Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
[linux-2.6.git] / 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_GOTEMP    0x0002
61 #define USB_DEVICE_ID_VERNIER_SKIP      0x0003
62 #define USB_DEVICE_ID_VERNIER_CYCLOPS   0x0004
63 #define USB_DEVICE_ID_VERNIER_LCSPEC    0x0006
64
65 #ifdef CONFIG_USB_DYNAMIC_MINORS
66 #define USB_LD_MINOR_BASE       0
67 #else
68 #define USB_LD_MINOR_BASE       176
69 #endif
70
71 /* table of devices that work with this driver */
72 static const struct usb_device_id ld_usb_table[] = {
73         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY) },
74         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY) },
75         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY) },
76         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_JWM) },
77         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_DMMP) },
78         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIP) },
79         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY1) },
80         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY2) },
81         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_VIDEOCOM) },
82         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_COM3LAB) },
83         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_TELEPORT) },
84         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_NETWORKANALYSER) },
85         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERCONTROL) },
86         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETEST) },
87         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_GOTEMP) },
88         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_SKIP) },
89         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_CYCLOPS) },
90         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_LCSPEC) },
91         { }                                     /* Terminating entry */
92 };
93 MODULE_DEVICE_TABLE(usb, ld_usb_table);
94 MODULE_VERSION("V0.13");
95 MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>");
96 MODULE_DESCRIPTION("LD USB Driver");
97 MODULE_LICENSE("GPL");
98 MODULE_SUPPORTED_DEVICE("LD USB Devices");
99
100 #ifdef CONFIG_USB_DEBUG
101         static int debug = 1;
102 #else
103         static int debug = 0;
104 #endif
105
106 /* Use our own dbg macro */
107 #define dbg_info(dev, format, arg...) do { if (debug) dev_info(dev , format , ## arg); } while (0)
108
109 /* Module parameters */
110 module_param(debug, int, S_IRUGO | S_IWUSR);
111 MODULE_PARM_DESC(debug, "Debug enabled or not");
112
113 /* All interrupt in transfers are collected in a ring buffer to
114  * avoid racing conditions and get better performance of the driver.
115  */
116 static int ring_buffer_size = 128;
117 module_param(ring_buffer_size, int, 0);
118 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
119
120 /* The write_buffer can contain more than one interrupt out transfer.
121  */
122 static int write_buffer_size = 10;
123 module_param(write_buffer_size, int, 0);
124 MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports");
125
126 /* As of kernel version 2.6.4 ehci-hcd uses an
127  * "only one interrupt transfer per frame" shortcut
128  * to simplify the scheduling of periodic transfers.
129  * This conflicts with our standard 1ms intervals for in and out URBs.
130  * We use default intervals of 2ms for in and 2ms for out transfers,
131  * which should be fast enough.
132  * Increase the interval to allow more devices that do interrupt transfers,
133  * or set to 1 to use the standard interval from the endpoint descriptors.
