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 */
98 static int read_buffer_size = 480;
99 module_param(read_buffer_size, int, 0);
100 MODULE_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 */
108 static int write_buffer_size = 480;
109 module_param(write_buffer_size, int, 0);
110 MODULE_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 */
122 static int packet_timeout = 50;
123 module_param(packet_timeout, int, 0);
124 MODULE_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 */
130 static int read_timeout = 200;
131 module_param(read_timeout, int, 0);
132 MODULE_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 */
143 static int interrupt_in_interval = 2;
144 module_param(interrupt_in_interval, int, 0);
145 MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms");
146
147 static int interrupt_out_interval = 8;
148 module_param(interrupt_out_interval, int, 0);
149 MODULE_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
159 struct tower_reset_reply {
160 __le16 size; /* little-endian */
161 __u8 err_code;
162 __u8 spare;
163 } __attribute__ ((packed));
164
165 struct tower_get_version_reply {
166 __le16 size; /* little-endian */
167 __u8 err_code;
168 __u8 spare;
169 __u8 major;
170 __u8 minor;
171 __le16 build_no; /* little-endian */
172 } __attribute__ ((packed));
173
174
175 /* table of devices that work with this driver */
176 static 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
181 MODULE_DEVICE_TABLE (usb, tower_table);
182 static DEFINE_MUTEX(open_disc_mutex);
183
184 #define LEGO_USB_TOWER_MINOR_BASE 160
185
186
187 /* Structure to hold all of our device specific stuff */
188 struct lego_usb_tower {
189 struct mutex lock; /* locks this structure */
190 struct usb_device* udev; /* save off the usb device pointer */
191 unsigned char minor; /* the starting minor number for this device */
192
193 int open_count; /* number of times this port has been opened */
194
195 char* read_buffer;
196 size_t read_buffer_length; /* this much came in */
197 size_t read_packet_length; /* this much will be returned on read */
198 spinlock_t read_buffer_lock;
199 int packet_timeout_jiffies;
200 unsigned long read_last_arrival;
201
202 wait_queue_head_t read_wait;
203 wait_queue_head_t write_wait;
204
205 char* interrupt_in_buffer;
206 struct usb_endpoint_descriptor* interrupt_in_endpoint;
207 struct urb* interrupt_in_urb;
208 int interrupt_in_interval;
209 int interrupt_in_running;
210 int interrupt_in_done;
211
212 char* interrupt_out_buffer;
213 struct usb_endpoint_descriptor* interrupt_out_endpoint;
214 struct urb* interrupt_out_urb;
215 int interrupt_out_interval;
216 int interrupt_out_busy;
217
218 };
219
220
221 /* local function prototypes */
222 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos);
223 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos);
224 static inline void tower_delete (struct lego_usb_tower *dev);
225 static int tower_open (struct inode *inode, struct file *file);
226 static int tower_release (struct inode *inode, struct file *file);
227 static __poll_t tower_poll (struct file *file, poll_table *wait);
228 static loff_t tower_llseek (struct file *file, loff_t off, int whence);
229
230 static void tower_abort_transfers (struct lego_usb_tower *dev);
231 static void tower_check_for_read_packet (struct lego_usb_tower *dev);
232 static void tower_interrupt_in_callback (struct urb *urb);
233 static void tower_interrupt_out_callback (struct urb *urb);
234
235 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id);
236 static void tower_disconnect (struct usb_interface *interface);
237
238
239 /* file operations needed when we register this driver */
240 static const struct file_operations tower_fops = {
