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_ctrlrequest *req;
163 struct usb_cdc_notification *dr;
167 dr = (struct usb_cdc_notification *)desc->sbuf;
176 set_bit(WDM_INT_STALL, &desc->flags);
177 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
178 goto sw; /* halt is cleared in work */
180 dev_err(&desc->intf->dev,
181 "nonzero urb status received: %d\n", status);
186 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
187 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
192 switch (dr->bNotificationType) {
193 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
194 dev_dbg(&desc->intf->dev,
195 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
196 dr->wIndex, dr->wLength);
199 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
201 dev_dbg(&desc->intf->dev,
202 "NOTIFY_NETWORK_CONNECTION %s network",
203 dr->wValue ? "connected to" : "disconnected from");
206 clear_bit(WDM_POLL_RUNNING, &desc->flags);
207 dev_err(&desc->intf->dev,
208 "unknown notification %d received: index %d len %d\n",
209 dr->bNotificationType, dr->wIndex, dr->wLength);
213 req->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
214 req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
216 req->wIndex = desc->inum;
217 req->wLength = cpu_to_le16(desc->wMaxCommand);
219 usb_fill_control_urb(
221 interface_to_usbdev(desc->intf),
222 /* using common endpoint 0 */
223 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
224 (unsigned char *)req,
230 desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
231 spin_lock(&desc->iuspin);
232 clear_bit(WDM_READ, &desc->flags);
233 set_bit(WDM_RESPONDING, &desc->flags);
234 if (!test_bit(WDM_DISCONNECTING, &desc->flags)
235 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
236 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
237 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
240 spin_unlock(&desc->iuspin);
242 clear_bit(WDM_RESPONDING, &desc->flags);
247 rv = schedule_work(&desc->rxwork);
249 dev_err(&desc->intf->dev,
250 "Cannot schedule work\n");
254 rv = usb_submit_urb(urb, GFP_ATOMIC);
256 dev_err(&desc->intf->dev,
257 "%s - usb_submit_urb failed with result %d\n",
262 static void kill_urbs(struct wdm_device *desc)
264 /* the order here is essential */
265 usb_kill_urb(desc->command);
266 usb_kill_urb(desc->validity);
267 usb_kill_urb(desc->response);
270 static void free_urbs(struct wdm_device *desc)
272 usb_free_urb(desc->validity);
273 usb_free_urb(desc->response);
274 usb_free_urb(desc->command);
277 static void cleanup(struct wdm_device *desc)
279 usb_buffer_free(interface_to_usbdev(desc->intf),
280 desc->wMaxPacketSize,
282 desc->validity->transfer_dma);
283 usb_buffer_free(interface_to_usbdev(desc->intf),
286 desc->response->transfer_dma);
294 static ssize_t wdm_write
295 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
298 int rv = -EMSGSIZE, r, we;
299 struct wdm_device *desc = file->private_data;
300 struct usb_ctrlrequest *req;
302 if (count > desc->wMaxCommand)
303 count = desc->wMaxCommand;
305 spin_lock_irq(&desc->iuspin);
308 spin_unlock_irq(&desc->iuspin);
312 desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
318 r = copy_from_user(buf, buffer, count);
325 /* concurrent writes and disconnect */
326 r = mutex_lock_interruptible(&desc->lock);
333 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
339 r = usb_autopm_get_interface(desc->intf);
345 if (!file->f_flags && O_NONBLOCK)
346 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
349 if (test_bit(WDM_IN_USE, &desc->flags))
357 usb_fill_control_urb(
359 interface_to_usbdev(desc->intf),
360 /* using common endpoint 0 */
361 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
362 (unsigned char *)req,
369 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
370 USB_RECIP_INTERFACE);
371 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
373 req->wIndex = desc->inum;
374 req->wLength = cpu_to_le16(count);
375 set_bit(WDM_IN_USE, &desc->flags);
377 rv = usb_submit_urb(desc->command, GFP_KERNEL);
380 clear_bit(WDM_IN_USE, &desc->flags);
381 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
383 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
387 usb_autopm_put_interface(desc->intf);
389 mutex_unlock(&desc->lock);
391 return rv < 0 ? rv : count;
394 static ssize_t wdm_read
395 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
399 struct wdm_device *desc = file->private_data;
402 rv = mutex_lock_interruptible(&desc->lock); /*concurrent reads */
406 if (desc->length == 0) {
409 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
