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[people/arne_f/kernel.git] / drivers / usb / class / cdc-wdm.c
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 /* forward declaration */
158 static int service_outstanding_interrupt(struct wdm_device *desc);
159
160 static void wdm_in_callback(struct urb *urb)
161 {
162 struct wdm_device *desc = urb->context;
163 int status = urb->status;
164 int length = urb->actual_length;
165
166 spin_lock(&desc->iuspin);
167 clear_bit(WDM_RESPONDING, &desc->flags);
168
169 if (status) {
170 switch (status) {
171 case -ENOENT:
172 dev_dbg(&desc->intf->dev,
173 "nonzero urb status received: -ENOENT\n");
174 goto skip_error;
175 case -ECONNRESET:
176 dev_dbg(&desc->intf->dev,
177 "nonzero urb status received: -ECONNRESET\n");
178 goto skip_error;
179 case -ESHUTDOWN:
180 dev_dbg(&desc->intf->dev,
181 "nonzero urb status received: -ESHUTDOWN\n");
182 goto skip_error;
183 case -EPIPE:
184 dev_err(&desc->intf->dev,
185 "nonzero urb status received: -EPIPE\n");
186 break;
187 default:
188 dev_err(&desc->intf->dev,
189 "Unexpected error %d\n", status);
190 break;
191 }
192 }
193
194 /*
195 * only set a new error if there is no previous error.
196 * Errors are only cleared during read/open
197 */
198 if (desc->rerr == 0)
199 desc->rerr = status;
200
201 if (length + desc->length > desc->wMaxCommand) {
202 /* The buffer would overflow */
203 set_bit(WDM_OVERFLOW, &desc->flags);
204 } else {
205 /* we may already be in overflow */
206 if (!test_bit(WDM_OVERFLOW, &desc->flags)) {
207 memmove(desc->ubuf + desc->length, desc->inbuf, length);
208 desc->length += length;
209 desc->reslength = length;
210 }
211 }
212 skip_error:
213 set_bit(WDM_READ, &desc->flags);
214 wake_up(&desc->wait);
215
216 if (desc->rerr) {
217 /*
218 * Since there was an error, userspace may decide to not read
219 * any data after poll'ing.
220 * We should respond to further attempts from the device to send
221 * data, so that we can get unstuck.
222 */
223 service_outstanding_interrupt(desc);
224 }
225
226 spin_unlock(&desc->iuspin);
227 }
228
229 static void wdm_int_callback(struct urb *urb)
230 {
231 int rv = 0;
232 int responding;
233 int status = urb->status;
234 struct wdm_device *desc;
235 struct usb_cdc_notification *dr;
236
237 desc = urb->context;
238 dr = (struct usb_cdc_notification *)desc->sbuf;
239
240 if (status) {
241 switch (status) {
242 case -ESHUTDOWN:
243 case -ENOENT:
244 case -ECONNRESET:
245 return; /* unplug */
246 case -EPIPE:
247 set_bit(WDM_INT_STALL, &desc->flags);
248 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
249 goto sw; /* halt is cleared in work */
250 default:
251 dev_err(&desc->intf->dev,
252 "nonzero urb status received: %d\n", status);
253 break;
254 }
255 }
256
257 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
258 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
259 urb->actual_length);
260 goto exit;
261 }
262
263 switch (dr->bNotificationType) {
264 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
265 dev_dbg(&desc->intf->dev,
266 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d\n",
267 le16_to_cpu(dr->wIndex), le16_to_cpu(dr->wLength));
268 break;
269
270 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
271
272 dev_dbg(&desc->intf->dev,
273 "NOTIFY_NETWORK_CONNECTION %s network\n",
274 dr->wValue ? "connected to" : "disconnected from");
275 goto exit;
276 case USB_CDC_NOTIFY_SPEED_CHANGE:
277 dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)\n",
278 urb->actual_length);
279 goto exit;
280 default:
281 clear_bit(WDM_POLL_RUNNING, &desc->flags);
282 dev_err(&desc->intf->dev,
283 "unknown notification %d received: index %d len %d\n",
284 dr->bNotificationType,
285 le16_to_cpu(dr->wIndex),
286 le16_to_cpu(dr->wLength));
287 goto exit;
288 }
289
290 spin_lock(&desc->iuspin);
291 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
292 if (!desc->resp_count++ && !responding
293 && !test_bit(WDM_DISCONNECTING, &desc->flags)
