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 __func__ 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 __func__ 53 * - read and log tower firmware version 54 * - reset tower on probe, avoids failure of first write 55 * 2004-03-09 - 0.7 Juergen Stuber <starblue@users.sourceforge.net> 56 * - timeout read now only after inactivity, shorten default accordingly 57 * 2004-03-11 - 0.8 Juergen Stuber <starblue@users.sourceforge.net> 58 * - log major, minor instead of possibly confusing device filename 59 * - whitespace cleanup 60 * 2004-03-12 - 0.9 Juergen Stuber <starblue@users.sourceforge.net> 61 * - normalize whitespace in debug messages 62 * - take care about endianness in control message responses 63 * 2004-03-13 - 0.91 Juergen Stuber <starblue@users.sourceforge.net> 64 * - make default intervals longer to accommodate current EHCI driver 65 * 2004-03-19 - 0.92 Juergen Stuber <starblue@users.sourceforge.net> 66 * - replaced atomic_t by memory barriers 67 * 2004-04-21 - 0.93 Juergen Stuber <starblue@users.sourceforge.net> 68 * - wait for completion of write urb in release (needed for remotecontrol) 69 * - corrected poll for write direction (missing negation) 70 * 2004-04-22 - 0.94 Juergen Stuber <starblue@users.sourceforge.net> 71 * - make device locking interruptible 72 * 2004-04-30 - 0.95 Juergen Stuber <starblue@users.sourceforge.net> 73 * - check for valid udev on resubmitting and unlinking urbs 74 * 2004-08-03 - 0.96 Juergen Stuber <starblue@users.sourceforge.net> 75 * - move reset into open to clean out spurious data 76 */ 77 78 #include <linux/kernel.h> 79 #include <linux/errno.h> 80 #include <linux/init.h> 81 #include <linux/slab.h> 82 #include <linux/module.h> 83 #include <linux/completion.h> 84 #include <linux/mutex.h> 85 #include <asm/uaccess.h> 86 #include <linux/usb.h> 87 #include <linux/poll.h> 88 89 90 #ifdef CONFIG_USB_DEBUG 91 static int debug = 4; 92 #else 93 static int debug = 0; 94 #endif 95 96 /* Use our own dbg macro */ 97 #undef dbg 98 #define dbg(lvl, format, arg...) do { if (debug >= lvl) printk(KERN_DEBUG __FILE__ ": " format "\n", ## arg); } while (0) 99 100 101 /* Version Information */ 102 #define DRIVER_VERSION "v0.96" 103 #define DRIVER_AUTHOR "Juergen Stuber <starblue@sourceforge.net>" 104 #define DRIVER_DESC "LEGO USB Tower Driver" 105 106 /* Module parameters */ 107 module_param(debug, int, S_IRUGO | S_IWUSR); 108 MODULE_PARM_DESC(debug, "Debug enabled or not"); 109 110 /* The defaults are chosen to work with the latest versions of leJOS and NQC. 111 */ 112 113 /* Some legacy software likes to receive packets in one piece. 114 * In this case read_buffer_size should exceed the maximal packet length 115 * (417 for datalog uploads), and packet_timeout should be set. 116 */ 117 static int read_buffer_size = 480; 118 module_param(read_buffer_size, int, 0); 119 MODULE_PARM_DESC(read_buffer_size, "Read buffer size"); 120 121 /* Some legacy software likes to send packets in one piece. 122 * In this case write_buffer_size should exceed the maximal packet length 123 * (417 for firmware and program downloads). 124 * A problem with long writes is that the following read may time out 125 * if the software is not prepared to wait long enough. 126 */ 127 static int write_buffer_size = 480; 128 module_param(write_buffer_size, int, 0); 129 MODULE_PARM_DESC(write_buffer_size, "Write buffer size"); 130 131 /* Some legacy software expects reads to contain whole LASM packets. 132 * To achieve this, characters which arrive before a packet timeout 133 * occurs will be returned in a single read operation. 134 * A problem with long reads is that the software may time out 135 * if it is not prepared to wait long enough. 