1 /*
2 * Frontier Designs Tranzport driver
3 *
4 * Copyright (C) 2007 Michael Taht (m@taht.net)
5 *
6 * Based on the usbled driver and ldusb drivers by
7 *
8 * Copyright (C) 2004 Greg Kroah-Hartman (greg@kroah.com)
9 * Copyright (C) 2005 Michael Hund <mhund@ld-didactic.de>
10 *
11 * The ldusb driver was, in turn, derived from Lego USB Tower driver
12 * Copyright (C) 2003 David Glance <advidgsf@sourceforge.net>
13 * 2001-2004 Juergen Stuber <starblue@users.sourceforge.net>
14 *
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License as
17 * published by the Free Software Foundation, version 2.
18 *
19 */
20
21 /*
22 * This driver uses a ring buffer for time critical reading of
23 * interrupt in reports and provides read and write methods for
24 * raw interrupt reports.
25 */
26
27 /* Note: this currently uses a dumb ringbuffer for reads and writes.
28 * A more optimal driver would cache and kill off outstanding urbs that are
29 * now invalid, and ignore ones that already were in the queue but valid
30 * as we only have 17 commands for the tranzport. In particular this is
31 * key for getting lights to flash in time as otherwise many commands
32 * can be buffered up before the light change makes it to the interface.
33 */
34
35 #include <linux/kernel.h>
36 #include <linux/errno.h>
37 #include <linux/init.h>
38 #include <linux/slab.h>
39 #include <linux/module.h>
40 #include <linux/mutex.h>
41
42 #include <linux/uaccess.h>
43 #include <linux/input.h>
44 #include <linux/usb.h>
45 #include <linux/poll.h>
46
47 /* Define these values to match your devices */
48 #define VENDOR_ID 0x165b
49 #define PRODUCT_ID 0x8101
50
51 #ifdef CONFIG_USB_DYNAMIC_MINORS
52 #define USB_TRANZPORT_MINOR_BASE 0
53 #else /* FIXME 177- is the another driver's minor - apply for a minor soon */
54 #define USB_TRANZPORT_MINOR_BASE 177
55 #endif
56
57 /* table of devices that work with this driver */
58 static const struct usb_device_id usb_tranzport_table[] = {
59 {USB_DEVICE(VENDOR_ID, PRODUCT_ID)},
60 {} /* Terminating entry */
61 };
62
63 MODULE_DEVICE_TABLE(usb, usb_tranzport_table);
64 MODULE_VERSION("0.35");
65 MODULE_AUTHOR("Mike Taht <m@taht.net>");
66 MODULE_DESCRIPTION("Tranzport USB Driver");
67 MODULE_LICENSE("GPL");
68 MODULE_SUPPORTED_DEVICE("Frontier Designs Tranzport Control Surface");
69
70 #define SUPPRESS_EXTRA_OFFLINE_EVENTS 1
71 #define COMPRESS_WHEEL_EVENTS 1
72 #define BUFFERED_READS 1
73 #define RING_BUFFER_SIZE 1000
74 #define WRITE_BUFFER_SIZE 34
75 #define TRANZPORT_USB_TIMEOUT 10
76 #define TRANZPORT_DEBUG 0
77
78 static int debug = TRANZPORT_DEBUG;
79
80 /* Use our own dbg macro */
81 #define dbg_info(dev, format, arg...) do \
82 { if (debug) dev_info(dev , format , ## arg); } while (0)
83
84 /* Module parameters */
85
86 module_param(debug, int, S_IRUGO | S_IWUSR);
87 MODULE_PARM_DESC(debug, "Debug enabled or not");
88
89 /* All interrupt in transfers are collected in a ring buffer to
90 * avoid racing conditions and get better performance of the driver.
91 */
92
93 static int ring_buffer_size = RING_BUFFER_SIZE;
94
95 module_param(ring_buffer_size, int, S_IRUGO);
96 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
97
98 /* The write_buffer can one day contain more than one interrupt out transfer.
99 */
100 static int write_buffer_size = WRITE_BUFFER_SIZE;
101 module_param(write_buffer_size, int, S_IRUGO);
102 MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
103
104 /*
105 * Increase the interval for debugging purposes.
106 * or set to 1 to use the standard interval from the endpoint descriptors.
