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 */ 98 static int read_buffer_size = 480; 99 module_param(read_buffer_size, int, 0); 100 MODULE_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 */ 108 static int write_buffer_size = 480; 109 module_param(write_buffer_size, int, 0); 110 MODULE_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 */ 122 static int packet_timeout = 50; 123 module_param(packet_timeout, int, 0); 124 MODULE_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 */ 130 static int read_timeout = 200; 131 module_param(read_timeout, int, 0); 132 MODULE_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 */ 143 static int interrupt_in_interval = 2; 144 module_param(interrupt_in_interval, int, 0); 145 MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms"); 146 147 static int interrupt_out_interval = 8; 148 module_param(interrupt_out_interval, int, 0); 149 MODULE_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 158 159 struct tower_reset_reply { 160 __le16 size; /* little-endian */ 161 __u8 err_code; 162 __u8 spare; 163 } __attribute__ ((packed)); 164 165 struct tower_get_version_reply { 166 __le16 size; /* little-endian */ 167 __u8 err_code; 168 __u8 spare; 169 __u8 major; 170 __u8 minor; 171 __le16 build_no; /* little-endian */ 172 } __attribute__ ((packed)); 173 174 175 /* table of devices that work with this driver */ 176 static const struct usb_device_id tower_table[] = { 177 { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) }, 178 { } /* Terminating entry */ 179 }; 180 181 MODULE_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 */ 187 struct 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_running; 210 int interrupt_in_done; 211 212 char* interrupt_out_buffer; 213 struct usb_endpoint_descriptor* interrupt_out_endpoint; 214 struct urb* interrupt_out_urb; 215 int interrupt_out_interval; 216 int interrupt_out_busy; 217 218 }; 219 220 221 /* local function prototypes */ 222 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos); 223 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos); 224 static inline void tower_delete (struct lego_usb_tower *dev); 225 static int tower_open (struct inode *inode, struct file *file); 226 static int tower_release (struct inode *inode, struct file *file); 227 static __poll_t tower_poll (struct file *file, poll_table *wait); 228 static loff_t tower_llseek (struct file *file, loff_t off, int whence); 229 230 static void tower_abort_transfers (struct lego_usb_tower *dev); 231 static void tower_check_for_read_packet (struct lego_usb_tower *dev); 232 static void tower_interrupt_in_callback (struct urb *urb); 233 static void tower_interrupt_out_callback (struct urb *urb); 234 235 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id); 236 static void tower_disconnect (struct usb_interface *interface); 237 238 239 /* file operations needed when we register this driver */ 240 static const struct file_operations tower_fops = { 241 .owner = THIS_MODULE, 242 .read = tower_read, 243 .write = tower_write, 244 .open = tower_open, 245 .release = tower_release, 246 .poll = tower_poll, 247 .llseek = tower_llseek, 248 }; 249 250 static char *legousbtower_devnode(struct device *dev, umode_t *mode) 251 { 252 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev)); 253 } 254 255 /* 256 * usb class driver info in order to get a minor number from the usb core, 257 * and to have the device registered with the driver core 258 */ 259 static struct usb_class_driver tower_class = { 260 .name = "legousbtower%d", 261 .devnode = legousbtower_devnode, 262 .fops = &tower_fops, 263 .minor_base = LEGO_USB_TOWER_MINOR_BASE, 264 }; 265 266 267 /* usb specific object needed to register this driver with the usb subsystem */ 268 static struct usb_driver tower_driver = { 269 .name = "legousbtower", 270 .probe = tower_probe, 271 .disconnect = tower_disconnect, 272 .id_table = tower_table, 273 }; 274 275 276 /** 277 * lego_usb_tower_debug_data 278 */ 279 static inline void lego_usb_tower_debug_data(struct device *dev, 280 const char *function, int size, 281 const unsigned char *data) 282 { 283 dev_dbg(dev, "%s - length = %d, data = %*ph\n", 284 function, size, size, data); 285 } 286 