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dt-bindings: mtd: ingenic: Use standard ecc-engine property
[linux/fpc-iii.git] / drivers / usb / class / cdc-wdm.c
blob9e9caff905d52abcdb2048c6e580d1f17eb3cf9d
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, !test_bit(WDM_IN_USE, &desc->flags));
591
592 /* cannot dereference desc->intf if WDM_DISCONNECTING */
593 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags))
594 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
595 desc->werr);
596
597 return usb_translate_errors(desc->werr);
598 }
599
600 static __poll_t wdm_poll(struct file *file, struct poll_table_struct *wait)
601 {
602 struct wdm_device *desc = file->private_data;
603 unsigned long flags;
604 __poll_t mask = 0;
605
606 spin_lock_irqsave(&desc->iuspin, flags);
607 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
608 mask = EPOLLHUP | EPOLLERR;
609 spin_unlock_irqrestore(&desc->iuspin, flags);
610 goto desc_out;
611 }
612 if (test_bit(WDM_READ, &desc->flags))
613 mask = EPOLLIN | EPOLLRDNORM;
614 if (desc->rerr || desc->werr)
615 mask |= EPOLLERR;
616 if (!test_bit(WDM_IN_USE, &desc->flags))
617 mask |= EPOLLOUT | EPOLLWRNORM;
618 spin_unlock_irqrestore(&desc->iuspin, flags);
619
620 poll_wait(file, &desc->wait, wait);
621
622 desc_out:
623 return mask;
624 }
625
626 static int wdm_open(struct inode *inode, struct file *file)
627 {
628 int minor = iminor(inode);
629 int rv = -ENODEV;
630 struct usb_interface *intf;
631 struct wdm_device *desc;
632
633 mutex_lock(&wdm_mutex);
634 desc = wdm_find_device_by_minor(minor);
635 if (!desc)
636 goto out;
637
638 intf = desc->intf;
639 if (test_bit(WDM_DISCONNECTING, &desc->flags))
640 goto out;
641 file->private_data = desc;
642
643 rv = usb_autopm_get_interface(desc->intf);
644 if (rv < 0) {
645 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
646 goto out;
647 }
648
649 /* using write lock to protect desc->count */
650 mutex_lock(&desc->wlock);
651 if (!desc->count++) {
652 desc->werr = 0;
653 desc->rerr = 0;
654 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
655 if (rv < 0) {
656 desc->count--;
657 dev_err(&desc->intf->dev,
658 "Error submitting int urb - %d\n", rv);
659 rv = usb_translate_errors(rv);
660 }
661 } else {
662 rv = 0;
663 }
664 mutex_unlock(&desc->wlock);
665 if (desc->count == 1)
666 desc->manage_power(intf, 1);
667 usb_autopm_put_interface(desc->intf);
668 out:
669 mutex_unlock(&wdm_mutex);
670 return rv;
671 }
672
673 static int wdm_release(struct inode *inode, struct file *file)
674 {
675 struct wdm_device *desc = file->private_data;
676
677 mutex_lock(&wdm_mutex);
678
679 /* using write lock to protect desc->count */
680 mutex_lock(&desc->wlock);
681 desc->count--;
682 mutex_unlock(&desc->wlock);
683
684 if (!desc->count) {
685 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
686 dev_dbg(&desc->intf->dev, "wdm_release: cleanup\n");
687 kill_urbs(desc);
688 spin_lock_irq(&desc->iuspin);
689 desc->resp_count = 0;
690 spin_unlock_irq(&desc->iuspin);
691 desc->manage_power(desc->intf, 0);
692 } else {
693 /* must avoid dev_printk here as desc->intf is invalid */
694 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
695 cleanup(desc);
696 }
697 }
698 mutex_unlock(&wdm_mutex);
699 return 0;
700 }
701
702 static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
703 {
704 struct wdm_device *desc = file->private_data;
705 int rv = 0;
706
707 switch (cmd) {
708 case IOCTL_WDM_MAX_COMMAND:
709 if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand)))
710 rv = -EFAULT;
711 break;
712 default:
713 rv = -ENOTTY;
714 }
715 return rv;
716 }
717
718 static const struct file_operations wdm_fops = {
719 .owner = THIS_MODULE,
720 .read = wdm_read,
721 .write = wdm_write,
722 .open = wdm_open,
723 .flush = wdm_flush,
724 .release = wdm_release,
