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/alphatrack.c

  1 /*
  2  * Frontier Designs Alphatrack 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 /*
 28  * Note: this currently uses a dumb ringbuffer for reads and writes.
 29  * A more optimal driver would cache and kill off outstanding urbs that are
 30  * now invalid, and ignore ones that already were in the queue but valid
 31  * as we only have 30 commands for the alphatrack. In particular this is
 32  * key for getting lights to flash in time as otherwise many commands
 33  * can be buffered up before the light change makes it to the interface.
 34  */
 35 
 36 #include <linux/kernel.h>
 37 #include <linux/errno.h>
 38 #include <linux/slab.h>
 39 #include <linux/module.h>
 40 #include <linux/kobject.h>
 41 #include <linux/mutex.h>
 42 
 43 #include <linux/uaccess.h>
 44 #include <linux/input.h>
 45 #include <linux/usb.h>
 46 #include <linux/poll.h>
 47 
 48 #include "alphatrack.h"
 49 
 50 #define VENDOR_ID       0x165b
 51 #define PRODUCT_ID      0xfad1
 52 
 53 #ifdef CONFIG_USB_DYNAMIC_MINORS
 54 #define USB_ALPHATRACK_MINOR_BASE       0
 55 #else
 56 /* FIXME 176 - is another driver's minor - apply for that */
 57 #define USB_ALPHATRACK_MINOR_BASE       176
 58 #endif
 59 
 60 /* table of devices that work with this driver */
 61 static const struct usb_device_id usb_alphatrack_table[] = {
 62         {USB_DEVICE(VENDOR_ID, PRODUCT_ID)},
 63         {}                      /* Terminating entry */
 64 };
 65 
 66 MODULE_DEVICE_TABLE(usb, usb_alphatrack_table);
 67 MODULE_VERSION("0.41");
 68 MODULE_AUTHOR("Mike Taht <m@taht.net>");
 69 MODULE_DESCRIPTION("Alphatrack USB Driver");
 70 MODULE_LICENSE("GPL");
 71 MODULE_SUPPORTED_DEVICE("Frontier Designs Alphatrack Control Surface");
 72 
 73 /* These aren't done yet */
 74 
 75 #define SUPPRESS_EXTRA_ONLINE_EVENTS 0
 76 #define BUFFERED_WRITES 0
 77 #define SUPPRESS_EXTRA_OFFLINE_EVENTS 0
 78 #define COMPRESS_FADER_EVENTS 0
 79 
 80 #define BUFFERED_READS 1
 81 #define RING_BUFFER_SIZE 512
 82 #define WRITE_BUFFER_SIZE 34
 83 #define ALPHATRACK_USB_TIMEOUT 10
 84 #define OUTPUT_CMD_SIZE 8
 85 #define INPUT_CMD_SIZE 12
 86 #define ALPHATRACK_DEBUG 0
 87 
 88 static int debug = ALPHATRACK_DEBUG;
 89 
 90 /* Use our own dbg macro */
 91 #define dbg_info(dev, format, arg...) do \
 92         { if (debug) dev_info(dev , format , ## arg); } while (0)
 93 
 94 #define alphatrack_ocmd_info(dev, cmd, format, arg...)
 95 
 96 #define alphatrack_icmd_info(dev, cmd, format, arg...)
 97 
 98 /* Module parameters */
 99 
100 module_param(debug, int, S_IRUGO | S_IWUSR);
101 MODULE_PARM_DESC(debug, "Debug enabled or not");
102 
103 /*
104  * All interrupt in transfers are collected in a ring buffer to
105  * avoid racing conditions and get better performance of the driver.
106  */
107 
108 static int ring_buffer_size = RING_BUFFER_SIZE;
109 
110 module_param(ring_buffer_size, int, S_IRUGO);
111 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size");
112 
113 /* The write_buffer can one day contain more than one interrupt out transfer.*/
114 
115 static int write_buffer_size = WRITE_BUFFER_SIZE;
116 module_param(write_buffer_size, int, S_IRUGO);
117 MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
118 
119 /*
120  * Increase the interval for debugging purposes.
121  * or set to 1 to use the standard interval from the endpoint descriptors.
