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/skbuff.h>
25 #include <linux/usb.h>
26 #include <linux/usb/cdc.h>
27 #include <linux/wwan.h>
28 #include <asm/byteorder.h>
29 #include <asm/unaligned.h>
30 #include <linux/usb/cdc-wdm.h>
32 #define DRIVER_AUTHOR "Oliver Neukum"
33 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
35 static const struct usb_device_id wdm_ids[] = {
37 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
38 USB_DEVICE_ID_MATCH_INT_SUBCLASS,
39 .bInterfaceClass = USB_CLASS_COMM,
40 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
45 MODULE_DEVICE_TABLE (usb, wdm_ids);
47 #define WDM_MINOR_BASE 176
51 #define WDM_DISCONNECTING 2
54 #define WDM_INT_STALL 5
55 #define WDM_POLL_RUNNING 6
56 #define WDM_RESPONDING 7
57 #define WDM_SUSPENDING 8
58 #define WDM_RESETTING 9
59 #define WDM_OVERFLOW 10
60 #define WDM_WWAN_IN_USE 11
64 /* we cannot wait forever at flush() */
65 #define WDM_FLUSH_TIMEOUT (30 * HZ)
67 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
68 #define WDM_DEFAULT_BUFSIZE 256
70 static DEFINE_MUTEX(wdm_mutex);
71 static DEFINE_SPINLOCK(wdm_device_list_lock);
72 static LIST_HEAD(wdm_device_list);
74 /* --- method tables --- */
77 u8 *inbuf; /* buffer for response */
78 u8 *outbuf; /* buffer for command */
79 u8 *sbuf; /* buffer for status */
80 u8 *ubuf; /* buffer for copy to user space */
85 struct usb_interface *intf;
86 struct usb_ctrlrequest *orq;
87 struct usb_ctrlrequest *irq;
103 wait_queue_head_t wait;
104 struct work_struct rxwork;
105 struct work_struct service_outs_intr;
110 struct list_head device_list;
111 int (*manage_power)(struct usb_interface *, int);
113 enum wwan_port_type wwanp_type;
114 struct wwan_port *wwanp;
117 static struct usb_driver wdm_driver;
119 /* return intfdata if we own the interface, else look up intf in the list */
120 static struct wdm_device *wdm_find_device(struct usb_interface *intf)
122 struct wdm_device *desc;
124 spin_lock(&wdm_device_list_lock);
125 list_for_each_entry(desc, &wdm_device_list, device_list)
126 if (desc->intf == intf)
130 spin_unlock(&wdm_device_list_lock);
135 static struct wdm_device *wdm_find_device_by_minor(int minor)
137 struct wdm_device *desc;
139 spin_lock(&wdm_device_list_lock);
140 list_for_each_entry(desc, &wdm_device_list, device_list)
141 if (desc->intf->minor == minor)
145 spin_unlock(&wdm_device_list_lock);
150 /* --- callbacks --- */
151 static void wdm_out_callback(struct urb *urb)
153 struct wdm_device *desc;
157 spin_lock_irqsave(&desc->iuspin, flags);
158 desc->werr = urb->status;
159 spin_unlock_irqrestore(&desc->iuspin, flags);
162 clear_bit(WDM_IN_USE, &desc->flags);
163 wake_up_all(&desc->wait);
166 static void wdm_wwan_rx(struct wdm_device *desc, int length);
168 static void wdm_in_callback(struct urb *urb)
171 struct wdm_device *desc = urb->context;
172 int status = urb->status;
173 int length = urb->actual_length;
175 spin_lock_irqsave(&desc->iuspin, flags);
176 clear_bit(WDM_RESPONDING, &desc->flags);
181 dev_dbg(&desc->intf->dev,
182 "nonzero urb status received: -ENOENT\n");
185 dev_dbg(&desc->intf->dev,
186 "nonzero urb status received: -ECONNRESET\n");
189 dev_dbg(&desc->intf->dev,
190 "nonzero urb status received: -ESHUTDOWN\n");
193 dev_err(&desc->intf->dev,
194 "nonzero urb status received: -EPIPE\n");
197 dev_err(&desc->intf->dev,
198 "Unexpected error %d\n", status);
203 if (test_bit(WDM_WWAN_IN_USE, &desc->flags)) {
204 wdm_wwan_rx(desc, length);
209 * only set a new error if there is no previous error.
