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Linux 4.16.11
[linux/fpc-iii.git] / drivers / usb / class / cdc-wdm.c
bloba0d284ef3f40ad369cc34f093bb15723124ef4a2
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 int werr;
100 int rerr;
101 int resp_count;
102
103 struct list_head device_list;
104 int (*manage_power)(struct usb_interface *, int);
105 };
106
107 static struct usb_driver wdm_driver;
108
109 /* return intfdata if we own the interface, else look up intf in the list */
110 static struct wdm_device *wdm_find_device(struct usb_interface *intf)
111 {
112 struct wdm_device *desc;
113
114 spin_lock(&wdm_device_list_lock);
115 list_for_each_entry(desc, &wdm_device_list, device_list)
116 if (desc->intf == intf)
117 goto found;
118 desc = NULL;
119 found:
120 spin_unlock(&wdm_device_list_lock);
121
122 return desc;
123 }
124
125 static struct wdm_device *wdm_find_device_by_minor(int minor)
126 {
127 struct wdm_device *desc;
128
129 spin_lock(&wdm_device_list_lock);
130 list_for_each_entry(desc, &wdm_device_list, device_list)
131 if (desc->intf->minor == minor)
132 goto found;
133 desc = NULL;
134 found:
135 spin_unlock(&wdm_device_list_lock);
136
137 return desc;
138 }
139
140 /* --- callbacks --- */
141 static void wdm_out_callback(struct urb *urb)
142 {
143 struct wdm_device *desc;
144 desc = urb->context;
145 spin_lock(&desc->iuspin);
146 desc->werr = urb->status;
147 spin_unlock(&desc->iuspin);
148 kfree(desc->outbuf);
149 desc->outbuf = NULL;
150 clear_bit(WDM_IN_USE, &desc->flags);
151 wake_up(&desc->wait);
152 }
153
154 /* forward declaration */
155 static int service_outstanding_interrupt(struct wdm_device *desc);
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\n");
171 goto skip_error;
172 case -ECONNRESET:
173 dev_dbg(&desc->intf->dev,
174 "nonzero urb status received: -ECONNRESET\n");
175 goto skip_error;
176 case -ESHUTDOWN:
177 dev_dbg(&desc->intf->dev,
178 "nonzero urb status received: -ESHUTDOWN\n");
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 /*
192 * only set a new error if there is no previous error.
193 * Errors are only cleared during read/open
194 * Avoid propagating -EPIPE (stall) to userspace since it is
195 * better handled as an empty read
196 */
197 if (desc->rerr == 0 && status != -EPIPE)
198 desc->rerr = status;
199
200 if (length + desc->length > desc->wMaxCommand) {
201 /* The buffer would overflow */
202 set_bit(WDM_OVERFLOW, &desc->flags);
203 } else {
204 /* we may already be in overflow */
205 if (!test_bit(WDM_OVERFLOW, &desc->flags)) {
206 memmove(desc->ubuf + desc->length, desc->inbuf, length);
207 desc->length += length;
208 desc->reslength = length;
209 }
210 }
211 skip_error:
212 set_bit(WDM_READ, &desc->flags);
213 wake_up(&desc->wait);
214
215 if (desc->rerr) {
216 /*
217 * Since there was an error, userspace may decide to not read
218 * any data after poll'ing.
219 * We should respond to further attempts from the device to send
220 * data, so that we can get unstuck.
