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"); 120 121 /* All interrupt in transfers are collected in a ring buffer to 122 * avoid racing conditions and get better performance of the driver. 123 */ 124 static int ring_buffer_size = 128; 125 module_param(ring_buffer_size, int, 0000); 126 MODULE_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 */ 130 static int write_buffer_size = 10; 131 module_param(write_buffer_size, int, 0000); 132 MODULE_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 */ 143 static int min_interrupt_in_interval = 2; 144 module_param(min_interrupt_in_interval, int, 0000); 145 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms"); 146 147 static int min_interrupt_out_interval = 2; 148 module_param(min_interrupt_out_interval, int, 0000); 149 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms"); 150 151 /* Structure to hold all of our device specific stuff */ 152 struct ld_usb { 153 struct kref kref; 154 struct mutex mutex; /* locks this structure */ 155 struct usb_interface *intf; /* save off the usb interface pointer */ 156 unsigned long disconnected:1; 157 158 int open_count; /* number of times this port has been opened */ 159 160 char *ring_buffer; 161 unsigned int ring_head; 162 unsigned int ring_tail; 163 164 wait_queue_head_t read_wait; 165 wait_queue_head_t write_wait; 166 167 char *interrupt_in_buffer; 168 struct usb_endpoint_descriptor *interrupt_in_endpoint; 169 struct urb *interrupt_in_urb; 170 int interrupt_in_interval; 171 size_t interrupt_in_endpoint_size; 172 int interrupt_in_running; 173 int interrupt_in_done; 174 int buffer_overflow; 175 spinlock_t rbsl; 176 177 char *interrupt_out_buffer; 178 struct usb_endpoint_descriptor *interrupt_out_endpoint; 179 struct urb *interrupt_out_urb; 180 int interrupt_out_interval; 181 size_t interrupt_out_endpoint_size; 182 int interrupt_out_busy; 183 }; 184 185 static struct usb_driver ld_usb_driver; 186 187 /* 188 * ld_usb_abort_transfers 189 * aborts transfers and frees associated data structures 190 */ 191 static void ld_usb_abort_transfers(struct ld_usb *dev) 192 { 193 /* shutdown transfer */ 194 if (dev->interrupt_in_running) { 195 dev->interrupt_in_running = 0; 196 usb_kill_urb(dev->interrupt_in_urb); 197 } 198 if (dev->interrupt_out_busy) 199 usb_kill_urb(dev->interrupt_out_urb); 200 } 201 202 /* 203 * ld_usb_delete 204 */ 205 static void ld_usb_delete(struct kref *kref) 206 { 207 struct ld_usb *dev = container_of(kref, struct ld_usb, kref); 208 209 /* free data structures */ 210 usb_free_urb(dev->interrupt_in_urb); 211 usb_free_urb(dev->interrupt_out_urb); 212 kfree(dev->ring_buffer); 213 kfree(dev->interrupt_in_buffer); 214 kfree(dev->interrupt_out_buffer); 215 kfree(dev); 216 } 217 218 /* 219 * ld_usb_interrupt_in_callback 220 */ 221 static void ld_usb_interrupt_in_callback(struct urb *urb) 222 { 223 struct ld_usb *dev = urb->context; 224 size_t *actual_buffer; 225 unsigned int next_ring_head; 226 int status = urb->status; 227 unsigned long flags; 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_irqsave(&dev->rbsl, flags); 240 goto resubmit; /* maybe we can recover */ 241 } 242 } 243 244 spin_lock_irqsave(&dev->rbsl, flags); 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) { 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_irqrestore(&dev->rbsl, flags); 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 stream_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 kref_get(&dev->kref); 362 363 /* save device in the file's private structure */ 364 file->private_data = dev; 365 366 unlock_exit: 367 mutex_unlock(&dev->mutex); 368 369 return retval; 370 } 371 372 /* 373 * ld_usb_release 374 */ 375 static int ld_usb_release(struct inode *inode, struct file *file) 376 { 377 struct ld_usb *dev; 378 int retval = 0; 379 380 dev = file->private_data; 381 382 if (dev == NULL) { 383 retval = -ENODEV; 384 goto exit; 385 } 386 387 mutex_lock(&dev->mutex); 388 389 if (dev->disconnected) 390 goto unlock_exit; 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 kref_put(&dev->kref, ld_usb_delete); 401 exit: 402 return retval; 403 } 404 405 /* 406 * ld_usb_poll 407 */ 408 static __poll_t ld_usb_poll(struct file *file, poll_table *wait) 409 { 410 struct ld_usb *dev; 411 __poll_t mask = 0; 412 413 dev = file->private_data; 414 415 if (dev->disconnected) 416 return EPOLLERR | EPOLLHUP; 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 |= EPOLLIN | EPOLLRDNORM; 423 if (!dev->interrupt_out_busy) 424 mask |= EPOLLOUT | EPOLLWRNORM; 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->disconnected) { 