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...) \ 99 do { \ 100 if (debug >= lvl) \ 101 printk(KERN_DEBUG "%s: " format "\n", __FILE__, ##arg); \ 102 } while (0) 103 104 /* Version Information */ 105 #define DRIVER_VERSION "v0.96" 106 #define DRIVER_AUTHOR "Juergen Stuber <starblue@sourceforge.net>" 107 #define DRIVER_DESC "LEGO USB Tower Driver" 108 109 /* Module parameters */ 110 module_param(debug, int, S_IRUGO | S_IWUSR); 111 MODULE_PARM_DESC(debug, "Debug enabled or not"); 112 113 /* The defaults are chosen to work with the latest versions of leJOS and NQC. 114 */ 115 116 /* Some legacy software likes to receive packets in one piece. 117 * In this case read_buffer_size should exceed the maximal packet length 118 * (417 for datalog uploads), and packet_timeout should be set. 119 */ 120 static int read_buffer_size = 480; 121 module_param(read_buffer_size, int, 0); 122 MODULE_PARM_DESC(read_buffer_size, "Read buffer size"); 123 124 /* Some legacy software likes to send packets in one piece. 125 * In this case write_buffer_size should exceed the maximal packet length 126 * (417 for firmware and program downloads). 127 * A problem with long writes is that the following read may time out 128 * if the software is not prepared to wait long enough. 129 */ 130 static int write_buffer_size = 480; 131 module_param(write_buffer_size, int, 0); 132 MODULE_PARM_DESC(write_buffer_size, "Write buffer size"); 133 134 /* Some legacy software expects reads to contain whole LASM packets. 135 * To achieve this, characters which arrive before a packet timeout 136 * occurs will be returned in a single read operation. 137 * A problem with long reads is that the software may time out 138 * if it is not prepared to wait long enough. 139 * The packet timeout should be greater than the time between the 140 * reception of subsequent characters, which should arrive about 141 * every 5ms for the standard 2400 baud. 142 * Set it to 0 to disable. 143 */ 144 static int packet_timeout = 50; 145 module_param(packet_timeout, int, 0); 146 MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms"); 147 148 /* Some legacy software expects blocking reads to time out. 149 * Timeout occurs after the specified time of read and write inactivity. 150 * Set it to 0 to disable. 151 */ 152 static int read_timeout = 200; 153 module_param(read_timeout, int, 0); 154 MODULE_PARM_DESC(read_timeout, "Read timeout in ms"); 155 156 /* As of kernel version 2.6.4 ehci-hcd uses an 157 * "only one interrupt transfer per frame" shortcut 158 * to simplify the scheduling of periodic transfers. 159 * This conflicts with our standard 1ms intervals for in and out URBs. 160 * We use default intervals of 2ms for in and 8ms for out transfers, 161 * which is fast enough for 2400 baud and allows a small additional load. 162 * Increase the interval to allow more devices that do interrupt transfers, 163 * or set to 0 to use the standard interval from the endpoint descriptors. 164 */ 165 static int interrupt_in_interval = 2; 166 module_param(interrupt_in_interval, int, 0); 167 MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms"); 168 169 static int interrupt_out_interval = 8; 170 module_param(interrupt_out_interval, int, 0); 171 MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms"); 172 173 /* Define these values to match your device */ 174 #define LEGO_USB_TOWER_VENDOR_ID 0x0694 175 #define LEGO_USB_TOWER_PRODUCT_ID 0x0001 176 177 /* Vendor requests */ 178 #define LEGO_USB_TOWER_REQUEST_RESET 0x04 179 #define LEGO_USB_TOWER_REQUEST_GET_VERSION 0xFD 180 181 struct tower_reset_reply { 182 __le16 size; /* little-endian */ 183 __u8 err_code; 184 __u8 spare; 185 } __attribute__ ((packed)); 186 187 struct tower_get_version_reply { 188 __le16 size; /* little-endian */ 189 __u8 err_code; 190 __u8 spare; 191 __u8 major; 192 __u8 minor; 193 __le16 