221 */
222 service_outstanding_interrupt(desc);
223 }
224
225 spin_unlock(&desc->iuspin);
226 }
227
228 static void wdm_int_callback(struct urb *urb)
229 {
230 int rv = 0;
231 int responding;
232 int status = urb->status;
233 struct wdm_device *desc;
234 struct usb_cdc_notification *dr;
235
236 desc = urb->context;
237 dr = (struct usb_cdc_notification *)desc->sbuf;
238
239 if (status) {
240 switch (status) {
241 case -ESHUTDOWN:
242 case -ENOENT:
243 case -ECONNRESET:
244 return; /* unplug */
245 case -EPIPE:
246 set_bit(WDM_INT_STALL, &desc->flags);
247 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
248 goto sw; /* halt is cleared in work */
249 default:
250 dev_err(&desc->intf->dev,
251 "nonzero urb status received: %d\n", status);
252 break;
253 }
254 }
255
256 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
257 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
258 urb->actual_length);
259 goto exit;
260 }
261
262 switch (dr->bNotificationType) {
263 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
264 dev_dbg(&desc->intf->dev,
265 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d\n",
266 le16_to_cpu(dr->wIndex), le16_to_cpu(dr->wLength));
267 break;
268
269 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
270
271 dev_dbg(&desc->intf->dev,
272 "NOTIFY_NETWORK_CONNECTION %s network\n",
273 dr->wValue ? "connected to" : "disconnected from");
274 goto exit;
275 case USB_CDC_NOTIFY_SPEED_CHANGE:
276 dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)\n",
277 urb->actual_length);
278 goto exit;
279 default:
280 clear_bit(WDM_POLL_RUNNING, &desc->flags);
281 dev_err(&desc->intf->dev,
282 "unknown notification %d received: index %d len %d\n",
283 dr->bNotificationType,
284 le16_to_cpu(dr->wIndex),
285 le16_to_cpu(dr->wLength));
286 goto exit;
287 }
288
289 spin_lock(&desc->iuspin);
290 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
291 if (!desc->resp_count++ && !responding
292 && !test_bit(WDM_DISCONNECTING, &desc->flags)
293 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
294 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
295 dev_dbg(&desc->intf->dev, "submit response URB %d\n", rv);
296 }
297 spin_unlock(&desc->iuspin);
298 if (rv < 0) {
299 clear_bit(WDM_RESPONDING, &desc->flags);
300 if (rv == -EPERM)
301 return;
302 if (rv == -ENOMEM) {
303 sw:
304 rv = schedule_work(&desc->rxwork);
305 if (rv)
306 dev_err(&desc->intf->dev,
307 "Cannot schedule work\n");
308 }
309 }
310 exit:
311 rv = usb_submit_urb(urb, GFP_ATOMIC);
312 if (rv)
313 dev_err(&desc->intf->dev,
314 "%s - usb_submit_urb failed with result %d\n",
315 __func__, rv);
316
317 }
318
319 static void kill_urbs(struct wdm_device *desc)
320 {
321 /* the order here is essential */
322 usb_kill_urb(desc->command);
323 usb_kill_urb(desc->validity);
324 usb_kill_urb(desc->response);
325 }
326
327 static void free_urbs(struct wdm_device *desc)
328 {
329 usb_free_urb(desc->validity);
330 usb_free_urb(desc->response);
331 usb_free_urb(desc->command);
332 }
333
334 static void cleanup(struct wdm_device *desc)
335 {
336 kfree(desc->sbuf);
337 kfree(desc->inbuf);
338 kfree(desc->orq);
339 kfree(desc->irq);
340 kfree(desc->ubuf);
341 free_urbs(desc);
342 kfree(desc);
343 }
344
345 static ssize_t wdm_write
346 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
347 {
348 u8 *buf;
349 int rv = -EMSGSIZE, r, we;
350 struct wdm_device *desc = file->private_data;
351 struct usb_ctrlrequest *req;
352
353 if (count > desc->wMaxCommand)
354 count = desc->wMaxCommand;
355
356 spin_lock_irq(&desc->iuspin);
357 we = desc->werr;
358 desc->werr = 0;
359 spin_unlock_irq(&desc->iuspin);
