4 * This driver supports USB CDC WCM Device Management.
6 * Copyright (c) 2007-2009 Oliver Neukum
8 * Some code taken from cdc-acm.c
10 * Released under the GPLv2.
12 * Many thanks to Carl Nordbeck
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/slab.h>
17 #include <linux/module.h>
18 #include <linux/mutex.h>
19 #include <linux/uaccess.h>
20 #include <linux/bitops.h>
21 #include <linux/poll.h>
22 #include <linux/usb.h>
23 #include <linux/usb/cdc.h>
24 #include <asm/byteorder.h>
25 #include <asm/unaligned.h>
30 #define DRIVER_VERSION "v0.03"
31 #define DRIVER_AUTHOR "Oliver Neukum"
32 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
34 static const struct usb_device_id wdm_ids[] = {
36 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
37 USB_DEVICE_ID_MATCH_INT_SUBCLASS,
38 .bInterfaceClass = USB_CLASS_COMM,
39 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
44 MODULE_DEVICE_TABLE (usb, wdm_ids);
46 #define WDM_MINOR_BASE 176
50 #define WDM_DISCONNECTING 2
53 #define WDM_INT_STALL 5
54 #define WDM_POLL_RUNNING 6
55 #define WDM_RESPONDING 7
56 #define WDM_SUSPENDING 8
61 static DEFINE_MUTEX(wdm_mutex);
63 /* --- method tables --- */
66 u8 *inbuf; /* buffer for response */
67 u8 *outbuf; /* buffer for command */
68 u8 *sbuf; /* buffer for status */
69 u8 *ubuf; /* buffer for copy to user space */
74 struct usb_interface *intf;
75 struct usb_ctrlrequest *orq;
76 struct usb_ctrlrequest *irq;
91 wait_queue_head_t wait;
92 struct work_struct rxwork;
97 static struct usb_driver wdm_driver;
99 /* --- callbacks --- */
100 static void wdm_out_callback(struct urb *urb)
102 struct wdm_device *desc;
104 spin_lock(&desc->iuspin);
105 desc->werr = urb->status;
106 spin_unlock(&desc->iuspin);
107 clear_bit(WDM_IN_USE, &desc->flags);
109 wake_up(&desc->wait);
112 static void wdm_in_callback(struct urb *urb)
114 struct wdm_device *desc = urb->context;
115 int status = urb->status;
117 spin_lock(&desc->iuspin);
118 clear_bit(WDM_RESPONDING, &desc->flags);
123 dev_dbg(&desc->intf->dev,
124 "nonzero urb status received: -ENOENT");
127 dev_dbg(&desc->intf->dev,
128 "nonzero urb status received: -ECONNRESET");
131 dev_dbg(&desc->intf->dev,
132 "nonzero urb status received: -ESHUTDOWN");
135 dev_err(&desc->intf->dev,
136 "nonzero urb status received: -EPIPE\n");
139 dev_err(&desc->intf->dev,
140 "Unexpected error %d\n", status);
146 desc->reslength = urb->actual_length;
147 memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
148 desc->length += desc->reslength;
150 wake_up(&desc->wait);
152 set_bit(WDM_READ, &desc->flags);
153 spin_unlock(&desc->iuspin);
156 static void wdm_int_callback(struct urb *urb)
159 int status = urb->status;
160 struct wdm_device *desc;
161 struct usb_cdc_notification *dr;
164 dr = (struct usb_cdc_notification *)desc->sbuf;
173 set_bit(WDM_INT_STALL, &desc->flags);
174 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
175 goto sw; /* halt is cleared in work */
177 dev_err(&desc->intf->dev,
178 "nonzero urb status received: %d\n", status);
183 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
184 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
189 switch (dr->bNotificationType) {
190 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
191 dev_dbg(&desc->intf->dev,
192 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
193 dr->wIndex, dr->wLength);
196 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
198 dev_dbg(&desc->intf->dev,
199 "NOTIFY_NETWORK_CONNECTION %s network",
200 dr->wValue ? "connected to" : "disconnected from");
203 clear_bit(WDM_POLL_RUNNING, &desc->flags);
204 dev_err(&desc->intf->dev,
205 "unknown notification %d received: index %d len %d\n",
206 dr->bNotificationType, dr->wIndex, dr->wLength);
210 spin_lock(&desc->iuspin);
211 clear_bit(WDM_READ, &desc->flags);
212 set_bit(WDM_RESPONDING, &desc->flags);
213 if (!test_bit(WDM_DISCONNECTING, &desc->flags)
214 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
