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;
436 * clear WDM_READ flag and possibly submit the read urb if resp_count
439 * Called with desc->iuspin locked
441 static int clear_wdm_read_flag(struct wdm_device *desc)
445 clear_bit(WDM_READ, &desc->flags);
447 /* submit read urb only if the device is waiting for it */
448 if (!desc->resp_count || !--desc->resp_count)
451 set_bit(WDM_RESPONDING, &desc->flags);
452 spin_unlock_irq(&desc->iuspin);
453 rv = usb_submit_urb(desc->response, GFP_KERNEL);
454 spin_lock_irq(&desc->iuspin);
456 dev_err(&desc->intf->dev,
457 "usb_submit_urb failed with result %d\n", rv);
459 /* make sure the next notification trigger a submit */
460 clear_bit(WDM_RESPONDING, &desc->flags);
461 desc->resp_count = 0;
467 static ssize_t wdm_read
468 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
472 struct wdm_device *desc = file->private_data;
475 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
479 cntr = ACCESS_ONCE(desc->length);
483 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
487 if (test_bit(WDM_OVERFLOW, &desc->flags)) {
488 clear_bit(WDM_OVERFLOW, &desc->flags);
493 if (file->f_flags & O_NONBLOCK) {
494 if (!test_bit(WDM_READ, &desc->flags)) {
495 rv = cntr ? cntr : -EAGAIN;
500 rv = wait_event_interruptible(desc->wait,
501 test_bit(WDM_READ, &desc->flags));
504 /* may have happened while we slept */
505 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
509 if (test_bit(WDM_RESETTING, &desc->flags)) {
513 usb_mark_last_busy(interface_to_usbdev(desc->intf));
519 spin_lock_irq(&desc->iuspin);
521 if (desc->rerr) { /* read completed, error happened */
523 spin_unlock_irq(&desc->iuspin);
528 * recheck whether we've lost the race
529 * against the completion handler
531 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
532 spin_unlock_irq(&desc->iuspin);
536 if (!desc->reslength) { /* zero length read */
537 dev_dbg(&desc->intf->dev, "%s: zero length - clearing WDM_READ\n", __func__);
538 rv = clear_wdm_read_flag(desc);
539 spin_unlock_irq(&desc->iuspin);
545 spin_unlock_irq(&desc->iuspin);
550 rv = copy_to_user(buffer, desc->ubuf, cntr);
556 spin_lock_irq(&desc->iuspin);
558 for (i = 0; i < desc->length - cntr; i++)
559 desc->ubuf[i] = desc->ubuf[i + cntr];
561 desc->length -= cntr;
562 /* in case we had outstanding data */
564 clear_wdm_read_flag(desc);
565 spin_unlock_irq(&desc->iuspin);
569 mutex_unlock(&desc->rlock);
573 static int wdm_flush(struct file *file, fl_owner_t id)
575 struct wdm_device *desc = file->private_data;
577 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
579 /* cannot dereference desc->intf if WDM_DISCONNECTING */
580 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags))
581 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
584 return usb_translate_errors(desc->werr);
587 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
589 struct wdm_device *desc = file->private_data;
591 unsigned int mask = 0;
593 spin_lock_irqsave(&desc->iuspin, flags);
594 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
595 mask = POLLHUP | POLLERR;
596 spin_unlock_irqrestore(&desc->iuspin, flags);
599 if (test_bit(WDM_READ, &desc->flags))
600 mask = POLLIN | POLLRDNORM;
601 if (desc->rerr || desc->werr)
603 if (!test_bit(WDM_IN_USE, &desc->flags))
604 mask |= POLLOUT | POLLWRNORM;
605 spin_unlock_irqrestore(&desc->iuspin, flags);
607 poll_wait(file, &desc->wait, wait);
613 static int wdm_open(struct inode *inode, struct file *file)
615 int minor = iminor(inode);
617 struct usb_interface *intf;
618 struct wdm_device *desc;
620 mutex_lock(&wdm_mutex);
621 desc = wdm_find_device_by_minor(minor);
626 if (test_bit(WDM_DISCONNECTING, &desc->flags))
628 file->private_data = desc;
630 rv = usb_autopm_get_interface(desc->intf);
632 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
636 /* using write lock to protect desc->count */
637 mutex_lock(&desc->wlock);
638 if (!desc->count++) {
641 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
644 dev_err(&desc->intf->dev,
645 "Error submitting int urb - %d\n", rv);
646 rv = usb_translate_errors(rv);
651 mutex_unlock(&desc->wlock);
652 if (desc->count == 1)
653 desc->manage_power(intf, 1);
654 usb_autopm_put_interface(desc->intf);
656 mutex_unlock(&wdm_mutex);
660 static int wdm_release(struct inode *inode, struct file *file)
662 struct wdm_device *desc = file->private_data;
664 mutex_lock(&wdm_mutex);
666 /* using write lock to protect desc->count */
667 mutex_lock(&desc->wlock);
669 mutex_unlock(&desc->wlock);
672 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
673 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
675 spin_lock_irq(&desc->iuspin);
676 desc->resp_count = 0;
677 spin_unlock_irq(&desc->iuspin);
678 desc->manage_power(desc->intf, 0);
680 /* must avoid dev_printk here as desc->intf is invalid */
681 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
685 mutex_unlock(&wdm_mutex);
689 static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
