1 // SPDX-License-Identifier: GPL-2.0
5 * This driver supports USB CDC WCM Device Management.
7 * Copyright (c) 2007-2009 Oliver Neukum
9 * Some code taken from cdc-acm.c
11 * Released under the GPLv2.
13 * Many thanks to Carl Nordbeck
15 #include <linux/kernel.h>
16 #include <linux/errno.h>
17 #include <linux/ioctl.h>
18 #include <linux/slab.h>
19 #include <linux/module.h>
20 #include <linux/mutex.h>
21 #include <linux/uaccess.h>
22 #include <linux/bitops.h>
23 #include <linux/poll.h>
24 #include <linux/usb.h>
25 #include <linux/usb/cdc.h>
26 #include <asm/byteorder.h>
27 #include <asm/unaligned.h>
28 #include <linux/usb/cdc-wdm.h>
30 #define DRIVER_AUTHOR "Oliver Neukum"
31 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
33 static const struct usb_device_id wdm_ids[] = {
35 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
36 USB_DEVICE_ID_MATCH_INT_SUBCLASS,
37 .bInterfaceClass = USB_CLASS_COMM,
38 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
43 MODULE_DEVICE_TABLE (usb, wdm_ids);
45 #define WDM_MINOR_BASE 176
49 #define WDM_DISCONNECTING 2
52 #define WDM_INT_STALL 5
53 #define WDM_POLL_RUNNING 6
54 #define WDM_RESPONDING 7
55 #define WDM_SUSPENDING 8
56 #define WDM_RESETTING 9
57 #define WDM_OVERFLOW 10
61 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
62 #define WDM_DEFAULT_BUFSIZE 256
64 static DEFINE_MUTEX(wdm_mutex);
65 static DEFINE_SPINLOCK(wdm_device_list_lock);
66 static LIST_HEAD(wdm_device_list);
68 /* --- method tables --- */
71 u8 *inbuf; /* buffer for response */
72 u8 *outbuf; /* buffer for command */
73 u8 *sbuf; /* buffer for status */
74 u8 *ubuf; /* buffer for copy to user space */
79 struct usb_interface *intf;
80 struct usb_ctrlrequest *orq;
81 struct usb_ctrlrequest *irq;
97 wait_queue_head_t wait;
98 struct work_struct rxwork;
103 struct list_head device_list;
104 int (*manage_power)(struct usb_interface *, int);
107 static struct usb_driver wdm_driver;
109 /* return intfdata if we own the interface, else look up intf in the list */
110 static struct wdm_device *wdm_find_device(struct usb_interface *intf)
112 struct wdm_device *desc;
114 spin_lock(&wdm_device_list_lock);
115 list_for_each_entry(desc, &wdm_device_list, device_list)
116 if (desc->intf == intf)
120 spin_unlock(&wdm_device_list_lock);
125 static struct wdm_device *wdm_find_device_by_minor(int minor)
127 struct wdm_device *desc;
129 spin_lock(&wdm_device_list_lock);
130 list_for_each_entry(desc, &wdm_device_list, device_list)
131 if (desc->intf->minor == minor)
135 spin_unlock(&wdm_device_list_lock);
140 /* --- callbacks --- */
141 static void wdm_out_callback(struct urb *urb)
143 struct wdm_device *desc;
145 spin_lock(&desc->iuspin);
146 desc->werr = urb->status;
147 spin_unlock(&desc->iuspin);
150 clear_bit(WDM_IN_USE, &desc->flags);
151 wake_up(&desc->wait);
154 /* forward declaration */
155 static int service_outstanding_interrupt(struct wdm_device *desc);
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\n");
173 dev_dbg(&desc->intf->dev,
174 "nonzero urb status received: -ECONNRESET\n");
177 dev_dbg(&desc->intf->dev,
178 "nonzero urb status received: -ESHUTDOWN\n");
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 * only set a new error if there is no previous error.
