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 static char *legousbtower_nodename(struct device *dev) 270 { 271 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev)); 272 } 273 274 /* 275 * usb class driver info in order to get a minor number from the usb core, 276 * and to have the device registered with the driver core 277 */ 278 static struct usb_class_driver tower_class = { 279 .name = "legousbtower%d", 280 .nodename = legousbtower_nodename, 281 .fops = &tower_fops, 282 .minor_base = LEGO_USB_TOWER_MINOR_BASE, 283 }; 284 285 286 /* usb specific object needed to register this driver with the usb subsystem */ 287 static struct usb_driver tower_driver = { 288 .name = "legousbtower", 289 .probe = tower_probe, 290 .disconnect = tower_disconnect, 291 .id_table = tower_table, 292 }; 293 294 295 /** 296 * lego_usb_tower_debug_data 297 */ 298 static inline void lego_usb_tower_debug_data (int level, const char *function, int size, const unsigned char *data) 299 { 300 int i; 301 302 if (debug < level) 303 return; 304 305 printk (KERN_DEBUG __FILE__": %s - length = %d, data = ", function, size); 306 for (i = 0; i < size; ++i) { 307 printk ("%.2x ", data[i]); 308 } 309 printk ("\n"); 310 } 311 312 313 /** 314 * tower_delete 315 */ 316 static inline void tower_delete (struct lego_usb_tower *dev) 317 { 318 dbg(2, "%s: enter", __func__); 319 320 tower_abort_transfers (dev); 321 322 /* free data structures */ 323 usb_free_urb(dev->interrupt_in_urb); 324 usb_free_urb(dev->interrupt_out_urb); 325 kfree (dev->read_buffer); 326 kfree (dev->interrupt_in_buffer); 327 kfree (dev->interrupt_out_buffer); 328 kfree (dev); 329 330 dbg(2, "%s: leave", __func__); 331 } 332 333 334 /** 335 * tower_open 336 */ 337 static int tower_open (struct inode *inode, struct file *file) 338 { 339 struct lego_usb_tower *dev = NULL; 340 int subminor; 341 int retval = 0; 342 struct usb_interface *interface; 343 struct tower_reset_reply reset_reply; 344 int result; 345 346 dbg(2, "%s: enter", __func__); 347 348 nonseekable_open(inode, file); 349 subminor = iminor(inode); 350 351 interface = usb_find_interface (&tower_driver, subminor); 352 353 if (!interface) { 354 err ("%s - error, can't find device for minor %d", 355 __func__, subminor); 356 retval = -ENODEV; 357 goto exit; 358 } 359 360 mutex_lock(&open_disc_mutex); 361 dev = usb_get_intfdata(interface); 362 363 if (!dev) { 364 mutex_unlock(&open_disc_mutex); 365 retval = -ENODEV; 366 goto exit; 367 } 368 369 /* lock this device */ 370 if (mutex_lock_interruptible(&dev->lock)) { 371 mutex_unlock(&open_disc_mutex); 372 retval = -ERESTARTSYS; 373 goto exit; 374 } 375 376 377 /* allow opening only once */ 378 if (dev->open_count) { 379 mutex_unlock(&open_disc_mutex); 380 retval = -EBUSY; 381 goto unlock_exit; 382 } 383 dev->open_count = 1; 384 mutex_unlock(&open_disc_mutex); 385 386 /* reset the tower */ 387 result = usb_control_msg (dev->udev, 388 usb_rcvctrlpipe(dev->udev, 0), 389 LEGO_USB_TOWER_REQUEST_RESET, 390 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 391 0, 392 0, 393 &reset_reply, 394 sizeof(reset_reply), 395 1000); 396 if (result < 0) { 397 err("LEGO USB Tower reset control request failed"); 398 retval = result; 399 goto unlock_exit; 400 } 401 402 /* initialize in direction */ 403 dev->read_buffer_length = 0; 404 dev->read_packet_length = 0; 405 usb_fill_int_urb (dev->interrupt_in_urb, 406 dev->udev, 407 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress), 408 dev->interrupt_in_buffer, 409 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), 