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 May 28, 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 uint32_t 82.Fn libusb20_tr_get_length "struct libusb20_transfer *xfer" "uint16_t fr_index" 83.Ft void 84.Fn libusb20_tr_set_length "struct libusb20_transfer *xfer" "uint32_t length" "uint16_t fr_index" 85.Ft void 86.Fn libusb20_tr_set_priv_sc0 "struct libusb20_transfer *xfer" "void *sc0" 87.Ft void 88.Fn libusb20_tr_set_priv_sc1 "struct libusb20_transfer *xfer" "void *sc1" 89.Ft void 90.Fn libusb20_tr_set_timeout "struct libusb20_transfer *xfer" "uint32_t timeout" 91.Ft void 92.Fn libusb20_tr_set_total_frames "struct libusb20_transfer *xfer" "uint32_t nframes" 93.Ft void 94.Fn libusb20_tr_setup_bulk "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t timeout" 95.Ft void 96.Fn libusb20_tr_setup_control "struct libusb20_transfer *xfer" "void *psetup" "void *pbuf" "uint32_t timeout" 97.Ft void 98.Fn libusb20_tr_setup_intr "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t timeout" 99.Ft void 100.Fn libusb20_tr_setup_isoc "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint61_t fr_index" 101.Ft void 102.Fn libusb20_tr_start "struct libusb20_transfer *xfer" 103.Ft void 104.Fn libusb20_tr_stop "struct libusb20_transfer *xfer" 105.Ft void 106.Fn libusb20_tr_submit "struct libusb20_transfer *xfer" 107.Ft void * 108.Fn libusb20_tr_get_priv_sc0 "struct libusb20_transfer *xfer" 109.Ft void * 110.Fn libusb20_tr_get_priv_sc1 "struct libusb20_transfer *xfer" 111.Ft const char * 112.Fn libusb20_dev_get_backend_name "struct libusb20_device *" 113.Ft int 114.Fn libusb20_dev_get_info "struct libusb20_device *pdev" "struct usb_device_info *pinfo" 115.Ft int 116.Fn libusb20_dev_get_iface_desc "struct libusb20_device *pdev" "uint8_t iface_index" "char *buf" "uint8_t len" 117.Ft const char * 118.Fn libusb20_dev_get_desc "struct libusb20_device *pdev" 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_request_sync "struct libusb20_device *pdev" "struct LIBUSB20_CONTROL_SETUP_DECODED *setup" "void *data" "uint16_t *pactlen" "uint32_t timeout" "uint8_t flags" 137.Ft int 138.Fn libusb20_dev_req_string_sync "struct libusb20_device *pdev" "uint8_t index" "uint16_t langid" "void *ptr" "uint16_t len" 139.Ft int 140.Fn libusb20_dev_req_string_simple_sync "struct libusb20_device *pdev" "uint8_t index" "void *ptr" "uint16_t len" 141.Ft int 142.Fn libusb20_dev_reset "struct libusb20_device *pdev" 143.Ft int 144.Fn libusb20_dev_set_power_mode "struct libusb20_device *pdev" "uint8_t power_mode" 145.Ft uint8_t 146.Fn libusb20_dev_get_power_mode "struct libusb20_device *pdev" 147.Ft int 148.Fn libusb20_dev_set_alt_index "struct libusb20_device *pdev" "uint8_t iface_index" "uint8_t alt_index" 149.Ft struct LIBUSB20_DEVICE_DESC_DECODED * 150.Fn libusb20_dev_get_device_desc "struct libusb20_device *pdev" 151.Ft struct libusb20_config * 152.Fn libusb20_dev_alloc_config "struct libusb20_device *pdev" "uint8_t config_index" 153.Ft struct libusb20_device * 154.Fn libusb20_dev_alloc "void" 155.Ft uint8_t 156.Fn libusb20_dev_get_address "struct libusb20_device *pdev" 157.Ft uint8_t 158.Fn libusb20_dev_get_bus_number "struct libusb20_device *pdev" 159.Ft uint8_t 160.Fn libusb20_dev_get_mode "struct libusb20_device *pdev" 161.Ft uint8_t 162.Fn libusb20_dev_get_speed "struct libusb20_device *pdev" 163.Ft uint8_t 164.Fn libusb20_dev_get_config_index "struct libusb20_device *pdev" 165.Ft void 166.Fn libusb20_dev_free "struct libusb20_device *pdev" 167.Ft void 168.Fn libusb20_dev_set_debug "struct libusb20_device *pdev" "int debug" 169.Ft void 170.Fn libusb20_dev_wait_process "struct libusb20_device *pdev" "int timeout" 171.Ft int 172.Fn