725 .poll = wdm_poll,
726 .unlocked_ioctl = wdm_ioctl,
727 .compat_ioctl = wdm_ioctl,
728 .llseek = noop_llseek,
729 };
730
731 static struct usb_class_driver wdm_class = {
732 .name = "cdc-wdm%d",
733 .fops = &wdm_fops,
734 .minor_base = WDM_MINOR_BASE,
735 };
736
737 /* --- error handling --- */
738 static void wdm_rxwork(struct work_struct *work)
739 {
740 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
741 unsigned long flags;
742 int rv = 0;
743 int responding;
744
745 spin_lock_irqsave(&desc->iuspin, flags);
746 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
747 spin_unlock_irqrestore(&desc->iuspin, flags);
748 } else {
749 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
750 spin_unlock_irqrestore(&desc->iuspin, flags);
751 if (!responding)
752 rv = usb_submit_urb(desc->response, GFP_KERNEL);
753 if (rv < 0 && rv != -EPERM) {
754 spin_lock_irqsave(&desc->iuspin, flags);
755 clear_bit(WDM_RESPONDING, &desc->flags);
756 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
757 schedule_work(&desc->rxwork);
758 spin_unlock_irqrestore(&desc->iuspin, flags);
759 }
760 }
761 }
762
763 static void service_interrupt_work(struct work_struct *work)
764 {
765 struct wdm_device *desc;
766
767 desc = container_of(work, struct wdm_device, service_outs_intr);
768
769 spin_lock_irq(&desc->iuspin);
770 service_outstanding_interrupt(desc);
771 if (!desc->resp_count) {
772 set_bit(WDM_READ, &desc->flags);
773 wake_up(&desc->wait);
774 }
775 spin_unlock_irq(&desc->iuspin);
776 }
777
778 /* --- hotplug --- */
779
780 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
781 u16 bufsize, int (*manage_power)(struct usb_interface *, int))
782 {
783 int rv = -ENOMEM;
784 struct wdm_device *desc;
785
786 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
787 if (!desc)
788 goto out;
789 INIT_LIST_HEAD(&desc->device_list);
790 mutex_init(&desc->rlock);
791 mutex_init(&desc->wlock);
792 spin_lock_init(&desc->iuspin);
793 init_waitqueue_head(&desc->wait);
794 desc->wMaxCommand = bufsize;
795 /* this will be expanded and needed in hardware endianness */
796 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
797 desc->intf = intf;
798 INIT_WORK(&desc->rxwork, wdm_rxwork);
799 INIT_WORK(&desc->service_outs_intr, service_interrupt_work);
800
801 rv = -EINVAL;
802 if (!usb_endpoint_is_int_in(ep))
803 goto err;
804
805 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
806
807 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
808 if (!desc->orq)
809 goto err;
810 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
811 if (!desc->irq)
812 goto err;
813
814 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
815 if (!desc->validity)
816 goto err;
817
818 desc->response = usb_alloc_urb(0, GFP_KERNEL);
819 if (!desc->response)
820 goto err;
821
822 desc->command = usb_alloc_urb(0, GFP_KERNEL);
823 if (!desc->command)
824 goto err;
825
826 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
827 if (!desc->ubuf)
828 goto err;
829
830 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
831 if (!desc->sbuf)
832 goto err;
833
834 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
835 if (!desc->inbuf)
836 goto err;
837
838 usb_fill_int_urb(
839 desc->validity,
840 interface_to_usbdev(intf),
841 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
842 desc->sbuf,
843 desc->wMaxPacketSize,
844 wdm_int_callback,
845 desc,
846 ep->bInterval
847 );
848
849 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
850 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
851 desc->irq->wValue = 0;
852 desc->irq->wIndex = desc->inum; /* already converted */
853 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
854
855 usb_fill_control_urb(
856 desc->response,
857 interface_to_usbdev(intf),
858 /* using common endpoint 0 */
859 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
