drivers/staging/frontier/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 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 19)
  49 #include frontier_compat.h
  50 #endif
  51
  52 /* Define these values to match your devices */
  53 #define VENDOR_ID   0x165b
  54 #define PRODUCT_ID      0x8101
  55
  56 #ifdef CONFIG_USB_DYNAMIC_MINORS
  57 #define USB_TRANZPORT_MINOR_BASE        0
  58 #else
  59 // FIXME 176 - is the ldusb driver's minor - apply for a minor soon
  60 #define USB_TRANZPORT_MINOR_BASE        177
  61 #endif
  62
  63 /* table of devices that work with this driver */
  64 static struct usb_device_id usb_tranzport_table [] = {
  65         { USB_DEVICE(VENDOR_ID, PRODUCT_ID) },
  66         { }                                     /* Terminating entry */
  67 };
  68
  69 MODULE_DEVICE_TABLE(usb, usb_tranzport_table);
  70 MODULE_VERSION("0.33");
  71 MODULE_AUTHOR("Mike Taht <m@taht.net>");
  72 MODULE_DESCRIPTION("Tranzport USB Driver");
  73 MODULE_LICENSE("GPL");
  74 MODULE_SUPPORTED_DEVICE("Frontier Designs Tranzport Control Surface");
  75
  76 /* These two aren't done yet */
  77
  78 #define SUPPRESS_EXTRA_ONLINE_EVENTS 0
  79 #define BUFFERED_WRITES 0
  80
  81 #define SUPPRESS_EXTRA_OFFLINE_EVENTS 1
  82 #define COMPRESS_WHEEL_EVENTS 1
  83 #define BUFFERED_READS 1
  84 #define RING_BUFFER_SIZE 1000
  85 #define WRITE_BUFFER_SIZE 34
  86 #define TRANZPORT_USB_TIMEOUT 10
  87
  88
  89 static int debug = 0;
  90
  91 /* Use our own dbg macro */
  92 #define dbg_info(dev, format, arg...) do { if (debug) dev_info(dev , format , ## arg); } while (0)
  93
  94 /* Module parameters */
  95
  96 module_param(debug, int, S_IRUGO | S_IWUSR);
  97 MODULE_PARM_DESC(debug, "Debug enabled or not");
  98
  99 /* All interrupt in transfers are collected in a ring buffer to
 100  * avoid racing conditions and get better performance of the driver.
 101  */
 102
 103 static int ring_buffer_size = RING_BUFFER_SIZE;
 104
 105 module_param(ring_buffer_size, int,  S_IRUGO);
 106 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
 107
 108 /* The write_buffer can one day contain more than one interrupt out transfer.
 109  */
 110 static int write_buffer_size = WRITE_BUFFER_SIZE;
 111 module_param(write_buffer_size, int,  S_IRUGO);
 112 MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
 113
 114 /*
 115  * Increase the interval for debugging purposes.
 116  * or set to 1 to use the standard interval from the endpoint descriptors.
 117  */
 118
 119 static int min_interrupt_in_interval = TRANZPORT_USB_TIMEOUT;
 120 module_param(min_interrupt_in_interval, int, 0);
 121 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
 122
 123 static int min_interrupt_out_interval = TRANZPORT_USB_TIMEOUT;
 124 module_param(min_interrupt_out_interval, int, 0);
 125 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
 126
 127 struct tranzport_cmd {
 128     unsigned char cmd[8];
 129 };
 130
 131 enum LightID {
 132         LightRecord = 0,
 133         LightTrackrec,
 134         LightTrackmute,
 135         LightTracksolo,
 136         LightAnysolo,
 137         LightLoop,
 138         LightPunch
 139         };
 140
 141 /* Structure to hold all of our device specific stuff */
 142
 143 struct usb_tranzport {
 144         struct semaphore        sem;            /* locks this structure */
 145         struct usb_interface*   intf;           /* save off the usb interface pointer */
 146
 147         int                     open_count;     /* number of times this port has been opened */
 148
 149         struct tranzport_cmd    (*ring_buffer)[RING_BUFFER_SIZE]; /* just make c happy */
 150         unsigned int            ring_head;
 151         unsigned int            ring_tail;
 152
 153         wait_queue_head_t       read_wait;
 154         wait_queue_head_t       write_wait;
 155
 156         unsigned char*          interrupt_in_buffer;
 157         struct usb_endpoint_descriptor* interrupt_in_endpoint;
 158         struct urb*             interrupt_in_urb;
 159         int                     interrupt_in_interval;
 160         size_t  interrupt_in_endpoint_size;
 161         int                     interrupt_in_running;
 162         int                     interrupt_in_done;
 163
 164         char*                   interrupt_out_buffer;
 165         struct usb_endpoint_descriptor* interrupt_out_endpoint;
 166         struct urb*             interrupt_out_urb;
 167         int                     interrupt_out_interval;
 168         size_t  interrupt_out_endpoint_size;
 169         int                     interrupt_out_busy;
 170
 171         /* Sysfs and translation support */
 172
 173         int event; /* alternate interface to events */
 174         int wheel; /* - for negative, 0 for none, + for positive */
 175         unsigned char dump_state; /* 0 if disabled 1 if enabled */
 176         unsigned char enable; /* 0 if disabled 1 if enabled */
 177         unsigned char offline; /* if the device is out of range or asleep */