libusb20_be_get_template "struct libusb20_backend *pbe" "int *ptemp" 173.Ft int 174.Fn libusb20_be_set_template "struct libusb20_backend *pbe" "int temp" 175.Ft int 176.Fn libusb20_be_get_dev_quirk "struct libusb20_backend *pber", "uint16_t index" "struct libusb20_quirk *pq" 177.Ft int 178.Fn libusb20_be_get_quirk_name "struct libusb20_backend *pbe" "uint16_t index" "struct libusb20_quirk *pq" 179.Ft int 180.Fn libusb20_be_add_dev_quirk "struct libusb20_backend *pbe" "struct libusb20_quirk *pq" 181.Ft int 182.Fn libusb20_be_remove_dev_quirk "struct libusb20_backend *pbe" "struct libusb20_quirk *pq" 183.Ft struct libusb20_backend * 184.Fn libusb20_be_alloc_default "void" 185.Ft struct libusb20_backend * 186.Fn libusb20_be_alloc_freebsd "void" 187.Ft struct libusb20_backend * 188.Fn libusb20_be_alloc_linux "void" 189.Ft struct libusb20_device * 190.Fn libusb20_be_device_foreach "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 191.Ft void 192.Fn libusb20_be_dequeue_device "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 193.Ft void 194.Fn libusb20_be_enqueue_device "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 195.Ft void 196.Fn libusb20_be_free "struct libusb20_backend *pbe" 197.Ft uint8_t 198.Fn libusb20_me_get_1 "const struct libusb20_me_struct *me" "uint16_t off" 199.Ft uint16_t 200.Fn libusb20_me_get_2 "const struct libusb20_me_struct *me" "uint16_t off" 201.Ft uint16_t 202.Fn libusb20_me_encode "void *pdata" "uint16_t len" "const void *pdecoded" 203.Ft uint16_t 204.Fn libusb20_me_decode "const void *pdata" "uint16_t len" "void *pdecoded" 205.Ft "const uint8_t *" 206.Fn libusb20_desc_foreach "const struct libusb20_me_struct *me" "const uint8_t *pdesc" 207. 208. 209.Sh DESCRIPTION 210. 211The 212.Nm 213library implements functions to be able to easily access and control 214USB through the USB file system interface. 215. 216. 217.Sh USB TRANSFER OPERATIONS 218. 219.Pp 220. 221.Fn libusb20_tr_close 222will release all kernel resources associated with an USB 223.Fa xfer . 224. 225This function returns zero upon success. 226. 227Non-zero return values indicate a LIBUSB20_ERROR value. 228. 229.Pp 230. 231.Fn libusb20_tr_open 232will allocate kernel buffer resources according to 233.Fa max_buf_size 234and 235.Fa max_frame_count 236associated with an USB 237.Fa pxfer 238and bind the transfer to the specified 239.Fa ep_no . 240.Fa max_buf_size 241is the minimum buffer size which the data transport layer has to support. 242If 243.Fa max_buf_size 244is zero, the 245.Nm 246library will use wMaxPacketSize to compute the buffer size. 247This can be useful for isochronous transfers. 248The actual buffer size can be greater than 249.Fa max_buf_size 250and is returned by 251.Fn libusb20_tr_get_max_total_length . 252. 253This function returns zero upon success. 254. 255Non-zero return values indicate a LIBUSB20_ERROR value. 256. 257.Pp 258. 259.Fn libusb20_tr_get_pointer 260will return a pointer to the allocated USB transfer according to the 261.Fa pdev 262and 263.Fa tr_index 264arguments. 265. 266This function returns NULL in case of failure. 267. 268.Pp 269. 270.Fn libusb20_tr_get_time_complete 271will return the completion time of an USB transfer in 272millisecond units. This function is most useful for isochronous USB 273transfers when doing echo cancelling. 274. 275.Pp 276. 277.Fn libusb20_tr_get_actual_frames 278will return the actual number of USB frames after an USB 279transfer completed. A value of zero means that no data was transferred. 280. 281.Pp 282. 283.Fn libusb20_tr_get_actual_length 284will return the sum of the actual length for all 285transferred USB frames for the given USB transfer. 286. 