1 /** 2 * Generic USB driver for report based interrupt in/out devices 3 * like LD Didactic's USB devices. LD Didactic's USB devices are 4 * HID devices which do not use HID report definitons (they use 5 * raw interrupt in and our reports only for communication). 6 * 7 * This driver uses a ring buffer for time critical reading of 8 * interrupt in reports and provides read and write methods for 9 * raw interrupt reports (similar to the Windows HID driver). 10 * Devices based on the book USB COMPLETE by Jan Axelson may need 11 * such a compatibility to the Windows HID driver. 12 * 13 * Copyright (C) 2005 Michael Hund <mhund@ld-didactic.de> 14 * 15 * This program is free software; you can redistribute it and/or 16 * modify it under the terms of the GNU General Public License as 17 * published by the Free Software Foundation; either version 2 of 18 * the License, or (at your option) any later version. 19 * 20 * Derived from Lego USB Tower driver 21 * Copyright (C) 2003 David Glance <advidgsf@sourceforge.net> 22 * 2001-2004 Juergen Stuber <starblue@users.sourceforge.net> 23 * 24 * V0.1 (mh) Initial version 25 * V0.11 (mh) Added raw support for HID 1.0 devices (no interrupt out endpoint) 26 * V0.12 (mh) Added kmalloc check for string buffer 27 * V0.13 (mh) Added support for LD X-Ray and Machine Test System 28 */ 29 30 #include <linux/kernel.h> 31 #include <linux/errno.h> 32 #include <linux/init.h> 33 #include <linux/slab.h> 34 #include <linux/module.h> 35 #include <linux/mutex.h> 36 37 #include <asm/uaccess.h> 38 #include <linux/input.h> 39 #include <linux/usb.h> 40 #include <linux/poll.h> 41 42 /* Define these values to match your devices */ 43 #define USB_VENDOR_ID_LD 0x0f11 /* USB Vendor ID of LD Didactic GmbH */ 44 #define USB_DEVICE_ID_LD_CASSY 0x1000 /* USB Product ID of CASSY-S */ 45 #define USB_DEVICE_ID_LD_POCKETCASSY 0x1010 /* USB Product ID of Pocket-CASSY */ 46 #define USB_DEVICE_ID_LD_MOBILECASSY 0x1020 /* USB Product ID of Mobile-CASSY */ 47 #define USB_DEVICE_ID_LD_JWM 0x1080 /* USB Product ID of Joule and Wattmeter */ 48 #define USB_DEVICE_ID_LD_DMMP 0x1081 /* USB Product ID of Digital Multimeter P (reserved) */ 49 #define USB_DEVICE_ID_LD_UMIP 0x1090 /* USB Product ID of UMI P */ 50 #define USB_DEVICE_ID_LD_XRAY1 0x1100 /* USB Product ID of X-Ray Apparatus */ 51 #define USB_DEVICE_ID_LD_XRAY2 0x1101 /* USB Product ID of X-Ray Apparatus */ 52 #define USB_DEVICE_ID_LD_VIDEOCOM 0x1200 /* USB Product ID of VideoCom */ 53 #define USB_DEVICE_ID_LD_COM3LAB 0x2000 /* USB Product ID of COM3LAB */ 54 #define USB_DEVICE_ID_LD_TELEPORT 0x2010 /* USB Product ID of Terminal Adapter */ 55 #define USB_DEVICE_ID_LD_NETWORKANALYSER 0x2020 /* USB Product ID of Network Analyser */ 56 #define USB_DEVICE_ID_LD_POWERCONTROL 0x2030 /* USB Product ID of Converter Control Unit */ 57 #define USB_DEVICE_ID_LD_MACHINETEST 0x2040 /* USB Product ID of Machine Test System */ 58 59 #define USB_VENDOR_ID_VERNIER 0x08f7 60 #define USB_DEVICE_ID_VERNIER_GOTEMP 0x0002 61 #define USB_DEVICE_ID_VERNIER_SKIP 0x0003 62 #define USB_DEVICE_ID_VERNIER_CYCLOPS 0x0004 63 #define USB_DEVICE_ID_VERNIER_LCSPEC 0x0006 64 65 #ifdef CONFIG_USB_DYNAMIC_MINORS 66 #define USB_LD_MINOR_BASE 0 67 #else 68 #define USB_LD_MINOR_BASE 176 69 #endif 70 71 /* table of devices that work with this driver */ 72 static const struct usb_device_id ld_usb_table[] = { 73 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY) }, 74 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY) }, 75 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY) }, 76 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_JWM) }, 