libs/surfaces/frontier/kernel_drivers/tranzport.c

   1 /*
   2  * Frontier Designs Tranzport driver
   3  *
   4  * Copyright (C) 2007 Michael Taht (m@taht.net)
   5  *
   6  * Based on the usbled driver and ldusb drivers by
   7  *
   8  * Copyright (C) 2004 Greg Kroah-Hartman (greg@kroah.com)
   9  * Copyright (C) 2005 Michael Hund <mhund@ld-didactic.de>
  10  *
  11  * The ldusb driver was, in turn, derived from Lego USB Tower driver
  12  * Copyright (C) 2003 David Glance <advidgsf@sourceforge.net>
  13  *               2001-2004 Juergen Stuber <starblue@users.sourceforge.net>
  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, version 2.
  18  *
  19  */
  20
  21 /**
  22  * This driver uses a ring buffer for time critical reading of
  23  * interrupt in reports and provides read and write methods for
  24  * raw interrupt reports.
  25  */
  26
  27 /* Note: this currently uses a dumb ringbuffer for reads and writes.
  28  * A more optimal driver would cache and kill off outstanding urbs that are
  29  * now invalid, and ignore ones that already were in the queue but valid
  30  * as we only have 17 commands for the tranzport. In particular this is
  31  * key for getting lights to flash in time as otherwise many commands
  32  * can be buffered up before the light change makes it to the interface.
  33 */
  34
  35 #include <linux/kernel.h>
  36 #include <linux/errno.h>
  37 #include <linux/init.h>
  38 #include <linux/slab.h>
  39 #include <linux/module.h>
  40 #include <linux/mutex.h>
  41 #include <linux/version.h>
  42
  43 #include <asm/uaccess.h>
  44 #include <linux/input.h>
  45 #include <linux/usb.h>
  46 #include <linux/poll.h>
  47
  48 /* Define these values to match your devices */
  49 #define VENDOR_ID       0x165b
  50 #define PRODUCT_ID      0x8101
  51
  52 #ifdef CONFIG_USB_DYNAMIC_MINORS
  53 #define USB_TRANZPORT_MINOR_BASE        0
  54 #else
  55 // FIXME 176 - is the ldusb driver's minor - apply for that
  56 #define USB_TRANZPORT_MINOR_BASE        176
  57 #endif
  58
  59 /* table of devices that work with this driver */
  60 static struct usb_device_id usb_tranzport_table [] = {
  61         { USB_DEVICE(VENDOR_ID, PRODUCT_ID) },
  62         { }                                     /* Terminating entry */
  63 };
  64 MODULE_DEVICE_TABLE(usb, usb_tranzport_table);
  65 MODULE_VERSION("0.29");
  66 MODULE_AUTHOR("Mike Taht <m@taht.net>");
  67 MODULE_DESCRIPTION("Tranzport USB Driver");
  68 MODULE_LICENSE("GPL");
  69 MODULE_SUPPORTED_DEVICE("Frontier Designs Control Surface");
  70
  71
  72 /* make this work on older kernel versions */
  73
  74 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 19)
  75
  76 /**
  77  * usb_endpoint_dir_out - check if the endpoint has OUT direction
  78  * @epd: endpoint to be checked
  79  *
  80  * Returns true if the endpoint is of type OUT, otherwise it returns false.
  81  */
  82
  83 static inline int usb_endpoint_dir_out(const struct usb_endpoint_descriptor *epd)
  84 {
  85        return ((epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT);
  86 }
  87
  88 static inline int usb_endpoint_dir_in(const struct usb_endpoint_descriptor *epd)
  89 {
  90        return ((epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN);
  91 }
  92
  93
  94 /**
  95  * usb_endpoint_xfer_int - check if the endpoint has interrupt transfer type
  96  * @epd: endpoint to be checked
  97  *
  98  * Returns true if the endpoint is of type interrupt, otherwise it returns
  99  * false.
 100  */
 101 static inline int usb_endpoint_xfer_int(const struct usb_endpoint_descriptor *epd)
 102 {
 103        return ((epd->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
 104                USB_ENDPOINT_XFER_INT);
 105 }
 106
 107
 108 /**
 109  * usb_endpoint_is_int_in - check if the endpoint is interrupt IN
 110  * @epd: endpoint to be checked
 111  *
 112  * Returns true if the endpoint has interrupt transfer type and IN direction,
 113  * otherwise it returns false.
 114  */
 115
 116 static inline int usb_endpoint_is_int_in(const struct usb_endpoint_descriptor *epd)
 117 {
 118        return (usb_endpoint_xfer_int(epd) && usb_endpoint_dir_in(epd));
 119 }
 120
 121 /**
 122  * usb_endpoint_is_int_out - check if the endpoint is interrupt OUT
 123  * @epd: endpoint to be checked
 124  *
 125  * Returns true if the endpoint has interrupt transfer type and OUT direction,
 126  * otherwise it returns false.
