drivers/usb/misc/ldusb.c

   1 /**
   2  * Generic USB driver for report based interrupt in/out devices
   3  * like LD Didactic's USB devices. LD Didactic's USB devices are
   4  * HID devices which do not use HID report definitons (they use
   5  * raw interrupt in and our reports only for communication).
   6  *
   7  * This driver uses a ring buffer for time critical reading of
   8  * interrupt in reports and provides read and write methods for
   9  * raw interrupt reports (similar to the Windows HID driver).
  10  * Devices based on the book USB COMPLETE by Jan Axelson may need
  11  * such a compatibility to the Windows HID driver.
  12  *
  13  * Copyright (C) 2005 Michael Hund <mhund@ld-didactic.de>
  14  *
  15  *      This program is free software; you can redistribute it and/or
  16  *      modify it under the terms of the GNU General Public License as
  17  *      published by the Free Software Foundation; either version 2 of
  18  *      the License, or (at your option) any later version.
  19  *
  20  * Derived from Lego USB Tower driver
  21  * Copyright (C) 2003 David Glance <advidgsf@sourceforge.net>
  22  *               2001-2004 Juergen Stuber <starblue@users.sourceforge.net>
  23  */
  24
  25 #include <linux/kernel.h>
  26 #include <linux/errno.h>
  27 #include <linux/init.h>
  28 #include <linux/slab.h>
  29 #include <linux/module.h>
  30 #include <linux/mutex.h>
  31
  32 #include <asm/uaccess.h>
  33 #include <linux/input.h>
  34 #include <linux/usb.h>
  35 #include <linux/poll.h>
  36
  37 /* Define these values to match your devices */
  38 #define USB_VENDOR_ID_LD                0x0f11  /* USB Vendor ID of LD Didactic GmbH */
  39 #define USB_DEVICE_ID_LD_CASSY          0x1000  /* USB Product ID of CASSY-S modules with 8 bytes endpoint size */
  40 #define USB_DEVICE_ID_LD_CASSY2         0x1001  /* USB Product ID of CASSY-S modules with 64 bytes endpoint size */
  41 #define USB_DEVICE_ID_LD_POCKETCASSY    0x1010  /* USB Product ID of Pocket-CASSY */
  42 #define USB_DEVICE_ID_LD_POCKETCASSY2   0x1011  /* USB Product ID of Pocket-CASSY 2 (reserved) */
  43 #define USB_DEVICE_ID_LD_MOBILECASSY    0x1020  /* USB Product ID of Mobile-CASSY */
  44 #define USB_DEVICE_ID_LD_MOBILECASSY2   0x1021  /* USB Product ID of Mobile-CASSY 2 (reserved) */
  45 #define USB_DEVICE_ID_LD_MICROCASSYVOLTAGE      0x1031  /* USB Product ID of Micro-CASSY Voltage */
  46 #define USB_DEVICE_ID_LD_MICROCASSYCURRENT      0x1032  /* USB Product ID of Micro-CASSY Current */
  47 #define USB_DEVICE_ID_LD_MICROCASSYTIME         0x1033  /* USB Product ID of Micro-CASSY Time (reserved) */
  48 #define USB_DEVICE_ID_LD_MICROCASSYTEMPERATURE  0x1035  /* USB Product ID of Micro-CASSY Temperature */
  49 #define USB_DEVICE_ID_LD_MICROCASSYPH           0x1038  /* USB Product ID of Micro-CASSY pH */
  50 #define USB_DEVICE_ID_LD_JWM            0x1080  /* USB Product ID of Joule and Wattmeter */
  51 #define USB_DEVICE_ID_LD_DMMP           0x1081  /* USB Product ID of Digital Multimeter P (reserved) */
  52 #define USB_DEVICE_ID_LD_UMIP           0x1090  /* USB Product ID of UMI P */
  53 #define USB_DEVICE_ID_LD_UMIC           0x10A0  /* USB Product ID of UMI C */
  54 #define USB_DEVICE_ID_LD_UMIB           0x10B0  /* USB Product ID of UMI B */
  55 #define USB_DEVICE_ID_LD_XRAY           0x1100  /* USB Product ID of X-Ray Apparatus 55481 */
  56 #define USB_DEVICE_ID_LD_XRAY2          0x1101  /* USB Product ID of X-Ray Apparatus 554800 */
  57 #define USB_DEVICE_ID_LD_XRAYCT         0x1110  /* USB Product ID of X-Ray Apparatus CT 554821*/
  58 #define USB_DEVICE_ID_LD_VIDEOCOM       0x1200  /* USB Product ID of VideoCom */
  59 #define USB_DEVICE_ID_LD_MOTOR          0x1210  /* USB Product ID of Motor (reserved) */
  60 #define USB_DEVICE_ID_LD_COM3LAB        0x2000  /* USB Product ID of COM3LAB */
  61 #define USB_DEVICE_ID_LD_TELEPORT       0x2010  /* USB Product ID of Terminal Adapter */
  62 #define USB_DEVICE_ID_LD_NETWORKANALYSER 0x2020 /* USB Product ID of Network Analyser */
  63 #define USB_DEVICE_ID_LD_POWERCONTROL   0x2030  /* USB Product ID of Converter Control Unit */
  64 #define USB_DEVICE_ID_LD_MACHINETEST    0x2040  /* USB Product ID of Machine Test System */
  65 #define USB_DEVICE_ID_LD_MOSTANALYSER   0x2050  /* USB Product ID of MOST Protocol Analyser */
