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 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License as 10 * published by the Free Software Foundation; either version 2 of 11 * the License, or (at your option) any later version. 12 * 13 * derived from USB Skeleton driver - 0.5 14 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com) 15 * 16 * History: 17 * 18 * 2001-10-13 - 0.1 js 19 * - first version 20 * 2001-11-03 - 0.2 js 21 * - simplified buffering, one-shot URBs for writing 22 * 2001-11-10 - 0.3 js 23 * - removed IOCTL (setting power/mode is more complicated, postponed) 24 * 2001-11-28 - 0.4 js 25 * - added vendor commands for mode of operation and power level in open 26 * 2001-12-04 - 0.5 js 27 * - set IR mode by default (by oversight 0.4 set VLL mode) 28 * 2002-01-11 - 0.5? pcchan 29 * - make read buffer reusable and work around bytes_to_write issue between 30 * uhci and legusbtower 31 * 2002-09-23 - 0.52 david (david@csse.uwa.edu.au) 32 * - imported into lejos project 33 * - changed wake_up to wake_up_interruptible 34 * - changed to use lego0 rather than tower0 35 * - changed dbg() to use __func__ rather than deprecated __func__ 36 * 2003-01-12 - 0.53 david (david@csse.uwa.edu.au) 37 * - changed read and write to write everything or 38 * timeout (from a patch by Chris Riesen and Brett Thaeler driver) 39 * - added ioctl functionality to set timeouts 40 * 2003-07-18 - 0.54 davidgsf (david@csse.uwa.edu.au) 41 * - initial import into LegoUSB project 42 * - merge of existing LegoUSB.c driver 43 * 2003-07-18 - 0.56 davidgsf (david@csse.uwa.edu.au) 44 * - port to 2.6 style driver 45 * 2004-02-29 - 0.6 Juergen Stuber <starblue@users.sourceforge.net> 46 * - fix locking 47 * - unlink read URBs which are no longer needed 48 * - allow increased buffer size, eliminates need for timeout on write 49 * - have read URB running continuously 50 * - added poll 51 * - forbid seeking 52 * - added nonblocking I/O 53 * - changed back __func__ to __func__ 54 * - read and log tower firmware version 55 * - reset tower on probe, avoids failure of first write 56 * 2004-03-09 - 0.7 Juergen Stuber <starblue@users.sourceforge.net> 57 * - timeout read now only after inactivity, shorten default accordingly 58 * 2004-03-11 - 0.8 Juergen Stuber <starblue@users.sourceforge.net> 59 * - log major, minor instead of possibly confusing device filename 60 * - whitespace cleanup 61 * 2004-03-12 - 0.9 Juergen Stuber <starblue@users.sourceforge.net> 62 * - normalize whitespace in debug messages 63 * - take care about endianness in control message responses 64 * 2004-03-13 - 0.91 Juergen Stuber <starblue@users.sourceforge.net> 65 * - make default intervals longer to accommodate current EHCI driver 66 * 2004-03-19 - 0.92 Juergen Stuber <starblue@users.sourceforge.net> 67 * - replaced atomic_t by memory barriers 68 * 2004-04-21 - 0.93 Juergen Stuber <starblue@users.sourceforge.net> 69 * - wait for completion of write urb in release (needed for remotecontrol) 70 * - corrected poll for write direction (missing negation) 71 * 2004-04-22 - 0.94 Juergen Stuber <starblue@users.sourceforge.net> 72 * - make device locking interruptible 73 * 2004-04-30 - 0.95 Juergen Stuber <starblue@users.sourceforge.net> 74 * - check for valid udev on resubmitting and unlinking urbs 75 * 2004-08-03 - 0.96 Juergen Stuber <starblue@users.sourceforge.net> 76 * - move reset into open to clean out spurious data 77 */ 78 79 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 80 81 #include <linux/kernel.h> 82 #include <linux/errno.h> 83 #include <linux/slab.h> 84 #include <linux/module.h> 85 #include <linux/completion.h> 86 #include <linux/mutex.h> 87 #include <linux/uaccess.h> 88 #include <linux/usb.h> 89 #include <linux/poll.h> 90 91 92 #define DRIVER_AUTHOR "Juergen Stuber <starblue@sourceforge.net>" 93 #define DRIVER_DESC "LEGO USB Tower Driver" 94 95 96 /* The defaults are chosen to work with the latest versions of leJOS and NQC. 97 */ 98 99 /* Some legacy software likes to receive packets in one piece. 