1// SPDX-License-Identifier: GPL-2.0+ 2/* 3 * LEGO USB Tower driver 4 * 5 * Copyright (C) 2003 David Glance <davidgsf@sourceforge.net> 6 * 2001-2004 Juergen Stuber <starblue@users.sourceforge.net> 7 * 8 * derived from USB Skeleton driver - 0.5 9 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com) 10 * 11 * History: 12 * 13 * 2001-10-13 - 0.1 js 14 * - first version 15 * 2001-11-03 - 0.2 js 16 * - simplified buffering, one-shot URBs for writing 17 * 2001-11-10 - 0.3 js 18 * - removed IOCTL (setting power/mode is more complicated, postponed) 19 * 2001-11-28 - 0.4 js 20 * - added vendor commands for mode of operation and power level in open 21 * 2001-12-04 - 0.5 js 22 * - set IR mode by default (by oversight 0.4 set VLL mode) 23 * 2002-01-11 - 0.5? pcchan 24 * - make read buffer reusable and work around bytes_to_write issue between 25 * uhci and legusbtower 26 * 2002-09-23 - 0.52 david (david@csse.uwa.edu.au) 27 * - imported into lejos project 28 * - changed wake_up to wake_up_interruptible 29 * - changed to use lego0 rather than tower0 30 * - changed dbg() to use __func__ rather than deprecated __func__ 31 * 2003-01-12 - 0.53 david (david@csse.uwa.edu.au) 32 * - changed read and write to write everything or 33 * timeout (from a patch by Chris Riesen and Brett Thaeler driver) 34 * - added ioctl functionality to set timeouts 35 * 2003-07-18 - 0.54 davidgsf (david@csse.uwa.edu.au) 36 * - initial import into LegoUSB project 37 * - merge of existing LegoUSB.c driver 38 * 2003-07-18 - 0.56 davidgsf (david@csse.uwa.edu.au) 39 * - port to 2.6 style driver 40 * 2004-02-29 - 0.6 Juergen Stuber <starblue@users.sourceforge.net> 41 * - fix locking 42 * - unlink read URBs which are no longer needed 43 * - allow increased buffer size, eliminates need for timeout on write 44 * - have read URB running continuously 45 * - added poll 46 * - forbid seeking 47 * - added nonblocking I/O 48 * - changed back __func__ to __func__ 49 * - read and log tower firmware version 50 * - reset tower on probe, avoids failure of first write 51 * 2004-03-09 - 0.7 Juergen Stuber <starblue@users.sourceforge.net> 52 * - timeout read now only after inactivity, shorten default accordingly 53 * 2004-03-11 - 0.8 Juergen Stuber <starblue@users.sourceforge.net> 54 * - log major, minor instead of possibly confusing device filename 55 * - whitespace cleanup 56 * 2004-03-12 - 0.9 Juergen Stuber <starblue@users.sourceforge.net> 57 * - normalize whitespace in debug messages 58 * - take care about endianness in control message responses 59 * 2004-03-13 - 0.91 Juergen Stuber <starblue@users.sourceforge.net> 60 * - make default intervals longer to accommodate current EHCI driver 61 * 2004-03-19 - 0.92 Juergen Stuber <starblue@users.sourceforge.net> 62 * - replaced atomic_t by memory barriers 63 * 2004-04-21 - 0.93 Juergen Stuber <starblue@users.sourceforge.net> 64 * - wait for completion of write urb in release (needed for remotecontrol) 65 * - corrected poll for write direction (missing negation) 66 * 2004-04-22 - 0.94 Juergen Stuber <starblue@users.sourceforge.net> 67 * - make device locking interruptible 68 * 2004-04-30 - 0.95 Juergen Stuber <starblue@users.sourceforge.net> 69 * - check for valid udev on resubmitting and unlinking urbs 70 * 2004-08-03 - 0.96 Juergen Stuber <starblue@users.sourceforge.net> 71 * - move reset into open to clean out spurious data 72 */ 73 74#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 75 76#include <linux/kernel.h> 77#include <linux/errno.h> 78#include <linux/slab.h> 79#include <linux/module.h> 80#include <linux/completion.h> 81#include <linux/mutex.h> 82#include <linux/uaccess.h> 83#include <linux/usb.h> 84#include <linux/poll.h> 85 86 87#define DRIVER_AUTHOR "Juergen Stuber <starblue@sourceforge.net>" 88#define DRIVER_DESC "LEGO USB Tower Driver" 89 90 91/* The defaults are chosen to work with the latest versions of leJOS and NQC. 92 */ 93 94/* Some legacy software likes to receive packets in one piece. 