77 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_DMMP) }, 78 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIP) }, 79 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY1) }, 80 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY2) }, 81 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_VIDEOCOM) }, 82 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_COM3LAB) }, 83 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_TELEPORT) }, 84 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_NETWORKANALYSER) }, 85 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERCONTROL) }, 86 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETEST) }, 87 { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_GOTEMP) }, 88 { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_SKIP) }, 89 { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_CYCLOPS) }, 90 { USB_DEVICE(USB_VENDOR_ID_VERNIER, USB_DEVICE_ID_VERNIER_LCSPEC) }, 91 { } /* Terminating entry */ 92 }; 93 MODULE_DEVICE_TABLE(usb, ld_usb_table); 94 MODULE_VERSION("V0.13"); 95 MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>"); 96 MODULE_DESCRIPTION("LD USB Driver"); 97 MODULE_LICENSE("GPL"); 98 MODULE_SUPPORTED_DEVICE("LD USB Devices"); 99 100 #ifdef CONFIG_USB_DEBUG 101 static int debug = 1; 102 #else 103 static int debug = 0; 104 #endif 105 106 /* Use our own dbg macro */ 107 #define dbg_info(dev, format, arg...) do { if (debug) dev_info(dev , format , ## arg); } while (0) 108 109 /* Module parameters */ 110 module_param(debug, int, S_IRUGO | S_IWUSR); 111 MODULE_PARM_DESC(debug, "Debug enabled or not"); 112 113 /* All interrupt in transfers are collected in a ring buffer to 114 * avoid racing conditions and get better performance of the driver. 115 */ 116 static int ring_buffer_size = 128; 117 module_param(ring_buffer_size, int, 0); 118 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports"); 119 120 /* The write_buffer can contain more than one interrupt out transfer. 121 */ 122 static int write_buffer_size = 10; 123 module_param(write_buffer_size, int, 0); 124 MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports"); 125 126 /* As of kernel version 2.6.4 ehci-hcd uses an 127 * "only one interrupt transfer per frame" shortcut 128 * to simplify the scheduling of periodic transfers. 129 * This conflicts with our standard 1ms intervals for in and out URBs. 130 * We use default intervals of 2ms for in and 2ms for out transfers, 131 * which should be fast enough. 132 * Increase the interval to allow more devices that do interrupt transfers, 133 * or set to 1 to use the standard interval from the endpoint descriptors. 134 */ 135 static int min_interrupt_in_interval = 2; 136 module_param(min_interrupt_in_interval, int, 0); 137 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms"); 138 139 static int min_interrupt_out_interval = 2; 140 module_param(min_interrupt_out_interval, int, 0); 141 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms"); 142 143 /* Structure to hold all of our device specific stuff */ 144 struct ld_usb { 145 struct mutex mutex; /* locks this structure */ 146 struct usb_interface* intf; /* save off the usb interface pointer */ 147 148 int open_count; /* number of times this port has been opened */ 149 150 char* ring_buffer; 151 unsigned int ring_head; 152 unsigned int ring_tail; 153 154 wait_queue_head_t read_wait; 155 wait_queue_head_t write_wait; 156 157 char* interrupt_in_buffer; 158 struct usb_endpoint_descriptor* interrupt_in_endpoint; 159 struct urb* interrupt_in_urb; 160 int interrupt_in_interval; 