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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#include <linux/kernel.h>
79#include <linux/errno.h>
80#include <linux/init.h>
81#include <linux/slab.h>
82#include <linux/module.h>
83#include <linux/completion.h>
84#include <linux/mutex.h>
85#include <asm/uaccess.h>
86#include <linux/usb.h>
87#include <linux/poll.h>
88
89
90#ifdef CONFIG_USB_DEBUG
91 static int debug = 4;
92#else
93 static int debug = 0;
94#endif
95
96/* Use our own dbg macro */
97#undef dbg
98#define dbg(lvl, format, arg...) \
99do { \
100 if (debug >= lvl) \
101 printk(KERN_DEBUG "%s: " format "\n", __FILE__, ##arg); \
102} while (0)
103
104/* Version Information */
105#define DRIVER_VERSION "v0.96"
106#define DRIVER_AUTHOR "Juergen Stuber <starblue@sourceforge.net>"
107#define DRIVER_DESC "LEGO USB Tower Driver"
108
109/* Module parameters */
110module_param(debug, int, S_IRUGO | S_IWUSR);
111MODULE_PARM_DESC(debug, "Debug enabled or not");
112
113/* The defaults are chosen to work with the latest versions of leJOS and NQC.
114 */
115
116/* Some legacy software likes to receive packets in one piece.
117 * In this case read_buffer_size should exceed the maximal packet length
118 * (417 for datalog uploads), and packet_timeout should be set.
119 */
120static int read_buffer_size = 480;
121module_param(read_buffer_size, int, 0);
122MODULE_PARM_DESC(read_buffer_size, "Read buffer size");
123
124/* Some legacy software likes to send packets in one piece.
125 * In this case write_buffer_size should exceed the maximal packet length
126 * (417 for firmware and program downloads).
127 * A problem with long writes is that the following read may time out
128 * if the software is not prepared to wait long enough.
129 */
130static int write_buffer_size = 480;
131module_param(write_buffer_size, int, 0);
132MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
133
134/* Some legacy software expects reads to contain whole LASM packets.
135 * To achieve this, characters which arrive before a packet timeout
136 * occurs will be returned in a single read operation.
137 * A problem with long reads is that the software may time out
138 * if it is not prepared to wait long enough.
139 * The packet timeout should be greater than the time between the
140 * reception of subsequent characters, which should arrive about
141 * every 5ms for the standard 2400 baud.
142 * Set it to 0 to disable.
143 */
144static int packet_timeout = 50;
145module_param(packet_timeout, int, 0);
146MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms");
147
148/* Some legacy software expects blocking reads to time out.
149 * Timeout occurs after the specified time of read and write inactivity.
150 * Set it to 0 to disable.
151 */
152static int read_timeout = 200;
153module_param(read_timeout, int, 0);
154MODULE_PARM_DESC(read_timeout, "Read timeout in ms");
155
156/* As of kernel version 2.6.4 ehci-hcd uses an
157 * "only one interrupt transfer per frame" shortcut
158 * to simplify the scheduling of periodic transfers.
159 * This conflicts with our standard 1ms intervals for in and out URBs.
160 * We use default intervals of 2ms for in and 8ms for out transfers,
161 * which is fast enough for 2400 baud and allows a small additional load.
162 * Increase the interval to allow more devices that do interrupt transfers,
163 * or set to 0 to use the standard interval from the endpoint descriptors.