 178         unsigned char compress_wheel; /* flag to compress wheel events */
 179         unsigned char light; /* 7 bits used */
 180         unsigned char last_cmd[8];
 181         unsigned char last_input[8];
 182         unsigned char screen[40]; // We'll also have cells
 183
 184 };
 185
 186 /* prevent races between open() and disconnect() */
 187 static DEFINE_MUTEX(disconnect_mutex);
 188
 189 static struct usb_driver usb_tranzport_driver;
 190
 191 /**
 192  *      usb_tranzport_abort_transfers
 193  *      aborts transfers and frees associated data structures
 194  */
 195 static void usb_tranzport_abort_transfers(struct usb_tranzport *dev)
 196 {
 197         /* shutdown transfer */
 198         if (dev->interrupt_in_running) {
 199                 dev->interrupt_in_running = 0;
 200                 if (dev->intf)
 201                         usb_kill_urb(dev->interrupt_in_urb);
 202         }
 203         if (dev->interrupt_out_busy)
 204                 if (dev->intf)
 205                         usb_kill_urb(dev->interrupt_out_urb);
 206 }
 207
 208 // FIXME ~light not good enough or correct - need atomic set_bit
 209
 210 #define show_set_light(value)   \
 211 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)               \
 212 {                                                                       \
 213         struct usb_interface *intf = to_usb_interface(dev);             \
 214         struct usb_tranzport *t = usb_get_intfdata(intf);               \
 215         enum LightID light = value;                                     \
 216         int temp = (1 && (t->light & (1 << light)));                    \
 217         return sprintf(buf, "%d\n", temp );                             \
 218 }                                                                       \
 219 static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)    \
 220 {                                                                       \
 221         struct usb_interface *intf = to_usb_interface(dev);             \
 222         struct usb_tranzport *t = usb_get_intfdata(intf);               \
 223         int temp = simple_strtoul(buf, NULL, 10);                       \
 224         enum LightID light = (temp << value) & (t->light << value);     \
 225         t->light = (t->light & ~light) ;                                \
 226         return count;                                                   \
 227 }                                                                       \
 228 static DEVICE_ATTR(value, S_IWUGO | S_IRUGO, show_##value, set_##value);
 229
 230 show_set_light(LightRecord);
 231 show_set_light(LightTrackrec);
 232 show_set_light(LightTrackmute);
 233 show_set_light(LightTracksolo);
 234 show_set_light(LightAnysolo);
 235 show_set_light(LightLoop);
 236 show_set_light(LightPunch);
 237
 238
 239 #define show_set_int(value)     \
 240 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)               \
 241 {                                                                       \
 242         struct usb_interface *intf = to_usb_interface(dev);             \
 243         struct usb_tranzport *t = usb_get_intfdata(intf);                       \
 244                                                                         \
 245         return sprintf(buf, "%d\n", t->value);                  \
 246 }                                                                       \
 247 static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)    \
 248 {                                                                       \
 249         struct usb_interface *intf = to_usb_interface(dev);             \
 250         struct usb_tranzport *t = usb_get_intfdata(intf);                       \
 251         int temp = simple_strtoul(buf, NULL, 10);                       \
 252                                                                         \
 253         t->value = temp;                                                \
 254         return count;                                                   \
 255 }                                                                       \
 256 static DEVICE_ATTR(value, S_IWUGO | S_IRUGO, show_##value, set_##value);
 257
 258 show_set_int(enable);
 259 show_set_int(offline);
 260 show_set_int(compress_wheel);
 261 show_set_int(dump_state);
 262 show_set_int(wheel);
 263 show_set_int(event);
 264
 265 #define show_set_cmd(value)     \
 266 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)               \
 267 {                                                                       \
 268         struct usb_interface *intf = to_usb_interface(dev);             \
 269         struct usb_tranzport *t = usb_get_intfdata(intf);                       \
 270                                                                         \
 271         return sprintf(buf, "%d\n", t->value);                  \
 272 }                                                                       \
