linux/drivers/usb/misc/adutux.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * adutux - driver for ADU devices from Ontrak Control Systems
   4 * This is an experimental driver. Use at your own risk.
   5 * This driver is not supported by Ontrak Control Systems.
   6 *
   7 * Copyright (c) 2003 John Homppi (SCO, leave this notice here)
   8 *
   9 * derived from the Lego USB Tower driver 0.56:
  10 * Copyright (c) 2003 David Glance <davidgsf@sourceforge.net>
  11 *               2001 Juergen Stuber <stuber@loria.fr>
  12 * that was derived from USB Skeleton driver - 0.5
  13 * Copyright (c) 2001 Greg Kroah-Hartman (greg@kroah.com)
  14 *
  15 */
  16
  17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  18
  19#include <linux/kernel.h>
  20#include <linux/sched/signal.h>
  21#include <linux/errno.h>
  22#include <linux/slab.h>
  23#include <linux/module.h>
  24#include <linux/usb.h>
  25#include <linux/mutex.h>
  26#include <linux/uaccess.h>
  27
  28#define DRIVER_AUTHOR "John Homppi"
  29#define DRIVER_DESC "adutux (see www.ontrak.net)"
  30
  31/* Define these values to match your device */
  32#define ADU_VENDOR_ID 0x0a07
  33#define ADU_PRODUCT_ID 0x0064
  34
  35/* table of devices that work with this driver */
  36static const struct usb_device_id device_table[] = {
  37        { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID) },          /* ADU100 */
  38        { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+20) },       /* ADU120 */
  39        { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+30) },       /* ADU130 */
  40        { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+100) },      /* ADU200 */
  41        { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+108) },      /* ADU208 */
  42        { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+118) },      /* ADU218 */
  43        { } /* Terminating entry */
  44};
  45
  46MODULE_DEVICE_TABLE(usb, device_table);
  47
  48#ifdef CONFIG_USB_DYNAMIC_MINORS
  49#define ADU_MINOR_BASE  0
  50#else
  51#define ADU_MINOR_BASE  67
  52#endif
  53
  54/* we can have up to this number of device plugged in at once */
  55#define MAX_DEVICES     16
  56
  57#define COMMAND_TIMEOUT (2*HZ)
  58
  59/*
  60 * The locking scheme is a vanilla 3-lock:
  61 *   adu_device.buflock: A spinlock, covers what IRQs touch.
  62 *   adutux_mutex:       A Static lock to cover open_count. It would also cover
  63 *                       any globals, but we don't have them in 2.6.
  64 *   adu_device.mtx:     A mutex to hold across sleepers like copy_from_user.
  65 *                       It covers all of adu_device, except the open_count
  66 *                       and what .buflock covers.
  67 */
  68
  69/* Structure to hold all of our device specific stuff */
  70struct adu_device {
  71        struct mutex            mtx;
  72        struct usb_device *udev; /* save off the usb device pointer */
  73        struct usb_interface *interface;
  74        unsigned int            minor; /* the starting minor number for this device */
  75        char                    serial_number[8];
  76
  77        int                     open_count; /* number of times this port has been opened */
  78        unsigned long           disconnected:1;
  79
  80        char            *read_buffer_primary;
  81        int                     read_buffer_length;
  82        char            *read_buffer_secondary;
  83        int                     secondary_head;
  84        int                     secondary_tail;
  85        spinlock_t              buflock;
  86
  87        wait_queue_head_t       read_wait;
  88        wait_queue_head_t       write_wait;
  89
  90        char            *interrupt_in_buffer;
  91        struct usb_endpoint_descriptor *interrupt_in_endpoint;
  92        struct urb      *interrupt_in_urb;
  93        int                     read_urb_finished;
  94
  95        char            *interrupt_out_buffer;
  96        struct usb_endpoint_descriptor *interrupt_out_endpoint;
  97        struct urb      *interrupt_out_urb;
  98        int                     out_urb_finished;
  99};
 100
 101static DEFINE_MUTEX(adutux_mutex);
 102
 103static struct usb_driver adu_driver;
 104
 105static inline void adu_debug_data(struct device *dev, const char *function,
 106                                  int size, const unsigned char *data)
 107{
 108        dev_dbg(dev, "%s - length = %d, data = %*ph\n",
 109                function, size, size, data);
 110}
 111
 112/*
 113 * adu_abort_transfers
 114 *      aborts transfers and frees associated data structures
 115 */
 116static void adu_abort_transfers(struct adu_device *dev)
 117{
 118        unsigned long flags;
 119
 120        if (dev->disconnected)
 121                return;
 122
 123        /* shutdown transfer */
 124
