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_devnode(struct device *dev, mode_t *mode) 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 .devnode = legousbtower_devnode, 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 if (!dev->udev) 556 return POLLERR | POLLHUP; 557 558 poll_wait(file, &dev->read_wait, wait); 559 poll_wait(file, &dev->write_wait, wait); 560 561 tower_check_for_read_packet(dev); 562 if (dev->read_packet_length > 0) { 563 mask |= POLLIN | POLLRDNORM; 564 } 565 if (!dev->interrupt_out_busy) { 566 mask |= POLLOUT | POLLWRNORM; 567 } 568 569 dbg(2, "%s: leave, mask = %d", __func__, mask); 570 571 return mask; 572 } 573 574 575 /** 576 * tower_llseek 577 */ 578 static loff_t tower_llseek (struct file *file, loff_t off, int whence) 579 { 580 return -ESPIPE; /* unseekable */ 581 } 582 583 584 /** 585 * tower_read 586 */ 587 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 588 { 589 struct lego_usb_tower *dev; 590 size_t bytes_to_read; 591 int i; 592 int retval = 0; 593 unsigned long timeout = 0; 594 595 dbg(2, "%s: enter, count = %Zd", __func__, count); 596 597 dev = (struct lego_usb_tower *)file->private_data; 598 599 /* lock this object */ 600 if (mutex_lock_interruptible(&dev->lock)) { 601 retval = -ERESTARTSYS; 602 goto exit; 603 } 604 605 /* verify that the device wasn't unplugged */ 606 if (dev->udev == NULL) { 607 retval = -ENODEV; 608 err("No device or device unplugged %d", retval); 609 goto unlock_exit; 610 } 611 612 /* verify that we actually have some data to read */ 613 if (count == 0) { 614 dbg(1, "%s: read request of 0 bytes", __func__); 615 goto unlock_exit; 616 } 617 618 if (read_timeout) { 619 timeout = jiffies + read_timeout * HZ / 1000; 620 } 621 622 /* wait for data */ 623 tower_check_for_read_packet (dev); 624 while (dev->read_packet_length == 0) { 625 if (file->f_flags & O_NONBLOCK) { 626 retval = -EAGAIN; 627 goto unlock_exit; 628 } 629 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 630 if (retval < 0) { 631 goto unlock_exit; 632 } 633 634 /* reset read timeout during read or write activity */ 635 if (read_timeout 636 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 637 timeout = jiffies + read_timeout * HZ / 1000; 638 } 639 /* check for read timeout */ 640 if (read_timeout && time_after (jiffies, timeout)) { 641 retval = -ETIMEDOUT; 642 goto unlock_exit; 643 } 644 tower_check_for_read_packet (dev); 645 } 646 647 /* copy the data from read_buffer into userspace */ 648 bytes_to_read = min(count, dev->read_packet_length); 649 650 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { 651 retval = -EFAULT; 652 goto unlock_exit; 653 } 654 655 spin_lock_irq (&dev->read_buffer_lock); 656 dev->read_buffer_length -= bytes_to_read; 657 dev->read_packet_length -= bytes_to_read; 658 for (i=0; i<dev->read_buffer_length; i++) { 659 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 660 } 661 spin_unlock_irq (&dev->read_buffer_lock); 662 663 retval = bytes_to_read; 664 665 unlock_exit: 666 /* unlock the device */ 667 mutex_unlock(&dev->lock); 668 669 exit: 670 dbg(2, "%s: leave, return value %d", __func__, retval); 671 return retval; 672 } 673 674 675 /** 676 * tower_write 677 */ 678 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 679 { 680 struct lego_usb_tower *dev; 681 size_t bytes_to_write; 682 int retval = 0; 683 684 dbg(2, "%s: enter, count = %Zd", __func__, count); 685 686 dev = (struct lego_usb_tower *)file->private_data; 687 688 /* lock this object */ 689 if (mutex_lock_interruptible(&dev->lock)) { 690 retval = -ERESTARTSYS; 691 goto exit; 692 } 693 694 /* verify that the device wasn't unplugged */ 695 if (dev->udev == NULL) { 696 retval = -ENODEV; 697 err("No device or device unplugged %d", retval); 698 goto unlock_exit; 699 } 700 701 /* verify that we actually have some data to write */ 702 if (count == 0) { 703 dbg(1, "%s: write request of 0 bytes", __func__); 704 goto unlock_exit; 705 } 706 707 /* wait until previous transfer is finished */ 708 while (dev->interrupt_out_busy) { 709 if (file->f_flags & O_NONBLOCK) { 710 retval = -EAGAIN; 711 goto unlock_exit; 712 } 713 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); 714 if (retval) { 715 goto unlock_exit; 716 } 717 } 718 719 /* write the data into interrupt_out_buffer from userspace */ 720 bytes_to_write = min_t(int, count, write_buffer_size); 721 dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __func__, count, bytes_to_write); 722 723 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { 724 retval = -EFAULT; 725 goto unlock_exit; 726 } 727 728 /* send off the urb */ 729 usb_fill_int_urb(dev->interrupt_out_urb, 730 dev->udev, 731 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 732 dev->interrupt_out_buffer, 733 bytes_to_write, 734 tower_interrupt_out_callback, 735 dev, 736 dev->interrupt_out_interval); 737 738 dev->interrupt_out_busy = 1; 739 wmb(); 740 741 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); 742 if (retval) { 743 dev->interrupt_out_busy = 0; 744 err("Couldn't submit interrupt_out_urb %d", retval); 745 goto unlock_exit; 746 } 747 retval = bytes_to_write; 748 749 unlock_exit: 750 /* unlock the device */ 751 mutex_unlock(&dev->lock); 752 753 exit: 754 dbg(2, "%s: leave, return value %d", __func__, retval); 755 756 return retval; 757 } 758 759 760 /** 761 * tower_interrupt_in_callback 762 */ 763 static void tower_interrupt_in_callback (struct urb *urb) 764 { 765 struct lego_usb_tower *dev = urb->context; 766 int status = urb->status; 767 int retval; 768 769 dbg(4, "%s: enter, status %d", __func__, status); 770 771 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 772 773 if (status) { 774 if (status == -ENOENT || 775 status == -ECONNRESET || 776 status == -ESHUTDOWN) { 777 goto exit; 778 } else { 779 dbg(1, "%s: nonzero status received: %d", __func__, status); 780 goto resubmit; /* maybe we can recover */ 781 } 782 } 783 784 if (urb->actual_length > 0) { 785 spin_lock (&dev->read_buffer_lock); 786 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 787 memcpy (dev->read_buffer + dev->read_buffer_length, 788 dev->interrupt_in_buffer, 789 urb->actual_length); 790 dev->read_buffer_length += urb->actual_length; 791 dev->read_last_arrival = jiffies; 792 dbg(3, "%s: received %d bytes", __func__, urb->actual_length); 793 } else { 794 printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __func__, urb->actual_length); 795 } 796 spin_unlock (&dev->read_buffer_lock); 797 } 798 799 resubmit: 800 /* resubmit if we're still running */ 801 if (dev->interrupt_in_running && dev->udev) { 802 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); 803 if (retval) { 804 err("%s: usb_submit_urb failed (%d)", __func__, retval); 805 } 806 } 807 808 exit: 809 dev->interrupt_in_done = 1; 810 wake_up_interruptible (&dev->read_wait); 811 812 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 813 dbg(4, "%s: leave, status %d", __func__, status); 814 } 815 816 817 /** 818 * tower_interrupt_out_callback 819 */ 820 static void tower_interrupt_out_callback (struct urb *urb) 821 { 822 struct lego_usb_tower *dev = urb->context; 823 int status = urb->status; 824 825 dbg(4, "%s: enter, status %d", __func__, status); 826 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 827 828 /* sync/async unlink faults aren't errors */ 829 if (status && !