100 * In this case read_buffer_size should exceed the maximal packet length 101 * (417 for datalog uploads), and packet_timeout should be set. 102 */ 103 static int read_buffer_size = 480; 104 module_param(read_buffer_size, int, 0); 105 MODULE_PARM_DESC(read_buffer_size, "Read buffer size"); 106 107 /* Some legacy software likes to send packets in one piece. 108 * In this case write_buffer_size should exceed the maximal packet length 109 * (417 for firmware and program downloads). 110 * A problem with long writes is that the following read may time out 111 * if the software is not prepared to wait long enough. 112 */ 113 static int write_buffer_size = 480; 114 module_param(write_buffer_size, int, 0); 115 MODULE_PARM_DESC(write_buffer_size, "Write buffer size"); 116 117 /* Some legacy software expects reads to contain whole LASM packets. 118 * To achieve this, characters which arrive before a packet timeout 119 * occurs will be returned in a single read operation. 120 * A problem with long reads is that the software may time out 121 * if it is not prepared to wait long enough. 122 * The packet timeout should be greater than the time between the 123 * reception of subsequent characters, which should arrive about 124 * every 5ms for the standard 2400 baud. 125 * Set it to 0 to disable. 126 */ 127 static int packet_timeout = 50; 128 module_param(packet_timeout, int, 0); 129 MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms"); 130 131 /* Some legacy software expects blocking reads to time out. 132 * Timeout occurs after the specified time of read and write inactivity. 133 * Set it to 0 to disable. 134 */ 135 static int read_timeout = 200; 136 module_param(read_timeout, int, 0); 137 MODULE_PARM_DESC(read_timeout, "Read timeout in ms"); 138 139 /* As of kernel version 2.6.4 ehci-hcd uses an 140 * "only one interrupt transfer per frame" shortcut 141 * to simplify the scheduling of periodic transfers. 142 * This conflicts with our standard 1ms intervals for in and out URBs. 143 * We use default intervals of 2ms for in and 8ms for out transfers, 144 * which is fast enough for 2400 baud and allows a small additional load. 145 * Increase the interval to allow more devices that do interrupt transfers, 146 * or set to 0 to use the standard interval from the endpoint descriptors. 147 */ 148 static int interrupt_in_interval = 2; 149 module_param(interrupt_in_interval, int, 0); 150 MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms"); 151 152 static int interrupt_out_interval = 8; 153 module_param(interrupt_out_interval, int, 0); 154 MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms"); 155 156 /* Define these values to match your device */ 157 #define LEGO_USB_TOWER_VENDOR_ID 0x0694 158 #define LEGO_USB_TOWER_PRODUCT_ID 0x0001 159 160 /* Vendor requests */ 161 #define LEGO_USB_TOWER_REQUEST_RESET 0x04 162 #define LEGO_USB_TOWER_REQUEST_GET_VERSION 0xFD 163 164 struct tower_reset_reply { 165 __le16 size; /* little-endian */ 166 __u8 err_code; 167 __u8 spare; 168 } __attribute__ ((packed)); 169 170 struct tower_get_version_reply { 171 __le16 size; /* little-endian */ 172 __u8 err_code; 173 __u8 spare; 