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1/*
2 * LEGO USB Tower driver
3 *
4 * Copyright (C) 2003 David Glance <davidgsf@sourceforge.net>
5 * 2001-2004 Juergen Stuber <starblue@users.sourceforge.net>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of
10 * the License, or (at your option) any later version.
11 *
12 * derived from USB Skeleton driver - 0.5
13 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
14 *
15 * History:
16 *
17 * 2001-10-13 - 0.1 js
18 * - first version
19 * 2001-11-03 - 0.2 js
20 * - simplified buffering, one-shot URBs for writing
21 * 2001-11-10 - 0.3 js
22 * - removed IOCTL (setting power/mode is more complicated, postponed)
23 * 2001-11-28 - 0.4 js
24 * - added vendor commands for mode of operation and power level in open
25 * 2001-12-04 - 0.5 js
26 * - set IR mode by default (by oversight 0.4 set VLL mode)
27 * 2002-01-11 - 0.5? pcchan
28 * - make read buffer reusable and work around bytes_to_write issue between
29 * uhci and legusbtower
30 * 2002-09-23 - 0.52 david (david@csse.uwa.edu.au)
31 * - imported into lejos project
32 * - changed wake_up to wake_up_interruptible
33 * - changed to use lego0 rather than tower0
34 * - changed dbg() to use __func__ rather than deprecated __func__
35 * 2003-01-12 - 0.53 david (david@csse.uwa.edu.au)
36 * - changed read and write to write everything or
37 * timeout (from a patch by Chris Riesen and Brett Thaeler driver)
38 * - added ioctl functionality to set timeouts
39 * 2003-07-18 - 0.54 davidgsf (david@csse.uwa.edu.au)
40 * - initial import into LegoUSB project
41 * - merge of existing LegoUSB.c driver
42 * 2003-07-18 - 0.56 davidgsf (david@csse.uwa.edu.au)
43 * - port to 2.6 style driver
44 * 2004-02-29 - 0.6 Juergen Stuber <starblue@users.sourceforge.net>
45 * - fix locking
46 * - unlink read URBs which are no longer needed
47 * - allow increased buffer size, eliminates need for timeout on write
48 * - have read URB running continuously
49 * - added poll
50 * - forbid seeking
51 * - added nonblocking I/O
52 * - changed back __func__ to __func__
53 * - read and log tower firmware version
54 * - reset tower on probe, avoids failure of first write
55 * 2004-03-09 - 0.7 Juergen Stuber <starblue@users.sourceforge.net>
56 * - timeout read now only after inactivity, shorten default accordingly
57 * 2004-03-11 - 0.8 Juergen Stuber <starblue@users.sourceforge.net>
58 * - log major, minor instead of possibly confusing device filename
59 * - whitespace cleanup
60 * 2004-03-12 - 0.9 Juergen Stuber <starblue@users.sourceforge.net>
61 * - normalize whitespace in debug messages
62 * - take care about endianness in control message responses
63 * 2004-03-13 - 0.91 Juergen Stuber <starblue@users.sourceforge.net>
64 * - make default intervals longer to accommodate current EHCI driver
65 * 2004-03-19 - 0.92 Juergen Stuber <starblue@users.sourceforge.net>
66 * - replaced atomic_t by memory barriers
67 * 2004-04-21 - 0.93 Juergen Stuber <starblue@users.sourceforge.net>
68 * - wait for completion of write urb in release (needed for remotecontrol)
69 * - corrected poll for write direction (missing negation)
70 * 2004-04-22 - 0.94 Juergen Stuber <starblue@users.sourceforge.net>
71 * - make device locking interruptible
72 * 2004-04-30 - 0.95 Juergen Stuber <starblue@users.sourceforge.net>
73 * - check for valid udev on resubmitting and unlinking urbs
74 * 2004-08-03 - 0.96 Juergen Stuber <starblue@users.sourceforge.net>
75 * - move reset into open to clean out spurious data
76 */
77
78#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
79
80#include <linux/kernel.h>
81#include <linux/errno.h>
82#include <linux/slab.h>
83#include <linux/module.h>
84#include <linux/completion.h>
85#include <linux/mutex.h>
86#include <asm/uaccess.h>
87#include <linux/usb.h>
88#include <linux/poll.h>
89
90
91/* Version Information */
92#define DRIVER_VERSION "v0.96"
93#define DRIVER_AUTHOR "Juergen Stuber <starblue@sourceforge.net>"
94#define DRIVER_DESC "LEGO USB Tower Driver"
95
96
97/* The defaults are chosen to work with the latest versions of leJOS and NQC.
98 */
99
100/* Some legacy software likes to receive packets in one piece.
101 * In this case read_buffer_size should exceed the maximal packet length
102 * (417 for datalog uploads), and packet_timeout should be set.
103 */
104static int read_buffer_size = 480;
105module_param(read_buffer_size, int, 0);
106MODULE_PARM_DESC(read_buffer_size, "Read buffer size");
107
108/* Some legacy software likes to send packets in one piece.
109 * In this case write_buffer_size should exceed the maximal packet length
110 * (417 for firmware and program downloads).
111 * A problem with long writes is that the following read may time out
112 * if the software is not prepared to wait long enough.
113 */
114static int write_buffer_size = 480;
115module_param(write_buffer_size, int, 0);
116MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
117
118/* Some legacy software expects reads to contain whole LASM packets.
119 * To achieve this, characters which arrive before a packet timeout
120 * occurs will be returned in a single read operation.
121 * A problem with long reads is that the software may time out
122 * if it is not prepared to wait long enough.
123 * The packet timeout should be greater than the time between the
124 * reception of subsequent characters, which should arrive about
125 * every 5ms for the standard 2400 baud.
126 * Set it to 0 to disable.
127 */
128static int packet_timeout = 50;
129module_param(packet_timeout, int, 0);
130MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms");
131
132/* Some legacy software expects blocking reads to time out.
133 * Timeout occurs after the specified time of read and write inactivity.
134 * Set it to 0 to disable.
135 */
136static int read_timeout = 200;
137module_param(read_timeout, int, 0);
138MODULE_PARM_DESC(read_timeout, "Read timeout in ms");
139
140/* As of kernel version 2.6.4 ehci-hcd uses an
141 * "only one interrupt transfer per frame" shortcut
142 * to simplify the scheduling of periodic transfers.
143 * This conflicts with our standard 1ms intervals for in and out URBs.
144 * We use default intervals of 2ms for in and 8ms for out transfers,
145 * which is fast enough for 2400 baud and allows a small additional load.
146 * Increase the interval to allow more devices that do interrupt transfers,
147 * or set to 0 to use the standard interval from the endpoint descriptors.