95 * In this case read_buffer_size should exceed the maximal packet length 96 * (417 for datalog uploads), and packet_timeout should be set. 97 */ 98static int read_buffer_size = 480; 99module_param(read_buffer_size, int, 0); 100MODULE_PARM_DESC(read_buffer_size, "Read buffer size"); 101 102/* Some legacy software likes to send packets in one piece. 103 * In this case write_buffer_size should exceed the maximal packet length 104 * (417 for firmware and program downloads). 105 * A problem with long writes is that the following read may time out 106 * if the software is not prepared to wait long enough. 107 */ 108static int write_buffer_size = 480; 109module_param(write_buffer_size, int, 0); 110MODULE_PARM_DESC(write_buffer_size, "Write buffer size"); 111 112/* Some legacy software expects reads to contain whole LASM packets. 113 * To achieve this, characters which arrive before a packet timeout 114 * occurs will be returned in a single read operation. 115 * A problem with long reads is that the software may time out 116 * if it is not prepared to wait long enough. 117 * The packet timeout should be greater than the time between the 118 * reception of subsequent characters, which should arrive about 119 * every 5ms for the standard 2400 baud. 120 * Set it to 0 to disable. 121 */ 122static int packet_timeout = 50; 123module_param(packet_timeout, int, 0); 124MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms"); 125 126/* Some legacy software expects blocking reads to time out. 127 * Timeout occurs after the specified time of read and write inactivity. 128 * Set it to 0 to disable. 129 */ 130static int read_timeout = 200; 131module_param(read_timeout, int, 0); 132MODULE_PARM_DESC(read_timeout, "Read timeout in ms"); 133 134/* As of kernel version 2.6.4 ehci-hcd uses an 135 * "only one interrupt transfer per frame" shortcut 136 * to simplify the scheduling of periodic transfers. 137 * This conflicts with our standard 1ms intervals for in and out URBs. 138 * We use default intervals of 2ms for in and 8ms for out transfers, 139 * which is fast enough for 2400 baud and allows a small additional load. 140 * Increase the interval to allow more devices that do interrupt transfers, 141 * or set to 0 to use the standard interval from the endpoint descriptors. 142 */ 143static int interrupt_in_interval = 2; 144module_param(interrupt_in_interval, int, 0); 145MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms"); 146 147static int interrupt_out_interval = 8; 148module_param(interrupt_out_interval, int, 0); 149MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms"); 150 151/* Define these values to match your device */ 152#define LEGO_USB_TOWER_VENDOR_ID 0x0694 153#define LEGO_USB_TOWER_PRODUCT_ID 0x0001 154 155/* Vendor requests */ 156#define LEGO_USB_TOWER_REQUEST_RESET 0x04 157#define LEGO_USB_TOWER_REQUEST_GET_VERSION 0xFD 158 159struct tower_reset_reply { 160 __le16 size; 161 __u8 err_code; 162 __u8 spare; 163}; 164 165struct tower_get_version_reply { 166 __le16 size; 167 __u8 err_code; 168 __u8 spare; 169 __u8 major; 170 __u8 minor; 171 __le16 build_no; 172}; 173 174 175/* table of devices that work with this driver */ 176static const struct usb_device_id tower_table[] = { 177 { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) }, 178 { } /* Terminating entry */ 179}; 180 181MODULE_DEVICE_TABLE(usb, tower_table); 182 183#define LEGO_USB_TOWER_MINOR_BASE 160 184 185 186/* Structure to hold all of our device specific stuff */ 187struct lego_usb_tower { 188 struct mutex lock; /* locks