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 42#include <linux/uaccess.h> 43#include <linux/input.h> 44#include <linux/usb.h> 45#include <linux/poll.h> 46 47/* Define these values to match your devices */ 48#define VENDOR_ID 0x165b 49#define PRODUCT_ID 0x8101 50 51#ifdef CONFIG_USB_DYNAMIC_MINORS 52#define USB_TRANZPORT_MINOR_BASE 0 53#else 54#define USB_TRANZPORT_MINOR_BASE 177 55#endif 56 57/* table of devices that work with this driver */ 58static const struct usb_device_id usb_tranzport_table[] = { 59 {USB_DEVICE(VENDOR_ID, PRODUCT_ID)}, 60 {} /* Terminating entry */ 61}; 62 63MODULE_DEVICE_TABLE(usb, usb_tranzport_table); 64MODULE_VERSION("0.35"); 65MODULE_AUTHOR("Mike Taht <m@taht.net>"); 66MODULE_DESCRIPTION("Tranzport USB Driver"); 67MODULE_LICENSE("GPL"); 68MODULE_SUPPORTED_DEVICE("Frontier Designs Tranzport Control Surface"); 69 70#define SUPPRESS_EXTRA_OFFLINE_EVENTS 1 71#define COMPRESS_WHEEL_EVENTS 1 72#define BUFFERED_READS 1 73#define RING_BUFFER_SIZE 1000 74#define WRITE_BUFFER_SIZE 34 75#define TRANZPORT_USB_TIMEOUT 10 76#define TRANZPORT_DEBUG 0 77 78static int debug = TRANZPORT_DEBUG; 79 80/* Use our own dbg macro */ 81#define dbg_info(dev, format, arg...) do \ 82 { if (debug) dev_info(dev , format , ## arg); } while (0) 83 84/* Module parameters */ 85 86module_param(debug, int, S_IRUGO | S_IWUSR); 87MODULE_PARM_DESC(debug, "Debug enabled or not"); 88 89/* All interrupt in transfers are collected in a ring buffer to 90 * avoid racing conditions and get better performance of the driver. 91 */ 92 93static int ring_buffer_size = RING_BUFFER_SIZE; 94 95module_param(ring_buffer_size, int, S_IRUGO); 96MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports"); 97 98/* The write_buffer can one day contain more than one interrupt out transfer. 99 */ 100static int write_buffer_size = WRITE_BUFFER_SIZE; 101module_param(write_buffer_size, int, S_IRUGO); 102MODULE_PARM_DESC(write_buffer_size, "Write buffer size"); 103 104/* 105 * Increase the interval for debugging purposes. 106 * or set to 1 to use the standard interval from the endpoint descriptors. 107 */ 108 109static int min_interrupt_in_interval = TRANZPORT_USB_TIMEOUT; 110module_param(min_interrupt_in_interval, int, 0); 111MODULE_PARM_DESC(min_interrupt_in_interval, 112 "Minimum interrupt in interval in ms"); 113 114static int min_interrupt_out_interval = TRANZPORT_USB_TIMEOUT; 115module_param(min_interrupt_out_interval, int, 0); 116MODULE_PARM_DESC(min_interrupt_out_interval, 117 "Minimum interrupt out interval in ms"); 118 119struct tranzport_cmd { 120 unsigned char cmd[8]; 121}; 122 123/* Structure to hold all of our device specific stuff */ 124 125struct usb_tranzport { 126 struct mutex mtx; /* locks this structure */ 127 struct usb_interface *intf; /* save off the usb interface pointer */ 128 int open_count; /* number of times this port opened */ 129 struct tranzport_cmd (*ring_buffer)[RING_BUFFER_SIZE]; 130 unsigned int ring_head; 131 unsigned int ring_tail; 132 wait_queue_head_t read_wait; 133 wait_queue_head_t write_wait; 134 unsigned char *interrupt_in_buffer; 135 struct usb_endpoint_descriptor *interrupt_in_endpoint; 136 struct urb *interrupt_in_urb; 137 int interrupt_in_interval; 138 size_t interrupt_in_endpoint_size; 139 int interrupt_in_running; 140 int interrupt_in_done; 141 char *interrupt_out_buffer; 142 struct usb_endpoint_descriptor *interrupt_out_endpoint; 143 struct urb *interrupt_out_urb; 144 int interrupt_out_interval; 145 size_t interrupt_out_endpoint_size; 146 int interrupt_out_busy; 147 148 /* Sysfs support */ 149 150 unsigned char enable; /* 0 if disabled 1 if enabled */ 151 unsigned char offline; /* if the device is out of range or asleep */ 152 unsigned char compress_wheel; /* flag to compress wheel events */ 153}; 154 155/* prevent races between open() and disconnect() */ 156static DEFINE_MUTEX(disconnect_mutex); 157 158static struct usb_driver usb_tranzport_driver; 159 160/** 161 * usb_tranzport_abort_transfers 162 * aborts transfers and frees associated data structures 163 */ 164static void usb_tranzport_abort_transfers(struct usb_tranzport *dev) 165{ 166 /* shutdown transfer */ 167 if (dev->interrupt_in_running) { 168 dev->interrupt_in_running = 0; 169 if (dev->intf) 170 usb_kill_urb(dev->interrupt_in_urb); 171 } 172 if (dev->interrupt_out_busy) 173 if (dev->intf) 174 usb_kill_urb(dev->interrupt_out_urb); 175} 176 177#define show_int(value) \ 178 static ssize_t show_##value(struct device *dev, \ 179 struct device_attribute *attr, char *buf) \ 180 { \ 181 struct usb_interface *intf = to_usb_interface(dev); \ 182 struct usb_tranzport *t = usb_get_intfdata(intf); \ 183 return sprintf(buf, "%d\n", t->value); \ 184 } \ 185 static DEVICE_ATTR(value, S_IRUGO, show_##value, NULL); 186 187#define show_set_int(value) \ 188 static ssize_t show_##value(struct device *dev, \ 189 struct device_attribute *attr, char *buf) \ 190 { \ 191 struct usb_interface *intf = to_usb_interface(dev); \ 192 struct usb_tranzport *t = usb_get_intfdata(intf); \ 193 return sprintf(buf, "%d\n", t->value); \ 194 } \ 195 static ssize_t set_##value(struct device *dev, \ 196 struct device_attribute *attr, \ 197 const char *buf, size_t count) \ 198 { \ 199 struct usb_interface *intf = to_usb_interface(dev); \ 200 struct usb_tranzport *t = usb_get_intfdata(intf); \ 201 unsigned long temp; \ 202 if (strict_strtoul(buf, 10, &temp)) \ 203 return -EINVAL; \ 204 t->value = temp; \ 205 return count; \ 206 } \ 207 static DEVICE_ATTR(value, S_IWUSR | S_IRUGO, show_##value, set_##value); 208 209show_int(enable); 210show_int(offline); 211show_set_int(compress_wheel); 212 213/** 214 * usb_tranzport_delete 215 */ 216static void usb_tranzport_delete(struct usb_tranzport *dev) 217{ 218 usb_tranzport_abort_transfers(dev); 219 if (dev->intf != NULL) { 220 device_remove_file(&dev->intf->dev, &dev_attr_enable); 221 device_remove_file(&dev->intf->dev, &dev_attr_offline); 222 device_remove_file(&dev->intf->dev, &dev_attr_compress_wheel); 223 } 224 225 /* free data structures */ 226 usb_free_urb(dev->interrupt_in_urb); 227 usb_free_urb(dev->interrupt_out_urb); 228 kfree(dev->ring_buffer); 229 kfree(dev->interrupt_in_buffer); 230 kfree(dev->interrupt_out_buffer); 231 kfree(dev); 232} 233 234/** 235 * usb_tranzport_interrupt_in_callback 236 */ 237 238static void usb_tranzport_interrupt_in_callback(struct urb *urb) 239{ 240 struct usb_tranzport *dev = urb->context; 241 unsigned int next_ring_head; 242 int retval = -1; 243 244 if (urb->status) { 245 if (urb->status == -ENOENT || 246 urb->status == -ECONNRESET || 247 urb->status == -ESHUTDOWN) { 248 goto exit; 249 } else { 250 dbg_info(&dev->intf->dev, 251 "%s: nonzero status received: %d\n", 252 __func__, urb->status); 253 goto resubmit; /* maybe we can recover */ 254 } 255 } 256 257 if (urb->actual_length != 8) { 258 dev_warn(&dev->intf->dev, 259 "Urb length was %d bytes!!" 