  66 #define USB_DEVICE_ID_LD_MOSTANALYSER2  0x2051  /* USB Product ID of MOST Protocol Analyser 2 */
  67 #define USB_DEVICE_ID_LD_ABSESP         0x2060  /* USB Product ID of ABS ESP */
  68 #define USB_DEVICE_ID_LD_AUTODATABUS    0x2070  /* USB Product ID of Automotive Data Buses */
  69 #define USB_DEVICE_ID_LD_MCT            0x2080  /* USB Product ID of Microcontroller technique */
  70 #define USB_DEVICE_ID_LD_HYBRID         0x2090  /* USB Product ID of Automotive Hybrid */
  71 #define USB_DEVICE_ID_LD_HEATCONTROL    0x20A0  /* USB Product ID of Heat control */
  72
  73 #define USB_VENDOR_ID_VERNIER           0x08f7
  74 #define USB_DEVICE_ID_VERNIER_GOTEMP    0x0002
  75 #define USB_DEVICE_ID_VERNIER_SKIP      0x0003
  76 #define USB_DEVICE_ID_VERNIER_CYCLOPS   0x0004
  77 #define USB_DEVICE_ID_VERNIER_LCSPEC    0x0006
  78
  79 #ifdef CONFIG_USB_DYNAMIC_MINORS
  80 #define USB_LD_MINOR_BASE       0
  81 #else
  82 #define USB_LD_MINOR_BASE       176
  83 #endif
  84
  85 /* table of devices that work with this driver */
  86 static const struct usb_device_id ld_usb_table[] = {
  87         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY) },
  88         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY2) },
  89         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY) },
  90         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY2) },
  91         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY) },
  92         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY2) },
  93         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYVOLTAGE) },
  94         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYCURRENT) },
  95         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYTIME) },
  96         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYTEMPERATURE) },
  97         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYPH) },
  98         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_JWM) },
  99         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_DMMP) },
 100         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIP) },
 101         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIC) },
 102         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIB) },
 103         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY) },
 104         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY2) },
 105         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_VIDEOCOM) },
 106         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOTOR) },
 107         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_COM3LAB) },
 108         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_TELEPORT) },
 109         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_NETWORKANALYSER) },
 110         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERCONTROL) },
 111         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETEST) },
 112         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOSTANALYSER) },
 113         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOSTANALYSER2) },
 114         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_ABSESP) },
 115         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_AUTODATABUS) },
 116         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MCT) },
 117         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_HYBRID) },
 118         { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_HEATCONTROL) },
 119         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_GOTEMP) },
 120         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_SKIP) },
 121         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_CYCLOPS) },
 122         { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_LCSPEC) },
 123         { }                                     /* Terminating entry */
 124 };
 125 MODULE_DEVICE_TABLE(usb, ld_usb_table);
 126 MODULE_VERSION("V0.14");
 127 MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>");
 128 MODULE_DESCRIPTION("LD USB Driver");
 129 MODULE_LICENSE("GPL");
 130 MODULE_SUPPORTED_DEVICE("LD USB Devices");
 131
 132 /* All interrupt in transfers are collected in a ring buffer to
 133  * avoid racing conditions and get better performance of the driver.
