1 /* 2 * LEGO USB Tower driver 3 * 4 * Copyright (C) 2003 David Glance <davidgsf@sourceforge.net> 5 * 2001-2004 Juergen Stuber <starblue@users.sourceforge.net> 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License as 9 * published by the Free Software Foundation; either version 2 of 10 * the License, or (at your option) any later version. 11 * 12 * derived from USB Skeleton driver - 0.5 13 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com) 14 * 15 * History: 16 * 17 * 2001-10-13 - 0.1 js 18 * - first version 19 * 2001-11-03 - 0.2 js 20 * - simplified buffering, one-shot URBs for writing 21 * 2001-11-10 - 0.3 js 22 * - removed IOCTL (setting power/mode is more complicated, postponed) 23 * 2001-11-28 - 0.4 js 24 * - added vendor commands for mode of operation and power level in open 25 * 2001-12-04 - 0.5 js 26 * - set IR mode by default (by oversight 0.4 set VLL mode) 27 * 2002-01-11 - 0.5? pcchan 28 * - make read buffer reusable and work around bytes_to_write issue between 29 * uhci and legusbtower 30 * 2002-09-23 - 0.52 david (david@csse.uwa.edu.au) 31 * - imported into lejos project 32 * - changed wake_up to wake_up_interruptible 33 * - changed to use lego0 rather than tower0 34 * - changed dbg() to use __func__ rather than deprecated __func__ 35 * 2003-01-12 - 0.53 david (david@csse.uwa.edu.au) 36 * - changed read and write to write everything or 37 * timeout (from a patch by Chris Riesen and Brett Thaeler driver) 38 * - added ioctl functionality to set timeouts 39 * 2003-07-18 - 0.54 davidgsf (david@csse.uwa.edu.au) 40 * - initial import into LegoUSB project 41 * - merge of existing LegoUSB.c driver 42 * 2003-07-18 - 0.56 davidgsf (david@csse.uwa.edu.au) 43 * - port to 2.6 style driver 44 * 2004-02-29 - 0.6 Juergen Stuber <starblue@users.sourceforge.net> 45 * - fix locking 46 * - unlink read URBs which are no longer needed 47 * - allow increased buffer size, eliminates need for timeout on write 48 * - have read URB running continuously 49 * - added poll 50 * - forbid seeking 51 * - added nonblocking I/O 52 * - changed back __func__ to __func__ 53 * - read and log tower firmware version 54 * - reset tower on probe, avoids failure of first write 55 * 2004-03-09 - 0.7 Juergen Stuber <starblue@users.sourceforge.net> 56 * - timeout read now only after inactivity, shorten default accordingly 57 * 2004-03-11 - 0.8 Juergen Stuber <starblue@users.sourceforge.net> 58 * - log major, minor instead of possibly confusing device filename 59 * - whitespace cleanup 60 * 2004-03-12 - 0.9 Juergen Stuber <starblue@users.sourceforge.net> 61 * - normalize whitespace in debug messages 62 * - take care about endianness in control message responses 63 * 2004-03-13 - 0.91 Juergen Stuber <starblue@users.sourceforge.net> 64 * - make default intervals longer to accommodate current EHCI driver 65 * 2004-03-19 - 0.92 Juergen Stuber <starblue@users.sourceforge.net> 66 * - replaced atomic_t by memory barriers 67 * 2004-04-21 - 0.93 Juergen Stuber <starblue@users.sourceforge.net> 68 * - wait for completion of write urb in release (needed for remotecontrol) 69 * - corrected poll for write direction (missing negation) 70 * 2004-04-22 - 0.94 Juergen Stuber <starblue@users.sourceforge.net> 71 * - make device locking interruptible 72 * 2004-04-30 - 0.95 Juergen Stuber <starblue@users.sourceforge.net> 73 * - check for valid udev on resubmitting and unlinking urbs 74 * 2004-08-03 - 0.96 Juergen Stuber <starblue@users.sourceforge.net> 75 * - move reset into open to clean out spurious data 76 */ 77 78 #include <linux/kernel.h> 79 #include <linux/errno.h> 80 #include <linux/init.h> 81 #include <linux/slab.h> 82 #include <linux/module.h> 83 #include <linux/completion.h> 84 #include <linux/mutex.h> 85 #include <asm/uaccess.h> 86 #include <linux/usb.h> 87 #include <linux/poll.h> 88 89 90 #ifdef CONFIG_USB_DEBUG 91 static int debug = 4; 92 #else 93 static int debug = 0; 94 #endif 95 96 /* Use our own dbg macro */ 97 #undef dbg 98 #define dbg(lvl, format, arg...) \ 