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...) \
99 do { \
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 */
110 module_param(debug, int, S_IRUGO | S_IWUSR);
111 MODULE_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 */
120 static int read_buffer_size = 480;
121 module_param(read_buffer_size, int, 0);
122 MODULE_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 */
130 static int write_buffer_size = 480;
131 module_param(write_buffer_size, int, 0);
132 MODULE_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 */
144 static int packet_timeout = 50;
145 module_param(packet_timeout, int, 0);
146 MODULE_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 */
152 static int read_timeout = 200;
153 module_param(read_timeout, int, 0);
154 MODULE_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 */
165 static int interrupt_in_interval = 2;
166 module_param(interrupt_in_interval, int, 0);
167 MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms");
168
169 static int interrupt_out_interval = 8;
170 module_param(interrupt_out_interval, int, 0);
171 MODULE_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
181 struct tower_reset_reply {
182 __le16 size; /* little-endian */
183 __u8 err_code;
184 __u8 spare;
185 } __attribute__ ((packed));
186
187 struct 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 */
198 static 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
203 MODULE_DEVICE_TABLE (usb, tower_table);
204 static 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 */
210 struct 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 */
244 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos);
245 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos);
246 static inline void tower_delete (struct lego_usb_tower *dev);
247 static int tower_open (struct inode *inode, struct file *file);
248 static int tower_release (struct inode *inode, struct file *file);
249 static unsigned int tower_poll (struct file *file, poll_table *wait);
250 static loff_t tower_llseek (struct file *file, loff_t off, int whence);
251
252 static void tower_abort_transfers (struct lego_usb_tower *dev);
253 static void tower_check_for_read_packet (struct lego_usb_tower *dev);
254 static void tower_interrupt_in_callback (struct urb *urb);
255 static void tower_interrupt_out_callback (struct urb *urb);
256
257 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id);
258 static void tower_disconnect (struct usb_interface *interface);
259
260
261 /* file operations needed when we register this driver */
262 static 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
legousbtower_devnode(struct device * dev,umode_t * mode)272 static char *legousbtower_devnode(struct device *dev, umode_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 */
281 static 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 */
290 static 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 */
lego_usb_tower_debug_data(int level,const char * function,int size,const unsigned char * data)301 static 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 */
tower_delete(struct lego_usb_tower * dev)319 static 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 */
tower_open(struct inode * inode,struct file * file)340 static 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 printk(KERN_ERR "%s - error, can't find device for minor %d\n",
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 dev_err(&dev->udev->dev,
401 "LEGO USB Tower reset control request failed\n");
402 retval = result;
403 goto unlock_exit;
404 }
405
406 /* initialize in direction */
407 dev->read_buffer_length = 0;
408 dev->read_packet_length = 0;
409 usb_fill_int_urb (dev->interrupt_in_urb,
410 dev->udev,
411 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress),
412 dev->interrupt_in_buffer,
413 usb_endpoint_maxp(dev->interrupt_in_endpoint),
414 tower_interrupt_in_callback,
415 dev,
416 dev->interrupt_in_interval);
417
418 dev->interrupt_in_running = 1;
419 dev->interrupt_in_done = 0;
420 mb();
421
422 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL);
423 if (retval) {
424 dev_err(&dev->udev->dev,
425 "Couldn't submit interrupt_in_urb %d\n", retval);
426 dev->interrupt_in_running = 0;
427 dev->open_count = 0;
428 goto unlock_exit;
429 }
430