294 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
295 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
296 dev_dbg(&desc->intf->dev, "submit response URB %d\n", rv);
297 }
298 spin_unlock(&desc->iuspin);
299 if (rv < 0) {
300 clear_bit(WDM_RESPONDING, &desc->flags);
301 if (rv == -EPERM)
302 return;
303 if (rv == -ENOMEM) {
304 sw:
305 rv = schedule_work(&desc->rxwork);
306 if (rv)
307 dev_err(&desc->intf->dev,
308 "Cannot schedule work\n");
309 }
310 }
311 exit:
312 rv = usb_submit_urb(urb, GFP_ATOMIC);
313 if (rv)
314 dev_err(&desc->intf->dev,
315 "%s - usb_submit_urb failed with result %d\n",
316 __func__, rv);
317
318 }
319
320 static void kill_urbs(struct wdm_device *desc)
321 {
322 /* the order here is essential */
323 usb_kill_urb(desc->command);
324 usb_kill_urb(desc->validity);
325 usb_kill_urb(desc->response);
326 }
327
328 static void free_urbs(struct wdm_device *desc)
329 {
330 usb_free_urb(desc->validity);
331 usb_free_urb(desc->response);
332 usb_free_urb(desc->command);
333 }
334
335 static void cleanup(struct wdm_device *desc)
336 {
337 kfree(desc->sbuf);
338 kfree(desc->inbuf);
339 kfree(desc->orq);
340 kfree(desc->irq);
341 kfree(desc->ubuf);
342 free_urbs(desc);
343 kfree(desc);
344 }
345
346 static ssize_t wdm_write
347 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
348 {
349 u8 *buf;
350 int rv = -EMSGSIZE, r, we;
351 struct wdm_device *desc = file->private_data;
352 struct usb_ctrlrequest *req;
353
354 if (count > desc->wMaxCommand)
355 count = desc->wMaxCommand;
356
357 spin_lock_irq(&desc->iuspin);
358 we = desc->werr;
359 desc->werr = 0;
360 spin_unlock_irq(&desc->iuspin);
361 if (we < 0)
362 return usb_translate_errors(we);
363
364 buf = kmalloc(count, GFP_KERNEL);
365 if (!buf) {
366 rv = -ENOMEM;
367 goto outnl;
368 }
369
370 r = copy_from_user(buf, buffer, count);
371 if (r > 0) {
372 rv = -EFAULT;
373 goto out_free_mem;
374 }
375
376 /* concurrent writes and disconnect */
377 r = mutex_lock_interruptible(&desc->wlock);
378 rv = -ERESTARTSYS;
379 if (r)
380 goto out_free_mem;
381
382 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
383 rv = -ENODEV;
384 goto out_free_mem_lock;
385 }
386
387 r = usb_autopm_get_interface(desc->intf);
388 if (r < 0) {
389 rv = usb_translate_errors(r);
390 goto out_free_mem_lock;
391 }
392
393 if (!(file->f_flags & O_NONBLOCK))
394 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
395 &desc->flags));
396 else
397 if (test_bit(WDM_IN_USE, &desc->flags))
398 r = -EAGAIN;
399
400 if (test_bit(WDM_RESETTING, &desc->flags))
401 r = -EIO;
402
403 if (r < 0) {
404 rv = r;
405 goto out_free_mem_pm;
406 }
407
408 req = desc->orq;
409 usb_fill_control_urb(
410 desc->command,
411 interface_to_usbdev(desc->intf),
412 /* using common endpoint 0 */
413 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
414 (unsigned char *)req,
415 buf,
416 count,
417 wdm_out_callback,
418 desc
419 );
420
421 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
422 USB_RECIP_INTERFACE);
423 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
424 req->wValue = 0;
425 req->wIndex = desc->inum; /* already converted */
426 req->wLength = cpu_to_le16(count);
427 set_bit(WDM_IN_USE, &desc->flags);
428 desc->outbuf = buf;
429
430 rv = usb_submit_urb(desc->command, GFP_KERNEL);
431 if (rv < 0) {
432 desc->outbuf = NULL;
433 clear_bit(WDM_IN_USE, &desc->flags);
434 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
435 rv = usb_translate_errors(rv);
436 goto out_free_mem_pm;
437 } else {
438 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d\n",
439 le16_to_cpu(req->wIndex));
440 }
441
442 usb_autopm_put_interface(desc->intf);
443 mutex_unlock(&desc->wlock);
444 outnl:
445 return rv < 0 ? rv : count;
446
447 out_free_mem_pm:
448 usb_autopm_put_interface(desc->intf);
449 out_free_mem_lock:
450 mutex_unlock(&desc->wlock);
451 out_free_mem:
452 kfree(buf);
453 return rv;
454 }
455
456 /*
457 * Submit the read urb if resp_count is non-zero.
