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 /* file operations needed when we register this driver */ 258 static const struct file_operations tower_fops = { 259 .owner = THIS_MODULE, 260 .read = tower_read, 261 .write = tower_write, 262 .open = tower_open, 263 .release = tower_release, 264 .poll = tower_poll, 265 .llseek = tower_llseek, 266 }; 267 268 /* 269 * usb class driver info in order to get a minor number from the usb core, 270 * and to have the device registered with the driver core 271 */ 272 static struct usb_class_driver tower_class = { 273 .name = "legousbtower%d", 274 .fops = &tower_fops, 275 .minor_base = LEGO_USB_TOWER_MINOR_BASE, 276 }; 277 278 279 /* usb specific object needed to register this driver with the usb subsystem */ 280 static struct usb_driver tower_driver = { 281 .name = "legousbtower", 282 .probe = tower_probe, 283 .disconnect = tower_disconnect, 284 .id_table = tower_table, 285 }; 286 287 288 /** 289 * lego_usb_tower_debug_data 290 */ 291 static inline void lego_usb_tower_debug_data (int level, const char *function, int size, const unsigned char *data) 292 { 293 int i; 294 295 if (debug < level) 296 return; 297 298 printk (KERN_DEBUG __FILE__": %s - length = %d, data = ", function, size); 299 for (i = 0; i < size; ++i) { 300 printk ("%.2x ", data[i]); 301 } 302 printk ("\n"); 303 } 304 305 306 /** 307 * tower_delete 308 */ 309 static inline void tower_delete (struct lego_usb_tower *dev) 310 { 311 dbg(2, "%s: enter", __FUNCTION__); 312 313 tower_abort_transfers (dev); 314 315 /* free data structures */ 316 usb_free_urb(dev->interrupt_in_urb); 317 usb_free_urb(dev->interrupt_out_urb); 318 kfree (dev->read_buffer); 319 kfree (dev->interrupt_in_buffer); 320 kfree (dev->interrupt_out_buffer); 321 kfree (dev); 322 323 dbg(2, "%s: leave", __FUNCTION__); 324 } 325 326 327 /** 328 * tower_open 329 */ 330 static int tower_open (struct inode *inode, struct file *file) 331 { 332 struct lego_usb_tower *dev = NULL; 333 int subminor; 334 int retval = 0; 335 struct usb_interface *interface; 336 struct tower_reset_reply reset_reply; 337 int result; 338 339 dbg(2, "%s: enter", __FUNCTION__); 340 341 nonseekable_open(inode, file); 342 subminor = iminor(inode); 343 344 interface = usb_find_interface (&tower_driver, subminor); 345 346 if (!interface) { 347 err ("%s - error, can't find device for minor %d", 348 __FUNCTION__, subminor); 349 retval = -ENODEV; 350 goto exit; 351 } 352 353 dev = usb_get_intfdata(interface); 354 355 if (!dev) { 356 retval = -ENODEV; 357 goto exit; 358 } 359 360 /* lock this device */ 361 if (down_interruptible (&dev->sem)) { 362 retval = -ERESTARTSYS; 363 goto exit; 364 } 365 366 /* allow opening only once */ 367 if (dev->open_count) { 368 retval = -EBUSY; 369 goto unlock_exit; 370 } 371 dev->open_count = 1; 372 373 /* reset the tower */ 374 result = usb_control_msg (dev->udev, 375 usb_rcvctrlpipe(dev->udev, 0), 376 LEGO_USB_TOWER_REQUEST_RESET, 377 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 378 0, 379 0, 380 &reset_reply, 381 sizeof(reset_reply), 382 1000); 383 if (result < 0) { 384 err("LEGO USB Tower reset control request failed"); 385 retval = result; 386 goto unlock_exit; 387 } 388 389 /* initialize in direction */ 390 dev->read_buffer_length = 0; 391 dev->read_packet_length = 0; 392 usb_fill_int_urb (dev->interrupt_in_urb, 393 dev->udev, 394 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress), 395 dev->interrupt_in_buffer, 396 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), 