860 (unsigned char *)desc->irq,
861 desc->inbuf,
862 desc->wMaxCommand,
863 wdm_in_callback,
864 desc
865 );
866
867 desc->manage_power = manage_power;
868
869 spin_lock(&wdm_device_list_lock);
870 list_add(&desc->device_list, &wdm_device_list);
871 spin_unlock(&wdm_device_list_lock);
872
873 rv = usb_register_dev(intf, &wdm_class);
874 if (rv < 0)
875 goto err;
876 else
877 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
878 out:
879 return rv;
880 err:
881 spin_lock(&wdm_device_list_lock);
882 list_del(&desc->device_list);
883 spin_unlock(&wdm_device_list_lock);
884 cleanup(desc);
885 return rv;
886 }
887
888 static int wdm_manage_power(struct usb_interface *intf, int on)
889 {
890 /* need autopm_get/put here to ensure the usbcore sees the new value */
891 int rv = usb_autopm_get_interface(intf);
892
893 intf->needs_remote_wakeup = on;
894 if (!rv)
895 usb_autopm_put_interface(intf);
896 return 0;
897 }
898
899 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
900 {
901 int rv = -EINVAL;
902 struct usb_host_interface *iface;
903 struct usb_endpoint_descriptor *ep;
904 struct usb_cdc_parsed_header hdr;
905 u8 *buffer = intf->altsetting->extra;
906 int buflen = intf->altsetting->extralen;
907 u16 maxcom = WDM_DEFAULT_BUFSIZE;
908
909 if (!buffer)
910 goto err;
911
912 cdc_parse_cdc_header(&hdr, intf, buffer, buflen);
913
914 if (hdr.usb_cdc_dmm_desc)
915 maxcom = le16_to_cpu(hdr.usb_cdc_dmm_desc->wMaxCommand);
916
917 iface = intf->cur_altsetting;
918 if (iface->desc.bNumEndpoints != 1)
919 goto err;
920 ep = &iface->endpoint[0].desc;
921
922 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
923
924 err:
925 return rv;
926 }
927
928 /**
929 * usb_cdc_wdm_register - register a WDM subdriver
930 * @intf: usb interface the subdriver will associate with
931 * @ep: interrupt endpoint to monitor for notifications
932 * @bufsize: maximum message size to support for read/write
933 *
934 * Create WDM usb class character device and associate it with intf
935 * without binding, allowing another driver to manage the interface.
936 *
937 * The subdriver will manage the given interrupt endpoint exclusively
938 * and will issue control requests referring to the given intf. It
939 * will otherwise avoid interferring, and in particular not do
940 * usb_set_intfdata/usb_get_intfdata on intf.
941 *
942 * The return value is a pointer to the subdriver's struct usb_driver.
943 * The registering driver is responsible for calling this subdriver's
944 * disconnect, suspend, resume, pre_reset and post_reset methods from
945 * its own.
946 */
947 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
948 struct usb_endpoint_descriptor *ep,
949 int bufsize,
950 int (*manage_power)(struct usb_interface *, int))
951 {
952 int rv = -EINVAL;
953
954 rv = wdm_create(intf, ep, bufsize, manage_power);
955 if (rv < 0)
956 goto err;
957
958 return &wdm_driver;
959 err:
960 return ERR_PTR(rv);
961 }
962 EXPORT_SYMBOL(usb_cdc_wdm_register);
963
964 static void wdm_disconnect(struct usb_interface *intf)
965 {
966 struct wdm_device *desc;
967 unsigned long flags;
968
969 usb_deregister_dev(intf, &wdm_class);
970 desc = wdm_find_device(intf);
971 mutex_lock(&wdm_mutex);
972
973 /* the spinlock makes sure no new urbs are generated in the callbacks */
974 spin_lock_irqsave(&desc->iuspin, flags);
975 set_bit(WDM_DISCONNECTING, &desc->flags);
976 set_bit(WDM_READ, &desc->flags);
977 /* to terminate pending flushes */
978 clear_bit(WDM_IN_USE, &desc->flags);
979 spin_unlock_irqrestore(&desc->iuspin, flags);
980 wake_up_all(&desc->wait);
981 mutex_lock(&desc->rlock);
982 mutex_lock(&desc->wlock);
983 kill_urbs(desc);
984 cancel_work_sync(&desc->rxwork);
985 cancel_work_sync(&desc->service_outs_intr);
986 mutex_unlock(&desc->wlock);
987 mutex_unlock(&desc->rlock);