 134  */
 135 static int ring_buffer_size = 128;
 136 module_param(ring_buffer_size, int, 0);
 137 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
 138
 139 /* The write_buffer can contain more than one interrupt out transfer.
 140  */
 141 static int write_buffer_size = 10;
 142 module_param(write_buffer_size, int, 0);
 143 MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports");
 144
 145 /* As of kernel version 2.6.4 ehci-hcd uses an
 146  * "only one interrupt transfer per frame" shortcut
 147  * to simplify the scheduling of periodic transfers.
 148  * This conflicts with our standard 1ms intervals for in and out URBs.
 149  * We use default intervals of 2ms for in and 2ms for out transfers,
 150  * which should be fast enough.
 151  * Increase the interval to allow more devices that do interrupt transfers,
 152  * or set to 1 to use the standard interval from the endpoint descriptors.
 153  */
 154 static int min_interrupt_in_interval = 2;
 155 module_param(min_interrupt_in_interval, int, 0);
 156 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
 157
 158 static int min_interrupt_out_interval = 2;
 159 module_param(min_interrupt_out_interval, int, 0);
 160 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
 161
 162 /* Structure to hold all of our device specific stuff */
 163 struct ld_usb {
 164         struct mutex            mutex;          /* locks this structure */
 165         struct usb_interface*   intf;           /* save off the usb interface pointer */
 166
 167         int                     open_count;     /* number of times this port has been opened */
 168
 169         char*                   ring_buffer;
 170         unsigned int            ring_head;
 171         unsigned int            ring_tail;
 172
 173         wait_queue_head_t       read_wait;
 174         wait_queue_head_t       write_wait;
 175
 176         char*                   interrupt_in_buffer;
 177         struct usb_endpoint_descriptor* interrupt_in_endpoint;
 178         struct urb*             interrupt_in_urb;
 179         int                     interrupt_in_interval;
 180         size_t                  interrupt_in_endpoint_size;
 181         int                     interrupt_in_running;
 182         int                     interrupt_in_done;
 183         int                     buffer_overflow;
 184         spinlock_t              rbsl;
 185
 186         char*                   interrupt_out_buffer;
 187         struct usb_endpoint_descriptor* interrupt_out_endpoint;
 188         struct urb*             interrupt_out_urb;
 189         int                     interrupt_out_interval;
 190         size_t                  interrupt_out_endpoint_size;
 191         int                     interrupt_out_busy;
 192 };
 193
 194 static struct usb_driver ld_usb_driver;
 195
 196 /**
 197  *      ld_usb_abort_transfers
 198  *      aborts transfers and frees associated data structures
 199  */
 200 static void ld_usb_abort_transfers(struct ld_usb *dev)
 201 {
 202         /* shutdown transfer */
 203         if (dev->interrupt_in_running) {
 204                 dev->interrupt_in_running = 0;
 205                 if (dev->intf)
 206                         usb_kill_urb(dev->interrupt_in_urb);
 207         }
 208         if (dev->interrupt_out_busy)
 209                 if (dev->intf)
 210                         usb_kill_urb(dev->interrupt_out_urb);
 211 }
 212
 213 /**
 214  *      ld_usb_delete
 215  */
 216 static void ld_usb_delete(struct ld_usb *dev)
 217 {
 218         ld_usb_abort_transfers(dev);
 219
 220         /* free data structures */
 221         usb_free_urb(dev->interrupt_in_urb);
 222         usb_free_urb(dev->interrupt_out_urb);
 223         kfree(dev->ring_buffer);
 224         kfree(dev->interrupt_in_buffer);
 225         kfree(dev->interrupt_out_buffer);
 226         kfree(dev);
 227 }
 228
 229 /**
 230  *      ld_usb_interrupt_in_callback
 231  */
 232 static void ld_usb_interrupt_in_callback(struct urb *urb)
 233 {
 234         struct ld_usb *dev = urb->context;
 235         size_t *actual_buffer;
 236         unsigned int next_ring_head;
 237         int status = urb->status;
 238         int retval;
 239
 240         if (status) {
 241                 if (status == -ENOENT ||
 242                     status == -ECONNRESET ||
 243                     status == -ESHUTDOWN) {
 244                         goto exit;