 127  */
 128
 129 static inline int usb_endpoint_is_int_out(const struct usb_endpoint_descriptor *epd)
 130 {
 131        return (usb_endpoint_xfer_int(epd) && usb_endpoint_dir_out(epd));
 132 }
 133
 134 #endif /* older kernel versions */
 135
 136 /* These two aren't done yet */
 137
 138 #define SUPPRESS_EXTRA_ONLINE_EVENTS 0
 139 #define BUFFERED_WRITES 0
 140
 141 #define SUPPRESS_EXTRA_OFFLINE_EVENTS 1
 142 #define COMPRESS_WHEEL_EVENTS 1
 143 #define BUFFERED_READS 1
 144 #define RING_BUFFER_SIZE 1000
 145 #define WRITE_BUFFER_SIZE 34
 146 #define TRANZPORT_USB_TIMEOUT 10
 147
 148
 149 static int debug = 0;
 150
 151 /* Use our own dbg macro */
 152 #define dbg_info(dev, format, arg...) do { if (debug) dev_info(dev , format , ## arg); } while (0)
 153
 154 /* Module parameters */
 155
 156 module_param(debug, int, S_IRUGO | S_IWUSR);
 157 MODULE_PARM_DESC(debug, "Debug enabled or not");
 158
 159 /* All interrupt in transfers are collected in a ring buffer to
 160  * avoid racing conditions and get better performance of the driver.
 161  */
 162
 163 static int ring_buffer_size = RING_BUFFER_SIZE;
 164
 165 module_param(ring_buffer_size, int,  S_IRUGO);
 166 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
 167
 168 /* The write_buffer can one day contain more than one interrupt out transfer.
 169  */
 170 static int write_buffer_size = WRITE_BUFFER_SIZE;
 171 module_param(write_buffer_size, int,  S_IRUGO);
 172 MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
 173
 174 /*
 175  * Increase the interval for debugging purposes.
 176  * or set to 1 to use the standard interval from the endpoint descriptors.
 177  */
 178
 179 static int min_interrupt_in_interval = TRANZPORT_USB_TIMEOUT;
 180 module_param(min_interrupt_in_interval, int, 0);
 181 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
 182
 183 static int min_interrupt_out_interval = TRANZPORT_USB_TIMEOUT;
 184 module_param(min_interrupt_out_interval, int, 0);
 185 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
 186
 187 struct tranzport_cmd {
 188     unsigned char cmd[8];
 189 };
 190
 191 /* Structure to hold all of our device specific stuff */
 192 struct usb_tranzport {
 193         struct semaphore        sem;            /* locks this structure */
 194         struct usb_interface*   intf;           /* save off the usb interface pointer */
 195
 196         int                     open_count;     /* number of times this port has been opened */
 197
 198         struct tranzport_cmd    (*ring_buffer)[RING_BUFFER_SIZE]; /* just make c happy */
 199         unsigned int            ring_head;
 200         unsigned int            ring_tail;
 201
 202         wait_queue_head_t       read_wait;
 203         wait_queue_head_t       write_wait;
 204
 205         unsigned char*          interrupt_in_buffer;
 206         struct usb_endpoint_descriptor* interrupt_in_endpoint;
 207         struct urb*             interrupt_in_urb;
 208         int                     interrupt_in_interval;
 209         size_t                  interrupt_in_endpoint_size;
 210         int                     interrupt_in_running;
 211         int                     interrupt_in_done;
 212
 213         char*                   interrupt_out_buffer;
 214         struct usb_endpoint_descriptor* interrupt_out_endpoint;
 215         struct urb*             interrupt_out_urb;
 216         int                     interrupt_out_interval;
 217         size_t                  interrupt_out_endpoint_size;
 218         int                     interrupt_out_busy;
 219
 220         /* Sysfs support - most of these are not hooked up yet */
 221
 222     int event; /* alternate interface to events */
 223     int wheel; /* - for negative, 0 for none, + for positive */
 224     int lights;
 225     unsigned char dump_state; /* 0 if disabled 1 if enabled */
 226     unsigned char enable; /* 0 if disabled 1 if enabled */
 227     unsigned char offline; /* if the device is out of range or asleep */
 228     unsigned char compress_wheel; /* flag to compress wheel events */
 229     unsigned char  LightRecord;
 230     unsigned char  LightTrackrec;
 231     unsigned char  LightTrackmute;
 232     unsigned char  LightTracksolo;
 233     unsigned char  LightAnysolo;
 234     unsigned char  LightLoop;
 235     unsigned char  LightPunch;
 236     unsigned char  last_cmd[8];
 237     unsigned char  screen[40]; // We'll also have cells
 238
 239 };
 240
 241 /* prevent races between open() and disconnect() */
 242 static DEFINE_MUTEX(disconnect_mutex);
 243
 244 static struct usb_driver usb_tranzport_driver;
 245
 246 /**
 247  *      usb_tranzport_abort_transfers
 248  *      aborts transfers and frees associated data structures
 249  */
 250 static void usb_tranzport_abort_transfers(struct usb_tranzport *dev)
 251 {
 252         /* shutdown transfer */
 253         if (dev->interrupt_in_running) {
 254                 dev->interrupt_in_running = 0;
 255                 if (dev->intf)
 256                         usb_kill_urb(dev->interrupt_in_urb);
 257         }
 258         if (dev->interrupt_out_busy)
 259                 if (dev->intf)
 260                         usb_kill_urb(dev->interrupt_out_urb);
 261 }
 262
 263 #define show_set_light(value)   \
 264 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)               \
 265 {                                                                       \
 266         struct usb_interface *intf = to_usb_interface(dev);             \
 267         struct usb_tranzport *t = usb_get_intfdata(intf);                       \
 268                                                                         \
 269         return sprintf(buf, "%d\n", t->value);                  \