99 do { \ 100 if (debug >= lvl) \ 101 printk(KERN_DEBUG "%s: " format "\n", __FILE__, ##arg); \ 102 } while (0) 103 104 /* Version Information */ 105 #define DRIVER_VERSION "v0.96" 106 #define DRIVER_AUTHOR "Juergen Stuber <starblue@sourceforge.net>" 107 #define DRIVER_DESC "LEGO USB Tower Driver" 108 109 /* Module parameters */ 110 module_param(debug, int, S_IRUGO | S_IWUSR); 111 MODULE_PARM_DESC(debug, "Debug enabled or not"); 112 113 /* The defaults are chosen to work with the latest versions of leJOS and NQC. 114 */ 115 116 /* Some legacy software likes to receive packets in one piece. 117 * In this case read_buffer_size should exceed the maximal packet length 118 * (417 for datalog uploads), and packet_timeout should be set. 119 */ 120 static int read_buffer_size = 480; 121 module_param(read_buffer_size, int, 0); 122 MODULE_PARM_DESC(read_buffer_size, "Read buffer size"); 123 124 /* Some legacy software likes to send packets in one piece. 125 * In this case write_buffer_size should exceed the maximal packet length 126 * (417 for firmware and program downloads). 127 * A problem with long writes is that the following read may time out 128 * if the software is not prepared to wait long enough. 129 */ 130 static int write_buffer_size = 480; 131 module_param(write_buffer_size, int, 0); 132 MODULE_PARM_DESC(write_buffer_size, "Write buffer size"); 133 134 /* Some legacy software expects reads to contain whole LASM packets. 135 * To achieve this, characters which arrive before a packet timeout 136 * occurs will be returned in a single read operation. 137 * A problem with long reads is that the software may time out 138 * if it is not prepared to wait long enough. 139 * The packet timeout should be greater than the time between the 140 * reception of subsequent characters, which should arrive about 141 * every 5ms for the standard 2400 baud. 142 * Set it to 0 to disable. 143 */ 144 static int packet_timeout = 50; 145 module_param(packet_timeout, int, 0); 146 MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms"); 147 148 /* Some legacy software expects blocking reads to time out. 149 * Timeout occurs after the specified time of read and write inactivity. 150 * Set it to 0 to disable. 151 */ 152 static int read_timeout = 200; 153 module_param(read_timeout, int, 0); 154 MODULE_PARM_DESC(read_timeout, "Read timeout in ms"); 155 156 /* As of kernel version 2.6.4 ehci-hcd uses an 157 * "only one interrupt transfer per frame" shortcut 158 * to simplify the scheduling of periodic transfers. 159 * This conflicts with our standard 1ms intervals for in and out URBs. 160 * We use default intervals of 2ms for in and 8ms for out transfers, 161 * which is fast enough for 2400 baud and allows a small additional load. 162 * Increase the interval to allow more devices that do interrupt transfers, 163 * or set to 0 to use the standard interval from the endpoint descriptors. 164 */ 165 static int interrupt_in_interval = 2; 166 module_param(interrupt_in_interval, int, 0); 167 MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms"); 168 169 static int interrupt_out_interval = 8; 170 module_param(interrupt_out_interval, int, 0); 171 MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms"); 172 173 /* Define these values to match your device */ 174 #define LEGO_USB_TOWER_VENDOR_ID 0x0694 175 #define LEGO_USB_TOWER_PRODUCT_ID 0x0001 176 177 /* Vendor requests */ 178 #define LEGO_USB_TOWER_REQUEST_RESET 0x04 179 #define LEGO_USB_TOWER_REQUEST_GET_VERSION 0xFD 180 181 struct tower_reset_reply { 182 __le16 size; /* little-endian */ 183 __u8 err_code; 184 __u8 spare; 185 } __attribute__ ((packed)); 186 187 struct tower_get_version_reply { 188 __le16 size; /* little-endian */ 189 __u8 err_code; 190 __u8 spare; 191 __u8 major; 192 __u8 minor; 193 __le16 build_no; /* little-endian */ 194 } __attribute__ ((packed)); 195 196 197 /* table of devices that work with this driver */ 198 static const struct usb_device_id tower_table[] = { 199 { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) }, 200 { } /* Terminating entry */ 201 }; 202 203 MODULE_DEVICE_TABLE (usb, tower_table); 204 static DEFINE_MUTEX(open_disc_mutex); 205 206 #define LEGO_USB_TOWER_MINOR_BASE 160 207 208 209 /* Structure to hold all of our device specific stuff */ 210 struct lego_usb_tower { 211 struct mutex lock; /* locks this structure */ 212 struct usb_device* udev; /* save off the usb device pointer */ 213 unsigned char minor; /* the starting minor number for this device */ 214 215 int open_count; /* number of times this port has been opened */ 216 217 char* read_buffer; 218 size_t read_buffer_length; /* this much came in */ 219 size_t read_packet_length; /* this much will be returned on read */ 220 spinlock_t read_buffer_lock; 221 int packet_timeout_jiffies; 222 unsigned long read_last_arrival; 223 224 wait_queue_head_t read_wait; 225 wait_queue_head_t write_wait; 226 227 char* interrupt_in_buffer; 228 struct usb_endpoint_descriptor* interrupt_in_endpoint; 229 struct urb* interrupt_in_urb; 230 int interrupt_in_interval; 231 int interrupt_in_running; 232 int interrupt_in_done; 233 234 char* interrupt_out_buffer; 235 struct usb_endpoint_descriptor* interrupt_out_endpoint; 236 struct urb* interrupt_out_urb; 237 int interrupt_out_interval; 238 int interrupt_out_busy; 239 240 }; 241 242 243 /* local function prototypes */ 244 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos); 245 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos); 246 static inline void tower_delete (struct lego_usb_tower *dev); 247 static int tower_open (struct inode *inode, struct file *file); 248 static int tower_release (struct inode *inode, struct file *file); 249 static unsigned int tower_poll (struct file *file, poll_table *wait); 250 static loff_t tower_llseek (struct file *file, loff_t off, int whence); 251 252 static void tower_abort_transfers (struct lego_usb_tower *dev); 253 static void tower_check_for_read_packet (struct lego_usb_tower *dev); 254 static void tower_interrupt_in_callback (struct urb *urb); 255 static void tower_interrupt_out_callback (struct urb *urb); 256 257 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id); 258 static void tower_disconnect (struct usb_interface *interface); 259 260 261 /* file operations needed when we register this driver */ 262 static const struct file_operations tower_fops = { 263 .owner = THIS_MODULE, 264 .read = tower_read, 265 .write = tower_write, 266 .open = tower_open, 267 .release = tower_release, 268 .poll = tower_poll, 269 .llseek = tower_llseek, 270 }; 271 272 static char *legousbtower_devnode(struct device *dev, umode_t *mode) 273 { 274 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev)); 275 } 276 277 /* 278 * usb class driver info in order to get a minor number from the usb core, 279 * and to have the device registered with the driver core 280 */ 281 static struct usb_class_driver tower_class = { 282 .name = "legousbtower%d", 283 .devnode = legousbtower_devnode, 284 .fops = &tower_fops, 285 .minor_base = LEGO_USB_TOWER_MINOR_BASE, 286 }; 287 288 289 /* usb specific object needed to register this driver with the usb subsystem */ 290 static struct usb_driver tower_driver = { 291 .name = "legousbtower", 292 .probe = tower_probe, 293 .disconnect = tower_disconnect, 294 .id_table = tower_table, 295 }; 296 297 298 /** 299 * lego_usb_tower_debug_data 300 */ 301 static inline void lego_usb_tower_debug_data (int level, const char *function, int size, const unsigned char *data) 302 { 303 int i; 304 305 if (debug < level) 306 return; 307 308 printk (KERN_DEBUG "%s: %s - length = %d, data = ", __FILE__, function, size); 309 for (i = 0; i < size; ++i) { 310 printk ("%.2x ", data[i]); 311 } 312 printk ("\n"); 313 } 314 315 316 /** 317 * tower_delete 318 */ 319 static inline void tower_delete (struct lego_usb_tower *dev) 320 { 321 dbg(2, "%s: enter", __func__); 322 323 tower_abort_transfers (dev); 324 325 /* free data structures */ 326 