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 */ 78 static 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 }; 116 MODULE_DEVICE_TABLE(usb, ld_usb_table); 117 MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>"); 118 MODULE_DESCRIPTION("LD USB Driver"); 119 MODULE_LICENSE("GPL"); 120 MODULE_SUPPORTED_DEVICE("LD USB Devices"); 121 122 /* All interrupt in transfers are collected in a ring buffer to 123 * avoid racing conditions and get better performance of the driver. 124 */ 125 static int ring_buffer_size = 128; 126 module_param(ring_buffer_size, int, 0000); 127 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports"); 128 129 /* The write_buffer can contain more than one interrupt out transfer. 130 */ 131 static int write_buffer_size = 10; 132 module_param(write_buffer_size, int, 0000); 133 MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports"); 134 135 /* As of kernel version 2.6.4 ehci-hcd uses an 136 * "only one interrupt transfer per frame" shortcut 137 * to simplify the scheduling of periodic transfers. 138 * This conflicts with our standard 1ms intervals for in and out URBs. 139 * We use default intervals of 2ms for in and 2ms for out transfers, 140 * which should be fast enough. 141 * Increase the interval to allow more devices that do interrupt transfers, 142 * or set to 1 to use the standard interval from the endpoint descriptors. 143 */ 144 static int min_interrupt_in_interval = 2; 145 module_param(min_interrupt_in_interval, int, 0000); 146 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms"); 147 148 static int min_interrupt_out_interval = 2; 149 module_param(min_interrupt_out_interval, int, 0000); 150 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms"); 151 152 /* Structure to hold all of our device specific stuff */ 153 struct ld_usb { 154 struct mutex mutex; /* locks this structure */ 155 struct usb_interface *intf; /* save off the usb interface pointer */ 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 }; 183 184 static struct usb_driver ld_usb_driver; 185 186 /** 187 * ld_usb_abort_transfers 188 * aborts transfers and frees associated data structures 189 */ 190 static 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 if (dev->intf) 196 usb_kill_urb(dev->interrupt_in_urb); 197 } 198 if (dev->interrupt_out_busy) 199 if (dev->intf) 200 usb_kill_urb(dev->interrupt_out_urb); 201 } 202 203 /** 204 * ld_usb_delete 205 */ 206 static void ld_usb_delete(struct ld_usb *dev) 207 { 208 ld_usb_abort_transfers(dev); 209 210 /* free data structures */ 211 usb_free_urb(dev->interrupt_in_urb); 212 usb_free_urb(dev->interrupt_out_urb); 213 kfree(dev->ring_buffer); 214 kfree(dev->interrupt_in_buffer); 215 kfree(dev->interrupt_out_buffer); 216 kfree(dev); 217 } 218 219 /** 220 * ld_usb_interrupt_in_callback 221 */ 222 static void ld_usb_interrupt_in_callback(struct urb *urb) 223 { 224 struct ld_usb *dev = urb->context; 225 size_t *actual_buffer; 226 unsigned int next_ring_head; 227 int status = urb->status; 228 unsigned long flags; 229 int retval; 230 231 if (status) { 232 if (status == -ENOENT || 233 status == -ECONNRESET || 234 status == -ESHUTDOWN) { 235 goto exit; 236 } else { 237 dev_dbg(&dev->intf->dev, 238 "%s: nonzero status received: %d\n", __func__, 239 status); 240 spin_lock_irqsave(&dev->rbsl, flags); 241 goto resubmit; /* maybe we can recover */ 242 } 243 } 244 245 spin_lock_irqsave(&dev->rbsl, flags); 246 if (urb->actual_length > 0) { 247 next_ring_head = (dev->ring_head+1) % ring_buffer_size; 248 if (next_ring_head != dev->ring_tail) { 249 actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_head * (sizeof(size_t)+dev->interrupt_in_endpoint_size)); 250 /* actual_buffer gets urb->actual_length + interrupt_in_buffer */ 251 *actual_buffer = urb->actual_length; 252 memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length); 253 dev->ring_head = next_ring_head; 254 dev_dbg(&dev->intf->dev, "%s: received %d bytes\n", 255 __func__, urb->actual_length); 256 } else { 257 dev_warn(&dev->intf->dev, 258 "Ring buffer overflow, %d bytes dropped\n", 259 urb->actual_length); 260 dev->buffer_overflow = 1; 261 } 262 } 263 264 resubmit: 265 /* resubmit if we're still running */ 266 if (dev->interrupt_in_running && !dev->buffer_overflow && dev->intf) { 267 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC); 268 if (retval) { 269 dev_err(&dev->intf->dev, 270 "usb_submit_urb failed (%d)\n", retval); 271 dev->buffer_overflow = 1; 272 } 273 } 274 spin_unlock_irqrestore(&dev->rbsl, flags); 275 exit: 276 dev->interrupt_in_done = 1; 277 wake_up_interruptible(&dev->read_wait); 278 } 279 280 /** 281 * ld_usb_interrupt_out_callback 282 */ 283 static void ld_usb_interrupt_out_callback(struct urb *urb) 284 { 285 struct ld_usb *dev = urb->context; 286 int status = urb->status; 287 288 /* sync/async unlink faults aren't errors */ 289 if (status && !(status == -ENOENT || 290 status == -ECONNRESET || 291 status == -ESHUTDOWN)) 292 dev_dbg(&dev->intf->dev, 293 "%s - nonzero write interrupt status received: %d\n", 294 __func__, status); 295 296 dev->interrupt_out_busy = 0; 297 wake_up_interruptible(&dev->write_wait); 298 } 299 300 /** 301 * ld_usb_open 302 */ 303 static int ld_usb_open(struct inode *inode, struct file *file) 304 { 305 struct ld_usb *dev; 306 int subminor; 307 int retval; 308 struct usb_interface *interface; 309 310 nonseekable_open(inode, file); 311 subminor = iminor(inode); 312 313 interface = usb_find_interface(&ld_usb_driver, subminor); 314 315 if (!interface) { 316 printk(KERN_ERR "%s - error, can't find device for minor %d\n", 317 __func__, subminor); 318 return -ENODEV; 319 } 320 321 dev = usb_get_intfdata(interface); 322 323 if (!dev) 324 return -ENODEV; 325 326 /* lock this device */ 327 if (mutex_lock_interruptible(&dev->mutex)) 328 return -ERESTARTSYS; 329 330 /* allow opening only once */ 331 if (dev->open_count) { 332 retval = -EBUSY; 333 goto unlock_exit; 334 } 335 dev->open_count = 1; 336 337 /* initialize in direction */ 338 dev->ring_head = 0; 339 dev->ring_tail = 0; 340 dev->buffer_overflow = 0; 341 usb_fill_int_urb(dev->interrupt_in_urb, 342 interface_to_usbdev(interface), 343 usb_rcvintpipe(interface_to_usbdev(interface), 344 dev->interrupt_in_endpoint->bEndpointAddress), 345 dev->interrupt_in_buffer, 346 dev->interrupt_in_endpoint_size, 347 ld_usb_interrupt_in_callback, 348 dev, 349 dev->interrupt_in_interval); 350 351 dev->interrupt_in_running = 1; 352 dev->interrupt_in_done = 0; 353 354 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL); 355 if (retval) { 356 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval); 357 dev->interrupt_in_running = 0; 358 dev->open_count = 0; 359 goto unlock_exit; 360 } 361 362 /* save device in the file's private structure */ 363 file->private_data = dev; 364 365 unlock_exit: 366 mutex_unlock(&dev->mutex); 367 368 return retval; 369 } 370 371 /** 372 * ld_usb_release 373 */ 374 static int ld_usb_release(struct inode *inode, struct file *file) 375 { 376 struct ld_usb *dev; 377 int retval = 0; 378 379 dev = file->private_data; 