148 */
149static int interrupt_in_interval = 2;
150module_param(interrupt_in_interval, int, 0);
151MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms");
152
153static int interrupt_out_interval = 8;
154module_param(interrupt_out_interval, int, 0);
155MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms");
156
157/* Define these values to match your device */
158#define LEGO_USB_TOWER_VENDOR_ID 0x0694
159#define LEGO_USB_TOWER_PRODUCT_ID 0x0001
160
161/* Vendor requests */
162#define LEGO_USB_TOWER_REQUEST_RESET 0x04
163#define LEGO_USB_TOWER_REQUEST_GET_VERSION 0xFD
164
165struct tower_reset_reply {
166 __le16 size; /* little-endian */
167 __u8 err_code;
168 __u8 spare;
169} __attribute__ ((packed));
170
171struct tower_get_version_reply {
172 __le16 size; /* little-endian */
173 __u8 err_code;
174 __u8 spare;
175 __u8 major;
176 __u8 minor;
177 __le16 build_no; /* little-endian */
178} __attribute__ ((packed));
179
180
181/* table of devices that work with this driver */
182static const struct usb_device_id tower_table[] = {
183 { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) },
184 { } /* Terminating entry */
185};
186
187MODULE_DEVICE_TABLE (usb, tower_table);
188static DEFINE_MUTEX(open_disc_mutex);
189
190#define LEGO_USB_TOWER_MINOR_BASE 160
191
192
193/* Structure to hold all of our device specific stuff */
194struct lego_usb_tower {
195 struct mutex lock; /* locks this structure */
196 struct usb_device* udev; /* save off the usb device pointer */
197 unsigned char minor; /* the starting minor number for this device */
198
199 int open_count; /* number of times this port has been opened */
200
201 char* read_buffer;
202 size_t read_buffer_length; /* this much came in */
203 size_t read_packet_length; /* this much will be returned on read */
204 spinlock_t read_buffer_lock;
205 int packet_timeout_jiffies;
206 unsigned long read_last_arrival;
207
208 wait_queue_head_t read_wait;
209 wait_queue_head_t write_wait;
210
211 char* interrupt_in_buffer;
212 struct usb_endpoint_descriptor* interrupt_in_endpoint;
213 struct urb* interrupt_in_urb;
214 int interrupt_in_interval;
215 int interrupt_in_running;
216 int interrupt_in_done;
217
218 char* interrupt_out_buffer;
219 struct usb_endpoint_descriptor* interrupt_out_endpoint;
220 struct urb* interrupt_out_urb;
221 int interrupt_out_interval;
222 int interrupt_out_busy;
223
224};
225
226
227/* local function prototypes */
228static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos);
229static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos);
230static inline void tower_delete (struct lego_usb_tower *dev);
231static int tower_open (struct inode *inode, struct file *file);
232static int tower_release (struct inode *inode, struct file *file);
233static unsigned int tower_poll (struct file *file, poll_table *wait);
234static loff_t tower_llseek (struct file *file, loff_t off, int whence);
235
236static void tower_abort_transfers (struct lego_usb_tower *dev);
237static void tower_check_for_read_packet (struct lego_usb_tower *dev);
238static void tower_interrupt_in_callback (struct urb *urb);
239static void tower_interrupt_out_callback (struct urb *urb);
240
241static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id);
242static void tower_disconnect (struct usb_interface *interface);
243
244
245/* file operations needed when we register this driver */
246static const struct file_operations tower_fops = {
247 .owner = THIS_MODULE,
248 .read = tower_read,
249 .write = tower_write,
250 .open = tower_open,
251 .release = tower_release,
252 .poll = tower_poll,
253 .llseek = tower_llseek,
254};
255
256static char *legousbtower_devnode(struct device *dev, umode_t *mode)
257{
258 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
259}
260
261/*
262 * usb class driver info in order to get a minor number from the usb core,
263 * and to have the device registered with the driver core
264 */
265static struct usb_class_driver tower_class = {
266 .name = "legousbtower%d",
267 .devnode = legousbtower_devnode,
268 .fops = &tower_fops,
269 .minor_base = LEGO_USB_TOWER_MINOR_BASE,
270};
271
272
273/* usb specific object needed to register this driver with the usb subsystem */
274static struct usb_driver tower_driver = {
275 .name = "legousbtower",
276 .probe = tower_probe,
277 .disconnect = tower_disconnect,
278 .id_table = tower_table,
279};
280
281
282/**
283 * lego_usb_tower_debug_data
284 */
285static inline void lego_usb_tower_debug_data(struct device *dev,
286 const char *function, int size,
287 const unsigned char *data)
288{
289 dev_dbg(dev, "%s - length = %d, data = %*ph\n",
290 function, size, size, data);
291}
292
293
294/**
295 * tower_delete
296 */
297static inline void tower_delete (struct lego_usb_tower *dev)
298{
299 tower_abort_transfers (dev);
300
301 /* free data structures */
302 usb_free_urb(dev->interrupt_in_urb);
303 usb_free_urb(dev->interrupt_out_urb);
304 kfree (dev->read_buffer);
305 kfree (dev->interrupt_in_buffer);
306 kfree (dev->interrupt_out_buffer);
307 kfree (dev);
308}
309
310
311/**
312 * tower_open
313 */
314static int tower_open (struct inode *inode, struct file *file)
315{
316 struct lego_usb_tower *dev = NULL;
317 int subminor;
318 int retval = 0;
319 struct usb_interface *interface;
320 struct tower_reset_reply reset_reply;
321 int result;
322
323 nonseekable_open(inode, file);
324 subminor = iminor(inode);
325
326 interface = usb_find_interface (&tower_driver, subminor);
327
328 if (!interface) {
329 pr_err("error, can't find device for minor %d\n", subminor);
330 retval = -ENODEV;
331 goto exit;
332 }
333
334 mutex_lock(&open_disc_mutex);
335 dev = usb_get_intfdata(interface);
336
337 if (!dev) {
338 mutex_unlock(&open_disc_mutex);
339 retval = -ENODEV;
340 goto exit;
341 }
342
343 /* lock this device */
344 if (mutex_lock_interruptible(&dev->lock)) {
345 mutex_unlock(&open_disc_mutex);
346 retval = -ERESTARTSYS;
347 goto exit;
348 }
349
350
351 /* allow opening only once */
352 if (dev->open_count) {
353 mutex_unlock(&open_disc_mutex);
354 retval = -EBUSY;
355 goto unlock_exit;
356 }
357 dev->open_count = 1;
358 mutex_unlock(&open_disc_mutex);
359
360 /* reset the tower */
361 result = usb_control_msg (dev->udev,
362 usb_rcvctrlpipe(dev->udev, 0),
363 LEGO_USB_TOWER_REQUEST_RESET,
364 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
365 0,
366 0,
367 &reset_reply,
368 sizeof(reset_reply),
369 1000);
370 if (result < 0) {
371 dev_err(&dev->udev->dev,
372 "LEGO USB Tower reset control request failed\n");
373 retval = result;
374 goto unlock_exit;
375 }
376
377 /* initialize in direction */
378 dev->read_buffer_length = 0;
379 dev->read_packet_length = 0;
380 usb_fill_int_urb (dev->interrupt_in_urb,
381 dev->udev,
382 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress),
383 dev->interrupt_in_buffer,
384 usb_endpoint_maxp(dev->interrupt_in_endpoint),
385 tower_interrupt_in_callback,
386 dev,
387 dev->interrupt_in_interval);
388
389 dev->interrupt_in_running = 1;
390 dev->interrupt_in_done = 0;
391 mb();
392
393 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL);
394 if (retval) {
395 dev_err(&dev->udev->dev,
396 "Couldn't submit interrupt_in_urb %d\n", retval);
397 dev->interrupt_in_running = 0;
398 dev->open_count = 0;
399 goto unlock_exit;
400 }
401
402 /* save device in the file's private structure */
403 file->private_data = dev;
404
405unlock_exit:
406 mutex_unlock(&dev->lock);
407
408exit:
409 return retval;
410}
411
412/**
413 * tower_release
414 */
415static int tower_release (struct inode *inode, struct file *file)
416{
417 struct lego_usb_tower *dev;
418 int retval = 0;
419
420 dev = file->private_data;
421
422 if (dev == NULL) {
423 retval = -ENODEV;
424 goto exit_nolock;
425 }
426
427 mutex_lock(&open_disc_mutex);
428 if (mutex_lock_interruptible(&dev->lock)) {
429 retval = -ERESTARTSYS;
430 goto exit;
431 }
432
433 if (dev->open_count != 1) {
434 dev_dbg(&dev->udev->dev, "%s: device not opened exactly once\n",
435 __func__);
436 retval = -ENODEV;
437 goto unlock_exit;
438 }
439 if (dev->udev == NULL) {
440 /* the device was unplugged before the file was released */
441
442 /* unlock here as tower_delete frees dev */
443 mutex_unlock(&dev->lock);
444 tower_delete (dev);
445 goto exit;
446 }
447
448 /* wait until write transfer is finished */
449 if (dev->interrupt_out_busy) {
450 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
451 }
452 tower_abort_transfers (dev);
453 dev->open_count = 0;
454
455unlock_exit:
456 mutex_unlock(&dev->lock);
457
458exit:
459 mutex_unlock(&open_disc_mutex);
460exit_nolock:
461 return retval;
462}
463
464
465/**
466 * tower_abort_transfers
467 * aborts transfers and frees associated data structures
468 */
469static void tower_abort_transfers (struct lego_usb_tower *dev)
470{
471 if (dev == NULL)
472 return;
473
474 /* shutdown transfer */
475 if (dev->interrupt_in_running) {
476 dev->interrupt_in_running = 0;
477 mb();
478 if (dev->udev)
479 usb_kill_urb (dev->interrupt_in_urb);
480 }
481 if (dev->interrupt_out_busy && dev->udev)
482 usb_kill_urb(dev->interrupt_out_urb);
483}
484
485
486/**
487 * tower_check_for_read_packet
488 *
489 * To get correct semantics for signals and non-blocking I/O
490 * with packetizing we pretend not to see any data in the read buffer
491 * until it has been there unchanged for at least
492 * dev->packet_timeout_jiffies, or until the buffer is full.