 270 }                                                                       \
 271 static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)    \
 272 {                                                                       \
 273         struct usb_interface *intf = to_usb_interface(dev);             \
 274         struct usb_tranzport *t = usb_get_intfdata(intf);                       \
 275         int temp = simple_strtoul(buf, NULL, 10);                       \
 276                                                                         \
 277         t->value = temp;                                                \
 278         return count;                                                   \
 279 }                                                                       \
 280 static DEVICE_ATTR(value, S_IWUGO | S_IRUGO, show_##value, set_##value);
 281
 282 show_set_light(LightRecord);
 283 show_set_light(LightTrackrec);
 284 show_set_light(LightTrackmute);
 285 show_set_light(LightTracksolo);
 286 show_set_light(LightAnysolo);
 287 show_set_light(LightLoop);
 288 show_set_light(LightPunch);
 289
 290 show_set_light(enable);
 291 show_set_light(offline);
 292 show_set_light(compress_wheel);
 293 show_set_light(dump_state);
 294
 295 #define show_set_int(value)     \
 296 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)               \
 297 {                                                                       \
 298         struct usb_interface *intf = to_usb_interface(dev);             \
 299         struct usb_tranzport *t = usb_get_intfdata(intf);                       \
 300                                                                         \
 301         return sprintf(buf, "%d\n", t->value);                  \
 302 }                                                                       \
 303 static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)    \
 304 {                                                                       \
 305         struct usb_interface *intf = to_usb_interface(dev);             \
 306         struct usb_tranzport *t = usb_get_intfdata(intf);                       \
 307         int temp = simple_strtoul(buf, NULL, 10);                       \
 308                                                                         \
 309         t->value = temp;                                                \
 310         return count;                                                   \
 311 }                                                                       \
 312 static DEVICE_ATTR(value, S_IWUGO | S_IRUGO, show_##value, set_##value);
 313
 314 show_set_int(wheel);
 315 show_set_int(event);
 316
 317 #define show_set_cmd(value)     \
 318 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)               \
 319 {                                                                       \
 320         struct usb_interface *intf = to_usb_interface(dev);             \
 321         struct usb_tranzport *t = usb_get_intfdata(intf);                       \
 322                                                                         \
 323         return sprintf(buf, "%d\n", t->value);                  \
 324 }                                                                       \
 325 static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)    \
 326 {                                                                       \
 327         struct usb_interface *intf = to_usb_interface(dev);             \
 328         struct usb_tranzport *t = usb_get_intfdata(intf);                       \
 329         int temp = simple_strtoul(buf, NULL, 10);                       \
 330                                                                         \
 331         t->value = temp;                                                \
 332         return count;                                                   \
 333 }                                                                       \
 334 static DEVICE_ATTR(value, S_IWUGO | S_IRUGO, show_##value, set_##value);
 335
 336
 337
 338
 339 /**
 340  *      usb_tranzport_delete
 341  */
 342 static void usb_tranzport_delete(struct usb_tranzport *dev)
 343 {
 344         usb_tranzport_abort_transfers(dev);
 345         /*  This is just too twisted to be correct */
 346         if(dev->intf != NULL) {
 347         device_remove_file(&dev->intf->dev, &dev_attr_LightRecord);
 348         device_remove_file(&dev->intf->dev, &dev_attr_LightTrackrec);
 349         device_remove_file(&dev->intf->dev, &dev_attr_LightTrackmute);
 350         device_remove_file(&dev->intf->dev, &dev_attr_LightTracksolo);
 351         device_remove_file(&dev->intf->dev, &dev_attr_LightTrackmute);
 352         device_remove_file(&dev->intf->dev, &dev_attr_LightAnysolo);
 353         device_remove_file(&dev->intf->dev, &dev_attr_LightLoop);
 354         device_remove_file(&dev->intf->dev, &dev_attr_LightPunch);
 355         device_remove_file(&dev->intf->dev, &dev_attr_wheel);
 356         device_remove_file(&dev->intf->dev, &dev_attr_enable);
 357         device_remove_file(&dev->intf->dev, &dev_attr_event);
 358         device_remove_file(&dev->intf->dev, &dev_attr_offline);
 359         device_remove_file(&dev->intf->dev, &dev_attr_compress_wheel);
 360
 361         device_remove_file(&dev->intf->dev, &dev_attr_dump_state);
 362         }
 363
 364         /* free data structures */
 365         usb_free_urb(dev->interrupt_in_urb);
 366         usb_free_urb(dev->interrupt_out_urb);
 367         kfree(dev->ring_buffer);
 368         kfree(dev->interrupt_in_buffer);
 369         kfree(dev->interrupt_out_buffer);
 370         kfree(dev);
 371 }
 372
 373 /**
 374  *      usb_tranzport_interrupt_in_callback
 375  */