134  */
135 static int min_interrupt_in_interval = 2;
136 module_param(min_interrupt_in_interval, int, 0);
137 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
138
139 static int min_interrupt_out_interval = 2;
140 module_param(min_interrupt_out_interval, int, 0);
141 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
142
143 /* Structure to hold all of our device specific stuff */
144 struct ld_usb {
145         struct mutex            mutex;          /* locks this structure */
146         struct usb_interface*   intf;           /* save off the usb interface pointer */
147
148         int                     open_count;     /* number of times this port has been opened */
149
150         char*                   ring_buffer;
151         unsigned int            ring_head;
152         unsigned int            ring_tail;
153
154         wait_queue_head_t       read_wait;
155         wait_queue_head_t       write_wait;
156
157         char*                   interrupt_in_buffer;
158         struct usb_endpoint_descriptor* interrupt_in_endpoint;
159         struct urb*             interrupt_in_urb;
160         int                     interrupt_in_interval;
161         size_t                  interrupt_in_endpoint_size;
162         int                     interrupt_in_running;
163         int                     interrupt_in_done;
164         int                     buffer_overflow;
165         spinlock_t              rbsl;
166
167         char*                   interrupt_out_buffer;
168         struct usb_endpoint_descriptor* interrupt_out_endpoint;
169         struct urb*             interrupt_out_urb;
170         int                     interrupt_out_interval;
171         size_t                  interrupt_out_endpoint_size;
172         int                     interrupt_out_busy;
173 };
174
175 static struct usb_driver ld_usb_driver;
176
177 /**
178  *      ld_usb_abort_transfers
179  *      aborts transfers and frees associated data structures
180  */
181 static void ld_usb_abort_transfers(struct ld_usb *dev)
182 {
183         /* shutdown transfer */
184         if (dev->interrupt_in_running) {
185                 dev->interrupt_in_running = 0;
186                 if (dev->intf)
187                         usb_kill_urb(dev->interrupt_in_urb);
188         }
189         if (dev->interrupt_out_busy)
190                 if (dev->intf)
191                         usb_kill_urb(dev->interrupt_out_urb);
192 }
193
194 /**
195  *      ld_usb_delete
196  */
197 static void ld_usb_delete(struct ld_usb *dev)
198 {
199         ld_usb_abort_transfers(dev);
200
201         /* free data structures */
202         usb_free_urb(dev->interrupt_in_urb);
203         usb_free_urb(dev->interrupt_out_urb);
204         kfree(dev->ring_buffer);
205         kfree(dev->interrupt_in_buffer);
206         kfree(dev->interrupt_out_buffer);
207         kfree(dev);
208 }
209
210 /**
211  *      ld_usb_interrupt_in_callback
212  */
213 static void ld_usb_interrupt_in_callback(struct urb *urb)
214 {
215         struct ld_usb *dev = urb->context;
216         size_t *actual_buffer;
217         unsigned int next_ring_head;
218         int status = urb->status;
219         int retval;
220
221         if (status) {
222                 if (status == -ENOENT ||
223                     status == -ECONNRESET ||
224                     status == -ESHUTDOWN) {
225                         goto exit;
226                 } else {
227                         dbg_info(&dev->intf->dev, "%s: nonzero status received: %d\n",
228                                  __func__, status);
229                         spin_lock(&dev->rbsl);
230                         goto resubmit; /* maybe we can recover */
231                 }
232         }
233
234         spin_lock(&dev->rbsl);
235         if (urb->actual_length > 0) {
236                 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
237                 if (next_ring_head != dev->ring_tail) {
238                         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_head*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
239                         /* actual_buffer gets urb->actual_length + interrupt_in_buffer */
240                         *actual_buffer = urb->actual_length;
241                         memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length);
242                         dev->ring_head = next_ring_head;
243                         dbg_info(&dev->intf->dev, "%s: received %d bytes\n",
244                                  __func__, urb->actual_length);
245                 } else {
246                         dev_warn(&dev->intf->dev,
247                                  "Ring buffer overflow, %d bytes dropped\n",
248                                  urb->actual_length);
249                         dev->buffer_overflow = 1;
250                 }
251         }
252
