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;
92 wait_queue_head_t wait;
93 struct work_struct rxwork;
98 static struct usb_driver wdm_driver;
100 /* --- callbacks --- */
101 static void wdm_out_callback(struct urb *urb)
103 struct wdm_device *desc;
105 spin_lock(&desc->iuspin);
106 desc->werr = urb->status;
107 spin_unlock(&desc->iuspin);
108 clear_bit(WDM_IN_USE, &desc->flags);
110 wake_up(&desc->wait);
113 static void wdm_in_callback(struct urb *urb)
115 struct wdm_device *desc = urb->context;
116 int status = urb->status;
118 spin_lock(&desc->iuspin);
119 clear_bit(WDM_RESPONDING, &desc->flags);
124 dev_dbg(&desc->intf->dev,
125 "nonzero urb status received: -ENOENT");
128 dev_dbg(&desc->intf->dev,
129 "nonzero urb status received: -ECONNRESET");
132 dev_dbg(&desc->intf->dev,
133 "nonzero urb status received: -ESHUTDOWN");
136 dev_err(&desc->intf->dev,
137 "nonzero urb status received: -EPIPE\n");
140 dev_err(&desc->intf->dev,
141 "Unexpected error %d\n", status);
147 desc->reslength = urb->actual_length;
148 memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
149 desc->length += desc->reslength;
151 wake_up(&desc->wait);
153 set_bit(WDM_READ, &desc->flags);
154 spin_unlock(&desc->iuspin);
157 static void wdm_int_callback(struct urb *urb)
160 int status = urb->status;
161 struct wdm_device *desc;
162 struct usb_cdc_notification *dr;
165 dr = (struct usb_cdc_notification *)desc->sbuf;
174 set_bit(WDM_INT_STALL, &desc->flags);
175 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
176 goto sw; /* halt is cleared in work */
178 dev_err(&desc->intf->dev,
179 "nonzero urb status received: %d\n", status);
184 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
185 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
190 switch (dr->bNotificationType) {
191 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
192 dev_dbg(&desc->intf->dev,
193 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
194 dr->wIndex, dr->wLength);
197 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
199 dev_dbg(&desc->intf->dev,
200 "NOTIFY_NETWORK_CONNECTION %s network",
201 dr->wValue ? "connected to" : "disconnected from");
204 clear_bit(WDM_POLL_RUNNING, &desc->flags);
205 dev_err(&desc->intf->dev,
206 "unknown notification %d received: index %d len %d\n",
207 dr->bNotificationType, dr->wIndex, dr->wLength);
211 spin_lock(&desc->iuspin);
212 clear_bit(WDM_READ, &desc->flags);
213 set_bit(WDM_RESPONDING, &desc->flags);
214 if (!test_bit(WDM_DISCONNECTING, &desc->flags)
215 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
216 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
217 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
220 spin_unlock(&desc->iuspin);
222 clear_bit(WDM_RESPONDING, &desc->flags);
227 rv = schedule_work(&desc->rxwork);
229 dev_err(&desc->intf->dev,
230 "Cannot schedule work\n");
234 rv = usb_submit_urb(urb, GFP_ATOMIC);
236 dev_err(&desc->intf->dev,
237 "%s - usb_submit_urb failed with result %d\n",
242 static void kill_urbs(struct wdm_device *desc)
244 /* the order here is essential */
245 usb_kill_urb(desc->command);
246 usb_kill_urb(desc->validity);
247 usb_kill_urb(desc->response);
250 static void free_urbs(struct wdm_device *desc)
252 usb_free_urb(desc->validity);
253 usb_free_urb(desc->response);
254 usb_free_urb(desc->command);
257 static void cleanup(struct wdm_device *desc)
259 usb_free_coherent(interface_to_usbdev(desc->intf),
260 desc->wMaxPacketSize,
262 desc->validity->transfer_dma);
263 usb_free_coherent(interface_to_usbdev(desc->intf),
264 desc->bMaxPacketSize0,
266 desc->response->transfer_dma);
274 static ssize_t wdm_write
275 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
278 int rv = -EMSGSIZE, r, we;
279 struct wdm_device *desc = file->private_data;
280 struct usb_ctrlrequest *req;
