1.\" 2.\" Copyright (c) 2008 Hans Petter Selasky 3.\" 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25.\" SUCH DAMAGE. 26.\" 27.\" $FreeBSD$ 28.\" 29.Dd April 5, 2009 30.Dt LIBUSB 3 31.Os 32.Sh NAME 33.Nm libusb 34. 35.Nd "USB access library" 36. 37. 38.Sh LIBRARY 39. 40. 41USB access library (libusb -lusb) 42. 43. 44. 45.Sh SYNOPSIS 46.In libusb20.h 47.Ft int 48.Fn libusb20_tr_close "struct libusb20_transfer *xfer" 49.Ft int 50.Fn libusb20_tr_open "struct libusb20_transfer *xfer" "uint32_t max_buf_size" "uint32_t max_frame_count" "uint8_t ep_no" 51.Ft struct libusb20_transfer* 52.Fn libusb20_tr_get_pointer "struct libusb20_device *pdev" "uint16_t tr_index" 53.Ft uint16_t 54.Fn libusb20_tr_get_time_complete "struct libusb20_transfer *xfer" 55.Ft uint32_t 56.Fn libusb20_tr_get_actual_frames "struct libusb20_transfer *xfer" 57.Ft uint32_t 58.Fn libusb20_tr_get_actual_length "struct libusb20_transfer *xfer" 59.Ft uint32_t 60.Fn libusb20_tr_get_max_frames "struct libusb20_transfer *xfer" 61.Ft uint32_t 62.Fn libusb20_tr_get_max_packet_length "struct libusb20_transfer *xfer" 63.Ft uint32_t 64.Fn libusb20_tr_get_max_total_length "struct libusb20_transfer *xfer" 65.Ft uint8_t 66.Fn libusb20_tr_get_status "struct libusb20_transfer *xfer" 67.Ft uint8_t 68.Fn libusb20_tr_pending "struct libusb20_transfer *xfer" 69.Ft void 70.Fn libusb20_tr_callback_wrapper "struct libusb20_transfer *xfer" 71.Ft void 72.Fn libusb20_tr_clear_stall_sync "struct libusb20_transfer *xfer" 73.Ft void 74.Fn libusb20_tr_drain "struct libusb20_transfer *xfer" 75.Ft void 76.Fn libusb20_tr_set_buffer "struct libusb20_transfer *xfer" "void *buffer" "uint16_t fr_index" 77.Ft void 78.Fn libusb20_tr_set_callback "struct libusb20_transfer *xfer" "libusb20_tr_callback_t *cb" 79.Ft void 80.Fn libusb20_tr_set_flags "struct libusb20_transfer *xfer" "uint8_t flags" 81.Ft void 82.Fn libusb20_tr_set_length "struct libusb20_transfer *xfer" "uint32_t length" "uint16_t fr_index" 83.Ft void 84.Fn libusb20_tr_set_priv_sc0 "struct libusb20_transfer *xfer" "void *sc0" 85.Ft void 86.Fn libusb20_tr_set_priv_sc1 "struct libusb20_transfer *xfer" "void *sc1" 87.Ft void 88.Fn libusb20_tr_set_timeout "struct libusb20_transfer *xfer" "uint32_t timeout" 89.Ft void 90.Fn libusb20_tr_set_total_frames "struct libusb20_transfer *xfer" "uint32_t nframes" 91.Ft void 92.Fn libusb20_tr_setup_bulk "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t timeout" 93.Ft void 94.Fn libusb20_tr_setup_control "struct libusb20_transfer *xfer" "void *psetup" "void *pbuf" "uint32_t timeout" 95.Ft void 96.Fn libusb20_tr_setup_intr "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t timeout" 97.Ft void 98.Fn libusb20_tr_setup_isoc "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint61_t fr_index" 99.Ft void 100.Fn libusb20_tr_start "struct libusb20_transfer *xfer" 101.Ft void 102.Fn libusb20_tr_stop "struct libusb20_transfer *xfer" 103.Ft void 104.Fn libusb20_tr_submit "struct libusb20_transfer *xfer" 105.Ft void * 106.Fn libusb20_tr_get_priv_sc0 "struct libusb20_transfer *xfer" 107.Ft void * 108.Fn libusb20_tr_get_priv_sc1 "struct libusb20_transfer *xfer" 109.Ft const char * 110.Fn libusb20_dev_get_backend_name "struct libusb20_device *" 111.Ft int 112.Fn libusb20_dev_get_info "struct libusb20_device *pdev" "struct usb2_device_info *pinfo" 113.Ft int 114.Fn libusb20_dev_get_iface_desc "struct libusb20_device *pdev" "uint8_t iface_index" "char *buf" "uint8_t len" 115.Ft const char * 116.Fn libusb20_dev_get_desc "struct libusb20_device *pdev" 117.Ft int 118.Fn libusb20_dev_claim_interface "struct libusb20_device *pdev" "uint8_t iface_index" 119.Ft int 120.Fn libusb20_dev_close "struct libusb20_device *pdev" 121.Ft int 122.Fn libusb20_dev_detach_kernel_driver "struct libusb20_device *pdev" "uint8_t iface_index" 123.Ft int 124.Fn libusb20_dev_set_config_index "struct