Version:  2.0.40 2.2.26 2.4.37 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15

Linux/drivers/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/slab.h>
 19 #include <linux/sched.h>
 20 #include <linux/mutex.h>
 21 #include <linux/poll.h>
 22 #include <linux/usb/iowarrior.h>
 23 
 24 /* Version Information */
 25 #define DRIVER_VERSION "v0.4.0"
 26 #define DRIVER_AUTHOR "Christian Lucht <lucht@codemercs.com>"
 27 #define DRIVER_DESC "USB IO-Warrior driver (Linux 2.6.x)"
 28 
 29 #define USB_VENDOR_ID_CODEMERCS         1984
 30 /* low speed iowarrior */
 31 #define USB_DEVICE_ID_CODEMERCS_IOW40   0x1500
 32 #define USB_DEVICE_ID_CODEMERCS_IOW24   0x1501
 33 #define USB_DEVICE_ID_CODEMERCS_IOWPV1  0x1511
 34 #define USB_DEVICE_ID_CODEMERCS_IOWPV2  0x1512
 35 /* full speed iowarrior */
 36 #define USB_DEVICE_ID_CODEMERCS_IOW56   0x1503
 37 
 38 /* Get a minor range for your devices from the usb maintainer */
 39 #ifdef CONFIG_USB_DYNAMIC_MINORS
 40 #define IOWARRIOR_MINOR_BASE    0
 41 #else
 42 #define IOWARRIOR_MINOR_BASE    208     // SKELETON_MINOR_BASE 192 + 16, not official yet
 43 #endif
 44 
 45 /* interrupt input queue size */
 46 #define MAX_INTERRUPT_BUFFER 16
 47 /*
 48    maximum number of urbs that are submitted for writes at the same time,
 49    this applies to the IOWarrior56 only!
 50    IOWarrior24 and IOWarrior40 use synchronous usb_control_msg calls.
 51 */
 52 #define MAX_WRITES_IN_FLIGHT 4
 53 
 54 /* Use our own dbg macro */
 55 #undef dbg
 56 #define dbg( format, arg... ) do { if( debug ) printk( KERN_DEBUG __FILE__ ": " format "\n" , ## arg ); } while ( 0 )
 57 
 58 MODULE_AUTHOR(DRIVER_AUTHOR);
 59 MODULE_DESCRIPTION(DRIVER_DESC);
 60 MODULE_LICENSE("GPL");
 61 
 62 /* Module parameters */
 63 static DEFINE_MUTEX(iowarrior_mutex);
 64 static bool 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 = 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 empty */
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 = 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(count, GFP_KERNEL);
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 = 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         mutex_lock(&iowarrior_mutex);
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)
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                         memset(&info, 0, sizeof(info));
556                         /* directly from the descriptor */
557                         info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
558                         info.product = dev->product_id;
559                         info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
560 
561                         /* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
562                         info.speed = le16_to_cpu(dev->udev->speed);
563                         info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
564                         info.report_size = dev->report_size;
565 
566                         /* serial number string has been read earlier 8 chars or empty string */
567                         memcpy(info.serial, dev->chip_serial,
568                                sizeof(dev->chip_serial));
569                         if (cfg_descriptor == NULL) {
570                                 info.power = -1;        /* no information available */
571                         } else {
572                                 /* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
573                                 info.power = cfg_descriptor->bMaxPower * 2;
574                         }
575                         io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
576                                          sizeof(struct iowarrior_info));
577                         if (io_res)
578                                 retval = -EFAULT;
579                         break;
580                 }
581         default:
582                 /* return that we did not understand this ioctl call */
583                 retval = -ENOTTY;
584                 break;
585         }
586 error_out:
587         /* unlock the device */
588         mutex_unlock(&dev->mutex);
589         mutex_unlock(&iowarrior_mutex);
590         kfree(buffer);
591         return retval;
592 }
593 
594 /**
595  *      iowarrior_open
596  */
597 static int iowarrior_open(struct inode *inode, struct file *file)
598 {
599         struct iowarrior *dev = NULL;
600         struct usb_interface *interface;
601         int subminor;
602         int retval = 0;
603 
604         dbg("%s", __func__);
605 
606         mutex_lock(&iowarrior_mutex);
607         subminor = iminor(inode);
608 
609         interface = usb_find_interface(&iowarrior_driver, subminor);
610         if (!interface) {
611                 mutex_unlock(&iowarrior_mutex);
612                 printk(KERN_ERR "%s - error, can't find device for minor %d\n",
613                        __func__, subminor);
614                 return -ENODEV;
615         }
616 
617         mutex_lock(&iowarrior_open_disc_lock);
618         dev = usb_get_intfdata(interface);
619         if (!dev) {
620                 mutex_unlock(&iowarrior_open_disc_lock);
621                 mutex_unlock(&iowarrior_mutex);
622                 return -ENODEV;
623         }
624 
625         mutex_lock(&dev->mutex);
626         mutex_unlock(&iowarrior_open_disc_lock);
627 
628         /* Only one process can open each device, no sharing. */
629         if (dev->opened) {
630                 retval = -EBUSY;
631                 goto out;
632         }
633 
634         /* setup interrupt handler for receiving values */
635         if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
636                 dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
637                 retval = -EFAULT;
638                 goto out;
639         }
640         /* increment our usage count for the driver */
641         ++dev->opened;
642         /* save our object in the file's private structure */
643         file->private_data = dev;
644         retval = 0;
645 
646 out:
647         mutex_unlock(&dev->mutex);
648         mutex_unlock(&iowarrior_mutex);
649         return retval;
650 }
651 
652 /**
653  *      iowarrior_release
654  */
655 static int iowarrior_release(struct inode *inode, struct file *file)
656 {
657         struct iowarrior *dev;
658         int retval = 0;
659 
660         dev = file->private_data;
661         if (dev == NULL) {
662                 return -ENODEV;
663         }
664 
665         dbg("%s - minor %d", __func__, dev->minor);
666 
667         /* lock our device */
668         mutex_lock(&dev->mutex);
669 
670         if (dev->opened <= 0) {
671                 retval = -ENODEV;       /* close called more than once */
672                 mutex_unlock(&dev->mutex);
673         } else {
674                 dev->opened = 0;        /* we're closing now */
675                 retval = 0;
676                 if (dev->present) {
677                         /*
678                            The device is still connected so we only shutdown
679                            pending read-/write-ops.