260 "Do something intelligent\n", 261 urb->actual_length); 262 } else { 263 dbg_info(&dev->intf->dev, 264 "%s: received: %02x%02x%02x%02x%02x%02x%02x%02x\n", 265 __func__, dev->interrupt_in_buffer[0], 266 dev->interrupt_in_buffer[1], 267 dev->interrupt_in_buffer[2], 268 dev->interrupt_in_buffer[3], 269 dev->interrupt_in_buffer[4], 270 dev->interrupt_in_buffer[5], 271 dev->interrupt_in_buffer[6], 272 dev->interrupt_in_buffer[7]); 273#if SUPPRESS_EXTRA_OFFLINE_EVENTS 274 if (dev->offline == 2 && dev->interrupt_in_buffer[1] == 0xff) 275 goto resubmit; 276 if (dev->offline == 1 && dev->interrupt_in_buffer[1] == 0xff) { 277 dev->offline = 2; 278 goto resubmit; 279 } 280 281 /* Always pass one offline event up the stack */ 282 if (dev->offline > 0 && dev->interrupt_in_buffer[1] != 0xff) 283 dev->offline = 0; 284 if (dev->offline == 0 && dev->interrupt_in_buffer[1] == 0xff) 285 dev->offline = 1; 286 287#endif /* SUPPRESS_EXTRA_OFFLINE_EVENTS */ 288 dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n", 289 __func__, dev->ring_head, dev->ring_tail); 290 291 next_ring_head = (dev->ring_head + 1) % ring_buffer_size; 292 293 if (next_ring_head != dev->ring_tail) { 294 memcpy(&((*dev->ring_buffer)[dev->ring_head]), 295 dev->interrupt_in_buffer, urb->actual_length); 296 dev->ring_head = next_ring_head; 297 retval = 0; 298 memset(dev->interrupt_in_buffer, 0, urb->actual_length); 299 } else { 300 dev_warn(&dev->intf->dev, 301 "Ring buffer overflow, %d bytes dropped\n", 302 urb->actual_length); 303 memset(dev->interrupt_in_buffer, 0, urb->actual_length); 304 } 305 } 306 307resubmit: 308/* resubmit if we're still running */ 309 if (dev->interrupt_in_running && dev->intf) { 310 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC); 311 if (retval) 312 dev_err(&dev->intf->dev, 313 "usb_submit_urb failed (%d)\n", retval); 314 } 315 316exit: 317 dev->interrupt_in_done = 1; 318 wake_up_interruptible(&dev->read_wait); 319} 320 321/** 322 * usb_tranzport_interrupt_out_callback 323 */ 324static void usb_tranzport_interrupt_out_callback(struct urb *urb) 325{ 326 struct usb_tranzport *dev = urb->context; 327 /* sync/async unlink faults aren't errors */ 328 if (urb->status && !(urb->status == -ENOENT || 329 urb->status == -ECONNRESET || 330 urb->status == -ESHUTDOWN)) 331 dbg_info(&dev->intf->dev, 332 "%s - nonzero write interrupt status received: %d\n", 333 __func__, urb->status); 334 335 dev->interrupt_out_busy = 0; 336 wake_up_interruptible(&dev->write_wait); 337} 338/** 339 * usb_tranzport_open 340 */ 341static int usb_tranzport_open(struct inode *inode, struct file *file) 342{ 343 struct usb_tranzport *dev; 344 int subminor; 345 int retval = 0; 346 struct usb_interface *interface; 347 348 nonseekable_open(inode, file); 349 subminor = iminor(inode); 350 351 mutex_lock(&disconnect_mutex); 352 353 interface = usb_find_interface(&usb_tranzport_driver, subminor); 354 355 if (!interface) { 356 err("%s - error, can't find device for minor %d\n", 357 __func__, subminor); 358 retval = -ENODEV; 359 goto unlock_disconnect_exit; 360 } 361 362 dev = usb_get_intfdata(interface); 363 364 if (!dev) { 365 retval = -ENODEV; 366 goto unlock_disconnect_exit; 367 } 368 369 /* lock this device */ 370 if (mutex_lock_interruptible(&dev->mtx)) { 371 retval = -ERESTARTSYS; 372 goto unlock_disconnect_exit; 373 } 374 375 /* allow opening only once */ 376 if (dev->open_count) { 377 retval = -EBUSY; 