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;
93 wait_queue_head_t wait;
94 struct work_struct rxwork;
99 static struct usb_driver wdm_driver;
101 /* --- callbacks --- */
102 static void wdm_out_callback(struct urb *urb)
104 struct wdm_device *desc;
106 spin_lock(&desc->iuspin);
107 desc->werr = urb->status;
108 spin_unlock(&desc->iuspin);
109 clear_bit(WDM_IN_USE, &desc->flags);
111 wake_up(&desc->wait);
114 static void wdm_in_callback(struct urb *urb)
116 struct wdm_device *desc = urb->context;
117 int status = urb->status;
119 spin_lock(&desc->iuspin);
120 clear_bit(WDM_RESPONDING, &desc->flags);
125 dev_dbg(&desc->intf->dev,
126 "nonzero urb status received: -ENOENT");
129 dev_dbg(&desc->intf->dev,
130 "nonzero urb status received: -ECONNRESET");
133 dev_dbg(&desc->intf->dev,
134 "nonzero urb status received: -ESHUTDOWN");
137 dev_err(&desc->intf->dev,
138 "nonzero urb status received: -EPIPE\n");
141 dev_err(&desc->intf->dev,
142 "Unexpected error %d\n", status);
148 desc->reslength = urb->actual_length;
149 memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
150 desc->length += desc->reslength;
152 wake_up(&desc->wait);
154 set_bit(WDM_READ, &desc->flags);
155 spin_unlock(&desc->iuspin);
158 static void wdm_int_callback(struct urb *urb)
161 int status = urb->status;
162 struct wdm_device *desc;
163 struct usb_cdc_notification *dr;
166 dr = (struct usb_cdc_notification *)desc->sbuf;
175 set_bit(WDM_INT_STALL, &desc->flags);
176 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
177 goto sw; /* halt is cleared in work */
179 dev_err(&desc->intf->dev,
180 "nonzero urb status received: %d\n", status);
185 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
186 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
191 switch (dr->bNotificationType) {
192 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
193 dev_dbg(&desc->intf->dev,
194 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
195 dr->wIndex, dr->wLength);
198 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
200 dev_dbg(&desc->intf->dev,
201 "NOTIFY_NETWORK_CONNECTION %s network",
202 dr->wValue ? "connected to" : "disconnected from");
205 clear_bit(WDM_POLL_RUNNING, &desc->flags);
206 dev_err(&desc->intf->dev,
207 "unknown notification %d received: index %d len %d\n",
208 dr->bNotificationType, dr->wIndex, dr->wLength);
212 spin_lock(&desc->iuspin);
213 clear_bit(WDM_READ, &desc->flags);
214 set_bit(WDM_RESPONDING, &desc->flags);
215 if (!test_bit(WDM_DISCONNECTING, &desc->flags)
216 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
217 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
218 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
221 spin_unlock(&desc->iuspin);
223 clear_bit(WDM_RESPONDING, &desc->flags);
228 rv = schedule_work(&desc->rxwork);
230 dev_err(&desc->intf->dev,
231 "Cannot schedule work\n");
235 rv = usb_submit_urb(urb, GFP_ATOMIC);
237 dev_err(&desc->intf->dev,
238 "%s - usb_submit_urb failed with result %d\n",
243 static void kill_urbs(struct wdm_device *desc)
245 /* the order here is essential */
246 usb_kill_urb(desc->command);
247 usb_kill_urb(desc->validity);
248 usb_kill_urb(desc->response);
251 static void free_urbs(struct wdm_device *desc)
253 usb_free_urb(desc->validity);
254 usb_free_urb(desc->response);
255 usb_free_urb(desc->command);
258 static void cleanup(struct wdm_device *desc)
269 static ssize_t wdm_write
270 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
273 int rv = -EMSGSIZE, r, we;
274 struct wdm_device *desc = file->private_data;
275 struct usb_ctrlrequest *req;
277 if (count > desc->wMaxCommand)