 273 static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)    \
 274 {                                                                       \
 275         struct usb_interface *intf = to_usb_interface(dev);             \
 276         struct usb_tranzport *t = usb_get_intfdata(intf);                       \
 277         int temp = simple_strtoul(buf, NULL, 10);                       \
 278                                                                         \
 279         t->value = temp;                                                \
 280         return count;                                                   \
 281 }                                                                       \
 282 static DEVICE_ATTR(value, S_IWUGO | S_IRUGO, show_##value, set_##value);
 283
 284
 285
 286
 287 /**
 288  *      usb_tranzport_delete
 289  */
 290 static void usb_tranzport_delete(struct usb_tranzport *dev)
 291 {
 292         usb_tranzport_abort_transfers(dev);
 293         /*  This is just too twisted to be correct */
 294         if(dev->intf != NULL) {
 295         device_remove_file(&dev->intf->dev, &dev_attr_LightRecord);
 296         device_remove_file(&dev->intf->dev, &dev_attr_LightTrackrec);
 297         device_remove_file(&dev->intf->dev, &dev_attr_LightTrackmute);
 298         device_remove_file(&dev->intf->dev, &dev_attr_LightTracksolo);
 299         device_remove_file(&dev->intf->dev, &dev_attr_LightTrackmute);
 300         device_remove_file(&dev->intf->dev, &dev_attr_LightAnysolo);
 301         device_remove_file(&dev->intf->dev, &dev_attr_LightLoop);
 302         device_remove_file(&dev->intf->dev, &dev_attr_LightPunch);
 303         device_remove_file(&dev->intf->dev, &dev_attr_wheel);
 304         device_remove_file(&dev->intf->dev, &dev_attr_enable);
 305         device_remove_file(&dev->intf->dev, &dev_attr_event);
 306         device_remove_file(&dev->intf->dev, &dev_attr_offline);
 307         device_remove_file(&dev->intf->dev, &dev_attr_compress_wheel);
 308
 309         device_remove_file(&dev->intf->dev, &dev_attr_dump_state);
 310         }
 311
 312         /* free data structures */
 313         usb_free_urb(dev->interrupt_in_urb);
 314         usb_free_urb(dev->interrupt_out_urb);
 315         kfree(dev->ring_buffer);
 316         kfree(dev->interrupt_in_buffer);
 317         kfree(dev->interrupt_out_buffer);
 318         kfree(dev);
 319 }
 320
 321 /**
 322  *      usb_tranzport_interrupt_in_callback
 323  */
 324
 325 static void usb_tranzport_interrupt_in_callback(struct urb *urb)
 326 {
 327         struct usb_tranzport *dev = urb->context;
 328         unsigned int next_ring_head;
 329         int retval = -1;
 330
 331         if (urb->status) {
 332                 if (urb->status == -ENOENT ||
 333                     urb->status == -ECONNRESET ||
 334                     urb->status == -ESHUTDOWN) {
 335                         goto exit;
 336                 } else {
 337                         dbg_info(&dev->intf->dev, "%s: nonzero status received: %d\n",
 338                                  __FUNCTION__, urb->status);
 339                         goto resubmit; /* maybe we can recover */
 340                 }
 341         }
 342
 343         if (urb->actual_length != 8) {
 344                 dev_warn(&dev->intf->dev,
 345                          "Urb length was %d bytes!! Do something intelligent \n", urb->actual_length);
 346         } else {
 347                 dbg_info(&dev->intf->dev, "%s: received: %02x%02x%02x%02x%02x%02x%02x%02x\n",
 348                          __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]);
 349 #if SUPPRESS_EXTRA_OFFLINE_EVENTS
 350                 if(dev->offline == 2 && dev->interrupt_in_buffer[1] == 0xff) { goto resubmit; }
 351                 if(dev->offline == 1 && dev->interrupt_in_buffer[1] == 0xff) { dev->offline = 2; goto resubmit; }
 352
 353 /* Always pass one offline event up the stack */
 354                 if(dev->offline > 0 && dev->interrupt_in_buffer[1] != 0xff) { dev->offline = 0; }
 355                 if(dev->offline == 0 && dev->interrupt_in_buffer[1] == 0xff) { dev->offline = 1; }
 356
 357 #endif
 358                 dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n", __FUNCTION__,dev->ring_head,dev->ring_tail);
 359
 360                 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
 361
 362                 if (next_ring_head != dev->ring_tail) {
 363                         memcpy(&((*dev->ring_buffer)[dev->ring_head]), dev->interrupt_in_buffer, urb->actual_length);
 364                         dev->ring_head = next_ring_head;
 365                         retval = 0;
 366                         memset(dev->interrupt_in_buffer, 0, urb->actual_length);
 367                 } else {
 368                         dev_warn(&dev->intf->dev,
 369                                  "Ring buffer overflow, %d bytes dropped\n",
 370                                  urb->actual_length);