493 */
494static void tower_check_for_read_packet (struct lego_usb_tower *dev)
495{
496 spin_lock_irq (&dev->read_buffer_lock);
497 if (!packet_timeout
498 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies)
499 || dev->read_buffer_length == read_buffer_size) {
500 dev->read_packet_length = dev->read_buffer_length;
501 }
502 dev->interrupt_in_done = 0;
503 spin_unlock_irq (&dev->read_buffer_lock);
504}
505
506
507/**
508 * tower_poll
509 */
510static unsigned int tower_poll (struct file *file, poll_table *wait)
511{
512 struct lego_usb_tower *dev;
513 unsigned int mask = 0;
514
515 dev = file->private_data;
516
517 if (!dev->udev)
518 return POLLERR | POLLHUP;
519
520 poll_wait(file, &dev->read_wait, wait);
521 poll_wait(file, &dev->write_wait, wait);
522
523 tower_check_for_read_packet(dev);
524 if (dev->read_packet_length > 0) {
525 mask |= POLLIN | POLLRDNORM;
526 }
527 if (!dev->interrupt_out_busy) {
528 mask |= POLLOUT | POLLWRNORM;
529 }
530
531 return mask;
532}
533
534
535/**
536 * tower_llseek
537 */
538static loff_t tower_llseek (struct file *file, loff_t off, int whence)
539{
540 return -ESPIPE; /* unseekable */
541}
542
543
544/**
545 * tower_read
546 */
547static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
548{
549 struct lego_usb_tower *dev;
550 size_t bytes_to_read;
551 int i;
552 int retval = 0;
553 unsigned long timeout = 0;
554
555 dev = file->private_data;
556
557 /* lock this object */
558 if (mutex_lock_interruptible(&dev->lock)) {
559 retval = -ERESTARTSYS;
560 goto exit;
561 }
562
563 /* verify that the device wasn't unplugged */
564 if (dev->udev == NULL) {
565 retval = -ENODEV;
566 pr_err("No device or device unplugged %d\n", retval);
567 goto unlock_exit;
568 }
569
570 /* verify that we actually have some data to read */
571 if (count == 0) {
572 dev_dbg(&dev->udev->dev, "read request of 0 bytes\n");
573 goto unlock_exit;
574 }
575
576 if (read_timeout) {
577 timeout = jiffies + msecs_to_jiffies(read_timeout);
578 }
579
580 /* wait for data */
581 tower_check_for_read_packet (dev);
582 while (dev->read_packet_length == 0) {
583 if (file->f_flags & O_NONBLOCK) {
584 retval = -EAGAIN;
585 goto unlock_exit;
586 }
587 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies);
588 if (retval < 0) {
589 goto unlock_exit;
590 }
591
592 /* reset read timeout during read or write activity */
593 if (read_timeout
594 && (dev->read_buffer_length || dev->interrupt_out_busy)) {
595 timeout = jiffies + msecs_to_jiffies(read_timeout);
596 }
597 /* check for read timeout */
598 if (read_timeout && time_after (jiffies, timeout)) {
599 retval = -ETIMEDOUT;
600 goto unlock_exit;
601 }
602 tower_check_for_read_packet (dev);
603 }
604
605 /* copy the data from read_buffer into userspace */
606 bytes_to_read = min(count, dev->read_packet_length);
607
608 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) {
609 retval = -EFAULT;
610 goto unlock_exit;
611 }
612
613 spin_lock_irq (&dev->read_buffer_lock);
614 dev->read_buffer_length -= bytes_to_read;
615 dev->read_packet_length -= bytes_to_read;
616 for (i=0; i<dev->read_buffer_length; i++) {
617 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read];
618 }
619 spin_unlock_irq (&dev->read_buffer_lock);
620
621 retval = bytes_to_read;
622
623unlock_exit:
624 /* unlock the device */
625 mutex_unlock(&dev->lock);
626
627exit:
628 return retval;
629}
630
631
632/**
633 * tower_write
634 */
635static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
636{
637 struct lego_usb_tower *dev;
638 size_t bytes_to_write;
639 int retval = 0;
640
641 dev = file->private_data;
642
643 /* lock this object */
644 if (mutex_lock_interruptible(&dev->lock)) {
645 retval = -ERESTARTSYS;
646 goto exit;
647 }
648
649 /* verify that the device wasn't unplugged */
650 if (dev->udev == NULL) {
651 retval = -ENODEV;
652 pr_err("No device or device unplugged %d\n", retval);
653 goto unlock_exit;
654 }
655
656 /* verify that we actually have some data to write */
657 if (count == 0) {
658 dev_dbg(&dev->udev->dev, "write request of 0 bytes\n");
659 goto unlock_exit;
660 }
661
662 /* wait until previous transfer is finished */
663 while (dev->interrupt_out_busy) {
664 if (file->f_flags & O_NONBLOCK) {
665 retval = -EAGAIN;
666 goto unlock_exit;
667 }
668 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy);
669 if (retval) {
670 goto unlock_exit;
671 }
672 }
673
674 /* write the data into interrupt_out_buffer from userspace */
675 bytes_to_write = min_t(int, count, write_buffer_size);
676 dev_dbg(&dev->udev->dev, "%s: count = %Zd, bytes_to_write = %Zd\n",
677 __func__, count, bytes_to_write);
678
679 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) {
680 retval = -EFAULT;
681 goto unlock_exit;
682 }
683
684 /* send off the urb */
685 usb_fill_int_urb(dev->interrupt_out_urb,
686 dev->udev,
687 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
688 dev->interrupt_out_buffer,
689 bytes_to_write,
690 tower_interrupt_out_callback,
691 dev,
692 dev->interrupt_out_interval);
693
694 dev->interrupt_out_busy = 1;
695 wmb();
696
697 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL);
698 if (retval) {
699 dev->interrupt_out_busy = 0;
700 dev_err(&dev->udev->dev,
701 "Couldn't submit interrupt_out_urb %d\n", retval);
702 goto unlock_exit;
703 }
704 retval = bytes_to_write;
705
706unlock_exit:
707 /* unlock the device */
708 mutex_unlock(&dev->lock);
709
710exit:
711 return retval;
712}
713
714
715/**
716 * tower_interrupt_in_callback
717 */
718static void tower_interrupt_in_callback (struct urb *urb)
719{
720 struct lego_usb_tower *dev = urb->context;
721 int status = urb->status;
722 int retval;
723
724 lego_usb_tower_debug_data(&dev->udev->dev, __func__,
725 urb->actual_length, urb->transfer_buffer);
726
727 if (status) {
728 if (status == -ENOENT ||
729 status == -ECONNRESET ||
730 status == -ESHUTDOWN) {
731 goto exit;
732 } else {
733 dev_dbg(&dev->udev->dev,
734 "%s: nonzero status received: %d\n", __func__,
735 status);
736 goto resubmit; /* maybe we can recover */
737 }
738 }
739
740 if (urb->actual_length > 0) {
741 spin_lock (&dev->read_buffer_lock);
742 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) {