161 size_t interrupt_in_endpoint_size; 162 int interrupt_in_running; 163 int interrupt_in_done; 164 int buffer_overflow; 165 spinlock_t rbsl; 166 167 char* interrupt_out_buffer; 168 struct usb_endpoint_descriptor* interrupt_out_endpoint; 169 struct urb* interrupt_out_urb; 170 int interrupt_out_interval; 171 size_t interrupt_out_endpoint_size; 172 int interrupt_out_busy; 173 }; 174 175 static struct usb_driver ld_usb_driver; 176 177 /** 178 * ld_usb_abort_transfers 179 * aborts transfers and frees associated data structures 180 */ 181 static void ld_usb_abort_transfers(struct ld_usb *dev) 182 { 183 /* shutdown transfer */ 184 if (dev->interrupt_in_running) { 185 dev->interrupt_in_running = 0; 186 if (dev->intf) 187 usb_kill_urb(dev->interrupt_in_urb); 188 } 189 if (dev->interrupt_out_busy) 190 if (dev->intf) 191 usb_kill_urb(dev->interrupt_out_urb); 192 } 193 194 /** 195 * ld_usb_delete 196 */ 197 static void ld_usb_delete(struct ld_usb *dev) 198 { 199 ld_usb_abort_transfers(dev); 200 201 /* free data structures */ 202 usb_free_urb(dev->interrupt_in_urb); 203 usb_free_urb(dev->interrupt_out_urb); 204 kfree(dev->ring_buffer); 205 kfree(dev->interrupt_in_buffer); 206 kfree(dev->interrupt_out_buffer); 207 kfree(dev); 208 } 209 210 /** 211 * ld_usb_interrupt_in_callback 212 */ 213 static void ld_usb_interrupt_in_callback(struct urb *urb) 214 { 215 struct ld_usb *dev = urb->context; 216 size_t *actual_buffer; 217 unsigned int next_ring_head; 218 int status = urb->status; 219 int retval; 220 221 if (status) { 222 if (status == -ENOENT || 223 status == -ECONNRESET || 224 status == -ESHUTDOWN) { 225 goto exit; 226 } else { 227 dbg_info(&dev->intf->dev, "%s: nonzero status received: %d\n", 228 __func__, status); 229 spin_lock(&dev->rbsl); 230 goto resubmit; /* maybe we can recover */ 231 } 232 } 233 234 spin_lock(&dev->rbsl); 235 if (urb->actual_length > 0) { 236 next_ring_head = (dev->ring_head+1) % ring_buffer_size; 237 if (next_ring_head != dev->ring_tail) { 238 actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_head*(sizeof(size_t)+dev->interrupt_in_endpoint_size)); 239 /* actual_buffer gets urb->actual_length + interrupt_in_buffer */ 240 *actual_buffer = urb->actual_length; 241 memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length); 242 dev->ring_head = next_ring_head; 243 dbg_info(&dev->intf->dev, "%s: received %d bytes\n", 244 __func__, urb->actual_length); 245 } else { 246 dev_warn(&dev->intf->dev, 247 "Ring buffer overflow, %d bytes dropped\n", 248 urb->actual_length); 249 dev->buffer_overflow = 1; 250 } 251 } 252 253 resubmit: 254 /* resubmit if we're still running */ 255 if (dev->interrupt_in_running && !dev->buffer_overflow && dev->intf) { 256 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC); 257 if (retval) { 258 dev_err(&dev->intf->dev, 259 "usb_submit_urb failed (%d)\n", retval); 260 dev->buffer_overflow = 1; 261 } 262 } 263 spin_unlock(&dev->rbsl); 264 exit: 265 dev->interrupt_in_done = 1; 266 wake_up_interruptible(&dev->read_wait); 267 } 268 269 /** 270 * ld_usb_interrupt_out_callback 271 */ 272 static void ld_usb_interrupt_out_callback(struct urb *urb) 273 { 274 struct ld_usb *dev = urb->context; 275 int status = urb->status; 276 277 /* sync/async unlink faults aren't errors */ 278 if (status && !