164 */
165static int interrupt_in_interval = 2;
166module_param(interrupt_in_interval, int, 0);
167MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms");
168
169static int interrupt_out_interval = 8;
170module_param(interrupt_out_interval, int, 0);
171MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms");
172
173/* Define these values to match your device */
174#define LEGO_USB_TOWER_VENDOR_ID 0x0694
175#define LEGO_USB_TOWER_PRODUCT_ID 0x0001
176
177/* Vendor requests */
178#define LEGO_USB_TOWER_REQUEST_RESET 0x04
179#define LEGO_USB_TOWER_REQUEST_GET_VERSION 0xFD
180
181struct tower_reset_reply {
182 __le16 size; /* little-endian */
183 __u8 err_code;
184 __u8 spare;
185} __attribute__ ((packed));
186
187struct tower_get_version_reply {
188 __le16 size; /* little-endian */
189 __u8 err_code;
190 __u8 spare;
191 __u8 major;
192 __u8 minor;
193 __le16 build_no; /* little-endian */
194} __attribute__ ((packed));
195
196
197/* table of devices that work with this driver */
198static const struct usb_device_id tower_table[] = {
199 { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) },
200 { } /* Terminating entry */
201};
202
203MODULE_DEVICE_TABLE (usb, tower_table);
204static DEFINE_MUTEX(open_disc_mutex);
205
206#define LEGO_USB_TOWER_MINOR_BASE 160
207
208
209/* Structure to hold all of our device specific stuff */
210struct lego_usb_tower {
211 struct mutex lock; /* locks this structure */
212 struct usb_device* udev; /* save off the usb device pointer */
213 unsigned char minor; /* the starting minor number for this device */
214
215 int open_count; /* number of times this port has been opened */
216
217 char* read_buffer;
218 size_t read_buffer_length; /* this much came in */
219 size_t read_packet_length; /* this much will be returned on read */
220 spinlock_t read_buffer_lock;
221 int packet_timeout_jiffies;
222 unsigned long read_last_arrival;
223
224 wait_queue_head_t read_wait;
225 wait_queue_head_t write_wait;
226
227 char* interrupt_in_buffer;
228 struct usb_endpoint_descriptor* interrupt_in_endpoint;
229 struct urb* interrupt_in_urb;
230 int interrupt_in_interval;
231 int interrupt_in_running;
232 int interrupt_in_done;
233
234 char* interrupt_out_buffer;
235 struct usb_endpoint_descriptor* interrupt_out_endpoint;
236 struct urb* interrupt_out_urb;
237 int interrupt_out_interval;
238 int interrupt_out_busy;
239
240};
241
242
243/* local function prototypes */
244static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos);
245static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos);
246static inline void tower_delete (struct lego_usb_tower *dev);
247static int tower_open (struct inode *inode, struct file *file);
248static int tower_release (struct inode *inode, struct file *file);
249static unsigned int tower_poll (struct file *file, poll_table *wait);
250static loff_t tower_llseek (struct file *file, loff_t off, int whence);
251
252static void tower_abort_transfers (struct lego_usb_tower *dev);
253static void tower_check_for_read_packet (struct lego_usb_tower *dev);
254static void tower_interrupt_in_callback (struct urb *urb);
255static void tower_interrupt_out_callback (struct urb *urb);
256
257static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id);
258static void tower_disconnect (struct usb_interface *interface);
259
260
261/* file operations needed when we register this driver */
262static const struct file_operations tower_fops = {
263 .owner = THIS_MODULE,
264 .read = tower_read,
265 .write = tower_write,
266 .open = tower_open,
267 .release = tower_release,
268 .poll = tower_poll,
269 .llseek = tower_llseek,
270};
271
272static char *legousbtower_devnode(struct device *dev, mode_t *mode)
273{
274 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
275}
276
277/*
278 * usb class driver info in order to get a minor number from the usb core,
279 * and to have the device registered with the driver core
280 */
281static struct usb_class_driver tower_class = {
282 .name = "legousbtower%d",
283 .devnode = legousbtower_devnode,
284 .fops = &tower_fops,
285 .minor_base = LEGO_USB_TOWER_MINOR_BASE,
286};
287
288
289/* usb specific object needed to register this driver with the usb subsystem */
290static struct usb_driver tower_driver = {
291 .name = "legousbtower",
292 .probe = tower_probe,
293 .disconnect = tower_disconnect,
294 .id_table = tower_table,
295};
296
297
298/**
299 * lego_usb_tower_debug_data
300 */
301static inline void lego_usb_tower_debug_data (int level, const char *function, int size, const unsigned char *data)
302{
303 int i;
304
305 if (debug < level)
306 return;
307
308 printk (KERN_DEBUG "%s: %s - length = %d, data = ", __FILE__, function, size);
309 for (i = 0; i < size; ++i) {
310 printk ("%.2x ", data[i]);
311 }
312 printk ("\n");
313}
314
315
316/**
317 * tower_delete
318 */
319static inline void tower_delete (struct lego_usb_tower *dev)
320{
321 dbg(2, "%s: enter", __func__);
322
323 tower_abort_transfers (dev);
