device *desc;
216 struct usb_cdc_notification *dr;
217
218 desc = urb->context;
219 dr = (struct usb_cdc_notification *)desc->sbuf;
220
221 if (status) {
222 switch (status) {
223 case -ESHUTDOWN:
224 case -ENOENT:
225 case -ECONNRESET:
226 return; /* unplug */
227 case -EPIPE:
228 set_bit(WDM_INT_STALL, &desc->flags);
229 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
230 goto sw; /* halt is cleared in work */
231 default:
232 dev_err(&desc->intf->dev,
233 "nonzero urb status received: %d\n", status);
234 break;
235 }
236 }
237
238 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
239 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
240 urb->actual_length);
241 goto exit;
242 }
243
244 switch (dr->bNotificationType) {
245 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
246 dev_dbg(&desc->intf->dev,
247 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
248 dr->wIndex, dr->wLength);
249 break;
250
251 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
252
253 dev_dbg(&desc->intf->dev,
254 "NOTIFY_NETWORK_CONNECTION %s network",
255 dr->wValue ? "connected to" : "disconnected from");
256 goto exit;
257 case USB_CDC_NOTIFY_SPEED_CHANGE:
258 dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)",
259 urb->actual_length);
260 goto exit;
261 default:
262 clear_bit(WDM_POLL_RUNNING, &desc->flags);
263 dev_err(&desc->intf->dev,
264 "unknown notification %d received: index %d len %d\n",
265 dr->bNotificationType, dr->wIndex, dr->wLength);
266 goto exit;
267 }
268
269 spin_lock(&desc->iuspin);
270 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
271 if (!desc->resp_count++ && !responding
272 && !test_bit(WDM_DISCONNECTING, &desc->flags)
273 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
274 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
275 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
276 __func__, rv);
277 }
278 spin_unlock(&desc->iuspin);
279 if (rv < 0) {
280 clear_bit(WDM_RESPONDING, &desc->flags);
281 if (rv == -EPERM)
282 return;
283 if (rv == -ENOMEM) {
284 sw:
285 rv = schedule_work(&desc->rxwork);
286 if (rv)
287 dev_err(&desc->intf->dev,
288 "Cannot schedule work\n");
289 }
290 }
291 exit:
292 rv = usb_submit_urb(urb, GFP_ATOMIC);
293 if (rv)
294 dev_err(&desc->intf->dev,
295 "%s - usb_submit_urb failed with result %d\n",
296 __func__, rv);
297
298 }
299
300 static void kill_urbs(struct wdm_device *desc)
301 {
302 /* the order here is essential */
303 usb_kill_urb(desc->command);
304 usb_kill_urb(desc->validity);
305 usb_kill_urb(desc->response);
306 }
307
308 static void free_urbs(struct wdm_device *desc)
309 {
310 usb_free_urb(desc->validity);
311 usb_free_urb(desc->response);
312 usb_free_urb(desc->command);
313 }
314
315 static void cleanup(struct wdm_device *desc)
316 {
317 kfree(desc->sbuf);
318 kfree(desc->inbuf);
319 kfree(desc->orq);
320 kfree(desc->irq);
321 kfree(desc->ubuf);
322 free_urbs(desc);
323 kfree(desc);
324 }
325
326 static ssize_t wdm_write
327 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
328 {
329 u8 *buf;
330 int rv = -EMSGSIZE, r, we;
331 struct wdm_device *desc = file->private_data;
332 struct usb_ctrlrequest *req;
333
334 if (count > desc->wMaxCommand)
335 count = desc->wMaxCommand;
336
337 spin_lock_irq(&desc->iuspin);
338 we = desc->werr;
339 desc->werr = 0;
340 spin_unlock_irq(&desc->iuspin);
341 if (we < 0)
342 return -EIO;
343
344 buf = kmalloc(count, GFP_KERNEL);
345 if (!buf) {
346 rv = -ENOMEM;
347 goto outnl;
348 }
349
350 r = copy_from_user(buf, buffer, count);
351 if (r > 0) {
352 kfree(buf);
353 rv = -EFAULT;
354 goto outnl;
355 }
356
357 /* concurrent writes and disconnect */
