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net: DCB: Validate DCB_ATTR_DCB_BUFFER argument
[linux/fpc-iii.git] / drivers / usb / class / cdc-wdm.c
blob70afb2ca1eabde070ff163ce7dd96fce5da93f71
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * cdc-wdm.c
4 *
5 * This driver supports USB CDC WCM Device Management.
6 *
7 * Copyright (c) 2007-2009 Oliver Neukum
8 *
9 * Some code taken from cdc-acm.c
10 *
11 * Released under the GPLv2.
12 *
13 * Many thanks to Carl Nordbeck
14 */
15 #include <linux/kernel.h>
16 #include <linux/errno.h>
17 #include <linux/ioctl.h>
18 #include <linux/slab.h>
19 #include <linux/module.h>
20 #include <linux/mutex.h>
21 #include <linux/uaccess.h>
22 #include <linux/bitops.h>
23 #include <linux/poll.h>
24 #include <linux/usb.h>
25 #include <linux/usb/cdc.h>
26 #include <asm/byteorder.h>
27 #include <asm/unaligned.h>
28 #include <linux/usb/cdc-wdm.h>
29
30 #define DRIVER_AUTHOR "Oliver Neukum"
31 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
32
33 static const struct usb_device_id wdm_ids[] = {
34 {
35 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
36 USB_DEVICE_ID_MATCH_INT_SUBCLASS,
37 .bInterfaceClass = USB_CLASS_COMM,
38 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
39 },
40 { }
41 };
42
43 MODULE_DEVICE_TABLE (usb, wdm_ids);
44
45 #define WDM_MINOR_BASE 176
46
47
48 #define WDM_IN_USE 1
49 #define WDM_DISCONNECTING 2
50 #define WDM_RESULT 3
51 #define WDM_READ 4
52 #define WDM_INT_STALL 5
53 #define WDM_POLL_RUNNING 6
54 #define WDM_RESPONDING 7
55 #define WDM_SUSPENDING 8
56 #define WDM_RESETTING 9
57 #define WDM_OVERFLOW 10
58
59 #define WDM_MAX 16
60
61 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
62 #define WDM_DEFAULT_BUFSIZE 256
63
64 static DEFINE_MUTEX(wdm_mutex);
65 static DEFINE_SPINLOCK(wdm_device_list_lock);
66 static LIST_HEAD(wdm_device_list);
67
68 /* --- method tables --- */
69
70 struct wdm_device {
71 u8 *inbuf; /* buffer for response */
72 u8 *outbuf; /* buffer for command */
73 u8 *sbuf; /* buffer for status */
74 u8 *ubuf; /* buffer for copy to user space */
75
76 struct urb *command;
77 struct urb *response;
78 struct urb *validity;
79 struct usb_interface *intf;
80 struct usb_ctrlrequest *orq;
81 struct usb_ctrlrequest *irq;
82 spinlock_t iuspin;
83
84 unsigned long flags;
85 u16 bufsize;
86 u16 wMaxCommand;
87 u16 wMaxPacketSize;
88 __le16 inum;
89 int reslength;
90 int length;
91 int read;
92 int count;
93 dma_addr_t shandle;
94 dma_addr_t ihandle;
95 struct mutex wlock;
96 struct mutex rlock;
97 wait_queue_head_t wait;
98 struct work_struct rxwork;
99 struct work_struct service_outs_intr;
100 int werr;
101 int rerr;
102 int resp_count;
103
104 struct list_head device_list;
105 int (*manage_power)(struct usb_interface *, int);
106 };
107
108 static struct usb_driver wdm_driver;
109
110 /* return intfdata if we own the interface, else look up intf in the list */
111 static struct wdm_device *wdm_find_device(struct usb_interface *intf)
112 {
113 struct wdm_device *desc;
114
115 spin_lock(&wdm_device_list_lock);
116 list_for_each_entry(desc, &wdm_device_list, device_list)
117 if (desc->intf == intf)
118 goto found;
119 desc = NULL;
120 found:
121 spin_unlock(&wdm_device_list_lock);
122
123 return desc;
124 }
125
126 static struct wdm_device *wdm_find_device_by_minor(int minor)
127 {
128 struct wdm_device *desc;
129
130 spin_lock(&wdm_device_list_lock);
131 list_for_each_entry(desc, &wdm_device_list, device_list)
132 if (desc->intf->minor == minor)
133 goto found;
134 desc = NULL;
135 found:
136 spin_unlock(&wdm_device_list_lock);
137
138 return desc;
139 }
140
141 /* --- callbacks --- */
142 static void wdm_out_callback(struct urb *urb)
143 {