210 * Errors are only cleared during read/open
211 * Avoid propagating -EPIPE (stall) to userspace since it is
212 * better handled as an empty read
214 if (desc->rerr == 0 && status != -EPIPE)
217 if (length + desc->length > desc->wMaxCommand) {
218 /* The buffer would overflow */
219 set_bit(WDM_OVERFLOW, &desc->flags);
221 /* we may already be in overflow */
222 if (!test_bit(WDM_OVERFLOW, &desc->flags)) {
223 memmove(desc->ubuf + desc->length, desc->inbuf, length);
224 desc->length += length;
225 desc->reslength = length;
232 * Since there was an error, userspace may decide to not read
233 * any data after poll'ing.
234 * We should respond to further attempts from the device to send
235 * data, so that we can get unstuck.
237 schedule_work(&desc->service_outs_intr);
239 set_bit(WDM_READ, &desc->flags);
240 wake_up(&desc->wait);
243 spin_unlock_irqrestore(&desc->iuspin, flags);
246 static void wdm_int_callback(struct urb *urb)
251 int status = urb->status;
252 struct wdm_device *desc;
253 struct usb_cdc_notification *dr;
256 dr = (struct usb_cdc_notification *)desc->sbuf;
265 set_bit(WDM_INT_STALL, &desc->flags);
266 dev_err(&desc->intf->dev, "Stall on int endpoint\n");
267 goto sw; /* halt is cleared in work */
269 dev_err(&desc->intf->dev,
270 "nonzero urb status received: %d\n", status);
275 if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
276 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
281 switch (dr->bNotificationType) {
282 case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
283 dev_dbg(&desc->intf->dev,
284 "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d\n",
285 le16_to_cpu(dr->wIndex), le16_to_cpu(dr->wLength));
288 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
290 dev_dbg(&desc->intf->dev,
291 "NOTIFY_NETWORK_CONNECTION %s network\n",
292 dr->wValue ? "connected to" : "disconnected from");
294 case USB_CDC_NOTIFY_SPEED_CHANGE:
295 dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)\n",
299 clear_bit(WDM_POLL_RUNNING, &desc->flags);
300 dev_err(&desc->intf->dev,
301 "unknown notification %d received: index %d len %d\n",
302 dr->bNotificationType,
303 le16_to_cpu(dr->wIndex),
304 le16_to_cpu(dr->wLength));
308 spin_lock_irqsave(&desc->iuspin, flags);
309 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
310 if (!desc->resp_count++ && !responding
311 && !test_bit(WDM_DISCONNECTING, &desc->flags)
312 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
313 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
314 dev_dbg(&desc->intf->dev, "submit response URB %d\n", rv);
316 spin_unlock_irqrestore(&desc->iuspin, flags);
318 clear_bit(WDM_RESPONDING, &desc->flags);
323 rv = schedule_work(&desc->rxwork);
325 dev_err(&desc->intf->dev,
326 "Cannot schedule work\n");
330 rv = usb_submit_urb(urb, GFP_ATOMIC);
332 dev_err(&desc->intf->dev,
333 "%s - usb_submit_urb failed with result %d\n",
338 static void poison_urbs(struct wdm_device *desc)
340 /* the order here is essential */
341 usb_poison_urb(desc->command);
342 usb_poison_urb(desc->validity);
343 usb_poison_urb(desc->response);
346 static void unpoison_urbs(struct wdm_device *desc)
349 * the order here is not essential
350 * it is symmetrical just to be nice
352 usb_unpoison_urb(desc->response);
353 usb_unpoison_urb(desc->validity);
354 usb_unpoison_urb(desc->command);
357 static void free_urbs(struct wdm_device *desc)
359 usb_free_urb(desc->validity);
360 usb_free_urb(desc->response);
361 usb_free_urb(desc->command);
364 static void cleanup(struct wdm_device *desc)
375 static ssize_t wdm_write
376 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
379 int rv = -EMSGSIZE, r, we;
380 struct wdm_device *desc = file->private_data;
381 struct usb_ctrlrequest *req;
383 if (count > desc->wMaxCommand)
384 count = desc->wMaxCommand;
386 spin_lock_irq(&desc->iuspin);
389 spin_unlock_irq(&desc->iuspin);
391 return usb_translate_errors(we);
393 buf = memdup_user(buffer, count);
397 /* concurrent writes and disconnect */
398 r = mutex_lock_interruptible(&desc->wlock);
403 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
405 goto out_free_mem_lock;
408 r = usb_autopm_get_interface(desc->intf);
410 rv = usb_translate_errors(r);
