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 static DEFINE_MUTEX(open_disc_mutex); 183 184 #define LEGO_USB_TOWER_MINOR_BASE 160 185 186 187 /* Structure to hold all of our device specific stuff */ 188 struct lego_usb_tower { 189 struct mutex lock; /* locks this structure */ 190 struct usb_device* udev; /* save off the usb device pointer */ 191 unsigned char minor; /* the starting minor number for this device */ 192 193 int open_count; /* number of times this port has been opened */ 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 unsigned int 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 tower_abort_transfers (dev); 294 295 /* free data structures */ 296 usb_free_urb(dev->interrupt_in_urb); 297 usb_free_urb(dev->interrupt_out_urb); 298 kfree (dev->read_buffer); 299 kfree (dev->interrupt_in_buffer); 300 kfree (dev->interrupt_out_buffer); 301 kfree (dev); 302 } 303 304 305 /** 306 * tower_open 307 */ 308 static int tower_open (struct inode *inode, struct file *file) 309 { 310 struct lego_usb_tower *dev = NULL; 311 int subminor; 312 int retval = 0; 313 struct usb_interface *interface; 314 struct tower_reset_reply *reset_reply; 315 int result; 316 317 reset_reply = kmalloc(sizeof(*reset_reply), GFP_KERNEL); 318 319 if (!reset_reply) { 320 retval = -ENOMEM; 321 goto exit; 322 } 323 324 nonseekable_open(inode, file); 325 subminor = iminor(inode); 326 327 interface = usb_find_interface (&tower_driver, subminor); 328 329 if (!interface) { 330 pr_err("error, can't find device for minor %d\n", subminor); 331 retval = -ENODEV; 332 goto exit; 333 } 334 335 mutex_lock(&open_disc_mutex); 336 dev = usb_get_intfdata(interface); 337 338 if (!dev) { 339 mutex_unlock(&open_disc_mutex); 340 retval = -ENODEV; 341 goto exit; 342 } 343 344 /* lock this device */ 345 if (mutex_lock_interruptible(&dev->lock)) { 346 mutex_unlock(&open_disc_mutex); 347 retval = -ERESTARTSYS; 348 goto exit; 349 } 350 351 352 /* allow opening only once */ 353 if (dev->open_count) { 354 mutex_unlock(&open_disc_mutex); 355 retval = -EBUSY; 356 goto unlock_exit; 357 } 358 dev->open_count = 1; 359 mutex_unlock(&open_disc_mutex); 360 361 /* reset the tower */ 362 result = usb_control_msg (dev->udev, 363 usb_rcvctrlpipe(dev->udev, 0), 364 LEGO_USB_TOWER_REQUEST_RESET, 365 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 366 0, 367 0, 368 reset_reply, 369 sizeof(*reset_reply), 370 1000); 371 if (result < 0) { 372 dev_err(&dev->udev->dev, 373 "LEGO USB Tower reset control request failed\n"); 374 retval = result; 375 goto unlock_exit; 376 } 377 378 /* initialize in direction */ 379 dev->read_buffer_length = 0; 380 dev->read_packet_length = 0; 381 usb_fill_int_urb (dev->interrupt_in_urb, 382 dev->udev, 383 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress), 384 dev->interrupt_in_buffer, 385 usb_endpoint_maxp(dev->interrupt_in_endpoint), 386 tower_interrupt_in_callback, 387 dev, 388 dev->interrupt_in_interval); 389 390 dev->interrupt_in_running = 1; 391 dev->interrupt_in_done = 0; 392 mb(); 393 394 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL); 395 if (retval) { 396 dev_err(&dev->udev->dev, 397 "Couldn't submit interrupt_in_urb %d\n", retval); 398 dev->interrupt_in_running = 0; 399 dev->open_count = 0; 400 goto unlock_exit; 401 } 402 403 /* save device in the file's private structure */ 404 file->private_data = dev; 405 406 unlock_exit: 407 mutex_unlock(&dev->lock); 408 409 exit: 410 kfree(reset_reply); 411 return retval; 412 } 413 414 /** 415 * tower_release 416 */ 417 static int tower_release (struct inode *inode, struct file *file) 418 { 419 struct lego_usb_tower *dev; 420 int retval = 