122  */
123 
124 static int min_interrupt_in_interval = ALPHATRACK_USB_TIMEOUT;
125 module_param(min_interrupt_in_interval, int, 0);
126 MODULE_PARM_DESC(min_interrupt_in_interval,
127                  "Minimum interrupt in interval in ms");
128 
129 static int min_interrupt_out_interval = ALPHATRACK_USB_TIMEOUT;
130 module_param(min_interrupt_out_interval, int, 0);
131 MODULE_PARM_DESC(min_interrupt_out_interval,
132                  "Minimum interrupt out interval in ms");
133 
134 /* Structure to hold all of our device specific stuff */
135 
136 struct usb_alphatrack {
137         struct mutex mtx;       /* locks this structure */
138         struct usb_interface *intf;     /* save off the usb interface pointer */
139         int open_count;         /* number of times this port has been opened */
140 
141         /* make gcc happy */
142         struct alphatrack_icmd (*ring_buffer)[RING_BUFFER_SIZE];
143         struct alphatrack_ocmd (*write_buffer)[WRITE_BUFFER_SIZE];
144         unsigned int ring_head;
145         unsigned int ring_tail;
146 
147         wait_queue_head_t read_wait;
148         wait_queue_head_t write_wait;
149 
150         unsigned char *interrupt_in_buffer;
151         unsigned char *oldi_buffer;
152         struct usb_endpoint_descriptor *interrupt_in_endpoint;
153         struct urb *interrupt_in_urb;
154         int interrupt_in_interval;
155         size_t interrupt_in_endpoint_size;
156         int interrupt_in_running;
157         int interrupt_in_done;
158 
159         char *interrupt_out_buffer;
160         struct usb_endpoint_descriptor *interrupt_out_endpoint;
161         struct urb *interrupt_out_urb;
162         int interrupt_out_interval;
163         size_t interrupt_out_endpoint_size;
164         int interrupt_out_busy;
165 
166         atomic_t writes_pending;
167         int event;              /* alternate interface to events */
168         int fader;              /* 10 bits */
169         int lights;             /* 23 bits */
170         unsigned char dump_state;       /* 0 if disabled 1 if enabled */
171         unsigned char enable;   /* 0 if disabled 1 if enabled */
172         unsigned char offline;  /* if the device is out of range or asleep */
173         unsigned char verbose;  /* be verbose in error reporting */
174         unsigned char last_cmd[OUTPUT_CMD_SIZE];
175         unsigned char screen[32];
176 };
177 
178 /* prevent races between open() and disconnect() */
179 static DEFINE_MUTEX(disconnect_mutex);
180 
181 /* forward declaration */
182 
183 static struct usb_driver usb_alphatrack_driver;
184 
185 /**
186  *      usb_alphatrack_abort_transfers
187  *      aborts transfers and frees associated data structures
188  */
189 static void usb_alphatrack_abort_transfers(struct usb_alphatrack *dev)
190 {
191         /* shutdown transfer */
192         if (dev->interrupt_in_running) {
193                 dev->interrupt_in_running = 0;
194                 if (dev->intf)
195                         usb_kill_urb(dev->interrupt_in_urb);
196         }
197         if (dev->interrupt_out_busy)
198                 if (dev->intf)
199                         usb_kill_urb(dev->interrupt_out_urb);
200 }
201 
202 /** usb_alphatrack_delete */
203 static void usb_alphatrack_delete(struct usb_alphatrack *dev)
204 {
205         usb_alphatrack_abort_transfers(dev);
206         usb_free_urb(dev->interrupt_in_urb);
207         usb_free_urb(dev->interrupt_out_urb);
208         kfree(dev->ring_buffer);
209         kfree(dev->interrupt_in_buffer);
210         kfree(dev->interrupt_out_buffer);
211         kfree(dev->oldi_buffer);
212         kfree(dev->write_buffer);
213         kfree(dev);
214 }
215 
216 /** usb_alphatrack_interrupt_in_callback */
217 
218 static void usb_alphatrack_interrupt_in_callback(struct urb *urb)
219 {
220         struct usb_alphatrack *dev = urb->context;
221         unsigned int next_ring_head;
222         int retval = -1;
223 
224         if (urb->status) {
225                 if (urb->status == -ENOENT ||
226                     urb->status == -ECONNRESET || urb->status == -ESHUTDOWN) {
227                         goto exit;
228                 } else {
229                         dbg_info(&dev->intf->dev,
230                                  "%s: nonzero status received: %d\n", __func__,
231                                  urb->status);
232                         goto resubmit;  /* maybe we can recover */
233                 }
234         }
235 