 125        /* XXX Anchor these instead */
 126        spin_lock_irqsave(&dev->buflock, flags);
 127        if (!dev->read_urb_finished) {
 128                spin_unlock_irqrestore(&dev->buflock, flags);
 129                usb_kill_urb(dev->interrupt_in_urb);
 130        } else
 131                spin_unlock_irqrestore(&dev->buflock, flags);
 132
 133        spin_lock_irqsave(&dev->buflock, flags);
 134        if (!dev->out_urb_finished) {
 135                spin_unlock_irqrestore(&dev->buflock, flags);
 136                wait_event_timeout(dev->write_wait, dev->out_urb_finished,
 137                        COMMAND_TIMEOUT);
 138                usb_kill_urb(dev->interrupt_out_urb);
 139        } else
 140                spin_unlock_irqrestore(&dev->buflock, flags);
 141}
 142
 143static void adu_delete(struct adu_device *dev)
 144{
 145        /* free data structures */
 146        usb_free_urb(dev->interrupt_in_urb);
 147        usb_free_urb(dev->interrupt_out_urb);
 148        kfree(dev->read_buffer_primary);
 149        kfree(dev->read_buffer_secondary);
 150        kfree(dev->interrupt_in_buffer);
 151        kfree(dev->interrupt_out_buffer);
 152        usb_put_dev(dev->udev);
 153        kfree(dev);
 154}
 155
 156static void adu_interrupt_in_callback(struct urb *urb)
 157{
 158        struct adu_device *dev = urb->context;
 159        int status = urb->status;
 160        unsigned long flags;
 161
 162        adu_debug_data(&dev->udev->dev, __func__,
 163                       urb->actual_length, urb->transfer_buffer);
 164
 165        spin_lock_irqsave(&dev->buflock, flags);
 166
 167        if (status != 0) {
 168                if ((status != -ENOENT) && (status != -ECONNRESET) &&
 169                        (status != -ESHUTDOWN)) {
 170                        dev_dbg(&dev->udev->dev,
 171                                "%s : nonzero status received: %d\n",
 172                                __func__, status);
 173                }
 174                goto exit;
 175        }
 176
 177        if (urb->actual_length > 0 && dev->interrupt_in_buffer[0] != 0x00) {
 178                if (dev->read_buffer_length <
 179                    (4 * usb_endpoint_maxp(dev->interrupt_in_endpoint)) -
 180                     (urb->actual_length)) {
 181                        memcpy (dev->read_buffer_primary +
 182                                dev->read_buffer_length,
 183                                dev->interrupt_in_buffer, urb->actual_length);
 184
 185                        dev->read_buffer_length += urb->actual_length;
 186                        dev_dbg(&dev->udev->dev, "%s reading  %d\n", __func__,
 187                                urb->actual_length);
 188                } else {
 189                        dev_dbg(&dev->udev->dev, "%s : read_buffer overflow\n",
 190                                __func__);
 191                }
 192        }
 193
 194exit:
 195        dev->read_urb_finished = 1;
 196        spin_unlock_irqrestore(&dev->buflock, flags);
 197        /* always wake up so we recover from errors */
 198        wake_up_interruptible(&dev->read_wait);
 199}
 200
 201static void adu_interrupt_out_callback(struct urb *urb)
 202{
 203        struct adu_device *dev = urb->context;
 204        int status = urb->status;
 205        unsigned long flags;
 206
 207        adu_debug_data(&dev->udev->dev, __func__,
 208                       urb->actual_length, urb->transfer_buffer);
 209
 210        if (status != 0) {
 211                if ((status != -ENOENT) &&
 212                    (status != -ESHUTDOWN) &&
 213                    (status != -ECONNRESET)) {
 214                        dev_dbg(&dev->udev->dev,
 215                                "%s :nonzero status received: %d\n", __func__,
 216                                status);
 217                }
 218                return;
 219        }
 220
 221        spin_lock_irqsave(&dev->buflock, flags);
 222        dev->out_urb_finished = 1;
 223        wake_up(&dev->write_wait);
 224        spin_unlock_irqrestore(&dev->buflock, flags);
 225}
 226
 227static int adu_open(struct inode *inode, struct file *file)
 228{
 229        struct adu_device *dev = NULL;
 230        struct usb_interface *interface;
 231        int subminor;
 232        int retval;
 233
 234        subminor = iminor(inode);
 235
 236        retval = mutex_lock_interruptible(&adutux_mutex);
 237        if (retval)
 238                goto exit_no_lock;
 239
 240        interface = usb_find_interface(&adu_driver, subminor);
 241        if (!interface) {
 242                pr_err("%s - error, can't find device for minor %d\n",
 243                       __func__, subminor);
 244                retval = -ENODEV;
 245                goto exit_no_device;
 246        }
 247
 248        dev = usb_get_intfdata(interface);
 249        if (!dev) {
