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 __FUNCTION__ 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 __FUNCTION__ 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 #include <linux/kernel.h> 79 #include <linux/errno.h> 80 #include <linux/init.h> 81 #include <linux/slab.h> 82 #include <linux/module.h> 83 #include <linux/completion.h> 84 #include <linux/mutex.h> 85 #include <asm/uaccess.h> 86 #include <linux/usb.h> 87 #include <linux/poll.h> 88 89 90 #ifdef CONFIG_USB_DEBUG 91 static int debug = 4; 92 #else 93 static int debug = 0; 94 #endif 95 96 /* Use our own dbg macro */ 97 #undef dbg 98 #define dbg(lvl, format, arg...) do { if (debug >= lvl) printk(KERN_DEBUG __FILE__ ": " format "\n", ## arg); } while (0) 99 100 101 /* Version Information */ 102 #define DRIVER_VERSION "v0.96" 103 #define DRIVER_AUTHOR "Juergen Stuber <starblue@sourceforge.net>" 104 #define DRIVER_DESC "LEGO USB Tower Driver" 105 106 /* Module parameters */ 107 module_param(debug, int, S_IRUGO | S_IWUSR); 108 MODULE_PARM_DESC(debug, "Debug enabled or not"); 109 110 /* The defaults are chosen to work with the latest versions of leJOS and NQC. 111 */ 112 113 /* Some legacy software likes to receive packets in one piece. 114 * In this case read_buffer_size should exceed the maximal packet length 115 * (417 for datalog uploads), and packet_timeout should be set. 116 */ 117 static int read_buffer_size = 480; 118 module_param(read_buffer_size, int, 0); 119 MODULE_PARM_DESC(read_buffer_size, "Read buffer size"); 120 121 /* Some legacy software likes to send packets in one piece. 122 * In this case write_buffer_size should exceed the maximal packet length 123 * (417 for firmware and program downloads). 124 * A problem with long writes is that the following read may time out 125 * if the software is not prepared to wait long enough. 126 */ 127 static int write_buffer_size = 480; 128 module_param(write_buffer_size, int, 0); 129 MODULE_PARM_DESC(write_buffer_size, "Write buffer size"); 130 131 /* Some legacy software expects reads to contain whole LASM packets. 132 * To achieve this, characters which arrive before a packet timeout 133 * occurs will be returned in a single read operation. 134 * A problem with long reads is that the software may time out 135 * if it is not prepared to wait long enough. 136 * The packet timeout should be greater than the time between the 137 * reception of subsequent characters, which should arrive about 138 * every 5ms for the standard 2400 baud. 139 * Set it to 0 to disable. 140 */ 141 static int packet_timeout = 50; 142 module_param(packet_timeout, int, 0); 143 MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms"); 144 145 /* Some legacy software expects blocking reads to time out. 146 * Timeout occurs after the specified time of read and write inactivity. 147 * Set it to 0 to disable. 148 */ 149 static int read_timeout = 200; 150 module_param(read_timeout, int, 0); 151 MODULE_PARM_DESC(read_timeout, "Read timeout in ms"); 152 153 /* As of kernel version 2.6.4 ehci-hcd uses an 154 * "only one interrupt transfer per frame" shortcut 155 * to simplify the scheduling of periodic transfers. 156 * This conflicts with our standard 1ms intervals for in and out URBs. 157 * We use default intervals of 2ms for in and 8ms for out transfers, 158 * which is fast enough for 2400 baud and allows a small additional load. 159 * Increase the interval to allow more devices that do interrupt transfers, 160 * or set to 0 to use the standard interval from the endpoint descriptors. 