241 .owner = THIS_MODULE,
242 .read = tower_read,
243 .write = tower_write,
244 .open = tower_open,
245 .release = tower_release,
246 .poll = tower_poll,
247 .llseek = tower_llseek,
248 };
249
legousbtower_devnode(struct device * dev,umode_t * mode)250 static char *legousbtower_devnode(struct device *dev, umode_t *mode)
251 {
252 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
253 }
254
255 /*
256 * usb class driver info in order to get a minor number from the usb core,
257 * and to have the device registered with the driver core
258 */
259 static struct usb_class_driver tower_class = {
260 .name = "legousbtower%d",
261 .devnode = legousbtower_devnode,
262 .fops = &tower_fops,
263 .minor_base = LEGO_USB_TOWER_MINOR_BASE,
264 };
265
266
267 /* usb specific object needed to register this driver with the usb subsystem */
268 static struct usb_driver tower_driver = {
269 .name = "legousbtower",
270 .probe = tower_probe,
271 .disconnect = tower_disconnect,
272 .id_table = tower_table,
273 };
274
275
276 /**
277 * lego_usb_tower_debug_data
278 */
lego_usb_tower_debug_data(struct device * dev,const char * function,int size,const unsigned char * data)279 static inline void lego_usb_tower_debug_data(struct device *dev,
280 const char *function, int size,
281 const unsigned char *data)
282 {
283 dev_dbg(dev, "%s - length = %d, data = %*ph\n",
284 function, size, size, data);
285 }
286
287
288 /**
289 * tower_delete
290 */
tower_delete(struct lego_usb_tower * dev)291 static inline void tower_delete (struct lego_usb_tower *dev)
292 {
293 tower_abort_transfers (dev);
294
295 /* free data structures */
296 usb_free_urb(dev->interrupt_in_urb);
297 usb_free_urb(dev->interrupt_out_urb);
298 kfree (dev->read_buffer);
299 kfree (dev->interrupt_in_buffer);
300 kfree (dev->interrupt_out_buffer);
301 kfree (dev);
302 }
303
304
305 /**
306 * tower_open
307 */
tower_open(struct inode * inode,struct file * file)308 static int tower_open (struct inode *inode, struct file *file)
309 {
310 struct lego_usb_tower *dev = NULL;
311 int subminor;
312 int retval = 0;
313 struct usb_interface *interface;
314 struct tower_reset_reply *reset_reply;
315 int result;
316
317 reset_reply = kmalloc(sizeof(*reset_reply), GFP_KERNEL);
318
319 if (!reset_reply) {
320 retval = -ENOMEM;
321 goto exit;
322 }
323
324 nonseekable_open(inode, file);
325 subminor = iminor(inode);
326
327 interface = usb_find_interface (&tower_driver, subminor);
328
329 if (!interface) {
330 pr_err("error, can't find device for minor %d\n", subminor);
331 retval = -ENODEV;
332 goto exit;
333 }
334
335 mutex_lock(&open_disc_mutex);
336 dev = usb_get_intfdata(interface);
337
338 if (!dev) {
339 mutex_unlock(&open_disc_mutex);
340 retval = -ENODEV;
341 goto exit;
342 }
343
344 /* lock this device */
345 if (mutex_lock_interruptible(&dev->lock)) {
346 mutex_unlock(&open_disc_mutex);
347 retval = -ERESTARTSYS;
348 goto exit;
349 }
350
351
352 /* allow opening only once */
353 if (dev->open_count) {
354 mutex_unlock(&open_disc_mutex);
355 retval = -EBUSY;
356 goto unlock_exit;
357 }
358 dev->open_count = 1;
359 mutex_unlock(&open_disc_mutex);
360
361 /* reset the tower */
362 result = usb_control_msg (dev->udev,
363 usb_rcvctrlpipe(dev->udev, 0),
364 LEGO_USB_TOWER_REQUEST_RESET,
365 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
366 0,
367 0,
368 reset_reply,
369 sizeof(*reset_reply),
370 1000);
371 if (result < 0) {
372 dev_err(&dev->udev->dev,
373 "LEGO USB Tower reset control request failed\n");
374 retval = result;
375 goto unlock_exit;
376 }
377
378 /* initialize in direction */
379 dev->read_buffer_length = 0;
380 dev->read_packet_length = 0;
381 usb_fill_int_urb (dev->interrupt_in_urb,
