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 /* 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 reset_reply = kmalloc(sizeof(*reset_reply), GFP_KERNEL); 324 325 if (!reset_reply) { 326 retval = -ENOMEM; 327 goto exit; 328 } 329 330 nonseekable_open(inode, file); 331 subminor = iminor(inode); 332 333 interface = usb_find_interface (&tower_driver, subminor); 334 335 if (!interface) { 336 pr_err("error, can't find device for minor %d\n", subminor); 337 retval = -ENODEV; 338 goto exit; 339 } 340 341 mutex_lock(&open_disc_mutex); 342 dev = usb_get_intfdata(interface); 343 344 if (!dev) { 345 mutex_unlock(&open_disc_mutex); 346 retval = -ENODEV; 347 goto exit; 348 } 349 350 /* lock this device */ 351 if (mutex_lock_interruptible(&dev->lock)) { 352 mutex_unlock(&open_disc_mutex); 353 retval = -ERESTARTSYS; 354 goto exit; 355 } 356 357 358 /* allow opening only once */ 359 if (dev->open_count) { 360 mutex_unlock(&open_disc_mutex); 361 retval = -EBUSY; 362 goto unlock_exit; 363 } 364 dev->open_count = 1; 365 mutex_unlock(&open_disc_mutex); 366 367 /* reset the tower */ 368 result = usb_control_msg (dev->udev, 369 usb_rcvctrlpipe(dev->udev, 0), 370 LEGO_USB_TOWER_REQUEST_RESET, 371 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 372 0, 373 0, 374 reset_reply, 375 sizeof(*reset_reply), 376 1000); 377 if (result < 0) { 378 dev_err(&dev->udev->dev, 379 "LEGO USB Tower reset control request failed\n"); 380 retval = result; 381 goto unlock_exit; 382 } 383 384 /* initialize in direction */ 385 dev->read_buffer_length = 0; 386 dev->read_packet_length = 0; 387 usb_fill_int_urb (dev->interrupt_in_urb, 388 dev->udev, 389 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress), 390 dev->interrupt_in_buffer, 391 usb_endpoint_maxp(dev->interrupt_in_endpoint), 392 tower_interrupt_in_callback, 393 dev, 394 dev->interrupt_in_interval); 395 396 dev->interrupt_in_running = 1; 397 dev->interrupt_in_done = 0; 398 mb(); 399 400 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL); 401 if (retval) { 402 dev_err(&dev->udev->dev, 403 "Couldn't submit interrupt_in_urb %d\n", retval); 404 dev->interrupt_in_running = 0; 405 dev->open_count = 0; 406 goto unlock_exit; 407 } 408 409 /* save device in the file's private structure */ 410 file->private_data = dev; 411 412 unlock_exit: 413 mutex_unlock(&dev->lock); 414 415 exit: 416 kfree(reset_reply); 417 return retval; 418 } 419 420 /** 421 * tower_release 422 */ 423 static int tower_release (struct inode *inode, struct file *file) 424 { 425 struct lego_usb_tower *dev; 426 int retval = 0; 427 428 dev = file->private_data; 429 430 if (dev == NULL) { 431 retval = -ENODEV; 432 goto exit_nolock; 433 } 434 435 mutex_lock(&open_disc_mutex); 436 if (mutex_lock_interruptible(&dev->lock)) { 437 retval = -ERESTARTSYS; 438 goto exit; 439 } 440 441 if (dev->open_count != 1) { 442 dev_dbg(&dev->udev->dev, "%s: device not opened exactly once\n", 443 __func__); 444 retval = -ENODEV; 445 goto unlock_exit; 446 } 447 if (dev->udev == NULL) { 448 /* the device was unplugged before the file was released */ 449 450 /* unlock here as tower_delete frees dev */ 451 mutex_unlock(&dev->lock); 452 tower_delete (dev); 453 goto exit; 454 } 455 456 /* wait until write transfer is finished */ 457 if (dev->interrupt_out_busy) { 458 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 459 } 460 tower_abort_transfers (dev); 461 dev->open_count = 0; 462 463 unlock_exit: 