(status == -ENOENT || 830 status == -ECONNRESET || 831 status == -ESHUTDOWN)) { 832 dbg(1, "%s - nonzero write bulk status received: %d", 833 __func__, status); 834 } 835 836 dev->interrupt_out_busy = 0; 837 wake_up_interruptible(&dev->write_wait); 838 839 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 840 dbg(4, "%s: leave, status %d", __func__, status); 841 } 842 843 844 /** 845 * tower_probe 846 * 847 * Called by the usb core when a new device is connected that it thinks 848 * this driver might be interested in. 849 */ 850 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) 851 { 852 struct usb_device *udev = interface_to_usbdev(interface); 853 struct lego_usb_tower *dev = NULL; 854 struct usb_host_interface *iface_desc; 855 struct usb_endpoint_descriptor* endpoint; 856 struct tower_get_version_reply get_version_reply; 857 int i; 858 int retval = -ENOMEM; 859 int result; 860 861 dbg(2, "%s: enter", __func__); 862 863 if (udev == NULL) 864 dev_info(&interface->dev, "udev is NULL.\n"); 865 866 /* allocate memory for our device state and initialize it */ 867 868 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL); 869 870 if (dev == NULL) { 871 err ("Out of memory"); 872 goto exit; 873 } 874 875 mutex_init(&dev->lock); 876 877 dev->udev = udev; 878 dev->open_count = 0; 879 880 dev->read_buffer = NULL; 881 dev->read_buffer_length = 0; 882 dev->read_packet_length = 0; 883 spin_lock_init (&dev->read_buffer_lock); 884 dev->packet_timeout_jiffies = packet_timeout * HZ / 1000; 885 dev->read_last_arrival = jiffies; 886 887 init_waitqueue_head (&dev->read_wait); 888 init_waitqueue_head (&dev->write_wait); 889 890 dev->interrupt_in_buffer = NULL; 891 dev->interrupt_in_endpoint = NULL; 892 dev->interrupt_in_urb = NULL; 893 dev->interrupt_in_running = 0; 894 dev->interrupt_in_done = 0; 895 896 dev->interrupt_out_buffer = NULL; 897 dev->interrupt_out_endpoint = NULL; 898 dev->interrupt_out_urb = NULL; 899 dev->interrupt_out_busy = 0; 900 901 iface_desc = interface->cur_altsetting; 902 903 /* set up the endpoint information */ 904 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 905 endpoint = &iface_desc->endpoint[i].desc; 906 907 if (usb_endpoint_xfer_int(endpoint)) { 908 if (usb_endpoint_dir_in(endpoint)) 909 dev->interrupt_in_endpoint = endpoint; 910 else 911 dev->interrupt_out_endpoint = endpoint; 912 } 913 } 914 if(dev->interrupt_in_endpoint == NULL) { 915 err("interrupt in endpoint not found"); 916 goto error; 917 } 918 if (dev->interrupt_out_endpoint == NULL) { 919 err("interrupt out endpoint not found"); 920 goto error; 921 } 922 923 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); 924 if (!dev->read_buffer) { 925 err("Couldn't allocate read_buffer"); 926 goto error; 927 } 928 dev->interrupt_in_buffer = kmalloc (le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), GFP_KERNEL); 929 if (!dev->interrupt_in_buffer) { 930 err("Couldn't allocate interrupt_in_buffer"); 931 goto error; 932 } 933 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 934 if (!dev->interrupt_in_urb) { 935 err("Couldn't allocate interrupt_in_urb"); 936 goto error; 937 } 938 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL); 939 if (!dev->interrupt_out_buffer) { 940 err("Couldn't allocate interrupt_out_buffer"); 941 goto error; 942 } 943 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 944 if (!dev->interrupt_out_urb) { 945 err("Couldn't allocate interrupt_out_urb"); 946 goto error; 947 } 948 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 949 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 950 951 /* we can register the device now, as it is ready */ 