1// SPDX-License-Identifier: GPL-2.0+ 2/* 3 * Generic USB driver for report based interrupt in/out devices 4 * like LD Didactic's USB devices. LD Didactic's USB devices are 5 * HID devices which do not use HID report definitons (they use 6 * raw interrupt in and our reports only for communication). 7 * 8 * This driver uses a ring buffer for time critical reading of 9 * interrupt in reports and provides read and write methods for 10 * raw interrupt reports (similar to the Windows HID driver). 11 * Devices based on the book USB COMPLETE by Jan Axelson may need 12 * such a compatibility to the Windows HID driver. 13 * 14 * Copyright (C) 2005 Michael Hund <mhund@ld-didactic.de> 15 * 16 * Derived from Lego USB Tower driver 17 * Copyright (C) 2003 David Glance <advidgsf@sourceforge.net> 18 * 2001-2004 Juergen Stuber <starblue@users.sourceforge.net> 19 */ 20 21#include <linux/kernel.h> 22#include <linux/errno.h> 23#include <linux/slab.h> 24#include <linux/module.h> 25#include <linux/mutex.h> 26 27#include <linux/uaccess.h> 28#include <linux/input.h> 29#include <linux/usb.h> 30#include <linux/poll.h> 31 32/* Define these values to match your devices */ 33#define USB_VENDOR_ID_LD 0x0f11 /* USB Vendor ID of LD Didactic GmbH */ 34#define USB_DEVICE_ID_LD_CASSY 0x1000 /* USB Product ID of CASSY-S modules with 8 bytes endpoint size */ 35#define USB_DEVICE_ID_LD_CASSY2 0x1001 /* USB Product ID of CASSY-S modules with 64 bytes endpoint size */ 36#define USB_DEVICE_ID_LD_POCKETCASSY 0x1010 /* USB Product ID of Pocket-CASSY */ 37#define USB_DEVICE_ID_LD_POCKETCASSY2 0x1011 /* USB Product ID of Pocket-CASSY 2 (reserved) */ 38#define USB_DEVICE_ID_LD_MOBILECASSY 0x1020 /* USB Product ID of Mobile-CASSY */ 39#define USB_DEVICE_ID_LD_MOBILECASSY2 0x1021 /* USB Product ID of Mobile-CASSY 2 (reserved) */ 40#define USB_DEVICE_ID_LD_MICROCASSYVOLTAGE 0x1031 /* USB Product ID of Micro-CASSY Voltage */ 41#define USB_DEVICE_ID_LD_MICROCASSYCURRENT 0x1032 /* USB Product ID of Micro-CASSY Current */ 42#define USB_DEVICE_ID_LD_MICROCASSYTIME 0x1033 /* USB Product ID of Micro-CASSY Time (reserved) */ 43#define USB_DEVICE_ID_LD_MICROCASSYTEMPERATURE 0x1035 /* USB Product ID of Micro-CASSY Temperature */ 44#define USB_DEVICE_ID_LD_MICROCASSYPH 0x1038 /* USB Product ID of Micro-CASSY pH */ 45#define USB_DEVICE_ID_LD_POWERANALYSERCASSY 0x1040 /* USB Product ID of Power Analyser CASSY */ 46#define USB_DEVICE_ID_LD_CONVERTERCONTROLLERCASSY 0x1042 /* USB Product ID of Converter Controller CASSY */ 47#define USB_DEVICE_ID_LD_MACHINETESTCASSY 0x1043 /* USB Product ID of Machine Test CASSY */ 48#define USB_DEVICE_ID_LD_JWM 0x1080 /* USB Product ID of Joule and Wattmeter */ 49#define USB_DEVICE_ID_LD_DMMP 0x1081 /* USB Product ID of Digital Multimeter P (reserved) */ 50#define USB_DEVICE_ID_LD_UMIP 0x1090 /* USB Product ID of UMI P */ 51#define USB_DEVICE_ID_LD_UMIC 0x10A0 /* USB Product ID of UMI C */ 52#define USB_DEVICE_ID_LD_UMIB 0x10B0 /* USB Product ID of UMI B */ 53#define USB_DEVICE_ID_LD_XRAY 0x1100 /* USB Product ID of X-Ray Apparatus 55481 */ 54#define USB_DEVICE_ID_LD_XRAY2 0x1101 /* USB Product ID of X-Ray Apparatus 554800 */ 55#define USB_DEVICE_ID_LD_XRAYCT 0x1110 /* USB Product ID of X-Ray Apparatus CT 554821*/ 56#define USB_DEVICE_ID_LD_VIDEOCOM 0x1200 /* USB Product ID of VideoCom */ 57#define USB_DEVICE_ID_LD_MOTOR 0x1210 /* USB Product ID of Motor (reserved) */ 58#define USB_DEVICE_ID_LD_COM3LAB 0x2000 /* USB Product ID of COM3LAB */ 59#define USB_DEVICE_ID_LD_TELEPORT 0x2010 /* USB Product ID of Terminal Adapter */ 60#define USB_DEVICE_ID_LD_NETWORKANALYSER 0x2020 /* USB Product ID of Network Analyser */ 61#define USB_DEVICE_ID_LD_POWERCONTROL 0x2030 /* USB Product ID of Converter Control Unit */ 62#define USB_DEVICE_ID_LD_MACHINETEST 