464 mutex_unlock(&dev->lock); 465 466 exit: 467 mutex_unlock(&open_disc_mutex); 468 exit_nolock: 469 return retval; 470 } 471 472 473 /** 474 * tower_abort_transfers 475 * aborts transfers and frees associated data structures 476 */ 477 static void tower_abort_transfers (struct lego_usb_tower *dev) 478 { 479 if (dev == NULL) 480 return; 481 482 /* shutdown transfer */ 483 if (dev->interrupt_in_running) { 484 dev->interrupt_in_running = 0; 485 mb(); 486 if (dev->udev) 487 usb_kill_urb (dev->interrupt_in_urb); 488 } 489 if (dev->interrupt_out_busy && dev->udev) 490 usb_kill_urb(dev->interrupt_out_urb); 491 } 492 493 494 /** 495 * tower_check_for_read_packet 496 * 497 * To get correct semantics for signals and non-blocking I/O 498 * with packetizing we pretend not to see any data in the read buffer 499 * until it has been there unchanged for at least 500 * dev->packet_timeout_jiffies, or until the buffer is full. 501 */ 502 static void tower_check_for_read_packet (struct lego_usb_tower *dev) 503 { 504 spin_lock_irq (&dev->read_buffer_lock); 505 if (!packet_timeout 506 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) 507 || dev->read_buffer_length == read_buffer_size) { 508 dev->read_packet_length = dev->read_buffer_length; 509 } 510 dev->interrupt_in_done = 0; 511 spin_unlock_irq (&dev->read_buffer_lock); 512 } 513 514 515 /** 516 * tower_poll 517 */ 518 static unsigned int tower_poll (struct file *file, poll_table *wait) 519 { 520 struct lego_usb_tower *dev; 521 unsigned int mask = 0; 522 523 dev = file->private_data; 524 525 if (!dev->udev) 526 return POLLERR | POLLHUP; 527 528 poll_wait(file, &dev->read_wait, wait); 529 poll_wait(file, &dev->write_wait, wait); 530 531 tower_check_for_read_packet(dev); 532 if (dev->read_packet_length > 0) { 533 mask |= POLLIN | POLLRDNORM; 534 } 535 if (!dev->interrupt_out_busy) { 536 mask |= POLLOUT | POLLWRNORM; 537 } 538 539 return mask; 540 } 541 542 543 /** 544 * tower_llseek 545 */ 546 static loff_t tower_llseek (struct file *file, loff_t off, int whence) 547 { 548 return -ESPIPE; /* unseekable */ 549 } 550 551 552 /** 553 * tower_read 554 */ 555 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 556 { 557 struct lego_usb_tower *dev; 558 size_t bytes_to_read; 559 int i; 560 int retval = 0; 561 unsigned long timeout = 0; 562 563 dev = file->private_data; 564 565 /* lock this object */ 566 if (mutex_lock_interruptible(&dev->lock)) { 567 retval = -ERESTARTSYS; 568 goto exit; 569 } 570 571 /* verify that the device wasn't unplugged */ 572 if (dev->udev == NULL) { 573 retval = -ENODEV; 574 pr_err("No device or device unplugged %d\n", retval); 575 goto unlock_exit; 576 } 577 578 /* verify that we actually have some data to read */ 579 if (count == 0) { 580 dev_dbg(&dev->udev->dev, "read request of 0 bytes\n"); 581 goto unlock_exit; 582 } 583 584 if (read_timeout) { 585 timeout = jiffies + msecs_to_jiffies(read_timeout); 586 } 587 588 /* wait for data */ 589 tower_check_for_read_packet (dev); 590 while (dev->read_packet_length == 0) { 591 if (file->f_flags & O_NONBLOCK) { 592 retval = -EAGAIN; 593 goto unlock_exit; 594 } 595 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 596 if (retval < 0) { 597 goto unlock_exit; 598 } 599 600 /* reset read timeout during read or write activity */ 601 if (read_timeout 602 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 603 timeout = jiffies + msecs_to_jiffies(read_timeout); 