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