 376
 377 static void usb_tranzport_interrupt_in_callback(struct urb *urb)
 378 {
 379         struct usb_tranzport *dev = urb->context;
 380         unsigned int next_ring_head;
 381         int retval = -1;
 382
 383         if (urb->status) {
 384                 if (urb->status == -ENOENT ||
 385                     urb->status == -ECONNRESET ||
 386                     urb->status == -ESHUTDOWN) {
 387                         goto exit;
 388                 } else {
 389                         dbg_info(&dev->intf->dev, "%s: nonzero status received: %d\n",
 390                                  __FUNCTION__, urb->status);
 391                         goto resubmit; /* maybe we can recover */
 392                 }
 393         }
 394
 395         if (urb->actual_length != 8) {
 396                 dev_warn(&dev->intf->dev,
 397                          "Urb length was %d bytes!! Do something intelligent \n", urb->actual_length);
 398         } else {
 399                 dbg_info(&dev->intf->dev, "%s: received: %02x%02x%02x%02x%02x%02x%02x%02x\n",
 400                          __FUNCTION__, dev->interrupt_in_buffer[0],dev->interrupt_in_buffer[1],dev->interrupt_in_buffer[2],dev->interrupt_in_buffer[3],dev->interrupt_in_buffer[4],dev->interrupt_in_buffer[5],dev->interrupt_in_buffer[6],dev->interrupt_in_buffer[7]);
 401 #if SUPPRESS_EXTRA_OFFLINE_EVENTS
 402                 if(dev->offline == 2 && dev->interrupt_in_buffer[1] == 0xff) { goto resubmit; }
 403                 if(dev->offline == 1 && dev->interrupt_in_buffer[1] == 0xff) { dev->offline = 2; goto resubmit; }
 404
 405 /* Always pass one offline event up the stack */
 406                 if(dev->offline > 0 && dev->interrupt_in_buffer[1] != 0xff) { dev->offline = 0; }
 407                 if(dev->offline == 0 && dev->interrupt_in_buffer[1] == 0xff) { dev->offline = 1; }
 408
 409 #endif
 410                 dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n", __FUNCTION__,dev->ring_head,dev->ring_tail);
 411
 412                 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
 413
 414                 if (next_ring_head != dev->ring_tail) {
 415                         memcpy(&((*dev->ring_buffer)[dev->ring_head]), dev->interrupt_in_buffer, urb->actual_length);
 416                         dev->ring_head = next_ring_head;
 417                         retval = 0;
 418                         memset(dev->interrupt_in_buffer, 0, urb->actual_length);
 419                 } else {
 420                         dev_warn(&dev->intf->dev,
 421                                  "Ring buffer overflow, %d bytes dropped\n",
 422                                  urb->actual_length);
 423                         memset(dev->interrupt_in_buffer, 0, urb->actual_length);
 424                 }
 425         }
 426
 427 resubmit:
 428         /* resubmit if we're still running */
 429         if (dev->interrupt_in_running && dev->intf) {
 430                 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
 431                 if (retval)
 432                         dev_err(&dev->intf->dev,
 433                                 "usb_submit_urb failed (%d)\n", retval);
 434         }
 435
 436 exit:
 437         dev->interrupt_in_done = 1;
 438         wake_up_interruptible(&dev->read_wait);
 439 }
 440
 441 /**
 442  *      usb_tranzport_interrupt_out_callback
 443  */
 444 static void usb_tranzport_interrupt_out_callback(struct urb *urb)
 445 {
 446         struct usb_tranzport *dev = urb->context;
 447
 448         /* sync/async ::g_unlink faults aren't errors */
 449         if (urb->status && !(urb->status == -ENOENT ||
 450                              urb->status == -ECONNRESET ||
 451                              urb->status == -ESHUTDOWN))
 452                 dbg_info(&dev->intf->dev,
 453                          "%s - nonzero write interrupt status received: %d\n",
 454                          __FUNCTION__, urb->status);
 455
 456         dev->interrupt_out_busy = 0;
 457         wake_up_interruptible(&dev->write_wait);
 458 }
 459
 460 /**
 461  *      usb_tranzport_open
 462  */
 463 static int usb_tranzport_open(struct inode *inode, struct file *file)
 464 {
 465         struct usb_tranzport *dev;
 466         int subminor;
 467         int retval = 0;
 468         struct usb_interface *interface;
 469
 470         nonseekable_open(inode, file);
 471         subminor = iminor(inode);
 472
 473         mutex_lock(&disconnect_mutex);
 474
 475         interface = usb_find_interface(&usb_tranzport_driver, subminor);
 476
 477         if (!interface) {
 478                 err("%s - error, can't find device for minor %d\n",
 479                      __FUNCTION__, subminor);
 480                 retval = -ENODEV;
 481                 goto unlock_disconnect_exit;
 482         }
 483
 484         dev = usb_get_intfdata(interface);
 485
 486         if (!dev) {
 487                 retval = -ENODEV;
 488                 goto unlock_disconnect_exit;
 489         }
 490
 491         /* lock this device */
 492         if (down_interruptible(&dev->sem)) {
 493                 retval = -ERESTARTSYS;
 494                 goto unlock_disconnect_exit;
 495         }
 496
 497         /* allow opening only once */
 498         if (dev->open_count) {
 499                 retval = -EBUSY;
 500                 goto unlock_exit;
 501         }
 502         dev->open_count = 1;
 503
 504         /* initialize in direction */
 505         dev->ring_head = 0;
 506         dev->ring_tail = 0;
 507         usb_fill_int_urb(dev->interrupt_in_urb,
 508                          interface_to_usbdev(interface),
 509                          usb_rcvintpipe(interface_to_usbdev(interface),