0x2040 /* USB Product ID of Machine Test System */ 63#define USB_DEVICE_ID_LD_MOSTANALYSER 0x2050 /* USB Product ID of MOST Protocol Analyser */ 64#define USB_DEVICE_ID_LD_MOSTANALYSER2 0x2051 /* USB Product ID of MOST Protocol Analyser 2 */ 65#define USB_DEVICE_ID_LD_ABSESP 0x2060 /* USB Product ID of ABS ESP */ 66#define USB_DEVICE_ID_LD_AUTODATABUS 0x2070 /* USB Product ID of Automotive Data Buses */ 67#define USB_DEVICE_ID_LD_MCT 0x2080 /* USB Product ID of Microcontroller technique */ 68#define USB_DEVICE_ID_LD_HYBRID 0x2090 /* USB Product ID of Automotive Hybrid */ 69#define USB_DEVICE_ID_LD_HEATCONTROL 0x20A0 /* USB Product ID of Heat control */ 70 71#ifdef CONFIG_USB_DYNAMIC_MINORS 72#define USB_LD_MINOR_BASE 0 73#else 74#define USB_LD_MINOR_BASE 176 75#endif 76 77/* table of devices that work with this driver */ 78static const struct usb_device_id ld_usb_table[] = { 79 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY) }, 80 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY2) }, 81 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY) }, 82 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY2) }, 83 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY) }, 84 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY2) }, 85 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYVOLTAGE) }, 86 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYCURRENT) }, 87 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYTIME) }, 88 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYTEMPERATURE) }, 89 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYPH) }, 90 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERANALYSERCASSY) }, 91 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CONVERTERCONTROLLERCASSY) }, 92 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETESTCASSY) }, 93 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_JWM) }, 94 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_DMMP) }, 95 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIP) }, 96 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIC) }, 97 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIB) }, 98 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY) }, 99 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY2) }, 100 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_VIDEOCOM) }, 101 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOTOR) }, 102 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_COM3LAB) }, 103 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_TELEPORT) }, 104 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_NETWORKANALYSER) }, 105 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERCONTROL) }, 106 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETEST) }, 107 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOSTANALYSER) }, 108 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOSTANALYSER2) }, 109 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_ABSESP) }, 110 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_AUTODATABUS) }, 111 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MCT) }, 112 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_HYBRID) }, 113 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_HEATCONTROL) }, 114 { } /* Terminating entry */ 115}; 116MODULE_DEVICE_TABLE(usb, ld_usb_table); 117MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>"); 118MODULE_DESCRIPTION("LD USB Driver"); 119MODULE_LICENSE("GPL"); 120 121/* All interrupt in transfers are collected in a ring buffer to 122 * avoid racing conditions and get better performance of the driver. 123 */ 124static int ring_buffer_size = 128; 125module_param(ring_buffer_size, int, 0000); 126MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports"); 127 128/* The write_buffer can contain more than one interrupt out transfer. 