324
325 /* free data structures */
326 usb_free_urb(dev->interrupt_in_urb);
327 usb_free_urb(dev->interrupt_out_urb);
328 kfree (dev->read_buffer);
329 kfree (dev->interrupt_in_buffer);
330 kfree (dev->interrupt_out_buffer);
331 kfree (dev);
332
333 dbg(2, "%s: leave", __func__);
334}
335
336
337/**
338 * tower_open
339 */
340static int tower_open (struct inode *inode, struct file *file)
341{
342 struct lego_usb_tower *dev = NULL;
343 int subminor;
344 int retval = 0;
345 struct usb_interface *interface;
346 struct tower_reset_reply reset_reply;
347 int result;
348
349 dbg(2, "%s: enter", __func__);
350
351 nonseekable_open(inode, file);
352 subminor = iminor(inode);
353
354 interface = usb_find_interface (&tower_driver, subminor);
355
356 if (!interface) {
357 err ("%s - error, can't find device for minor %d",
358 __func__, subminor);
359 retval = -ENODEV;
360 goto exit;
361 }
362
363 mutex_lock(&open_disc_mutex);
364 dev = usb_get_intfdata(interface);
365
366 if (!dev) {
367 mutex_unlock(&open_disc_mutex);
368 retval = -ENODEV;
369 goto exit;
370 }
371
372 /* lock this device */
373 if (mutex_lock_interruptible(&dev->lock)) {
374 mutex_unlock(&open_disc_mutex);
375 retval = -ERESTARTSYS;
376 goto exit;
377 }
378
379
380 /* allow opening only once */
381 if (dev->open_count) {
382 mutex_unlock(&open_disc_mutex);
383 retval = -EBUSY;
384 goto unlock_exit;
385 }
386 dev->open_count = 1;
387 mutex_unlock(&open_disc_mutex);
388
389 /* reset the tower */
390 result = usb_control_msg (dev->udev,
391 usb_rcvctrlpipe(dev->udev, 0),
392 LEGO_USB_TOWER_REQUEST_RESET,
393 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
394 0,
395 0,
396 &reset_reply,
397 sizeof(reset_reply),
398 1000);
399 if (result < 0) {
400 err("LEGO USB Tower reset control request failed");
401 retval = result;
402 goto unlock_exit;
403 }
404
405 /* initialize in direction */
406 dev->read_buffer_length = 0;
407 dev->read_packet_length = 0;
408 usb_fill_int_urb (dev->interrupt_in_urb,
409 dev->udev,
410 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress),
411 dev->interrupt_in_buffer,
412 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
413 tower_interrupt_in_callback,
414 dev,
415 dev->interrupt_in_interval);
416
417 dev->interrupt_in_running = 1;
418 dev->interrupt_in_done = 0;
419 mb();
420
421 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL);
422 if (retval) {
423 err("Couldn't submit interrupt_in_urb %d", retval);
424 dev->interrupt_in_running = 0;
425 dev->open_count = 0;
426 goto unlock_exit;
427 }
428
429 /* save device in the file's private structure */
430 file->private_data = dev;
431
432unlock_exit:
433 mutex_unlock(&dev->lock);
434
435exit:
436 dbg(2, "%s: leave, return value %d ", __func__, retval);
437
438 return retval;
439}
440
441/**
442 * tower_release
443 */
444static int tower_release (struct inode *inode, struct file *file)
445{
446 struct lego_usb_tower *dev;
447 int retval = 0;
448
449 dbg(2, "%s: enter", __func__);
450
451 dev = file->private_data;
452
453 if (dev == NULL) {
454 dbg(1, "%s: object is NULL", __func__);
455 retval = -ENODEV;
456 goto exit_nolock;
457 }
458
459 mutex_lock(&open_disc_mutex);
460 if (mutex_lock_interruptible(&dev->lock)) {
461 retval = -ERESTARTSYS;
462 goto exit;
463 }
464
465 if (dev->open_count != 1) {
466 dbg(1, "%s: device not opened exactly once", __func__);
467 retval = -ENODEV;
468 goto unlock_exit;
469 }
470 if (dev->udev == NULL) {
471 /* the device was unplugged before the file was released */
472
473 /* unlock here as tower_delete frees dev */
474 mutex_unlock(&dev->lock);
475 tower_delete (dev);
476 goto exit;
477 }
478
479 /* wait until write transfer is finished */
480 if (dev->interrupt_out_busy) {
481 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
482 }
483 tower_abort_transfers (dev);
484 dev->open_count = 0;
485
486unlock_exit:
487 mutex_unlock(&dev->lock);
488
489exit:
490 mutex_unlock(&open_disc_mutex);
491exit_nolock:
492 dbg(2, "%s: leave, return value %d", __func__, retval);
493 return retval;
494}
495
496
497/**
498 * tower_abort_transfers
499 * aborts transfers and frees associated data structures
500 */
501static void tower_abort_transfers (struct lego_usb_tower *dev)
502{
503 dbg(2, "%s: enter", __func__);
504
505 if (dev == NULL) {
506 dbg(1, "%s: dev is null", __func__);
507 goto exit;
508 }
509
510 /* shutdown transfer */
511 if (dev->interrupt_in_running) {
512 dev->interrupt_in_running = 0;
513 mb();
514 if (dev->udev)
515 usb_kill_urb (dev->interrupt_in_urb);
516 }
517 if (dev->interrupt_out_busy && dev->udev)
518 usb_kill_urb(dev->interrupt_out_urb);
519
520exit:
521 dbg(2, "%s: leave", __func__);
522}
523
524
525/**
526 * tower_check_for_read_packet
527 *
528 * To get correct semantics for signals and non-blocking I/O
529 * with packetizing we pretend not to see any data in the read buffer
530 * until it has been there unchanged for at least
531 * dev->packet_timeout_jiffies, or until the buffer is full.