378 goto unlock_exit; 379 } 380 dev->open_count = 1; 381 382 /* initialize in direction */ 383 dev->ring_head = 0; 384 dev->ring_tail = 0; 385 usb_fill_int_urb(dev->interrupt_in_urb, 386 interface_to_usbdev(interface), 387 usb_rcvintpipe(interface_to_usbdev(interface), 388 dev->interrupt_in_endpoint-> 389 bEndpointAddress), 390 dev->interrupt_in_buffer, 391 dev->interrupt_in_endpoint_size, 392 usb_tranzport_interrupt_in_callback, dev, 393 dev->interrupt_in_interval); 394 395 dev->interrupt_in_running = 1; 396 dev->interrupt_in_done = 0; 397 dev->enable = 1; 398 dev->offline = 0; 399 dev->compress_wheel = 1; 400 401 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL); 402 if (retval) { 403 dev_err(&interface->dev, 404 "Couldn't submit interrupt_in_urb %d\n", retval); 405 dev->interrupt_in_running = 0; 406 dev->open_count = 0; 407 goto unlock_exit; 408 } 409 410 /* save device in the file's private structure */ 411 file->private_data = dev; 412 413unlock_exit: 414 mutex_unlock(&dev->mtx); 415 416unlock_disconnect_exit: 417 mutex_unlock(&disconnect_mutex); 418 419 return retval; 420} 421 422/** 423 * usb_tranzport_release 424 */ 425static int usb_tranzport_release(struct inode *inode, struct file *file) 426{ 427 struct usb_tranzport *dev; 428 int retval = 0; 429 430 dev = file->private_data; 431 432 if (dev == NULL) { 433 retval = -ENODEV; 434 goto exit; 435 } 436 437 if (mutex_lock_interruptible(&dev->mtx)) { 438 retval = -ERESTARTSYS; 439 goto exit; 440 } 441 442 if (dev->open_count != 1) { 443 retval = -ENODEV; 444 goto unlock_exit; 445 } 446 447 if (dev->intf == NULL) { 448 /* the device was unplugged before the file was released */ 449 mutex_unlock(&dev->mtx); 450 /* unlock here as usb_tranzport_delete frees dev */ 451 usb_tranzport_delete(dev); 452 retval = -ENODEV; 453 goto exit; 454 } 455 456 /* wait until write transfer is finished */ 457 if (dev->interrupt_out_busy) 458 wait_event_interruptible_timeout(dev->write_wait, 459 !dev->interrupt_out_busy, 460 2 * HZ); 461 usb_tranzport_abort_transfers(dev); 462 dev->open_count = 0; 463 464unlock_exit: 465 mutex_unlock(&dev->mtx); 466 467exit: 468 return retval; 469} 470 471/** 472 * usb_tranzport_poll 473 */ 474static unsigned int usb_tranzport_poll(struct file *file, poll_table * wait) 475{ 476 struct usb_tranzport *dev; 477 unsigned int mask = 0; 478 dev = file->private_data; 479 poll_wait(file, &dev->read_wait, wait); 480 poll_wait(file, &dev->write_wait, wait); 481 if (dev->ring_head != dev->ring_tail) 482 mask |= POLLIN | POLLRDNORM; 483 if (!dev->interrupt_out_busy) 484 mask |= POLLOUT | POLLWRNORM; 485 return mask; 486} 487/** 488 * usb_tranzport_read 489 */ 490 491static ssize_t usb_tranzport_read(struct file *file, char __user *buffer, 492 size_t count, loff_t *ppos) 493{ 494 struct usb_tranzport *dev; 495 int retval = 0; 496#if BUFFERED_READS 497 int c = 0; 498#endif 499#if COMPRESS_WHEEL_EVENTS 500 signed char oldwheel; 501 signed char newwheel; 502 int cancompress = 1; 503 int next_tail; 504#endif 505 506 /* do I have such a thing as a null event? */ 507 508 dev = file->private_data; 509 510 /* verify that we actually have some data to read */ 511 if (count == 0) 512 goto exit; 513 514 /* lock this object */ 515 if (mutex_lock_interruptible(&dev->mtx)) { 516 retval = -ERESTARTSYS; 517 goto exit; 518 } 519 520 /* verify that the device wasn't unplugged */ if (dev->intf == NULL) { 521 retval = -ENODEV; 522 