431 /* save device in the file's private structure */
432 file->private_data = dev;
433
434 unlock_exit:
435 mutex_unlock(&dev->lock);
436
437 exit:
438 dbg(2, "%s: leave, return value %d ", __func__, retval);
439
440 return retval;
441 }
442
443 /**
444 * tower_release
445 */
tower_release(struct inode * inode,struct file * file)446 static int tower_release (struct inode *inode, struct file *file)
447 {
448 struct lego_usb_tower *dev;
449 int retval = 0;
450
451 dbg(2, "%s: enter", __func__);
452
453 dev = file->private_data;
454
455 if (dev == NULL) {
456 dbg(1, "%s: object is NULL", __func__);
457 retval = -ENODEV;
458 goto exit_nolock;
459 }
460
461 mutex_lock(&open_disc_mutex);
462 if (mutex_lock_interruptible(&dev->lock)) {
463 retval = -ERESTARTSYS;
464 goto exit;
465 }
466
467 if (dev->open_count != 1) {
468 dbg(1, "%s: device not opened exactly once", __func__);
469 retval = -ENODEV;
470 goto unlock_exit;
471 }
472 if (dev->udev == NULL) {
473 /* the device was unplugged before the file was released */
474
475 /* unlock here as tower_delete frees dev */
476 mutex_unlock(&dev->lock);
477 tower_delete (dev);
478 goto exit;
479 }
480
481 /* wait until write transfer is finished */
482 if (dev->interrupt_out_busy) {
483 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
484 }
485 tower_abort_transfers (dev);
486 dev->open_count = 0;
487
488 unlock_exit:
489 mutex_unlock(&dev->lock);
490
491 exit:
492 mutex_unlock(&open_disc_mutex);
493 exit_nolock:
494 dbg(2, "%s: leave, return value %d", __func__, retval);
495 return retval;
496 }
497
498
499 /**
500 * tower_abort_transfers
501 * aborts transfers and frees associated data structures
502 */
tower_abort_transfers(struct lego_usb_tower * dev)503 static void tower_abort_transfers (struct lego_usb_tower *dev)
504 {
505 dbg(2, "%s: enter", __func__);
506
507 if (dev == NULL) {
508 dbg(1, "%s: dev is null", __func__);
509 goto exit;
510 }
511
512 /* shutdown transfer */
513 if (dev->interrupt_in_running) {
514 dev->interrupt_in_running = 0;
515 mb();
516 if (dev->udev)
517 usb_kill_urb (dev->interrupt_in_urb);
518 }
519 if (dev->interrupt_out_busy && dev->udev)
520 usb_kill_urb(dev->interrupt_out_urb);
521
522 exit:
523 dbg(2, "%s: leave", __func__);
524 }
525
526
527 /**
528 * tower_check_for_read_packet
529 *
530 * To get correct semantics for signals and non-blocking I/O
531 * with packetizing we pretend not to see any data in the read buffer
532 * until it has been there unchanged for at least
533 * dev->packet_timeout_jiffies, or until the buffer is full.
534 */
tower_check_for_read_packet(struct lego_usb_tower * dev)535 static void tower_check_for_read_packet (struct lego_usb_tower *dev)
536 {
537 spin_lock_irq (&dev->read_buffer_lock);
538 if (!packet_timeout
539 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies)
540 || dev->read_buffer_length == read_buffer_size) {
541 dev->read_packet_length = dev->read_buffer_length;
542 }
543 dev->interrupt_in_done = 0;
544 spin_unlock_irq (&dev->read_buffer_lock);
545 }
546
547
548 /**
549 * tower_poll
550 */
tower_poll(struct file * file,poll_table * wait)551 static unsigned int tower_poll (struct file *file, poll_table *wait)
552 {
553 struct lego_usb_tower *dev;
554 unsigned int mask = 0;
555
556 dbg(2, "%s: enter", __func__);
557
558 dev = file->private_data;
559
560 if (!dev->udev)
561 return POLLERR | POLLHUP;
562
563 poll_wait(file, &dev->read_wait, wait);
564 poll_wait(file, &dev->write_wait, wait);
565
566 tower_check_for_read_packet(dev);
567 if (dev->read_packet_length > 0) {
568 mask |= POLLIN | POLLRDNORM;
569 }
570 if (!dev->interrupt_out_busy) {
571 mask |= POLLOUT | POLLWRNORM;
572 }
573
574 dbg(2, "%s: leave, mask = %d", __func__, mask);
575
576 return mask;
577 }
578
579
580 /**
581 * tower_llseek
582 */
tower_llseek(struct file * file,loff_t off,int whence)583 static loff_t tower_llseek (struct file *file, loff_t off, int whence)
584 {
585 return -ESPIPE; /* unseekable */
586 }
587
588
589 /**
590 * tower_read
591 */
tower_read(struct file * file,char __user * buffer,size_t count,loff_t * ppos)592 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
593 {
594 struct lego_usb_tower *dev;
595 size_t bytes_to_read;
596 int i;
597 int retval = 0;
598 unsigned long timeout = 0;
599
600 dbg(2, "%s: enter, count = %Zd", __func__, count);
601