397 tower_interrupt_in_callback, 398 dev, 399 dev->interrupt_in_interval); 400 401 dev->interrupt_in_running = 1; 402 dev->interrupt_in_done = 0; 403 mb(); 404 405 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL); 406 if (retval) { 407 err("Couldn't submit interrupt_in_urb %d", retval); 408 dev->interrupt_in_running = 0; 409 dev->open_count = 0; 410 goto unlock_exit; 411 } 412 413 /* save device in the file's private structure */ 414 file->private_data = dev; 415 416 unlock_exit: 417 up (&dev->sem); 418 419 exit: 420 dbg(2, "%s: leave, return value %d ", __FUNCTION__, retval); 421 422 return retval; 423 } 424 425 /** 426 * tower_release 427 */ 428 static int tower_release (struct inode *inode, struct file *file) 429 { 430 struct lego_usb_tower *dev; 431 int retval = 0; 432 433 dbg(2, "%s: enter", __FUNCTION__); 434 435 dev = (struct lego_usb_tower *)file->private_data; 436 437 if (dev == NULL) { 438 dbg(1, "%s: object is NULL", __FUNCTION__); 439 retval = -ENODEV; 440 goto exit; 441 } 442 443 if (down_interruptible (&dev->sem)) { 444 retval = -ERESTARTSYS; 445 goto exit; 446 } 447 448 if (dev->open_count != 1) { 449 dbg(1, "%s: device not opened exactly once", __FUNCTION__); 450 retval = -ENODEV; 451 goto unlock_exit; 452 } 453 if (dev->udev == NULL) { 454 /* the device was unplugged before the file was released */ 455 up (&dev->sem); /* unlock here as tower_delete frees dev */ 456 tower_delete (dev); 457 goto exit; 458 } 459 460 /* wait until write transfer is finished */ 461 if (dev->interrupt_out_busy) { 462 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 463 } 464 tower_abort_transfers (dev); 465 dev->open_count = 0; 466 467 unlock_exit: 468 up (&dev->sem); 469 470 exit: 471 dbg(2, "%s: leave, return value %d", __FUNCTION__, retval); 472 return retval; 473 } 474 475 476 /** 477 * tower_abort_transfers 478 * aborts transfers and frees associated data structures 479 */ 480 static void tower_abort_transfers (struct lego_usb_tower *dev) 481 { 482 dbg(2, "%s: enter", __FUNCTION__); 483 484 if (dev == NULL) { 485 dbg(1, "%s: dev is null", __FUNCTION__); 486 goto exit; 487 } 488 489 /* shutdown transfer */ 490 if (dev->interrupt_in_running) { 491 dev->interrupt_in_running = 0; 492 mb(); 493 if (dev->udev) 494 usb_kill_urb (dev->interrupt_in_urb); 495 } 496 if (dev->interrupt_out_busy && dev->udev) 497 usb_kill_urb(dev->interrupt_out_urb); 498 499 exit: 500 dbg(2, "%s: leave", __FUNCTION__); 501 } 502 503 504 /** 505 * tower_check_for_read_packet 506 * 507 * To get correct semantics for signals and non-blocking I/O 508 * with packetizing we pretend not to see any data in the read buffer 509 * until it has been there unchanged for at least 510 * dev->packet_timeout_jiffies, or until the buffer is full. 511 */ 512 static void tower_check_for_read_packet (struct lego_usb_tower *dev) 513 { 514 spin_lock_irq (&dev->read_buffer_lock); 515 if (!packet_timeout 516 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) 517 || dev->read_buffer_length == read_buffer_size) { 518 dev->read_packet_length = dev->read_buffer_length; 519 } 520 dev->interrupt_in_done = 0; 521 spin_unlock_irq (&dev->read_buffer_lock); 522 } 523 524 525 /** 526 * tower_poll 527 */ 528 static unsigned int tower_poll (struct file *file, poll_table *wait) 529 { 530 struct lego_usb_tower *dev; 531 unsigned int mask = 0; 532 533 dbg(2, "%s: enter", __FUNCTION__); 534 535 dev = file->private_data; 536 537 poll_wait(file, &dev->read_wait, wait); 538 poll_wait(file, &dev->write_wait, wait); 