1 /* 2 * LEGO USB Tower driver 3 * 4 * Copyright (C) 2003 David Glance <davidgsf@sourceforge.net> 5 * 2001-2004 Juergen Stuber <starblue@users.sourceforge.net> 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License as 9 * published by the Free Software Foundation; either version 2 of 10 * the License, or (at your option) any later version. 11 * 12 * derived from USB Skeleton driver - 0.5 13 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com) 14 * 15 * History: 16 * 17 * 2001-10-13 - 0.1 js 18 * - first version 19 * 2001-11-03 - 0.2 js 20 * - simplified buffering, one-shot URBs for writing 21 * 2001-11-10 - 0.3 js 22 * - removed IOCTL (setting power/mode is more complicated, postponed) 23 * 2001-11-28 - 0.4 js 24 * - added vendor commands for mode of operation and power level in open 25 * 2001-12-04 - 0.5 js 26 * - set IR mode by default (by oversight 0.4 set VLL mode) 27 * 2002-01-11 - 0.5? pcchan 28 * - make read buffer reusable and work around bytes_to_write issue between 29 * uhci and legusbtower 30 * 2002-09-23 - 0.52 david (david@csse.uwa.edu.au) 31 * - imported into lejos project 32 * - changed wake_up to wake_up_interruptible 33 * - changed to use lego0 rather than tower0 34 * - changed dbg() to use __func__ rather than deprecated __func__ 35 * 2003-01-12 - 0.53 david (david@csse.uwa.edu.au) 36 * - changed read and write to write everything or 37 * timeout (from a patch by Chris Riesen and Brett Thaeler driver) 38 * - added ioctl functionality to set timeouts 39 * 2003-07-18 - 0.54 davidgsf (david@csse.uwa.edu.au) 40 * - initial import into LegoUSB project 41 * - merge of existing LegoUSB.c driver 42 * 2003-07-18 - 0.56 davidgsf (david@csse.uwa.edu.au) 43 * - port to 2.6 style driver 44 * 2004-02-29 - 0.6 Juergen Stuber <starblue@users.sourceforge.net> 45 * - fix locking 46 * - unlink read URBs which are no longer needed 47 * - allow increased buffer size, eliminates need for timeout on write 48 * - have read URB running continuously 49 * - added poll 50 * - forbid seeking 51 * - added nonblocking I/O 52 * - changed back __func__ to __func__ 53 * - read and log tower firmware version 54 * - reset tower on probe, avoids failure of first write 55 * 2004-03-09 - 0.7 Juergen Stuber <starblue@users.sourceforge.net> 56 * - timeout read now only after inactivity, shorten default accordingly 57 * 2004-03-11 - 0.8 Juergen Stuber <starblue@users.sourceforge.net> 58 * - log major, minor instead of possibly confusing device filename 59 * - whitespace cleanup 60 * 2004-03-12 - 0.9 Juergen Stuber <starblue@users.sourceforge.net> 61 * - normalize whitespace in debug messages 62 * - take care about endianness in control message responses 63 * 2004-03-13 - 0.91 Juergen Stuber <starblue@users.sourceforge.net> 64 * - make default intervals longer to accommodate current EHCI driver 65 * 2004-03-19 - 0.92 Juergen Stuber <starblue@users.sourceforge.net> 66 * - replaced atomic_t by memory barriers 67 * 2004-04-21 - 0.93 Juergen Stuber <starblue@users.sourceforge.net> 68 * - wait for completion of write urb in release (needed for remotecontrol) 69 * - corrected poll for write direction (missing negation) 70 * 2004-04-22 - 0.94 Juergen Stuber <starblue@users.sourceforge.net> 71 * - make device locking interruptible 72 * 2004-04-30 - 0.95 Juergen Stuber <starblue@users.sourceforge.net> 73 * - check for valid udev on resubmitting and unlinking urbs 74 * 2004-08-03 - 0.96 Juergen Stuber <starblue@users.sourceforge.net> 75 * - move reset into open to clean out spurious data 76 */ 77 78 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 79 80 #include <linux/kernel.h> 81 #include <linux/errno.h> 82 #include <linux/slab.h> 83 #include <linux/module.h> 84 #include <linux/completion.h> 85 #include <linux/mutex.h> 86 #include <linux/uaccess.h> 87 #include <linux/usb.h> 88 #include <linux/poll.h> 89 90 91 #define DRIVER_AUTHOR "Juergen Stuber <starblue@sourceforge.net>" 92 #define DRIVER_DESC "LEGO USB Tower Driver" 93 94 95 /* The defaults are chosen to work with the latest versions of leJOS and NQC. 96 */ 97 98 /* Some legacy software likes to receive packets in one piece. 