 250                retval = -ENODEV;
 251                goto exit_no_device;
 252        }
 253
 254        /* check that nobody else is using the device */
 255        if (dev->open_count) {
 256                retval = -EBUSY;
 257                goto exit_no_device;
 258        }
 259
 260        ++dev->open_count;
 261        dev_dbg(&dev->udev->dev, "%s: open count %d\n", __func__,
 262                dev->open_count);
 263
 264        /* save device in the file's private structure */
 265        file->private_data = dev;
 266
 267        /* initialize in direction */
 268        dev->read_buffer_length = 0;
 269
 270        /* fixup first read by having urb waiting for it */
 271        usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
 272                         usb_rcvintpipe(dev->udev,
 273                                        dev->interrupt_in_endpoint->bEndpointAddress),
 274                         dev->interrupt_in_buffer,
 275                         usb_endpoint_maxp(dev->interrupt_in_endpoint),
 276                         adu_interrupt_in_callback, dev,
 277                         dev->interrupt_in_endpoint->bInterval);
 278        dev->read_urb_finished = 0;
 279        if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL))
 280                dev->read_urb_finished = 1;
 281        /* we ignore failure */
 282        /* end of fixup for first read */
 283
 284        /* initialize out direction */
 285        dev->out_urb_finished = 1;
 286
 287        retval = 0;
 288
 289exit_no_device:
 290        mutex_unlock(&adutux_mutex);
 291exit_no_lock:
 292        return retval;
 293}
 294
 295static void adu_release_internal(struct adu_device *dev)
 296{
 297        /* decrement our usage count for the device */
 298        --dev->open_count;
 299        dev_dbg(&dev->udev->dev, "%s : open count %d\n", __func__,
 300                dev->open_count);
 301        if (dev->open_count <= 0) {
 302                adu_abort_transfers(dev);
 303                dev->open_count = 0;
 304        }
 305}
 306
 307static int adu_release(struct inode *inode, struct file *file)
 308{
 309        struct adu_device *dev;
 310        int retval = 0;
 311
 312        if (file == NULL) {
 313                retval = -ENODEV;
 314                goto exit;
 315        }
 316
 317        dev = file->private_data;
 318        if (dev == NULL) {
 319                retval = -ENODEV;
 320                goto exit;
 321        }
 322
 323        mutex_lock(&adutux_mutex); /* not interruptible */
 324
 325        if (dev->open_count <= 0) {
 326                dev_dbg(&dev->udev->dev, "%s : device not opened\n", __func__);
 327                retval = -ENODEV;
 328                goto unlock;
 329        }
 330
 331        adu_release_internal(dev);
 332        if (dev->disconnected) {
 333                /* the device was unplugged before the file was released */
 334                if (!dev->open_count)   /* ... and we're the last user */
 335                        adu_delete(dev);
 336        }
 337unlock:
 338        mutex_unlock(&adutux_mutex);
 339exit:
 340        return retval;
 341}
 342
 343static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
 344                        loff_t *ppos)
 345{
 346        struct adu_device *dev;
 347        size_t bytes_read = 0;
 348        size_t bytes_to_read = count;
 349        int retval = 0;
 350        int timeout = 0;
 351        int should_submit = 0;
 352        unsigned long flags;
 353        DECLARE_WAITQUEUE(wait, current);
 354
 355        dev = file->private_data;
 356        if (mutex_lock_interruptible(&dev->mtx))
 357                return -ERESTARTSYS;
 358
 359        /* verify that the device wasn't unplugged */
 360        if (dev->disconnected) {
 361                retval = -ENODEV;
 362                pr_err("No device or device unplugged %d\n", retval);
 363                goto exit;
 364        }
 365
 366        /* verify that some data was requested */
 367        if (count == 0) {
 368                dev_dbg(&dev->udev->dev, "%s : read request of 0 bytes\n",
 369                        __func__);
 370                goto exit;
 371        }
 372
 373        timeout = COMMAND_TIMEOUT;
 374        dev_dbg(&dev->udev->dev, "%s : about to start looping\n", __func__);
 375        while (bytes_to_read) {
 376                size_t data_in_secondary = dev->secondary_tail - dev->secondary_head;
 377                dev_dbg(&dev->udev->dev,
 378                        "%s : while, data_in_secondary=%zu, status=%d\n",
 379                        __func__, data_in_secondary,
 380                        dev->interrupt_in_urb->status);
 381
 382                if (data_in_secondary) {
 383                        /* drain secondary buffer */
 384                        size_t amount = min(bytes_to_read, data_in_secondary);