usb_free_urb(dev->interrupt_in_urb); 327 usb_free_urb(dev->interrupt_out_urb); 328 kfree (dev->read_buffer); 329 kfree (dev->interrupt_in_buffer); 330 kfree (dev->interrupt_out_buffer); 331 kfree (dev); 332 333 dbg(2, "%s: leave", __func__); 334 } 335 336 337 /** 338 * tower_open 339 */ 340 static int tower_open (struct inode *inode, struct file *file) 341 { 342 struct lego_usb_tower *dev = NULL; 343 int subminor; 344 int retval = 0; 345 struct usb_interface *interface; 346 struct tower_reset_reply reset_reply; 347 int result; 348 349 dbg(2, "%s: enter", __func__); 350 351 nonseekable_open(inode, file); 352 subminor = iminor(inode); 353 354 interface = usb_find_interface (&tower_driver, subminor); 355 356 if (!interface) { 357 err ("%s - error, can't find device for minor %d", 358 __func__, subminor); 359 retval = -ENODEV; 360 goto exit; 361 } 362 363 mutex_lock(&open_disc_mutex); 364 dev = usb_get_intfdata(interface); 365 366 if (!dev) { 367 mutex_unlock(&open_disc_mutex); 368 retval = -ENODEV; 369 goto exit; 370 } 371 372 /* lock this device */ 373 if (mutex_lock_interruptible(&dev->lock)) { 374 mutex_unlock(&open_disc_mutex); 375 retval = -ERESTARTSYS; 376 goto exit; 377 } 378 379 380 /* allow opening only once */ 381 if (dev->open_count) { 382 mutex_unlock(&open_disc_mutex); 383 retval = -EBUSY; 384 goto unlock_exit; 385 } 386 dev->open_count = 1; 387 mutex_unlock(&open_disc_mutex); 388 389 /* reset the tower */ 390 result = usb_control_msg (dev->udev, 391 usb_rcvctrlpipe(dev->udev, 0), 392 LEGO_USB_TOWER_REQUEST_RESET, 393 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 394 0, 395 0, 396 &reset_reply, 397 sizeof(reset_reply), 398 1000); 399 if (result < 0) { 400 err("LEGO USB Tower reset control request failed"); 401 retval = result; 402 goto unlock_exit; 403 } 404 405 /* initialize in direction */ 406 dev->read_buffer_length = 0; 407 dev->read_packet_length = 0; 408 usb_fill_int_urb (dev->interrupt_in_urb, 409 dev->udev, 410 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress), 411 dev->interrupt_in_buffer, 412 usb_endpoint_maxp(dev->interrupt_in_endpoint), 413 tower_interrupt_in_callback, 414 dev, 415 dev->interrupt_in_interval); 416 417 dev->interrupt_in_running = 1; 418 dev->interrupt_in_done = 0; 419 mb(); 420 421 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL); 422 if (retval) { 423 err("Couldn't submit interrupt_in_urb %d", retval); 424 dev->interrupt_in_running = 0; 425 dev->open_count = 0; 426 goto unlock_exit; 427 } 428 429 /* save device in the file's private structure */ 430 file->private_data = dev; 431 432 unlock_exit: 433 mutex_unlock(&dev->lock); 434 435 exit: 436 dbg(2, "%s: leave, return value %d ", __func__, retval); 437 438 return retval; 439 } 440 441 /** 442 * tower_release 443 */ 444 static int tower_release (struct inode *inode, struct file *file) 445 { 446 struct lego_usb_tower *dev; 447 int retval = 0; 448 449 dbg(2, "%s: enter", __func__); 450 451 dev = file->private_data; 452 453 if (dev == NULL) { 454 dbg(1, "%s: object is NULL", __func__); 455 retval = -ENODEV; 456 goto exit_nolock; 457 } 458 459 mutex_lock(&open_disc_mutex); 460 if (mutex_lock_interruptible(&dev->lock)) { 461 retval = -ERESTARTSYS; 462 goto exit; 463 } 464 465 if (dev->open_count != 1) { 466 dbg(1, "%s: device not opened exactly once", __func__); 467 retval = -ENODEV; 468 goto unlock_exit; 469 } 470 if (dev->udev == NULL) { 471 /* the device was unplugged before the file was released */ 472 473 /* unlock here as tower_delete frees dev */ 474 mutex_unlock(&dev->lock); 475 tower_delete (dev); 476 goto exit; 477 } 478 479 /* wait until write transfer is finished */ 480 if (dev->interrupt_out_busy) { 481 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 482 } 483 tower_abort_transfers (dev); 484 dev->open_count = 0; 485 486 unlock_exit: 487 mutex_unlock(&dev->lock); 488 489 exit: 490 mutex_unlock(&open_disc_mutex); 491 exit_nolock: 492 dbg(2, "%s: leave, return value %d", __func__, retval); 493 return retval; 