278 count = desc->wMaxCommand;
280 spin_lock_irq(&desc->iuspin);
283 spin_unlock_irq(&desc->iuspin);
287 desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
293 r = copy_from_user(buf, buffer, count);
300 /* concurrent writes and disconnect */
301 r = mutex_lock_interruptible(&desc->lock);
308 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
314 r = usb_autopm_get_interface(desc->intf);
320 if (!(file->f_flags & O_NONBLOCK))
321 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
324 if (test_bit(WDM_IN_USE, &desc->flags))
332 usb_fill_control_urb(
334 interface_to_usbdev(desc->intf),
335 /* using common endpoint 0 */
336 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
337 (unsigned char *)req,
344 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
345 USB_RECIP_INTERFACE);
346 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
348 req->wIndex = desc->inum;
349 req->wLength = cpu_to_le16(count);
350 set_bit(WDM_IN_USE, &desc->flags);
352 rv = usb_submit_urb(desc->command, GFP_KERNEL);
355 clear_bit(WDM_IN_USE, &desc->flags);
356 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
358 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
362 usb_autopm_put_interface(desc->intf);
364 mutex_unlock(&desc->lock);
366 return rv < 0 ? rv : count;
369 static ssize_t wdm_read
370 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
374 struct wdm_device *desc = file->private_data;
377 rv = mutex_lock_interruptible(&desc->lock); /*concurrent reads */
381 if (desc->length == 0) {
384 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
389 if (file->f_flags & O_NONBLOCK) {
390 if (!test_bit(WDM_READ, &desc->flags)) {
391 rv = cntr ? cntr : -EAGAIN;
396 rv = wait_event_interruptible(desc->wait,
397 test_bit(WDM_READ, &desc->flags));
400 /* may have happened while we slept */
401 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
405 usb_mark_last_busy(interface_to_usbdev(desc->intf));
411 spin_lock_irq(&desc->iuspin);
413 if (desc->rerr) { /* read completed, error happened */
415 spin_unlock_irq(&desc->iuspin);
420 * recheck whether we've lost the race
421 * against the completion handler
423 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
424 spin_unlock_irq(&desc->iuspin);
427 if (!desc->reslength) { /* zero length read */
428 spin_unlock_irq(&desc->iuspin);
431 clear_bit(WDM_READ, &desc->flags);
432 spin_unlock_irq(&desc->iuspin);
435 cntr = count > desc->length ? desc->length : count;
436 rv = copy_to_user(buffer, desc->ubuf, cntr);
442 for (i = 0; i < desc->length - cntr; i++)
443 desc->ubuf[i] = desc->ubuf[i + cntr];
445 desc->length -= cntr;
446 /* in case we had outstanding data */
448 clear_bit(WDM_READ, &desc->flags);
452 mutex_unlock(&desc->lock);
456 static int wdm_flush(struct file *file, fl_owner_t id)
458 struct wdm_device *desc = file->private_data;
460 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
462 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
468 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
470 struct wdm_device *desc = file->private_data;
472 unsigned int mask = 0;
474 spin_lock_irqsave(&desc->iuspin, flags);
475 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
477 spin_unlock_irqrestore(&desc->iuspin, flags);
480 if (test_bit(WDM_READ, &desc->flags))
481 mask = POLLIN | POLLRDNORM;
482 if (desc->rerr || desc->werr)
484 if (!test_bit(WDM_IN_USE, &desc->flags))
485 mask |= POLLOUT | POLLWRNORM;
486 spin_unlock_irqrestore(&desc->iuspin, flags);
488 poll_wait(file, &desc->wait, wait);
494 static int wdm_open(struct inode *inode, struct file *file)
496 int minor = iminor(inode);
