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