107 */
108
109 static int min_interrupt_in_interval = TRANZPORT_USB_TIMEOUT;
110 module_param(min_interrupt_in_interval, int, 0);
111 MODULE_PARM_DESC(min_interrupt_in_interval,
112 "Minimum interrupt in interval in ms");
113
114 static int min_interrupt_out_interval = TRANZPORT_USB_TIMEOUT;
115 module_param(min_interrupt_out_interval, int, 0);
116 MODULE_PARM_DESC(min_interrupt_out_interval,
117 "Minimum interrupt out interval in ms");
118
119 struct tranzport_cmd {
120 unsigned char cmd[8];
121 };
122
123 /* Structure to hold all of our device specific stuff */
124
125 struct usb_tranzport {
126 struct mutex mtx; /* locks this structure */
127 struct usb_interface *intf; /* save off the usb interface pointer */
128 int open_count; /* number of times this port opened */
129 struct tranzport_cmd (*ring_buffer)[RING_BUFFER_SIZE];
130 unsigned int ring_head;
131 unsigned int ring_tail;
132 wait_queue_head_t read_wait;
133 wait_queue_head_t write_wait;
134 unsigned char *interrupt_in_buffer;
135 struct usb_endpoint_descriptor *interrupt_in_endpoint;
136 struct urb *interrupt_in_urb;
137 int interrupt_in_interval;
138 size_t interrupt_in_endpoint_size;
139 int interrupt_in_running;
140 int interrupt_in_done;
141 char *interrupt_out_buffer;
142 struct usb_endpoint_descriptor *interrupt_out_endpoint;
143 struct urb *interrupt_out_urb;
144 int interrupt_out_interval;
145 size_t interrupt_out_endpoint_size;
146 int interrupt_out_busy;
147
148 /* Sysfs support */
149
150 unsigned char enable; /* 0 if disabled 1 if enabled */
151 unsigned char offline; /* if the device is out of range or asleep */
152 unsigned char compress_wheel; /* flag to compress wheel events */
153 };
154
155 /* prevent races between open() and disconnect() */
156 static DEFINE_MUTEX(disconnect_mutex);
157
158 static struct usb_driver usb_tranzport_driver;
159
160 /**
161 * usb_tranzport_abort_transfers
162 * aborts transfers and frees associated data structures
163 */
usb_tranzport_abort_transfers(struct usb_tranzport * dev)164 static void usb_tranzport_abort_transfers(struct usb_tranzport *dev)
165 {
166 /* shutdown transfer */
167 if (dev->interrupt_in_running) {
168 dev->interrupt_in_running = 0;
169 if (dev->intf)
170 usb_kill_urb(dev->interrupt_in_urb);
171 }
172 if (dev->interrupt_out_busy)
173 if (dev->intf)
174 usb_kill_urb(dev->interrupt_out_urb);
175 }
176
177 #define show_int(value) \
178 static ssize_t show_##value(struct device *dev, \
179 struct device_attribute *attr, char *buf) \
180 { \
181 struct usb_interface *intf = to_usb_interface(dev); \
182 struct usb_tranzport *t = usb_get_intfdata(intf); \
183 return sprintf(buf, "%d\n", t->value); \
184 } \
185 static DEVICE_ATTR(value, S_IRUGO, show_##value, NULL);
186
187 #define show_set_int(value) \
188 static ssize_t show_##value(struct device *dev, \
189 struct device_attribute *attr, char *buf) \
190 { \
191 struct usb_interface *intf = to_usb_interface(dev); \
192 struct usb_tranzport *t = usb_get_intfdata(intf); \
193 return sprintf(buf, "%d\n", t->value); \
194 } \
195 static ssize_t set_##value(struct device *dev, \
196 struct device_attribute *attr, \
197 const char *buf, size_t count) \
198 { \
199 struct usb_interface *intf = to_usb_interface(dev); \
200 struct usb_tranzport *t = usb_get_intfdata(intf); \
201 unsigned long temp; \
202 if (kstrtoul(buf, 10, &temp)) \
203 return -EINVAL; \
204 t->value = temp; \
205 return count; \
206 } \
207 static DEVICE_ATTR(value, S_IWUSR | S_IRUGO, show_##value, set_##value);
208
209 show_int(enable);
210 show_int(offline);
211 show_set_int(compress_wheel);
212
213 /**
214 * usb_tranzport_delete
215 */
usb_tranzport_delete(struct usb_tranzport * dev)216 static void usb_tranzport_delete(struct usb_tranzport *dev)
