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/smp_lock.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 #ifdef CONFIG_USB_DEBUG 92 static int debug = 4; 93 #else 94 static int debug = 0; 95 #endif 96 97 /* Use our own dbg macro */ 98 #undef dbg 99 #define dbg(lvl, format, arg...) do { if (debug >= lvl) printk(KERN_DEBUG __FILE__ ": " format "\n", ## arg); } while (0) 100 101 102 /* Version Information */ 103 #define DRIVER_VERSION "v0.96" 104 #define DRIVER_AUTHOR "Juergen Stuber <starblue@sourceforge.net>" 105 #define DRIVER_DESC "LEGO USB Tower Driver" 106 107 /* Module parameters */ 108 module_param(debug, int, S_IRUGO | S_IWUSR); 109 MODULE_PARM_DESC(debug, "Debug enabled or not"); 110 111 /* The defaults are chosen to work with the latest versions of leJOS and NQC. 112 */ 113 114 /* Some legacy software likes to receive packets in one piece. 115 * In this case read_buffer_size should exceed the maximal packet length 116 * (417 for datalog uploads), and packet_timeout should be set. 117 */ 118 static int read_buffer_size = 480; 119 module_param(read_buffer_size, int, 0); 120 MODULE_PARM_DESC(read_buffer_size, "Read buffer size"); 121 122 /* Some legacy software likes to send packets in one piece. 123 * In this case write_buffer_size should exceed the maximal packet length 124 * (417 for firmware and program downloads). 125 * A problem with long writes is that the following read may time out 126 * if the software is not prepared to wait long enough. 127 */ 128 static int write_buffer_size = 480; 129 module_param(write_buffer_size, int, 0); 130 MODULE_PARM_DESC(write_buffer_size, "Write buffer size"); 131 132 /* Some legacy software expects reads to contain whole LASM packets. 133 * To achieve this, characters which arrive before a packet timeout 134 * occurs will be returned in a single read operation. 135 * A problem with long reads is that the software may time out 136 * if it is not prepared to wait long enough. 137 * The packet timeout should be greater than the time between the 138 * reception of subsequent characters, which should arrive about 139 * every 5ms for the standard 2400 baud. 140 * Set it to 0 to disable. 141 */ 142 static int packet_timeout = 50; 143 module_param(packet_timeout, int, 0); 144 MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms"); 145 146 /* Some legacy software expects blocking reads to time out. 147 * Timeout occurs after the specified time of read and write inactivity. 148 * Set it to 0 to disable. 149 */ 150 static int read_timeout = 200; 151 module_param(read_timeout, int, 0); 152 MODULE_PARM_DESC(read_timeout, "Read timeout in ms"); 153 154 /* As of kernel version 2.6.4 ehci-hcd uses an 155 * "only one interrupt transfer per frame" shortcut 156 * to simplify the scheduling of periodic transfers. 157 * This conflicts with our standard 1ms intervals for in and out URBs. 158 * We use default intervals of 2ms for in and 8ms for out transfers, 159 * which is fast enough for 2400 baud and allows a small additional load. 160 * Increase the interval to allow more devices that do interrupt transfers, 161 * or set to 0 to use the standard interval from the endpoint descriptors. 