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73
74#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
75
76#include <linux/kernel.h>
77#include <linux/errno.h>
78#include <linux/slab.h>
79#include <linux/module.h>
80#include <linux/completion.h>
81#include <linux/mutex.h>
82#include <linux/uaccess.h>
83#include <linux/usb.h>
84#include <linux/poll.h>
85
86
87#define DRIVER_AUTHOR "Juergen Stuber <starblue@sourceforge.net>"
88#define DRIVER_DESC "LEGO USB Tower Driver"
89
90
91
92
93
94
95
96
97
98static int read_buffer_size = 480;
99module_param(read_buffer_size, int, 0);
100MODULE_PARM_DESC(read_buffer_size, "Read buffer size");
101
102
103
104
105
106
107
108static int write_buffer_size = 480;
109module_param(write_buffer_size, int, 0);
110MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
111
112
113
114
115
116
117
118
119
120
121
122static int packet_timeout = 50;
123module_param(packet_timeout, int, 0);
124MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms");
125
126
127
128
129
130static int read_timeout = 200;
131module_param(read_timeout, int, 0);
132MODULE_PARM_DESC(read_timeout, "Read timeout in ms");
133
134
135
136
137
138
139
140
141
142
143static int interrupt_in_interval = 2;
144module_param(interrupt_in_interval, int, 0);
145MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms");
146
147static int interrupt_out_interval = 8;
148module_param(interrupt_out_interval, int, 0);
149MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms");
150
151
152#define LEGO_USB_TOWER_VENDOR_ID 0x0694
153#define LEGO_USB_TOWER_PRODUCT_ID 0x0001
154
155
156#define LEGO_USB_TOWER_REQUEST_RESET 0x04
157#define LEGO_USB_TOWER_REQUEST_GET_VERSION 0xFD
158
159struct tower_reset_reply {
160 __le16 size;
161 __u8 err_code;
162 __u8 spare;
163};
164
165struct tower_get_version_reply {
166 __le16 size;
167 __u8 err_code;
168 __u8 spare;
169 __u8 major;
170 __u8 minor;
171 __le16 build_no;
172};
173
174
175
176static const struct usb_device_id tower_table[] = {
177 { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) },
178 { }
179};
180
181MODULE_DEVICE_TABLE(usb, tower_table);
182
183#define LEGO_USB_TOWER_MINOR_BASE 160
184
185
186
187struct lego_usb_tower {
188 struct mutex lock;
189 struct usb_device *udev;
190 unsigned char minor;
191
192 int open_count;
193 unsigned long disconnected:1;
194
195 char *read_buffer;
196 size_t read_buffer_length;
197 size_t read_packet_length;
198 spinlock_t read_buffer_lock;
199 int packet_timeout_jiffies;
200 unsigned long read_last_arrival;
201
202 wait_queue_head_t read_wait;
203 wait_queue_head_t write_wait;
204
205 char *interrupt_in_buffer;
206 struct usb_endpoint_descriptor *interrupt_in_endpoint;
207 struct urb *interrupt_in_urb;
208 int interrupt_in_interval;
209 int interrupt_in_done;
210
211 char *interrupt_out_buffer;
212 struct usb_endpoint_descriptor *interrupt_out_endpoint;
213 struct urb *interrupt_out_urb;
214 int interrupt_out_interval;
215 int interrupt_out_busy;
216
217};
218
219
220
221static ssize_t tower_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos);
222static ssize_t tower_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos);
223static inline void tower_delete(struct lego_usb_tower *dev);
224static int tower_open(struct inode *inode, struct file *file);
225static int tower_release(struct inode *inode, struct file *file);
226static __poll_t tower_poll(struct file *file, poll_table *wait);
227static loff_t tower_llseek(struct file *file, loff_t off, int whence);
228
229static void tower_check_for_read_packet(struct lego_usb_tower *dev);
230static void tower_interrupt_in_callback(struct urb *urb);