287.Pp 288. 289.Fn libusb20_tr_get_max_frames 290will return the maximum number of USB frames that were 291allocated when an USB transfer was setup for the given USB transfer. 292. 293.Pp 294. 295.Fn libusb20_tr_get_max_packet_length 296will return the maximum packet length in bytes 297associated with the given USB transfer. 298. 299The packet length can be used round up buffer sizes so that short USB 300packets are avoided for proxy buffers. 301. 302. 303.Pp 304. 305.Fn libusb20_tr_get_max_total_length 306function will return the maximum value for the length sum of all 307USB frames associated with an USB transfer. 308. 309.Pp 310. 311.Fn libusb20_tr_get_status 312will return the status of an USB transfer. 313. 314Status values are defined by a set of LIBUSB20_TRANSFER_XXX enums. 315. 316.Pp 317. 318.Fn libusb20_tr_pending 319will return non-zero if the given USB transfer is 320pending for completion. 321. 322Else this function returns zero. 323. 324.Pp 325. 326.Fn libusb20_tr_callback_wrapper 327This is an internal function used to wrap asynchronous USB callbacks. 328. 329.Pp 330. 331.Fn libusb20_tr_clear_stall_sync 332This is an internal function used to synchronously clear the stall on 333the given USB transfer. 334. 335Please see the USB specification for more information on stall 336clearing. 337. 338If the given USB transfer is pending when this function is called, the 339USB transfer will complete with an error after that this function has 340been called. 341. 342.Pp 343. 344.Fn libusb20_tr_drain 345will stop the given USB transfer and will not return 346until the USB transfer has been stopped in hardware. 347. 348.Pp 349. 350.Fn libusb20_tr_set_buffer 351is used to set the 352.Fa buffer 353pointer for the given USB transfer and 354.Fa fr_index . 355. 356Typically the frame index is zero. 357. 358. 359.Pp 360. 361.Fn libusb20_tr_set_callback 362is used to set the USB callback for asynchronous USB 363transfers. 364. 365The callback type is defined by libusb20_tr_callback_t. 366. 367.Pp 368. 369.Fn libusb20_tr_set_flags 370is used to set various USB flags for the given USB transfer. 371.Bl -tag 372.It LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK 373Report a short frame as error. 374.It LIBUSB20_TRANSFER_MULTI_SHORT_NOT_OK 375Multiple short frames are not allowed. 376.It LIBUSB20_TRANSFER_FORCE_SHORT 377All transmitted frames are short terminated. 378.It LIBUSB20_TRANSFER_DO_CLEAR_STALL 379Will do a clear-stall before starting the transfer. 380.El 381. 382.Pp 383. 384.Fn libusb20_tr_get_length 385returns the length of the given USB frame by index. 386After an USB transfer is complete the USB frame length will get updated to the actual transferred length. 387. 388.Pp 389. 390.Fn libusb20_tr_set_length 391sets the length of the given USB frame by index. 392. 393.Pp 394. 395.Fn libusb20_tr_set_priv_sc0 396sets private driver pointer number zero. 397. 398.Pp 399. 400.Fn libusb20_tr_set_priv_sc1 401sets private driver pointer number one. 402. 403.Pp 404. 405.Fn libusb20_tr_set_timeout 406sets the timeout for the given USB transfer. 407. 408A timeout value of zero means no timeout. 409. 410The timeout is given in milliseconds. 411. 412.Pp 413. 414.Fn libusb20_tr_set_total_frames 415sets the total number of frames that should be executed when the USB transfer is submitted. 416. 417The total number of USB frames must be less than the maximum number of USB frames associated with the given USB transfer. 418. 419.Pp 420. 421.Fn libusb20_tr_setup_bulk 422is a helper function for setting up a single frame USB BULK transfer. 423. 424.Pp 425. 