411 goto out_free_mem_lock;
414 if (!(file->f_flags & O_NONBLOCK))
415 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
418 if (test_bit(WDM_IN_USE, &desc->flags))
421 if (test_bit(WDM_RESETTING, &desc->flags))
424 if (test_bit(WDM_DISCONNECTING, &desc->flags))
429 goto out_free_mem_pm;
433 usb_fill_control_urb(
435 interface_to_usbdev(desc->intf),
436 /* using common endpoint 0 */
437 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
438 (unsigned char *)req,
445 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
446 USB_RECIP_INTERFACE);
447 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
449 req->wIndex = desc->inum; /* already converted */
450 req->wLength = cpu_to_le16(count);
451 set_bit(WDM_IN_USE, &desc->flags);
454 rv = usb_submit_urb(desc->command, GFP_KERNEL);
457 clear_bit(WDM_IN_USE, &desc->flags);
458 wake_up_all(&desc->wait); /* for wdm_wait_for_response() */
459 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
460 rv = usb_translate_errors(rv);
461 goto out_free_mem_pm;
463 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d\n",
464 le16_to_cpu(req->wIndex));
467 usb_autopm_put_interface(desc->intf);
468 mutex_unlock(&desc->wlock);
472 usb_autopm_put_interface(desc->intf);
474 mutex_unlock(&desc->wlock);
481 * Submit the read urb if resp_count is non-zero.
483 * Called with desc->iuspin locked
485 static int service_outstanding_interrupt(struct wdm_device *desc)
489 /* submit read urb only if the device is waiting for it */
490 if (!desc->resp_count || !--desc->resp_count)
493 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
497 if (test_bit(WDM_RESETTING, &desc->flags)) {
502 set_bit(WDM_RESPONDING, &desc->flags);
503 spin_unlock_irq(&desc->iuspin);
504 rv = usb_submit_urb(desc->response, GFP_KERNEL);
505 spin_lock_irq(&desc->iuspin);
507 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
508 dev_err(&desc->intf->dev,
509 "usb_submit_urb failed with result %d\n", rv);
511 /* make sure the next notification trigger a submit */
512 clear_bit(WDM_RESPONDING, &desc->flags);
513 desc->resp_count = 0;
519 static ssize_t wdm_read
520 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
524 struct wdm_device *desc = file->private_data;
527 rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
531 cntr = READ_ONCE(desc->length);
535 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
539 if (test_bit(WDM_OVERFLOW, &desc->flags)) {
540 clear_bit(WDM_OVERFLOW, &desc->flags);
545 if (file->f_flags & O_NONBLOCK) {
546 if (!test_bit(WDM_READ, &desc->flags)) {
552 rv = wait_event_interruptible(desc->wait,
553 test_bit(WDM_READ, &desc->flags));
556 /* may have happened while we slept */
557 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
561 if (test_bit(WDM_RESETTING, &desc->flags)) {
565 usb_mark_last_busy(interface_to_usbdev(desc->intf));
571 spin_lock_irq(&desc->iuspin);
573 if (desc->rerr) { /* read completed, error happened */
574 rv = usb_translate_errors(desc->rerr);
576 spin_unlock_irq(&desc->iuspin);
580 * recheck whether we've lost the race
581 * against the completion handler
583 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
584 spin_unlock_irq(&desc->iuspin);
588 if (!desc->reslength) { /* zero length read */
589 dev_dbg(&desc->intf->dev, "zero length - clearing WDM_READ\n");
590 clear_bit(WDM_READ, &desc->flags);
591 rv = service_outstanding_interrupt(desc);
592 spin_unlock_irq(&desc->iuspin);
598 spin_unlock_irq(&desc->iuspin);
603 rv = copy_to_user(buffer, desc->ubuf, cntr);
609 spin_lock_irq(&desc->iuspin);
611 for (i = 0; i < desc->length - cntr; i++)
612 desc->ubuf[i] = desc->ubuf[i + cntr];
614 desc->length -= cntr;
615 /* in case we had outstanding data */
617 clear_bit(WDM_READ, &desc->flags);
618 service_outstanding_interrupt(desc);
620 spin_unlock_irq(&desc->iuspin);
624 mutex_unlock(&desc->rlock);
628 static int wdm_wait_for_response(struct file *file, long timeout)
630 struct wdm_device *desc = file->private_data;
631 long rv; /* Use long here because (int) MAX_SCHEDULE_TIMEOUT < 0. */
634 * Needs both flags. We cannot do with one because resetting it would
635 * cause a race with write() yet we need to signal a disconnect.