174 __u8 major; 175 __u8 minor; 176 __le16 build_no; /* little-endian */ 177 } __attribute__ ((packed)); 178 179 180 /* table of devices that work with this driver */ 181 static const struct usb_device_id tower_table[] = { 182 { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) }, 183 { } /* Terminating entry */ 184 }; 185 186 MODULE_DEVICE_TABLE (usb, tower_table); 187 static DEFINE_MUTEX(open_disc_mutex); 188 189 #define LEGO_USB_TOWER_MINOR_BASE 160 190 191 192 /* Structure to hold all of our device specific stuff */ 193 struct lego_usb_tower { 194 struct mutex lock; /* locks this structure */ 195 struct usb_device* udev; /* save off the usb device pointer */ 196 unsigned char minor; /* the starting minor number for this device */ 197 198 int open_count; /* number of times this port has been opened */ 199 200 char* read_buffer; 201 size_t read_buffer_length; /* this much came in */ 202 size_t read_packet_length; /* this much will be returned on read */ 203 spinlock_t read_buffer_lock; 204 int packet_timeout_jiffies; 205 unsigned long read_last_arrival; 206 207 wait_queue_head_t read_wait; 208 wait_queue_head_t write_wait; 209 210 char* interrupt_in_buffer; 211 struct usb_endpoint_descriptor* interrupt_in_endpoint; 212 struct urb* interrupt_in_urb; 213 int interrupt_in_interval; 214 int interrupt_in_running; 215 int interrupt_in_done; 216 217 char* interrupt_out_buffer; 218 struct usb_endpoint_descriptor* interrupt_out_endpoint; 219 struct urb* interrupt_out_urb; 220 int interrupt_out_interval; 221 int interrupt_out_busy; 222 223 }; 224 225 226 /* local function prototypes */ 227 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos); 228 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos); 229 static inline void tower_delete (struct lego_usb_tower *dev); 230 static int tower_open (struct inode *inode, struct file *file); 231 static int tower_release (struct inode *inode, struct file *file); 232 static unsigned int tower_poll (struct file *file, poll_table *wait); 233 static loff_t tower_llseek (struct file *file, loff_t off, int whence); 234 235 static void tower_abort_transfers (struct lego_usb_tower *dev); 236 static void tower_check_for_read_packet (struct lego_usb_tower *dev); 237 static void tower_interrupt_in_callback (struct urb *urb); 238 static void tower_interrupt_out_callback (struct urb *urb); 239 240 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id); 241 static void tower_disconnect (struct usb_interface *interface); 242 243 244 /* file operations needed when we register this driver */ 245 static const struct file_operations tower_fops = { 246 .owner = THIS_MODULE, 247 .read = tower_read, 248 .write = tower_write, 249 .open = tower_open, 250 .release = tower_release, 251 .poll = tower_poll, 252 .llseek = tower_llseek, 253 }; 254 255 static char *legousbtower_devnode(struct device *dev, umode_t *mode) 256 { 257 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev)); 258 } 259 260 /* 261 * usb class driver info in order to get a minor number from the usb core, 262 * and to have the device registered with the driver core 263 */ 264 static struct usb_class_driver tower_class = { 265 .name = "legousbtower%d", 266 .devnode = legousbtower_devnode, 267 .fops = &tower_fops, 268 .minor_base = LEGO_USB_TOWER_MINOR_BASE, 269 }; 270 271 272 /* usb specific object needed to register this driver with the usb subsystem */ 273 static struct usb_driver tower_driver = { 274 .name = "legousbtower", 275 .probe = tower_probe, 276 .disconnect = tower_disconnect, 277 .id_table = tower_table, 278 }; 279 280 281 /** 282 * lego_usb_tower_debug_data 283 */ 284 static inline void lego_usb_tower_debug_data(struct device *dev, 285 const char *function, int size, 286 const unsigned char *data) 287 { 288 dev_dbg(dev, "%s - length = %d, data = %*ph\n", 289 function, size, size, data); 290 } 291 292 293 /** 294 * tower_delete 295 */ 296 static inline void tower_delete (struct lego_usb_tower *dev) 297 { 298 tower_abort_transfers (dev); 299 300 /* free data structures */ 301 usb_free_urb(dev->interrupt_in_urb); 302 usb_free_urb(dev->interrupt_out_urb); 303 kfree (dev->read_buffer); 304 kfree (dev->interrupt_in_buffer); 305 kfree (dev->interrupt_out_buffer); 306 kfree (dev); 307 } 308 309 310 /** 311 * tower_open 312 */ 313 static int tower_open (struct inode *inode, struct file *file) 314 { 315 struct lego_usb_tower *dev = NULL; 316 int subminor; 317 int retval = 0; 318 struct usb_interface *interface; 319 struct tower_reset_reply *reset_reply; 320 int result; 321 322 reset_reply = kmalloc(sizeof(*reset_reply), GFP_KERNEL); 323 324 if (!reset_reply) { 325 retval = -ENOMEM; 326 goto exit; 327 } 328 329 nonseekable_open(inode, file); 330 subminor = iminor(inode); 331 332 interface = usb_find_interface (&tower_driver, subminor); 333 334 if (!interface) { 335 pr_err("error, can't find device for minor %d\n", subminor); 336 retval = -ENODEV; 337 goto exit; 338 } 339 340 mutex_lock(&open_disc_mutex); 341 dev = usb_get_intfdata(interface); 342 343 if (!dev) { 344 mutex_unlock(&open_disc_mutex); 345 retval = -ENODEV; 346 goto exit; 347 } 348 349 /* lock this device */ 350 if (mutex_lock_interruptible(&dev->lock)) { 351 mutex_unlock(&open_disc_mutex); 352 retval = -ERESTARTSYS; 353 goto exit; 354 } 355 356 357 /* allow opening only once */ 358 if (dev->open_count) { 359 mutex_unlock(&open_disc_mutex); 360 retval = -EBUSY; 361 goto unlock_exit; 362 } 363 dev->open_count = 1; 364 mutex_unlock(&open_disc_mutex); 365 366 /* reset the tower */ 367 result = usb_control_msg (dev->udev, 368 usb_rcvctrlpipe(dev->udev, 0), 369 LEGO_USB_TOWER_REQUEST_RESET, 370 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 371 0, 372 0, 373 reset_reply, 374 sizeof(*reset_reply), 375 1000); 376 if (result < 0) { 377 dev_err(&dev->udev->dev, 378 "LEGO USB Tower reset control request failed\n"); 379 retval = result; 380 goto unlock_exit; 381 } 382 383 /* initialize in direction */ 384 dev->read_buffer_length = 0; 385 dev->read_packet_length = 0; 386 usb_fill_int_urb (dev->interrupt_in_urb, 387 dev->udev, 388 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress), 389 dev->interrupt_in_buffer, 390 usb_endpoint_maxp(dev->interrupt_in_endpoint), 391 tower_interrupt_in_callback, 392 dev, 393 dev->interrupt_in_interval); 394 395 dev->interrupt_in_running = 1; 396 dev->interrupt_in_done = 0; 397 mb(); 398 399 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL); 400 if (retval) { 401 dev_err(&dev->udev->dev, 402 "Couldn't submit interrupt_in_urb %d\n", retval); 403 dev->interrupt_in_running = 0; 404 dev->open_count = 0; 405 goto unlock_exit; 406 } 407 408 /* save device in the file's private structure */ 409 file->private_data = dev; 410 411 unlock_exit: 412 mutex_unlock(&dev->lock); 413 414 exit: 415 kfree(reset_reply); 416 return retval; 417 } 418 419 /** 420 * tower_release 421 */ 422 static int tower_release (struct inode *inode, struct file *file) 423 { 424 struct lego_usb_tower *dev; 425 int retval = 0; 426 427 dev = file->private_data; 428 429 if (dev == NULL) { 430 retval = -ENODEV; 431 goto exit_nolock; 432 } 433 434 mutex_lock(&open_disc_mutex); 435 if (mutex_lock_interruptible(&dev->lock)) { 