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