743 memcpy (dev->read_buffer + dev->read_buffer_length,
744 dev->interrupt_in_buffer,
745 urb->actual_length);
746 dev->read_buffer_length += urb->actual_length;
747 dev->read_last_arrival = jiffies;
748 dev_dbg(&dev->udev->dev, "%s: received %d bytes\n",
749 __func__, urb->actual_length);
750 } else {
751 pr_warn("read_buffer overflow, %d bytes dropped\n",
752 urb->actual_length);
753 }
754 spin_unlock (&dev->read_buffer_lock);
755 }
756
757resubmit:
758 /* resubmit if we're still running */
759 if (dev->interrupt_in_running && dev->udev) {
760 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC);
761 if (retval)
762 dev_err(&dev->udev->dev,
763 "%s: usb_submit_urb failed (%d)\n",
764 __func__, retval);
765 }
766
767exit:
768 dev->interrupt_in_done = 1;
769 wake_up_interruptible (&dev->read_wait);
770}
771
772
773/**
774 * tower_interrupt_out_callback
775 */
776static void tower_interrupt_out_callback (struct urb *urb)
777{
778 struct lego_usb_tower *dev = urb->context;
779 int status = urb->status;
780
781 lego_usb_tower_debug_data(&dev->udev->dev, __func__,
782 urb->actual_length, urb->transfer_buffer);
783
784 /* sync/async unlink faults aren't errors */
785 if (status && !(status == -ENOENT ||
786 status == -ECONNRESET ||
787 status == -ESHUTDOWN)) {
788 dev_dbg(&dev->udev->dev,
789 "%s: nonzero write bulk status received: %d\n", __func__,
790 status);
791 }
792
793 dev->interrupt_out_busy = 0;
794 wake_up_interruptible(&dev->write_wait);
795}
796
797
798/**
799 * tower_probe
800 *
801 * Called by the usb core when a new device is connected that it thinks
802 * this driver might be interested in.
803 */
804static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id)
805{
806 struct device *idev = &interface->dev;
807 struct usb_device *udev = interface_to_usbdev(interface);
808 struct lego_usb_tower *dev = NULL;
809 struct usb_host_interface *iface_desc;
810 struct usb_endpoint_descriptor* endpoint;
811 struct tower_get_version_reply get_version_reply;
812 int i;
813 int retval = -ENOMEM;
814 int result;
815
816 /* allocate memory for our device state and initialize it */
817
818 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL);
819
820 if (dev == NULL) {
821 dev_err(idev, "Out of memory\n");
822 goto exit;
823 }
824
825 mutex_init(&dev->lock);
826
827 dev->udev = udev;
828 dev->open_count = 0;
829
830 dev->read_buffer = NULL;
831 dev->read_buffer_length = 0;
832 dev->read_packet_length = 0;
833 spin_lock_init (&dev->read_buffer_lock);
834 dev->packet_timeout_jiffies = msecs_to_jiffies(packet_timeout);
835 dev->read_last_arrival = jiffies;
836
837 init_waitqueue_head (&dev->read_wait);
838 init_waitqueue_head (&dev->write_wait);
839
840 dev->interrupt_in_buffer = NULL;
841 dev->interrupt_in_endpoint = NULL;
842 dev->interrupt_in_urb = NULL;
843 dev->interrupt_in_running = 0;
844 dev->interrupt_in_done = 0;
845
846 dev->interrupt_out_buffer = NULL;
847 dev->interrupt_out_endpoint = NULL;
848 dev->interrupt_out_urb = NULL;
849 dev->interrupt_out_busy = 0;
850
851 iface_desc = interface->cur_altsetting;
852
853 /* set up the endpoint information */
854 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
855 endpoint = &iface_desc->endpoint[i].desc;
856
857 if (usb_endpoint_xfer_int(endpoint)) {
858 if (usb_endpoint_dir_in(endpoint))
859 dev->interrupt_in_endpoint = endpoint;
860 else
861 dev->interrupt_out_endpoint = endpoint;
862 }
863 }
864 if(dev->interrupt_in_endpoint == NULL) {
865 dev_err(idev, "interrupt in endpoint not found\n");
866 goto error;
867 }
868 if (dev->interrupt_out_endpoint == NULL) {
869 dev_err(idev, "interrupt out endpoint not found\n");
870 goto error;
871 }
872
873 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL);
874 if (!dev->read_buffer) {
875 dev_err(idev, "Couldn't allocate read_buffer\n");
876 goto error;
877 }
878 dev->interrupt_in_buffer = kmalloc (usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL);
879 if (!dev->interrupt_in_buffer) {
880 dev_err(idev, "Couldn't allocate interrupt_in_buffer\n");
881 goto error;
882 }
883 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
884 if (!dev->interrupt_in_urb) {
885 dev_err(idev, "Couldn't allocate interrupt_in_urb\n");
886 goto error;
887 }
888 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL);
889 if (!dev->interrupt_out_buffer) {
890 dev_err(idev, "Couldn't allocate interrupt_out_buffer\n");
891 goto error;
892 }
893 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
894 if (!dev->interrupt_out_urb) {
895 dev_err(idev, "Couldn't allocate interrupt_out_urb\n");
896 goto error;
897 }
898 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
899 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
900
901 /* we can register the device now, as it is ready */
902 usb_set_intfdata (interface, dev);
903
904 retval = usb_register_dev (interface, &tower_class);
905
906 if (retval) {
907 /* something prevented us from registering this driver */
908 dev_err(idev, "Not able to get a minor for this device.\n");
909 usb_set_intfdata (interface, NULL);
910 goto error;
911 }
912 dev->minor = interface->minor;
913
914 /* let the user know what node this device is now attached to */
915 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major "
916 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE),
917 USB_MAJOR, dev->minor);
918
919 /* get the firmware version and log it */
920 result = usb_control_msg (udev,
921 usb_rcvctrlpipe(udev, 0),
922 LEGO_USB_TOWER_REQUEST_GET_VERSION,
923 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
924 0,
925 0,
926 &get_version_reply,
927 sizeof(get_version_reply),
928 1000);
929 if (result < 0) {
930 dev_err(idev, "LEGO USB Tower get version control request failed\n");
931 retval = result;
932 goto error;
933 }
934 dev_info(&interface->dev, "LEGO USB Tower firmware version is %d.%d "
935 "build %d\n", get_version_reply.major,
936 get_version_reply.minor,
937 le16_to_cpu(get_version_reply.build_no));
938
939
940exit:
941 return retval;
942
943error:
944 tower_delete(dev);
945 return retval;
946}
947
948
949/**
950 * tower_disconnect
951 *
952 * Called by the usb core when the device is removed from the system.