162 */ 163 static int interrupt_in_interval = 2; 164 module_param(interrupt_in_interval, int, 0); 165 MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms"); 166 167 static int interrupt_out_interval = 8; 168 module_param(interrupt_out_interval, int, 0); 169 MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms"); 170 171 /* Define these values to match your device */ 172 #define LEGO_USB_TOWER_VENDOR_ID 0x0694 173 #define LEGO_USB_TOWER_PRODUCT_ID 0x0001 174 175 /* Vendor requests */ 176 #define LEGO_USB_TOWER_REQUEST_RESET 0x04 177 #define LEGO_USB_TOWER_REQUEST_GET_VERSION 0xFD 178 179 struct tower_reset_reply { 180 __le16 size; /* little-endian */ 181 __u8 err_code; 182 __u8 spare; 183 } __attribute__ ((packed)); 184 185 struct tower_get_version_reply { 186 __le16 size; /* little-endian */ 187 __u8 err_code; 188 __u8 spare; 189 __u8 major; 190 __u8 minor; 191 __le16 build_no; /* little-endian */ 192 } __attribute__ ((packed)); 193 194 195 /* table of devices that work with this driver */ 196 static struct usb_device_id tower_table [] = { 197 { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) }, 198 { } /* Terminating entry */ 199 }; 200 201 MODULE_DEVICE_TABLE (usb, tower_table); 202 203 #define LEGO_USB_TOWER_MINOR_BASE 160 204 205 206 /* Structure to hold all of our device specific stuff */ 207 struct lego_usb_tower { 208 struct semaphore sem; /* locks this structure */ 209 struct usb_device* udev; /* save off the usb device pointer */ 210 unsigned char minor; /* the starting minor number for this device */ 211 212 int open_count; /* number of times this port has been opened */ 213 214 char* read_buffer; 215 size_t read_buffer_length; /* this much came in */ 216 size_t read_packet_length; /* this much will be returned on read */ 217 spinlock_t read_buffer_lock; 218 int packet_timeout_jiffies; 219 unsigned long read_last_arrival; 220 221 wait_queue_head_t read_wait; 222 wait_queue_head_t write_wait; 223 224 char* interrupt_in_buffer; 225 struct usb_endpoint_descriptor* interrupt_in_endpoint; 226 struct urb* interrupt_in_urb; 227 int interrupt_in_interval; 228 int interrupt_in_running; 229 int interrupt_in_done; 230 231 char* interrupt_out_buffer; 232 struct usb_endpoint_descriptor* interrupt_out_endpoint; 233 struct urb* interrupt_out_urb; 234 int interrupt_out_interval; 235 int interrupt_out_busy; 236 237 }; 238 239 240 /* local function prototypes */ 241 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos); 242 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos); 243 static inline void tower_delete (struct lego_usb_tower *dev); 244 static int tower_open (struct inode *inode, struct file *file); 245 static int tower_release (struct inode *inode, struct file *file); 246 static unsigned int tower_poll (struct file *file, poll_table *wait); 247 static loff_t tower_llseek (struct file *file, loff_t off, int whence); 248 249 static void tower_abort_transfers (struct lego_usb_tower *dev); 250 static void tower_check_for_read_packet (struct lego_usb_tower *dev); 251 static void tower_interrupt_in_callback (struct urb *urb); 252 static void tower_interrupt_out_callback (struct urb *urb); 253 254 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id); 255 static void tower_disconnect (struct usb_interface *interface); 256 257 258 /* prevent races between open() and disconnect */ 259 static DEFINE_MUTEX (disconnect_mutex); 260 261 /* file operations needed when we register this driver */ 262 static const struct file_operations tower_fops = { 263 .owner = THIS_MODULE, 264 .read = tower_read, 265 .write = tower_write, 266 .open = tower_open, 267 .release = tower_release, 268 .poll = tower_poll, 269 .llseek = tower_llseek, 270 }; 271 272 /* 273 * usb class driver info in order to get a minor