build_no; /* little-endian */ 194 } __attribute__ ((packed)); 195 196 197 /* table of devices that work with this driver */ 198 static const struct usb_device_id tower_table[] = { 199 { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) }, 200 { } /* Terminating entry */ 201 }; 202 203 MODULE_DEVICE_TABLE (usb, tower_table); 204 static DEFINE_MUTEX(open_disc_mutex); 205 206 #define LEGO_USB_TOWER_MINOR_BASE 160 207 208 209 /* Structure to hold all of our device specific stuff */ 210 struct lego_usb_tower { 211 struct mutex lock; /* locks this structure */ 212 struct usb_device* udev; /* save off the usb device pointer */ 213 unsigned char minor; /* the starting minor number for this device */ 214 215 int open_count; /* number of times this port has been opened */ 216 217 char* read_buffer; 218 size_t read_buffer_length; /* this much came in */ 219 size_t read_packet_length; /* this much will be returned on read */ 220 spinlock_t read_buffer_lock; 221 int packet_timeout_jiffies; 222 unsigned long read_last_arrival; 223 224 wait_queue_head_t read_wait; 225 wait_queue_head_t write_wait; 226 227 char* interrupt_in_buffer; 228 struct usb_endpoint_descriptor* interrupt_in_endpoint; 229 struct urb* interrupt_in_urb; 230 int interrupt_in_interval; 231 int interrupt_in_running; 232 int interrupt_in_done; 233 234 char* interrupt_out_buffer; 235 struct usb_endpoint_descriptor* interrupt_out_endpoint; 236 struct urb* interrupt_out_urb; 237 int interrupt_out_interval; 238 int interrupt_out_busy; 239 240 }; 241 242 243 /* local function prototypes */ 244 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos); 245 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos); 246 static inline void tower_delete (struct lego_usb_tower *dev); 247 static int tower_open (struct inode *inode, struct file *file); 248 static int tower_release (struct inode *inode, struct file *file); 249 static unsigned int tower_poll (struct file *file, poll_table *wait); 250 static loff_t tower_llseek (struct file *file, loff_t off, int whence); 251 252 static void tower_abort_transfers (struct lego_usb_tower *dev); 253 static void tower_check_for_read_packet (struct lego_usb_tower *dev); 254 static void tower_interrupt_in_callback (struct urb *urb); 255 static void tower_interrupt_out_callback (struct urb *urb); 256 257 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id); 258 static void tower_disconnect (struct usb_interface *interface); 259 260 261 /* file operations needed when we register this driver */ 262 static const 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 static char *legousbtower_devnode(struct device *dev, umode_t *mode) 273 { 274 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev)); 275 } 276 277 /* 278 * usb class driver info in order to get a minor number from the usb core, 279 * and to have the device registered with the driver core 280 */ 281 static struct usb_class_driver tower_class = { 282 .name = "legousbtower%d", 283 .devnode = legousbtower_devnode, 284 .fops = &tower_fops, 285 .minor_base = LEGO_USB_TOWER_MINOR_BASE, 286 }; 287 288 289 /* usb specific object needed to register this driver with the usb subsystem */ 290 static struct usb_driver tower_driver = { 291 .name = "legousbtower", 292 .probe = tower_probe, 293 .disconnect = tower_disconnect, 294 .id_table = tower_table, 295 }; 296 297 298 /** 299 * lego_usb_tower_debug_data 300 */ 301 static inline void lego_usb_tower_debug_data (int level, const char *function, int size, const unsigned char *data) 302 { 303 int i; 304 305 if (debug < level) 306 return; 307 308 printk (KERN_DEBUG "%s: %s - length = %d, data = ", __FILE__, function, size); 309 for (i = 0; i < size; ++i) { 310 printk ("%.2x ", data[i]); 311 } 312 printk ("\n"); 313 } 314 315 316 /** 317 * tower_delete 318 */ 319 static inline void tower_delete (struct lego_usb_tower *dev) 