360 if (we < 0)
361 return usb_translate_errors(we);
362
363 buf = memdup_user(buffer, count);
364 if (IS_ERR(buf))
365 return PTR_ERR(buf);
366
367 /* concurrent writes and disconnect */
368 r = mutex_lock_interruptible(&desc->wlock);
369 rv = -ERESTARTSYS;
370 if (r)
371 goto out_free_mem;
372
373 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
374 rv = -ENODEV;
375 goto out_free_mem_lock;
376 }
377
378 r = usb_autopm_get_interface(desc->intf);
379 if (r < 0) {
380 rv = usb_translate_errors(r);
381 goto out_free_mem_lock;
382 }
383
384 if (!(file->f_flags & O_NONBLOCK))
385 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
386 &desc->flags));
387 else
388 if (test_bit(WDM_IN_USE, &desc->flags))
389 r = -EAGAIN;
390
391 if (test_bit(WDM_RESETTING, &desc->flags))
392 r = -EIO;
393
394 if (r < 0) {
395 rv = r;
396 goto out_free_mem_pm;
397 }
398
399 req = desc->orq;
400 usb_fill_control_urb(
401 desc->command,
402 interface_to_usbdev(desc->intf),
403 /* using common endpoint 0 */
404 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
405 (unsigned char *)req,
406 buf,
407 count,
408 wdm_out_callback,
409 desc
410 );
411
412 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
413 USB_RECIP_INTERFACE);
414 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
415 req->wValue = 0;
416 req->wIndex = desc->inum; /* already converted */
417 req->wLength = cpu_to_le16(count);
418 set_bit(WDM_IN_USE, &desc->flags);
419 desc->outbuf = buf;
420
421 rv = usb_submit_urb(desc->command, GFP_KERNEL);
422 if (rv < 0) {
423 desc->outbuf = NULL;
424 clear_bit(WDM_IN_USE, &desc->flags);
425 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
426 rv = usb_translate_errors(rv);
427 goto out_free_mem_pm;
428 } else {
429 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d\n",
430 le16_to_cpu(req->wIndex));
431 }
432
433 usb_autopm_put_interface(desc->intf);
434 mutex_unlock(&desc->wlock);
435 return count;
436
437 out_free_mem_pm:
438 usb_autopm_put_interface(desc->intf);
439 out_free_mem_lock:
440 mutex_unlock(&desc->wlock);
441 out_free_mem:
442 kfree(buf);
443 return rv;
444 }
445
446 /*
447 * Submit the read urb if resp_count is non-zero.
448 *
449 * Called with desc->iuspin locked
450 */
451 static int service_outstanding_interrupt(struct wdm_device *desc)
452 {
453 int rv = 0;
454
455 /* submit read urb only if the device is waiting for it */
456 if (!desc->resp_count || !--desc->resp_count)
457 goto out;
458
459 set_bit(WDM_RESPONDING, &desc->flags);
460 spin_unlock_irq(&desc->iuspin);
461 rv = usb_submit_urb(desc->response, GFP_KERNEL);
462 spin_lock_irq(&desc->iuspin);
463 if (rv) {
464 dev_err(&desc->intf->dev,
465 "usb_submit_urb failed with result %d\n", rv);
466
467 /* make sure the next notification trigger a submit */
468 clear_bit(WDM_RESPONDING, &desc->flags);
469 desc->resp_count = 0;
470 }
471 out:
472 return rv;
473 }
474
475 static ssize_t wdm_read
476 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
477 {
478 int rv, cntr;
479 int i = 0;
480 struct wdm_device *desc = file->private_data;
481
482
483 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
484 if (rv < 0)
485 return -ERESTARTSYS;
486
487 cntr = READ_ONCE(desc->length);
488 if (cntr == 0) {
489 desc->read = 0;
490 retry:
491 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
492 rv = -ENODEV;
493 goto err;
494 }
495 if (test_bit(WDM_OVERFLOW, &desc->flags)) {
496 clear_bit(WDM_OVERFLOW, &desc->flags);
497 rv = -ENOBUFS;
498 goto err;
499 }
500 i++;
501 if (file->f_flags & O_NONBLOCK) {
502 if (!test_bit(WDM_READ, &desc->flags)) {
503 rv = -EAGAIN;
504 goto err;
505 }
506 rv = 0;
507 } else {