358 r = mutex_lock_interruptible(&desc->wlock);
359 rv = -ERESTARTSYS;
360 if (r) {
361 kfree(buf);
362 goto outnl;
363 }
364
365 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
366 kfree(buf);
367 rv = -ENODEV;
368 goto outnp;
369 }
370
371 r = usb_autopm_get_interface(desc->intf);
372 if (r < 0) {
373 kfree(buf);
374 rv = usb_translate_errors(r);
375 goto outnp;
376 }
377
378 if (!(file->f_flags & O_NONBLOCK))
379 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
380 &desc->flags));
381 else
382 if (test_bit(WDM_IN_USE, &desc->flags))
383 r = -EAGAIN;
384
385 if (test_bit(WDM_RESETTING, &desc->flags))
386 r = -EIO;
387
388 if (r < 0) {
389 kfree(buf);
390 rv = r;
391 goto out;
392 }
393
394 req = desc->orq;
395 usb_fill_control_urb(
396 desc->command,
397 interface_to_usbdev(desc->intf),
398 /* using common endpoint 0 */
399 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
400 (unsigned char *)req,
401 buf,
402 count,
403 wdm_out_callback,
404 desc
405 );
406
407 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
408 USB_RECIP_INTERFACE);
409 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
410 req->wValue = 0;
411 req->wIndex = desc->inum;
412 req->wLength = cpu_to_le16(count);
413 set_bit(WDM_IN_USE, &desc->flags);
414 desc->outbuf = buf;
415
416 rv = usb_submit_urb(desc->command, GFP_KERNEL);
417 if (rv < 0) {
418 kfree(buf);
419 desc->outbuf = NULL;
420 clear_bit(WDM_IN_USE, &desc->flags);
421 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
422 rv = usb_translate_errors(rv);
423 } else {
424 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
425 req->wIndex);
426 }
427 out:
428 usb_autopm_put_interface(desc->intf);
429 outnp:
430 mutex_unlock(&desc->wlock);
431 outnl:
432 return rv < 0 ? rv : count;
433 }
434
435 /*
436 * clear WDM_READ flag and possibly submit the read urb if resp_count
437 * is non-zero.
438 *
439 * Called with desc->iuspin locked
440 */
441 static int clear_wdm_read_flag(struct wdm_device *desc)
442 {
443 int rv = 0;
444
445 clear_bit(WDM_READ, &desc->flags);
446
447 /* submit read urb only if the device is waiting for it */
448 if (!desc->resp_count || !--desc->resp_count)
449 goto out;
450
451 set_bit(WDM_RESPONDING, &desc->flags);
452 spin_unlock_irq(&desc->iuspin);
453 rv = usb_submit_urb(desc->response, GFP_KERNEL);
454 spin_lock_irq(&desc->iuspin);
455 if (rv) {
456 dev_err(&desc->intf->dev,
457 "usb_submit_urb failed with result %d\n", rv);
458
459 /* make sure the next notification trigger a submit */
460 clear_bit(WDM_RESPONDING, &desc->flags);
461 desc->resp_count = 0;
462 }
463 out:
464 return rv;
465 }
466
467 static ssize_t wdm_read
468 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
469 {
470 int rv, cntr;
471 int i = 0;
472 struct wdm_device *desc = file->private_data;
473
474
475 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
476 if (rv < 0)
477 return -ERESTARTSYS;
478
479 cntr = ACCESS_ONCE(desc->length);
480 if (cntr == 0) {
481 desc->read = 0;
482 retry:
483 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
484 rv = -ENODEV;
485 goto err;
486 }
487 if (test_bit(WDM_OVERFLOW, &desc->flags)) {
488 clear_bit(WDM_OVERFLOW, &desc->flags);
489 rv = -ENOBUFS;
490 goto err;
491 }
492 i++;
493 if (file->f_flags & O_NONBLOCK) {
494 if (!test_bit(WDM_READ, &desc->flags)) {
495 rv = cntr ? cntr : -EAGAIN;
496 goto err;
497 }
498 rv = 0;
499 } else {
500 rv = wait_event_interruptible(desc->wait,
501 test_bit(WDM_READ, &desc->flags));
502 }
503
504 /* may have happened while we slept */
505 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
506 rv = -ENODEV;
507 goto err;
508 }
509 if (test_bit(WDM_RESETTING, &desc->flags)) {
