Merge git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog
[linux-2.6] / drivers / usb / misc / ldusb.c
1 /**
2  * Generic USB driver for report based interrupt in/out devices
3  * like LD Didactic's USB devices. LD Didactic's USB devices are
4  * HID devices which do not use HID report definitons (they use
5  * raw interrupt in and our reports only for communication).
6  *
7  * This driver uses a ring buffer for time critical reading of
8  * interrupt in reports and provides read and write methods for
9  * raw interrupt reports (similar to the Windows HID driver).
10  * Devices based on the book USB COMPLETE by Jan Axelson may need
11  * such a compatibility to the Windows HID driver.
12  *
13  * Copyright (C) 2005 Michael Hund <mhund@ld-didactic.de>
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; either version 2 of
18  *      the License, or (at your option) any later version.
19  *
20  * Derived from Lego USB Tower driver
21  * Copyright (C) 2003 David Glance <advidgsf@sourceforge.net>
22  *               2001-2004 Juergen Stuber <starblue@users.sourceforge.net>
23  *
24  * V0.1  (mh) Initial version
25  * V0.11 (mh) Added raw support for HID 1.0 devices (no interrupt out endpoint)
26  * V0.12 (mh) Added kmalloc check for string buffer
27  * V0.13 (mh) Added support for LD X-Ray and Machine Test System
28  */
29
30 #include <linux/kernel.h>
31 #include <linux/errno.h>
32 #include <linux/init.h>
33 #include <linux/slab.h>
34 #include <linux/module.h>
35 #include <linux/mutex.h>
36
37 #include <asm/uaccess.h>
38 #include <linux/input.h>
39 #include <linux/usb.h>
40 #include <linux/poll.h>
41
42 /* Define these values to match your devices */
43 #define USB_VENDOR_ID_LD                0x0f11  /* USB Vendor ID of LD Didactic GmbH */
44 #define USB_DEVICE_ID_LD_CASSY          0x1000  /* USB Product ID of CASSY-S */
45 #define USB_DEVICE_ID_LD_POCKETCASSY    0x1010  /* USB Product ID of Pocket-CASSY */
46 #define USB_DEVICE_ID_LD_MOBILECASSY    0x1020  /* USB Product ID of Mobile-CASSY */
47 #define USB_DEVICE_ID_LD_JWM            0x1080  /* USB Product ID of Joule and Wattmeter */
48 #define USB_DEVICE_ID_LD_DMMP           0x1081  /* USB Product ID of Digital Multimeter P (reserved) */
49 #define USB_DEVICE_ID_LD_UMIP           0x1090  /* USB Product ID of UMI P */
50 #define USB_DEVICE_ID_LD_XRAY1          0x1100  /* USB Product ID of X-Ray Apparatus */
51 #define USB_DEVICE_ID_LD_XRAY2          0x1101  /* USB Product ID of X-Ray Apparatus */
52 #define USB_DEVICE_ID_LD_VIDEOCOM       0x1200  /* USB Product ID of VideoCom */
53 #define USB_DEVICE_ID_LD_COM3LAB        0x2000  /* USB Product ID of COM3LAB */
54 #define USB_DEVICE_ID_LD_TELEPORT       0x2010  /* USB Product ID of Terminal Adapter */
55 #define USB_DEVICE_ID_LD_NETWORKANALYSER 0x2020 /* USB Product ID of Network Analyser */
56 #define USB_DEVICE_ID_LD_POWERCONTROL   0x2030  /* USB Product ID of Converter Control Unit */
57 #define USB_DEVICE_ID_LD_MACHINETEST    0x2040  /* USB Product ID of Machine Test System */
58
59 #define USB_VENDOR_ID_VERNIER           0x08f7
60 #define USB_DEVICE_ID_VERNIER_LABPRO    0x0001
61 #define USB_DEVICE_ID_VERNIER_GOTEMP    0x0002
62 #define USB_DEVICE_ID_VERNIER_SKIP      0x0003
63 #define USB_DEVICE_ID_VERNIER_CYCLOPS   0x0004
64
65 #define USB_VENDOR_ID_MICROCHIP         0x04d8
66 #define USB_DEVICE_ID_PICDEM            0x000c
67