320 { 321 dbg(2, "%s: enter", __func__); 322 323 tower_abort_transfers (dev); 324 325 /* free data structures */ 326 usb_free_urb(dev->interrupt_in_urb); 327 usb_free_urb(dev->interrupt_out_urb); 328 kfree (dev->read_buffer); 329 kfree (dev->interrupt_in_buffer); 330 kfree (dev->interrupt_out_buffer); 331 kfree (dev); 332 333 dbg(2, "%s: leave", __func__); 334 } 335 336 337 /** 338 * tower_open 339 */ 340 static int tower_open (struct inode *inode, struct file *file) 341 { 342 struct lego_usb_tower *dev = NULL; 343 int subminor; 344 int retval = 0; 345 struct usb_interface *interface; 346 struct tower_reset_reply reset_reply; 347 int result; 348 349 dbg(2, "%s: enter", __func__); 350 351 nonseekable_open(inode, file); 352 subminor = iminor(inode); 353 354 interface = usb_find_interface (&tower_driver, subminor); 355 356 if (!interface) { 357 printk(KERN_ERR "%s - error, can't find device for minor %d\n", 358 __func__, subminor); 359 retval = -ENODEV; 360 goto exit; 361 } 362 363 mutex_lock(&open_disc_mutex); 364 dev = usb_get_intfdata(interface); 365 366 if (!dev) { 367 mutex_unlock(&open_disc_mutex); 368 retval = -ENODEV; 369 goto exit; 370 } 371 372 /* lock this device */ 373 if (mutex_lock_interruptible(&dev->lock)) { 374 mutex_unlock(&open_disc_mutex); 375 retval = -ERESTARTSYS; 376 goto exit; 377 } 378 379 380 /* allow opening only once */ 381 if (dev->open_count) { 382 mutex_unlock(&open_disc_mutex); 383 retval = -EBUSY; 384 goto unlock_exit; 385 } 386 dev->open_count = 1; 387 mutex_unlock(&open_disc_mutex); 388 389 /* reset the tower */ 390 result = usb_control_msg (dev->udev, 391 usb_rcvctrlpipe(dev->udev, 0), 392 LEGO_USB_TOWER_REQUEST_RESET, 393 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 394 0, 395 0, 396 &reset_reply, 397 sizeof(reset_reply), 398 1000); 399 if (result < 0) { 400 dev_err(&dev->udev->dev, 401 "LEGO USB Tower reset control request failed\n"); 402 retval = result; 403 goto unlock_exit; 404 } 405 406 /* initialize in direction */ 407 dev->read_buffer_length = 0; 408 dev->read_packet_length = 0; 409 usb_fill_int_urb (dev->interrupt_in_urb, 410 dev->udev, 411 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress), 412 dev->interrupt_in_buffer, 413 usb_endpoint_maxp(dev->interrupt_in_endpoint), 414 tower_interrupt_in_callback, 415 dev, 416 dev->interrupt_in_interval); 417 418 dev->interrupt_in_running = 1; 419 dev->interrupt_in_done = 0; 420 mb(); 421 422 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL); 423 if (retval) { 424 dev_err(&dev->udev->dev, 425 "Couldn't submit interrupt_in_urb %d\n", retval); 426 dev->interrupt_in_running = 0; 427 dev->open_count = 0; 428 goto unlock_exit; 429 } 430 431 /* save device in the file's private structure */ 432 file->private_data = dev; 433 434 unlock_exit: 435 mutex_unlock(&dev->lock); 436 437 exit: 438 dbg(2, "%s: leave, return value %d ", __func__, retval); 439 440 return retval; 441 } 442 443 /** 444 * tower_release 445 */ 446 static int tower_release (struct inode *inode, struct file *file) 447 { 448 struct lego_usb_tower *dev; 449 int retval = 0; 450 451 dbg(2, "%s: enter", __func__); 452 453 dev = file->private_data; 454 455 if (dev == NULL) { 456 dbg(1, "%s: object is NULL", __func__); 457 retval = -ENODEV; 458 goto exit_nolock; 459 } 460 461 mutex_lock(&open_disc_mutex); 462 if (mutex_lock_interruptible(&dev->lock)) { 463 retval = -ERESTARTSYS; 464 goto exit; 465 } 466 467 if (dev->open_count != 1) { 468 dbg(1, "%s: device not opened exactly once", __func__); 469 retval = -ENODEV; 470 goto unlock_exit; 471 } 472 if (dev->udev == NULL) { 473 /* the device was unplugged before the file was released */ 474 475 /* unlock here as tower_delete frees dev */ 476 mutex_unlock(&dev->lock); 477 tower_delete (dev); 478 goto exit; 479 } 480 481 /* wait until write transfer is finished */ 482 if (dev->interrupt_out_busy) { 