161 */ 162 static int interrupt_in_interval = 2; 163 module_param(interrupt_in_interval, int, 0); 164 MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms"); 165 166 static int interrupt_out_interval = 8; 167 module_param(interrupt_out_interval, int, 0); 168 MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms"); 169 170 /* Define these values to match your device */ 171 #define LEGO_USB_TOWER_VENDOR_ID 0x0694 172 #define LEGO_USB_TOWER_PRODUCT_ID 0x0001 173 174 /* Vendor requests */ 175 #define LEGO_USB_TOWER_REQUEST_RESET 0x04 176 #define LEGO_USB_TOWER_REQUEST_GET_VERSION 0xFD 177 178 struct tower_reset_reply { 179 __le16 size; /* little-endian */ 180 __u8 err_code; 181 __u8 spare; 182 } __attribute__ ((packed)); 183 184 struct tower_get_version_reply { 185 __le16 size; /* little-endian */ 186 __u8 err_code; 187 __u8 spare; 188 __u8 major; 189 __u8 minor; 190 __le16 build_no; /* little-endian */ 191 } __attribute__ ((packed)); 192 193 194 /* table of devices that work with this driver */ 195 static struct usb_device_id tower_table [] = { 196 { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) }, 197 { } /* Terminating entry */ 198 }; 199 200 MODULE_DEVICE_TABLE (usb, tower_table); 201 202 #define LEGO_USB_TOWER_MINOR_BASE 160 203 204 205 /* Structure to hold all of our device specific stuff */ 206 struct lego_usb_tower { 207 struct semaphore sem; /* locks this structure */ 208 struct usb_device* udev; /* save off the usb device pointer */ 209 unsigned char minor; /* the starting minor number for this device */ 210 211 int open_count; /* number of times this port has been opened */ 212 213 char* read_buffer; 214 size_t read_buffer_length; /* this much came in */ 215 size_t read_packet_length; /* this much will be returned on read */ 216 spinlock_t read_buffer_lock; 217 int packet_timeout_jiffies; 218 unsigned long read_last_arrival; 219 220 wait_queue_head_t read_wait; 221 wait_queue_head_t write_wait; 222 223 char* interrupt_in_buffer; 224 struct usb_endpoint_descriptor* interrupt_in_endpoint; 225 struct urb* interrupt_in_urb; 226 int interrupt_in_interval; 227 int interrupt_in_running; 228 int interrupt_in_done; 229 230 char* interrupt_out_buffer; 231 struct usb_endpoint_descriptor* interrupt_out_endpoint; 232 struct urb* interrupt_out_urb; 233 int interrupt_out_interval; 234 int interrupt_out_busy; 235 236 }; 237 238 239 /* local function prototypes */ 240 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos); 241 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos); 242 static inline void tower_delete (struct lego_usb_tower *dev); 243 static int tower_open (struct inode *inode, struct file *file); 244 static int tower_release (struct inode *inode, struct file *file); 245 static unsigned int tower_poll (struct file *file, poll_table *wait); 246 static loff_t tower_llseek (struct file *file, loff_t off, int whence); 247 248 static void tower_abort_transfers (struct lego_usb_tower *dev); 249 static void tower_check_for_read_packet (struct lego_usb_tower *dev); 250 static void tower_interrupt_in_callback (struct urb *urb); 251 static void tower_interrupt_out_callback (struct urb *urb); 252 253 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id); 254 static void tower_disconnect (struct usb_interface *interface); 255 256 257 /* prevent races between open() and disconnect */ 258 static DEFINE_MUTEX (disconnect_mutex); 259 260 /* file operations needed when we register this driver */ 261 static const struct file_operations