215 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
216 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
219 spin_unlock(&desc->iuspin);
221 clear_bit(WDM_RESPONDING, &desc->flags);
226 rv = schedule_work(&desc->rxwork);
228 dev_err(&desc->intf->dev,
229 "Cannot schedule work\n");
233 rv = usb_submit_urb(urb, GFP_ATOMIC);
235 dev_err(&desc->intf->dev,
236 "%s - usb_submit_urb failed with result %d\n",
241 static void kill_urbs(struct wdm_device *desc)
243 /* the order here is essential */
244 usb_kill_urb(desc->command);
245 usb_kill_urb(desc->validity);
246 usb_kill_urb(desc->response);
249 static void free_urbs(struct wdm_device *desc)
251 usb_free_urb(desc->validity);
252 usb_free_urb(desc->response);
253 usb_free_urb(desc->command);
256 static void cleanup(struct wdm_device *desc)
267 static ssize_t wdm_write
268 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
271 int rv = -EMSGSIZE, r, we;
272 struct wdm_device *desc = file->private_data;
273 struct usb_ctrlrequest *req;
275 if (count > desc->wMaxCommand)
276 count = desc->wMaxCommand;
278 spin_lock_irq(&desc->iuspin);
281 spin_unlock_irq(&desc->iuspin);
285 desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
291 r = copy_from_user(buf, buffer, count);
298 /* concurrent writes and disconnect */
299 r = mutex_lock_interruptible(&desc->lock);
306 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
312 r = usb_autopm_get_interface(desc->intf);
318 if (!(file->f_flags & O_NONBLOCK))
319 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
322 if (test_bit(WDM_IN_USE, &desc->flags))
330 usb_fill_control_urb(
332 interface_to_usbdev(desc->intf),
333 /* using common endpoint 0 */
334 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
335 (unsigned char *)req,
342 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
343 USB_RECIP_INTERFACE);
344 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
346 req->wIndex = desc->inum;
347 req->wLength = cpu_to_le16(count);
348 set_bit(WDM_IN_USE, &desc->flags);
350 rv = usb_submit_urb(desc->command, GFP_KERNEL);
353 clear_bit(WDM_IN_USE, &desc->flags);
354 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
356 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
360 usb_autopm_put_interface(desc->intf);
362 mutex_unlock(&desc->lock);
364 return rv < 0 ? rv : count;
367 static ssize_t wdm_read
368 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
372 struct wdm_device *desc = file->private_data;
375 rv = mutex_lock_interruptible(&desc->lock); /*concurrent reads */
379 if (desc->length == 0) {
382 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
387 if (file->f_flags & O_NONBLOCK) {
388 if (!test_bit(WDM_READ, &desc->flags)) {
389 rv = cntr ? cntr : -EAGAIN;
394 rv = wait_event_interruptible(desc->wait,
395 test_bit(WDM_READ, &desc->flags));
398 /* may have happened while we slept */
399 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
403 usb_mark_last_busy(interface_to_usbdev(desc->intf));
409 spin_lock_irq(&desc->iuspin);
411 if (desc->rerr) { /* read completed, error happened */
413 spin_unlock_irq(&desc->iuspin);
418 * recheck whether we've lost the race
419 * against the completion handler
421 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
422 spin_unlock_irq(&desc->iuspin);
425 if (!desc->reslength) { /* zero length read */
426 spin_unlock_irq(&desc->iuspin);
429 clear_bit(WDM_READ, &desc->flags);
430 spin_unlock_irq(&desc->iuspin);
433 cntr = count > desc->length ? desc->length : count;
434 rv = copy_to_user(buffer, desc->ubuf, cntr);
440 for (i = 0; i < desc->length - cntr; i++)
441 desc->ubuf[i] = desc->ubuf[i + cntr];
443 desc->length -= cntr;
444 /* in case we had outstanding data */
446 clear_bit(WDM_READ, &desc->flags);
450 mutex_unlock(&desc->lock);
454 static int wdm_flush(struct file *file, fl_owner_t id)
456 struct wdm_device *desc = file->private_data;
458 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