532 */
533static void tower_check_for_read_packet (struct lego_usb_tower *dev)
534{
535 spin_lock_irq (&dev->read_buffer_lock);
536 if (!packet_timeout
537 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies)
538 || dev->read_buffer_length == read_buffer_size) {
539 dev->read_packet_length = dev->read_buffer_length;
540 }
541 dev->interrupt_in_done = 0;
542 spin_unlock_irq (&dev->read_buffer_lock);
543}
544
545
546/**
547 * tower_poll
548 */
549static unsigned int tower_poll (struct file *file, poll_table *wait)
550{
551 struct lego_usb_tower *dev;
552 unsigned int mask = 0;
553
554 dbg(2, "%s: enter", __func__);
555
556 dev = file->private_data;
557
558 if (!dev->udev)
559 return POLLERR | POLLHUP;
560
561 poll_wait(file, &dev->read_wait, wait);
562 poll_wait(file, &dev->write_wait, wait);
563
564 tower_check_for_read_packet(dev);
565 if (dev->read_packet_length > 0) {
566 mask |= POLLIN | POLLRDNORM;
567 }
568 if (!dev->interrupt_out_busy) {
569 mask |= POLLOUT | POLLWRNORM;
570 }
571
572 dbg(2, "%s: leave, mask = %d", __func__, mask);
573
574 return mask;
575}
576
577
578/**
579 * tower_llseek
580 */
581static loff_t tower_llseek (struct file *file, loff_t off, int whence)
582{
583 return -ESPIPE; /* unseekable */
584}
585
586
587/**
588 * tower_read
589 */
590static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
591{
592 struct lego_usb_tower *dev;
593 size_t bytes_to_read;
594 int i;
595 int retval = 0;
596 unsigned long timeout = 0;
597
598 dbg(2, "%s: enter, count = %Zd", __func__, count);
599
600 dev = file->private_data;
601
602 /* lock this object */
603 if (mutex_lock_interruptible(&dev->lock)) {
604 retval = -ERESTARTSYS;
605 goto exit;
606 }
607
608 /* verify that the device wasn't unplugged */
609 if (dev->udev == NULL) {
610 retval = -ENODEV;
611 err("No device or device unplugged %d", retval);
612 goto unlock_exit;
613 }
614
615 /* verify that we actually have some data to read */
616 if (count == 0) {
617 dbg(1, "%s: read request of 0 bytes", __func__);
618 goto unlock_exit;
619 }
620
621 if (read_timeout) {
622 timeout = jiffies + read_timeout * HZ / 1000;
623 }
624
625 /* wait for data */
626 tower_check_for_read_packet (dev);
627 while (dev->read_packet_length == 0) {
628 if (file->f_flags & O_NONBLOCK) {
629 retval = -EAGAIN;
630 goto unlock_exit;
631 }
632 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies);
633 if (retval < 0) {
634 goto unlock_exit;
635 }
636
637 /* reset read timeout during read or write activity */
638 if (read_timeout
639 && (dev->read_buffer_length || dev->interrupt_out_busy)) {
640 timeout = jiffies + read_timeout * HZ / 1000;
641 }
642 /* check for read timeout */
643 if (read_timeout && time_after (jiffies, timeout)) {
644 retval = -ETIMEDOUT;
645 goto unlock_exit;
646 }
647 tower_check_for_read_packet (dev);
648 }
649
650 /* copy the data from read_buffer into userspace */
651 bytes_to_read = min(count, dev->read_packet_length);
652
653 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) {
654 retval = -EFAULT;
655 goto unlock_exit;
656 }
657
658 spin_lock_irq (&dev->read_buffer_lock);
659 dev->read_buffer_length -= bytes_to_read;
660 dev->read_packet_length -= bytes_to_read;
661 for (i=0; i<dev->read_buffer_length; i++) {
662 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read];
663 }
664 spin_unlock_irq (&dev->read_buffer_lock);
665
666 retval = bytes_to_read;
667
668unlock_exit:
669 /* unlock the device */
670 mutex_unlock(&dev->lock);
671
672exit:
673 dbg(2, "%s: leave, return value %d", __func__, retval);
674 return retval;
675}
676
677
678/**
679 * tower_write
680 */
681static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
682{
683 struct lego_usb_tower *dev;
684 size_t bytes_to_write;
685 int retval = 0;
686
687 dbg(2, "%s: enter, count = %Zd", __func__, count);
688
689 dev = file->private_data;
690
691 /* lock this object */
692 if (mutex_lock_interruptible(&dev->lock)) {
693 retval = -ERESTARTSYS;
694 goto exit;
695 }
696
697 /* verify that the device wasn't unplugged */
698 if (dev->udev == NULL) {
699 retval = -ENODEV;
700 err("No device or device unplugged %d", retval);
