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/ioctl.h>
17 #include <linux/slab.h>
18 #include <linux/module.h>
19 #include <linux/mutex.h>
20 #include <linux/uaccess.h>
21 #include <linux/bitops.h>
22 #include <linux/poll.h>
23 #include <linux/usb.h>
24 #include <linux/usb/cdc.h>
25 #include <asm/byteorder.h>
26 #include <asm/unaligned.h>
27 #include <linux/usb/cdc-wdm.h>
32 #define DRIVER_VERSION "v0.03"
33 #define DRIVER_AUTHOR "Oliver Neukum"
34 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
36 static const struct usb_device_id wdm_ids[] = {
38 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
39 USB_DEVICE_ID_MATCH_INT_SUBCLASS,
40 .bInterfaceClass = USB_CLASS_COMM,
41 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
46 MODULE_DEVICE_TABLE (usb, wdm_ids);
48 #define WDM_MINOR_BASE 176
52 #define WDM_DISCONNECTING 2
55 #define WDM_INT_STALL 5
56 #define WDM_POLL_RUNNING 6
57 #define WDM_RESPONDING 7
58 #define WDM_SUSPENDING 8
59 #define WDM_RESETTING 9
60 #define WDM_OVERFLOW 10
64 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
65 #define WDM_DEFAULT_BUFSIZE 256
67 static DEFINE_MUTEX(wdm_mutex);
68 static DEFINE_SPINLOCK(wdm_device_list_lock);
69 static LIST_HEAD(wdm_device_list);
71 /* --- method tables --- */
74 u8 *inbuf; /* buffer for response */
75 u8 *outbuf; /* buffer for command */
76 u8 *sbuf; /* buffer for status */
77 u8 *ubuf; /* buffer for copy to user space */
82 struct usb_interface *intf;
83 struct usb_ctrlrequest *orq;
84 struct usb_ctrlrequest *irq;
100 wait_queue_head_t wait;
101 struct work_struct rxwork;
106 struct list_head device_list;
107 int (*manage_power)(struct usb_interface *, int);
110 static struct usb_driver wdm_driver;
112 /* return intfdata if we own the interface, else look up intf in the list */
113 static struct wdm_device *wdm_find_device(struct usb_interface *intf)
115 struct wdm_device *desc;
117 spin_lock(&wdm_device_list_lock);
118 list_for_each_entry(desc, &wdm_device_list, device_list)
119 if (desc->intf == intf)
123 spin_unlock(&wdm_device_list_lock);
128 static struct wdm_device *wdm_find_device_by_minor(int minor)
130 struct wdm_device *desc;
132 spin_lock(&wdm_device_list_lock);
133 list_for_each_entry(desc, &wdm_device_list, device_list)
134 if (desc->intf->minor == minor)
138 spin_unlock(&wdm_device_list_lock);
143 /* --- callbacks --- */
144 static void wdm_out_callback(struct urb *urb)
146 struct wdm_device *desc;
148 spin_lock(&desc->iuspin);
149 desc->werr = urb->status;
150 spin_unlock(&desc->iuspin);
153 clear_bit(WDM_IN_USE, &desc->flags);
154 wake_up(&desc->wait);
157 static void wdm_in_callback(struct urb *urb)
159 struct wdm_device *desc = urb->context;
160 int status = urb->status;
161 int length = urb->actual_length;
163 spin_lock(&desc->iuspin);
164 clear_bit(WDM_RESPONDING, &desc->flags);
169 dev_dbg(&desc->intf->dev,
170 "nonzero urb status received: -ENOENT");
173 dev_dbg(&desc->intf->dev,
174 "nonzero urb status received: -ECONNRESET");
177 dev_dbg(&desc->intf->dev,
178 "nonzero urb status received: -ESHUTDOWN");
181 dev_err(&desc->intf->dev,
182 "nonzero urb status received: -EPIPE\n");
185 dev_err(&desc->intf->dev,
186 "Unexpected error %d\n", status);
192 if (length + desc->length > desc->wMaxCommand) {
193 /* The buffer would overflow */
194 set_bit(WDM_OVERFLOW, &desc->flags);
196 /* we may already be in overflow */
197 if (!test_bit(WDM_OVERFLOW, &desc->flags)) {
198 memmove(desc->ubuf + desc->length, desc->inbuf, length);