136 * The packet timeout should be greater than the time between the 137 * reception of subsequent characters, which should arrive about 138 * every 5ms for the standard 2400 baud. 139 * Set it to 0 to disable. 140 */ 141 static int packet_timeout = 50; 142 module_param(packet_timeout, int, 0); 143 MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms"); 144 145 /* Some legacy software expects blocking reads to time out. 146 * Timeout occurs after the specified time of read and write inactivity. 147 * Set it to 0 to disable. 148 */ 149 static int read_timeout = 200; 150 module_param(read_timeout, int, 0); 151 MODULE_PARM_DESC(read_timeout, "Read timeout in ms"); 152 153 /* As of kernel version 2.6.4 ehci-hcd uses an 154 * "only one interrupt transfer per frame" shortcut 155 * to simplify the scheduling of periodic transfers. 156 * This conflicts with our standard 1ms intervals for in and out URBs. 157 * We use default intervals of 2ms for in and 8ms for out transfers, 158 * which is fast enough for 2400 baud and allows a small additional load. 159 * Increase the interval to allow more devices that do interrupt transfers, 160 * or set to 0 to use the standard interval from the endpoint descriptors. 161 */ 162 static int interrupt_in_interval = 2; 163 module_param(interrupt_in_interval, int, 0); 164 MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms"); 165 166 static int interrupt_out_interval = 8; 167 module_param(interrupt_out_interval, int, 0); 168 MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms"); 169 170 /* Define these values to match your device */ 171 #define LEGO_USB_TOWER_VENDOR_ID 0x0694 172 #define LEGO_USB_TOWER_PRODUCT_ID 0x0001 173 174 /* Vendor requests */ 175 #define LEGO_USB_TOWER_REQUEST_RESET 0x04 176 #define LEGO_USB_TOWER_REQUEST_GET_VERSION 0xFD 177 178 struct tower_reset_reply { 179 __le16 size; /* little-endian */ 180 __u8 err_code; 181 __u8 spare; 182 } __attribute__ ((packed)); 183 184 struct tower_get_version_reply { 185 __le16 size; /* little-endian */ 186 __u8 err_code; 187 __u8 spare; 188 __u8 major; 189 __u8 minor; 190 __le16 build_no; /* little-endian */ 191 } __attribute__ ((packed)); 192 193 194 /* table of devices that work with this driver */ 195 static struct usb_device_id tower_table [] = { 196 { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) }, 197 { } /* Terminating entry */ 198 }; 199 200 MODULE_DEVICE_TABLE (usb, tower_table); 201 static DEFINE_MUTEX(open_disc_mutex); 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 mutex lock; /* locks this structure */ 209 struct usb_device* udev; /* save off the usb device pointer */ 210 unsigned char minor; /* the starting minor number for this device */ 211 212 int open_count; /* number of times this port has been opened */ 213 214 char* read_buffer; 215 size_t read_buffer_length; /* this much came in */ 216 size_t read_packet_length; /* this much will be returned on read */ 217 spinlock_t read_buffer_lock; 218 int packet_timeout_jiffies; 219 unsigned long read_last_arrival; 220 221 wait_queue_head_t read_wait; 222 wait_queue_head_t write_wait; 223 224 char* interrupt_in_buffer; 225 struct usb_endpoint_descriptor* interrupt_in_endpoint; 226 struct urb* interrupt_in_urb; 227 int interrupt_in_interval; 228 int interrupt_in_running; 229 int interrupt_in_done; 230 231 char* interrupt_out_buffer; 232 struct usb_endpoint_descriptor* interrupt_out_endpoint; 233 struct urb* interrupt_out_urb; 234 int interrupt_out_interval; 235 int interrupt_out_busy; 236 237 }; 238 239 240 /* local function prototypes */ 241 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos); 