Version:  2.0.40 2.2.26 2.4.37 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15

Linux/drivers/staging/frontier/tranzport.c

  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/slab.h>
 38 #include <linux/module.h>
 39 #include <linux/mutex.h>
 40 
 41 #include <linux/uaccess.h>
 42 #include <linux/input.h>
 43 #include <linux/usb.h>
 44 #include <linux/poll.h>
 45 
 46 /* Define these values to match your devices */
 47 #define VENDOR_ID   0x165b
 48 #define PRODUCT_ID  0x8101
 49 
 50 #ifdef CONFIG_USB_DYNAMIC_MINORS
 51 #define USB_TRANZPORT_MINOR_BASE        0
 52 #else  /* FIXME 177- is the another driver's minor - apply for a minor soon */
 53 #define USB_TRANZPORT_MINOR_BASE        177
 54 #endif
 55 
 56 /* table of devices that work with this driver */
 57 static const struct usb_device_id usb_tranzport_table[] = {
 58         {USB_DEVICE(VENDOR_ID, PRODUCT_ID)},
 59         {}                      /* Terminating entry */
 60 };
 61 
 62 MODULE_DEVICE_TABLE(usb, usb_tranzport_table);
 63 MODULE_VERSION("0.35");
 64 MODULE_AUTHOR("Mike Taht <m@taht.net>");
 65 MODULE_DESCRIPTION("Tranzport USB Driver");
 66 MODULE_LICENSE("GPL");
 67 MODULE_SUPPORTED_DEVICE("Frontier Designs Tranzport Control Surface");
 68 
 69 #define SUPPRESS_EXTRA_OFFLINE_EVENTS 1
 70 #define COMPRESS_WHEEL_EVENTS 1
 71 #define BUFFERED_READS 1
 72 #define RING_BUFFER_SIZE 1000
 73 #define WRITE_BUFFER_SIZE 34
 74 #define TRANZPORT_USB_TIMEOUT 10
 75 #define TRANZPORT_DEBUG 0
 76 
 77 static int debug = TRANZPORT_DEBUG;
 78 
 79 /* Use our own dbg macro */
 80 #define dbg_info(dev, format, arg...) do                        \
 81         { if (debug) dev_info(dev , format , ## arg); } while (0)
 82 
 83 /* Module parameters */
 84 
 85 module_param(debug, int, S_IRUGO | S_IWUSR);
 86 MODULE_PARM_DESC(debug, "Debug enabled or not");
 87 
 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 /*
 99  * The write_buffer can one day contain more than one interrupt out transfer.
100  */
101 static int write_buffer_size = WRITE_BUFFER_SIZE;
102 module_param(write_buffer_size, int, S_IRUGO);
103 MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
104 
105 /*
106  * Increase the interval for debugging purposes.
107  * or set to 1 to use the standard interval from the endpoint descriptors.
108  */
109 
110 static int min_interrupt_in_interval = TRANZPORT_USB_TIMEOUT;
111 module_param(min_interrupt_in_interval, int, 0);
112 MODULE_PARM_DESC(min_interrupt_in_interval,
113                 "Minimum interrupt in interval in ms");
114 
115 static int min_interrupt_out_interval = TRANZPORT_USB_TIMEOUT;
116 module_param(min_interrupt_out_interval, int, 0);
117 MODULE_PARM_DESC(min_interrupt_out_interval,
118                 "Minimum interrupt out interval in ms");
119 
120 struct tranzport_cmd {
121         unsigned char cmd[8];
122 };
123 
124 /* Structure to hold all of our device specific stuff */
125 
126 struct usb_tranzport {
127         struct mutex mtx;       /* locks this structure */
128         struct usb_interface *intf;     /* save off the usb interface pointer */
129         int open_count;         /* number of times this port opened */
130         struct tranzport_cmd (*ring_buffer)[RING_BUFFER_SIZE];
131         unsigned int ring_head;
132         unsigned int ring_tail;
133         wait_queue_head_t read_wait;
134         wait_queue_head_t write_wait;
135         unsigned char *interrupt_in_buffer;
136         struct usb_endpoint_descriptor *interrupt_in_endpoint;
137         struct urb *interrupt_in_urb;
138         int interrupt_in_interval;
139         size_t interrupt_in_endpoint_size;
140         int interrupt_in_running;
141         int interrupt_in_done;
142         char *interrupt_out_buffer;
143         struct usb_endpoint_descriptor *interrupt_out_endpoint;
144         struct urb *interrupt_out_urb;
145         int interrupt_out_interval;
146         size_t interrupt_out_endpoint_size;
147         int interrupt_out_busy;
148 
149         /* Sysfs support */
150 
151         unsigned char enable;   /* 0 if disabled 1 if enabled */
152         unsigned char offline;  /* if the device is out of range or asleep */