282 if (count > desc->wMaxCommand)
283 count = desc->wMaxCommand;
285 spin_lock_irq(&desc->iuspin);
288 spin_unlock_irq(&desc->iuspin);
292 desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
298 r = copy_from_user(buf, buffer, count);
305 /* concurrent writes and disconnect */
306 r = mutex_lock_interruptible(&desc->lock);
313 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
319 r = usb_autopm_get_interface(desc->intf);
325 if (!(file->f_flags & O_NONBLOCK))
326 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
329 if (test_bit(WDM_IN_USE, &desc->flags))
337 usb_fill_control_urb(
339 interface_to_usbdev(desc->intf),
340 /* using common endpoint 0 */
341 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
342 (unsigned char *)req,
349 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
350 USB_RECIP_INTERFACE);
351 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
353 req->wIndex = desc->inum;
354 req->wLength = cpu_to_le16(count);
355 set_bit(WDM_IN_USE, &desc->flags);
357 rv = usb_submit_urb(desc->command, GFP_KERNEL);
360 clear_bit(WDM_IN_USE, &desc->flags);
361 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
363 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
367 usb_autopm_put_interface(desc->intf);
369 mutex_unlock(&desc->lock);
371 return rv < 0 ? rv : count;
374 static ssize_t wdm_read
375 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
379 struct wdm_device *desc = file->private_data;
382 rv = mutex_lock_interruptible(&desc->lock); /*concurrent reads */
386 if (desc->length == 0) {
389 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
394 if (file->f_flags & O_NONBLOCK) {
395 if (!test_bit(WDM_READ, &desc->flags)) {
396 rv = cntr ? cntr : -EAGAIN;
401 rv = wait_event_interruptible(desc->wait,
402 test_bit(WDM_READ, &desc->flags));
405 /* may have happened while we slept */
406 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
410 usb_mark_last_busy(interface_to_usbdev(desc->intf));
416 spin_lock_irq(&desc->iuspin);
418 if (desc->rerr) { /* read completed, error happened */
420 spin_unlock_irq(&desc->iuspin);
425 * recheck whether we've lost the race
426 * against the completion handler
428 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
429 spin_unlock_irq(&desc->iuspin);
432 if (!desc->reslength) { /* zero length read */
433 spin_unlock_irq(&desc->iuspin);
436 clear_bit(WDM_READ, &desc->flags);
437 spin_unlock_irq(&desc->iuspin);
440 cntr = count > desc->length ? desc->length : count;
441 rv = copy_to_user(buffer, desc->ubuf, cntr);
447 for (i = 0; i < desc->length - cntr; i++)
448 desc->ubuf[i] = desc->ubuf[i + cntr];
450 desc->length -= cntr;
451 /* in case we had outstanding data */
453 clear_bit(WDM_READ, &desc->flags);
457 mutex_unlock(&desc->lock);
461 static int wdm_flush(struct file *file, fl_owner_t id)
463 struct wdm_device *desc = file->private_data;
465 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
467 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
473 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
475 struct wdm_device *desc = file->private_data;
477 unsigned int mask = 0;
479 spin_lock_irqsave(&desc->iuspin, flags);
480 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
482 spin_unlock_irqrestore(&desc->iuspin, flags);
485 if (test_bit(WDM_READ, &desc->flags))
486 mask = POLLIN | POLLRDNORM;
487 if (desc->rerr || desc->werr)
489 if (!test_bit(WDM_IN_USE, &desc->flags))
490 mask |= POLLOUT | POLLWRNORM;
491 spin_unlock_irqrestore(&desc->iuspin, flags);
493 poll_wait(file, &desc->wait, wait);
499 static int wdm_open(struct inode *inode, struct file *file)
501 int minor = iminor(inode);
503 struct usb_interface *intf;
504 struct wdm_device *desc;
506 mutex_lock(&wdm_mutex);
507 intf = usb_find_interface(&wdm_driver, minor);
511 desc = usb_get_intfdata(intf);
