Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
[linux-2.6.git] / drivers / usb / misc / iowarrior.c
1 /*
2  *  Native support for the I/O-Warrior USB devices
3  *
4  *  Copyright (c) 2003-2005  Code Mercenaries GmbH
5  *  written by Christian Lucht <lucht@codemercs.com>
6  *
7  *  based on
8
9  *  usb-skeleton.c by Greg Kroah-Hartman  <greg@kroah.com>
10  *  brlvger.c by Stephane Dalton  <sdalton@videotron.ca>
11  *           and St�hane Doyon   <s.doyon@videotron.ca>
12  *
13  *  Released under the GPLv2.
14  */
15
16 #include <linux/module.h>
17 #include <linux/usb.h>
18 #include <linux/init.h>
19 #include <linux/slab.h>
20 #include <linux/sched.h>
21 #include <linux/mutex.h>
22 #include <linux/poll.h>
23 #include <linux/usb/iowarrior.h>
24
25 /* Version Information */
26 #define DRIVER_VERSION "v0.4.0"
27 #define DRIVER_AUTHOR "Christian Lucht <lucht@codemercs.com>"
28 #define DRIVER_DESC "USB IO-Warrior driver (Linux 2.6.x)"
29
30 #define USB_VENDOR_ID_CODEMERCS         1984
31 /* low speed iowarrior */
32 #define USB_DEVICE_ID_CODEMERCS_IOW40   0x1500
33 #define USB_DEVICE_ID_CODEMERCS_IOW24   0x1501
34 #define USB_DEVICE_ID_CODEMERCS_IOWPV1  0x1511
35 #define USB_DEVICE_ID_CODEMERCS_IOWPV2  0x1512
36 /* full speed iowarrior */
37 #define USB_DEVICE_ID_CODEMERCS_IOW56   0x1503
38
39 /* Get a minor range for your devices from the usb maintainer */
40 #ifdef CONFIG_USB_DYNAMIC_MINORS
41 #define IOWARRIOR_MINOR_BASE    0
42 #else
43 #define IOWARRIOR_MINOR_BASE    208     // SKELETON_MINOR_BASE 192 + 16, not offical yet
44 #endif
45
46 /* interrupt input queue size */
47 #define MAX_INTERRUPT_BUFFER 16
48 /*
49    maximum number of urbs that are submitted for writes at the same time,
50    this applies to the IOWarrior56 only!
51    IOWarrior24 and IOWarrior40 use synchronous usb_control_msg calls.
52 */
53 #define MAX_WRITES_IN_FLIGHT 4
54
55 /* Use our own dbg macro */
56 #undef dbg
57 #define dbg( format, arg... ) do { if( debug ) printk( KERN_DEBUG __FILE__ ": " format "\n" , ## arg ); } while ( 0 )
58
59 MODULE_AUTHOR(DRIVER_AUTHOR);
60 MODULE_DESCRIPTION(DRIVER_DESC);
61 MODULE_LICENSE("GPL");
62
63 /* Module parameters */
64 static DEFINE_MUTEX(iowarrior_mutex);
65 static int debug = 0;
66 module_param(debug, bool, 0644);
67 MODULE_PARM_DESC(debug, "debug=1 enables debugging messages");
68
69 static struct usb_driver iowarrior_driver;
70 static DEFINE_MUTEX(iowarrior_open_disc_lock);
71
72 /*--------------*/
73 /*     data     */
74 /*--------------*/
75
76 /* Structure to hold all of our device specific stuff */
77 struct iowarrior {
78         struct mutex mutex;                     /* locks this structure */
79         struct usb_device *udev;                /* save off the usb device pointer */
80         struct usb_interface *interface;        /* the interface for this device */
81         unsigned char minor;                    /* the starting minor number for this device */
82         struct usb_endpoint_descriptor *int_out_endpoint;       /* endpoint for reading (needed for IOW56 only) */
83         struct usb_endpoint_descriptor *int_in_endpoint;        /* endpoint for reading */
84         struct urb *int_in_urb;         /* the urb for reading data */
85         unsigned char *int_in_buffer;   /* buffer for data to be read */
86         unsigned char serial_number;    /* to detect lost packages */
87         unsigned char *read_queue;      /* size is MAX_INTERRUPT_BUFFER * packet size */
88         wait_queue_head_t read_wait;
89         wait_queue_head_t write_wait;   /* wait-queue for writing to the device */
90         atomic_t write_busy;            /* number of write-urbs submitted */
91         atomic_t read_idx;
92         atomic_t intr_idx;
93         spinlock_t intr_idx_lock;       /* protects intr_idx */
94         atomic_t overflow_flag;         /* signals an index 'rollover' */
95         int present;                    /* this is 1 as long as the device is connected */
96         int opened;                     /* this is 1 if the device is currently open */
97         char chip_serial[9];            /* the serial number string of the chip connected */
98         int report_size;                /* number of bytes in a report */
99         u16 product_id;
100 };
101
102 /*--------------*/
103 /*    globals   */
104 /*--------------*/
105
106 /*
107  *  USB spec identifies 5 second timeouts.