199 desc->length += length;
200 desc->reslength = length;
204 wake_up(&desc->wait);
206 set_bit(WDM_READ, &desc->flags);
207 spin_unlock(&desc->iuspin);
210 static void wdm_int_callback(struct urb *urb)
214 int status = urb->status;
215 struct wdm_device *desc;
216 struct usb_cdc_notification *dr;
219 dr = (struct usb_cdc_notification *)desc->sbuf;
228 set_bit(WDM_INT_STALL, &desc->flags);
229 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
230 goto sw; /* halt is cleared in work */
232 dev_err(&desc->intf->dev,
233 "nonzero urb status received: %d\n", status);
238 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
239 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
244 switch (dr->bNotificationType) {
245 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
246 dev_dbg(&desc->intf->dev,
247 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
248 dr->wIndex, dr->wLength);
251 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
253 dev_dbg(&desc->intf->dev,
254 "NOTIFY_NETWORK_CONNECTION %s network",
255 dr->wValue ? "connected to" : "disconnected from");
257 case USB_CDC_NOTIFY_SPEED_CHANGE:
258 dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)",
262 clear_bit(WDM_POLL_RUNNING, &desc->flags);
263 dev_err(&desc->intf->dev,
264 "unknown notification %d received: index %d len %d\n",
265 dr->bNotificationType, dr->wIndex, dr->wLength);
269 spin_lock(&desc->iuspin);
270 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
271 if (!desc->resp_count++ && !responding
272 && !test_bit(WDM_DISCONNECTING, &desc->flags)
273 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
274 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
275 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
278 spin_unlock(&desc->iuspin);
280 clear_bit(WDM_RESPONDING, &desc->flags);
285 rv = schedule_work(&desc->rxwork);
287 dev_err(&desc->intf->dev,
288 "Cannot schedule work\n");
292 rv = usb_submit_urb(urb, GFP_ATOMIC);
294 dev_err(&desc->intf->dev,
295 "%s - usb_submit_urb failed with result %d\n",
300 static void kill_urbs(struct wdm_device *desc)
302 /* the order here is essential */
303 usb_kill_urb(desc->command);
304 usb_kill_urb(desc->validity);
305 usb_kill_urb(desc->response);
308 static void free_urbs(struct wdm_device *desc)
310 usb_free_urb(desc->validity);
311 usb_free_urb(desc->response);
312 usb_free_urb(desc->command);
315 static void cleanup(struct wdm_device *desc)
326 static ssize_t wdm_write
327 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
330 int rv = -EMSGSIZE, r, we;
331 struct wdm_device *desc = file->private_data;
332 struct usb_ctrlrequest *req;
334 if (count > desc->wMaxCommand)
335 count = desc->wMaxCommand;
337 spin_lock_irq(&desc->iuspin);
340 spin_unlock_irq(&desc->iuspin);
344 buf = kmalloc(count, GFP_KERNEL);
350 r = copy_from_user(buf, buffer, count);
357 /* concurrent writes and disconnect */
358 r = mutex_lock_interruptible(&desc->wlock);
365 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
371 r = usb_autopm_get_interface(desc->intf);
374 rv = usb_translate_errors(r);
378 if (!(file->f_flags & O_NONBLOCK))
379 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
382 if (test_bit(WDM_IN_USE, &desc->flags))
385 if (test_bit(WDM_RESETTING, &desc->flags))
395 usb_fill_control_urb(
397 interface_to_usbdev(desc->intf),
398 /* using common endpoint 0 */
399 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
400 (unsigned char *)req,