236         if (urb->actual_length != INPUT_CMD_SIZE) {
237                 dev_warn(&dev->intf->dev,
238                          "Urb length was %d bytes!! Do something intelligent\n",
239                          urb->actual_length);
240         } else {
241                 alphatrack_ocmd_info(&dev->intf->dev,
242                                      &(*dev->ring_buffer)[dev->ring_tail].cmd,
243                                      "%s", "bla");
244                 if (memcmp
245                     (dev->interrupt_in_buffer, dev->oldi_buffer,
246                      INPUT_CMD_SIZE) == 0) {
247                         goto resubmit;
248                 }
249                 memcpy(dev->oldi_buffer, dev->interrupt_in_buffer,
250                        INPUT_CMD_SIZE);
251 
252 #if SUPPRESS_EXTRA_OFFLINE_EVENTS
253                 if (dev->offline == 2 && dev->interrupt_in_buffer[1] == 0xff)
254                         goto resubmit;
255                 if (dev->offline == 1 && dev->interrupt_in_buffer[1] == 0xff) {
256                         dev->offline = 2;
257                         goto resubmit;
258                 }
259 /* Always pass one offline event up the stack */
260                 if (dev->offline > 0 && dev->interrupt_in_buffer[1] != 0xff)
261                         dev->offline = 0;
262                 if (dev->offline == 0 && dev->interrupt_in_buffer[1] == 0xff)
263                         dev->offline = 1;
264 #endif
265                 dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n",
266                          __func__, dev->ring_head, dev->ring_tail);
267                 next_ring_head = (dev->ring_head + 1) % ring_buffer_size;
268 
269                 if (next_ring_head != dev->ring_tail) {
270                         memcpy(&((*dev->ring_buffer)[dev->ring_head]),
271                                dev->interrupt_in_buffer, urb->actual_length);
272                         dev->ring_head = next_ring_head;
273                         retval = 0;
274                         memset(dev->interrupt_in_buffer, 0, urb->actual_length);
275                 } else {
276                         dev_warn(&dev->intf->dev,
277                                  "Ring buffer overflow, %d bytes dropped\n",
278                                  urb->actual_length);
279                         memset(dev->interrupt_in_buffer, 0, urb->actual_length);
280                 }
281         }
282 
283 resubmit:
284         /* resubmit if we're still running */
285         if (dev->interrupt_in_running && dev->intf) {
286                 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
287                 if (retval)
288                         dev_err(&dev->intf->dev,
289                                 "usb_submit_urb failed (%d)\n", retval);
290         }
291 
292 exit:
293         dev->interrupt_in_done = 1;
294         wake_up_interruptible(&dev->read_wait);
295 }
296 
297 /** usb_alphatrack_interrupt_out_callback */
298 static void usb_alphatrack_interrupt_out_callback(struct urb *urb)
299 {
300         struct usb_alphatrack *dev = urb->context;
301 
302         /* sync/async unlink faults aren't errors */
303         if (urb->status && !(urb->status == -ENOENT ||
304                              urb->status == -ECONNRESET ||
305                              urb->status == -ESHUTDOWN))
306                 dbg_info(&dev->intf->dev,
307                          "%s - nonzero write interrupt status received: %d\n",
308                          __func__, urb->status);
309         atomic_dec(&dev->writes_pending);
310         dev->interrupt_out_busy = 0;
311         wake_up_interruptible(&dev->write_wait);
312 }
313 
314 /** usb_alphatrack_open */
315 static int usb_alphatrack_open(struct inode *inode, struct file *file)
316 {
317         struct usb_alphatrack *dev;
318         int subminor;
319         int retval = 0;
320         struct usb_interface *interface;
321 
322         nonseekable_open(inode, file);
323         subminor = iminor(inode);
324 
325         mutex_lock(&disconnect_mutex);
326 
327         interface = usb_find_interface(&usb_alphatrack_driver, subminor);
328 
329         if (!interface) {
330                 pr_err("%s - error, can't find device for minor %d\n",
331                        __func__, subminor);
332                 retval = -ENODEV;
333                 goto unlock_disconnect_exit;
334         }
335 
336         dev = usb_get_intfdata(interface);
337 
338         if (!dev) {
