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