508 rv = wait_event_interruptible(desc->wait,
509 test_bit(WDM_READ, &desc->flags));
510 }
511
512 /* may have happened while we slept */
513 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
514 rv = -ENODEV;
515 goto err;
516 }
517 if (test_bit(WDM_RESETTING, &desc->flags)) {
518 rv = -EIO;
519 goto err;
520 }
521 usb_mark_last_busy(interface_to_usbdev(desc->intf));
522 if (rv < 0) {
523 rv = -ERESTARTSYS;
524 goto err;
525 }
526
527 spin_lock_irq(&desc->iuspin);
528
529 if (desc->rerr) { /* read completed, error happened */
530 rv = usb_translate_errors(desc->rerr);
531 desc->rerr = 0;
532 spin_unlock_irq(&desc->iuspin);
533 goto err;
534 }
535 /*
536 * recheck whether we've lost the race
537 * against the completion handler
538 */
539 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
540 spin_unlock_irq(&desc->iuspin);
541 goto retry;
542 }
543
544 if (!desc->reslength) { /* zero length read */
545 dev_dbg(&desc->intf->dev, "zero length - clearing WDM_READ\n");
546 clear_bit(WDM_READ, &desc->flags);
547 rv = service_outstanding_interrupt(desc);
548 spin_unlock_irq(&desc->iuspin);
549 if (rv < 0)
550 goto err;
551 goto retry;
552 }
553 cntr = desc->length;
554 spin_unlock_irq(&desc->iuspin);
555 }
556
557 if (cntr > count)
558 cntr = count;
559 rv = copy_to_user(buffer, desc->ubuf, cntr);
560 if (rv > 0) {
561 rv = -EFAULT;
562 goto err;
563 }
564
565 spin_lock_irq(&desc->iuspin);
566
567 for (i = 0; i < desc->length - cntr; i++)
568 desc->ubuf[i] = desc->ubuf[i + cntr];
569
570 desc->length -= cntr;
571 /* in case we had outstanding data */
572 if (!desc->length) {
573 clear_bit(WDM_READ, &desc->flags);
574 service_outstanding_interrupt(desc);
575 }
576 spin_unlock_irq(&desc->iuspin);
577 rv = cntr;
578
579 err:
580 mutex_unlock(&desc->rlock);
581 return rv;
582 }
583
584 static int wdm_flush(struct file *file, fl_owner_t id)
585 {
586 struct wdm_device *desc = file->private_data;
587
588 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
589
590 /* cannot dereference desc->intf if WDM_DISCONNECTING */
591 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags))
592 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
593 desc->werr);
594
595 return usb_translate_errors(desc->werr);
596 }
597
598 static __poll_t wdm_poll(struct file *file, struct poll_table_struct *wait)
599 {
600 struct wdm_device *desc = file->private_data;
601 unsigned long flags;
602 __poll_t mask = 0;
603
604 spin_lock_irqsave(&desc->iuspin, flags);
605 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
606 mask = EPOLLHUP | EPOLLERR;
607 spin_unlock_irqrestore(&desc->iuspin, flags);
608 goto desc_out;
609 }
610 if (test_bit(WDM_READ, &desc->flags))
611 mask = EPOLLIN | EPOLLRDNORM;
612 if (desc->rerr || desc->werr)
613 mask |= EPOLLERR;
614 if (!test_bit(WDM_IN_USE, &desc->flags))
615 mask |= EPOLLOUT | EPOLLWRNORM;
616 spin_unlock_irqrestore(&desc->iuspin, flags);
617
618 poll_wait(file, &desc->wait, wait);
619
620 desc_out:
621 return mask;
622 }
623
624 static int wdm_open(struct inode *inode, struct file *file)
625 {
626 int minor = iminor(inode);
627 int rv = -ENODEV;
628 struct usb_interface *intf;
629 struct wdm_device *desc;
630
631 mutex_lock(&wdm_mutex);
632 desc = wdm_find_device_by_minor(minor);
633 if (!desc)
634 goto out;
635
636 intf = desc->intf;
637 if (test_bit(WDM_DISCONNECTING, &desc->flags))
638 goto out;
639 file->private_data = desc;
640
641 rv = usb_autopm_get_interface(desc->intf);
642 if (rv < 0) {
643 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
644 goto out;
645 }
646
647 /* using write lock to protect desc->count */
648 mutex_lock(&desc->wlock);
649 if (!desc->count++) {