0; 421 422 dev = file->private_data; 423 424 if (dev == NULL) { 425 retval = -ENODEV; 426 goto exit_nolock; 427 } 428 429 mutex_lock(&open_disc_mutex); 430 if (mutex_lock_interruptible(&dev->lock)) { 431 retval = -ERESTARTSYS; 432 goto exit; 433 } 434 435 if (dev->open_count != 1) { 436 dev_dbg(&dev->udev->dev, "%s: device not opened exactly once\n", 437 __func__); 438 retval = -ENODEV; 439 goto unlock_exit; 440 } 441 if (dev->udev == NULL) { 442 /* the device was unplugged before the file was released */ 443 444 /* unlock here as tower_delete frees dev */ 445 mutex_unlock(&dev->lock); 446 tower_delete (dev); 447 goto exit; 448 } 449 450 /* wait until write transfer is finished */ 451 if (dev->interrupt_out_busy) { 452 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 453 } 454 tower_abort_transfers (dev); 455 dev->open_count = 0; 456 457 unlock_exit: 458 mutex_unlock(&dev->lock); 459 460 exit: 461 mutex_unlock(&open_disc_mutex); 462 exit_nolock: 463 return retval; 464 } 465 466 467 /** 468 * tower_abort_transfers 469 * aborts transfers and frees associated data structures 470 */ 471 static void tower_abort_transfers (struct lego_usb_tower *dev) 472 { 473 if (dev == NULL) 474 return; 475 476 /* shutdown transfer */ 477 if (dev->interrupt_in_running) { 478 dev->interrupt_in_running = 0; 479 mb(); 480 if (dev->udev) 481 usb_kill_urb (dev->interrupt_in_urb); 482 } 483 if (dev->interrupt_out_busy && dev->udev) 484 usb_kill_urb(dev->interrupt_out_urb); 485 } 486 487 488 /** 489 * tower_check_for_read_packet 490 * 491 * To get correct semantics for signals and non-blocking I/O 492 * with packetizing we pretend not to see any data in the read buffer 493 * until it has been there unchanged for at least 494 * dev->packet_timeout_jiffies, or until the buffer is full. 495 */ 496 static void tower_check_for_read_packet (struct lego_usb_tower *dev) 497 { 498 spin_lock_irq (&dev->read_buffer_lock); 499 if (!packet_timeout 500 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) 501 || dev->read_buffer_length == read_buffer_size) { 502 dev->read_packet_length = dev->read_buffer_length; 503 } 504 dev->interrupt_in_done = 0; 505 spin_unlock_irq (&dev->read_buffer_lock); 506 } 507 508 509 /** 510 * tower_poll 511 */ 512 static unsigned int tower_poll (struct file *file, poll_table *wait) 513 { 514 struct lego_usb_tower *dev; 515 unsigned int mask = 0; 516 517 dev = file->private_data; 518 519 if (!dev->udev) 520 return POLLERR | POLLHUP; 521 522 poll_wait(file, &dev->read_wait, wait); 523 poll_wait(file, &dev->write_wait, wait); 524 525 tower_check_for_read_packet(dev); 526 if (dev->read_packet_length > 0) { 527 mask |= POLLIN | POLLRDNORM; 528 } 529 if (!dev->interrupt_out_busy) { 530 mask |= POLLOUT | POLLWRNORM; 531 } 532 533 return mask; 534 } 535 536 537 /** 538 * tower_llseek 539 */ 540 static loff_t tower_llseek (struct file *file, loff_t off, int whence) 541 { 542 return -ESPIPE; /* unseekable */ 543 } 544 545 546 /** 547 * tower_read 548 */ 549 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 550 { 551 struct lego_usb_tower *dev; 552 size_t bytes_to_read; 553 int i; 554 int retval = 0; 555 unsigned long timeout = 0; 556 557 dev = file->private_data; 558 559 /* lock this object */ 560 if (mutex_lock_interruptible(&dev->lock)) { 561 retval = -ERESTARTSYS; 562 goto exit; 563 } 564 565 /* verify that the device wasn't unplugged */ 566 if (dev->udev == NULL) { 567 retval = -ENODEV; 568 pr_err("No device or device unplugged %d\n", retval); 569 goto unlock_exit; 570 } 571 572 /* verify that we actually have some data to read */ 573 if (count == 0) { 574 dev_dbg(&dev->udev->dev, "read