153         unsigned char compress_wheel;   /* flag to compress wheel events */
154 };
155 
156 /* prevent races between open() and disconnect() */
157 static DEFINE_MUTEX(disconnect_mutex);
158 
159 static struct usb_driver usb_tranzport_driver;
160 
161 /**
162  *      usb_tranzport_abort_transfers
163  *      aborts transfers and frees associated data structures
164  */
165 static void usb_tranzport_abort_transfers(struct usb_tranzport *dev)
166 {
167         /* shutdown transfer */
168         if (dev->interrupt_in_running) {
169                 dev->interrupt_in_running = 0;
170                 if (dev->intf)
171                         usb_kill_urb(dev->interrupt_in_urb);
172         }
173         if (dev->interrupt_out_busy)
174                 if (dev->intf)
175                         usb_kill_urb(dev->interrupt_out_urb);
176 }
177 
178 #define show_int(value) \
179         static ssize_t value##_show(struct device *dev, \
180                               struct device_attribute *attr, char *buf) \
181         {       \
182                 struct usb_interface *intf = to_usb_interface(dev);     \
183                 struct usb_tranzport *t = usb_get_intfdata(intf);       \
184                 return sprintf(buf, "%d\n", t->value);  \
185         }       \
186         static DEVICE_ATTR_RO(value)
187 
188 #define show_set_int(value)     \
189         static ssize_t value##_show(struct device *dev, \
190                               struct device_attribute *attr, char *buf) \
191         {       \
192                 struct usb_interface *intf = to_usb_interface(dev);     \
193                 struct usb_tranzport *t = usb_get_intfdata(intf);       \
194                 return sprintf(buf, "%d\n", t->value);  \
195         }       \
196         static ssize_t value##_store(struct device *dev,        \
197                              struct device_attribute *attr,             \
198                              const char *buf, size_t count)             \
199         {       \
200                 struct usb_interface *intf = to_usb_interface(dev);     \
201                 struct usb_tranzport *t = usb_get_intfdata(intf);       \
202                 unsigned long temp;     \
203                 if (kstrtoul(buf, 10, &temp))   \
204                         return -EINVAL; \
205                 t->value = temp;        \
206                 return count;   \
207         }       \
208         static DEVICE_ATTR_RW(value)
209 
210 show_int(enable);
211 show_int(offline);
212 show_set_int(compress_wheel);
213 
214 /**
215  *      usb_tranzport_delete
216  */
217 static void usb_tranzport_delete(struct usb_tranzport *dev)
218 {
219         usb_tranzport_abort_transfers(dev);
220         if (dev->intf != NULL) {
221                 device_remove_file(&dev->intf->dev, &dev_attr_enable);
222                 device_remove_file(&dev->intf->dev, &dev_attr_offline);
223                 device_remove_file(&dev->intf->dev, &dev_attr_compress_wheel);
224         }
225 
226         /* free data structures */
227         usb_free_urb(dev->interrupt_in_urb);
228         usb_free_urb(dev->interrupt_out_urb);
229         kfree(dev->ring_buffer);
230         kfree(dev->interrupt_in_buffer);
231         kfree(dev->interrupt_out_buffer);
232         kfree(dev);
233 }
234 
235 /**
236  *      usb_tranzport_interrupt_in_callback
237  */
238 
239 static void usb_tranzport_interrupt_in_callback(struct urb *urb)
240 {
241         struct usb_tranzport *dev = urb->context;
242         unsigned int next_ring_head;
243         int retval = -1;
244 
245         if (urb->status) {
246                 if (urb->status == -ENOENT ||
247                         urb->status == -ECONNRESET ||
248                         urb->status == -ESHUTDOWN) {
249                         goto exit;
250                 } else {
251                         dbg_info(&dev->intf->dev,
252                                  "%s: nonzero status received: %d\n",
253                                  __func__, urb->status);
254                         goto resubmit;  /* maybe we can recover */
255                 }
256         }
257 
258         if (urb->actual_length != 8) {
259                 dev_warn(&dev->intf->dev,