426.Fn libusb20_tr_setup_control 427is a helper function for setting up a single or dual 428frame USB CONTROL transfer depending on the control transfer length. 429. 430.Pp 431. 432.Fn libusb20_tr_setup_intr 433is a helper function for setting up a single frame USB INTERRUPT transfer. 434. 435.Pp 436. 437.Fn libusb20_tr_setup_isoc 438is a helper function for setting up a multi frame USB ISOCHRONOUS transfer. 439. 440.Pp 441. 442.Fn libusb20_tr_start 443will get the USB transfer started, if not already 444started. 445. 446This function will not get the transfer queued in hardware. 447. 448This function is non-blocking. 449. 450.Pp 451. 452.Fn libusb20_tr_stop 453will get the USB transfer stopped, if not already stopped. 454. 455This function is non-blocking, which means that the actual stop can 456happen after the return of this function. 457. 458.Pp 459. 460.Fn libusb20_tr_submit 461will get the USB transfer queued in hardware. 462. 463. 464.Pp 465. 466.Fn libusb20_tr_get_priv_sc0 467returns private driver pointer number zero associated 468with an USB transfer. 469. 470. 471.Pp 472. 473.Fn libusb20_tr_get_priv_sc1 474returns private driver pointer number one associated 475with an USB transfer. 476. 477. 478.Sh USB DEVICE OPERATIONS 479. 480.Pp 481. 482.Fn libusb20_dev_get_backend_name 483returns a zero terminated string describing the backend used. 484. 485.Pp 486. 487.Fn libusb20_dev_get_info 488retrives the BSD specific usb_device_info structure into the memory location given by 489.Fa pinfo . 490The USB device given by 491.Fa pdev 492must be opened before this function will succeed. 493This function returns zero on success else a LIBUSB20_ERROR value is returned. 494. 495.Pp 496. 497.Fn libusb20_dev_get_iface_desc 498retrieves the kernel interface description for the given USB 499.Fa iface_index . 500The format of the USB interface description is: "drivername<unit>: <description>" 501The description string is always zero terminated. 502A zero length string is written in case no driver is attached to the given interface. 503The USB device given by 504.Fa pdev 505must be opened before this function will succeed. 506This function returns zero on success else a LIBUSB20_ERROR value is returned. 507. 508.Pp 509. 510.Fn libusb20_dev_get_desc 511returns a zero terminated string describing the given USB device. 512The format of the string is: "drivername<unit>: <description>" 513. 514.Pp 515. 516.Fn libusb20_dev_close 517will close the given USB device. 518. 519This function returns zero on success else a LIBUSB20_ERROR value is 520returned. 521. 522.Pp 523. 524.Fn libusb20_dev_detach_kernel_driver 525will try to detach the kernel driver for the USB interface given by 526.Fa iface_index . 527. 528This function returns zero on success else a LIBUSB20_ERROR value is 529returned. 530. 531.Pp 532. 533.Fn libusb20_dev_set_config_index 534will try to set the configuration index on an USB 535device. 536. 537The first configuration index is zero. 538. 539The un-configure index is 255. 540. 541This function returns zero on success else a LIBUSB20_ERROR value is returned. 542. 543.Pp 544. 545.Fn libusb20_dev_get_debug 546returns the debug level of an USB device. 547. 548.Pp 549. 550.Fn libusb20_dev_get_fd 551returns the file descriptor of the given USB device. 552. 553A negative value is returned when no file descriptor is present. 554. 555The file descriptor can be used for polling purposes. 556. 557.Pp 558. 559.Fn libusb20_dev_kernel_driver_active 560returns a non-zero value if a kernel driver is active on 561the given USB interface. 562. 563Else zero is returned. 564. 565.Pp 566. 567.Fn libusb20_dev_open 568opens an USB device so that setting up USB transfers 569becomes possible. 570. 