539 540 tower_check_for_read_packet(dev); 541 if (dev->read_packet_length > 0) { 542 mask |= POLLIN | POLLRDNORM; 543 } 544 if (!dev->interrupt_out_busy) { 545 mask |= POLLOUT | POLLWRNORM; 546 } 547 548 dbg(2, "%s: leave, mask = %d", __FUNCTION__, mask); 549 550 return mask; 551 } 552 553 554 /** 555 * tower_llseek 556 */ 557 static loff_t tower_llseek (struct file *file, loff_t off, int whence) 558 { 559 return -ESPIPE; /* unseekable */ 560 } 561 562 563 /** 564 * tower_read 565 */ 566 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 567 { 568 struct lego_usb_tower *dev; 569 size_t bytes_to_read; 570 int i; 571 int retval = 0; 572 unsigned long timeout = 0; 573 574 dbg(2, "%s: enter, count = %Zd", __FUNCTION__, count); 575 576 dev = (struct lego_usb_tower *)file->private_data; 577 578 /* lock this object */ 579 if (down_interruptible (&dev->sem)) { 580 retval = -ERESTARTSYS; 581 goto exit; 582 } 583 584 /* verify that the device wasn't unplugged */ 585 if (dev->udev == NULL) { 586 retval = -ENODEV; 587 err("No device or device unplugged %d", retval); 588 goto unlock_exit; 589 } 590 591 /* verify that we actually have some data to read */ 592 if (count == 0) { 593 dbg(1, "%s: read request of 0 bytes", __FUNCTION__); 594 goto unlock_exit; 595 } 596 597 if (read_timeout) { 598 timeout = jiffies + read_timeout * HZ / 1000; 599 } 600 601 /* wait for data */ 602 tower_check_for_read_packet (dev); 603 while (dev->read_packet_length == 0) { 604 if (file->f_flags & O_NONBLOCK) { 605 retval = -EAGAIN; 606 goto unlock_exit; 607 } 608 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 609 if (retval < 0) { 610 goto unlock_exit; 611 } 612 613 /* reset read timeout during read or write activity */ 614 if (read_timeout 615 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 616 timeout = jiffies + read_timeout * HZ / 1000; 617 } 618 /* check for read timeout */ 619 if (read_timeout && time_after (jiffies, timeout)) { 620 retval = -ETIMEDOUT; 621 goto unlock_exit; 622 } 623 tower_check_for_read_packet (dev); 624 } 625 626 /* copy the data from read_buffer into userspace */ 627 bytes_to_read = min(count, dev->read_packet_length); 628 629 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { 630 retval = -EFAULT; 631 goto unlock_exit; 632 } 633 634 spin_lock_irq (&dev->read_buffer_lock); 635 dev->read_buffer_length -= bytes_to_read; 636 dev->read_packet_length -= bytes_to_read; 637 for (i=0; i<dev->read_buffer_length; i++) { 638 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 639 } 640 spin_unlock_irq (&dev->read_buffer_lock); 641 642 retval = bytes_to_read; 643 644 unlock_exit: 645 /* unlock the device */ 646 up (&dev->sem); 647 648 exit: 649 dbg(2, "%s: leave, return value %d", __FUNCTION__, retval); 650 return retval; 651 } 652 653 654 /** 655 * tower_write 656 */ 657 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 658 { 659 struct lego_usb_tower *dev; 660 size_t bytes_to_write; 661 int retval = 0; 662 663 dbg(2, "%s: enter, count = %Zd", __FUNCTION__, count); 664 665 dev = (struct lego_usb_tower *)file->private_data; 666 667 /* lock this object */ 668 if (down_interruptible (&dev->sem)) { 669 retval = -ERESTARTSYS; 670 goto exit; 671 } 672 673 /* verify that the device wasn't unplugged */ 674 if (dev->udev == NULL) { 675 retval = -ENODEV; 676 err("No device or device unplugged %d", retval); 677 goto unlock_exit; 678 } 679 680 /* verify that we actually have some data to write */ 681 if (count == 0) { 682 dbg(1, "%s: write request of 0 bytes", __FUNCTION__); 683 goto unlock_exit; 684 } 685 686 /* wait until previous transfer is finished */ 687 while (dev->interrupt_out_busy) { 688 if (file->f_flags & O_NONBLOCK) { 689 retval = -EAGAIN; 690 goto unlock_exit; 691 } 692 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); 693 if (retval) { 694 goto unlock_exit; 695 } 696 } 697 698 /* write the data into interrupt_out_buffer from userspace */ 699 bytes_to_write = min_t(int, count, write_buffer_size); 700 dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __FUNCTION__, count, bytes_to_write); 701 702 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { 703 retval = -EFAULT; 704 goto unlock_exit; 705 } 706 707 /* send off the urb */ 708 usb_fill_int_urb(dev->interrupt_out_urb, 709 dev->udev, 710 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 711 dev->interrupt_out_buffer, 712 bytes_to_write, 713 tower_interrupt_out_callback, 714 dev, 715 dev->interrupt_out_interval); 716 717 dev->interrupt_out_busy = 1; 718 wmb(); 719 720 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); 721 if (retval) { 722 dev->interrupt_out_busy = 0; 723 err("Couldn't submit interrupt_out_urb %d", retval); 724 goto unlock_exit; 725 } 726 retval = bytes_to_write; 727 728 unlock_exit: 729 /* unlock the device */ 730 up (&dev->sem); 731 732 exit: 733 dbg(2, "%s: leave, return value %d", __FUNCTION__, retval); 734 735 return retval; 736 } 737 738 739 /** 740 * tower_interrupt_in_callback 741 */ 742 static void tower_interrupt_in_callback (struct urb *urb) 743 { 744 struct lego_usb_tower *dev = (struct lego_usb_tower *)urb->context; 745 int retval; 746 747 dbg(4, "%s: enter, status %d", __FUNCTION__, urb->status); 748 749 lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer); 750 751 if (urb->status) { 752 if (urb->status == -ENOENT || 753 urb->status == -ECONNRESET || 754 urb->status == -ESHUTDOWN) { 755 goto exit; 756 } else { 757 dbg(1, "%s: nonzero status received: %d", __FUNCTION__, urb->status); 758 goto resubmit; /* maybe we can recover */ 759 } 760 } 761 762 if (urb->actual_length > 0) { 763 spin_lock (&dev->read_buffer_lock); 764 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 765 memcpy (dev->read_buffer + dev->read_buffer_length, 766 dev->interrupt_in_buffer, 767 urb->actual_length); 768 dev->read_buffer_length += urb->actual_length; 769 dev->read_last_arrival = jiffies; 770 dbg(3, "%s: received %d bytes", __FUNCTION__, urb->actual_length); 771 } else { 772 printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __FUNCTION__, urb->actual_length); 773 } 774 spin_unlock (&dev->read_buffer_lock); 775 } 776 777 resubmit: 778 /* resubmit if we're still running */ 779 if (dev->interrupt_in_running && dev->udev) { 780 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); 781 if (retval) { 782 err("%s: usb_submit_urb failed (%d)", __FUNCTION__, retval); 783 } 784 } 785 786 exit: 787 dev->interrupt_in_done = 1; 788 wake_up_interruptible (&dev->read_wait); 789 790 lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer); 791 dbg(4, "%s: leave, status %d", __FUNCTION__, urb->status); 792 } 793 794 795 /** 796 * tower_interrupt_out_callback 797 */ 798 static void tower_interrupt_out_callback (struct urb *urb) 799 { 800 struct lego_usb_tower *dev = (struct lego_usb_tower *)urb->context; 801 802 dbg(4, "%s: enter, status %d", __FUNCTION__, urb->status); 803 lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer); 804 805 /* sync/async unlink faults aren't errors */ 806 if (urb->status && !