637 rv = wait_event_interruptible_timeout(desc->wait,
638 !test_bit(WDM_IN_USE, &desc->flags) ||
639 test_bit(WDM_DISCONNECTING, &desc->flags),
643 * To report the correct error. This is best effort.
644 * We are inevitably racing with the hardware.
646 if (test_bit(WDM_DISCONNECTING, &desc->flags))
653 spin_lock_irq(&desc->iuspin);
656 spin_unlock_irq(&desc->iuspin);
658 return usb_translate_errors(rv);
663 * You need to send a signal when you react to malicious or defective hardware.
664 * Also, don't abort when fsync() returned -EINVAL, for older kernels which do
665 * not implement wdm_flush() will return -EINVAL.
667 static int wdm_fsync(struct file *file, loff_t start, loff_t end, int datasync)
669 return wdm_wait_for_response(file, MAX_SCHEDULE_TIMEOUT);
673 * Same with wdm_fsync(), except it uses finite timeout in order to react to
674 * malicious or defective hardware which ceased communication after close() was
675 * implicitly called due to process termination.
677 static int wdm_flush(struct file *file, fl_owner_t id)
679 return wdm_wait_for_response(file, WDM_FLUSH_TIMEOUT);
682 static __poll_t wdm_poll(struct file *file, struct poll_table_struct *wait)
684 struct wdm_device *desc = file->private_data;
688 spin_lock_irqsave(&desc->iuspin, flags);
689 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
690 mask = EPOLLHUP | EPOLLERR;
691 spin_unlock_irqrestore(&desc->iuspin, flags);
694 if (test_bit(WDM_READ, &desc->flags))
695 mask = EPOLLIN | EPOLLRDNORM;
696 if (desc->rerr || desc->werr)
698 if (!test_bit(WDM_IN_USE, &desc->flags))
699 mask |= EPOLLOUT | EPOLLWRNORM;
700 spin_unlock_irqrestore(&desc->iuspin, flags);
702 poll_wait(file, &desc->wait, wait);
708 static int wdm_open(struct inode *inode, struct file *file)
710 int minor = iminor(inode);
712 struct usb_interface *intf;
713 struct wdm_device *desc;
715 mutex_lock(&wdm_mutex);
716 desc = wdm_find_device_by_minor(minor);
721 if (test_bit(WDM_DISCONNECTING, &desc->flags))
723 file->private_data = desc;
725 if (test_bit(WDM_WWAN_IN_USE, &desc->flags)) {
730 rv = usb_autopm_get_interface(desc->intf);
732 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
736 /* using write lock to protect desc->count */
737 mutex_lock(&desc->wlock);
738 if (!desc->count++) {
741 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
744 dev_err(&desc->intf->dev,
745 "Error submitting int urb - %d\n", rv);
746 rv = usb_translate_errors(rv);
751 mutex_unlock(&desc->wlock);
752 if (desc->count == 1)
753 desc->manage_power(intf, 1);
754 usb_autopm_put_interface(desc->intf);
756 mutex_unlock(&wdm_mutex);
760 static int wdm_release(struct inode *inode, struct file *file)
762 struct wdm_device *desc = file->private_data;
764 mutex_lock(&wdm_mutex);
766 /* using write lock to protect desc->count */
767 mutex_lock(&desc->wlock);
769 mutex_unlock(&desc->wlock);
772 if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
773 dev_dbg(&desc->intf->dev, "wdm_release: cleanup\n");
775 spin_lock_irq(&desc->iuspin);
776 desc->resp_count = 0;
777 spin_unlock_irq(&desc->iuspin);
778 desc->manage_power(desc->intf, 0);
781 /* must avoid dev_printk here as desc->intf is invalid */
782 pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
786 mutex_unlock(&wdm_mutex);
790 static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
792 struct wdm_device *desc = file->private_data;