99 * In this case read_buffer_size should exceed the maximal packet length 100 * (417 for datalog uploads), and packet_timeout should be set. 101 */ 102 static int read_buffer_size = 480; 103 module_param(read_buffer_size, int, 0); 104 MODULE_PARM_DESC(read_buffer_size, "Read buffer size"); 105 106 /* Some legacy software likes to send packets in one piece. 107 * In this case write_buffer_size should exceed the maximal packet length 108 * (417 for firmware and program downloads). 109 * A problem with long writes is that the following read may time out 110 * if the software is not prepared to wait long enough. 111 */ 112 static int write_buffer_size = 480; 113 module_param(write_buffer_size, int, 0); 114 MODULE_PARM_DESC(write_buffer_size, "Write buffer size"); 115 116 /* Some legacy software expects reads to contain whole LASM packets. 117 * To achieve this, characters which arrive before a packet timeout 118 * occurs will be returned in a single read operation. 119 * A problem with long reads is that the software may time out 120 * if it is not prepared to wait long enough. 121 * The packet timeout should be greater than the time between the 122 * reception of subsequent characters, which should arrive about 123 * every 5ms for the standard 2400 baud. 124 * Set it to 0 to disable. 125 */ 126 static int packet_timeout = 50; 127 module_param(packet_timeout, int, 0); 128 MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms"); 129 130 /* Some legacy software expects blocking reads to time out. 131 * Timeout occurs after the specified time of read and write inactivity. 132 * Set it to 0 to disable. 133 */ 134 static int read_timeout = 200; 135 module_param(read_timeout, int, 0); 136 MODULE_PARM_DESC(read_timeout, "Read timeout in ms"); 137 138 /* As of kernel version 2.6.4 ehci-hcd uses an 139 * "only one interrupt transfer per frame" shortcut 140 * to simplify the scheduling of periodic transfers. 141 * This conflicts with our standard 1ms intervals for in and out URBs. 142 * We use default intervals of 2ms for in and 8ms for out transfers, 143 * which is fast enough for 2400 baud and allows a small additional load. 144 * Increase the interval to allow more devices that do interrupt transfers, 145 * or set to 0 to use the standard interval from the endpoint descriptors. 146 */ 147 static int interrupt_in_interval = 2; 148 module_param(interrupt_in_interval, int, 0); 149 MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms"); 150 151 static int interrupt_out_interval = 8; 152 module_param(interrupt_out_interval, int, 0); 153 MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms"); 154 155 /* Define these values to match your device */ 156 #define LEGO_USB_TOWER_VENDOR_ID 0x0694 157 #define LEGO_USB_TOWER_PRODUCT_ID 0x0001 158 159 /* Vendor requests */ 160 #define LEGO_USB_TOWER_REQUEST_RESET 0x04 161 #define LEGO_USB_TOWER_REQUEST_GET_VERSION 0xFD 162 163 struct tower_reset_reply { 164 __le16 size; /* little-endian */ 165 __u8 err_code; 166 __u8 spare; 167 } __attribute__ ((packed)); 168 169 struct tower_get_version_reply { 170 __le16 size; /* little-endian */ 171 __u8 err_code; 172 __u8 spare; 173 __u8 major; 174 __u8 minor; 175 __le16 build_no; /* little-endian */ 176 } __attribute__ ((packed)); 177 178 179 /* table of devices that work with this driver */ 180 static const struct usb_device_id tower_table[] = { 181 { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) }, 182 { } /* Terminating entry */ 183 }; 184 185 MODULE_DEVICE_TABLE (usb, tower_table); 186 static DEFINE_MUTEX(open_disc_mutex); 187 188 #define LEGO_USB_TOWER_MINOR_BASE 160 189 190 191 /* Structure to hold all of our device specific stuff */ 192 struct lego_usb_tower { 193 struct mutex lock; /* locks this structure */ 194 struct usb_device* udev; /* save off the usb device pointer */ 195 unsigned char minor; /* the starting minor number for this device */ 196 197 int open_count; /* number of times this port has been opened */ 198 199 char* read_buffer; 200 size_t read_buffer_length; /* this much came in */ 201 size_t read_packet_length; /* this much will be returned on read */ 202 spinlock_t read_buffer_lock; 203 int packet_timeout_jiffies; 204 unsigned long read_last_arrival; 205 206 wait_queue_head_t read_wait; 207 wait_queue_head_t write_wait; 208 209 char* interrupt_in_buffer; 210 struct usb_endpoint_descriptor* interrupt_in_endpoint; 211 struct urb* interrupt_in_urb; 212 int interrupt_in_interval; 213 int interrupt_in_running; 214 int interrupt_in_done; 215 216 char* interrupt_out_buffer; 217 struct usb_endpoint_descriptor* interrupt_out_endpoint; 218 struct urb* interrupt_out_urb; 219 int interrupt_out_interval; 220 int interrupt_out_busy; 221 222 }; 223 224 225 /* local function prototypes */ 226 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos); 227 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos); 228 static inline void tower_delete (struct lego_usb_tower *dev); 229 static int tower_open (struct inode *inode, struct file *file); 230 static int tower_release (struct inode *inode, struct file *file); 231 static unsigned int tower_poll (struct file *file, poll_table *wait); 232 static loff_t tower_llseek (struct file *file, loff_t off, int whence); 233 234 static void tower_abort_transfers (struct lego_usb_tower *dev); 235 static void tower_check_for_read_packet (struct lego_usb_tower *dev); 236 static void tower_interrupt_in_callback (struct urb *urb); 237 static void tower_interrupt_out_callback (struct urb *urb); 238 239 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id); 240 static void tower_disconnect (struct usb_interface *interface); 241 242 243 /* file operations needed when we register this driver */ 244 static const struct file_operations tower_fops = { 245 .owner = THIS_MODULE, 246 .read = tower_read, 247 .write = tower_write, 248 .open = tower_open, 249 .release = tower_release, 250 .poll = tower_poll, 251 .llseek = tower_llseek, 252 }; 253 254 static char *legousbtower_devnode(struct device *dev, umode_t *mode) 255 { 256 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev)); 257 } 258 259 /* 260 * usb class driver info in order to get a minor number from the usb core, 261 * and to have the device registered with the driver core 262 */ 263 static struct usb_class_driver tower_class = { 264 .name = "legousbtower%d", 265 .devnode = legousbtower_devnode, 266 .fops = &tower_fops, 267 .minor_base = LEGO_USB_TOWER_MINOR_BASE, 268 }; 269 270 271 /* usb specific object needed to register this driver with the usb subsystem */ 272 static struct usb_driver tower_driver = { 273 .name = "legousbtower", 274 .probe = tower_probe, 275 .disconnect = tower_disconnect, 