193 * Errors are only cleared during read/open
194 * Avoid propagating -EPIPE (stall) to userspace since it is
195 * better handled as an empty read
197 if (desc->rerr == 0 && status != -EPIPE)
200 if (length + desc->length > desc->wMaxCommand) {
201 /* The buffer would overflow */
202 set_bit(WDM_OVERFLOW, &desc->flags);
204 /* we may already be in overflow */
205 if (!test_bit(WDM_OVERFLOW, &desc->flags)) {
206 memmove(desc->ubuf + desc->length, desc->inbuf, length);
207 desc->length += length;
208 desc->reslength = length;
212 set_bit(WDM_READ, &desc->flags);
213 wake_up(&desc->wait);
217 * Since there was an error, userspace may decide to not read
218 * any data after poll'ing.
219 * We should respond to further attempts from the device to send
220 * data, so that we can get unstuck.
222 service_outstanding_interrupt(desc);
225 spin_unlock(&desc->iuspin);
228 static void wdm_int_callback(struct urb *urb)
232 int status = urb->status;
233 struct wdm_device *desc;
234 struct usb_cdc_notification *dr;
237 dr = (struct usb_cdc_notification *)desc->sbuf;
246 set_bit(WDM_INT_STALL, &desc->flags);
247 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
248 goto sw; /* halt is cleared in work */
250 dev_err(&desc->intf->dev,
251 "nonzero urb status received: %d\n", status);
256 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
257 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
262 switch (dr->bNotificationType) {
263 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
264 dev_dbg(&desc->intf->dev,
265 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d\n",
266 le16_to_cpu(dr->wIndex), le16_to_cpu(dr->wLength));
269 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
271 dev_dbg(&desc->intf->dev,
272 "NOTIFY_NETWORK_CONNECTION %s network\n",
273 dr->wValue ? "connected to" : "disconnected from");
275 case USB_CDC_NOTIFY_SPEED_CHANGE:
276 dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)\n",
280 clear_bit(WDM_POLL_RUNNING, &desc->flags);
281 dev_err(&desc->intf->dev,
282 "unknown notification %d received: index %d len %d\n",
283 dr->bNotificationType,
284 le16_to_cpu(dr->wIndex),
285 le16_to_cpu(dr->wLength));
289 spin_lock(&desc->iuspin);
290 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
291 if (!desc->resp_count++ && !responding
292 && !test_bit(WDM_DISCONNECTING, &desc->flags)
293 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
294 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
295 dev_dbg(&desc->intf->dev, "submit response URB %d\n", rv);
297 spin_unlock(&desc->iuspin);
299 clear_bit(WDM_RESPONDING, &desc->flags);
304 rv = schedule_work(&desc->rxwork);
306 dev_err(&desc->intf->dev,
307 "Cannot schedule work\n");
311 rv = usb_submit_urb(urb, GFP_ATOMIC);
313 dev_err(&desc->intf->dev,
314 "%s - usb_submit_urb failed with result %d\n",
319 static void kill_urbs(struct wdm_device *desc)
321 /* the order here is essential */
322 usb_kill_urb(desc->command);
323 usb_kill_urb(desc->validity);
324 usb_kill_urb(desc->response);
327 static void free_urbs(struct wdm_device *desc)
329 usb_free_urb(desc->validity);
330 usb_free_urb(desc->response);
331 usb_free_urb(desc->command);
334 static void cleanup(struct wdm_device *desc)
345 static ssize_t wdm_write
346 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
349 int rv = -EMSGSIZE, r, we;
350 struct wdm_device *desc = file->private_data;
351 struct usb_ctrlrequest *req;
353 if (count > desc->wMaxCommand)
354 count = desc->wMaxCommand;
356 spin_lock_irq(&desc->iuspin);
359 spin_unlock_irq(&desc->iuspin);
361 return usb_translate_errors(we);
363 buf = memdup_user(buffer, count);
367 /* concurrent writes and disconnect */
368 r = mutex_lock_interruptible(&desc->wlock);
373 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
375 goto out_free_mem_lock;
378 r = usb_autopm_get_interface(desc->intf);
380 rv = usb_translate_errors(r);
381 goto out_free_mem_lock;
384 if (!(file->f_flags & O_NONBLOCK))
385 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
388 if (test_bit(WDM_IN_USE, &desc->flags))
391 if (test_bit(WDM_RESETTING, &desc->flags))
396 goto out_free_mem_pm;
400 usb_fill_control_urb(
402 interface_to_usbdev(desc->intf),
403 /* using common endpoint 0 */
404 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
405 (unsigned char *)req,
412 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
413 USB_RECIP_INTERFACE);
414 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
416 req->wIndex = desc->inum; /* already converted */
417 req->wLength = cpu_to_le16(count);
418 set_bit(WDM_IN_USE, &desc->flags);
421 rv = usb_submit_urb(desc->command, GFP_KERNEL);
424 clear_bit(WDM_IN_USE, &desc->flags);
425 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
426 rv = usb_translate_errors(rv);
427 goto out_free_mem_pm;
429 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d\n",
430 le16_to_cpu(req->wIndex));
433 usb_autopm_put_interface(desc->intf);
434 mutex_unlock(&desc->wlock);
438 usb_autopm_put_interface(desc->intf);
440 mutex_unlock(&desc->wlock);
447 * Submit the read urb if resp_count is non-zero.