602 dev = file->private_data;
603
604 /* lock this object */
605 if (mutex_lock_interruptible(&dev->lock)) {
606 retval = -ERESTARTSYS;
607 goto exit;
608 }
609
610 /* verify that the device wasn't unplugged */
611 if (dev->udev == NULL) {
612 retval = -ENODEV;
613 printk(KERN_ERR "legousbtower: No device or device unplugged %d\n", retval);
614 goto unlock_exit;
615 }
616
617 /* verify that we actually have some data to read */
618 if (count == 0) {
619 dbg(1, "%s: read request of 0 bytes", __func__);
620 goto unlock_exit;
621 }
622
623 if (read_timeout) {
624 timeout = jiffies + read_timeout * HZ / 1000;
625 }
626
627 /* wait for data */
628 tower_check_for_read_packet (dev);
629 while (dev->read_packet_length == 0) {
630 if (file->f_flags & O_NONBLOCK) {
631 retval = -EAGAIN;
632 goto unlock_exit;
633 }
634 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies);
635 if (retval < 0) {
636 goto unlock_exit;
637 }
638
639 /* reset read timeout during read or write activity */
640 if (read_timeout
641 && (dev->read_buffer_length || dev->interrupt_out_busy)) {
642 timeout = jiffies + read_timeout * HZ / 1000;
643 }
644 /* check for read timeout */
645 if (read_timeout && time_after (jiffies, timeout)) {
646 retval = -ETIMEDOUT;
647 goto unlock_exit;
648 }
649 tower_check_for_read_packet (dev);
650 }
651
652 /* copy the data from read_buffer into userspace */
653 bytes_to_read = min(count, dev->read_packet_length);
654
655 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) {
656 retval = -EFAULT;
657 goto unlock_exit;
658 }
659
660 spin_lock_irq (&dev->read_buffer_lock);
661 dev->read_buffer_length -= bytes_to_read;
662 dev->read_packet_length -= bytes_to_read;
663 for (i=0; i<dev->read_buffer_length; i++) {
664 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read];
665 }
666 spin_unlock_irq (&dev->read_buffer_lock);
667
668 retval = bytes_to_read;
669
670 unlock_exit:
671 /* unlock the device */
672 mutex_unlock(&dev->lock);
673
674 exit:
675 dbg(2, "%s: leave, return value %d", __func__, retval);
676 return retval;
677 }
678
679
680 /**
681 * tower_write
682 */
tower_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos)683 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
684 {
685 struct lego_usb_tower *dev;
686 size_t bytes_to_write;
687 int retval = 0;
688
689 dbg(2, "%s: enter, count = %Zd", __func__, count);
690
691 dev = file->private_data;
692
693 /* lock this object */
694 if (mutex_lock_interruptible(&dev->lock)) {
695 retval = -ERESTARTSYS;
696 goto exit;
697 }
698
699 /* verify that the device wasn't unplugged */
700 if (dev->udev == NULL) {
701 retval = -ENODEV;
702 printk(KERN_ERR "legousbtower: No device or device unplugged %d\n", retval);
703 goto unlock_exit;
704 }
705
706 /* verify that we actually have some data to write */
707 if (count == 0) {
708 dbg(1, "%s: write request of 0 bytes", __func__);
709 goto unlock_exit;
710 }
711
712 /* wait until previous transfer is finished */
713 while (dev->interrupt_out_busy) {
714 if (file->f_flags & O_NONBLOCK) {
715 retval = -EAGAIN;
716 goto unlock_exit;
717 }
718 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy);
719 if (retval) {
720 goto unlock_exit;
721 }
722 }
723
724 /* write the data into interrupt_out_buffer from userspace */
725 bytes_to_write = min_t(int, count, write_buffer_size);
726 dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __func__, count, bytes_to_write);
727
728 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) {
729 retval = -EFAULT;
730 goto unlock_exit;
731 }
732
733 /* send off the urb */
734 usb_fill_int_urb(dev->interrupt_out_urb,
735 dev->udev,
736 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
737 dev->interrupt_out_buffer,
738 bytes_to_write,
739 tower_interrupt_out_callback,
740 dev,
741 dev->interrupt_out_interval);
742
743 dev->interrupt_out_busy = 1;
744 wmb();
745
746 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL);
747 if (retval) {
748 dev->interrupt_out_busy = 0;
749 dev_err(&dev->udev->dev,
750 "Couldn't submit interrupt_out_urb %d\n", retval);
751 goto unlock_exit;
752 }
753 retval = bytes_to_write;
754
755 unlock_exit:
756 /* unlock the device */
757 mutex_unlock(&dev->lock);
758
759 exit:
760 dbg(2, "%s: leave, return value %d", __func__, retval);
761
762 return retval;
763 }
764
765
766 /**