410 tower_interrupt_in_callback, 411 dev, 412 dev->interrupt_in_interval); 413 414 dev->interrupt_in_running = 1; 415 dev->interrupt_in_done = 0; 416 mb(); 417 418 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL); 419 if (retval) { 420 err("Couldn't submit interrupt_in_urb %d", retval); 421 dev->interrupt_in_running = 0; 422 dev->open_count = 0; 423 goto unlock_exit; 424 } 425 426 /* save device in the file's private structure */ 427 file->private_data = dev; 428 429 unlock_exit: 430 mutex_unlock(&dev->lock); 431 432 exit: 433 dbg(2, "%s: leave, return value %d ", __func__, retval); 434 435 return retval; 436 } 437 438 /** 439 * tower_release 440 */ 441 static int tower_release (struct inode *inode, struct file *file) 442 { 443 struct lego_usb_tower *dev; 444 int retval = 0; 445 446 dbg(2, "%s: enter", __func__); 447 448 dev = (struct lego_usb_tower *)file->private_data; 449 450 if (dev == NULL) { 451 dbg(1, "%s: object is NULL", __func__); 452 retval = -ENODEV; 453 goto exit_nolock; 454 } 455 456 mutex_lock(&open_disc_mutex); 457 if (mutex_lock_interruptible(&dev->lock)) { 458 retval = -ERESTARTSYS; 459 goto exit; 460 } 461 462 if (dev->open_count != 1) { 463 dbg(1, "%s: device not opened exactly once", __func__); 464 retval = -ENODEV; 465 goto unlock_exit; 466 } 467 if (dev->udev == NULL) { 468 /* the device was unplugged before the file was released */ 469 470 /* unlock here as tower_delete frees dev */ 471 mutex_unlock(&dev->lock); 472 tower_delete (dev); 473 goto exit; 474 } 475 476 /* wait until write transfer is finished */ 477 if (dev->interrupt_out_busy) { 478 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 479 } 480 tower_abort_transfers (dev); 481 dev->open_count = 0; 482 483 unlock_exit: 484 mutex_unlock(&dev->lock); 485 486 exit: 487 mutex_unlock(&open_disc_mutex); 488 exit_nolock: 489 dbg(2, "%s: leave, return value %d", __func__, retval); 490 return retval; 491 } 492 493 494 /** 495 * tower_abort_transfers 496 * aborts transfers and frees associated data structures 497 */ 498 static void tower_abort_transfers (struct lego_usb_tower *dev) 499 { 500 dbg(2, "%s: enter", __func__); 501 502 if (dev == NULL) { 503 dbg(1, "%s: dev is null", __func__); 504 goto exit; 505 } 506 507 /* shutdown transfer */ 508 if (dev->interrupt_in_running) { 509 dev->interrupt_in_running = 0; 510 mb(); 511 if (dev->udev) 512 usb_kill_urb (dev->interrupt_in_urb); 513 } 514 if (dev->interrupt_out_busy && dev->udev) 515 usb_kill_urb(dev->interrupt_out_urb); 516 517 exit: 518 dbg(2, "%s: leave", __func__); 519 } 520 521 522 /** 523 * tower_check_for_read_packet 524 * 525 * To get correct semantics for signals and non-blocking I/O 526 * with packetizing we pretend not to see any data in the read buffer 527 * until it has been there unchanged for at least 528 * dev->packet_timeout_jiffies, or until the buffer is full. 529 */ 530 static void tower_check_for_read_packet (struct lego_usb_tower *dev) 531 { 532 spin_lock_irq (&dev->read_buffer_lock); 533 if (!packet_timeout 534 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) 535 || dev->read_buffer_length == read_buffer_size) { 536 dev->read_packet_length = dev->read_buffer_length; 537 } 538 dev->interrupt_in_done = 0; 539 spin_unlock_irq (&dev->read_buffer_lock); 540 } 541 542 543 /** 544 * tower_poll 545 */ 546 static unsigned int tower_poll (struct file *file, poll_table *wait) 547 { 548 struct lego_usb_tower *dev; 549 unsigned int mask = 0; 550 551 dbg(2, "%s: enter", __func__); 552 553 dev = file->private_data; 554 555 