407 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
408 USB_RECIP_INTERFACE);
409 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
411 req->wIndex = desc->inum;
412 req->wLength = cpu_to_le16(count);
413 set_bit(WDM_IN_USE, &desc->flags);
416 rv = usb_submit_urb(desc->command, GFP_KERNEL);
420 clear_bit(WDM_IN_USE, &desc->flags);
421 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
422 rv = usb_translate_errors(rv);
424 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
428 usb_autopm_put_interface(desc->intf);
430 mutex_unlock(&desc->wlock);
432 return rv < 0 ? rv : count;
435 static ssize_t wdm_read
436 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
440 struct wdm_device *desc = file->private_data;
443 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
447 cntr = ACCESS_ONCE(desc->length);
451 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
455 if (test_bit(WDM_OVERFLOW, &desc->flags)) {
456 clear_bit(WDM_OVERFLOW, &desc->flags);
461 if (file->f_flags & O_NONBLOCK) {
462 if (!test_bit(WDM_READ, &desc->flags)) {
463 rv = cntr ? cntr : -EAGAIN;
468 rv = wait_event_interruptible(desc->wait,
469 test_bit(WDM_READ, &desc->flags));
472 /* may have happened while we slept */
473 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
477 if (test_bit(WDM_RESETTING, &desc->flags)) {
481 usb_mark_last_busy(interface_to_usbdev(desc->intf));
487 spin_lock_irq(&desc->iuspin);
489 if (desc->rerr) { /* read completed, error happened */
491 spin_unlock_irq(&desc->iuspin);
496 * recheck whether we've lost the race
497 * against the completion handler
499 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
500 spin_unlock_irq(&desc->iuspin);
504 if (!desc->reslength) { /* zero length read */
505 dev_dbg(&desc->intf->dev, "%s: zero length - clearing WDM_READ\n", __func__);
506 clear_bit(WDM_READ, &desc->flags);
507 spin_unlock_irq(&desc->iuspin);
511 spin_unlock_irq(&desc->iuspin);
516 rv = copy_to_user(buffer, desc->ubuf, cntr);
522 spin_lock_irq(&desc->iuspin);
524 for (i = 0; i < desc->length - cntr; i++)
525 desc->ubuf[i] = desc->ubuf[i + cntr];
527 desc->length -= cntr;
528 /* in case we had outstanding data */
530 clear_bit(WDM_READ, &desc->flags);
532 if (--desc->resp_count) {
533 set_bit(WDM_RESPONDING, &desc->flags);
534 spin_unlock_irq(&desc->iuspin);
536 rv = usb_submit_urb(desc->response, GFP_KERNEL);
538 dev_err(&desc->intf->dev,
539 "%s: usb_submit_urb failed with result %d\n",
541 spin_lock_irq(&desc->iuspin);
542 clear_bit(WDM_RESPONDING, &desc->flags);
543 spin_unlock_irq(&desc->iuspin);
546 rv = schedule_work(&desc->rxwork);
548 dev_err(&desc->intf->dev, "Cannot schedule work\n");
550 spin_lock_irq(&desc->iuspin);
551 desc->resp_count = 0;
552 spin_unlock_irq(&desc->iuspin);
556 spin_unlock_irq(&desc->iuspin);
558 spin_unlock_irq(&desc->iuspin);
563 mutex_unlock(&desc->rlock);
567 static int wdm_flush(struct file *file, fl_owner_t id)
569 struct wdm_device *desc = file->private_data;
571 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
573 /* cannot dereference desc->intf if WDM_DISCONNECTING */
574 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags))
575 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
578 return usb_translate_errors(desc->werr);
581 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
583 struct wdm_device *desc = file->private_data;
585 unsigned int mask = 0;
587 spin_lock_irqsave(&desc->iuspin, flags);
588 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