449 * Called with desc->iuspin locked
451 static int service_outstanding_interrupt(struct wdm_device *desc)
455 /* submit read urb only if the device is waiting for it */
456 if (!desc->resp_count || !--desc->resp_count)
459 set_bit(WDM_RESPONDING, &desc->flags);
460 spin_unlock_irq(&desc->iuspin);
461 rv = usb_submit_urb(desc->response, GFP_KERNEL);
462 spin_lock_irq(&desc->iuspin);
464 dev_err(&desc->intf->dev,
465 "usb_submit_urb failed with result %d\n", rv);
467 /* make sure the next notification trigger a submit */
468 clear_bit(WDM_RESPONDING, &desc->flags);
469 desc->resp_count = 0;
475 static ssize_t wdm_read
476 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
480 struct wdm_device *desc = file->private_data;
483 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
487 cntr = READ_ONCE(desc->length);
491 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
495 if (test_bit(WDM_OVERFLOW, &desc->flags)) {
496 clear_bit(WDM_OVERFLOW, &desc->flags);
501 if (file->f_flags & O_NONBLOCK) {
502 if (!test_bit(WDM_READ, &desc->flags)) {
508 rv = wait_event_interruptible(desc->wait,
509 test_bit(WDM_READ, &desc->flags));
512 /* may have happened while we slept */
513 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
517 if (test_bit(WDM_RESETTING, &desc->flags)) {
521 usb_mark_last_busy(interface_to_usbdev(desc->intf));
527 spin_lock_irq(&desc->iuspin);
529 if (desc->rerr) { /* read completed, error happened */
530 rv = usb_translate_errors(desc->rerr);
532 spin_unlock_irq(&desc->iuspin);
536 * recheck whether we've lost the race
537 * against the completion handler
539 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
540 spin_unlock_irq(&desc->iuspin);
544 if (!desc->reslength) { /* zero length read */
545 dev_dbg(&desc->intf->dev, "zero length - clearing WDM_READ\n");
546 clear_bit(WDM_READ, &desc->flags);
547 rv = service_outstanding_interrupt(desc);
548 spin_unlock_irq(&desc->iuspin);
554 spin_unlock_irq(&desc->iuspin);
559 rv = copy_to_user(buffer, desc->ubuf, cntr);
565 spin_lock_irq(&desc->iuspin);
567 for (i = 0; i < desc->length - cntr; i++)
568 desc->ubuf[i] = desc->ubuf[i + cntr];
570 desc->length -= cntr;
571 /* in case we had outstanding data */
573 clear_bit(WDM_READ, &desc->flags);
574 service_outstanding_interrupt(desc);
576 spin_unlock_irq(&desc->iuspin);
580 mutex_unlock(&desc->rlock);
584 static int wdm_flush(struct file *file, fl_owner_t id)
586 struct wdm_device *desc = file->private_data;
588 wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
590 /* cannot dereference desc->intf if WDM_DISCONNECTING */
591 if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags))
592 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
595 return usb_translate_errors(desc->werr);
598 static __poll_t wdm_poll(struct file *file, struct poll_table_struct *wait)
600 struct wdm_device *desc = file->private_data;
604 spin_lock_irqsave(&desc->iuspin, flags);
605 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
606 mask = POLLHUP | POLLERR;
607 spin_unlock_irqrestore(&desc->iuspin, flags);
610 if (test_bit(WDM_READ, &desc->flags))
611 mask = POLLIN | POLLRDNORM;
612 if (desc->rerr || desc->werr)
614 if (!test_bit(WDM_IN_USE, &desc->flags))
615 mask |= POLLOUT | POLLWRNORM;
