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_free_coherent(interface_to_usbdev(desc->intf),
280 desc->wMaxPacketSize,
282 desc->validity->transfer_dma);
283 usb_free_coherent(interface_to_usbdev(desc->intf),
284 desc->bMaxPacketSize0,
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++) {
547 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
550 dev_err(&desc->intf->dev,
551 "Error submitting int urb - %d\n", rv);
556 mutex_unlock(&desc->lock);
557 usb_autopm_put_interface(desc->intf);
559 mutex_unlock(&wdm_mutex);
563 static int wdm_release(struct inode *inode, struct file *file)
565 struct wdm_device *desc = file->private_data;
567 mutex_lock(&wdm_mutex);
568 mutex_lock(&desc->lock);
570 mutex_unlock(&desc->lock);
573 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
575 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
576 desc->intf->needs_remote_wakeup = 0;
578 mutex_unlock(&wdm_mutex);
582 static const struct file_operations wdm_fops = {
583 .owner = THIS_MODULE,
588 .release = wdm_release,
590 .llseek = noop_llseek,
593 static struct usb_class_driver wdm_class = {
596 .minor_base = WDM_MINOR_BASE,
599 /* --- error handling --- */
600 static void wdm_rxwork(struct work_struct *work)
602 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
606 spin_lock_irqsave(&desc->iuspin, flags);
607 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
608 spin_unlock_irqrestore(&desc->iuspin, flags);
610 spin_unlock_irqrestore(&desc->iuspin, flags);
611 rv = usb_submit_urb(desc->response, GFP_KERNEL);
612 if (rv < 0 && rv != -EPERM) {
613 spin_lock_irqsave(&desc->iuspin, flags);
614 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
615 schedule_work(&desc->rxwork);
616 spin_unlock_irqrestore(&desc->iuspin, flags);
621 /* --- hotplug --- */
623 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
626 struct usb_device *udev = interface_to_usbdev(intf);
627 struct wdm_device *desc;
628 struct usb_host_interface *iface;
629 struct usb_endpoint_descriptor *ep;
630 struct usb_cdc_dmm_desc *dmhd;
631 u8 *buffer = intf->altsetting->extra;
632 int buflen = intf->altsetting->extralen;
639 if (buffer [1] != USB_DT_CS_INTERFACE) {
640 dev_err(&intf->dev, "skipping garbage\n");
644 switch (buffer [2]) {
645 case USB_CDC_HEADER_TYPE:
647 case USB_CDC_DMM_TYPE:
648 dmhd = (struct usb_cdc_dmm_desc *)buffer;
649 maxcom = le16_to_cpu(dmhd->wMaxCommand);
651 "Finding maximum buffer length: %d", maxcom);
655 "Ignoring extra header, type %d, length %d\n",
656 buffer[2], buffer[0]);
665 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
668 mutex_init(&desc->lock);
669 spin_lock_init(&desc->iuspin);
670 init_waitqueue_head(&desc->wait);
671 desc->wMaxCommand = maxcom;
672 /* this will be expanded and needed in hardware endianness */
673 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
675 INIT_WORK(&desc->rxwork, wdm_rxwork);
678 iface = intf->cur_altsetting;
679 if (iface->desc.bNumEndpoints != 1)
681 ep = &iface->endpoint[0].desc;
682 if (!ep || !usb_endpoint_is_int_in(ep))
685 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
686 desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
688 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
691 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
695 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
699 desc->response = usb_alloc_urb(0, GFP_KERNEL);
703 desc->command = usb_alloc_urb(0, GFP_KERNEL);
707 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
711 desc->sbuf = usb_alloc_coherent(interface_to_usbdev(intf),
712 desc->wMaxPacketSize,
714 &desc->validity->transfer_dma);
718 desc->inbuf = usb_alloc_coherent(interface_to_usbdev(intf),
