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