tower_fops = { 262 .owner = THIS_MODULE, 263 .read = tower_read, 264 .write = tower_write, 265 .open = tower_open, 266 .release = tower_release, 267 .poll = tower_poll, 268 .llseek = tower_llseek, 269 }; 270 271 /* 272 * usb class driver info in order to get a minor number from the usb core, 273 * and to have the device registered with the driver core 274 */ 275 static struct usb_class_driver tower_class = { 276 .name = "legousbtower%d", 277 .fops = &tower_fops, 278 .minor_base = LEGO_USB_TOWER_MINOR_BASE, 279 }; 280 281 282 /* usb specific object needed to register this driver with the usb subsystem */ 283 static struct usb_driver tower_driver = { 284 .name = "legousbtower", 285 .probe = tower_probe, 286 .disconnect = tower_disconnect, 287 .id_table = tower_table, 288 }; 289 290 291 /** 292 * lego_usb_tower_debug_data 293 */ 294 static inline void lego_usb_tower_debug_data (int level, const char *function, int size, const unsigned char *data) 295 { 296 int i; 297 298 if (debug < level) 299 return; 300 301 printk (KERN_DEBUG __FILE__": %s - length = %d, data = ", function, size); 302 for (i = 0; i < size; ++i) { 303 printk ("%.2x ", data[i]); 304 } 305 printk ("\n"); 306 } 307 308 309 /** 310 * tower_delete 311 */ 312 static inline void tower_delete (struct lego_usb_tower *dev) 313 { 314 dbg(2, "%s: enter", __FUNCTION__); 315 316 tower_abort_transfers (dev); 317 318 /* free data structures */ 319 usb_free_urb(dev->interrupt_in_urb); 320 usb_free_urb(dev->interrupt_out_urb); 321 kfree (dev->read_buffer); 322 kfree (dev->interrupt_in_buffer); 323 kfree (dev->interrupt_out_buffer); 324 kfree (dev); 325 326 dbg(2, "%s: leave", __FUNCTION__); 327 } 328 329 330 /** 331 * tower_open 332 */ 333 static int tower_open (struct inode *inode, struct file *file) 334 { 335 struct lego_usb_tower *dev = NULL; 336 int subminor; 337 int retval = 0; 338 struct usb_interface *interface; 339 struct tower_reset_reply reset_reply; 340 int result; 341 342 dbg(2, "%s: enter", __FUNCTION__); 343 344 nonseekable_open(inode, file); 345 subminor = iminor(inode); 346 347 mutex_lock (&disconnect_mutex); 348 349 interface = usb_find_interface (&tower_driver, subminor); 350 351 if (!interface) { 352 err ("%s - error, can't find device for minor %d", 353 __FUNCTION__, subminor); 354 retval = -ENODEV; 355 goto unlock_disconnect_exit; 356 } 357 358 dev = usb_get_intfdata(interface); 359 360 if (!dev) { 361 retval = -ENODEV; 362 goto unlock_disconnect_exit; 363 } 364 365 /* lock this device */ 366 if (down_interruptible (&dev->sem)) { 367 retval = -ERESTARTSYS; 368 goto unlock_disconnect_exit; 369 } 370 371 /* allow opening only once */ 372 if (dev->open_count) { 373 retval = -EBUSY; 374 goto unlock_exit; 375 } 376 dev->open_count = 1; 377 378 /* reset the tower */ 379 result = usb_control_msg (dev->udev, 380 usb_rcvctrlpipe(dev->udev, 0), 381 LEGO_USB_TOWER_REQUEST_RESET, 382 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 383 0, 384 0, 385 &reset_reply, 386 sizeof(reset_reply), 387 1000); 388 if (result < 0) { 389 err("LEGO USB Tower reset control request failed"); 390 retval = result; 391 goto unlock_exit; 392 } 393 394 /* initialize in direction */ 395 dev->read_buffer_length = 0; 396 dev->read_packet_length = 0; 397 usb_fill_int_urb (dev->interrupt_in_urb, 398 dev->udev, 399 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress), 400 dev->interrupt_in_buffer, 401 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), 402 tower_interrupt_in_callback, 403 dev, 404 dev->interrupt_in_interval); 