(status == -ENOENT || 279 status == -ECONNRESET || 280 status == -ESHUTDOWN)) 281 dbg_info(&dev->intf->dev, 282 "%s - nonzero write interrupt status received: %d\n", 283 __func__, status); 284 285 dev->interrupt_out_busy = 0; 286 wake_up_interruptible(&dev->write_wait); 287 } 288 289 /** 290 * ld_usb_open 291 */ 292 static int ld_usb_open(struct inode *inode, struct file *file) 293 { 294 struct ld_usb *dev; 295 int subminor; 296 int retval; 297 struct usb_interface *interface; 298 299 nonseekable_open(inode, file); 300 subminor = iminor(inode); 301 302 interface = usb_find_interface(&ld_usb_driver, subminor); 303 304 if (!interface) { 305 err("%s - error, can't find device for minor %d\n", 306 __func__, subminor); 307 return -ENODEV; 308 } 309 310 dev = usb_get_intfdata(interface); 311 312 if (!dev) 313 return -ENODEV; 314 315 /* lock this device */ 316 if (mutex_lock_interruptible(&dev->mutex)) 317 return -ERESTARTSYS; 318 319 /* allow opening only once */ 320 if (dev->open_count) { 321 retval = -EBUSY; 322 goto unlock_exit; 323 } 324 dev->open_count = 1; 325 326 /* initialize in direction */ 327 dev->ring_head = 0; 328 dev->ring_tail = 0; 329 dev->buffer_overflow = 0; 330 usb_fill_int_urb(dev->interrupt_in_urb, 331 interface_to_usbdev(interface), 332 usb_rcvintpipe(interface_to_usbdev(interface), 333 dev->interrupt_in_endpoint->bEndpointAddress), 334 dev->interrupt_in_buffer, 335 dev->interrupt_in_endpoint_size, 336 ld_usb_interrupt_in_callback, 337 dev, 338 dev->interrupt_in_interval); 339 340 dev->interrupt_in_running = 1; 341 dev->interrupt_in_done = 0; 342 343 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL); 344 if (retval) { 345 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval); 346 dev->interrupt_in_running = 0; 347 dev->open_count = 0; 348 goto unlock_exit; 349 } 350 351 /* save device in the file's private structure */ 352 file->private_data = dev; 353 354 unlock_exit: 355 mutex_unlock(&dev->mutex); 356 357 return retval; 358 } 359 360 /** 361 * ld_usb_release 362 */ 363 static int ld_usb_release(struct inode *inode, struct file *file) 364 { 365 struct ld_usb *dev; 366 int retval = 0; 367 368 dev = file->private_data; 369 370 if (dev == NULL) { 371 retval = -ENODEV; 372 goto exit; 373 } 374 375 if (mutex_lock_interruptible(&dev->mutex)) { 376 retval = -ERESTARTSYS; 377 goto exit; 378 } 379 380 if (dev->open_count != 1) { 381 retval = -ENODEV; 382 goto unlock_exit; 383 } 384 if (dev->intf == NULL) { 385 /* the device was unplugged before the file was released */ 386 mutex_unlock(&dev->mutex); 387 /* unlock here as ld_usb_delete frees dev */ 388 ld_usb_delete(dev); 389 goto exit; 390 } 391 392 /* wait until write transfer is finished */ 393 if (dev->interrupt_out_busy) 394 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 395 ld_usb_abort_transfers(dev); 396 dev->open_count = 0; 397 398 unlock_exit: 399 mutex_unlock(&dev->mutex); 400 401 exit: 402 return retval; 403 } 404 405 /** 406 * ld_usb_poll 407 */ 408 static unsigned int ld_usb_poll(struct file *file, poll_table *wait) 409 { 410 struct ld_usb *dev; 411 unsigned int mask = 0; 412 413 dev = file->private_data; 414 415 if (!dev->intf) 416 return POLLERR | POLLHUP; 417 418 poll_wait(file, &dev->read_wait, wait); 419 poll_wait(file, &dev->write_wait, wait); 420 421 if (dev->ring_head != dev->ring_tail) 422 mask |= POLLIN | POLLRDNORM; 423 if (!dev->interrupt_out_busy) 424 mask |= POLLOUT | POLLWRNORM; 425 426 return mask; 427 } 428 429 /** 430 * ld_usb_read 431 */ 432 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count, 433 loff_t *ppos) 434 { 435 struct ld_usb *dev; 436 size_t *actual_buffer; 437 size_t bytes_to_read; 438 int retval = 0; 439 int rv; 440 441 dev = file->private_data; 442 443 /* verify that we actually have some data to read */ 444 if (count == 0) 445 goto exit; 446 447 /* lock this object */ 448 if (mutex_lock_interruptible(&dev->mutex)) { 449 