510 rv = -EIO;
511 goto err;
512 }
513 usb_mark_last_busy(interface_to_usbdev(desc->intf));
514 if (rv < 0) {
515 rv = -ERESTARTSYS;
516 goto err;
517 }
518
519 spin_lock_irq(&desc->iuspin);
520
521 if (desc->rerr) { /* read completed, error happened */
522 desc->rerr = 0;
523 spin_unlock_irq(&desc->iuspin);
524 rv = -EIO;
525 goto err;
526 }
527 /*
528 * recheck whether we've lost the race
529 * against the completion handler
530 */
531 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
532 spin_unlock_irq(&desc->iuspin);
533 goto retry;
534 }
535
536 if (!desc->reslength) { /* zero length read */
537 dev_dbg(&desc->intf->dev, "%s: zero length - clearing WDM_READ\n", __func__);
538 rv = clear_wdm_read_flag(desc);
539 spin_unlock_irq(&desc->iuspin);
540 if (rv < 0)
541 goto err;
542 goto retry;
543 }
544 cntr = desc->length;
545 spin_unlock_irq(&desc->iuspin);
546 }
547
548 if (cntr > count)
549 cntr = count;
550 rv = copy_to_user(buffer, desc->ubuf, cntr);
551 if (rv > 0) {
552 rv = -EFAULT;
553 goto err;
554 }
555
556 spin_lock_irq(&desc->iuspin);
557
558 for (i = 0; i < desc->length - cntr; i++)
559 desc->ubuf[i] = desc->ubuf[i + cntr];
560
561 desc->length -= cntr;
562 /* in case we had outstanding data */
563 if (!desc->length)
564 clear_wdm_read_flag(desc);
565 spin_unlock_irq(&desc->iuspin);
566 rv = cntr;
567
568 err:
569 mutex_unlock(&desc->rlock);
570 return rv;
571 }
572
573 static int wdm_flush(struct file *file, fl_owner_t id)
574 {
575 struct wdm_device *desc = file->private_data;
576
577 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
578
579 /* cannot dereference desc->intf if WDM_DISCONNECTING */
580 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags))
581 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
582 desc->werr);
583
584 return usb_translate_errors(desc->werr);
585 }
586
587 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
588 {
589 struct wdm_device *desc = file->private_data;
590 unsigned long flags;
591 unsigned int mask = 0;
592
593 spin_lock_irqsave(&desc->iuspin, flags);
594 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
595 mask = POLLHUP | POLLERR;
596 spin_unlock_irqrestore(&desc->iuspin, flags);
597 goto desc_out;
598 }
599 if (test_bit(WDM_READ, &desc->flags))
600 mask = POLLIN | POLLRDNORM;
601 if (desc->rerr || desc->werr)
602 mask |= POLLERR;
603 if (!test_bit(WDM_IN_USE, &desc->flags))
604 mask |= POLLOUT | POLLWRNORM;
605 spin_unlock_irqrestore(&desc->iuspin, flags);
606
607 poll_wait(file, &desc->wait, wait);
608
609 desc_out:
610 return mask;
611 }
612
613 static int wdm_open(struct inode *inode, struct file *file)
614 {
615 int minor = iminor(inode);
616 int rv = -ENODEV;
617 struct usb_interface *intf;
618 struct wdm_device *desc;
619
620 mutex_lock(&wdm_mutex);
621 desc = wdm_find_device_by_minor(minor);
622 if (!desc)
623 goto out;
624
625 intf = desc->intf;
626 if (test_bit(WDM_DISCONNECTING, &desc->flags))
627 goto out;
628 file->private_data = desc;
629
630 rv = usb_autopm_get_interface(desc->intf);
631 if (rv < 0) {
632 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
633 goto out;
634 }
635
636 /* using write lock to protect desc->count */
637 mutex_lock(&desc->wlock);
638 if (!desc->count++) {
639 desc->werr = 0;
640 desc->rerr = 0;
641 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
642 if (rv < 0) {
643 desc->count--;
644 dev_err(&desc->intf->dev,
645 "Error submitting int urb - %d\n", rv);
646 rv = usb_translate_errors(rv);
647 }
648 } else {
649 rv = 0;
650 }
651 mutex_unlock(&desc->wlock);
652 if (desc->count == 1)
653 desc->manage_power(intf, 1);
654 usb_autopm_put_interface(desc->intf);
