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