108  */
109 #define GET_TIMEOUT 5
110 #define USB_REQ_GET_REPORT  0x01
111 //#if 0
112 static int usb_get_report(struct usb_device *dev,
113                           struct usb_host_interface *inter, unsigned char type,
114                           unsigned char id, void *buf, int size)
115 {
116         return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
117                                USB_REQ_GET_REPORT,
118                                USB_DIR_IN | USB_TYPE_CLASS |
119                                USB_RECIP_INTERFACE, (type << 8) + id,
120                                inter->desc.bInterfaceNumber, buf, size,
121                                GET_TIMEOUT*HZ);
122 }
123 //#endif
124
125 #define USB_REQ_SET_REPORT 0x09
126
127 static int usb_set_report(struct usb_interface *intf, unsigned char type,
128                           unsigned char id, void *buf, int size)
129 {
130         return usb_control_msg(interface_to_usbdev(intf),
131                                usb_sndctrlpipe(interface_to_usbdev(intf), 0),
132                                USB_REQ_SET_REPORT,
133                                USB_TYPE_CLASS | USB_RECIP_INTERFACE,
134                                (type << 8) + id,
135                                intf->cur_altsetting->desc.bInterfaceNumber, buf,
136                                size, HZ);
137 }
138
139 /*---------------------*/
140 /* driver registration */
141 /*---------------------*/
142 /* table of devices that work with this driver */
143 static const struct usb_device_id iowarrior_ids[] = {
144         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW40)},
145         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24)},
146         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV1)},
147         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV2)},
148         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56)},
149         {}                      /* Terminating entry */
150 };
151 MODULE_DEVICE_TABLE(usb, iowarrior_ids);
152
153 /*
154  * USB callback handler for reading data
155  */
156 static void iowarrior_callback(struct urb *urb)
157 {
158         struct iowarrior *dev = urb->context;
159         int intr_idx;
160         int read_idx;
161         int aux_idx;
162         int offset;
163         int status = urb->status;
164         int retval;
165
166         switch (status) {
167         case 0:
168                 /* success */
169                 break;
170         case -ECONNRESET:
171         case -ENOENT:
172         case -ESHUTDOWN:
173                 return;
174         default:
175                 goto exit;
176         }
177
178         spin_lock(&dev->intr_idx_lock);
179         intr_idx = atomic_read(&dev->intr_idx);
180         /* aux_idx become previous intr_idx */
181         aux_idx = (intr_idx == 0) ? (MAX_INTERRUPT_BUFFER - 1) : (intr_idx - 1);
182         read_idx = atomic_read(&dev->read_idx);
183
184         /* queue is not empty and it's interface 0 */
185         if ((intr_idx != read_idx)
186             && (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0)) {
187                 /* + 1 for serial number */
188                 offset = aux_idx * (dev->report_size + 1);
189                 if (!memcmp
190                     (dev->read_queue + offset, urb->transfer_buffer,
191                      dev->report_size)) {
192                         /* equal values on interface 0 will be ignored */
193                         spin_unlock(&dev->intr_idx_lock);
194                         goto exit;
195                 }
196         }
197
198         /* aux_idx become next intr_idx */
199         aux_idx = (intr_idx == (MAX_INTERRUPT_BUFFER - 1)) ? 0 : (intr_idx + 1);
200         if (read_idx == aux_idx) {
201                 /* queue full, dropping oldest input */
202                 read_idx = (++read_idx == MAX_INTERRUPT_BUFFER) ? 0 : read_idx;
203                 atomic_set(&dev->read_idx, read_idx);
204                 atomic_set(&dev->overflow_flag, 1);
205         }
206
207         /* +1 for serial number */
208         offset = intr_idx * (dev->report_size + 1);
209         memcpy(dev->read_queue + offset, urb->transfer_buffer,
210                dev->report_size);
211         *(dev->read_queue + offset + (dev->report_size)) = dev->serial_number++;
212