68 #ifdef CONFIG_USB_DYNAMIC_MINORS
69 #define USB_LD_MINOR_BASE       0
70 #else
71 #define USB_LD_MINOR_BASE       176
72 #endif
73
74 /* table of devices that work with this driver */
75 static struct usb_device_id ld_usb_table [] = {
76         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY) },
77         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY) },
78         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY) },
79         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_JWM) },
80         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_DMMP) },
81         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIP) },
82         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY1) },
83         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY2) },
84         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_VIDEOCOM) },
85         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_COM3LAB) },
86         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_TELEPORT) },
87         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_NETWORKANALYSER) },
88         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERCONTROL) },
89         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETEST) },
90         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_LABPRO) },
91         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_GOTEMP) },
92         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_SKIP) },
93         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_CYCLOPS) },
94         { USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_PICDEM) },
95         { }                                     /* Terminating entry */
96 };
97 MODULE_DEVICE_TABLE(usb, ld_usb_table);
98 MODULE_VERSION("V0.13");
99 MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>");
100 MODULE_DESCRIPTION("LD USB Driver");
101 MODULE_LICENSE("GPL");
102 MODULE_SUPPORTED_DEVICE("LD USB Devices");
103
104 #ifdef CONFIG_USB_DEBUG
105         static int debug = 1;
106 #else
107         static int debug = 0;
108 #endif
109
110 /* Use our own dbg macro */
111 #define dbg_info(dev, format, arg...) do { if (debug) dev_info(dev , format , ## arg); } while (0)
112
113 /* Module parameters */
114 module_param(debug, int, S_IRUGO | S_IWUSR);
115 MODULE_PARM_DESC(debug, "Debug enabled or not");
116
117 /* All interrupt in transfers are collected in a ring buffer to
118  * avoid racing conditions and get better performance of the driver.
119  */
120 static int ring_buffer_size = 128;
121 module_param(ring_buffer_size, int, 0);
122 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
123
124 /* The write_buffer can contain more than one interrupt out transfer.
125  */
126 static int write_buffer_size = 10;
127 module_param(write_buffer_size, int, 0);
128 MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports");
129
130 /* As of kernel version 2.6.4 ehci-hcd uses an
131  * "only one interrupt transfer per frame" shortcut
132  * to simplify the scheduling of periodic transfers.
133  * This conflicts with our standard 1ms intervals for in and out URBs.
134  * We use default intervals of 2ms for in and 2ms for out transfers,
135  * which should be fast enough.
136  * Increase the interval to allow more devices that do interrupt transfers,
137  * or set to 1 to use the standard interval from the endpoint descriptors.