276 .id_table = tower_table, 277 }; 278 279 280 /** 281 * lego_usb_tower_debug_data 282 */ 283 static inline void lego_usb_tower_debug_data(struct device *dev, 284 const char *function, int size, 285 const unsigned char *data) 286 { 287 dev_dbg(dev, "%s - length = %d, data = %*ph\n", 288 function, size, size, data); 289 } 290 291 292 /** 293 * tower_delete 294 */ 295 static inline void tower_delete (struct lego_usb_tower *dev) 296 { 297 tower_abort_transfers (dev); 298 299 /* free data structures */ 300 usb_free_urb(dev->interrupt_in_urb); 301 usb_free_urb(dev->interrupt_out_urb); 302 kfree (dev->read_buffer); 303 kfree (dev->interrupt_in_buffer); 304 kfree (dev->interrupt_out_buffer); 305 kfree (dev); 306 } 307 308 309 /** 310 * tower_open 311 */ 312 static int tower_open (struct inode *inode, struct file *file) 313 { 314 struct lego_usb_tower *dev = NULL; 315 int subminor; 316 int retval = 0; 317 struct usb_interface *interface; 318 struct tower_reset_reply *reset_reply; 319 int result; 320 321 reset_reply = kmalloc(sizeof(*reset_reply), GFP_KERNEL); 322 323 if (!reset_reply) { 324 retval = -ENOMEM; 325 goto exit; 326 } 327 328 nonseekable_open(inode, file); 329 subminor = iminor(inode); 330 331 interface = usb_find_interface (&tower_driver, subminor); 332 333 if (!interface) { 334 pr_err("error, can't find device for minor %d\n", subminor); 335 retval = -ENODEV; 336 goto exit; 337 } 338 339 mutex_lock(&open_disc_mutex); 340 dev = usb_get_intfdata(interface); 341 342 if (!dev) { 343 mutex_unlock(&open_disc_mutex); 344 retval = -ENODEV; 345 goto exit; 346 } 347 348 /* lock this device */ 349 if (mutex_lock_interruptible(&dev->lock)) { 350 mutex_unlock(&open_disc_mutex); 351 retval = -ERESTARTSYS; 352 goto exit; 353 } 354 355 356 /* allow opening only once */ 357 if (dev->open_count) { 358 mutex_unlock(&open_disc_mutex); 359 retval = -EBUSY; 360 goto unlock_exit; 361 } 362 dev->open_count = 1; 363 mutex_unlock(&open_disc_mutex); 364 365 /* reset the tower */ 366 result = usb_control_msg (dev->udev, 367 usb_rcvctrlpipe(dev->udev, 0), 368 LEGO_USB_TOWER_REQUEST_RESET, 369 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 370 0, 371 0, 372 reset_reply, 373 sizeof(*reset_reply), 374 1000); 375 if (result < 0) { 376 dev_err(&dev->udev->dev, 377 "LEGO USB Tower reset control request failed\n"); 378 retval = result; 379 goto unlock_exit; 380 } 381 382 /* initialize in direction */ 383 dev->read_buffer_length = 0; 384 dev->read_packet_length = 0; 385 usb_fill_int_urb (dev->interrupt_in_urb, 386 dev->udev, 387 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress), 388 dev->interrupt_in_buffer, 389 usb_endpoint_maxp(dev->interrupt_in_endpoint), 390 tower_interrupt_in_callback, 391 dev, 392 dev->interrupt_in_interval); 393 394 dev->interrupt_in_running = 1; 395 dev->interrupt_in_done = 0; 396 mb(); 397 398 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL); 399 if (retval) { 400 dev_err(&dev->udev->dev, 401 "Couldn't submit interrupt_in_urb %d\n", retval); 402 dev->interrupt_in_running = 0; 403 dev->open_count = 0; 404 goto unlock_exit; 405 } 406 407 /* save device in the file's private structure */ 408 file->private_data = dev; 409 410 unlock_exit: 411 mutex_unlock(&dev->lock); 412 413 exit: 414 kfree(reset_reply); 415 return retval; 416 } 417 418 /** 419 * tower_release 420 */ 421 static int tower_release (struct inode *inode, struct file *file) 422 { 423 struct lego_usb_tower *dev; 424 int retval = 0; 425 426 dev = file->private_data; 427 428 if (dev == NULL) { 429 retval = -ENODEV; 430 goto exit_nolock; 431 } 432 433 