382 dev->udev,
383 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress),
384 dev->interrupt_in_buffer,
385 usb_endpoint_maxp(dev->interrupt_in_endpoint),
386 tower_interrupt_in_callback,
387 dev,
388 dev->interrupt_in_interval);
389
390 dev->interrupt_in_running = 1;
391 dev->interrupt_in_done = 0;
392 mb();
393
394 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL);
395 if (retval) {
396 dev_err(&dev->udev->dev,
397 "Couldn't submit interrupt_in_urb %d\n", retval);
398 dev->interrupt_in_running = 0;
399 dev->open_count = 0;
400 goto unlock_exit;
401 }
402
403 /* save device in the file's private structure */
404 file->private_data = dev;
405
406 unlock_exit:
407 mutex_unlock(&dev->lock);
408
409 exit:
410 kfree(reset_reply);
411 return retval;
412 }
413
414 /**
415 * tower_release
416 */
tower_release(struct inode * inode,struct file * file)417 static int tower_release (struct inode *inode, struct file *file)
418 {
419 struct lego_usb_tower *dev;
420 int retval = 0;
421
422 dev = file->private_data;
423
424 if (dev == NULL) {
425 retval = -ENODEV;
426 goto exit_nolock;
427 }
428
429 mutex_lock(&open_disc_mutex);
430 if (mutex_lock_interruptible(&dev->lock)) {
431 retval = -ERESTARTSYS;
432 goto exit;
433 }
434
435 if (dev->open_count != 1) {
436 dev_dbg(&dev->udev->dev, "%s: device not opened exactly once\n",
437 __func__);
438 retval = -ENODEV;
439 goto unlock_exit;
440 }
441 if (dev->udev == NULL) {
442 /* the device was unplugged before the file was released */
443
444 /* unlock here as tower_delete frees dev */
445 mutex_unlock(&dev->lock);
446 tower_delete (dev);
447 goto exit;
448 }
449
450 /* wait until write transfer is finished */
451 if (dev->interrupt_out_busy) {
452 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
453 }
454 tower_abort_transfers (dev);
455 dev->open_count = 0;
456
457 unlock_exit:
458 mutex_unlock(&dev->lock);
459
460 exit:
461 mutex_unlock(&open_disc_mutex);
462 exit_nolock:
463 return retval;
464 }
465
466
467 /**
468 * tower_abort_transfers
469 * aborts transfers and frees associated data structures
470 */
tower_abort_transfers(struct lego_usb_tower * dev)471 static void tower_abort_transfers (struct lego_usb_tower *dev)
472 {
473 if (dev == NULL)
474 return;
475
476 /* shutdown transfer */
477 if (dev->interrupt_in_running) {
478 dev->interrupt_in_running = 0;
479 mb();
480 if (dev->udev)
481 usb_kill_urb (dev->interrupt_in_urb);
482 }
483 if (dev->interrupt_out_busy && dev->udev)
484 usb_kill_urb(dev->interrupt_out_urb);
485 }
486
487
488 /**
489 * tower_check_for_read_packet
490 *
491 * To get correct semantics for signals and non-blocking I/O
492 * with packetizing we pretend not to see any data in the read buffer
493 * until it has been there unchanged for at least
494 * dev->packet_timeout_jiffies, or until the buffer is full.
495 */
tower_check_for_read_packet(struct lego_usb_tower * dev)496 static void tower_check_for_read_packet (struct lego_usb_tower *dev)
497 {
498 spin_lock_irq (&dev->read_buffer_lock);
499 if (!packet_timeout
500 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies)
501 || dev->read_buffer_length == read_buffer_size) {
502 dev->read_packet_length = dev->read_buffer_length;
503 }
504 dev->interrupt_in_done = 0;
505 spin_unlock_irq (&dev->read_buffer_lock);
506 }
507
508
509 /**
510 * tower_poll
511 */
tower_poll(struct file * file,poll_table * wait)512 static __poll_t tower_poll (struct file *file, poll_table *wait)
513 {
514 struct lego_usb_tower *dev;
515 __poll_t mask = 0;
516
517 dev = file->private_data;
518
519 if (!dev->udev)
520 return EPOLLERR | EPOLLHUP;
521
522 poll_wait(file, &dev->read_wait, wait);
523 poll_wait(file, &dev->write_wait, wait);