604 } 605 /* check for read timeout */ 606 if (read_timeout && time_after (jiffies, timeout)) { 607 retval = -ETIMEDOUT; 608 goto unlock_exit; 609 } 610 tower_check_for_read_packet (dev); 611 } 612 613 /* copy the data from read_buffer into userspace */ 614 bytes_to_read = min(count, dev->read_packet_length); 615 616 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { 617 retval = -EFAULT; 618 goto unlock_exit; 619 } 620 621 spin_lock_irq (&dev->read_buffer_lock); 622 dev->read_buffer_length -= bytes_to_read; 623 dev->read_packet_length -= bytes_to_read; 624 for (i=0; i<dev->read_buffer_length; i++) { 625 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 626 } 627 spin_unlock_irq (&dev->read_buffer_lock); 628 629 retval = bytes_to_read; 630 631 unlock_exit: 632 /* unlock the device */ 633 mutex_unlock(&dev->lock); 634 635 exit: 636 return retval; 637 } 638 639 640 /** 641 * tower_write 642 */ 643 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 644 { 645 struct lego_usb_tower *dev; 646 size_t bytes_to_write; 647 int retval = 0; 648 649 dev = file->private_data; 650 651 /* lock this object */ 652 if (mutex_lock_interruptible(&dev->lock)) { 653 retval = -ERESTARTSYS; 654 goto exit; 655 } 656 657 /* verify that the device wasn't unplugged */ 658 if (dev->udev == NULL) { 659 retval = -ENODEV; 660 pr_err("No device or device unplugged %d\n", retval); 661 goto unlock_exit; 662 } 663 664 /* verify that we actually have some data to write */ 665 if (count == 0) { 666 dev_dbg(&dev->udev->dev, "write request of 0 bytes\n"); 667 goto unlock_exit; 668 } 669 670 /* wait until previous transfer is finished */ 671 while (dev->interrupt_out_busy) { 672 if (file->f_flags & O_NONBLOCK) { 673 retval = -EAGAIN; 674 goto unlock_exit; 675 } 676 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); 677 if (retval) { 678 goto unlock_exit; 679 } 680 } 681 682 /* write the data into interrupt_out_buffer from userspace */ 683 bytes_to_write = min_t(int, count, write_buffer_size); 684 dev_dbg(&dev->udev->dev, "%s: count = %zd, bytes_to_write = %zd\n", 685 __func__, count, bytes_to_write); 686 687 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { 688 retval = -EFAULT; 689 goto unlock_exit; 690 } 691 692 /* send off the urb */ 693 usb_fill_int_urb(dev->interrupt_out_urb, 694 dev->udev, 695 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 696 dev->interrupt_out_buffer, 697 bytes_to_write, 698 tower_interrupt_out_callback, 699 dev, 700 dev->interrupt_out_interval); 701 702 dev->interrupt_out_busy = 1; 703 wmb(); 704 705 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); 706 if (retval) { 707 dev->interrupt_out_busy = 0; 708 dev_err(&dev->udev->dev, 709 "Couldn't submit interrupt_out_urb %d\n", retval); 710 goto unlock_exit; 711 } 712 retval = bytes_to_write; 713 714 unlock_exit: 715 /* unlock the device */ 716 mutex_unlock(&dev->lock); 717 718 exit: 719 return retval; 720 } 721 722 723 /** 724 * tower_interrupt_in_callback 725 */ 726 static void tower_interrupt_in_callback (struct urb *urb) 727 { 728 struct lego_usb_tower *dev = urb->context; 729 int status = urb->status; 730 int retval; 731 732 lego_usb_tower_debug_data(&dev->udev->dev, __func__, 733 urb->actual_length, urb->transfer_buffer); 734 735 if (status) { 736 if (status == -ENOENT || 737 status == -ECONNRESET || 738 status == -ESHUTDOWN) { 739 goto exit; 740 } else { 741 dev_dbg(&dev->udev->dev, 742 "%s: nonzero