request of 0 bytes\n"); 575 goto unlock_exit; 576 } 577 578 if (read_timeout) { 579 timeout = jiffies + msecs_to_jiffies(read_timeout); 580 } 581 582 /* wait for data */ 583 tower_check_for_read_packet (dev); 584 while (dev->read_packet_length == 0) { 585 if (file->f_flags & O_NONBLOCK) { 586 retval = -EAGAIN; 587 goto unlock_exit; 588 } 589 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 590 if (retval < 0) { 591 goto unlock_exit; 592 } 593 594 /* reset read timeout during read or write activity */ 595 if (read_timeout 596 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 597 timeout = jiffies + msecs_to_jiffies(read_timeout); 598 } 599 /* check for read timeout */ 600 if (read_timeout && time_after (jiffies, timeout)) { 601 retval = -ETIMEDOUT; 602 goto unlock_exit; 603 } 604 tower_check_for_read_packet (dev); 605 } 606 607 /* copy the data from read_buffer into userspace */ 608 bytes_to_read = min(count, dev->read_packet_length); 609 610 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { 611 retval = -EFAULT; 612 goto unlock_exit; 613 } 614 615 spin_lock_irq (&dev->read_buffer_lock); 616 dev->read_buffer_length -= bytes_to_read; 617 dev->read_packet_length -= bytes_to_read; 618 for (i=0; i<dev->read_buffer_length; i++) { 619 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 620 } 621 spin_unlock_irq (&dev->read_buffer_lock); 622 623 retval = bytes_to_read; 624 625 unlock_exit: 626 /* unlock the device */ 627 mutex_unlock(&dev->lock); 628 629 exit: 630 return retval; 631 } 632 633 634 /** 635 * tower_write 636 */ 637 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 638 { 639 struct lego_usb_tower *dev; 640 size_t bytes_to_write; 641 int retval = 0; 642 643 dev = file->private_data; 644 645 /* lock this object */ 646 if (mutex_lock_interruptible(&dev->lock)) { 647 retval = -ERESTARTSYS; 648 goto exit; 649 } 650 651 /* verify that the device wasn't unplugged */ 652 if (dev->udev == NULL) { 653 retval = -ENODEV; 654 pr_err("No device or device unplugged %d\n", retval); 655 goto unlock_exit; 656 } 657 658 /* verify that we actually have some data to write */ 659 if (count == 0) { 660 dev_dbg(&dev->udev->dev, "write request of 0 bytes\n"); 661 goto unlock_exit; 662 } 663 664 /* wait until previous transfer is finished */ 665 while (dev->interrupt_out_busy) { 666 if (file->f_flags & O_NONBLOCK) { 667 retval = -EAGAIN; 668 goto unlock_exit; 669 } 670 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); 671 if (retval) { 672 goto unlock_exit; 673 } 674 } 675 676 /* write the data into interrupt_out_buffer from userspace */ 677 bytes_to_write = min_t(int, count, write_buffer_size); 678 dev_dbg(&dev->udev->dev, "%s: count = %zd, bytes_to_write = %zd\n", 679 __func__, count, bytes_to_write); 680 681 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { 682 retval = -EFAULT; 683 goto unlock_exit; 684 } 685 686 /* send off the urb */ 687 usb_fill_int_urb(dev->interrupt_out_urb, 688 dev->udev, 689 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 690 dev->interrupt_out_buffer, 691 bytes_to_write, 692 tower_interrupt_out_callback, 693 dev, 694 dev->interrupt_out_interval); 695 696 dev->interrupt_out_busy = 1; 697 wmb(); 698 699 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); 700 if (retval) { 701 dev->interrupt_out_busy = 0; 702 dev_err(&dev->udev->dev, 703 "Couldn't submit interrupt_out_urb %d\n", retval); 704 goto unlock_exit; 705 } 706 retval = bytes_to_write; 707 708 unlock_exit: 709 /* unlock the device */ 710 mutex_unlock(&dev->lock); 711 712 exit: 713 return retval; 714 } 715 716 717 /** 718 * tower_interrupt_in_callback 719 */ 720 static void