231static void tower_interrupt_out_callback(struct urb *urb);
232
233static int tower_probe(struct usb_interface *interface, const struct usb_device_id *id);
234static void tower_disconnect(struct usb_interface *interface);
235
236
237
238static const struct file_operations tower_fops = {
239 .owner = THIS_MODULE,
240 .read = tower_read,
241 .write = tower_write,
242 .open = tower_open,
243 .release = tower_release,
244 .poll = tower_poll,
245 .llseek = tower_llseek,
246};
247
248static char *legousbtower_devnode(struct device *dev, umode_t *mode)
249{
250 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
251}
252
253
254
255
256
257static struct usb_class_driver tower_class = {
258 .name = "legousbtower%d",
259 .devnode = legousbtower_devnode,
260 .fops = &tower_fops,
261 .minor_base = LEGO_USB_TOWER_MINOR_BASE,
262};
263
264
265
266static struct usb_driver tower_driver = {
267 .name = "legousbtower",
268 .probe = tower_probe,
269 .disconnect = tower_disconnect,
270 .id_table = tower_table,
271};
272
273
274
275
276
277static inline void lego_usb_tower_debug_data(struct device *dev,
278 const char *function, int size,
279 const unsigned char *data)
280{
281 dev_dbg(dev, "%s - length = %d, data = %*ph\n",
282 function, size, size, data);
283}
284
285
286
287
288
289static inline void tower_delete(struct lego_usb_tower *dev)
290{
291
292 usb_free_urb(dev->interrupt_in_urb);
293 usb_free_urb(dev->interrupt_out_urb);
294 kfree(dev->read_buffer);
295 kfree(dev->interrupt_in_buffer);
296 kfree(dev->interrupt_out_buffer);
297 usb_put_dev(dev->udev);
298 kfree(dev);
299}
300
301
302
303
304
305static int tower_open(struct inode *inode, struct file *file)
306{
307 struct lego_usb_tower *dev = NULL;
308 int subminor;
309 int retval = 0;
310 struct usb_interface *interface;
311 struct tower_reset_reply reset_reply;
312 int result;
313
314 nonseekable_open(inode, file);
315 subminor = iminor(inode);
316
317 interface = usb_find_interface(&tower_driver, subminor);
318 if (!interface) {
319 pr_err("error, can't find device for minor %d\n", subminor);
320 retval = -ENODEV;
321 goto exit;
322 }
323
324 dev = usb_get_intfdata(interface);
325 if (!dev) {
326 retval = -ENODEV;
327 goto exit;
328 }
329
330
331 if (mutex_lock_interruptible(&dev->lock)) {
332 retval = -ERESTARTSYS;
333 goto exit;
334 }
335
336
337
338 if (dev->open_count) {
339 retval = -EBUSY;
340 goto unlock_exit;
341 }
342
343
344 result = usb_control_msg_recv(dev->udev, 0,
345 LEGO_USB_TOWER_REQUEST_RESET,
346 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
347 0, 0,
348 &reset_reply, sizeof(reset_reply), 1000,
349 GFP_KERNEL);
350 if (result < 0) {
351 dev_err(&dev->udev->dev,
352 "LEGO USB Tower reset control request failed\n");
353 retval = result;
354 goto unlock_exit;
355 }
356
357
358 dev->read_buffer_length = 0;
359 dev->read_packet_length = 0;
360 usb_fill_int_urb(dev->interrupt_in_urb,
361 dev->udev,
362 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress),
363 dev->interrupt_in_buffer,
364 usb_endpoint_maxp(dev->interrupt_in_endpoint),
365 tower_interrupt_in_callback,
366 dev,
367 dev->interrupt_in_interval);
368
369 dev->interrupt_in_done = 0;
370 mb();
371
372 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
373 if (retval) {
374 dev_err(&dev->udev->dev,
375 "Couldn't submit interrupt_in_urb %d\n", retval);
376 goto unlock_exit;
377 }
378
379
380 file->private_data = dev;
381
382 dev->open_count = 1;
383
384unlock_exit:
385 mutex_unlock(&dev->lock);
386
387exit:
388 return retval;
389}
390
391
392
393
394static int tower_release(struct inode *inode, struct file *file)
395{
396 struct lego_usb_tower *dev;
397 int retval = 0;
398