this structure */ 189 struct usb_device *udev; /* save off the usb device pointer */ 190 unsigned char minor; /* the starting minor number for this device */ 191 192 int open_count; /* number of times this port has been opened */ 193 unsigned long disconnected:1; 194 195 char *read_buffer; 196 size_t read_buffer_length; /* this much came in */ 197 size_t read_packet_length; /* this much will be returned on read */ 198 spinlock_t read_buffer_lock; 199 int packet_timeout_jiffies; 200 unsigned long read_last_arrival; 201 202 wait_queue_head_t read_wait; 203 wait_queue_head_t write_wait; 204 205 char *interrupt_in_buffer; 206 struct usb_endpoint_descriptor *interrupt_in_endpoint; 207 struct urb *interrupt_in_urb; 208 int interrupt_in_interval; 209 int interrupt_in_done; 210 211 char *interrupt_out_buffer; 212 struct usb_endpoint_descriptor *interrupt_out_endpoint; 213 struct urb *interrupt_out_urb; 214 int interrupt_out_interval; 215 int interrupt_out_busy; 216 217}; 218 219 220/* local function prototypes */ 221static ssize_t tower_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos); 222static ssize_t tower_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos); 223static inline void tower_delete(struct lego_usb_tower *dev); 224static int tower_open(struct inode *inode, struct file *file); 225static int tower_release(struct inode *inode, struct file *file); 226static __poll_t tower_poll(struct file *file, poll_table *wait); 227static loff_t tower_llseek(struct file *file, loff_t off, int whence); 228 229static void tower_check_for_read_packet(struct lego_usb_tower *dev); 230static void tower_interrupt_in_callback(struct urb *urb); 231static void tower_interrupt_out_callback(struct urb *urb); 232 233static int tower_probe(struct usb_interface *interface, const struct usb_device_id *id); 234static void tower_disconnect(struct usb_interface *interface); 235 236 237/* file operations needed when we register this driver */ 238static const struct file_operations tower_fops = { 239 .owner = THIS_MODULE, 240 .read = tower_read, 241 .write = tower_write, 242 .open = tower_open, 243 .release = tower_release, 244 .poll = tower_poll, 245 .llseek = tower_llseek, 246}; 247 248static char *legousbtower_devnode(const struct device *dev, umode_t *mode) 249{ 250 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev)); 251} 252 253/* 254 * usb class driver info in order to get a minor number from the usb core, 255 * and to have the device registered with the driver core 256 */ 257static struct usb_class_driver tower_class = { 258 .name = "legousbtower%d", 259 .devnode = legousbtower_devnode, 260 .fops = &tower_fops, 261 .minor_base = LEGO_USB_TOWER_MINOR_BASE, 262}; 263 264 265/* usb specific object needed to register this driver with the usb subsystem */ 266static struct usb_driver tower_driver = { 267 .name = "legousbtower", 268 .probe = tower_probe, 269 .disconnect = tower_disconnect, 270 .id_table = tower_table, 271}; 272 273 274/* 275 * lego_usb_tower_debug_data 276 */ 277static inline void lego_usb_tower_debug_data(struct device *dev, 278 const char *function, int size, 279 const unsigned char *data) 280{ 281 dev_dbg(dev, "%s - length = %d, data = %*ph\n", 282 function, size, size, data); 283} 284 285 286/* 287 * tower_delete 288 */ 289static inline void tower_delete(struct lego_usb_tower *dev) 290{ 291 /* free data structures */ 292 usb_free_urb(dev->interrupt_in_urb); 293 usb_free_urb(dev->interrupt_out_urb); 294 kfree(dev->read_buffer); 295 kfree(dev->interrupt_in_buffer); 296 kfree(dev->interrupt_out_buffer); 297 usb_put_dev(dev->udev); 298 kfree(dev); 299} 300 301 302/* 303 * tower_open 304 */ 305static int tower_open(struct inode *inode, struct file *file) 306{ 307 struct lego_usb_tower *dev = NULL; 308 int subminor; 309 int retval = 0; 310 struct usb_interface *interface; 311 struct tower_reset_reply reset_reply; 312 int result; 313 314 nonseekable_open(inode, file); 315 subminor = iminor(inode); 316 317 interface = usb_find_interface(&tower_driver, subminor); 318 if (!interface) { 319 pr_err("error, can't find device for minor %d\n", subminor); 320 retval = -ENODEV; 321 goto exit; 322 } 323 324 dev = usb_get_intfdata(interface); 325 if (!dev) { 326 retval = -ENODEV; 327 goto exit; 328 } 329 330 /* lock this device */ 331 if (mutex_lock_interruptible(&dev->lock)) { 332 retval = -ERESTARTSYS; 333 goto exit; 334 } 335 336 337 /* allow opening only once */ 338 if (dev->open_count) { 339 retval = -EBUSY; 340 goto unlock_exit; 341 } 342 343 /* reset the tower */ 344 result = usb_control_msg_recv(dev->udev, 0, 345 LEGO_USB_TOWER_REQUEST_RESET, 346 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 347 0, 0, 348 &reset_reply, sizeof(reset_reply), 1000, 349 GFP_KERNEL); 350 if (result < 0) { 351 dev_err(&dev->udev->dev, 352 "LEGO USB Tower reset control request failed\n"); 353 retval = result; 354 goto unlock_exit; 355 } 356 357 /* initialize in direction */ 358 dev->read_buffer_length = 0; 359 dev->read_packet_length = 0; 360 usb_fill_int_urb(dev->interrupt_in_urb, 361 dev->udev, 362 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress), 363 dev->interrupt_in_buffer, 364 usb_endpoint_maxp(dev->interrupt_in_endpoint), 365 tower_interrupt_in_callback, 366 dev, 367 dev->interrupt_in_interval); 368 369 dev->interrupt_in_done = 0; 370 mb(); 371 372 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL); 373 if (retval) { 374 dev_err(&dev->udev->dev, 375 "Couldn't submit interrupt_in_urb %d\n", retval); 376 goto unlock_exit; 377 } 378 379 /* save device in the file's private structure */ 380 file->private_data = dev; 381 382 dev->open_count = 1; 383 384unlock_exit: 385 mutex_unlock(&dev->lock); 386 387exit: 388 return retval; 389} 390 391/* 392 * tower_release 393 */ 394static int tower_release(struct inode *inode, struct file *file) 395{ 396 struct lego_usb_tower *dev; 397 int retval = 0; 398 399 dev = file->private_data; 400 if (dev == NULL) { 401 retval = -ENODEV; 402 goto exit; 403 } 404 405 mutex_lock(&dev->lock); 406 407 if (dev->disconnected) { 408 /* the device was unplugged before the file was released */ 409 410 /* unlock here as tower_delete frees dev */ 411 mutex_unlock(&dev->lock); 412 tower_delete(dev); 413 goto exit; 414 } 415 416 /* wait until write transfer is finished */ 417 if (dev->interrupt_out_busy) { 418 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 419 2 * HZ); 420 } 421 422 /* shutdown transfers */ 423 usb_kill_urb(dev->interrupt_in_urb); 424 usb_kill_urb(dev->interrupt_out_urb); 425 426 dev->open_count = 0; 427 428 mutex_unlock(&dev->lock); 429exit: 430 return retval; 431} 432 433/* 434 * tower_check_for_read_packet 435 * 436 * To get correct semantics for signals and non-blocking I/O 437 * with packetizing we pretend not to see any data in the read buffer 438 * until it has been there unchanged for at least 439 * dev->packet_timeout_jiffies, or until the buffer is full. 440 */ 441static void tower_check_for_read_packet(struct lego_usb_tower *dev) 442{ 443 spin_lock_irq(&dev->read_buffer_lock); 444 if (!packet_timeout 445 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) 446 || dev->read_buffer_length == read_buffer_size) { 447 dev->read_packet_length = dev->read_buffer_length; 448 } 449 dev->interrupt_in_done = 0; 450 spin_unlock_irq(&dev->read_buffer_lock); 451} 452 453 454/* 455 * tower_poll 456 */ 457static __poll_t tower_poll(struct file *file, poll_table *wait) 458{ 459 struct lego_usb_tower *dev; 460 __poll_t mask = 0; 461 462 dev = file->private_data; 463 464 if (dev->disconnected) 465 return EPOLLERR | EPOLLHUP; 466 467 poll_wait(file, &dev->read_wait, wait); 468 poll_wait(file, &dev->write_wait, wait); 469 470 tower_check_for_read_packet(dev); 471 if (dev->read_packet_length > 0) 472 mask |= EPOLLIN | EPOLLRDNORM; 473 if (!dev->interrupt_out_busy) 474 mask |= EPOLLOUT | EPOLLWRNORM; 475 476 return mask; 477} 478 479 480/* 481 * tower_llseek 482 */ 483static loff_t tower_llseek(struct file *file, loff_t off, int whence) 484{ 485 return -ESPIPE; /* unseekable */ 486} 487 488 489/* 490 * tower_read 491 */ 492static ssize_t tower_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) 493{ 494 struct lego_usb_tower *dev; 495 size_t bytes_to_read; 496 int i; 497 int retval = 0; 498 unsigned long timeout = 0; 499 500 dev = file->private_data; 501 502 /* lock this object */ 503 if (mutex_lock_interruptible(&dev->lock)) { 504 retval = -ERESTARTSYS; 505 goto exit; 506 } 507 508 /* verify that the device wasn't unplugged */ 509 if (dev->disconnected) { 510 retval = -ENODEV; 511 goto unlock_exit; 512 } 513 514 /* verify that we actually have some data to read */ 515 if (count == 0) { 516 dev_dbg(&dev->udev->dev, "read request of 0 bytes\n"); 517 goto unlock_exit; 518 } 519 520 if (read_timeout) 521 timeout = jiffies + msecs_to_jiffies(read_timeout); 522 523 /* wait for data */ 524 tower_check_for_read_packet(dev); 525 while (dev->read_packet_length == 0) { 526 if (file->f_flags & O_NONBLOCK) { 527 retval = -EAGAIN; 528 goto unlock_exit; 529 } 530 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 531 if (retval < 0) 532 goto unlock_exit; 533 534 /* reset read timeout during read or write activity */ 535 if (read_timeout 536 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 537 timeout = jiffies + msecs_to_jiffies(read_timeout); 538 } 539 /* check for read timeout */ 540 if (read_timeout && time_after(jiffies, timeout)) { 541 retval = -ETIMEDOUT; 542 goto unlock_exit; 543 } 544 tower_check_for_read_packet(dev); 545 } 546 547 /* copy the data from read_buffer into userspace */ 548 bytes_to_read = min(count, dev->read_packet_length); 549 550 if (copy_to_user(buffer, dev->read_buffer, bytes_to_read)) { 551 retval = -EFAULT; 552 goto unlock_exit; 553 } 554 555 spin_lock_irq(&dev->read_buffer_lock); 556 dev->read_buffer_length -= bytes_to_read; 557 dev->read_packet_length -= bytes_to_read; 558 for (i = 0; i < dev->read_buffer_length; i++) 559 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 560 spin_unlock_irq(&dev->read_buffer_lock); 561 562 retval = bytes_to_read; 563 564unlock_exit: 565 /* unlock the device */ 566 mutex_unlock(&dev->lock); 567 568exit: 569 return retval; 570} 571 572 573/* 574 * tower_write 575 */ 576static ssize_t tower_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 577{ 578 struct lego_usb_tower *dev; 579 size_t bytes_to_write; 580 int retval = 0; 581 582 dev = file->private_data; 583 584 /* lock this object */ 585 if (mutex_lock_interruptible(&dev->lock)) { 586 retval = -ERESTARTSYS; 587 goto exit; 588 } 589 590 /* verify that the device wasn't unplugged */ 591 if (dev->disconnected) { 592 retval = -ENODEV; 593 goto unlock_exit; 594 } 595 596 /* verify that we actually have some data to write */ 597 if (count == 0) { 598 dev_dbg(&dev->udev->dev, "write request of 0 bytes\n"); 599 goto unlock_exit; 600 } 601 602 /* wait until previous transfer is finished */ 603 while (dev->interrupt_out_busy) { 604 if (file->f_flags & O_NONBLOCK) { 605 retval = -EAGAIN; 606 goto unlock_exit; 607 } 608 retval = wait_event_interruptible(dev->write_wait, 609 !dev->interrupt_out_busy); 610 if (retval) 611 goto unlock_exit; 612 } 613 614 /* write the data into interrupt_out_buffer from userspace */ 615 bytes_to_write = min_t(int, count, write_buffer_size); 616 dev_dbg(&dev->udev->dev, "%s: count = %zd, bytes_to_write = %zd\n", 617 __func__, count, bytes_to_write); 618 619 if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) { 620 retval = -EFAULT; 621 goto unlock_exit; 622 } 623 624 /* send off the urb */ 625 usb_fill_int_urb(dev->interrupt_out_urb, 626 dev->udev, 627 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 628 dev->interrupt_out_buffer, 629 bytes_to_write, 630 tower_interrupt_out_callback, 631 dev, 632 dev->interrupt_out_interval); 633 634 dev->interrupt_out_busy = 1; 635 wmb(); 636 637 retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL); 638 if (retval) { 639 dev->interrupt_out_busy = 0; 640 dev_err(&dev->udev->dev, 641 "Couldn't submit interrupt_out_urb %d\n", retval); 642 goto unlock_exit; 643 } 644 retval = bytes_to_write; 645 646unlock_exit: 647 /* unlock the device */ 648 mutex_unlock(&dev->lock); 649 650exit: 651 return retval; 652} 653 654 655/* 656 * tower_interrupt_in_callback 657 */ 658static void tower_interrupt_in_callback(struct urb *urb) 659{ 660 struct lego_usb_tower *dev = urb->context; 661 int status = urb->status; 662 int retval; 663 unsigned long flags; 664 665 lego_usb_tower_debug_data(&dev->udev->dev, __func__, 666 urb->actual_length, urb->transfer_buffer); 667 668 if (status) { 669 if (status == -ENOENT || 670 status == -ECONNRESET || 671 status == -ESHUTDOWN) { 672 goto exit; 673 } else { 674 dev_dbg(&dev->udev->dev, 675 "%s: nonzero status received: %d\n", __func__, 676 status); 677 goto resubmit; /* maybe we can recover */ 678 } 679 } 680 681 if (urb->actual_length > 0) { 682 spin_lock_irqsave(&dev->read_buffer_lock, flags); 683 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 684 memcpy(dev->read_buffer + dev->read_buffer_length, 685 dev->interrupt_in_buffer, 686 urb->actual_length); 687 dev->read_buffer_length += urb->actual_length; 688 dev->read_last_arrival = jiffies; 689 dev_dbg(&dev->udev->dev, "%s: received %d bytes\n", 690 __func__, urb->actual_length); 691 } else { 692 pr_warn("read_buffer overflow, %d bytes dropped\n", 693 urb->actual_length); 694 } 695 spin_unlock_irqrestore(&dev->read_buffer_lock, flags); 696 } 697 698resubmit: 699 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC); 700 if (retval) { 701 dev_err(&dev->udev->dev, "%s: usb_submit_urb failed (%d)\n", 702 __func__, retval); 703 } 704exit: 705 dev->interrupt_in_done = 1; 706 wake_up_interruptible(&dev->read_wait); 707} 708 709 710/* 711 * tower_interrupt_out_callback 712 */ 713static void tower_interrupt_out_callback(struct urb *urb) 714{ 715 struct lego_usb_tower *dev = urb->context; 716 int status = urb->status; 717 718 lego_usb_tower_debug_data(&dev->udev->dev, __func__, 719 urb->actual_length, urb->transfer_buffer); 720 721 /* sync/async unlink faults aren't errors */ 722 if (status && !(status == -ENOENT || 723 status == -ECONNRESET || 724 status == -ESHUTDOWN)) { 725 dev_dbg(&dev->udev->dev, 726 "%s: nonzero write bulk status received: %d\n", __func__, 727 status); 728 } 729 730 dev->interrupt_out_busy = 0; 731 wake_up_interruptible(&dev->write_wait); 732} 733 734 735/* 736 * tower_probe 737 * 738 * Called by the usb core when a new device is connected that it thinks 739 * this driver might be interested in. 740 */ 741static int tower_probe(struct usb_interface *interface, const struct usb_device_id *id) 742{ 743 struct device *idev = &interface->dev; 744 struct usb_device *udev = interface_to_usbdev(interface); 745 struct lego_usb_tower *dev; 746 struct tower_get_version_reply get_version_reply; 747 int retval = -ENOMEM; 748 int result; 749 750 /* allocate memory for our device state and initialize it */ 751 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 752 