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);
111 clear_bit(WDM_IN_USE, &desc->flags);
113 wake_up(&desc->wait);
116 static void wdm_in_callback(struct urb *urb)
118 struct wdm_device *desc = urb->context;
119 int status = urb->status;
121 spin_lock(&desc->iuspin);
122 clear_bit(WDM_RESPONDING, &desc->flags);
127 dev_dbg(&desc->intf->dev,
128 "nonzero urb status received: -ENOENT");
131 dev_dbg(&desc->intf->dev,
132 "nonzero urb status received: -ECONNRESET");
135 dev_dbg(&desc->intf->dev,
136 "nonzero urb status received: -ESHUTDOWN");
139 dev_err(&desc->intf->dev,
140 "nonzero urb status received: -EPIPE\n");
143 dev_err(&desc->intf->dev,
144 "Unexpected error %d\n", status);
150 desc->reslength = urb->actual_length;
151 memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
152 desc->length += desc->reslength;
154 wake_up(&desc->wait);
156 set_bit(WDM_READ, &desc->flags);
157 spin_unlock(&desc->iuspin);
160 static void wdm_int_callback(struct urb *urb)
163 int status = urb->status;
164 struct wdm_device *desc;
165 struct usb_ctrlrequest *req;
166 struct usb_cdc_notification *dr;
170 dr = (struct usb_cdc_notification *)desc->sbuf;
179 set_bit(WDM_INT_STALL, &desc->flags);
180 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
181 goto sw; /* halt is cleared in work */
183 dev_err(&desc->intf->dev,
184 "nonzero urb status received: %d\n", status);
189 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
190 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
195 switch (dr->bNotificationType) {
196 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
197 dev_dbg(&desc->intf->dev,
198 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
199 dr->wIndex, dr->wLength);
202 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
204 dev_dbg(&desc->intf->dev,
205 "NOTIFY_NETWORK_CONNECTION %s network",
206 dr->wValue ? "connected to" : "disconnected from");
209 clear_bit(WDM_POLL_RUNNING, &desc->flags);
210 dev_err(&desc->intf->dev,
211 "unknown notification %d received: index %d len %d\n",
212 dr->bNotificationType, dr->wIndex, dr->wLength);
216 req->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
217 req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
219 req->wIndex = desc->inum;
220 req->wLength = cpu_to_le16(desc->wMaxCommand);
222 usb_fill_control_urb(
224 interface_to_usbdev(desc->intf),
225 /* using common endpoint 0 */
226 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
227 (unsigned char *)req,
233 desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
234 spin_lock(&desc->iuspin);
235 clear_bit(WDM_READ, &desc->flags);
236 set_bit(WDM_RESPONDING, &desc->flags);
237 if (!test_bit(WDM_DISCONNECTING, &desc->flags)
238 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
239 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
240 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
243 spin_unlock(&desc->iuspin);
245 clear_bit(WDM_RESPONDING, &desc->flags);
250 rv = schedule_work(&desc->rxwork);
252 dev_err(&desc->intf->dev,
253 "Cannot schedule work\n");
257 rv = usb_submit_urb(urb, GFP_ATOMIC);
259 dev_err(&desc->intf->dev,
260 "%s - usb_submit_urb failed with result %d\n",
265 static void kill_urbs(struct wdm_device *desc)
267 /* the order here is essential */
268 usb_kill_urb(desc->command);
269 usb_kill_urb(desc->validity);
270 usb_kill_urb(desc->response);
273 static void free_urbs(struct wdm_device *desc)
275 usb_free_urb(desc->validity);
276 usb_free_urb(desc->response);
277 usb_free_urb(desc->command);
280 static void cleanup(struct wdm_device *desc)
282 usb_free_coherent(interface_to_usbdev(desc->intf),
283 desc->wMaxPacketSize,
285 desc->validity->transfer_dma);
286 usb_free_coherent(interface_to_usbdev(desc->intf),
287 desc->bMaxPacketSize0,
289 desc->response->transfer_dma);
297 static ssize_t wdm_write