213         atomic_set(&dev->intr_idx, aux_idx);
214         spin_unlock(&dev->intr_idx_lock);
215         /* tell the blocking read about the new data */
216         wake_up_interruptible(&dev->read_wait);
217
218 exit:
219         retval = usb_submit_urb(urb, GFP_ATOMIC);
220         if (retval)
221                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed with result %d\n",
222                         __func__, retval);
223
224 }
225
226 /*
227  * USB Callback handler for write-ops
228  */
229 static void iowarrior_write_callback(struct urb *urb)
230 {
231         struct iowarrior *dev;
232         int status = urb->status;
233
234         dev = urb->context;
235         /* sync/async unlink faults aren't errors */
236         if (status &&
237             !(status == -ENOENT ||
238               status == -ECONNRESET || status == -ESHUTDOWN)) {
239                 dbg("%s - nonzero write bulk status received: %d",
240                     __func__, status);
241         }
242         /* free up our allocated buffer */
243         usb_free_coherent(urb->dev, urb->transfer_buffer_length,
244                           urb->transfer_buffer, urb->transfer_dma);
245         /* tell a waiting writer the interrupt-out-pipe is available again */
246         atomic_dec(&dev->write_busy);
247         wake_up_interruptible(&dev->write_wait);
248 }
249
250 /**
251  *      iowarrior_delete
252  */
253 static inline void iowarrior_delete(struct iowarrior *dev)
254 {
255         dbg("%s - minor %d", __func__, dev->minor);
256         kfree(dev->int_in_buffer);
257         usb_free_urb(dev->int_in_urb);
258         kfree(dev->read_queue);
259         kfree(dev);
260 }
261
262 /*---------------------*/
263 /* fops implementation */
264 /*---------------------*/
265
266 static int read_index(struct iowarrior *dev)
267 {
268         int intr_idx, read_idx;
269
270         read_idx = atomic_read(&dev->read_idx);
271         intr_idx = atomic_read(&dev->intr_idx);
272
273         return (read_idx == intr_idx ? -1 : read_idx);
274 }
275
276 /**
277  *  iowarrior_read
278  */
279 static ssize_t iowarrior_read(struct file *file, char __user *buffer,
280                               size_t count, loff_t *ppos)
281 {
282         struct iowarrior *dev;
283         int read_idx;
284         int offset;
285
286         dev = file->private_data;
287
288         /* verify that the device wasn't unplugged */
289         if (dev == NULL || !dev->present)
290                 return -ENODEV;
291
292         dbg("%s - minor %d, count = %zd", __func__, dev->minor, count);
293
294         /* read count must be packet size (+ time stamp) */
295         if ((count != dev->report_size)
296             && (count != (dev->report_size + 1)))
297                 return -EINVAL;
298
299         /* repeat until no buffer overrun in callback handler occur */
300         do {
301                 atomic_set(&dev->overflow_flag, 0);
302                 if ((read_idx = read_index(dev)) == -1) {
303                         /* queue emty */
304                         if (file->f_flags & O_NONBLOCK)
305                                 return -EAGAIN;
306                         else {
307                                 //next line will return when there is either new data, or the device is unplugged
308                                 int r = wait_event_interruptible(dev->read_wait,
309                                                                  (!dev->present
310                                                                   || (read_idx =
311                                                                       read_index
312                                                                       (dev)) !=
313                                                                   -1));
314                                 if (r) {
315                                         //we were interrupted by a signal
316                                         return -ERESTART;
317                                 }
318                                 if (!dev->present) {
319                                         //The device was unplugged
320                                         return -ENODEV;
321                                 }
322                                 if (read_idx == -1) {
323                                         // Can this happen ???