405 406 dev->interrupt_in_running = 1; 407 dev->interrupt_in_done = 0; 408 mb(); 409 410 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL); 411 if (retval) { 412 err("Couldn't submit interrupt_in_urb %d", retval); 413 dev->interrupt_in_running = 0; 414 dev->open_count = 0; 415 goto unlock_exit; 416 } 417 418 /* save device in the file's private structure */ 419 file->private_data = dev; 420 421 unlock_exit: 422 up (&dev->sem); 423 424 unlock_disconnect_exit: 425 mutex_unlock (&disconnect_mutex); 426 427 dbg(2, "%s: leave, return value %d ", __FUNCTION__, retval); 428 429 return retval; 430 } 431 432 /** 433 * tower_release 434 */ 435 static int tower_release (struct inode *inode, struct file *file) 436 { 437 struct lego_usb_tower *dev; 438 int retval = 0; 439 440 dbg(2, "%s: enter", __FUNCTION__); 441 442 dev = (struct lego_usb_tower *)file->private_data; 443 444 if (dev == NULL) { 445 dbg(1, "%s: object is NULL", __FUNCTION__); 446 retval = -ENODEV; 447 goto exit; 448 } 449 450 if (down_interruptible (&dev->sem)) { 451 retval = -ERESTARTSYS; 452 goto exit; 453 } 454 455 if (dev->open_count != 1) { 456 dbg(1, "%s: device not opened exactly once", __FUNCTION__); 457 retval = -ENODEV; 458 goto unlock_exit; 459 } 460 if (dev->udev == NULL) { 461 /* the device was unplugged before the file was released */ 462 up (&dev->sem); /* unlock here as tower_delete frees dev */ 463 tower_delete (dev); 464 goto exit; 465 } 466 467 /* wait until write transfer is finished */ 468 if (dev->interrupt_out_busy) { 469 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 470 } 471 tower_abort_transfers (dev); 472 dev->open_count = 0; 473 474 unlock_exit: 475 up (&dev->sem); 476 477 exit: 478 dbg(2, "%s: leave, return value %d", __FUNCTION__, retval); 479 return retval; 480 } 481 482 483 /** 484 * tower_abort_transfers 485 * aborts transfers and frees associated data structures 486 */ 487 static void tower_abort_transfers (struct lego_usb_tower *dev) 488 { 489 dbg(2, "%s: enter", __FUNCTION__); 490 491 if (dev == NULL) { 492 dbg(1, "%s: dev is null", __FUNCTION__); 493 goto exit; 494 } 495 496 /* shutdown transfer */ 497 if (dev->interrupt_in_running) { 498 dev->interrupt_in_running = 0; 499 mb(); 500 if (dev->udev) 501 usb_kill_urb (dev->interrupt_in_urb); 502 } 503 if (dev->interrupt_out_busy && dev->udev) 504 usb_kill_urb(dev->interrupt_out_urb); 505 506 exit: 507 dbg(2, "%s: leave", __FUNCTION__); 508 } 509 510 511 /** 512 * tower_check_for_read_packet 513 * 514 * To get correct semantics for signals and non-blocking I/O 515 * with packetizing we pretend not to see any data in the read buffer 516 * until it has been there unchanged for at least 517 * dev->packet_timeout_jiffies, or until the buffer is full. 518 */ 519 static void tower_check_for_read_packet (struct lego_usb_tower *dev) 520 { 521 spin_lock_irq (&dev->read_buffer_lock); 522 if (!packet_timeout 523 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) 524 || dev->read_buffer_length == read_buffer_size) { 525 dev->read_packet_length = dev->read_buffer_length; 526 } 527 dev->interrupt_in_done = 0; 528 spin_unlock_irq (&dev->read_buffer_lock); 529 } 530 531 532 /** 533 * tower_poll 534 */ 535 static unsigned int tower_poll (struct file *file, poll_table *wait) 536 { 537 struct lego_usb_tower *dev; 538 unsigned int mask = 0; 539 540 dbg(2, "%s: enter", __FUNCTION__); 541 542 dev = file->private_data; 543 544 poll_wait(file, &dev->read_wait, wait); 545 poll_wait(file, &dev->write_wait, wait); 546 547 