242 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos); 243 static inline void tower_delete (struct lego_usb_tower *dev); 244 static int tower_open (struct inode *inode, struct file *file); 245 static int tower_release (struct inode *inode, struct file *file); 246 static unsigned int tower_poll (struct file *file, poll_table *wait); 247 static loff_t tower_llseek (struct file *file, loff_t off, int whence); 248 249 static void tower_abort_transfers (struct lego_usb_tower *dev); 250 static void tower_check_for_read_packet (struct lego_usb_tower *dev); 251 static void tower_interrupt_in_callback (struct urb *urb); 252 static void tower_interrupt_out_callback (struct urb *urb); 253 254 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id); 255 static void tower_disconnect (struct usb_interface *interface); 256 257 258 /* file operations needed when we register this driver */ 259 static const struct file_operations tower_fops = { 260 .owner = THIS_MODULE, 261 .read = tower_read, 262 .write = tower_write, 263 .open = tower_open, 264 .release = tower_release, 265 .poll = tower_poll, 266 .llseek = tower_llseek, 267 }; 268 269 /* 270 * usb class driver info in order to get a minor number from the usb core, 271 * and to have the device registered with the driver core 272 */ 273 static struct usb_class_driver tower_class = { 274 .name = "legousbtower%d", 275 .fops = &tower_fops, 276 .minor_base = LEGO_USB_TOWER_MINOR_BASE, 277 }; 278 279 280 /* usb specific object needed to register this driver with the usb subsystem */ 281 static struct usb_driver tower_driver = { 282 .name = "legousbtower", 283 .probe = tower_probe, 284 .disconnect = tower_disconnect, 285 .id_table = tower_table, 286 }; 287 288 289 /** 290 * lego_usb_tower_debug_data 291 */ 292 static inline void lego_usb_tower_debug_data (int level, const char *function, int size, const unsigned char *data) 293 { 294 int i; 295 296 if (debug < level) 297 return; 298 299 printk (KERN_DEBUG __FILE__": %s - length = %d, data = ", function, size); 300 for (i = 0; i < size; ++i) { 301 printk ("%.2x ", data[i]); 302 } 303 printk ("\n"); 304 } 305 306 307 /** 308 * tower_delete 309 */ 310 static inline void tower_delete (struct lego_usb_tower *dev) 311 { 312 dbg(2, "%s: enter", __func__); 313 314 tower_abort_transfers (dev); 315 316 /* free data structures */ 317 usb_free_urb(dev->interrupt_in_urb); 318 usb_free_urb(dev->interrupt_out_urb); 319 kfree (dev->read_buffer); 320 kfree (dev->interrupt_in_buffer); 321 kfree (dev->interrupt_out_buffer); 322 kfree (dev); 323 324 dbg(2, "%s: leave", __func__); 325 } 326 327 328 /** 329 * tower_open 330 */ 331 static int tower_open (struct inode *inode, struct file *file) 332 { 333 struct lego_usb_tower *dev = NULL; 334 int subminor; 335 int retval = 0; 336 struct usb_interface *interface; 337 struct tower_reset_reply reset_reply; 338 int result; 339 340 dbg(2, "%s: enter", __func__); 341 342 nonseekable_open(inode, file); 343 subminor = iminor(inode); 344 345 interface = usb_find_interface (&tower_driver, subminor); 346 347 if (!interface) { 348 err ("%s - error, can't find device for minor %d", 349 __func__, subminor); 350 retval = -ENODEV; 351 goto exit; 352 } 353 354 mutex_lock(&open_disc_mutex); 355 dev = usb_get_intfdata(interface); 356 357 if (!dev) { 358 mutex_unlock(&open_disc_mutex); 359 retval = -ENODEV; 360 goto exit; 361 } 362 363 /* lock this device */ 364 if (mutex_lock_interruptible(&dev->lock)) { 365 mutex_unlock(&open_disc_mutex); 366 retval = -ERESTARTSYS; 367 goto exit; 368 } 369 370 371 /* allow opening only once */ 372 if (dev->open_count) { 373 