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