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
60 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
61 #define WDM_DEFAULT_BUFSIZE 256
63 static DEFINE_MUTEX(wdm_mutex);
65 /* --- method tables --- */
68 u8 *inbuf; /* buffer for response */
69 u8 *outbuf; /* buffer for command */
70 u8 *sbuf; /* buffer for status */
71 u8 *ubuf; /* buffer for copy to user space */
76 struct usb_interface *intf;
77 struct usb_ctrlrequest *orq;
78 struct usb_ctrlrequest *irq;
95 wait_queue_head_t wait;
96 struct work_struct rxwork;
101 static struct usb_driver wdm_driver;
103 /* --- callbacks --- */
104 static void wdm_out_callback(struct urb *urb)
106 struct wdm_device *desc;
108 spin_lock(&desc->iuspin);
109 desc->werr = urb->status;
110 spin_unlock(&desc->iuspin);
113 clear_bit(WDM_IN_USE, &desc->flags);
114 wake_up(&desc->wait);
117 static void wdm_in_callback(struct urb *urb)
119 struct wdm_device *desc = urb->context;
120 int status = urb->status;
122 spin_lock(&desc->iuspin);
123 clear_bit(WDM_RESPONDING, &desc->flags);
128 dev_dbg(&desc->intf->dev,
129 "nonzero urb status received: -ENOENT");
132 dev_dbg(&desc->intf->dev,
133 "nonzero urb status received: -ECONNRESET");
136 dev_dbg(&desc->intf->dev,
137 "nonzero urb status received: -ESHUTDOWN");
140 dev_err(&desc->intf->dev,
141 "nonzero urb status received: -EPIPE\n");
144 dev_err(&desc->intf->dev,
145 "Unexpected error %d\n", status);
151 desc->reslength = urb->actual_length;
152 memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
153 desc->length += desc->reslength;
155 wake_up(&desc->wait);
157 set_bit(WDM_READ, &desc->flags);
158 spin_unlock(&desc->iuspin);
161 static void wdm_int_callback(struct urb *urb)
164 int status = urb->status;
165 struct wdm_device *desc;
166 struct usb_ctrlrequest *req;
167 struct usb_cdc_notification *dr;
171 dr = (struct usb_cdc_notification *)desc->sbuf;
180 set_bit(WDM_INT_STALL, &desc->flags);
181 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
182 goto sw; /* halt is cleared in work */
184 dev_err(&desc->intf->dev,
185 "nonzero urb status received: %d\n", status);
190 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
191 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
196 switch (dr->bNotificationType) {
197 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
198 dev_dbg(&desc->intf->dev,
199 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
200 dr->wIndex, dr->wLength);
203 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
205 dev_dbg(&desc->intf->dev,
206 "NOTIFY_NETWORK_CONNECTION %s network",
207 dr->wValue ? "connected to" : "disconnected from");
210 clear_bit(WDM_POLL_RUNNING, &desc->flags);
211 dev_err(&desc->intf->dev,
212 "unknown notification %d received: index %d len %d\n",
213 dr->bNotificationType, dr->wIndex, dr->wLength);
217 req->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
218 req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
220 req->wIndex = desc->inum;
221 req->wLength = cpu_to_le16(desc->wMaxCommand);
223 usb_fill_control_urb(
225 interface_to_usbdev(desc->intf),
226 /* using common endpoint 0 */
227 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
228 (unsigned char *)req,
234 desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
235 spin_lock(&desc->iuspin);
236 clear_bit(WDM_READ, &desc->flags);
237 set_bit(WDM_RESPONDING, &desc->flags);
238 if (!test_bit(WDM_DISCONNECTING, &desc->flags)
239 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
240 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
241 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
244 spin_unlock(&desc->iuspin);
246 clear_bit(WDM_RESPONDING, &desc->flags);
251 rv = schedule_work(&desc->rxwork);
253 dev_err(&desc->intf->dev,
254 "Cannot schedule work\n");
258 rv = usb_submit_urb(urb, GFP_ATOMIC);
260 dev_err(&desc->intf->dev,
261 "%s - usb_submit_urb failed with result %d\n",
266 static void kill_urbs(struct wdm_device *desc)
268 /* the order here is essential */
269 usb_kill_urb(desc->command);
270 usb_kill_urb(desc->validity);