129 */ 130static int write_buffer_size = 10; 131module_param(write_buffer_size, int, 0000); 132MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports"); 133 134/* As of kernel version 2.6.4 ehci-hcd uses an 135 * "only one interrupt transfer per frame" shortcut 136 * to simplify the scheduling of periodic transfers. 137 * This conflicts with our standard 1ms intervals for in and out URBs. 138 * We use default intervals of 2ms for in and 2ms for out transfers, 139 * which should be fast enough. 140 * Increase the interval to allow more devices that do interrupt transfers, 141 * or set to 1 to use the standard interval from the endpoint descriptors. 142 */ 143static int min_interrupt_in_interval = 2; 144module_param(min_interrupt_in_interval, int, 0000); 145MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms"); 146 147static int min_interrupt_out_interval = 2; 148module_param(min_interrupt_out_interval, int, 0000); 149MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms"); 150 151/* Structure to hold all of our device specific stuff */ 152struct ld_usb { 153 struct mutex mutex; /* locks this structure */ 154 struct usb_interface *intf; /* save off the usb interface pointer */ 155 unsigned long disconnected:1; 156 157 int open_count; /* number of times this port has been opened */ 158 159 char *ring_buffer; 160 unsigned int ring_head; 161 unsigned int ring_tail; 162 163 wait_queue_head_t read_wait; 164 wait_queue_head_t write_wait; 165 166 char *interrupt_in_buffer; 167 struct usb_endpoint_descriptor *interrupt_in_endpoint; 168 struct urb *interrupt_in_urb; 169 int interrupt_in_interval; 170 size_t interrupt_in_endpoint_size; 171 int interrupt_in_running; 172 int interrupt_in_done; 173 int buffer_overflow; 174 spinlock_t rbsl; 175 176 char *interrupt_out_buffer; 177 struct usb_endpoint_descriptor *interrupt_out_endpoint; 178 struct urb *interrupt_out_urb; 179 int interrupt_out_interval; 180 size_t interrupt_out_endpoint_size; 181 int interrupt_out_busy; 182}; 183 184static struct usb_driver ld_usb_driver; 185 186/* 187 * ld_usb_abort_transfers 188 * aborts transfers and frees associated data structures 189 */ 190static void ld_usb_abort_transfers(struct ld_usb *dev) 191{ 192 /* shutdown transfer */ 193 if (dev->interrupt_in_running) { 194 dev->interrupt_in_running = 0; 195 usb_kill_urb(dev->interrupt_in_urb); 196 } 197 if (dev->interrupt_out_busy) 198 usb_kill_urb(dev->interrupt_out_urb); 199} 200 201/* 202 * ld_usb_delete 203 */ 204static void ld_usb_delete(struct ld_usb *dev) 205{ 206 /* free data structures */ 207 usb_free_urb(dev->interrupt_in_urb); 208 usb_free_urb(dev->interrupt_out_urb); 209 kfree(dev->ring_buffer); 210 kfree(dev->interrupt_in_buffer); 211 kfree(dev->interrupt_out_buffer); 212 kfree(dev); 213} 214 215/* 216 * ld_usb_interrupt_in_callback 217 */ 218static void ld_usb_interrupt_in_callback(struct urb *urb) 219{ 220 struct ld_usb *dev = urb->context; 221 size_t *actual_buffer; 222 unsigned int next_ring_head; 223 int status = urb->status; 224 unsigned long flags; 225 int retval; 226 227 if (status) { 228 if (status == -ENOENT || 229 status == -ECONNRESET || 230 status == -ESHUTDOWN) { 231 goto exit; 232 } else { 233 dev_dbg(&dev->intf->dev, 234 "%s: nonzero status received: %d\n", __func__, 235 status); 236 spin_lock_irqsave(&dev->rbsl, flags); 237 goto resubmit; /* maybe we can recover */ 238 } 239 } 240 241 spin_lock_irqsave(&dev->rbsl, flags); 242 if (urb->actual_length > 0) { 243 next_ring_head = (dev->ring_head+1) % ring_buffer_size; 244 if (next_ring_head != dev->ring_tail) { 245 actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_head * (sizeof(size_t)+dev->interrupt_in_endpoint_size)); 