tower_check_for_read_packet(dev); 548 if (dev->read_packet_length > 0) { 549 mask |= POLLIN | POLLRDNORM; 550 } 551 if (!dev->interrupt_out_busy) { 552 mask |= POLLOUT | POLLWRNORM; 553 } 554 555 dbg(2, "%s: leave, mask = %d", __FUNCTION__, mask); 556 557 return mask; 558 } 559 560 561 /** 562 * tower_llseek 563 */ 564 static loff_t tower_llseek (struct file *file, loff_t off, int whence) 565 { 566 return -ESPIPE; /* unseekable */ 567 } 568 569 570 /** 571 * tower_read 572 */ 573 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 574 { 575 struct lego_usb_tower *dev; 576 size_t bytes_to_read; 577 int i; 578 int retval = 0; 579 unsigned long timeout = 0; 580 581 dbg(2, "%s: enter, count = %Zd", __FUNCTION__, count); 582 583 dev = (struct lego_usb_tower *)file->private_data; 584 585 /* lock this object */ 586 if (down_interruptible (&dev->sem)) { 587 retval = -ERESTARTSYS; 588 goto exit; 589 } 590 591 /* verify that the device wasn't unplugged */ 592 if (dev->udev == NULL) { 593 retval = -ENODEV; 594 err("No device or device unplugged %d", retval); 595 goto unlock_exit; 596 } 597 598 /* verify that we actually have some data to read */ 599 if (count == 0) { 600 dbg(1, "%s: read request of 0 bytes", __FUNCTION__); 601 goto unlock_exit; 602 } 603 604 if (read_timeout) { 605 timeout = jiffies + read_timeout * HZ / 1000; 606 } 607 608 /* wait for data */ 609 tower_check_for_read_packet (dev); 610 while (dev->read_packet_length == 0) { 611 if (file->f_flags & O_NONBLOCK) { 612 retval = -EAGAIN; 613 goto unlock_exit; 614 } 615 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 616 if (retval < 0) { 617 goto unlock_exit; 618 } 619 620 /* reset read timeout during read or write activity */ 621 if (read_timeout 622 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 623 timeout = jiffies + read_timeout * HZ / 1000; 624 } 625 /* check for read timeout */ 626 if (read_timeout && time_after (jiffies, timeout)) { 627 retval = -ETIMEDOUT; 628 goto unlock_exit; 629 } 630 tower_check_for_read_packet (dev); 631 } 632 633 /* copy the data from read_buffer into userspace */ 634 bytes_to_read = min(count, dev->read_packet_length); 635 636 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { 637 retval = -EFAULT; 638 goto unlock_exit; 639 } 640 641 spin_lock_irq (&dev->read_buffer_lock); 642 dev->read_buffer_length -= bytes_to_read; 643 dev->read_packet_length -= bytes_to_read; 644 for (i=0; i<dev->read_buffer_length; i++) { 645 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 646 } 647 spin_unlock_irq (&dev->read_buffer_lock); 648 649 retval = bytes_to_read; 650 651 unlock_exit: 652 /* unlock the device */ 653 up (&dev->sem); 654 655 exit: 656 dbg(2, "%s: leave, return value %d", __FUNCTION__, retval); 657 return retval; 658 } 659 660 661 /** 662 * tower_write 663 */ 664 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 665 { 666 struct lego_usb_tower *dev; 667 size_t bytes_to_write; 668 int retval = 0; 669 670 dbg(2, "%s: enter, count = %Zd", __FUNCTION__, count); 671 672 dev = (struct lego_usb_tower *)file->private_data; 673 674 /* lock this object */ 675 if (down_interruptible (&dev->sem)) { 676 retval = -ERESTARTSYS; 677 goto exit; 678 } 679 680 /* verify that the device wasn't unplugged */ 681 if (dev->udev == NULL) { 682 retval = -ENODEV; 683 err("No device or device unplugged %d", retval); 684 goto unlock_exit; 685 } 686 687 /* verify that we actually have some data to write */ 688 if (count == 0) { 689 dbg(1, "%s: write request of 0 bytes", __FUNCTION__); 690 goto