399 dev = file->private_data;
400 if (dev == NULL) {
401 retval = -ENODEV;
402 goto exit;
403 }
404
405 mutex_lock(&dev->lock);
406
407 if (dev->disconnected) {
408
409
410
411 mutex_unlock(&dev->lock);
412 tower_delete(dev);
413 goto exit;
414 }
415
416
417 if (dev->interrupt_out_busy) {
418 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy,
419 2 * HZ);
420 }
421
422
423 usb_kill_urb(dev->interrupt_in_urb);
424 usb_kill_urb(dev->interrupt_out_urb);
425
426 dev->open_count = 0;
427
428 mutex_unlock(&dev->lock);
429exit:
430 return retval;
431}
432
433
434
435
436
437
438
439
440
441static void tower_check_for_read_packet(struct lego_usb_tower *dev)
442{
443 spin_lock_irq(&dev->read_buffer_lock);
444 if (!packet_timeout
445 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies)
446 || dev->read_buffer_length == read_buffer_size) {
447 dev->read_packet_length = dev->read_buffer_length;
448 }
449 dev->interrupt_in_done = 0;
450 spin_unlock_irq(&dev->read_buffer_lock);
451}
452
453
454
455
456
457static __poll_t tower_poll(struct file *file, poll_table *wait)
458{
459 struct lego_usb_tower *dev;
460 __poll_t mask = 0;
461
462 dev = file->private_data;
463
464 if (dev->disconnected)
465 return EPOLLERR | EPOLLHUP;
466
467 poll_wait(file, &dev->read_wait, wait);
468 poll_wait(file, &dev->write_wait, wait);
469
470 tower_check_for_read_packet(dev);
471 if (dev->read_packet_length > 0)
472 mask |= EPOLLIN | EPOLLRDNORM;
473 if (!dev->interrupt_out_busy)
474 mask |= EPOLLOUT | EPOLLWRNORM;
475
476 return mask;
477}
478
479
480
481
482
483static loff_t tower_llseek(struct file *file, loff_t off, int whence)
484{
485 return -ESPIPE;
486}
487
488
489
490
491
492static ssize_t tower_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
493{
494 struct lego_usb_tower *dev;
495 size_t bytes_to_read;
496 int i;
497 int retval = 0;
498 unsigned long timeout = 0;
499
500 dev = file->private_data;
501
502
503 if (mutex_lock_interruptible(&dev->lock)) {
504 retval = -ERESTARTSYS;
505 goto exit;
506 }
507
508
509 if (dev->disconnected) {
510 retval = -ENODEV;
511 goto unlock_exit;
512 }
513
514
515 if (count == 0) {
516 dev_dbg(&dev->udev->dev, "read request of 0 bytes\n");
517 goto unlock_exit;
518 }
519
520 if (read_timeout)
521 timeout = jiffies + msecs_to_jiffies(read_timeout);
522
523
524 tower_check_for_read_packet(dev);
525 while (dev->read_packet_length == 0) {
526 if (file->f_flags & O_NONBLOCK) {
527 retval = -EAGAIN;
528 goto unlock_exit;
529 }
530 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies);
531 if (retval < 0)
532 goto unlock_exit;
533
534
535 if (read_timeout
536 && (dev->read_buffer_length || dev->interrupt_out_busy)) {
537 timeout = jiffies + msecs_to_jiffies(read_timeout);
538 }
539
540 if (read_timeout && time_after(jiffies, timeout)) {
541 retval = -ETIMEDOUT;
542 goto unlock_exit;
543 }
544 tower_check_for_read_packet(dev);
545 }
546
547
548 bytes_to_read = min(count, dev->read_packet_length);
549
550 if (copy_to_user(buffer, dev->read_buffer, bytes_to_read)) {
551 retval = -EFAULT;
552 goto unlock_exit;
553 }
554
555 spin_lock_irq(&dev->read_buffer_lock);
556 dev->read_buffer_length -= bytes_to_read;
557 dev->read_packet_length -= bytes_to_read;
558 for (i = 0; i < dev->read_buffer_length; i++)
559 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read];
560 spin_unlock_irq(&dev->read_buffer_lock);
561
562 retval = bytes_to_read;
563
564unlock_exit:
565
566 mutex_unlock(&dev->lock);
567
568exit:
569 return retval;
570}
571
572
573
574
575
576static ssize_t tower_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
577{
578 struct lego_usb_tower *dev;
579 size_t bytes_to_write;