287 288 /** 289 * tower_delete 290 */ 291 static inline void tower_delete (struct lego_usb_tower *dev) 292 { 293 /* free data structures */ 294 usb_free_urb(dev->interrupt_in_urb); 295 usb_free_urb(dev->interrupt_out_urb); 296 kfree (dev->read_buffer); 297 kfree (dev->interrupt_in_buffer); 298 kfree (dev->interrupt_out_buffer); 299 usb_put_dev(dev->udev); 300 kfree (dev); 301 } 302 303 304 /** 305 * tower_open 306 */ 307 static int tower_open (struct inode *inode, struct file *file) 308 { 309 struct lego_usb_tower *dev = NULL; 310 int subminor; 311 int retval = 0; 312 struct usb_interface *interface; 313 struct tower_reset_reply *reset_reply; 314 int result; 315 316 reset_reply = kmalloc(sizeof(*reset_reply), GFP_KERNEL); 317 318 if (!reset_reply) { 319 retval = -ENOMEM; 320 goto exit; 321 } 322 323 nonseekable_open(inode, file); 324 subminor = iminor(inode); 325 326 interface = usb_find_interface (&tower_driver, subminor); 327 328 if (!interface) { 329 pr_err("error, can't find device for minor %d\n", subminor); 330 retval = -ENODEV; 331 goto exit; 332 } 333 334 dev = usb_get_intfdata(interface); 335 if (!dev) { 336 retval = -ENODEV; 337 goto exit; 338 } 339 340 /* lock this device */ 341 if (mutex_lock_interruptible(&dev->lock)) { 342 retval = -ERESTARTSYS; 343 goto exit; 344 } 345 346 347 /* allow opening only once */ 348 if (dev->open_count) { 349 retval = -EBUSY; 350 goto unlock_exit; 351 } 352 353 /* reset the tower */ 354 result = usb_control_msg (dev->udev, 355 usb_rcvctrlpipe(dev->udev, 0), 356 LEGO_USB_TOWER_REQUEST_RESET, 357 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 358 0, 359 0, 360 reset_reply, 361 sizeof(*reset_reply), 362 1000); 363 if (result < 0) { 364 dev_err(&dev->udev->dev, 365 "LEGO USB Tower reset control request failed\n"); 366 retval = result; 367 goto unlock_exit; 368 } 369 370 /* initialize in direction */ 371 dev->read_buffer_length = 0; 372 dev->read_packet_length = 0; 373 usb_fill_int_urb (dev->interrupt_in_urb, 374 dev->udev, 375 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress), 376 dev->interrupt_in_buffer, 377 usb_endpoint_maxp(dev->interrupt_in_endpoint), 378 tower_interrupt_in_callback, 379 dev, 380 dev->interrupt_in_interval); 381 382 dev->interrupt_in_running = 1; 383 dev->interrupt_in_done = 0; 384 mb(); 385 386 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL); 387 if (retval) { 388 dev_err(&dev->udev->dev, 389 "Couldn't submit interrupt_in_urb %d\n", retval); 390 dev->interrupt_in_running = 0; 391 goto unlock_exit; 392 } 393 394 /* save device in the file's private structure */ 395 file->private_data = dev; 396 397 dev->open_count = 1; 398 399 unlock_exit: 400 mutex_unlock(&dev->lock); 401 402 exit: 403 kfree(reset_reply); 404 return retval; 405 } 406 407 /** 408 * tower_release 409 */ 410 static int tower_release (struct inode *inode, struct file *file) 411 { 412 struct lego_usb_tower *dev; 413 int retval = 0; 414 415 dev = file->private_data; 416 417 if (dev == NULL) { 418 retval = -ENODEV; 419 goto exit; 420 } 421 422 mutex_lock(&dev->lock); 423 424 if (dev->open_count != 1) { 425 dev_dbg(&dev->udev->dev, "%s: device not opened exactly once\n", 426 __func__); 427 retval = -ENODEV; 428 goto unlock_exit; 429 } 430 431 if (dev->disconnected) { 432 /* the device was unplugged before the file was released */ 433 434 /* unlock here as tower_delete frees dev */ 435 mutex_unlock(&dev->lock); 436 tower_delete (dev); 437 goto exit; 438 } 439 440 /* wait until write transfer is finished */ 441 if (dev->interrupt_out_busy) { 442 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 443 } 444 tower_abort_transfers (dev); 445 dev->open_count = 0; 446 447 unlock_exit: 448 mutex_unlock(&dev->lock); 449 exit: 450 return retval; 451 } 452 453 454 /** 455 * tower_abort_transfers 456 * aborts transfers and frees associated data structures 457 */ 458 static void tower_abort_transfers (struct lego_usb_tower *dev) 459 { 460 /* shutdown transfer */ 461 if (dev->interrupt_in_running) { 462 dev->interrupt_in_running = 0; 463 mb(); 464 usb_kill_urb(dev->interrupt_in_urb); 465 } 466 if (dev->interrupt_out_busy) 467 usb_kill_urb(dev->interrupt_out_urb); 468 } 469 470 471 /** 472 * tower_check_for_read_packet 