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/config.h> 79 #include <linux/kernel.h> 80 #include <linux/errno.h> 81 #include <linux/init.h> 82 #include <linux/slab.h> 83 #include <linux/module.h> 84 #include <linux/smp_lock.h> 85 #include <linux/completion.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, struct pt_regs *regs); 252 static void tower_interrupt_out_callback (struct urb *urb, struct pt_regs *regs); 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 DECLARE_MUTEX (disconnect_sem); 260 261 /* file operations needed when we register this driver */ 262 static 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 devfs and the driver core 275 */ 276 static struct usb_class_driver tower_class = { 277 .name = "usb/legousbtower%d", 278 .fops = &tower_fops, 279 .mode = S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH, 280 .minor_base = LEGO_USB_TOWER_MINOR_BASE, 281 }; 282 283 284 /* usb specific object needed to register this driver with the usb subsystem */ 285 static struct usb_driver tower_driver = { 286 .owner = THIS_MODULE, 287 .name = "legousbtower", 288 .probe = tower_probe, 289 .disconnect = tower_disconnect, 290 .id_table = tower_table, 291 }; 292 293 294 /** 295 * lego_usb_tower_debug_data 296 */ 297 static inline void lego_usb_tower_debug_data (int level, const char *function, int size, const unsigned char *data) 298 { 299 int i; 300 301 if (debug < level) 302 return; 303 304 printk (KERN_DEBUG __FILE__": %s - length = %d, data = ", function, size); 305 for (i = 0; i < size; ++i) { 306 printk ("%.2x ", data[i]); 307 } 308 printk ("\n"); 309 } 310 311 312 /** 313 * tower_delete 314 */ 315 static inline void tower_delete (struct lego_usb_tower *dev) 316 { 317 dbg(2, "%s: enter", __FUNCTION__); 318 319 tower_abort_transfers (dev); 320 321 /* free data structures */ 322 if (dev->interrupt_in_urb != NULL) { 323 usb_free_urb (dev->interrupt_in_urb); 324 } 325 if (dev->interrupt_out_urb != NULL) { 326 usb_free_urb (dev->interrupt_out_urb); 327 } 328 kfree (dev->read_buffer); 329 kfree (dev->interrupt_in_buffer); 330 kfree (dev->interrupt_out_buffer); 331 kfree (dev); 332 333 dbg(2, "%s: leave", __FUNCTION__); 334 } 335 336 337 /** 338 * tower_open 339 */ 340 static int tower_open (struct inode *inode, struct file *file) 341 { 342 struct lego_usb_tower *dev = NULL; 343 int subminor; 344 int retval = 0; 345 struct usb_interface *interface; 346 struct tower_reset_reply reset_reply; 347 int result; 348 349 dbg(2, "%s: enter", __FUNCTION__); 350 351 nonseekable_open(inode, file); 352 subminor = iminor(inode); 353 354 down (&disconnect_sem); 355 356 interface = usb_find_interface (&tower_driver, subminor); 357 358 if (!interface) { 359 err ("%s - error, can't find device for minor %d", 360 __FUNCTION__, subminor); 361 retval = -ENODEV; 362 goto unlock_disconnect_exit; 363 } 364 365 dev = usb_get_intfdata(interface); 366 367 if (!dev) { 368 retval = -ENODEV; 369 goto unlock_disconnect_exit; 370 } 371 372 /* lock this device */ 373 if (down_interruptible (&dev->sem)) { 374 retval = -ERESTARTSYS; 375 goto unlock_disconnect_exit; 376 } 377 378 /* allow opening only once */ 379 if (dev->open_count) { 380 retval = -EBUSY; 381 goto unlock_exit; 382 } 383 dev->open_count = 1; 384 385 /* reset the tower */ 386 result = usb_control_msg (dev->udev, 387 usb_rcvctrlpipe(dev->udev, 0), 388 LEGO_USB_TOWER_REQUEST_RESET, 389 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 390 0, 391 0, 392 &reset_reply, 393 sizeof(reset_reply), 394 1000); 395 if (result < 0) { 396 err("LEGO USB Tower reset control request failed"); 397 retval = result; 398 goto unlock_exit; 399 } 400 401 /* initialize in direction */ 402 dev->read_buffer_length = 0; 403 dev->read_packet_length = 0; 404 usb_fill_int_urb (dev->interrupt_in_urb, 405 dev->udev, 406 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress), 407 dev->interrupt_in_buffer, 408 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), 409 tower_interrupt_in_callback, 410 dev, 411 dev->interrupt_in_interval); 412 413 dev->interrupt_in_running = 1; 414 dev->interrupt_in_done = 0; 415 mb(); 416 417 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL); 418 if (retval) { 419 err("Couldn't submit interrupt_in_urb %d", retval); 420 dev->interrupt_in_running = 0; 421 dev->open_count = 0; 422 goto unlock_exit; 423 } 424 425 /* save device in the file's private structure */ 426 file->private_data = dev; 427 428 unlock_exit: 429 up (&dev->sem); 430 431 unlock_disconnect_exit: 432 up (&disconnect_sem); 433 434 dbg(2, "%s: leave, return value %d ", __FUNCTION__, retval); 435 436 return retval; 437 } 438 439 /** 440 * tower_release 441 */ 442 static int tower_release (struct inode *inode, struct file *file) 443 { 444 struct lego_usb_tower *dev; 445 int retval = 0; 446 447 dbg(2, "%s: enter", __FUNCTION__); 448 449 dev = (struct lego_usb_tower *)file->private_data; 450 451 if (dev == NULL) { 452 dbg(1, "%s: object is NULL", __FUNCTION__); 453 retval = -ENODEV; 454 goto exit; 455 } 456 457 if (down_interruptible (&dev->sem)) { 458 retval = -ERESTARTSYS; 459 goto exit; 460 } 461 462 if (dev->open_count != 1) { 463 dbg(1, "%s: device not opened exactly once", __FUNCTION__); 464 retval = -ENODEV; 465 goto unlock_exit; 466 } 467 if (dev->udev == NULL) { 468 /* the device was unplugged before the file was released */ 469 up (&dev->sem); /* unlock here as tower_delete frees dev */ 470 tower_delete (dev); 471 goto exit; 472 } 473 474 /* wait until write transfer is finished */ 475 if (dev->interrupt_out_busy) { 476 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 477 } 478 tower_abort_transfers (dev); 479 dev->open_count = 0; 480 481 unlock_exit: 482 up (&dev->sem); 483 484 exit: 485 dbg(2, "%s: leave, return value %d", __FUNCTION__, retval); 486 return retval; 487 } 488 489 490 /** 491 * tower_abort_transfers 492 * aborts transfers and frees associated data structures 493 */ 494 static void tower_abort_transfers (struct lego_usb_tower *dev) 495 { 496 dbg(2, "%s: enter", __FUNCTION__); 497 498 if (dev == NULL) { 499 dbg(1, "%s: dev is null", __FUNCTION__); 500 goto exit; 501 } 502 503 /* shutdown transfer */ 504 if (dev->interrupt_in_running) { 505 dev->interrupt_in_running = 0; 506 mb(); 507 if (dev->interrupt_in_urb != NULL && dev->udev) { 508 usb_kill_urb (dev->interrupt_in_urb); 509 } 510 } 511 if (dev->interrupt_out_busy) { 512 if (dev->interrupt_out_urb != NULL && dev->udev) { 513 usb_kill_urb (dev->interrupt_out_urb); 514 } 515 } 516 517 exit: 518 dbg(2, "%s: leave", __FUNCTION__); 519 } 520 521 522 /** 523 * tower_check_for_read_packet 524 * 525 * To get correct semantics for signals and non-blocking I/O 526 * with packetizing we pretend not to see any data in the read buffer 527 * until it has been there unchanged for at least 528 * dev->packet_timeout_jiffies, or until the buffer is full. 529 */ 530 static void tower_check_for_read_packet (struct lego_usb_tower *dev) 531 { 532 spin_lock_irq (&dev->read_buffer_lock); 533 if (!packet_timeout 534 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) 535 || dev->read_buffer_length == read_buffer_size) { 536 dev->read_packet_length = dev->read_buffer_length; 537 } 538 dev->interrupt_in_done = 0; 539 spin_unlock_irq (&dev->read_buffer_lock); 540 } 541 542 543 /** 544 * tower_poll 545 */ 