655 out:
656 mutex_unlock(&wdm_mutex);
657 return rv;
658 }
659
660 static int wdm_release(struct inode *inode, struct file *file)
661 {
662 struct wdm_device *desc = file->private_data;
663
664 mutex_lock(&wdm_mutex);
665
666 /* using write lock to protect desc->count */
667 mutex_lock(&desc->wlock);
668 desc->count--;
669 mutex_unlock(&desc->wlock);
670
671 if (!desc->count) {
672 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
673 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
674 kill_urbs(desc);
675 spin_lock_irq(&desc->iuspin);
676 desc->resp_count = 0;
677 spin_unlock_irq(&desc->iuspin);
678 desc->manage_power(desc->intf, 0);
679 } else {
680 /* must avoid dev_printk here as desc->intf is invalid */
681 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
682 cleanup(desc);
683 }
684 }
685 mutex_unlock(&wdm_mutex);
686 return 0;
687 }
688
689 static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
690 {
691 struct wdm_device *desc = file->private_data;
692 int rv = 0;
693
694 switch (cmd) {
695 case IOCTL_WDM_MAX_COMMAND:
696 if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand)))
697 rv = -EFAULT;
698 break;
699 default:
700 rv = -ENOTTY;
701 }
702 return rv;
703 }
704
705 static const struct file_operations wdm_fops = {
706 .owner = THIS_MODULE,
707 .read = wdm_read,
708 .write = wdm_write,
709 .open = wdm_open,
710 .flush = wdm_flush,
711 .release = wdm_release,
712 .poll = wdm_poll,
713 .unlocked_ioctl = wdm_ioctl,
714 .compat_ioctl = wdm_ioctl,
715 .llseek = noop_llseek,
716 };
717
718 static struct usb_class_driver wdm_class = {
719 .name = "cdc-wdm%d",
720 .fops = &wdm_fops,
721 .minor_base = WDM_MINOR_BASE,
722 };
723
724 /* --- error handling --- */
725 static void wdm_rxwork(struct work_struct *work)
726 {
727 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
728 unsigned long flags;
729 int rv = 0;
730 int responding;
731
732 spin_lock_irqsave(&desc->iuspin, flags);
733 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
734 spin_unlock_irqrestore(&desc->iuspin, flags);
735 } else {
736 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
737 spin_unlock_irqrestore(&desc->iuspin, flags);
738 if (!responding)
739 rv = usb_submit_urb(desc->response, GFP_KERNEL);
740 if (rv < 0 && rv != -EPERM) {
741 spin_lock_irqsave(&desc->iuspin, flags);
742 clear_bit(WDM_RESPONDING, &desc->flags);
743 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
744 schedule_work(&desc->rxwork);
745 spin_unlock_irqrestore(&desc->iuspin, flags);
746 }
747 }
748 }
749
750 /* --- hotplug --- */
751
752 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
753 u16 bufsize, int (*manage_power)(struct usb_interface *, int))
754 {
755 int rv = -ENOMEM;
756 struct wdm_device *desc;
757
758 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
759 if (!desc)
760 goto out;
761 INIT_LIST_HEAD(&desc->device_list);
762 mutex_init(&desc->rlock);
763 mutex_init(&desc->wlock);
764 spin_lock_init(&desc->iuspin);
765 init_waitqueue_head(&desc->wait);
766 desc->wMaxCommand = bufsize;
767 /* this will be expanded and needed in hardware endianness */
768 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
769 desc->intf = intf;
770 INIT_WORK(&desc->rxwork, wdm_rxwork);
771
772 rv = -EINVAL;
773 if (!usb_endpoint_is_int_in(ep))
774 goto err;
775
776 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
777
778 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
779 if (!desc->orq)
780 goto err;
781 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
782 if (!desc->irq)
783 goto err;
784
785 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
786 if (!desc->validity)
787 goto err;