988
989 /* the desc->intf pointer used as list key is now invalid */
990 spin_lock(&wdm_device_list_lock);
991 list_del(&desc->device_list);
992 spin_unlock(&wdm_device_list_lock);
993
994 if (!desc->count)
995 cleanup(desc);
996 else
997 dev_dbg(&intf->dev, "%d open files - postponing cleanup\n", desc->count);
998 mutex_unlock(&wdm_mutex);
999 }
1000
1001 #ifdef CONFIG_PM
1002 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
1003 {
1004 struct wdm_device *desc = wdm_find_device(intf);
1005 int rv = 0;
1006
1007 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
1008
1009 /* if this is an autosuspend the caller does the locking */
1010 if (!PMSG_IS_AUTO(message)) {
1011 mutex_lock(&desc->rlock);
1012 mutex_lock(&desc->wlock);
1013 }
1014 spin_lock_irq(&desc->iuspin);
1015
1016 if (PMSG_IS_AUTO(message) &&
1017 (test_bit(WDM_IN_USE, &desc->flags)
1018 || test_bit(WDM_RESPONDING, &desc->flags))) {
1019 spin_unlock_irq(&desc->iuspin);
1020 rv = -EBUSY;
1021 } else {
1022
1023 set_bit(WDM_SUSPENDING, &desc->flags);
1024 spin_unlock_irq(&desc->iuspin);
1025 /* callback submits work - order is essential */
1026 kill_urbs(desc);
1027 cancel_work_sync(&desc->rxwork);
1028 cancel_work_sync(&desc->service_outs_intr);
1029 }
1030 if (!PMSG_IS_AUTO(message)) {
1031 mutex_unlock(&desc->wlock);
1032 mutex_unlock(&desc->rlock);
1033 }
1034
1035 return rv;
1036 }
1037 #endif
1038
1039 static int recover_from_urb_loss(struct wdm_device *desc)
1040 {
1041 int rv = 0;
1042
1043 if (desc->count) {
1044 rv = usb_submit_urb(desc->validity, GFP_NOIO);
1045 if (rv < 0)
1046 dev_err(&desc->intf->dev,
1047 "Error resume submitting int urb - %d\n", rv);
1048 }
1049 return rv;
1050 }
1051
1052 #ifdef CONFIG_PM
1053 static int wdm_resume(struct usb_interface *intf)
1054 {
1055 struct wdm_device *desc = wdm_find_device(intf);
1056 int rv;
1057
1058 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
1059
1060 clear_bit(WDM_SUSPENDING, &desc->flags);
1061 rv = recover_from_urb_loss(desc);
1062
1063 return rv;
1064 }
1065 #endif
1066
1067 static int wdm_pre_reset(struct usb_interface *intf)
1068 {
1069 struct wdm_device *desc = wdm_find_device(intf);
1070
1071 /*
1072 * we notify everybody using poll of
1073 * an exceptional situation
1074 * must be done before recovery lest a spontaneous
1075 * message from the device is lost
1076 */
1077 spin_lock_irq(&desc->iuspin);
1078 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */
1079 set_bit(WDM_READ, &desc->flags); /* unblock read */
1080 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */
1081 desc->rerr = -EINTR;
1082 spin_unlock_irq(&desc->iuspin);
1083 wake_up_all(&desc->wait);
1084 mutex_lock(&desc->rlock);
1085 mutex_lock(&desc->wlock);
1086 kill_urbs(desc);
1087 cancel_work_sync(&desc->rxwork);
1088 cancel_work_sync(&desc->service_outs_intr);
1089 return 0;
1090 }
1091
1092 static int wdm_post_reset(struct usb_interface *intf)
1093 {
1094 struct wdm_device *desc = wdm_find_device(intf);
1095 int rv;
1096
1097 clear_bit(WDM_OVERFLOW, &desc->flags);
1098 clear_bit(WDM_RESETTING, &desc->flags);
1099 rv = recover_from_urb_loss(desc);
1100 mutex_unlock(&desc->wlock);
1101 mutex_unlock(&desc->rlock);
1102 return rv;
1103 }
1104
1105 static struct usb_driver wdm_driver = {
1106 .name = "cdc_wdm",
1107 .probe = wdm_probe,
1108 .disconnect = wdm_disconnect,
1109 #ifdef CONFIG_PM
1110 .suspend = wdm_suspend,
1111 .resume = wdm_resume,
1112 .reset_resume = wdm_resume,
1113 #endif
1114 .pre_reset = wdm_pre_reset,
1115 .post_reset = wdm_post_reset,
1116 .id_table = wdm_ids,
1117 .supports_autosuspend = 1,
1118 .disable_hub_initiated_lpm = 1,
1119 };
1120
1121 module_usb_driver(wdm_driver);
1122
1123 MODULE_AUTHOR(DRIVER_AUTHOR);
1124 MODULE_DESCRIPTION(DRIVER_DESC);
1125 MODULE_LICENSE("GPL");
Linux with added FPC-III support