298 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
301 int rv = -EMSGSIZE, r, we;
302 struct wdm_device *desc = file->private_data;
303 struct usb_ctrlrequest *req;
305 if (count > desc->wMaxCommand)
306 count = desc->wMaxCommand;
308 spin_lock_irq(&desc->iuspin);
311 spin_unlock_irq(&desc->iuspin);
315 desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
321 r = copy_from_user(buf, buffer, count);
328 /* concurrent writes and disconnect */
329 r = mutex_lock_interruptible(&desc->wlock);
336 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
342 r = usb_autopm_get_interface(desc->intf);
348 if (!(file->f_flags & O_NONBLOCK))
349 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
352 if (test_bit(WDM_IN_USE, &desc->flags))
360 usb_fill_control_urb(
362 interface_to_usbdev(desc->intf),
363 /* using common endpoint 0 */
364 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
365 (unsigned char *)req,
372 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
373 USB_RECIP_INTERFACE);
374 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
376 req->wIndex = desc->inum;
377 req->wLength = cpu_to_le16(count);
378 set_bit(WDM_IN_USE, &desc->flags);
380 rv = usb_submit_urb(desc->command, GFP_KERNEL);
383 clear_bit(WDM_IN_USE, &desc->flags);
384 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
386 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
390 usb_autopm_put_interface(desc->intf);
392 mutex_unlock(&desc->wlock);
394 return rv < 0 ? rv : count;
397 static ssize_t wdm_read
398 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
402 struct wdm_device *desc = file->private_data;
405 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
409 if (desc->length == 0) {
412 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
417 if (file->f_flags & O_NONBLOCK) {
418 if (!test_bit(WDM_READ, &desc->flags)) {
419 rv = cntr ? cntr : -EAGAIN;
424 rv = wait_event_interruptible(desc->wait,
425 test_bit(WDM_READ, &desc->flags));
428 /* may have happened while we slept */
429 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
433 usb_mark_last_busy(interface_to_usbdev(desc->intf));
439 spin_lock_irq(&desc->iuspin);
441 if (desc->rerr) { /* read completed, error happened */
443 spin_unlock_irq(&desc->iuspin);
448 * recheck whether we've lost the race
449 * against the completion handler
451 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
452 spin_unlock_irq(&desc->iuspin);
455 if (!desc->reslength) { /* zero length read */
456 spin_unlock_irq(&desc->iuspin);
459 clear_bit(WDM_READ, &desc->flags);
460 spin_unlock_irq(&desc->iuspin);
463 cntr = count > desc->length ? desc->length : count;
464 rv = copy_to_user(buffer, desc->ubuf, cntr);
470 for (i = 0; i < desc->length - cntr; i++)
471 desc->ubuf[i] = desc->ubuf[i + cntr];
473 spin_lock_irq(&desc->iuspin);
474 desc->length -= cntr;
475 spin_unlock_irq(&desc->iuspin);
476 /* in case we had outstanding data */
478 clear_bit(WDM_READ, &desc->flags);
482 mutex_unlock(&desc->rlock);
486 static int wdm_flush(struct file *file, fl_owner_t id)
488 struct wdm_device *desc = file->private_data;
490 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
492 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
498 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
500 struct wdm_device *desc = file->private_data;
502 unsigned int mask = 0;
504 spin_lock_irqsave(&desc->iuspin, flags);
505 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
507 spin_unlock_irqrestore(&desc->iuspin, flags);
510 if (test_bit(WDM_READ, &desc->flags))
511 mask = POLLIN | POLLRDNORM;
512 if (desc->rerr || desc->werr)
514 if (!test_bit(WDM_IN_USE, &desc->flags))
515 mask |= POLLOUT | POLLWRNORM;
516 spin_unlock_irqrestore(&desc->iuspin, flags);
518 poll_wait(file, &desc->wait, wait);
524 static int wdm_open(struct inode *inode, struct file *file)