 385                        if (copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount)) {
 386                                retval = -EFAULT;
 387                                goto exit;
 388                        }
 389                        dev->secondary_head += amount;
 390                        bytes_read += amount;
 391                        bytes_to_read -= amount;
 392                } else {
 393                        /* we check the primary buffer */
 394                        spin_lock_irqsave (&dev->buflock, flags);
 395                        if (dev->read_buffer_length) {
 396                                /* we secure access to the primary */
 397                                char *tmp;
 398                                dev_dbg(&dev->udev->dev,
 399                                        "%s : swap, read_buffer_length = %d\n",
 400                                        __func__, dev->read_buffer_length);
 401                                tmp = dev->read_buffer_secondary;
 402                                dev->read_buffer_secondary = dev->read_buffer_primary;
 403                                dev->read_buffer_primary = tmp;
 404                                dev->secondary_head = 0;
 405                                dev->secondary_tail = dev->read_buffer_length;
 406                                dev->read_buffer_length = 0;
 407                                spin_unlock_irqrestore(&dev->buflock, flags);
 408                                /* we have a free buffer so use it */
 409                                should_submit = 1;
 410                        } else {
 411                                /* even the primary was empty - we may need to do IO */
 412                                if (!dev->read_urb_finished) {
 413                                        /* somebody is doing IO */
 414                                        spin_unlock_irqrestore(&dev->buflock, flags);
 415                                        dev_dbg(&dev->udev->dev,
 416                                                "%s : submitted already\n",
 417                                                __func__);
 418                                } else {
 419                                        /* we must initiate input */
 420                                        dev_dbg(&dev->udev->dev,
 421                                                "%s : initiate input\n",
 422                                                __func__);
 423                                        dev->read_urb_finished = 0;
 424                                        spin_unlock_irqrestore(&dev->buflock, flags);
 425
 426                                        usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
 427                                                        usb_rcvintpipe(dev->udev,
 428                                                                dev->interrupt_in_endpoint->bEndpointAddress),
 429                                                         dev->interrupt_in_buffer,
 430                                                         usb_endpoint_maxp(dev->interrupt_in_endpoint),
 431                                                         adu_interrupt_in_callback,
 432                                                         dev,
 433                                                         dev->interrupt_in_endpoint->bInterval);
 434                                        retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 435                                        if (retval) {
 436                                                dev->read_urb_finished = 1;
 437                                                if (retval == -ENOMEM) {
 438                                                        retval = bytes_read ? bytes_read : -ENOMEM;
 439                                                }
 440                                                dev_dbg(&dev->udev->dev,
 441                                                        "%s : submit failed\n",
 442                                                        __func__);
 443                                                goto exit;
 444                                        }
 445                                }
 446
 447                                /* we wait for I/O to complete */
 448                                set_current_state(TASK_INTERRUPTIBLE);
 449                                add_wait_queue(&dev->read_wait, &wait);
 450                                spin_lock_irqsave(&dev->buflock, flags);
 451                                if (!dev->read_urb_finished) {
 452                                        spin_unlock_irqrestore(&dev->buflock, flags);
 453                                        timeout = schedule_timeout(COMMAND_TIMEOUT);
 454                                } else {