if (!dev) 753 goto exit; 754 755 mutex_init(&dev->lock); 756 dev->udev = usb_get_dev(udev); 757 spin_lock_init(&dev->read_buffer_lock); 758 dev->packet_timeout_jiffies = msecs_to_jiffies(packet_timeout); 759 dev->read_last_arrival = jiffies; 760 init_waitqueue_head(&dev->read_wait); 761 init_waitqueue_head(&dev->write_wait); 762 763 result = usb_find_common_endpoints_reverse(interface->cur_altsetting, 764 NULL, NULL, 765 &dev->interrupt_in_endpoint, 766 &dev->interrupt_out_endpoint); 767 if (result) { 768 dev_err(idev, "interrupt endpoints not found\n"); 769 retval = result; 770 goto error; 771 } 772 773 dev->read_buffer = kmalloc(read_buffer_size, GFP_KERNEL); 774 if (!dev->read_buffer) 775 goto error; 776 dev->interrupt_in_buffer = kmalloc(usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL); 777 if (!dev->interrupt_in_buffer) 778 goto error; 779 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 780 if (!dev->interrupt_in_urb) 781 goto error; 782 dev->interrupt_out_buffer = kmalloc(write_buffer_size, GFP_KERNEL); 783 if (!dev->interrupt_out_buffer) 784 goto error; 785 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 786 if (!dev->interrupt_out_urb) 787 goto error; 788 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 789 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 790 791 /* get the firmware version and log it */ 792 result = usb_control_msg_recv(udev, 0, 793 LEGO_USB_TOWER_REQUEST_GET_VERSION, 794 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 795 0, 796 0, 797 &get_version_reply, 798 sizeof(get_version_reply), 799 1000, GFP_KERNEL); 800 if (result) { 801 dev_err(idev, "get version request failed: %d\n", result); 802 retval = result; 803 goto error; 804 } 805 dev_info(&interface->dev, 806 "LEGO USB Tower firmware version is %d.%d build %d\n", 807 get_version_reply.major, 808 get_version_reply.minor, 809 le16_to_cpu(get_version_reply.build_no)); 810 811 /* we can register the device now, as it is ready */ 812 usb_set_intfdata(interface, dev); 813 814 retval = usb_register_dev(interface, &tower_class); 815 if (retval) { 816 /* something prevented us from registering this driver */ 817 dev_err(idev, "Not able to get a minor for this device.\n"); 818 goto error; 819 } 820 dev->minor = interface->minor; 821 822 /* let the user know what node this device is now attached to */ 823 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major " 824 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), 825 USB_MAJOR, dev->minor); 826 827exit: 828 return retval; 829 830error: 831 tower_delete(dev); 832 return retval; 833} 834 835 836/* 837 * tower_disconnect 838 * 839 * Called by the usb core when the device is removed from the system. 840 */ 841static void tower_disconnect(struct usb_interface *interface) 842{ 843 struct lego_usb_tower *dev; 844 int minor; 845 846 dev = usb_get_intfdata(interface); 847 848 minor = dev->minor; 849 850 /* give back our minor and prevent further open() */ 851 usb_deregister_dev(interface, &tower_class); 852 853 /* stop I/O */ 854 usb_poison_urb(dev->interrupt_in_urb); 855 usb_poison_urb(dev->interrupt_out_urb); 856 857 mutex_lock(&dev->lock); 858 859 /* if the device is not opened, then we clean up right now */ 860 if (!dev->open_count) { 861 mutex_unlock(&dev->lock); 862 tower_delete(dev); 863 } else { 864 dev->disconnected = 1; 865 /* wake up pollers */ 866 wake_up_interruptible_all(&dev->read_wait); 867 wake_up_interruptible_all(&dev->write_wait); 868 mutex_unlock(&dev->lock); 869 } 870 871 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n", 872 (minor - LEGO_USB_TOWER_MINOR_BASE)); 873} 874 875module_usb_driver(tower_driver); 876 877MODULE_AUTHOR(DRIVER_AUTHOR); 878MODULE_DESCRIPTION(DRIVER_DESC); 879MODULE_LICENSE("GPL"); 880