380 381 if (dev == NULL) { 382 retval = -ENODEV; 383 goto exit; 384 } 385 386 if (mutex_lock_interruptible(&dev->mutex)) { 387 retval = -ERESTARTSYS; 388 goto exit; 389 } 390 391 if (dev->open_count != 1) { 392 retval = -ENODEV; 393 goto unlock_exit; 394 } 395 if (dev->intf == NULL) { 396 /* the device was unplugged before the file was released */ 397 mutex_unlock(&dev->mutex); 398 /* unlock here as ld_usb_delete frees dev */ 399 ld_usb_delete(dev); 400 goto exit; 401 } 402 403 /* wait until write transfer is finished */ 404 if (dev->interrupt_out_busy) 405 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 406 ld_usb_abort_transfers(dev); 407 dev->open_count = 0; 408 409 unlock_exit: 410 mutex_unlock(&dev->mutex); 411 412 exit: 413 return retval; 414 } 415 416 /** 417 * ld_usb_poll 418 */ 419 static __poll_t ld_usb_poll(struct file *file, poll_table *wait) 420 { 421 struct ld_usb *dev; 422 __poll_t mask = 0; 423 424 dev = file->private_data; 425 426 if (!dev->intf) 427 return EPOLLERR | EPOLLHUP; 428 429 poll_wait(file, &dev->read_wait, wait); 430 poll_wait(file, &dev->write_wait, wait); 431 432 if (dev->ring_head != dev->ring_tail) 433 mask |= EPOLLIN | EPOLLRDNORM; 434 if (!dev->interrupt_out_busy) 435 mask |= EPOLLOUT | EPOLLWRNORM; 436 437 return mask; 438 } 439 440 /** 441 * ld_usb_read 442 */ 443 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count, 444 loff_t *ppos) 445 { 446 struct ld_usb *dev; 447 size_t *actual_buffer; 448 size_t bytes_to_read; 449 int retval = 0; 450 int rv; 451 452 dev = file->private_data; 453 454 /* verify that we actually have some data to read */ 455 if (count == 0) 456 goto exit; 457 458 /* lock this object */ 459 if (mutex_lock_interruptible(&dev->mutex)) { 460 retval = -ERESTARTSYS; 461 goto exit; 462 } 463 464 /* verify that the device wasn't unplugged */ 465 if (dev->intf == NULL) { 466 retval = -ENODEV; 467 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval); 468 goto unlock_exit; 469 } 470 471 /* wait for data */ 472 spin_lock_irq(&dev->rbsl); 473 if (dev->ring_head == dev->ring_tail) { 474 dev->interrupt_in_done = 0; 475 spin_unlock_irq(&dev->rbsl); 476 if (file->f_flags & O_NONBLOCK) { 477 retval = -EAGAIN; 478 goto unlock_exit; 479 } 480 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done); 481 if (retval < 0) 482 goto unlock_exit; 483 } else { 484 spin_unlock_irq(&dev->rbsl); 485 } 486 487 /* actual_buffer contains actual_length + interrupt_in_buffer */ 488 actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_tail * (sizeof(size_t)+dev->interrupt_in_endpoint_size)); 489 bytes_to_read = min(count, *actual_buffer); 490 if (bytes_to_read < *actual_buffer) 491 dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n", 492 *actual_buffer-bytes_to_read); 493 494 /* copy one interrupt_in_buffer from ring_buffer into userspace */ 495 if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) { 496 retval = -EFAULT; 497 goto unlock_exit; 498 } 499 dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size; 500 501 retval = bytes_to_read; 502 503 spin_lock_irq(&dev->rbsl); 504 if (dev->buffer_overflow) { 505 dev->buffer_overflow = 0; 506 spin_unlock_irq(&dev->rbsl); 507 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL); 508 if (rv < 0) 509 dev->buffer_overflow = 1; 510 } else { 511 spin_unlock_irq(&dev->rbsl); 512 } 513 514 unlock_exit: 515 /* unlock the device */ 516 mutex_unlock(&dev->mutex); 517 518 exit: 519 return retval; 520 } 521 522 /** 523 * ld_usb_write 524 */ 525 static ssize_t ld_usb_write(struct