217 {
218 usb_tranzport_abort_transfers(dev);
219 if (dev->intf != NULL) {
220 device_remove_file(&dev->intf->dev, &dev_attr_enable);
221 device_remove_file(&dev->intf->dev, &dev_attr_offline);
222 device_remove_file(&dev->intf->dev, &dev_attr_compress_wheel);
223 }
224
225 /* free data structures */
226 usb_free_urb(dev->interrupt_in_urb);
227 usb_free_urb(dev->interrupt_out_urb);
228 kfree(dev->ring_buffer);
229 kfree(dev->interrupt_in_buffer);
230 kfree(dev->interrupt_out_buffer);
231 kfree(dev);
232 }
233
234 /**
235 * usb_tranzport_interrupt_in_callback
236 */
237
usb_tranzport_interrupt_in_callback(struct urb * urb)238 static void usb_tranzport_interrupt_in_callback(struct urb *urb)
239 {
240 struct usb_tranzport *dev = urb->context;
241 unsigned int next_ring_head;
242 int retval = -1;
243
244 if (urb->status) {
245 if (urb->status == -ENOENT ||
246 urb->status == -ECONNRESET ||
247 urb->status == -ESHUTDOWN) {
248 goto exit;
249 } else {
250 dbg_info(&dev->intf->dev,
251 "%s: nonzero status received: %d\n",
252 __func__, urb->status);
253 goto resubmit; /* maybe we can recover */
254 }
255 }
256
257 if (urb->actual_length != 8) {
258 dev_warn(&dev->intf->dev,
259 "Urb length was %d bytes!!"
260 "Do something intelligent\n",
261 urb->actual_length);
262 } else {
263 dbg_info(&dev->intf->dev,
264 "%s: received: %02x%02x%02x%02x%02x%02x%02x%02x\n",
265 __func__, dev->interrupt_in_buffer[0],
266 dev->interrupt_in_buffer[1],
267 dev->interrupt_in_buffer[2],
268 dev->interrupt_in_buffer[3],
269 dev->interrupt_in_buffer[4],
270 dev->interrupt_in_buffer[5],
271 dev->interrupt_in_buffer[6],
272 dev->interrupt_in_buffer[7]);
273 #if SUPPRESS_EXTRA_OFFLINE_EVENTS
274 if (dev->offline == 2 && dev->interrupt_in_buffer[1] == 0xff)
275 goto resubmit;
276 if (dev->offline == 1 && dev->interrupt_in_buffer[1] == 0xff) {
277 dev->offline = 2;
278 goto resubmit;
279 }
280
281 /* Always pass one offline event up the stack */
282 if (dev->offline > 0 && dev->interrupt_in_buffer[1] != 0xff)
283 dev->offline = 0;
284 if (dev->offline == 0 && dev->interrupt_in_buffer[1] == 0xff)
285 dev->offline = 1;
286
287 #endif /* SUPPRESS_EXTRA_OFFLINE_EVENTS */
288 dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n",
289 __func__, dev->ring_head, dev->ring_tail);
290
291 next_ring_head = (dev->ring_head + 1) % ring_buffer_size;
292
293 if (next_ring_head != dev->ring_tail) {
294 memcpy(&((*dev->ring_buffer)[dev->ring_head]),
295 dev->interrupt_in_buffer, urb->actual_length);
296 dev->ring_head = next_ring_head;
297 retval = 0;
298 memset(dev->interrupt_in_buffer, 0, urb->actual_length);
299 } else {
300 dev_warn(&dev->intf->dev,
301 "Ring buffer overflow, %d bytes dropped\n",
302 urb->actual_length);
303 memset(dev->interrupt_in_buffer, 0, urb->actual_length);
304 }
305 }
306
307 resubmit:
308 /* resubmit if we're still running */
309 if (dev->interrupt_in_running && dev->intf) {
310 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
311 if (retval)
312 dev_err(&dev->intf->dev,
313 "usb_submit_urb failed (%d)\n", retval);
314 }
315
316 exit:
317 dev->interrupt_in_done = 1;
318 wake_up_interruptible(&dev->read_wait);
319 }
320
321 /**
322 * usb_tranzport_interrupt_out_callback
323 */
usb_tranzport_interrupt_out_callback(struct urb * urb)324 static void usb_tranzport_interrupt_out_callback(struct urb *urb)
325 {
326 struct usb_tranzport *dev = urb->context;
327 /* sync/async unlink faults aren't errors */
328 if (urb->status && !(urb->status == -ENOENT ||
329 urb->status == -ECONNRESET ||
330 urb->status == -ESHUTDOWN))
331 dbg_info(&dev->intf->dev,
332 "%s - nonzero write interrupt status received: %d\n",
333 __func__, urb->status);
334
335 dev->interrupt_out_busy = 0;
336 wake_up_interruptible(&dev->write_wait);