(urb->status == -ENOENT || 807 urb->status == -ECONNRESET || 808 urb->status == -ESHUTDOWN)) { 809 dbg(1, "%s - nonzero write bulk status received: %d", 810 __FUNCTION__, urb->status); 811 } 812 813 dev->interrupt_out_busy = 0; 814 wake_up_interruptible(&dev->write_wait); 815 816 lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer); 817 dbg(4, "%s: leave, status %d", __FUNCTION__, urb->status); 818 } 819 820 821 /** 822 * tower_probe 823 * 824 * Called by the usb core when a new device is connected that it thinks 825 * this driver might be interested in. 826 */ 827 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) 828 { 829 struct usb_device *udev = interface_to_usbdev(interface); 830 struct lego_usb_tower *dev = NULL; 831 struct usb_host_interface *iface_desc; 832 struct usb_endpoint_descriptor* endpoint; 833 struct tower_get_version_reply get_version_reply; 834 int i; 835 int retval = -ENOMEM; 836 int result; 837 838 dbg(2, "%s: enter", __FUNCTION__); 839 840 if (udev == NULL) { 841 info ("udev is NULL."); 842 } 843 844 /* allocate memory for our device state and initialize it */ 845 846 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL); 847 848 if (dev == NULL) { 849 err ("Out of memory"); 850 goto exit; 851 } 852 853 init_MUTEX (&dev->sem); 854 855 dev->udev = udev; 856 dev->open_count = 0; 857 858 dev->read_buffer = NULL; 859 dev->read_buffer_length = 0; 860 dev->read_packet_length = 0; 861 spin_lock_init (&dev->read_buffer_lock); 862 dev->packet_timeout_jiffies = packet_timeout * HZ / 1000; 863 dev->read_last_arrival = jiffies; 864 865 init_waitqueue_head (&dev->read_wait); 866 init_waitqueue_head (&dev->write_wait); 867 868 dev->interrupt_in_buffer = NULL; 869 dev->interrupt_in_endpoint = NULL; 870 dev->interrupt_in_urb = NULL; 871 dev->interrupt_in_running = 0; 872 dev->interrupt_in_done = 0; 873 874 dev->interrupt_out_buffer = NULL; 875 dev->interrupt_out_endpoint = NULL; 876 dev->interrupt_out_urb = NULL; 877 dev->interrupt_out_busy = 0; 878 879 iface_desc = interface->cur_altsetting; 880 881 /* set up the endpoint information */ 882 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 883 endpoint = &iface_desc->endpoint[i].desc; 884 885 if (usb_endpoint_xfer_int(endpoint)) { 886 if (usb_endpoint_dir_in(endpoint)) 887 dev->interrupt_in_endpoint = endpoint; 888 else 889 dev->interrupt_out_endpoint = endpoint; 890 } 891 } 892 if(dev->interrupt_in_endpoint == NULL) { 893 err("interrupt in endpoint not found"); 894 goto error; 895 } 896 if (dev->interrupt_out_endpoint == NULL) { 897 err("interrupt out endpoint not found"); 898 goto error; 899 } 900 901 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); 902 if (!dev->read_buffer) { 903 err("Couldn't allocate read_buffer"); 904 goto error; 905 } 906 dev->interrupt_in_buffer = kmalloc (le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), GFP_KERNEL); 907 if (!dev->interrupt_in_buffer) { 908 err("Couldn't allocate interrupt_in_buffer"); 909 goto error; 910 } 911 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 912 if (!dev->interrupt_in_urb) { 913 err("Couldn't allocate interrupt_in_urb"); 914 goto error; 915 } 916 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL); 917 if (!dev->interrupt_out_buffer) { 918 err("Couldn't allocate interrupt_out_buffer"); 919 goto error; 920 } 921 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 922 if (!dev->interrupt_out_urb) { 923 err("Couldn't allocate interrupt_out_urb"); 924 goto error; 925 } 