file *file, const char __user *buffer, 526 size_t count, loff_t *ppos) 527 { 528 struct ld_usb *dev; 529 size_t bytes_to_write; 530 int retval = 0; 531 532 dev = file->private_data; 533 534 /* verify that we actually have some data to write */ 535 if (count == 0) 536 goto exit; 537 538 /* lock this object */ 539 if (mutex_lock_interruptible(&dev->mutex)) { 540 retval = -ERESTARTSYS; 541 goto exit; 542 } 543 544 /* verify that the device wasn't unplugged */ 545 if (dev->intf == NULL) { 546 retval = -ENODEV; 547 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval); 548 goto unlock_exit; 549 } 550 551 /* wait until previous transfer is finished */ 552 if (dev->interrupt_out_busy) { 553 if (file->f_flags & O_NONBLOCK) { 554 retval = -EAGAIN; 555 goto unlock_exit; 556 } 557 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy); 558 if (retval < 0) { 559 goto unlock_exit; 560 } 561 } 562 563 /* write the data into interrupt_out_buffer from userspace */ 564 bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size); 565 if (bytes_to_write < count) 566 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n", count-bytes_to_write); 567 dev_dbg(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n", 568 __func__, count, bytes_to_write); 569 570 if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) { 571 retval = -EFAULT; 572 goto unlock_exit; 573 } 574 575 if (dev->interrupt_out_endpoint == NULL) { 576 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */ 577 retval = usb_control_msg(interface_to_usbdev(dev->intf), 578 usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0), 579 9, 580 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT, 581 1 << 8, 0, 582 dev->interrupt_out_buffer, 583 bytes_to_write, 584 USB_CTRL_SET_TIMEOUT * HZ); 585 if (retval < 0) 586 dev_err(&dev->intf->dev, 587 "Couldn't submit HID_REQ_SET_REPORT %d\n", 588 retval); 589 goto unlock_exit; 590 } 591 592 /* send off the urb */ 593 usb_fill_int_urb(dev->interrupt_out_urb, 594 interface_to_usbdev(dev->intf), 595 usb_sndintpipe(interface_to_usbdev(dev->intf), 596 dev->interrupt_out_endpoint->bEndpointAddress), 597 dev->interrupt_out_buffer, 598 bytes_to_write, 599 ld_usb_interrupt_out_callback, 600 dev, 601 dev->interrupt_out_interval); 602 603 dev->interrupt_out_busy = 1; 604 wmb(); 605 606 retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL); 607 if (retval) { 608 dev->interrupt_out_busy = 0; 609 dev_err(&dev->intf->dev, 610 "Couldn't submit interrupt_out_urb %d\n", retval); 611 goto unlock_exit; 612 } 613 retval = bytes_to_write; 614 615 unlock_exit: 616 /* unlock the device */ 617 mutex_unlock(&dev->mutex); 618 619 exit: 620 return retval; 621 } 622 623 /* file operations needed when we register this driver */ 624 static const struct file_operations ld_usb_fops = { 625 .owner = THIS_MODULE, 626 .read = ld_usb_read, 627 .write = ld_usb_write, 628 .open = ld_usb_open, 629 .release = ld_usb_release, 630 .poll = ld_usb_poll, 631 .llseek = no_llseek, 632 }; 633 634 /* 635 * usb class driver info in order to get a minor number from the usb core, 636 * and to have the device registered with the driver core 637 */ 638 static struct usb_class_driver ld_usb_class = { 639 .name = "ldusb%d", 640 .fops = &ld_usb_fops, 641 .minor_base = USB_LD_MINOR_BASE, 642 }; 643 644 /** 645 * ld_usb_probe 646 * 647 * Called by the usb core when a new device is connected that it thinks 648 * this driver might be interested in. 649 */ 650 static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id) 651 { 652 struct usb_device *udev = interface_to_usbdev(intf); 653 struct ld_usb *dev = NULL; 654 struct usb_host_interface *iface_desc; 655 char *buffer; 656 int retval = -ENOMEM; 657 int res; 658 659 /* allocate memory for our device state and initialize it */ 660 661 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 662 if (!dev) 663 goto exit; 664 mutex_init(&dev->mutex); 665 spin_lock_init(&dev->rbsl); 666 dev->intf = intf; 667 init_waitqueue_head(&dev->read_wait); 668 init_waitqueue_head(&dev->write_wait); 669 670 /* workaround for early firmware versions on fast computers */ 671 if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) && 672 ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) || 673 (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) && 674 (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) { 675 buffer = kmalloc(256, GFP_KERNEL); 676 if (!buffer) 677 goto error; 678 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */ 679 usb_string(udev, 255, buffer, 256); 680 kfree(buffer); 681 } 682 683 iface_desc = intf->cur_altsetting; 684 685 res = usb_find_last_int_in_endpoint(iface_desc, 686 &dev->interrupt_in_endpoint); 687 if (res) { 688 dev_err(&intf->dev, "Interrupt in endpoint not found\n"); 689 retval = res; 690 goto error; 691 } 692 693 res = usb_find_last_int_out_endpoint(iface_desc, 694 &dev->interrupt_out_endpoint); 695 if (res) 696 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n"); 697 698 dev->interrupt_in_endpoint_size = usb_endpoint_maxp(dev->interrupt_in_endpoint); 699 dev->ring_buffer = 700 kmalloc_array(ring_buffer_size, 701 sizeof(size_t) + dev->interrupt_in_endpoint_size, 702 GFP_KERNEL); 703 if (!dev->ring_buffer) 704 goto error; 705 dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL); 706 if (!dev->interrupt_in_buffer) 707 goto error; 708 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 709 if (!dev->interrupt_in_urb) 710 goto error; 711 dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? usb_endpoint_maxp(dev->interrupt_out_endpoint) : 712 udev->descriptor.bMaxPacketSize0; 713 dev->interrupt_out_buffer = 714 kmalloc_array(write_buffer_size, 715 dev->interrupt_out_endpoint_size, GFP_KERNEL); 716 if (!dev->interrupt_out_buffer) 717 goto error; 718 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 719 if (!dev->interrupt_out_urb) 720 goto error; 721 dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval; 722 if (dev->interrupt_out_endpoint) 723 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : 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); 739 740 exit: 741 return retval; 742 743 error: 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 */ 754 static 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 mutex_lock(&dev->mutex); 768 769 /* if the device is not opened, then we clean up right now */ 770 if (!dev->open_count) { 771 mutex_unlock(&dev->mutex); 772 ld_usb_delete(dev); 773 } else { 774 dev->intf = NULL; 775 /* wake up pollers */ 776 wake_up_interruptible_all(&dev->read_wait); 777 wake_up_interruptible_all(&dev->write_wait); 778 mutex_unlock(&dev->mutex); 779 } 780 781 dev_info(&intf->dev, "LD USB Device #%d now disconnected\n", 782 (minor - USB_LD_MINOR_BASE)); 783 } 784 785 /* usb specific object needed to register this driver with the usb subsystem */ 786 static struct usb_driver ld_usb_driver = { 787 .name = "ldusb", 788 .probe = ld_usb_probe, 789 .disconnect = ld_usb_disconnect, 790 .id_table = ld_usb_table, 791 }; 792 793 module_usb_driver(ld_usb_driver); 794 795