339                 retval = -ENODEV;
340                 goto unlock_disconnect_exit;
341         }
342 
343         /* lock this device */
344         if (mutex_lock_interruptible(&dev->mtx)) {
345                 retval = -ERESTARTSYS;
346                 goto unlock_disconnect_exit;
347         }
348 
349         /* allow opening only once */
350         if (dev->open_count) {
351                 retval = -EBUSY;
352                 goto unlock_exit;
353         }
354         dev->open_count = 1;
355 
356         /* initialize in direction */
357         dev->ring_head = 0;
358         dev->ring_tail = 0;
359         usb_fill_int_urb(dev->interrupt_in_urb,
360                          interface_to_usbdev(interface),
361                          usb_rcvintpipe(interface_to_usbdev(interface),
362                                         dev->interrupt_in_endpoint->
363                                         bEndpointAddress),
364                          dev->interrupt_in_buffer,
365                          dev->interrupt_in_endpoint_size,
366                          usb_alphatrack_interrupt_in_callback, dev,
367                          dev->interrupt_in_interval);
368 
369         dev->interrupt_in_running = 1;
370         dev->interrupt_in_done = 0;
371         dev->enable = 1;
372         dev->offline = 0;
373 
374         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
375         if (retval) {
376                 dev_err(&interface->dev,
377                         "Couldn't submit interrupt_in_urb %d\n", retval);
378                 dev->interrupt_in_running = 0;
379                 dev->open_count = 0;
380                 goto unlock_exit;
381         }
382 
383         /* save device in the file's private structure */
384         file->private_data = dev;
385 
386 unlock_exit:
387         mutex_unlock(&dev->mtx);
388 
389 unlock_disconnect_exit:
390         mutex_unlock(&disconnect_mutex);
391 
392         return retval;
393 }
394 
395 /** usb_alphatrack_release */
396 static int usb_alphatrack_release(struct inode *inode, struct file *file)
397 {
398         struct usb_alphatrack *dev;
399         int retval = 0;
400 
401         dev = file->private_data;
402 
403         if (dev == NULL) {
404                 retval = -ENODEV;
405                 goto exit;
406         }
407 
408         if (mutex_lock_interruptible(&dev->mtx)) {
409                 retval = -ERESTARTSYS;
410                 goto exit;
411         }
412 
413         if (dev->open_count != 1) {
414                 retval = -ENODEV;
415                 goto unlock_exit;
416         }
417 
418         if (dev->intf == NULL) {
419                 /* the device was unplugged before the file was released */
420                 mutex_unlock(&dev->mtx);
421                 /* unlock here as usb_alphatrack_delete frees dev */
422                 usb_alphatrack_delete(dev);
423                 retval = -ENODEV;
424                 goto exit;
425         }
426 
427         /* wait until write transfer is finished */
428         if (dev->interrupt_out_busy)
429                 wait_event_interruptible_timeout(dev->write_wait,
430                                                  !dev->interrupt_out_busy,
431                                                  2 * HZ);
432         usb_alphatrack_abort_transfers(dev);
433         dev->open_count = 0;
434 
435 unlock_exit:
436         mutex_unlock(&dev->mtx);
437 
438 exit:
439         return retval;
440 }
441 
442 /** usb_alphatrack_poll */
443 static unsigned int usb_alphatrack_poll(struct file *file, poll_table *wait)
444 {
445         struct usb_alphatrack *dev;
446         unsigned int mask = 0;
447 
448         dev = file->private_data;
449 
450         poll_wait(file, &dev->read_wait, wait);
451         poll_wait(file, &dev->write_wait, wait);
452 
453         if (dev->ring_head != dev->ring_tail)
454                 mask |= POLLIN | POLLRDNORM;
455         if (!dev->interrupt_out_busy)
456                 mask |= POLLOUT | POLLWRNORM;
457 
458         return mask;
459 }
460 
461 /** usb_alphatrack_read */
462 static ssize_t usb_alphatrack_read(struct file *file, char __user *buffer,
463                                    size_t count, loff_t *ppos)
464 {
465         struct usb_alphatrack *dev;
466         int retval = 0;
467 
468         int c = 0;
469 
470         dev = file->private_data;
471 
472         /* verify that we actually have some data to read */
473         if (count == 0)
474                 goto exit;