retval = -ERESTARTSYS; 450 goto exit; 451 } 452 453 /* verify that the device wasn't unplugged */ 454 if (dev->intf == NULL) { 455 retval = -ENODEV; 456 err("No device or device unplugged %d\n", retval); 457 goto unlock_exit; 458 } 459 460 /* wait for data */ 461 spin_lock_irq(&dev->rbsl); 462 if (dev->ring_head == dev->ring_tail) { 463 dev->interrupt_in_done = 0; 464 spin_unlock_irq(&dev->rbsl); 465 if (file->f_flags & O_NONBLOCK) { 466 retval = -EAGAIN; 467 goto unlock_exit; 468 } 469 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done); 470 if (retval < 0) 471 goto unlock_exit; 472 } else { 473 spin_unlock_irq(&dev->rbsl); 474 } 475 476 /* actual_buffer contains actual_length + interrupt_in_buffer */ 477 actual_buffer = (size_t*)(dev->ring_buffer + dev->ring_tail*(sizeof(size_t)+dev->interrupt_in_endpoint_size)); 478 bytes_to_read = min(count, *actual_buffer); 479 if (bytes_to_read < *actual_buffer) 480 dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n", 481 *actual_buffer-bytes_to_read); 482 483 /* copy one interrupt_in_buffer from ring_buffer into userspace */ 484 if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) { 485 retval = -EFAULT; 486 goto unlock_exit; 487 } 488 dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size; 489 490 retval = bytes_to_read; 491 492 spin_lock_irq(&dev->rbsl); 493 if (dev->buffer_overflow) { 494 dev->buffer_overflow = 0; 495 spin_unlock_irq(&dev->rbsl); 496 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL); 497 if (rv < 0) 498 dev->buffer_overflow = 1; 499 } else { 500 spin_unlock_irq(&dev->rbsl); 501 } 502 503 unlock_exit: 504 /* unlock the device */ 505 mutex_unlock(&dev->mutex); 506 507 exit: 508 return retval; 509 } 510 511 /** 512 * ld_usb_write 513 */ 514 static ssize_t ld_usb_write(struct file *file, const char __user *buffer, 515 size_t count, loff_t *ppos) 516 { 517 struct ld_usb *dev; 518 size_t bytes_to_write; 519 int retval = 0; 520 521 dev = file->private_data; 522 523 /* verify that we actually have some data to write */ 524 if (count == 0) 525 goto exit; 526 527 /* lock this object */ 528 if (mutex_lock_interruptible(&dev->mutex)) { 529 retval = -ERESTARTSYS; 530 goto exit; 531 } 532 533 /* verify that the device wasn't unplugged */ 534 if (dev->intf == NULL) { 535 retval = -ENODEV; 536 err("No device or device unplugged %d\n", retval); 537 goto unlock_exit; 538 } 539 540 /* wait until previous transfer is finished */ 541 if (dev->interrupt_out_busy) { 542 if (file->f_flags & O_NONBLOCK) { 543 retval = -EAGAIN; 544 goto unlock_exit; 545 } 546 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy); 547 if (retval < 0) { 548 goto unlock_exit; 549 } 550 } 551 552 /* write the data into interrupt_out_buffer from userspace */ 553 bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size); 554 if (bytes_to_write < count) 555 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n",count-bytes_to_write); 556 dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n", __func__, count, bytes_to_write); 557 558 if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) { 559 retval = -EFAULT; 560 goto unlock_exit; 561 } 562 563 if (dev->interrupt_out_endpoint == NULL) { 564 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */ 565 retval = usb_control_msg(interface_to_usbdev(dev->intf), 566 usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0), 567 9, 568 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT, 569 1 << 8, 0, 570 dev->interrupt_out_buffer, 571 bytes_to_write, 572 USB_CTRL_SET_TIMEOUT * HZ); 573 if (retval < 0) 574 err("Couldn't submit HID_REQ_SET_REPORT %d\n", retval); 575 goto unlock_exit; 576 } 577 578 /* send off the urb */ 579 usb_fill_int_urb(dev->interrupt_out_urb, 580 interface_to_usbdev(dev->intf), 581 usb_sndintpipe(interface_to_usbdev(dev->intf), 582 dev->interrupt_out_endpoint->bEndpointAddress), 583 dev->interrupt_out_buffer, 584 bytes_to_write, 585 ld_usb_interrupt_out_callback, 586 dev, 587 dev->interrupt_out_interval); 588 589 dev->interrupt_out_busy = 1; 590 wmb(); 591 592 retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL); 593 if (retval) { 594 dev->interrupt_out_busy = 0; 595 err("Couldn't submit interrupt_out_urb %d\n", retval); 596 goto unlock_exit; 597 } 598 retval = bytes_to_write; 599 600 unlock_exit: 601 /* unlock the device */ 602 mutex_unlock(&dev->mutex); 603 604 exit: 605 return retval; 606 } 607 608 /* file operations needed when we register this driver */ 609 static const struct file_operations ld_usb_fops = { 610 .owner = THIS_MODULE, 611 .read = ld_usb_read, 612 .write = ld_usb_write, 613 .open = ld_usb_open, 614 .release = ld_usb_release, 615 .poll = ld_usb_poll, 616 .llseek = no_llseek, 617 }; 618 619 /* 620 * usb class driver info in order to get a minor number from the usb core, 621 * and to have the device registered with the driver core 622 */ 623 static struct usb_class_driver ld_usb_class = { 624 .name = "ldusb%d", 625 .fops = &ld_usb_fops, 626 .minor_base = USB_LD_MINOR_BASE, 627 }; 628 629 /** 630 * ld_usb_probe 631 * 632 * Called by the usb core when a new device is connected that it thinks 633 * this driver might be interested in. 634 */ 635 static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id) 636 { 637 struct usb_device *udev = interface_to_usbdev(intf); 638 struct ld_usb *dev = NULL; 639 struct usb_host_interface *iface_desc; 640 struct usb_endpoint_descriptor *endpoint; 641 char *buffer; 642 int i; 643 int retval = -ENOMEM; 644 645 /* allocate memory for our device state and intialize it */ 646 647 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 648 if (dev == NULL) { 649 dev_err(&intf->dev, "Out of memory\n"); 650 goto exit; 651 } 652 mutex_init(&dev->mutex); 653 spin_lock_init(&dev->rbsl); 654 dev->intf = intf; 655 init_waitqueue_head(&dev->read_wait); 656 init_waitqueue_head(&dev->write_wait); 657 658 /* workaround for early firmware versions on fast computers */ 659 if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) && 660 ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) || 661 (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) && 662 (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) { 663 buffer = kmalloc(256, GFP_KERNEL); 664 if (buffer == NULL) { 665 dev_err(&intf->dev, "Couldn't allocate string buffer\n"); 666 goto error; 667 } 668 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */ 669 usb_string(udev, 255, buffer, 256); 670 kfree(buffer); 671 } 672 673 iface_desc = intf->cur_altsetting; 674 675 /* set up the endpoint information */ 676 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 677 endpoint = &iface_desc->endpoint[i].desc; 678 679 if (usb_endpoint_is_int_in(endpoint)) 680 dev->interrupt_in_endpoint = endpoint; 681 682 if (usb_endpoint_is_int_out(endpoint)) 683 dev->interrupt_out_endpoint = endpoint; 684 } 685 if (dev->interrupt_in_endpoint == NULL) { 686 dev_err(&intf->dev, "Interrupt in endpoint not found\n"); 687 goto error; 688 } 689 if (dev->interrupt_out_endpoint == NULL) 690 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n"); 691 692 dev->interrupt_in_endpoint_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize); 693 dev->ring_buffer = kmalloc(ring_buffer_size*(sizeof(size_t)+dev->interrupt_in_endpoint_size), GFP_KERNEL); 694 if (!dev->ring_buffer) { 695 dev_err(&intf->dev, "Couldn't allocate ring_buffer\n"); 696 goto error; 697 } 698 dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL); 699 if (!dev->interrupt_in_buffer) { 700 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n"); 701 goto error; 702 } 703 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 704 if (!dev->interrupt_in_urb) { 705 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n"); 706 goto error; 707 } 708 dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize) : 709 udev->descriptor.bMaxPacketSize0; 710 dev->interrupt_out_buffer = kmalloc(write_buffer_size*dev->interrupt_out_endpoint_size, GFP_KERNEL); 711 if (!dev->interrupt_out_buffer) { 712 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n"); 713 goto error; 714 } 715 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 716 if (!dev->interrupt_out_urb) { 717 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n"); 718 goto error; 719 } 720 dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 721 if (dev->interrupt_out_endpoint) 722 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval; 723 724 /* we can register the device now, as it is ready */ 725 usb_set_intfdata(intf, dev); 726 727 retval = usb_register_dev(intf, &ld_usb_class); 728 if (retval) { 729 /* something prevented us from registering this driver */ 730 dev_err(&intf->dev, "Not able to get a minor for this device.\n"); 731 usb_set_intfdata(intf, NULL); 732 goto error; 733 } 734 735 /* let the user know what node this device is now attached to */ 736 dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n", 737 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor); 738 739 exit: 740 return retval; 741 742 error: 743 ld_usb_delete(dev); 744 745 return retval; 746 } 747 748 /** 749 * ld_usb_disconnect 750 * 751 * Called by the usb core when the device is removed from the system. 752 */ 753 static void ld_usb_disconnect(struct usb_interface *intf) 754 { 755 struct ld_usb *dev; 756 int minor; 757 758 dev = usb_get_intfdata(intf); 759 usb_set_intfdata(intf, NULL); 760 761 minor = intf->minor; 762 763 /* give back our minor */ 764 usb_deregister_dev(intf, &ld_usb_class); 765 766 mutex_lock(&dev->mutex); 767 768 /* if the device is not opened, then we clean up right now */ 769 if (!dev->open_count) { 770 mutex_unlock(&dev->mutex); 771 ld_usb_delete(dev); 772 } else { 773 dev->intf = NULL; 774 /* wake up pollers */ 775 wake_up_interruptible_all(&dev->read_wait); 776 wake_up_interruptible_all(&dev->write_wait); 777 mutex_unlock(&dev->mutex); 778 } 779 780 dev_info(&intf->dev, "LD USB Device #%d now disconnected\n", 781 (minor - USB_LD_MINOR_BASE)); 782 } 783 784 /* usb specific object needed to register this driver with the usb subsystem */ 785 static struct usb_driver ld_usb_driver = { 786 .name = "ldusb", 787 .probe = ld_usb_probe, 788 .disconnect = ld_usb_disconnect, 789 .id_table = ld_usb_table, 790 }; 791 792 /** 793 * ld_usb_init 794 */ 795 static int __init ld_usb_init(void) 796 { 797 int retval; 798 799 /* register this driver with the USB subsystem */ 800 retval = usb_register(&ld_usb_driver); 801 if (retval) 802 err("usb_register failed for the %s driver. Error number %d\n", __FILE__, retval); 803 804 return retval; 805 } 806 807 /** 808 * ld_usb_exit 809 */ 810 static void __exit ld_usb_exit(void) 811 { 812 /* deregister this driver with the USB subsystem */ 813 usb_deregister(&ld_usb_driver); 814 } 815 816 module_init(ld_usb_init); 817 module_exit(ld_usb_exit); 818 819