788
789 desc->response = usb_alloc_urb(0, GFP_KERNEL);
790 if (!desc->response)
791 goto err;
792
793 desc->command = usb_alloc_urb(0, GFP_KERNEL);
794 if (!desc->command)
795 goto err;
796
797 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
798 if (!desc->ubuf)
799 goto err;
800
801 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
802 if (!desc->sbuf)
803 goto err;
804
805 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
806 if (!desc->inbuf)
807 goto err;
808
809 usb_fill_int_urb(
810 desc->validity,
811 interface_to_usbdev(intf),
812 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
813 desc->sbuf,
814 desc->wMaxPacketSize,
815 wdm_int_callback,
816 desc,
817 ep->bInterval
818 );
819
820 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
821 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
822 desc->irq->wValue = 0;
823 desc->irq->wIndex = desc->inum;
824 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
825
826 usb_fill_control_urb(
827 desc->response,
828 interface_to_usbdev(intf),
829 /* using common endpoint 0 */
830 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
831 (unsigned char *)desc->irq,
832 desc->inbuf,
833 desc->wMaxCommand,
834 wdm_in_callback,
835 desc
836 );
837
838 desc->manage_power = manage_power;
839
840 spin_lock(&wdm_device_list_lock);
841 list_add(&desc->device_list, &wdm_device_list);
842 spin_unlock(&wdm_device_list_lock);
843
844 rv = usb_register_dev(intf, &wdm_class);
845 if (rv < 0)
846 goto err;
847 else
848 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
849 out:
850 return rv;
851 err:
852 spin_lock(&wdm_device_list_lock);
853 list_del(&desc->device_list);
854 spin_unlock(&wdm_device_list_lock);
855 cleanup(desc);
856 return rv;
857 }
858
859 static int wdm_manage_power(struct usb_interface *intf, int on)
860 {
861 /* need autopm_get/put here to ensure the usbcore sees the new value */
862 int rv = usb_autopm_get_interface(intf);
863
864 intf->needs_remote_wakeup = on;
865 if (!rv)
866 usb_autopm_put_interface(intf);
867 return 0;
868 }
869
870 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
871 {
872 int rv = -EINVAL;
873 struct usb_host_interface *iface;
874 struct usb_endpoint_descriptor *ep;
875 struct usb_cdc_dmm_desc *dmhd;
876 u8 *buffer = intf->altsetting->extra;
877 int buflen = intf->altsetting->extralen;
878 u16 maxcom = WDM_DEFAULT_BUFSIZE;
879
880 if (!buffer)
881 goto err;
882 while (buflen > 2) {
883 if (buffer[1] != USB_DT_CS_INTERFACE) {
884 dev_err(&intf->dev, "skipping garbage\n");
885 goto next_desc;
886 }
887
888 switch (buffer[2]) {
889 case USB_CDC_HEADER_TYPE:
890 break;
891 case USB_CDC_DMM_TYPE:
892 dmhd = (struct usb_cdc_dmm_desc *)buffer;
893 maxcom = le16_to_cpu(dmhd->wMaxCommand);
894 dev_dbg(&intf->dev,
895 "Finding maximum buffer length: %d", maxcom);
896 break;
897 default:
898 dev_err(&intf->dev,
899 "Ignoring extra header, type %d, length %d\n",
900 buffer[2], buffer[0]);
901 break;
902 }
903 next_desc:
904 buflen -= buffer[0];
905 buffer += buffer[0];
906 }
907
908 iface = intf->cur_altsetting;
909 if (iface->desc.bNumEndpoints != 1)
910 goto err;
911 ep = &iface->endpoint[0].desc;
912
913 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
914
915 err:
916 return rv;
917 }
918
919 /**
920 * usb_cdc_wdm_register - register a WDM subdriver
921 * @intf: usb interface the subdriver will associate with
922 * @ep: interrupt endpoint to monitor for notifications
923 * @bufsize: maximum message size to support for read/write
924 *
925 * Create WDM usb class character device and associate it with intf
926 * without binding, allowing another driver to manage the interface.