 245                 } else {
 246                         dev_dbg(&dev->intf->dev,
 247                                 "%s: nonzero status received: %d\n", __func__,
 248                                 status);
 249                         spin_lock(&dev->rbsl);
 250                         goto resubmit; /* maybe we can recover */
 251                 }
 252         }
 253
 254         spin_lock(&dev->rbsl);
 255         if (urb->actual_length > 0) {
 256                 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
 257                 if (next_ring_head != dev->ring_tail) {
 258                         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_head*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 259                         /* actual_buffer gets urb->actual_length + interrupt_in_buffer */
 260                         *actual_buffer = urb->actual_length;
 261                         memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length);
 262                         dev->ring_head = next_ring_head;
 263                         dev_dbg(&dev->intf->dev, "%s: received %d bytes\n",
 264                                 __func__, urb->actual_length);
 265                 } else {
 266                         dev_warn(&dev->intf->dev,
 267                                  "Ring buffer overflow, %d bytes dropped\n",
 268                                  urb->actual_length);
 269                         dev->buffer_overflow = 1;
 270                 }
 271         }
 272
 273 resubmit:
 274         /* resubmit if we're still running */
 275         if (dev->interrupt_in_running && !dev->buffer_overflow && dev->intf) {
 276                 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
 277                 if (retval) {
 278                         dev_err(&dev->intf->dev,
 279                                 "usb_submit_urb failed (%d)\n", retval);
 280                         dev->buffer_overflow = 1;
 281                 }
 282         }
 283         spin_unlock(&dev->rbsl);
 284 exit:
 285         dev->interrupt_in_done = 1;
 286         wake_up_interruptible(&dev->read_wait);
 287 }
 288
 289 /**
 290  *      ld_usb_interrupt_out_callback
 291  */
 292 static void ld_usb_interrupt_out_callback(struct urb *urb)
 293 {
 294         struct ld_usb *dev = urb->context;
 295         int status = urb->status;
 296
 297         /* sync/async unlink faults aren't errors */
 298         if (status && !(status == -ENOENT ||
 299                         status == -ECONNRESET ||
 300                         status == -ESHUTDOWN))
 301                 dev_dbg(&dev->intf->dev,
 302                         "%s - nonzero write interrupt status received: %d\n",
 303                         __func__, status);
 304
 305         dev->interrupt_out_busy = 0;
 306         wake_up_interruptible(&dev->write_wait);
 307 }
 308
 309 /**
 310  *      ld_usb_open
 311  */
 312 static int ld_usb_open(struct inode *inode, struct file *file)
 313 {
 314         struct ld_usb *dev;
 315         int subminor;
 316         int retval;
 317         struct usb_interface *interface;
 318
 319         nonseekable_open(inode, file);
 320         subminor = iminor(inode);
 321
 322         interface = usb_find_interface(&ld_usb_driver, subminor);
 323
 324         if (!interface) {
 325                 printk(KERN_ERR "%s - error, can't find device for minor %d\n",
 326                        __func__, subminor);
 327                 return -ENODEV;
 328         }
 329
 330         dev = usb_get_intfdata(interface);
 331
 332         if (!dev)
 333                 return -ENODEV;
 334
 335         /* lock this device */
 336         if (mutex_lock_interruptible(&dev->mutex))
 337                 return -ERESTARTSYS;
 338
 339         /* allow opening only once */
 340         if (dev->open_count) {
 341                 retval = -EBUSY;
 342                 goto unlock_exit;
 343         }
 344         dev->open_count = 1;
 345
 346         /* initialize in direction */
 347         dev->ring_head = 0;
 348         dev->ring_tail = 0;
 349         dev->buffer_overflow = 0;
 350         usb_fill_int_urb(dev->interrupt_in_urb,
 351                          interface_to_usbdev(interface),
 352                          usb_rcvintpipe(interface_to_usbdev(interface),
 353                                         dev->interrupt_in_endpoint->bEndpointAddress),