138  */
139 static int min_interrupt_in_interval = 2;
140 module_param(min_interrupt_in_interval, int, 0);
141 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
142
143 static int min_interrupt_out_interval = 2;
144 module_param(min_interrupt_out_interval, int, 0);
145 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
146
147 /* Structure to hold all of our device specific stuff */
148 struct ld_usb {
149         struct semaphore        sem;            /* locks this structure */
150         struct usb_interface*   intf;           /* save off the usb interface pointer */
151
152         int                     open_count;     /* number of times this port has been opened */
153
154         char*                   ring_buffer;
155         unsigned int            ring_head;
156         unsigned int            ring_tail;
157
158         wait_queue_head_t       read_wait;
159         wait_queue_head_t       write_wait;
160
161         char*                   interrupt_in_buffer;
162         struct usb_endpoint_descriptor* interrupt_in_endpoint;
163         struct urb*             interrupt_in_urb;
164         int                     interrupt_in_interval;
165         size_t                  interrupt_in_endpoint_size;
166         int                     interrupt_in_running;
167         int                     interrupt_in_done;
168         int                     buffer_overflow;
169         spinlock_t              rbsl;
170
171         char*                   interrupt_out_buffer;
172         struct usb_endpoint_descriptor* interrupt_out_endpoint;
173         struct urb*             interrupt_out_urb;
174         int                     interrupt_out_interval;
175         size_t                  interrupt_out_endpoint_size;
176         int                     interrupt_out_busy;
177 };
178
179 static struct usb_driver ld_usb_driver;
180
181 /**
182  *      ld_usb_abort_transfers
183  *      aborts transfers and frees associated data structures
184  */
185 static void ld_usb_abort_transfers(struct ld_usb *dev)
186 {
187         /* shutdown transfer */
188         if (dev->interrupt_in_running) {
189                 dev->interrupt_in_running = 0;
190                 if (dev->intf)
191                         usb_kill_urb(dev->interrupt_in_urb);
192         }
193         if (dev->interrupt_out_busy)
194                 if (dev->intf)
195                         usb_kill_urb(dev->interrupt_out_urb);
196 }
197
198 /**
199  *      ld_usb_delete
200  */
201 static void ld_usb_delete(struct ld_usb *dev)
202 {
203         ld_usb_abort_transfers(dev);
204
205         /* free data structures */
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);
212 }
213
214 /**
215  *      ld_usb_interrupt_in_callback
216  */
217 static void ld_usb_interrupt_in_callback(struct urb *urb)
218 {
219         struct ld_usb *dev = urb->context;
220         size_t *actual_buffer;
221         unsigned int next_ring_head;
222         int status = urb->status;
223         int retval;
224
225         if (status) {
226                 if (status == -ENOENT ||
227                     status == -ECONNRESET ||
228                     status == -ESHUTDOWN) {
229                         goto exit;
230                 } else {
231                         dbg_info(&dev->intf->dev, "%s: nonzero status received: %d\n",
232                                  __FUNCTION__, status);
233                         spin_lock(&dev->rbsl);
234                         goto resubmit; /* maybe we can recover */
235                 }
236         }
237
238         spin_lock(&dev->rbsl);
239         if (urb->actual_length > 0) {
240                 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
241                 if (next_ring_head != dev->ring_tail) {
242                         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_head*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
243                         /* actual_buffer gets urb->actual_length + interrupt_in_buffer */
244                         *actual_buffer = urb->actual_length;
245                         memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length);
246                         dev->ring_head = next_ring_head;
247                         dbg_info(&dev->intf->dev, "%s: received %d bytes\n",
248                                  __FUNCTION__, urb->actual_length);
249                 } else {
250                         dev_warn(&dev->intf->dev,
251                                  "Ring buffer overflow, %d bytes dropped\n",
252                                  urb->actual_length);
253                         dev->buffer_overflow = 1;
254                 }
255         }
256
257 resubmit:
258         /* resubmit if we're still running */
259         if (dev->interrupt_in_running && !dev->buffer_overflow && dev->intf) {
260                 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
261                 if (retval) {