number from the usb core, 274 * and to have the device registered with the driver core 275 */ 276 static struct usb_class_driver tower_class = { 277 .name = "legousbtower%d", 278 .fops = &tower_fops, 279 .minor_base = LEGO_USB_TOWER_MINOR_BASE, 280 }; 281 282 283 /* usb specific object needed to register this driver with the usb subsystem */ 284 static struct usb_driver tower_driver = { 285 .name = "legousbtower", 286 .probe = tower_probe, 287 .disconnect = tower_disconnect, 288 .id_table = tower_table, 289 }; 290 291 292 /** 293 * lego_usb_tower_debug_data 294 */ 295 static inline void lego_usb_tower_debug_data (int level, const char *function, int size, const unsigned char *data) 296 { 297 int i; 298 299 if (debug < level) 300 return; 301 302 printk (KERN_DEBUG __FILE__": %s - length = %d, data = ", function, size); 303 for (i = 0; i < size; ++i) { 304 printk ("%.2x ", data[i]); 305 } 306 printk ("\n"); 307 } 308 309 310 /** 311 * tower_delete 312 */ 313 static inline void tower_delete (struct lego_usb_tower *dev) 314 { 315 dbg(2, "%s: enter", __FUNCTION__); 316 317 tower_abort_transfers (dev); 318 319 /* free data structures */ 320 usb_free_urb(dev->interrupt_in_urb); 321 usb_free_urb(dev->interrupt_out_urb); 322 kfree (dev->read_buffer); 323 kfree (dev->interrupt_in_buffer); 324 kfree (dev->interrupt_out_buffer); 325 kfree (dev); 326 327 dbg(2, "%s: leave", __FUNCTION__); 328 } 329 330 331 /** 332 * tower_open 333 */ 334 static int tower_open (struct inode *inode, struct file *file) 335 { 336 struct lego_usb_tower *dev = NULL; 337 int subminor; 338 int retval = 0; 339 struct usb_interface *interface; 340 struct tower_reset_reply reset_reply; 341 int result; 342 343 dbg(2, "%s: enter", __FUNCTION__); 344 345 nonseekable_open(inode, file); 346 subminor = iminor(inode); 347 348 mutex_lock (&disconnect_mutex); 349 350 interface = usb_find_interface (&tower_driver, subminor); 351 352 if (!interface) { 353 err ("%s - error, can't find device for minor %d", 354 __FUNCTION__, subminor); 355 retval = -ENODEV; 356 goto unlock_disconnect_exit; 357 } 358 359 dev = usb_get_intfdata(interface); 360 361 if (!dev) { 362 retval = -ENODEV; 363 goto unlock_disconnect_exit; 364 } 365 366 /* lock this device */ 367 if (down_interruptible (&dev->sem)) { 368 retval = -ERESTARTSYS; 369 goto unlock_disconnect_exit; 370 } 371 372 /* allow opening only once */ 373 if (dev->open_count) { 374 retval = -EBUSY; 375 goto unlock_exit; 376 } 377 dev->open_count = 1; 378 379 /* reset the tower */ 380 result = usb_control_msg (dev->udev, 381 usb_rcvctrlpipe(dev->udev, 0), 382 LEGO_USB_TOWER_REQUEST_RESET, 383 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 384 0, 385 0, 386 &reset_reply, 387 sizeof(reset_reply), 388 1000); 389 if (result < 0) { 390 err("LEGO USB Tower reset control request failed"); 391 retval = result; 392 goto unlock_exit; 393 } 394 395 /* initialize in direction */ 396 dev->read_buffer_length = 0; 397 dev->read_packet_length = 0; 398 usb_fill_int_urb (dev->interrupt_in_urb, 399 dev->udev, 400 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress), 401 dev->interrupt_in_buffer, 402 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), 403 tower_interrupt_in_callback, 404 dev, 405 dev->interrupt_in_interval); 406 407 dev->interrupt_in_running = 1; 408 dev->interrupt_in_done = 0; 409 mb(); 410 411 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL); 412 if (retval) { 413 err("Couldn't submit interrupt_in_urb %d", retval); 