455 retval = -ENODEV; 456 printk(KERN_ERR "ldusb: 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 while (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; 472 473 spin_lock_irq(&dev->rbsl); 474 } 475 spin_unlock_irq(&dev->rbsl); 476 477 /* actual_buffer contains actual_length + interrupt_in_buffer */ 478 actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_tail * (sizeof(size_t)+dev->interrupt_in_endpoint_size)); 479 if (*actual_buffer > dev->interrupt_in_endpoint_size) { 480 retval = -EIO; 481 goto unlock_exit; 482 } 483 bytes_to_read = min(count, *actual_buffer); 484 if (bytes_to_read < *actual_buffer) 485 dev_warn(&dev->intf->dev, "Read buffer overflow, %zu bytes dropped\n", 486 *actual_buffer-bytes_to_read); 487 488 /* copy one interrupt_in_buffer from ring_buffer into userspace */ 489 if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) { 490 retval = -EFAULT; 491 goto unlock_exit; 492 } 493 retval = bytes_to_read; 494 495 spin_lock_irq(&dev->rbsl); 496 dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size; 497 498 if (dev->buffer_overflow) { 499 dev->buffer_overflow = 0; 500 spin_unlock_irq(&dev->rbsl); 501 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL); 502 if (rv < 0) 503 dev->buffer_overflow = 1; 504 } else { 505 spin_unlock_irq(&dev->rbsl); 506 } 507 508 unlock_exit: 509 /* unlock the device */ 510 mutex_unlock(&dev->mutex); 511 512 exit: 513 return retval; 514 } 515 516 /* 517 * ld_usb_write 518 */ 519 static ssize_t ld_usb_write(struct file *file, const char __user *buffer, 520 size_t count, loff_t *ppos) 521 { 522 struct ld_usb *dev; 523 size_t bytes_to_write; 524 int retval = 0; 525 526 dev = file->private_data; 527 528 /* verify that we actually have some data to write */ 529 if (count == 0) 530 goto exit; 531 532 /* lock this object */ 533 if (mutex_lock_interruptible(&dev->mutex)) { 534 retval = -ERESTARTSYS; 535 goto exit; 536 } 537 538 /* verify that the device wasn't unplugged */ 539 if (dev->disconnected) { 540 retval = -ENODEV; 541 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval); 542 goto unlock_exit; 543 } 544 545 /* wait until previous transfer is finished */ 546 if (dev->interrupt_out_busy) { 547 if (file->f_flags & O_NONBLOCK) { 548 retval = -EAGAIN; 549 goto unlock_exit; 550 } 551 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy); 552 if (retval < 0) { 553 goto unlock_exit; 554 } 555 } 556 557 /* write the data into interrupt_out_buffer from userspace */ 558 bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size); 559 if (bytes_to_write < count) 560 dev_warn(&dev->intf->dev, "Write buffer overflow, %zu bytes dropped\n", 561 count - bytes_to_write); 562 dev_dbg(&dev->intf->dev, "%s: count = %zu, bytes_to_write = %zu\n", 563 __func__, count, bytes_to_write); 564 565 if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) { 566 retval = -EFAULT; 567 goto unlock_exit; 568 } 569 570 if (dev->interrupt_out_endpoint == NULL) { 571 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */ 572 retval = usb_control_msg(interface_to_usbdev(dev->intf), 573 usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0), 574 9, 575 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT, 576 1 << 8, 0, 577 dev->interrupt_out_buffer, 578 bytes_to_write, 579 USB_CTRL_SET_TIMEOUT); 580 if (retval < 0) 581 dev_err(&dev->intf->dev, 582 "Couldn't submit HID_REQ_SET_REPORT %d\n", 583 retval); 584 goto unlock_exit; 585 } 586 587 /* send off the urb */ 588 usb_fill_int_urb(dev->interrupt_out_urb, 589 interface_to_usbdev(dev->intf), 590 usb_sndintpipe(interface_to_usbdev(dev->intf), 591 dev->interrupt_out_endpoint->bEndpointAddress), 592 dev->interrupt_out_buffer, 593 bytes_to_write, 594 ld_usb_interrupt_out_callback, 595 dev, 596 dev->interrupt_out_interval); 597 598 dev->interrupt_out_busy = 1; 599 wmb(); 600 601 retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL); 602 if (retval) { 603 dev->interrupt_out_busy = 0; 604 dev_err(&dev->intf->dev, 605 "Couldn't submit interrupt_out_urb %d\n", retval); 606 goto unlock_exit; 607 } 608 retval = bytes_to_write; 609 610 unlock_exit: 611 /* unlock the device */ 612 mutex_unlock(&dev->mutex); 613 614 exit: 615 return retval; 616 } 617 618 /* file operations needed when we register this driver */ 619 static const struct file_operations ld_usb_fops = { 620 .owner = THIS_MODULE, 621 .read = ld_usb_read, 622 .write = ld_usb_write, 623 .open = ld_usb_open, 624 .release = ld_usb_release, 625 .poll = ld_usb_poll, 626 }; 627 628 /* 629 * usb class driver info in order to get a minor number from the usb core, 630 * and