246 /* actual_buffer gets urb->actual_length + interrupt_in_buffer */ 247 *actual_buffer = urb->actual_length; 248 memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length); 249 dev->ring_head = next_ring_head; 250 dev_dbg(&dev->intf->dev, "%s: received %d bytes\n", 251 __func__, urb->actual_length); 252 } else { 253 dev_warn(&dev->intf->dev, 254 "Ring buffer overflow, %d bytes dropped\n", 255 urb->actual_length); 256 dev->buffer_overflow = 1; 257 } 258 } 259 260resubmit: 261 /* resubmit if we're still running */ 262 if (dev->interrupt_in_running && !dev->buffer_overflow) { 263 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC); 264 if (retval) { 265 dev_err(&dev->intf->dev, 266 "usb_submit_urb failed (%d)\n", retval); 267 dev->buffer_overflow = 1; 268 } 269 } 270 spin_unlock_irqrestore(&dev->rbsl, flags); 271exit: 272 dev->interrupt_in_done = 1; 273 wake_up_interruptible(&dev->read_wait); 274} 275 276/* 277 * ld_usb_interrupt_out_callback 278 */ 279static void ld_usb_interrupt_out_callback(struct urb *urb) 280{ 281 struct ld_usb *dev = urb->context; 282 int status = urb->status; 283 284 /* sync/async unlink faults aren't errors */ 285 if (status && !(status == -ENOENT || 286 status == -ECONNRESET || 287 status == -ESHUTDOWN)) 288 dev_dbg(&dev->intf->dev, 289 "%s - nonzero write interrupt status received: %d\n", 290 __func__, status); 291 292 dev->interrupt_out_busy = 0; 293 wake_up_interruptible(&dev->write_wait); 294} 295 296/* 297 * ld_usb_open 298 */ 299static int ld_usb_open(struct inode *inode, struct file *file) 300{ 301 struct ld_usb *dev; 302 int subminor; 303 int retval; 304 struct usb_interface *interface; 305 306 stream_open(inode, file); 307 subminor = iminor(inode); 308 309 interface = usb_find_interface(&ld_usb_driver, subminor); 310 311 if (!interface) { 312 printk(KERN_ERR "%s - error, can't find device for minor %d\n", 313 __func__, subminor); 314 return -ENODEV; 315 } 316 317 dev = usb_get_intfdata(interface); 318 319 if (!dev) 320 return -ENODEV; 321 322 /* lock this device */ 323 if (mutex_lock_interruptible(&dev->mutex)) 324 return -ERESTARTSYS; 325 326 /* allow opening only once */ 327 if (dev->open_count) { 328 retval = -EBUSY; 329 goto unlock_exit; 330 } 331 dev->open_count = 1; 332 333 /* initialize in direction */ 334 dev->ring_head = 0; 335 dev->ring_tail = 0; 336 dev->buffer_overflow = 0; 337 usb_fill_int_urb(dev->interrupt_in_urb, 338 interface_to_usbdev(interface), 339 usb_rcvintpipe(interface_to_usbdev(interface), 340 dev->interrupt_in_endpoint->bEndpointAddress), 341 dev->interrupt_in_buffer, 342 dev->interrupt_in_endpoint_size, 343 ld_usb_interrupt_in_callback, 344 dev, 345 dev->interrupt_in_interval); 346 347 dev->interrupt_in_running = 1; 348 dev->interrupt_in_done = 0; 349 350 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL); 351 if (retval) { 352 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval); 353 dev->interrupt_in_running = 0; 354 dev->open_count = 0; 355 goto unlock_exit; 356 } 357 358 /* save device in the file's private structure */ 359 file->private_data = dev; 360 361unlock_exit: 362 mutex_unlock(&dev->mutex); 363 364 return retval; 365} 366 367/* 368 * ld_usb_release 369 */ 370static int ld_usb_release(struct inode *inode, struct file *file) 371{ 372 struct ld_usb *dev; 373 int retval = 0; 374 375 dev = file->private_data; 376 377 if (dev == NULL) { 378 retval = -ENODEV; 379 goto exit; 380 } 381 382 mutex_lock(&dev->mutex); 383 384 if (dev->open_count != 1) { 385 retval = -ENODEV; 386 goto unlock_exit; 387 } 388 if (dev->disconnected) { 389 /* the device was unplugged before the file was released */ 390 mutex_unlock(&dev->mutex); 391 /* unlock here as ld_usb_delete frees dev */ 392 ld_usb_delete(dev); 393 