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 <asm/uaccess.h> 87 #include <linux/usb.h> 88 #include <linux/poll.h> 89 90 91 /* Version Information */ 92 #define DRIVER_VERSION "v0.96" 93 #define DRIVER_AUTHOR "Juergen Stuber <starblue@sourceforge.net>" 94 #define DRIVER_DESC "LEGO USB Tower Driver" 95 96 97 /* The defaults are chosen to work with the latest versions of leJOS and NQC. 98 */ 99 100 /* Some legacy software likes to receive packets in one piece. 101 * In this case read_buffer_size should exceed the maximal packet length 102 * (417 for datalog uploads), and packet_timeout should be set. 103 */ 104 static int read_buffer_size = 480; 105 module_param(read_buffer_size, int, 0); 106 MODULE_PARM_DESC(read_buffer_size, "Read buffer size"); 107 108 /* Some legacy software likes to send packets in one piece. 109 * In this case write_buffer_size should exceed the maximal packet length 110 * (417 for firmware and program downloads). 111 * A problem with long writes is that the following read may time out 112 * if the software is not prepared to wait long enough. 113 */ 114 static int write_buffer_size = 480; 115 module_param(write_buffer_size, int, 0); 116 MODULE_PARM_DESC(write_buffer_size, "Write buffer size"); 117 118 /* Some legacy software expects reads to contain whole LASM packets. 119 * To achieve this, characters which arrive before a packet timeout 120 * occurs will be returned in a single read operation. 121 * A problem with long reads is that the software may time out 122 * if it is not prepared to wait long enough. 123 * The packet timeout should be greater than the time between the 124 * reception of subsequent characters, which should arrive about 125 * every 5ms for the standard 2400 baud. 126 * Set it to 0 to disable. 127 */ 128 static int packet_timeout = 50; 129 module_param(packet_timeout, int, 0); 130 MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms"); 131 132 /* Some legacy software expects blocking reads to time out. 133 * Timeout occurs after the specified time of read and write inactivity. 134 * Set it to 0 to disable. 135 */ 136 static int read_timeout = 200; 137 module_param(read_timeout, int, 0); 138 MODULE_PARM_DESC(read_timeout, "Read timeout in ms"); 139 140 /* As of kernel version 2.6.4 ehci-hcd uses an 141 * "only one interrupt transfer per frame" shortcut 142 * to simplify the scheduling of periodic transfers. 143 * This conflicts with our standard 1ms intervals for in and out URBs. 144 * We use default intervals of 2ms for in and 8ms for out transfers, 145 * which is fast enough for 2400 baud and allows a small additional load. 146 * Increase the interval to allow more devices that do interrupt transfers, 147 * or set to 0 to use the standard interval from the endpoint descriptors. 148 */ 149 static int interrupt_in_interval = 2; 150 module_param(interrupt_in_interval, int, 0); 151 MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms"); 152 153 static int interrupt_out_interval = 8; 154 module_param(interrupt_out_interval, int, 0); 155 MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms"); 156 157 /* Define these values to match your device */ 158 #define LEGO_USB_TOWER_VENDOR_ID 0x0694 159 #define LEGO_USB_TOWER_PRODUCT_ID 0x0001 160 161 /* Vendor requests */ 162 #define LEGO_USB_TOWER_REQUEST_RESET 0x04 163 #define LEGO_USB_TOWER_REQUEST_GET_VERSION 0xFD 164 165 struct tower_reset_reply { 166 __le16 size; /* little-endian */ 167 __u8 err_code; 168 __u8 spare; 169 } __attribute__ ((packed)); 170 171 struct tower_get_version_reply { 172 __le16 size; /* little-endian */ 173 __u8 err_code; 174 __u8 spare; 175 __u8 