546 static unsigned int tower_poll (struct file *file, poll_table *wait) 547 { 548 struct lego_usb_tower *dev; 549 unsigned int mask = 0; 550 551 dbg(2, "%s: enter", __FUNCTION__); 552 553 dev = file->private_data; 554 555 poll_wait(file, &dev->read_wait, wait); 556 poll_wait(file, &dev->write_wait, wait); 557 558 tower_check_for_read_packet(dev); 559 if (dev->read_packet_length > 0) { 560 mask |= POLLIN | POLLRDNORM; 561 } 562 if (!dev->interrupt_out_busy) { 563 mask |= POLLOUT | POLLWRNORM; 564 } 565 566 dbg(2, "%s: leave, mask = %d", __FUNCTION__, mask); 567 568 return mask; 569 } 570 571 572 /** 573 * tower_llseek 574 */ 575 static loff_t tower_llseek (struct file *file, loff_t off, int whence) 576 { 577 return -ESPIPE; /* unseekable */ 578 } 579 580 581 /** 582 * tower_read 583 */ 584 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 585 { 586 struct lego_usb_tower *dev; 587 size_t bytes_to_read; 588 int i; 589 int retval = 0; 590 unsigned long timeout = 0; 591 592 dbg(2, "%s: enter, count = %Zd", __FUNCTION__, count); 593 594 dev = (struct lego_usb_tower *)file->private_data; 595 596 /* lock this object */ 597 if (down_interruptible (&dev->sem)) { 598 retval = -ERESTARTSYS; 599 goto exit; 600 } 601 602 /* verify that the device wasn't unplugged */ 603 if (dev->udev == NULL) { 604 retval = -ENODEV; 605 err("No device or device unplugged %d", retval); 606 goto unlock_exit; 607 } 608 609 /* verify that we actually have some data to read */ 610 if (count == 0) { 611 dbg(1, "%s: read request of 0 bytes", __FUNCTION__); 612 goto unlock_exit; 613 } 614 615 if (read_timeout) { 616 timeout = jiffies + read_timeout * HZ / 1000; 617 } 618 619 /* wait for data */ 620 tower_check_for_read_packet (dev); 621 while (dev->read_packet_length == 0) { 622 if (file->f_flags & O_NONBLOCK) { 623 retval = -EAGAIN; 624 goto unlock_exit; 625 } 626 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 627 if (retval < 0) { 628 goto unlock_exit; 629 } 630 631 /* reset read timeout during read or write activity */ 632 if (read_timeout 633 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 634 timeout = jiffies + read_timeout * HZ / 1000; 635 } 636 /* check for read timeout */ 637 if (read_timeout && time_after (jiffies, timeout)) { 638 retval = -ETIMEDOUT; 639 goto unlock_exit; 640 } 641 tower_check_for_read_packet (dev); 642 } 643 644 /* copy the data from read_buffer into userspace */ 645 bytes_to_read = min(count, dev->read_packet_length); 646 647 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { 648 retval = -EFAULT; 649 goto unlock_exit; 650 } 651 652 spin_lock_irq (&dev->read_buffer_lock); 653 dev->read_buffer_length -= bytes_to_read; 654 dev->read_packet_length -= bytes_to_read; 655 for (i=0; i<dev->read_buffer_length; i++) { 656 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 657 } 658 spin_unlock_irq (&dev->read_buffer_lock); 659 660 retval = bytes_to_read; 661 662 unlock_exit: 663 /* unlock the device */ 664 up (&dev->sem); 665 666 exit: 667 dbg(2, "%s: leave, return value %d", __FUNCTION__, retval); 668 return retval; 669 } 670 671 672 /** 673 * tower_write 674 */ 675 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 676 { 677 struct lego_usb_tower *dev; 678 size_t bytes_to_write; 679 int retval = 0; 680 681 dbg(2, "%s: enter, count = %Zd", __FUNCTION__, count); 682 683 dev = (struct lego_usb_tower *)file->private_data; 684 685 /* lock this object */ 686 if (down_interruptible (&dev->sem)) { 687 retval = -ERESTARTSYS; 688 goto exit; 689 } 690 691 /* verify that the device wasn't unplugged */ 692 if (dev->udev == NULL) { 693 retval = -ENODEV; 694 err("No device or device unplugged %d", retval); 695 goto unlock_exit; 696 } 697 698 /* verify that we actually have some data to write */ 699 if (count == 0) { 700 dbg(1, "%s: write request of 0 bytes", __FUNCTION__); 701 goto unlock_exit; 702 } 703 704 /* wait until previous transfer is finished */ 705 while (dev->interrupt_out_busy) { 706 if (file->f_flags & O_NONBLOCK) { 707 retval = -EAGAIN; 708 goto unlock_exit; 709 } 710 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); 711 if (retval) { 712 goto unlock_exit; 713 } 714 } 715 716 /* write the data into interrupt_out_buffer from userspace */ 717 bytes_to_write = min_t(int, count, write_buffer_size); 718 dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __FUNCTION__, count, bytes_to_write); 719 720 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { 721 retval = -EFAULT; 722 goto unlock_exit; 723 } 724 725 /* send off the urb */ 726 usb_fill_int_urb(dev->interrupt_out_urb, 727 dev->udev, 728 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 729 dev->interrupt_out_buffer, 730 bytes_to_write, 731 tower_interrupt_out_callback, 732 dev, 733 dev->interrupt_out_interval); 734 735 dev->interrupt_out_busy = 1; 736 wmb(); 737 738 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); 739 if (retval) { 740 dev->interrupt_out_busy = 0; 741 err("Couldn't submit interrupt_out_urb %d", retval); 742 goto unlock_exit; 743 } 744 retval = bytes_to_write; 745 746 unlock_exit: 747 /* unlock the device */ 748 up (&dev->sem); 749 750 exit: 751 dbg(2, "%s: leave, return value %d", __FUNCTION__, retval); 752 753 return retval; 754 } 755 756 757 /** 758 * tower_interrupt_in_callback 759 */ 760 static void tower_interrupt_in_callback (struct urb *urb, struct pt_regs *regs) 761 { 762 struct lego_usb_tower *dev = (struct lego_usb_tower *)urb->context; 763 int retval; 764 765 dbg(4, "%s: enter, status %d", __FUNCTION__, urb->status); 766 767 lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer); 768 769 if (urb->status) { 770 if (urb->status == -ENOENT || 771 urb->status == -ECONNRESET || 772 urb->status == -ESHUTDOWN) { 773 goto exit; 774 } else { 775 dbg(1, "%s: nonzero status received: %d", __FUNCTION__, urb->status); 776 goto resubmit; /* maybe we can recover */ 777 } 778 } 779 780 if (urb->actual_length > 0) { 781 spin_lock (&dev->read_buffer_lock); 782 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 783 memcpy (dev->read_buffer + dev->read_buffer_length, 784 dev->interrupt_in_buffer, 785 urb->actual_length); 786 dev->read_buffer_length += urb->actual_length; 787 dev->read_last_arrival = jiffies; 788 dbg(3, "%s: received %d bytes", __FUNCTION__, urb->actual_length); 789 } else { 790 printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __FUNCTION__, urb->actual_length); 791 } 792 spin_unlock (&dev->read_buffer_lock); 793 } 794 795 resubmit: 796 /* resubmit if we're still running */ 797 if (dev->interrupt_in_running && dev->udev) { 798 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); 799 if (retval) { 800 err("%s: usb_submit_urb failed (%d)", __FUNCTION__, retval); 801 } 802 } 803 804 exit: 805 dev->interrupt_in_done = 1; 806 wake_up_interruptible (&dev->read_wait); 807 808 lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer); 809 dbg(4, "%s: leave, status %d", __FUNCTION__, urb->status); 810 } 811 812 813 /** 814 * tower_interrupt_out_callback 815 */ 816 static void tower_interrupt_out_callback (struct urb *urb, struct pt_regs *regs) 817 { 818 struct lego_usb_tower *dev = (struct lego_usb_tower *)urb->context; 819 820 dbg(4, "%s: enter, status %d", __FUNCTION__, urb->status); 821 lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer); 822 823 /* sync/async unlink faults aren't errors */ 824 if (urb->status && !