goto exit; 394 } 395 396 /* wait until write transfer is finished */ 397 if (dev->interrupt_out_busy) 398 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 399 ld_usb_abort_transfers(dev); 400 dev->open_count = 0; 401 402unlock_exit: 403 mutex_unlock(&dev->mutex); 404 405exit: 406 return retval; 407} 408 409/* 410 * ld_usb_poll 411 */ 412static __poll_t ld_usb_poll(struct file *file, poll_table *wait) 413{ 414 struct ld_usb *dev; 415 __poll_t mask = 0; 416 417 dev = file->private_data; 418 419 if (dev->disconnected) 420 return EPOLLERR | EPOLLHUP; 421 422 poll_wait(file, &dev->read_wait, wait); 423 poll_wait(file, &dev->write_wait, wait); 424 425 if (dev->ring_head != dev->ring_tail) 426 mask |= EPOLLIN | EPOLLRDNORM; 427 if (!dev->interrupt_out_busy) 428 mask |= EPOLLOUT | EPOLLWRNORM; 429 430 return mask; 431} 432 433/* 434 * ld_usb_read 435 */ 436static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count, 437 loff_t *ppos) 438{ 439 struct ld_usb *dev; 440 size_t *actual_buffer; 441 size_t bytes_to_read; 442 int retval = 0; 443 int rv; 444 445 dev = file->private_data; 446 447 /* verify that we actually have some data to read */ 448 if (count == 0) 449 goto exit; 450 451 /* lock this object */ 452 if (mutex_lock_interruptible(&dev->mutex)) { 453 retval = -ERESTARTSYS; 454 goto exit; 455 } 456 457 /* verify that the device wasn't unplugged */ 458 if (dev->disconnected) { 459 retval = -ENODEV; 460 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval); 461 goto unlock_exit; 462 } 463 464 /* wait for data */ 465 spin_lock_irq(&dev->rbsl); 466 while (dev->ring_head == dev->ring_tail) { 467 dev->interrupt_in_done = 0; 468 spin_unlock_irq(&dev->rbsl); 469 if (file->f_flags & O_NONBLOCK) { 470 retval = -EAGAIN; 471 goto unlock_exit; 472 } 473 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done); 474 if (retval < 0) 475 goto unlock_exit; 476 477 spin_lock_irq(&dev->rbsl); 478 } 479 spin_unlock_irq(&dev->rbsl); 480 481 /* actual_buffer contains actual_length + interrupt_in_buffer */ 482 actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_tail * (sizeof(size_t)+dev->interrupt_in_endpoint_size)); 483 if (*actual_buffer > dev->interrupt_in_endpoint_size) { 484 retval = -EIO; 485 goto unlock_exit; 486 } 487 bytes_to_read = min(count, *actual_buffer); 488 if (bytes_to_read < *actual_buffer) 489 dev_warn(&dev->intf->dev, "Read buffer overflow, %zu bytes dropped\n", 490 *actual_buffer-bytes_to_read); 491 492 /* copy one interrupt_in_buffer from ring_buffer into userspace */ 493 if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) { 494 retval = -EFAULT; 495 goto unlock_exit; 496 } 497 retval = bytes_to_read; 498 499 spin_lock_irq(&dev->rbsl); 500 dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size; 501 502 if (dev->buffer_overflow) { 503 dev->buffer_overflow = 0; 504 spin_unlock_irq(&dev->rbsl); 505 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL); 506 if (rv < 0) 507 dev->buffer_overflow = 1; 508 } else { 509 spin_unlock_irq(&dev->rbsl); 510 } 511 512unlock_exit: 513 /* unlock the device */ 514 mutex_unlock(&dev->mutex); 515 516exit: 517 return retval; 518} 519 520/* 521 * ld_usb_write 522 */ 523static ssize_t ld_usb_write(struct file *file, const char __user *buffer, 524 size_t count, loff_t *ppos) 525{ 526 struct ld_usb *dev; 527 size_t bytes_to_write; 528 int retval = 0; 529 530 dev = file->private_data; 531 532 /* verify that we actually have some data to write */ 533 if (count == 0) 534 goto exit; 535 536 /* lock this object */ 537 if (mutex_lock_interruptible(&dev->mutex)) { 538 retval = -ERESTARTSYS; 539 goto exit; 540 } 541 542 /* verify that the device wasn't unplugged */ 543 if (dev->disconnected) { 544 retval = -ENODEV; 545 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval); 