unlock_exit; 691 } 692 693 /* wait until previous transfer is finished */ 694 while (dev->interrupt_out_busy) { 695 if (file->f_flags & O_NONBLOCK) { 696 retval = -EAGAIN; 697 goto unlock_exit; 698 } 699 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); 700 if (retval) { 701 goto unlock_exit; 702 } 703 } 704 705 /* write the data into interrupt_out_buffer from userspace */ 706 bytes_to_write = min_t(int, count, write_buffer_size); 707 dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __FUNCTION__, count, bytes_to_write); 708 709 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { 710 retval = -EFAULT; 711 goto unlock_exit; 712 } 713 714 /* send off the urb */ 715 usb_fill_int_urb(dev->interrupt_out_urb, 716 dev->udev, 717 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 718 dev->interrupt_out_buffer, 719 bytes_to_write, 720 tower_interrupt_out_callback, 721 dev, 722 dev->interrupt_out_interval); 723 724 dev->interrupt_out_busy = 1; 725 wmb(); 726 727 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); 728 if (retval) { 729 dev->interrupt_out_busy = 0; 730 err("Couldn't submit interrupt_out_urb %d", retval); 731 goto unlock_exit; 732 } 733 retval = bytes_to_write; 734 735 unlock_exit: 736 /* unlock the device */ 737 up (&dev->sem); 738 739 exit: 740 dbg(2, "%s: leave, return value %d", __FUNCTION__, retval); 741 742 return retval; 743 } 744 745 746 /** 747 * tower_interrupt_in_callback 748 */ 749 static void tower_interrupt_in_callback (struct urb *urb) 750 { 751 struct lego_usb_tower *dev = (struct lego_usb_tower *)urb->context; 752 int retval; 753 754 dbg(4, "%s: enter, status %d", __FUNCTION__, urb->status); 755 756 lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer); 757 758 if (urb->status) { 759 if (urb->status == -ENOENT || 760 urb->status == -ECONNRESET || 761 urb->status == -ESHUTDOWN) { 762 goto exit; 763 } else { 764 dbg(1, "%s: nonzero status received: %d", __FUNCTION__, urb->status); 765 goto resubmit; /* maybe we can recover */ 766 } 767 } 768 769 if (urb->actual_length > 0) { 770 spin_lock (&dev->read_buffer_lock); 771 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 772 memcpy (dev->read_buffer + dev->read_buffer_length, 773 dev->interrupt_in_buffer, 774 urb->actual_length); 775 dev->read_buffer_length += urb->actual_length; 776 dev->read_last_arrival = jiffies; 777 dbg(3, "%s: received %d bytes", __FUNCTION__, urb->actual_length); 778 } else { 779 printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __FUNCTION__, urb->actual_length); 780 } 781 spin_unlock (&dev->read_buffer_lock); 782 } 783 784 resubmit: 785 /* resubmit if we're still running */ 786 if (dev->interrupt_in_running && dev->udev) { 787 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); 788 if (retval) { 789 err("%s: usb_submit_urb failed (%d)", __FUNCTION__, retval); 790 } 791 } 792 793 exit: 794 dev->interrupt_in_done = 1; 795 wake_up_interruptible (&dev->read_wait); 796 797 lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer); 798 dbg(4, "%s: leave, status %d", __FUNCTION__, urb->status); 799 } 800 801 802 /** 803 * tower_interrupt_out_callback 804 */ 805 static void tower_interrupt_out_callback (struct urb *urb) 806 { 807 struct lego_usb_tower *dev = (struct lego_usb_tower *)urb->context; 808 809 dbg(4, "%s: enter, status %d", __FUNCTION__, urb->status); 810 lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer); 811 812 /* sync/async unlink faults aren't errors */ 813 if (urb->status && !