poll_wait(file, &dev->read_wait, wait); 556 poll_wait(file, &dev->write_wait, wait); 557 558 tower_check_for_read_packet(dev); 559 if (dev->read_packet_length > 0) { 560 mask |= POLLIN | POLLRDNORM; 561 } 562 if (!dev->interrupt_out_busy) { 563 mask |= POLLOUT | POLLWRNORM; 564 } 565 566 dbg(2, "%s: leave, mask = %d", __func__, mask); 567 568 return mask; 569 } 570 571 572 /** 573 * tower_llseek 574 */ 575 static loff_t tower_llseek (struct file *file, loff_t off, int whence) 576 { 577 return -ESPIPE; /* unseekable */ 578 } 579 580 581 /** 582 * tower_read 583 */ 584 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 585 { 586 struct lego_usb_tower *dev; 587 size_t bytes_to_read; 588 int i; 589 int retval = 0; 590 unsigned long timeout = 0; 591 592 dbg(2, "%s: enter, count = %Zd", __func__, count); 593 594 dev = (struct lego_usb_tower *)file->private_data; 595 596 /* lock this object */ 597 if (mutex_lock_interruptible(&dev->lock)) { 598 retval = -ERESTARTSYS; 599 goto exit; 600 } 601 602 /* verify that the device wasn't unplugged */ 603 if (dev->udev == NULL) { 604 retval = -ENODEV; 605 err("No device or device unplugged %d", retval); 606 goto unlock_exit; 607 } 608 609 /* verify that we actually have some data to read */ 610 if (count == 0) { 611 dbg(1, "%s: read request of 0 bytes", __func__); 612 goto unlock_exit; 613 } 614 615 if (read_timeout) { 616 timeout = jiffies + read_timeout * HZ / 1000; 617 } 618 619 /* wait for data */ 620 tower_check_for_read_packet (dev); 621 while (dev->read_packet_length == 0) { 622 if (file->f_flags & O_NONBLOCK) { 623 retval = -EAGAIN; 624 goto unlock_exit; 625 } 626 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 627 if (retval < 0) { 628 goto unlock_exit; 629 } 630 631 /* reset read timeout during read or write activity */ 632 if (read_timeout 633 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 634 timeout = jiffies + read_timeout * HZ / 1000; 635 } 636 /* check for read timeout */ 637 if (read_timeout && time_after (jiffies, timeout)) { 638 retval = -ETIMEDOUT; 639 goto unlock_exit; 640 } 641 tower_check_for_read_packet (dev); 642 } 643 644 /* copy the data from read_buffer into userspace */ 645 bytes_to_read = min(count, dev->read_packet_length); 646 647 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { 648 retval = -EFAULT; 649 goto unlock_exit; 650 } 651 652 spin_lock_irq (&dev->read_buffer_lock); 653 dev->read_buffer_length -= bytes_to_read; 654 dev->read_packet_length -= bytes_to_read; 655 for (i=0; i<dev->read_buffer_length; i++) { 656 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 657 } 658 spin_unlock_irq (&dev->read_buffer_lock); 659 660 retval = bytes_to_read; 661 662 unlock_exit: 663 /* unlock the device */ 664 mutex_unlock(&dev->lock); 665 666 exit: 667 dbg(2, "%s: leave, return value %d", __func__, retval); 668 return retval; 669 } 670 671 672 /** 673 * tower_write 674 */ 675 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 676 { 677 struct lego_usb_tower *dev; 678 size_t bytes_to_write; 679 int retval = 0; 680 681 dbg(2, "%s: enter, count = %Zd", __func__, count); 682 683 dev = (struct lego_usb_tower *)file->private_data; 684 685 /* lock this object */ 686 if (mutex_lock_interruptible(&dev->lock)) { 687 retval = -ERESTARTSYS; 688 goto exit; 689 } 690 691 /* verify that the device wasn't unplugged */ 692 if (dev->udev == NULL) { 693 retval = -ENODEV; 694 err("No device or device unplugged %d", retval); 695 goto unlock_exit; 696 } 697 698 /* verify that we actually have some data to write */ 699 if (count == 0) { 700 dbg(1, "%s: write request of 0 bytes", __func__); 701 goto unlock_exit; 702 } 703 704 /* wait until previous transfer is finished */ 705 while (dev->interrupt_out_busy) { 706 if (file->f_flags & O_NONBLOCK) { 707 retval = -EAGAIN; 708 goto unlock_exit; 709 } 710 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); 711 if (retval) { 712 goto unlock_exit; 713 } 714 } 715 716 /* write the data into interrupt_out_buffer from userspace */ 717 bytes_to_write = min_t(int, count, write_buffer_size); 718 dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __func__, count, bytes_to_write); 719 720 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { 721 retval = -EFAULT; 722 goto unlock_exit; 723 } 724 725 /* send off the urb */ 726 usb_fill_int_urb(dev->interrupt_out_urb, 727 dev->udev, 728 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 729 dev->interrupt_out_buffer, 730 bytes_to_write, 731 tower_interrupt_out_callback, 732 dev, 733 dev->interrupt_out_interval); 734 735 dev->interrupt_out_busy = 1; 736 wmb(); 737 738 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); 739 if (retval) { 740 dev->interrupt_out_busy = 0; 741 err("Couldn't submit interrupt_out_urb %d", retval); 742 goto unlock_exit; 743 } 744 retval = bytes_to_write; 745 746 unlock_exit: 747 /* unlock the device */ 748 mutex_unlock(&dev->lock); 749 750 exit: 751 dbg(2, "%s: leave, return value %d", __func__, retval); 752 753 return retval; 754 } 755 756 757 /** 758 * tower_interrupt_in_callback 759 */ 760 static void tower_interrupt_in_callback (struct urb *urb) 761 { 762 struct lego_usb_tower *dev = urb->context; 763 int status = urb->status; 764 int retval; 765 766 dbg(4, "%s: enter, status %d", __func__, status); 767 768 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 769 770 if (status) { 771 if (status == -ENOENT || 772 status == -ECONNRESET || 773 status == -ESHUTDOWN) { 774 goto exit; 775 } else { 776 dbg(1, "%s: nonzero status received: %d", __func__, status); 777 goto resubmit; /* maybe we can recover */ 778 } 779 } 780 781 if (urb->actual_length > 0) { 782 spin_lock (&dev->read_buffer_lock); 783 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 784 memcpy (dev->read_buffer + dev->read_buffer_length, 785 dev->interrupt_in_buffer, 786 urb->actual_length); 787 dev->read_buffer_length += urb->actual_length; 788 dev->read_last_arrival = jiffies; 789 dbg(3, "%s: received %d bytes", __func__, urb->actual_length); 790 } else { 791 printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __func__, urb->actual_length); 792 } 793 spin_unlock (&dev->read_buffer_lock); 794 } 795 796 resubmit: 797 /* resubmit if we're still running */ 798 if (dev->interrupt_in_running && dev->udev) { 799 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); 800 if (retval) { 801 err("%s: usb_submit_urb failed (%d)", __func__, retval); 802 } 803 } 804 805 exit: 806 dev->interrupt_in_done = 1; 807 wake_up_interruptible (&dev->read_wait); 808 809 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 810 dbg(4, "%s: leave, status %d", __func__, status); 811 } 812 813 814 /** 815 * tower_interrupt_out_callback 816 */ 817 static void tower_interrupt_out_callback (struct urb *urb) 818 { 819 struct lego_usb_tower *dev = urb->context; 820 int status = urb->status; 821 822 dbg(4, "%s: enter, status %d", __func__, status); 823 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 824 825 /* sync/async unlink faults aren't errors */ 826 if (status && !