414 dev->interrupt_in_running = 0; 415 dev->open_count = 0; 416 goto unlock_exit; 417 } 418 419 /* save device in the file's private structure */ 420 file->private_data = dev; 421 422 unlock_exit: 423 up (&dev->sem); 424 425 unlock_disconnect_exit: 426 mutex_unlock (&disconnect_mutex); 427 428 dbg(2, "%s: leave, return value %d ", __FUNCTION__, retval); 429 430 return retval; 431 } 432 433 /** 434 * tower_release 435 */ 436 static int tower_release (struct inode *inode, struct file *file) 437 { 438 struct lego_usb_tower *dev; 439 int retval = 0; 440 441 dbg(2, "%s: enter", __FUNCTION__); 442 443 dev = (struct lego_usb_tower *)file->private_data; 444 445 if (dev == NULL) { 446 dbg(1, "%s: object is NULL", __FUNCTION__); 447 retval = -ENODEV; 448 goto exit; 449 } 450 451 if (down_interruptible (&dev->sem)) { 452 retval = -ERESTARTSYS; 453 goto exit; 454 } 455 456 if (dev->open_count != 1) { 457 dbg(1, "%s: device not opened exactly once", __FUNCTION__); 458 retval = -ENODEV; 459 goto unlock_exit; 460 } 461 if (dev->udev == NULL) { 462 /* the device was unplugged before the file was released */ 463 up (&dev->sem); /* unlock here as tower_delete frees dev */ 464 tower_delete (dev); 465 goto exit; 466 } 467 468 /* wait until write transfer is finished */ 469 if (dev->interrupt_out_busy) { 470 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 471 } 472 tower_abort_transfers (dev); 473 dev->open_count = 0; 474 475 unlock_exit: 476 up (&dev->sem); 477 478 exit: 479 dbg(2, "%s: leave, return value %d", __FUNCTION__, retval); 480 return retval; 481 } 482 483 484 /** 485 * tower_abort_transfers 486 * aborts transfers and frees associated data structures 487 */ 488 static void tower_abort_transfers (struct lego_usb_tower *dev) 489 { 490 dbg(2, "%s: enter", __FUNCTION__); 491 492 if (dev == NULL) { 493 dbg(1, "%s: dev is null", __FUNCTION__); 494 goto exit; 495 } 496 497 /* shutdown transfer */ 498 if (dev->interrupt_in_running) { 499 dev->interrupt_in_running = 0; 500 mb(); 501 if (dev->udev) 502 usb_kill_urb (dev->interrupt_in_urb); 503 } 504 if (dev->interrupt_out_busy && dev->udev) 505 usb_kill_urb(dev->interrupt_out_urb); 506 507 exit: 508 dbg(2, "%s: leave", __FUNCTION__); 509 } 510 511 512 /** 513 * tower_check_for_read_packet 514 * 515 * To get correct semantics for signals and non-blocking I/O 516 * with packetizing we pretend not to see any data in the read buffer 517 * until it has been there unchanged for at least 518 * dev->packet_timeout_jiffies, or until the buffer is full. 519 */ 520 static void tower_check_for_read_packet (struct lego_usb_tower *dev) 521 { 522 spin_lock_irq (&dev->read_buffer_lock); 523 if (!packet_timeout 524 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) 525 || dev->read_buffer_length == read_buffer_size) { 526 dev->read_packet_length = dev->read_buffer_length; 527 } 528 dev->interrupt_in_done = 0; 529 spin_unlock_irq (&dev->read_buffer_lock); 530 } 531 532 533 /** 534 * tower_poll 535 */ 536 static unsigned int tower_poll (struct file *file, poll_table *wait) 537 { 538 struct lego_usb_tower *dev; 539 unsigned int mask = 0; 540 541 dbg(2, "%s: enter", __FUNCTION__); 542 543 dev = file->private_data; 544 545 poll_wait(file, &dev->read_wait, wait); 546 poll_wait(file, &dev->write_wait, wait); 547 548 tower_check_for_read_packet(dev); 549 if (dev->read_packet_length > 0) { 550 mask |= POLLIN | POLLRDNORM; 551 } 552 if (!dev->interrupt_out_busy) { 553 mask |= POLLOUT | POLLWRNORM; 554 } 555 556 dbg(2, "%s: leave, mask = %d", __FUNCTION__, mask); 557 558 return mask; 559 } 560 561 562 /** 563 * tower_llseek 564 */ 565 static loff_t tower_llseek (struct file *file, loff_t off, int whence) 566 { 567 return -ESPIPE; /* unseekable */ 568 } 569 570 571 /** 572 * tower_read 573 */ 574 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 575 { 576 struct lego_usb_tower *dev; 577 size_t bytes_to_read; 578 int i; 579 int retval = 0; 580 unsigned long timeout = 0; 581 582 dbg(2, "%s: enter, count = %Zd", __FUNCTION__, count); 583 584 dev = (struct lego_usb_tower *)file->private_data; 585 586 /* lock this object */ 587 if (down_interruptible (&dev->sem)) { 588 retval = -ERESTARTSYS; 589 goto exit; 590 } 591 592 /* verify that the device wasn't unplugged */ 593 if (dev->udev == NULL) { 594 retval = -ENODEV; 595 err("No device or device unplugged %d", retval); 596 goto unlock_exit; 597 } 598 599 /* verify that we actually have some data to read */ 600 if (count == 0) { 601 dbg(1, "%s: read request of 0 bytes", __FUNCTION__); 602 goto unlock_exit; 603 } 604 605 if (read_timeout) { 606 timeout = jiffies + read_timeout * HZ / 1000; 607 } 608 609 /* wait for data */ 610 tower_check_for_read_packet (dev); 611 while (dev->read_packet_length == 0) { 612 if (file->f_flags & O_NONBLOCK) { 613 retval = -EAGAIN; 614 goto unlock_exit; 615 } 616 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 617 if (retval < 0) { 618 goto unlock_exit; 619 } 620 621 /* reset read timeout during read or write activity */ 622 if (read_timeout 623 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 624 timeout = jiffies + read_timeout * HZ / 1000; 625 } 626 /* check for read timeout */ 627 if (read_timeout && time_after (jiffies, timeout)) { 628 retval = -ETIMEDOUT; 629 goto unlock_exit; 630 } 631 tower_check_for_read_packet (dev); 632 } 633 634 /* copy the data from read_buffer into userspace */ 635 bytes_to_read = min(count, dev->read_packet_length); 636 637 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { 638 retval = -EFAULT; 639 goto unlock_exit; 640 } 641 642 spin_lock_irq (&dev->read_buffer_lock); 643 dev->read_buffer_length -= bytes_to_read; 644 dev->read_packet_length -= bytes_to_read; 645 for (i=0; i<dev->read_buffer_length; i++) { 646 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 647 } 648 spin_unlock_irq (&dev->read_buffer_lock); 649 650 retval = bytes_to_read; 651 652 unlock_exit: 653 /* unlock the device */ 654 up (&dev->sem); 655 656 exit: 657 dbg(2, "%s: leave, return value %d", __FUNCTION__, retval); 658 return retval; 659 } 660 661 662 /** 663 * tower_write 664 */ 665 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 666 { 667 struct lego_usb_tower *dev; 668 size_t bytes_to_write; 669 int retval = 0; 670 671 dbg(2, "%s: enter, count = %Zd", __FUNCTION__, count); 672 673 dev = (struct lego_usb_tower *)file->private_data; 674 675 /* lock this object */ 676 if (down_interruptible (&dev->sem)) { 677 retval = -ERESTARTSYS; 678 goto exit; 679 } 680 681 /* verify that the device wasn't unplugged */ 682 if (dev->udev == NULL) { 683 retval = -ENODEV; 684 err("No device or device unplugged %d", retval); 685 goto unlock_exit; 686 } 687 688 /* verify that we actually have some data to write */ 689 if (count == 0) { 690 dbg(1, "%s: write request of 0 bytes", __FUNCTION__); 691 goto unlock_exit; 692 } 693 694 /* wait until previous transfer is finished */ 695 while (dev->interrupt_out_busy) { 696 if (file->f_flags & O_NONBLOCK) { 697 retval = -EAGAIN; 698 goto unlock_exit; 699 } 700 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); 701 if (retval) { 702 goto unlock_exit; 703 } 704 } 705 706 /* write the data into interrupt_out_buffer from userspace */ 707 bytes_to_write = min_t(int, count, write_buffer_size); 708 dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __FUNCTION__, count, bytes_to_write); 709 710 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { 711 retval = -EFAULT; 712 goto unlock_exit; 713 } 714 715 /* send off the urb */ 716 usb_fill_int_urb(dev->interrupt_out_urb, 717 dev->udev, 718 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 719 dev->interrupt_out_buffer, 720 bytes_to_write, 721 tower_interrupt_out_callback, 722 dev, 723 dev->interrupt_out_interval); 724 725 dev->interrupt_out_busy = 1; 726 wmb(); 727 728 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); 729 if (retval) { 730 dev->interrupt_out_busy = 0; 731 err("Couldn't submit interrupt_out_urb %d", retval); 732 goto unlock_exit; 733 } 734 retval = bytes_to_write; 735 736 unlock_exit: 737 /* unlock the device */ 738 up (&dev->sem); 739 740 exit: 741 dbg(2, "%s: leave, return value %d", __FUNCTION__, retval); 742 743 return retval; 744 } 745 746 747 /** 748 * tower_interrupt_in_callback 749 */ 750 static void tower_interrupt_in_callback (struct urb *urb) 751 { 752 struct lego_usb_tower *dev = (struct lego_usb_tower *)urb->context; 753 int retval; 754 755 dbg(4, "%s: enter, status %d", __FUNCTION__, urb->status); 756 757 lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer); 758 759 if (urb->status) { 760 if (urb->status == -ENOENT || 761 urb->status == -ECONNRESET || 762 urb->status == -ESHUTDOWN) { 763 goto exit; 764 } else { 765 dbg(1, "%s: nonzero status received: %d", __FUNCTION__, urb->status); 766 goto resubmit; /* maybe we can recover */ 767 } 768 } 769 770 if (urb->actual_length > 0) { 771 spin_lock (&dev->read_buffer_lock); 772 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 773 memcpy (dev->read_buffer + dev->read_buffer_length, 774 dev->interrupt_in_buffer, 775 urb->actual_length); 776 dev->read_buffer_length += urb->actual_length; 777 dev->read_last_arrival = jiffies; 778 dbg(3, "%s: received %d bytes", __FUNCTION__, urb->actual_length); 779 } else { 780 printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __FUNCTION__, urb->actual_length); 781 } 782 spin_unlock (&dev->read_buffer_lock); 783 } 784 785 resubmit: 786 /* resubmit if we're still running */ 787 if (dev->interrupt_in_running && dev->udev) { 788 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); 789 if (retval) { 790 err("%s: usb_submit_urb failed (%d)", __FUNCTION__, retval); 791 } 792 } 793 794 exit: 795 dev->interrupt_in_done = 1; 796 wake_up_interruptible (&dev->read_wait); 797 798 lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer); 799 dbg(4, "%s: leave, status %d", __FUNCTION__, urb->status); 800 } 801 802 803 /** 804 * tower_interrupt_out_callback 805 */ 806 static void tower_interrupt_out_callback (struct urb *urb) 807 { 808 struct lego_usb_tower *dev = (struct lego_usb_tower *)urb->context; 809 810 dbg(4, "%s: enter, status %d", __FUNCTION__, urb->status); 811 lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer); 812 813 /* sync/async unlink faults aren't errors */ 814 if (urb->status && !