589 mask = POLLHUP | POLLERR;
590 spin_unlock_irqrestore(&desc->iuspin, flags);
593 if (test_bit(WDM_READ, &desc->flags))
594 mask = POLLIN | POLLRDNORM;
595 if (desc->rerr || desc->werr)
597 if (!test_bit(WDM_IN_USE, &desc->flags))
598 mask |= POLLOUT | POLLWRNORM;
599 spin_unlock_irqrestore(&desc->iuspin, flags);
601 poll_wait(file, &desc->wait, wait);
607 static int wdm_open(struct inode *inode, struct file *file)
609 int minor = iminor(inode);
611 struct usb_interface *intf;
612 struct wdm_device *desc;
614 mutex_lock(&wdm_mutex);
615 desc = wdm_find_device_by_minor(minor);
620 if (test_bit(WDM_DISCONNECTING, &desc->flags))
622 file->private_data = desc;
624 rv = usb_autopm_get_interface(desc->intf);
626 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
630 /* using write lock to protect desc->count */
631 mutex_lock(&desc->wlock);
632 if (!desc->count++) {
635 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
638 dev_err(&desc->intf->dev,
639 "Error submitting int urb - %d\n", rv);
640 rv = usb_translate_errors(rv);
645 mutex_unlock(&desc->wlock);
646 if (desc->count == 1)
647 desc->manage_power(intf, 1);
648 usb_autopm_put_interface(desc->intf);
650 mutex_unlock(&wdm_mutex);
654 static int wdm_release(struct inode *inode, struct file *file)
656 struct wdm_device *desc = file->private_data;
658 mutex_lock(&wdm_mutex);
660 /* using write lock to protect desc->count */
661 mutex_lock(&desc->wlock);
663 mutex_unlock(&desc->wlock);
666 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
667 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
669 spin_lock_irq(&desc->iuspin);
670 desc->resp_count = 0;
671 spin_unlock_irq(&desc->iuspin);
672 desc->manage_power(desc->intf, 0);
674 /* must avoid dev_printk here as desc->intf is invalid */
675 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
679 mutex_unlock(&wdm_mutex);
683 static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
685 struct wdm_device *desc = file->private_data;
689 case IOCTL_WDM_MAX_COMMAND:
690 if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand)))
699 static const struct file_operations wdm_fops = {
700 .owner = THIS_MODULE,
705 .release = wdm_release,
707 .unlocked_ioctl = wdm_ioctl,
708 .compat_ioctl = wdm_ioctl,
709 .llseek = noop_llseek,
712 static struct usb_class_driver wdm_class = {
715 .minor_base = WDM_MINOR_BASE,
718 /* --- error handling --- */
719 static void wdm_rxwork(struct work_struct *work)
721 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
726 spin_lock_irqsave(&desc->iuspin, flags);
727 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
728 spin_unlock_irqrestore(&desc->iuspin, flags);
730 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
731 spin_unlock_irqrestore(&desc->iuspin, flags);
733 rv = usb_submit_urb(desc->response, GFP_KERNEL);
734 if (rv < 0 && rv != -EPERM) {
735 spin_lock_irqsave(&desc->iuspin, flags);
736 clear_bit(WDM_RESPONDING, &desc->flags);
737 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
738 schedule_work(&desc->rxwork);
739 spin_unlock_irqrestore(&desc->iuspin, flags);
744 /* --- hotplug --- */
746 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
747 u16 bufsize, int (*manage_power)(struct usb_interface *, int))
750 struct wdm_device *desc;
752 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
755 INIT_LIST_HEAD(&desc->device_list);
756 mutex_init(&desc->rlock);
757 mutex_init(&desc->wlock);
758 spin_lock_init(&desc->iuspin);
759 init_waitqueue_head(&desc->wait);
