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 if (dev == NULL) 461 return; 462 463 /* shutdown transfer */ 464 if (dev->interrupt_in_running) { 465 dev->interrupt_in_running = 0; 466 mb(); 467 usb_kill_urb(dev->interrupt_in_urb); 468 } 469 if (dev->interrupt_out_busy) 470 usb_kill_urb(dev->interrupt_out_urb); 471 } 472 473 474 /** 475 * tower_check_for_read_packet 476 * 477 * To get correct semantics for signals and non-blocking I/O 478 * with packetizing we pretend not to see any data in the read buffer 479 * until it has been there unchanged for at least 480 * dev->packet_timeout_jiffies, or until the buffer is full. 481 */ 482 static void tower_check_for_read_packet (struct lego_usb_tower *dev) 483 { 484 spin_lock_irq (&dev->read_buffer_lock); 485 if (!packet_timeout 486 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) 487 || dev->read_buffer_length == read_buffer_size) { 488 dev->read_packet_length = dev->read_buffer_length; 489 } 490 dev->interrupt_in_done = 0; 491 spin_unlock_irq (&dev->read_buffer_lock); 492 } 493 494 495 /** 496 * tower_poll 497 */ 498 static __poll_t tower_poll (struct file *file, poll_table *wait) 499 { 500 struct lego_usb_tower *dev; 501 __poll_t mask = 0; 502 503 dev = file->private_data; 504 505 if (dev->disconnected) 506 return EPOLLERR | EPOLLHUP; 507 508 poll_wait(file, &dev->read_wait, wait); 509 poll_wait(file, &dev->write_wait, wait); 510 511 tower_check_for_read_packet(dev); 512 if (dev->read_packet_length > 0) { 513 mask |= EPOLLIN | EPOLLRDNORM; 514 } 515 if (!dev->interrupt_out_busy) { 516 mask |= EPOLLOUT | EPOLLWRNORM; 517 } 518 519 return mask; 520 } 521 522 523 /** 524 * tower_llseek 525 */ 526 static loff_t tower_llseek (struct file *file, loff_t off, int whence) 527 { 528 return -ESPIPE; /* unseekable */ 529 } 530 531 532 /** 533 * tower_read 534 */ 535 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 536 { 537 struct lego_usb_tower *dev; 538 size_t bytes_to_read; 539 int i; 540 int retval = 0; 541 unsigned long timeout = 0; 542 543 dev = file->private_data; 544 545 /* lock this object */ 546 if (mutex_lock_interruptible(&dev->lock)) { 547 retval = -ERESTARTSYS; 548 goto exit; 549 } 550 551 /* verify that the device wasn't unplugged */ 552 if (dev->disconnected) { 553 retval = -ENODEV; 554 pr_err("No device or device unplugged %d\n", retval); 555 goto unlock_exit; 556 } 557 558 /* verify that we actually have some data to read */ 559 if (count == 0) { 560 dev_dbg(&dev->udev->dev, "read request of 0 bytes\n"); 561 goto unlock_exit; 562 } 563 564 if (read_timeout) { 565 timeout = jiffies + msecs_to_jiffies(read_timeout); 566 } 567 568 /* wait for data */ 569 tower_check_for_read_packet (dev); 570 while (dev->read_packet_length == 0) { 571 if (file->f_flags & O_NONBLOCK) { 572 retval = -EAGAIN; 573 goto unlock_exit; 574 } 575 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 576 if (retval < 0) { 577 goto unlock_exit; 578 } 579 580 /* reset read timeout during read or write activity */ 581 if (read_timeout 582 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 583 timeout = jiffies + msecs_to_jiffies(read_timeout); 584 } 585 /* check for read timeout */ 586 if (read_timeout && time_after (jiffies, timeout)) { 587 retval = -ETIMEDOUT; 588 goto unlock_exit; 589 } 590 tower_check_for_read_packet (dev); 591 } 592 593 /* copy the data from read_buffer into userspace */ 594 bytes_to_read = min(count, dev->read_packet_length); 595 596 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { 597 retval = -EFAULT; 598 goto unlock_exit; 599 } 600 601 spin_lock_irq (&dev->read_buffer_lock); 602 dev->read_buffer_length -= bytes_to_read; 603 dev->read_packet_length -= bytes_to_read; 604 for (i=0; i<dev->read_buffer_length; i++) { 605 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 606 } 607 spin_unlock_irq (&dev->read_buffer_lock); 608 609 retval = bytes_to_read; 610 611 unlock_exit: 612 /* unlock the device */ 613 mutex_unlock(&dev->lock); 614 615 exit: 616 return retval; 617 } 618 619 620 /** 621 * tower_write 622 */ 623 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 624 { 625 struct lego_usb_tower *dev; 626 size_t bytes_to_write; 627 int retval = 0; 628 629 dev = file->private_data; 630 631 /* lock this object */ 632 if (mutex_lock_interruptible(&dev->lock)) { 633 retval = -ERESTARTSYS; 634 goto exit; 635 } 636 637 /* verify that the device wasn't unplugged */ 638 if (dev->disconnected) { 639 retval = -ENODEV; 640 pr_err("No device or device unplugged %d\n", retval); 641 goto unlock_exit; 642 } 643 644 /* verify that we actually have some data to write */ 645 if (count == 0) { 646 dev_dbg(&dev->udev->dev, "write request of 0 bytes\n"); 647 goto unlock_exit; 648 } 649 650 /* wait until previous transfer is finished */ 651 while (dev->interrupt_out_busy) { 652 if (file->f_flags & O_NONBLOCK) { 653 retval = -EAGAIN; 654 goto unlock_exit; 655 } 656 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); 657 if (retval) { 658 goto unlock_exit; 659 } 660 } 661 662 /* write the data into interrupt_out_buffer from userspace */ 663 bytes_to_write = min_t(int, count, write_buffer_size); 664 dev_dbg(&dev->udev->dev, "%s: count = %zd, bytes_to_write = %zd\n", 665 __func__, count, bytes_to_write); 666 667 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { 668 retval = -EFAULT; 669 goto unlock_exit; 670 } 671 672 /* send off the urb */ 673 usb_fill_int_urb(dev->interrupt_out_urb, 674 dev->udev, 675 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 676 dev->interrupt_out_buffer, 677 bytes_to_write, 678 tower_interrupt_out_callback, 679 dev, 680 dev->interrupt_out_interval); 681 682 dev->interrupt_out_busy = 1; 683 wmb(); 684 685 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); 686 if (retval) { 687 dev->interrupt_out_busy = 0; 688 dev_err(&dev->udev->dev, 689 "Couldn't submit interrupt_out_urb %d\n", retval); 690 goto unlock_exit; 691 } 692 retval = bytes_to_write; 693 694 unlock_exit: 695 /* unlock the device */ 696 mutex_unlock(&dev->lock); 697 698 exit: 699 return retval; 700 } 701 702 703 /** 704 * tower_interrupt_in_callback 705 */ 706 static void tower_interrupt_in_callback (struct urb *urb) 707 { 708 struct lego_usb_tower *dev = urb->context; 709 int status = urb->status; 710 int retval; 711 unsigned long flags; 712 713 lego_usb_tower_debug_data(&dev->udev->dev, __func__, 714 urb->actual_length, urb->transfer_buffer); 715 716 if (status) { 717 if (status == -ENOENT || 718 status == -ECONNRESET || 719 status == -ESHUTDOWN) { 720 goto exit; 721 } else { 722 dev_dbg(&dev->udev->dev, 723 "%s: nonzero status received: %d\n", __func__, 724 status); 725 goto resubmit; /* maybe we can recover */ 726 } 727 } 728 729 if (urb->actual_length > 0) { 730 spin_lock_irqsave(&dev->read_buffer_lock, flags); 731 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 732 memcpy (dev->read_buffer + dev->read_buffer_length, 733 dev->interrupt_in_buffer, 734 urb->actual_length); 735 dev->read_buffer_length += urb->actual_length; 736 dev->read_last_arrival = jiffies; 737 dev_dbg(&dev->udev->dev, "%s: received %d bytes\n", 738 __func__, urb->actual_length); 739 } else { 740 pr_warn("read_buffer overflow, %d bytes dropped\n", 741 urb->actual_length); 742 } 743 spin_unlock_irqrestore(&dev->read_buffer_lock, flags); 744 } 745 746 resubmit: 747 /* resubmit if we're still running */ 748 if (dev->interrupt_in_running) { 749 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); 750 if (retval) 751 dev_err(&dev->udev->dev, 752 "%s: usb_submit_urb failed (%d)\n", 753 __func__, retval); 754 } 755 756 exit: 757 dev->interrupt_in_done = 1; 758 wake_up_interruptible (&dev->read_wait); 759 } 760 761 762 /** 763 * tower_interrupt_out_callback 764 */ 765 static void tower_interrupt_out_callback (struct urb *urb) 766 { 767 struct lego_usb_tower *dev = urb->context; 768 int status = urb->status; 769 770 lego_usb_tower_debug_data(&dev->udev->dev, __func__, 771 urb->actual_length, urb->transfer_buffer); 772 773 /* sync/async unlink faults aren't errors */ 774 if (status && !(status == -ENOENT || 775 status == -ECONNRESET || 776 status == -ESHUTDOWN)) { 777 dev_dbg(&dev->udev->dev, 778 "%s: nonzero write bulk status received: %d\n", __func__, 779 status); 780 } 781 782 dev->interrupt_out_busy = 0; 783 wake_up_interruptible(&dev->write_wait); 784 } 785 786 787 /** 788 * tower_probe 789 * 790 * Called by the usb core when a new device is connected that it thinks 791 * this driver might be interested in. 792 */ 793 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) 794 { 795 struct device *idev = &interface->dev; 796 struct usb_device *udev = interface_to_usbdev(interface); 797 struct lego_usb_tower *dev = NULL; 798 struct tower_get_version_reply *get_version_reply = NULL; 799 int retval = -ENOMEM; 800 int result; 801 802 /* allocate memory for our device state and initialize it */ 803 804 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL); 805 806 if (!dev) 807 goto exit; 808 809 mutex_init(&dev->lock); 