err("No device or device unplugged %d\n", retval); 523 goto unlock_exit; 524 } 525 526 while (dev->ring_head == dev->ring_tail) { 527 528 if (file->f_flags & O_NONBLOCK) { 529 retval = -EAGAIN; 530 goto unlock_exit; 531 } 532 /* atomic_cmp_exchange(&dev->interrupt_in_done,0,0); */ 533 dev->interrupt_in_done = 0; 534 retval = wait_event_interruptible(dev->read_wait, 535 dev->interrupt_in_done); 536 if (retval < 0) 537 goto unlock_exit; 538 } 539 540 dbg_info(&dev->intf->dev, 541 "%s: copying to userspace: " 542 "%02x%02x%02x%02x%02x%02x%02x%02x\n", 543 __func__, 544 (*dev->ring_buffer)[dev->ring_tail].cmd[0], 545 (*dev->ring_buffer)[dev->ring_tail].cmd[1], 546 (*dev->ring_buffer)[dev->ring_tail].cmd[2], 547 (*dev->ring_buffer)[dev->ring_tail].cmd[3], 548 (*dev->ring_buffer)[dev->ring_tail].cmd[4], 549 (*dev->ring_buffer)[dev->ring_tail].cmd[5], 550 (*dev->ring_buffer)[dev->ring_tail].cmd[6], 551 (*dev->ring_buffer)[dev->ring_tail].cmd[7]); 552 553#if BUFFERED_READS 554 c = 0; 555 while ((c < count) && (dev->ring_tail != dev->ring_head)) { 556 557#if COMPRESS_WHEEL_EVENTS 558 next_tail = (dev->ring_tail+1) % ring_buffer_size; 559 if (dev->compress_wheel) 560 cancompress = 1; 561 while (dev->ring_head != next_tail && cancompress == 1) { 562 newwheel = (*dev->ring_buffer)[next_tail].cmd[6]; 563 oldwheel = (*dev->ring_buffer)[dev->ring_tail].cmd[6]; 564 dbg_info(&dev->intf->dev, 565 "%s: trying to compress: " 566 "%02x%02x%02x%02x%02x%02x%02x%02x\n", 567 __func__, 568 (*dev->ring_buffer)[dev->ring_tail].cmd[0], 569 (*dev->ring_buffer)[dev->ring_tail].cmd[1], 570 (*dev->ring_buffer)[dev->ring_tail].cmd[2], 571 (*dev->ring_buffer)[dev->ring_tail].cmd[3], 572 (*dev->ring_buffer)[dev->ring_tail].cmd[4], 573 (*dev->ring_buffer)[dev->ring_tail].cmd[5], 574 (*dev->ring_buffer)[dev->ring_tail].cmd[6], 575 (*dev->ring_buffer)[dev->ring_tail].cmd[7]); 576 577 if (((*dev->ring_buffer)[dev->ring_tail].cmd[6] != 0 && 578 (*dev->ring_buffer)[next_tail].cmd[6] != 0) && 579 ((newwheel > 0 && oldwheel > 0) || 580 (newwheel < 0 && oldwheel < 0)) && 581 ((*dev->ring_buffer)[dev->ring_tail].cmd[2] == 582 (*dev->ring_buffer)[next_tail].cmd[2]) && 583 ((*dev->ring_buffer)[dev->ring_tail].cmd[3] == 584 (*dev->ring_buffer)[next_tail].cmd[3]) && 585 ((*dev->ring_buffer)[dev->ring_tail].cmd[4] == 586 (*dev->ring_buffer)[next_tail].cmd[4]) && 587 ((*dev->ring_buffer)[dev->ring_tail].cmd[5] == 588 (*dev->ring_buffer)[next_tail].cmd[5])) { 589 dbg_info(&dev->intf->dev, 590 "%s: should compress: " 591 "%02x%02x%02x%02x%02x%02x%02x%02x\n", 592 __func__, 593 (*dev->ring_buffer)[dev->ring_tail]. 594 cmd[0], 595 (*dev->ring_buffer)[dev->ring_tail]. 596 cmd[1], 597 (*dev->ring_buffer)[dev->ring_tail]. 598 cmd[2], 599 (*dev->ring_buffer)[dev->ring_tail]. 600 cmd[3], 601 (*dev->ring_buffer)[dev->ring_tail]. 602 cmd[4], 603 (*dev->ring_buffer)[dev->ring_tail]. 604 cmd[5], 605 (*dev->ring_buffer)[dev->ring_tail]. 606 cmd[6], 607 (*dev->ring_buffer)[dev->ring_tail]. 608 cmd[7]); 609 newwheel += oldwheel; 610 if (oldwheel > 0 && !(newwheel > 0)) { 611 newwheel = 0x7f; 612 cancompress = 0; 613 } 614 if (oldwheel < 0 && !