571The number of USB transfers can be zero which means only control 572transfers are allowed. 573. 574This function returns zero on success else a LIBUSB20_ERROR value is 575returned. 576. 577A return value of LIBUSB20_ERROR_BUSY means that the device is already 578opened. 579. 580.Pp 581. 582.Fn libusb20_dev_process 583is called to sync kernel USB transfers with userland USB 584transfers. 585. 586This function returns zero on success else a LIBUSB20_ERROR value is 587returned typically indicating that the given USB device has been 588detached. 589. 590.Pp 591. 592.Fn libusb20_dev_request_sync 593will perform a synchronous control request on the given 594USB device. 595. 596Before this call will succeed the USB device must be opened. 597. 598.Fa setup 599is a pointer to a decoded and host endian SETUP packet. 600.Fa data 601is a pointer to a data transfer buffer associated with the control transaction. This argument can be NULL. 602.Fa pactlen 603is a pointer to a variable that will hold the actual transfer length after the control transaction is complete. 604.Fa timeout 605is the transaction timeout given in milliseconds. 606A timeout of zero means no timeout. 607.Fa flags 608is used to specify transaction flags, for example LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK. 609. 610This function returns zero on success else a LIBUSB20_ERROR value is 611returned. 612. 613.Pp 614. 615.Fn libusb20_dev_req_string_sync 616will synchronously request an USB string by language ID 617and string index into the given buffer limited by a maximum length. 618. 619This function returns zero on success else a LIBUSB20_ERROR value is 620returned. 621. 622.Pp 623. 624.Fn libusb20_dev_req_string_simple_sync 625will synchronously request an USB string using the 626default language ID and convert the string into ASCII before storing 627the string into the given buffer limited by a maximum length which 628includes the terminating zero. 629. 630This function returns zero on success else a LIBUSB20_ERROR value is 631returned. 632. 633. 634.Pp 635. 636.Fn libusb20_dev_reset 637will try to BUS reset the given USB device and restore 638the last set USB configuration. 639. 640This function returns zero on success else a LIBUSB20_ERROR value is 641returned. 642. 643.Pp 644. 645.Fn libusb20_dev_set_power_mode 646sets the power mode of the USB device. 647. 648Valid power modes: 649.Bl -tag 650.It LIBUSB20_POWER_OFF 651.It LIBUSB20_POWER_ON 652.It LIBUSB20_POWER_SAVE 653.It LIBUSB20_POWER_SUSPEND 654.It LIBUSB20_POWER_RESUME 655.El 656. 657This function returns zero on success else a LIBUSB20_ERROR value is 658returned. 659. 660.Pp 661. 662.Fn libusb20_dev_get_power_mode 663returns the currently selected power mode for the given 664USB device. 665. 666.Pp 667. 668.Fn libusb20_dev_set_alt_index 669will try to set the given alternate index for the given 670USB interface index. 671. 672This function returns zero on success else a LIBUSB20_ERROR value is 673returned. 674. 675.Pp 676. 677.Fn libusb20_dev_get_device_desc 678returns a pointer to the decoded and host endian version 679of the device descriptor. 680. 681The USB device need not be opened when calling this function. 682. 683.Pp 684. 685.Fn libusb20_dev_alloc_config 686will read out and decode the USB config descriptor for 687the given USB device and config index. This function returns a pointer 688to the decoded configuration which must eventually be passed to 689free(). NULL is returned in case of failure. 690. 691.Pp 692. 693.Fn libusb20_dev_alloc 694is an internal function to allocate a new USB device. 695. 696.Pp 697. 698.Fn libusb20_dev_get_address 699returns the internal and not necessarily the real 700hardware address of the given USB device. 