tower_interrupt_in_callback (struct urb *urb) 721 { 722 struct lego_usb_tower *dev = urb->context; 723 int status = urb->status; 724 int retval; 725 726 lego_usb_tower_debug_data(&dev->udev->dev, __func__, 727 urb->actual_length, urb->transfer_buffer); 728 729 if (status) { 730 if (status == -ENOENT || 731 status == -ECONNRESET || 732 status == -ESHUTDOWN) { 733 goto exit; 734 } else { 735 dev_dbg(&dev->udev->dev, 736 "%s: nonzero status received: %d\n", __func__, 737 status); 738 goto resubmit; /* maybe we can recover */ 739 } 740 } 741 742 if (urb->actual_length > 0) { 743 spin_lock (&dev->read_buffer_lock); 744 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 745 memcpy (dev->read_buffer + dev->read_buffer_length, 746 dev->interrupt_in_buffer, 747 urb->actual_length); 748 dev->read_buffer_length += urb->actual_length; 749 dev->read_last_arrival = jiffies; 750 dev_dbg(&dev->udev->dev, "%s: received %d bytes\n", 751 __func__, urb->actual_length); 752 } else { 753 pr_warn("read_buffer overflow, %d bytes dropped\n", 754 urb->actual_length); 755 } 756 spin_unlock (&dev->read_buffer_lock); 757 } 758 759 resubmit: 760 /* resubmit if we're still running */ 761 if (dev->interrupt_in_running && dev->udev) { 762 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); 763 if (retval) 764 dev_err(&dev->udev->dev, 765 "%s: usb_submit_urb failed (%d)\n", 766 __func__, retval); 767 } 768 769 exit: 770 dev->interrupt_in_done = 1; 771 wake_up_interruptible (&dev->read_wait); 772 } 773 774 775 /** 776 * tower_interrupt_out_callback 777 */ 778 static void tower_interrupt_out_callback (struct urb *urb) 779 { 780 struct lego_usb_tower *dev = urb->context; 781 int status = urb->status; 782 783 lego_usb_tower_debug_data(&dev->udev->dev, __func__, 784 urb->actual_length, urb->transfer_buffer); 785 786 /* sync/async unlink faults aren't errors */ 787 if (status && !(status == -ENOENT || 788 status == -ECONNRESET || 789 status == -ESHUTDOWN)) { 790 dev_dbg(&dev->udev->dev, 791 "%s: nonzero write bulk status received: %d\n", __func__, 792 status); 793 } 794 795 dev->interrupt_out_busy = 0; 796 wake_up_interruptible(&dev->write_wait); 797 } 798 799 800 /** 801 * tower_probe 802 * 803 * Called by the usb core when a new device is connected that it thinks 804 * this driver might be interested in. 805 */ 806 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) 807 { 808 struct device *idev = &interface->dev; 809 struct usb_device *udev = interface_to_usbdev(interface); 810 struct lego_usb_tower *dev = NULL; 811 struct tower_get_version_reply *get_version_reply = NULL; 812 int retval = -ENOMEM; 813 int result; 814 815 /* allocate memory for our device state and initialize it */ 816 817 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL); 818 819 if (!dev) 820 goto exit; 821 822 mutex_init(&dev->lock); 823 824 dev->udev = udev; 825 dev->open_count = 0; 826 827 dev->read_buffer = NULL; 828 dev->read_buffer_length = 0; 829 dev->read_packet_length = 0; 830 spin_lock_init (&dev->read_buffer_lock); 831 dev->packet_timeout_jiffies = msecs_to_jiffies(packet_timeout); 832 dev->read_last_arrival = jiffies; 833 834 init_waitqueue_head (&dev->read_wait); 835 init_waitqueue_head (&dev->write_wait); 836 837 dev->interrupt_in_buffer = NULL; 838 dev->interrupt_in_endpoint = NULL; 839 dev->interrupt_in_urb = NULL; 840 dev->interrupt_in_running = 0; 841 dev->interrupt_in_done = 0; 842 843 dev->interrupt_out_buffer = NULL; 844 dev->interrupt_out_endpoint = NULL; 845 dev->interrupt_out_urb = NULL; 846 dev->interrupt_out_busy = 0; 847 848 result = usb_find_common_endpoints_reverse(interface->cur_altsetting, 849 NULL, NULL, 