324                                         return 0;
325                                 }
326                         }
327                 }
328
329                 offset = read_idx * (dev->report_size + 1);
330                 if (copy_to_user(buffer, dev->read_queue + offset, count)) {
331                         return -EFAULT;
332                 }
333         } while (atomic_read(&dev->overflow_flag));
334
335         read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
336         atomic_set(&dev->read_idx, read_idx);
337         return count;
338 }
339
340 /*
341  * iowarrior_write
342  */
343 static ssize_t iowarrior_write(struct file *file,
344                                const char __user *user_buffer,
345                                size_t count, loff_t *ppos)
346 {
347         struct iowarrior *dev;
348         int retval = 0;
349         char *buf = NULL;       /* for IOW24 and IOW56 we need a buffer */
350         struct urb *int_out_urb = NULL;
351
352         dev = file->private_data;
353
354         mutex_lock(&dev->mutex);
355         /* verify that the device wasn't unplugged */
356         if (!dev->present) {
357                 retval = -ENODEV;
358                 goto exit;
359         }
360         dbg("%s - minor %d, count = %zd", __func__, dev->minor, count);
361         /* if count is 0 we're already done */
362         if (count == 0) {
363                 retval = 0;
364                 goto exit;
365         }
366         /* We only accept full reports */
367         if (count != dev->report_size) {
368                 retval = -EINVAL;
369                 goto exit;
370         }
371         switch (dev->product_id) {
372         case USB_DEVICE_ID_CODEMERCS_IOW24:
373         case USB_DEVICE_ID_CODEMERCS_IOWPV1:
374         case USB_DEVICE_ID_CODEMERCS_IOWPV2:
375         case USB_DEVICE_ID_CODEMERCS_IOW40:
376                 /* IOW24 and IOW40 use a synchronous call */
377                 buf = kmalloc(count, GFP_KERNEL);
378                 if (!buf) {
379                         retval = -ENOMEM;
380                         goto exit;
381                 }
382                 if (copy_from_user(buf, user_buffer, count)) {
383                         retval = -EFAULT;
384                         kfree(buf);
385                         goto exit;
386                 }
387                 retval = usb_set_report(dev->interface, 2, 0, buf, count);
388                 kfree(buf);
389                 goto exit;
390                 break;
391         case USB_DEVICE_ID_CODEMERCS_IOW56:
392                 /* The IOW56 uses asynchronous IO and more urbs */
393                 if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
394                         /* Wait until we are below the limit for submitted urbs */
395                         if (file->f_flags & O_NONBLOCK) {
396                                 retval = -EAGAIN;
397                                 goto exit;
398                         } else {
399                                 retval = wait_event_interruptible(dev->write_wait,
400                                                                   (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
401                                 if (retval) {
402                                         /* we were interrupted by a signal */
403                                         retval = -ERESTART;
404                                         goto exit;
405                                 }
406                                 if (!dev->present) {
407                                         /* The device was unplugged */
408                                         retval = -ENODEV;
409                                         goto exit;
410                                 }
411                                 if (!dev->opened) {
412                                         /* We were closed while waiting for an URB */
413                                         retval = -ENODEV;
414                                         goto exit;
415                                 }
416                         }
417                 }
418                 atomic_inc(&dev->write_busy);
419                 int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
420                 if (!int_out_urb) {
421                         retval = -ENOMEM;
422                         dbg("%s Unable to allocate urb ", __func__);
423                         goto error_no_urb;
424                 }
425                 buf = usb_alloc_coherent(dev->udev, dev->report_size,
426                                          GFP_KERNEL, &int_out_urb->transfer_dma);
427                 if (!buf) {
428                         retval = -ENOMEM;
429                         dbg("%s Unable to allocate buffer ", __func__);
430                         goto error_no_buffer;
431                 }
432                 usb_fill_int_urb(int_out_urb, dev->udev,
433                                  usb_sndintpipe(dev->udev,