760 desc->wMaxCommand = bufsize;
761 /* this will be expanded and needed in hardware endianness */
762 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
764 INIT_WORK(&desc->rxwork, wdm_rxwork);
767 if (!usb_endpoint_is_int_in(ep))
770 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
772 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
775 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
779 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
783 desc->response = usb_alloc_urb(0, GFP_KERNEL);
787 desc->command = usb_alloc_urb(0, GFP_KERNEL);
791 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
795 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
799 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
805 interface_to_usbdev(intf),
806 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
808 desc->wMaxPacketSize,
814 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
815 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
816 desc->irq->wValue = 0;
817 desc->irq->wIndex = desc->inum;
818 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
820 usb_fill_control_urb(
822 interface_to_usbdev(intf),
823 /* using common endpoint 0 */
824 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
825 (unsigned char *)desc->irq,
832 desc->manage_power = manage_power;
834 spin_lock(&wdm_device_list_lock);
835 list_add(&desc->device_list, &wdm_device_list);
836 spin_unlock(&wdm_device_list_lock);
838 rv = usb_register_dev(intf, &wdm_class);
842 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
846 spin_lock(&wdm_device_list_lock);
847 list_del(&desc->device_list);
848 spin_unlock(&wdm_device_list_lock);
853 static int wdm_manage_power(struct usb_interface *intf, int on)
855 /* need autopm_get/put here to ensure the usbcore sees the new value */
856 int rv = usb_autopm_get_interface(intf);
860 intf->needs_remote_wakeup = on;
861 usb_autopm_put_interface(intf);
866 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
869 struct usb_host_interface *iface;
870 struct usb_endpoint_descriptor *ep;
871 struct usb_cdc_dmm_desc *dmhd;
872 u8 *buffer = intf->altsetting->extra;
873 int buflen = intf->altsetting->extralen;
874 u16 maxcom = WDM_DEFAULT_BUFSIZE;
879 if (buffer[1] != USB_DT_CS_INTERFACE) {
880 dev_err(&intf->dev, "skipping garbage\n");
885 case USB_CDC_HEADER_TYPE:
887 case USB_CDC_DMM_TYPE:
888 dmhd = (struct usb_cdc_dmm_desc *)buffer;
889 maxcom = le16_to_cpu(dmhd->wMaxCommand);
891 "Finding maximum buffer length: %d", maxcom);
895 "Ignoring extra header, type %d, length %d\n",
896 buffer[2], buffer[0]);
904 iface = intf->cur_altsetting;
905 if (iface->desc.bNumEndpoints != 1)
907 ep = &iface->endpoint[0].desc;
909 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
916 * usb_cdc_wdm_register - register a WDM subdriver
917 * @intf: usb interface the subdriver will associate with
918 * @ep: interrupt endpoint to monitor for notifications
919 * @bufsize: maximum message size to support for read/write
921 * Create WDM usb class character device and associate it with intf
922 * without binding, allowing another driver to manage the interface.
924 * The subdriver will manage the given interrupt endpoint exclusively
925 * and will issue control requests referring to the given intf. It
926 * will otherwise avoid interferring, and in particular not do
927 * usb_set_intfdata/usb_get_intfdata on intf.
929 * The return value is a pointer to the subdriver's struct usb_driver.
