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 int retval; 229 230 if (status) { 231 if (status == -ENOENT || 232 status == -ECONNRESET || 233 status == -ESHUTDOWN) { 234 goto exit; 235 } else { 236 dev_dbg(&dev->intf->dev, 237 "%s: nonzero status received: %d\n", __func__, 238 status); 239 spin_lock(&dev->rbsl); 240 goto resubmit; /* maybe we can recover */ 241 } 242 } 243 244 spin_lock(&dev->rbsl); 245 if (urb->actual_length > 0) { 246 next_ring_head = (dev->ring_head+1) % ring_buffer_size; 247 if (next_ring_head != dev->ring_tail) { 248 actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_head * (sizeof(size_t)+dev->interrupt_in_endpoint_size)); 249 /* actual_buffer gets urb->actual_length + interrupt_in_buffer */ 250 *actual_buffer = urb->actual_length; 251 memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length); 252 dev->ring_head = next_ring_head; 253 dev_dbg(&dev->intf->dev, "%s: received %d bytes\n", 254 __func__, urb->actual_length); 255 } else { 256 dev_warn(&dev->intf->dev, 257 "Ring buffer overflow, %d bytes dropped\n", 258 urb->actual_length); 259 dev->buffer_overflow = 1; 260 } 261 } 262 263 resubmit: 264 /* resubmit if we're still running */ 265 if (dev->interrupt_in_running && !dev->buffer_overflow && dev->intf) { 266 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC); 267 if (retval) { 268 dev_err(&dev->intf->dev, 269 "usb_submit_urb failed (%d)\n", retval); 270 dev->buffer_overflow = 1; 271 } 272 } 273 spin_unlock(&dev->rbsl); 274 exit: 275 dev->interrupt_in_done = 1; 276 wake_up_interruptible(&dev->read_wait); 277 } 278 279 /** 280 * ld_usb_interrupt_out_callback 281 */ 282 static void ld_usb_interrupt_out_callback(struct urb *urb) 283 { 284 struct ld_usb *dev = urb->context; 285 int status = urb->status; 286 287 /* sync/async unlink faults aren't errors */ 288 if (status && !(status == -ENOENT || 289 status == -ECONNRESET || 290 status == -ESHUTDOWN)) 291 dev_dbg(&dev->intf->dev, 292 "%s - nonzero write interrupt status received: %d\n", 293 __func__, status); 294 295 dev->interrupt_out_busy = 0; 296 wake_up_interruptible(&dev->write_wait); 297 } 298 299 /** 300 * ld_usb_open 301 */ 302 static int ld_usb_open(struct inode *inode, struct file *file) 303 { 304 struct ld_usb *dev; 305 int subminor; 306 int retval; 307 struct usb_interface *interface; 308 309 nonseekable_open(inode, file); 310 subminor = iminor(inode); 311 312 interface = usb_find_interface(&ld_usb_driver, subminor); 313 314 if (!interface) { 315 printk(KERN_ERR "%s - error, can't find device for minor %d\n", 316 __func__, subminor); 317 return -ENODEV; 318 } 319 320 dev = usb_get_intfdata(interface); 321 322 if (!dev) 323 return -ENODEV; 324 325 /* lock this device */ 326 if (mutex_lock_interruptible(&dev->mutex)) 327 return -ERESTARTSYS; 328 329 /* allow opening only once */ 330 if (dev->open_count) { 331 retval = -EBUSY; 332 goto unlock_exit; 333 } 334 dev->open_count = 1; 335 336 /* initialize in direction */ 337 dev->ring_head = 0; 338 dev->ring_tail = 0; 339 dev->buffer_overflow = 0; 340 usb_fill_int_urb(dev->interrupt_in_urb, 341 interface_to_usbdev(interface), 342 usb_rcvintpipe(interface_to_usbdev(interface), 343 dev->interrupt_in_endpoint->bEndpointAddress), 344 dev->interrupt_in_buffer, 345 dev->interrupt_in_endpoint_size, 346 ld_usb_interrupt_in_callback, 347 dev, 348 dev->interrupt_in_interval); 349 350 dev->interrupt_in_running = 1; 351 dev->interrupt_in_done = 0; 352 353 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL); 354 if (retval) { 355 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval); 356 dev->interrupt_in_running = 0; 357 dev->open_count = 0; 358 goto unlock_exit; 359 } 360 361 /* save device in the file's private structure */ 362 file->private_data = dev; 363 364 unlock_exit: 365 mutex_unlock(&dev->mutex); 366 367 return retval; 368 } 369 370 /** 371 * ld_usb_release 372 */ 373 static int ld_usb_release(struct inode *inode, struct file *file) 374 { 375 struct ld_usb *dev; 376 int retval = 0; 377 378 dev = file->private_data; 379 380 if (dev == NULL) { 381 retval = -ENODEV; 382 goto exit; 383 } 384 385 if (mutex_lock_interruptible(&dev->mutex)) { 386 retval = -ERESTARTSYS; 387 goto exit; 388 } 389 390 if (dev->open_count != 1) { 391 retval = -ENODEV; 392 goto unlock_exit; 393 } 394 if (dev->intf == NULL) { 395 /* the device was unplugged before the file was released */ 396 mutex_unlock(&dev->mutex); 397 /* unlock here as ld_usb_delete frees dev */ 398 ld_usb_delete(dev); 399 goto exit; 400 } 401 402 /* wait until write transfer is finished */ 403 if (dev->interrupt_out_busy) 404 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); 405 ld_usb_abort_transfers(dev); 406 dev->open_count = 0; 407 408 unlock_exit: 409 mutex_unlock(&dev->mutex); 410 411 exit: 412 return retval; 413 } 414 415 /** 416 * ld_usb_poll 417 */ 418 static __poll_t ld_usb_poll(struct file *file, poll_table *wait) 419 { 420 struct ld_usb *dev; 421 __poll_t mask = 0; 422 423 dev = file->private_data; 424 425 if (!dev->intf) 426 return EPOLLERR | EPOLLHUP; 427 428 poll_wait(file, &dev->read_wait, wait); 