major; 176 __u8 minor; 177 __le16 build_no; /* little-endian */ 178 } __attribute__ ((packed)); 179 180 181 /* table of devices that work with this driver */ 182 static const struct usb_device_id tower_table[] = { 183 { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) }, 184 { } /* Terminating entry */ 185 }; 186 187 MODULE_DEVICE_TABLE (usb, tower_table); 188 static DEFINE_MUTEX(open_disc_mutex); 189 190 #define LEGO_USB_TOWER_MINOR_BASE 160 191 192 193 /* Structure to hold all of our device specific stuff */ 194 struct lego_usb_tower { 195 struct mutex lock; /* locks this structure */ 196 struct usb_device* udev; /* save off the usb device pointer */ 197 unsigned char minor; /* the starting minor number for this device */ 198 199 int open_count; /* number of times this port has been opened */ 200 201 char* read_buffer; 202 size_t read_buffer_length; /* this much came in */ 203 size_t read_packet_length; /* this much will be returned on read */ 204 spinlock_t read_buffer_lock; 205 int packet_timeout_jiffies; 206 unsigned long read_last_arrival; 207 208 wait_queue_head_t read_wait; 209 wait_queue_head_t write_wait; 210 211 char* interrupt_in_buffer; 212 struct usb_endpoint_descriptor* interrupt_in_endpoint; 213 struct urb* interrupt_in_urb; 214 int interrupt_in_interval; 215 int interrupt_in_running; 216 int interrupt_in_done; 217 218 char* interrupt_out_buffer; 219 struct usb_endpoint_descriptor* interrupt_out_endpoint; 220 struct urb* interrupt_out_urb; 221 int interrupt_out_interval; 222 int interrupt_out_busy; 223 224 }; 225 226 227 /* local function prototypes */ 228 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos); 229 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos); 230 static inline void tower_delete (struct lego_usb_tower *dev); 231 static int tower_open (struct inode *inode, struct file *file); 232 static int tower_release (struct inode *inode, struct file *file); 233 static unsigned int tower_poll (struct file *file, poll_table *wait); 234 static loff_t tower_llseek (struct file *file, loff_t off, int whence); 235 236 static void tower_abort_transfers (struct lego_usb_tower *dev); 237 static void tower_check_for_read_packet (struct lego_usb_tower *dev); 238 static void tower_interrupt_in_callback (struct urb *urb); 239 static void tower_interrupt_out_callback (struct urb *urb); 240 241 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id); 242 static void tower_disconnect (struct usb_interface *interface); 243 244 245 /* file operations needed when we register this driver */ 246 static const struct file_operations tower_fops = { 247 .owner = THIS_MODULE, 248 .read = tower_read, 249 .write = tower_write, 250 .open = tower_open, 251 .release = tower_release, 252 .poll = tower_poll, 253 .llseek = tower_llseek, 254 }; 255 256 static char *legousbtower_devnode(struct device *dev, umode_t *mode) 257 { 258 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev)); 259 } 260 261 /* 262 * usb class driver info in order to get a minor number from the usb core, 263 * and to have the device registered with the driver core 264 */ 265 static struct usb_class_driver tower_class = { 266 .name = "legousbtower%d", 267 .devnode = legousbtower_devnode, 268 .fops = &tower_fops, 269 .minor_base = LEGO_USB_TOWER_MINOR_BASE, 270 }; 271 272 273 /* usb specific object needed to register this driver with the usb subsystem */ 274 static struct usb_driver tower_driver = { 275 .name = "legousbtower", 276 .probe = tower_probe, 277 .disconnect = tower_disconnect, 278 .id_table = tower_table, 279 }; 280 281 282 /** 283 * lego_usb_tower_debug_data 284 */ 285 static