 354                          dev->interrupt_in_buffer,
 355                          dev->interrupt_in_endpoint_size,
 356                          ld_usb_interrupt_in_callback,
 357                          dev,
 358                          dev->interrupt_in_interval);
 359
 360         dev->interrupt_in_running = 1;
 361         dev->interrupt_in_done = 0;
 362
 363         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 364         if (retval) {
 365                 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
 366                 dev->interrupt_in_running = 0;
 367                 dev->open_count = 0;
 368                 goto unlock_exit;
 369         }
 370
 371         /* save device in the file's private structure */
 372         file->private_data = dev;
 373
 374 unlock_exit:
 375         mutex_unlock(&dev->mutex);
 376
 377         return retval;
 378 }
 379
 380 /**
 381  *      ld_usb_release
 382  */
 383 static int ld_usb_release(struct inode *inode, struct file *file)
 384 {
 385         struct ld_usb *dev;
 386         int retval = 0;
 387
 388         dev = file->private_data;
 389
 390         if (dev == NULL) {
 391                 retval = -ENODEV;
 392                 goto exit;
 393         }
 394
 395         if (mutex_lock_interruptible(&dev->mutex)) {
 396                 retval = -ERESTARTSYS;
 397                 goto exit;
 398         }
 399
 400         if (dev->open_count != 1) {
 401                 retval = -ENODEV;
 402                 goto unlock_exit;
 403         }
 404         if (dev->intf == NULL) {
 405                 /* the device was unplugged before the file was released */
 406                 mutex_unlock(&dev->mutex);
 407                 /* unlock here as ld_usb_delete frees dev */
 408                 ld_usb_delete(dev);
 409                 goto exit;
 410         }
 411
 412         /* wait until write transfer is finished */
 413         if (dev->interrupt_out_busy)
 414                 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
 415         ld_usb_abort_transfers(dev);
 416         dev->open_count = 0;
 417
 418 unlock_exit:
 419         mutex_unlock(&dev->mutex);
 420
 421 exit:
 422         return retval;
 423 }
 424
 425 /**
 426  *      ld_usb_poll
 427  */
 428 static unsigned int ld_usb_poll(struct file *file, poll_table *wait)
 429 {
 430         struct ld_usb *dev;
 431         unsigned int mask = 0;
 432
 433         dev = file->private_data;
 434
 435         if (!dev->intf)
 436                 return POLLERR | POLLHUP;
 437
 438         poll_wait(file, &dev->read_wait, wait);
 439         poll_wait(file, &dev->write_wait, wait);
 440
 441         if (dev->ring_head != dev->ring_tail)
 442                 mask |= POLLIN | POLLRDNORM;
 443         if (!dev->interrupt_out_busy)
 444                 mask |= POLLOUT | POLLWRNORM;
 445
 446         return mask;
 447 }
 448
 449 /**
 450  *      ld_usb_read
 451  */
 452 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
 453                            loff_t *ppos)
 454 {
 455         struct ld_usb *dev;
 456         size_t *actual_buffer;
 457         size_t bytes_to_read;
 458         int retval = 0;
 459         int rv;
 460
 461         dev = file->private_data;
 462
 463         /* verify that we actually have some data to read */
 464         if (count == 0)
 465                 goto exit;
 466
 467         /* lock this object */
 468         if (mutex_lock_interruptible(&dev->mutex)) {
 469                 retval = -ERESTARTSYS;
 470                 goto exit;
 471         }
 472
 473         /* verify that the device wasn't unplugged */
 474         if (dev->intf == NULL) {
 475                 retval = -ENODEV;
 476                 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
 477                 goto unlock_exit;
 478         }
 479
 480         /* wait for data */
 481         spin_lock_irq(&dev->rbsl);
 482         if (dev->ring_head == dev->ring_tail) {
 483                 dev->interrupt_in_done = 0;
 484                 spin_unlock_irq(&dev->rbsl);
 485                 if (file->f_flags & O_NONBLOCK) {
 486                         retval = -EAGAIN;
 487                         goto unlock_exit;
 488                 }
 489                 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
 490                 if (retval < 0)
 491                         goto unlock_exit;