mutex_lock(&open_disc_mutex); 434 if (mutex_lock_interruptible(&dev->lock)) { 435 retval = -ERESTARTSYS; 436 goto exit; 437 } 438 439 if (dev->open_count != 1) { 440 dev_dbg(&dev->udev->dev, "%s: device not opened exactly once\n", 441 __func__); 442 retval = -ENODEV; 443 goto unlock_exit; 444 } 445 if (dev->udev == NULL) { 446 /* the device was unplugged before the file was released */ 447 448 /* unlock here as tower_delete frees dev */ 449 mutex_unlock(&dev->lock); 450 tower_delete (dev); 451 goto exit; 452 } 453 454 /* wait until write transfer is finished */ 455 if (dev->interrupt_out_busy) { 456 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 457 } 458 tower_abort_transfers (dev); 459 dev->open_count = 0; 460 461 unlock_exit: 462 mutex_unlock(&dev->lock); 463 464 exit: 465 mutex_unlock(&open_disc_mutex); 466 exit_nolock: 467 return retval; 468 } 469 470 471 /** 472 * tower_abort_transfers 473 * aborts transfers and frees associated data structures 474 */ 475 static void tower_abort_transfers (struct lego_usb_tower *dev) 476 { 477 if (dev == NULL) 478 return; 479 480 /* shutdown transfer */ 481 if (dev->interrupt_in_running) { 482 dev->interrupt_in_running = 0; 483 mb(); 484 if (dev->udev) 485 usb_kill_urb (dev->interrupt_in_urb); 486 } 487 if (dev->interrupt_out_busy && dev->udev) 488 usb_kill_urb(dev->interrupt_out_urb); 489 } 490 491 492 /** 493 * tower_check_for_read_packet 494 * 495 * To get correct semantics for signals and non-blocking I/O 496 * with packetizing we pretend not to see any data in the read buffer 497 * until it has been there unchanged for at least 498 * dev->packet_timeout_jiffies, or until the buffer is full. 499 */ 500 static void tower_check_for_read_packet (struct lego_usb_tower *dev) 501 { 502 spin_lock_irq (&dev->read_buffer_lock); 503 if (!packet_timeout 504 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) 505 || dev->read_buffer_length == read_buffer_size) { 506 dev->read_packet_length = dev->read_buffer_length; 507 } 508 dev->interrupt_in_done = 0; 509 spin_unlock_irq (&dev->read_buffer_lock); 510 } 511 512 513 /** 514 * tower_poll 515 */ 516 static unsigned int tower_poll (struct file *file, poll_table *wait) 517 { 518 struct lego_usb_tower *dev; 519 unsigned int mask = 0; 520 521 dev = file->private_data; 522 523 if (!dev->udev) 524 return POLLERR | POLLHUP; 525 526 poll_wait(file, &dev->read_wait, wait); 527 poll_wait(file, &dev->write_wait, wait); 528 529 tower_check_for_read_packet(dev); 530 if (dev->read_packet_length > 0) { 531 mask |= POLLIN | POLLRDNORM; 532 } 533 if (!dev->interrupt_out_busy) { 534 mask |= POLLOUT | POLLWRNORM; 535 } 536 537 return mask; 538 } 539 540 541 /** 542 * tower_llseek 543 */ 544 static loff_t tower_llseek (struct file *file, loff_t off, int whence) 545 { 546 return -ESPIPE; /* unseekable */ 547 } 548 549 550 /** 551 * tower_read 552 */ 553 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 554 { 555 struct lego_usb_tower *dev; 556 size_t bytes_to_read; 557 int i; 558 int retval = 0; 559 unsigned long timeout = 0; 560 561 dev = file->private_data; 562 563 /* lock this object */ 564 if (mutex_lock_interruptible(&dev->lock)) { 565 retval = -ERESTARTSYS; 566 goto exit; 567 } 568 569 /* verify that the device wasn't unplugged */ 570 if (dev->udev == NULL) { 571 retval = -ENODEV; 572 pr_err("No device or device unplugged %d\n", retval); 573 goto unlock_exit; 574 } 575 576 /* verify that we actually have some data to read */ 577 if (count == 0) { 578 dev_dbg(&dev->udev->dev, "read request of 0 bytes\n"); 579 goto unlock_exit; 580 } 581 582 if (read_timeout) { 583 timeout = jiffies + msecs_to_jiffies(read_timeout); 584 } 585 586 /* wait for data */ 587 tower_check_for_read_packet (dev); 588 while (dev->read_packet_length == 0) { 589 if (file->f_flags & O_NONBLOCK) { 590 retval = -EAGAIN; 591 goto unlock_exit; 592 } 593 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 594 if (retval < 0) { 595 goto unlock_exit; 596 } 597 598 /* reset read timeout during read or write activity */ 599 if (read_timeout 600 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 601 timeout = jiffies + msecs_to_jiffies(read_timeout); 602 } 603 /* check for read timeout */ 604 if (read_timeout && time_after (jiffies, timeout)) { 605 retval = -ETIMEDOUT; 606 goto unlock_exit; 607 } 608 tower_check_for_read_packet (dev); 609 } 610 611 /* copy the data from read_buffer into userspace */ 612 bytes_to_read = min(count, dev->read_packet_length); 613 614 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { 615 retval = -EFAULT; 616 goto unlock_exit; 617 } 618 619 spin_lock_irq (&dev->read_buffer_lock); 620 dev->read_buffer_length -= bytes_to_read; 621 dev->read_packet_length -= bytes_to_read; 622 for (i=0; i<dev->read_buffer_length; i++) { 623 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 624 } 625 spin_unlock_irq (&dev->read_buffer_lock); 626 627 retval = bytes_to_read; 628 629 unlock_exit: 630 /* unlock the device */ 631 mutex_unlock(&dev->lock); 632 633 exit: 634 return retval; 635 } 636 637 638 /** 639 * tower_write 640 */ 641 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 642 { 643 struct lego_usb_tower *dev; 644 size_t bytes_to_write; 645 int retval = 0; 646 647 dev = file->private_data; 648 649 /* lock this object */ 650 if (mutex_lock_interruptible(&dev->lock)) { 651 retval = -ERESTARTSYS; 652 goto exit; 653 } 654 655 /* verify that the device wasn't unplugged */ 656 if (dev->udev == NULL) { 657 retval = -ENODEV; 658 pr_err("No device or device unplugged %d\n", retval); 659 goto unlock_exit; 660 } 661 662 /* verify that we actually have some data to write */ 663 if (count == 0) { 664 dev_dbg(&dev->udev->dev, "write request of 0 bytes\n"); 665 goto unlock_exit; 666 } 667 668 /* wait until previous transfer is finished */ 669 while (dev->interrupt_out_busy) { 670 if (file->f_flags & O_NONBLOCK) { 671 retval = -EAGAIN; 672 goto unlock_exit; 673 } 674 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); 675 if (retval) { 676 goto unlock_exit; 677 } 678 } 679 680 /* write the data into interrupt_out_buffer from userspace */ 681 bytes_to_write = min_t(int, count, write_buffer_size); 682 dev_dbg(&dev->udev->dev, "%s: count = %zd, bytes_to_write = %zd\n", 683 __func__, count, bytes_to_write); 684 685 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { 686 retval = -EFAULT; 687 goto unlock_exit; 688 } 689 690 /* send off the urb */ 691 usb_fill_int_urb(dev->interrupt_out_urb, 692 dev->udev, 693 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 694 dev->interrupt_out_buffer, 695 bytes_to_write, 696 tower_interrupt_out_callback, 697 dev, 698 dev->interrupt_out_interval); 699 700 dev->interrupt_out_busy = 1; 701 wmb(); 702 703 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); 704 if (retval) { 705 dev->interrupt_out_busy = 0; 706 dev_err(&dev->udev->dev, 707 "Couldn't submit interrupt_out_urb %d\n", retval); 708 goto unlock_exit; 709 } 710 retval = bytes_to_write; 711 712 unlock_exit: 713 /* unlock the device */ 714 mutex_unlock(&dev->lock); 715 716 exit: 717 return retval; 718 } 719 720 721 /** 722 * tower_interrupt_in_callback 723 */ 724 static void tower_interrupt_in_callback (struct urb *urb) 725 { 726 struct