(urb->status == -ENOENT || 825 urb->status == -ECONNRESET || 826 urb->status == -ESHUTDOWN)) { 827 dbg(1, "%s - nonzero write bulk status received: %d", 828 __FUNCTION__, urb->status); 829 } 830 831 dev->interrupt_out_busy = 0; 832 wake_up_interruptible(&dev->write_wait); 833 834 lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer); 835 dbg(4, "%s: leave, status %d", __FUNCTION__, urb->status); 836 } 837 838 839 /** 840 * tower_probe 841 * 842 * Called by the usb core when a new device is connected that it thinks 843 * this driver might be interested in. 844 */ 845 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) 846 { 847 struct usb_device *udev = interface_to_usbdev(interface); 848 struct lego_usb_tower *dev = NULL; 849 struct usb_host_interface *iface_desc; 850 struct usb_endpoint_descriptor* endpoint; 851 struct tower_get_version_reply get_version_reply; 852 int i; 853 int retval = -ENOMEM; 854 int result; 855 856 dbg(2, "%s: enter", __FUNCTION__); 857 858 if (udev == NULL) { 859 info ("udev is NULL."); 860 } 861 862 /* allocate memory for our device state and intialize it */ 863 864 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL); 865 866 if (dev == NULL) { 867 err ("Out of memory"); 868 goto exit; 869 } 870 871 init_MUTEX (&dev->sem); 872 873 dev->udev = udev; 874 dev->open_count = 0; 875 876 dev->read_buffer = NULL; 877 dev->read_buffer_length = 0; 878 dev->read_packet_length = 0; 879 spin_lock_init (&dev->read_buffer_lock); 880 dev->packet_timeout_jiffies = packet_timeout * HZ / 1000; 881 dev->read_last_arrival = jiffies; 882 883 init_waitqueue_head (&dev->read_wait); 884 init_waitqueue_head (&dev->write_wait); 885 886 dev->interrupt_in_buffer = NULL; 887 dev->interrupt_in_endpoint = NULL; 888 dev->interrupt_in_urb = NULL; 889 dev->interrupt_in_running = 0; 890 dev->interrupt_in_done = 0; 891 892 dev->interrupt_out_buffer = NULL; 893 dev->interrupt_out_endpoint = NULL; 894 dev->interrupt_out_urb = NULL; 895 dev->interrupt_out_busy = 0; 896 897 iface_desc = interface->cur_altsetting; 898 899 /* set up the endpoint information */ 900 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 901 endpoint = &iface_desc->endpoint[i].desc; 902 903 if (((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN) && 904 ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)) { 905 dev->interrupt_in_endpoint = endpoint; 906 } 907 908 if (((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT) && 909 ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)) { 910 dev->interrupt_out_endpoint = endpoint; 911 } 912 } 913 if(dev->interrupt_in_endpoint == NULL) { 914 err("interrupt in endpoint not found"); 915 goto error; 916 } 917 if (dev->interrupt_out_endpoint == NULL) { 918 err("interrupt out endpoint not found"); 919 goto error; 920 } 921 922 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); 923 if (!dev->read_buffer) { 924 err("Couldn't allocate read_buffer"); 925 goto error; 926 } 927 dev->interrupt_in_buffer = kmalloc (le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), GFP_KERNEL); 928 if (!dev->interrupt_in_buffer) { 929 err("Couldn't allocate interrupt_in_buffer"); 930 goto error; 931 } 932 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 933 if (!dev->interrupt_in_urb) { 934 err("Couldn't allocate interrupt_in_urb"); 935 goto error; 936 } 937 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL); 938 if (!dev->interrupt_out_buffer) { 939 err("Couldn't allocate interrupt_out_buffer"); 940 goto error; 941 } 942 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 943 if (!dev->interrupt_out_urb) { 944 