483 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 484 } 485 tower_abort_transfers (dev); 486 dev->open_count = 0; 487 488 unlock_exit: 489 mutex_unlock(&dev->lock); 490 491 exit: 492 mutex_unlock(&open_disc_mutex); 493 exit_nolock: 494 dbg(2, "%s: leave, return value %d", __func__, retval); 495 return retval; 496 } 497 498 499 /** 500 * tower_abort_transfers 501 * aborts transfers and frees associated data structures 502 */ 503 static void tower_abort_transfers (struct lego_usb_tower *dev) 504 { 505 dbg(2, "%s: enter", __func__); 506 507 if (dev == NULL) { 508 dbg(1, "%s: dev is null", __func__); 509 goto exit; 510 } 511 512 /* shutdown transfer */ 513 if (dev->interrupt_in_running) { 514 dev->interrupt_in_running = 0; 515 mb(); 516 if (dev->udev) 517 usb_kill_urb (dev->interrupt_in_urb); 518 } 519 if (dev->interrupt_out_busy && dev->udev) 520 usb_kill_urb(dev->interrupt_out_urb); 521 522 exit: 523 dbg(2, "%s: leave", __func__); 524 } 525 526 527 /** 528 * tower_check_for_read_packet 529 * 530 * To get correct semantics for signals and non-blocking I/O 531 * with packetizing we pretend not to see any data in the read buffer 532 * until it has been there unchanged for at least 533 * dev->packet_timeout_jiffies, or until the buffer is full. 534 */ 535 static void tower_check_for_read_packet (struct lego_usb_tower *dev) 536 { 537 spin_lock_irq (&dev->read_buffer_lock); 538 if (!packet_timeout 539 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) 540 || dev->read_buffer_length == read_buffer_size) { 541 dev->read_packet_length = dev->read_buffer_length; 542 } 543 dev->interrupt_in_done = 0; 544 spin_unlock_irq (&dev->read_buffer_lock); 545 } 546 547 548 /** 549 * tower_poll 550 */ 551 static unsigned int tower_poll (struct file *file, poll_table *wait) 552 { 553 struct lego_usb_tower *dev; 554 unsigned int mask = 0; 555 556 dbg(2, "%s: enter", __func__); 557 558 dev = file->private_data; 559 560 if (!dev->udev) 561 return POLLERR | POLLHUP; 562 563 poll_wait(file, &dev->read_wait, wait); 564 poll_wait(file, &dev->write_wait, wait); 565 566 tower_check_for_read_packet(dev); 567 if (dev->read_packet_length > 0) { 568 mask |= POLLIN | POLLRDNORM; 569 } 570 if (!dev->interrupt_out_busy) { 571 mask |= POLLOUT | POLLWRNORM; 572 } 573 574 dbg(2, "%s: leave, mask = %d", __func__, mask); 575 576 return mask; 577 } 578 579 580 /** 581 * tower_llseek 582 */ 583 static loff_t tower_llseek (struct file *file, loff_t off, int whence) 584 { 585 return -ESPIPE; /* unseekable */ 586 } 587 588 589 /** 590 * tower_read 591 */ 592 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 593 { 594 struct lego_usb_tower *dev; 595 size_t bytes_to_read; 596 int i; 597 int retval = 0; 598 unsigned long timeout = 0; 599 600 dbg(2, "%s: enter, count = %Zd", __func__, count); 601 602 dev = file->private_data; 603 604 /* lock this object */ 605 if (mutex_lock_interruptible(&dev->lock)) { 606 retval = -ERESTARTSYS; 607 goto exit; 608 } 609 610 /* verify that the device wasn't unplugged */ 611 if (dev->udev == NULL) { 612 retval = -ENODEV; 613 printk(KERN_ERR "legousbtower: No device or device unplugged %d\n", retval); 614 goto unlock_exit; 615 } 616 617 /* verify that we actually have some data to read */ 618 if (count == 0) { 619 dbg(1, "%s: read request of 0 bytes", __func__); 620 goto unlock_exit; 621 } 622 623 if (read_timeout) { 624 timeout = jiffies + read_timeout * HZ / 1000; 625 } 626 627 /* wait for data */ 628 tower_check_for_read_packet (dev); 629 while (dev->read_packet_length == 0) { 630 if (file->f_flags & O_NONBLOCK) { 631 retval = -EAGAIN; 632 goto unlock_exit; 633 } 634 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 635 if (retval < 0) { 636 goto unlock_exit; 637 } 638 639 /* reset read timeout during read or write activity */ 640 if (read_timeout 641 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 