271 usb_kill_urb(desc->response);
274 static void free_urbs(struct wdm_device *desc)
276 usb_free_urb(desc->validity);
277 usb_free_urb(desc->response);
278 usb_free_urb(desc->command);
281 static void cleanup(struct wdm_device *desc)
283 usb_free_coherent(interface_to_usbdev(desc->intf),
284 desc->wMaxPacketSize,
286 desc->validity->transfer_dma);
287 usb_free_coherent(interface_to_usbdev(desc->intf),
288 desc->bMaxPacketSize0,
290 desc->response->transfer_dma);
298 static ssize_t wdm_write
299 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
302 int rv = -EMSGSIZE, r, we;
303 struct wdm_device *desc = file->private_data;
304 struct usb_ctrlrequest *req;
306 if (count > desc->wMaxCommand)
307 count = desc->wMaxCommand;
309 spin_lock_irq(&desc->iuspin);
312 spin_unlock_irq(&desc->iuspin);
316 buf = kmalloc(count, GFP_KERNEL);
322 r = copy_from_user(buf, buffer, count);
329 /* concurrent writes and disconnect */
330 r = mutex_lock_interruptible(&desc->wlock);
337 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
343 r = usb_autopm_get_interface(desc->intf);
349 if (!(file->f_flags & O_NONBLOCK))
350 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
353 if (test_bit(WDM_IN_USE, &desc->flags))
361 usb_fill_control_urb(
363 interface_to_usbdev(desc->intf),
364 /* using common endpoint 0 */
365 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
366 (unsigned char *)req,
373 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
374 USB_RECIP_INTERFACE);
375 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
377 req->wIndex = desc->inum;
378 req->wLength = cpu_to_le16(count);
379 set_bit(WDM_IN_USE, &desc->flags);
382 rv = usb_submit_urb(desc->command, GFP_KERNEL);
386 clear_bit(WDM_IN_USE, &desc->flags);
387 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
389 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
393 usb_autopm_put_interface(desc->intf);
395 mutex_unlock(&desc->wlock);
397 return rv < 0 ? rv : count;
400 static ssize_t wdm_read
401 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
405 struct wdm_device *desc = file->private_data;
408 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
412 cntr = ACCESS_ONCE(desc->length);
416 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
421 if (file->f_flags & O_NONBLOCK) {
422 if (!test_bit(WDM_READ, &desc->flags)) {
423 rv = cntr ? cntr : -EAGAIN;
428 rv = wait_event_interruptible(desc->wait,
429 test_bit(WDM_READ, &desc->flags));
432 /* may have happened while we slept */
433 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
437 usb_mark_last_busy(interface_to_usbdev(desc->intf));
443 spin_lock_irq(&desc->iuspin);
445 if (desc->rerr) { /* read completed, error happened */
447 spin_unlock_irq(&desc->iuspin);
452 * recheck whether we've lost the race
453 * against the completion handler
455 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
456 spin_unlock_irq(&desc->iuspin);
459 if (!desc->reslength) { /* zero length read */
460 spin_unlock_irq(&desc->iuspin);
464 spin_unlock_irq(&desc->iuspin);
469 rv = copy_to_user(buffer, desc->ubuf, cntr);
475 spin_lock_irq(&desc->iuspin);
477 for (i = 0; i < desc->length - cntr; i++)
478 desc->ubuf[i] = desc->ubuf[i + cntr];
480 desc->length -= cntr;
481 /* in case we had outstanding data */
483 clear_bit(WDM_READ, &desc->flags);
485 spin_unlock_irq(&desc->iuspin);
490 mutex_unlock(&desc->rlock);
494 static int wdm_flush(struct file *file, fl_owner_t id)
496 struct wdm_device *desc = file->private_data;
498 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
500 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
503 return usb_translate_errors(desc->werr);
506 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
508 struct wdm_device *desc = file->private_data;
510 unsigned int mask = 0;
512 spin_lock_irqsave(&desc->iuspin, flags);
513 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
515 spin_unlock_irqrestore(&desc->iuspin, flags);
518 if (test_bit(WDM_READ, &desc->flags))
519 mask = POLLIN | POLLRDNORM;
520 if (desc->rerr || desc->werr)
522 if (!test_bit(WDM_IN_USE, &desc->flags))