 371                         memset(dev->interrupt_in_buffer, 0, urb->actual_length);
 372                 }
 373         }
 374
 375 resubmit:
 376         /* resubmit if we're still running */
 377         if (dev->interrupt_in_running && dev->intf) {
 378                 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
 379                 if (retval)
 380                         dev_err(&dev->intf->dev,
 381                                 "usb_submit_urb failed (%d)\n", retval);
 382         }
 383
 384 exit:
 385         dev->interrupt_in_done = 1;
 386         wake_up_interruptible(&dev->read_wait);
 387 }
 388
 389 /**
 390  *      usb_tranzport_interrupt_out_callback
 391  */
 392 static void usb_tranzport_interrupt_out_callback(struct urb *urb)
 393 {
 394         struct usb_tranzport *dev = urb->context;
 395
 396         /* sync/async unlink faults aren't errors */
 397         if (urb->status && !(urb->status == -ENOENT ||
 398                              urb->status == -ECONNRESET ||
 399                              urb->status == -ESHUTDOWN))
 400                 dbg_info(&dev->intf->dev,
 401                          "%s - nonzero write interrupt status received: %d\n",
 402                          __FUNCTION__, urb->status);
 403
 404         dev->interrupt_out_busy = 0;
 405         wake_up_interruptible(&dev->write_wait);
 406 }
 407
 408 /**
 409  *      usb_tranzport_open
 410  */
 411 static int usb_tranzport_open(struct inode *inode, struct file *file)
 412 {
 413         struct usb_tranzport *dev;
 414         int subminor;
 415         int retval = 0;
 416         struct usb_interface *interface;
 417
 418         nonseekable_open(inode, file);
 419         subminor = iminor(inode);
 420
 421         mutex_lock(&disconnect_mutex);
 422
 423         interface = usb_find_interface(&usb_tranzport_driver, subminor);
 424
 425         if (!interface) {
 426                 err("%s - error, can't find device for minor %d\n",
 427                      __FUNCTION__, subminor);
 428                 retval = -ENODEV;
 429                 goto unlock_disconnect_exit;
 430         }
 431
 432         dev = usb_get_intfdata(interface);
 433
 434         if (!dev) {
 435                 retval = -ENODEV;
 436                 goto unlock_disconnect_exit;
 437         }
 438
 439         /* lock this device */
 440         if (down_interruptible(&dev->sem)) {
 441                 retval = -ERESTARTSYS;
 442                 goto unlock_disconnect_exit;
 443         }
 444
 445         /* allow opening only once */
 446         if (dev->open_count) {
 447                 retval = -EBUSY;
 448                 goto unlock_exit;
 449         }
 450         dev->open_count = 1;
 451
 452         /* initialize in direction */
 453         dev->ring_head = 0;
 454         dev->ring_tail = 0;
 455         usb_fill_int_urb(dev->interrupt_in_urb,
 456                          interface_to_usbdev(interface),
 457                          usb_rcvintpipe(interface_to_usbdev(interface),
 458                                         dev->interrupt_in_endpoint->bEndpointAddress),
 459                          dev->interrupt_in_buffer,
 460                          dev->interrupt_in_endpoint_size,
 461                          usb_tranzport_interrupt_in_callback,
 462                          dev,
 463                          dev->interrupt_in_interval);
 464
 465         dev->interrupt_in_running = 1;
 466         dev->interrupt_in_done = 0;
 467         dev->enable = 1;
 468         dev->offline = 0;
 469         dev->compress_wheel = 1;
 470
 471         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 472         if (retval) {
 473                 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
 474                 dev->interrupt_in_running = 0;
 475                 dev->open_count = 0;
 476                 goto unlock_exit;
 477         }
 478
 479         /* save device in the file's private structure */
 480         file->private_data = dev;
 481
 482
 483 unlock_exit:
 484         up(&dev->sem);
 485
 486 unlock_disconnect_exit:
 487         mutex_unlock(&disconnect_mutex);
 488
 489         return retval;
 490 }
 491
 492 /**
 493  *      usb_tranzport_release
 494  */
 495 static int usb_tranzport_release(struct inode *inode, struct file *file)
 496 {
 497         struct usb_tranzport *dev;
 498         int retval = 0;
 499
 500         dev = file->private_data;
 501
 502         if (dev == NULL) {
 503                 retval = -ENODEV;
 504                 goto exit;
 505         }
 506
 507         if (down_interruptible(&dev->sem)) {
 508                 retval = -ERESTARTSYS;
 509                 goto exit;
 510         }
 511
 512         if (dev->open_count != 1) {
 513                 retval = -ENODEV;
 514                 goto unlock_exit;
 515         }
 516
 517         if (dev->intf == NULL) {
 518                 /* the device was unplugged before the file was released */
 519                 up(&dev->sem);