 510                                         dev->interrupt_in_endpoint->bEndpointAddress),
 511                          dev->interrupt_in_buffer,
 512                          dev->interrupt_in_endpoint_size,
 513                          usb_tranzport_interrupt_in_callback,
 514                          dev,
 515                          dev->interrupt_in_interval);
 516
 517         dev->interrupt_in_running = 1;
 518         dev->interrupt_in_done = 0;
 519         dev->enable = 1;
 520         dev->offline = 0;
 521         dev->compress_wheel = 1;
 522
 523         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 524         if (retval) {
 525                 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
 526                 dev->interrupt_in_running = 0;
 527                 dev->open_count = 0;
 528                 goto unlock_exit;
 529         }
 530
 531         /* save device in the file's private structure */
 532         file->private_data = dev;
 533
 534
 535 unlock_exit:
 536         up(&dev->sem);
 537
 538 unlock_disconnect_exit:
 539         mutex_unlock(&disconnect_mutex);
 540
 541         return retval;
 542 }
 543
 544 /**
 545  *      usb_tranzport_release
 546  */
 547 static int usb_tranzport_release(struct inode *inode, struct file *file)
 548 {
 549         struct usb_tranzport *dev;
 550         int retval = 0;
 551
 552         dev = file->private_data;
 553
 554         if (dev == NULL) {
 555                 retval = -ENODEV;
 556                 goto exit;
 557         }
 558
 559         if (down_interruptible(&dev->sem)) {
 560                 retval = -ERESTARTSYS;
 561                 goto exit;
 562         }
 563
 564         if (dev->open_count != 1) {
 565                 retval = -ENODEV;
 566                 goto unlock_exit;
 567         }
 568
 569         if (dev->intf == NULL) {
 570                 /* the device was unplugged before the file was released */
 571                 up(&dev->sem);
 572                 /* unlock here as usb_tranzport_delete frees dev */
 573                 usb_tranzport_delete(dev);
 574                 retval = -ENODEV;
 575                 goto exit;
 576         }
 577
 578         /* wait until write transfer is finished */
 579         if (dev->interrupt_out_busy)
 580                 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
 581         usb_tranzport_abort_transfers(dev);
 582         dev->open_count = 0;
 583
 584 unlock_exit:
 585         up(&dev->sem);
 586
 587 exit:
 588         return retval;
 589 }
 590
 591 /**
 592  *      usb_tranzport_poll
 593  */
 594 static unsigned int usb_tranzport_poll(struct file *file, poll_table *wait)
 595 {
 596         struct usb_tranzport *dev;
 597         unsigned int mask = 0;
 598
 599         dev = file->private_data;
 600
 601         poll_wait(file, &dev->read_wait, wait);
 602         poll_wait(file, &dev->write_wait, wait);
 603
 604         if (dev->ring_head != dev->ring_tail)
 605                 mask |= POLLIN | POLLRDNORM;
 606         if (!dev->interrupt_out_busy)
 607                 mask |= POLLOUT | POLLWRNORM;
 608
 609         return mask;
 610 }
 611
 612 /**
 613  *      usb_tranzport_read
 614  */
 615 static ssize_t usb_tranzport_read(struct file *file, char __user *buffer, size_t count,
 616                            loff_t *ppos)
 617 {
 618         struct usb_tranzport *dev;
 619         size_t bytes_to_read;
 620         int retval = 0;
 621
 622 #if BUFFERED_READS
 623         int c = 0;
 624 #endif
 625
 626 #if COMPRESS_WHEEL_EVENTS
 627         signed char oldwheel;
 628         signed char newwheel;
 629         int cancompress = 1;
 630         int next_tail;
 631 #endif
 632
 633 /* do I have such a thing as a null event? */
 634
 635         dev = file->private_data;
 636
 637         /* verify that we actually have some data to read */
 638         if (count == 0)
 639                 goto exit;
 640
 641         /* lock this object */
 642         if (down_interruptible(&dev->sem)) {
 643                 retval = -ERESTARTSYS;
 644                 goto exit;
 645         }
 646
 647         /* verify that the device wasn't unplugged */
 648         if (dev->intf == NULL) {
 649                 retval = -ENODEV;
 650                 err("No device or device unplugged %d\n", retval);
 651                 goto unlock_exit;
 652         }
 653
 654         while (dev->ring_head == dev->ring_tail) {
 655
 656                 if (file->f_flags & O_NONBLOCK) {
 657                         retval = -EAGAIN;
 658                         goto unlock_exit;
 659                 }
 660                 // atomic_cmp_exchange(&dev->interrupt_in_done,0,0);
 661                 dev->interrupt_in_done = 0 ; /* tiny race - FIXME: make atomic? */
 662                 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
 663                 if (retval < 0) {
 664                         goto unlock_exit;
 665                 }
 666         }
 667
 668         dbg_info(&dev->intf->dev, "%s: copying to userspace: %02x%02x%02x%02x%02x%02x%02x%02x\n",
 669                          __FUNCTION__, (*dev->ring_buffer)[dev->ring_tail].cmd[0],(*dev->ring_buffer)[dev->ring_tail].cmd[1],(*dev->ring_buffer)[dev->ring_tail].cmd[2],(*dev->ring_buffer)[dev->ring_tail].cmd[3],(*dev->ring_buffer)[dev->ring_tail].cmd[4],(*dev->ring_buffer)[dev->ring_tail].cmd[5],(*dev->ring_buffer)[dev->ring_tail].cmd[6],(*dev->ring_buffer)[dev->ring_tail].cmd[7]);
 670
 671 #if BUFFERED_READS
 672            c = 0;
 673            while((c < count) && (dev->ring_tail != dev->ring_head)) {
 674
 675 /* This started off in the lower level service routine, and I moved it here. Then my brain died. Not done yet. */
 676 #if COMPRESS_WHEEL_EVENTS