475 
476         /* lock this object */
477         if (mutex_lock_interruptible(&dev->mtx)) {
478                 retval = -ERESTARTSYS;
479                 goto exit;
480         }
481 
482         /* verify that the device wasn't unplugged */
483         if (dev->intf == NULL) {
484                 retval = -ENODEV;
485                 pr_err("%s: No device or device unplugged %d\n",
486                        __func__, retval);
487                 goto unlock_exit;
488         }
489 
490         while (dev->ring_head == dev->ring_tail) {
491                 if (file->f_flags & O_NONBLOCK) {
492                         retval = -EAGAIN;
493                         goto unlock_exit;
494                 }
495                 dev->interrupt_in_done = 0;
496                 retval =
497                     wait_event_interruptible(dev->read_wait,
498                                              dev->interrupt_in_done);
499                 if (retval < 0)
500                         goto unlock_exit;
501         }
502 
503         alphatrack_ocmd_info(&dev->intf->dev,
504                              &(*dev->ring_buffer)[dev->ring_tail].cmd, "%s",
505                              ": copying to userspace");
506 
507         c = 0;
508         while ((c < count) && (dev->ring_tail != dev->ring_head)) {
509                 if (copy_to_user
510                     (&buffer[c], &(*dev->ring_buffer)[dev->ring_tail],
511                      INPUT_CMD_SIZE)) {
512                         retval = -EFAULT;
513                         goto unlock_exit;
514                 }
515                 dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size;
516                 c += INPUT_CMD_SIZE;
517                 dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n",
518                          __func__, dev->ring_head, dev->ring_tail);
519         }
520         retval = c;
521 
522 unlock_exit:
523         /* unlock the device */
524         mutex_unlock(&dev->mtx);
525 
526 exit:
527         return retval;
528 }
529 
530 /** usb_alphatrack_write */
531 static ssize_t usb_alphatrack_write(struct file *file,
532                                     const char __user *buffer, size_t count,
533                                     loff_t *ppos)
534 {
535         struct usb_alphatrack *dev;
536         size_t bytes_to_write;
537         int retval = 0;
538 
539         dev = file->private_data;
540 
541         /* verify that we actually have some data to write */
542         if (count == 0)
543                 goto exit;
544 
545         /* lock this object */
546         if (mutex_lock_interruptible(&dev->mtx)) {
547                 retval = -ERESTARTSYS;
548                 goto exit;
549         }
550 
551         /* verify that the device wasn't unplugged */
552         if (dev->intf == NULL) {
553                 retval = -ENODEV;
554                 pr_err("%s: No device or device unplugged %d\n",
555                        __func__, retval);
556                 goto unlock_exit;
557         }
558 
559         /* wait until previous transfer is finished */
560         if (dev->interrupt_out_busy) {
561                 if (file->f_flags & O_NONBLOCK) {
562                         retval = -EAGAIN;
563                         goto unlock_exit;
564                 }
565                 retval =
566                     wait_event_interruptible(dev->write_wait,
567                                              !dev->interrupt_out_busy);
568                 if (retval < 0)
569                         goto unlock_exit;
570         }
571 
572         /* write the data into interrupt_out_buffer from userspace */
573         /* FIXME - if you write more than 12 bytes this breaks */
574         bytes_to_write =
575             min(count, write_buffer_size * dev->interrupt_out_endpoint_size);
576         if (bytes_to_write < count)
577                 dev_warn(&dev->intf->dev,
578                          "Write buffer overflow, %zd bytes dropped\n",
579                          count - bytes_to_write);
580 
581         dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n",
582                  __func__, count, bytes_to_write);
583 
584         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
585                 retval = -EFAULT;
586                 goto unlock_exit;
587         }
588 
589         if (dev->interrupt_out_endpoint == NULL) {
590                 dev_err(&dev->intf->dev, "Endpoint should not be null!\n");