337 }
338 /**
339 * usb_tranzport_open
340 */
usb_tranzport_open(struct inode * inode,struct file * file)341 static int usb_tranzport_open(struct inode *inode, struct file *file)
342 {
343 struct usb_tranzport *dev;
344 int subminor;
345 int retval = 0;
346 struct usb_interface *interface;
347
348 nonseekable_open(inode, file);
349 subminor = iminor(inode);
350
351 mutex_lock(&disconnect_mutex);
352
353 interface = usb_find_interface(&usb_tranzport_driver, subminor);
354
355 if (!interface) {
356 pr_err("%s - error, can't find device for minor %d\n",
357 __func__, subminor);
358 retval = -ENODEV;
359 goto unlock_disconnect_exit;
360 }
361
362 dev = usb_get_intfdata(interface);
363
364 if (!dev) {
365 retval = -ENODEV;
366 goto unlock_disconnect_exit;
367 }
368
369 /* lock this device */
370 if (mutex_lock_interruptible(&dev->mtx)) {
371 retval = -ERESTARTSYS;
372 goto unlock_disconnect_exit;
373 }
374
375 /* allow opening only once */
376 if (dev->open_count) {
377 retval = -EBUSY;
378 goto unlock_exit;
379 }
380 dev->open_count = 1;
381
382 /* initialize in direction */
383 dev->ring_head = 0;
384 dev->ring_tail = 0;
385 usb_fill_int_urb(dev->interrupt_in_urb,
386 interface_to_usbdev(interface),
387 usb_rcvintpipe(interface_to_usbdev(interface),
388 dev->interrupt_in_endpoint->
389 bEndpointAddress),
390 dev->interrupt_in_buffer,
391 dev->interrupt_in_endpoint_size,
392 usb_tranzport_interrupt_in_callback, dev,
393 dev->interrupt_in_interval);
394
395 dev->interrupt_in_running = 1;
396 dev->interrupt_in_done = 0;
397 dev->enable = 1;
398 dev->offline = 0;
399 dev->compress_wheel = 1;
400
401 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
402 if (retval) {
403 dev_err(&interface->dev,
404 "Couldn't submit interrupt_in_urb %d\n", retval);
405 dev->interrupt_in_running = 0;
406 dev->open_count = 0;
407 goto unlock_exit;
408 }
409
410 /* save device in the file's private structure */
411 file->private_data = dev;
412
413 unlock_exit:
414 mutex_unlock(&dev->mtx);
415
416 unlock_disconnect_exit:
417 mutex_unlock(&disconnect_mutex);
418
419 return retval;
420 }
421
422 /**
423 * usb_tranzport_release
424 */
usb_tranzport_release(struct inode * inode,struct file * file)425 static int usb_tranzport_release(struct inode *inode, struct file *file)
426 {
427 struct usb_tranzport *dev;
428 int retval = 0;
429
430 dev = file->private_data;
431
432 if (dev == NULL) {
433 retval = -ENODEV;
434 goto exit;
435 }
436
437 if (mutex_lock_interruptible(&dev->mtx)) {
438 retval = -ERESTARTSYS;
439 goto exit;
440 }
441
442 if (dev->open_count != 1) {
443 retval = -ENODEV;
444 goto unlock_exit;
445 }
446
447 if (dev->intf == NULL) {
448 /* the device was unplugged before the file was released */
449 mutex_unlock(&dev->mtx);
450 /* unlock here as usb_tranzport_delete frees dev */
451 usb_tranzport_delete(dev);
452 retval = -ENODEV;
453 goto exit;
454 }
455
456 /* wait until write transfer is finished */
457 if (dev->interrupt_out_busy)
458 wait_event_interruptible_timeout(dev->write_wait,
459 !dev->interrupt_out_busy,
460 2 * HZ);
461 usb_tranzport_abort_transfers(dev);
462 dev->open_count = 0;
463
464 unlock_exit:
465 mutex_unlock(&dev->mtx);
466
467 exit:
468 return retval;
469 }
470
471 /**
472 * usb_tranzport_poll
473 */
usb_tranzport_poll(struct file * file,poll_table * wait)474 static unsigned int usb_tranzport_poll(struct file *file, poll_table *wait)
475 {
476 struct usb_tranzport *dev;
477 unsigned int mask = 0;
478 dev = file->private_data;
479 poll_wait(file, &dev->read_wait, wait);
480 poll_wait(file, &dev->write_wait, wait);
481 if (dev->ring_head != dev->ring_tail)
482 mask |= POLLIN | POLLRDNORM;
483 if (!dev->interrupt_out_busy)
484 mask |= POLLOUT | POLLWRNORM;