926 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 927 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 928 929 /* we can register the device now, as it is ready */ 930 usb_set_intfdata (interface, dev); 931 932 retval = usb_register_dev (interface, &tower_class); 933 934 if (retval) { 935 /* something prevented us from registering this driver */ 936 err ("Not able to get a minor for this device."); 937 usb_set_intfdata (interface, NULL); 938 goto error; 939 } 940 dev->minor = interface->minor; 941 942 /* let the user know what node this device is now attached to */ 943 info ("LEGO USB Tower #%d now attached to major %d minor %d", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), USB_MAJOR, dev->minor); 944 945 /* get the firmware version and log it */ 946 result = usb_control_msg (udev, 947 usb_rcvctrlpipe(udev, 0), 948 LEGO_USB_TOWER_REQUEST_GET_VERSION, 949 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 950 0, 951 0, 952 &get_version_reply, 953 sizeof(get_version_reply), 954 1000); 955 if (result < 0) { 956 err("LEGO USB Tower get version control request failed"); 957 retval = result; 958 goto error; 959 } 960 info("LEGO USB Tower firmware version is %d.%d build %d", 961 get_version_reply.major, 962 get_version_reply.minor, 963 le16_to_cpu(get_version_reply.build_no)); 964 965 966 exit: 967 dbg(2, "%s: leave, return value 0x%.8lx (dev)", __FUNCTION__, (long) dev); 968 969 return retval; 970 971 error: 972 tower_delete(dev); 973 return retval; 974 } 975 976 977 /** 978 * tower_disconnect 979 * 980 * Called by the usb core when the device is removed from the system. 981 */ 982 static void tower_disconnect (struct usb_interface *interface) 983 { 984 struct lego_usb_tower *dev; 985 int minor; 986 987 dbg(2, "%s: enter", __FUNCTION__); 988 989 dev = usb_get_intfdata (interface); 990 usb_set_intfdata (interface, NULL); 991 992 minor = dev->minor; 993 994 /* give back our minor */ 995 usb_deregister_dev (interface, &tower_class); 996 997 down (&dev->sem); 998 999 /* if the device is not opened, then we clean up right now */ 1000 if (!dev->open_count) { 1001 up (&dev->sem); 1002 tower_delete (dev); 1003 } else { 1004 dev->udev = NULL; 1005 up (&dev->sem); 1006 } 1007 1008 info("LEGO USB Tower #%d now disconnected", (minor - LEGO_USB_TOWER_MINOR_BASE)); 1009 1010 dbg(2, "%s: leave", __FUNCTION__); 1011 } 1012 1013 1014 1015 /** 1016 * lego_usb_tower_init 1017 */ 1018 static int __init lego_usb_tower_init(void) 1019 { 1020 int result; 1021 int retval = 0; 1022 1023 dbg(2, "%s: enter", __FUNCTION__); 1024 1025 /* register this driver with the USB subsystem */ 1026 result = usb_register(&tower_driver); 1027 if (result < 0) { 1028 err("usb_register failed for the "__FILE__" driver. Error number %d", result); 1029 retval = -1; 1030 goto exit; 1031 } 1032 1033 info(DRIVER_DESC " " DRIVER_VERSION); 1034 1035 exit: 1036 dbg(2, "%s: leave, return value %d", __FUNCTION__, retval); 1037 1038 return retval; 1039 } 1040 1041 1042 /** 1043 * lego_usb_tower_exit 1044 */ 1045 static void __exit lego_usb_tower_exit(void) 1046 { 1047 dbg(2, "%s: enter", __FUNCTION__); 1048 1049 /* deregister this driver with the USB subsystem */ 1050 usb_deregister (&tower_driver); 1051 1052 dbg(2, "%s: leave", __FUNCTION__); 1053 } 1054 1055 module_init (lego_usb_tower_init); 1056 module_exit (lego_usb_tower_exit); 1057 1058 MODULE_AUTHOR(DRIVER_AUTHOR); 1059 MODULE_DESCRIPTION(DRIVER_DESC); 1060 #ifdef MODULE_LICENSE 1061 MODULE_LICENSE("GPL"); 1062 #endif 1063