 520                 /* unlock here as usb_tranzport_delete frees dev */
 521                 usb_tranzport_delete(dev);
 522                 retval = -ENODEV;
 523                 goto exit;
 524         }
 525
 526         /* wait until write transfer is finished */
 527         if (dev->interrupt_out_busy)
 528                 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
 529         usb_tranzport_abort_transfers(dev);
 530         dev->open_count = 0;
 531
 532 unlock_exit:
 533         up(&dev->sem);
 534
 535 exit:
 536         return retval;
 537 }
 538
 539 /**
 540  *      usb_tranzport_poll
 541  */
 542 static unsigned int usb_tranzport_poll(struct file *file, poll_table *wait)
 543 {
 544         struct usb_tranzport *dev;
 545         unsigned int mask = 0;
 546
 547         dev = file->private_data;
 548
 549         poll_wait(file, &dev->read_wait, wait);
 550         poll_wait(file, &dev->write_wait, wait);
 551
 552         if (dev->ring_head != dev->ring_tail)
 553                 mask |= POLLIN | POLLRDNORM;
 554         if (!dev->interrupt_out_busy)
 555                 mask |= POLLOUT | POLLWRNORM;
 556
 557         return mask;
 558 }
 559
 560 /**
 561  *      usb_tranzport_read
 562  */
 563 static ssize_t usb_tranzport_read(struct file *file, char __user *buffer, size_t count,
 564                            loff_t *ppos)
 565 {
 566         struct usb_tranzport *dev;
 567         int retval = 0;
 568
 569 #if BUFFERED_READS
 570         int c = 0;
 571 #endif
 572
 573 #if COMPRESS_WHEEL_EVENTS
 574         signed char oldwheel;
 575         signed char newwheel;
 576         int cancompress = 1;
 577         int next_tail;
 578 #endif
 579
 580 /* do I have such a thing as a null event? */
 581
 582         dev = file->private_data;
 583
 584         /* verify that we actually have some data to read */
 585         if (count == 0)
 586                 goto exit;
 587
 588         /* lock this object */
 589         if (down_interruptible(&dev->sem)) {
 590                 retval = -ERESTARTSYS;
 591                 goto exit;
 592         }
 593
 594         /* verify that the device wasn't unplugged */
 595         if (dev->intf == NULL) {
 596                 retval = -ENODEV;
 597                 err("No device or device unplugged %d\n", retval);
 598                 goto unlock_exit;
 599         }
 600
 601         while (dev->ring_head == dev->ring_tail) {
 602
 603                 if (file->f_flags & O_NONBLOCK) {
 604                         retval = -EAGAIN;
 605                         goto unlock_exit;
 606                 }
 607                 // atomic_cmp_exchange(&dev->interrupt_in_done,0,0);
 608                 dev->interrupt_in_done = 0 ; /* tiny race - FIXME: make atomic? */
 609                 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
 610                 if (retval < 0) {
 611                         goto unlock_exit;
 612                 }
 613         }
 614
 615         dbg_info(&dev->intf->dev, "%s: copying to userspace: %02x%02x%02x%02x%02x%02x%02x%02x\n",
 616                          __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]);
 617
 618 #if BUFFERED_READS
 619            c = 0;
 620            while((c < count) && (dev->ring_tail != dev->ring_head)) {
 621
 622 /* This started off in the lower level service routine, and I moved it here. Then my brain died. Not done yet. */
 623 #if COMPRESS_WHEEL_EVENTS
 624                 next_tail = (dev->ring_tail+1) % ring_buffer_size;
 625                 if(dev->compress_wheel) cancompress = 1;
 626                 while(dev->ring_head != next_tail && cancompress == 1 ) {
 627                         newwheel = (*dev->ring_buffer)[next_tail].cmd[6];
 628                         oldwheel = (*dev->ring_buffer)[dev->ring_tail].cmd[6];
 629                         // if both are wheel events, and no buttons have changes (FIXME, do I have to check?),
 630                         // and we are the same sign, we can compress +- 7F
 631                         // FIXME: saner check for overflow! - max of +- 7F
 632                         // FIXME the math is wrong for going in reverse, actually, as the midi spec doesn't allow signed chars
 633
 634         dbg_info(&dev->intf->dev, "%s: trying to compress: %02x%02x%02x%02x%02x %02x %02x %02x\n",
 635                          __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]);
 636
 637
 638                         if(((*dev->ring_buffer)[dev->ring_tail].cmd[6] != 0 &&
 639                             (*dev->ring_buffer)[next_tail].cmd[6] != 0 ) &&
 640                                 ((newwheel > 0 && oldwheel > 0) ||
 641                                 (newwheel < 0 && oldwheel < 0)) &&
 642                                 ((*dev->ring_buffer)[dev->ring_tail].cmd[2] == (*dev->ring_buffer)[next_tail].cmd[2]) &&
 643                                 ((*dev->ring_buffer)[dev->ring_tail].cmd[3] == (*dev->ring_buffer)[next_tail].cmd[3]) &&