767 * tower_interrupt_in_callback
768 */
tower_interrupt_in_callback(struct urb * urb)769 static void tower_interrupt_in_callback (struct urb *urb)
770 {
771 struct lego_usb_tower *dev = urb->context;
772 int status = urb->status;
773 int retval;
774
775 dbg(4, "%s: enter, status %d", __func__, status);
776
777 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
778
779 if (status) {
780 if (status == -ENOENT ||
781 status == -ECONNRESET ||
782 status == -ESHUTDOWN) {
783 goto exit;
784 } else {
785 dbg(1, "%s: nonzero status received: %d", __func__, status);
786 goto resubmit; /* maybe we can recover */
787 }
788 }
789
790 if (urb->actual_length > 0) {
791 spin_lock (&dev->read_buffer_lock);
792 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) {
793 memcpy (dev->read_buffer + dev->read_buffer_length,
794 dev->interrupt_in_buffer,
795 urb->actual_length);
796 dev->read_buffer_length += urb->actual_length;
797 dev->read_last_arrival = jiffies;
798 dbg(3, "%s: received %d bytes", __func__, urb->actual_length);
799 } else {
800 printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __func__, urb->actual_length);
801 }
802 spin_unlock (&dev->read_buffer_lock);
803 }
804
805 resubmit:
806 /* resubmit if we're still running */
807 if (dev->interrupt_in_running && dev->udev) {
808 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC);
809 if (retval)
810 dev_err(&dev->udev->dev,
811 "%s: usb_submit_urb failed (%d)\n",
812 __func__, retval);
813 }
814
815 exit:
816 dev->interrupt_in_done = 1;
817 wake_up_interruptible (&dev->read_wait);
818
819 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
820 dbg(4, "%s: leave, status %d", __func__, status);
821 }
822
823
824 /**
825 * tower_interrupt_out_callback
826 */
tower_interrupt_out_callback(struct urb * urb)827 static void tower_interrupt_out_callback (struct urb *urb)
828 {
829 struct lego_usb_tower *dev = urb->context;
830 int status = urb->status;
831
832 dbg(4, "%s: enter, status %d", __func__, status);
833 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
834
835 /* sync/async unlink faults aren't errors */
836 if (status && !(status == -ENOENT ||
837 status == -ECONNRESET ||
838 status == -ESHUTDOWN)) {
839 dbg(1, "%s - nonzero write bulk status received: %d",
840 __func__, status);
841 }
842
843 dev->interrupt_out_busy = 0;
844 wake_up_interruptible(&dev->write_wait);
845
846 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
847 dbg(4, "%s: leave, status %d", __func__, status);
848 }
849
850
851 /**
852 * tower_probe
853 *
854 * Called by the usb core when a new device is connected that it thinks
855 * this driver might be interested in.
856 */
tower_probe(struct usb_interface * interface,const struct usb_device_id * id)857 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id)
858 {
859 struct device *idev = &interface->dev;
860 struct usb_device *udev = interface_to_usbdev(interface);
861 struct lego_usb_tower *dev = NULL;
862 struct usb_host_interface *iface_desc;
863 struct usb_endpoint_descriptor* endpoint;
864 struct tower_get_version_reply get_version_reply;
865 int i;
866 int retval = -ENOMEM;
867 int result;
868
869 dbg(2, "%s: enter", __func__);
870
871 /* allocate memory for our device state and initialize it */
872
873 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL);
874
875 if (dev == NULL) {
876 dev_err(idev, "Out of memory\n");
877 goto exit;
878 }
879
880 mutex_init(&dev->lock);
881
882 dev->udev = udev;
883 dev->open_count = 0;
884
885 dev->read_buffer = NULL;
886 dev->read_buffer_length = 0;
887 dev->read_packet_length = 0;
888 spin_lock_init (&dev->read_buffer_lock);
889 dev->packet_timeout_jiffies = packet_timeout * HZ / 1000;
890 dev->read_last_arrival = jiffies;
891
892 init_waitqueue_head (&dev->read_wait);
893 init_waitqueue_head (&dev->write_wait);
894
895 dev->interrupt_in_buffer = NULL;
896 dev->interrupt_in_endpoint = NULL;
897 dev->interrupt_in_urb = NULL;
898 dev->interrupt_in_running = 0;
899 dev->interrupt_in_done = 0;
900
901 dev->interrupt_out_buffer = NULL;
902 dev->interrupt_out_endpoint = NULL;
903 dev->interrupt_out_urb = NULL;
904 dev->interrupt_out_busy = 0;
905
906 iface_desc = interface->cur_altsetting;
907
908 /* set up the endpoint information */
909 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