262                         dev_err(&dev->intf->dev,
263                                 "usb_submit_urb failed (%d)\n", retval);
264                         dev->buffer_overflow = 1;
265                 }
266         }
267         spin_unlock(&dev->rbsl);
268 exit:
269         dev->interrupt_in_done = 1;
270         wake_up_interruptible(&dev->read_wait);
271 }
272
273 /**
274  *      ld_usb_interrupt_out_callback
275  */
276 static void ld_usb_interrupt_out_callback(struct urb *urb)
277 {
278         struct ld_usb *dev = urb->context;
279         int status = urb->status;
280
281         /* sync/async unlink faults aren't errors */
282         if (status && !(status == -ENOENT ||
283                         status == -ECONNRESET ||
284                         status == -ESHUTDOWN))
285                 dbg_info(&dev->intf->dev,
286                          "%s - nonzero write interrupt status received: %d\n",
287                          __FUNCTION__, status);
288
289         dev->interrupt_out_busy = 0;
290         wake_up_interruptible(&dev->write_wait);
291 }
292
293 /**
294  *      ld_usb_open
295  */
296 static int ld_usb_open(struct inode *inode, struct file *file)
297 {
298         struct ld_usb *dev;
299         int subminor;
300         int retval;
301         struct usb_interface *interface;
302
303         nonseekable_open(inode, file);
304         subminor = iminor(inode);
305
306         interface = usb_find_interface(&ld_usb_driver, subminor);
307
308         if (!interface) {
309                 err("%s - error, can't find device for minor %d\n",
310                      __FUNCTION__, subminor);
311                 return -ENODEV;
312         }
313
314         dev = usb_get_intfdata(interface);
315
316         if (!dev)
317                 return -ENODEV;
318
319         /* lock this device */
320         if (down_interruptible(&dev->sem))
321                 return -ERESTARTSYS;
322
323         /* allow opening only once */
324         if (dev->open_count) {
325                 retval = -EBUSY;
326                 goto unlock_exit;
327         }
328         dev->open_count = 1;
329
330         /* initialize in direction */
331         dev->ring_head = 0;
332         dev->ring_tail = 0;
333         dev->buffer_overflow = 0;
334         usb_fill_int_urb(dev->interrupt_in_urb,
335                          interface_to_usbdev(interface),
336                          usb_rcvintpipe(interface_to_usbdev(interface),
337                                         dev->interrupt_in_endpoint->bEndpointAddress),
338                          dev->interrupt_in_buffer,
339                          dev->interrupt_in_endpoint_size,
340                          ld_usb_interrupt_in_callback,
341                          dev,
342                          dev->interrupt_in_interval);
343
344         dev->interrupt_in_running = 1;
345         dev->interrupt_in_done = 0;
346
347         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
348         if (retval) {
349                 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
350                 dev->interrupt_in_running = 0;
351                 dev->open_count = 0;
352                 goto unlock_exit;
353         }
354
355         /* save device in the file's private structure */
356         file->private_data = dev;
357
358 unlock_exit:
359         up(&dev->sem);
360
361         return retval;
362 }
363
364 /**
365  *      ld_usb_release
366  */
367 static int ld_usb_release(struct inode *inode, struct file *file)
368 {
369         struct ld_usb *dev;
370         int retval = 0;
371
372         dev = file->private_data;
373
374         if (dev == NULL) {
375                 retval = -ENODEV;
376                 goto exit;
377         }
378
379         if (down_interruptible(&dev->sem)) {
380                 retval = -ERESTARTSYS;
381                 goto exit;
382         }
383
384         if (dev->open_count != 1) {
385                 retval = -ENODEV;
386                 goto unlock_exit;
387         }
388         if (dev->intf == NULL) {
389                 /* the device was unplugged before the file was released */
390                 up(&dev->sem);
391                 /* unlock here as ld_usb_delete frees dev */
392                 ld_usb_delete(dev);
393                 goto exit;
394         }
395
396         /* wait until write transfer is finished */
397         if (dev->interrupt_out_busy)
398                 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
399         ld_usb_abort_transfers(dev);
400         dev->open_count = 0;
401
402 unlock_exit:
403         up(&dev->sem);
404
405 exit:
406         return retval;
407 }
408
409 /**
410  *      ld_usb_poll
411  */
412 static unsigned int ld_usb_poll(struct file *file, poll_table *wait)
413 {
414         struct ld_usb *dev;
415         unsigned int mask = 0;
416
417         dev = file->private_data;
418
419         poll_wait(file, &dev->read_wait, wait);