 492         } else {
 493                 spin_unlock_irq(&dev->rbsl);
 494         }
 495
 496         /* actual_buffer contains actual_length + interrupt_in_buffer */
 497         actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_tail*(sizeof(size_t)+dev->interrupt_in_endpoint_size));
 498         bytes_to_read = min(count, *actual_buffer);
 499         if (bytes_to_read < *actual_buffer)
 500                 dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
 501                          *actual_buffer-bytes_to_read);
 502
 503         /* copy one interrupt_in_buffer from ring_buffer into userspace */
 504         if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
 505                 retval = -EFAULT;
 506                 goto unlock_exit;
 507         }
 508         dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
 509
 510         retval = bytes_to_read;
 511
 512         spin_lock_irq(&dev->rbsl);
 513         if (dev->buffer_overflow) {
 514                 dev->buffer_overflow = 0;
 515                 spin_unlock_irq(&dev->rbsl);
 516                 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 517                 if (rv < 0)
 518                         dev->buffer_overflow = 1;
 519         } else {
 520                 spin_unlock_irq(&dev->rbsl);
 521         }
 522
 523 unlock_exit:
 524         /* unlock the device */
 525         mutex_unlock(&dev->mutex);
 526
 527 exit:
 528         return retval;
 529 }
 530
 531 /**
 532  *      ld_usb_write
 533  */
 534 static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
 535                             size_t count, loff_t *ppos)
 536 {
 537         struct ld_usb *dev;
 538         size_t bytes_to_write;
 539         int retval = 0;
 540
 541         dev = file->private_data;
 542
 543         /* verify that we actually have some data to write */
 544         if (count == 0)
 545                 goto exit;
 546
 547         /* lock this object */
 548         if (mutex_lock_interruptible(&dev->mutex)) {
 549                 retval = -ERESTARTSYS;
 550                 goto exit;
 551         }
 552
 553         /* verify that the device wasn't unplugged */
 554         if (dev->intf == NULL) {
 555                 retval = -ENODEV;
 556                 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
 557                 goto unlock_exit;
 558         }
 559
 560         /* wait until previous transfer is finished */
 561         if (dev->interrupt_out_busy) {
 562                 if (file->f_flags & O_NONBLOCK) {
 563                         retval = -EAGAIN;
 564                         goto unlock_exit;
 565                 }
 566                 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
 567                 if (retval < 0) {
 568                         goto unlock_exit;
 569                 }
 570         }
 571
 572         /* write the data into interrupt_out_buffer from userspace */
 573         bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
 574         if (bytes_to_write < count)
 575                 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n",count-bytes_to_write);
 576         dev_dbg(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n",
 577                 __func__, count, bytes_to_write);
 578
 579         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
 580                 retval = -EFAULT;
 581                 goto unlock_exit;
 582         }
 583
 584         if (dev->interrupt_out_endpoint == NULL) {
 585                 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */
 586                 retval = usb_control_msg(interface_to_usbdev(dev->intf),
 587                                          usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0),
 588                                          9,
 589                                          USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 590                                          1 << 8, 0,
 591                                          dev->interrupt_out_buffer,
 592                                          bytes_to_write,
 593                                          USB_CTRL_SET_TIMEOUT * HZ);
 594                 if (retval < 0)
 595                         dev_err(&dev->intf->dev,
 596                                 "Couldn't submit HID_REQ_SET_REPORT %d\n",
 597                                 retval);