(status == -ENOENT || 827 status == -ECONNRESET || 828 status == -ESHUTDOWN)) { 829 dbg(1, "%s - nonzero write bulk status received: %d", 830 __func__, status); 831 } 832 833 dev->interrupt_out_busy = 0; 834 wake_up_interruptible(&dev->write_wait); 835 836 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 837 dbg(4, "%s: leave, status %d", __func__, status); 838 } 839 840 841 /** 842 * tower_probe 843 * 844 * Called by the usb core when a new device is connected that it thinks 845 * this driver might be interested in. 846 */ 847 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) 848 { 849 struct usb_device *udev = interface_to_usbdev(interface); 850 struct lego_usb_tower *dev = NULL; 851 struct usb_host_interface *iface_desc; 852 struct usb_endpoint_descriptor* endpoint; 853 struct tower_get_version_reply get_version_reply; 854 int i; 855 int retval = -ENOMEM; 856 int result; 857 858 dbg(2, "%s: enter", __func__); 859 860 if (udev == NULL) 861 dev_info(&interface->dev, "udev is NULL.\n"); 862 863 /* allocate memory for our device state and initialize it */ 864 865 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL); 866 867 if (dev == NULL) { 868 err ("Out of memory"); 869 goto exit; 870 } 871 872 mutex_init(&dev->lock); 873 874 dev->udev = udev; 875 dev->open_count = 0; 876 877 dev->read_buffer = NULL; 878 dev->read_buffer_length = 0; 879 dev->read_packet_length = 0; 880 spin_lock_init (&dev->read_buffer_lock); 881 dev->packet_timeout_jiffies = packet_timeout * HZ / 1000; 882 dev->read_last_arrival = jiffies; 883 884 init_waitqueue_head (&dev->read_wait); 885 init_waitqueue_head (&dev->write_wait); 886 887 dev->interrupt_in_buffer = NULL; 888 dev->interrupt_in_endpoint = NULL; 889 dev->interrupt_in_urb = NULL; 890 dev->interrupt_in_running = 0; 891 dev->interrupt_in_done = 0; 892 893 dev->interrupt_out_buffer = NULL; 894 dev->interrupt_out_endpoint = NULL; 895 dev->interrupt_out_urb = NULL; 896 dev->interrupt_out_busy = 0; 897 898 iface_desc = interface->cur_altsetting; 899 900 /* set up the endpoint information */ 901 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 902 endpoint = &iface_desc->endpoint[i].desc; 903 904 if (usb_endpoint_xfer_int(endpoint)) { 905 if (usb_endpoint_dir_in(endpoint)) 906 dev->interrupt_in_endpoint = endpoint; 907 else 908 dev->interrupt_out_endpoint = endpoint; 909 } 910 } 911 if(dev->interrupt_in_endpoint == NULL) { 912 err("interrupt in endpoint not found"); 913 goto error; 914 } 915 if (dev->interrupt_out_endpoint == NULL) { 916 err("interrupt out endpoint not found"); 917 goto error; 918 } 919 920 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); 921 if (!dev->read_buffer) { 922 err("Couldn't allocate read_buffer"); 923 goto error; 924 } 925 dev->interrupt_in_buffer = kmalloc (le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), GFP_KERNEL); 926 if (!dev->interrupt_in_buffer) { 927 err("Couldn't allocate interrupt_in_buffer"); 928 goto error; 929 } 930 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 931 if (!dev->interrupt_in_urb) { 932 err("Couldn't allocate interrupt_in_urb"); 933 goto error; 934 } 935 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL); 936 if (!dev->interrupt_out_buffer) { 937 err("Couldn't allocate interrupt_out_buffer"); 938 goto error; 939 } 940 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 941 if (!dev->interrupt_out_urb) { 942 err("Couldn't allocate interrupt_out_urb"); 943 goto error; 944 } 945 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 946 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 947 948 /* we can register the device