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);