 677                 next_tail = (dev->ring_tail+1) % ring_buffer_size;
 678                 if(dev->compress_wheel) cancompress = 1;
 679                 while(dev->ring_head != next_tail && cancompress == 1 ) {
 680                         newwheel = (*dev->ring_buffer)[next_tail].cmd[6];
 681                         oldwheel = (*dev->ring_buffer)[dev->ring_tail].cmd[6];
 682                         // if both are wheel events, and no buttons have changes (FIXME, do I have to check?),
 683                         // and we are the same sign, we can compress +- 7F
 684                         // FIXME: saner check for overflow! - max of +- 7F
 685                         // FIXME the math is wrong for going in reverse, actually, as the midi spec doesn't allow signed chars
 686
 687         dbg_info(&dev->intf->dev, "%s: trying to compress: %02x%02x%02x%02x%02x %02x %02x %02x\n",
 688                          __FUNCTION__, (*dev->ring_buffer)[dev->ring_tail].cmd[0],(*dev->ring_buffer)[dev->ring_tail].cmd[1],(*dev->ring_buffer)[dev->ring_tail].cmd[2],(*dev->ring_buffer)[dev->ring_tail].cmd[3],(*dev->ring_buffer)[dev->ring_tail].cmd[4],(*dev->ring_buffer)[dev->ring_tail].cmd[5],(*dev->ring_buffer)[dev->ring_tail].cmd[6],(*dev->ring_buffer)[dev->ring_tail].cmd[7]);
 689
 690
 691                         if(((*dev->ring_buffer)[dev->ring_tail].cmd[6] != 0 &&
 692                             (*dev->ring_buffer)[next_tail].cmd[6] != 0 ) &&
 693                                 ((newwheel > 0 && oldwheel > 0) ||
 694                                 (newwheel < 0 && oldwheel < 0)) &&
 695                                 ((*dev->ring_buffer)[dev->ring_tail].cmd[2] == (*dev->ring_buffer)[next_tail].cmd[2]) &&
 696                                 ((*dev->ring_buffer)[dev->ring_tail].cmd[3] == (*dev->ring_buffer)[next_tail].cmd[3]) &&
 697                                 ((*dev->ring_buffer)[dev->ring_tail].cmd[4] == (*dev->ring_buffer)[next_tail].cmd[4]) &&
 698                                 ((*dev->ring_buffer)[dev->ring_tail].cmd[5] == (*dev->ring_buffer)[next_tail].cmd[5]))
 699  {
 700         dbg_info(&dev->intf->dev, "%s: should compress: %02x%02x%02x%02x%02x%02x%02x%02x\n",
 701                          __FUNCTION__, (*dev->ring_buffer)[dev->ring_tail].cmd[0],(*dev->ring_buffer)[dev->ring_tail].cmd[1],(*dev->ring_buffer)[dev->ring_tail].cmd[2],(*dev->ring_buffer)[dev->ring_tail].cmd[3],(*dev->ring_buffer)[dev->ring_tail].cmd[4],(*dev->ring_buffer)[dev->ring_tail].cmd[5],(*dev->ring_buffer)[dev->ring_tail].cmd[6],(*dev->ring_buffer)[dev->ring_tail].cmd[7]);
 702
 703                                 newwheel += oldwheel;
 704                                 if(oldwheel > 0 && !(newwheel > 0)) {
 705                                         newwheel = 0x7f;
 706                                         cancompress = 0;
 707                                 }
 708                                 if(oldwheel < 0 && !(newwheel < 0)) {
 709                                         newwheel = 0x80;
 710                                         cancompress = 0;
 711                                 }
 712
 713                                 (*dev->ring_buffer)[next_tail].cmd[6] = newwheel;
 714                                 dev->ring_tail = next_tail;
 715                                 next_tail = (dev->ring_tail+1) % ring_buffer_size;
 716                         } else {
 717                                 cancompress = 0;
 718                         }
 719                 }
 720 #endif /* COMPRESS_WHEEL_EVENTS */
 721
 722                 if (copy_to_user(&buffer[c], &(*dev->ring_buffer)[dev->ring_tail], 8)) {
 723                         retval = -EFAULT;
 724                         goto unlock_exit;
 725                 }
 726
 727                 dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
 728                 c+=8;
 729                 dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n", __FUNCTION__,dev->ring_head,dev->ring_tail);
 730            }
 731            retval = c;
 732
 733 #else
 734         if (copy_to_user(buffer, &(*dev->ring_buffer)[dev->ring_tail], 8)) {
 735                 retval = -EFAULT;
 736                 goto unlock_exit;
 737         }
 738
 739         dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
 740         dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n", __FUNCTION__,dev->ring_head,dev->ring_tail);
 741
 742         retval = 8;
 743 #endif /* BUFFERED_READS */
 744
 745 unlock_exit:
 746         /* unlock the device */
 747         up(&dev->sem);
 748
 749 exit:
 750         return retval;
 751 }
 752
 753 /**
 754  *      usb_tranzport_write
 755  */
 756 static ssize_t usb_tranzport_write(struct file *file, const char __user *buffer,
 757                             size_t count, loff_t *ppos)
 758 {
 759         struct usb_tranzport *dev;
 760         size_t bytes_to_write;
 761         int retval = 0;
 762
 763         dev = file->private_data;
 764
 765         /* verify that we actually have some data to write */
 766         if (count == 0)
 767                 goto exit;
 768
 769         /* lock this object */
 770         if (down_interruptible(&dev->sem)) {
 771                 retval = -ERESTARTSYS;
 772                 goto exit;
 773         }
 774
 775         /* verify that the device wasn't unplugged */
 776         if (dev->intf == NULL) {
 777                 retval = -ENODEV;
 778                 err("No device or device unplugged %d\n", retval);
 779                 goto unlock_exit;
 780         }
 781
 782         /* wait until previous transfer is finished */
 783         if (dev->interrupt_out_busy) {
 784                 if (file->f_flags & O_NONBLOCK) {
 785                         retval = -EAGAIN;