253 resubmit:
254         /* resubmit if we're still running */
255         if (dev->interrupt_in_running && !dev->buffer_overflow && dev->intf) {
256                 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
257                 if (retval) {
258                         dev_err(&dev->intf->dev,
259                                 "usb_submit_urb failed (%d)\n", retval);
260                         dev->buffer_overflow = 1;
261                 }
262         }
263         spin_unlock(&dev->rbsl);
264 exit:
265         dev->interrupt_in_done = 1;
266         wake_up_interruptible(&dev->read_wait);
267 }
268
269 /**
270  *      ld_usb_interrupt_out_callback
271  */
272 static void ld_usb_interrupt_out_callback(struct urb *urb)
273 {
274         struct ld_usb *dev = urb->context;
275         int status = urb->status;
276
277         /* sync/async unlink faults aren't errors */
278         if (status && !(status == -ENOENT ||
279                         status == -ECONNRESET ||
280                         status == -ESHUTDOWN))
281                 dbg_info(&dev->intf->dev,
282                          "%s - nonzero write interrupt status received: %d\n",
283                          __func__, status);
284
285         dev->interrupt_out_busy = 0;
286         wake_up_interruptible(&dev->write_wait);
287 }
288
289 /**
290  *      ld_usb_open
291  */
292 static int ld_usb_open(struct inode *inode, struct file *file)
293 {
294         struct ld_usb *dev;
295         int subminor;
296         int retval;
297         struct usb_interface *interface;
298
299         nonseekable_open(inode, file);
300         subminor = iminor(inode);
301
302         interface = usb_find_interface(&ld_usb_driver, subminor);
303
304         if (!interface) {
305                 err("%s - error, can't find device for minor %d\n",
306                      __func__, subminor);
307                 return -ENODEV;
308         }
309
310         dev = usb_get_intfdata(interface);
311
312         if (!dev)
313                 return -ENODEV;
314
315         /* lock this device */
316         if (mutex_lock_interruptible(&dev->mutex))
317                 return -ERESTARTSYS;
318
319         /* allow opening only once */
320         if (dev->open_count) {
321                 retval = -EBUSY;
322                 goto unlock_exit;
323         }
324         dev->open_count = 1;
325
326         /* initialize in direction */
327         dev->ring_head = 0;
328         dev->ring_tail = 0;
329         dev->buffer_overflow = 0;
330         usb_fill_int_urb(dev->interrupt_in_urb,
331                          interface_to_usbdev(interface),
332                          usb_rcvintpipe(interface_to_usbdev(interface),
333                                         dev->interrupt_in_endpoint->bEndpointAddress),
334                          dev->interrupt_in_buffer,
335                          dev->interrupt_in_endpoint_size,
336                          ld_usb_interrupt_in_callback,
337                          dev,
338                          dev->interrupt_in_interval);
339
340         dev->interrupt_in_running = 1;
341         dev->interrupt_in_done = 0;
342
343         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
344         if (retval) {
345                 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
346                 dev->interrupt_in_running = 0;
347                 dev->open_count = 0;
348                 goto unlock_exit;
349         }
350
351         /* save device in the file's private structure */
352         file->private_data = dev;
353
354 unlock_exit:
355         mutex_unlock(&dev->mutex);
356
357         return retval;
358 }
359
360 /**
361  *      ld_usb_release
362  */
363 static int ld_usb_release(struct inode *inode, struct file *file)
364 {
365         struct ld_usb *dev;
366         int retval = 0;
367
368         dev = file->private_data;
369
370         if (dev == NULL) {
371                 retval = -ENODEV;
372                 goto exit;
373         }
374
375         if (mutex_lock_interruptible(&dev->mutex)) {
376                 retval = -ERESTARTSYS;
377                 goto exit;
378         }
379
380         if (dev->open_count != 1) {
381                 retval = -ENODEV;
382                 goto unlock_exit;
383         }
384         if (dev->intf == NULL) {
385                 /* the device was unplugged before the file was released */
386                 mutex_unlock(&dev->mutex);
387                 /* unlock here as ld_usb_delete frees dev */
388                 ld_usb_delete(dev);
389                 goto exit;
390         }
391
392         /* wait until write transfer is finished */
393         if (dev->interrupt_out_busy)
394                 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
395         ld_usb_abort_transfers(dev);
396         dev->open_count = 0;
397
398 unlock_exit:
399         mutex_unlock(&dev->mutex);
400
401 exit:
402         return retval;
403 }
404
405 /**
406  *      ld_usb_poll
407  */
408 static unsigned int ld_usb_poll(struct file *file, poll_table *wait)
409 {
410         struct ld_usb *dev;
411         unsigned int mask = 0;
412
413         dev = file->private_data;
414
415         if (!dev->intf)
416                 return POLLERR | POLLHUP;
417
418         poll_wait(file, &dev->read_wait, wait);
419         poll_wait(file, &dev->write_wait, wait);
420
421         if (dev->ring_head != dev->ring_tail)
422                 mask |= POLLIN | POLLRDNORM;
423         if (!dev->interrupt_out_busy)
424                 mask |= POLLOUT | POLLWRNORM;
425
426         return mask;
427 }
428
429 /**
430  *      ld_usb_read
431  */
432 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
433                            loff_t *ppos)
434 {
435         struct ld_usb *dev;
436         size_t *actual_buffer;
437         size_t bytes_to_read;
438         int retval = 0;
439         int rv;
440
441         dev = file->private_data;
442
443         /* verify that we actually have some data to read */
444         if (count == 0)
445                 goto exit;
446
447         /* lock this object */
448         if (mutex_lock_interruptible(&dev->mutex)) {
449                 retval = -ERESTARTSYS;
450                 goto exit;
451         }
452
453         /* verify that the device wasn't unplugged */
454         if (dev->intf == NULL) {
455                 retval = -ENODEV;
456                 err("No device or device unplugged %d\n", retval);
457                 goto unlock_exit;
458         }
459
460         /* wait for data */
461         spin_lock_irq(&dev->rbsl);
462         if (dev->ring_head == dev->ring_tail) {
463                 dev->interrupt_in_done = 0;
464                 spin_unlock_irq(&dev->rbsl);
465                 if (file->f_flags & O_NONBLOCK) {
466                         retval = -EAGAIN;
467                         goto unlock_exit;
468                 }
469                 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
470                 if (retval < 0)
471                         goto unlock_exit;
472         } else {
473                 spin_unlock_irq(&dev->rbsl);
474         }
475
476         /* actual_buffer contains actual_length + interrupt_in_buffer */
477         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_tail*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
478         bytes_to_read = min(count, *actual_buffer);
479         if (bytes_to_read < *actual_buffer)
480                 dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
481                          *actual_buffer-bytes_to_read);
482
483         /* copy one interrupt_in_buffer from ring_buffer into userspace */
484         if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
485                 retval = -EFAULT;
486                 goto unlock_exit;
487         }
488         dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
489
490         retval = bytes_to_read;
491
492         spin_lock_irq(&dev->rbsl);
493         if (dev->buffer_overflow) {
494                 dev->buffer_overflow = 0;
495                 spin_unlock_irq(&dev->rbsl);
496                 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
497                 if (rv < 0)
498                         dev->buffer_overflow = 1;
499         } else {
500                 spin_unlock_irq(&dev->rbsl);
501         }
502
503 unlock_exit:
504         /* unlock the device */
505         mutex_unlock(&dev->mutex);
506
507 exit:
508         return retval;
509 }
510
511 /**
512  *      ld_usb_write
513  */
514 static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
515                             size_t count, loff_t *ppos)
516 {
517         struct ld_usb *dev;
518         size_t bytes_to_write;
519         int retval = 0;
520
521         dev = file->private_data;
522
523         /* verify that we actually have some data to write */
524         if (count == 0)
525                 goto exit;
526
527         /* lock this object */
528         if (mutex_lock_interruptible(&dev->mutex)) {
529                 retval = -ERESTARTSYS;
530                 goto exit;
531         }
532
533         /* verify that the device wasn't unplugged */
534         if (dev->intf == NULL) {
535                 retval = -ENODEV;
536                 err("No device or device unplugged %d\n", retval);
537                 goto unlock_exit;
538         }
539
540         /* wait until previous transfer is finished */
541         if (dev->interrupt_out_busy) {
542                 if (file->f_flags & O_NONBLOCK) {
543                         retval = -EAGAIN;
544                         goto unlock_exit;
545                 }
546                 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
547                 if (retval < 0) {