523 mask |= POLLOUT | POLLWRNORM;
524 spin_unlock_irqrestore(&desc->iuspin, flags);
526 poll_wait(file, &desc->wait, wait);
532 static int wdm_open(struct inode *inode, struct file *file)
534 int minor = iminor(inode);
536 struct usb_interface *intf;
537 struct wdm_device *desc;
539 mutex_lock(&wdm_mutex);
540 intf = usb_find_interface(&wdm_driver, minor);
544 desc = usb_get_intfdata(intf);
545 if (test_bit(WDM_DISCONNECTING, &desc->flags))
547 file->private_data = desc;
549 rv = usb_autopm_get_interface(desc->intf);
551 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
554 intf->needs_remote_wakeup = 1;
556 /* using write lock to protect desc->count */
557 mutex_lock(&desc->wlock);
558 if (!desc->count++) {
561 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
564 dev_err(&desc->intf->dev,
565 "Error submitting int urb - %d\n", rv);
570 mutex_unlock(&desc->wlock);
571 usb_autopm_put_interface(desc->intf);
573 mutex_unlock(&wdm_mutex);
577 static int wdm_release(struct inode *inode, struct file *file)
579 struct wdm_device *desc = file->private_data;
581 mutex_lock(&wdm_mutex);
583 /* using write lock to protect desc->count */
584 mutex_lock(&desc->wlock);
586 mutex_unlock(&desc->wlock);
589 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
591 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
592 desc->intf->needs_remote_wakeup = 0;
596 mutex_unlock(&wdm_mutex);
600 static const struct file_operations wdm_fops = {
601 .owner = THIS_MODULE,
606 .release = wdm_release,
608 .llseek = noop_llseek,
611 static struct usb_class_driver wdm_class = {
614 .minor_base = WDM_MINOR_BASE,
617 /* --- error handling --- */
618 static void wdm_rxwork(struct work_struct *work)
620 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
624 spin_lock_irqsave(&desc->iuspin, flags);
625 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
626 spin_unlock_irqrestore(&desc->iuspin, flags);
628 spin_unlock_irqrestore(&desc->iuspin, flags);
629 rv = usb_submit_urb(desc->response, GFP_KERNEL);
630 if (rv < 0 && rv != -EPERM) {
631 spin_lock_irqsave(&desc->iuspin, flags);
632 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
633 schedule_work(&desc->rxwork);
634 spin_unlock_irqrestore(&desc->iuspin, flags);
639 /* --- hotplug --- */
641 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
644 struct usb_device *udev = interface_to_usbdev(intf);
645 struct wdm_device *desc;
646 struct usb_host_interface *iface;
647 struct usb_endpoint_descriptor *ep;
648 struct usb_cdc_dmm_desc *dmhd;
649 u8 *buffer = intf->altsetting->extra;
650 int buflen = intf->altsetting->extralen;
651 u16 maxcom = WDM_DEFAULT_BUFSIZE;
657 if (buffer [1] != USB_DT_CS_INTERFACE) {
658 dev_err(&intf->dev, "skipping garbage\n");
662 switch (buffer [2]) {
663 case USB_CDC_HEADER_TYPE:
665 case USB_CDC_DMM_TYPE:
666 dmhd = (struct usb_cdc_dmm_desc *)buffer;
667 maxcom = le16_to_cpu(dmhd->wMaxCommand);
669 "Finding maximum buffer length: %d", maxcom);
673 "Ignoring extra header, type %d, length %d\n",
674 buffer[2], buffer[0]);
683 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
686 mutex_init(&desc->rlock);
687 mutex_init(&desc->wlock);
688 spin_lock_init(&desc->iuspin);
689 init_waitqueue_head(&desc->wait);
690 desc->wMaxCommand = maxcom;
691 /* this will be expanded and needed in hardware endianness */
692 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
694 INIT_WORK(&desc->rxwork, wdm_rxwork);
697 iface = intf->cur_altsetting;
698 if (iface->desc.bNumEndpoints != 1)
700 ep = &iface->endpoint[0].desc;
701 if (!ep || !usb_endpoint_is_int_in(ep))
704 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
705 desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
707 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
710 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
714 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
718 desc->response = usb_alloc_urb(0, GFP_KERNEL);
722 desc->command = usb_alloc_urb(0, GFP_KERNEL);
726 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