libusb20_device *pdev" "uint8_t configIndex" 125.Ft int 126.Fn libusb20_dev_get_debug "struct libusb20_device *pdev" 127.Ft int 128.Fn libusb20_dev_get_fd "struct libusb20_device *pdev" 129.Ft int 130.Fn libusb20_dev_kernel_driver_active "struct libusb20_device *pdev" "uint8_t iface_index" 131.Ft int 132.Fn libusb20_dev_open "struct libusb20_device *pdev" "uint16_t transfer_max" 133.Ft int 134.Fn libusb20_dev_process "struct libusb20_device *pdev" 135.Ft int 136.Fn libusb20_dev_release_interface "struct libusb20_device *pdev" "uint8_t iface_index" 137.Ft int 138.Fn libusb20_dev_request_sync "struct libusb20_device *pdev" "struct LIBUSB20_CONTROL_SETUP_DECODED *setup" "void *data" "uint16_t *pactlen" "uint32_t timeout" "uint8_t flags" 139.Ft int 140.Fn libusb20_dev_req_string_sync "struct libusb20_device *pdev" "uint8_t index" "uint16_t langid" "void *ptr" "uint16_t len" 141.Ft int 142.Fn libusb20_dev_req_string_simple_sync "struct libusb20_device *pdev" "uint8_t index" "void *ptr" "uint16_t len" 143.Ft int 144.Fn libusb20_dev_reset "struct libusb20_device *pdev" 145.Ft int 146.Fn libusb20_dev_set_power_mode "struct libusb20_device *pdev" "uint8_t power_mode" 147.Ft uint8_t 148.Fn libusb20_dev_get_power_mode "struct libusb20_device *pdev" 149.Ft int 150.Fn libusb20_dev_set_alt_index "struct libusb20_device *pdev" "uint8_t iface_index" "uint8_t alt_index" 151.Ft int 152.Fn libusb20_dev_get_device_desc "struct libusb20_device *pdev" "uint8_t iface_indexr", "char *buf" "uint8_t len" 153.Ft struct libusb20_config * 154.Fn libusb20_dev_alloc_config "struct libusb20_device *pdev" "uint8_t config_index" 155.Ft struct libusb20_device * 156.Fn libusb20_dev_alloc "void" 157.Ft uint8_t 158.Fn libusb20_dev_get_address "struct libusb20_device *pdev" 159.Ft uint8_t 160.Fn libusb20_dev_get_bus_number "struct libusb20_device *pdev" 161.Ft uint8_t 162.Fn libusb20_dev_get_mode "struct libusb20_device *pdev" 163.Ft uint8_t 164.Fn libusb20_dev_get_speed "struct libusb20_device *pdev" 165.Ft uint8_t 166.Fn libusb20_dev_get_config_index "struct libusb20_device *pdev" 167.Ft void 168.Fn libusb20_dev_free "struct libusb20_device *pdev" 169.Ft void 170.Fn libusb20_dev_set_debug "struct libusb20_device *pdev" "int debug" 171.Ft void 172.Fn libusb20_dev_wait_process "struct libusb20_device *pdev" "int timeout" 173.Ft int 174.Fn libusb20_be_get_template "struct libusb20_backend *pbe" "int *ptemp" 175.Ft int 176.Fn libusb20_be_set_template "struct libusb20_backend *pbe" "int temp" 177.Ft int 178.Fn libusb20_be_get_dev_quirk "struct libusb20_backend *pber", "uint16_t index" "struct libusb20_quirk *pq" 179.Ft int 180.Fn libusb20_be_get_quirk_name "struct libusb20_backend *pbe" "uint16_t index" "struct libusb20_quirk *pq" 181.Ft int 182.Fn libusb20_be_add_dev_quirk "struct libusb20_backend *pbe" "struct libusb20_quirk *pq" 183.Ft int 184.Fn libusb20_be_remove_dev_quirk "struct libusb20_backend *pbe" "struct libusb20_quirk *pq" 185.Ft struct libusb20_backend * 186.Fn libusb20_be_alloc_linux "void" 187.Ft struct libusb20_device * 188.Fn libusb20_be_device_foreach "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 189.Ft void 190.Fn libusb20_be_dequeue_device "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 191.Ft void 192.Fn libusb20_be_enqueue_device "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 193.Ft void 194.Fn libusb20_be_free "struct libusb20_backend *pbe" 195.Ft uint8_t 196.Fn libusb20_me_get_1 "const struct libusb20_me_struct *me" "uint16_t off" 197.Ft uint16_t 198.Fn libusb20_me_get_2 "const struct libusb20_me_struct *me" "uint16_t off" 199.Ft uint16_t 200.Fn libusb20_me_encode "void *pdata" "uint16_t len" "const void *pdecoded" 201.Ft uint16_t 202.Fn libusb20_me_decode "const void *pdata" "uint16_t len" "void *pdecoded" 203.Ft "const uint8_t *" 204.Fn libusb20_desc_foreach "const struct libusb20_me_struct *me" "const uint8_t *pdesc" 205. 