616 spin_unlock_irqrestore(&desc->iuspin, flags);
618 poll_wait(file, &desc->wait, wait);
624 static int wdm_open(struct inode *inode, struct file *file)
626 int minor = iminor(inode);
628 struct usb_interface *intf;
629 struct wdm_device *desc;
631 mutex_lock(&wdm_mutex);
632 desc = wdm_find_device_by_minor(minor);
637 if (test_bit(WDM_DISCONNECTING, &desc->flags))
639 file->private_data = desc;
641 rv = usb_autopm_get_interface(desc->intf);
643 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
647 /* using write lock to protect desc->count */
648 mutex_lock(&desc->wlock);
649 if (!desc->count++) {
652 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
655 dev_err(&desc->intf->dev,
656 "Error submitting int urb - %d\n", rv);
657 rv = usb_translate_errors(rv);
662 mutex_unlock(&desc->wlock);
663 if (desc->count == 1)
664 desc->manage_power(intf, 1);
665 usb_autopm_put_interface(desc->intf);
667 mutex_unlock(&wdm_mutex);
671 static int wdm_release(struct inode *inode, struct file *file)
673 struct wdm_device *desc = file->private_data;
675 mutex_lock(&wdm_mutex);
677 /* using write lock to protect desc->count */
678 mutex_lock(&desc->wlock);
680 mutex_unlock(&desc->wlock);
683 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
684 dev_dbg(&desc->intf->dev, "wdm_release: cleanup\n");
686 spin_lock_irq(&desc->iuspin);
687 desc->resp_count = 0;
688 spin_unlock_irq(&desc->iuspin);
689 desc->manage_power(desc->intf, 0);
691 /* must avoid dev_printk here as desc->intf is invalid */
692 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
696 mutex_unlock(&wdm_mutex);
700 static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
702 struct wdm_device *desc = file->private_data;
706 case IOCTL_WDM_MAX_COMMAND:
707 if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand)))
716 static const struct file_operations wdm_fops = {
717 .owner = THIS_MODULE,
722 .release = wdm_release,
724 .unlocked_ioctl = wdm_ioctl,
725 .compat_ioctl = wdm_ioctl,
726 .llseek = noop_llseek,
729 static struct usb_class_driver wdm_class = {
732 .minor_base = WDM_MINOR_BASE,
735 /* --- error handling --- */
736 static void wdm_rxwork(struct work_struct *work)
738 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
743 spin_lock_irqsave(&desc->iuspin, flags);
744 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
745 spin_unlock_irqrestore(&desc->iuspin, flags);
747 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
748 spin_unlock_irqrestore(&desc->iuspin, flags);
750 rv = usb_submit_urb(desc->response, GFP_KERNEL);
751 if (rv < 0 && rv != -EPERM) {
752 spin_lock_irqsave(&desc->iuspin, flags);
753 clear_bit(WDM_RESPONDING, &desc->flags);
754 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
755 schedule_work(&desc->rxwork);
756 spin_unlock_irqrestore(&desc->iuspin, flags);
761 /* --- hotplug --- */
763 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
764 u16 bufsize, int (*manage_power)(struct usb_interface *, int))
767 struct wdm_device *desc;
769 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
772 INIT_LIST_HEAD(&desc->device_list);
773 mutex_init(&desc->rlock);
774 mutex_init(&desc->wlock);
775 spin_lock_init(&desc->iuspin);
776 init_waitqueue_head(&desc->wait);
777 desc->wMaxCommand = bufsize;