 786                         goto unlock_exit;
 787                 }
 788                 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
 789                 if (retval < 0) {
 790                         goto unlock_exit;
 791                 }
 792         }
 793
 794         /* write the data into interrupt_out_buffer from userspace */
 795         bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
 796         if (bytes_to_write < count)
 797                 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n",count-bytes_to_write);
 798
 799         dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n", __FUNCTION__, count, bytes_to_write);
 800
 801         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
 802                 retval = -EFAULT;
 803                 goto unlock_exit;
 804         }
 805
 806         if (dev->interrupt_out_endpoint == NULL) {
 807                 err("Endpoint should not be be null! \n");
 808                 goto unlock_exit;
 809         }
 810
 811         /* send off the urb */
 812         usb_fill_int_urb(dev->interrupt_out_urb,
 813                          interface_to_usbdev(dev->intf),
 814                          usb_sndintpipe(interface_to_usbdev(dev->intf),
 815                                         dev->interrupt_out_endpoint->bEndpointAddress),
 816                          dev->interrupt_out_buffer,
 817                          bytes_to_write,
 818                          usb_tranzport_interrupt_out_callback,
 819                          dev,
 820                          dev->interrupt_out_interval);
 821
 822         dev->interrupt_out_busy = 1;
 823         wmb();
 824
 825         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 826         if (retval) {
 827                 dev->interrupt_out_busy = 0;
 828                 err("Couldn't submit interrupt_out_urb %d\n", retval);
 829                 goto unlock_exit;
 830         }
 831         retval = bytes_to_write;
 832
 833 unlock_exit:
 834         /* unlock the device */
 835         up(&dev->sem);
 836
 837 exit:
 838         return retval;
 839 }
 840
 841 /* file operations needed when we register this driver */
 842 static const struct file_operations usb_tranzport_fops = {
 843         .owner =        THIS_MODULE,
 844         .read  =        usb_tranzport_read,
 845         .write =        usb_tranzport_write,
 846         .open =         usb_tranzport_open,
 847         .release =      usb_tranzport_release,
 848         .poll =         usb_tranzport_poll,
 849 };
 850
 851 /*
 852  * usb class driver info in order to get a minor number from the usb core,
 853  * and to have the device registered with the driver core
 854  */
 855 static struct usb_class_driver usb_tranzport_class = {
 856         .name =         "tranzport%d",
 857         .fops =         &usb_tranzport_fops,
 858         .minor_base =   USB_TRANZPORT_MINOR_BASE,
 859 };
 860
 861
 862 /**
 863  *      usb_tranzport_probe
 864  *
 865  *      Called by the usb core when a new device is connected that it thinks
 866  *      this driver might be interested in.
 867  */
 868 static int usb_tranzport_probe(struct usb_interface *intf, const struct usb_device_id *id)
 869 {
 870         struct usb_device *udev = interface_to_usbdev(intf);
 871         struct usb_tranzport *dev = NULL;
 872         struct usb_host_interface *iface_desc;
 873         struct usb_endpoint_descriptor *endpoint;
 874         int i;
 875         int true_size;
 876         int retval = -ENOMEM;
 877
 878         /* allocate memory for our device state and intialize it */
 879
 880         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 881         if (dev == NULL) {
 882                 dev_err(&intf->dev, "Out of memory\n");
 883                 goto exit;
 884         }
 885         init_MUTEX(&dev->sem);
 886         dev->intf = intf;
 887         init_waitqueue_head(&dev->read_wait);
 888         init_waitqueue_head(&dev->write_wait);
 889
 890         iface_desc = intf->cur_altsetting;
 891
 892         /* set up the endpoint information */
 893         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 894                 endpoint = &iface_desc->endpoint[i].desc;
 895
 896                 if (usb_endpoint_is_int_in(endpoint))
 897                         dev->interrupt_in_endpoint = endpoint;
 898
 899                 if (usb_endpoint_is_int_out(endpoint))
 900                         dev->interrupt_out_endpoint = endpoint;
 901         }
 902         if (dev->interrupt_in_endpoint == NULL) {
 903                 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
 904                 goto error;
 905         }
 906         if (dev->interrupt_out_endpoint == NULL)
 907                 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
 908
 909
 910         dev->interrupt_in_endpoint_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
 911
 912         if (dev->interrupt_in_endpoint_size != 8)
 913             dev_warn(&intf->dev, "Interrupt in endpoint size is not 8!\n");
 914
 915         if(ring_buffer_size == 0) { ring_buffer_size = RING_BUFFER_SIZE; }
 916         true_size = min(ring_buffer_size,RING_BUFFER_SIZE);
 917         /* FIXME - there are more usb_alloc routines for dma correctness. Needed? */
 918
 919         dev->ring_buffer = kmalloc((true_size*sizeof(struct tranzport_cmd))+8, GFP_KERNEL);
 920
 921         if (!dev->ring_buffer) {
 922                 dev_err(&intf->dev, "Couldn't allocate ring_buffer of size %d\n",true_size);
 923                 goto error;
 924         }
 925         dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
 926         if (!dev->interrupt_in_buffer) {