458 *
459 * Called with desc->iuspin locked
460 */
461 static int service_outstanding_interrupt(struct wdm_device *desc)
462 {
463 int rv = 0;
464
465 /* submit read urb only if the device is waiting for it */
466 if (!desc->resp_count || !--desc->resp_count)
467 goto out;
468
469 set_bit(WDM_RESPONDING, &desc->flags);
470 spin_unlock_irq(&desc->iuspin);
471 rv = usb_submit_urb(desc->response, GFP_KERNEL);
472 spin_lock_irq(&desc->iuspin);
473 if (rv) {
474 dev_err(&desc->intf->dev,
475 "usb_submit_urb failed with result %d\n", rv);
476
477 /* make sure the next notification trigger a submit */
478 clear_bit(WDM_RESPONDING, &desc->flags);
479 desc->resp_count = 0;
480 }
481 out:
482 return rv;
483 }
484
485 static ssize_t wdm_read
486 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
487 {
488 int rv, cntr;
489 int i = 0;
490 struct wdm_device *desc = file->private_data;
491
492
493 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
494 if (rv < 0)
495 return -ERESTARTSYS;
496
497 cntr = ACCESS_ONCE(desc->length);
498 if (cntr == 0) {
499 desc->read = 0;
500 retry:
501 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
502 rv = -ENODEV;
503 goto err;
504 }
505 if (test_bit(WDM_OVERFLOW, &desc->flags)) {
506 clear_bit(WDM_OVERFLOW, &desc->flags);
507 rv = -ENOBUFS;
508 goto err;
509 }
510 i++;
511 if (file->f_flags & O_NONBLOCK) {
512 if (!test_bit(WDM_READ, &desc->flags)) {
513 rv = cntr ? cntr : -EAGAIN;
514 goto err;
515 }
516 rv = 0;
517 } else {
518 rv = wait_event_interruptible(desc->wait,
519 test_bit(WDM_READ, &desc->flags));
520 }
521
522 /* may have happened while we slept */
523 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
524 rv = -ENODEV;
525 goto err;
526 }
527 if (test_bit(WDM_RESETTING, &desc->flags)) {
528 rv = -EIO;
529 goto err;
530 }
531 usb_mark_last_busy(interface_to_usbdev(desc->intf));
532 if (rv < 0) {
533 rv = -ERESTARTSYS;
534 goto err;
535 }
536
537 spin_lock_irq(&desc->iuspin);
538
539 if (desc->rerr) { /* read completed, error happened */
540 rv = usb_translate_errors(desc->rerr);
541 desc->rerr = 0;
542 spin_unlock_irq(&desc->iuspin);
543 goto err;
544 }
545 /*
546 * recheck whether we've lost the race
547 * against the completion handler
548 */
549 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
550 spin_unlock_irq(&desc->iuspin);
551 goto retry;
552 }
553
554 if (!desc->reslength) { /* zero length read */
555 dev_dbg(&desc->intf->dev, "zero length - clearing WDM_READ\n");
556 clear_bit(WDM_READ, &desc->flags);
557 rv = service_outstanding_interrupt(desc);
558 spin_unlock_irq(&desc->iuspin);
559 if (rv < 0)
560 goto err;
561 goto retry;
562 }
563 cntr = desc->length;
564 spin_unlock_irq(&desc->iuspin);
565 }
566
567 if (cntr > count)
568 cntr = count;
569 rv = copy_to_user(buffer, desc->ubuf, cntr);
570 if (rv > 0) {
571 rv = -EFAULT;
572 goto err;
573 }
574
575 spin_lock_irq(&desc->iuspin);
576
577 for (i = 0; i < desc->length - cntr; i++)
578 desc->ubuf[i] = desc->ubuf[i + cntr];
579
580 desc->length -= cntr;
581 /* in case we had outstanding data */
582 if (!desc->length) {
583 clear_bit(WDM_READ, &desc->flags);
584 service_outstanding_interrupt(desc);
585 }
586 spin_unlock_irq(&desc->iuspin);
587 rv = cntr;
588
589 err:
590 mutex_unlock(&desc->rlock);
591 return rv;
592 }
593
594 static int wdm_flush(struct file *file, fl_owner_t id)
595 {
596 struct wdm_device *desc = file->private_data;
597
598 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
599
600 /* cannot dereference desc->intf if WDM_DISCONNECTING */
