linux/drivers/usb/misc/iowarrior.c
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   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
  59MODULE_AUTHOR(DRIVER_AUTHOR);
  60MODULE_DESCRIPTION(DRIVER_DESC);
  61MODULE_LICENSE("GPL");
  62
  63/* Module parameters */
  64static DEFINE_MUTEX(iowarrior_mutex);
  65static bool debug = 0;
  66module_param(debug, bool, 0644);
  67MODULE_PARM_DESC(debug, "debug=1 enables debugging messages");
  68
  69static struct usb_driver iowarrior_driver;
  70static DEFINE_MUTEX(iowarrior_open_disc_lock);
  71
  72/*--------------*/
  73/*     data     */
  74/*--------------*/
  75
  76/* Structure to hold all of our device specific stuff */
  77struct 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
 112static 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
 127static 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 */
 143static 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};
 151MODULE_DEVICE_TABLE(usb, iowarrior_ids);
 152
 153/*
 154 * USB callback handler for reading data
 155 */
 156static 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
 218exit:
 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 */
 229static 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 */
 253static 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
 266static 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 */
 279static 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 */
 343static 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        }
 462error:
 463        usb_free_coherent(dev->udev, dev->report_size, buf,
 464                          int_out_urb->transfer_dma);
 465error_no_buffer:
 466        usb_free_urb(int_out_urb);
 467error_no_urb:
 468        atomic_dec(&dev->write_busy);
 469        wake_up_interruptible(&dev->write_wait);
 470exit:
 471        mutex_unlock(&dev->mutex);
 472        return retval;
 473}
 474
 475/**
 476 *      iowarrior_ioctl
 477 */
 478static 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        }
 587error_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 */
 598static 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                printk(KERN_ERR "%s - error, can't find device for minor %d\n",
 614                       __func__, 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
 647out:
 648        mutex_unlock(&dev->mutex);
 649        mutex_unlock(&iowarrior_mutex);
 650        return retval;
 651}
 652
 653/**
 654 *      iowarrior_release
 655 */
 656static 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
 695static 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 */
 726static 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
 737static char *iowarrior_devnode(struct device *dev, umode_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 */
 746static 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 */
 762static 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 = usb_endpoint_maxp(dev->int_in_endpoint);
 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
 873error:
 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 */
 883static 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 */
 923static struct usb_driver iowarrior_driver = {
 924        .name = "iowarrior",
 925        .probe = iowarrior_probe,
 926        .disconnect = iowarrior_disconnect,
 927        .id_table = iowarrior_ids,
 928};
 929
 930module_usb_driver(iowarrior_driver);
 931