 598                 goto unlock_exit;
 599         }
 600
 601         /* send off the urb */
 602         usb_fill_int_urb(dev->interrupt_out_urb,
 603                          interface_to_usbdev(dev->intf),
 604                          usb_sndintpipe(interface_to_usbdev(dev->intf),
 605                                         dev->interrupt_out_endpoint->bEndpointAddress),
 606                          dev->interrupt_out_buffer,
 607                          bytes_to_write,
 608                          ld_usb_interrupt_out_callback,
 609                          dev,
 610                          dev->interrupt_out_interval);
 611
 612         dev->interrupt_out_busy = 1;
 613         wmb();
 614
 615         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 616         if (retval) {
 617                 dev->interrupt_out_busy = 0;
 618                 dev_err(&dev->intf->dev,
 619                         "Couldn't submit interrupt_out_urb %d\n", retval);
 620                 goto unlock_exit;
 621         }
 622         retval = bytes_to_write;
 623
 624 unlock_exit:
 625         /* unlock the device */
 626         mutex_unlock(&dev->mutex);
 627
 628 exit:
 629         return retval;
 630 }
 631
 632 /* file operations needed when we register this driver */
 633 static const struct file_operations ld_usb_fops = {
 634         .owner =        THIS_MODULE,
 635         .read  =        ld_usb_read,
 636         .write =        ld_usb_write,
 637         .open =         ld_usb_open,
 638         .release =      ld_usb_release,
 639         .poll =         ld_usb_poll,
 640         .llseek =       no_llseek,
 641 };
 642
 643 /*
 644  * usb class driver info in order to get a minor number from the usb core,
 645  * and to have the device registered with the driver core
 646  */
 647 static struct usb_class_driver ld_usb_class = {
 648         .name =         "ldusb%d",
 649         .fops =         &ld_usb_fops,
 650         .minor_base =   USB_LD_MINOR_BASE,
 651 };
 652
 653 /**
 654  *      ld_usb_probe
 655  *
 656  *      Called by the usb core when a new device is connected that it thinks
 657  *      this driver might be interested in.
 658  */
 659 static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
 660 {
 661         struct usb_device *udev = interface_to_usbdev(intf);
 662         struct ld_usb *dev = NULL;
 663         struct usb_host_interface *iface_desc;
 664         struct usb_endpoint_descriptor *endpoint;
 665         char *buffer;
 666         int i;
 667         int retval = -ENOMEM;
 668
 669         /* allocate memory for our device state and initialize it */
 670
 671         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 672         if (dev == NULL) {
 673                 dev_err(&intf->dev, "Out of memory\n");
 674                 goto exit;
 675         }
 676         mutex_init(&dev->mutex);
 677         spin_lock_init(&dev->rbsl);
 678         dev->intf = intf;
 679         init_waitqueue_head(&dev->read_wait);
 680         init_waitqueue_head(&dev->write_wait);
 681
 682         /* workaround for early firmware versions on fast computers */
 683         if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) &&
 684             ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) ||
 685              (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) &&
 686             (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) {
 687                 buffer = kmalloc(256, GFP_KERNEL);
 688                 if (buffer == NULL) {
 689                         dev_err(&intf->dev, "Couldn't allocate string buffer\n");
 690                         goto error;
 691                 }
 692                 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */
 693                 usb_string(udev, 255, buffer, 256);
 694                 kfree(buffer);
 695         }
 696
 697         iface_desc = intf->cur_altsetting;
 698
 699         /* set up the endpoint information */
 700         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 701                 endpoint = &iface_desc->endpoint[i].desc;
 702
 703                 if (usb_endpoint_is_int_in(endpoint))
 704                         dev->interrupt_in_endpoint = endpoint;
 705
 706                 if (usb_endpoint_is_int_out(endpoint))
 707                         dev->interrupt_out_endpoint = endpoint;
 708         }
 709         if (dev->interrupt_in_endpoint == NULL) {