701 goto unlock_exit;
702 }
703
704 /* verify that we actually have some data to write */
705 if (count == 0) {
706 dbg(1, "%s: write request of 0 bytes", __func__);
707 goto unlock_exit;
708 }
709
710 /* wait until previous transfer is finished */
711 while (dev->interrupt_out_busy) {
712 if (file->f_flags & O_NONBLOCK) {
713 retval = -EAGAIN;
714 goto unlock_exit;
715 }
716 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy);
717 if (retval) {
718 goto unlock_exit;
719 }
720 }
721
722 /* write the data into interrupt_out_buffer from userspace */
723 bytes_to_write = min_t(int, count, write_buffer_size);
724 dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __func__, count, bytes_to_write);
725
726 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) {
727 retval = -EFAULT;
728 goto unlock_exit;
729 }
730
731 /* send off the urb */
732 usb_fill_int_urb(dev->interrupt_out_urb,
733 dev->udev,
734 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
735 dev->interrupt_out_buffer,
736 bytes_to_write,
737 tower_interrupt_out_callback,
738 dev,
739 dev->interrupt_out_interval);
740
741 dev->interrupt_out_busy = 1;
742 wmb();
743
744 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL);
745 if (retval) {
746 dev->interrupt_out_busy = 0;
747 err("Couldn't submit interrupt_out_urb %d", retval);
748 goto unlock_exit;
749 }
750 retval = bytes_to_write;
751
752unlock_exit:
753 /* unlock the device */
754 mutex_unlock(&dev->lock);
755
756exit:
757 dbg(2, "%s: leave, return value %d", __func__, retval);
758
759 return retval;
760}
761
762
763/**
764 * tower_interrupt_in_callback
765 */
766static void tower_interrupt_in_callback (struct urb *urb)
767{
768 struct lego_usb_tower *dev = urb->context;
769 int status = urb->status;
770 int retval;
771
772 dbg(4, "%s: enter, status %d", __func__, status);
773
774 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
775
776 if (status) {
777 if (status == -ENOENT ||
778 status == -ECONNRESET ||
779 status == -ESHUTDOWN) {
780 goto exit;
781 } else {
782 dbg(1, "%s: nonzero status received: %d", __func__, status);
783 goto resubmit; /* maybe we can recover */
784 }
785 }
786
787 if (urb->actual_length > 0) {
788 spin_lock (&dev->read_buffer_lock);
789 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) {
790 memcpy (dev->read_buffer + dev->read_buffer_length,
791 dev->interrupt_in_buffer,
792 urb->actual_length);
793 dev->read_buffer_length += urb->actual_length;
794 dev->read_last_arrival = jiffies;
795 dbg(3, "%s: received %d bytes", __func__, urb->actual_length);
796 } else {
797 printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __func__, urb->actual_length);
798 }
799 spin_unlock (&dev->read_buffer_lock);
800 }
801
802resubmit:
803 /* resubmit if we're still running */
804 if (dev->interrupt_in_running && dev->udev) {
805 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC);
806 if (retval) {
807 err("%s: usb_submit_urb failed (%d)", __func__, retval);
808 }
809 }
810
811exit:
812 dev->interrupt_in_done = 1;
813 wake_up_interruptible (&dev->read_wait);
814
815 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
816 dbg(4, "%s: leave, status %d", __func__, status);
817}
818
819
820/**
821 * tower_interrupt_out_callback
822 */
823static void tower_interrupt_out_callback (struct urb *urb)
824{
825 struct lego_usb_tower *dev = urb->context;
826 int status = urb->status;
827
828 dbg(4, "%s: enter, status %d", __func__, status);
829 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
830
831 /* sync/async unlink faults aren't errors */
832 if (status && !(status == -ENOENT ||
833 status == -ECONNRESET ||
834 status == -ESHUTDOWN)) {
835 dbg(1, "%s - nonzero write bulk status received: %d",
836 __func__, status);
837 }
838
839 dev->interrupt_out_busy = 0;
840 wake_up_interruptible(&dev->write_wait);
841
842 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
843 dbg(4, "%s: leave, status %d", __func__, status);
844}
845
846
847/**
848 * tower_probe
849 *
850 * Called by the usb core when a new device is connected that it thinks
851 * this driver might be interested in.