691 struct wdm_device *desc = file->private_data;
695 case IOCTL_WDM_MAX_COMMAND:
696 if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand)))
705 static const struct file_operations wdm_fops = {
706 .owner = THIS_MODULE,
711 .release = wdm_release,
713 .unlocked_ioctl = wdm_ioctl,
714 .compat_ioctl = wdm_ioctl,
715 .llseek = noop_llseek,
718 static struct usb_class_driver wdm_class = {
721 .minor_base = WDM_MINOR_BASE,
724 /* --- error handling --- */
725 static void wdm_rxwork(struct work_struct *work)
727 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
732 spin_lock_irqsave(&desc->iuspin, flags);
733 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
734 spin_unlock_irqrestore(&desc->iuspin, flags);
736 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
737 spin_unlock_irqrestore(&desc->iuspin, flags);
739 rv = usb_submit_urb(desc->response, GFP_KERNEL);
740 if (rv < 0 && rv != -EPERM) {
741 spin_lock_irqsave(&desc->iuspin, flags);
742 clear_bit(WDM_RESPONDING, &desc->flags);
743 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
744 schedule_work(&desc->rxwork);
745 spin_unlock_irqrestore(&desc->iuspin, flags);
750 /* --- hotplug --- */
752 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
753 u16 bufsize, int (*manage_power)(struct usb_interface *, int))
756 struct wdm_device *desc;
758 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
761 INIT_LIST_HEAD(&desc->device_list);
762 mutex_init(&desc->rlock);
763 mutex_init(&desc->wlock);
764 spin_lock_init(&desc->iuspin);
765 init_waitqueue_head(&desc->wait);
766 desc->wMaxCommand = bufsize;
767 /* this will be expanded and needed in hardware endianness */
768 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
770 INIT_WORK(&desc->rxwork, wdm_rxwork);
773 if (!usb_endpoint_is_int_in(ep))
776 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
778 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
781 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
785 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
789 desc->response = usb_alloc_urb(0, GFP_KERNEL);
793 desc->command = usb_alloc_urb(0, GFP_KERNEL);
797 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
801 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
805 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
811 interface_to_usbdev(intf),
812 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
814 desc->wMaxPacketSize,
820 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
821 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
822 desc->irq->wValue = 0;
823 desc->irq->wIndex = desc->inum;
824 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
826 usb_fill_control_urb(
828 interface_to_usbdev(intf),
829 /* using common endpoint 0 */
830 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
831 (unsigned char *)desc->irq,
838 desc->manage_power = manage_power;
840 spin_lock(&wdm_device_list_lock);
841 list_add(&desc->device_list, &wdm_device_list);
842 spin_unlock(&wdm_device_list_lock);
844 rv = usb_register_dev(intf, &wdm_class);
848 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
852 spin_lock(&wdm_device_list_lock);
853 list_del(&desc->device_list);
854 spin_unlock(&wdm_device_list_lock);
859 static int wdm_manage_power(struct usb_interface *intf, int on)
861 /* need autopm_get/put here to ensure the usbcore sees the new value */
862 int rv = usb_autopm_get_interface(intf);
864 intf->needs_remote_wakeup = on;
866 usb_autopm_put_interface(intf);
870 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
873 struct usb_host_interface *iface;
874 struct usb_endpoint_descriptor *ep;
875 struct usb_cdc_dmm_desc *dmhd;
876 u8 *buffer = intf->altsetting->extra;
877 int buflen = intf->altsetting->extralen;
878 u16 maxcom = WDM_DEFAULT_BUFSIZE;
883 if (buffer[1] != USB_DT_CS_INTERFACE) {
884 dev_err(&intf->dev, "skipping garbage\n");
889 case USB_CDC_HEADER_TYPE:
891 case USB_CDC_DMM_TYPE:
892 dmhd = (struct usb_cdc_dmm_desc *)buffer;
893 maxcom = le16_to_cpu(dmhd->wMaxCommand);
895 "Finding maximum buffer length: %d", maxcom);
899 "Ignoring extra header, type %d, length %d\n",
900 buffer[2], buffer[0]);
908 iface = intf->cur_altsetting;
909 if (iface->desc.bNumEndpoints != 1)
911 ep = &iface->endpoint[0].desc;
913 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
920 * usb_cdc_wdm_register - register a WDM subdriver
921 * @intf: usb interface the subdriver will associate with
922 * @ep: interrupt endpoint to monitor for notifications
923 * @bufsize: maximum message size to support for read/write
925 * Create WDM usb class character device and associate it with intf
926 * without binding, allowing another driver to manage the interface.
928 * The subdriver will manage the given interrupt endpoint exclusively
929 * and will issue control requests referring to the given intf. It
930 * will otherwise avoid interferring, and in particular not do
931 * usb_set_intfdata/usb_get_intfdata on intf.
933 * The return value is a pointer to the subdriver's struct usb_driver.