144 struct wdm_device *desc;
145 unsigned long flags;
146
147 desc = urb->context;
148 spin_lock_irqsave(&desc->iuspin, flags);
149 desc->werr = urb->status;
150 spin_unlock_irqrestore(&desc->iuspin, flags);
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 unsigned long flags;
160 struct wdm_device *desc = urb->context;
161 int status = urb->status;
162 int length = urb->actual_length;
163
164 spin_lock_irqsave(&desc->iuspin, flags);
165 clear_bit(WDM_RESPONDING, &desc->flags);
166
167 if (status) {
168 switch (status) {
169 case -ENOENT:
170 dev_dbg(&desc->intf->dev,
171 "nonzero urb status received: -ENOENT\n");
172 goto skip_error;
173 case -ECONNRESET:
174 dev_dbg(&desc->intf->dev,
175 "nonzero urb status received: -ECONNRESET\n");
176 goto skip_error;
177 case -ESHUTDOWN:
178 dev_dbg(&desc->intf->dev,
179 "nonzero urb status received: -ESHUTDOWN\n");
180 goto skip_error;
181 case -EPIPE:
182 dev_err(&desc->intf->dev,
183 "nonzero urb status received: -EPIPE\n");
184 break;
185 default:
186 dev_err(&desc->intf->dev,
187 "Unexpected error %d\n", status);
188 break;
189 }
190 }
191
192 /*
193 * only set a new error if there is no previous error.
194 * Errors are only cleared during read/open
195 * Avoid propagating -EPIPE (stall) to userspace since it is
196 * better handled as an empty read
197 */
198 if (desc->rerr == 0 && status != -EPIPE)
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
214 if (desc->rerr) {
215 /*
216 * Since there was an error, userspace may decide to not read
217 * any data after poll'ing.
218 * We should respond to further attempts from the device to send
219 * data, so that we can get unstuck.
220 */
221 schedule_work(&desc->service_outs_intr);
222 } else {
223 set_bit(WDM_READ, &desc->flags);
224 wake_up(&desc->wait);
225 }
226 spin_unlock_irqrestore(&desc->iuspin, flags);
227 }
228
229 static void wdm_int_callback(struct urb *urb)
230 {
231 unsigned long flags;
232 int rv = 0;
233 int responding;
234 int status = urb->status;
235 struct wdm_device *desc;
236 struct usb_cdc_notification *dr;
237
238 desc = urb->context;
239 dr = (struct usb_cdc_notification *)desc->sbuf;
240
241 if (status) {
242 switch (status) {
243 case -ESHUTDOWN:
244 case -ENOENT:
245 case -ECONNRESET:
246 return; /* unplug */
247 case -EPIPE:
248 set_bit(WDM_INT_STALL, &desc->flags);
249 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
250 goto sw; /* halt is cleared in work */
251 default:
252 dev_err(&desc->intf->dev,
253 "nonzero urb status received: %d\n", status);
254 break;
255 }
256 }
257
258 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
259 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
260 urb->actual_length);
261 goto exit;
262 }
263
264 switch (dr->bNotificationType) {
265 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
266 dev_dbg(&desc->intf->dev,
267 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d\n",
268 le16_to_cpu(dr->wIndex), le16_to_cpu(dr->wLength));
269 break;
270
271 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
272
273 dev_dbg(&desc->intf->dev,
274 "NOTIFY_NETWORK_CONNECTION %s network\n",
275 dr->wValue ? "connected to" : "disconnected from");
276 goto exit;
277 case USB_CDC_NOTIFY_SPEED_CHANGE:
278 dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)\n",
279 urb->actual_length);
280 goto exit;
281 default:
282 clear_bit(WDM_POLL_RUNNING, &desc->flags);
283 dev_err(&desc->intf->dev,
284 "unknown notification %d received: index %d len %d\n",
285 dr->bNotificationType,
286 le16_to_cpu(dr->wIndex),
287 le16_to_cpu(dr->wLength));
288 goto exit;
289 }
290
291 spin_lock_irqsave(&desc->iuspin, flags);
292 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