260                         "Urb length was %d bytes!! 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  */
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  */
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  */
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  */
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 
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: %02x%02x%02x%02x%02x%02x%02x%02x\n",
545                  __func__,
546                  (*dev->ring_buffer)[dev->ring_tail].cmd[0],
547                  (*dev->ring_buffer)[dev->ring_tail].cmd[1],
548                  (*dev->ring_buffer)[dev->ring_tail].cmd[2],
549                  (*dev->ring_buffer)[dev->ring_tail].cmd[3],
550                  (*dev->ring_buffer)[dev->ring_tail].cmd[4],
551                  (*dev->ring_buffer)[dev->ring_tail].cmd[5],
552                  (*dev->ring_buffer)[dev->ring_tail].cmd[6],
553                  (*dev->ring_buffer)[dev->ring_tail].cmd[7]);
554 
555 #if BUFFERED_READS
556         c = 0;
557         while ((c < count) && (dev->ring_tail != dev->ring_head)) {
558 
559 #if COMPRESS_WHEEL_EVENTS
560                 next_tail = (dev->ring_tail+1) % ring_buffer_size;
561                 if (dev->compress_wheel)
562                         cancompress = 1;
563                 while (dev->ring_head != next_tail && cancompress == 1) {
564                         newwheel = (*dev->ring_buffer)[next_tail].cmd[6];
565                         oldwheel = (*dev->ring_buffer)[dev->ring_tail].cmd[6];
566                         /* if both are wheel events, and
567                          * no buttons have changes (FIXME, do I have to check?),
568                          * and we are the same sign, we can compress +- 7F
569                          */
570                         dbg_info(&dev->intf->dev,
571                                 "%s: trying to compress: %02x%02x%02x%02x%02x%02x%02x%02x\n",
572                                 __func__,
573                                 (*dev->ring_buffer)[dev->ring_tail].cmd[0],
574                                 (*dev->ring_buffer)[dev->ring_tail].cmd[1],
575                                 (*dev->ring_buffer)[dev->ring_tail].cmd[2],
576                                 (*dev->ring_buffer)[dev->ring_tail].cmd[3],
577                                 (*dev->ring_buffer)[dev->ring_tail].cmd[4],
578                                 (*dev->ring_buffer)[dev->ring_tail].cmd[5],
579                                 (*dev->ring_buffer)[dev->ring_tail].cmd[6],
580                                 (*dev->ring_buffer)[dev->ring_tail].cmd[7]);
581 
582                         if (((*dev->ring_buffer)[dev->ring_tail].cmd[6] != 0 &&
583                                 (*dev->ring_buffer)[next_tail].cmd[6] != 0) &&
584                                 ((newwheel > 0 && oldwheel > 0) ||
585                                         (newwheel < 0 && oldwheel < 0)) &&
586                                 ((*dev->ring_buffer)[dev->ring_tail].cmd[2] ==
587                                 (*dev->ring_buffer)[next_tail].cmd[2]) &&
588                                 ((*dev->ring_buffer)[dev->ring_tail].cmd[3] ==
589                                 (*dev->ring_buffer)[next_tail].cmd[3]) &&
590                                 ((*dev->ring_buffer)[dev->ring_tail].cmd[4] ==
591                                 (*dev->ring_buffer)[next_tail].cmd[4]) &&
592                                 ((*dev->ring_buffer)[dev->ring_tail].cmd[5] ==
593                                 (*dev->ring_buffer)[next_tail].cmd[5])) {
594                                 dbg_info(&dev->intf->dev,
595                                         "%s: should compress: "
596                                         "%02x%02x%02x%02x%02x%02x%02x%02x\n",
597                                         __func__,
598                                         (*dev->ring_buffer)[dev->ring_tail].
599                                         cmd[0],
600                                         (*dev->ring_buffer)[dev->ring_tail].
601                                         cmd[1],
602                                         (*dev->ring_buffer)[dev->ring_tail].