473 * 474 * To get correct semantics for signals and non-blocking I/O 475 * with packetizing we pretend not to see any data in the read buffer 476 * until it has been there unchanged for at least 477 * dev->packet_timeout_jiffies, or until the buffer is full. 478 */ 479 static void tower_check_for_read_packet (struct lego_usb_tower *dev) 480 { 481 spin_lock_irq (&dev->read_buffer_lock); 482 if (!packet_timeout 483 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) 484 || dev->read_buffer_length == read_buffer_size) { 485 dev->read_packet_length = dev->read_buffer_length; 486 } 487 dev->interrupt_in_done = 0; 488 spin_unlock_irq (&dev->read_buffer_lock); 489 } 490 491 492 /** 493 * tower_poll 494 */ 495 static __poll_t tower_poll (struct file *file, poll_table *wait) 496 { 497 struct lego_usb_tower *dev; 498 __poll_t mask = 0; 499 500 dev = file->private_data; 501 502 if (dev->disconnected) 503 return EPOLLERR | EPOLLHUP; 504 505 poll_wait(file, &dev->read_wait, wait); 506 poll_wait(file, &dev->write_wait, wait); 507 508 tower_check_for_read_packet(dev); 509 if (dev->read_packet_length > 0) { 510 mask |= EPOLLIN | EPOLLRDNORM; 511 } 512 if (!dev->interrupt_out_busy) { 513 mask |= EPOLLOUT | EPOLLWRNORM; 514 } 515 516 return mask; 517 } 518 519 520 /** 521 * tower_llseek 522 */ 523 static loff_t tower_llseek (struct file *file, loff_t off, int whence) 524 { 525 return -ESPIPE; /* unseekable */ 526 } 527 528 529 /** 530 * tower_read 531 */ 532 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 533 { 534 struct lego_usb_tower *dev; 535 size_t bytes_to_read; 536 int i; 537 int retval = 0; 538 unsigned long timeout = 0; 539 540 dev = file->private_data; 541 542 /* lock this object */ 543 if (mutex_lock_interruptible(&dev->lock)) { 544 retval = -ERESTARTSYS; 545 goto exit; 546 } 547 548 /* verify that the device wasn't unplugged */ 549 if (dev->disconnected) { 550 retval = -ENODEV; 551 pr_err("No device or device unplugged %d\n", retval); 552 goto unlock_exit; 553 } 554 555 /* verify that we actually have some data to read */ 556 if (count == 0) { 557 dev_dbg(&dev->udev->dev, "read request of 0 bytes\n"); 558 goto unlock_exit; 559 } 560 561 if (read_timeout) { 562 timeout = jiffies + msecs_to_jiffies(read_timeout); 563 } 564 565 /* wait for data */ 566 tower_check_for_read_packet (dev); 567 while (dev->read_packet_length == 0) { 568 if (file->f_flags & O_NONBLOCK) { 569 retval = -EAGAIN; 570 goto unlock_exit; 571 } 572 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 573 if (retval < 0) { 574 goto unlock_exit; 575 } 576 577 /* reset read timeout during read or write activity */ 578 if (read_timeout 579 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 580 timeout = jiffies + msecs_to_jiffies(read_timeout); 581 } 582 /* check for read timeout */ 583 if (read_timeout && time_after (jiffies, timeout)) { 584 retval = -ETIMEDOUT; 585 goto unlock_exit; 586 } 587 tower_check_for_read_packet (dev); 588 } 589 590 /* copy the data from read_buffer into userspace */ 591 bytes_to_read = min(count, dev->read_packet_length); 592 593 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { 594 retval = -EFAULT; 595 goto unlock_exit; 596 } 597 598 spin_lock_irq (&dev->read_buffer_lock); 599 dev->read_buffer_length -= bytes_to_read; 600 dev->read_packet_length -= bytes_to_read; 601 for (i=0; i<dev->read_buffer_length; i++) { 602 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 603 } 604 spin_unlock_irq (&dev->read_buffer_lock); 605 606 retval = bytes_to_read; 607 608 unlock_exit: 609 /* unlock the device */ 610 mutex_unlock(&dev->lock); 611 612 exit: 613 return retval; 614 } 615 616 617 /** 618 * tower_write 619 */ 620 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 621 { 622 struct lego_usb_tower *dev; 623 size_t bytes_to_write; 624 int retval = 0; 625 626 dev = file->private_data; 627 628 /* lock this object */ 629 if (mutex_lock_interruptible(&dev->lock)) { 630 retval = -ERESTARTSYS; 631 goto exit; 632 } 633 634 /* verify that the device wasn't unplugged */ 635 if (dev->disconnected) { 636 retval = -ENODEV; 637 pr_err("No device or device unplugged %d\n", retval); 638 goto unlock_exit; 639 } 640 641 /* verify that we actually