434                                                 dev->int_out_endpoint->bEndpointAddress),
435                                  buf, dev->report_size,
436                                  iowarrior_write_callback, dev,
437                                  dev->int_out_endpoint->bInterval);
438                 int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
439                 if (copy_from_user(buf, user_buffer, count)) {
440                         retval = -EFAULT;
441                         goto error;
442                 }
443                 retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
444                 if (retval) {
445                         dbg("%s submit error %d for urb nr.%d", __func__,
446                             retval, atomic_read(&dev->write_busy));
447                         goto error;
448                 }
449                 /* submit was ok */
450                 retval = count;
451                 usb_free_urb(int_out_urb);
452                 goto exit;
453                 break;
454         default:
455                 /* what do we have here ? An unsupported Product-ID ? */
456                 dev_err(&dev->interface->dev, "%s - not supported for product=0x%x\n",
457                         __func__, dev->product_id);
458                 retval = -EFAULT;
459                 goto exit;
460                 break;
461         }
462 error:
463         usb_free_coherent(dev->udev, dev->report_size, buf,
464                           int_out_urb->transfer_dma);
465 error_no_buffer:
466         usb_free_urb(int_out_urb);
467 error_no_urb:
468         atomic_dec(&dev->write_busy);
469         wake_up_interruptible(&dev->write_wait);
470 exit:
471         mutex_unlock(&dev->mutex);
472         return retval;
473 }
474
475 /**
476  *      iowarrior_ioctl
477  */
478 static long iowarrior_ioctl(struct file *file, unsigned int cmd,
479                                                         unsigned long arg)
480 {
481         struct iowarrior *dev = NULL;
482         __u8 *buffer;
483         __u8 __user *user_buffer;
484         int retval;
485         int io_res;             /* checks for bytes read/written and copy_to/from_user results */
486
487         dev = file->private_data;
488         if (dev == NULL) {
489                 return -ENODEV;
490         }
491
492         buffer = kzalloc(dev->report_size, GFP_KERNEL);
493         if (!buffer)
494                 return -ENOMEM;
495
496         /* lock this object */
497         mutex_lock(&iowarrior_mutex);
498         mutex_lock(&dev->mutex);
499
500         /* verify that the device wasn't unplugged */
501         if (!dev->present) {
502                 retval = -ENODEV;
503                 goto error_out;
504         }
505
506         dbg("%s - minor %d, cmd 0x%.4x, arg %ld", __func__, dev->minor, cmd,
507             arg);
508
509         retval = 0;
510         io_res = 0;
511         switch (cmd) {
512         case IOW_WRITE:
513                 if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
514                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
515                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
516                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
517                         user_buffer = (__u8 __user *)arg;
518                         io_res = copy_from_user(buffer, user_buffer,
519                                                 dev->report_size);
520                         if (io_res) {
521                                 retval = -EFAULT;
522                         } else {
523                                 io_res = usb_set_report(dev->interface, 2, 0,
524                                                         buffer,
525                                                         dev->report_size);
526                                 if (io_res < 0)
527                                         retval = io_res;
528                         }
529                 } else {
530                         retval = -EINVAL;
531                         dev_err(&dev->interface->dev,
532                                 "ioctl 'IOW_WRITE' is not supported for product=0x%x.\n",
533                                 dev->product_id);
534                 }
535                 break;
536         case IOW_READ:
537                 user_buffer = (__u8 __user *)arg;
538                 io_res = usb_get_report(dev->udev,
539                                         dev->interface->cur_altsetting, 1, 0,
540                                         buffer, dev->report_size);
541                 if (io_res < 0)
542                         retval = io_res;
543                 else {
544                         io_res = copy_to_user(user_buffer, buffer, dev->report_size);
545                         if (io_res)
546                                 retval = -EFAULT;
547                 }
548                 break;
549         case IOW_GETINFO:
550                 {
551                         /* Report available information for the device */