485 return mask;
486 }
487 /**
488 * usb_tranzport_read
489 */
490
usb_tranzport_read(struct file * file,char __user * buffer,size_t count,loff_t * ppos)491 static ssize_t usb_tranzport_read(struct file *file, char __user *buffer,
492 size_t count, loff_t *ppos)
493 {
494 struct usb_tranzport *dev;
495 int retval = 0;
496 #if BUFFERED_READS
497 int c = 0;
498 #endif
499 #if COMPRESS_WHEEL_EVENTS
500 signed char oldwheel;
501 signed char newwheel;
502 int cancompress = 1;
503 int next_tail;
504 #endif
505
506 /* do I have such a thing as a null event? */
507
508 dev = file->private_data;
509
510 /* verify that we actually have some data to read */
511 if (count == 0)
512 goto exit;
513
514 /* lock this object */
515 if (mutex_lock_interruptible(&dev->mtx)) {
516 retval = -ERESTARTSYS;
517 goto exit;
518 }
519
520 /* verify that the device wasn't unplugged */
521 if (dev->intf == NULL) {
522 retval = -ENODEV;
523 pr_err("%s: No device or device unplugged %d\n",
524 __func__, retval);
525 goto unlock_exit;
526 }
527
528 while (dev->ring_head == dev->ring_tail) {
529
530 if (file->f_flags & O_NONBLOCK) {
531 retval = -EAGAIN;
532 goto unlock_exit;
533 }
534 /* tiny race - FIXME: make atomic? */
535 /* atomic_cmp_exchange(&dev->interrupt_in_done,0,0); */
536 dev->interrupt_in_done = 0;
537 retval = wait_event_interruptible(dev->read_wait,
538 dev->interrupt_in_done);
539 if (retval < 0)
540 goto unlock_exit;
541 }
542
543 dbg_info(&dev->intf->dev,
544 "%s: copying to userspace: "
545 "%02x%02x%02x%02x%02x%02x%02x%02x\n",
546 __func__,
547 (*dev->ring_buffer)[dev->ring_tail].cmd[0],
548 (*dev->ring_buffer)[dev->ring_tail].cmd[1],
549 (*dev->ring_buffer)[dev->ring_tail].cmd[2],
550 (*dev->ring_buffer)[dev->ring_tail].cmd[3],
551 (*dev->ring_buffer)[dev->ring_tail].cmd[4],
552 (*dev->ring_buffer)[dev->ring_tail].cmd[5],
553 (*dev->ring_buffer)[dev->ring_tail].cmd[6],
554 (*dev->ring_buffer)[dev->ring_tail].cmd[7]);
555
556 #if BUFFERED_READS
557 c = 0;
558 while ((c < count) && (dev->ring_tail != dev->ring_head)) {
559
560 #if COMPRESS_WHEEL_EVENTS
561 next_tail = (dev->ring_tail+1) % ring_buffer_size;
562 if (dev->compress_wheel)
563 cancompress = 1;
564 while (dev->ring_head != next_tail && cancompress == 1) {
565 newwheel = (*dev->ring_buffer)[next_tail].cmd[6];
566 oldwheel = (*dev->ring_buffer)[dev->ring_tail].cmd[6];
567 /* if both are wheel events, and
568 no buttons have changes (FIXME, do I have to check?),
569 and we are the same sign, we can compress +- 7F
570 */
571 dbg_info(&dev->intf->dev,
572 "%s: trying to compress: "
573 "%02x%02x%02x%02x%02x%02x%02x%02x\n",
574 __func__,
575 (*dev->ring_buffer)[dev->ring_tail].cmd[0],
576 (*dev->ring_buffer)[dev->ring_tail].cmd[1],
577 (*dev->ring_buffer)[dev->ring_tail].cmd[2],
578 (*dev->ring_buffer)[dev->ring_tail].cmd[3],
579 (*dev->ring_buffer)[dev->ring_tail].cmd[4],
580 (*dev->ring_buffer)[dev->ring_tail].cmd[5],
581 (*dev->ring_buffer)[dev->ring_tail].cmd[6],
582 (*dev->ring_buffer)[dev->ring_tail].cmd[7]);
583
584 if (((*dev->ring_buffer)[dev->ring_tail].cmd[6] != 0 &&
585 (*dev->ring_buffer)[next_tail].cmd[6] != 0) &&
586 ((newwheel > 0 && oldwheel > 0) ||
587 (newwheel < 0 && oldwheel < 0)) &&
588 ((*dev->ring_buffer)[dev->ring_tail].cmd[2] ==
589 (*dev->ring_buffer)[next_tail].cmd[2]) &&
590 ((*dev->ring_buffer)[dev->ring_tail].cmd[3] ==
591 (*dev->ring_buffer)[next_tail].cmd[3]) &&
592 ((*dev->ring_buffer)[dev->ring_tail].cmd[4] ==
593 (*dev->ring_buffer)[next_tail].cmd[4]) &&
594 ((*dev->ring_buffer)[dev->ring_tail].cmd[5] ==
595 (*dev->ring_buffer)[next_tail].cmd[5])) {
596 dbg_info(&dev->intf->dev,
597 "%s: should compress: "
598 "%02x%02x%02x%02x%02x%02x%02x%02x\n",
599 __func__,
600 (*dev->ring_buffer)[dev->ring_tail].