642 timeout = jiffies + read_timeout * HZ / 1000; 643 } 644 /* check for read timeout */ 645 if (read_timeout && time_after (jiffies, timeout)) { 646 retval = -ETIMEDOUT; 647 goto unlock_exit; 648 } 649 tower_check_for_read_packet (dev); 650 } 651 652 /* copy the data from read_buffer into userspace */ 653 bytes_to_read = min(count, dev->read_packet_length); 654 655 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { 656 retval = -EFAULT; 657 goto unlock_exit; 658 } 659 660 spin_lock_irq (&dev->read_buffer_lock); 661 dev->read_buffer_length -= bytes_to_read; 662 dev->read_packet_length -= bytes_to_read; 663 for (i=0; i<dev->read_buffer_length; i++) { 664 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 665 } 666 spin_unlock_irq (&dev->read_buffer_lock); 667 668 retval = bytes_to_read; 669 670 unlock_exit: 671 /* unlock the device */ 672 mutex_unlock(&dev->lock); 673 674 exit: 675 dbg(2, "%s: leave, return value %d", __func__, retval); 676 return retval; 677 } 678 679 680 /** 681 * tower_write 682 */ 683 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 684 { 685 struct lego_usb_tower *dev; 686 size_t bytes_to_write; 687 int retval = 0; 688 689 dbg(2, "%s: enter, count = %Zd", __func__, count); 690 691 dev = file->private_data; 692 693 /* lock this object */ 694 if (mutex_lock_interruptible(&dev->lock)) { 695 retval = -ERESTARTSYS; 696 goto exit; 697 } 698 699 /* verify that the device wasn't unplugged */ 700 if (dev->udev == NULL) { 701 retval = -ENODEV; 702 printk(KERN_ERR "legousbtower: No device or device unplugged %d\n", retval); 703 goto unlock_exit; 704 } 705 706 /* verify that we actually have some data to write */ 707 if (count == 0) { 708 dbg(1, "%s: write request of 0 bytes", __func__); 709 goto unlock_exit; 710 } 711 712 /* wait until previous transfer is finished */ 713 while (dev->interrupt_out_busy) { 714 if (file->f_flags & O_NONBLOCK) { 715 retval = -EAGAIN; 716 goto unlock_exit; 717 } 718 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); 719 if (retval) { 720 goto unlock_exit; 721 } 722 } 723 724 /* write the data into interrupt_out_buffer from userspace */ 725 bytes_to_write = min_t(int, count, write_buffer_size); 726 dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __func__, count, bytes_to_write); 727 728 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { 729 retval = -EFAULT; 730 goto unlock_exit; 731 } 732 733 /* send off the urb */ 734 usb_fill_int_urb(dev->interrupt_out_urb, 735 dev->udev, 736 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 737 dev->interrupt_out_buffer, 738 bytes_to_write, 739 tower_interrupt_out_callback, 740 dev, 741 dev->interrupt_out_interval); 742 743 dev->interrupt_out_busy = 1; 744 wmb(); 745 746 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); 747 if (retval) { 748 dev->interrupt_out_busy = 0; 749 dev_err(&dev->udev->dev, 750 "Couldn't submit interrupt_out_urb %d\n", retval); 751 goto unlock_exit; 752 } 753 retval = bytes_to_write; 754 755 unlock_exit: 756 /* unlock the device */ 757 mutex_unlock(&dev->lock); 758 759 exit: 760 dbg(2, "%s: leave, return value %d", __func__, retval); 761 762 return retval; 763 } 764 765 766 /** 767 * tower_interrupt_in_callback 768 */ 769 static void tower_interrupt_in_callback (struct urb *urb) 770 { 771 struct lego_usb_tower *dev = urb->context; 772 int status = urb->status; 773 int retval; 774 775 dbg(4, "%s: enter, status %d", __func__, status); 776 777 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 778 779 if (status) { 780 if (status == -ENOENT || 781 status == -ECONNRESET || 782 status == -ESHUTDOWN) { 783 goto exit; 784 } else { 785 dbg(1, "%s: nonzero status received: %d", __func__, status); 786 goto resubmit; /* maybe we can recover */ 787 } 788 } 789 790 if (urb->actual_length > 0) { 791 spin_lock (&dev->read_buffer_lock); 792 