952 usb_set_intfdata (interface, dev); 953 954 retval = usb_register_dev (interface, &tower_class); 955 956 if (retval) { 957 /* something prevented us from registering this driver */ 958 err ("Not able to get a minor for this device."); 959 usb_set_intfdata (interface, NULL); 960 goto error; 961 } 962 dev->minor = interface->minor; 963 964 /* let the user know what node this device is now attached to */ 965 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major " 966 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), 967 USB_MAJOR, dev->minor); 968 969 /* get the firmware version and log it */ 970 result = usb_control_msg (udev, 971 usb_rcvctrlpipe(udev, 0), 972 LEGO_USB_TOWER_REQUEST_GET_VERSION, 973 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 974 0, 975 0, 976 &get_version_reply, 977 sizeof(get_version_reply), 978 1000); 979 if (result < 0) { 980 err("LEGO USB Tower get version control request failed"); 981 retval = result; 982 goto error; 983 } 984 dev_info(&interface->dev, "LEGO USB Tower firmware version is %d.%d " 985 "build %d\n", get_version_reply.major, 986 get_version_reply.minor, 987 le16_to_cpu(get_version_reply.build_no)); 988 989 990 exit: 991 dbg(2, "%s: leave, return value 0x%.8lx (dev)", __func__, (long) dev); 992 993 return retval; 994 995 error: 996 tower_delete(dev); 997 return retval; 998 } 999 1000 1001 /** 1002 * tower_disconnect 1003 * 1004 * Called by the usb core when the device is removed from the system. 1005 */ 1006 static void tower_disconnect (struct usb_interface *interface) 1007 { 1008 struct lego_usb_tower *dev; 1009 int minor; 1010 1011 dbg(2, "%s: enter", __func__); 1012 1013 dev = usb_get_intfdata (interface); 1014 mutex_lock(&open_disc_mutex); 1015 usb_set_intfdata (interface, NULL); 1016 1017 minor = dev->minor; 1018 1019 /* give back our minor */ 1020 usb_deregister_dev (interface, &tower_class); 1021 1022 mutex_lock(&dev->lock); 1023 mutex_unlock(&open_disc_mutex); 1024 1025 /* if the device is not opened, then we clean up right now */ 1026 if (!dev->open_count) { 1027 mutex_unlock(&dev->lock); 1028 tower_delete (dev); 1029 } else { 1030 dev->udev = NULL; 1031 /* wake up pollers */ 1032 wake_up_interruptible_all(&dev->read_wait); 1033 wake_up_interruptible_all(&dev->write_wait); 1034 mutex_unlock(&dev->lock); 1035 } 1036 1037 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n", 1038 (minor - LEGO_USB_TOWER_MINOR_BASE)); 1039 1040 dbg(2, "%s: leave", __func__); 1041 } 1042 1043 1044 1045 /** 1046 * lego_usb_tower_init 1047 */ 1048 static int __init lego_usb_tower_init(void) 1049 { 1050 int result; 1051 int retval = 0; 1052 1053 dbg(2, "%s: enter", __func__); 1054 1055 /* register this driver with the USB subsystem */ 1056 result = usb_register(&tower_driver); 1057 if (result < 0) { 1058 err("usb_register failed for the "__FILE__" driver. Error number %d", result); 1059 retval = -1; 1060 goto exit; 1061 } 1062 1063 printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":" 1064 DRIVER_DESC "\n"); 1065 1066 exit: 1067 dbg(2, "%s: leave, return value %d", __func__, retval); 1068 1069 return retval; 1070 } 1071 1072 1073 /** 1074 * lego_usb_tower_exit 1075 */ 1076 static void __exit lego_usb_tower_exit(void) 1077 { 1078 dbg(2, "%s: enter", __func__); 1079 1080 /* deregister this driver with the USB subsystem */ 1081 usb_deregister (&tower_driver); 1082 1083 dbg(2, "%s: leave", __func__); 1084 } 1085 1086 module_init (lego_usb_tower_init); 1087 module_exit (lego_usb_tower_exit); 1088 1089 MODULE_AUTHOR(DRIVER_AUTHOR); 1090 MODULE_DESCRIPTION(DRIVER_DESC); 1091 #ifdef MODULE_LICENSE 1092 MODULE_LICENSE("GPL"); 1093 #endif 1094