603                                         cmd[2],
604                                         (*dev->ring_buffer)[dev->ring_tail].
605                                         cmd[3],
606                                         (*dev->ring_buffer)[dev->ring_tail].
607                                         cmd[4],
608                                         (*dev->ring_buffer)[dev->ring_tail].
609                                         cmd[5],
610                                         (*dev->ring_buffer)[dev->ring_tail].
611                                         cmd[6],
612                                         (*dev->ring_buffer)[dev->ring_tail].
613                                         cmd[7]);
614                                 newwheel += oldwheel;
615                                 if (oldwheel > 0 && !(newwheel > 0)) {
616                                         newwheel = 0x7f;
617                                         cancompress = 0;
618                                 }
619                                 if (oldwheel < 0 && !(newwheel < 0)) {
620                                         newwheel = 0x80;
621                                         cancompress = 0;
622                                 }
623 
624                                 (*dev->ring_buffer)[next_tail].cmd[6] =
625                                         newwheel;
626                                 dev->ring_tail = next_tail;
627                                 next_tail =
628                                         (dev->ring_tail + 1) % ring_buffer_size;
629                         } else {
630                                 cancompress = 0;
631                         }
632                 }
633 #endif /* COMPRESS_WHEEL_EVENTS */
634                 if (copy_to_user(
635                                 &buffer[c],
636                                 &(*dev->ring_buffer)[dev->ring_tail], 8)) {
637                         retval = -EFAULT;
638                         goto unlock_exit;
639                 }
640                 dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size;
641                 c += 8;
642                 dbg_info(&dev->intf->dev,
643                          "%s: head, tail are %x, %x\n",
644                          __func__, dev->ring_head, dev->ring_tail);
645         }
646         retval = c;
647 
648 #else
649 /*  if (copy_to_user(buffer, &(*dev->ring_buffer)[dev->ring_tail], 8)) { */
650         retval = -EFAULT;
651         goto unlock_exit;
652 }
653 
654 dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size;
655 dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n",
656          __func__, dev->ring_head, dev->ring_tail);
657 
658 retval = 8;
659 #endif /* BUFFERED_READS */
660 
661 unlock_exit:
662 /* unlock the device */
663 mutex_unlock(&dev->mtx);
664 
665 exit:
666 return retval;
667 }
668 
669 /**
670  *      usb_tranzport_write
671  */
672 static ssize_t usb_tranzport_write(struct file *file,
673                                 const char __user *buffer, size_t count,
674                                 loff_t *ppos)
675 {
676         struct usb_tranzport *dev;
677         size_t bytes_to_write;
678         int retval = 0;
679 
680         dev = file->private_data;
681 
682         /* verify that we actually have some data to write */
683         if (count == 0)
684                 goto exit;
685 
686         /* lock this object */
687         if (mutex_lock_interruptible(&dev->mtx)) {
688                 retval = -ERESTARTSYS;
689                 goto exit;
690         }
691         /* verify that the device wasn't unplugged */
692         if (dev->intf == NULL) {
693                 retval = -ENODEV;
694                 pr_err("%s: No device or device unplugged %d\n",
695                        __func__, retval);
696                 goto unlock_exit;
697         }
698 
699         /* wait until previous transfer is finished */
700         if (dev->interrupt_out_busy) {
701                 if (file->f_flags & O_NONBLOCK) {
702                         retval = -EAGAIN;
703                         goto unlock_exit;
704                 }
705                 retval = wait_event_interruptible(dev->write_wait,
706                                                 !dev->interrupt_out_busy);
707                 if (retval < 0)
708                         goto unlock_exit;
709         }
710 
711         /* write the data into interrupt_out_buffer from userspace */
712         bytes_to_write = min(count,
713                         write_buffer_size *
714                         dev->interrupt_out_endpoint_size);
715         if (bytes_to_write < count)
716                 dev_warn(&dev->intf->dev,
717                         "Write buffer overflow, %zd bytes dropped\n",
718                         count - bytes_to_write);