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 793 memcpy (dev->read_buffer + dev->read_buffer_length, 794 dev->interrupt_in_buffer, 795 urb->actual_length); 796 dev->read_buffer_length += urb->actual_length; 797 dev->read_last_arrival = jiffies; 798 dbg(3, "%s: received %d bytes", __func__, urb->actual_length); 799 } else { 800 printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __func__, urb->actual_length); 801 } 802 spin_unlock (&dev->read_buffer_lock); 803 } 804 805 resubmit: 806 /* resubmit if we're still running */ 807 if (dev->interrupt_in_running && dev->udev) { 808 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); 809 if (retval) 810 dev_err(&dev->udev->dev, 811 "%s: usb_submit_urb failed (%d)\n", 812 __func__, retval); 813 } 814 815 exit: 816 dev->interrupt_in_done = 1; 817 wake_up_interruptible (&dev->read_wait); 818 819 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 820 dbg(4, "%s: leave, status %d", __func__, status); 821 } 822 823 824 /** 825 * tower_interrupt_out_callback 826 */ 827 static void tower_interrupt_out_callback (struct urb *urb) 828 { 829 struct lego_usb_tower *dev = urb->context; 830 int status = urb->status; 831 832 dbg(4, "%s: enter, status %d", __func__, status); 833 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 834 835 /* sync/async unlink faults aren't errors */ 836 if (status && !(status == -ENOENT || 837 status == -ECONNRESET || 838 status == -ESHUTDOWN)) { 839 dbg(1, "%s - nonzero write bulk status received: %d", 840 __func__, status); 841 } 842 843 dev->interrupt_out_busy = 0; 844 wake_up_interruptible(&dev->write_wait); 845 846 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 847 dbg(4, "%s: leave, status %d", __func__, status); 848 } 849 850 851 /** 852 * tower_probe 853 * 854 * Called by the usb core when a new device is connected that it thinks 855 * this driver might be interested in. 856 */ 857 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) 858 { 859 struct device *idev = &interface->dev; 860 struct usb_device *udev = interface_to_usbdev(interface); 861 struct lego_usb_tower *dev = NULL; 862 struct usb_host_interface *iface_desc; 863 struct usb_endpoint_descriptor* endpoint; 864 struct tower_get_version_reply get_version_reply; 865 int i; 866 int retval = -ENOMEM; 867 int result; 868 869 dbg(2, "%s: enter", __func__); 870 871 /* allocate memory for our device state and initialize it */ 872 873 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL); 874 875 if (dev == NULL) { 876 dev_err(idev, "Out of memory\n"); 877 goto exit; 878 } 879 880 mutex_init(&dev->lock); 881 882 dev->udev = udev; 883 dev->open_count = 0; 884 885 dev->read_buffer = NULL; 886 dev->read_buffer_length = 0; 887 dev->read_packet_length = 0; 888 spin_lock_init (&dev->read_buffer_lock); 889 dev->packet_timeout_jiffies = packet_timeout * HZ / 1000; 890 dev->read_last_arrival = jiffies; 891 892 init_waitqueue_head (&dev->read_wait); 893 init_waitqueue_head (&dev->write_wait); 894 895 dev->interrupt_in_buffer = NULL; 896 dev->interrupt_in_endpoint = NULL; 897 dev->interrupt_in_urb = NULL; 898 dev->interrupt_in_running = 0; 899 dev->interrupt_in_done = 0; 900 901 dev->interrupt_out_buffer = NULL; 902 dev->interrupt_out_endpoint = NULL; 903 dev->interrupt_out_urb = NULL; 904 dev->interrupt_out_busy = 0; 905 906 iface_desc = interface->cur_altsetting; 907 908 /* set up the endpoint information */ 909 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 910 endpoint = &iface_desc->endpoint[i].desc; 911 912 if (usb_endpoint_xfer_int(endpoint)) { 913 if (usb_endpoint_dir_in(endpoint)) 914 dev->interrupt_in_endpoint = endpoint; 915 else 916 dev->interrupt_out_endpoint = endpoint; 917 } 918 } 919 if(dev->interrupt_in_endpoint == NULL) { 920 dev_err(idev, "interrupt in endpoint not found\n"); 921 goto error; 922 } 923 if (dev->interrupt_out_endpoint == NULL) { 924 