206. 207.Sh DESCRIPTION 208. 209The 210.Nm 211library implements functions to be able to easily access and control 212USB through the USB file system interface. 213. 214. 215.Sh USB TRANSFER OPERATIONS 216. 217.Pp 218. 219.Fn libusb20_tr_close 220will release all kernel resources associated with an USB 221.Fa xfer . 222. 223This function returns zero upon success. 224. 225Non-zero return values indicate a LIBUSB20_ERROR value. 226. 227.Pp 228. 229.Fn libusb20_tr_open 230will allocate kernel resources like 231.Fa max_buf_size 232and 233.Fa max_frame_count 234associated with an USB 235.Fa pxfer 236and bind the transfer to the specified 237.Fa ep_no . 238. 239This function returns zero upon success. 240. 241Non-zero return values indicate a LIBUSB20_ERROR value. 242. 243.Pp 244. 245.Fn libusb20_tr_get_pointer 246will return a pointer to the allocated USB transfer according to the 247.Fa pdev 248and 249.Fa tr_index 250arguments. 251. 252This function returns NULL in case of failure. 253. 254.Pp 255. 256.Fn libusb20_tr_get_time_complete 257will return the completion time of an USB transfer in 258millisecond units. This function is most useful for isochronous USB 259transfers when doing echo cancelling. 260. 261.Pp 262. 263.Fn libusb20_tr_get_actual_frames 264will return the actual number of USB frames after an USB 265transfer completed. A value of zero means that no data was transferred. 266. 267.Pp 268. 269.Fn libusb20_tr_get_actual_length 270will return the sum of the actual length for all 271transferred USB frames for the given USB transfer. 272. 273.Pp 274. 275.Fn libusb20_tr_get_max_frames 276will return the maximum number of USB frames that were 277allocated when an USB transfer was setup for the given USB transfer. 278. 279.Pp 280. 281.Fn libusb20_tr_get_max_packet_length 282will return the maximum packet length in bytes 283associated with the given USB transfer. 284. 285The packet length can be used round up buffer sizes so that short USB 286packets are avoided for proxy buffers. 287. 288. 289.Pp 290. 291.Fn libusb20_tr_get_max_total_length 292function will return the maximum value for the length sum of all 293USB frames associated with an USB transfer. 294. 295.Pp 296. 297.Fn libusb20_tr_get_status 298will return the status of an USB transfer. 299. 300Status values are defined by a set of LIBUSB20_TRANSFER_XXX enums. 301. 302.Pp 303. 304.Fn libusb20_tr_pending 305will return non-zero if the given USB transfer is 306pending for completion. 307. 308Else this function returns zero. 309. 310.Pp 311. 312.Fn libusb20_tr_callback_wrapper 313This is an internal function used to wrap asynchronous USB callbacks. 314. 315.Pp 316. 317.Fn libusb20_tr_clear_stall_sync 318This is an internal function used to synchronously clear the stall on 319the given USB transfer. 320. 321Please see the USB specification for more information on stall 322clearing. 323. 324If the given USB transfer is pending when this function is called, the 325USB transfer will complete with an error after that this function has 326been called. 327. 328.Pp 329. 330.Fn libusb20_tr_drain 331will stop the given USB transfer and will not return 332until the USB transfer has been stopped in hardware. 333. 334.Pp 335. 336.Fn libusb20_tr_set_buffer 337is used to set the 338.Fa buffer 339pointer for the given USB transfer and 340.Fa fr_index . 341. 342Typically the frame index is zero. 343. 344. 345.Pp 346. 347.Fn libusb20_tr_set_callback 348is used to set the USB callback for asynchronous USB 349transfers. 350. 351The callback type is defined by libusb20_tr_callback_t. 352. 353.Pp 354. 355.Fn libusb20_tr_set_flags 356is used to set various USB flags for the given USB transfer. 357.Bl -tag 358.It LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK 359Report a short frame as error. 360.It LIBUSB20_TRANSFER_MULTI_SHORT_NOT_OK 361Multiple short frames are not allowed. 