927 *
928 * The subdriver will manage the given interrupt endpoint exclusively
929 * and will issue control requests referring to the given intf. It
930 * will otherwise avoid interferring, and in particular not do
931 * usb_set_intfdata/usb_get_intfdata on intf.
932 *
933 * The return value is a pointer to the subdriver's struct usb_driver.
934 * The registering driver is responsible for calling this subdriver's
935 * disconnect, suspend, resume, pre_reset and post_reset methods from
936 * its own.
937 */
938 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
939 struct usb_endpoint_descriptor *ep,
940 int bufsize,
941 int (*manage_power)(struct usb_interface *, int))
942 {
943 int rv = -EINVAL;
944
945 rv = wdm_create(intf, ep, bufsize, manage_power);
946 if (rv < 0)
947 goto err;
948
949 return &wdm_driver;
950 err:
951 return ERR_PTR(rv);
952 }
953 EXPORT_SYMBOL(usb_cdc_wdm_register);
954
955 static void wdm_disconnect(struct usb_interface *intf)
956 {
957 struct wdm_device *desc;
958 unsigned long flags;
959
960 usb_deregister_dev(intf, &wdm_class);
961 desc = wdm_find_device(intf);
962 mutex_lock(&wdm_mutex);
963
964 /* the spinlock makes sure no new urbs are generated in the callbacks */
965 spin_lock_irqsave(&desc->iuspin, flags);
966 set_bit(WDM_DISCONNECTING, &desc->flags);
967 set_bit(WDM_READ, &desc->flags);
968 /* to terminate pending flushes */
969 clear_bit(WDM_IN_USE, &desc->flags);
970 spin_unlock_irqrestore(&desc->iuspin, flags);
971 wake_up_all(&desc->wait);
972 mutex_lock(&desc->rlock);
973 mutex_lock(&desc->wlock);
974 kill_urbs(desc);
975 cancel_work_sync(&desc->rxwork);
976 mutex_unlock(&desc->wlock);
977 mutex_unlock(&desc->rlock);
978
979 /* the desc->intf pointer used as list key is now invalid */
980 spin_lock(&wdm_device_list_lock);
981 list_del(&desc->device_list);
982 spin_unlock(&wdm_device_list_lock);
983
984 if (!desc->count)
985 cleanup(desc);
986 else
987 dev_dbg(&intf->dev, "%s: %d open files - postponing cleanup\n", __func__, desc->count);
988 mutex_unlock(&wdm_mutex);
989 }
990
991 #ifdef CONFIG_PM
992 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
993 {
994 struct wdm_device *desc = wdm_find_device(intf);
995 int rv = 0;
996
997 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
998
999 /* if this is an autosuspend the caller does the locking */
1000 if (!PMSG_IS_AUTO(message)) {
1001 mutex_lock(&desc->rlock);
1002 mutex_lock(&desc->wlock);
1003 }
1004 spin_lock_irq(&desc->iuspin);
1005
1006 if (PMSG_IS_AUTO(message) &&
1007 (test_bit(WDM_IN_USE, &desc->flags)
1008 || test_bit(WDM_RESPONDING, &desc->flags))) {
1009 spin_unlock_irq(&desc->iuspin);
1010 rv = -EBUSY;
1011 } else {
1012
1013 set_bit(WDM_SUSPENDING, &desc->flags);
