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