650 desc->werr = 0;
651 desc->rerr = 0;
652 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
653 if (rv < 0) {
654 desc->count--;
655 dev_err(&desc->intf->dev,
656 "Error submitting int urb - %d\n", rv);
657 rv = usb_translate_errors(rv);
658 }
659 } else {
660 rv = 0;
661 }
662 mutex_unlock(&desc->wlock);
663 if (desc->count == 1)
664 desc->manage_power(intf, 1);
665 usb_autopm_put_interface(desc->intf);
666 out:
667 mutex_unlock(&wdm_mutex);
668 return rv;
669 }
670
671 static int wdm_release(struct inode *inode, struct file *file)
672 {
673 struct wdm_device *desc = file->private_data;
674
675 mutex_lock(&wdm_mutex);
676
677 /* using write lock to protect desc->count */
678 mutex_lock(&desc->wlock);
679 desc->count--;
680 mutex_unlock(&desc->wlock);
681
682 if (!desc->count) {
683 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
684 dev_dbg(&desc->intf->dev, "wdm_release: cleanup\n");
685 kill_urbs(desc);
686 spin_lock_irq(&desc->iuspin);
687 desc->resp_count = 0;
688 spin_unlock_irq(&desc->iuspin);
689 desc->manage_power(desc->intf, 0);
690 } else {
691 /* must avoid dev_printk here as desc->intf is invalid */
692 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
693 cleanup(desc);
694 }
695 }
696 mutex_unlock(&wdm_mutex);
697 return 0;
698 }
699
700 static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
701 {
702 struct wdm_device *desc = file->private_data;
703 int rv = 0;
704
705 switch (cmd) {
706 case IOCTL_WDM_MAX_COMMAND:
707 if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand)))
708 rv = -EFAULT;
709 break;
710 default:
711 rv = -ENOTTY;
712 }
713 return rv;
714 }
715
716 static const struct file_operations wdm_fops = {
717 .owner = THIS_MODULE,
718 .read = wdm_read,
719 .write = wdm_write,
720 .open = wdm_open,
721 .flush = wdm_flush,
722 .release = wdm_release,
723 .poll = wdm_poll,
724 .unlocked_ioctl = wdm_ioctl,
725 .compat_ioctl = wdm_ioctl,
726 .llseek = noop_llseek,
727 };
728
729 static struct usb_class_driver wdm_class = {
730 .name = "cdc-wdm%d",
731 .fops = &wdm_fops,
732 .minor_base = WDM_MINOR_BASE,
733 };
734
735 /* --- error handling --- */
736 static void wdm_rxwork(struct work_struct *work)
737 {
738 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
739 unsigned long flags;
740 int rv = 0;
741 int responding;
742
743 spin_lock_irqsave(&desc->iuspin, flags);
744 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
745 spin_unlock_irqrestore(&desc->iuspin, flags);
746 } else {
747 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
748 spin_unlock_irqrestore(&desc->iuspin, flags);
749 if (!responding)
750 rv = usb_submit_urb(desc->response, GFP_KERNEL);
751 if (rv < 0 && rv != -EPERM) {
752 spin_lock_irqsave(&desc->iuspin, flags);
753 clear_bit(WDM_RESPONDING, &desc->flags);
754 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
755 schedule_work(&desc->rxwork);
756 spin_unlock_irqrestore(&desc->iuspin, flags);
757 }
758 }
759 }
760
761 /* --- hotplug --- */
762
763 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
764 u16 bufsize, int (*manage_power)(struct usb_interface *, int))
765 {
766 int rv = -ENOMEM;
767 struct wdm_device *desc;
768
769 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
770 if (!desc)
771 goto out;
772 INIT_LIST_HEAD(&desc->device_list);
773 mutex_init(&desc->rlock);
774 mutex_init(&desc->wlock);
775 spin_lock_init(&desc->iuspin);
776 init_waitqueue_head(&desc->wait);
777 desc->wMaxCommand = bufsize;
778 /* this will be expanded and needed in hardware endianness */
779 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
780 desc->intf = intf;
781 INIT_WORK(&desc->rxwork, wdm_rxwork);