dev_err(idev, "interrupt out endpoint not found\n"); 925 goto error; 926 } 927 928 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); 929 if (!dev->read_buffer) { 930 dev_err(idev, "Couldn't allocate read_buffer\n"); 931 goto error; 932 } 933 dev->interrupt_in_buffer = kmalloc (usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL); 934 if (!dev->interrupt_in_buffer) { 935 dev_err(idev, "Couldn't allocate interrupt_in_buffer\n"); 936 goto error; 937 } 938 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 939 if (!dev->interrupt_in_urb) { 940 dev_err(idev, "Couldn't allocate interrupt_in_urb\n"); 941 goto error; 942 } 943 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL); 944 if (!dev->interrupt_out_buffer) { 945 dev_err(idev, "Couldn't allocate interrupt_out_buffer\n"); 946 goto error; 947 } 948 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 949 if (!dev->interrupt_out_urb) { 950 dev_err(idev, "Couldn't allocate interrupt_out_urb\n"); 951 goto error; 952 } 953 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 954 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 955 956 /* we can register the device now, as it is ready */ 957 usb_set_intfdata (interface, dev); 958 959 retval = usb_register_dev (interface, &tower_class); 960 961 if (retval) { 962 /* something prevented us from registering this driver */ 963 dev_err(idev, "Not able to get a minor for this device.\n"); 964 usb_set_intfdata (interface, NULL); 965 goto error; 966 } 967 dev->minor = interface->minor; 968 969 /* let the user know what node this device is now attached to */ 970 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major " 971 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), 972 USB_MAJOR, dev->minor); 973 974 /* get the firmware version and log it */ 975 result = usb_control_msg (udev, 976 usb_rcvctrlpipe(udev, 0), 977 LEGO_USB_TOWER_REQUEST_GET_VERSION, 978 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 979 0, 980 0, 981 &get_version_reply, 982 sizeof(get_version_reply), 983 1000); 984 if (result < 0) { 985 dev_err(idev, "LEGO USB Tower get version control request failed\n"); 986 retval = result; 987 goto error; 988 } 989 dev_info(&interface->dev, "LEGO USB Tower firmware version is %d.%d " 990 "build %d\n", get_version_reply.major, 991 get_version_reply.minor, 992 le16_to_cpu(get_version_reply.build_no)); 993 994 995 exit: 996 dbg(2, "%s: leave, return value 0x%.8lx (dev)", __func__, (long) dev); 997 998 return retval; 999 1000 error: 1001 tower_delete(dev); 1002 return retval; 1003 } 1004 1005 1006 /** 1007 * tower_disconnect 1008 * 1009 * Called by the usb core when the device is removed from the system. 1010 */ 1011 static void tower_disconnect (struct usb_interface *interface) 1012 { 1013 struct lego_usb_tower *dev; 1014 int minor; 1015 1016 dbg(2, "%s: enter", __func__); 1017 1018 dev = usb_get_intfdata (interface); 1019 mutex_lock(&open_disc_mutex); 1020 usb_set_intfdata (interface, NULL); 1021 1022 minor = dev->minor; 1023 1024 /* give back our minor */ 1025 usb_deregister_dev (interface, &tower_class); 1026 1027 mutex_lock(&dev->lock); 1028 mutex_unlock(&open_disc_mutex); 1029 1030 /* if the device is not opened, then we clean up right now */ 1031 if (!dev->open_count) { 1032 mutex_unlock(&dev->lock); 1033 tower_delete (dev); 1034 } else { 1035 dev->udev = NULL; 1036 /* wake up pollers */ 1037 wake_up_interruptible_all(&dev->read_wait); 1038 wake_up_interruptible_all(&dev->write_wait); 1039 mutex_unlock(&dev->lock); 1040 } 1041 1042 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n", 1043 (minor - LEGO_USB_TOWER_MINOR_BASE)); 1044 1045 dbg(2, "%s: leave", __func__); 1046 } 1047 1048 module_usb_driver(tower_driver); 1049 1050 MODULE_AUTHOR(DRIVER_AUTHOR); 1051 MODULE_DESCRIPTION(DRIVER_DESC); 1052 #ifdef MODULE_LICENSE 1053 MODULE_LICENSE("GPL"); 1054 #endif 1055