796 case IOCTL_WDM_MAX_COMMAND:
797 if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand)))
806 static const struct file_operations wdm_fops = {
807 .owner = THIS_MODULE,
813 .release = wdm_release,
815 .unlocked_ioctl = wdm_ioctl,
816 .compat_ioctl = compat_ptr_ioctl,
817 .llseek = noop_llseek,
820 static struct usb_class_driver wdm_class = {
823 .minor_base = WDM_MINOR_BASE,
826 /* --- WWAN framework integration --- */
828 static int wdm_wwan_port_start(struct wwan_port *port)
830 struct wdm_device *desc = wwan_port_get_drvdata(port);
832 /* The interface is both exposed via the WWAN framework and as a
833 * legacy usbmisc chardev. If chardev is already open, just fail
834 * to prevent concurrent usage. Otherwise, switch to WWAN mode.
836 mutex_lock(&wdm_mutex);
838 mutex_unlock(&wdm_mutex);
841 set_bit(WDM_WWAN_IN_USE, &desc->flags);
842 mutex_unlock(&wdm_mutex);
844 desc->manage_power(desc->intf, 1);
847 wwan_port_txon(port);
849 /* Start getting events */
850 return usb_submit_urb(desc->validity, GFP_KERNEL);
853 static void wdm_wwan_port_stop(struct wwan_port *port)
855 struct wdm_device *desc = wwan_port_get_drvdata(port);
857 /* Stop all transfers and disable WWAN mode */
859 desc->manage_power(desc->intf, 0);
860 clear_bit(WDM_READ, &desc->flags);
861 clear_bit(WDM_WWAN_IN_USE, &desc->flags);
865 static void wdm_wwan_port_tx_complete(struct urb *urb)
867 struct sk_buff *skb = urb->context;
868 struct wdm_device *desc = skb_shinfo(skb)->destructor_arg;
870 usb_autopm_put_interface(desc->intf);
871 wwan_port_txon(desc->wwanp);
875 static int wdm_wwan_port_tx(struct wwan_port *port, struct sk_buff *skb)
877 struct wdm_device *desc = wwan_port_get_drvdata(port);
878 struct usb_interface *intf = desc->intf;
879 struct usb_ctrlrequest *req = desc->orq;
882 rv = usb_autopm_get_interface(intf);
886 usb_fill_control_urb(
888 interface_to_usbdev(intf),
889 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
890 (unsigned char *)req,
893 wdm_wwan_port_tx_complete,
897 req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
898 req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
900 req->wIndex = desc->inum;
901 req->wLength = cpu_to_le16(skb->len);
903 skb_shinfo(skb)->destructor_arg = desc;
905 rv = usb_submit_urb(desc->command, GFP_KERNEL);
907 usb_autopm_put_interface(intf);
908 else /* One transfer at a time, stop TX until URB completion */
909 wwan_port_txoff(port);
914 static const struct wwan_port_ops wdm_wwan_port_ops = {
915 .start = wdm_wwan_port_start,
916 .stop = wdm_wwan_port_stop,
917 .tx = wdm_wwan_port_tx,
920 static void wdm_wwan_init(struct wdm_device *desc)
922 struct usb_interface *intf = desc->intf;
923 struct wwan_port *port;
925 /* Only register to WWAN core if protocol/type is known */
926 if (desc->wwanp_type == WWAN_PORT_UNKNOWN) {
927 dev_info(&intf->dev, "Unknown control protocol\n");
931 port = wwan_create_port(&intf->dev, desc->wwanp_type, &wdm_wwan_port_ops, desc);
933 dev_err(&intf->dev, "%s: Unable to create WWAN port\n",
934 dev_name(intf->usb_dev));
941 static void wdm_wwan_deinit(struct wdm_device *desc)
946 wwan_remove_port(desc->wwanp);
950 static void wdm_wwan_rx(struct wdm_device *desc, int length)
952 struct wwan_port *port = desc->wwanp;
955 /* Forward data to WWAN port */
956 skb = alloc_skb(length, GFP_ATOMIC);