status received: %d\n", __func__, 743 status); 744 goto resubmit; /* maybe we can recover */ 745 } 746 } 747 748 if (urb->actual_length > 0) { 749 spin_lock (&dev->read_buffer_lock); 750 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 751 memcpy (dev->read_buffer + dev->read_buffer_length, 752 dev->interrupt_in_buffer, 753 urb->actual_length); 754 dev->read_buffer_length += urb->actual_length; 755 dev->read_last_arrival = jiffies; 756 dev_dbg(&dev->udev->dev, "%s: received %d bytes\n", 757 __func__, urb->actual_length); 758 } else { 759 pr_warn("read_buffer overflow, %d bytes dropped\n", 760 urb->actual_length); 761 } 762 spin_unlock (&dev->read_buffer_lock); 763 } 764 765 resubmit: 766 /* resubmit if we're still running */ 767 if (dev->interrupt_in_running && dev->udev) { 768 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); 769 if (retval) 770 dev_err(&dev->udev->dev, 771 "%s: usb_submit_urb failed (%d)\n", 772 __func__, retval); 773 } 774 775 exit: 776 dev->interrupt_in_done = 1; 777 wake_up_interruptible (&dev->read_wait); 778 } 779 780 781 /** 782 * tower_interrupt_out_callback 783 */ 784 static void tower_interrupt_out_callback (struct urb *urb) 785 { 786 struct lego_usb_tower *dev = urb->context; 787 int status = urb->status; 788 789 lego_usb_tower_debug_data(&dev->udev->dev, __func__, 790 urb->actual_length, urb->transfer_buffer); 791 792 /* sync/async unlink faults aren't errors */ 793 if (status && !(status == -ENOENT || 794 status == -ECONNRESET || 795 status == -ESHUTDOWN)) { 796 dev_dbg(&dev->udev->dev, 797 "%s: nonzero write bulk status received: %d\n", __func__, 798 status); 799 } 800 801 dev->interrupt_out_busy = 0; 802 wake_up_interruptible(&dev->write_wait); 803 } 804 805 806 /** 807 * tower_probe 808 * 809 * Called by the usb core when a new device is connected that it thinks 810 * this driver might be interested in. 811 */ 812 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) 813 { 814 struct device *idev = &interface->dev; 815 struct usb_device *udev = interface_to_usbdev(interface); 816 struct lego_usb_tower *dev = NULL; 817 struct tower_get_version_reply *get_version_reply = NULL; 818 int retval = -ENOMEM; 819 int result; 820 821 /* allocate memory for our device state and initialize it */ 822 823 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL); 824 825 if (!dev) 826 goto exit; 827 828 mutex_init(&dev->lock); 829 830 dev->udev = udev; 831 dev->open_count = 0; 832 833 dev->read_buffer = NULL; 834 dev->read_buffer_length = 0; 835 dev->read_packet_length = 0; 836 spin_lock_init (&dev->read_buffer_lock); 837 dev->packet_timeout_jiffies = msecs_to_jiffies(packet_timeout); 838 dev->read_last_arrival = jiffies; 839 840 init_waitqueue_head (&dev->read_wait); 841 init_waitqueue_head (&dev->write_wait); 842 843 dev->interrupt_in_buffer = NULL; 844 dev->interrupt_in_endpoint = NULL; 845 dev->interrupt_in_urb = NULL; 846 dev->interrupt_in_running = 0; 847 dev->interrupt_in_done = 0; 848 849 dev->interrupt_out_buffer = NULL; 850 dev->interrupt_out_endpoint = NULL; 851 dev->interrupt_out_urb = NULL; 852 dev->interrupt_out_busy = 0; 853 854 result = usb_find_common_endpoints_reverse(interface->cur_altsetting, 855 NULL, NULL, 856 &dev->interrupt_in_endpoint, 857 &dev->interrupt_out_endpoint); 858 if (result) { 859 dev_err(idev, "interrupt endpoints not found\n"); 860 retval = result; 861 goto error; 862 } 863 864 