524
525 tower_check_for_read_packet(dev);
526 if (dev->read_packet_length > 0) {
527 mask |= EPOLLIN | EPOLLRDNORM;
528 }
529 if (!dev->interrupt_out_busy) {
530 mask |= EPOLLOUT | EPOLLWRNORM;
531 }
532
533 return mask;
534 }
535
536
537 /**
538 * tower_llseek
539 */
tower_llseek(struct file * file,loff_t off,int whence)540 static loff_t tower_llseek (struct file *file, loff_t off, int whence)
541 {
542 return -ESPIPE; /* unseekable */
543 }
544
545
546 /**
547 * tower_read
548 */
tower_read(struct file * file,char __user * buffer,size_t count,loff_t * ppos)549 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
550 {
551 struct lego_usb_tower *dev;
552 size_t bytes_to_read;
553 int i;
554 int retval = 0;
555 unsigned long timeout = 0;
556
557 dev = file->private_data;
558
559 /* lock this object */
560 if (mutex_lock_interruptible(&dev->lock)) {
561 retval = -ERESTARTSYS;
562 goto exit;
563 }
564
565 /* verify that the device wasn't unplugged */
566 if (dev->udev == NULL) {
567 retval = -ENODEV;
568 pr_err("No device or device unplugged %d\n", retval);
569 goto unlock_exit;
570 }
571
572 /* verify that we actually have some data to read */
573 if (count == 0) {
574 dev_dbg(&dev->udev->dev, "read request of 0 bytes\n");
575 goto unlock_exit;
576 }
577
578 if (read_timeout) {
579 timeout = jiffies + msecs_to_jiffies(read_timeout);
580 }
581
582 /* wait for data */
583 tower_check_for_read_packet (dev);
584 while (dev->read_packet_length == 0) {
585 if (file->f_flags & O_NONBLOCK) {
586 retval = -EAGAIN;
587 goto unlock_exit;
588 }
589 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies);
590 if (retval < 0) {
591 goto unlock_exit;
592 }
593
594 /* reset read timeout during read or write activity */
595 if (read_timeout
596 && (dev->read_buffer_length || dev->interrupt_out_busy)) {
597 timeout = jiffies + msecs_to_jiffies(read_timeout);
598 }
599 /* check for read timeout */
600 if (read_timeout && time_after (jiffies, timeout)) {
601 retval = -ETIMEDOUT;
602 goto unlock_exit;
603 }
604 tower_check_for_read_packet (dev);
605 }
606
607 /* copy the data from read_buffer into userspace */
608 bytes_to_read = min(count, dev->read_packet_length);
609
610 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) {
611 retval = -EFAULT;
612 goto unlock_exit;
613 }
614
615 spin_lock_irq (&dev->read_buffer_lock);
616 dev->read_buffer_length -= bytes_to_read;
617 dev->read_packet_length -= bytes_to_read;
618 for (i=0; i<dev->read_buffer_length; i++) {
619 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read];
620 }
621 spin_unlock_irq (&dev->read_buffer_lock);
622
623 retval = bytes_to_read;
624
625 unlock_exit:
626 /* unlock the device */
627 mutex_unlock(&dev->lock);
628
629 exit:
630 return retval;
631 }
632
633
634 /**
635 * tower_write
636 */
tower_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos)637 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
638 {
639 struct lego_usb_tower *dev;
640 size_t bytes_to_write;
641 int retval = 0;
642
643 dev = file->private_data;
644
645 /* lock this object */
646 if (mutex_lock_interruptible(&dev->lock)) {
647 retval = -ERESTARTSYS;
648 goto exit;
649 }
650
651 /* verify that the device wasn't unplugged */
652 if (dev->udev == NULL) {
653 retval = -ENODEV;
654 pr_err("No device or device unplugged %d\n", retval);
655 goto unlock_exit;
656 }
657
658 /* verify that we actually have some data to write */
659 if (count == 0) {
660 dev_dbg(&dev->udev->dev, "write request of 0 bytes\n");
661 goto unlock_exit;
662 }
663
664 /* wait until previous transfer is finished */
665 while (dev->interrupt_out_busy) {
666 if (file->f_flags & O_NONBLOCK) {
667 retval = -EAGAIN;
668 goto unlock_exit;