420         poll_wait(file, &dev->write_wait, wait);
421
422         if (dev->ring_head != dev->ring_tail)
423                 mask |= POLLIN | POLLRDNORM;
424         if (!dev->interrupt_out_busy)
425                 mask |= POLLOUT | POLLWRNORM;
426
427         return mask;
428 }
429
430 /**
431  *      ld_usb_read
432  */
433 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
434                            loff_t *ppos)
435 {
436         struct ld_usb *dev;
437         size_t *actual_buffer;
438         size_t bytes_to_read;
439         int retval = 0;
440         int rv;
441
442         dev = file->private_data;
443
444         /* verify that we actually have some data to read */
445         if (count == 0)
446                 goto exit;
447
448         /* lock this object */
449         if (down_interruptible(&dev->sem)) {
450                 retval = -ERESTARTSYS;
451                 goto exit;
452         }
453
454         /* verify that the device wasn't unplugged */
455         if (dev->intf == NULL) {
456                 retval = -ENODEV;
457                 err("No device or device unplugged %d\n", retval);
458                 goto unlock_exit;
459         }
460
461         /* wait for data */
462         spin_lock_irq(&dev->rbsl);
463         if (dev->ring_head == dev->ring_tail) {
464                 dev->interrupt_in_done = 0;
465                 spin_unlock_irq(&dev->rbsl);
466                 if (file->f_flags & O_NONBLOCK) {
467                         retval = -EAGAIN;
468                         goto unlock_exit;
469                 }
470                 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
471                 if (retval < 0)
472                         goto unlock_exit;
473         } else {
474                 spin_unlock_irq(&dev->rbsl);
475         }
476
477         /* actual_buffer contains actual_length + interrupt_in_buffer */
478         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_tail*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
479         bytes_to_read = min(count, *actual_buffer);
480         if (bytes_to_read < *actual_buffer)
481                 dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
482                          *actual_buffer-bytes_to_read);
483
484         /* copy one interrupt_in_buffer from ring_buffer into userspace */
485         if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
486                 retval = -EFAULT;
487                 goto unlock_exit;
488         }
489         dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
490
491         retval = bytes_to_read;
492
493         spin_lock_irq(&dev->rbsl);
494         if (dev->buffer_overflow) {
495                 dev->buffer_overflow = 0;
496                 spin_unlock_irq(&dev->rbsl);
497                 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
498                 if (rv < 0)
499                         dev->buffer_overflow = 1;
500         } else {
501                 spin_unlock_irq(&dev->rbsl);
502         }
503
504 unlock_exit:
505         /* unlock the device */
506         up(&dev->sem);
507
508 exit:
509         return retval;
510 }
511
512 /**
513  *      ld_usb_write
514  */
515 static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
516                             size_t count, loff_t *ppos)
517 {
518         struct ld_usb *dev;
519         size_t bytes_to_write;
520         int retval = 0;
521
522         dev = file->private_data;
523
524         /* verify that we actually have some data to write */
525         if (count == 0)
526                 goto exit;
527
528         /* lock this object */
529         if (down_interruptible(&dev->sem)) {
530                 retval = -ERESTARTSYS;
531                 goto exit;
532         }
533
534         /* verify that the device wasn't unplugged */
535         if (dev->intf == NULL) {
536                 retval = -ENODEV;
537                 err("No device or device unplugged %d\n", retval);
538                 goto unlock_exit;
539         }
540
541         /* wait until previous transfer is finished */
542         if (dev->interrupt_out_busy) {
543                 if (file->f_flags & O_NONBLOCK) {
544                         retval = -EAGAIN;
545                         goto unlock_exit;
546                 }
547                 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
548                 if (retval < 0) {
549                         goto unlock_exit;
550                 }
551         }
552
553         /* write the data into interrupt_out_buffer from userspace */
554         bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
555         if (bytes_to_write < count)
556                 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n",count-bytes_to_write);
557         dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n", __FUNCTION__, count, bytes_to_write);
558