inline void lego_usb_tower_debug_data(struct device *dev, 286 const char *function, int size, 287 const unsigned char *data) 288 { 289 dev_dbg(dev, "%s - length = %d, data = %*ph\n", 290 function, size, size, data); 291 } 292 293 294 /** 295 * tower_delete 296 */ 297 static inline void tower_delete (struct lego_usb_tower *dev) 298 { 299 tower_abort_transfers (dev); 300 301 /* free data structures */ 302 usb_free_urb(dev->interrupt_in_urb); 303 usb_free_urb(dev->interrupt_out_urb); 304 kfree (dev->read_buffer); 305 kfree (dev->interrupt_in_buffer); 306 kfree (dev->interrupt_out_buffer); 307 kfree (dev); 308 } 309 310 311 /** 312 * tower_open 313 */ 314 static int tower_open (struct inode *inode, struct file *file) 315 { 316 struct lego_usb_tower *dev = NULL; 317 int subminor; 318 int retval = 0; 319 struct usb_interface *interface; 320 struct tower_reset_reply reset_reply; 321 int result; 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 mutex_lock(&open_disc_mutex); 335 dev = usb_get_intfdata(interface); 336 337 if (!dev) { 338 mutex_unlock(&open_disc_mutex); 339 retval = -ENODEV; 340 goto exit; 341 } 342 343 /* lock this device */ 344 if (mutex_lock_interruptible(&dev->lock)) { 345 mutex_unlock(&open_disc_mutex); 346 retval = -ERESTARTSYS; 347 goto exit; 348 } 349 350 351 /* allow opening only once */ 352 if (dev->open_count) { 353 mutex_unlock(&open_disc_mutex); 354 retval = -EBUSY; 355 goto unlock_exit; 356 } 357 dev->open_count = 1; 358 mutex_unlock(&open_disc_mutex); 359 360 /* reset the tower */ 361 result = usb_control_msg (dev->udev, 362 usb_rcvctrlpipe(dev->udev, 0), 363 LEGO_USB_TOWER_REQUEST_RESET, 364 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 365 0, 366 0, 367 &reset_reply, 368 sizeof(reset_reply), 369 1000); 370 if (result < 0) { 371 dev_err(&dev->udev->dev, 372 "LEGO USB Tower reset control request failed\n"); 373 retval = result; 374 goto unlock_exit; 375 } 376 377 /* initialize in direction */ 378 dev->read_buffer_length = 0; 379 dev->read_packet_length = 0; 380 usb_fill_int_urb (dev->interrupt_in_urb, 381 dev->udev, 382 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress), 383 dev->interrupt_in_buffer, 384 usb_endpoint_maxp(dev->interrupt_in_endpoint), 385 tower_interrupt_in_callback, 386 dev, 387 dev->interrupt_in_interval); 388 389 dev->interrupt_in_running = 1; 390 dev->interrupt_in_done = 0; 391 mb(); 392 393 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL); 394 if (retval) { 395 dev_err(&dev->udev->dev, 396 "Couldn't submit interrupt_in_urb %d\n", retval); 397 dev->interrupt_in_running = 0; 398 dev->open_count = 0; 399 goto unlock_exit; 400 } 401 402 /* save device in the file's private structure */ 403 file->private_data = dev; 404 405 unlock_exit: 406 mutex_unlock(&dev->lock); 407 408 exit: 409 return retval; 410 } 411 412 /** 413 * tower_release 414 */ 415 static int tower_release (struct inode *inode, struct file *file) 416 { 417 struct lego_usb_tower *dev; 418 int retval = 0; 419 420 dev = file->private_data; 421 422 if (dev == NULL) { 423 retval = -ENODEV; 424 goto exit_nolock; 425 } 426 427 mutex_lock(&open_disc_mutex); 428 if (mutex_lock_interruptible(&dev->lock)) { 429 retval = -ERESTARTSYS; 430 goto exit; 431 } 432 433 if (dev->open_count != 1) { 434 dev_dbg(&dev->udev->dev, "%s: device not opened exactly once\n", 435 __func__); 436 retval = -ENODEV; 437 goto unlock_exit; 438 } 439 if (dev->udev == NULL) { 440 /* the device was unplugged before the file was released */ 441 442 /* unlock here as tower_delete frees dev */ 443 mutex_unlock(&dev->lock); 444 tower_delete (dev); 445 goto exit; 446 } 447 448 /* wait until