460 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
466 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
468 struct wdm_device *desc = file->private_data;
470 unsigned int mask = 0;
472 spin_lock_irqsave(&desc->iuspin, flags);
473 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
475 spin_unlock_irqrestore(&desc->iuspin, flags);
478 if (test_bit(WDM_READ, &desc->flags))
479 mask = POLLIN | POLLRDNORM;
480 if (desc->rerr || desc->werr)
482 if (!test_bit(WDM_IN_USE, &desc->flags))
483 mask |= POLLOUT | POLLWRNORM;
484 spin_unlock_irqrestore(&desc->iuspin, flags);
486 poll_wait(file, &desc->wait, wait);
492 static int wdm_open(struct inode *inode, struct file *file)
494 int minor = iminor(inode);
496 struct usb_interface *intf;
497 struct wdm_device *desc;
499 mutex_lock(&wdm_mutex);
500 intf = usb_find_interface(&wdm_driver, minor);
504 desc = usb_get_intfdata(intf);
505 if (test_bit(WDM_DISCONNECTING, &desc->flags))
507 file->private_data = desc;
509 rv = usb_autopm_get_interface(desc->intf);
511 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
514 intf->needs_remote_wakeup = 1;
516 mutex_lock(&desc->lock);
517 if (!desc->count++) {
520 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
523 dev_err(&desc->intf->dev,
524 "Error submitting int urb - %d\n", rv);
529 mutex_unlock(&desc->lock);
530 usb_autopm_put_interface(desc->intf);
532 mutex_unlock(&wdm_mutex);
536 static int wdm_release(struct inode *inode, struct file *file)
538 struct wdm_device *desc = file->private_data;
540 mutex_lock(&wdm_mutex);
541 mutex_lock(&desc->lock);
543 mutex_unlock(&desc->lock);
546 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
548 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
549 desc->intf->needs_remote_wakeup = 0;
551 mutex_unlock(&wdm_mutex);
555 static const struct file_operations wdm_fops = {
556 .owner = THIS_MODULE,
561 .release = wdm_release,
563 .llseek = noop_llseek,
566 static struct usb_class_driver wdm_class = {
569 .minor_base = WDM_MINOR_BASE,
572 /* --- error handling --- */
573 static void wdm_rxwork(struct work_struct *work)
575 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
579 spin_lock_irqsave(&desc->iuspin, flags);
580 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
581 spin_unlock_irqrestore(&desc->iuspin, flags);
583 spin_unlock_irqrestore(&desc->iuspin, flags);
584 rv = usb_submit_urb(desc->response, GFP_KERNEL);
585 if (rv < 0 && rv != -EPERM) {
586 spin_lock_irqsave(&desc->iuspin, flags);
587 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
588 schedule_work(&desc->rxwork);
589 spin_unlock_irqrestore(&desc->iuspin, flags);
594 /* --- hotplug --- */
596 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
599 struct wdm_device *desc;
600 struct usb_host_interface *iface;
601 struct usb_endpoint_descriptor *ep;
602 struct usb_cdc_dmm_desc *dmhd;
603 u8 *buffer = intf->altsetting->extra;
604 int buflen = intf->altsetting->extralen;
611 if (buffer [1] != USB_DT_CS_INTERFACE) {
612 dev_err(&intf->dev, "skipping garbage\n");
616 switch (buffer [2]) {
617 case USB_CDC_HEADER_TYPE:
619 case USB_CDC_DMM_TYPE:
620 dmhd = (struct usb_cdc_dmm_desc *)buffer;
621 maxcom = le16_to_cpu(dmhd->wMaxCommand);
623 "Finding maximum buffer length: %d", maxcom);
627 "Ignoring extra header, type %d, length %d\n",
628 buffer[2], buffer[0]);
637 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
640 mutex_init(&desc->lock);
641 spin_lock_init(&desc->iuspin);
642 init_waitqueue_head(&desc->wait);
643 desc->wMaxCommand = maxcom;
644 /* this will be expanded and needed in hardware endianness */
645 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
647 INIT_WORK(&desc->rxwork, wdm_rxwork);
650 iface = intf->cur_altsetting;
651 if (iface->desc.bNumEndpoints != 1)
653 ep = &iface->endpoint[0].desc;
654 if (!ep || !usb_endpoint_is_int_in(ep))
657 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
659 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