810 811 dev->udev = usb_get_dev(udev); 812 dev->open_count = 0; 813 dev->disconnected = 0; 814 815 dev->read_buffer = NULL; 816 dev->read_buffer_length = 0; 817 dev->read_packet_length = 0; 818 spin_lock_init (&dev->read_buffer_lock); 819 dev->packet_timeout_jiffies = msecs_to_jiffies(packet_timeout); 820 dev->read_last_arrival = jiffies; 821 822 init_waitqueue_head (&dev->read_wait); 823 init_waitqueue_head (&dev->write_wait); 824 825 dev->interrupt_in_buffer = NULL; 826 dev->interrupt_in_endpoint = NULL; 827 dev->interrupt_in_urb = NULL; 828 dev->interrupt_in_running = 0; 829 dev->interrupt_in_done = 0; 830 831 dev->interrupt_out_buffer = NULL; 832 dev->interrupt_out_endpoint = NULL; 833 dev->interrupt_out_urb = NULL; 834 dev->interrupt_out_busy = 0; 835 836 result = usb_find_common_endpoints_reverse(interface->cur_altsetting, 837 NULL, NULL, 838 &dev->interrupt_in_endpoint, 839 &dev->interrupt_out_endpoint); 840 if (result) { 841 dev_err(idev, "interrupt endpoints not found\n"); 842 retval = result; 843 goto error; 844 } 845 846 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); 847 if (!dev->read_buffer) 848 goto error; 849 dev->interrupt_in_buffer = kmalloc (usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL); 850 if (!dev->interrupt_in_buffer) 851 goto error; 852 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 853 if (!dev->interrupt_in_urb) 854 goto error; 855 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL); 856 if (!dev->interrupt_out_buffer) 857 goto error; 858 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 859 if (!dev->interrupt_out_urb) 860 goto error; 861 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 862 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 863 864 get_version_reply = kmalloc(sizeof(*get_version_reply), GFP_KERNEL); 865 866 if (!get_version_reply) { 867 retval = -ENOMEM; 868 goto error; 869 } 870 871 /* get the firmware version and log it */ 872 result = usb_control_msg (udev, 873 usb_rcvctrlpipe(udev, 0), 874 LEGO_USB_TOWER_REQUEST_GET_VERSION, 875 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 876 0, 877 0, 878 get_version_reply, 879 sizeof(*get_version_reply), 880 1000); 881 if (result != sizeof(*get_version_reply)) { 882 if (result >= 0) 883 result = -EIO; 884 dev_err(idev, "get version request failed: %d\n", result); 885 retval = result; 886 goto error; 887 } 888 dev_info(&interface->dev, 889 "LEGO USB Tower firmware version is %d.%d build %d\n", 890 get_version_reply->major, 891 get_version_reply->minor, 892 le16_to_cpu(get_version_reply->build_no)); 893 894 /* we can register the device now, as it is ready */ 895 usb_set_intfdata (interface, dev); 896 897 retval = usb_register_dev (interface, &tower_class); 898 899 if (retval) { 900 /* something prevented us from registering this driver */ 901 dev_err(idev, "Not able to get a minor for this device.\n"); 902 goto error; 903 } 904 dev->minor = interface->minor; 905 906 /* let the user know what node this device is now attached to */ 907 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major " 908 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), 909 USB_MAJOR, dev->minor); 910 911 exit: 912 kfree(get_version_reply); 913 return retval; 914 915 error: 916 kfree(get_version_reply); 917 tower_delete(dev); 918 return retval; 919 } 920 921 922 /** 923 * tower_disconnect 924 * 925 * Called by the usb core when the device is removed from the system. 926 */ 927 static void tower_disconnect (struct usb_interface *interface) 928 { 929 struct lego_usb_tower *dev; 930 int minor; 931 932 dev = usb_get_intfdata (interface); 933 934 minor = dev->minor; 935 936 /* give back our minor and prevent further open() */ 937 usb_deregister_dev (interface, &tower_class); 938 939 /* stop I/O */ 940 usb_poison_urb(dev->interrupt_in_urb); 941 usb_poison_urb(dev->interrupt_out_urb); 942 943 mutex_lock(&dev->lock); 944 945 /* if the device is not opened, then we clean up right now */ 946 if (!dev->open_count) { 947 mutex_unlock(&dev->lock); 948 tower_delete (dev); 949 } else { 950 dev->disconnected = 1; 951 /* wake up pollers */ 952 wake_up_interruptible_all(&dev->read_wait); 953 wake_up_interruptible_all(&dev->write_wait); 954 mutex_unlock(&dev->lock); 955 } 956 957 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n", 958 (minor - LEGO_USB_TOWER_MINOR_BASE)); 959 } 960 961 module_usb_driver(tower_driver); 962 963 MODULE_AUTHOR(DRIVER_AUTHOR); 964 MODULE_DESCRIPTION(DRIVER_DESC); 965 MODULE_LICENSE("GPL"); 966