have some data to write */ 642 if (count == 0) { 643 dev_dbg(&dev->udev->dev, "write request of 0 bytes\n"); 644 goto unlock_exit; 645 } 646 647 /* wait until previous transfer is finished */ 648 while (dev->interrupt_out_busy) { 649 if (file->f_flags & O_NONBLOCK) { 650 retval = -EAGAIN; 651 goto unlock_exit; 652 } 653 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); 654 if (retval) { 655 goto unlock_exit; 656 } 657 } 658 659 /* write the data into interrupt_out_buffer from userspace */ 660 bytes_to_write = min_t(int, count, write_buffer_size); 661 dev_dbg(&dev->udev->dev, "%s: count = %zd, bytes_to_write = %zd\n", 662 __func__, count, bytes_to_write); 663 664 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { 665 retval = -EFAULT; 666 goto unlock_exit; 667 } 668 669 /* send off the urb */ 670 usb_fill_int_urb(dev->interrupt_out_urb, 671 dev->udev, 672 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 673 dev->interrupt_out_buffer, 674 bytes_to_write, 675 tower_interrupt_out_callback, 676 dev, 677 dev->interrupt_out_interval); 678 679 dev->interrupt_out_busy = 1; 680 wmb(); 681 682 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); 683 if (retval) { 684 dev->interrupt_out_busy = 0; 685 dev_err(&dev->udev->dev, 686 "Couldn't submit interrupt_out_urb %d\n", retval); 687 goto unlock_exit; 688 } 689 retval = bytes_to_write; 690 691 unlock_exit: 692 /* unlock the device */ 693 mutex_unlock(&dev->lock); 694 695 exit: 696 return retval; 697 } 698 699 700 /** 701 * tower_interrupt_in_callback 702 */ 703 static void tower_interrupt_in_callback (struct urb *urb) 704 { 705 struct lego_usb_tower *dev = urb->context; 706 int status = urb->status; 707 int retval; 708 unsigned long flags; 709 710 lego_usb_tower_debug_data(&dev->udev->dev, __func__, 711 urb->actual_length, urb->transfer_buffer); 712 713 if (status) { 714 if (status == -ENOENT || 715 status == -ECONNRESET || 716 status == -ESHUTDOWN) { 717 goto exit; 718 } else { 719 dev_dbg(&dev->udev->dev, 720 "%s: nonzero status received: %d\n", __func__, 721 status); 722 goto resubmit; /* maybe we can recover */ 723 } 724 } 725 726 if (urb->actual_length > 0) { 727 spin_lock_irqsave(&dev->read_buffer_lock, flags); 728 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 729 memcpy (dev->read_buffer + dev->read_buffer_length, 730 dev->interrupt_in_buffer, 731 urb->actual_length); 732 dev->read_buffer_length += urb->actual_length; 733 dev->read_last_arrival = jiffies; 734 dev_dbg(&dev->udev->dev, "%s: received %d bytes\n", 735 __func__, urb->actual_length); 736 } else { 737 pr_warn("read_buffer overflow, %d bytes dropped\n", 738 urb->actual_length); 739 } 740 spin_unlock_irqrestore(&dev->read_buffer_lock, flags); 741 } 742 743 resubmit: 744 /* resubmit if we're still running */ 745 if (dev->interrupt_in_running) { 746 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); 747 if (retval) 748 dev_err(&dev->udev->dev, 749 "%s: usb_submit_urb failed (%d)\n", 750 __func__, retval); 751 } 752 753 exit: 754 dev->interrupt_in_done = 1; 755 wake_up_interruptible (&dev->read_wait); 756 } 757 758 759 /** 760 * tower_interrupt_out_callback 761 */ 762 static void tower_interrupt_out_callback (struct urb *urb) 763 { 764 struct lego_usb_tower *dev = urb->context; 765 int status = urb->status; 766 767 lego_usb_tower_debug_data(&dev->udev->dev, __func__, 768 urb->actual_length, urb->transfer_buffer); 769 770 /* sync/async unlink faults aren't errors */ 771 if (status && !(status == -ENOENT || 772 status == -ECONNRESET || 773 status == -ESHUTDOWN)) { 774 dev_dbg(&dev->udev->dev, 775 "%s: nonzero write bulk status received: %d\n", __func__, 776 status); 777 } 778 779 dev->interrupt_out_busy = 0; 780 wake_up_interruptible(&dev->write_wait); 781 } 782 783 784 /** 785 * tower_probe 786 * 787 * Called by the usb core when a new device is connected that it thinks 788 * this driver might be interested in. 789 */ 790 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) 791 { 792 struct device *idev = &interface->dev; 793 struct usb_device *udev = interface_to_usbdev(interface); 794 struct lego_usb_tower *dev; 795 struct tower_get_version_reply *get_version_reply = NULL; 796 int retval = -ENOMEM; 797 