662 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
666 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
670 desc->response = usb_alloc_urb(0, GFP_KERNEL);
674 desc->command = usb_alloc_urb(0, GFP_KERNEL);
678 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
682 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
686 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
692 interface_to_usbdev(intf),
693 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
695 desc->wMaxPacketSize,
701 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
702 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
703 desc->irq->wValue = 0;
704 desc->irq->wIndex = desc->inum;
705 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
707 usb_fill_control_urb(
709 interface_to_usbdev(intf),
710 /* using common endpoint 0 */
711 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
712 (unsigned char *)desc->irq,
719 usb_set_intfdata(intf, desc);
720 rv = usb_register_dev(intf, &wdm_class);
724 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
725 intf->minor - WDM_MINOR_BASE);
729 usb_set_intfdata(intf, NULL);
741 static void wdm_disconnect(struct usb_interface *intf)
743 struct wdm_device *desc;
746 usb_deregister_dev(intf, &wdm_class);
747 mutex_lock(&wdm_mutex);
748 desc = usb_get_intfdata(intf);
750 /* the spinlock makes sure no new urbs are generated in the callbacks */
751 spin_lock_irqsave(&desc->iuspin, flags);
752 set_bit(WDM_DISCONNECTING, &desc->flags);
753 set_bit(WDM_READ, &desc->flags);
754 /* to terminate pending flushes */
755 clear_bit(WDM_IN_USE, &desc->flags);
756 spin_unlock_irqrestore(&desc->iuspin, flags);
757 mutex_lock(&desc->lock);
759 cancel_work_sync(&desc->rxwork);
760 mutex_unlock(&desc->lock);
761 wake_up_all(&desc->wait);
764 mutex_unlock(&wdm_mutex);
768 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
770 struct wdm_device *desc = usb_get_intfdata(intf);
773 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
775 /* if this is an autosuspend the caller does the locking */
776 if (!PMSG_IS_AUTO(message))
777 mutex_lock(&desc->lock);
778 spin_lock_irq(&desc->iuspin);
780 if (PMSG_IS_AUTO(message) &&
781 (test_bit(WDM_IN_USE, &desc->flags)
782 || test_bit(WDM_RESPONDING, &desc->flags))) {
783 spin_unlock_irq(&desc->iuspin);
787 set_bit(WDM_SUSPENDING, &desc->flags);
788 spin_unlock_irq(&desc->iuspin);
789 /* callback submits work - order is essential */
791 cancel_work_sync(&desc->rxwork);
793 if (!PMSG_IS_AUTO(message))
794 mutex_unlock(&desc->lock);
800 static int recover_from_urb_loss(struct wdm_device *desc)
805 rv = usb_submit_urb(desc->validity, GFP_NOIO);
807 dev_err(&desc->intf->dev,
808 "Error resume submitting int urb - %d\n", rv);
814 static int wdm_resume(struct usb_interface *intf)
816 struct wdm_device *desc = usb_get_intfdata(intf);
819 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
821 clear_bit(WDM_SUSPENDING, &desc->flags);
822 rv = recover_from_urb_loss(desc);
828 static int wdm_pre_reset(struct usb_interface *intf)
830 struct wdm_device *desc = usb_get_intfdata(intf);
832 mutex_lock(&desc->lock);
836 * we notify everybody using poll of
837 * an exceptional situation
838 * must be done before recovery lest a spontaneous
839 * message from the device is lost
841 spin_lock_irq(&desc->iuspin);
843 spin_unlock_irq(&desc->iuspin);
844 wake_up_all(&desc->wait);
848 static int wdm_post_reset(struct usb_interface *intf)
850 struct wdm_device *desc = usb_get_intfdata(intf);
853 rv = recover_from_urb_loss(desc);
854 mutex_unlock(&desc->lock);
858 static struct usb_driver wdm_driver = {
861 .disconnect = wdm_disconnect,
863 .suspend = wdm_suspend,
864 .resume = wdm_resume,
865 .reset_resume = wdm_resume,
867 .pre_reset = wdm_pre_reset,
868 .post_reset = wdm_post_reset,
870 .supports_autosuspend = 1,
873 module_usb_driver(wdm_driver);
875 MODULE_AUTHOR(DRIVER_AUTHOR);
876 MODULE_DESCRIPTION(DRIVER_DESC);
877 MODULE_LICENSE("GPL");