293 if (!desc->resp_count++ && !responding
294 && !test_bit(WDM_DISCONNECTING, &desc->flags)
295 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
296 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
297 dev_dbg(&desc->intf->dev, "submit response URB %d\n", rv);
298 }
299 spin_unlock_irqrestore(&desc->iuspin, flags);
300 if (rv < 0) {
301 clear_bit(WDM_RESPONDING, &desc->flags);
302 if (rv == -EPERM)
303 return;
304 if (rv == -ENOMEM) {
305 sw:
306 rv = schedule_work(&desc->rxwork);
307 if (rv)
308 dev_err(&desc->intf->dev,
309 "Cannot schedule work\n");
310 }
311 }
312 exit:
313 rv = usb_submit_urb(urb, GFP_ATOMIC);
314 if (rv)
315 dev_err(&desc->intf->dev,
316 "%s - usb_submit_urb failed with result %d\n",
317 __func__, rv);
318
319 }
320
321 static void kill_urbs(struct wdm_device *desc)
322 {
323 /* the order here is essential */
324 usb_kill_urb(desc->command);
325 usb_kill_urb(desc->validity);
326 usb_kill_urb(desc->response);
327 }
328
329 static void free_urbs(struct wdm_device *desc)
330 {
331 usb_free_urb(desc->validity);
332 usb_free_urb(desc->response);
333 usb_free_urb(desc->command);
334 }
335
336 static void cleanup(struct wdm_device *desc)
337 {
338 kfree(desc->sbuf);
339 kfree(desc->inbuf);
340 kfree(desc->orq);
341 kfree(desc->irq);
342 kfree(desc->ubuf);
343 free_urbs(desc);
344 kfree(desc);
345 }
346
347 static ssize_t wdm_write
348 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
349 {
350 u8 *buf;
351 int rv = -EMSGSIZE, r, we;
352 struct wdm_device *desc = file->private_data;
353 struct usb_ctrlrequest *req;
354
355 if (count > desc->wMaxCommand)
356 count = desc->wMaxCommand;
357
358 spin_lock_irq(&desc->iuspin);
359 we = desc->werr;
360 desc->werr = 0;
361 spin_unlock_irq(&desc->iuspin);
362 if (we < 0)
363 return usb_translate_errors(we);
364
365 buf = memdup_user(buffer, count);
366 if (IS_ERR(buf))
367 return PTR_ERR(buf);
368
369 /* concurrent writes and disconnect */
370 r = mutex_lock_interruptible(&desc->wlock);
371 rv = -ERESTARTSYS;
372 if (r)
373 goto out_free_mem;
374
375 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
376 rv = -ENODEV;
377 goto out_free_mem_lock;
378 }
379
380 r = usb_autopm_get_interface(desc->intf);
381 if (r < 0) {
382 rv = usb_translate_errors(r);
383 goto out_free_mem_lock;
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 rv = r;
398 goto out_free_mem_pm;
399 }
400
401 req = desc->orq;
402 usb_fill_control_urb(
403 desc->command,
404 interface_to_usbdev(desc->intf),
405 /* using common endpoint 0 */
406 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
407 (unsigned char *)req,
408 buf,
409 count,
410 wdm_out_callback,
411 desc
412 );
413
414 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
415 USB_RECIP_INTERFACE);
416 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
417 req->wValue = 0;
418 req->wIndex = desc->inum; /* already converted */
419 req->wLength = cpu_to_le16(count);
420 set_bit(WDM_IN_USE, &desc->flags);
421 desc->outbuf = buf;
422
423 rv = usb_submit_urb(desc->command, GFP_KERNEL);
424 if (rv < 0) {
425 desc->outbuf = NULL;
426 clear_bit(WDM_IN_USE, &desc->flags);
427 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
428 rv = usb_translate_errors(rv);
429 goto out_free_mem_pm;
430 } else {
431 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d\n",
432 le16_to_cpu(req->wIndex));
433 }
434
435 usb_autopm_put_interface(desc->intf);
436 mutex_unlock(&desc->wlock);
437 return count;
438
439 out_free_mem_pm:
440 usb_autopm_put_interface(desc->intf);
441 out_free_mem_lock:
442 mutex_unlock(&desc->wlock);
443 out_free_mem:
444 kfree(buf);
445 return rv;
446 }
447
448 /*
449 * Submit the read urb if resp_count is non-zero.