362.It LIBUSB20_TRANSFER_FORCE_SHORT 363All transmitted frames are short terminated. 364.It LIBUSB20_TRANSFER_DO_CLEAR_STALL 365Will do a clear-stall before starting the transfer. 366.El 367. 368.Pp 369. 370.Fn libusb20_tr_set_length 371sets the length of a given USB transfer and frame index. 372. 373.Pp 374. 375.Fn libusb20_tr_set_priv_sc0 376sets private driver pointer number zero. 377. 378.Pp 379. 380.Fn libusb20_tr_set_priv_sc1 381sets private driver pointer number one. 382. 383.Pp 384. 385.Fn libusb20_tr_set_timeout 386sets the timeout for the given USB transfer. 387. 388A timeout value of zero means no timeout. 389. 390The timeout is given in milliseconds. 391. 392.Pp 393. 394.Fn libusb20_tr_set_total_frames 395sets the total number of frames that should be executed when the USB transfer is submitted. 396. 397The total number of USB frames must be less than the maximum number of USB frames associated with the given USB transfer. 398. 399.Pp 400. 401.Fn libusb20_tr_setup_bulk 402is a helper function for setting up a single frame USB BULK transfer. 403. 404.Pp 405. 406.Fn libusb20_tr_setup_control 407is a helper function for setting up a single or dual 408frame USB CONTROL transfer depending on the control transfer length. 409. 410.Pp 411. 412.Fn libusb20_tr_setup_intr 413is a helper function for setting up a single frame USB INTERRUPT transfer. 414. 415.Pp 416. 417.Fn libusb20_tr_setup_isoc 418is a helper function for setting up a multi frame USB ISOCHRONOUS transfer. 419. 420.Pp 421. 422.Fn libusb20_tr_start 423will get the USB transfer started, if not already 424started. 425. 426This function will not get the transfer queued in hardware. 427. 428This function is non-blocking. 429. 430.Pp 431. 432.Fn libusb20_tr_stop 433will get the USB transfer stopped, if not already stopped. 434. 435This function is non-blocking, which means that the actual stop can 436happen after the return of this function. 437. 438.Pp 439. 440.Fn libusb20_tr_submit 441will get the USB transfer queued in hardware. 442. 443. 444.Pp 445. 446.Fn libusb20_tr_get_priv_sc0 447returns private driver pointer number zero associated 448with an USB transfer. 449. 450. 451.Pp 452. 453.Fn libusb20_tr_get_priv_sc1 454returns private driver pointer number one associated 455with an USB transfer. 456. 457. 458.Sh USB DEVICE OPERATIONS 459. 460.Pp 461. 462.Fn libusb20_dev_get_backend_name 463returns a zero terminated string describing the backend used. 464. 465.Pp 466. 467.Fn libusb20_dev_get_info 468retrives the BSD specific usb2_device_info structure into the memory location given by 469.Fa pinfo . 470The USB device given by 471.Fa pdev 472must be opened before this function will succeed. 473This function returns zero on success else a LIBUSB20_ERROR value is returned. 474. 475.Pp 476. 477.Fn libusb20_dev_get_iface_desc 478retrieves the kernel interface description for the given USB 479.Fa iface_index . 480The format of the USB interface description is: "drivername<unit>: <description>" 481The description string is always zero terminated. 482A zero length string is written in case no driver is attached to the given interface. 483The USB device given by 484.Fa pdev 485must be opened before this function will succeed. 486This function returns zero on success else a LIBUSB20_ERROR value is returned. 487. 488.Pp 489. 490.Fn libusb20_dev_get_desc 491returns a zero terminated string describing the given USB device. 492The format of the string is: "drivername<unit>: <description>" 493. 494.Pp 495. 496.Fn libusb20_dev_claim_interface 497This function will try to claim the given USB interface given by 498.Fa iface_index . 499This function returns zero on success else a LIBUSB20_ERROR value is 500returned. 501. 502.Pp 503. 504.Fn libusb20_dev_close 505will close the given USB device. 506. 