429 poll_wait(file, &dev->write_wait, wait); 430 431 if (dev->ring_head != dev->ring_tail) 432 mask |= EPOLLIN | EPOLLRDNORM; 433 if (!dev->interrupt_out_busy) 434 mask |= EPOLLOUT | EPOLLWRNORM; 435 436 return mask; 437 } 438 439 /** 440 * ld_usb_read 441 */ 442 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count, 443 loff_t *ppos) 444 { 445 struct ld_usb *dev; 446 size_t *actual_buffer; 447 size_t bytes_to_read; 448 int retval = 0; 449 int rv; 450 451 dev = file->private_data; 452 453 /* verify that we actually have some data to read */ 454 if (count == 0) 455 goto exit; 456 457 /* lock this object */ 458 if (mutex_lock_interruptible(&dev->mutex)) { 459 retval = -ERESTARTSYS; 460 goto exit; 461 } 462 463 /* verify that the device wasn't unplugged */ 464 if (dev->intf == NULL) { 465 retval = -ENODEV; 466 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval); 467 goto unlock_exit; 468 } 469 470 /* wait for data */ 471 spin_lock_irq(&dev->rbsl); 472 if (dev->ring_head == dev->ring_tail) { 473 dev->interrupt_in_done = 0; 474 spin_unlock_irq(&dev->rbsl); 475 if (file->f_flags & O_NONBLOCK) { 476 retval = -EAGAIN; 477 goto unlock_exit; 478 } 479 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done); 480 if (retval < 0) 481 goto unlock_exit; 482 } else { 483 spin_unlock_irq(&dev->rbsl); 484 } 485 486 /* actual_buffer contains actual_length + interrupt_in_buffer */ 487 actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_tail * (sizeof(size_t)+dev->interrupt_in_endpoint_size)); 488 bytes_to_read = min(count, *actual_buffer); 489 if (bytes_to_read < *actual_buffer) 490 dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n", 491 *actual_buffer-bytes_to_read); 492 493 /* copy one interrupt_in_buffer from ring_buffer into userspace */ 494 if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) { 495 retval = -EFAULT; 496 goto unlock_exit; 497 } 498 dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size; 499 500 retval = bytes_to_read; 501 502 spin_lock_irq(&dev->rbsl); 503 if (dev->buffer_overflow) { 504 dev->buffer_overflow = 0; 505 spin_unlock_irq(&dev->rbsl); 506 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL); 507 if (rv < 0) 508 dev->buffer_overflow = 1; 509 } else { 510 spin_unlock_irq(&dev->rbsl); 511 } 512 513 unlock_exit: 514 /* unlock the device */ 515 mutex_unlock(&dev->mutex); 516 517 exit: 518 return retval; 519 } 520 521 /** 522 * ld_usb_write 523 */ 524 static ssize_t ld_usb_write(struct file *file, const char __user *buffer, 525 size_t count, loff_t *ppos) 526 { 527 struct ld_usb *dev; 528 size_t bytes_to_write; 529 int retval = 0; 530 531 dev = file->private_data; 532 533 /* verify that we actually have some data to write */ 534 if (count == 0) 535 goto exit; 536 537 /* lock this object */ 538 if (mutex_lock_interruptible(&dev->mutex)) { 539 retval = -ERESTARTSYS; 540 goto exit; 541 } 542 543 /* verify that the device wasn't unplugged */ 544 if (dev->intf == NULL) { 545 retval = -ENODEV; 546 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval); 547 goto unlock_exit; 548 } 549 550 /* wait until previous transfer is finished */ 551 if (dev->interrupt_out_busy) { 552 if (file->f_flags & O_NONBLOCK) { 553 retval = -EAGAIN; 554 goto unlock_exit; 555 } 556 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy); 557 if (retval < 0) { 558 goto unlock_exit; 559 } 560 } 561 562 /* write the data into interrupt_out_buffer from userspace */ 563 bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size); 564 if (bytes_to_write < count) 565 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n", count-bytes_to_write); 566 dev_dbg(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\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 * HZ); 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; 613 614 unlock_exit: 615 /* unlock the device */ 616 mutex_unlock(&dev->mutex); 617 618 exit: 619 return retval; 620 } 621 622 /* file operations needed when we register this driver */ 623 static 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 */ 637 static 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 */ 649 static 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 = 699 kmalloc_array(ring_buffer_size, 700 sizeof(size_t) + dev->interrupt_in_endpoint_size, 701 GFP_KERNEL); 702 if (!dev->ring_buffer) 703 goto error; 704 dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL); 705 if (!dev->interrupt_in_buffer) 706 goto error; 707 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 708 if (!dev->interrupt_in_urb) 709 goto error; 710 dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? usb_endpoint_maxp(dev->interrupt_out_endpoint) : 711 udev->descriptor.bMaxPacketSize0; 712 dev->interrupt_out_buffer = 713 kmalloc_array(write_buffer_size, 714 dev->interrupt_out_endpoint_size, GFP_KERNEL); 715 if (!dev->interrupt_out_buffer) 716 goto error; 717 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 718 if (!dev->interrupt_out_urb) 719 goto error; 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 module_usb_driver(ld_usb_driver); 793 794