960 memcpy(skb_put(skb, length), desc->inbuf, length);
961 wwan_port_rx(port, skb);
963 /* inbuf has been copied, it is safe to check for outstanding data */
964 schedule_work(&desc->service_outs_intr);
966 #else /* CONFIG_WWAN */
967 static void wdm_wwan_init(struct wdm_device *desc) {}
968 static void wdm_wwan_deinit(struct wdm_device *desc) {}
969 static void wdm_wwan_rx(struct wdm_device *desc, int length) {}
970 #endif /* CONFIG_WWAN */
972 /* --- error handling --- */
973 static void wdm_rxwork(struct work_struct *work)
975 struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
980 spin_lock_irqsave(&desc->iuspin, flags);
981 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
982 spin_unlock_irqrestore(&desc->iuspin, flags);
984 responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
985 spin_unlock_irqrestore(&desc->iuspin, flags);
987 rv = usb_submit_urb(desc->response, GFP_KERNEL);
988 if (rv < 0 && rv != -EPERM) {
989 spin_lock_irqsave(&desc->iuspin, flags);
990 clear_bit(WDM_RESPONDING, &desc->flags);
991 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
992 schedule_work(&desc->rxwork);
993 spin_unlock_irqrestore(&desc->iuspin, flags);
998 static void service_interrupt_work(struct work_struct *work)
1000 struct wdm_device *desc;
1002 desc = container_of(work, struct wdm_device, service_outs_intr);
1004 spin_lock_irq(&desc->iuspin);
1005 service_outstanding_interrupt(desc);
1006 if (!desc->resp_count) {
1007 set_bit(WDM_READ, &desc->flags);
1008 wake_up(&desc->wait);
1010 spin_unlock_irq(&desc->iuspin);
1013 /* --- hotplug --- */
1015 static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
1016 u16 bufsize, enum wwan_port_type type,
1017 int (*manage_power)(struct usb_interface *, int))
1020 struct wdm_device *desc;
1022 desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
1025 INIT_LIST_HEAD(&desc->device_list);
1026 mutex_init(&desc->rlock);
1027 mutex_init(&desc->wlock);
1028 spin_lock_init(&desc->iuspin);
1029 init_waitqueue_head(&desc->wait);
1030 desc->wMaxCommand = bufsize;
1031 /* this will be expanded and needed in hardware endianness */
1032 desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
1034 desc->wwanp_type = type;
1035 INIT_WORK(&desc->rxwork, wdm_rxwork);
1036 INIT_WORK(&desc->service_outs_intr, service_interrupt_work);
1038 if (!usb_endpoint_is_int_in(ep)) {
1043 desc->wMaxPacketSize = usb_endpoint_maxp(ep);
1045 desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
1048 desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
1052 desc->validity = usb_alloc_urb(0, GFP_KERNEL);
1053 if (!desc->validity)
1056 desc->response = usb_alloc_urb(0, GFP_KERNEL);
1057 if (!desc->response)
1060 desc->command = usb_alloc_urb(0, GFP_KERNEL);
1064 desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
1068 desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
1072 desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
1078 interface_to_usbdev(intf),
1079 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
1081 desc->wMaxPacketSize,
1087 desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
1088 desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
1089 desc->irq->wValue = 0;
1090 desc->irq->wIndex = desc->inum; /* already converted */
1091 desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
1093 usb_fill_control_urb(
1095 interface_to_usbdev(intf),