782
783 rv = -EINVAL;
784 if (!usb_endpoint_is_int_in(ep))
785 goto err;
786
787 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
788
789 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
790 if (!desc->orq)
791 goto err;
792 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
793 if (!desc->irq)
794 goto err;
795
796 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
797 if (!desc->validity)
798 goto err;
799
800 desc->response = usb_alloc_urb(0, GFP_KERNEL);
801 if (!desc->response)
802 goto err;
803
804 desc->command = usb_alloc_urb(0, GFP_KERNEL);
805 if (!desc->command)
806 goto err;
807
808 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
809 if (!desc->ubuf)
810 goto err;
811
812 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
813 if (!desc->sbuf)
814 goto err;
815
816 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
817 if (!desc->inbuf)
818 goto err;
819
820 usb_fill_int_urb(
821 desc->validity,
822 interface_to_usbdev(intf),
823 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
824 desc->sbuf,
825 desc->wMaxPacketSize,
826 wdm_int_callback,
827 desc,
828 ep->bInterval
829 );
830
831 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
832 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
833 desc->irq->wValue = 0;
834 desc->irq->wIndex = desc->inum; /* already converted */
835 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
836
837 usb_fill_control_urb(
838 desc->response,
839 interface_to_usbdev(intf),
840 /* using common endpoint 0 */
841 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
842 (unsigned char *)desc->irq,
843 desc->inbuf,
844 desc->wMaxCommand,
845 wdm_in_callback,
846 desc
847 );
848
849 desc->manage_power = manage_power;
850
851 spin_lock(&wdm_device_list_lock);
852 list_add(&desc->device_list, &wdm_device_list);
853 spin_unlock(&wdm_device_list_lock);
854
855 rv = usb_register_dev(intf, &wdm_class);
856 if (rv < 0)
857 goto err;
858 else
859 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
860 out:
861 return rv;
862 err:
863 spin_lock(&wdm_device_list_lock);
864 list_del(&desc->device_list);
865 spin_unlock(&wdm_device_list_lock);
866 cleanup(desc);
867 return rv;
868 }
869
870 static int wdm_manage_power(struct usb_interface *intf, int on)
871 {
872 /* need autopm_get/put here to ensure the usbcore sees the new value */
873 int rv = usb_autopm_get_interface(intf);
874
875 intf->needs_remote_wakeup = on;
876 if (!rv)
877 usb_autopm_put_interface(intf);
878 return 0;
879 }
880
881 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
882 {
883 int rv = -EINVAL;
884 struct usb_host_interface *iface;
885 struct usb_endpoint_descriptor *ep;
886 struct usb_cdc_parsed_header hdr;
887 u8 *buffer = intf->altsetting->extra;
888 int buflen = intf->altsetting->extralen;
889 u16 maxcom = WDM_DEFAULT_BUFSIZE;
890
891 if (!buffer)
892 goto err;
893
894 cdc_parse_cdc_header(&hdr, intf, buffer, buflen);
895
896 if (hdr.usb_cdc_dmm_desc)
897 maxcom = le16_to_cpu(hdr.usb_cdc_dmm_desc->wMaxCommand);
898
899 iface = intf->cur_altsetting;
900 if (iface->desc.bNumEndpoints != 1)
901 goto err;
902 ep = &iface->endpoint[0].desc;
903
904 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
905
906 err:
907 return rv;
908 }
909
910 /**
911 * usb_cdc_wdm_register - register a WDM subdriver
912 * @intf: usb interface the subdriver will associate with
913 * @ep: interrupt endpoint to monitor for notifications
914 * @bufsize: maximum message size to support for read/write
915 *
916 * Create WDM usb class character device and associate it with intf
917 * without binding, allowing another driver to manage the interface.