934 * The registering driver is responsible for calling this subdriver's
935 * disconnect, suspend, resume, pre_reset and post_reset methods from
938 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
939 struct usb_endpoint_descriptor *ep,
941 int (*manage_power)(struct usb_interface *, int))
945 rv = wdm_create(intf, ep, bufsize, manage_power);
953 EXPORT_SYMBOL(usb_cdc_wdm_register);
955 static void wdm_disconnect(struct usb_interface *intf)
957 struct wdm_device *desc;
960 usb_deregister_dev(intf, &wdm_class);
961 desc = wdm_find_device(intf);
962 mutex_lock(&wdm_mutex);
964 /* the spinlock makes sure no new urbs are generated in the callbacks */
965 spin_lock_irqsave(&desc->iuspin, flags);
966 set_bit(WDM_DISCONNECTING, &desc->flags);
967 set_bit(WDM_READ, &desc->flags);
968 /* to terminate pending flushes */
969 clear_bit(WDM_IN_USE, &desc->flags);
970 spin_unlock_irqrestore(&desc->iuspin, flags);
971 wake_up_all(&desc->wait);
972 mutex_lock(&desc->rlock);
973 mutex_lock(&desc->wlock);
975 cancel_work_sync(&desc->rxwork);
976 mutex_unlock(&desc->wlock);
977 mutex_unlock(&desc->rlock);
979 /* the desc->intf pointer used as list key is now invalid */
980 spin_lock(&wdm_device_list_lock);
981 list_del(&desc->device_list);
982 spin_unlock(&wdm_device_list_lock);
987 dev_dbg(&intf->dev, "%s: %d open files - postponing cleanup\n", __func__, desc->count);
988 mutex_unlock(&wdm_mutex);
992 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
994 struct wdm_device *desc = wdm_find_device(intf);
997 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
999 /* if this is an autosuspend the caller does the locking */
1000 if (!PMSG_IS_AUTO(message)) {
1001 mutex_lock(&desc->rlock);
1002 mutex_lock(&desc->wlock);
1004 spin_lock_irq(&desc->iuspin);
1006 if (PMSG_IS_AUTO(message) &&
1007 (test_bit(WDM_IN_USE, &desc->flags)
1008 || test_bit(WDM_RESPONDING, &desc->flags))) {
1009 spin_unlock_irq(&desc->iuspin);
1013 set_bit(WDM_SUSPENDING, &desc->flags);
1014 spin_unlock_irq(&desc->iuspin);
1015 /* callback submits work - order is essential */
1017 cancel_work_sync(&desc->rxwork);
1019 if (!PMSG_IS_AUTO(message)) {
1020 mutex_unlock(&desc->wlock);
1021 mutex_unlock(&desc->rlock);
1028 static int recover_from_urb_loss(struct wdm_device *desc)
1033 rv = usb_submit_urb(desc->validity, GFP_NOIO);
1035 dev_err(&desc->intf->dev,
1036 "Error resume submitting int urb - %d\n", rv);
1042 static int wdm_resume(struct usb_interface *intf)
1044 struct wdm_device *desc = wdm_find_device(intf);
1047 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
1049 clear_bit(WDM_SUSPENDING, &desc->flags);
1050 rv = recover_from_urb_loss(desc);
1056 static int wdm_pre_reset(struct usb_interface *intf)
1058 struct wdm_device *desc = wdm_find_device(intf);
1061 * we notify everybody using poll of
1062 * an exceptional situation
1063 * must be done before recovery lest a spontaneous
1064 * message from the device is lost
1066 spin_lock_irq(&desc->iuspin);
1067 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */
1068 set_bit(WDM_READ, &desc->flags); /* unblock read */
1069 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */
1070 desc->rerr = -EINTR;
1071 spin_unlock_irq(&desc->iuspin);
1072 wake_up_all(&desc->wait);
1073 mutex_lock(&desc->rlock);
1074 mutex_lock(&desc->wlock);
1076 cancel_work_sync(&desc->rxwork);
1080 static int wdm_post_reset(struct usb_interface *intf)
1082 struct wdm_device *desc = wdm_find_device(intf);
1085 clear_bit(WDM_OVERFLOW, &desc->flags);
1086 clear_bit(WDM_RESETTING, &desc->flags);
1087 rv = recover_from_urb_loss(desc);
1088 mutex_unlock(&desc->wlock);
1089 mutex_unlock(&desc->rlock);
1093 static struct usb_driver wdm_driver = {
1096 .disconnect = wdm_disconnect,
1098 .suspend = wdm_suspend,
1099 .resume = wdm_resume,
1100 .reset_resume = wdm_resume,
1102 .pre_reset = wdm_pre_reset,
1103 .post_reset = wdm_post_reset,
1104 .id_table = wdm_ids,
1105 .supports_autosuspend = 1,
1106 .disable_hub_initiated_lpm = 1,
1109 module_usb_driver(wdm_driver);
1111 MODULE_AUTHOR(DRIVER_AUTHOR);
1112 MODULE_DESCRIPTION(DRIVER_DESC);
1113 MODULE_LICENSE("GPL");