512 if (test_bit(WDM_DISCONNECTING, &desc->flags))
514 file->private_data = desc;
516 rv = usb_autopm_get_interface(desc->intf);
518 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
521 intf->needs_remote_wakeup = 1;
523 mutex_lock(&desc->lock);
524 if (!desc->count++) {
527 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
530 dev_err(&desc->intf->dev,
531 "Error submitting int urb - %d\n", rv);
536 mutex_unlock(&desc->lock);
537 usb_autopm_put_interface(desc->intf);
539 mutex_unlock(&wdm_mutex);
543 static int wdm_release(struct inode *inode, struct file *file)
545 struct wdm_device *desc = file->private_data;
547 mutex_lock(&wdm_mutex);
548 mutex_lock(&desc->lock);
550 mutex_unlock(&desc->lock);
553 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
555 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
556 desc->intf->needs_remote_wakeup = 0;
558 mutex_unlock(&wdm_mutex);
562 static const struct file_operations wdm_fops = {
563 .owner = THIS_MODULE,
568 .release = wdm_release,
570 .llseek = noop_llseek,
573 static struct usb_class_driver wdm_class = {
576 .minor_base = WDM_MINOR_BASE,
579 /* --- error handling --- */
580 static void wdm_rxwork(struct work_struct *work)
582 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
586 spin_lock_irqsave(&desc->iuspin, flags);
587 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
588 spin_unlock_irqrestore(&desc->iuspin, flags);
590 spin_unlock_irqrestore(&desc->iuspin, flags);
591 rv = usb_submit_urb(desc->response, GFP_KERNEL);
592 if (rv < 0 && rv != -EPERM) {
593 spin_lock_irqsave(&desc->iuspin, flags);
594 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
595 schedule_work(&desc->rxwork);
596 spin_unlock_irqrestore(&desc->iuspin, flags);
601 /* --- hotplug --- */
603 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
606 struct usb_device *udev = interface_to_usbdev(intf);
607 struct wdm_device *desc;
608 struct usb_host_interface *iface;
609 struct usb_endpoint_descriptor *ep;
610 struct usb_cdc_dmm_desc *dmhd;
611 u8 *buffer = intf->altsetting->extra;
612 int buflen = intf->altsetting->extralen;
619 if (buffer [1] != USB_DT_CS_INTERFACE) {
620 dev_err(&intf->dev, "skipping garbage\n");
624 switch (buffer [2]) {
625 case USB_CDC_HEADER_TYPE:
627 case USB_CDC_DMM_TYPE:
628 dmhd = (struct usb_cdc_dmm_desc *)buffer;
629 maxcom = le16_to_cpu(dmhd->wMaxCommand);
631 "Finding maximum buffer length: %d", maxcom);
635 "Ignoring extra header, type %d, length %d\n",
636 buffer[2], buffer[0]);
645 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
648 mutex_init(&desc->lock);
649 spin_lock_init(&desc->iuspin);
650 init_waitqueue_head(&desc->wait);
651 desc->wMaxCommand = maxcom;
652 /* this will be expanded and needed in hardware endianness */
653 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
655 INIT_WORK(&desc->rxwork, wdm_rxwork);
658 iface = intf->cur_altsetting;
659 if (iface->desc.bNumEndpoints != 1)
661 ep = &iface->endpoint[0].desc;
662 if (!ep || !usb_endpoint_is_int_in(ep))
665 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
666 desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
668 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
671 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
675 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
679 desc->response = usb_alloc_urb(0, GFP_KERNEL);
683 desc->command = usb_alloc_urb(0, GFP_KERNEL);
687 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
691 desc->sbuf = usb_alloc_coherent(interface_to_usbdev(intf),
692 desc->wMaxPacketSize,
694 &desc->validity->transfer_dma);
698 desc->inbuf = usb_alloc_coherent(interface_to_usbdev(intf),
701 &desc->response->transfer_dma);
707 interface_to_usbdev(intf),
708 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
710 desc->wMaxPacketSize,