918 *
919 * The subdriver will manage the given interrupt endpoint exclusively
920 * and will issue control requests referring to the given intf. It
921 * will otherwise avoid interferring, and in particular not do
922 * usb_set_intfdata/usb_get_intfdata on intf.
923 *
924 * The return value is a pointer to the subdriver's struct usb_driver.
925 * The registering driver is responsible for calling this subdriver's
926 * disconnect, suspend, resume, pre_reset and post_reset methods from
927 * its own.
928 */
929 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
930 struct usb_endpoint_descriptor *ep,
931 int bufsize,
932 int (*manage_power)(struct usb_interface *, int))
933 {
934 int rv = -EINVAL;
935
936 rv = wdm_create(intf, ep, bufsize, manage_power);
937 if (rv < 0)
938 goto err;
939
940 return &wdm_driver;
941 err:
942 return ERR_PTR(rv);
943 }
944 EXPORT_SYMBOL(usb_cdc_wdm_register);
945
946 static void wdm_disconnect(struct usb_interface *intf)
947 {
948 struct wdm_device *desc;
949 unsigned long flags;
950
951 usb_deregister_dev(intf, &wdm_class);
952 desc = wdm_find_device(intf);
953 mutex_lock(&wdm_mutex);
954
955 /* the spinlock makes sure no new urbs are generated in the callbacks */
956 spin_lock_irqsave(&desc->iuspin, flags);
957 set_bit(WDM_DISCONNECTING, &desc->flags);
958 set_bit(WDM_READ, &desc->flags);
959 /* to terminate pending flushes */
960 clear_bit(WDM_IN_USE, &desc->flags);
961 spin_unlock_irqrestore(&desc->iuspin, flags);
962 wake_up_all(&desc->wait);
963 mutex_lock(&desc->rlock);
964 mutex_lock(&desc->wlock);
965 kill_urbs(desc);
966 cancel_work_sync(&desc->rxwork);
967 mutex_unlock(&desc->wlock);
968 mutex_unlock(&desc->rlock);
969
970 /* the desc->intf pointer used as list key is now invalid */
971 spin_lock(&wdm_device_list_lock);
972 list_del(&desc->device_list);
973 spin_unlock(&wdm_device_list_lock);
974
975 if (!desc->count)
976 cleanup(desc);
977 else
978 dev_dbg(&intf->dev, "%d open files - postponing cleanup\n", desc->count);
979 mutex_unlock(&wdm_mutex);
980 }
981
982 #ifdef CONFIG_PM
983 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
984 {
985 struct wdm_device *desc = wdm_find_device(intf);
986 int rv = 0;
987
988 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
989
990 /* if this is an autosuspend the caller does the locking */
991 if (!PMSG_IS_AUTO(message)) {
992 mutex_lock(&desc->rlock);
993 mutex_lock(&desc->wlock);
994 }
995 spin_lock_irq(&desc->iuspin);
996
997 if (PMSG_IS_AUTO(message) &&
998 (test_bit(WDM_IN_USE, &desc->flags)
999 || test_bit(WDM_RESPONDING, &desc->flags))) {
1000 spin_unlock_irq(&desc->iuspin);
1001 rv = -EBUSY;
1002 } else {
1003
1004 set_bit(WDM_SUSPENDING, &desc->flags);