450 *
451 * Called with desc->iuspin locked
452 */
453 static int service_outstanding_interrupt(struct wdm_device *desc)
454 {
455 int rv = 0;
456
457 /* submit read urb only if the device is waiting for it */
458 if (!desc->resp_count || !--desc->resp_count)
459 goto out;
460
461 set_bit(WDM_RESPONDING, &desc->flags);
462 spin_unlock_irq(&desc->iuspin);
463 rv = usb_submit_urb(desc->response, GFP_KERNEL);
464 spin_lock_irq(&desc->iuspin);
465 if (rv) {
466 dev_err(&desc->intf->dev,
467 "usb_submit_urb failed with result %d\n", rv);
468
469 /* make sure the next notification trigger a submit */
470 clear_bit(WDM_RESPONDING, &desc->flags);
471 desc->resp_count = 0;
472 }
473 out:
474 return rv;
475 }
476
477 static ssize_t wdm_read
478 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
479 {
480 int rv, cntr;
481 int i = 0;
482 struct wdm_device *desc = file->private_data;
483
484
485 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
486 if (rv < 0)
487 return -ERESTARTSYS;
488
489 cntr = READ_ONCE(desc->length);
490 if (cntr == 0) {
491 desc->read = 0;
492 retry:
493 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
494 rv = -ENODEV;
495 goto err;
496 }
497 if (test_bit(WDM_OVERFLOW, &desc->flags)) {
498 clear_bit(WDM_OVERFLOW, &desc->flags);
499 rv = -ENOBUFS;
500 goto err;
501 }
502 i++;
503 if (file->f_flags & O_NONBLOCK) {
504 if (!test_bit(WDM_READ, &desc->flags)) {
505 rv = -EAGAIN;
506 goto err;
507 }
508 rv = 0;
509 } else {
510 rv = wait_event_interruptible(desc->wait,
511 test_bit(WDM_READ, &desc->flags));
512 }
513
514 /* may have happened while we slept */
515 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
516 rv = -ENODEV;
517 goto err;
518 }
519 if (test_bit(WDM_RESETTING, &desc->flags)) {
520 rv = -EIO;
521 goto err;
522 }
523 usb_mark_last_busy(interface_to_usbdev(desc->intf));
524 if (rv < 0) {
525 rv = -ERESTARTSYS;
526 goto err;
527 }
528
529 spin_lock_irq(&desc->iuspin);
530
531 if (desc->rerr) { /* read completed, error happened */
532 rv = usb_translate_errors(desc->rerr);
533 desc->rerr = 0;
534 spin_unlock_irq(&desc->iuspin);
535 goto err;
536 }
537 /*
538 * recheck whether we've lost the race
539 * against the completion handler
540 */
541 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
542 spin_unlock_irq(&desc->iuspin);
543 goto retry;
544 }
545
546 if (!desc->reslength) { /* zero length read */
547 dev_dbg(&desc->intf->dev, "zero length - clearing WDM_READ\n");
548 clear_bit(WDM_READ, &desc->flags);
549 rv = service_outstanding_interrupt(desc);
550 spin_unlock_irq(&desc->iuspin);
551 if (rv < 0)
552 goto err;
553 goto retry;
554 }
555 cntr = desc->length;
556 spin_unlock_irq(&desc->iuspin);
557 }
558
559 if (cntr > count)
560 cntr = count;
561 rv = copy_to_user(buffer, desc->ubuf, cntr);
562 if (rv > 0) {
563 rv = -EFAULT;
564 goto err;
565 }
566
567 spin_lock_irq(&desc->iuspin);
568
569 for (i = 0; i < desc->length - cntr; i++)
570 desc->ubuf[i] = desc->ubuf[i + cntr];
571
572 desc->length -= cntr;
573 /* in case we had outstanding data */
574 if (!desc->length) {
575 clear_bit(WDM_READ, &desc->flags);
576 service_outstanding_interrupt(desc);
577 }
578 spin_unlock_irq(&desc->iuspin);
579 rv = cntr;
580
581 err:
582 mutex_unlock(&desc->rlock);
583 return rv;
584 }
585
586 static int wdm_flush(struct file *file, fl_owner_t id)
587 {
588 struct wdm_device *desc = file->private_data;
589
590 wait_event(desc->wait,
591 /*
592 * needs both flags. We cannot do with one
593 * because resetting it would cause a race
594 * with write() yet we need to signal
595 * a disconnect
596 */
597 !test_bit(WDM_IN_USE, &desc->flags) ||
598 test_bit(WDM_DISCONNECTING, &desc->flags));
599
600 /* cannot dereference desc->intf if WDM_DISCONNECTING */