591                 goto unlock_exit;
592         }
593 
594         /* send off the urb */
595         usb_fill_int_urb(dev->interrupt_out_urb,
596                          interface_to_usbdev(dev->intf),
597                          usb_sndintpipe(interface_to_usbdev(dev->intf),
598                                         dev->interrupt_out_endpoint->
599                                         bEndpointAddress),
600                          dev->interrupt_out_buffer, bytes_to_write,
601                          usb_alphatrack_interrupt_out_callback, dev,
602                          dev->interrupt_out_interval);
603         dev->interrupt_out_busy = 1;
604         atomic_inc(&dev->writes_pending);
605         wmb();
606 
607         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
608         if (retval) {
609                 dev->interrupt_out_busy = 0;
610                 dev_err(&dev->intf->dev,
611                         "Couldn't submit interrupt_out_urb %d\n", retval);
612                 atomic_dec(&dev->writes_pending);
613                 goto unlock_exit;
614         }
615         retval = bytes_to_write;
616 
617 unlock_exit:
618         /* unlock the device */
619         mutex_unlock(&dev->mtx);
620 
621 exit:
622         return retval;
623 }
624 
625 /* file operations needed when we register this driver */
626 static const struct file_operations usb_alphatrack_fops = {
627         .owner = THIS_MODULE,
628         .read = usb_alphatrack_read,
629         .write = usb_alphatrack_write,
630         .open = usb_alphatrack_open,
631         .release = usb_alphatrack_release,
632         .poll = usb_alphatrack_poll,
633         .llseek = no_llseek,
634 };
635 
636 /*
637  * usb class driver info in order to get a minor number from the usb core,
638  * and to have the device registered with the driver core
639  */
640 
641 static struct usb_class_driver usb_alphatrack_class = {
642         .name = "alphatrack%d",
643         .fops = &usb_alphatrack_fops,
644         .minor_base = USB_ALPHATRACK_MINOR_BASE,
645 };
646 
647 /**
648  *      usb_alphatrack_probe
649  *
650  *      Called by the usb core when a new device is connected that it thinks
651  *      this driver might be interested in.
652  */
653 static int usb_alphatrack_probe(struct usb_interface *intf,
654                                 const struct usb_device_id *id)
655 {
656         struct usb_device *udev = interface_to_usbdev(intf);
657         struct usb_alphatrack *dev = NULL;
658         struct usb_host_interface *iface_desc;
659         struct usb_endpoint_descriptor *endpoint;
660         int i;
661         int true_size;
662         int retval = -ENOMEM;
663 
664         /* allocate memory for our device state and initialize it */
665 
666         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
667         if (dev == NULL)
668                 goto exit;
669 
670         mutex_init(&dev->mtx);
671         dev->intf = intf;
672         init_waitqueue_head(&dev->read_wait);
673         init_waitqueue_head(&dev->write_wait);
674 
675         iface_desc = intf->cur_altsetting;
676 
677         /* set up the endpoint information */
678         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
679                 endpoint = &iface_desc->endpoint[i].desc;
680 
681                 if (usb_endpoint_is_int_in(endpoint))
682                         dev->interrupt_in_endpoint = endpoint;
683 
684                 if (usb_endpoint_is_int_out(endpoint))
685                         dev->interrupt_out_endpoint = endpoint;
686         }
687         if (dev->interrupt_in_endpoint == NULL) {
688                 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
689                 goto error;
690         }
691         if (dev->interrupt_out_endpoint == NULL)
692                 dev_warn(&intf->dev,
693                          "Interrupt out endpoint not found (using control endpoint instead)\n");
694 
695         dev->interrupt_in_endpoint_size =
696             le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
697 
698         if (dev->interrupt_in_endpoint_size != 64)
699                 dev_warn(&intf->dev, "Interrupt in endpoint size is not 64!\n");
700 
701         if (ring_buffer_size == 0)
702                 ring_buffer_size = RING_BUFFER_SIZE;
703 
704         true_size = min(ring_buffer_size, RING_BUFFER_SIZE);
705 
706         /*
707          * FIXME - there are more usb_alloc routines for dma correctness.
708          * Needed?