(newwheel < 0)) { 615 newwheel = 0x80; 616 cancompress = 0; 617 } 618 619 (*dev->ring_buffer)[next_tail].cmd[6] = 620 newwheel; 621 dev->ring_tail = next_tail; 622 next_tail = 623 (dev->ring_tail + 1) % ring_buffer_size; 624 } else { 625 cancompress = 0; 626 } 627 } 628#endif /* COMPRESS_WHEEL_EVENTS */ 629 if (copy_to_user( 630 &buffer[c], 631 &(*dev->ring_buffer)[dev->ring_tail], 8)) { 632 retval = -EFAULT; 633 goto unlock_exit; 634 } 635 dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size; 636 c += 8; 637 dbg_info(&dev->intf->dev, 638 "%s: head, tail are %x, %x\n", 639 __func__, dev->ring_head, dev->ring_tail); 640 } 641 retval = c; 642 643#else 644/* if (copy_to_user(buffer, &(*dev->ring_buffer)[dev->ring_tail], 8)) { */ 645 retval = -EFAULT; 646 goto unlock_exit; 647} 648 649dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size; 650dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n", 651 __func__, dev->ring_head, dev->ring_tail); 652 653retval = 8; 654#endif /* BUFFERED_READS */ 655 656unlock_exit: 657/* unlock the device */ 658mutex_unlock(&dev->mtx); 659 660exit: 661return retval; 662} 663 664/** 665 * usb_tranzport_write 666 */ 667static ssize_t usb_tranzport_write(struct file *file, 668 const char __user *buffer, size_t count, 669 loff_t *ppos) 670{ 671 struct usb_tranzport *dev; 672 size_t bytes_to_write; 673 int retval = 0; 674 675 dev = file->private_data; 676 677 /* verify that we actually have some data to write */ 678 if (count == 0) 679 goto exit; 680 681 /* lock this object */ 682 if (mutex_lock_interruptible(&dev->mtx)) { 683 retval = -ERESTARTSYS; 684 goto exit; 685 } 686 /* verify that the device wasn't unplugged */ 687 if (dev->intf == NULL) { 688 retval = -ENODEV; 689 err("No device or device unplugged %d\n", retval); 690 goto unlock_exit; 691 } 692 693 /* wait until previous transfer is finished */ 694 if (dev->interrupt_out_busy) { 695 if (file->f_flags & O_NONBLOCK) { 696 retval = -EAGAIN; 697 goto unlock_exit; 698 } 699 retval = wait_event_interruptible(dev->write_wait, 700 !dev->interrupt_out_busy); 701 if (retval < 0) 702 goto unlock_exit; 703 } 704 705 /* write the data into interrupt_out_buffer from userspace */ 706 bytes_to_write = min(count, 707 write_buffer_size * 708 dev->interrupt_out_endpoint_size); 709 if (bytes_to_write < count) 710 dev_warn(&dev->intf->dev, 711 "Write buffer overflow, %zd bytes dropped\n", 712 count - bytes_to_write); 713 714 dbg_info(&dev->intf->dev, 715 "%s: count = %zd, bytes_to_write = %zd\n", __func__, 716 count, bytes_to_write); 717 718 if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) { 719 retval = -EFAULT; 720 goto unlock_exit; 721 } 722 723 if (dev->interrupt_out_endpoint == NULL) { 724 err("Endpoint should not be be null!\n"); 725 goto unlock_exit; 726 } 727 728 /* send off the urb */ 729 usb_fill_int_urb(dev->interrupt_out_urb, 730 interface_to_usbdev(dev->intf), 731 usb_sndintpipe(interface_to_usbdev(dev->intf), 732 dev->interrupt_out_endpoint-> 733 bEndpointAddress), 734 dev->interrupt_out_buffer, bytes_to_write, 735 usb_tranzport_interrupt_out_callback, dev, 736 dev->interrupt_out_interval); 737 738 dev->interrupt_out_busy = 1; 739 wmb(); 740 741 retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL); 742 if (retval) { 743 dev->interrupt_out_busy = 0; 744 err("Couldn't submit interrupt_out_urb %d\n", retval); 745 goto unlock_exit; 746 } 747 retval = bytes_to_write; 748 749unlock_exit: 750 /* unlock the device */ 751 mutex_unlock(&dev->mtx); 752 753exit: 754 return retval; 755} 756 757/* file operations needed when we register this driver */ 758static const struct file_operations usb_tranzport_fops = { 759 .owner = THIS_MODULE, 760 .read = usb_tranzport_read, 761 .write = usb_tranzport_write, 762 .open = usb_tranzport_open, 763 .release = usb_tranzport_release, 764 .poll = usb_tranzport_poll, 765}; 766 767/* 768 * usb class driver info in order to get a minor number from the usb core, 769 * and to have the device registered with the driver core 770 */ 771static struct usb_class_driver usb_tranzport_class = { 772 .name = "tranzport%d", 773 .fops = &usb_tranzport_fops, 774 .minor_base = USB_TRANZPORT_MINOR_BASE, 775}; 776 777/** 778 * usb_tranzport_probe 779 * 780 * Called by the usb core when a new device is connected that it thinks 781 * this driver might be interested in. 782 */ 783static int usb_tranzport_probe(struct usb_interface *intf, 784 const struct usb_device_id *id) { 785 struct usb_device *udev = interface_to_usbdev(intf); 786 struct usb_tranzport *dev = NULL; 787 struct usb_host_interface *iface_desc; 788 struct usb_endpoint_descriptor *endpoint; 789 int i; 790 int true_size; 791 int retval = -ENOMEM; 792 793 /* allocate memory for our device state and intialize it */ 794 795 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 796 if (dev == NULL) { 797 dev_err(&intf->dev, "Out of memory\n"); 798 goto exit; 799 } 800 mutex_init(&dev->mtx); 801 dev->intf = intf; 802 init_waitqueue_head(&dev->read_wait); 803 init_waitqueue_head(&dev->write_wait); 804 805 iface_desc = intf->cur_altsetting; 806 807 /* set up the endpoint information */ 808 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 809 endpoint = &iface_desc->endpoint[i].desc; 810 811 if (usb_endpoint_is_int_in(endpoint)) 812 dev->interrupt_in_endpoint = endpoint; 813 814 if (usb_endpoint_is_int_out(endpoint)) 815 dev->interrupt_out_endpoint = endpoint; 816 } 817 if (dev->interrupt_in_endpoint == NULL) { 818 dev_err(&intf->dev, "Interrupt in endpoint not found\n"); 819 goto error; 820 } 821 if (dev->interrupt_out_endpoint == NULL) 822 dev_warn(&intf->dev, 823 "Interrupt out endpoint not found" 824 "(using control endpoint instead)\n"); 825 826 dev->interrupt_in_endpoint_size = 827 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize); 828 829 if (dev->interrupt_in_endpoint_size != 8) 830 dev_warn(&intf->dev, "Interrupt in endpoint size is not 8!\n"); 831 832 if (ring_buffer_size == 0) 833 ring_buffer_size = RING_BUFFER_SIZE; 834 true_size = min(ring_buffer_size, RING_BUFFER_SIZE); 835 836 837 dev->ring_buffer = 838 kmalloc((true_size * sizeof(struct tranzport_cmd)) + 8, GFP_KERNEL); 839 840 if (!dev->ring_buffer) { 841 dev_err(&intf->dev, 842 "Couldn't allocate ring_buffer size %d\n", true_size); 843 goto error; 844 } 845 dev->interrupt_in_buffer = 846 kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL); 847 if (!dev->interrupt_in_buffer) { 848 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n"); 849 goto error; 850 } 851 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 852 if (!dev->interrupt_in_urb) { 853 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n"); 854 goto error; 855 } 856 dev->interrupt_out_endpoint_size = 857 dev->interrupt_out_endpoint ? 858 le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize) : 859 udev->descriptor.bMaxPacketSize0; 860 861 if (dev->interrupt_out_endpoint_size != 8) 862 dev_warn(&intf->dev, 863 "Interrupt out endpoint size is not 8!)