 455                                        spin_unlock_irqrestore(&dev->buflock, flags);
 456                                        set_current_state(TASK_RUNNING);
 457                                }
 458                                remove_wait_queue(&dev->read_wait, &wait);
 459
 460                                if (timeout <= 0) {
 461                                        dev_dbg(&dev->udev->dev,
 462                                                "%s : timeout\n", __func__);
 463                                        retval = bytes_read ? bytes_read : -ETIMEDOUT;
 464                                        goto exit;
 465                                }
 466
 467                                if (signal_pending(current)) {
 468                                        dev_dbg(&dev->udev->dev,
 469                                                "%s : signal pending\n",
 470                                                __func__);
 471                                        retval = bytes_read ? bytes_read : -EINTR;
 472                                        goto exit;
 473                                }
 474                        }
 475                }
 476        }
 477
 478        retval = bytes_read;
 479        /* if the primary buffer is empty then use it */
 480        spin_lock_irqsave(&dev->buflock, flags);
 481        if (should_submit && dev->read_urb_finished) {
 482                dev->read_urb_finished = 0;
 483                spin_unlock_irqrestore(&dev->buflock, flags);
 484                usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
 485                                 usb_rcvintpipe(dev->udev,
 486                                        dev->interrupt_in_endpoint->bEndpointAddress),
 487                                dev->interrupt_in_buffer,
 488                                usb_endpoint_maxp(dev->interrupt_in_endpoint),
 489                                adu_interrupt_in_callback,
 490                                dev,
 491                                dev->interrupt_in_endpoint->bInterval);
 492                if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL) != 0)
 493                        dev->read_urb_finished = 1;
 494                /* we ignore failure */
 495        } else {
 496                spin_unlock_irqrestore(&dev->buflock, flags);
 497        }
 498
 499exit:
 500        /* unlock the device */
 501        mutex_unlock(&dev->mtx);
 502
 503        return retval;
 504}
 505
 506static ssize_t adu_write(struct file *file, const __user char *buffer,
 507                         size_t count, loff_t *ppos)
 508{
 509        DECLARE_WAITQUEUE(waita, current);
 510        struct adu_device *dev;
 511        size_t bytes_written = 0;
 512        size_t bytes_to_write;
 513        size_t buffer_size;
 514        unsigned long flags;
 515        int retval;
 516
 517        dev = file->private_data;
 518
 519        retval = mutex_lock_interruptible(&dev->mtx);
 520        if (retval)
 521                goto exit_nolock;
 522
 523        /* verify that the device wasn't unplugged */
 524        if (dev->disconnected) {
 525                retval = -ENODEV;
 526                pr_err("No device or device unplugged %d\n", retval);
 527                goto exit;
 528        }
 529
 530        /* verify that we actually have some data to write */
 531        if (count == 0) {
 532                dev_dbg(&dev->udev->dev, "%s : write request of 0 bytes\n",
 533                        __func__);
 534                goto exit;
 535        }
 536
 537        while (count > 0) {
 538                add_wait_queue(&dev->write_wait, &waita);
 539                set_current_state(TASK_INTERRUPTIBLE);
 540                spin_lock_irqsave(&dev->buflock, flags);
 541                if (!dev->out_urb_finished) {
 542                        spin_unlock_irqrestore(&dev->buflock, flags);
 543
 544                        mutex_unlock(&dev->mtx);
 545                        if (signal_pending(current)) {
 546                                dev_dbg(&dev->udev->dev, "%s : interrupted\n",
 547                                        __func__);
 548                                set_current_state(TASK_RUNNING);
 549                                retval = -EINTR;
 550                                goto exit_onqueue;
 551                        }
 552                        if (schedule_timeout(COMMAND_TIMEOUT) == 0) {
 553                                dev_dbg(&dev->udev->dev,
 554                                        "%s - command timed out.\n", __func__);
 555                                retval = -ETIMEDOUT;
 556                                goto exit_onqueue;
 557                        }
 558                        remove_wait_queue(&dev->write_wait, &waita);
 559                        retval = mutex_lock_interruptible(&dev->mtx);