1005 spin_unlock_irq(&desc->iuspin);
1006 /* callback submits work - order is essential */
1007 kill_urbs(desc);
1008 cancel_work_sync(&desc->rxwork);
1009 }
1010 if (!PMSG_IS_AUTO(message)) {
1011 mutex_unlock(&desc->wlock);
1012 mutex_unlock(&desc->rlock);
1013 }
1014
1015 return rv;
1016 }
1017 #endif
1018
1019 static int recover_from_urb_loss(struct wdm_device *desc)
1020 {
1021 int rv = 0;
1022
1023 if (desc->count) {
1024 rv = usb_submit_urb(desc->validity, GFP_NOIO);
1025 if (rv < 0)
1026 dev_err(&desc->intf->dev,
1027 "Error resume submitting int urb - %d\n", rv);
1028 }
1029 return rv;
1030 }
1031
1032 #ifdef CONFIG_PM
1033 static int wdm_resume(struct usb_interface *intf)
1034 {
1035 struct wdm_device *desc = wdm_find_device(intf);
1036 int rv;
1037
1038 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
1039
1040 clear_bit(WDM_SUSPENDING, &desc->flags);
1041 rv = recover_from_urb_loss(desc);
1042
1043 return rv;
1044 }
1045 #endif
1046
1047 static int wdm_pre_reset(struct usb_interface *intf)
1048 {
1049 struct wdm_device *desc = wdm_find_device(intf);
1050
1051 /*
1052 * we notify everybody using poll of
1053 * an exceptional situation
1054 * must be done before recovery lest a spontaneous
1055 * message from the device is lost
1056 */
1057 spin_lock_irq(&desc->iuspin);
1058 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */
1059 set_bit(WDM_READ, &desc->flags); /* unblock read */
1060 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */
1061 desc->rerr = -EINTR;
1062 spin_unlock_irq(&desc->iuspin);
1063 wake_up_all(&desc->wait);
1064 mutex_lock(&desc->rlock);
1065 mutex_lock(&desc->wlock);
1066 kill_urbs(desc);
1067 cancel_work_sync(&desc->rxwork);
1068 return 0;
1069 }
1070
1071 static int wdm_post_reset(struct usb_interface *intf)
1072 {
1073 struct wdm_device *desc = wdm_find_device(intf);
1074 int rv;
1075
1076 clear_bit(WDM_OVERFLOW, &desc->flags);
1077 clear_bit(WDM_RESETTING, &desc->flags);
1078 rv = recover_from_urb_loss(desc);
1079 mutex_unlock(&desc->wlock);
1080 mutex_unlock(&desc->rlock);
1081 return 0;
1082 }
1083
1084 static struct usb_driver wdm_driver = {
1085 .name = "cdc_wdm",
1086 .probe = wdm_probe,
1087 .disconnect = wdm_disconnect,
1088 #ifdef CONFIG_PM
1089 .suspend = wdm_suspend,
1090 .resume = wdm_resume,
1091 .reset_resume = wdm_resume,
1092 #endif
1093 .pre_reset = wdm_pre_reset,
1094 .post_reset = wdm_post_reset,
1095 .id_table = wdm_ids,
1096 .supports_autosuspend = 1,
1097 .disable_hub_initiated_lpm = 1,
1098 };
1099
1100 module_usb_driver(wdm_driver);
1101
1102 MODULE_AUTHOR(DRIVER_AUTHOR);
1103 MODULE_DESCRIPTION(DRIVER_DESC);
1104 MODULE_LICENSE("GPL");
Linux with added FPC-III support