write transfer is finished */ 449 if (dev->interrupt_out_busy) { 450 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 451 } 452 tower_abort_transfers (dev); 453 dev->open_count = 0; 454 455 unlock_exit: 456 mutex_unlock(&dev->lock); 457 458 exit: 459 mutex_unlock(&open_disc_mutex); 460 exit_nolock: 461 return retval; 462 } 463 464 465 /** 466 * tower_abort_transfers 467 * aborts transfers and frees associated data structures 468 */ 469 static void tower_abort_transfers (struct lego_usb_tower *dev) 470 { 471 if (dev == NULL) 472 return; 473 474 /* shutdown transfer */ 475 if (dev->interrupt_in_running) { 476 dev->interrupt_in_running = 0; 477 mb(); 478 if (dev->udev) 479 usb_kill_urb (dev->interrupt_in_urb); 480 } 481 if (dev->interrupt_out_busy && dev->udev) 482 usb_kill_urb(dev->interrupt_out_urb); 483 } 484 485 486 /** 487 * tower_check_for_read_packet 488 * 489 * To get correct semantics for signals and non-blocking I/O 490 * with packetizing we pretend not to see any data in the read buffer 491 * until it has been there unchanged for at least 492 * dev->packet_timeout_jiffies, or until the buffer is full. 493 */ 494 static void tower_check_for_read_packet (struct lego_usb_tower *dev) 495 { 496 spin_lock_irq (&dev->read_buffer_lock); 497 if (!packet_timeout 498 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) 499 || dev->read_buffer_length == read_buffer_size) { 500 dev->read_packet_length = dev->read_buffer_length; 501 } 502 dev->interrupt_in_done = 0; 503 spin_unlock_irq (&dev->read_buffer_lock); 504 } 505 506 507 /** 508 * tower_poll 509 */ 510 static unsigned int tower_poll (struct file *file, poll_table *wait) 511 { 512 struct lego_usb_tower *dev; 513 unsigned int mask = 0; 514 515 dev = file->private_data; 516 517 if (!dev->udev) 518 return POLLERR | POLLHUP; 519 520 poll_wait(file, &dev->read_wait, wait); 521 poll_wait(file, &dev->write_wait, wait); 522 523 tower_check_for_read_packet(dev); 524 if (dev->read_packet_length > 0) { 525 mask |= POLLIN | POLLRDNORM; 526 } 527 if (!dev->interrupt_out_busy) { 528 mask |= POLLOUT | POLLWRNORM; 529 } 530 531 return mask; 532 } 533 534 535 /** 536 * tower_llseek 537 */ 538 static loff_t tower_llseek (struct file *file, loff_t off, int whence) 539 { 540 return -ESPIPE; /* unseekable */ 541 } 542 543 544 /** 545 * tower_read 546 */ 547 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 548 { 549 struct lego_usb_tower *dev; 550 size_t bytes_to_read; 551 int i; 552 int retval = 0; 553 unsigned long timeout = 0; 554 555 dev = file->private_data; 556 557 /* lock this object */ 558 if (mutex_lock_interruptible(&dev->lock)) { 559 retval = -ERESTARTSYS; 560 goto exit; 561 } 562 563 /* verify that the device wasn't unplugged */ 564 if (dev->udev == NULL) { 565 retval = -ENODEV; 566 pr_err("No device or device unplugged %d\n", retval); 567 goto unlock_exit; 568 } 569 570 /* verify that we actually have some data to read */ 571 if (count == 0) { 572 dev_dbg(&dev->udev->dev, "read request of 0 bytes\n"); 573 goto unlock_exit; 574 } 575 576 if (read_timeout) { 577 timeout = jiffies + msecs_to_jiffies(read_timeout); 578 } 579 580 /* wait for data */ 581 tower_check_for_read_packet (dev); 582 while (dev->read_packet_length == 0) { 583 if (file->f_flags & O_NONBLOCK) { 584 retval = -EAGAIN; 585 goto unlock_exit; 586 } 587 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 588 if (retval < 0) { 589 goto unlock_exit; 590 } 591 592 /* reset read timeout during read or write activity */ 593 if (read_timeout 594 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 595 timeout = jiffies + msecs_to_jiffies(read_timeout); 596 } 