507This function returns zero on success else a LIBUSB20_ERROR value is 508returned. 509. 510.Pp 511. 512.Fn libusb20_dev_detach_kernel_driver 513will try to detach the kernel driver for the USB interface given by 514.Fa iface_index . 515. 516This function returns zero on success else a LIBUSB20_ERROR value is 517returned. 518. 519.Pp 520. 521.Fn libusb20_dev_set_config_index 522will try to set the configuration index on an USB 523device. 524. 525The first configuration index is zero. 526. 527The un-configure index is 255. 528. 529This function returns zero on success else a LIBUSB20_ERROR value is returned. 530. 531.Pp 532. 533.Fn libusb20_dev_get_debug 534returns the debug level of an USB device. 535. 536.Pp 537. 538.Fn libusb20_dev_get_fd 539returns the file descriptor of the given USB device. 540. 541A negative value is returned when no file descriptor is present. 542. 543The file descriptor can be used for polling purposes. 544. 545.Pp 546. 547.Fn libusb20_dev_kernel_driver_active 548returns a non-zero value if a kernel driver is active on 549the given USB interface. 550. 551Else zero is returned. 552. 553.Pp 554. 555.Fn libusb20_dev_open 556opens an USB device so that setting up USB transfers 557becomes possible. 558. 559The number of USB transfers can be zero which means only control 560transfers are allowed. 561. 562This function returns zero on success else a LIBUSB20_ERROR value is 563returned. 564. 565A return value of LIBUSB20_ERROR_BUSY means that the device is already 566opened. 567. 568.Pp 569. 570.Fn libusb20_dev_process 571is called to sync kernel USB transfers with userland USB 572transfers. 573. 574This function returns zero on success else a LIBUSB20_ERROR value is 575returned typically indicating that the given USB device has been 576detached. 577. 578.Pp 579. 580.Fn libusb20_dev_release_interface 581will try to release a claimed USB interface for the specified USB device. 582. 583This function returns zero on success else a LIBUSB20_ERROR value is 584returned. 585. 586.Pp 587. 588.Fn libusb20_dev_request_sync 589will perform a synchronous control request on the given 590USB device. 591. 592Before this call will succeed the USB device must be opened. 593. 594.Fa setup 595is a pointer to a decoded and host endian SETUP packet. 596.Fa data 597is a pointer to a data transfer buffer associated with the control transaction. This argument can be NULL. 598.Fa pactlen 599is a pointer to a variable that will hold the actual transfer length after the control transaction is complete. 600.Fa timeout 601is the transaction timeout given in milliseconds. 602A timeout of zero means no timeout. 603.Fa flags 604is used to specify transaction flags, for example LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK. 605. 606This function returns zero on success else a LIBUSB20_ERROR value is 607returned. 608. 609.Pp 610. 611.Fn libusb20_dev_req_string_sync 612will synchronously request an USB string by language ID 613and string index into the given buffer limited by a maximum length. 614. 615This function returns zero on success else a LIBUSB20_ERROR value is 616returned. 617. 618.Pp 619. 620.Fn libusb20_dev_req_string_simple_sync 621will synchronously request an USB string using the 622default language ID and convert the string into ASCII before storing 623the string into the given buffer limited by a maximum length which 624includes the terminating zero. 625. 626This function returns zero on success else a LIBUSB20_ERROR value is 627returned. 628. 629. 630.Pp 631. 632.Fn libusb20_dev_reset 633will try to BUS reset the given USB device and restore 634the last set USB configuration. 635. 636This function returns zero on success else a LIBUSB20_ERROR value is 637returned. 638. 639.Pp 640. 641.Fn libusb20_dev_set_power_mode 642sets the power mode of the USB device. 643. 