526 int minor = iminor(inode);
528 struct usb_interface *intf;
529 struct wdm_device *desc;
531 mutex_lock(&wdm_mutex);
532 intf = usb_find_interface(&wdm_driver, minor);
536 desc = usb_get_intfdata(intf);
537 if (test_bit(WDM_DISCONNECTING, &desc->flags))
539 file->private_data = desc;
541 rv = usb_autopm_get_interface(desc->intf);
543 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
546 intf->needs_remote_wakeup = 1;
548 /* using write lock to protect desc->count */
549 mutex_lock(&desc->wlock);
550 if (!desc->count++) {
553 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
556 dev_err(&desc->intf->dev,
557 "Error submitting int urb - %d\n", rv);
562 mutex_unlock(&desc->wlock);
563 usb_autopm_put_interface(desc->intf);
565 mutex_unlock(&wdm_mutex);
569 static int wdm_release(struct inode *inode, struct file *file)
571 struct wdm_device *desc = file->private_data;
573 mutex_lock(&wdm_mutex);
575 /* using write lock to protect desc->count */
576 mutex_lock(&desc->wlock);
578 mutex_unlock(&desc->wlock);
581 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
583 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
584 desc->intf->needs_remote_wakeup = 0;
586 mutex_unlock(&wdm_mutex);
590 static const struct file_operations wdm_fops = {
591 .owner = THIS_MODULE,
596 .release = wdm_release,
598 .llseek = noop_llseek,
601 static struct usb_class_driver wdm_class = {
604 .minor_base = WDM_MINOR_BASE,
607 /* --- error handling --- */
608 static void wdm_rxwork(struct work_struct *work)
610 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
614 spin_lock_irqsave(&desc->iuspin, flags);
615 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
616 spin_unlock_irqrestore(&desc->iuspin, flags);
618 spin_unlock_irqrestore(&desc->iuspin, flags);
619 rv = usb_submit_urb(desc->response, GFP_KERNEL);
620 if (rv < 0 && rv != -EPERM) {
621 spin_lock_irqsave(&desc->iuspin, flags);
622 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
623 schedule_work(&desc->rxwork);
624 spin_unlock_irqrestore(&desc->iuspin, flags);
629 /* --- hotplug --- */
631 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
634 struct usb_device *udev = interface_to_usbdev(intf);
635 struct wdm_device *desc;
636 struct usb_host_interface *iface;
637 struct usb_endpoint_descriptor *ep;
638 struct usb_cdc_dmm_desc *dmhd;
639 u8 *buffer = intf->altsetting->extra;
640 int buflen = intf->altsetting->extralen;
641 u16 maxcom = WDM_DEFAULT_BUFSIZE;
647 if (buffer [1] != USB_DT_CS_INTERFACE) {
648 dev_err(&intf->dev, "skipping garbage\n");
652 switch (buffer [2]) {
653 case USB_CDC_HEADER_TYPE:
655 case USB_CDC_DMM_TYPE:
656 dmhd = (struct usb_cdc_dmm_desc *)buffer;
657 maxcom = le16_to_cpu(dmhd->wMaxCommand);
659 "Finding maximum buffer length: %d", maxcom);
663 "Ignoring extra header, type %d, length %d\n",
664 buffer[2], buffer[0]);
673 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
676 mutex_init(&desc->rlock);
677 mutex_init(&desc->wlock);
678 spin_lock_init(&desc->iuspin);
679 init_waitqueue_head(&desc->wait);
680 desc->wMaxCommand = maxcom;
681 /* this will be expanded and needed in hardware endianness */
682 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
684 INIT_WORK(&desc->rxwork, wdm_rxwork);
687 iface = intf->cur_altsetting;
688 if (iface->desc.bNumEndpoints != 1)
690 ep = &iface->endpoint[0].desc;
691 if (!ep || !usb_endpoint_is_int_in(ep))
694 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
695 desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
697 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
700 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
704 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
708 desc->response = usb_alloc_urb(0, GFP_KERNEL);
712 desc->command = usb_alloc_urb(0, GFP_KERNEL);
716 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