715 desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
717 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
718 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
719 desc->irq->wValue = 0;
720 desc->irq->wIndex = desc->inum;
721 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
723 usb_fill_control_urb(
725 interface_to_usbdev(desc->intf),
726 /* using common endpoint 0 */
727 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
728 (unsigned char *)desc->irq,
734 desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
736 usb_set_intfdata(intf, desc);
737 rv = usb_register_dev(intf, &wdm_class);
741 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
742 intf->minor - WDM_MINOR_BASE);
746 usb_set_intfdata(intf, NULL);
747 usb_free_coherent(interface_to_usbdev(desc->intf),
748 desc->bMaxPacketSize0,
750 desc->response->transfer_dma);
752 usb_free_coherent(interface_to_usbdev(desc->intf),
753 desc->wMaxPacketSize,
755 desc->validity->transfer_dma);
765 static void wdm_disconnect(struct usb_interface *intf)
767 struct wdm_device *desc;
770 usb_deregister_dev(intf, &wdm_class);
771 mutex_lock(&wdm_mutex);
772 desc = usb_get_intfdata(intf);
774 /* the spinlock makes sure no new urbs are generated in the callbacks */
775 spin_lock_irqsave(&desc->iuspin, flags);
776 set_bit(WDM_DISCONNECTING, &desc->flags);
777 set_bit(WDM_READ, &desc->flags);
778 /* to terminate pending flushes */
779 clear_bit(WDM_IN_USE, &desc->flags);
780 spin_unlock_irqrestore(&desc->iuspin, flags);
781 mutex_lock(&desc->lock);
783 cancel_work_sync(&desc->rxwork);
784 mutex_unlock(&desc->lock);
785 wake_up_all(&desc->wait);
788 mutex_unlock(&wdm_mutex);
792 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
794 struct wdm_device *desc = usb_get_intfdata(intf);
797 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
799 /* if this is an autosuspend the caller does the locking */
800 if (!PMSG_IS_AUTO(message))
801 mutex_lock(&desc->lock);
802 spin_lock_irq(&desc->iuspin);
804 if (PMSG_IS_AUTO(message) &&
805 (test_bit(WDM_IN_USE, &desc->flags)
806 || test_bit(WDM_RESPONDING, &desc->flags))) {
807 spin_unlock_irq(&desc->iuspin);
811 set_bit(WDM_SUSPENDING, &desc->flags);
812 spin_unlock_irq(&desc->iuspin);
813 /* callback submits work - order is essential */
815 cancel_work_sync(&desc->rxwork);
817 if (!PMSG_IS_AUTO(message))
818 mutex_unlock(&desc->lock);
824 static int recover_from_urb_loss(struct wdm_device *desc)
829 rv = usb_submit_urb(desc->validity, GFP_NOIO);
831 dev_err(&desc->intf->dev,
832 "Error resume submitting int urb - %d\n", rv);
838 static int wdm_resume(struct usb_interface *intf)
840 struct wdm_device *desc = usb_get_intfdata(intf);
843 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
845 clear_bit(WDM_SUSPENDING, &desc->flags);
846 rv = recover_from_urb_loss(desc);
852 static int wdm_pre_reset(struct usb_interface *intf)
854 struct wdm_device *desc = usb_get_intfdata(intf);
856 mutex_lock(&desc->lock);
860 * we notify everybody using poll of
861 * an exceptional situation
862 * must be done before recovery lest a spontaneous
863 * message from the device is lost
865 spin_lock_irq(&desc->iuspin);
867 spin_unlock_irq(&desc->iuspin);
868 wake_up_all(&desc->wait);
872 static int wdm_post_reset(struct usb_interface *intf)
874 struct wdm_device *desc = usb_get_intfdata(intf);
877 rv = recover_from_urb_loss(desc);
878 mutex_unlock(&desc->lock);
882 static struct usb_driver wdm_driver = {
885 .disconnect = wdm_disconnect,
887 .suspend = wdm_suspend,
888 .resume = wdm_resume,
889 .reset_resume = wdm_resume,
891 .pre_reset = wdm_pre_reset,
892 .post_reset = wdm_post_reset,
894 .supports_autosuspend = 1,
897 module_usb_driver(wdm_driver);
899 MODULE_AUTHOR(DRIVER_AUTHOR);
900 MODULE_DESCRIPTION(DRIVER_DESC);
901 MODULE_LICENSE("GPL");