953 */
954static void tower_disconnect (struct usb_interface *interface)
955{
956 struct lego_usb_tower *dev;
957 int minor;
958
959 dev = usb_get_intfdata (interface);
960 mutex_lock(&open_disc_mutex);
961 usb_set_intfdata (interface, NULL);
962
963 minor = dev->minor;
964
965 /* give back our minor */
966 usb_deregister_dev (interface, &tower_class);
967
968 mutex_lock(&dev->lock);
969 mutex_unlock(&open_disc_mutex);
970
971 /* if the device is not opened, then we clean up right now */
972 if (!dev->open_count) {
973 mutex_unlock(&dev->lock);
974 tower_delete (dev);
975 } else {
976 dev->udev = NULL;
977 /* wake up pollers */
978 wake_up_interruptible_all(&dev->read_wait);
979 wake_up_interruptible_all(&dev->write_wait);
980 mutex_unlock(&dev->lock);
981 }
982
983 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n",
984 (minor - LEGO_USB_TOWER_MINOR_BASE));
985}
986
987module_usb_driver(tower_driver);
988
989MODULE_AUTHOR(DRIVER_AUTHOR);
990MODULE_DESCRIPTION(DRIVER_DESC);
991#ifdef MODULE_LICENSE
992MODULE_LICENSE("GPL");
993#endif
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * LEGO USB Tower driver
4 *
5 * Copyright (C) 2003 David Glance <davidgsf@sourceforge.net>
6 * 2001-2004 Juergen Stuber <starblue@users.sourceforge.net>
7 *
8 * derived from USB Skeleton driver - 0.5
9 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
10 *
11 * History:
12 *
13 * 2001-10-13 - 0.1 js
14 * - first version
15 * 2001-11-03 - 0.2 js
16 * - simplified buffering, one-shot URBs for writing
17 * 2001-11-10 - 0.3 js
18 * - removed IOCTL (setting power/mode is more complicated, postponed)
19 * 2001-11-28 - 0.4 js
20 * - added vendor commands for mode of operation and power level in open
21 * 2001-12-04 - 0.5 js
22 * - set IR mode by default (by oversight 0.4 set VLL mode)
23 * 2002-01-11 - 0.5? pcchan
24 * - make read buffer reusable and work around bytes_to_write issue between
25 * uhci and legusbtower
26 * 2002-09-23 - 0.52 david (david@csse.uwa.edu.au)
27 * - imported into lejos project
28 * - changed wake_up to wake_up_interruptible
29 * - changed to use lego0 rather than tower0
30 * - changed dbg() to use __func__ rather than deprecated __func__
31 * 2003-01-12 - 0.53 david (david@csse.uwa.edu.au)
32 * - changed read and write to write everything or
33 * timeout (from a patch by Chris Riesen and Brett Thaeler driver)
34 * - added ioctl functionality to set timeouts
35 * 2003-07-18 - 0.54 davidgsf (david@csse.uwa.edu.au)
36 * - initial import into LegoUSB project
37 * - merge of existing LegoUSB.c driver
38 * 2003-07-18 - 0.56 davidgsf (david@csse.uwa.edu.au)
39 * - port to 2.6 style driver
40 * 2004-02-29 - 0.6 Juergen Stuber <starblue@users.sourceforge.net>
41 * - fix locking
42 * - unlink read URBs which are no longer needed
43 * - allow increased buffer size, eliminates need for timeout on write
44 * - have read URB running continuously
45 * - added poll
46 * - forbid seeking
47 * - added nonblocking I/O
48 * - changed back __func__ to __func__
49 * - read and log tower firmware version
50 * - reset tower on probe, avoids failure of first write
51 * 2004-03-09 - 0.7 Juergen Stuber <starblue@users.sourceforge.net>
52 * - timeout read now only after inactivity, shorten default accordingly
53 * 2004-03-11 - 0.8 Juergen Stuber <starblue@users.sourceforge.net>
54 * - log major, minor instead of possibly confusing device filename
55 * - whitespace cleanup
56 * 2004-03-12 - 0.9 Juergen Stuber <starblue@users.sourceforge.net>
57 * - normalize whitespace in debug messages
58 * - take care about endianness in control message responses
59 * 2004-03-13 - 0.91 Juergen Stuber <starblue@users.sourceforge.net>
60 * - make default intervals longer to accommodate current EHCI driver
61 * 2004-03-19 - 0.92 Juergen Stuber <starblue@users.sourceforge.net>
62 * - replaced atomic_t by memory barriers
63 * 2004-04-21 - 0.93 Juergen Stuber <starblue@users.sourceforge.net>
64 * - wait for completion of write urb in release (needed for remotecontrol)
65 * - corrected poll for write direction (missing negation)
66 * 2004-04-22 - 0.94 Juergen Stuber <starblue@users.sourceforge.net>
67 * - make device locking interruptible
68 * 2004-04-30 - 0.95 Juergen Stuber <starblue@users.sourceforge.net>
69 * - check for valid udev on resubmitting and unlinking urbs
70 * 2004-08-03 - 0.96 Juergen Stuber <starblue@users.sourceforge.net>
71 * - move reset into open to clean out spurious data
72 */
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/* The defaults are chosen to work with the latest versions of leJOS and NQC.
92 */
93
94/* Some legacy software likes to receive packets in one piece.
95 * In this case read_buffer_size should exceed the maximal packet length
96 * (417 for datalog uploads), and packet_timeout should be set.
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/* Some legacy software likes to send packets in one piece.
103 * In this case write_buffer_size should exceed the maximal packet length
104 * (417 for firmware and program downloads).
105 * A problem with long writes is that the following read may time out
106 * if the software is not prepared to wait long enough.
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/* Some legacy software expects reads to contain whole LASM packets.
113 * To achieve this, characters which arrive before a packet timeout
114 * occurs will be returned in a single read operation.
115 * A problem with long reads is that the software may time out
116 * if it is not prepared to wait long enough.
117 * The packet timeout should be greater than the time between the
118 * reception of subsequent characters, which should arrive about
119 * every 5ms for the standard 2400 baud.
120 * Set it to 0 to disable.
121 */
122static int packet_timeout = 50;
123module_param(packet_timeout, int, 0);
124MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms");
125
126/* Some legacy software expects blocking reads to time out.
127 * Timeout occurs after the specified time of read and write inactivity.
128 * Set it to 0 to disable.
129 */
130static int read_timeout = 200;
131module_param(read_timeout, int, 0);
132MODULE_PARM_DESC(read_timeout, "Read timeout in ms");
133
134/* As of kernel version 2.6.4 ehci-hcd uses an
135 * "only one interrupt transfer per frame" shortcut
136 * to simplify the scheduling of periodic transfers.
137 * This conflicts with our standard 1ms intervals for in and out URBs.
138 * We use default intervals of 2ms for in and 8ms for out transfers,
139 * which is fast enough for 2400 baud and allows a small additional load.
140 * Increase the interval to allow more devices that do interrupt transfers,
141 * or set to 0 to use the standard interval from the endpoint descriptors.