644Valid power modes: 645.Bl -tag 646.It LIBUSB20_POWER_OFF 647.It LIBUSB20_POWER_ON 648.It LIBUSB20_POWER_SAVE 649.It LIBUSB20_POWER_SUSPEND 650.It LIBUSB20_POWER_RESUME 651.El 652. 653This function returns zero on success else a LIBUSB20_ERROR value is 654returned. 655. 656.Pp 657. 658.Fn libusb20_dev_get_power_mode 659returns the currently selected power mode for the given 660USB device. 661. 662.Pp 663. 664.Fn libusb20_dev_set_alt_index 665will try to set the given alternate index for the given 666USB interface index. 667. 668This function returns zero on success else a LIBUSB20_ERROR value is 669returned. 670. 671.Pp 672. 673.Fn libusb20_dev_get_device_desc 674returns a pointer to the decoded and host endian version 675of the device descriptor. 676. 677The USB device need not be opened when calling this function. 678. 679.Pp 680. 681.Fn libusb20_dev_alloc_config 682will read out and decode the USB config descriptor for 683the given USB device and config index. This function returns a pointer 684to the decoded configuration which must eventually be passed to 685free(). NULL is returned in case of failure. 686. 687.Pp 688. 689.Fn libusb20_dev_alloc 690is an internal function to allocate a new USB device. 691. 692.Pp 693. 694.Fn libusb20_dev_get_address 695returns the internal and not necessarily the real 696hardware address of the given USB device. 697. 698.Pp 699. 700.Fn libusb20_dev_get_bus_number 701returns the internal bus number which the given USB 702device belongs to. 703. 704.Pp 705. 706.Fn libusb20_dev_get_mode 707returns the current operation mode of the USB entity. 708. 709Valid return values are: 710.Bl -tag 711.It LIBUSB20_MODE_HOST 712.It LIBUSB20_MODE_DEVICE 713.El 714. 715.Pp 716. 717.Fn libusb20_dev_get_speed 718returns the current speed of the given USB device. 719. 720.Bl -tag 721.It LIBUSB20_SPEED_UNKNOWN 722.It LIBUSB20_SPEED_LOW 723.It LIBUSB20_SPEED_FULL 724.It LIBUSB20_SPEED_HIGH 725.It LIBUSB20_SPEED_VARIABLE 726.It LIBUSB20_SPEED_SUPER 727.El 728. 729.Pp 730. 731.Fn libusb20_dev_get_config_index 732This function returns the currently select config index for the given 733USB device. 734. 735.Pp 736. 737.Fn libusb20_dev_free 738will free the given USB device and all associated USB 739transfers. 740. 741.Pp 742. 743.Fn libusb20_dev_set_debug 744will set the debug level for the given USB device. 745. 746.Pp 747. 748.Fn libusb20_dev_wait_process 749function will wait until a pending USB transfer has completed on 750the given USB device. 751. 752A timeout value can be specified which is passed on to the 753.Xr 2 poll 754function. 755. 756.Sh USB BACKEND OPERATIONS 757. 758.Fn libusb20_be_get_template 759will return the currently selected global USB device 760side mode template into the integer pointer 761.Fa ptemp . 762This function returns zero on success else a LIBUSB20_ERROR value is 763returned. 764. 765.Pp 766. 767.Fn libusb20_be_set_template 768will set the global USB device side mode template to 769.Fa temp . 770The new template is not activated until after the next USB 771enumeration. 772The template number decides how the USB device will present itself to 773the USB Host, like Mass Storage Device, USB Ethernet Device. Also see 774the 775.Xr usb2_template 4 776module. 777This function returns zero on success else a LIBUSB20_ERROR value is 778returned. 779. 780.Pp 781. 782.Fn libusb20_be_get_dev_quirk 783This function will return the device quirk according to 784.Fa index 785into the libusb20_quirk structure pointed to by 786.Fa pq . 787This function returns zero on success else a LIBUSB20_ERROR value is 788returned. 789. 790If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 791returned. 792. 793.Pp 794. 795.Fn libusb20_be_get_quirk_name 796will return the quirk name according to 797.Fa index 798into the libusb20_quirk structure pointed to by 799.Fa pq . 800This function returns zero on success else a LIBUSB20_ERROR value is 801returned. 