 560                        if (retval) {
 561                                retval = bytes_written ? bytes_written : retval;
 562                                goto exit_nolock;
 563                        }
 564
 565                        dev_dbg(&dev->udev->dev,
 566                                "%s : in progress, count = %zd\n",
 567                                __func__, count);
 568                } else {
 569                        spin_unlock_irqrestore(&dev->buflock, flags);
 570                        set_current_state(TASK_RUNNING);
 571                        remove_wait_queue(&dev->write_wait, &waita);
 572                        dev_dbg(&dev->udev->dev, "%s : sending, count = %zd\n",
 573                                __func__, count);
 574
 575                        /* write the data into interrupt_out_buffer from userspace */
 576                        buffer_size = usb_endpoint_maxp(dev->interrupt_out_endpoint);
 577                        bytes_to_write = count > buffer_size ? buffer_size : count;
 578                        dev_dbg(&dev->udev->dev,
 579                                "%s : buffer_size = %zd, count = %zd, bytes_to_write = %zd\n",
 580                                __func__, buffer_size, count, bytes_to_write);
 581
 582                        if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write) != 0) {
 583                                retval = -EFAULT;
 584                                goto exit;
 585                        }
 586
 587                        /* send off the urb */
 588                        usb_fill_int_urb(
 589                                dev->interrupt_out_urb,
 590                                dev->udev,
 591                                usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
 592                                dev->interrupt_out_buffer,
 593                                bytes_to_write,
 594                                adu_interrupt_out_callback,
 595                                dev,
 596                                dev->interrupt_out_endpoint->bInterval);
 597                        dev->interrupt_out_urb->actual_length = bytes_to_write;
 598                        dev->out_urb_finished = 0;
 599                        retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 600                        if (retval < 0) {
 601                                dev->out_urb_finished = 1;
 602                                dev_err(&dev->udev->dev, "Couldn't submit "
 603                                        "interrupt_out_urb %d\n", retval);
 604                                goto exit;
 605                        }
 606
 607                        buffer += bytes_to_write;
 608                        count -= bytes_to_write;
 609
 610                        bytes_written += bytes_to_write;
 611                }
 612        }
 613        mutex_unlock(&dev->mtx);
 614        return bytes_written;
 615
 616exit:
 617        mutex_unlock(&dev->mtx);
 618exit_nolock:
 619        return retval;
 620
 621exit_onqueue:
 622        remove_wait_queue(&dev->write_wait, &waita);
 623        return retval;
 624}
 625
 626/* file operations needed when we register this driver */
 627static const struct file_operations adu_fops = {
 628        .owner = THIS_MODULE,
 629        .read  = adu_read,
 630        .write = adu_write,
 631        .open = adu_open,
 632        .release = adu_release,
 633        .llseek = noop_llseek,
 634};
 635
 636/*
 637 * usb class driver info in order to get a minor number from the usb core,
 638 * and to have the device registered with devfs and the driver core
 639 */
 640static struct usb_class_driver adu_class = {
 641        .name = "usb/adutux%d",
 642        .fops = &adu_fops,
 643        .minor_base = ADU_MINOR_BASE,
 644};
 645
 646/*
 647 * adu_probe
 648 *
 649 * Called by the usb core when a new device is connected that it thinks
 650 * this driver might be interested in.
 651 */
 652static int adu_probe(struct usb_interface *interface,
 653                     const struct usb_device_id *id)
 654{
 655        struct usb_device *udev = interface_to_usbdev(interface);
 656        struct adu_device *dev = NULL;
 657        int retval = -ENOMEM;
 658        int in_end_size;
 659        int out_end_size;
 660        int res;
 661
 662        /* allocate memory for our device state and initialize it */
 663        dev = kzalloc(sizeof(struct adu_device), GFP_KERNEL);
 664        if (!dev)
 665                return -ENOMEM;
 666
 667        mutex_init(&dev->mtx);
 668        spin_lock_init(&dev->buflock);
 669        dev->udev = usb_get_dev(udev);
 670        init_waitqueue_head(&dev->read_wait);
 671        init_waitqueue_head(&dev->write_wait);
 672
 673        res = usb_find_common_endpoints_reverse(interface->cur_altsetting,