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/* Define these values to match your device */
152#define LEGO_USB_TOWER_VENDOR_ID 0x0694
153#define LEGO_USB_TOWER_PRODUCT_ID 0x0001
154
155/* Vendor requests */
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; /* little-endian */
161 __u8 err_code;
162 __u8 spare;
163} __attribute__ ((packed));
164
165struct tower_get_version_reply {
166 __le16 size; /* little-endian */
167 __u8 err_code;
168 __u8 spare;
169 __u8 major;
170 __u8 minor;
171 __le16 build_no; /* little-endian */
172} __attribute__ ((packed));
173
174
175/* table of devices that work with this driver */
176static const struct usb_device_id tower_table[] = {
177 { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) },
178 { } /* Terminating entry */
179};
180
181MODULE_DEVICE_TABLE (usb, tower_table);
182
183#define LEGO_USB_TOWER_MINOR_BASE 160
184
185
186/* Structure to hold all of our device specific stuff */
187struct lego_usb_tower {
188 struct mutex lock; /* locks this structure */
189 struct usb_device* udev; /* save off the usb device pointer */
190 unsigned char minor; /* the starting minor number for this device */
191
192 int open_count; /* number of times this port has been opened */
193 unsigned long disconnected:1;
194
195 char* read_buffer;
196 size_t read_buffer_length; /* this much came in */
197 size_t read_packet_length; /* this much will be returned on read */
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_running;
210 int interrupt_in_done;
211
212 char* interrupt_out_buffer;
213 struct usb_endpoint_descriptor* interrupt_out_endpoint;
214 struct urb* interrupt_out_urb;
215 int interrupt_out_interval;
216 int interrupt_out_busy;
217
218};
219
220
221/* local function prototypes */
222static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos);
223static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos);
224static inline void tower_delete (struct lego_usb_tower *dev);
225static int tower_open (struct inode *inode, struct file *file);
226static int tower_release (struct inode *inode, struct file *file);
227static __poll_t tower_poll (struct file *file, poll_table *wait);
228static loff_t tower_llseek (struct file *file, loff_t off, int whence);
229
230static void tower_abort_transfers (struct lego_usb_tower *dev);
231static void tower_check_for_read_packet (struct lego_usb_tower *dev);
232static void tower_interrupt_in_callback (struct urb *urb);
233static void tower_interrupt_out_callback (struct urb *urb);
234
235static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id);
236static void tower_disconnect (struct usb_interface *interface);
237
238
239/* file operations needed when we register this driver */
240static const struct file_operations tower_fops = {
241 .owner = THIS_MODULE,
242 .read = tower_read,
243 .write = tower_write,
244 .open = tower_open,
245 .release = tower_release,
246 .poll = tower_poll,
247 .llseek = tower_llseek,
248};
249
250static char *legousbtower_devnode(struct device *dev, umode_t *mode)
251{
252 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
253}
254
255/*
256 * usb class driver info in order to get a minor number from the usb core,
257 * and to have the device registered with the driver core
258 */
259static struct usb_class_driver tower_class = {
260 .name = "legousbtower%d",
261 .devnode = legousbtower_devnode,
262 .fops = &tower_fops,
263 .minor_base = LEGO_USB_TOWER_MINOR_BASE,
264};
265
266
267/* usb specific object needed to register this driver with the usb subsystem */
268static struct usb_driver tower_driver = {
269 .name = "legousbtower",
270 .probe = tower_probe,
271 .disconnect = tower_disconnect,
272 .id_table = tower_table,
273};
274
275
276/**
277 * lego_usb_tower_debug_data
278 */
279static inline void lego_usb_tower_debug_data(struct device *dev,
280 const char *function, int size,
281 const unsigned char *data)
282{
283 dev_dbg(dev, "%s - length = %d, data = %*ph\n",
284 function, size, size, data);
285}
286
287
288/**
289 * tower_delete
290 */
291static inline void tower_delete (struct lego_usb_tower *dev)
292{
293 /* free data structures */
294 usb_free_urb(dev->interrupt_in_urb);
295 usb_free_urb(dev->interrupt_out_urb);
296 kfree (dev->read_buffer);
297 kfree (dev->interrupt_in_buffer);
298 kfree (dev->interrupt_out_buffer);
299 usb_put_dev(dev->udev);
300 kfree (dev);
301}
302
303
304/**
305 * tower_open
306 */
307static int tower_open (struct inode *inode, struct file *file)
308{
309 struct lego_usb_tower *dev = NULL;
310 int subminor;
311 int retval = 0;
312 struct usb_interface *interface;
313 struct tower_reset_reply *reset_reply;
314 int result;
315
316 reset_reply = kmalloc(sizeof(*reset_reply), GFP_KERNEL);
317
318 if (!reset_reply) {
319 retval = -ENOMEM;
320 goto exit;
321 }
322
323 nonseekable_open(inode, file);
324 subminor = iminor(inode);
325
326 interface = usb_find_interface (&tower_driver, subminor);
327
328 if (!interface) {
329 pr_err("error, can't find device for minor %d\n", subminor);
330 retval = -ENODEV;
331 goto exit;
332 }
333
334 dev = usb_get_intfdata(interface);
335 if (!dev) {
336 retval = -ENODEV;
337 goto exit;
338 }
339
340 /* lock this device */
341 if (mutex_lock_interruptible(&dev->lock)) {
342 retval = -ERESTARTSYS;
343 goto exit;
344 }
345
346
347 /* allow opening only once */
348 if (dev->open_count) {
349 retval = -EBUSY;
350 goto unlock_exit;
351 }
352
353 /* reset the tower */
354 result = usb_control_msg (dev->udev,
355 usb_rcvctrlpipe(dev->udev, 0),
356 LEGO_USB_TOWER_REQUEST_RESET,
357 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
358 0,
359 0,
360 reset_reply,
361 sizeof(*reset_reply),
362 1000);
363 if (result < 0) {
364 dev_err(&dev->udev->dev,
365 "LEGO USB Tower reset control request failed\n");
366 retval = result;
367 goto unlock_exit;
368 }
369
370 /* initialize in direction */
371 dev->read_buffer_length = 0;
372 dev->read_packet_length = 0;
373 usb_fill_int_urb (dev->interrupt_in_urb,
374 dev->udev,
375 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress),
376 dev->interrupt_in_buffer,
377 usb_endpoint_maxp(dev->interrupt_in_endpoint),
378 tower_interrupt_in_callback,
379 dev,
380 dev->interrupt_in_interval);
381
382 dev->interrupt_in_running = 1;
383 dev->interrupt_in_done = 0;
384 mb();
385
386 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL);
387 if (retval) {
388 dev_err(&dev->udev->dev,
389 "Couldn't submit interrupt_in_urb %d\n", retval);
390 dev->interrupt_in_running = 0;
391 goto unlock_exit;
392 }
393
394 /* save device in the file's private structure */
395 file->private_data = dev;
396
397 dev->open_count = 1;
398
399unlock_exit:
400 mutex_unlock(&dev->lock);
401
402exit:
403 kfree(reset_reply);
404 return retval;
405}
406
407/**
408 * tower_release
409 */
410static int tower_release (struct inode *inode, struct file *file)
411{
412 struct lego_usb_tower *dev;
413 int retval = 0;
414
415 dev = file->private_data;
416
417 if (dev == NULL) {
418 retval = -ENODEV;
419 goto exit;
420 }
421
422 mutex_lock(&dev->lock);
423
424 if (dev->open_count != 1) {
425 dev_dbg(&dev->udev->dev, "%s: device not opened exactly once\n",
426 __func__);
427 retval = -ENODEV;
428 goto unlock_exit;
429 }
430
431 if (dev->disconnected) {
432 /* the device was unplugged before the file was released */
433
434 /* unlock here as tower_delete frees dev */
435 mutex_unlock(&dev->lock);
436 tower_delete (dev);
437 goto exit;
438 }
439
440 /* wait until write transfer is finished */
441 if (dev->interrupt_out_busy) {
442 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
443 }
444 tower_abort_transfers (dev);
445 dev->open_count = 0;
446
447unlock_exit:
448 mutex_unlock(&dev->lock);
449exit:
450 return retval;
451}
452
453
454/**
455 * tower_abort_transfers
456 * aborts transfers and frees associated data structures
457 */
458static void tower_abort_transfers (struct lego_usb_tower *dev)
459{
460 if (dev == NULL)
461 return;
462
463 /* shutdown transfer */
464 if (dev->interrupt_in_running) {
465 dev->interrupt_in_running = 0;
466 mb();
467 usb_kill_urb(dev->interrupt_in_urb);
468 }
469 if (dev->interrupt_out_busy)
470 usb_kill_urb(dev->interrupt_out_urb);
471}
472
473
474/**
475 * tower_check_for_read_packet
476 *
477 * To get correct semantics for signals and non-blocking I/O
478 * with packetizing we pretend not to see any data in the read buffer
479 * until it has been there unchanged for at least
480 * dev->packet_timeout_jiffies, or until the buffer is full.