559         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
560                 retval = -EFAULT;
561                 goto unlock_exit;
562         }
563
564         if (dev->interrupt_out_endpoint == NULL) {
565                 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */
566                 retval = usb_control_msg(interface_to_usbdev(dev->intf),
567                                          usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0),
568                                          9,
569                                          USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
570                                          1 << 8, 0,
571                                          dev->interrupt_out_buffer,
572                                          bytes_to_write,
573                                          USB_CTRL_SET_TIMEOUT * HZ);
574                 if (retval < 0)
575                         err("Couldn't submit HID_REQ_SET_REPORT %d\n", retval);
576                 goto unlock_exit;
577         }
578
579         /* send off the urb */
580         usb_fill_int_urb(dev->interrupt_out_urb,
581                          interface_to_usbdev(dev->intf),
582                          usb_sndintpipe(interface_to_usbdev(dev->intf),
583                                         dev->interrupt_out_endpoint->bEndpointAddress),
584                          dev->interrupt_out_buffer,
585                          bytes_to_write,
586                          ld_usb_interrupt_out_callback,
587                          dev,
588                          dev->interrupt_out_interval);
589
590         dev->interrupt_out_busy = 1;
591         wmb();
592
593         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
594         if (retval) {
595                 dev->interrupt_out_busy = 0;
596                 err("Couldn't submit interrupt_out_urb %d\n", retval);
597                 goto unlock_exit;
598         }
599         retval = bytes_to_write;
600
601 unlock_exit:
602         /* unlock the device */
603         up(&dev->sem);
604
605 exit:
606         return retval;
607 }
608
609 /* file operations needed when we register this driver */
610 static const struct file_operations ld_usb_fops = {
611         .owner =        THIS_MODULE,
612         .read  =        ld_usb_read,
613         .write =        ld_usb_write,
614         .open =         ld_usb_open,
615         .release =      ld_usb_release,
616         .poll =         ld_usb_poll,
617 };
618
619 /*
620  * usb class driver info in order to get a minor number from the usb core,
621  * and to have the device registered with the driver core
622  */
623 static struct usb_class_driver ld_usb_class = {
624         .name =         "ldusb%d",
625         .fops =         &ld_usb_fops,
626         .minor_base =   USB_LD_MINOR_BASE,
627 };
628
629 /**
630  *      ld_usb_probe
631  *
632  *      Called by the usb core when a new device is connected that it thinks
633  *      this driver might be interested in.
634  */
635 static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
636 {
637         struct usb_device *udev = interface_to_usbdev(intf);
638         struct ld_usb *dev = NULL;
639         struct usb_host_interface *iface_desc;
640         struct usb_endpoint_descriptor *endpoint;
641         char *buffer;
642         int i;
643         int retval = -ENOMEM;
644
645         /* allocate memory for our device state and intialize it */
646
647         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
648         if (dev == NULL) {
649                 dev_err(&intf->dev, "Out of memory\n");
650                 goto exit;
651         }
652         init_MUTEX(&dev->sem);
653         spin_lock_init(&dev->rbsl);
654         dev->intf = intf;
655         init_waitqueue_head(&dev->read_wait);
656         init_waitqueue_head(&dev->write_wait);
657
658         /* workaround for early firmware versions on fast computers */
659         if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) &&
660             ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) ||
661              (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) &&
662             (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) {
663                 buffer = kmalloc(256, GFP_KERNEL);
664                 if (buffer == NULL) {
665                         dev_err(&intf->dev, "Couldn't allocate string buffer\n");
666                         goto error;
667                 }
668                 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */
669                 usb_string(udev, 255, buffer, 256);
670                 kfree(buffer);
671         }
672
673         iface_desc = intf->cur_altsetting;
674
675         /* set up the endpoint information */
676         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
677                 endpoint = &iface_desc->endpoint[i].desc;
678
679                 if (usb_endpoint_is_int_in(endpoint))