601 cmd[0],
602 (*dev->ring_buffer)[dev->ring_tail].
603 cmd[1],
604 (*dev->ring_buffer)[dev->ring_tail].
605 cmd[2],
606 (*dev->ring_buffer)[dev->ring_tail].
607 cmd[3],
608 (*dev->ring_buffer)[dev->ring_tail].
609 cmd[4],
610 (*dev->ring_buffer)[dev->ring_tail].
611 cmd[5],
612 (*dev->ring_buffer)[dev->ring_tail].
613 cmd[6],
614 (*dev->ring_buffer)[dev->ring_tail].
615 cmd[7]);
616 newwheel += oldwheel;
617 if (oldwheel > 0 && !(newwheel > 0)) {
618 newwheel = 0x7f;
619 cancompress = 0;
620 }
621 if (oldwheel < 0 && !(newwheel < 0)) {
622 newwheel = 0x80;
623 cancompress = 0;
624 }
625
626 (*dev->ring_buffer)[next_tail].cmd[6] =
627 newwheel;
628 dev->ring_tail = next_tail;
629 next_tail =
630 (dev->ring_tail + 1) % ring_buffer_size;
631 } else {
632 cancompress = 0;
633 }
634 }
635 #endif /* COMPRESS_WHEEL_EVENTS */
636 if (copy_to_user(
637 &buffer[c],
638 &(*dev->ring_buffer)[dev->ring_tail], 8)) {
639 retval = -EFAULT;
640 goto unlock_exit;
641 }
642 dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size;
643 c += 8;
644 dbg_info(&dev->intf->dev,
645 "%s: head, tail are %x, %x\n",
646 __func__, dev->ring_head, dev->ring_tail);
647 }
648 retval = c;
649
650 #else
651 /* if (copy_to_user(buffer, &(*dev->ring_buffer)[dev->ring_tail], 8)) { */
652 retval = -EFAULT;
653 goto unlock_exit;
654 }
655
656 dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size;
657 dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n",
658 __func__, dev->ring_head, dev->ring_tail);
659
660 retval = 8;
661 #endif /* BUFFERED_READS */
662
663 unlock_exit:
664 /* unlock the device */
665 mutex_unlock(&dev->mtx);
666
667 exit:
668 return retval;
669 }
670
671 /**
672 * usb_tranzport_write
673 */
674 static ssize_t usb_tranzport_write(struct file *file,
675 const char __user *buffer, size_t count,
676 loff_t *ppos)
677 {
678 struct usb_tranzport *dev;
679 size_t bytes_to_write;
680 int retval = 0;
681
682 dev = file->private_data;
683
684 /* verify that we actually have some data to write */
685 if (count == 0)
686 goto exit;
687
688 /* lock this object */
689 if (mutex_lock_interruptible(&dev->mtx)) {
690 retval = -ERESTARTSYS;
691 goto exit;
692 }
693 /* verify that the device wasn't unplugged */
694 if (dev->intf == NULL) {
695 retval = -ENODEV;
696 pr_err("%s: No device or device unplugged %d\n",
697 __func__, retval);
698 goto unlock_exit;
699 }
700
701 /* wait until previous transfer is finished */
702 if (dev->interrupt_out_busy) {
703 if (file->f_flags & O_NONBLOCK) {
704 retval = -EAGAIN;
705 goto unlock_exit;
706 }
707 retval = wait_event_interruptible(dev->write_wait,
708 !dev->interrupt_out_busy);
709 if (retval < 0)
710 goto unlock_exit;
711 }
712
713 /* write the data into interrupt_out_buffer from userspace */
714 bytes_to_write = min(count,
715 write_buffer_size *
716 dev->interrupt_out_endpoint_size);
717 if (bytes_to_write < count)
718 dev_warn(&dev->intf->dev,
719 "Write buffer overflow, %zd bytes dropped\n",
720 count - bytes_to_write);
721
722 dbg_info(&dev->intf->dev,
723 "%s: count = %zd, bytes_to_write = %zd\n", __func__,
724 count, bytes_to_write);
725
726 if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
727 retval = -EFAULT;
728 goto unlock_exit;
729 }
730
731 if (dev->interrupt_out_endpoint == NULL) {
732 dev_err(&dev->intf->dev, "Endpoint should not be be null!\n");
733 goto unlock_exit;