601 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags))
602 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
603 desc->werr);
604
605 return usb_translate_errors(desc->werr);
606 }
607
608 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
609 {
610 struct wdm_device *desc = file->private_data;
611 unsigned long flags;
612 unsigned int mask = 0;
613
614 spin_lock_irqsave(&desc->iuspin, flags);
615 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
616 mask = POLLHUP | POLLERR;
617 spin_unlock_irqrestore(&desc->iuspin, flags);
618 goto desc_out;
619 }
620 if (test_bit(WDM_READ, &desc->flags))
621 mask = POLLIN | POLLRDNORM;
622 if (desc->rerr || desc->werr)
623 mask |= POLLERR;
624 if (!test_bit(WDM_IN_USE, &desc->flags))
625 mask |= POLLOUT | POLLWRNORM;
626 spin_unlock_irqrestore(&desc->iuspin, flags);
627
628 poll_wait(file, &desc->wait, wait);
629
630 desc_out:
631 return mask;
632 }
633
634 static int wdm_open(struct inode *inode, struct file *file)
635 {
636 int minor = iminor(inode);
637 int rv = -ENODEV;
638 struct usb_interface *intf;
639 struct wdm_device *desc;
640
641 mutex_lock(&wdm_mutex);
642 desc = wdm_find_device_by_minor(minor);
643 if (!desc)
644 goto out;
645
646 intf = desc->intf;
647 if (test_bit(WDM_DISCONNECTING, &desc->flags))
648 goto out;
649 file->private_data = desc;
650
651 rv = usb_autopm_get_interface(desc->intf);
652 if (rv < 0) {
653 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
654 goto out;
655 }
656
657 /* using write lock to protect desc->count */
658 mutex_lock(&desc->wlock);
659 if (!desc->count++) {
660 desc->werr = 0;
661 desc->rerr = 0;
662 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
663 if (rv < 0) {
664 desc->count--;
665 dev_err(&desc->intf->dev,
666 "Error submitting int urb - %d\n", rv);
667 rv = usb_translate_errors(rv);
668 }
669 } else {
670 rv = 0;
671 }
672 mutex_unlock(&desc->wlock);
673 if (desc->count == 1)
674 desc->manage_power(intf, 1);
675 usb_autopm_put_interface(desc->intf);
676 out:
677 mutex_unlock(&wdm_mutex);
678 return rv;
679 }
680
681 static int wdm_release(struct inode *inode, struct file *file)
682 {
683 struct wdm_device *desc = file->private_data;
684
685 mutex_lock(&wdm_mutex);
686
687 /* using write lock to protect desc->count */
688 mutex_lock(&desc->wlock);
689 desc->count--;
690 mutex_unlock(&desc->wlock);
691
692 if (!desc->count) {
693 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
694 dev_dbg(&desc->intf->dev, "wdm_release: cleanup\n");
695 kill_urbs(desc);
696 spin_lock_irq(&desc->iuspin);
697 desc->resp_count = 0;
698 spin_unlock_irq(&desc->iuspin);
699 desc->manage_power(desc->intf, 0);
700 } else {
701 /* must avoid dev_printk here as desc->intf is invalid */
702 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
703 cleanup(desc);
704 }
705 }
706 mutex_unlock(&wdm_mutex);
707 return 0;
708 }
709
710 static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
711 {
712 struct wdm_device *desc = file->private_data;
713 int rv = 0;
714
715 switch (cmd) {
716 case IOCTL_WDM_MAX_COMMAND:
717 if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand)))
718 rv = -EFAULT;
719 break;
720 default:
721 rv = -ENOTTY;
722 }
723 return rv;
724 }
725
726 static const struct file_operations wdm_fops = {
727 .owner = THIS_MODULE,
728 .read = wdm_read,
729 .write = wdm_write,
730 .open = wdm_open,
731 .flush = wdm_flush,
732 .release = wdm_release,
733 .poll = wdm_poll,
734 .unlocked_ioctl = wdm_ioctl,
735 .compat_ioctl = wdm_ioctl,
736 .llseek = noop_llseek,
737 };
738
739 static struct usb_class_driver wdm_class = {