1096 /* using common endpoint 0 */
1097 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
1098 (unsigned char *)desc->irq,
1105 desc->manage_power = manage_power;
1107 spin_lock(&wdm_device_list_lock);
1108 list_add(&desc->device_list, &wdm_device_list);
1109 spin_unlock(&wdm_device_list_lock);
1111 rv = usb_register_dev(intf, &wdm_class);
1115 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
1117 wdm_wwan_init(desc);
1122 spin_lock(&wdm_device_list_lock);
1123 list_del(&desc->device_list);
1124 spin_unlock(&wdm_device_list_lock);
1129 static int wdm_manage_power(struct usb_interface *intf, int on)
1131 /* need autopm_get/put here to ensure the usbcore sees the new value */
1132 int rv = usb_autopm_get_interface(intf);
1134 intf->needs_remote_wakeup = on;
1136 usb_autopm_put_interface(intf);
1140 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
1143 struct usb_host_interface *iface;
1144 struct usb_endpoint_descriptor *ep;
1145 struct usb_cdc_parsed_header hdr;
1146 u8 *buffer = intf->altsetting->extra;
1147 int buflen = intf->altsetting->extralen;
1148 u16 maxcom = WDM_DEFAULT_BUFSIZE;
1153 cdc_parse_cdc_header(&hdr, intf, buffer, buflen);
1155 if (hdr.usb_cdc_dmm_desc)
1156 maxcom = le16_to_cpu(hdr.usb_cdc_dmm_desc->wMaxCommand);
1158 iface = intf->cur_altsetting;
1159 if (iface->desc.bNumEndpoints != 1)
1161 ep = &iface->endpoint[0].desc;
1163 rv = wdm_create(intf, ep, maxcom, WWAN_PORT_UNKNOWN, &wdm_manage_power);
1170 * usb_cdc_wdm_register - register a WDM subdriver
1171 * @intf: usb interface the subdriver will associate with
1172 * @ep: interrupt endpoint to monitor for notifications
1173 * @bufsize: maximum message size to support for read/write
1174 * @type: Type/protocol of the transported data (MBIM, QMI...)
1175 * @manage_power: call-back invoked during open and release to
1176 * manage the device's power
1177 * Create WDM usb class character device and associate it with intf
1178 * without binding, allowing another driver to manage the interface.
1180 * The subdriver will manage the given interrupt endpoint exclusively
1181 * and will issue control requests referring to the given intf. It
1182 * will otherwise avoid interferring, and in particular not do
1183 * usb_set_intfdata/usb_get_intfdata on intf.
1185 * The return value is a pointer to the subdriver's struct usb_driver.
1186 * The registering driver is responsible for calling this subdriver's
1187 * disconnect, suspend, resume, pre_reset and post_reset methods from
1190 struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
1191 struct usb_endpoint_descriptor *ep,
1192 int bufsize, enum wwan_port_type type,
1193 int (*manage_power)(struct usb_interface *, int))
1197 rv = wdm_create(intf, ep, bufsize, type, manage_power);
1205 EXPORT_SYMBOL(usb_cdc_wdm_register);
1207 static void wdm_disconnect(struct usb_interface *intf)
1209 struct wdm_device *desc;
1210 unsigned long flags;
1212 usb_deregister_dev(intf, &wdm_class);
1213 desc = wdm_find_device(intf);
1214 mutex_lock(&wdm_mutex);
1216 wdm_wwan_deinit(desc);
1218 /* the spinlock makes sure no new urbs are generated in the callbacks */
1219 spin_lock_irqsave(&desc->iuspin, flags);
1220 set_bit(WDM_DISCONNECTING, &desc->flags);
1221 set_bit(WDM_READ, &desc->flags);
1222 spin_unlock_irqrestore(&desc->iuspin, flags);
1223 wake_up_all(&desc->wait);
1224 mutex_lock(&desc->rlock);