 644                                 ((*dev->ring_buffer)[dev->ring_tail].cmd[4] == (*dev->ring_buffer)[next_tail].cmd[4]) &&
 645                                 ((*dev->ring_buffer)[dev->ring_tail].cmd[5] == (*dev->ring_buffer)[next_tail].cmd[5]))
 646  {
 647         dbg_info(&dev->intf->dev, "%s: should compress: %02x%02x%02x%02x%02x%02x%02x%02x\n",
 648                          __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]);
 649
 650                                 newwheel += oldwheel;
 651                                 if(oldwheel > 0 && !(newwheel > 0)) {
 652                                         newwheel = 0x7f;
 653                                         cancompress = 0;
 654                                 }
 655                                 if(oldwheel < 0 && !(newwheel < 0)) {
 656                                         newwheel = 0x80;
 657                                         cancompress = 0;
 658                                 }
 659
 660                                 (*dev->ring_buffer)[next_tail].cmd[6] = newwheel;
 661                                 dev->ring_tail = next_tail;
 662                                 next_tail = (dev->ring_tail+1) % ring_buffer_size;
 663                         } else {
 664                                 cancompress = 0;
 665                         }
 666                 }
 667 #endif /* COMPRESS_WHEEL_EVENTS */
 668
 669                 if (copy_to_user(&buffer[c], &(*dev->ring_buffer)[dev->ring_tail], 8)) {
 670                         retval = -EFAULT;
 671                         goto unlock_exit;
 672                 }
 673
 674                 dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
 675                 c+=8;
 676                 dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n", __FUNCTION__,dev->ring_head,dev->ring_tail);
 677            }
 678            retval = c;
 679
 680 #else
 681         if (copy_to_user(buffer, &(*dev->ring_buffer)[dev->ring_tail], 8)) {
 682                 retval = -EFAULT;
 683                 goto unlock_exit;
 684         }
 685
 686         dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
 687         dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n", __FUNCTION__,dev->ring_head,dev->ring_tail);
 688
 689         retval = 8;
 690 #endif /* BUFFERED_READS */
 691
 692 unlock_exit:
 693         /* unlock the device */
 694         up(&dev->sem);
 695
 696 exit:
 697         return retval;
 698 }
 699
 700 /**
 701  *      usb_tranzport_write
 702  */
 703 static ssize_t usb_tranzport_write(struct file *file, const char __user *buffer,
 704                             size_t count, loff_t *ppos)
 705 {
 706         struct usb_tranzport *dev;
 707         size_t bytes_to_write;
 708         int retval = 0;
 709
 710         dev = file->private_data;
 711
 712         /* verify that we actually have some data to write */
 713         if (count == 0)
 714                 goto exit;
 715
 716         /* lock this object */
 717         if (down_interruptible(&dev->sem)) {
 718                 retval = -ERESTARTSYS;
 719                 goto exit;
 720         }
 721
 722         /* verify that the device wasn't unplugged */
 723         if (dev->intf == NULL) {
 724                 retval = -ENODEV;
 725                 err("No device or device unplugged %d\n", retval);
 726                 goto unlock_exit;
 727         }
 728
 729         /* wait until previous transfer is finished */
 730         if (dev->interrupt_out_busy) {
 731                 if (file->f_flags & O_NONBLOCK) {
 732                         retval = -EAGAIN;
 733                         goto unlock_exit;
 734                 }
 735                 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
 736                 if (retval < 0) {
 737                         goto unlock_exit;
 738                 }
 739         }
 740
 741         /* write the data into interrupt_out_buffer from userspace */
 742         bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
 743         if (bytes_to_write < count)
 744                 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n",count-bytes_to_write);
 745
 746         dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n", __FUNCTION__, count, bytes_to_write);
 747
 748         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
 749                 retval = -EFAULT;
 750                 goto unlock_exit;
 751         }
 752
 753         if (dev->interrupt_out_endpoint == NULL) {
 754                 err("Endpoint should not be be null! \n");
 755                 goto unlock_exit;
 756         }
 757
 758         /* send off the urb */
 759         usb_fill_int_urb(dev->interrupt_out_urb,
 760                          interface_to_usbdev(dev->intf),
 761                          usb_sndintpipe(interface_to_usbdev(dev->intf),
 762                                         dev->interrupt_out_endpoint->bEndpointAddress),