680                          */
681                         usb_kill_urb(dev->int_in_urb);
682                         wake_up_interruptible(&dev->read_wait);
683                         wake_up_interruptible(&dev->write_wait);
684                         mutex_unlock(&dev->mutex);
685                 } else {
686                         /* The device was unplugged, cleanup resources */
687                         mutex_unlock(&dev->mutex);
688                         iowarrior_delete(dev);
689                 }
690         }
691         return retval;
692 }
693 
694 static unsigned iowarrior_poll(struct file *file, poll_table * wait)
695 {
696         struct iowarrior *dev = file->private_data;
697         unsigned int mask = 0;
698 
699         if (!dev->present)
700                 return POLLERR | POLLHUP;
701 
702         poll_wait(file, &dev->read_wait, wait);
703         poll_wait(file, &dev->write_wait, wait);
704 
705         if (!dev->present)
706                 return POLLERR | POLLHUP;
707 
708         if (read_index(dev) != -1)
709                 mask |= POLLIN | POLLRDNORM;
710 
711         if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
712                 mask |= POLLOUT | POLLWRNORM;
713         return mask;
714 }
715 
716 /*
717  * File operations needed when we register this driver.
718  * This assumes that this driver NEEDS file operations,
719  * of course, which means that the driver is expected
720  * to have a node in the /dev directory. If the USB
721  * device were for a network interface then the driver
722  * would use "struct net_driver" instead, and a serial
723  * device would use "struct tty_driver".
724  */
725 static const struct file_operations iowarrior_fops = {
726         .owner = THIS_MODULE,
727         .write = iowarrior_write,
728         .read = iowarrior_read,
729         .unlocked_ioctl = iowarrior_ioctl,
730         .open = iowarrior_open,
731         .release = iowarrior_release,
732         .poll = iowarrior_poll,
733         .llseek = noop_llseek,
734 };
735 
736 static char *iowarrior_devnode(struct device *dev, umode_t *mode)
737 {
738         return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
739 }
740 
741 /*
742  * usb class driver info in order to get a minor number from the usb core,
743  * and to have the device registered with devfs and the driver core
744  */
745 static struct usb_class_driver iowarrior_class = {
746         .name = "iowarrior%d",
747         .devnode = iowarrior_devnode,
748         .fops = &iowarrior_fops,
749         .minor_base = IOWARRIOR_MINOR_BASE,
750 };
751 
752 /*---------------------------------*/
753 /*  probe and disconnect functions */
754 /*---------------------------------*/
755 /**
756  *      iowarrior_probe
757  *
758  *      Called by the usb core when a new device is connected that it thinks
759  *      this driver might be interested in.