601 if (test_bit(WDM_DISCONNECTING, &desc->flags))
602 return -ENODEV;
603 if (desc->werr < 0)
604 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
605 desc->werr);
606
607 return usb_translate_errors(desc->werr);
608 }
609
610 static __poll_t wdm_poll(struct file *file, struct poll_table_struct *wait)
611 {
612 struct wdm_device *desc = file->private_data;
613 unsigned long flags;
614 __poll_t mask = 0;
615
616 spin_lock_irqsave(&desc->iuspin, flags);
617 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
618 mask = EPOLLHUP | EPOLLERR;
619 spin_unlock_irqrestore(&desc->iuspin, flags);
620 goto desc_out;
621 }
622 if (test_bit(WDM_READ, &desc->flags))
623 mask = EPOLLIN | EPOLLRDNORM;
624 if (desc->rerr || desc->werr)
625 mask |= EPOLLERR;
626 if (!test_bit(WDM_IN_USE, &desc->flags))
627 mask |= EPOLLOUT | EPOLLWRNORM;
628 spin_unlock_irqrestore(&desc->iuspin, flags);
629
630 poll_wait(file, &desc->wait, wait);
631
632 desc_out:
633 return mask;
634 }
635
636 static int wdm_open(struct inode *inode, struct file *file)
637 {
638 int minor = iminor(inode);
639 int rv = -ENODEV;
640 struct usb_interface *intf;
641 struct wdm_device *desc;
642
643 mutex_lock(&wdm_mutex);
644 desc = wdm_find_device_by_minor(minor);
645 if (!desc)
646 goto out;
647
648 intf = desc->intf;
649 if (test_bit(WDM_DISCONNECTING, &desc->flags))
650 goto out;
651 file->private_data = desc;
652
653 rv = usb_autopm_get_interface(desc->intf);
654 if (rv < 0) {
655 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
656 goto out;
657 }
658
659 /* using write lock to protect desc->count */
660 mutex_lock(&desc->wlock);
661 if (!desc->count++) {
662 desc->werr = 0;
663 desc->rerr = 0;
664 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
665 if (rv < 0) {
666 desc->count--;
667 dev_err(&desc->intf->dev,
668 "Error submitting int urb - %d\n", rv);
669 rv = usb_translate_errors(rv);
670 }
671 } else {
672 rv = 0;
673 }
674 mutex_unlock(&desc->wlock);
675 if (desc->count == 1)
676 desc->manage_power(intf, 1);
677 usb_autopm_put_interface(desc->intf);
678 out:
679 mutex_unlock(&wdm_mutex);
680 return rv;
681 }
682
683 static int wdm_release(struct inode *inode, struct file *file)
684 {
685 struct wdm_device *desc = file->private_data;
686
687 mutex_lock(&wdm_mutex);
688
689 /* using write lock to protect desc->count */
690 mutex_lock(&desc->wlock);
691 desc->count--;
692 mutex_unlock(&desc->wlock);
693
694 if (!desc->count) {
695 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
696 dev_dbg(&desc->intf->dev, "wdm_release: cleanup\n");
697 kill_urbs(desc);
698 spin_lock_irq(&desc->iuspin);
699 desc->resp_count = 0;
700 spin_unlock_irq(&desc->iuspin);
701 desc->manage_power(desc->intf, 0);
702 } else {
703 /* must avoid dev_printk here as desc->intf is invalid */
704 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
705 cleanup(desc);
706 }
707 }
708 mutex_unlock(&wdm_mutex);
709 return 0;
710 }
711
712 static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
713 {
714 struct wdm_device *desc = file->private_data;
715 int rv = 0;
716
717 switch (cmd) {
718 case IOCTL_WDM_MAX_COMMAND:
719 if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand)))
720 rv = -EFAULT;
721 break;
722 default:
723 rv = -ENOTTY;
724 }
725 return rv;
726 }
727
728 static const struct file_operations wdm_fops = {
729 .owner = THIS_MODULE,
730 .read = wdm_read,
731 .write = wdm_write,
732 .open = wdm_open,
733 .flush = wdm_flush,
734 .release = wdm_release,
735 .poll = wdm_poll,
736 .unlocked_ioctl = wdm_ioctl,
737 .compat_ioctl = wdm_ioctl,
738 .llseek = noop_llseek,
739 };
740
741 static struct usb_class_driver wdm_class = {
742 .name = "cdc-wdm%d",
743 .fops = &wdm_fops,