436 retval = -ERESTARTSYS; 437 goto exit; 438 } 439 440 if (dev->open_count != 1) { 441 dev_dbg(&dev->udev->dev, "%s: device not opened exactly once\n", 442 __func__); 443 retval = -ENODEV; 444 goto unlock_exit; 445 } 446 if (dev->udev == NULL) { 447 /* the device was unplugged before the file was released */ 448 449 /* unlock here as tower_delete frees dev */ 450 mutex_unlock(&dev->lock); 451 tower_delete (dev); 452 goto exit; 453 } 454 455 /* wait until write transfer is finished */ 456 if (dev->interrupt_out_busy) { 457 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 458 } 459 tower_abort_transfers (dev); 460 dev->open_count = 0; 461 462 unlock_exit: 463 mutex_unlock(&dev->lock); 464 465 exit: 466 mutex_unlock(&open_disc_mutex); 467 exit_nolock: 468 return retval; 469 } 470 471 472 /** 473 * tower_abort_transfers 474 * aborts transfers and frees associated data structures 475 */ 476 static void tower_abort_transfers (struct lego_usb_tower *dev) 477 { 478 if (dev == NULL) 479 return; 480 481 /* shutdown transfer */ 482 if (dev->interrupt_in_running) { 483 dev->interrupt_in_running = 0; 484 mb(); 485 if (dev->udev) 486 usb_kill_urb (dev->interrupt_in_urb); 487 } 488 if (dev->interrupt_out_busy && dev->udev) 489 usb_kill_urb(dev->interrupt_out_urb); 490 } 491 492 493 /** 494 * tower_check_for_read_packet 495 * 496 * To get correct semantics for signals and non-blocking I/O 497 * with packetizing we pretend not to see any data in the read buffer 498 * until it has been there unchanged for at least 499 * dev->packet_timeout_jiffies, or until the buffer is full. 500 */ 501 static void tower_check_for_read_packet (struct lego_usb_tower *dev) 502 { 503 spin_lock_irq (&dev->read_buffer_lock); 504 if (!packet_timeout 505 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) 506 || dev->read_buffer_length == read_buffer_size) { 507 dev->read_packet_length = dev->read_buffer_length; 508 } 509 dev->interrupt_in_done = 0; 510 spin_unlock_irq (&dev->read_buffer_lock); 511 } 512 513 514 /** 515 * tower_poll 516 */ 517 static unsigned int tower_poll (struct file *file, poll_table *wait) 518 { 519 struct lego_usb_tower *dev; 520 unsigned int mask = 0; 521 522 dev = file->private_data; 523 524 if (!dev->udev) 525 return POLLERR | POLLHUP; 526 527 poll_wait(file, &dev->read_wait, wait); 528 poll_wait(file, &dev->write_wait, wait); 529 530 tower_check_for_read_packet(dev); 531 if (dev->read_packet_length > 0) { 532 mask |= POLLIN | POLLRDNORM; 533 } 534 if (!dev->interrupt_out_busy) { 535 mask |= POLLOUT | POLLWRNORM; 536 } 537 538 return mask; 539 } 540 541 542 /** 543 * tower_llseek 544 */ 545 static loff_t tower_llseek (struct file *file, loff_t off, int whence) 546 { 547 return -ESPIPE; /* unseekable */ 548 } 549 550 551 /** 552 * tower_read 553 */ 554 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 555 { 556 struct lego_usb_tower *dev; 557 size_t bytes_to_read; 558 int i; 559 int retval = 0; 560 unsigned long timeout = 0; 561 562 dev = file->private_data; 563 564 /* lock this object */ 565 if (mutex_lock_interruptible(&dev->lock)) { 566 retval = -ERESTARTSYS; 567 goto exit; 568 } 569 570 /* verify that the device wasn't unplugged */ 571 if (dev->udev == NULL) { 572 retval = -ENODEV; 573 pr_err("No device or device unplugged %d\n", retval); 574 goto unlock_exit; 575 } 576 577 /* verify that we actually have some data to read */ 578 if (count == 0) { 579 dev_dbg(&dev->udev->dev, "read request of 0 bytes\n"); 580 goto unlock_exit; 581 } 582 583 if (read_timeout) { 584 timeout = jiffies + msecs_to_jiffies(read_timeout); 585 } 586 587 /* wait for data */ 588 tower_check_for_read_packet (dev); 589 while (dev->read_packet_length == 0) { 590 if (file->f_flags & O_NONBLOCK) { 591 retval = -EAGAIN; 592 goto unlock_exit; 593 } 594 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 595 if (retval < 0) { 596 goto unlock_exit; 597 } 598 599 /* reset read timeout during read or write activity */ 600 if (read_timeout 601 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 602 timeout = jiffies + msecs_to_jiffies(read_timeout); 603 } 604 /* check for read timeout */ 605 if (read_timeout && time_after (jiffies, timeout)) { 606 retval = -ETIMEDOUT; 607 goto unlock_exit; 608 } 609 tower_check_for_read_packet (dev); 610 } 611 612 /* copy the data from read_buffer into userspace */ 613 bytes_to_read = min(count, dev->read_packet_length); 614 615 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { 616 retval = -EFAULT; 617 goto unlock_exit; 618 } 619 620 spin_lock_irq (&dev->read_buffer_lock); 621 dev->read_buffer_length -= bytes_to_read; 622 dev->read_packet_length -= bytes_to_read; 623 for (i=0; i<dev->read_buffer_length; i++) { 624 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 625 } 626 spin_unlock_irq (&dev->read_buffer_lock); 627 628 retval = bytes_to_read; 629 630 unlock_exit: 631 /* unlock the device */ 632 mutex_unlock(&dev->lock); 633 634 exit: 635 return retval; 636 } 637 638 639 /** 640 * tower_write 641 */ 642 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 643 { 644 struct lego_usb_tower *dev; 645 size_t bytes_to_write; 646 int retval = 0; 647 648 dev = file->private_data; 649 650 /* lock this object */ 651 if (mutex_lock_interruptible(&dev->lock)) { 652 retval = -ERESTARTSYS; 653 goto exit; 654 } 655 656 /* verify that the device wasn't unplugged */ 657 if (dev->udev == NULL) { 658 retval = -ENODEV; 659 pr_err("No device or device unplugged %d\n", retval); 660 goto unlock_exit; 661 } 662 663 /* verify that we actually have some data to write */ 664 if (count == 0) { 665 dev_dbg(&dev->udev->dev, "write request of 0 bytes\n"); 666 goto unlock_exit; 667 } 668 669 /* wait until previous transfer is finished */ 670 while (dev->interrupt_out_busy) { 671 if (file->f_flags & O_NONBLOCK) { 672 retval = -EAGAIN; 673 goto unlock_exit; 674 } 675 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); 676 if (retval) { 677 goto unlock_exit; 678 } 679 } 680 681 /* write the data into interrupt_out_buffer from userspace */ 682 bytes_to_write = min_t(int, count, write_buffer_size); 683 dev_dbg(&dev->udev->dev, "%s: count = %zd, bytes_to_write = %zd\n", 684 __func__, count, bytes_to_write); 685 686 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { 687 retval = -EFAULT; 688 goto unlock_exit; 689 } 690 691 /* send off the urb */ 692 usb_fill_int_urb(dev->interrupt_out_urb, 693 dev->udev, 694 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 695 dev->interrupt_out_buffer, 696 bytes_to_write, 697 tower_interrupt_out_callback, 698 dev, 699 dev->interrupt_out_interval); 700 701 dev->interrupt_out_busy = 1; 702 wmb(); 703 704 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); 705 if (retval) { 706 dev->interrupt_out_busy = 0; 707 dev_err(&dev->udev->dev, 708 "Couldn't submit interrupt_out_urb %d\n", retval); 709 goto unlock_exit; 710 } 711 retval = bytes_to_write; 712 713 unlock_exit: 714 /* unlock the device */ 715 mutex_unlock(&dev->lock); 716 717 exit: 718 return retval; 719 } 720 721 722 /** 723 * tower_interrupt_in_callback 724 */ 725 static void tower_interrupt_in_callback (struct urb *urb) 726 { 727 struct lego_usb_tower *dev = urb->context; 