597 /* check for read timeout */ 598 if (read_timeout && time_after (jiffies, timeout)) { 599 retval = -ETIMEDOUT; 600 goto unlock_exit; 601 } 602 tower_check_for_read_packet (dev); 603 } 604 605 /* copy the data from read_buffer into userspace */ 606 bytes_to_read = min(count, dev->read_packet_length); 607 608 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { 609 retval = -EFAULT; 610 goto unlock_exit; 611 } 612 613 spin_lock_irq (&dev->read_buffer_lock); 614 dev->read_buffer_length -= bytes_to_read; 615 dev->read_packet_length -= bytes_to_read; 616 for (i=0; i<dev->read_buffer_length; i++) { 617 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 618 } 619 spin_unlock_irq (&dev->read_buffer_lock); 620 621 retval = bytes_to_read; 622 623 unlock_exit: 624 /* unlock the device */ 625 mutex_unlock(&dev->lock); 626 627 exit: 628 return retval; 629 } 630 631 632 /** 633 * tower_write 634 */ 635 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 636 { 637 struct lego_usb_tower *dev; 638 size_t bytes_to_write; 639 int retval = 0; 640 641 dev = file->private_data; 642 643 /* lock this object */ 644 if (mutex_lock_interruptible(&dev->lock)) { 645 retval = -ERESTARTSYS; 646 goto exit; 647 } 648 649 /* verify that the device wasn't unplugged */ 650 if (dev->udev == NULL) { 651 retval = -ENODEV; 652 pr_err("No device or device unplugged %d\n", retval); 653 goto unlock_exit; 654 } 655 656 /* verify that we actually have some data to write */ 657 if (count == 0) { 658 dev_dbg(&dev->udev->dev, "write request of 0 bytes\n"); 659 goto unlock_exit; 660 } 661 662 /* wait until previous transfer is finished */ 663 while (dev->interrupt_out_busy) { 664 if (file->f_flags & O_NONBLOCK) { 665 retval = -EAGAIN; 666 goto unlock_exit; 667 } 668 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); 669 if (retval) { 670 goto unlock_exit; 671 } 672 } 673 674 /* write the data into interrupt_out_buffer from userspace */ 675 bytes_to_write = min_t(int, count, write_buffer_size); 676 dev_dbg(&dev->udev->dev, "%s: count = %Zd, bytes_to_write = %Zd\n", 677 __func__, count, bytes_to_write); 678 679 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { 680 retval = -EFAULT; 681 goto unlock_exit; 682 } 683 684 /* send off the urb */ 685 usb_fill_int_urb(dev->interrupt_out_urb, 686 dev->udev, 687 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 688 dev->interrupt_out_buffer, 689 bytes_to_write, 690 tower_interrupt_out_callback, 691 dev, 692 dev->interrupt_out_interval); 693 694 dev->interrupt_out_busy = 1; 695 wmb(); 696 697 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); 698 if (retval) { 699 dev->interrupt_out_busy = 0; 700 dev_err(&dev->udev->dev, 701 "Couldn't submit interrupt_out_urb %d\n", retval); 702 goto unlock_exit; 703 } 704 retval = bytes_to_write; 705 706 unlock_exit: 707 /* unlock the device */ 708 mutex_unlock(&dev->lock); 709 710 exit: 711 return retval; 712 } 713 714 715 /** 716 * tower_interrupt_in_callback 717 */ 718 static void tower_interrupt_in_callback (struct urb *urb) 719 { 720 struct lego_usb_tower *dev = urb->context; 721 int status = urb->status; 722 int retval; 723 724 lego_usb_tower_debug_data(&dev->udev->dev, __func__, 725 urb->actual_length, urb->transfer_buffer); 726 727 if (status) { 728 if (status == -ENOENT || 729 status == -ECONNRESET || 730 status == -ESHUTDOWN) { 731 goto exit; 732 } else { 733 dev_dbg(&dev->udev->dev, 734 "%s: nonzero status received: %d\n", __func__, 735 status); 736 goto resubmit; /* maybe we can recover */ 737 } 738 } 739 740 if (urb->actual_length > 0) { 741 spin_lock (&dev->read_buffer_lock); 742 