to have the device registered with the driver core 631 */ 632 static struct usb_class_driver ld_usb_class = { 633 .name = "ldusb%d", 634 .fops = &ld_usb_fops, 635 .minor_base = USB_LD_MINOR_BASE, 636 }; 637 638 /* 639 * ld_usb_probe 640 * 641 * Called by the usb core when a new device is connected that it thinks 642 * this driver might be interested in. 643 */ 644 static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id) 645 { 646 struct usb_device *udev = interface_to_usbdev(intf); 647 struct ld_usb *dev = NULL; 648 struct usb_host_interface *iface_desc; 649 char *buffer; 650 int retval = -ENOMEM; 651 int res; 652 653 /* allocate memory for our device state and initialize it */ 654 655 dev = kzalloc_obj(*dev); 656 if (!dev) 657 goto exit; 658 659 kref_init(&dev->kref); 660 mutex_init(&dev->mutex); 661 spin_lock_init(&dev->rbsl); 662 dev->intf = intf; 663 init_waitqueue_head(&dev->read_wait); 664 init_waitqueue_head(&dev->write_wait); 665 666 /* workaround for early firmware versions on fast computers */ 667 if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) && 668 ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) || 669 (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) && 670 (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) { 671 buffer = kmalloc(256, GFP_KERNEL); 672 if (!buffer) 673 goto error; 674 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */ 675 usb_string(udev, 255, buffer, 256); 676 kfree(buffer); 677 } 678 679 iface_desc = intf->cur_altsetting; 680 681 res = usb_find_last_int_in_endpoint(iface_desc, 682 &dev->interrupt_in_endpoint); 683 if (res) { 684 dev_err(&intf->dev, "Interrupt in endpoint not found\n"); 685 retval = res; 686 goto error; 687 } 688 689 res = usb_find_last_int_out_endpoint(iface_desc, 690 &dev->interrupt_out_endpoint); 691 if (res) 692 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n"); 693 694 dev->interrupt_in_endpoint_size = usb_endpoint_maxp(dev->interrupt_in_endpoint); 695 dev->ring_buffer = kcalloc(ring_buffer_size, 696 sizeof(size_t) + dev->interrupt_in_endpoint_size, 697 GFP_KERNEL); 698 if (!dev->ring_buffer) 699 goto error; 700 dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL); 701 if (!dev->interrupt_in_buffer) 702 goto error; 703 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL); 704 if (!dev->interrupt_in_urb) 705 goto error; 706 dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? usb_endpoint_maxp(dev->interrupt_out_endpoint) : 707 udev->descriptor.bMaxPacketSize0; 708 dev->interrupt_out_buffer = 709 kmalloc_array(write_buffer_size, 710 dev->interrupt_out_endpoint_size, GFP_KERNEL); 711 if (!dev->interrupt_out_buffer) 712 goto error; 713 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL); 714 if (!dev->interrupt_out_urb) 715 goto error; 716 dev->interrupt_in_interval = max_t(int, min_interrupt_in_interval, 717 dev->interrupt_in_endpoint->bInterval); 718 if (dev->interrupt_out_endpoint) 719 dev->interrupt_out_interval = max_t(int, min_interrupt_out_interval, 720 dev->interrupt_out_endpoint->bInterval); 721 722 /* we can register the device now, as it is ready */ 723 usb_set_intfdata(intf, dev); 724 725 retval = usb_register_dev(intf, &ld_usb_class); 726 if (retval) { 727 /* something prevented us from registering this driver */ 728 dev_err(&intf->dev, "Not able to get a minor for this device.\n"); 729 usb_set_intfdata(intf, NULL); 730 goto error; 731 } 732 733 /* let the user know what node this device is now attached to */ 734 dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n", 735 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor); 736 737 exit: 738 return retval; 739 740 error: 741 kref_put(&dev->kref, ld_usb_delete); 742 743 return retval; 744 } 745 746 /* 747 * ld_usb_disconnect 748 * 749 * Called by the usb core when the device is removed from the system. 750 */ 751 static void ld_usb_disconnect(struct usb_interface *intf) 752 { 753 struct ld_usb *dev; 754 int minor; 755 756 dev = usb_get_intfdata(intf); 757 usb_set_intfdata(intf, NULL); 758 759 minor = intf->minor; 760 761 /* give back our minor */ 762 usb_deregister_dev(intf, &ld_usb_class); 763 764 usb_poison_urb(dev->interrupt_in_urb); 765 usb_poison_urb(dev->interrupt_out_urb); 766 767 mutex_lock(&dev->mutex); 768 769 dev->disconnected = 1; 770 771 if (dev->open_count) { 772 /* wake up pollers */ 773 wake_up_interruptible_all(&dev->read_wait); 774 wake_up_interruptible_all(&dev->write_wait); 775 } 776 777 mutex_unlock(&dev->mutex); 778 779 kref_put(&dev->kref, ld_usb_delete); 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