740 .name = "cdc-wdm%d",
741 .fops = &wdm_fops,
742 .minor_base = WDM_MINOR_BASE,
743 };
744
745 /* --- error handling --- */
746 static void wdm_rxwork(struct work_struct *work)
747 {
748 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
749 unsigned long flags;
750 int rv = 0;
751 int responding;
752
753 spin_lock_irqsave(&desc->iuspin, flags);
754 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
755 spin_unlock_irqrestore(&desc->iuspin, flags);
756 } else {
757 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
758 spin_unlock_irqrestore(&desc->iuspin, flags);
759 if (!responding)
760 rv = usb_submit_urb(desc->response, GFP_KERNEL);
761 if (rv < 0 && rv != -EPERM) {
762 spin_lock_irqsave(&desc->iuspin, flags);
763 clear_bit(WDM_RESPONDING, &desc->flags);
764 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
765 schedule_work(&desc->rxwork);
766 spin_unlock_irqrestore(&desc->iuspin, flags);
767 }
768 }
769 }
770
771 /* --- hotplug --- */
772
773 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
774 u16 bufsize, int (*manage_power)(struct usb_interface *, int))
775 {
776 int rv = -ENOMEM;
777 struct wdm_device *desc;
778
779 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
780 if (!desc)
781 goto out;
782 INIT_LIST_HEAD(&desc->device_list);
783 mutex_init(&desc->rlock);
784 mutex_init(&desc->wlock);
785 spin_lock_init(&desc->iuspin);
786 init_waitqueue_head(&desc->wait);
787 desc->wMaxCommand = bufsize;
788 /* this will be expanded and needed in hardware endianness */
789 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
790 desc->intf = intf;
791 INIT_WORK(&desc->rxwork, wdm_rxwork);
792
793 rv = -EINVAL;
794 if (!usb_endpoint_is_int_in(ep))
795 goto err;
796
797 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
798
799 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
800 if (!desc->orq)
801 goto err;
802 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
803 if (!desc->irq)
804 goto err;
805
806 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
807 if (!desc->validity)
808 goto err;
809
810 desc->response = usb_alloc_urb(0, GFP_KERNEL);
811 if (!desc->response)
812 goto err;
813
814 desc->command = usb_alloc_urb(0, GFP_KERNEL);
815 if (!desc->command)
816 goto err;
817
818 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
819 if (!desc->ubuf)
820 goto err;
821
822 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
823 if (!desc->sbuf)
824 goto err;
825
826 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
827 if (!desc->inbuf)
828 goto err;
829
830 usb_fill_int_urb(
831 desc->validity,
832 interface_to_usbdev(intf),
833 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
834 desc->sbuf,
835 desc->wMaxPacketSize,
836 wdm_int_callback,
837 desc,
838 ep->bInterval
839 );
840
841 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
842 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
843 desc->irq->wValue = 0;
844 desc->irq->wIndex = desc->inum; /* already converted */
845 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
846
847 usb_fill_control_urb(
848 desc->response,
849 interface_to_usbdev(intf),
850 /* using common endpoint 0 */
851 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
852 (unsigned char *)desc->irq,
853 desc->inbuf,
854 desc->wMaxCommand,
855 wdm_in_callback,
856 desc
857 );
858
859 desc->manage_power = manage_power;
860
861 spin_lock(&wdm_device_list_lock);
862 list_add(&desc->device_list, &wdm_device_list);
863 spin_unlock(&wdm_device_list_lock);
864
865 rv = usb_register_dev(intf, &wdm_class);
866 if (rv < 0)