669 }
670 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy);
671 if (retval) {
672 goto unlock_exit;
673 }
674 }
675
676 /* write the data into interrupt_out_buffer from userspace */
677 bytes_to_write = min_t(int, count, write_buffer_size);
678 dev_dbg(&dev->udev->dev, "%s: count = %zd, bytes_to_write = %zd\n",
679 __func__, count, bytes_to_write);
680
681 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) {
682 retval = -EFAULT;
683 goto unlock_exit;
684 }
685
686 /* send off the urb */
687 usb_fill_int_urb(dev->interrupt_out_urb,
688 dev->udev,
689 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
690 dev->interrupt_out_buffer,
691 bytes_to_write,
692 tower_interrupt_out_callback,
693 dev,
694 dev->interrupt_out_interval);
695
696 dev->interrupt_out_busy = 1;
697 wmb();
698
699 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL);
700 if (retval) {
701 dev->interrupt_out_busy = 0;
702 dev_err(&dev->udev->dev,
703 "Couldn't submit interrupt_out_urb %d\n", retval);
704 goto unlock_exit;
705 }
706 retval = bytes_to_write;
707
708 unlock_exit:
709 /* unlock the device */
710 mutex_unlock(&dev->lock);
711
712 exit:
713 return retval;
714 }
715
716
717 /**
718 * tower_interrupt_in_callback
719 */
tower_interrupt_in_callback(struct urb * urb)720 static void tower_interrupt_in_callback (struct urb *urb)
721 {
722 struct lego_usb_tower *dev = urb->context;
723 int status = urb->status;
724 int retval;
725 unsigned long flags;
726
727 lego_usb_tower_debug_data(&dev->udev->dev, __func__,
728 urb->actual_length, urb->transfer_buffer);
729
730 if (status) {
731 if (status == -ENOENT ||
732 status == -ECONNRESET ||
733 status == -ESHUTDOWN) {
734 goto exit;
735 } else {
736 dev_dbg(&dev->udev->dev,
737 "%s: nonzero status received: %d\n", __func__,
738 status);
739 goto resubmit; /* maybe we can recover */
740 }
741 }
742
743 if (urb->actual_length > 0) {
744 spin_lock_irqsave(&dev->read_buffer_lock, flags);
745 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) {
746 memcpy (dev->read_buffer + dev->read_buffer_length,
747 dev->interrupt_in_buffer,
748 urb->actual_length);
749 dev->read_buffer_length += urb->actual_length;
750 dev->read_last_arrival = jiffies;
751 dev_dbg(&dev->udev->dev, "%s: received %d bytes\n",
752 __func__, urb->actual_length);
753 } else {
754 pr_warn("read_buffer overflow, %d bytes dropped\n",
755 urb->actual_length);
756 }
757 spin_unlock_irqrestore(&dev->read_buffer_lock, flags);
758 }
759
760 resubmit:
761 /* resubmit if we're still running */
762 if (dev->interrupt_in_running && dev->udev) {
763 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC);
764 if (retval)
765 dev_err(&dev->udev->dev,
766 "%s: usb_submit_urb failed (%d)\n",
767 __func__, retval);
768 }
769
770 exit:
771 dev->interrupt_in_done = 1;
772 wake_up_interruptible (&dev->read_wait);
773 }
774
775
776 /**
777 * tower_interrupt_out_callback
778 */
tower_interrupt_out_callback(struct urb * urb)779 static void tower_interrupt_out_callback (struct urb *urb)
780 {
781 struct lego_usb_tower *dev = urb->context;
782 int status = urb->status;
783
784 lego_usb_tower_debug_data(&dev->udev->dev, __func__,
785 urb->actual_length, urb->transfer_buffer);
786
787 /* sync/async unlink faults aren't errors */
788 if (status && !(status == -ENOENT ||
789 status == -ECONNRESET ||
790 status == -ESHUTDOWN)) {
791 dev_dbg(&dev->udev->dev,
792 "%s: nonzero write bulk status received: %d\n", __func__,
793 status);
794 }
795
796 dev->interrupt_out_busy = 0;
797 wake_up_interruptible(&dev->write_wait);
798 }
799
800
801 /**
802 * tower_probe
803 *
804 * Called by the usb core when a new device is connected that it thinks
805 * this driver might be interested in.