719 
720         dbg_info(&dev->intf->dev,
721                 "%s: count = %zd, bytes_to_write = %zd\n", __func__,
722                 count, bytes_to_write);
723 
724         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
725                 retval = -EFAULT;
726                 goto unlock_exit;
727         }
728 
729         if (dev->interrupt_out_endpoint == NULL) {
730                 dev_err(&dev->intf->dev, "Endpoint should not be null!\n");
731                 goto unlock_exit;
732         }
733 
734         /* send off the urb */
735         usb_fill_int_urb(dev->interrupt_out_urb,
736                         interface_to_usbdev(dev->intf),
737                         usb_sndintpipe(interface_to_usbdev(dev->intf),
738                                 dev->interrupt_out_endpoint->
739                                 bEndpointAddress),
740                         dev->interrupt_out_buffer, bytes_to_write,
741                         usb_tranzport_interrupt_out_callback, dev,
742                         dev->interrupt_out_interval);
743 
744         dev->interrupt_out_busy = 1;
745         wmb();
746 
747         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
748         if (retval) {
749                 dev->interrupt_out_busy = 0;
750                 dev_err(&dev->intf->dev,
751                         "Couldn't submit interrupt_out_urb %d\n", retval);
752                 goto unlock_exit;
753         }
754         retval = bytes_to_write;
755 
756 unlock_exit:
757         /* unlock the device */
758         mutex_unlock(&dev->mtx);
759 
760 exit:
761         return retval;
762 }
763 
764 /* file operations needed when we register this driver */
765 static const struct file_operations usb_tranzport_fops = {
766         .owner = THIS_MODULE,
767         .read = usb_tranzport_read,
768         .write = usb_tranzport_write,
769         .open = usb_tranzport_open,
770         .release = usb_tranzport_release,
771         .poll = usb_tranzport_poll,
772         .llseek = no_llseek,
773 };
774 
775 /*
776  * usb class driver info in order to get a minor number from the usb core,
777  * and to have the device registered with the driver core
778  */
779 static struct usb_class_driver usb_tranzport_class = {
780         .name = "tranzport%d",
781         .fops = &usb_tranzport_fops,
782         .minor_base = USB_TRANZPORT_MINOR_BASE,
783 };
784 
785 /**
786  *      usb_tranzport_probe
787  *
788  *      Called by the usb core when a new device is connected that it thinks
789  *      this driver might be interested in.
790  */
791 static int usb_tranzport_probe(struct usb_interface *intf,
792                                const struct usb_device_id *id) {
793         struct usb_device *udev = interface_to_usbdev(intf);
794         struct usb_tranzport *dev = NULL;
795         struct usb_host_interface *iface_desc;
796         struct usb_endpoint_descriptor *endpoint;
797         int i;
798         int true_size;
799         int retval = -ENOMEM;
800 
801         /* allocate memory for our device state and initialize it */
802 
803          dev = kzalloc(sizeof(*dev), GFP_KERNEL);
804         if (dev == NULL)
805                 goto exit;
806 
807         mutex_init(&dev->mtx);
808         dev->intf = intf;
809         init_waitqueue_head(&dev->read_wait);
810         init_waitqueue_head(&dev->write_wait);
811 
812         iface_desc = intf->cur_altsetting;
813 
814         /* set up the endpoint information */
815         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
816                 endpoint = &iface_desc->endpoint[i].desc;
817 
818                 if (usb_endpoint_is_int_in(endpoint))
819                         dev->interrupt_in_endpoint = endpoint;
820 
821                 if (usb_endpoint_is_int_out(endpoint))
822                         dev->interrupt_out_endpoint = endpoint;
823         }
824         if (dev->interrupt_in_endpoint == NULL) {
825                 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
826                 goto error;
827         }
828         if (dev->interrupt_out_endpoint == NULL)
829                 dev_warn(&intf->dev,
830                         "Interrupt out endpoint not found (using control endpoint instead)\n");
831 
832         dev->interrupt_in_endpoint_size =
833             le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
834 
835         if (dev->interrupt_in_endpoint_size != 8)
836                 dev_warn(&intf->dev, "Interrupt in endpoint size is not 8!\n");
837 
838         if (ring_buffer_size == 0)
839                 ring_buffer_size = RING_BUFFER_SIZE;
840         true_size = min(ring_buffer_size, RING_BUFFER_SIZE);
841 
842         /*
843          * FIXME - there are more usb_alloc routines for dma correctness.
844          * Needed?