1225 mutex_lock(&desc->wlock);
1227 cancel_work_sync(&desc->rxwork);
1228 cancel_work_sync(&desc->service_outs_intr);
1229 mutex_unlock(&desc->wlock);
1230 mutex_unlock(&desc->rlock);
1232 /* the desc->intf pointer used as list key is now invalid */
1233 spin_lock(&wdm_device_list_lock);
1234 list_del(&desc->device_list);
1235 spin_unlock(&wdm_device_list_lock);
1240 dev_dbg(&intf->dev, "%d open files - postponing cleanup\n", desc->count);
1241 mutex_unlock(&wdm_mutex);
1245 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
1247 struct wdm_device *desc = wdm_find_device(intf);
1250 dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
1252 /* if this is an autosuspend the caller does the locking */
1253 if (!PMSG_IS_AUTO(message)) {
1254 mutex_lock(&desc->rlock);
1255 mutex_lock(&desc->wlock);
1257 spin_lock_irq(&desc->iuspin);
1259 if (PMSG_IS_AUTO(message) &&
1260 (test_bit(WDM_IN_USE, &desc->flags)
1261 || test_bit(WDM_RESPONDING, &desc->flags))) {
1262 spin_unlock_irq(&desc->iuspin);
1266 set_bit(WDM_SUSPENDING, &desc->flags);
1267 spin_unlock_irq(&desc->iuspin);
1268 /* callback submits work - order is essential */
1270 cancel_work_sync(&desc->rxwork);
1271 cancel_work_sync(&desc->service_outs_intr);
1272 unpoison_urbs(desc);
1274 if (!PMSG_IS_AUTO(message)) {
1275 mutex_unlock(&desc->wlock);
1276 mutex_unlock(&desc->rlock);
1283 static int recover_from_urb_loss(struct wdm_device *desc)
1288 rv = usb_submit_urb(desc->validity, GFP_NOIO);
1290 dev_err(&desc->intf->dev,
1291 "Error resume submitting int urb - %d\n", rv);
1297 static int wdm_resume(struct usb_interface *intf)
1299 struct wdm_device *desc = wdm_find_device(intf);
1302 dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
1304 clear_bit(WDM_SUSPENDING, &desc->flags);
1305 rv = recover_from_urb_loss(desc);
1311 static int wdm_pre_reset(struct usb_interface *intf)
1313 struct wdm_device *desc = wdm_find_device(intf);
1316 * we notify everybody using poll of
1317 * an exceptional situation
1318 * must be done before recovery lest a spontaneous
1319 * message from the device is lost
1321 spin_lock_irq(&desc->iuspin);
1322 set_bit(WDM_RESETTING, &desc->flags); /* inform read/write */
1323 set_bit(WDM_READ, &desc->flags); /* unblock read */
1324 clear_bit(WDM_IN_USE, &desc->flags); /* unblock write */
1325 desc->rerr = -EINTR;
1326 spin_unlock_irq(&desc->iuspin);
1327 wake_up_all(&desc->wait);
1328 mutex_lock(&desc->rlock);
1329 mutex_lock(&desc->wlock);
1331 cancel_work_sync(&desc->rxwork);
1332 cancel_work_sync(&desc->service_outs_intr);
1336 static int wdm_post_reset(struct usb_interface *intf)
1338 struct wdm_device *desc = wdm_find_device(intf);
1341 unpoison_urbs(desc);
1342 clear_bit(WDM_OVERFLOW, &desc->flags);
1343 clear_bit(WDM_RESETTING, &desc->flags);
1344 rv = recover_from_urb_loss(desc);
1345 mutex_unlock(&desc->wlock);
1346 mutex_unlock(&desc->rlock);
1350 static struct usb_driver wdm_driver = {
1353 .disconnect = wdm_disconnect,
1355 .suspend = wdm_suspend,
1356 .resume = wdm_resume,
1357 .reset_resume = wdm_resume,
1359 .pre_reset = wdm_pre_reset,
1360 .post_reset = wdm_post_reset,
1361 .id_table = wdm_ids,
1362 .supports_autosuspend = 1,
1363 .disable_hub_initiated_lpm = 1,
1366 module_usb_driver(wdm_driver);
1368 MODULE_AUTHOR(DRIVER_AUTHOR);
1369 MODULE_DESCRIPTION(DRIVER_DESC);
1370 MODULE_LICENSE("GPL");