734 }
735
736 /* send off the urb */
737 usb_fill_int_urb(dev->interrupt_out_urb,
738 interface_to_usbdev(dev->intf),
739 usb_sndintpipe(interface_to_usbdev(dev->intf),
740 dev->interrupt_out_endpoint->
741 bEndpointAddress),
742 dev->interrupt_out_buffer, bytes_to_write,
743 usb_tranzport_interrupt_out_callback, dev,
744 dev->interrupt_out_interval);
745
746 dev->interrupt_out_busy = 1;
747 wmb();
748
749 retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
750 if (retval) {
751 dev->interrupt_out_busy = 0;
752 dev_err(&dev->intf->dev,
753 "Couldn't submit interrupt_out_urb %d\n", retval);
754 goto unlock_exit;
755 }
756 retval = bytes_to_write;
757
758 unlock_exit:
759 /* unlock the device */
760 mutex_unlock(&dev->mtx);
761
762 exit:
763 return retval;
764 }
765
766 /* file operations needed when we register this driver */
767 static const struct file_operations usb_tranzport_fops = {
768 .owner = THIS_MODULE,
769 .read = usb_tranzport_read,
770 .write = usb_tranzport_write,
771 .open = usb_tranzport_open,
772 .release = usb_tranzport_release,
773 .poll = usb_tranzport_poll,
774 .llseek = no_llseek,
775 };
776
777 /*
778 * usb class driver info in order to get a minor number from the usb core,
779 * and to have the device registered with the driver core
780 */
781 static struct usb_class_driver usb_tranzport_class = {
782 .name = "tranzport%d",
783 .fops = &usb_tranzport_fops,
784 .minor_base = USB_TRANZPORT_MINOR_BASE,
785 };
786
787 /**
788 * usb_tranzport_probe
789 *
790 * Called by the usb core when a new device is connected that it thinks
791 * this driver might be interested in.
792 */
793 static int usb_tranzport_probe(struct usb_interface *intf,
794 const struct usb_device_id *id) {
795 struct usb_device *udev = interface_to_usbdev(intf);
796 struct usb_tranzport *dev = NULL;
797 struct usb_host_interface *iface_desc;
798 struct usb_endpoint_descriptor *endpoint;
799 int i;
800 int true_size;
801 int retval = -ENOMEM;
802
803 /* allocate memory for our device state and initialize it */
804
805 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
806 if (dev == NULL)
807 goto exit;
808
809 mutex_init(&dev->mtx);
810 dev->intf = intf;
811 init_waitqueue_head(&dev->read_wait);
812 init_waitqueue_head(&dev->write_wait);
813
814 iface_desc = intf->cur_altsetting;
815
816 /* set up the endpoint information */
817 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
818 endpoint = &iface_desc->endpoint[i].desc;
819
820 if (usb_endpoint_is_int_in(endpoint))
821 dev->interrupt_in_endpoint = endpoint;
822
823 if (usb_endpoint_is_int_out(endpoint))
824 dev->interrupt_out_endpoint = endpoint;
825 }
826 if (dev->interrupt_in_endpoint == NULL) {
827 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
828 goto error;
829 }
830 if (dev->interrupt_out_endpoint == NULL)
831 dev_warn(&intf->dev,
832 "Interrupt out endpoint not found"
833 "(using control endpoint instead)\n");
834
835 dev->interrupt_in_endpoint_size =
836 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
837
838 if (dev->interrupt_in_endpoint_size != 8)
839 dev_warn(&intf->dev, "Interrupt in endpoint size is not 8!\n");
840
841 if (ring_buffer_size == 0)
842 ring_buffer_size = RING_BUFFER_SIZE;
843 true_size = min(ring_buffer_size, RING_BUFFER_SIZE);
844
845 /* FIXME - there are more usb_alloc routines for dma correctness.