int result; 798 799 /* allocate memory for our device state and initialize it */ 800 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 801 if (!dev) 802 goto exit; 803 804 mutex_init(&dev->lock); 805 dev->udev = usb_get_dev(udev); 806 spin_lock_init (&dev->read_buffer_lock); 807 dev->packet_timeout_jiffies = msecs_to_jiffies(packet_timeout); 808 dev->read_last_arrival = jiffies; 809 init_waitqueue_head (&dev->read_wait); 810 init_waitqueue_head (&dev->write_wait); 811 812 result = usb_find_common_endpoints_reverse(interface->cur_altsetting, 813 NULL, NULL, 814 &dev->interrupt_in_endpoint, 815 &dev->interrupt_out_endpoint); 816 if (result) { 817 dev_err(idev, "interrupt endpoints not found\n"); 818 retval = result; 819 goto error; 820 } 821 822 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); 823 if (!dev->read_buffer) 824 goto error; 825 dev->interrupt_in_buffer = kmalloc (usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL); 826 if (!dev->interrupt_in_buffer) 827 goto error; 828 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 829 if (!dev->interrupt_in_urb) 830 goto error; 831 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL); 832 if (!dev->interrupt_out_buffer) 833 goto error; 834 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 835 if (!dev->interrupt_out_urb) 836 goto error; 837 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 838 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 839 840 get_version_reply = kmalloc(sizeof(*get_version_reply), GFP_KERNEL); 841 842 if (!get_version_reply) { 843 retval = -ENOMEM; 844 goto error; 845 } 846 847 /* get the firmware version and log it */ 848 result = usb_control_msg (udev, 849 usb_rcvctrlpipe(udev, 0), 850 LEGO_USB_TOWER_REQUEST_GET_VERSION, 851 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 852 0, 853 0, 854 get_version_reply, 855 sizeof(*get_version_reply), 856 1000); 857 if (result != sizeof(*get_version_reply)) { 858 if (result >= 0) 859 result = -EIO; 860 dev_err(idev, "get version request failed: %d\n", result); 861 retval = result; 862 goto error; 863 } 864 dev_info(&interface->dev, 865 "LEGO USB Tower firmware version is %d.%d build %d\n", 866 get_version_reply->major, 867 get_version_reply->minor, 868 le16_to_cpu(get_version_reply->build_no)); 869 870 /* we can register the device now, as it is ready */ 871 usb_set_intfdata (interface, dev); 872 873 retval = usb_register_dev (interface, &tower_class); 874 875 if (retval) { 876 /* something prevented us from registering this driver */ 877 dev_err(idev, "Not able to get a minor for this device.\n"); 878 goto error; 879 } 880 dev->minor = interface->minor; 881 882 /* let the user know what node this device is now attached to */ 883 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major " 884 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), 885 USB_MAJOR, dev->minor); 886 887 exit: 888 kfree(get_version_reply); 889 return retval; 890 891 error: 892 kfree(get_version_reply); 893 tower_delete(dev); 894 return retval; 895 } 896 897 898 /** 899 * tower_disconnect 900 * 901 * Called by the usb core when the device is removed from the system. 902 */ 903 static void tower_disconnect (struct usb_interface *interface) 904 { 905 struct lego_usb_tower *dev; 906 int minor; 907 908 dev = usb_get_intfdata (interface); 909 910 minor = dev->minor; 911 912 /* give back our minor and prevent further open() */ 913 usb_deregister_dev (interface, &tower_class); 914 915 /* stop I/O */ 916 usb_poison_urb(dev->interrupt_in_urb); 917 usb_poison_urb(dev->interrupt_out_urb); 918 919 mutex_lock(&dev->lock); 920 921 /* if the device is not opened, then we clean up right now */ 922 if (!dev->open_count) { 923 mutex_unlock(&dev->lock); 924 tower_delete (dev); 925 } else { 926 dev->disconnected = 1; 927 /* wake up pollers */ 928 wake_up_interruptible_all(&dev->read_wait); 929 wake_up_interruptible_all(&dev->write_wait); 930 mutex_unlock(&dev->lock); 931 } 932 933 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n", 934 (minor - LEGO_USB_TOWER_MINOR_BASE)); 935 } 936 937 module_usb_driver(tower_driver); 938 939 MODULE_AUTHOR(DRIVER_AUTHOR); 940 MODULE_DESCRIPTION(DRIVER_DESC); 941 MODULE_LICENSE("GPL"); 942