778 /* this will be expanded and needed in hardware endianness */
779 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
781 INIT_WORK(&desc->rxwork, wdm_rxwork);
784 if (!usb_endpoint_is_int_in(ep))
787 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
789 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
792 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
796 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
800 desc->response = usb_alloc_urb(0, GFP_KERNEL);
804 desc->command = usb_alloc_urb(0, GFP_KERNEL);
808 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
812 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
816 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
822 interface_to_usbdev(intf),
823 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
825 desc->wMaxPacketSize,
831 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
832 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
833 desc->irq->wValue = 0;
834 desc->irq->wIndex = desc->inum; /* already converted */
835 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
837 usb_fill_control_urb(
839 interface_to_usbdev(intf),
840 /* using common endpoint 0 */
841 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
842 (unsigned char *)desc->irq,
849 desc->manage_power = manage_power;
851 spin_lock(&wdm_device_list_lock);
852 list_add(&desc->device_list, &wdm_device_list);
853 spin_unlock(&wdm_device_list_lock);
855 rv = usb_register_dev(intf, &wdm_class);
859 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
863 spin_lock(&wdm_device_list_lock);
864 list_del(&desc->device_list);
865 spin_unlock(&wdm_device_list_lock);
870 static int wdm_manage_power(struct usb_interface *intf, int on)
872 /* need autopm_get/put here to ensure the usbcore sees the new value */
873 int rv = usb_autopm_get_interface(intf);
875 intf->needs_remote_wakeup = on;
877 usb_autopm_put_interface(intf);
881 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
884 struct usb_host_interface *iface;
885 struct usb_endpoint_descriptor *ep;
886 struct usb_cdc_parsed_header hdr;
887 u8 *buffer = intf->altsetting->extra;
888 int buflen = intf->altsetting->extralen;
889 u16 maxcom = WDM_DEFAULT_BUFSIZE;
894 cdc_parse_cdc_header(&hdr, intf, buffer, buflen);
896 if (hdr.usb_cdc_dmm_desc)
897 maxcom = le16_to_cpu(hdr.usb_cdc_dmm_desc->wMaxCommand);
899 iface = intf->cur_altsetting;
900 if (iface->desc.bNumEndpoints != 1)
902 ep = &iface->endpoint[0].desc;
904 rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
911 * usb_cdc_wdm_register - register a WDM subdriver
912 * @intf: usb interface the subdriver will associate with
913 * @ep: interrupt endpoint to monitor for notifications
914 * @bufsize: maximum message size to support for read/write
916 * Create WDM usb class character device and associate it with intf
917 * without binding, allowing another driver to manage the interface.
919 * The subdriver will manage the given interrupt endpoint exclusively
920 * and will issue control requests referring to the given intf. It
921 * will otherwise avoid interferring, and in particular not do
922 * usb_set_intfdata/usb_get_intfdata on intf.
924 * The return value is a pointer to the subdriver's struct usb_driver.