(urb->status == -ENOENT || 814 urb->status == -ECONNRESET || 815 urb->status == -ESHUTDOWN)) { 816 dbg(1, "%s - nonzero write bulk status received: %d", 817 __FUNCTION__, urb->status); 818 } 819 820 dev->interrupt_out_busy = 0; 821 wake_up_interruptible(&dev->write_wait); 822 823 lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer); 824 dbg(4, "%s: leave, status %d", __FUNCTION__, urb->status); 825 } 826 827 828 /** 829 * tower_probe 830 * 831 * Called by the usb core when a new device is connected that it thinks 832 * this driver might be interested in. 833 */ 834 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) 835 { 836 struct usb_device *udev = interface_to_usbdev(interface); 837 struct lego_usb_tower *dev = NULL; 838 struct usb_host_interface *iface_desc; 839 struct usb_endpoint_descriptor* endpoint; 840 struct tower_get_version_reply get_version_reply; 841 int i; 842 int retval = -ENOMEM; 843 int result; 844 845 dbg(2, "%s: enter", __FUNCTION__); 846 847 if (udev == NULL) { 848 info ("udev is NULL."); 849 } 850 851 /* allocate memory for our device state and initialize it */ 852 853 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL); 854 855 if (dev == NULL) { 856 err ("Out of memory"); 857 goto exit; 858 } 859 860 init_MUTEX (&dev->sem); 861 862 dev->udev = udev; 863 dev->open_count = 0; 864 865 dev->read_buffer = NULL; 866 dev->read_buffer_length = 0; 867 dev->read_packet_length = 0; 868 spin_lock_init (&dev->read_buffer_lock); 869 dev->packet_timeout_jiffies = packet_timeout * HZ / 1000; 870 dev->read_last_arrival = jiffies; 871 872 init_waitqueue_head (&dev->read_wait); 873 init_waitqueue_head (&dev->write_wait); 874 875 dev->interrupt_in_buffer = NULL; 876 dev->interrupt_in_endpoint = NULL; 877 dev->interrupt_in_urb = NULL; 878 dev->interrupt_in_running = 0; 879 dev->interrupt_in_done = 0; 880 881 dev->interrupt_out_buffer = NULL; 882 dev->interrupt_out_endpoint = NULL; 883 dev->interrupt_out_urb = NULL; 884 dev->interrupt_out_busy = 0; 885 886 iface_desc = interface->cur_altsetting; 887 888 /* set up the endpoint information */ 889 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 890 endpoint = &iface_desc->endpoint[i].desc; 891 892 if (usb_endpoint_xfer_int(endpoint)) { 893 if (usb_endpoint_dir_in(endpoint)) 894 dev->interrupt_in_endpoint = endpoint; 895 else 896 dev->interrupt_out_endpoint = endpoint; 897 } 898 } 899 if(dev->interrupt_in_endpoint == NULL) { 900 err("interrupt in endpoint not found"); 901 goto error; 902 } 903 if (dev->interrupt_out_endpoint == NULL) { 904 err("interrupt out endpoint not found"); 905 goto error; 906 } 907 908 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); 909 if (!dev->read_buffer) { 910 err("Couldn't allocate read_buffer"); 911 goto error; 912 } 913 dev->interrupt_in_buffer = kmalloc (le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), GFP_KERNEL); 914 if (!dev->interrupt_in_buffer) { 915 err("Couldn't allocate interrupt_in_buffer"); 916 goto error; 917 } 918 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 919 if (!dev->interrupt_in_urb) { 920 err("Couldn't allocate interrupt_in_urb"); 921 goto error; 922 } 923 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL); 924 if (!dev->interrupt_out_buffer) { 925 err("Couldn't allocate interrupt_out_buffer"); 926 goto error; 927 } 928 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 929 if (!dev->interrupt_out_urb) { 930 err("Couldn't allocate interrupt_out_urb"); 931 goto error; 932 } 933 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 934 