552                         struct iowarrior_info info;
553                         /* needed for power consumption */
554                         struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
555
556                         memset(&info, 0, sizeof(info));
557                         /* directly from the descriptor */
558                         info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
559                         info.product = dev->product_id;
560                         info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
561
562                         /* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
563                         info.speed = le16_to_cpu(dev->udev->speed);
564                         info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
565                         info.report_size = dev->report_size;
566
567                         /* serial number string has been read earlier 8 chars or empty string */
568                         memcpy(info.serial, dev->chip_serial,
569                                sizeof(dev->chip_serial));
570                         if (cfg_descriptor == NULL) {
571                                 info.power = -1;        /* no information available */
572                         } else {
573                                 /* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
574                                 info.power = cfg_descriptor->bMaxPower * 2;
575                         }
576                         io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
577                                          sizeof(struct iowarrior_info));
578                         if (io_res)
579                                 retval = -EFAULT;
580                         break;
581                 }
582         default:
583                 /* return that we did not understand this ioctl call */
584                 retval = -ENOTTY;
585                 break;
586         }
587 error_out:
588         /* unlock the device */
589         mutex_unlock(&dev->mutex);
590         mutex_unlock(&iowarrior_mutex);
591         kfree(buffer);
592         return retval;
593 }
594
595 /**
596  *      iowarrior_open
597  */
598 static int iowarrior_open(struct inode *inode, struct file *file)
599 {
600         struct iowarrior *dev = NULL;
601         struct usb_interface *interface;
602         int subminor;
603         int retval = 0;
604
605         dbg("%s", __func__);
606
607         mutex_lock(&iowarrior_mutex);
608         subminor = iminor(inode);
609
610         interface = usb_find_interface(&iowarrior_driver, subminor);
611         if (!interface) {
612                 mutex_unlock(&iowarrior_mutex);
613                 err("%s - error, can't find device for minor %d", __func__,
614                     subminor);
615                 return -ENODEV;
616         }
617
618         mutex_lock(&iowarrior_open_disc_lock);
619         dev = usb_get_intfdata(interface);
620         if (!dev) {
621                 mutex_unlock(&iowarrior_open_disc_lock);
622                 mutex_unlock(&iowarrior_mutex);
623                 return -ENODEV;
624         }
625
626         mutex_lock(&dev->mutex);
627         mutex_unlock(&iowarrior_open_disc_lock);
628
629         /* Only one process can open each device, no sharing. */
630         if (dev->opened) {
631                 retval = -EBUSY;
632                 goto out;
633         }
634
635         /* setup interrupt handler for receiving values */
636         if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
637                 dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
638                 retval = -EFAULT;
639                 goto out;
640         }
641         /* increment our usage count for the driver */
642         ++dev->opened;
643         /* save our object in the file's private structure */
644         file->private_data = dev;
645         retval = 0;
646
647 out:
648         mutex_unlock(&dev->mutex);
649         mutex_unlock(&iowarrior_mutex);
650         return retval;
651 }
652
653 /**
654  *      iowarrior_release
655  */
656 static int iowarrior_release(struct inode *inode, struct file *file)
657 {
658         struct iowarrior *dev;
659         int retval = 0;
660
661         dev = file->private_data;
662         if (dev == NULL) {
663                 return -ENODEV;
664         }
665
666         dbg("%s - minor %d", __func__, dev->minor);
667
668         /* lock our device */
669         mutex_lock(&dev->mutex);
670
671         if (dev->opened <= 0) {
672                 retval = -ENODEV;       /* close called more than once */
673                 mutex_unlock(&dev->mutex);
674         } else {
675                 dev->opened = 0;        /* we're closeing now */
676                 retval = 0;
677                 if (dev->present) {
678                         /*
679                            The device is still connected so we only shutdown
680                            pending read-/write-ops.
