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