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 743 memcpy (dev->read_buffer + dev->read_buffer_length, 744 dev->interrupt_in_buffer, 745 urb->actual_length); 746 dev->read_buffer_length += urb->actual_length; 747 dev->read_last_arrival = jiffies; 748 dev_dbg(&dev->udev->dev, "%s: received %d bytes\n", 749 __func__, urb->actual_length); 750 } else { 751 pr_warn("read_buffer overflow, %d bytes dropped\n", 752 urb->actual_length); 753 } 754 spin_unlock (&dev->read_buffer_lock); 755 } 756 757 resubmit: 758 /* resubmit if we're still running */ 759 if (dev->interrupt_in_running && dev->udev) { 760 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); 761 if (retval) 762 dev_err(&dev->udev->dev, 763 "%s: usb_submit_urb failed (%d)\n", 764 __func__, retval); 765 } 766 767 exit: 768 dev->interrupt_in_done = 1; 769 wake_up_interruptible (&dev->read_wait); 770 } 771 772 773 /** 774 * tower_interrupt_out_callback 775 */ 776 static void tower_interrupt_out_callback (struct urb *urb) 777 { 778 struct lego_usb_tower *dev = urb->context; 779 int status = urb->status; 780 781 lego_usb_tower_debug_data(&dev->udev->dev, __func__, 782 urb->actual_length, urb->transfer_buffer); 783 784 /* sync/async unlink faults aren't errors */ 785 if (status && !(status == -ENOENT || 786 status == -ECONNRESET || 787 status == -ESHUTDOWN)) { 788 dev_dbg(&dev->udev->dev, 789 "%s: nonzero write bulk status received: %d\n", __func__, 790 status); 791 } 792 793 dev->interrupt_out_busy = 0; 794 wake_up_interruptible(&dev->write_wait); 795 } 796 797 798 /** 799 * tower_probe 800 * 801 * Called by the usb core when a new device is connected that it thinks 802 * this driver might be interested in. 803 */ 804 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) 805 { 806 struct device *idev = &interface->dev; 807 struct usb_device *udev = interface_to_usbdev(interface); 808 struct lego_usb_tower *dev = NULL; 809 struct usb_host_interface *iface_desc; 810 struct usb_endpoint_descriptor* endpoint; 811 struct tower_get_version_reply get_version_reply; 812 int i; 813 int retval = -ENOMEM; 814 int result; 815 816 /* allocate memory for our device state and initialize it */ 817 818 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL); 819 820 if (dev == NULL) { 821 dev_err(idev, "Out of memory\n"); 822 goto exit; 823 } 824 825 mutex_init(&dev->lock); 826 827 dev->udev = udev; 828 dev->open_count = 0; 829 830 dev->read_buffer = NULL; 831 dev->read_buffer_length = 0; 832 dev->read_packet_length = 0; 833 spin_lock_init (&dev->read_buffer_lock); 834 dev->packet_timeout_jiffies = msecs_to_jiffies(packet_timeout); 835 dev->read_last_arrival = jiffies; 836 837 init_waitqueue_head (&dev->read_wait); 838 init_waitqueue_head (&dev->write_wait); 839 840 dev->interrupt_in_buffer = NULL; 841 dev->interrupt_in_endpoint = NULL; 842 dev->interrupt_in_urb = NULL; 843 dev->interrupt_in_running = 0; 844 dev->interrupt_in_done = 0; 845 846 dev->interrupt_out_buffer = NULL; 847 dev->interrupt_out_endpoint = NULL; 848 dev->interrupt_out_urb = NULL; 849 dev->interrupt_out_busy = 0; 850 851 iface_desc = interface->cur_altsetting; 852 853 /* set up the endpoint information */ 854 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 855 endpoint = &iface_desc->endpoint[i].desc; 856 857 if (usb_endpoint_xfer_int(endpoint)) { 858 if (usb_endpoint_dir_in(endpoint)) 859 dev->interrupt_in_endpoint = endpoint; 860 else 861 dev->interrupt_out_endpoint = endpoint; 862 } 863 } 864 if(dev->interrupt_in_endpoint == NULL) { 865 dev_err(idev, "interrupt in endpoint not found\n"); 866 goto error; 867 } 868 if (dev->interrupt_out_endpoint == NULL) { 869 dev_err(idev, "interrupt