494 } 495 496 497 /** 498 * tower_abort_transfers 499 * aborts transfers and frees associated data structures 500 */ 501 static void tower_abort_transfers (struct lego_usb_tower *dev) 502 { 503 dbg(2, "%s: enter", __func__); 504 505 if (dev == NULL) { 506 dbg(1, "%s: dev is null", __func__); 507 goto exit; 508 } 509 510 /* shutdown transfer */ 511 if (dev->interrupt_in_running) { 512 dev->interrupt_in_running = 0; 513 mb(); 514 if (dev->udev) 515 usb_kill_urb (dev->interrupt_in_urb); 516 } 517 if (dev->interrupt_out_busy && dev->udev) 518 usb_kill_urb(dev->interrupt_out_urb); 519 520 exit: 521 dbg(2, "%s: leave", __func__); 522 } 523 524 525 /** 526 * tower_check_for_read_packet 527 * 528 * To get correct semantics for signals and non-blocking I/O 529 * with packetizing we pretend not to see any data in the read buffer 530 * until it has been there unchanged for at least 531 * dev->packet_timeout_jiffies, or until the buffer is full. 532 */ 533 static void tower_check_for_read_packet (struct lego_usb_tower *dev) 534 { 535 spin_lock_irq (&dev->read_buffer_lock); 536 if (!packet_timeout 537 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies) 538 || dev->read_buffer_length == read_buffer_size) { 539 dev->read_packet_length = dev->read_buffer_length; 540 } 541 dev->interrupt_in_done = 0; 542 spin_unlock_irq (&dev->read_buffer_lock); 543 } 544 545 546 /** 547 * tower_poll 548 */ 549 static unsigned int tower_poll (struct file *file, poll_table *wait) 550 { 551 struct lego_usb_tower *dev; 552 unsigned int mask = 0; 553 554 dbg(2, "%s: enter", __func__); 555 556 dev = file->private_data; 557 558 if (!dev->udev) 559 return POLLERR | POLLHUP; 560 561 poll_wait(file, &dev->read_wait, wait); 562 poll_wait(file, &dev->write_wait, wait); 563 564 tower_check_for_read_packet(dev); 565 if (dev->read_packet_length > 0) { 566 mask |= POLLIN | POLLRDNORM; 567 } 568 if (!dev->interrupt_out_busy) { 569 mask |= POLLOUT | POLLWRNORM; 570 } 571 572 dbg(2, "%s: leave, mask = %d", __func__, mask); 573 574 return mask; 575 } 576 577 578 /** 579 * tower_llseek 580 */ 581 static loff_t tower_llseek (struct file *file, loff_t off, int whence) 582 { 583 return -ESPIPE; /* unseekable */ 584 } 585 586 587 /** 588 * tower_read 589 */ 590 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos) 591 { 592 struct lego_usb_tower *dev; 593 size_t bytes_to_read; 594 int i; 595 int retval = 0; 596 unsigned long timeout = 0; 597 598 dbg(2, "%s: enter, count = %Zd", __func__, count); 599 600 dev = file->private_data; 601 602 /* lock this object */ 603 if (mutex_lock_interruptible(&dev->lock)) { 604 retval = -ERESTARTSYS; 605 goto exit; 606 } 607 608 /* verify that the device wasn't unplugged */ 609 if (dev->udev == NULL) { 610 retval = -ENODEV; 611 err("No device or device unplugged %d", retval); 612 goto unlock_exit; 613 } 614 615 /* verify that we actually have some data to read */ 616 if (count == 0) { 617 dbg(1, "%s: read request of 0 bytes", __func__); 618 goto unlock_exit; 619 } 620 621 if (read_timeout) { 622 timeout = jiffies + read_timeout * HZ / 1000; 623 } 624 625 /* wait for data */ 626 tower_check_for_read_packet (dev); 627 while (dev->read_packet_length == 0) { 628 if (file->f_flags & O_NONBLOCK) { 629 retval = -EAGAIN; 630 goto unlock_exit; 631 } 632 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies); 633 if (retval < 0) { 634 goto unlock_exit; 635 } 636 637 /* reset read timeout during read or write activity */ 638 if (read_timeout 639 && (dev->read_buffer_length || dev->interrupt_out_busy)) { 640 timeout = jiffies + read_timeout * HZ / 1000; 641 } 642 /* check for read timeout */ 643 if (read_timeout && time_after (jiffies, timeout)) { 644 retval = -ETIMEDOUT; 645 goto unlock_exit; 646 } 647 tower_check_for_read_packet (dev); 648 } 649 650 /* copy the data from read_buffer into userspace */ 651 bytes_to_read = min(count, dev->read_packet_length); 652 653 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) { 654 retval = -EFAULT; 655 