744 .minor_base = WDM_MINOR_BASE,
745 };
746
747 /* --- error handling --- */
748 static void wdm_rxwork(struct work_struct *work)
749 {
750 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
751 unsigned long flags;
752 int rv = 0;
753 int responding;
754
755 spin_lock_irqsave(&desc->iuspin, flags);
756 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
757 spin_unlock_irqrestore(&desc->iuspin, flags);
758 } else {
759 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
760 spin_unlock_irqrestore(&desc->iuspin, flags);
761 if (!responding)
762 rv = usb_submit_urb(desc->response, GFP_KERNEL);
763 if (rv < 0 && rv != -EPERM) {
764 spin_lock_irqsave(&desc->iuspin, flags);
765 clear_bit(WDM_RESPONDING, &desc->flags);
766 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
767 schedule_work(&desc->rxwork);
768 spin_unlock_irqrestore(&desc->iuspin, flags);
769 }
770 }
771 }
772
773 static void service_interrupt_work(struct work_struct *work)
774 {
775 struct wdm_device *desc;
776
777 desc = container_of(work, struct wdm_device, service_outs_intr);
778
779 spin_lock_irq(&desc->iuspin);
780 service_outstanding_interrupt(desc);
781 if (!desc->resp_count) {
782 set_bit(WDM_READ, &desc->flags);
783 wake_up(&desc->wait);
784 }
785 spin_unlock_irq(&desc->iuspin);
786 }
787
788 /* --- hotplug --- */
789
790 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
791 u16 bufsize, int (*manage_power)(struct usb_interface *, int))
792 {
793 int rv = -ENOMEM;
794 struct wdm_device *desc;
795
796 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
797 if (!desc)
798 goto out;
799 INIT_LIST_HEAD(&desc->device_list);
800 mutex_init(&desc->rlock);
801 mutex_init(&desc->wlock);
802 spin_lock_init(&desc->iuspin);
803 init_waitqueue_head(&desc->wait);
804 desc->wMaxCommand = bufsize;
805 /* this will be expanded and needed in hardware endianness */
806 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
807 desc->intf = intf;
808 INIT_WORK(&desc->rxwork, wdm_rxwork);
809 INIT_WORK(&desc->service_outs_intr, service_interrupt_work);
810
811 rv = -EINVAL;
812 if (!usb_endpoint_is_int_in(ep))
813 goto err;
814
815 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
816
817 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
818 if (!desc->orq)
819 goto err;
820 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
821 if (!desc->irq)
822 goto err;
823
824 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
825 if (!desc->validity)
826 goto err;
827
828 desc->response = usb_alloc_urb(0, GFP_KERNEL);
829 if (!desc->response)
830 goto err;
831
832 desc->command = usb_alloc_urb(0, GFP_KERNEL);
833 if (!desc->command)
834 goto err;
835
836 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
837 if (!desc->ubuf)
838 goto err;
839
840 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
841 if (!desc->sbuf)
842 goto err;
843
844 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
845 if (!desc->inbuf)
846 goto err;
847
848 usb_fill_int_urb(
849 desc->validity,
850 interface_to_usbdev(intf),
851 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
852 desc->sbuf,
853 desc->wMaxPacketSize,
854 wdm_int_callback,
855 desc,
856 ep->bInterval
857 );
858
859 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
860 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
861 desc->irq->wValue = 0;
862 desc->irq->wIndex = desc->inum; /* already converted */
863 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
864
865 usb_fill_control_urb(
866 desc->response,
867 interface_to_usbdev(intf),
868 /* using common endpoint 0 */
869 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
870 (unsigned char *)desc->irq,
871 desc->inbuf,
872 desc->wMaxCommand,
873 wdm_in_callback,