680                         dev->interrupt_in_endpoint = endpoint;
681
682                 if (usb_endpoint_is_int_out(endpoint))
683                         dev->interrupt_out_endpoint = endpoint;
684         }
685         if (dev->interrupt_in_endpoint == NULL) {
686                 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
687                 goto error;
688         }
689         if (dev->interrupt_out_endpoint == NULL)
690                 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
691
692         dev->interrupt_in_endpoint_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
693         dev->ring_buffer = kmalloc(ring_buffer_size*(sizeof(size_t)+dev->interrupt_in_endpoint_size), GFP_KERNEL);
694         if (!dev->ring_buffer) {
695                 dev_err(&intf->dev, "Couldn't allocate ring_buffer\n");
696                 goto error;
697         }
698         dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
699         if (!dev->interrupt_in_buffer) {
700                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
701                 goto error;
702         }
703         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
704         if (!dev->interrupt_in_urb) {
705                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
706                 goto error;
707         }
708         dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize) :
709                                                                          udev->descriptor.bMaxPacketSize0;
710         dev->interrupt_out_buffer = kmalloc(write_buffer_size*dev->interrupt_out_endpoint_size, GFP_KERNEL);
711         if (!dev->interrupt_out_buffer) {
712                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
713                 goto error;
714         }
715         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
716         if (!dev->interrupt_out_urb) {
717                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
718                 goto error;
719         }
720         dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
721         if (dev->interrupt_out_endpoint)
722                 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
723
724         /* we can register the device now, as it is ready */
725         usb_set_intfdata(intf, dev);
726
727         retval = usb_register_dev(intf, &ld_usb_class);
728         if (retval) {
729                 /* something prevented us from registering this driver */
730                 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
731                 usb_set_intfdata(intf, NULL);
732                 goto error;
733         }
734
735         /* let the user know what node this device is now attached to */
736         dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n",
737                 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor);
738
739 exit:
740         return retval;
741
742 error:
743         ld_usb_delete(dev);
744
745         return retval;
746 }
747
748 /**
749  *      ld_usb_disconnect
750  *
751  *      Called by the usb core when the device is removed from the system.
752  */
753 static void ld_usb_disconnect(struct usb_interface *intf)
754 {
755         struct ld_usb *dev;
756         int minor;
757
758         dev = usb_get_intfdata(intf);
759         usb_set_intfdata(intf, NULL);
760
761         minor = intf->minor;
762
763         /* give back our minor */
764         usb_deregister_dev(intf, &ld_usb_class);
765
766         down(&dev->sem);
767
768         /* if the device is not opened, then we clean up right now */
769         if (!dev->open_count) {
770                 up(&dev->sem);
771                 ld_usb_delete(dev);
772         } else {
773                 dev->intf = NULL;
774                 up(&dev->sem);
775         }
776
777         dev_info(&intf->dev, "LD USB Device #%d now disconnected\n",
778                  (minor - USB_LD_MINOR_BASE));
779 }
780
781 /* usb specific object needed to register this driver with the usb subsystem */
782 static struct usb_driver ld_usb_driver = {
783         .name =         "ldusb",
784         .probe =        ld_usb_probe,
785         .disconnect =   ld_usb_disconnect,
786         .id_table =     ld_usb_table,
787 };
788
789 /**
790  *      ld_usb_init
791  */
792 static int __init ld_usb_init(void)
793 {
794         int retval;
795
796         /* register this driver with the USB subsystem */
797         retval = usb_register(&ld_usb_driver);
798         if (retval)
799                 err("usb_register failed for the "__FILE__" driver. Error number %d\n", retval);
800
801         return retval;
802 }
803
804 /**
805  *      ld_usb_exit
806  */
807 static void __exit ld_usb_exit(void)
808 {
809         /* deregister this driver with the USB subsystem */
810         usb_deregister(&ld_usb_driver);
811 }
812
813 module_init(ld_usb_init);
814 module_exit(ld_usb_exit);
815