580 int retval = 0;
581
582 dev = file->private_data;
583
584
585 if (mutex_lock_interruptible(&dev->lock)) {
586 retval = -ERESTARTSYS;
587 goto exit;
588 }
589
590
591 if (dev->disconnected) {
592 retval = -ENODEV;
593 goto unlock_exit;
594 }
595
596
597 if (count == 0) {
598 dev_dbg(&dev->udev->dev, "write request of 0 bytes\n");
599 goto unlock_exit;
600 }
601
602
603 while (dev->interrupt_out_busy) {
604 if (file->f_flags & O_NONBLOCK) {
605 retval = -EAGAIN;
606 goto unlock_exit;
607 }
608 retval = wait_event_interruptible(dev->write_wait,
609 !dev->interrupt_out_busy);
610 if (retval)
611 goto unlock_exit;
612 }
613
614
615 bytes_to_write = min_t(int, count, write_buffer_size);
616 dev_dbg(&dev->udev->dev, "%s: count = %zd, bytes_to_write = %zd\n",
617 __func__, count, bytes_to_write);
618
619 if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
620 retval = -EFAULT;
621 goto unlock_exit;
622 }
623
624
625 usb_fill_int_urb(dev->interrupt_out_urb,
626 dev->udev,
627 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
628 dev->interrupt_out_buffer,
629 bytes_to_write,
630 tower_interrupt_out_callback,
631 dev,
632 dev->interrupt_out_interval);
633
634 dev->interrupt_out_busy = 1;
635 wmb();
636
637 retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
638 if (retval) {
639 dev->interrupt_out_busy = 0;
640 dev_err(&dev->udev->dev,
641 "Couldn't submit interrupt_out_urb %d\n", retval);
642 goto unlock_exit;
643 }
644 retval = bytes_to_write;
645
646unlock_exit:
647
648 mutex_unlock(&dev->lock);
649
650exit:
651 return retval;
652}
653
654
655
656
657
658static void tower_interrupt_in_callback(struct urb *urb)
659{
660 struct lego_usb_tower *dev = urb->context;
661 int status = urb->status;
662 int retval;
663 unsigned long flags;
664
665 lego_usb_tower_debug_data(&dev->udev->dev, __func__,
666 urb->actual_length, urb->transfer_buffer);
667
668 if (status) {
669 if (status == -ENOENT ||
670 status == -ECONNRESET ||
671 status == -ESHUTDOWN) {
672 goto exit;
673 } else {
674 dev_dbg(&dev->udev->dev,
675 "%s: nonzero status received: %d\n", __func__,
676 status);
677 goto resubmit;
678 }
679 }
680
681 if (urb->actual_length > 0) {
682 spin_lock_irqsave(&dev->read_buffer_lock, flags);
683 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) {
684 memcpy(dev->read_buffer + dev->read_buffer_length,
685 dev->interrupt_in_buffer,
686 urb->actual_length);
687 dev->read_buffer_length += urb->actual_length;
688 dev->read_last_arrival = jiffies;
689 dev_dbg(&dev->udev->dev, "%s: received %d bytes\n",
690 __func__, urb->actual_length);
691 } else {
692 pr_warn("read_buffer overflow, %d bytes dropped\n",
693 urb->actual_length);
694 }
695 spin_unlock_irqrestore(&dev->read_buffer_lock, flags);
696 }
697
698resubmit:
699 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
700 if (retval) {
701 dev_err(&dev->udev->dev, "%s: usb_submit_urb failed (%d)\n",
702 __func__, retval);
703 }
704exit:
705 dev->interrupt_in_done = 1;
706 wake_up_interruptible(&dev->read_wait);
707}
708
709
710
711
712
713static void tower_interrupt_out_callback(struct urb *urb)
714{
715 struct lego_usb_tower *dev = urb->context;
716 int status = urb->status;
717
718 lego_usb_tower_debug_data(&dev->udev->dev, __func__,
719 urb->actual_length, urb->transfer_buffer);
720
721
722 if (status && !(status == -ENOENT ||
723 status == -ECONNRESET ||
724 status == -ESHUTDOWN)) {
725 dev_dbg(&dev->udev->dev,
726 "%s: nonzero write bulk status received: %d\n", __func__,
727 status);
728 }
729
730 dev->interrupt_out_busy = 0;
731 wake_up_interruptible(&dev->write_wait);
732}
733
734
735
736
737
738
739
740