867 goto err;
868 else
869 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
870 out:
871 return rv;
872 err:
873 spin_lock(&wdm_device_list_lock);
874 list_del(&desc->device_list);
875 spin_unlock(&wdm_device_list_lock);
876 cleanup(desc);
877 return rv;
878 }
879
880 static int wdm_manage_power(struct usb_interface *intf, int on)
881 {
882 /* need autopm_get/put here to ensure the usbcore sees the new value */
883 int rv = usb_autopm_get_interface(intf);
884
885 intf->needs_remote_wakeup = on;
886 if (!rv)
887 usb_autopm_put_interface(intf);
888 return 0;
889 }
890
891 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
892 {
893 int rv = -EINVAL;
894 struct usb_host_interface *iface;
895 struct usb_endpoint_descriptor *ep;
896 struct usb_cdc_parsed_header hdr;
897 u8 *buffer = intf->altsetting->extra;
898 int buflen = intf->altsetting->extralen;
899 u16 maxcom = WDM_DEFAULT_BUFSIZE;
900
901 if (!buffer)
902 goto err;
903
904 cdc_parse_cdc_header(&hdr, intf, buffer, buflen);
905
906 if (hdr.usb_cdc_dmm_desc)
907 maxcom = le16_to_cpu(hdr.usb_cdc_dmm_desc->wMaxCommand);
908
909 iface = intf->cur_altsetting;
910 if (iface->desc.bNumEndpoints != 1)
911 goto err;
912 ep = &iface->endpoint[0].desc;
913
914 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
915
916 err:
917 return rv;
918 }
919
920 /**
921 * usb_cdc_wdm_register - register a WDM subdriver
922 * @intf: usb interface the subdriver will associate with
923 * @ep: interrupt endpoint to monitor for notifications
924 * @bufsize: maximum message size to support for read/write
925 *
926 * Create WDM usb class character device and associate it with intf
927 * without binding, allowing another driver to manage the interface.
928 *
929 * The subdriver will manage the given interrupt endpoint exclusively
930 * and will issue control requests referring to the given intf. It
931 * will otherwise avoid interferring, and in particular not do
932 * usb_set_intfdata/usb_get_intfdata on intf.
933 *
934 * The return value is a pointer to the subdriver's struct usb_driver.
935 * The registering driver is responsible for calling this subdriver's
936 * disconnect, suspend, resume, pre_reset and post_reset methods from
937 * its own.
938 */
939 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
940 struct usb_endpoint_descriptor *ep,
941 int bufsize,
942 int (*manage_power)(struct usb_interface *, int))
943 {
944 int rv = -EINVAL;
945
946 rv = wdm_create(intf, ep, bufsize, manage_power);
947 if (rv < 0)
948 goto err;
949
950 return &wdm_driver;
951 err:
952 return ERR_PTR(rv);
953 }
954 EXPORT_SYMBOL(usb_cdc_wdm_register);
955
956 static void wdm_disconnect(struct usb_interface *intf)
957 {
958 struct wdm_device *desc;
959 unsigned long flags;
960
961 usb_deregister_dev(intf, &wdm_class);
962 desc = wdm_find_device(intf);
963 mutex_lock(&wdm_mutex);
964
965 /* the spinlock makes sure no new urbs are generated in the callbacks */
966 spin_lock_irqsave(&desc->iuspin, flags);
967 set_bit(WDM_DISCONNECTING, &desc->flags);
968 set_bit(WDM_READ, &desc->flags);
969 /* to terminate pending flushes */
970 clear_bit(WDM_IN_USE, &desc->flags);
971 spin_unlock_irqrestore(&desc->iuspin, flags);
972 wake_up_all(&desc->wait);
973 mutex_lock(&desc->rlock);
974 mutex_lock(&desc->wlock);
975 kill_urbs(desc);
976 cancel_work_sync(&desc->rxwork);
977 mutex_unlock(&desc->wlock);
978 mutex_unlock(&desc->rlock);
979
980 /* the desc->intf pointer used as list key is now invalid */
981 spin_lock(&wdm_device_list_lock);
982 list_del(&desc->device_list);
983 spin_unlock(&wdm_device_list_lock);