(urb->status == -ENOENT || 815 urb->status == -ECONNRESET || 816 urb->status == -ESHUTDOWN)) { 817 dbg(1, "%s - nonzero write bulk status received: %d", 818 __FUNCTION__, urb->status); 819 } 820 821 dev->interrupt_out_busy = 0; 822 wake_up_interruptible(&dev->write_wait); 823 824 lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer); 825 dbg(4, "%s: leave, status %d", __FUNCTION__, urb->status); 826 } 827 828 829 /** 830 * tower_probe 831 * 832 * Called by the usb core when a new device is connected that it thinks 833 * this driver might be interested in. 834 */ 835 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) 836 { 837 struct usb_device *udev = interface_to_usbdev(interface); 838 struct lego_usb_tower *dev = NULL; 839 struct usb_host_interface *iface_desc; 840 struct usb_endpoint_descriptor* endpoint; 841 struct tower_get_version_reply get_version_reply; 842 int i; 843 int retval = -ENOMEM; 844 int result; 845 846 dbg(2, "%s: enter", __FUNCTION__); 847 848 if (udev == NULL) { 849 info ("udev is NULL."); 850 } 851 852 /* allocate memory for our device state and initialize it */ 853 854 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL); 855 856 if (dev == NULL) { 857 err ("Out of memory"); 858 goto exit; 859 } 860 861 init_MUTEX (&dev->sem); 862 863 dev->udev = udev; 864 dev->open_count = 0; 865 866 dev->read_buffer = NULL; 867 dev->read_buffer_length = 0; 868 dev->read_packet_length = 0; 869 spin_lock_init (&dev->read_buffer_lock); 870 dev->packet_timeout_jiffies = packet_timeout * HZ / 1000; 871 dev->read_last_arrival = jiffies; 872 873 init_waitqueue_head (&dev->read_wait); 874 init_waitqueue_head (&dev->write_wait); 875 876 dev->interrupt_in_buffer = NULL; 877 dev->interrupt_in_endpoint = NULL; 878 dev->interrupt_in_urb = NULL; 879 dev->interrupt_in_running = 0; 880 dev->interrupt_in_done = 0; 881 882 dev->interrupt_out_buffer = NULL; 883 dev->interrupt_out_endpoint = NULL; 884 dev->interrupt_out_urb = NULL; 885 dev->interrupt_out_busy = 0; 886 887 iface_desc = interface->cur_altsetting; 888 889 /* set up the endpoint information */ 890 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 891 endpoint = &iface_desc->endpoint[i].desc; 892 893 if (usb_endpoint_xfer_int(endpoint)) { 894 if (usb_endpoint_dir_in(endpoint)) 895 dev->interrupt_in_endpoint = endpoint; 896 else 897 dev->interrupt_out_endpoint = endpoint; 898 } 899 } 900 if(dev->interrupt_in_endpoint == NULL) { 901 err("interrupt in endpoint not found"); 902 goto error; 903 } 904 if (dev->interrupt_out_endpoint == NULL) { 905 err("interrupt out endpoint not found"); 906 goto error; 907 } 908 909 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); 910 if (!dev->read_buffer) { 911 err("Couldn't allocate read_buffer"); 912 goto error; 913 } 914 dev->interrupt_in_buffer = kmalloc (le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), GFP_KERNEL); 915 if (!dev->interrupt_in_buffer) { 916 err("Couldn't allocate interrupt_in_buffer"); 917 goto error; 918 } 919 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 920 if (!dev->interrupt_in_urb) { 921 err("Couldn't allocate interrupt_in_urb"); 922 goto error; 923 } 924 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL); 925 if (!dev->interrupt_out_buffer) { 926 err("Couldn't allocate interrupt_out_buffer"); 927 goto error; 928 } 929 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 930 if (!dev->interrupt_out_urb) { 931 err("Couldn't allocate interrupt_out_urb"); 932 goto error; 933 } 934 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 935 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 936 937 /* we can register the device now, as it is ready */ 938 usb_set_intfdata (interface, dev); 939 940 retval = usb_register_dev (interface, &tower_class); 941 942 if (retval) { 943 /* something prevented us from registering this driver */ 944 err ("Not able to get a minor for this device."); 945 usb_set_intfdata (interface, NULL); 946 goto error; 947 } 948 dev->minor = interface->minor; 949 950 /* let the user know what node this device is now attached to */ 951 info ("LEGO USB Tower #%d now attached to major %d minor %d", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), USB_MAJOR, dev->minor); 952 953 /* get the firmware version and log it */ 954 result = usb_control_msg (udev, 955 usb_rcvctrlpipe(udev, 0), 956 LEGO_USB_TOWER_REQUEST_GET_VERSION, 957 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 958 0, 959 0, 960 &get_version_reply, 961 sizeof(get_version_reply), 962 1000); 963 if (result < 0) { 964 err("LEGO USB Tower get version control request failed"); 965 retval = result; 966 goto error; 967 } 968 info("LEGO USB Tower firmware version is %d.%d build %d", 969 get_version_reply.major, 970 get_version_reply.minor, 971 le16_to_cpu(get_version_reply.build_no)); 972 973 974 exit: 975 dbg(2, "%s: leave, return value 0x%.8lx (dev)", __FUNCTION__, (long) dev); 976 977 return retval; 978 979 error: 980 tower_delete(dev); 981 return retval; 982 } 983 984 985 /** 986 * tower_disconnect 987 * 988 * Called by the usb core when the device is removed from the system. 989 */ 990 static void tower_disconnect (struct usb_interface *interface) 991 { 992 struct lego_usb_tower *dev; 993 int minor; 994 995 dbg(2, "%s: enter", __FUNCTION__); 996 997 mutex_lock (&disconnect_mutex); 998 999 dev = usb_get_intfdata (interface); 1000 usb_set_intfdata (interface, NULL); 1001 1002 1003 down (&dev->sem); 1004 1005 minor = dev->minor; 1006 1007 /* give back our minor */ 1008 usb_deregister_dev (interface, &tower_class); 1009 1010 /* if the device is not opened, then we clean up right now */ 1011 if (!dev->open_count) { 1012 up (&dev->sem); 1013 tower_delete (dev); 1014 } else { 1015 dev->udev = NULL; 1016 up (&dev->sem); 1017 } 1018 1019 mutex_unlock (&disconnect_mutex); 1020 1021 info("LEGO USB Tower #%d now disconnected", (minor - LEGO_USB_TOWER_MINOR_BASE)); 1022 1023 dbg(2, "%s: leave", __FUNCTION__); 1024 } 1025 1026 1027 1028 /** 1029 * lego_usb_tower_init 1030 */ 1031 static int __init lego_usb_tower_init(void) 1032 { 1033 int result; 1034 int retval = 0; 1035 1036 dbg(2, "%s: enter", __FUNCTION__); 1037 1038 /* register this driver with the USB subsystem */ 1039 result = usb_register(&tower_driver); 1040 if (result < 0) { 1041 err("usb_register failed for the "__FILE__" driver. Error number %d", result); 1042 retval = -1; 1043 goto exit; 1044 } 1045 1046 info(DRIVER_DESC " " DRIVER_VERSION); 1047 1048 exit: 1049 dbg(2, "%s: leave, return value %d", __FUNCTION__, retval); 1050 1051 return retval; 1052 } 1053 1054 1055 /** 1056 * lego_usb_tower_exit 1057 */ 1058 static void __exit lego_usb_tower_exit(void) 1059 { 1060 dbg(2, "%s: enter", __FUNCTION__); 1061 1062 /* deregister this driver with the USB subsystem */ 1063 usb_deregister (&tower_driver); 1064 1065 dbg(2, "%s: leave", __FUNCTION__); 1066 } 1067 1068 module_init (lego_usb_tower_init); 1069 module_exit (lego_usb_tower_exit); 1070 1071 MODULE_AUTHOR(DRIVER_AUTHOR); 1072 MODULE_DESCRIPTION(DRIVER_DESC); 1073 #ifdef MODULE_LICENSE 1074 MODULE_LICENSE("GPL"); 1075 #endif 1076