546 goto unlock_exit; 547 } 548 549 /* wait until previous transfer is finished */ 550 if (dev->interrupt_out_busy) { 551 if (file->f_flags & O_NONBLOCK) { 552 retval = -EAGAIN; 553 goto unlock_exit; 554 } 555 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy); 556 if (retval < 0) { 557 goto unlock_exit; 558 } 559 } 560 561 /* write the data into interrupt_out_buffer from userspace */ 562 bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size); 563 if (bytes_to_write < count) 564 dev_warn(&dev->intf->dev, "Write buffer overflow, %zu bytes dropped\n", 565 count - bytes_to_write); 566 dev_dbg(&dev->intf->dev, "%s: count = %zu, bytes_to_write = %zu\n", 567 __func__, count, bytes_to_write); 568 569 if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) { 570 retval = -EFAULT; 571 goto unlock_exit; 572 } 573 574 if (dev->interrupt_out_endpoint == NULL) { 575 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */ 576 retval = usb_control_msg(interface_to_usbdev(dev->intf), 577 usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0), 578 9, 579 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT, 580 1 << 8, 0, 581 dev->interrupt_out_buffer, 582 bytes_to_write, 583 USB_CTRL_SET_TIMEOUT); 584 if (retval < 0) 585 dev_err(&dev->intf->dev, 586 "Couldn't submit HID_REQ_SET_REPORT %d\n", 587 retval); 588 goto unlock_exit; 589 } 590 591 /* send off the urb */ 592 usb_fill_int_urb(dev->interrupt_out_urb, 593 interface_to_usbdev(dev->intf), 594 usb_sndintpipe(interface_to_usbdev(dev->intf), 595 dev->interrupt_out_endpoint->bEndpointAddress), 596 dev->interrupt_out_buffer, 597 bytes_to_write, 598 ld_usb_interrupt_out_callback, 599 dev, 600 dev->interrupt_out_interval); 601 602 dev->interrupt_out_busy = 1; 603 wmb(); 604 605 retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL); 606 if (retval) { 607 dev->interrupt_out_busy = 0; 608 dev_err(&dev->intf->dev, 609 "Couldn't submit interrupt_out_urb %d\n", retval); 610 goto unlock_exit; 611 } 612 retval = bytes_to_write; 613 614unlock_exit: 615 /* unlock the device */ 616 mutex_unlock(&dev->mutex); 617 618exit: 619 return retval; 620} 621 622/* file operations needed when we register this driver */ 623static const struct file_operations ld_usb_fops = { 624 .owner = THIS_MODULE, 625 .read = ld_usb_read, 626 .write = ld_usb_write, 627 .open = ld_usb_open, 628 .release = ld_usb_release, 629 .poll = ld_usb_poll, 630 .llseek = no_llseek, 631}; 632 633/* 634 * usb class driver info in order to get a minor number from the usb core, 635 * and to have the device registered with the driver core 636 */ 637static struct usb_class_driver ld_usb_class = { 638 .name = "ldusb%d", 639 .fops = &ld_usb_fops, 640 .minor_base = USB_LD_MINOR_BASE, 641}; 642 643/* 644 * ld_usb_probe 645 * 646 * Called by the usb core when a new device is connected that it thinks 647 * this driver might be interested in. 648 */ 649static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id) 650{ 651 struct usb_device *udev = interface_to_usbdev(intf); 652 struct ld_usb *dev = NULL; 653 struct usb_host_interface *iface_desc; 654 char *buffer; 655 int retval = -ENOMEM; 656 int res; 657 658 /* allocate memory for our device state and initialize it */ 659 660 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 661 if (!dev) 662 goto exit; 663 mutex_init(&dev->mutex); 664 spin_lock_init(&dev->rbsl); 665 dev->intf = intf; 666 init_waitqueue_head(&dev->read_wait); 667 init_waitqueue_head(&dev->write_wait); 668 669 /* workaround for early firmware versions on fast computers */ 670 if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) && 671 ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) || 672 (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) && 673 (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) { 674 buffer = kmalloc(256, GFP_KERNEL); 675 if (!buffer) 676 goto error; 677 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */ 678 usb_string(udev, 255, buffer, 256); 679 kfree(buffer); 680 } 681 682 iface_desc = intf->cur_altsetting; 683 684 res = usb_find_last_int_in_endpoint(iface_desc, 685 &dev->interrupt_in_endpoint); 686 if (res) { 687 dev_err(&intf->dev, "Interrupt in endpoint not found\n"); 688 retval = res; 689 goto error; 690 } 691 692 res = usb_find_last_int_out_endpoint(iface_desc, 693 &dev->interrupt_out_endpoint); 694 if (res) 695 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n"); 696 697 dev->interrupt_in_endpoint_size = usb_endpoint_maxp(dev->interrupt_in_endpoint); 698 dev->ring_buffer = kcalloc(ring_buffer_size, 699 sizeof(size_t) + dev->interrupt_in_endpoint_size, 700 GFP_KERNEL); 701 if (!dev->ring_buffer) 702 goto error; 703 dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL); 704 if (!dev->interrupt_in_buffer) 705 goto error; 706 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 707 if (!dev->interrupt_in_urb) 708 goto error; 709 dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? usb_endpoint_maxp(dev->interrupt_out_endpoint) : 710 udev->descriptor.bMaxPacketSize0; 711 dev->interrupt_out_buffer = 712 kmalloc_array(write_buffer_size, 713 dev->interrupt_out_endpoint_size, GFP_KERNEL); 714 if (!dev->interrupt_out_buffer) 715 goto error; 716 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 717 if (!dev->interrupt_out_urb) 718 goto error; 719 dev->interrupt_in_interval = max_t(int, min_interrupt_in_interval, 720 dev->interrupt_in_endpoint->bInterval); 721 if (dev->interrupt_out_endpoint) 722 dev->interrupt_out_interval = max_t(int, min_interrupt_out_interval, 723 dev->interrupt_out_endpoint->bInterval); 724 725 /* we can register the device now, as it is ready */ 726 usb_set_intfdata(intf, dev); 727 728 retval = usb_register_dev(intf, &ld_usb_class); 729 if (retval) { 730 /* something prevented us from registering this driver */ 731 dev_err(&intf->dev, "Not able to get a minor for this device.\n"); 732 usb_set_intfdata(intf, NULL); 733 goto error; 734 } 735 736 /* let the user know what node this device is now attached to */ 737 dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n", 738 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor); 739 740exit: 741 return retval; 742 743error: 744 ld_usb_delete(dev); 745 746 return retval; 747} 748 749/* 750 * ld_usb_disconnect 751 * 752 * Called by the usb core when the device is removed from the system. 753 */ 754static void ld_usb_disconnect(struct usb_interface *intf) 755{ 756 struct ld_usb *dev; 757 int minor; 758 759 dev = usb_get_intfdata(intf); 760 usb_set_intfdata(intf, NULL); 761 762 minor = intf->minor; 763 764 /* give back our minor */ 765 usb_deregister_dev(intf, &ld_usb_class); 766 767 usb_poison_urb(dev->interrupt_in_urb); 768 usb_poison_urb(dev->interrupt_out_urb); 769 770 mutex_lock(&dev->mutex); 771 772 /* if the device is not opened, then we clean up right now */ 773 if (!dev->open_count) { 774 mutex_unlock(&dev->mutex); 775 ld_usb_delete(dev); 776 } else { 777 dev->disconnected = 1; 778 /* wake up pollers */ 779 wake_up_interruptible_all(&dev->read_wait); 780 wake_up_interruptible_all(&dev->write_wait); 781 mutex_unlock(&dev->mutex); 782 } 783 784 dev_info(&intf->dev, "LD USB Device #%d now disconnected\n", 785 (minor - USB_LD_MINOR_BASE)); 786} 787 788/* usb specific object needed to register this driver with the usb subsystem */ 789static struct usb_driver ld_usb_driver = { 790 .name = "ldusb", 791 .probe = ld_usb_probe, 792 .disconnect = ld_usb_disconnect, 793 .id_table = ld_usb_table, 794}; 795 796module_usb_driver(ld_usb_driver); 797 798