lego_usb_tower *dev = urb->context; 727 int status = urb->status; 728 int retval; 729 730 lego_usb_tower_debug_data(&dev->udev->dev, __func__, 731 urb->actual_length, urb->transfer_buffer); 732 733 if (status) { 734 if (status == -ENOENT || 735 status == -ECONNRESET || 736 status == -ESHUTDOWN) { 737 goto exit; 738 } else { 739 dev_dbg(&dev->udev->dev, 740 "%s: nonzero status received: %d\n", __func__, 741 status); 742 goto resubmit; /* maybe we can recover */ 743 } 744 } 745 746 if (urb->actual_length > 0) { 747 spin_lock (&dev->read_buffer_lock); 748 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 749 memcpy (dev->read_buffer + dev->read_buffer_length, 750 dev->interrupt_in_buffer, 751 urb->actual_length); 752 dev->read_buffer_length += urb->actual_length; 753 dev->read_last_arrival = jiffies; 754 dev_dbg(&dev->udev->dev, "%s: received %d bytes\n", 755 __func__, urb->actual_length); 756 } else { 757 pr_warn("read_buffer overflow, %d bytes dropped\n", 758 urb->actual_length); 759 } 760 spin_unlock (&dev->read_buffer_lock); 761 } 762 763 resubmit: 764 /* resubmit if we're still running */ 765 if (dev->interrupt_in_running && dev->udev) { 766 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); 767 if (retval) 768 dev_err(&dev->udev->dev, 769 "%s: usb_submit_urb failed (%d)\n", 770 __func__, retval); 771 } 772 773 exit: 774 dev->interrupt_in_done = 1; 775 wake_up_interruptible (&dev->read_wait); 776 } 777 778 779 /** 780 * tower_interrupt_out_callback 781 */ 782 static void tower_interrupt_out_callback (struct urb *urb) 783 { 784 struct lego_usb_tower *dev = urb->context; 785 int status = urb->status; 786 787 lego_usb_tower_debug_data(&dev->udev->dev, __func__, 788 urb->actual_length, urb->transfer_buffer); 789 790 /* sync/async unlink faults aren't errors */ 791 if (status && !(status == -ENOENT || 792 status == -ECONNRESET || 793 status == -ESHUTDOWN)) { 794 dev_dbg(&dev->udev->dev, 795 "%s: nonzero write bulk status received: %d\n", __func__, 796 status); 797 } 798 799 dev->interrupt_out_busy = 0; 800 wake_up_interruptible(&dev->write_wait); 801 } 802 803 804 /** 805 * tower_probe 806 * 807 * Called by the usb core when a new device is connected that it thinks 808 * this driver might be interested in. 809 */ 810 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) 811 { 812 struct device *idev = &interface->dev; 813 struct usb_device *udev = interface_to_usbdev(interface); 814 struct lego_usb_tower *dev = NULL; 815 struct tower_get_version_reply *get_version_reply = NULL; 816 int retval = -ENOMEM; 817 int result; 818 819 /* allocate memory for our device state and initialize it */ 820 821 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL); 822 823 if (!dev) 824 goto exit; 825 826 mutex_init(&dev->lock); 827 828 dev->udev = udev; 829 dev->open_count = 0; 830 831 dev->read_buffer = NULL; 832 dev->read_buffer_length = 0; 833 dev->read_packet_length = 0; 834 spin_lock_init (&dev->read_buffer_lock); 835 dev->packet_timeout_jiffies = msecs_to_jiffies(packet_timeout); 836 dev->read_last_arrival = jiffies; 837 838 init_waitqueue_head (&dev->read_wait); 839 init_waitqueue_head (&dev->write_wait); 840 841 dev->interrupt_in_buffer = NULL; 842 dev->interrupt_in_endpoint = NULL; 843 dev->interrupt_in_urb = NULL; 844 dev->interrupt_in_running = 0; 845 dev->interrupt_in_done = 0; 846 847 dev->interrupt_out_buffer = NULL; 848 dev->interrupt_out_endpoint = NULL; 849 dev->interrupt_out_urb = NULL; 850 dev->interrupt_out_busy = 0; 851 852 result = usb_find_common_endpoints_reverse(interface->cur_altsetting, 853 NULL, NULL, 854 &dev->interrupt_in_endpoint, 