drivers/usb/misc/iowarrior.c

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