now, as it is ready */ 949 usb_set_intfdata (interface, dev); 950 951 retval = usb_register_dev (interface, &tower_class); 952 953 if (retval) { 954 /* something prevented us from registering this driver */ 955 err ("Not able to get a minor for this device."); 956 usb_set_intfdata (interface, NULL); 957 goto error; 958 } 959 dev->minor = interface->minor; 960 961 /* let the user know what node this device is now attached to */ 962 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major " 963 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), 964 USB_MAJOR, dev->minor); 965 966 /* get the firmware version and log it */ 967 result = usb_control_msg (udev, 968 usb_rcvctrlpipe(udev, 0), 969 LEGO_USB_TOWER_REQUEST_GET_VERSION, 970 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 971 0, 972 0, 973 &get_version_reply, 974 sizeof(get_version_reply), 975 1000); 976 if (result < 0) { 977 err("LEGO USB Tower get version control request failed"); 978 retval = result; 979 goto error; 980 } 981 dev_info(&interface->dev, "LEGO USB Tower firmware version is %d.%d " 982 "build %d\n", get_version_reply.major, 983 get_version_reply.minor, 984 le16_to_cpu(get_version_reply.build_no)); 985 986 987 exit: 988 dbg(2, "%s: leave, return value 0x%.8lx (dev)", __func__, (long) dev); 989 990 return retval; 991 992 error: 993 tower_delete(dev); 994 return retval; 995 } 996 997 998 /** 999 * tower_disconnect 1000 * 1001 * Called by the usb core when the device is removed from the system. 1002 */ 1003 static void tower_disconnect (struct usb_interface *interface) 1004 { 1005 struct lego_usb_tower *dev; 1006 int minor; 1007 1008 dbg(2, "%s: enter", __func__); 1009 1010 dev = usb_get_intfdata (interface); 1011 mutex_lock(&open_disc_mutex); 1012 usb_set_intfdata (interface, NULL); 1013 1014 minor = dev->minor; 1015 1016 /* give back our minor */ 1017 usb_deregister_dev (interface, &tower_class); 1018 1019 mutex_lock(&dev->lock); 1020 mutex_unlock(&open_disc_mutex); 1021 1022 /* if the device is not opened, then we clean up right now */ 1023 if (!dev->open_count) { 1024 mutex_unlock(&dev->lock); 1025 tower_delete (dev); 1026 } else { 1027 dev->udev = NULL; 1028 mutex_unlock(&dev->lock); 1029 } 1030 1031 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n", 1032 (minor - LEGO_USB_TOWER_MINOR_BASE)); 1033 1034 dbg(2, "%s: leave", __func__); 1035 } 1036 1037 1038 1039 /** 1040 * lego_usb_tower_init 1041 */ 1042 static int __init lego_usb_tower_init(void) 1043 { 1044 int result; 1045 int retval = 0; 1046 1047 dbg(2, "%s: enter", __func__); 1048 1049 /* register this driver with the USB subsystem */ 1050 result = usb_register(&tower_driver); 1051 if (result < 0) { 1052 err("usb_register failed for the "__FILE__" driver. Error number %d", result); 1053 retval = -1; 1054 goto exit; 1055 } 1056 1057 printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":" 1058 DRIVER_DESC "\n"); 1059 1060 exit: 1061 dbg(2, "%s: leave, return value %d", __func__, retval); 1062 1063 return retval; 1064 } 1065 1066 1067 /** 1068 * lego_usb_tower_exit 1069 */ 1070 static void __exit lego_usb_tower_exit(void) 1071 { 1072 dbg(2, "%s: enter", __func__); 1073 1074 /* deregister this driver with the USB subsystem */ 1075 usb_deregister (&tower_driver); 1076 1077 dbg(2, "%s: leave", __func__); 1078 } 1079 1080 module_init (lego_usb_tower_init); 1081 module_exit (lego_usb_tower_exit); 1082 1083 MODULE_AUTHOR(DRIVER_AUTHOR); 1084 MODULE_DESCRIPTION(DRIVER_DESC); 1085 #ifdef MODULE_LICENSE 1086 MODULE_LICENSE("GPL"); 1087 #endif 1088