719 desc->bMaxPacketSize0,
721 &desc->response->transfer_dma);
727 interface_to_usbdev(intf),
728 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
730 desc->wMaxPacketSize,
735 desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
737 usb_set_intfdata(intf, desc);
738 rv = usb_register_dev(intf, &wdm_class);
742 dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
743 intf->minor - WDM_MINOR_BASE);
747 usb_set_intfdata(intf, NULL);
748 usb_free_coherent(interface_to_usbdev(desc->intf),
749 desc->bMaxPacketSize0,
751 desc->response->transfer_dma);
753 usb_free_coherent(interface_to_usbdev(desc->intf),
754 desc->wMaxPacketSize,
756 desc->validity->transfer_dma);
766 static void wdm_disconnect(struct usb_interface *intf)
768 struct wdm_device *desc;
771 usb_deregister_dev(intf, &wdm_class);
772 mutex_lock(&wdm_mutex);
773 desc = usb_get_intfdata(intf);
775 /* the spinlock makes sure no new urbs are generated in the callbacks */
776 spin_lock_irqsave(&desc->iuspin, flags);
777 set_bit(WDM_DISCONNECTING, &desc->flags);
778 set_bit(WDM_READ, &desc->flags);
779 /* to terminate pending flushes */
780 clear_bit(WDM_IN_USE, &desc->flags);
781 spin_unlock_irqrestore(&desc->iuspin, flags);
782 mutex_lock(&desc->lock);
784 cancel_work_sync(&desc->rxwork);
785 mutex_unlock(&desc->lock);
786 wake_up_all(&desc->wait);
789 mutex_unlock(&wdm_mutex);
793 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
795 struct wdm_device *desc = usb_get_intfdata(intf);
798 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
800 /* if this is an autosuspend the caller does the locking */
801 if (!PMSG_IS_AUTO(message))
802 mutex_lock(&desc->lock);
803 spin_lock_irq(&desc->iuspin);
805 if (PMSG_IS_AUTO(message) &&
806 (test_bit(WDM_IN_USE, &desc->flags)
807 || test_bit(WDM_RESPONDING, &desc->flags))) {
808 spin_unlock_irq(&desc->iuspin);
812 set_bit(WDM_SUSPENDING, &desc->flags);
813 spin_unlock_irq(&desc->iuspin);
814 /* callback submits work - order is essential */
816 cancel_work_sync(&desc->rxwork);
818 if (!PMSG_IS_AUTO(message))
819 mutex_unlock(&desc->lock);
825 static int recover_from_urb_loss(struct wdm_device *desc)
830 rv = usb_submit_urb(desc->validity, GFP_NOIO);
832 dev_err(&desc->intf->dev,
833 "Error resume submitting int urb - %d\n", rv);
839 static int wdm_resume(struct usb_interface *intf)
841 struct wdm_device *desc = usb_get_intfdata(intf);
844 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
846 clear_bit(WDM_SUSPENDING, &desc->flags);
847 rv = recover_from_urb_loss(desc);
853 static int wdm_pre_reset(struct usb_interface *intf)
855 struct wdm_device *desc = usb_get_intfdata(intf);
857 mutex_lock(&desc->lock);
861 * we notify everybody using poll of
862 * an exceptional situation
863 * must be done before recovery lest a spontaneous
864 * message from the device is lost
866 spin_lock_irq(&desc->iuspin);
868 spin_unlock_irq(&desc->iuspin);
869 wake_up_all(&desc->wait);
873 static int wdm_post_reset(struct usb_interface *intf)
875 struct wdm_device *desc = usb_get_intfdata(intf);
878 rv = recover_from_urb_loss(desc);
879 mutex_unlock(&desc->lock);
883 static struct usb_driver wdm_driver = {
886 .disconnect = wdm_disconnect,
888 .suspend = wdm_suspend,
889 .resume = wdm_resume,
890 .reset_resume = wdm_resume,
892 .pre_reset = wdm_pre_reset,
893 .post_reset = wdm_post_reset,
895 .supports_autosuspend = 1,
898 /* --- low level module stuff --- */
900 static int __init wdm_init(void)
904 rv = usb_register(&wdm_driver);
909 static void __exit wdm_exit(void)
911 usb_deregister(&wdm_driver);
914 module_init(wdm_init);
915 module_exit(wdm_exit);
917 MODULE_AUTHOR(DRIVER_AUTHOR);
918 MODULE_DESCRIPTION(DRIVER_DESC);
919 MODULE_LICENSE("GPL");