806 */
tower_probe(struct usb_interface * interface,const struct usb_device_id * id)807 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id)
808 {
809 struct device *idev = &interface->dev;
810 struct usb_device *udev = interface_to_usbdev(interface);
811 struct lego_usb_tower *dev = NULL;
812 struct tower_get_version_reply *get_version_reply = NULL;
813 int retval = -ENOMEM;
814 int result;
815
816 /* allocate memory for our device state and initialize it */
817
818 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL);
819
820 if (!dev)
821 goto exit;
822
823 mutex_init(&dev->lock);
824
825 dev->udev = udev;
826 dev->open_count = 0;
827
828 dev->read_buffer = NULL;
829 dev->read_buffer_length = 0;
830 dev->read_packet_length = 0;
831 spin_lock_init (&dev->read_buffer_lock);
832 dev->packet_timeout_jiffies = msecs_to_jiffies(packet_timeout);
833 dev->read_last_arrival = jiffies;
834
835 init_waitqueue_head (&dev->read_wait);
836 init_waitqueue_head (&dev->write_wait);
837
838 dev->interrupt_in_buffer = NULL;
839 dev->interrupt_in_endpoint = NULL;
840 dev->interrupt_in_urb = NULL;
841 dev->interrupt_in_running = 0;
842 dev->interrupt_in_done = 0;
843
844 dev->interrupt_out_buffer = NULL;
845 dev->interrupt_out_endpoint = NULL;
846 dev->interrupt_out_urb = NULL;
847 dev->interrupt_out_busy = 0;
848
849 result = usb_find_common_endpoints_reverse(interface->cur_altsetting,
850 NULL, NULL,
851 &dev->interrupt_in_endpoint,
852 &dev->interrupt_out_endpoint);
853 if (result) {
854 dev_err(idev, "interrupt endpoints not found\n");
855 retval = result;
856 goto error;
857 }
858
859 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL);
860 if (!dev->read_buffer)
861 goto error;
862 dev->interrupt_in_buffer = kmalloc (usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL);
863 if (!dev->interrupt_in_buffer)
864 goto error;
865 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
866 if (!dev->interrupt_in_urb)
867 goto error;
868 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL);
869 if (!dev->interrupt_out_buffer)
870 goto error;
871 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
872 if (!dev->interrupt_out_urb)
873 goto error;
874 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
875 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
876
877 get_version_reply = kmalloc(sizeof(*get_version_reply), GFP_KERNEL);
878
879 if (!get_version_reply) {
880 retval = -ENOMEM;
881 goto error;
882 }
883
884 /* get the firmware version and log it */
885 result = usb_control_msg (udev,
886 usb_rcvctrlpipe(udev, 0),
887 LEGO_USB_TOWER_REQUEST_GET_VERSION,
888 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
889 0,
890 0,
891 get_version_reply,
892 sizeof(*get_version_reply),
893 1000);
894 if (result < 0) {
895 dev_err(idev, "LEGO USB Tower get version control request failed\n");
896 retval = result;
897 goto error;
898 }
899 dev_info(&interface->dev,
900 "LEGO USB Tower firmware version is %d.%d build %d\n",
901 get_version_reply->major,
902 get_version_reply->minor,
903 le16_to_cpu(get_version_reply->build_no));
904
905 /* we can register the device now, as it is ready */
906 usb_set_intfdata (interface, dev);
907
908 retval = usb_register_dev (interface, &tower_class);
909
910 if (retval) {
911 /* something prevented us from registering this driver */
912 dev_err(idev, "Not able to get a minor for this device.\n");
913 usb_set_intfdata (interface, NULL);
914 goto error;
915 }
916 dev->minor = interface->minor;
917
918 /* let the user know what node this device is now attached to */
919 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major "
920 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE),
921 USB_MAJOR, dev->minor);
922
923 exit:
924 kfree(get_version_reply);
925 return retval;
926
927 error:
928 kfree(get_version_reply);
929 tower_delete(dev);
930 return retval;
931 }
932
933
934 /**
935 * tower_disconnect
936 *
937 * Called by the usb core when the device is removed from the system.
938 */
tower_disconnect(struct usb_interface * interface)939 static void tower_disconnect (struct usb_interface *interface)
940 {
941 struct lego_usb_tower *dev;
942 int minor;
943
944 dev = usb_get_intfdata (interface);
945 mutex_lock(&open_disc_mutex);
946 usb_set_intfdata (interface, NULL);
947
948 minor = dev->minor;
949
950 /* give back our minor */
951 usb_deregister_dev (interface, &tower_class);
952
953 mutex_lock(&dev->lock);
954 mutex_unlock(&open_disc_mutex);
955
956 /* if the device is not opened, then we clean up right now */
957 if (!dev->open_count) {
958 mutex_unlock(&dev->lock);
959 tower_delete (dev);
960 } else {
961 dev->udev = NULL;
962 /* wake up pollers */
963 wake_up_interruptible_all(&dev->read_wait);
964 wake_up_interruptible_all(&dev->write_wait);
965 mutex_unlock(&dev->lock);
966 }
967
968 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n",
969 (minor - LEGO_USB_TOWER_MINOR_BASE));
970 }
971
972 module_usb_driver(tower_driver);
973
974 MODULE_AUTHOR(DRIVER_AUTHOR);
975 MODULE_DESCRIPTION(DRIVER_DESC);
976 #ifdef MODULE_LICENSE
977 MODULE_LICENSE("GPL");
978 #endif
979