\n"); 864 865 dev->interrupt_out_buffer = 866 kmalloc(write_buffer_size * dev->interrupt_out_endpoint_size, 867 GFP_KERNEL); 868 if (!dev->interrupt_out_buffer) { 869 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n"); 870 goto error; 871 } 872 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 873 if (!dev->interrupt_out_urb) { 874 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n"); 875 goto error; 876 } 877 dev->interrupt_in_interval = 878 min_interrupt_in_interval > 879 dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval 880 : dev->interrupt_in_endpoint->bInterval; 881 882 if (dev->interrupt_out_endpoint) { 883 dev->interrupt_out_interval = 884 min_interrupt_out_interval > 885 dev->interrupt_out_endpoint->bInterval ? 886 min_interrupt_out_interval : 887 dev->interrupt_out_endpoint->bInterval; 888 } 889 890 /* we can register the device now, as it is ready */ 891 usb_set_intfdata(intf, dev); 892 893 retval = usb_register_dev(intf, &usb_tranzport_class); 894 if (retval) { 895 /* something prevented us from registering this driver */ 896 dev_err(&intf->dev, 897 "Not able to get a minor for this device.\n"); 898 usb_set_intfdata(intf, NULL); 899 goto error; 900 } 901 902 retval = device_create_file(&intf->dev, &dev_attr_compress_wheel); 903 if (retval) 904 goto error; 905 retval = device_create_file(&intf->dev, &dev_attr_enable); 906 if (retval) 907 goto error; 908 retval = device_create_file(&intf->dev, &dev_attr_offline); 909 if (retval) 910 goto error; 911 912 /* let the user know what node this device is now attached to */ 913 dev_info(&intf->dev, 914 "Tranzport Device #%d now attached to major %d minor %d\n", 915 (intf->minor - USB_TRANZPORT_MINOR_BASE), USB_MAJOR, 916 intf->minor); 917 918exit: 919 return retval; 920 921error: 922 usb_tranzport_delete(dev); 923 return retval; 924} 925 926/** 927 * usb_tranzport_disconnect 928 * 929 * Called by the usb core when the device is removed from the system. 930 */ 931static void usb_tranzport_disconnect(struct usb_interface *intf) 932{ 933 struct usb_tranzport *dev; 934 int minor; 935 mutex_lock(&disconnect_mutex); 936 dev = usb_get_intfdata(intf); 937 usb_set_intfdata(intf, NULL); 938 mutex_lock(&dev->mtx); 939 minor = intf->minor; 940 /* give back our minor */ 941 usb_deregister_dev(intf, &usb_tranzport_class); 942 943 /* if the device is not opened, then we clean up right now */ 944 if (!dev->open_count) { 945 mutex_unlock(&dev->mtx); 946 usb_tranzport_delete(dev); 947 } else { 948 dev->intf = NULL; 949 mutex_unlock(&dev->mtx); 950 } 951 952 mutex_unlock(&disconnect_mutex); 953 954 dev_info(&intf->dev, "Tranzport Surface #%d now disconnected\n", 955 (minor - USB_TRANZPORT_MINOR_BASE)); 956} 957 958/* usb specific object needed to register this driver with the usb subsystem */ 959static struct usb_driver usb_tranzport_driver = { 960 .name = "tranzport", 961 .probe = usb_tranzport_probe, 962 .disconnect = usb_tranzport_disconnect, 963 .id_table = usb_tranzport_table, 964}; 965 966/** 967 * usb_tranzport_init 968 */ 969static int __init usb_tranzport_init(void) 970{ 971 int retval; 972 973 /* register this driver with the USB subsystem */ 974 retval = usb_register(&usb_tranzport_driver); 975 if (retval) 976 err("usb_register failed for the " __FILE__ 977 " driver. Error number %d\n", retval); 978 return retval; 979} 980/** 981 * usb_tranzport_exit 982 */ 983 984static void __exit usb_tranzport_exit(void) 985{ 986 /* deregister this driver with the USB subsystem */ 987 usb_deregister(&usb_tranzport_driver); 988} 989 990module_init(usb_tranzport_init); 991module_exit(usb_tranzport_exit); 992