out endpoint not found\n"); 870 goto error; 871 } 872 873 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); 874 if (!dev->read_buffer) { 875 dev_err(idev, "Couldn't allocate read_buffer\n"); 876 goto error; 877 } 878 dev->interrupt_in_buffer = kmalloc (usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL); 879 if (!dev->interrupt_in_buffer) { 880 dev_err(idev, "Couldn't allocate interrupt_in_buffer\n"); 881 goto error; 882 } 883 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 884 if (!dev->interrupt_in_urb) { 885 dev_err(idev, "Couldn't allocate interrupt_in_urb\n"); 886 goto error; 887 } 888 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL); 889 if (!dev->interrupt_out_buffer) { 890 dev_err(idev, "Couldn't allocate interrupt_out_buffer\n"); 891 goto error; 892 } 893 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 894 if (!dev->interrupt_out_urb) { 895 dev_err(idev, "Couldn't allocate interrupt_out_urb\n"); 896 goto error; 897 } 898 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 899 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 900 901 /* we can register the device now, as it is ready */ 902 usb_set_intfdata (interface, dev); 903 904 retval = usb_register_dev (interface, &tower_class); 905 906 if (retval) { 907 /* something prevented us from registering this driver */ 908 dev_err(idev, "Not able to get a minor for this device.\n"); 909 usb_set_intfdata (interface, NULL); 910 goto error; 911 } 912 dev->minor = interface->minor; 913 914 /* let the user know what node this device is now attached to */ 915 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major " 916 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), 917 USB_MAJOR, dev->minor); 918 919 /* get the firmware version and log it */ 920 result = usb_control_msg (udev, 921 usb_rcvctrlpipe(udev, 0), 922 LEGO_USB_TOWER_REQUEST_GET_VERSION, 923 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 924 0, 925 0, 926 &get_version_reply, 927 sizeof(get_version_reply), 928 1000); 929 if (result < 0) { 930 dev_err(idev, "LEGO USB Tower get version control request failed\n"); 931 retval = result; 932 goto error; 933 } 934 dev_info(&interface->dev, "LEGO USB Tower firmware version is %d.%d " 935 "build %d\n", get_version_reply.major, 936 get_version_reply.minor, 937 le16_to_cpu(get_version_reply.build_no)); 938 939 940 exit: 941 return retval; 942 943 error: 944 tower_delete(dev); 945 return retval; 946 } 947 948 949 /** 950 * tower_disconnect 951 * 952 * Called by the usb core when the device is removed from the system. 953 */ 954 static void tower_disconnect (struct usb_interface *interface) 955 { 956 struct lego_usb_tower *dev; 957 int minor; 958 959 dev = usb_get_intfdata (interface); 960 mutex_lock(&open_disc_mutex); 961 usb_set_intfdata (interface, NULL); 962 963 minor = dev->minor; 964 965 /* give back our minor */ 966 usb_deregister_dev (interface, &tower_class); 967 968 mutex_lock(&dev->lock); 969 mutex_unlock(&open_disc_mutex); 970 971 /* if the device is not opened, then we clean up right now */ 972 if (!dev->open_count) { 973 mutex_unlock(&dev->lock); 974 tower_delete (dev); 975 } else { 976 dev->udev = NULL; 977 /* wake up pollers */ 978 wake_up_interruptible_all(&dev->read_wait); 979 wake_up_interruptible_all(&dev->write_wait); 980 mutex_unlock(&dev->lock); 981 } 982 983 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n", 984 (minor - LEGO_USB_TOWER_MINOR_BASE)); 985 } 986 987 module_usb_driver(tower_driver); 988 989 MODULE_AUTHOR(DRIVER_AUTHOR); 990 MODULE_DESCRIPTION(DRIVER_DESC); 991 #ifdef MODULE_LICENSE 992 MODULE_LICENSE("GPL"); 993 #endif 994