728 int status = urb->status; 729 int retval; 730 731 lego_usb_tower_debug_data(&dev->udev->dev, __func__, 732 urb->actual_length, urb->transfer_buffer); 733 734 if (status) { 735 if (status == -ENOENT || 736 status == -ECONNRESET || 737 status == -ESHUTDOWN) { 738 goto exit; 739 } else { 740 dev_dbg(&dev->udev->dev, 741 "%s: nonzero status received: %d\n", __func__, 742 status); 743 goto resubmit; /* maybe we can recover */ 744 } 745 } 746 747 if (urb->actual_length > 0) { 748 spin_lock (&dev->read_buffer_lock); 749 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 750 memcpy (dev->read_buffer + dev->read_buffer_length, 751 dev->interrupt_in_buffer, 752 urb->actual_length); 753 dev->read_buffer_length += urb->actual_length; 754 dev->read_last_arrival = jiffies; 755 dev_dbg(&dev->udev->dev, "%s: received %d bytes\n", 756 __func__, urb->actual_length); 757 } else { 758 pr_warn("read_buffer overflow, %d bytes dropped\n", 759 urb->actual_length); 760 } 761 spin_unlock (&dev->read_buffer_lock); 762 } 763 764 resubmit: 765 /* resubmit if we're still running */ 766 if (dev->interrupt_in_running && dev->udev) { 767 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); 768 if (retval) 769 dev_err(&dev->udev->dev, 770 "%s: usb_submit_urb failed (%d)\n", 771 __func__, retval); 772 } 773 774 exit: 775 dev->interrupt_in_done = 1; 776 wake_up_interruptible (&dev->read_wait); 777 } 778 779 780 /** 781 * tower_interrupt_out_callback 782 */ 783 static void tower_interrupt_out_callback (struct urb *urb) 784 { 785 struct lego_usb_tower *dev = urb->context; 786 int status = urb->status; 787 788 lego_usb_tower_debug_data(&dev->udev->dev, __func__, 789 urb->actual_length, urb->transfer_buffer); 790 791 /* sync/async unlink faults aren't errors */ 792 if (status && !(status == -ENOENT || 793 status == -ECONNRESET || 794 status == -ESHUTDOWN)) { 795 dev_dbg(&dev->udev->dev, 796 "%s: nonzero write bulk status received: %d\n", __func__, 797 status); 798 } 799 800 dev->interrupt_out_busy = 0; 801 wake_up_interruptible(&dev->write_wait); 802 } 803 804 805 /** 806 * tower_probe 807 * 808 * Called by the usb core when a new device is connected that it thinks 809 * this driver might be interested in. 810 */ 811 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) 812 { 813 struct device *idev = &interface->dev; 814 struct usb_device *udev = interface_to_usbdev(interface); 815 struct lego_usb_tower *dev = NULL; 816 struct tower_get_version_reply *get_version_reply = NULL; 817 int retval = -ENOMEM; 818 int result; 819 820 /* allocate memory for our device state and initialize it */ 821 822 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL); 823 824 if (!dev) 825 goto exit; 826 827 mutex_init(&dev->lock); 828 829 dev->udev = udev; 830 dev->open_count = 0; 831 832 dev->read_buffer = NULL; 833 dev->read_buffer_length = 0; 834 dev->read_packet_length = 0; 835 spin_lock_init (&dev->read_buffer_lock); 836 dev->packet_timeout_jiffies = msecs_to_jiffies(packet_timeout); 837 dev->read_last_arrival = jiffies; 838 839 init_waitqueue_head (&dev->read_wait); 840 init_waitqueue_head (&dev->write_wait); 841 842 dev->interrupt_in_buffer = NULL; 843 dev->interrupt_in_endpoint = NULL; 844 dev->interrupt_in_urb = NULL; 845 dev->interrupt_in_running = 0; 846 dev->interrupt_in_done = 0; 847 848 dev->interrupt_out_buffer = NULL; 849 dev->interrupt_out_endpoint = NULL; 850 dev->interrupt_out_urb = NULL; 851 dev->interrupt_out_busy = 0; 852 853 result = usb_find_common_endpoints_reverse(interface->cur_altsetting, 854 NULL, NULL, 855 &dev->interrupt_in_endpoint, 856 &dev->interrupt_out_endpoint); 857 if (result) { 858 dev_err(idev, "interrupt endpoints not found\n"); 859 retval = result; 860 goto error; 861 } 862 863 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); 864 if (!dev->read_buffer) 865 goto error; 866 dev->interrupt_in_buffer = kmalloc (usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL); 867 if (!dev->interrupt_in_buffer) 868 goto error; 869 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 870 if (!dev->interrupt_in_urb) 871 goto error; 872 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL); 873 if (!dev->interrupt_out_buffer) 874 goto error; 875 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 876 if (!dev->interrupt_out_urb) 877 goto error; 878 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 879 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 880 881 get_version_reply = kmalloc(sizeof(*get_version_reply), GFP_KERNEL); 882 883 if (!get_version_reply) { 884 retval = -ENOMEM; 885 goto error; 886 } 887 888 /* get the firmware version and log it */ 889 result = usb_control_msg (udev, 890 usb_rcvctrlpipe(udev, 0), 891 LEGO_USB_TOWER_REQUEST_GET_VERSION, 892 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 893 0, 894 0, 895 get_version_reply, 896 sizeof(*get_version_reply), 897 1000); 898 if (result < 0) { 899 dev_err(idev, "LEGO USB Tower get version control request failed\n"); 900 retval = result; 901 goto error; 902 } 903 dev_info(&interface->dev, 904 "LEGO USB Tower firmware version is %d.%d build %d\n", 905 get_version_reply->major, 906 get_version_reply->minor, 907 le16_to_cpu(get_version_reply->build_no)); 908 909 /* we can register the device now, as it is ready */ 910 usb_set_intfdata (interface, dev); 911 912 retval = usb_register_dev (interface, &tower_class); 913 914 if (retval) { 915 /* something prevented us from registering this driver */ 916 dev_err(idev, "Not able to get a minor for this device.\n"); 917 usb_set_intfdata (interface, NULL); 918 goto error; 919 } 920 dev->minor = interface->minor; 921 922 /* let the user know what node this device is now attached to */ 923 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major " 924 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), 925 USB_MAJOR, dev->minor); 926 927 exit: 928 kfree(get_version_reply); 929 return retval; 930 931 error: 932 kfree(get_version_reply); 933 tower_delete(dev); 934 return retval; 935 } 936 937 938 /** 939 * tower_disconnect 940 * 941 * Called by the usb core when the device is removed from the system. 942 */ 943 static void tower_disconnect (struct usb_interface *interface) 944 { 945 struct lego_usb_tower *dev; 946 int minor; 947 948 dev = usb_get_intfdata (interface); 949 mutex_lock(&open_disc_mutex); 950 usb_set_intfdata (interface, NULL); 951 952 minor = dev->minor; 953 954 /* give back our minor */ 955 usb_deregister_dev (interface, &tower_class); 956 957 mutex_lock(&dev->lock); 958 mutex_unlock(&open_disc_mutex); 959 960 /* if the device is not opened, then we clean up right now */ 961 if (!dev->open_count) { 962 mutex_unlock(&dev->lock); 963 tower_delete (dev); 964 } else { 965 dev->udev = NULL; 966 /* wake up pollers */ 967 wake_up_interruptible_all(&dev->read_wait); 968 wake_up_interruptible_all(&dev->write_wait); 969 mutex_unlock(&dev->lock); 970 } 971 972 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n", 973 (minor - LEGO_USB_TOWER_MINOR_BASE)); 974 } 975 976 module_usb_driver(tower_driver); 977 978 MODULE_AUTHOR(DRIVER_AUTHOR); 979 MODULE_DESCRIPTION(DRIVER_DESC); 980 #ifdef MODULE_LICENSE 981 MODULE_LICENSE("GPL"); 982 #endif 983