 674                        NULL, NULL,
 675                        &dev->interrupt_in_endpoint,
 676                        &dev->interrupt_out_endpoint);
 677        if (res) {
 678                dev_err(&interface->dev, "interrupt endpoints not found\n");
 679                retval = res;
 680                goto error;
 681        }
 682
 683        in_end_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
 684        out_end_size = usb_endpoint_maxp(dev->interrupt_out_endpoint);
 685
 686        dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
 687        if (!dev->read_buffer_primary)
 688                goto error;
 689
 690        /* debug code prime the buffer */
 691        memset(dev->read_buffer_primary, 'a', in_end_size);
 692        memset(dev->read_buffer_primary + in_end_size, 'b', in_end_size);
 693        memset(dev->read_buffer_primary + (2 * in_end_size), 'c', in_end_size);
 694        memset(dev->read_buffer_primary + (3 * in_end_size), 'd', in_end_size);
 695
 696        dev->read_buffer_secondary = kmalloc((4 * in_end_size), GFP_KERNEL);
 697        if (!dev->read_buffer_secondary)
 698                goto error;
 699
 700        /* debug code prime the buffer */
 701        memset(dev->read_buffer_secondary, 'e', in_end_size);
 702        memset(dev->read_buffer_secondary + in_end_size, 'f', in_end_size);
 703        memset(dev->read_buffer_secondary + (2 * in_end_size), 'g', in_end_size);
 704        memset(dev->read_buffer_secondary + (3 * in_end_size), 'h', in_end_size);
 705
 706        dev->interrupt_in_buffer = kmalloc(in_end_size, GFP_KERNEL);
 707        if (!dev->interrupt_in_buffer)
 708                goto error;
 709
 710        /* debug code prime the buffer */
 711        memset(dev->interrupt_in_buffer, 'i', in_end_size);
 712
 713        dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 714        if (!dev->interrupt_in_urb)
 715                goto error;
 716        dev->interrupt_out_buffer = kmalloc(out_end_size, GFP_KERNEL);
 717        if (!dev->interrupt_out_buffer)
 718                goto error;
 719        dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 720        if (!dev->interrupt_out_urb)
 721                goto error;
 722
 723        if (!usb_string(udev, udev->descriptor.iSerialNumber, dev->serial_number,
 724                        sizeof(dev->serial_number))) {
 725                dev_err(&interface->dev, "Could not retrieve serial number\n");
 726                retval = -EIO;
 727                goto error;
 728        }
 729        dev_dbg(&interface->dev, "serial_number=%s", dev->serial_number);
 730
 731        /* we can register the device now, as it is ready */
 732        usb_set_intfdata(interface, dev);
 733
 734        retval = usb_register_dev(interface, &adu_class);
 735
 736        if (retval) {
 737                /* something prevented us from registering this driver */
 738                dev_err(&interface->dev, "Not able to get a minor for this device.\n");
 739                usb_set_intfdata(interface, NULL);
 740                goto error;
 741        }
 742
 743        dev->minor = interface->minor;
 744
 745        /* let the user know what node this device is now attached to */
 746        dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d\n",
 747                 le16_to_cpu(udev->descriptor.idProduct), dev->serial_number,
 748                 (dev->minor - ADU_MINOR_BASE));
 749
 750        return 0;
 751
 752error:
 753        adu_delete(dev);
 754        return retval;
 755}
 756
 757/*
 758 * adu_disconnect
 759 *
 760 * Called by the usb core when the device is removed from the system.
 761 */
 762static void adu_disconnect(struct usb_interface *interface)
 763{
 764        struct adu_device *dev;
 765
 766        dev = usb_get_intfdata(interface);
 767
 768        usb_deregister_dev(interface, &adu_class);
 769
 770        usb_poison_urb(dev->interrupt_in_urb);
 771        usb_poison_urb(dev->interrupt_out_urb);
 772
 773        mutex_lock(&adutux_mutex);
 774        usb_set_intfdata(interface, NULL);
 775
 776        mutex_lock(&dev->mtx);  /* not interruptible */
 777        dev->disconnected = 1;
 778        mutex_unlock(&dev->mtx);
 779
 780        /* if the device is not opened, then we clean up right now */
 781        if (!dev->open_count)
 782                adu_delete(dev);
 783
 784        mutex_unlock(&adutux_mutex);
 785}
 786
 787/* usb specific object needed to register this driver with the usb subsystem */
 788static struct usb_driver adu_driver = {
 789        .name = "adutux",
 790        .probe = adu_probe,
 791        .disconnect = adu_disconnect,
 792        .id_table = device_table,
 793};
 794
 795module_usb_driver(adu_driver);
 796
 797MODULE_AUTHOR(DRIVER_AUTHOR);
 798MODULE_DESCRIPTION(DRIVER_DESC);
 799MODULE_LICENSE("GPL");
 800