err("Couldn't allocate interrupt_out_urb"); 945 goto error; 946 } 947 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 948 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 949 950 /* we can register the device now, as it is ready */ 951 usb_set_intfdata (interface, dev); 952 953 retval = usb_register_dev (interface, &tower_class); 954 955 if (retval) { 956 /* something prevented us from registering this driver */ 957 err ("Not able to get a minor for this device."); 958 usb_set_intfdata (interface, NULL); 959 goto error; 960 } 961 dev->minor = interface->minor; 962 963 /* let the user know what node this device is now attached to */ 964 info ("LEGO USB Tower #%d now attached to major %d minor %d", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), USB_MAJOR, dev->minor); 965 966 /* get the firmware version and log it */ 967 result = usb_control_msg (udev, 968 usb_rcvctrlpipe(udev, 0), 969 LEGO_USB_TOWER_REQUEST_GET_VERSION, 970 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 971 0, 972 0, 973 &get_version_reply, 974 sizeof(get_version_reply), 975 1000); 976 if (result < 0) { 977 err("LEGO USB Tower get version control request failed"); 978 retval = result; 979 goto error; 980 } 981 info("LEGO USB Tower firmware version is %d.%d build %d", 982 get_version_reply.major, 983 get_version_reply.minor, 984 le16_to_cpu(get_version_reply.build_no)); 985 986 987 exit: 988 dbg(2, "%s: leave, return value 0x%.8lx (dev)", __FUNCTION__, (long) dev); 989 990 return retval; 991 992 error: 993 tower_delete(dev); 994 return retval; 995 } 996 997 998 /** 999 * tower_disconnect 1000 * 1001 * Called by the usb core when the device is removed from the system. 1002 */ 1003 static void tower_disconnect (struct usb_interface *interface) 1004 { 1005 struct lego_usb_tower *dev; 1006 int minor; 1007 1008 dbg(2, "%s: enter", __FUNCTION__); 1009 1010 down (&disconnect_sem); 1011 1012 dev = usb_get_intfdata (interface); 1013 usb_set_intfdata (interface, NULL); 1014 1015 1016 down (&dev->sem); 1017 1018 minor = dev->minor; 1019 1020 /* give back our minor */ 1021 usb_deregister_dev (interface, &tower_class); 1022 1023 /* if the device is not opened, then we clean up right now */ 1024 if (!dev->open_count) { 1025 up (&dev->sem); 1026 tower_delete (dev); 1027 } else { 1028 dev->udev = NULL; 1029 up (&dev->sem); 1030 } 1031 1032 up (&disconnect_sem); 1033 1034 info("LEGO USB Tower #%d now disconnected", (minor - LEGO_USB_TOWER_MINOR_BASE)); 1035 1036 dbg(2, "%s: leave", __FUNCTION__); 1037 } 1038 1039 1040 1041 /** 1042 * lego_usb_tower_init 1043 */ 1044 static int __init lego_usb_tower_init(void) 1045 { 1046 int result; 1047 int retval = 0; 1048 1049 dbg(2, "%s: enter", __FUNCTION__); 1050 1051 /* register this driver with the USB subsystem */ 1052 result = usb_register(&tower_driver); 1053 if (result < 0) { 1054 err("usb_register failed for the "__FILE__" driver. Error number %d", result); 1055 retval = -1; 1056 goto exit; 1057 } 1058 1059 info(DRIVER_DESC " " DRIVER_VERSION); 1060 1061 exit: 1062 dbg(2, "%s: leave, return value %d", __FUNCTION__, retval); 1063 1064 return retval; 1065 } 1066 1067 1068 /** 1069 * lego_usb_tower_exit 1070 */ 1071 static void __exit lego_usb_tower_exit(void) 1072 { 1073 dbg(2, "%s: enter", __FUNCTION__); 1074 1075 /* deregister this driver with the USB subsystem */ 1076 usb_deregister (&tower_driver); 1077 1078 dbg(2, "%s: leave", __FUNCTION__); 1079 } 1080 1081 module_init (lego_usb_tower_init); 1082 module_exit (lego_usb_tower_exit); 1083 1084 MODULE_AUTHOR(DRIVER_AUTHOR); 1085 MODULE_DESCRIPTION(DRIVER_DESC); 1086 #ifdef MODULE_LICENSE 1087 MODULE_LICENSE("GPL"); 1088 #endif 1089