mutex_unlock(&open_disc_mutex); 374 retval = -EBUSY; 375 goto unlock_exit; 376 } 377 dev->open_count = 1; 378 mutex_unlock(&open_disc_mutex); 379 380 /* reset the tower */ 381 result = usb_control_msg (dev->udev, 382 usb_rcvctrlpipe(dev->udev, 0), 383 LEGO_USB_TOWER_REQUEST_RESET, 384 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 385 0, 386 0, 387 &reset_reply, 388 sizeof(reset_reply), 389 1000); 390 if (result < 0) { 391 err("LEGO USB Tower reset control request failed"); 392 retval = result; 393 goto unlock_exit; 394 } 395 396 /* initialize in direction */ 397 dev->read_buffer_length = 0; 398 dev->read_packet_length = 0; 399 usb_fill_int_urb (dev->interrupt_in_urb, 400 dev->udev, 401 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress), 402 dev->interrupt_in_buffer, 403 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), 404 tower_interrupt_in_callback, 405 dev, 406 dev->interrupt_in_interval); 407 408 dev->interrupt_in_running = 1; 409 dev->interrupt_in_done = 0; 410 mb(); 411 412 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL); 413 if (retval) { 414 err("Couldn't submit interrupt_in_urb %d", retval); 415 dev->interrupt_in_running = 0; 416 dev->open_count = 0; 417 goto unlock_exit; 418 } 419 420 /* save device in the file's private structure */ 421 file->private_data = dev; 422 423 unlock_exit: 424 mutex_unlock(&dev->lock); 425 426 exit: 427 dbg(2, "%s: leave, return value %d ", __func__, retval); 428 429 return retval; 430 } 431 432 /** 433 * tower_release 434 */ 435 static int tower_release (struct inode *inode, struct file *file) 436 { 437 struct lego_usb_tower *dev; 438 int retval = 0; 439 440 dbg(2, "%s: enter", __func__); 441 442 dev = (struct lego_usb_tower *)file->private_data; 443 444 if (dev == NULL) { 445 dbg(1, "%s: object is NULL", __func__); 446 retval = -ENODEV; 447 goto exit_nolock; 448 } 449 450 mutex_lock(&open_disc_mutex); 451 if (mutex_lock_interruptible(&dev->lock)) { 452 retval = -ERESTARTSYS; 453 goto exit; 454 } 455 456 if (dev->open_count != 1) { 457 dbg(1, "%s: device not opened exactly once", __func__); 458 retval = -ENODEV; 459 goto unlock_exit; 460 } 461 if (dev->udev == NULL) { 462 /* the device was unplugged before the file was released */ 463 464 /* unlock here as tower_delete frees dev */ 465 mutex_unlock(&dev->lock); 466 tower_delete (dev); 467 goto exit; 468 } 469 470 /* wait until write transfer is finished */ 471 if (dev->interrupt_out_busy) { 472 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 473 } 474 tower_abort_transfers (dev); 475 dev->open_count = 0; 476 477 unlock_exit: 478 mutex_unlock(&dev->lock); 479 480 exit: 481 mutex_unlock(&open_disc_mutex); 482 exit_nolock: 483 dbg(2, "%s: leave, return value %d", __func__, 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", __func__); 495 496 if (dev == NULL) { 497 dbg(1, "%s: dev is null", __func__); 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->udev) 506 usb_kill_urb (dev->interrupt_in_urb); 507 } 508 if (dev->interrupt_out_busy && dev->udev) 509 usb_kill_urb(dev->interrupt_out_urb); 510 511 exit: 512 dbg(2, "%s: leave", __func__); 513 } 514 515 516 /** 517 * tower_check_for_read_packet 518 * 519 * To get correct semantics for signals and non-blocking I/O 520 * with packetizing we pretend not to see any data in the read buffer 521 * until it has been there unchanged for at least 522 * dev->packet_timeout_jiffies, or until the buffer is full. 523 */ 524 static void tower_check_for_read_packet (struct lego_usb_tower *dev) 525 { 526 spin_lock_irq (&dev->read_buffer_lock); 527 if (!packet_timeout 528 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) 529 || dev->read_buffer_length == read_buffer_size) { 530 dev->read_packet_length = dev->read_buffer_length; 531 } 532 dev->interrupt_in_done = 0; 533 spin_unlock_irq (&dev->read_buffer_lock); 534 } 535 536 537 /** 538 * tower_poll 539 */ 540 static unsigned int tower_poll (struct file *file, poll_table *wait) 541 { 542 struct lego_usb_tower *dev; 543 unsigned int mask = 0; 544 545 dbg(2, "%s: enter", __func__); 546 547 dev = file->private_data; 548 549 poll_wait(file, &dev->read_wait, wait); 550 poll_wait(file, &dev->write_wait, wait); 551 552 tower_check_for_read_packet(dev); 553 if (dev->read_packet_length > 0) { 554 mask |= POLLIN | POLLRDNORM; 555 } 556 if (!dev->interrupt_out_busy) { 557 mask |= POLLOUT | POLLWRNORM; 558 } 559 560 dbg(2, "%s: leave, mask = %d", __func__, mask); 561 562 return mask; 563 } 564 565 566 /** 567 * tower_llseek 568 */ 569 static loff_t tower_llseek (struct file *file, loff_t off, int whence) 570 { 571 return -ESPIPE; /* unseekable */ 572 } 573 574 575 /** 576 * tower_read 577 */ 578 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 579 { 580 struct lego_usb_tower *dev; 581 size_t bytes_to_read; 582 int i; 583 int retval = 0; 584 unsigned long timeout = 0; 585 586 dbg(2, "%s: enter, count = %Zd", __func__, count); 587 588 dev = (struct lego_usb_tower *)file->private_data; 589 590 /* lock this object */ 591 if (mutex_lock_interruptible(&dev->lock)) { 592 retval = -ERESTARTSYS; 593 goto exit; 594 } 595 596 /* verify that the device wasn't unplugged */ 597 if (dev->udev == NULL) { 598 retval = -ENODEV; 599 err("No device or device unplugged %d", retval); 600 goto unlock_exit; 601 } 602 603 /* verify that we actually have some data to read */ 604 if (count == 0) { 605 dbg(1, "%s: read request of 0 bytes", __func__); 606 goto unlock_exit; 607 } 608 609 if (read_timeout) { 610 timeout = jiffies + read_timeout * HZ / 1000; 611 } 612 613 /* wait for data */ 614 tower_check_for_read_packet (dev); 615 while (dev->read_packet_length == 0) { 616 if (file->f_flags & O_NONBLOCK) { 617 retval = -EAGAIN; 618 goto unlock_exit; 619 } 620 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 621 if (retval < 0) { 622 goto unlock_exit; 623 } 624 625 /* reset read timeout during read or write activity */ 626 if (read_timeout 627 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 628 timeout = jiffies + read_timeout * HZ / 1000; 629 } 630 /* check for read timeout */ 631 if (read_timeout && time_after (jiffies, timeout)) { 632 retval = -ETIMEDOUT; 633 goto unlock_exit; 634 } 635 tower_check_for_read_packet (dev); 636 } 637 638 /* copy the data from read_buffer into userspace */ 639 bytes_to_read = min(count, dev->read_packet_length); 640 641 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { 642 retval = -EFAULT; 643 goto unlock_exit; 644 } 645 646 spin_lock_irq (&dev->read_buffer_lock); 647 dev->read_buffer_length -= bytes_to_read; 648 dev->read_packet_length -= bytes_to_read; 649 for (i=0; i<dev->read_buffer_length; i++) { 650 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 651 } 652 spin_unlock_irq (&dev->read_buffer_lock); 653 654 retval = bytes_to_read; 655 656 unlock_exit: 657 /* unlock the device */ 658 mutex_unlock(&dev->lock); 659 660 exit: 661 dbg(2, "%s: leave, return value %d", __func__, retval); 662 return retval; 663 } 664 665 666 /** 667 * tower_write 668 */ 669 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 670 { 671 struct lego_usb_tower *dev; 672 size_t bytes_to_write; 673 int retval = 0; 674 675 dbg(2, "%s: enter, count = %Zd", __func__, count); 676 677 dev = (struct lego_usb_tower *)file->private_data; 678 679 /* lock this object */ 680 if (mutex_lock_interruptible(&dev->lock)) { 681 retval = -ERESTARTSYS; 682 goto exit; 683 } 684 685 /* verify that the device wasn't unplugged */ 686 if (dev->udev == NULL) { 687 retval = -ENODEV; 688 err("No device or device unplugged %d", retval); 689 goto unlock_exit; 690 } 691 692 /* verify that we actually have some data to write */ 693 if (count == 0) { 694 dbg(1, "%s: write request of 0 bytes", __func__); 695 goto unlock_exit; 696 } 697 698 /* wait until previous transfer is finished */ 699 while (dev->interrupt_out_busy) { 700 if (file->f_flags & O_NONBLOCK) { 701 retval = -EAGAIN; 702 goto unlock_exit; 703 } 704 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); 705 if (retval) { 706 goto unlock_exit; 707 } 708 } 709 710 /* write the data into interrupt_out_buffer from userspace */ 711 bytes_to_write = min_t(int, count, write_buffer_size); 712 dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __func__, count, bytes_to_write); 713 714 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { 715 retval = -EFAULT; 716 goto unlock_exit; 717 } 718 719 /* send off the urb */ 720 usb_fill_int_urb(dev->interrupt_out_urb, 721 dev->udev, 722 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 723 dev->interrupt_out_buffer, 724 bytes_to_write, 725 tower_interrupt_out_callback, 726 dev, 727 dev->interrupt_out_interval); 728 729 dev->interrupt_out_busy = 1; 730 wmb(); 731 732 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); 733 if (retval) { 734 dev->interrupt_out_busy = 0; 735 err("Couldn't submit interrupt_out_urb %d", retval); 736 goto unlock_exit; 737 } 738 retval = bytes_to_write; 739 740 unlock_exit: 741 /* unlock the device */ 742 mutex_unlock(&dev->lock); 743 744 exit: 745 dbg(2, "%s: leave, return value %d", __func__, retval); 746 747 return retval; 748 } 749 750 751 /** 752 * tower_interrupt_in_callback 753 */ 754 static void tower_interrupt_in_callback (struct urb *urb) 755 { 756 struct lego_usb_tower *dev = urb->context; 757 int status = urb->status; 758 int retval; 759 760 dbg(4, "%s: enter, status %d", __func__, status); 761 762 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 763 764 if (status) { 765 if (status == -ENOENT || 766 status == -ECONNRESET || 767 status == -ESHUTDOWN) { 768 goto exit; 769 } else { 770 dbg(1, "%s: nonzero status received: %d", __func__, status); 771 goto resubmit; /* maybe we can recover */ 772 } 773 } 774 775 if (urb->actual_length > 0) { 776 spin_lock (&dev->read_buffer_lock); 777 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 778 memcpy (dev->read_buffer + dev->read_buffer_length, 779 dev->interrupt_in_buffer, 780 urb->actual_length); 781 dev->read_buffer_length += urb->actual_length; 782 dev->read_last_arrival = jiffies; 783 dbg(3, "%s: received %d bytes", __func__, urb->actual_length); 784 } else { 785 printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __func__, urb->actual_length); 786 } 787 spin_unlock (&dev->read_buffer_lock); 788 } 789 790 resubmit: 791 /* resubmit if we're still running */ 792 if (dev->interrupt_in_running && dev->udev) { 793 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); 794 if (retval) { 795 err("%s: usb_submit_urb failed (%d)", __func__, retval); 796 } 797 } 798 799 exit: 800 dev->interrupt_in_done = 1; 801 wake_up_interruptible (&dev->read_wait); 802 803 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 804 dbg(4, "%s: leave, status %d", __func__, status); 805 } 806 807 808 /** 809 * tower_interrupt_out_callback 810 */ 811 static void tower_interrupt_out_callback (struct urb *urb) 812 { 813 struct lego_usb_tower *dev = urb->context; 814 int status = urb->status; 815 816 dbg(4, "%s: enter, status %d", __func__, status); 817 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 818 819 /* sync/async unlink faults aren't errors */ 820 if (status && !