414 if (file->f_flags & O_NONBLOCK) {
415 if (!test_bit(WDM_READ, &desc->flags)) {
416 rv = cntr ? cntr : -EAGAIN;
421 rv = wait_event_interruptible(desc->wait,
422 test_bit(WDM_READ, &desc->flags));
425 /* may have happened while we slept */
426 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
430 usb_mark_last_busy(interface_to_usbdev(desc->intf));
436 spin_lock_irq(&desc->iuspin);
438 if (desc->rerr) { /* read completed, error happened */
440 spin_unlock_irq(&desc->iuspin);
445 * recheck whether we've lost the race
446 * against the completion handler
448 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
449 spin_unlock_irq(&desc->iuspin);
452 if (!desc->reslength) { /* zero length read */
453 spin_unlock_irq(&desc->iuspin);
456 clear_bit(WDM_READ, &desc->flags);
457 spin_unlock_irq(&desc->iuspin);
460 cntr = count > desc->length ? desc->length : count;
461 rv = copy_to_user(buffer, desc->ubuf, cntr);
467 for (i = 0; i < desc->length - cntr; i++)
468 desc->ubuf[i] = desc->ubuf[i + cntr];
470 desc->length -= cntr;
471 /* in case we had outstanding data */
473 clear_bit(WDM_READ, &desc->flags);
477 mutex_unlock(&desc->lock);
481 static int wdm_flush(struct file *file, fl_owner_t id)
483 struct wdm_device *desc = file->private_data;
485 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
487 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
493 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
495 struct wdm_device *desc = file->private_data;
497 unsigned int mask = 0;
499 spin_lock_irqsave(&desc->iuspin, flags);
500 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
502 spin_unlock_irqrestore(&desc->iuspin, flags);
505 if (test_bit(WDM_READ, &desc->flags))
506 mask = POLLIN | POLLRDNORM;
507 if (desc->rerr || desc->werr)
509 if (!test_bit(WDM_IN_USE, &desc->flags))
510 mask |= POLLOUT | POLLWRNORM;
511 spin_unlock_irqrestore(&desc->iuspin, flags);
513 poll_wait(file, &desc->wait, wait);
519 static int wdm_open(struct inode *inode, struct file *file)
521 int minor = iminor(inode);
523 struct usb_interface *intf;
524 struct wdm_device *desc;
526 mutex_lock(&wdm_mutex);
527 intf = usb_find_interface(&wdm_driver, minor);
531 desc = usb_get_intfdata(intf);
532 if (test_bit(WDM_DISCONNECTING, &desc->flags))
534 file->private_data = desc;
536 rv = usb_autopm_get_interface(desc->intf);
538 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
541 intf->needs_remote_wakeup = 1;
543 mutex_lock(&desc->lock);
544 if (!desc->count++) {
545 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
548 dev_err(&desc->intf->dev,
549 "Error submitting int urb - %d\n", rv);
554 mutex_unlock(&desc->lock);
555 usb_autopm_put_interface(desc->intf);
557 mutex_unlock(&wdm_mutex);
561 static int wdm_release(struct inode *inode, struct file *file)
563 struct wdm_device *desc = file->private_data;
565 mutex_lock(&wdm_mutex);
566 mutex_lock(&desc->lock);
568 mutex_unlock(&desc->lock);
571 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
573 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
574 desc->intf->needs_remote_wakeup = 0;
576 mutex_unlock(&wdm_mutex);
580 static const struct file_operations wdm_fops = {
581 .owner = THIS_MODULE,
586 .release = wdm_release,
590 static struct usb_class_driver wdm_class = {
593 .minor_base = WDM_MINOR_BASE,
596 /* --- error handling --- */
597 static void wdm_rxwork(struct work_struct *work)
599 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
603 spin_lock_irqsave(&desc->iuspin, flags);
604 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
605 spin_unlock_irqrestore(&desc->iuspin, flags);
607 spin_unlock_irqrestore(&desc->iuspin, flags);
608 rv = usb_submit_urb(desc->response, GFP_KERNEL);
609 if (rv < 0 && rv != -EPERM) {
610 spin_lock_irqsave(&desc->iuspin, flags);
611 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
612 schedule_work(&desc->rxwork);
613 spin_unlock_irqrestore(&desc->iuspin, flags);
618 /* --- hotplug --- */
620 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
623 struct usb_device *udev = interface_to_usbdev(intf);
624 struct wdm_device *desc;
625 struct usb_host_interface *iface;
626 struct usb_endpoint_descriptor *ep;
627 struct usb_cdc_dmm_desc *dmhd;
628 u8 *buffer = intf->altsetting->extra;
629 int buflen = intf->altsetting->extralen;
636 if (buffer [1] != USB_DT_CS_INTERFACE) {
637 dev_err(&intf->dev, "skipping garbage\n");
641 switch (buffer [2]) {
642 case USB_CDC_HEADER_TYPE:
644 case USB_CDC_DMM_TYPE:
645 dmhd = (struct usb_cdc_dmm_desc *)buffer;
646 maxcom = le16_to_cpu(dmhd->wMaxCommand);