910 endpoint = &iface_desc->endpoint[i].desc;
911
912 if (usb_endpoint_xfer_int(endpoint)) {
913 if (usb_endpoint_dir_in(endpoint))
914 dev->interrupt_in_endpoint = endpoint;
915 else
916 dev->interrupt_out_endpoint = endpoint;
917 }
918 }
919 if(dev->interrupt_in_endpoint == NULL) {
920 dev_err(idev, "interrupt in endpoint not found\n");
921 goto error;
922 }
923 if (dev->interrupt_out_endpoint == NULL) {
924 dev_err(idev, "interrupt out endpoint not found\n");
925 goto error;
926 }
927
928 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL);
929 if (!dev->read_buffer) {
930 dev_err(idev, "Couldn't allocate read_buffer\n");
931 goto error;
932 }
933 dev->interrupt_in_buffer = kmalloc (usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL);
934 if (!dev->interrupt_in_buffer) {
935 dev_err(idev, "Couldn't allocate interrupt_in_buffer\n");
936 goto error;
937 }
938 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
939 if (!dev->interrupt_in_urb) {
940 dev_err(idev, "Couldn't allocate interrupt_in_urb\n");
941 goto error;
942 }
943 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL);
944 if (!dev->interrupt_out_buffer) {
945 dev_err(idev, "Couldn't allocate interrupt_out_buffer\n");
946 goto error;
947 }
948 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
949 if (!dev->interrupt_out_urb) {
950 dev_err(idev, "Couldn't allocate interrupt_out_urb\n");
951 goto error;
952 }
953 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
954 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
955
956 /* we can register the device now, as it is ready */
957 usb_set_intfdata (interface, dev);
958
959 retval = usb_register_dev (interface, &tower_class);
960
961 if (retval) {
962 /* something prevented us from registering this driver */
963 dev_err(idev, "Not able to get a minor for this device.\n");
964 usb_set_intfdata (interface, NULL);
965 goto error;
966 }
967 dev->minor = interface->minor;
968
969 /* let the user know what node this device is now attached to */
970 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major "
971 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE),
972 USB_MAJOR, dev->minor);
973
974 /* get the firmware version and log it */
975 result = usb_control_msg (udev,
976 usb_rcvctrlpipe(udev, 0),
977 LEGO_USB_TOWER_REQUEST_GET_VERSION,
978 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
979 0,
980 0,
981 &get_version_reply,
982 sizeof(get_version_reply),
983 1000);
984 if (result < 0) {
985 dev_err(idev, "LEGO USB Tower get version control request failed\n");
986 retval = result;
987 goto error;
988 }
989 dev_info(&interface->dev, "LEGO USB Tower firmware version is %d.%d "
990 "build %d\n", get_version_reply.major,
991 get_version_reply.minor,
992 le16_to_cpu(get_version_reply.build_no));
993
994
995 exit:
996 dbg(2, "%s: leave, return value 0x%.8lx (dev)", __func__, (long) dev);
997
998 return retval;
999
1000 error:
1001 tower_delete(dev);
1002 return retval;
1003 }
1004
1005
1006 /**
1007 * tower_disconnect
1008 *
1009 * Called by the usb core when the device is removed from the system.
1010 */
tower_disconnect(struct usb_interface * interface)1011 static void tower_disconnect (struct usb_interface *interface)
1012 {
1013 struct lego_usb_tower *dev;
1014 int minor;
1015
1016 dbg(2, "%s: enter", __func__);
1017
1018 dev = usb_get_intfdata (interface);
1019 mutex_lock(&open_disc_mutex);
1020 usb_set_intfdata (interface, NULL);
1021
1022 minor = dev->minor;
1023
1024 /* give back our minor */
1025 usb_deregister_dev (interface, &tower_class);
1026
1027 mutex_lock(&dev->lock);
1028 mutex_unlock(&open_disc_mutex);
1029
1030 /* if the device is not opened, then we clean up right now */
1031 if (!dev->open_count) {
1032 mutex_unlock(&dev->lock);
1033 tower_delete (dev);
1034 } else {
1035 dev->udev = NULL;
1036 /* wake up pollers */
1037 wake_up_interruptible_all(&dev->read_wait);
1038 wake_up_interruptible_all(&dev->write_wait);
1039 mutex_unlock(&dev->lock);
1040 }
1041
1042 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n",
1043 (minor - LEGO_USB_TOWER_MINOR_BASE));
1044
1045 dbg(2, "%s: leave", __func__);
1046 }
1047
1048 module_usb_driver(tower_driver);
1049
1050 MODULE_AUTHOR(DRIVER_AUTHOR);
1051 MODULE_DESCRIPTION(DRIVER_DESC);
1052 #ifdef MODULE_LICENSE
1053 MODULE_LICENSE("GPL");
1054 #endif
1055