850 &dev->interrupt_in_endpoint, 851 &dev->interrupt_out_endpoint); 852 if (result) { 853 dev_err(idev, "interrupt endpoints not found\n"); 854 retval = result; 855 goto error; 856 } 857 858 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); 859 if (!dev->read_buffer) 860 goto error; 861 dev->interrupt_in_buffer = kmalloc (usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL); 862 if (!dev->interrupt_in_buffer) 863 goto error; 864 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 865 if (!dev->interrupt_in_urb) 866 goto error; 867 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL); 868 if (!dev->interrupt_out_buffer) 869 goto error; 870 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 871 if (!dev->interrupt_out_urb) 872 goto error; 873 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 874 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 875 876 get_version_reply = kmalloc(sizeof(*get_version_reply), GFP_KERNEL); 877 878 if (!get_version_reply) { 879 retval = -ENOMEM; 880 goto error; 881 } 882 883 /* get the firmware version and log it */ 884 result = usb_control_msg (udev, 885 usb_rcvctrlpipe(udev, 0), 886 LEGO_USB_TOWER_REQUEST_GET_VERSION, 887 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 888 0, 889 0, 890 get_version_reply, 891 sizeof(*get_version_reply), 892 1000); 893 if (result < 0) { 894 dev_err(idev, "LEGO USB Tower get version control request failed\n"); 895 retval = result; 896 goto error; 897 } 898 dev_info(&interface->dev, 899 "LEGO USB Tower firmware version is %d.%d build %d\n", 900 get_version_reply->major, 901 get_version_reply->minor, 902 le16_to_cpu(get_version_reply->build_no)); 903 904 /* we can register the device now, as it is ready */ 905 usb_set_intfdata (interface, dev); 906 907 retval = usb_register_dev (interface, &tower_class); 908 909 if (retval) { 910 /* something prevented us from registering this driver */ 911 dev_err(idev, "Not able to get a minor for this device.\n"); 912 usb_set_intfdata (interface, NULL); 913 goto error; 914 } 915 dev->minor = interface->minor; 916 917 /* let the user know what node this device is now attached to */ 918 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major " 919 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), 920 USB_MAJOR, dev->minor); 921 922 exit: 923 kfree(get_version_reply); 924 return retval; 925 926 error: 927 kfree(get_version_reply); 928 tower_delete(dev); 929 return retval; 930 } 931 932 933 /** 934 * tower_disconnect 935 * 936 * Called by the usb core when the device is removed from the system. 937 */ 938 static void tower_disconnect (struct usb_interface *interface) 939 { 940 struct lego_usb_tower *dev; 941 int minor; 942 943 dev = usb_get_intfdata (interface); 944 mutex_lock(&open_disc_mutex); 945 usb_set_intfdata (interface, NULL); 946 947 minor = dev->minor; 948 949 /* give back our minor */ 950 usb_deregister_dev (interface, &tower_class); 951 952 mutex_lock(&dev->lock); 953 mutex_unlock(&open_disc_mutex); 954 955 /* if the device is not opened, then we clean up right now */ 956 if (!dev->open_count) { 957 mutex_unlock(&dev->lock); 958 tower_delete (dev); 959 } else { 960 dev->udev = NULL; 961 /* wake up pollers */ 962 wake_up_interruptible_all(&dev->read_wait); 963 wake_up_interruptible_all(&dev->write_wait); 964 mutex_unlock(&dev->lock); 965 } 966 967 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n", 968 (minor - LEGO_USB_TOWER_MINOR_BASE)); 969 } 970 971 module_usb_driver(tower_driver); 972 973 MODULE_AUTHOR(DRIVER_AUTHOR); 974 MODULE_DESCRIPTION(DRIVER_DESC); 975 #ifdef MODULE_LICENSE 976 MODULE_LICENSE("GPL"); 977 #endif 978