 763                          dev->interrupt_out_buffer,
 764                          bytes_to_write,
 765                          usb_tranzport_interrupt_out_callback,
 766                          dev,
 767                          dev->interrupt_out_interval);
 768
 769         dev->interrupt_out_busy = 1;
 770         wmb();
 771
 772         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 773         if (retval) {
 774                 dev->interrupt_out_busy = 0;
 775                 err("Couldn't submit interrupt_out_urb %d\n", retval);
 776                 goto unlock_exit;
 777         }
 778         retval = bytes_to_write;
 779
 780 unlock_exit:
 781         /* unlock the device */
 782         up(&dev->sem);
 783
 784 exit:
 785         return retval;
 786 }
 787
 788 /* file operations needed when we register this driver */
 789 static const struct file_operations usb_tranzport_fops = {
 790         .owner =        THIS_MODULE,
 791         .read  =        usb_tranzport_read,
 792         .write =        usb_tranzport_write,
 793         .open =         usb_tranzport_open,
 794         .release =      usb_tranzport_release,
 795         .poll =         usb_tranzport_poll,
 796 };
 797
 798 /*
 799  * usb class driver info in order to get a minor number from the usb core,
 800  * and to have the device registered with the driver core
 801  */
 802 static struct usb_class_driver usb_tranzport_class = {
 803         .name =         "tranzport%d",
 804         .fops =         &usb_tranzport_fops,
 805         .minor_base =   USB_TRANZPORT_MINOR_BASE,
 806 };
 807
 808
 809 /**
 810  *      usb_tranzport_probe
 811  *
 812  *      Called by the usb core when a new device is connected that it thinks
 813  *      this driver might be interested in.
 814  */
 815 static int usb_tranzport_probe(struct usb_interface *intf, const struct usb_device_id *id)
 816 {
 817         struct usb_device *udev = interface_to_usbdev(intf);
 818         struct usb_tranzport *dev = NULL;
 819         struct usb_host_interface *iface_desc;
 820         struct usb_endpoint_descriptor *endpoint;
 821         int i;
 822         int true_size;
 823         int retval = -ENOMEM;
 824
 825         /* allocate memory for our device state and intialize it */
 826
 827         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 828         if (dev == NULL) {
 829                 dev_err(&intf->dev, "Out of memory\n");
 830                 goto exit;
 831         }
 832         init_MUTEX(&dev->sem);
 833         dev->intf = intf;
 834         init_waitqueue_head(&dev->read_wait);
 835         init_waitqueue_head(&dev->write_wait);
 836
 837         iface_desc = intf->cur_altsetting;
 838
 839         /* set up the endpoint information */
 840         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 841                 endpoint = &iface_desc->endpoint[i].desc;
 842
 843                 if (usb_endpoint_is_int_in(endpoint))
 844                         dev->interrupt_in_endpoint = endpoint;
 845
 846                 if (usb_endpoint_is_int_out(endpoint))
 847                         dev->interrupt_out_endpoint = endpoint;
 848         }
 849         if (dev->interrupt_in_endpoint == NULL) {
 850                 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
 851                 goto error;
 852         }
 853         if (dev->interrupt_out_endpoint == NULL)
 854                 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
 855
 856
 857         dev->interrupt_in_endpoint_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
 858
 859         if (dev->interrupt_in_endpoint_size != 8)
 860             dev_warn(&intf->dev, "Interrupt in endpoint size is not 8!\n");
 861
 862         if(ring_buffer_size == 0) { ring_buffer_size = RING_BUFFER_SIZE; }
 863         true_size = min(ring_buffer_size,RING_BUFFER_SIZE);
 864         /* FIXME - there are more usb_alloc routines for dma correctness. Needed? */
 865
 866         dev->ring_buffer = kmalloc((true_size*sizeof(struct tranzport_cmd))+8, GFP_KERNEL);
 867
 868         if (!dev->ring_buffer) {
 869                 dev_err(&intf->dev, "Couldn't allocate ring_buffer of size %d\n",true_size);
 870                 goto error;
 871         }
 872         dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
 873         if (!dev->interrupt_in_buffer) {
 874                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
 875                 goto error;
 876         }
 877         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 878         if (!dev->interrupt_in_urb) {
 879                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
 880                 goto error;
 881         }
 882         dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize) :
 883                                                                          udev->descriptor.bMaxPacketSize0;
 884
 885         if (dev->interrupt_out_endpoint_size !=8)
 886                 dev_warn(&intf->dev, "Interrupt out endpoint size is not 8!)\n");