930 * The registering driver is responsible for calling this subdriver's
931 * disconnect, suspend, resume, pre_reset and post_reset methods from
934 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
935 struct usb_endpoint_descriptor *ep,
937 int (*manage_power)(struct usb_interface *, int))
941 rv = wdm_create(intf, ep, bufsize, manage_power);
949 EXPORT_SYMBOL(usb_cdc_wdm_register);
951 static void wdm_disconnect(struct usb_interface *intf)
953 struct wdm_device *desc;
956 usb_deregister_dev(intf, &wdm_class);
957 desc = wdm_find_device(intf);
958 mutex_lock(&wdm_mutex);
960 /* the spinlock makes sure no new urbs are generated in the callbacks */
961 spin_lock_irqsave(&desc->iuspin, flags);
962 set_bit(WDM_DISCONNECTING, &desc->flags);
963 set_bit(WDM_READ, &desc->flags);
964 /* to terminate pending flushes */
965 clear_bit(WDM_IN_USE, &desc->flags);
966 spin_unlock_irqrestore(&desc->iuspin, flags);
967 wake_up_all(&desc->wait);
968 mutex_lock(&desc->rlock);
969 mutex_lock(&desc->wlock);
971 cancel_work_sync(&desc->rxwork);
972 mutex_unlock(&desc->wlock);
973 mutex_unlock(&desc->rlock);
975 /* the desc->intf pointer used as list key is now invalid */
976 spin_lock(&wdm_device_list_lock);
977 list_del(&desc->device_list);
978 spin_unlock(&wdm_device_list_lock);
983 dev_dbg(&intf->dev, "%s: %d open files - postponing cleanup\n", __func__, desc->count);
984 mutex_unlock(&wdm_mutex);
988 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
990 struct wdm_device *desc = wdm_find_device(intf);
993 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
995 /* if this is an autosuspend the caller does the locking */
996 if (!PMSG_IS_AUTO(message)) {
997 mutex_lock(&desc->rlock);
998 mutex_lock(&desc->wlock);
1000 spin_lock_irq(&desc->iuspin);
1002 if (PMSG_IS_AUTO(message) &&
1003 (test_bit(WDM_IN_USE, &desc->flags)
1004 || test_bit(WDM_RESPONDING, &desc->flags))) {
1005 spin_unlock_irq(&desc->iuspin);
1009 set_bit(WDM_SUSPENDING, &desc->flags);
1010 spin_unlock_irq(&desc->iuspin);
1011 /* callback submits work - order is essential */
1013 cancel_work_sync(&desc->rxwork);
1015 if (!PMSG_IS_AUTO(message)) {
1016 mutex_unlock(&desc->wlock);
1017 mutex_unlock(&desc->rlock);
1024 static int recover_from_urb_loss(struct wdm_device *desc)
1029 rv = usb_submit_urb(desc->validity, GFP_NOIO);
1031 dev_err(&desc->intf->dev,
1032 "Error resume submitting int urb - %d\n", rv);
1038 static int wdm_resume(struct usb_interface *intf)
1040 struct wdm_device *desc = wdm_find_device(intf);
1043 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
1045 clear_bit(WDM_SUSPENDING, &desc->flags);
1046 rv = recover_from_urb_loss(desc);
1052 static int wdm_pre_reset(struct usb_interface *intf)
1054 struct wdm_device *desc = wdm_find_device(intf);
1057 * we notify everybody using poll of
1058 * an exceptional situation
1059 * must be done before recovery lest a spontaneous
1060 * message from the device is lost
1062 spin_lock_irq(&desc->iuspin);
1063 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */
1064 set_bit(WDM_READ, &desc->flags); /* unblock read */
1065 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */
1066 desc->rerr = -EINTR;
1067 spin_unlock_irq(&desc->iuspin);
1068 wake_up_all(&desc->wait);
1069 mutex_lock(&desc->rlock);
1070 mutex_lock(&desc->wlock);
1072 cancel_work_sync(&desc->rxwork);
1076 static int wdm_post_reset(struct usb_interface *intf)
1078 struct wdm_device *desc = wdm_find_device(intf);
1081 clear_bit(WDM_OVERFLOW, &desc->flags);
1082 clear_bit(WDM_RESETTING, &desc->flags);
1083 rv = recover_from_urb_loss(desc);
1084 mutex_unlock(&desc->wlock);
1085 mutex_unlock(&desc->rlock);
1089 static struct usb_driver wdm_driver = {
1092 .disconnect = wdm_disconnect,
1094 .suspend = wdm_suspend,
1095 .resume = wdm_resume,
1096 .reset_resume = wdm_resume,
1098 .pre_reset = wdm_pre_reset,
1099 .post_reset = wdm_post_reset,
1100 .id_table = wdm_ids,
1101 .supports_autosuspend = 1,
1102 .disable_hub_initiated_lpm = 1,
1105 module_usb_driver(wdm_driver);
1107 MODULE_AUTHOR(DRIVER_AUTHOR);
1108 MODULE_DESCRIPTION(DRIVER_DESC);
1109 MODULE_LICENSE("GPL");