goto unlock_exit; 656 } 657 658 spin_lock_irq (&dev->read_buffer_lock); 659 dev->read_buffer_length -= bytes_to_read; 660 dev->read_packet_length -= bytes_to_read; 661 for (i=0; i<dev->read_buffer_length; i++) { 662 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read]; 663 } 664 spin_unlock_irq (&dev->read_buffer_lock); 665 666 retval = bytes_to_read; 667 668 unlock_exit: 669 /* unlock the device */ 670 mutex_unlock(&dev->lock); 671 672 exit: 673 dbg(2, "%s: leave, return value %d", __func__, retval); 674 return retval; 675 } 676 677 678 /** 679 * tower_write 680 */ 681 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos) 682 { 683 struct lego_usb_tower *dev; 684 size_t bytes_to_write; 685 int retval = 0; 686 687 dbg(2, "%s: enter, count = %Zd", __func__, count); 688 689 dev = file->private_data; 690 691 /* lock this object */ 692 if (mutex_lock_interruptible(&dev->lock)) { 693 retval = -ERESTARTSYS; 694 goto exit; 695 } 696 697 /* verify that the device wasn't unplugged */ 698 if (dev->udev == NULL) { 699 retval = -ENODEV; 700 err("No device or device unplugged %d", retval); 701 goto unlock_exit; 702 } 703 704 /* verify that we actually have some data to write */ 705 if (count == 0) { 706 dbg(1, "%s: write request of 0 bytes", __func__); 707 goto unlock_exit; 708 } 709 710 /* wait until previous transfer is finished */ 711 while (dev->interrupt_out_busy) { 712 if (file->f_flags & O_NONBLOCK) { 713 retval = -EAGAIN; 714 goto unlock_exit; 715 } 716 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy); 717 if (retval) { 718 goto unlock_exit; 719 } 720 } 721 722 /* write the data into interrupt_out_buffer from userspace */ 723 bytes_to_write = min_t(int, count, write_buffer_size); 724 dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __func__, count, bytes_to_write); 725 726 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) { 727 retval = -EFAULT; 728 goto unlock_exit; 729 } 730 731 /* send off the urb */ 732 usb_fill_int_urb(dev->interrupt_out_urb, 733 dev->udev, 734 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), 735 dev->interrupt_out_buffer, 736 bytes_to_write, 737 tower_interrupt_out_callback, 738 dev, 739 dev->interrupt_out_interval); 740 741 dev->interrupt_out_busy = 1; 742 wmb(); 743 744 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL); 745 if (retval) { 746 dev->interrupt_out_busy = 0; 747 err("Couldn't submit interrupt_out_urb %d", retval); 748 goto unlock_exit; 749 } 750 retval = bytes_to_write; 751 752 unlock_exit: 753 /* unlock the device */ 754 mutex_unlock(&dev->lock); 755 756 exit: 757 dbg(2, "%s: leave, return value %d", __func__, retval); 758 759 return retval; 760 } 761 762 763 /** 764 * tower_interrupt_in_callback 765 */ 766 static void tower_interrupt_in_callback (struct urb *urb) 767 { 768 struct lego_usb_tower *dev = urb->context; 769 int status = urb->status; 770 int retval; 771 772 dbg(4, "%s: enter, status %d", __func__, status); 773 774 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 775 776 if (status) { 777 if (status == -ENOENT || 778 status == -ECONNRESET || 779 status == -ESHUTDOWN) { 780 goto exit; 781 } else { 782 dbg(1, "%s: nonzero status received: %d", __func__, status); 783 goto resubmit; /* maybe we can recover */ 784 } 785 } 786 787 if (urb->actual_length > 0) { 788 spin_lock (&dev->read_buffer_lock); 789 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { 790 memcpy (dev->read_buffer + dev->read_buffer_length, 791 dev->interrupt_in_buffer, 792 urb->actual_length); 793 dev->read_buffer_length += urb->actual_length; 794 dev->read_last_arrival = jiffies; 795 dbg(3, "%s: received %d bytes", __func__, urb->actual_length); 796 } else { 797 printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __func__, urb->actual_length); 798 } 799 spin_unlock (&dev->read_buffer_lock); 800 } 801 802 resubmit: 803 /* resubmit if we're still running */ 804 if (dev->interrupt_in_running && dev->udev) { 805 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC); 