481 */
482static void tower_check_for_read_packet (struct lego_usb_tower *dev)
483{
484 spin_lock_irq (&dev->read_buffer_lock);
485 if (!packet_timeout
486 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies)
487 || dev->read_buffer_length == read_buffer_size) {
488 dev->read_packet_length = dev->read_buffer_length;
489 }
490 dev->interrupt_in_done = 0;
491 spin_unlock_irq (&dev->read_buffer_lock);
492}
493
494
495/**
496 * tower_poll
497 */
498static __poll_t tower_poll (struct file *file, poll_table *wait)
499{
500 struct lego_usb_tower *dev;
501 __poll_t mask = 0;
502
503 dev = file->private_data;
504
505 if (dev->disconnected)
506 return EPOLLERR | EPOLLHUP;
507
508 poll_wait(file, &dev->read_wait, wait);
509 poll_wait(file, &dev->write_wait, wait);
510
511 tower_check_for_read_packet(dev);
512 if (dev->read_packet_length > 0) {
513 mask |= EPOLLIN | EPOLLRDNORM;
514 }
515 if (!dev->interrupt_out_busy) {
516 mask |= EPOLLOUT | EPOLLWRNORM;
517 }
518
519 return mask;
520}
521
522
523/**
524 * tower_llseek
525 */
526static loff_t tower_llseek (struct file *file, loff_t off, int whence)
527{
528 return -ESPIPE; /* unseekable */
529}
530
531
532/**
533 * tower_read
534 */
535static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
536{
537 struct lego_usb_tower *dev;
538 size_t bytes_to_read;
539 int i;
540 int retval = 0;
541 unsigned long timeout = 0;
542
543 dev = file->private_data;
544
545 /* lock this object */
546 if (mutex_lock_interruptible(&dev->lock)) {
547 retval = -ERESTARTSYS;
548 goto exit;
549 }
550
551 /* verify that the device wasn't unplugged */
552 if (dev->disconnected) {
553 retval = -ENODEV;
554 pr_err("No device or device unplugged %d\n", retval);
555 goto unlock_exit;
556 }
557
558 /* verify that we actually have some data to read */
559 if (count == 0) {
560 dev_dbg(&dev->udev->dev, "read request of 0 bytes\n");
561 goto unlock_exit;
562 }
563
564 if (read_timeout) {
565 timeout = jiffies + msecs_to_jiffies(read_timeout);
566 }
567
568 /* wait for data */
569 tower_check_for_read_packet (dev);
570 while (dev->read_packet_length == 0) {
571 if (file->f_flags & O_NONBLOCK) {
572 retval = -EAGAIN;
573 goto unlock_exit;
574 }
575 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies);
576 if (retval < 0) {
577 goto unlock_exit;
578 }
579
580 /* reset read timeout during read or write activity */
581 if (read_timeout
582 && (dev->read_buffer_length || dev->interrupt_out_busy)) {
583 timeout = jiffies + msecs_to_jiffies(read_timeout);
584 }
585 /* check for read timeout */
586 if (read_timeout && time_after (jiffies, timeout)) {
587 retval = -ETIMEDOUT;
588 goto unlock_exit;
589 }
590 tower_check_for_read_packet (dev);
591 }
592
593 /* copy the data from read_buffer into userspace */
594 bytes_to_read = min(count, dev->read_packet_length);
595
596 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) {
597 retval = -EFAULT;
598 goto unlock_exit;
599 }
600
601 spin_lock_irq (&dev->read_buffer_lock);
602 dev->read_buffer_length -= bytes_to_read;
603 dev->read_packet_length -= bytes_to_read;
604 for (i=0; i<dev->read_buffer_length; i++) {
605 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read];
606 }
607 spin_unlock_irq (&dev->read_buffer_lock);
608
609 retval = bytes_to_read;
610
611unlock_exit:
612 /* unlock the device */
613 mutex_unlock(&dev->lock);
614
615exit:
616 return retval;
617}
618
619
620/**
621 * tower_write
622 */
623static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
624{
625 struct lego_usb_tower *dev;
626 size_t bytes_to_write;
627 int retval = 0;
628
629 dev = file->private_data;
630
631 /* lock this object */
632 if (mutex_lock_interruptible(&dev->lock)) {
633 retval = -ERESTARTSYS;
634 goto exit;
635 }
636
637 /* verify that the device wasn't unplugged */
638 if (dev->disconnected) {
639 retval = -ENODEV;
640 pr_err("No device or device unplugged %d\n", retval);
641 goto unlock_exit;
642 }
643
644 /* verify that we actually have some data to write */
645 if (count == 0) {
646 dev_dbg(&dev->udev->dev, "write request of 0 bytes\n");
647 goto unlock_exit;
648 }
649
650 /* wait until previous transfer is finished */
651 while (dev->interrupt_out_busy) {
652 if (file->f_flags & O_NONBLOCK) {
653 retval = -EAGAIN;
654 goto unlock_exit;
655 }
656 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy);
657 if (retval) {
658 goto unlock_exit;
659 }
660 }
661
662 /* write the data into interrupt_out_buffer from userspace */
663 bytes_to_write = min_t(int, count, write_buffer_size);
664 dev_dbg(&dev->udev->dev, "%s: count = %zd, bytes_to_write = %zd\n",
665 __func__, count, bytes_to_write);
666
667 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) {
668 retval = -EFAULT;
669 goto unlock_exit;
670 }
671
672 /* send off the urb */
673 usb_fill_int_urb(dev->interrupt_out_urb,
674 dev->udev,
675 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
676 dev->interrupt_out_buffer,
677 bytes_to_write,
678 tower_interrupt_out_callback,
679 dev,
680 dev->interrupt_out_interval);
681
682 dev->interrupt_out_busy = 1;
683 wmb();
684
685 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL);
686 if (retval) {
687 dev->interrupt_out_busy = 0;
688 dev_err(&dev->udev->dev,
689 "Couldn't submit interrupt_out_urb %d\n", retval);
690 goto unlock_exit;
691 }
692 retval = bytes_to_write;
693
694unlock_exit:
695 /* unlock the device */
696 mutex_unlock(&dev->lock);
697
698exit:
699 return retval;
700}
701
702
703/**
704 * tower_interrupt_in_callback
705 */
706static void tower_interrupt_in_callback (struct urb *urb)
707{
708 struct lego_usb_tower *dev = urb->context;
709 int status = urb->status;
710 int retval;
711 unsigned long flags;
712
713 lego_usb_tower_debug_data(&dev->udev->dev, __func__,
714 urb->actual_length, urb->transfer_buffer);
715
716 if (status) {
717 if (status == -ENOENT ||
718 status == -ECONNRESET ||
719 status == -ESHUTDOWN) {
720 goto exit;
721 } else {
722 dev_dbg(&dev->udev->dev,
723 "%s: nonzero status received: %d\n", __func__,
724 status);
725 goto resubmit; /* maybe we can recover */
726 }
727 }
728
729 if (urb->actual_length > 0) {
730 spin_lock_irqsave(&dev->read_buffer_lock, flags);
731 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) {
732 memcpy (dev->read_buffer + dev->read_buffer_length,
733 dev->interrupt_in_buffer,
734 urb->actual_length);
735 dev->read_buffer_length += urb->actual_length;
736 dev->read_last_arrival = jiffies;
737 dev_dbg(&dev->udev->dev, "%s: received %d bytes\n",
738 __func__, urb->actual_length);
739 } else {
740 pr_warn("read_buffer overflow, %d bytes dropped\n",
741 urb->actual_length);
742 }
743 spin_unlock_irqrestore(&dev->read_buffer_lock, flags);
744 }
745
746resubmit:
747 /* resubmit if we're still running */
748 if (dev->interrupt_in_running) {
749 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC);
750 if (retval)
751 dev_err(&dev->udev->dev,
752 "%s: usb_submit_urb failed (%d)\n",
753 __func__, retval);
754 }
755
756exit:
757 dev->interrupt_in_done = 1;
758 wake_up_interruptible (&dev->read_wait);
759}
760
761
762/**
763 * tower_interrupt_out_callback
764 */
765static void tower_interrupt_out_callback (struct urb *urb)
766{
767 struct lego_usb_tower *dev = urb->context;
768 int status = urb->status;
769
770 lego_usb_tower_debug_data(&dev->udev->dev, __func__,
771 urb->actual_length, urb->transfer_buffer);
772
773 /* sync/async unlink faults aren't errors */
774 if (status && !(status == -ENOENT ||
775 status == -ECONNRESET ||
776 status == -ESHUTDOWN)) {
777 dev_dbg(&dev->udev->dev,
778 "%s: nonzero write bulk status received: %d\n", __func__,
779 status);
780 }
781
782 dev->interrupt_out_busy = 0;
783 wake_up_interruptible(&dev->write_wait);
784}
785
786
787/**
788 * tower_probe
789 *
790 * Called by the usb core when a new device is connected that it thinks
791 * this driver might be interested in.