852 */
853static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id)
854{
855 struct usb_device *udev = interface_to_usbdev(interface);
856 struct lego_usb_tower *dev = NULL;
857 struct usb_host_interface *iface_desc;
858 struct usb_endpoint_descriptor* endpoint;
859 struct tower_get_version_reply get_version_reply;
860 int i;
861 int retval = -ENOMEM;
862 int result;
863
864 dbg(2, "%s: enter", __func__);
865
866 if (udev == NULL)
867 dev_info(&interface->dev, "udev is NULL.\n");
868
869 /* allocate memory for our device state and initialize it */
870
871 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL);
872
873 if (dev == NULL) {
874 err ("Out of memory");
875 goto exit;
876 }
877
878 mutex_init(&dev->lock);
879
880 dev->udev = udev;
881 dev->open_count = 0;
882
883 dev->read_buffer = NULL;
884 dev->read_buffer_length = 0;
885 dev->read_packet_length = 0;
886 spin_lock_init (&dev->read_buffer_lock);
887 dev->packet_timeout_jiffies = packet_timeout * HZ / 1000;
888 dev->read_last_arrival = jiffies;
889
890 init_waitqueue_head (&dev->read_wait);
891 init_waitqueue_head (&dev->write_wait);
892
893 dev->interrupt_in_buffer = NULL;
894 dev->interrupt_in_endpoint = NULL;
895 dev->interrupt_in_urb = NULL;
896 dev->interrupt_in_running = 0;
897 dev->interrupt_in_done = 0;
898
899 dev->interrupt_out_buffer = NULL;
900 dev->interrupt_out_endpoint = NULL;
901 dev->interrupt_out_urb = NULL;
902 dev->interrupt_out_busy = 0;
903
904 iface_desc = interface->cur_altsetting;
905
906 /* set up the endpoint information */
907 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
908 endpoint = &iface_desc->endpoint[i].desc;
909
910 if (usb_endpoint_xfer_int(endpoint)) {
911 if (usb_endpoint_dir_in(endpoint))
912 dev->interrupt_in_endpoint = endpoint;
913 else
914 dev->interrupt_out_endpoint = endpoint;
915 }
916 }
917 if(dev->interrupt_in_endpoint == NULL) {
918 err("interrupt in endpoint not found");
919 goto error;
920 }
921 if (dev->interrupt_out_endpoint == NULL) {
922 err("interrupt out endpoint not found");
923 goto error;
924 }
925
926 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL);
927 if (!dev->read_buffer) {
928 err("Couldn't allocate read_buffer");
929 goto error;
930 }
931 dev->interrupt_in_buffer = kmalloc (le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), GFP_KERNEL);
932 if (!dev->interrupt_in_buffer) {
933 err("Couldn't allocate interrupt_in_buffer");
934 goto error;
935 }
936 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
937 if (!dev->interrupt_in_urb) {
938 err("Couldn't allocate interrupt_in_urb");
939 goto error;
940 }
941 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL);
942 if (!dev->interrupt_out_buffer) {
943 err("Couldn't allocate interrupt_out_buffer");
944 goto error;
945 }
946 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
947 if (!dev->interrupt_out_urb) {
948 err("Couldn't allocate interrupt_out_urb");
949 goto error;
950 }
951 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
952 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
953
954 /* we can register the device now, as it is ready */
955 usb_set_intfdata (interface, dev);
956
957 retval = usb_register_dev (interface, &tower_class);
958
959 if (retval) {
960 /* something prevented us from registering this driver */
961 err ("Not able to get a minor for this device.");
962 usb_set_intfdata (interface, NULL);
963 goto error;
964 }
965 dev->minor = interface->minor;
966
967 /* let the user know what node this device is now attached to */
968 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major "
969 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE),
970 USB_MAJOR, dev->minor);
971
972 /* get the firmware version and log it */
973 result = usb_control_msg (udev,
974 usb_rcvctrlpipe(udev, 0),
975 LEGO_USB_TOWER_REQUEST_GET_VERSION,
976 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
977 0,
978 0,
979 &get_version_reply,
980 sizeof(get_version_reply),
981 1000);
982 if (result < 0) {
983 err("LEGO USB Tower get version control request failed");
984 retval = result;
985 goto error;
986 }
987 dev_info(&interface->dev, "LEGO USB Tower firmware version is %d.%d "
988 "build %d\n", get_version_reply.major,
989 get_version_reply.minor,
990 le16_to_cpu(get_version_reply.build_no));
991
992
993exit:
994 dbg(2, "%s: leave, return value 0x%.8lx (dev)", __func__, (long) dev);
995
996 return retval;
997
998error:
999 tower_delete(dev);
1000 return retval;
1001}
1002
1003
1004/**
1005 * tower_disconnect
1006 *
1007 * Called by the usb core when the device is removed from the system.
1008 */