806 if (retval) { 807 err("%s: usb_submit_urb failed (%d)", __func__, retval); 808 } 809 } 810 811 exit: 812 dev->interrupt_in_done = 1; 813 wake_up_interruptible (&dev->read_wait); 814 815 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 816 dbg(4, "%s: leave, status %d", __func__, status); 817 } 818 819 820 /** 821 * tower_interrupt_out_callback 822 */ 823 static void tower_interrupt_out_callback (struct urb *urb) 824 { 825 struct lego_usb_tower *dev = urb->context; 826 int status = urb->status; 827 828 dbg(4, "%s: enter, status %d", __func__, status); 829 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 830 831 /* sync/async unlink faults aren't errors */ 832 if (status && !(status == -ENOENT || 833 status == -ECONNRESET || 834 status == -ESHUTDOWN)) { 835 dbg(1, "%s - nonzero write bulk status received: %d", 836 __func__, status); 837 } 838 839 dev->interrupt_out_busy = 0; 840 wake_up_interruptible(&dev->write_wait); 841 842 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer); 843 dbg(4, "%s: leave, status %d", __func__, status); 844 } 845 846 847 /** 848 * tower_probe 849 * 850 * Called by the usb core when a new device is connected that it thinks 851 * this driver might be interested in. 852 */ 853 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id) 854 { 855 struct usb_device *udev = interface_to_usbdev(interface); 856 struct lego_usb_tower *dev = NULL; 857 struct usb_host_interface *iface_desc; 858 struct usb_endpoint_descriptor* endpoint; 859 struct tower_get_version_reply get_version_reply; 860 int i; 861 int retval = -ENOMEM; 862 int result; 863 864 dbg(2, "%s: enter", __func__); 865 866 if (udev == NULL) 867 dev_info(&interface->dev, "udev is NULL.\n"); 868 869 /* allocate memory for our device state and initialize it */ 870 871 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL); 872 873 if (dev == NULL) { 874 err ("Out of memory"); 875 goto exit; 876 } 877 878 mutex_init(&dev->lock); 879 880 dev->udev = udev; 881 dev->open_count = 0; 882 883 dev->read_buffer = NULL; 884 dev->read_buffer_length = 0; 885 dev->read_packet_length = 0; 886 spin_lock_init (&dev->read_buffer_lock); 887 dev->packet_timeout_jiffies = packet_timeout * HZ / 1000; 888 dev->read_last_arrival = jiffies; 889 890 init_waitqueue_head (&dev->read_wait); 891 init_waitqueue_head (&dev->write_wait); 892 893 dev->interrupt_in_buffer = NULL; 894 dev->interrupt_in_endpoint = NULL; 895 dev->interrupt_in_urb = NULL; 896 dev->interrupt_in_running = 0; 897 dev->interrupt_in_done = 0; 898 899 dev->interrupt_out_buffer = NULL; 900 dev->interrupt_out_endpoint = NULL; 901 dev->interrupt_out_urb = NULL; 902 dev->interrupt_out_busy = 0; 903 904 iface_desc = interface->cur_altsetting; 905 906 /* set up the endpoint information */ 907 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 908 endpoint = &iface_desc->endpoint[i].desc; 909 910 if (usb_endpoint_xfer_int(endpoint)) { 911 if (usb_endpoint_dir_in(endpoint)) 912 dev->interrupt_in_endpoint = endpoint; 913 else 914 dev->interrupt_out_endpoint = endpoint; 915 } 916 } 917 if(dev->interrupt_in_endpoint == NULL) { 918 err("interrupt in endpoint not found"); 919 goto error; 920 } 921 if (dev->interrupt_out_endpoint == NULL) { 922 err("interrupt out endpoint not found"); 923 goto error; 924 } 925 926 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL); 927 if (!dev->read_buffer) { 928 err("Couldn't allocate read_buffer"); 929 goto error; 930 } 931 dev->interrupt_in_buffer = kmalloc (usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL); 932 if (!dev->interrupt_in_buffer) { 933 err("Couldn't allocate interrupt_in_buffer"); 934 goto error; 935 } 936 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 937 if (!dev->interrupt_in_urb) { 938 err("Couldn't allocate interrupt_in_urb"); 939 goto error; 940 } 941 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL); 942 if (!dev->interrupt_out_buffer) { 943 err("Couldn't allocate interrupt_out_buffer"); 944 goto error; 945 } 946 