760  */
761 static int iowarrior_probe(struct usb_interface *interface,
762                            const struct usb_device_id *id)
763 {
764         struct usb_device *udev = interface_to_usbdev(interface);
765         struct iowarrior *dev = NULL;
766         struct usb_host_interface *iface_desc;
767         struct usb_endpoint_descriptor *endpoint;
768         int i;
769         int retval = -ENOMEM;
770 
771         /* allocate memory for our device state and initialize it */
772         dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
773         if (dev == NULL) {
774                 dev_err(&interface->dev, "Out of memory\n");
775                 return retval;
776         }
777 
778         mutex_init(&dev->mutex);
779 
780         atomic_set(&dev->intr_idx, 0);
781         atomic_set(&dev->read_idx, 0);
782         spin_lock_init(&dev->intr_idx_lock);
783         atomic_set(&dev->overflow_flag, 0);
784         init_waitqueue_head(&dev->read_wait);
785         atomic_set(&dev->write_busy, 0);
786         init_waitqueue_head(&dev->write_wait);
787 
788         dev->udev = udev;
789         dev->interface = interface;
790 
791         iface_desc = interface->cur_altsetting;
792         dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
793 
794         /* set up the endpoint information */
795         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
796                 endpoint = &iface_desc->endpoint[i].desc;
797 
798                 if (usb_endpoint_is_int_in(endpoint))
799                         dev->int_in_endpoint = endpoint;
800                 if (usb_endpoint_is_int_out(endpoint))
801                         /* this one will match for the IOWarrior56 only */
802                         dev->int_out_endpoint = endpoint;
803         }
804         /* we have to check the report_size often, so remember it in the endianness suitable for our machine */
805         dev->report_size = usb_endpoint_maxp(dev->int_in_endpoint);
806         if ((dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) &&
807             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56))
808                 /* IOWarrior56 has wMaxPacketSize different from report size */
809                 dev->report_size = 7;
810 
811         /* create the urb and buffer for reading */
812         dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
813         if (!dev->int_in_urb) {
814                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
815                 goto error;
816         }
817         dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
818         if (!dev->int_in_buffer) {
819                 dev_err(&interface->dev, "Couldn't allocate int_in_buffer\n");
820                 goto error;
821         }
822         usb_fill_int_urb(dev->int_in_urb, dev->udev,
823                          usb_rcvintpipe(dev->udev,
824                                         dev->int_in_endpoint->bEndpointAddress),
825                          dev->int_in_buffer, dev->report_size,
826                          iowarrior_callback, dev,
827                          dev->int_in_endpoint->bInterval);
828         /* create an internal buffer for interrupt data from the device */
829         dev->read_queue =
830             kmalloc(((dev->report_size + 1) * MAX_INTERRUPT_BUFFER),
831                     GFP_KERNEL);
832         if (!dev->read_queue) {
833                 dev_err(&interface->dev, "Couldn't allocate read_queue\n");
834                 goto error;
835         }
836         /* Get the serial-number of the chip */
837         memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
838         usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
839                    sizeof(dev->chip_serial));
840         if (strlen(dev->chip_serial) != 8)
841                 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
842 
843         /* Set the idle timeout to 0, if this is interface 0 */
844         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
845             usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
846                             0x0A,
847                             USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
848                             0, NULL, 0, USB_CTRL_SET_TIMEOUT);
849         }
850         /* allow device read and ioctl */
851         dev->present = 1;
852 
853         /* we can register the device now, as it is ready */
854         usb_set_intfdata(interface, dev);
855 
856         retval = usb_register_dev(interface, &iowarrior_class);
857         if (retval) {
858                 /* something prevented us from registering this driver */
859                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
860                 usb_set_intfdata(interface, NULL);
861                 goto error;
862         }
863 
864         dev->minor = interface->minor;
865 
866         /* let the user know what node this device is now attached to */
867         dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
868                  "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
869                  iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
870         return retval;
871 
872 error:
873         iowarrior_delete(dev);
874         return retval;
875 }
876 
877 /**
878  *      iowarrior_disconnect
879  *
880  *      Called by the usb core when the device is removed from the system.
881  */
882 static void iowarrior_disconnect(struct usb_interface *interface)
883 {
884         struct iowarrior *dev;
885         int minor;
886 
887         dev = usb_get_intfdata(interface);
888         mutex_lock(&iowarrior_open_disc_lock);
889         usb_set_intfdata(interface, NULL);
890 
891         minor = dev->minor;
892 
893         /* give back our minor */
894         usb_deregister_dev(interface, &iowarrior_class);
895 
896         mutex_lock(&dev->mutex);
897 
898         /* prevent device read, write and ioctl */
899         dev->present = 0;
900 
901         mutex_unlock(&dev->mutex);
902         mutex_unlock(&iowarrior_open_disc_lock);
903 
904         if (dev->opened) {
905                 /* There is a process that holds a filedescriptor to the device ,
906                    so we only shutdown read-/write-ops going on.
907                    Deleting the device is postponed until close() was called.
908                  */
909                 usb_kill_urb(dev->int_in_urb);
910                 wake_up_interruptible(&dev->read_wait);
911                 wake_up_interruptible(&dev->write_wait);
912         } else {
913                 /* no process is using the device, cleanup now */
914                 iowarrior_delete(dev);
915         }
916 
917         dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
918                  minor - IOWARRIOR_MINOR_BASE);
919 }
920 
921 /* usb specific object needed to register this driver with the usb subsystem */
922 static struct usb_driver iowarrior_driver = {
923         .name = "iowarrior",
924         .probe = iowarrior_probe,
925         .disconnect = iowarrior_disconnect,
926         .id_table = iowarrior_ids,
927 };
928 
929 module_usb_driver(iowarrior_driver);
930 

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