1014 spin_unlock_irq(&desc->iuspin);
1015 /* callback submits work - order is essential */
1016 kill_urbs(desc);
1017 cancel_work_sync(&desc->rxwork);
1018 }
1019 if (!PMSG_IS_AUTO(message)) {
1020 mutex_unlock(&desc->wlock);
1021 mutex_unlock(&desc->rlock);
1022 }
1023
1024 return rv;
1025 }
1026 #endif
1027
1028 static int recover_from_urb_loss(struct wdm_device *desc)
1029 {
1030 int rv = 0;
1031
1032 if (desc->count) {
1033 rv = usb_submit_urb(desc->validity, GFP_NOIO);
1034 if (rv < 0)
1035 dev_err(&desc->intf->dev,
1036 "Error resume submitting int urb - %d\n", rv);
1037 }
1038 return rv;
1039 }
1040
1041 #ifdef CONFIG_PM
1042 static int wdm_resume(struct usb_interface *intf)
1043 {
1044 struct wdm_device *desc = wdm_find_device(intf);
1045 int rv;
1046
1047 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
1048
1049 clear_bit(WDM_SUSPENDING, &desc->flags);
1050 rv = recover_from_urb_loss(desc);
1051
1052 return rv;
1053 }
1054 #endif
1055
1056 static int wdm_pre_reset(struct usb_interface *intf)
1057 {
1058 struct wdm_device *desc = wdm_find_device(intf);
1059
1060 /*
1061 * we notify everybody using poll of
1062 * an exceptional situation
1063 * must be done before recovery lest a spontaneous
1064 * message from the device is lost
1065 */
1066 spin_lock_irq(&desc->iuspin);
1067 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */
1068 set_bit(WDM_READ, &desc->flags); /* unblock read */
1069 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */
1070 desc->rerr = -EINTR;
1071 spin_unlock_irq(&desc->iuspin);
1072 wake_up_all(&desc->wait);
1073 mutex_lock(&desc->rlock);
1074 mutex_lock(&desc->wlock);
1075 kill_urbs(desc);
1076 cancel_work_sync(&desc->rxwork);
1077 return 0;
1078 }
1079
1080 static int wdm_post_reset(struct usb_interface *intf)
1081 {
1082 struct wdm_device *desc = wdm_find_device(intf);
1083 int rv;
1084
1085 clear_bit(WDM_OVERFLOW, &desc->flags);
1086 clear_bit(WDM_RESETTING, &desc->flags);
1087 rv = recover_from_urb_loss(desc);
1088 mutex_unlock(&desc->wlock);
1089 mutex_unlock(&desc->rlock);
1090 return 0;
1091 }
1092
1093 static struct usb_driver wdm_driver = {
1094 .name = "cdc_wdm",
1095 .probe = wdm_probe,
1096 .disconnect = wdm_disconnect,
1097 #ifdef CONFIG_PM
1098 .suspend = wdm_suspend,
1099 .resume = wdm_resume,
1100 .reset_resume = wdm_resume,
1101 #endif
1102 .pre_reset = wdm_pre_reset,
1103 .post_reset = wdm_post_reset,
1104 .id_table = wdm_ids,
1105 .supports_autosuspend = 1,
1106 .disable_hub_initiated_lpm = 1,
1107 };
1108
1109 module_usb_driver(wdm_driver);
1110
1111 MODULE_AUTHOR(DRIVER_AUTHOR);
1112 MODULE_DESCRIPTION(DRIVER_DESC);
1113 MODULE_LICENSE("GPL");
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