548                         goto unlock_exit;
549                 }
550         }
551
552         /* write the data into interrupt_out_buffer from userspace */
553         bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
554         if (bytes_to_write < count)
555                 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n",count-bytes_to_write);
556         dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n", __func__, count, bytes_to_write);
557
558         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
559                 retval = -EFAULT;
560                 goto unlock_exit;
561         }
562
563         if (dev->interrupt_out_endpoint == NULL) {
564                 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */
565                 retval = usb_control_msg(interface_to_usbdev(dev->intf),
566                                          usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0),
567                                          9,
568                                          USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
569                                          1 << 8, 0,
570                                          dev->interrupt_out_buffer,
571                                          bytes_to_write,
572                                          USB_CTRL_SET_TIMEOUT * HZ);
573                 if (retval < 0)
574                         err("Couldn't submit HID_REQ_SET_REPORT %d\n", retval);
575                 goto unlock_exit;
576         }
577
578         /* send off the urb */
579         usb_fill_int_urb(dev->interrupt_out_urb,
580                          interface_to_usbdev(dev->intf),
581                          usb_sndintpipe(interface_to_usbdev(dev->intf),
582                                         dev->interrupt_out_endpoint->bEndpointAddress),
583                          dev->interrupt_out_buffer,
584                          bytes_to_write,
585                          ld_usb_interrupt_out_callback,
586                          dev,
587                          dev->interrupt_out_interval);
588
589         dev->interrupt_out_busy = 1;
590         wmb();
591
592         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
593         if (retval) {
594                 dev->interrupt_out_busy = 0;
595                 err("Couldn't submit interrupt_out_urb %d\n", retval);
596                 goto unlock_exit;
597         }
598         retval = bytes_to_write;
599
600 unlock_exit:
601         /* unlock the device */
602         mutex_unlock(&dev->mutex);
603
604 exit:
605         return retval;
606 }
607
608 /* file operations needed when we register this driver */
609 static const struct file_operations ld_usb_fops = {
610         .owner =        THIS_MODULE,
611         .read  =        ld_usb_read,
612         .write =        ld_usb_write,
613         .open =         ld_usb_open,
614         .release =      ld_usb_release,
615         .poll =         ld_usb_poll,
616         .llseek =       no_llseek,
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 initialize 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         mutex_init(&dev->mutex);
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         mutex_lock(&dev->mutex);
767
768         /* if the device is not opened, then we clean up right now */
769         if (!dev->open_count) {
770                 mutex_unlock(&dev->mutex);
771                 ld_usb_delete(dev);
772         } else {
773                 dev->intf = NULL;
774                 /* wake up pollers */
775                 wake_up_interruptible_all(&dev->read_wait);
776                 wake_up_interruptible_all(&dev->write_wait);
777                 mutex_unlock(&dev->mutex);
778         }
779
780         dev_info(&intf->dev, "LD USB Device #%d now disconnected\n",
781                  (minor - USB_LD_MINOR_BASE));
782 }
783
784 /* usb specific object needed to register this driver with the usb subsystem */
785 static struct usb_driver ld_usb_driver = {
786         .name =         "ldusb",
787         .probe =        ld_usb_probe,
788         .disconnect =   ld_usb_disconnect,
789         .id_table =     ld_usb_table,
790 };
791
792 /**
793  *      ld_usb_init
794  */
795 static int __init ld_usb_init(void)
796 {
797         int retval;
798
799         /* register this driver with the USB subsystem */
800         retval = usb_register(&ld_usb_driver);
801         if (retval)
802                 err("usb_register failed for the %s driver. Error number %d\n", __FILE__, retval);
803
804         return retval;
805 }
806
807 /**
808  *      ld_usb_exit
809  */
810 static void __exit ld_usb_exit(void)
811 {
812         /* deregister this driver with the USB subsystem */
813         usb_deregister(&ld_usb_driver);
814 }
815
816 module_init(ld_usb_init);
817 module_exit(ld_usb_exit);
818