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); 865 if (!dev->read_buffer) 866 goto error; 867 dev->interrupt_in_buffer = kmalloc (usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL); 868 if (!dev->interrupt_in_buffer) 869 goto error; 870 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 871 if (!dev->interrupt_in_urb) 872 goto error; 873 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL); 874 if (!dev->interrupt_out_buffer) 875 goto error; 876 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 877 if (!dev->interrupt_out_urb) 878 goto error; 879 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 880 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 881 882 get_version_reply = kmalloc(sizeof(*get_version_reply), GFP_KERNEL); 883 884 if (!get_version_reply) { 885 retval = -ENOMEM; 886 goto error; 887 } 888 889 /* get the firmware version and log it */ 890 result = usb_control_msg (udev, 891 usb_rcvctrlpipe(udev, 0), 892 LEGO_USB_TOWER_REQUEST_GET_VERSION, 893 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 894 0, 895 0, 896 get_version_reply, 897 sizeof(*get_version_reply), 898 1000); 899 if (result < 0) { 900 dev_err(idev, "LEGO USB Tower get version control request failed\n"); 901 retval = result; 902 goto error; 903 } 904 dev_info(&interface->dev, 905 "LEGO USB Tower firmware version is %d.%d build %d\n", 906 get_version_reply->major, 907 get_version_reply->minor, 908 le16_to_cpu(get_version_reply->build_no)); 909 910 /* we can register the device now, as it is ready */ 911 usb_set_intfdata (interface, dev); 912 913 retval = usb_register_dev (interface, &tower_class); 914 915 if (retval) { 916 /* something prevented us from registering this driver */ 917 dev_err(idev, "Not able to get a minor for this device.\n"); 918 usb_set_intfdata (interface, NULL); 919 goto error; 920 } 921 dev->minor = interface->minor; 922 923 /* let the user know what node this device is now attached to */ 924 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major " 925 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), 926 USB_MAJOR, dev->minor); 927 928 exit: 929 kfree(get_version_reply); 930 return retval; 931 932 error: 933 kfree(get_version_reply); 934 tower_delete(dev); 935 return retval; 936 } 937 938 939 /** 940 * tower_disconnect 941 * 942 * Called by the usb core when the device is removed from the system. 943 */ 944 static void tower_disconnect (struct usb_interface *interface) 945 { 946 struct lego_usb_tower *dev; 947 int minor; 948 949 dev = usb_get_intfdata (interface); 950 mutex_lock(&open_disc_mutex); 951 usb_set_intfdata (interface, NULL); 952 953 minor = dev->minor; 954 955 /* give back our minor */ 956 usb_deregister_dev (interface, &tower_class); 957 958 mutex_lock(&dev->lock); 959 mutex_unlock(&open_disc_mutex); 960 961 /* if the device is not opened, then we clean up right now */ 962 if (!dev->open_count) { 963 mutex_unlock(&dev->lock); 964 tower_delete (dev); 965 } else { 966 dev->udev = NULL; 967 /* wake up pollers */ 968 wake_up_interruptible_all(&dev->read_wait); 969 wake_up_interruptible_all(&dev->write_wait); 970 mutex_unlock(&dev->lock); 971 } 972 973 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n", 974 (minor - LEGO_USB_TOWER_MINOR_BASE)); 975 } 976 977 module_usb_driver(tower_driver); 978 979 MODULE_AUTHOR(DRIVER_AUTHOR); 980 MODULE_DESCRIPTION(DRIVER_DESC); 981 #ifdef MODULE_LICENSE 982 MODULE_LICENSE("GPL"); 983 #endif 984