792 */
793static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id)
794{
795 struct device *idev = &interface->dev;
796 struct usb_device *udev = interface_to_usbdev(interface);
797 struct lego_usb_tower *dev = NULL;
798 struct tower_get_version_reply *get_version_reply = NULL;
799 int retval = -ENOMEM;
800 int result;
801
802 /* allocate memory for our device state and initialize it */
803
804 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL);
805
806 if (!dev)
807 goto exit;
808
809 mutex_init(&dev->lock);
810
811 dev->udev = usb_get_dev(udev);
812 dev->open_count = 0;
813 dev->disconnected = 0;
814
815 dev->read_buffer = NULL;
816 dev->read_buffer_length = 0;
817 dev->read_packet_length = 0;
818 spin_lock_init (&dev->read_buffer_lock);
819 dev->packet_timeout_jiffies = msecs_to_jiffies(packet_timeout);
820 dev->read_last_arrival = jiffies;
821
822 init_waitqueue_head (&dev->read_wait);
823 init_waitqueue_head (&dev->write_wait);
824
825 dev->interrupt_in_buffer = NULL;
826 dev->interrupt_in_endpoint = NULL;
827 dev->interrupt_in_urb = NULL;
828 dev->interrupt_in_running = 0;
829 dev->interrupt_in_done = 0;
830
831 dev->interrupt_out_buffer = NULL;
832 dev->interrupt_out_endpoint = NULL;
833 dev->interrupt_out_urb = NULL;
834 dev->interrupt_out_busy = 0;
835
836 result = usb_find_common_endpoints_reverse(interface->cur_altsetting,
837 NULL, NULL,
838 &dev->interrupt_in_endpoint,
839 &dev->interrupt_out_endpoint);
840 if (result) {
841 dev_err(idev, "interrupt endpoints not found\n");
842 retval = result;
843 goto error;
844 }
845
846 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL);
847 if (!dev->read_buffer)
848 goto error;
849 dev->interrupt_in_buffer = kmalloc (usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL);
850 if (!dev->interrupt_in_buffer)
851 goto error;
852 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
853 if (!dev->interrupt_in_urb)
854 goto error;
855 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL);
856 if (!dev->interrupt_out_buffer)
857 goto error;
858 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
859 if (!dev->interrupt_out_urb)
860 goto error;
861 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
862 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
863
864 get_version_reply = kmalloc(sizeof(*get_version_reply), GFP_KERNEL);
865
866 if (!get_version_reply) {
867 retval = -ENOMEM;
868 goto error;
869 }
870
871 /* get the firmware version and log it */
872 result = usb_control_msg (udev,
873 usb_rcvctrlpipe(udev, 0),
874 LEGO_USB_TOWER_REQUEST_GET_VERSION,
875 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
876 0,
877 0,
878 get_version_reply,
879 sizeof(*get_version_reply),
880 1000);
881 if (result != sizeof(*get_version_reply)) {
882 if (result >= 0)
883 result = -EIO;
884 dev_err(idev, "get version request failed: %d\n", result);
885 retval = result;
886 goto error;
887 }
888 dev_info(&interface->dev,
889 "LEGO USB Tower firmware version is %d.%d build %d\n",
890 get_version_reply->major,
891 get_version_reply->minor,
892 le16_to_cpu(get_version_reply->build_no));
893
894 /* we can register the device now, as it is ready */
895 usb_set_intfdata (interface, dev);
896
897 retval = usb_register_dev (interface, &tower_class);
898
899 if (retval) {
900 /* something prevented us from registering this driver */
901 dev_err(idev, "Not able to get a minor for this device.\n");
902 goto error;
903 }
904 dev->minor = interface->minor;
905
906 /* let the user know what node this device is now attached to */
907 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major "
908 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE),
909 USB_MAJOR, dev->minor);
910
911exit:
912 kfree(get_version_reply);
913 return retval;
914
915error:
916 kfree(get_version_reply);
917 tower_delete(dev);
918 return retval;
919}
920
921
922/**
923 * tower_disconnect
924 *
925 * Called by the usb core when the device is removed from the system.
926 */
927static void tower_disconnect (struct usb_interface *interface)
928{
929 struct lego_usb_tower *dev;
930 int minor;
931
932 dev = usb_get_intfdata (interface);
933
934 minor = dev->minor;
935
936 /* give back our minor and prevent further open() */
937 usb_deregister_dev (interface, &tower_class);
938
939 /* stop I/O */
940 usb_poison_urb(dev->interrupt_in_urb);
941 usb_poison_urb(dev->interrupt_out_urb);
942
943 mutex_lock(&dev->lock);
944
945 /* if the device is not opened, then we clean up right now */
946 if (!dev->open_count) {
947 mutex_unlock(&dev->lock);
948 tower_delete (dev);
949 } else {
950 dev->disconnected = 1;
951 /* wake up pollers */
952 wake_up_interruptible_all(&dev->read_wait);
953 wake_up_interruptible_all(&dev->write_wait);
954 mutex_unlock(&dev->lock);
955 }
956
957 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n",
958 (minor - LEGO_USB_TOWER_MINOR_BASE));
959}
960
961module_usb_driver(tower_driver);
962
963MODULE_AUTHOR(DRIVER_AUTHOR);
964MODULE_DESCRIPTION(DRIVER_DESC);
965#ifdef MODULE_LICENSE
966MODULE_LICENSE("GPL");
967#endif