648 "Finding maximum buffer length: %d", maxcom);
652 "Ignoring extra header, type %d, length %d\n",
653 buffer[2], buffer[0]);
662 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
665 mutex_init(&desc->lock);
666 spin_lock_init(&desc->iuspin);
667 init_waitqueue_head(&desc->wait);
668 desc->wMaxCommand = maxcom;
669 /* this will be expanded and needed in hardware endianness */
670 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
672 INIT_WORK(&desc->rxwork, wdm_rxwork);
675 iface = intf->cur_altsetting;
676 if (iface->desc.bNumEndpoints != 1)
678 ep = &iface->endpoint[0].desc;
679 if (!ep || !usb_endpoint_is_int_in(ep))
682 desc->wMaxPacketSize = le16_to_cpu(ep->wMaxPacketSize);
683 desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
685 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
688 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
692 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
696 desc->response = usb_alloc_urb(0, GFP_KERNEL);
700 desc->command = usb_alloc_urb(0, GFP_KERNEL);
704 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
708 desc->sbuf = usb_buffer_alloc(interface_to_usbdev(intf),
709 desc->wMaxPacketSize,
711 &desc->validity->transfer_dma);
715 desc->inbuf = usb_buffer_alloc(interface_to_usbdev(intf),
716 desc->bMaxPacketSize0,
718 &desc->response->transfer_dma);
724 interface_to_usbdev(intf),
725 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
727 desc->wMaxPacketSize,
732 desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
734 usb_set_intfdata(intf, desc);
735 rv = usb_register_dev(intf, &wdm_class);
739 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
740 intf->minor - WDM_MINOR_BASE);
744 usb_set_intfdata(intf, NULL);
745 usb_buffer_free(interface_to_usbdev(desc->intf),
746 desc->bMaxPacketSize0,
748 desc->response->transfer_dma);
750 usb_buffer_free(interface_to_usbdev(desc->intf),
751 desc->wMaxPacketSize,
753 desc->validity->transfer_dma);
763 static void wdm_disconnect(struct usb_interface *intf)
765 struct wdm_device *desc;
768 usb_deregister_dev(intf, &wdm_class);
769 mutex_lock(&wdm_mutex);
770 desc = usb_get_intfdata(intf);
772 /* the spinlock makes sure no new urbs are generated in the callbacks */
773 spin_lock_irqsave(&desc->iuspin, flags);
774 set_bit(WDM_DISCONNECTING, &desc->flags);
775 set_bit(WDM_READ, &desc->flags);
776 /* to terminate pending flushes */
777 clear_bit(WDM_IN_USE, &desc->flags);
778 spin_unlock_irqrestore(&desc->iuspin, flags);
779 cancel_work_sync(&desc->rxwork);
780 mutex_lock(&desc->lock);
782 mutex_unlock(&desc->lock);
783 wake_up_all(&desc->wait);
786 mutex_unlock(&wdm_mutex);
789 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
791 struct wdm_device *desc = usb_get_intfdata(intf);
794 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
796 mutex_lock(&desc->lock);
797 spin_lock_irq(&desc->iuspin);
799 if ((message.event & PM_EVENT_AUTO) &&
800 (test_bit(WDM_IN_USE, &desc->flags)
801 || test_bit(WDM_RESPONDING, &desc->flags))) {
802 spin_unlock_irq(&desc->iuspin);
806 set_bit(WDM_SUSPENDING, &desc->flags);
807 spin_unlock_irq(&desc->iuspin);
808 cancel_work_sync(&desc->rxwork);
813 mutex_unlock(&desc->lock);
818 static int recover_from_urb_loss(struct wdm_device *desc)
823 rv = usb_submit_urb(desc->validity, GFP_NOIO);
825 dev_err(&desc->intf->dev,
826 "Error resume submitting int urb - %d\n", rv);
830 static int wdm_resume(struct usb_interface *intf)
832 struct wdm_device *desc = usb_get_intfdata(intf);
835 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
836 mutex_lock(&desc->lock);
837 clear_bit(WDM_SUSPENDING, &desc->flags);
838 rv = recover_from_urb_loss(desc);
839 mutex_unlock(&desc->lock);
843 static int wdm_pre_reset(struct usb_interface *intf)
845 struct wdm_device *desc = usb_get_intfdata(intf);
847 mutex_lock(&desc->lock);
851 static int wdm_post_reset(struct usb_interface *intf)
853 struct wdm_device *desc = usb_get_intfdata(intf);
856 rv = recover_from_urb_loss(desc);
857 mutex_unlock(&desc->lock);
861 static struct usb_driver wdm_driver = {
864 .disconnect = wdm_disconnect,
865 .suspend = wdm_suspend,
866 .resume = wdm_resume,
867 .reset_resume = wdm_resume,
868 .pre_reset = wdm_pre_reset,
869 .post_reset = wdm_post_reset,
871 .supports_autosuspend = 1,
874 /* --- low level module stuff --- */
876 static int __init wdm_init(void)
880 rv = usb_register(&wdm_driver);
885 static void __exit wdm_exit(void)
887 usb_deregister(&wdm_driver);
890 module_init(wdm_init);
891 module_exit(wdm_exit);
893 MODULE_AUTHOR(DRIVER_AUTHOR);
894 MODULE_DESCRIPTION(DRIVER_DESC);
895 MODULE_LICENSE("GPL");