984
985 if (!desc->count)
986 cleanup(desc);
987 else
988 dev_dbg(&intf->dev, "%d open files - postponing cleanup\n", desc->count);
989 mutex_unlock(&wdm_mutex);
990 }
991
992 #ifdef CONFIG_PM
993 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
994 {
995 struct wdm_device *desc = wdm_find_device(intf);
996 int rv = 0;
997
998 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
999
1000 /* if this is an autosuspend the caller does the locking */
1001 if (!PMSG_IS_AUTO(message)) {
1002 mutex_lock(&desc->rlock);
1003 mutex_lock(&desc->wlock);
1004 }
1005 spin_lock_irq(&desc->iuspin);
1006
1007 if (PMSG_IS_AUTO(message) &&
1008 (test_bit(WDM_IN_USE, &desc->flags)
1009 || test_bit(WDM_RESPONDING, &desc->flags))) {
1010 spin_unlock_irq(&desc->iuspin);
1011 rv = -EBUSY;
1012 } else {
1013
1014 set_bit(WDM_SUSPENDING, &desc->flags);
1015 spin_unlock_irq(&desc->iuspin);
1016 /* callback submits work - order is essential */
1017 kill_urbs(desc);
1018 cancel_work_sync(&desc->rxwork);
1019 }
1020 if (!PMSG_IS_AUTO(message)) {
1021 mutex_unlock(&desc->wlock);
1022 mutex_unlock(&desc->rlock);
1023 }
1024
1025 return rv;
1026 }
1027 #endif
1028
1029 static int recover_from_urb_loss(struct wdm_device *desc)
1030 {
1031 int rv = 0;
1032
1033 if (desc->count) {
1034 rv = usb_submit_urb(desc->validity, GFP_NOIO);
1035 if (rv < 0)
1036 dev_err(&desc->intf->dev,
1037 "Error resume submitting int urb - %d\n", rv);
1038 }
1039 return rv;
1040 }
1041
1042 #ifdef CONFIG_PM
1043 static int wdm_resume(struct usb_interface *intf)
1044 {
1045 struct wdm_device *desc = wdm_find_device(intf);
1046 int rv;
1047
1048 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
1049
1050 clear_bit(WDM_SUSPENDING, &desc->flags);
1051 rv = recover_from_urb_loss(desc);
1052
1053 return rv;
1054 }
1055 #endif
1056
1057 static int wdm_pre_reset(struct usb_interface *intf)
1058 {
1059 struct wdm_device *desc = wdm_find_device(intf);
1060
1061 /*
1062 * we notify everybody using poll of
1063 * an exceptional situation
1064 * must be done before recovery lest a spontaneous
1065 * message from the device is lost
1066 */
1067 spin_lock_irq(&desc->iuspin);
1068 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */
1069 set_bit(WDM_READ, &desc->flags); /* unblock read */
1070 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */
1071 desc->rerr = -EINTR;
1072 spin_unlock_irq(&desc->iuspin);
1073 wake_up_all(&desc->wait);
1074 mutex_lock(&desc->rlock);
1075 mutex_lock(&desc->wlock);
1076 kill_urbs(desc);
1077 cancel_work_sync(&desc->rxwork);
1078 return 0;
1079 }
1080
1081 static int wdm_post_reset(struct usb_interface *intf)
1082 {
1083 struct wdm_device *desc = wdm_find_device(intf);
1084 int rv;
1085
1086 clear_bit(WDM_OVERFLOW, &desc->flags);
1087 clear_bit(WDM_RESETTING, &desc->flags);
1088 rv = recover_from_urb_loss(desc);
1089 mutex_unlock(&desc->wlock);
1090 mutex_unlock(&desc->rlock);
1091 return 0;
1092 }
1093
1094 static struct usb_driver wdm_driver = {
1095 .name = "cdc_wdm",
1096 .probe = wdm_probe,
1097 .disconnect = wdm_disconnect,
1098 #ifdef CONFIG_PM
1099 .suspend = wdm_suspend,
1100 .resume = wdm_resume,
1101 .reset_resume = wdm_resume,
1102 #endif
1103 .pre_reset = wdm_pre_reset,
1104 .post_reset = wdm_post_reset,
1105 .id_table = wdm_ids,
1106 .supports_autosuspend = 1,
1107 .disable_hub_initiated_lpm = 1,
1108 };
1109
1110 module_usb_driver(wdm_driver);
1111
1112 MODULE_AUTHOR(DRIVER_AUTHOR);
1113 MODULE_DESCRIPTION(DRIVER_DESC);
1114 MODULE_LICENSE("GPL");
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