1009static void tower_disconnect (struct usb_interface *interface)
1010{
1011 struct lego_usb_tower *dev;
1012 int minor;
1013
1014 dbg(2, "%s: enter", __func__);
1015
1016 dev = usb_get_intfdata (interface);
1017 mutex_lock(&open_disc_mutex);
1018 usb_set_intfdata (interface, NULL);
1019
1020 minor = dev->minor;
1021
1022 /* give back our minor */
1023 usb_deregister_dev (interface, &tower_class);
1024
1025 mutex_lock(&dev->lock);
1026 mutex_unlock(&open_disc_mutex);
1027
1028 /* if the device is not opened, then we clean up right now */
1029 if (!dev->open_count) {
1030 mutex_unlock(&dev->lock);
1031 tower_delete (dev);
1032 } else {
1033 dev->udev = NULL;
1034 /* wake up pollers */
1035 wake_up_interruptible_all(&dev->read_wait);
1036 wake_up_interruptible_all(&dev->write_wait);
1037 mutex_unlock(&dev->lock);
1038 }
1039
1040 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n",
1041 (minor - LEGO_USB_TOWER_MINOR_BASE));
1042
1043 dbg(2, "%s: leave", __func__);
1044}
1045
1046
1047
1048/**
1049 * lego_usb_tower_init
1050 */
1051static int __init lego_usb_tower_init(void)
1052{
1053 int result;
1054 int retval = 0;
1055
1056 dbg(2, "%s: enter", __func__);
1057
1058 /* register this driver with the USB subsystem */
1059 result = usb_register(&tower_driver);
1060 if (result < 0) {
1061 err("usb_register failed for the %s driver. Error number %d", __FILE__, result);
1062 retval = -1;
1063 goto exit;
1064 }
1065
1066 printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
1067 DRIVER_DESC "\n");
1068
1069exit:
1070 dbg(2, "%s: leave, return value %d", __func__, retval);
1071
1072 return retval;
1073}
1074
1075
1076/**
1077 * lego_usb_tower_exit
1078 */
1079static void __exit lego_usb_tower_exit(void)
1080{
1081 dbg(2, "%s: enter", __func__);
1082
1083 /* deregister this driver with the USB subsystem */
1084 usb_deregister (&tower_driver);
1085
1086 dbg(2, "%s: leave", __func__);
1087}
1088
1089module_init (lego_usb_tower_init);
1090module_exit (lego_usb_tower_exit);
1091
1092MODULE_AUTHOR(DRIVER_AUTHOR);
1093MODULE_DESCRIPTION(DRIVER_DESC);
1094#ifdef MODULE_LICENSE
1095MODULE_LICENSE("GPL");
1096#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;
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/* 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_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/* local function prototypes */
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/* file operations needed when we register this driver */
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(const struct device *dev, umode_t *mode)
249{
250 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
251}
252
253/*
254 * usb class driver info in order to get a minor number from the usb core,
255 * and to have the device registered with the driver core
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/* usb specific object needed to register this driver with the usb subsystem */
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 * lego_usb_tower_debug_data
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 * tower_delete
288 */
289static inline void tower_delete(struct lego_usb_tower *dev)
290{
291 /* free data structures */
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 * tower_open
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 /* lock this device */
331 if (mutex_lock_interruptible(&dev->lock)) {
332 retval = -ERESTARTSYS;
333 goto exit;
334 }
335
336
337 /* allow opening only once */
338 if (dev->open_count) {
339 retval = -EBUSY;
340 goto unlock_exit;
341 }
342
343 /* reset the tower */
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 /* initialize in direction */
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 /* save device in the file's private structure */
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 * tower_release
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 /* the device was unplugged before the file was released */
409
410 /* unlock here as tower_delete frees dev */
411 mutex_unlock(&dev->lock);
412 tower_delete(dev);
413 goto exit;
414 }
415
416 /* wait until write transfer is finished */
417 if (dev->interrupt_out_busy) {
418 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy,
419 2 * HZ);
420 }
421
422 /* shutdown transfers */
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 * tower_check_for_read_packet
435 *
436 * To get correct semantics for signals and non-blocking I/O
437 * with packetizing we pretend not to see any data in the read buffer
438 * until it has been there unchanged for at least
439 * dev->packet_timeout_jiffies, or until the buffer is full.