 710                 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
 711                 goto error;
 712         }
 713         if (dev->interrupt_out_endpoint == NULL)
 714                 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
 715
 716         dev->interrupt_in_endpoint_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
 717         dev->ring_buffer = kmalloc(ring_buffer_size*(sizeof(size_t)+dev->interrupt_in_endpoint_size), GFP_KERNEL);
 718         if (!dev->ring_buffer) {
 719                 dev_err(&intf->dev, "Couldn't allocate ring_buffer\n");
 720                 goto error;
 721         }
 722         dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
 723         if (!dev->interrupt_in_buffer) {
 724                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
 725                 goto error;
 726         }
 727         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 728         if (!dev->interrupt_in_urb) {
 729                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
 730                 goto error;
 731         }
 732         dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? usb_endpoint_maxp(dev->interrupt_out_endpoint) :
 733                                                                          udev->descriptor.bMaxPacketSize0;
 734         dev->interrupt_out_buffer = kmalloc(write_buffer_size*dev->interrupt_out_endpoint_size, GFP_KERNEL);
 735         if (!dev->interrupt_out_buffer) {
 736                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
 737                 goto error;
 738         }
 739         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 740         if (!dev->interrupt_out_urb) {
 741                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
 742                 goto error;
 743         }
 744         dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
 745         if (dev->interrupt_out_endpoint)
 746                 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
 747
 748         /* we can register the device now, as it is ready */
 749         usb_set_intfdata(intf, dev);
 750
 751         retval = usb_register_dev(intf, &ld_usb_class);
 752         if (retval) {
 753                 /* something prevented us from registering this driver */
 754                 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
 755                 usb_set_intfdata(intf, NULL);
 756                 goto error;
 757         }
 758
 759         /* let the user know what node this device is now attached to */
 760         dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n",
 761                 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor);
 762
 763 exit:
 764         return retval;
 765
 766 error:
 767         ld_usb_delete(dev);
 768
 769         return retval;
 770 }
 771
 772 /**
 773  *      ld_usb_disconnect
 774  *
 775  *      Called by the usb core when the device is removed from the system.
 776  */
 777 static void ld_usb_disconnect(struct usb_interface *intf)
 778 {
 779         struct ld_usb *dev;
 780         int minor;
 781
 782         dev = usb_get_intfdata(intf);
 783         usb_set_intfdata(intf, NULL);
 784
 785         minor = intf->minor;
 786
 787         /* give back our minor */
 788         usb_deregister_dev(intf, &ld_usb_class);
 789
 790         mutex_lock(&dev->mutex);
 791
 792         /* if the device is not opened, then we clean up right now */
 793         if (!dev->open_count) {
 794                 mutex_unlock(&dev->mutex);
 795                 ld_usb_delete(dev);
 796         } else {
 797                 dev->intf = NULL;
 798                 /* wake up pollers */
 799                 wake_up_interruptible_all(&dev->read_wait);
 800                 wake_up_interruptible_all(&dev->write_wait);
 801                 mutex_unlock(&dev->mutex);
 802         }
 803
 804         dev_info(&intf->dev, "LD USB Device #%d now disconnected\n",
 805                  (minor - USB_LD_MINOR_BASE));
 806 }
 807
 808 /* usb specific object needed to register this driver with the usb subsystem */
 809 static struct usb_driver ld_usb_driver = {
 810         .name =         "ldusb",
 811         .probe =        ld_usb_probe,
 812         .disconnect =   ld_usb_disconnect,
 813         .id_table =     ld_usb_table,
 814 };
 815
 816 module_usb_driver(ld_usb_driver);
 817