 927                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
 928                 goto error;
 929         }
 930         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 931         if (!dev->interrupt_in_urb) {
 932                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
 933                 goto error;
 934         }
 935         dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize) :
 936                                                                          udev->descriptor.bMaxPacketSize0;
 937
 938         if (dev->interrupt_out_endpoint_size !=8)
 939                 dev_warn(&intf->dev, "Interrupt out endpoint size is not 8!)\n");
 940
 941         dev->interrupt_out_buffer = kmalloc(write_buffer_size*dev->interrupt_out_endpoint_size, GFP_KERNEL);
 942         if (!dev->interrupt_out_buffer) {
 943                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
 944                 goto error;
 945         }
 946         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 947         if (!dev->interrupt_out_urb) {
 948                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
 949                 goto error;
 950         }
 951         dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
 952         if (dev->interrupt_out_endpoint)
 953                 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
 954
 955         /* we can register the device now, as it is ready */
 956         usb_set_intfdata(intf, dev);
 957
 958         retval = usb_register_dev(intf, &usb_tranzport_class);
 959         if (retval) {
 960                 /* something prevented us from registering this driver */
 961                 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
 962                 usb_set_intfdata(intf, NULL);
 963                 goto error;
 964         }
 965
 966         if((retval = device_create_file(&intf->dev, &dev_attr_LightRecord))) goto error;
 967         if((retval = device_create_file(&intf->dev, &dev_attr_LightTrackrec))) goto error;
 968         if((retval = device_create_file(&intf->dev, &dev_attr_LightTrackmute))) goto error;
 969         if((retval = device_create_file(&intf->dev, &dev_attr_LightTracksolo))) goto error;
 970         if((retval = device_create_file(&intf->dev, &dev_attr_LightAnysolo))) goto error;
 971         if((retval = device_create_file(&intf->dev, &dev_attr_LightLoop))) goto error;
 972         if((retval = device_create_file(&intf->dev, &dev_attr_LightPunch))) goto error;
 973         if((retval = device_create_file(&intf->dev, &dev_attr_wheel))) goto error;
 974         if((retval = device_create_file(&intf->dev, &dev_attr_event))) goto error;
 975         if((retval = device_create_file(&intf->dev, &dev_attr_dump_state))) goto error;
 976         if((retval = device_create_file(&intf->dev, &dev_attr_compress_wheel))) goto error;
 977         if((retval = device_create_file(&intf->dev, &dev_attr_enable))) goto error;
 978         if((retval = device_create_file(&intf->dev, &dev_attr_offline))) goto error;
 979
 980         /* let the user know what node this device is now attached to */
 981         dev_info(&intf->dev, "Tranzport Device #%d now attached to major %d minor %d\n",
 982                 (intf->minor - USB_TRANZPORT_MINOR_BASE), USB_MAJOR, intf->minor);
 983
 984 exit:
 985         return retval;
 986
 987 error:
 988         usb_tranzport_delete(dev);
 989
 990         return retval;
 991 }
 992
 993 /**
 994  *      usb_tranzport_disconnect
 995  *
 996  *      Called by the usb core when the device is removed from the system.
 997  */
 998 static void usb_tranzport_disconnect(struct usb_interface *intf)
 999 {
1000         struct usb_tranzport *dev;
1001         int minor;
1002
1003         /* FIXME: The skel code calls lock_kernel here, doesn't use a mutex, needed? */
1004         mutex_lock(&disconnect_mutex);
1005
1006         dev = usb_get_intfdata(intf);
1007         usb_set_intfdata(intf, NULL);
1008
1009         down(&dev->sem);
1010
1011         minor = intf->minor;
1012
1013         /* give back our minor */
1014         usb_deregister_dev(intf, &usb_tranzport_class);
1015
1016         /* if the device is not opened, then we clean up right now */
1017         if (!dev->open_count) {
1018                 up(&dev->sem);
1019                 usb_tranzport_delete(dev);
1020         } else {
1021                 dev->intf = NULL;
1022                 up(&dev->sem);
1023         }
1024
1025         mutex_unlock(&disconnect_mutex);
1026
1027         dev_info(&intf->dev, "Tranzport Surface #%d now disconnected\n",
1028                  (minor - USB_TRANZPORT_MINOR_BASE));
1029 }
1030
1031 /* usb specific object needed to register this driver with the usb subsystem */
1032 static struct usb_driver usb_tranzport_driver = {
1033         .name =         "tranzport",
1034         .probe =        usb_tranzport_probe,
1035         .disconnect =   usb_tranzport_disconnect,
1036         .id_table =     usb_tranzport_table,
1037 };
1038
1039 /**
1040  *      usb_tranzport_init
1041  */
1042 static int __init usb_tranzport_init(void)
1043 {
1044         int retval;
1045
1046         /* register this driver with the USB subsystem */
1047         retval = usb_register(&usb_tranzport_driver);
1048         if (retval)
1049                 err("usb_register failed for the "__FILE__" driver. Error number %d\n", retval);
1050
1051         return retval;
1052 }
1053
1054 /**
1055  *      usb_tranzport_exit
1056  */
1057 static void __exit usb_tranzport_exit(void)
1058 {
1059         /* deregister this driver with the USB subsystem */
1060         usb_deregister(&usb_tranzport_driver);
1061 }
1062
1063 module_init(usb_tranzport_init);
1064 module_exit(usb_tranzport_exit);
1065