709          */
710         dev->ring_buffer = kmalloc_array(true_size,
711                                          sizeof(struct alphatrack_icmd),
712                                          GFP_KERNEL);
713         if (!dev->ring_buffer)
714                 goto error;
715 
716         dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size,
717                                            GFP_KERNEL);
718         if (!dev->interrupt_in_buffer)
719                 goto error;
720 
721         dev->oldi_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
722         if (!dev->oldi_buffer)
723                 goto error;
724 
725         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
726         if (!dev->interrupt_in_urb) {
727                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
728                 goto error;
729         }
730 
731         dev->interrupt_out_endpoint_size =
732             dev->interrupt_out_endpoint ? le16_to_cpu(dev->
733                                                       interrupt_out_endpoint->
734                                                       wMaxPacketSize) : udev->
735             descriptor.bMaxPacketSize0;
736 
737         if (dev->interrupt_out_endpoint_size != 64)
738                 dev_warn(&intf->dev,
739                          "Interrupt out endpoint size is not 64!)\n");
740 
741         if (write_buffer_size == 0)
742                 write_buffer_size = WRITE_BUFFER_SIZE;
743         true_size = min(write_buffer_size, WRITE_BUFFER_SIZE);
744 
745         dev->interrupt_out_buffer =
746                 kmalloc_array(true_size,
747                               dev->interrupt_out_endpoint_size,
748                               GFP_KERNEL);
749         if (!dev->interrupt_out_buffer)
750                 goto error;
751 
752         dev->write_buffer = kmalloc_array(true_size,
753                                           sizeof(struct alphatrack_ocmd),
754                                           GFP_KERNEL);
755         if (!dev->write_buffer)
756                 goto error;
757 
758         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
759         if (!dev->interrupt_out_urb) {
760                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
761                 goto error;
762         }
763         dev->interrupt_in_interval =
764             min_interrupt_in_interval >
765             dev->interrupt_in_endpoint->
766             bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->
767             bInterval;
768         if (dev->interrupt_out_endpoint)
769                 dev->interrupt_out_interval =
770                     min_interrupt_out_interval >
771                     dev->interrupt_out_endpoint->
772                     bInterval ? min_interrupt_out_interval : dev->
773                     interrupt_out_endpoint->bInterval;
774 
775         /* we can register the device now, as it is ready */
776         usb_set_intfdata(intf, dev);
777 
778         atomic_set(&dev->writes_pending, 0);
779         retval = usb_register_dev(intf, &usb_alphatrack_class);
780         if (retval) {
781                 /* something prevented us from registering this driver */
782                 dev_err(&intf->dev,
783                         "Not able to get a minor for this device.\n");
784                 usb_set_intfdata(intf, NULL);
785                 goto error;
786         }
787 
788         /* let the user know what node this device is now attached to */
789         dev_info(&intf->dev,
790                  "Alphatrack Device #%d now attached to major %d minor %d\n",
791                  (intf->minor - USB_ALPHATRACK_MINOR_BASE), USB_MAJOR,
792                  intf->minor);
793 
794 exit:
795         return retval;
796 
797 error:
798         usb_alphatrack_delete(dev);
799 
800         return retval;
801 }
802 
803 /**
804  *      usb_alphatrack_disconnect
805  *
806  *      Called by the usb core when the device is removed from the system.
807  */
808 static void usb_alphatrack_disconnect(struct usb_interface *intf)
809 {
810         struct usb_alphatrack *dev;
811         int minor;
812 
813         mutex_lock(&disconnect_mutex);
814 
815         dev = usb_get_intfdata(intf);
816         usb_set_intfdata(intf, NULL);
817 
818         mutex_lock(&dev->mtx);
819 
820         minor = intf->minor;
821 
822         /* give back our minor */
823         usb_deregister_dev(intf, &usb_alphatrack_class);
824 
825         /* if the device is not opened, then we clean up right now */
826         if (!dev->open_count) {
827                 mutex_unlock(&dev->mtx);
828                 usb_alphatrack_delete(dev);
829         } else {
830                 atomic_set(&dev->writes_pending, 0);
831                 dev->intf = NULL;
832                 mutex_unlock(&dev->mtx);
833         }
834 
835         mutex_unlock(&disconnect_mutex);
836 
837         dev_info(&intf->dev, "Alphatrack Surface #%d now disconnected\n",
838                  (minor - USB_ALPHATRACK_MINOR_BASE));
839 }
840 
841 /* usb specific object needed to register this driver with the usb subsystem */
842 static struct usb_driver usb_alphatrack_driver = {
843         .name = "alphatrack",
844         .probe = usb_alphatrack_probe,
845         .disconnect = usb_alphatrack_disconnect,
846         .id_table = usb_alphatrack_table,
847 };
848 
849 module_usb_driver(usb_alphatrack_driver);
850 

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