681                          */
682                         usb_kill_urb(dev->int_in_urb);
683                         wake_up_interruptible(&dev->read_wait);
684                         wake_up_interruptible(&dev->write_wait);
685                         mutex_unlock(&dev->mutex);
686                 } else {
687                         /* The device was unplugged, cleanup resources */
688                         mutex_unlock(&dev->mutex);
689                         iowarrior_delete(dev);
690                 }
691         }
692         return retval;
693 }
694
695 static unsigned iowarrior_poll(struct file *file, poll_table * wait)
696 {
697         struct iowarrior *dev = file->private_data;
698         unsigned int mask = 0;
699
700         if (!dev->present)
701                 return POLLERR | POLLHUP;
702
703         poll_wait(file, &dev->read_wait, wait);
704         poll_wait(file, &dev->write_wait, wait);
705
706         if (!dev->present)
707                 return POLLERR | POLLHUP;
708
709         if (read_index(dev) != -1)
710                 mask |= POLLIN | POLLRDNORM;
711
712         if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
713                 mask |= POLLOUT | POLLWRNORM;
714         return mask;
715 }
716
717 /*
718  * File operations needed when we register this driver.
719  * This assumes that this driver NEEDS file operations,
720  * of course, which means that the driver is expected
721  * to have a node in the /dev directory. If the USB
722  * device were for a network interface then the driver
723  * would use "struct net_driver" instead, and a serial
724  * device would use "struct tty_driver".
725  */
726 static const struct file_operations iowarrior_fops = {
727         .owner = THIS_MODULE,
728         .write = iowarrior_write,
729         .read = iowarrior_read,
730         .unlocked_ioctl = iowarrior_ioctl,
731         .open = iowarrior_open,
732         .release = iowarrior_release,
733         .poll = iowarrior_poll,
734         .llseek = noop_llseek,
735 };
736
737 static char *iowarrior_devnode(struct device *dev, mode_t *mode)
738 {
739         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
740 }
741
742 /*
743  * usb class driver info in order to get a minor number from the usb core,
744  * and to have the device registered with devfs and the driver core
745  */
746 static struct usb_class_driver iowarrior_class = {
747         .name = "iowarrior%d",
748         .devnode = iowarrior_devnode,
749         .fops = &iowarrior_fops,
750         .minor_base = IOWARRIOR_MINOR_BASE,
751 };
752
753 /*---------------------------------*/
754 /*  probe and disconnect functions */
755 /*---------------------------------*/
756 /**
757  *      iowarrior_probe
758  *
759  *      Called by the usb core when a new device is connected that it thinks
760  *      this driver might be interested in.
761  */
762 static int iowarrior_probe(struct usb_interface *interface,
763                            const struct usb_device_id *id)
764 {
765         struct usb_device *udev = interface_to_usbdev(interface);
766         struct iowarrior *dev = NULL;
767         struct usb_host_interface *iface_desc;
768         struct usb_endpoint_descriptor *endpoint;
769         int i;
770         int retval = -ENOMEM;
771
772         /* allocate memory for our device state and initialize it */
773         dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
774         if (dev == NULL) {
775                 dev_err(&interface->dev, "Out of memory\n");
776                 return retval;
777         }
778
779         mutex_init(&dev->mutex);
780
781         atomic_set(&dev->intr_idx, 0);
782         atomic_set(&dev->read_idx, 0);
783         spin_lock_init(&dev->intr_idx_lock);
784         atomic_set(&dev->overflow_flag, 0);
785         init_waitqueue_head(&dev->read_wait);
786         atomic_set(&dev->write_busy, 0);
787         init_waitqueue_head(&dev->write_wait);
788
789         dev->udev = udev;
790         dev->interface = interface;
791
792         iface_desc = interface->cur_altsetting;
793         dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
794
795         /* set up the endpoint information */
796         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
797                 endpoint = &iface_desc->endpoint[i].desc;
798
799                 if (usb_endpoint_is_int_in(endpoint))
800                         dev->int_in_endpoint = endpoint;
801                 if (usb_endpoint_is_int_out(endpoint))
802                         /* this one will match for the IOWarrior56 only */
803                         dev->int_out_endpoint = endpoint;
804         }
805         /* we have to check the report_size often, so remember it in the endianess suitable for our machine */
806         dev->report_size = le16_to_cpu(dev->int_in_endpoint->wMaxPacketSize);
807         if ((dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) &&
808             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56))
809                 /* IOWarrior56 has wMaxPacketSize different from report size */
810                 dev->report_size = 7;
811