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 947 if (!dev->interrupt_out_urb) { 948 err("Couldn't allocate interrupt_out_urb"); 949 goto error; 950 } 951 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 952 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 953 954 /* we can register the device now, as it is ready */ 955 usb_set_intfdata (interface, dev); 956 957 retval = usb_register_dev (interface, &tower_class); 958 959 if (retval) { 960 /* something prevented us from registering this driver */ 961 err ("Not able to get a minor for this device."); 962 usb_set_intfdata (interface, NULL); 963 goto error; 964 } 965 dev->minor = interface->minor; 966 967 /* let the user know what node this device is now attached to */ 968 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major " 969 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), 970 USB_MAJOR, dev->minor); 971 972 /* get the firmware version and log it */ 973 result = usb_control_msg (udev, 974 usb_rcvctrlpipe(udev, 0), 975 LEGO_USB_TOWER_REQUEST_GET_VERSION, 976 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE, 977 0, 978 0, 979 &get_version_reply, 980 sizeof(get_version_reply), 981 1000); 982 if (result < 0) { 983 err("LEGO USB Tower get version control request failed"); 984 retval = result; 985 goto error; 986 } 987 dev_info(&interface->dev, "LEGO USB Tower firmware version is %d.%d " 988 "build %d\n", get_version_reply.major, 989 get_version_reply.minor, 990 le16_to_cpu(get_version_reply.build_no)); 991 992 993 exit: 994 dbg(2, "%s: leave, return value 0x%.8lx (dev)", __func__, (long) dev); 995 996 return retval; 997 998 error: 999 tower_delete(dev); 1000 return retval; 1001 } 1002 1003 1004 /** 1005 * tower_disconnect 1006 * 1007 * Called by the usb core when the device is removed from the system. 1008 */ 1009 static void tower_disconnect (struct usb_interface *interface) 1010 { 1011 struct lego_usb_tower *dev; 1012 int minor; 1013 1014 dbg(2, "%s: enter", __func__); 1015 1016 dev = usb_get_intfdata (interface); 1017 mutex_lock(&open_disc_mutex); 1018 usb_set_intfdata (interface, NULL); 1019 1020 minor = dev->minor; 1021 1022 /* give back our minor */ 1023 usb_deregister_dev (interface, &tower_class); 1024 1025 mutex_lock(&dev->lock); 1026 mutex_unlock(&open_disc_mutex); 1027 1028 /* if the device is not opened, then we clean up right now */ 1029 if (!dev->open_count) { 1030 mutex_unlock(&dev->lock); 1031 tower_delete (dev); 1032 } else { 1033 dev->udev = NULL; 1034 /* wake up pollers */ 1035 wake_up_interruptible_all(&dev->read_wait); 1036 wake_up_interruptible_all(&dev->write_wait); 1037 mutex_unlock(&dev->lock); 1038 } 1039 1040 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n", 1041 (minor - LEGO_USB_TOWER_MINOR_BASE)); 1042 1043 dbg(2, "%s: leave", __func__); 1044 } 1045 1046 1047 1048 /** 1049 * lego_usb_tower_init 1050 */ 1051 static int __init lego_usb_tower_init(void) 1052 { 1053 int result; 1054 int retval = 0; 1055 1056 dbg(2, "%s: enter", __func__); 1057 1058 /* register this driver with the USB subsystem */ 1059 result = usb_register(&tower_driver); 1060 if (result < 0) { 1061 err("usb_register failed for the %s driver. Error number %d", __FILE__, result); 1062 retval = -1; 1063 goto exit; 1064 } 1065 1066 printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":" 1067 DRIVER_DESC "\n"); 1068 1069 exit: 1070 dbg(2, "%s: leave, return value %d", __func__, retval); 1071 1072 return retval; 1073 } 1074 1075 1076 /** 1077 * lego_usb_tower_exit 1078 */ 1079 static void __exit lego_usb_tower_exit(void) 1080 { 1081 dbg(2, "%s: enter", __func__); 1082 1083 /* deregister this driver with the USB subsystem */ 1084 usb_deregister (&tower_driver); 1085 1086 dbg(2, "%s: leave", __func__); 1087 } 1088 1089 module_init (lego_usb_tower_init); 1090 module_exit (lego_usb_tower_exit); 1091 1092 MODULE_AUTHOR(DRIVER_AUTHOR); 1093 MODULE_DESCRIPTION(DRIVER_DESC); 1094 #ifdef MODULE_LICENSE 1095 MODULE_LICENSE("GPL"); 1096 #endif 1097