855 &dev->interrupt_out_endpoint); 856 if (result) { 857 dev_err(idev, "interrupt endpoints not found\n"); 858 retval = result; 859 goto error; 860 } 861 862 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); 863 if (!dev->read_buffer) 864 goto error; 865 dev->interrupt_in_buffer = kmalloc (usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL); 866 if (!dev->interrupt_in_buffer) 867 goto error; 868 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 869 if (!dev->interrupt_in_urb) 870 goto error; 871 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL); 872 if (!dev->interrupt_out_buffer) 873 goto error; 874 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 875 if (!dev->interrupt_out_urb) 876 goto error; 877 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 878 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 879 880 get_version_reply = kmalloc(sizeof(*get_version_reply), GFP_KERNEL); 881 882 if (!get_version_reply) { 883 retval = -ENOMEM; 884 goto error; 885 } 886 887 /* get the firmware version and log it */ 888 result = usb_control_msg (udev, 889 usb_rcvctrlpipe(udev, 0), 890 LEGO_USB_TOWER_REQUEST_GET_VERSION, 891 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 892 0, 893 0, 894 get_version_reply, 895 sizeof(*get_version_reply), 896 1000); 897 if (result < 0) { 898 dev_err(idev, "LEGO USB Tower get version control request failed\n"); 899 retval = result; 900 goto error; 901 } 902 dev_info(&interface->dev, 903 "LEGO USB Tower firmware version is %d.%d build %d\n", 904 get_version_reply->major, 905 get_version_reply->minor, 906 le16_to_cpu(get_version_reply->build_no)); 907 908 /* we can register the device now, as it is ready */ 909 usb_set_intfdata (interface, dev); 910 911 retval = usb_register_dev (interface, &tower_class); 912 913 if (retval) { 914 /* something prevented us from registering this driver */ 915 dev_err(idev, "Not able to get a minor for this device.\n"); 916 usb_set_intfdata (interface, NULL); 917 goto error; 918 } 919 dev->minor = interface->minor; 920 921 /* let the user know what node this device is now attached to */ 922 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major " 923 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), 924 USB_MAJOR, dev->minor); 925 926 exit: 927 kfree(get_version_reply); 928 return retval; 929 930 error: 931 kfree(get_version_reply); 932 tower_delete(dev); 933 return retval; 934 } 935 936 937 /** 938 * tower_disconnect 939 * 940 * Called by the usb core when the device is removed from the system. 941 */ 942 static void tower_disconnect (struct usb_interface *interface) 943 { 944 struct lego_usb_tower *dev; 945 int minor; 946 947 dev = usb_get_intfdata (interface); 948 mutex_lock(&open_disc_mutex); 949 usb_set_intfdata (interface, NULL); 950 951 minor = dev->minor; 952 953 /* give back our minor */ 954 usb_deregister_dev (interface, &tower_class); 955 956 mutex_lock(&dev->lock); 957 mutex_unlock(&open_disc_mutex); 958 959 /* if the device is not opened, then we clean up right now */ 960 if (!dev->open_count) { 961 mutex_unlock(&dev->lock); 962 tower_delete (dev); 963 } else { 964 dev->udev = NULL; 965 /* wake up pollers */ 966 wake_up_interruptible_all(&dev->read_wait); 967 wake_up_interruptible_all(&dev->write_wait); 968 mutex_unlock(&dev->lock); 969 } 970 971 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n", 972 (minor - LEGO_USB_TOWER_MINOR_BASE)); 973 } 974 975 module_usb_driver(tower_driver); 976 977 MODULE_AUTHOR(DRIVER_AUTHOR); 978 MODULE_DESCRIPTION(DRIVER_DESC); 979 #ifdef MODULE_LICENSE 980 MODULE_LICENSE("GPL"); 981 #endif 982