874 desc
875 );
876
877 desc->manage_power = manage_power;
878
879 spin_lock(&wdm_device_list_lock);
880 list_add(&desc->device_list, &wdm_device_list);
881 spin_unlock(&wdm_device_list_lock);
882
883 rv = usb_register_dev(intf, &wdm_class);
884 if (rv < 0)
885 goto err;
886 else
887 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
888 out:
889 return rv;
890 err:
891 spin_lock(&wdm_device_list_lock);
892 list_del(&desc->device_list);
893 spin_unlock(&wdm_device_list_lock);
894 cleanup(desc);
895 return rv;
896 }
897
898 static int wdm_manage_power(struct usb_interface *intf, int on)
899 {
900 /* need autopm_get/put here to ensure the usbcore sees the new value */
901 int rv = usb_autopm_get_interface(intf);
902
903 intf->needs_remote_wakeup = on;
904 if (!rv)
905 usb_autopm_put_interface(intf);
906 return 0;
907 }
908
909 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
910 {
911 int rv = -EINVAL;
912 struct usb_host_interface *iface;
913 struct usb_endpoint_descriptor *ep;
914 struct usb_cdc_parsed_header hdr;
915 u8 *buffer = intf->altsetting->extra;
916 int buflen = intf->altsetting->extralen;
917 u16 maxcom = WDM_DEFAULT_BUFSIZE;
918
919 if (!buffer)
920 goto err;
921
922 cdc_parse_cdc_header(&hdr, intf, buffer, buflen);
923
924 if (hdr.usb_cdc_dmm_desc)
925 maxcom = le16_to_cpu(hdr.usb_cdc_dmm_desc->wMaxCommand);
926
927 iface = intf->cur_altsetting;
928 if (iface->desc.bNumEndpoints != 1)
929 goto err;
930 ep = &iface->endpoint[0].desc;
931
932 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
933
934 err:
935 return rv;
936 }
937
938 /**
939 * usb_cdc_wdm_register - register a WDM subdriver
940 * @intf: usb interface the subdriver will associate with
941 * @ep: interrupt endpoint to monitor for notifications
942 * @bufsize: maximum message size to support for read/write
943 *
944 * Create WDM usb class character device and associate it with intf
945 * without binding, allowing another driver to manage the interface.
946 *
947 * The subdriver will manage the given interrupt endpoint exclusively
948 * and will issue control requests referring to the given intf. It
949 * will otherwise avoid interferring, and in particular not do
950 * usb_set_intfdata/usb_get_intfdata on intf.
951 *
952 * The return value is a pointer to the subdriver's struct usb_driver.
953 * The registering driver is responsible for calling this subdriver's
954 * disconnect, suspend, resume, pre_reset and post_reset methods from
955 * its own.
956 */
957 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
958 struct usb_endpoint_descriptor *ep,
959 int bufsize,
960 int (*manage_power)(struct usb_interface *, int))
961 {
962 int rv;
963
964 rv = wdm_create(intf, ep, bufsize, manage_power);
965 if (rv < 0)
966 goto err;
967
968 return &wdm_driver;
969 err:
970 return ERR_PTR(rv);
971 }
972 EXPORT_SYMBOL(usb_cdc_wdm_register);
973
974 static void wdm_disconnect(struct usb_interface *intf)
975 {
976 struct wdm_device *desc;
977 unsigned long flags;
978
979 usb_deregister_dev(intf, &wdm_class);
980 desc = wdm_find_device(intf);
981 mutex_lock(&wdm_mutex);
982
983 /* the spinlock makes sure no new urbs are generated in the callbacks */
984 spin_lock_irqsave(&desc->iuspin, flags);
985 set_bit(WDM_DISCONNECTING, &desc->flags);
986 set_bit(WDM_READ, &desc->flags);
987 spin_unlock_irqrestore(&desc->iuspin, flags);
988 wake_up_all(&desc->wait);
989 mutex_lock(&desc->rlock);
990 mutex_lock(&desc->wlock);
991 kill_urbs(desc);
992 cancel_work_sync(&desc->rxwork);
993 cancel_work_sync(&desc->service_outs_intr);
994 mutex_unlock(&desc->wlock);
995 mutex_unlock(&desc->rlock);
996
997 /* the desc->intf pointer used as list key is now invalid */
998 spin_lock(&wdm_device_list_lock);