846 Needed? */
847
848 dev->ring_buffer =
849 kmalloc((true_size * sizeof(struct tranzport_cmd)) + 8, GFP_KERNEL);
850 if (!dev->ring_buffer)
851 goto error;
852
853 dev->interrupt_in_buffer =
854 kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
855 if (!dev->interrupt_in_buffer)
856 goto error;
857
858 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
859 if (!dev->interrupt_in_urb) {
860 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
861 goto error;
862 }
863 dev->interrupt_out_endpoint_size =
864 dev->interrupt_out_endpoint ?
865 le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize) :
866 udev->descriptor.bMaxPacketSize0;
867
868 if (dev->interrupt_out_endpoint_size != 8)
869 dev_warn(&intf->dev,
870 "Interrupt out endpoint size is not 8!)\n");
871
872 dev->interrupt_out_buffer =
873 kmalloc_array(write_buffer_size,
874 dev->interrupt_out_endpoint_size, GFP_KERNEL);
875 if (!dev->interrupt_out_buffer)
876 goto error;
877
878 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
879 if (!dev->interrupt_out_urb) {
880 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
881 goto error;
882 }
883 dev->interrupt_in_interval =
884 min_interrupt_in_interval >
885 dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval
886 : dev->interrupt_in_endpoint->bInterval;
887
888 if (dev->interrupt_out_endpoint) {
889 dev->interrupt_out_interval =
890 min_interrupt_out_interval >
891 dev->interrupt_out_endpoint->bInterval ?
892 min_interrupt_out_interval :
893 dev->interrupt_out_endpoint->bInterval;
894 }
895
896 /* we can register the device now, as it is ready */
897 usb_set_intfdata(intf, dev);
898
899 retval = usb_register_dev(intf, &usb_tranzport_class);
900 if (retval) {
901 /* something prevented us from registering this driver */
902 dev_err(&intf->dev,
903 "Not able to get a minor for this device.\n");
904 usb_set_intfdata(intf, NULL);
905 goto error;
906 }
907
908 retval = device_create_file(&intf->dev, &dev_attr_compress_wheel);
909 if (retval)
910 goto error;
911 retval = device_create_file(&intf->dev, &dev_attr_enable);
912 if (retval)
913 goto error;
914 retval = device_create_file(&intf->dev, &dev_attr_offline);
915 if (retval)
916 goto error;
917
918 /* let the user know what node this device is now attached to */
919 dev_info(&intf->dev,
920 "Tranzport Device #%d now attached to major %d minor %d\n",
921 (intf->minor - USB_TRANZPORT_MINOR_BASE), USB_MAJOR,
922 intf->minor);
923
924 exit:
925 return retval;
926
927 error:
928 usb_tranzport_delete(dev);
929 return retval;
930 }
931
932 /**
933 * usb_tranzport_disconnect
934 *
935 * Called by the usb core when the device is removed from the system.
936 */
937 static void usb_tranzport_disconnect(struct usb_interface *intf)
938 {
939 struct usb_tranzport *dev;
940 int minor;
941 mutex_lock(&disconnect_mutex);
942 dev = usb_get_intfdata(intf);
943 usb_set_intfdata(intf, NULL);
944 mutex_lock(&dev->mtx);
945 minor = intf->minor;
946 /* give back our minor */
947 usb_deregister_dev(intf, &usb_tranzport_class);
948
949 /* if the device is not opened, then we clean up right now */
950 if (!dev->open_count) {
951 mutex_unlock(&dev->mtx);
952 usb_tranzport_delete(dev);
953 } else {
954 dev->intf = NULL;
955 mutex_unlock(&dev->mtx);
956 }
957
958 mutex_unlock(&disconnect_mutex);
959
960 dev_info(&intf->dev, "Tranzport Surface #%d now disconnected\n",
961 (minor - USB_TRANZPORT_MINOR_BASE));
962 }
963
964 /* usb specific object needed to register this driver with the usb subsystem */
965 static struct usb_driver usb_tranzport_driver = {
966 .name = "tranzport",
967 .probe = usb_tranzport_probe,
968 .disconnect = usb_tranzport_disconnect,
969 .id_table = usb_tranzport_table,
970 };
971
972 module_usb_driver(usb_tranzport_driver);
973