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