741static int tower_probe(struct usb_interface *interface, const struct usb_device_id *id)
742{
743 struct device *idev = &interface->dev;
744 struct usb_device *udev = interface_to_usbdev(interface);
745 struct lego_usb_tower *dev;
746 struct tower_get_version_reply get_version_reply;
747 int retval = -ENOMEM;
748 int result;
749
750
751 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
752 if (!dev)
753 goto exit;
754
755 mutex_init(&dev->lock);
756 dev->udev = usb_get_dev(udev);
757 spin_lock_init(&dev->read_buffer_lock);
758 dev->packet_timeout_jiffies = msecs_to_jiffies(packet_timeout);
759 dev->read_last_arrival = jiffies;
760 init_waitqueue_head(&dev->read_wait);
761 init_waitqueue_head(&dev->write_wait);
762
763 result = usb_find_common_endpoints_reverse(interface->cur_altsetting,
764 NULL, NULL,
765 &dev->interrupt_in_endpoint,
766 &dev->interrupt_out_endpoint);
767 if (result) {
768 dev_err(idev, "interrupt endpoints not found\n");
769 retval = result;
770 goto error;
771 }
772
773 dev->read_buffer = kmalloc(read_buffer_size, GFP_KERNEL);
774 if (!dev->read_buffer)
775 goto error;
776 dev->interrupt_in_buffer = kmalloc(usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL);
777 if (!dev->interrupt_in_buffer)
778 goto error;
779 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
780 if (!dev->interrupt_in_urb)
781 goto error;
782 dev->interrupt_out_buffer = kmalloc(write_buffer_size, GFP_KERNEL);
783 if (!dev->interrupt_out_buffer)
784 goto error;
785 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
786 if (!dev->interrupt_out_urb)
787 goto error;
788 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
789 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
790
791
792 result = usb_control_msg_recv(udev, 0,
793 LEGO_USB_TOWER_REQUEST_GET_VERSION,
794 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
795 0,
796 0,
797 &get_version_reply,
798 sizeof(get_version_reply),
799 1000, GFP_KERNEL);
800 if (result) {
801 dev_err(idev, "get version request failed: %d\n", result);
802 retval = result;
803 goto error;
804 }
805 dev_info(&interface->dev,
806 "LEGO USB Tower firmware version is %d.%d build %d\n",
807 get_version_reply.major,
808 get_version_reply.minor,
809 le16_to_cpu(get_version_reply.build_no));
810
811
812 usb_set_intfdata(interface, dev);
813
814 retval = usb_register_dev(interface, &tower_class);
815 if (retval) {
816
817 dev_err(idev, "Not able to get a minor for this device.\n");
818 goto error;
819 }
820 dev->minor = interface->minor;
821
822
823 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major "
824 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE),
825 USB_MAJOR, dev->minor);
826
827exit:
828 return retval;
829
830error:
831 tower_delete(dev);
832 return retval;
833}
834
835
836
837
838
839
840
841static void tower_disconnect(struct usb_interface *interface)
842{
843 struct lego_usb_tower *dev;
844 int minor;
845
846 dev = usb_get_intfdata(interface);
847
848 minor = dev->minor;
849
850
851 usb_deregister_dev(interface, &tower_class);
852
853
854 usb_poison_urb(dev->interrupt_in_urb);
855 usb_poison_urb(dev->interrupt_out_urb);
856
857 mutex_lock(&dev->lock);
858
859
860 if (!dev->open_count) {
861 mutex_unlock(&dev->lock);
862 tower_delete(dev);
863 } else {
864 dev->disconnected = 1;
865
866 wake_up_interruptible_all(&dev->read_wait);
867 wake_up_interruptible_all(&dev->write_wait);
868 mutex_unlock(&dev->lock);
869 }
870
871 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n",
872 (minor - LEGO_USB_TOWER_MINOR_BASE));
873}
874
875module_usb_driver(tower_driver);
876
877MODULE_AUTHOR(DRIVER_AUTHOR);
878MODULE_DESCRIPTION(DRIVER_DESC);
879MODULE_LICENSE("GPL");
880