 887
 888         dev->interrupt_out_buffer = kmalloc(write_buffer_size*dev->interrupt_out_endpoint_size, GFP_KERNEL);
 889         if (!dev->interrupt_out_buffer) {
 890                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
 891                 goto error;
 892         }
 893         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 894         if (!dev->interrupt_out_urb) {
 895                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
 896                 goto error;
 897         }
 898         dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
 899         if (dev->interrupt_out_endpoint)
 900                 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
 901
 902         /* we can register the device now, as it is ready */
 903         usb_set_intfdata(intf, dev);
 904
 905         retval = usb_register_dev(intf, &usb_tranzport_class);
 906         if (retval) {
 907                 /* something prevented us from registering this driver */
 908                 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
 909                 usb_set_intfdata(intf, NULL);
 910                 goto error;
 911         }
 912
 913         if((retval = device_create_file(&intf->dev, &dev_attr_LightRecord))) goto error;
 914         if((retval = device_create_file(&intf->dev, &dev_attr_LightTrackrec))) goto error;
 915         if((retval = device_create_file(&intf->dev, &dev_attr_LightTrackmute))) goto error;
 916         if((retval = device_create_file(&intf->dev, &dev_attr_LightTracksolo))) goto error;
 917         if((retval = device_create_file(&intf->dev, &dev_attr_LightAnysolo))) goto error;
 918         if((retval = device_create_file(&intf->dev, &dev_attr_LightLoop))) goto error;
 919         if((retval = device_create_file(&intf->dev, &dev_attr_LightPunch))) goto error;
 920         if((retval = device_create_file(&intf->dev, &dev_attr_wheel))) goto error;
 921         if((retval = device_create_file(&intf->dev, &dev_attr_event))) goto error;
 922         if((retval = device_create_file(&intf->dev, &dev_attr_dump_state))) goto error;
 923         if((retval = device_create_file(&intf->dev, &dev_attr_compress_wheel))) goto error;
 924         if((retval = device_create_file(&intf->dev, &dev_attr_enable))) goto error;
 925         if((retval = device_create_file(&intf->dev, &dev_attr_offline))) goto error;
 926
 927         /* let the user know what node this device is now attached to */
 928         dev_info(&intf->dev, "Tranzport Device #%d now attached to major %d minor %d\n",
 929                 (intf->minor - USB_TRANZPORT_MINOR_BASE), USB_MAJOR, intf->minor);
 930
 931 exit:
 932         return retval;
 933
 934 error:
 935         usb_tranzport_delete(dev);
 936
 937         return retval;
 938 }
 939
 940 /**
 941  *      usb_tranzport_disconnect
 942  *
 943  *      Called by the usb core when the device is removed from the system.
 944  */
 945 static void usb_tranzport_disconnect(struct usb_interface *intf)
 946 {
 947         struct usb_tranzport *dev;
 948         int minor;
 949         mutex_lock(&disconnect_mutex);
 950         dev = usb_get_intfdata(intf);
 951         usb_set_intfdata(intf, NULL);
 952         down(&dev->sem);
 953         minor = intf->minor;
 954         /* give back our minor */
 955         usb_deregister_dev(intf, &usb_tranzport_class);
 956
 957         /* if the device is not opened, then we clean up right now */
 958         if (!dev->open_count) {
 959                 up(&dev->sem);
 960                 usb_tranzport_delete(dev);
 961         } else {
 962                 dev->intf = NULL;
 963                 up(&dev->sem);
 964         }
 965
 966         mutex_unlock(&disconnect_mutex);
 967
 968         dev_info(&intf->dev, "Tranzport Surface #%d now disconnected\n",
 969                  (minor - USB_TRANZPORT_MINOR_BASE));
 970 }
 971
 972 /* usb specific object needed to register this driver with the usb subsystem */
 973 static struct usb_driver usb_tranzport_driver = {
 974         .name =         "tranzport",
 975         .probe =        usb_tranzport_probe,
 976         .disconnect =   usb_tranzport_disconnect,
 977         .id_table =     usb_tranzport_table,
 978 };
 979
 980 /**
 981  *      usb_tranzport_init
 982  */
 983 static int __init usb_tranzport_init(void)
 984 {
 985         int retval;
 986
 987         /* register this driver with the USB subsystem */
 988         retval = usb_register(&usb_tranzport_driver);
 989         if (retval)
 990                 err("usb_register failed for the "__FILE__" driver. Error number %d\n", retval);
 991
 992         return retval;
 993 }
 994
 995 /**
 996  *      usb_tranzport_exit
 997  */
 998 static void __exit usb_tranzport_exit(void)
 999 {
1000         /* deregister this driver with the USB subsystem */
1001         usb_deregister(&usb_tranzport_driver);
1002 }
1003
1004 module_init(usb_tranzport_init);
1005 module_exit(usb_tranzport_exit);
1006