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 * tower_poll
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 * tower_llseek
482 */
483static loff_t tower_llseek(struct file *file, loff_t off, int whence)
484{
485 return -ESPIPE; /* unseekable */
486}
487
488
489/*
490 * tower_read
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 /* lock this object */
503 if (mutex_lock_interruptible(&dev->lock)) {
504 retval = -ERESTARTSYS;
505 goto exit;
506 }
507
508 /* verify that the device wasn't unplugged */
509 if (dev->disconnected) {
510 retval = -ENODEV;
511 goto unlock_exit;
512 }
513
514 /* verify that we actually have some data to read */
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 /* wait for data */
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 /* reset read timeout during read or write activity */
535 if (read_timeout
536 && (dev->read_buffer_length || dev->interrupt_out_busy)) {
537 timeout = jiffies + msecs_to_jiffies(read_timeout);
538 }
539 /* check for read timeout */
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 /* copy the data from read_buffer into userspace */
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 /* unlock the device */
566 mutex_unlock(&dev->lock);
567
568exit:
569 return retval;
570}
571
572
573/*
574 * tower_write
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 /* lock this object */
585 if (mutex_lock_interruptible(&dev->lock)) {
586 retval = -ERESTARTSYS;
587 goto exit;
588 }
589
590 /* verify that the device wasn't unplugged */
591 if (dev->disconnected) {
592 retval = -ENODEV;
593 goto unlock_exit;
594 }
595
596 /* verify that we actually have some data to write */
597 if (count == 0) {
598 dev_dbg(&dev->udev->dev, "write request of 0 bytes\n");
599 goto unlock_exit;
600 }
601
602 /* wait until previous transfer is finished */
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 /* write the data into interrupt_out_buffer from userspace */
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 /* send off the urb */
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 /* unlock the device */
648 mutex_unlock(&dev->lock);
649
650exit:
651 return retval;
652}
653
654
655/*
656 * tower_interrupt_in_callback
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; /* maybe we can recover */
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 * tower_interrupt_out_callback
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 /* sync/async unlink faults aren't errors */
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 * tower_probe
737 *
738 * Called by the usb core when a new device is connected that it thinks
739 * this driver might be interested in.
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 /* allocate memory for our device state and initialize it */
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 /* get the firmware version and log it */
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 /* we can register the device now, as it is ready */
812 usb_set_intfdata(interface, dev);
813
814 retval = usb_register_dev(interface, &tower_class);
815 if (retval) {
816 /* something prevented us from registering this driver */
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 /* let the user know what node this device is now attached to */
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 * tower_disconnect
838 *
839 * Called by the usb core when the device is removed from the system.
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 /* give back our minor and prevent further open() */
851 usb_deregister_dev(interface, &tower_class);
852
853 /* stop I/O */
854 usb_poison_urb(dev->interrupt_in_urb);
855 usb_poison_urb(dev->interrupt_out_urb);
856
857 mutex_lock(&dev->lock);
858
859 /* if the device is not opened, then we clean up right now */
860 if (!dev->open_count) {
861 mutex_unlock(&dev->lock);
862 tower_delete(dev);
863 } else {
864 dev->disconnected = 1;
865 /* wake up pollers */
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");