802. 803If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 804returned. 805. 806.Pp 807. 808.Fn libusb20_be_add_dev_quirk 809will add the libusb20_quirk structure pointed to by the 810.Fa pq 811argument into the device quirk list. 812. 813This function returns zero on success else a LIBUSB20_ERROR value is 814returned. 815. 816If the given quirk cannot be added LIBUSB20_ERROR_NO_MEM is 817returned. 818. 819.Pp 820. 821.Fn libusb20_be_remove_dev_quirk 822will remove the quirk matching the libusb20_quirk structure pointed to by the 823.Fa pq 824argument from the device quirk list. 825. 826This function returns zero on success else a LIBUSB20_ERROR value is 827returned. 828. 829If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 830returned. 831. 832.Fn libusb20_be_alloc_linux 833These functions are used to allocate a specific USB backend or the 834operating system default USB backend. Allocating a backend is a way to 835scan for currently present USB devices. 836. 837.Pp 838. 839.Fn libusb20_be_device_foreach 840is used to iterate USB devices present in a USB backend. 841. 842The starting value of 843.Fa pdev 844is NULL. 845. 846This function returns the next USB device in the list. 847. 848If NULL is returned the end of the USB device list has been reached. 849. 850.Pp 851. 852.Fn libusb20_be_dequeue_device 853will dequeue the given USB device pointer from the 854backend USB device list. 855. 856Dequeued USB devices will not be freed when the backend is freed. 857. 858.Pp 859. 860.Fn libusb20_be_enqueue_device 861This function will enqueue the given USB device pointer in the backend USB device list. 862. 863Enqueued USB devices will get freed when the backend is freed. 864. 865.Pp 866. 867.Fn libusb20_be_free 868will free the given backend and all USB devices in its device list. 869. 870. 871.Sh USB DESCRIPTOR PARSING 872. 873.Fn libusb20_me_get_1 pie offset 874This function will return a byte at the given byte offset of a message 875entity. 876. 877This function is safe against invalid offsets. 878. 879.Pp 880. 881.Fn libusb20_me_get_2 pie offset 882This function will return a little endian 16-bit value at the given byte offset of a message 883entity. 884. 885This function is safe against invalid offsets. 886. 887.Pp 888. 889.Fn libusb20_me_encode pbuf len pdecoded 890This function will encode a so-called *DECODED structure into binary 891format. 892. 893The total encoded length that will fit in the given buffer is 894returned. 895. 896If the buffer pointer is NULL no data will be written to the buffer 897location. 898. 899.Pp 900. 901.Fn libusb20_me_decode pbuf len pdecoded 902This function will decode a binary structure into a so-called *DECODED 903structure. 904. 905The total decoded length is returned. 906. 907The buffer pointer cannot be NULL. 908. 909. 910.Sh LIBUSB VERSION 0.1 COMPATIBILITY 911. 912.Fn usb_open 913.Fn usb_close 914.Fn usb_get_string 915.Fn usb_get_string_simple 916.Fn usb_get_descriptor_by_endpoint 917.Fn usb_get_descriptor 918.Fn usb_parse_descriptor 919.Fn usb_parse_configuration 920.Fn usb_destroy_configuration 921.Fn usb_fetch_and_parse_descriptors 922.Fn usb_bulk_write 923.Fn usb_bulk_read 924.Fn usb_interrupt_write 925.Fn usb_interrupt_read 926.Fn usb_control_msg 927.Fn usb_set_configuration 928.Fn usb_claim_interface 929.Fn usb_release_interface 930.Fn usb_set_altinterface 931.Fn usb_resetep 932.Fn usb_clear_halt 933.Fn usb_reset 934.Fn usb_strerror 935.Fn usb_init 936.Fn usb_set_debug 937.Fn usb_find_busses 938.Fn usb_find_devices 939.Fn usb_device 940.Fn usb_get_busses 941These functions are compliant with LibUSB version 0.1.12. 942. 943.Sh FILES 944. 945. 946/dev/usb 947.Sh SEE ALSO 948.Xr usb2_core 4 , 949.Xr usbconfig 8 950. 951. 952.Sh HISTORY 953. 954. 955Some parts of the 956.Nm 957API derives from the libusb project at sourceforge. 958