812         /* create the urb and buffer for reading */
813         dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
814         if (!dev->int_in_urb) {
815                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
816                 goto error;
817         }
818         dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
819         if (!dev->int_in_buffer) {
820                 dev_err(&interface->dev, "Couldn't allocate int_in_buffer\n");
821                 goto error;
822         }
823         usb_fill_int_urb(dev->int_in_urb, dev->udev,
824                          usb_rcvintpipe(dev->udev,
825                                         dev->int_in_endpoint->bEndpointAddress),
826                          dev->int_in_buffer, dev->report_size,
827                          iowarrior_callback, dev,
828                          dev->int_in_endpoint->bInterval);
829         /* create an internal buffer for interrupt data from the device */
830         dev->read_queue =
831             kmalloc(((dev->report_size + 1) * MAX_INTERRUPT_BUFFER),
832                     GFP_KERNEL);
833         if (!dev->read_queue) {
834                 dev_err(&interface->dev, "Couldn't allocate read_queue\n");
835                 goto error;
836         }
837         /* Get the serial-number of the chip */
838         memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
839         usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
840                    sizeof(dev->chip_serial));
841         if (strlen(dev->chip_serial) != 8)
842                 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
843
844         /* Set the idle timeout to 0, if this is interface 0 */
845         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
846             usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
847                             0x0A,
848                             USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
849                             0, NULL, 0, USB_CTRL_SET_TIMEOUT);
850         }
851         /* allow device read and ioctl */
852         dev->present = 1;
853
854         /* we can register the device now, as it is ready */
855         usb_set_intfdata(interface, dev);
856
857         retval = usb_register_dev(interface, &iowarrior_class);
858         if (retval) {
859                 /* something prevented us from registering this driver */
860                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
861                 usb_set_intfdata(interface, NULL);
862                 goto error;
863         }
864
865         dev->minor = interface->minor;
866
867         /* let the user know what node this device is now attached to */
868         dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
869                  "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
870                  iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
871         return retval;
872
873 error:
874         iowarrior_delete(dev);
875         return retval;
876 }
877
878 /**
879  *      iowarrior_disconnect
880  *
881  *      Called by the usb core when the device is removed from the system.
882  */
883 static void iowarrior_disconnect(struct usb_interface *interface)
884 {
885         struct iowarrior *dev;
886         int minor;
887
888         dev = usb_get_intfdata(interface);
889         mutex_lock(&iowarrior_open_disc_lock);
890         usb_set_intfdata(interface, NULL);
891
892         minor = dev->minor;
893
894         /* give back our minor */
895         usb_deregister_dev(interface, &iowarrior_class);
896
897         mutex_lock(&dev->mutex);
898
899         /* prevent device read, write and ioctl */
900         dev->present = 0;
901
902         mutex_unlock(&dev->mutex);
903         mutex_unlock(&iowarrior_open_disc_lock);
904
905         if (dev->opened) {
906                 /* There is a process that holds a filedescriptor to the device ,
907                    so we only shutdown read-/write-ops going on.
908                    Deleting the device is postponed until close() was called.
909                  */
910                 usb_kill_urb(dev->int_in_urb);
911                 wake_up_interruptible(&dev->read_wait);
912                 wake_up_interruptible(&dev->write_wait);
913         } else {
914                 /* no process is using the device, cleanup now */
915                 iowarrior_delete(dev);
916         }
917
918         dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
919                  minor - IOWARRIOR_MINOR_BASE);
920 }
921
922 /* usb specific object needed to register this driver with the usb subsystem */
923 static struct usb_driver iowarrior_driver = {
924         .name = "iowarrior",
925         .probe = iowarrior_probe,
926         .disconnect = iowarrior_disconnect,
927         .id_table = iowarrior_ids,
928 };
929
930 static int __init iowarrior_init(void)
931 {
932         return usb_register(&iowarrior_driver);
933 }
934
935 static void __exit iowarrior_exit(void)
936 {
937         usb_deregister(&iowarrior_driver);
938 }
939
940 module_init(iowarrior_init);
941 module_exit(iowarrior_exit);