720 desc->sbuf = usb_alloc_coherent(interface_to_usbdev(intf),
721 desc->wMaxPacketSize,
723 &desc->validity->transfer_dma);
727 desc->inbuf = usb_alloc_coherent(interface_to_usbdev(intf),
730 &desc->response->transfer_dma);
736 interface_to_usbdev(intf),
737 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
739 desc->wMaxPacketSize,
744 desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
746 usb_set_intfdata(intf, desc);
747 rv = usb_register_dev(intf, &wdm_class);
751 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
752 intf->minor - WDM_MINOR_BASE);
756 usb_set_intfdata(intf, NULL);
757 usb_free_coherent(interface_to_usbdev(desc->intf),
758 desc->bMaxPacketSize0,
760 desc->response->transfer_dma);
762 usb_free_coherent(interface_to_usbdev(desc->intf),
763 desc->wMaxPacketSize,
765 desc->validity->transfer_dma);
775 static void wdm_disconnect(struct usb_interface *intf)
777 struct wdm_device *desc;
780 usb_deregister_dev(intf, &wdm_class);
781 mutex_lock(&wdm_mutex);
782 desc = usb_get_intfdata(intf);
784 /* the spinlock makes sure no new urbs are generated in the callbacks */
785 spin_lock_irqsave(&desc->iuspin, flags);
786 set_bit(WDM_DISCONNECTING, &desc->flags);
787 set_bit(WDM_READ, &desc->flags);
788 /* to terminate pending flushes */
789 clear_bit(WDM_IN_USE, &desc->flags);
790 spin_unlock_irqrestore(&desc->iuspin, flags);
791 wake_up_all(&desc->wait);
792 mutex_lock(&desc->rlock);
793 mutex_lock(&desc->wlock);
795 cancel_work_sync(&desc->rxwork);
796 mutex_unlock(&desc->wlock);
797 mutex_unlock(&desc->rlock);
800 mutex_unlock(&wdm_mutex);
804 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
806 struct wdm_device *desc = usb_get_intfdata(intf);
809 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
811 /* if this is an autosuspend the caller does the locking */
812 if (!PMSG_IS_AUTO(message)) {
813 mutex_lock(&desc->rlock);
814 mutex_lock(&desc->wlock);
816 spin_lock_irq(&desc->iuspin);
818 if (PMSG_IS_AUTO(message) &&
819 (test_bit(WDM_IN_USE, &desc->flags)
820 || test_bit(WDM_RESPONDING, &desc->flags))) {
821 spin_unlock_irq(&desc->iuspin);
825 set_bit(WDM_SUSPENDING, &desc->flags);
826 spin_unlock_irq(&desc->iuspin);
827 /* callback submits work - order is essential */
829 cancel_work_sync(&desc->rxwork);
831 if (!PMSG_IS_AUTO(message)) {
832 mutex_unlock(&desc->wlock);
833 mutex_unlock(&desc->rlock);
840 static int recover_from_urb_loss(struct wdm_device *desc)
845 rv = usb_submit_urb(desc->validity, GFP_NOIO);
847 dev_err(&desc->intf->dev,
848 "Error resume submitting int urb - %d\n", rv);
854 static int wdm_resume(struct usb_interface *intf)
856 struct wdm_device *desc = usb_get_intfdata(intf);
859 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
861 clear_bit(WDM_SUSPENDING, &desc->flags);
862 rv = recover_from_urb_loss(desc);
868 static int wdm_pre_reset(struct usb_interface *intf)
870 struct wdm_device *desc = usb_get_intfdata(intf);
872 mutex_lock(&desc->rlock);
873 mutex_lock(&desc->wlock);
877 * we notify everybody using poll of
878 * an exceptional situation
879 * must be done before recovery lest a spontaneous
880 * message from the device is lost
882 spin_lock_irq(&desc->iuspin);
884 spin_unlock_irq(&desc->iuspin);
885 wake_up_all(&desc->wait);
889 static int wdm_post_reset(struct usb_interface *intf)
891 struct wdm_device *desc = usb_get_intfdata(intf);
894 rv = recover_from_urb_loss(desc);
895 mutex_unlock(&desc->wlock);
896 mutex_unlock(&desc->rlock);
900 static struct usb_driver wdm_driver = {
903 .disconnect = wdm_disconnect,
905 .suspend = wdm_suspend,
906 .resume = wdm_resume,
907 .reset_resume = wdm_resume,
909 .pre_reset = wdm_pre_reset,
910 .post_reset = wdm_post_reset,
912 .supports_autosuspend = 1,
915 module_usb_driver(wdm_driver);
917 MODULE_AUTHOR(DRIVER_AUTHOR);
918 MODULE_DESCRIPTION(DRIVER_DESC);
919 MODULE_LICENSE("GPL");