(status == -ENOENT || 821 status == -ECONNRESET || 822 status == -ESHUTDOWN)) { 823 dbg(1, "%s - nonzero write bulk status received: %d", 824 __func__, status); 825 } 826 827 dev->interrupt_out_busy = 0; 828 wake_up_interruptible(&dev->write_wait); 829 830 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 831 dbg(4, "%s: leave, status %d", __func__, status); 832 } 833 834 835 /** 836 * tower_probe 837 * 838 * Called by the usb core when a new device is connected that it thinks 839 * this driver might be interested in. 840 */ 841 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) 842 { 843 struct usb_device *udev = interface_to_usbdev(interface); 844 struct lego_usb_tower *dev = NULL; 845 struct usb_host_interface *iface_desc; 846 struct usb_endpoint_descriptor* endpoint; 847 struct tower_get_version_reply get_version_reply; 848 int i; 849 int retval = -ENOMEM; 850 int result; 851 852 dbg(2, "%s: enter", __func__); 853 854 if (udev == NULL) 855 dev_info(&interface->dev, "udev is NULL.\n"); 856 857 /* allocate memory for our device state and initialize it */ 858 859 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL); 860 861 if (dev == NULL) { 862 err ("Out of memory"); 863 goto exit; 864 } 865 866 mutex_init(&dev->lock); 867 868 dev->udev = udev; 869 dev->open_count = 0; 870 871 dev->read_buffer = NULL; 872 dev->read_buffer_length = 0; 873 dev->read_packet_length = 0; 874 spin_lock_init (&dev->read_buffer_lock); 875 dev->packet_timeout_jiffies = packet_timeout * HZ / 1000; 876 dev->read_last_arrival = jiffies; 877 878 init_waitqueue_head (&dev->read_wait); 879 init_waitqueue_head (&dev->write_wait); 880 881 dev->interrupt_in_buffer = NULL; 882 dev->interrupt_in_endpoint = NULL; 883 dev->interrupt_in_urb = NULL; 884 dev->interrupt_in_running = 0; 885 dev->interrupt_in_done = 0; 886 887 dev->interrupt_out_buffer = NULL; 888 dev->interrupt_out_endpoint = NULL; 889 dev->interrupt_out_urb = NULL; 890 dev->interrupt_out_busy = 0; 891 892 iface_desc = interface->cur_altsetting; 893 894 /* set up the endpoint information */ 895 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 896 endpoint = &iface_desc->endpoint[i].desc; 897 898 if (usb_endpoint_xfer_int(endpoint)) { 899 if (usb_endpoint_dir_in(endpoint)) 900 dev->interrupt_in_endpoint = endpoint; 901 else 902 dev->interrupt_out_endpoint = endpoint; 903 } 904 } 905 if(dev->interrupt_in_endpoint == NULL) { 906 err("interrupt in endpoint not found"); 907 goto error; 908 } 909 if (dev->interrupt_out_endpoint == NULL) { 910 err("interrupt out endpoint not found"); 911 goto error; 912 } 913 914 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); 915 if (!dev->read_buffer) { 916 err("Couldn't allocate read_buffer"); 917 goto error; 918 } 919 dev->interrupt_in_buffer = kmalloc (le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), GFP_KERNEL); 920 if (!dev->interrupt_in_buffer) { 921 err("Couldn't allocate interrupt_in_buffer"); 922 goto error; 923 } 924 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 925 if (!dev->interrupt_in_urb) { 926 err("Couldn't allocate interrupt_in_urb"); 927 goto error; 928 } 929 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL); 930 if (!dev->interrupt_out_buffer) { 931 err("Couldn't allocate interrupt_out_buffer"); 932 goto error; 933 } 934 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 935 if (!dev->interrupt_out_urb) { 936 err("Couldn't allocate interrupt_out_urb"); 937 goto error; 938 } 939 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 