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 935 936 /* we can register the device now, as it is ready */ 937 usb_set_intfdata (interface, dev); 938 939 retval = usb_register_dev (interface, &tower_class); 940 941 if (retval) { 942 /* something prevented us from registering this driver */ 943 err ("Not able to get a minor for this device."); 944 usb_set_intfdata (interface, NULL); 945 goto error; 946 } 947 dev->minor = interface->minor; 948 949 /* let the user know what node this device is now attached to */ 950 info ("LEGO USB Tower #%d now attached to major %d minor %d", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), USB_MAJOR, dev->minor); 951 952 /* get the firmware version and log it */ 953 result = usb_control_msg (udev, 954 usb_rcvctrlpipe(udev, 0), 955 LEGO_USB_TOWER_REQUEST_GET_VERSION, 956 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 957 0, 958 0, 959 &get_version_reply, 960 sizeof(get_version_reply), 961 1000); 962 if (result < 0) { 963 err("LEGO USB Tower get version control request failed"); 964 retval = result; 965 goto error; 966 } 967 info("LEGO USB Tower firmware version is %d.%d build %d", 968 get_version_reply.major, 969 get_version_reply.minor, 970 le16_to_cpu(get_version_reply.build_no)); 971 972 973 exit: 974 dbg(2, "%s: leave, return value 0x%.8lx (dev)", __FUNCTION__, (long) dev); 975 976 return retval; 977 978 error: 979 tower_delete(dev); 980 return retval; 981 } 982 983 984 /** 985 * tower_disconnect 986 * 987 * Called by the usb core when the device is removed from the system. 988 */ 989 static void tower_disconnect (struct usb_interface *interface) 990 { 991 struct lego_usb_tower *dev; 992 int minor; 993 994 dbg(2, "%s: enter", __FUNCTION__); 995 996 mutex_lock (&disconnect_mutex); 997 998 dev = usb_get_intfdata (interface); 999 usb_set_intfdata (interface, NULL); 1000 1001 1002 down (&dev->sem); 1003 1004 minor = dev->minor; 1005 1006 /* give back our minor */ 1007 usb_deregister_dev (interface, &tower_class); 1008 1009 /* if the device is not opened, then we clean up right now */ 1010 if (!dev->open_count) { 1011 up (&dev->sem); 1012 tower_delete (dev); 1013 } else { 1014 dev->udev = NULL; 1015 up (&dev->sem); 1016 } 1017 1018 mutex_unlock (&disconnect_mutex); 1019 1020 info("LEGO USB Tower #%d now disconnected", (minor - LEGO_USB_TOWER_MINOR_BASE)); 1021 1022 dbg(2, "%s: leave", __FUNCTION__); 1023 } 1024 1025 1026 1027 /** 1028 * lego_usb_tower_init 1029 */ 1030 static int __init lego_usb_tower_init(void) 1031 { 1032 int result; 1033 int retval = 0; 1034 1035 dbg(2, "%s: enter", __FUNCTION__); 1036 1037 /* register this driver with the USB subsystem */ 1038 result = usb_register(&tower_driver); 1039 if (result < 0) { 1040 err("usb_register failed for the "__FILE__" driver. Error number %d", result); 1041 retval = -1; 1042 goto exit; 1043 } 1044 1045 info(DRIVER_DESC " " DRIVER_VERSION); 1046 1047 exit: 1048 dbg(2, "%s: leave, return value %d", __FUNCTION__, retval); 1049 1050 return retval; 1051 } 1052 1053 1054 /** 1055 * lego_usb_tower_exit 1056 */ 1057 static void __exit lego_usb_tower_exit(void) 1058 { 1059 dbg(2, "%s: enter", __FUNCTION__); 1060 1061 /* deregister this driver with the USB subsystem */ 1062 usb_deregister (&tower_driver); 1063 1064 dbg(2, "%s: leave", __FUNCTION__); 1065 } 1066 1067 module_init (lego_usb_tower_init); 1068 module_exit (lego_usb_tower_exit); 1069 1070 MODULE_AUTHOR(DRIVER_AUTHOR); 1071 MODULE_DESCRIPTION(DRIVER_DESC); 1072 #ifdef MODULE_LICENSE 1073 MODULE_LICENSE("GPL"); 1074 #endif 1075