925 * The registering driver is responsible for calling this subdriver's
926 * disconnect, suspend, resume, pre_reset and post_reset methods from
929 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
930 struct usb_endpoint_descriptor *ep,
932 int (*manage_power)(struct usb_interface *, int))
936 rv = wdm_create(intf, ep, bufsize, manage_power);
944 EXPORT_SYMBOL(usb_cdc_wdm_register);
946 static void wdm_disconnect(struct usb_interface *intf)
948 struct wdm_device *desc;
951 usb_deregister_dev(intf, &wdm_class);
952 desc = wdm_find_device(intf);
953 mutex_lock(&wdm_mutex);
955 /* the spinlock makes sure no new urbs are generated in the callbacks */
956 spin_lock_irqsave(&desc->iuspin, flags);
957 set_bit(WDM_DISCONNECTING, &desc->flags);
958 set_bit(WDM_READ, &desc->flags);
959 /* to terminate pending flushes */
960 clear_bit(WDM_IN_USE, &desc->flags);
961 spin_unlock_irqrestore(&desc->iuspin, flags);
962 wake_up_all(&desc->wait);
963 mutex_lock(&desc->rlock);
964 mutex_lock(&desc->wlock);
966 cancel_work_sync(&desc->rxwork);
967 mutex_unlock(&desc->wlock);
968 mutex_unlock(&desc->rlock);
970 /* the desc->intf pointer used as list key is now invalid */
971 spin_lock(&wdm_device_list_lock);
972 list_del(&desc->device_list);
973 spin_unlock(&wdm_device_list_lock);
978 dev_dbg(&intf->dev, "%d open files - postponing cleanup\n", desc->count);
979 mutex_unlock(&wdm_mutex);
983 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
985 struct wdm_device *desc = wdm_find_device(intf);
988 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
990 /* if this is an autosuspend the caller does the locking */
991 if (!PMSG_IS_AUTO(message)) {
992 mutex_lock(&desc->rlock);
993 mutex_lock(&desc->wlock);
995 spin_lock_irq(&desc->iuspin);
997 if (PMSG_IS_AUTO(message) &&
998 (test_bit(WDM_IN_USE, &desc->flags)
999 || test_bit(WDM_RESPONDING, &desc->flags))) {
1000 spin_unlock_irq(&desc->iuspin);
1004 set_bit(WDM_SUSPENDING, &desc->flags);
1005 spin_unlock_irq(&desc->iuspin);
1006 /* callback submits work - order is essential */
1008 cancel_work_sync(&desc->rxwork);
1010 if (!PMSG_IS_AUTO(message)) {
1011 mutex_unlock(&desc->wlock);
1012 mutex_unlock(&desc->rlock);
1019 static int recover_from_urb_loss(struct wdm_device *desc)
1024 rv = usb_submit_urb(desc->validity, GFP_NOIO);
1026 dev_err(&desc->intf->dev,
1027 "Error resume submitting int urb - %d\n", rv);
1033 static int wdm_resume(struct usb_interface *intf)
1035 struct wdm_device *desc = wdm_find_device(intf);
1038 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
1040 clear_bit(WDM_SUSPENDING, &desc->flags);
1041 rv = recover_from_urb_loss(desc);
1047 static int wdm_pre_reset(struct usb_interface *intf)
1049 struct wdm_device *desc = wdm_find_device(intf);
1052 * we notify everybody using poll of
1053 * an exceptional situation
1054 * must be done before recovery lest a spontaneous
1055 * message from the device is lost
1057 spin_lock_irq(&desc->iuspin);
1058 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */
1059 set_bit(WDM_READ, &desc->flags); /* unblock read */
1060 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */
1061 desc->rerr = -EINTR;
1062 spin_unlock_irq(&desc->iuspin);
1063 wake_up_all(&desc->wait);
1064 mutex_lock(&desc->rlock);
1065 mutex_lock(&desc->wlock);
1067 cancel_work_sync(&desc->rxwork);
1071 static int wdm_post_reset(struct usb_interface *intf)
1073 struct wdm_device *desc = wdm_find_device(intf);
1076 clear_bit(WDM_OVERFLOW, &desc->flags);
1077 clear_bit(WDM_RESETTING, &desc->flags);
1078 rv = recover_from_urb_loss(desc);
1079 mutex_unlock(&desc->wlock);
1080 mutex_unlock(&desc->rlock);
1084 static struct usb_driver wdm_driver = {
1087 .disconnect = wdm_disconnect,
1089 .suspend = wdm_suspend,
1090 .resume = wdm_resume,
1091 .reset_resume = wdm_resume,
1093 .pre_reset = wdm_pre_reset,
1094 .post_reset = wdm_post_reset,
1095 .id_table = wdm_ids,
1096 .supports_autosuspend = 1,
1097 .disable_hub_initiated_lpm = 1,
1100 module_usb_driver(wdm_driver);
1102 MODULE_AUTHOR(DRIVER_AUTHOR);
1103 MODULE_DESCRIPTION(DRIVER_DESC);
1104 MODULE_LICENSE("GPL");