498 struct usb_interface *intf;
499 struct wdm_device *desc;
501 mutex_lock(&wdm_mutex);
502 intf = usb_find_interface(&wdm_driver, minor);
506 desc = usb_get_intfdata(intf);
507 if (test_bit(WDM_DISCONNECTING, &desc->flags))
509 file->private_data = desc;
511 rv = usb_autopm_get_interface(desc->intf);
513 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
516 intf->needs_remote_wakeup = 1;
518 mutex_lock(&desc->lock);
519 if (!desc->count++) {
522 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
525 dev_err(&desc->intf->dev,
526 "Error submitting int urb - %d\n", rv);
531 mutex_unlock(&desc->lock);
532 usb_autopm_put_interface(desc->intf);
534 mutex_unlock(&wdm_mutex);
538 static int wdm_release(struct inode *inode, struct file *file)
540 struct wdm_device *desc = file->private_data;
542 mutex_lock(&wdm_mutex);
543 mutex_lock(&desc->lock);
545 mutex_unlock(&desc->lock);
548 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
550 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
551 desc->intf->needs_remote_wakeup = 0;
553 mutex_unlock(&wdm_mutex);
557 static const struct file_operations wdm_fops = {
558 .owner = THIS_MODULE,
563 .release = wdm_release,
565 .llseek = noop_llseek,
568 static struct usb_class_driver wdm_class = {
571 .minor_base = WDM_MINOR_BASE,
574 /* --- error handling --- */
575 static void wdm_rxwork(struct work_struct *work)
577 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
581 spin_lock_irqsave(&desc->iuspin, flags);
582 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
583 spin_unlock_irqrestore(&desc->iuspin, flags);
585 spin_unlock_irqrestore(&desc->iuspin, flags);
586 rv = usb_submit_urb(desc->response, GFP_KERNEL);
587 if (rv < 0 && rv != -EPERM) {
588 spin_lock_irqsave(&desc->iuspin, flags);
589 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
590 schedule_work(&desc->rxwork);
591 spin_unlock_irqrestore(&desc->iuspin, flags);
596 /* --- hotplug --- */
598 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
601 struct wdm_device *desc;
602 struct usb_host_interface *iface;
603 struct usb_endpoint_descriptor *ep;
604 struct usb_cdc_dmm_desc *dmhd;
605 u8 *buffer = intf->altsetting->extra;
606 int buflen = intf->altsetting->extralen;
607 u16 maxcom = WDM_DEFAULT_BUFSIZE;
613 if (buffer [1] != USB_DT_CS_INTERFACE) {
614 dev_err(&intf->dev, "skipping garbage\n");
618 switch (buffer [2]) {
619 case USB_CDC_HEADER_TYPE:
621 case USB_CDC_DMM_TYPE:
622 dmhd = (struct usb_cdc_dmm_desc *)buffer;
623 maxcom = le16_to_cpu(dmhd->wMaxCommand);
625 "Finding maximum buffer length: %d", maxcom);
629 "Ignoring extra header, type %d, length %d\n",
630 buffer[2], buffer[0]);
639 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
642 mutex_init(&desc->lock);
643 spin_lock_init(&desc->iuspin);
644 init_waitqueue_head(&desc->wait);
645 desc->wMaxCommand = maxcom;
646 /* this will be expanded and needed in hardware endianness */
647 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
649 INIT_WORK(&desc->rxwork, wdm_rxwork);
652 iface = intf->cur_altsetting;
653 if (iface->desc.bNumEndpoints != 1)
655 ep = &iface->endpoint[0].desc;
656 if (!ep || !usb_endpoint_is_int_in(ep))
659 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
661 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
664 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
668 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
672 desc->response = usb_alloc_urb(0, GFP_KERNEL);
676 desc->command = usb_alloc_urb(0, GFP_KERNEL);
680 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
684 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