730 desc->sbuf = usb_alloc_coherent(interface_to_usbdev(intf),
731 desc->wMaxPacketSize,
733 &desc->validity->transfer_dma);
737 desc->inbuf = usb_alloc_coherent(interface_to_usbdev(intf),
740 &desc->response->transfer_dma);
746 interface_to_usbdev(intf),
747 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
749 desc->wMaxPacketSize,
754 desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
756 usb_set_intfdata(intf, desc);
757 rv = usb_register_dev(intf, &wdm_class);
761 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
762 intf->minor - WDM_MINOR_BASE);
766 usb_set_intfdata(intf, NULL);
767 usb_free_coherent(interface_to_usbdev(desc->intf),
768 desc->bMaxPacketSize0,
770 desc->response->transfer_dma);
772 usb_free_coherent(interface_to_usbdev(desc->intf),
773 desc->wMaxPacketSize,
775 desc->validity->transfer_dma);
785 static void wdm_disconnect(struct usb_interface *intf)
787 struct wdm_device *desc;
790 usb_deregister_dev(intf, &wdm_class);
791 mutex_lock(&wdm_mutex);
792 desc = usb_get_intfdata(intf);
794 /* the spinlock makes sure no new urbs are generated in the callbacks */
795 spin_lock_irqsave(&desc->iuspin, flags);
796 set_bit(WDM_DISCONNECTING, &desc->flags);
797 set_bit(WDM_READ, &desc->flags);
798 /* to terminate pending flushes */
799 clear_bit(WDM_IN_USE, &desc->flags);
800 spin_unlock_irqrestore(&desc->iuspin, flags);
801 wake_up_all(&desc->wait);
802 mutex_lock(&desc->rlock);
803 mutex_lock(&desc->wlock);
805 cancel_work_sync(&desc->rxwork);
806 mutex_unlock(&desc->wlock);
807 mutex_unlock(&desc->rlock);
810 mutex_unlock(&wdm_mutex);
814 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
816 struct wdm_device *desc = usb_get_intfdata(intf);
819 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
821 /* if this is an autosuspend the caller does the locking */
822 if (!PMSG_IS_AUTO(message)) {
823 mutex_lock(&desc->rlock);
824 mutex_lock(&desc->wlock);
826 spin_lock_irq(&desc->iuspin);
828 if (PMSG_IS_AUTO(message) &&
829 (test_bit(WDM_IN_USE, &desc->flags)
830 || test_bit(WDM_RESPONDING, &desc->flags))) {
831 spin_unlock_irq(&desc->iuspin);
835 set_bit(WDM_SUSPENDING, &desc->flags);
836 spin_unlock_irq(&desc->iuspin);
837 /* callback submits work - order is essential */
839 cancel_work_sync(&desc->rxwork);
841 if (!PMSG_IS_AUTO(message)) {
842 mutex_unlock(&desc->wlock);
843 mutex_unlock(&desc->rlock);
850 static int recover_from_urb_loss(struct wdm_device *desc)
855 rv = usb_submit_urb(desc->validity, GFP_NOIO);
857 dev_err(&desc->intf->dev,
858 "Error resume submitting int urb - %d\n", rv);
864 static int wdm_resume(struct usb_interface *intf)
866 struct wdm_device *desc = usb_get_intfdata(intf);
869 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
871 clear_bit(WDM_SUSPENDING, &desc->flags);
872 rv = recover_from_urb_loss(desc);
878 static int wdm_pre_reset(struct usb_interface *intf)
880 struct wdm_device *desc = usb_get_intfdata(intf);
882 mutex_lock(&desc->rlock);
883 mutex_lock(&desc->wlock);
887 * we notify everybody using poll of
888 * an exceptional situation
889 * must be done before recovery lest a spontaneous
890 * message from the device is lost
892 spin_lock_irq(&desc->iuspin);
894 spin_unlock_irq(&desc->iuspin);
895 wake_up_all(&desc->wait);
899 static int wdm_post_reset(struct usb_interface *intf)
901 struct wdm_device *desc = usb_get_intfdata(intf);
904 rv = recover_from_urb_loss(desc);
905 mutex_unlock(&desc->wlock);
906 mutex_unlock(&desc->rlock);
910 static struct usb_driver wdm_driver = {
913 .disconnect = wdm_disconnect,
915 .suspend = wdm_suspend,
916 .resume = wdm_resume,
917 .reset_resume = wdm_resume,
919 .pre_reset = wdm_pre_reset,
920 .post_reset = wdm_post_reset,
922 .supports_autosuspend = 1,
925 /* --- low level module stuff --- */
927 static int __init wdm_init(void)
931 rv = usb_register(&wdm_driver);
936 static void __exit wdm_exit(void)
938 usb_deregister(&wdm_driver);
941 module_init(wdm_init);
942 module_exit(wdm_exit);
944 MODULE_AUTHOR(DRIVER_AUTHOR);
945 MODULE_DESCRIPTION(DRIVER_DESC);
946 MODULE_LICENSE("GPL");