999 list_del(&desc->device_list);
1000 spin_unlock(&wdm_device_list_lock);
1001
1002 if (!desc->count)
1003 cleanup(desc);
1004 else
1005 dev_dbg(&intf->dev, "%d open files - postponing cleanup\n", desc->count);
1006 mutex_unlock(&wdm_mutex);
1007 }
1008
1009 #ifdef CONFIG_PM
1010 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
1011 {
1012 struct wdm_device *desc = wdm_find_device(intf);
1013 int rv = 0;
1014
1015 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
1016
1017 /* if this is an autosuspend the caller does the locking */
1018 if (!PMSG_IS_AUTO(message)) {
1019 mutex_lock(&desc->rlock);
1020 mutex_lock(&desc->wlock);
1021 }
1022 spin_lock_irq(&desc->iuspin);
1023
1024 if (PMSG_IS_AUTO(message) &&
1025 (test_bit(WDM_IN_USE, &desc->flags)
1026 || test_bit(WDM_RESPONDING, &desc->flags))) {
1027 spin_unlock_irq(&desc->iuspin);
1028 rv = -EBUSY;
1029 } else {
1030
1031 set_bit(WDM_SUSPENDING, &desc->flags);
1032 spin_unlock_irq(&desc->iuspin);
1033 /* callback submits work - order is essential */
1034 kill_urbs(desc);
1035 cancel_work_sync(&desc->rxwork);
1036 cancel_work_sync(&desc->service_outs_intr);
1037 }
1038 if (!PMSG_IS_AUTO(message)) {
1039 mutex_unlock(&desc->wlock);
1040 mutex_unlock(&desc->rlock);
1041 }
1042
1043 return rv;
1044 }
1045 #endif
1046
1047 static int recover_from_urb_loss(struct wdm_device *desc)
1048 {
1049 int rv = 0;
1050
1051 if (desc->count) {
1052 rv = usb_submit_urb(desc->validity, GFP_NOIO);
1053 if (rv < 0)
1054 dev_err(&desc->intf->dev,
1055 "Error resume submitting int urb - %d\n", rv);
1056 }
1057 return rv;
1058 }
1059
1060 #ifdef CONFIG_PM
1061 static int wdm_resume(struct usb_interface *intf)
1062 {
1063 struct wdm_device *desc = wdm_find_device(intf);
1064 int rv;
1065
1066 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
1067
1068 clear_bit(WDM_SUSPENDING, &desc->flags);
1069 rv = recover_from_urb_loss(desc);
1070
1071 return rv;
1072 }
1073 #endif
1074
1075 static int wdm_pre_reset(struct usb_interface *intf)
1076 {
1077 struct wdm_device *desc = wdm_find_device(intf);
1078
1079 /*
1080 * we notify everybody using poll of
1081 * an exceptional situation
1082 * must be done before recovery lest a spontaneous
1083 * message from the device is lost
1084 */
1085 spin_lock_irq(&desc->iuspin);
1086 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */
1087 set_bit(WDM_READ, &desc->flags); /* unblock read */
1088 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */
1089 desc->rerr = -EINTR;
1090 spin_unlock_irq(&desc->iuspin);
1091 wake_up_all(&desc->wait);
1092 mutex_lock(&desc->rlock);
1093 mutex_lock(&desc->wlock);
1094 kill_urbs(desc);
1095 cancel_work_sync(&desc->rxwork);
1096 cancel_work_sync(&desc->service_outs_intr);
1097 return 0;
1098 }
1099
1100 static int wdm_post_reset(struct usb_interface *intf)
1101 {
1102 struct wdm_device *desc = wdm_find_device(intf);
1103 int rv;
1104
1105 clear_bit(WDM_OVERFLOW, &desc->flags);
1106 clear_bit(WDM_RESETTING, &desc->flags);
1107 rv = recover_from_urb_loss(desc);
1108 mutex_unlock(&desc->wlock);
1109 mutex_unlock(&desc->rlock);
1110 return rv;
1111 }
1112
1113 static struct usb_driver wdm_driver = {
1114 .name = "cdc_wdm",
1115 .probe = wdm_probe,
1116 .disconnect = wdm_disconnect,
1117 #ifdef CONFIG_PM
1118 .suspend = wdm_suspend,
1119 .resume = wdm_resume,
1120 .reset_resume = wdm_resume,
1121 #endif
1122 .pre_reset = wdm_pre_reset,
1123 .post_reset = wdm_post_reset,
1124 .id_table = wdm_ids,
1125 .supports_autosuspend = 1,
1126 .disable_hub_initiated_lpm = 1,
1127 };
1128
1129 module_usb_driver(wdm_driver);
1130
1131 MODULE_AUTHOR(DRIVER_AUTHOR);
1132 MODULE_DESCRIPTION(DRIVER_DESC);
1133 MODULE_LICENSE("GPL");
Linux with added FPC-III support