845          */
846 
847         dev->ring_buffer =
848             kmalloc((true_size * sizeof(struct tranzport_cmd)) + 8, GFP_KERNEL);
849         if (!dev->ring_buffer)
850                 goto error;
851 
852         dev->interrupt_in_buffer =
853             kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
854         if (!dev->interrupt_in_buffer)
855                 goto error;
856 
857         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
858         if (!dev->interrupt_in_urb) {
859                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
860                 goto error;
861         }
862         dev->interrupt_out_endpoint_size =
863             dev->interrupt_out_endpoint ?
864             le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize) :
865             udev->descriptor.bMaxPacketSize0;
866 
867         if (dev->interrupt_out_endpoint_size != 8)
868                 dev_warn(&intf->dev,
869                          "Interrupt out endpoint size is not 8!)\n");
870 
871         dev->interrupt_out_buffer =
872                 kmalloc_array(write_buffer_size,
873                               dev->interrupt_out_endpoint_size, GFP_KERNEL);
874         if (!dev->interrupt_out_buffer)
875                 goto error;
876 
877         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
878         if (!dev->interrupt_out_urb) {
879                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
880                 goto error;
881         }
882         dev->interrupt_in_interval =
883             min_interrupt_in_interval >
884             dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval
885             : dev->interrupt_in_endpoint->bInterval;
886 
887         if (dev->interrupt_out_endpoint) {
888                 dev->interrupt_out_interval =
889                     min_interrupt_out_interval >
890                     dev->interrupt_out_endpoint->bInterval ?
891                     min_interrupt_out_interval :
892                     dev->interrupt_out_endpoint->bInterval;
893         }
894 
895         /* we can register the device now, as it is ready */
896         usb_set_intfdata(intf, dev);
897 
898         retval = usb_register_dev(intf, &usb_tranzport_class);
899         if (retval) {
900                 /* something prevented us from registering this driver */
901                 dev_err(&intf->dev,
902                         "Not able to get a minor for this device.\n");
903                 usb_set_intfdata(intf, NULL);
904                 goto error;
905         }
906 
907         retval = device_create_file(&intf->dev, &dev_attr_compress_wheel);
908         if (retval)
909                 goto error;
910         retval = device_create_file(&intf->dev, &dev_attr_enable);
911         if (retval)
912                 goto error;
913         retval = device_create_file(&intf->dev, &dev_attr_offline);
914         if (retval)
915                 goto error;
916 
917         /* let the user know what node this device is now attached to */
918         dev_info(&intf->dev,
919                 "Tranzport Device #%d now attached to major %d minor %d\n",
920                 (intf->minor - USB_TRANZPORT_MINOR_BASE), USB_MAJOR,
921                 intf->minor);
922 
923 exit:
924         return retval;
925 
926 error:
927         usb_tranzport_delete(dev);
928         return retval;
929 }
930 
931 /**
932  *      usb_tranzport_disconnect
933  *
934  *      Called by the usb core when the device is removed from the system.
935  */
936 static void usb_tranzport_disconnect(struct usb_interface *intf)
937 {
938         struct usb_tranzport *dev;
939         int minor;
940         mutex_lock(&disconnect_mutex);
941         dev = usb_get_intfdata(intf);
942         usb_set_intfdata(intf, NULL);
943         mutex_lock(&dev->mtx);
944         minor = intf->minor;
945         /* give back our minor */
946         usb_deregister_dev(intf, &usb_tranzport_class);
947 
948         /* if the device is not opened, then we clean up right now */
949         if (!dev->open_count) {
950                 mutex_unlock(&dev->mtx);
951                 usb_tranzport_delete(dev);
952         } else {
953                 dev->intf = NULL;
954                 mutex_unlock(&dev->mtx);
955         }
956 
957         mutex_unlock(&disconnect_mutex);
958 
959         dev_info(&intf->dev, "Tranzport Surface #%d now disconnected\n",
960                 (minor - USB_TRANZPORT_MINOR_BASE));
961 }
962 
963 /* usb specific object needed to register this driver with the usb subsystem */
964 static struct usb_driver usb_tranzport_driver = {
965         .name = "tranzport",
966         .probe = usb_tranzport_probe,
967         .disconnect = usb_tranzport_disconnect,
968         .id_table = usb_tranzport_table,
969 };
970 
971 module_usb_driver(usb_tranzport_driver);
972 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us