940 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 941 942 /* we can register the device now, as it is ready */ 943 usb_set_intfdata (interface, dev); 944 945 retval = usb_register_dev (interface, &tower_class); 946 947 if (retval) { 948 /* something prevented us from registering this driver */ 949 err ("Not able to get a minor for this device."); 950 usb_set_intfdata (interface, NULL); 951 goto error; 952 } 953 dev->minor = interface->minor; 954 955 /* let the user know what node this device is now attached to */ 956 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major " 957 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), 958 USB_MAJOR, dev->minor); 959 960 /* get the firmware version and log it */ 961 result = usb_control_msg (udev, 962 usb_rcvctrlpipe(udev, 0), 963 LEGO_USB_TOWER_REQUEST_GET_VERSION, 964 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 965 0, 966 0, 967 &get_version_reply, 968 sizeof(get_version_reply), 969 1000); 970 if (result < 0) { 971 err("LEGO USB Tower get version control request failed"); 972 retval = result; 973 goto error; 974 } 975 dev_info(&interface->dev, "LEGO USB Tower firmware version is %d.%d " 976 "build %d\n", get_version_reply.major, 977 get_version_reply.minor, 978 le16_to_cpu(get_version_reply.build_no)); 979 980 981 exit: 982 dbg(2, "%s: leave, return value 0x%.8lx (dev)", __func__, (long) dev); 983 984 return retval; 985 986 error: 987 tower_delete(dev); 988 return retval; 989 } 990 991 992 /** 993 * tower_disconnect 994 * 995 * Called by the usb core when the device is removed from the system. 996 */ 997 static void tower_disconnect (struct usb_interface *interface) 998 { 999 struct lego_usb_tower *dev; 1000 int minor; 1001 1002 dbg(2, "%s: enter", __func__); 1003 1004 dev = usb_get_intfdata (interface); 1005 mutex_lock(&open_disc_mutex); 1006 usb_set_intfdata (interface, NULL); 1007 1008 minor = dev->minor; 1009 1010 /* give back our minor */ 1011 usb_deregister_dev (interface, &tower_class); 1012 1013 mutex_lock(&dev->lock); 1014 mutex_unlock(&open_disc_mutex); 1015 1016 /* if the device is not opened, then we clean up right now */ 1017 if (!dev->open_count) { 1018 mutex_unlock(&dev->lock); 1019 tower_delete (dev); 1020 } else { 1021 dev->udev = NULL; 1022 mutex_unlock(&dev->lock); 1023 } 1024 1025 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n", 1026 (minor - LEGO_USB_TOWER_MINOR_BASE)); 1027 1028 dbg(2, "%s: leave", __func__); 1029 } 1030 1031 1032 1033 /** 1034 * lego_usb_tower_init 1035 */ 1036 static int __init lego_usb_tower_init(void) 1037 { 1038 int result; 1039 int retval = 0; 1040 1041 dbg(2, "%s: enter", __func__); 1042 1043 /* register this driver with the USB subsystem */ 1044 result = usb_register(&tower_driver); 1045 if (result < 0) { 1046 err("usb_register failed for the "__FILE__" driver. Error number %d", result); 1047 retval = -1; 1048 goto exit; 1049 } 1050 1051 printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":" 1052 DRIVER_DESC "\n"); 1053 1054 exit: 1055 dbg(2, "%s: leave, return value %d", __func__, retval); 1056 1057 return retval; 1058 } 1059 1060 1061 /** 1062 * lego_usb_tower_exit 1063 */ 1064 static void __exit lego_usb_tower_exit(void) 1065 { 1066 dbg(2, "%s: enter", __func__); 1067 1068 /* deregister this driver with the USB subsystem */ 1069 usb_deregister (&tower_driver); 1070 1071 dbg(2, "%s: leave", __func__); 1072 } 1073 1074 module_init (lego_usb_tower_init); 1075 module_exit (lego_usb_tower_exit); 1076 1077 MODULE_AUTHOR(DRIVER_AUTHOR); 1078 MODULE_DESCRIPTION(DRIVER_DESC); 1079 #ifdef MODULE_LICENSE 1080 MODULE_LICENSE("GPL"); 1081 #endif 1082