688 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
694 interface_to_usbdev(intf),
695 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
697 desc->wMaxPacketSize,
703 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
704 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
705 desc->irq->wValue = 0;
706 desc->irq->wIndex = desc->inum;
707 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
709 usb_fill_control_urb(
711 interface_to_usbdev(intf),
712 /* using common endpoint 0 */
713 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
714 (unsigned char *)desc->irq,
721 usb_set_intfdata(intf, desc);
722 rv = usb_register_dev(intf, &wdm_class);
726 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
730 usb_set_intfdata(intf, NULL);
742 static void wdm_disconnect(struct usb_interface *intf)
744 struct wdm_device *desc;
747 usb_deregister_dev(intf, &wdm_class);
748 mutex_lock(&wdm_mutex);
749 desc = usb_get_intfdata(intf);
751 /* the spinlock makes sure no new urbs are generated in the callbacks */
752 spin_lock_irqsave(&desc->iuspin, flags);
753 set_bit(WDM_DISCONNECTING, &desc->flags);
754 set_bit(WDM_READ, &desc->flags);
755 /* to terminate pending flushes */
756 clear_bit(WDM_IN_USE, &desc->flags);
757 spin_unlock_irqrestore(&desc->iuspin, flags);
758 mutex_lock(&desc->lock);
760 cancel_work_sync(&desc->rxwork);
761 mutex_unlock(&desc->lock);
762 wake_up_all(&desc->wait);
765 mutex_unlock(&wdm_mutex);
769 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
771 struct wdm_device *desc = usb_get_intfdata(intf);
774 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
776 /* if this is an autosuspend the caller does the locking */
777 if (!PMSG_IS_AUTO(message))
778 mutex_lock(&desc->lock);
779 spin_lock_irq(&desc->iuspin);
781 if (PMSG_IS_AUTO(message) &&
782 (test_bit(WDM_IN_USE, &desc->flags)
783 || test_bit(WDM_RESPONDING, &desc->flags))) {
784 spin_unlock_irq(&desc->iuspin);
788 set_bit(WDM_SUSPENDING, &desc->flags);
789 spin_unlock_irq(&desc->iuspin);
790 /* callback submits work - order is essential */
792 cancel_work_sync(&desc->rxwork);
794 if (!PMSG_IS_AUTO(message))
795 mutex_unlock(&desc->lock);
801 static int recover_from_urb_loss(struct wdm_device *desc)
806 rv = usb_submit_urb(desc->validity, GFP_NOIO);
808 dev_err(&desc->intf->dev,
809 "Error resume submitting int urb - %d\n", rv);
815 static int wdm_resume(struct usb_interface *intf)
817 struct wdm_device *desc = usb_get_intfdata(intf);
820 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
822 clear_bit(WDM_SUSPENDING, &desc->flags);
823 rv = recover_from_urb_loss(desc);
829 static int wdm_pre_reset(struct usb_interface *intf)
831 struct wdm_device *desc = usb_get_intfdata(intf);
833 mutex_lock(&desc->lock);
837 * we notify everybody using poll of
838 * an exceptional situation
839 * must be done before recovery lest a spontaneous
840 * message from the device is lost
842 spin_lock_irq(&desc->iuspin);
844 spin_unlock_irq(&desc->iuspin);
845 wake_up_all(&desc->wait);
849 static int wdm_post_reset(struct usb_interface *intf)
851 struct wdm_device *desc = usb_get_intfdata(intf);
854 rv = recover_from_urb_loss(desc);
855 mutex_unlock(&desc->lock);
859 static struct usb_driver wdm_driver = {
862 .disconnect = wdm_disconnect,
864 .suspend = wdm_suspend,
865 .resume = wdm_resume,
866 .reset_resume = wdm_resume,
868 .pre_reset = wdm_pre_reset,
869 .post_reset = wdm_post_reset,
871 .supports_autosuspend = 1,
874 module_usb_driver(wdm_driver);
876 MODULE_AUTHOR(DRIVER_AUTHOR);
877 MODULE_DESCRIPTION(DRIVER_DESC);
878 MODULE_LICENSE("GPL");