701. 702.Pp 703. 704.Fn libusb20_dev_get_bus_number 705returns the internal bus number which the given USB 706device belongs to. 707. 708.Pp 709. 710.Fn libusb20_dev_get_mode 711returns the current operation mode of the USB entity. 712. 713Valid return values are: 714.Bl -tag 715.It LIBUSB20_MODE_HOST 716.It LIBUSB20_MODE_DEVICE 717.El 718. 719.Pp 720. 721.Fn libusb20_dev_get_speed 722returns the current speed of the given USB device. 723. 724.Bl -tag 725.It LIBUSB20_SPEED_UNKNOWN 726.It LIBUSB20_SPEED_LOW 727.It LIBUSB20_SPEED_FULL 728.It LIBUSB20_SPEED_HIGH 729.It LIBUSB20_SPEED_VARIABLE 730.It LIBUSB20_SPEED_SUPER 731.El 732. 733.Pp 734. 735.Fn libusb20_dev_get_config_index 736This function returns the currently select config index for the given 737USB device. 738. 739.Pp 740. 741.Fn libusb20_dev_free 742will free the given USB device and all associated USB 743transfers. 744. 745.Pp 746. 747.Fn libusb20_dev_set_debug 748will set the debug level for the given USB device. 749. 750.Pp 751. 752.Fn libusb20_dev_wait_process 753function will wait until a pending USB transfer has completed on 754the given USB device. 755. 756A timeout value can be specified which is passed on to the 757.Xr poll 2 758function. 759. 760.Sh USB BACKEND OPERATIONS 761. 762.Fn libusb20_be_get_template 763will return the currently selected global USB device 764side mode template into the integer pointer 765.Fa ptemp . 766This function returns zero on success else a LIBUSB20_ERROR value is 767returned. 768. 769.Pp 770. 771.Fn libusb20_be_set_template 772will set the global USB device side mode template to 773.Fa temp . 774The new template is not activated until after the next USB 775enumeration. 776The template number decides how the USB device will present itself to 777the USB Host, like Mass Storage Device, USB Ethernet Device. Also see 778the 779.Xr usb2_template 4 780module. 781This function returns zero on success else a LIBUSB20_ERROR value is 782returned. 783. 784.Pp 785. 786.Fn libusb20_be_get_dev_quirk 787This function will return the device quirk according to 788.Fa index 789into the libusb20_quirk structure pointed to by 790.Fa pq . 791This function returns zero on success else a LIBUSB20_ERROR value is 792returned. 793. 794If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 795returned. 796. 797.Pp 798. 799.Fn libusb20_be_get_quirk_name 800will return the quirk name according to 801.Fa index 802into the libusb20_quirk structure pointed to by 803.Fa pq . 804This function returns zero on success else a LIBUSB20_ERROR value is 805returned. 806. 807If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 808returned. 809. 810.Pp 811. 812.Fn libusb20_be_add_dev_quirk 813will add the libusb20_quirk structure pointed to by the 814.Fa pq 815argument into the device quirk list. 816. 817This function returns zero on success else a LIBUSB20_ERROR value is 818returned. 819. 820If the given quirk cannot be added LIBUSB20_ERROR_NO_MEM is 821returned. 822. 823.Pp 824. 825.Fn libusb20_be_remove_dev_quirk 826will remove the quirk matching the libusb20_quirk structure pointed to by the 827.Fa pq 828argument from the device quirk list. 829. 830This function returns zero on success else a LIBUSB20_ERROR value is 831returned. 832. 833If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 834returned. 835. 836.Pp 837. 838.Fn libusb20_be_alloc_default 839.Fn libusb20_be_alloc_freebsd 840.Fn libusb20_be_alloc_linux 841These functions are used to allocate a specific USB backend or the 842operating system default USB backend. Allocating a backend is a way to 843scan for currently present USB devices. 844. 845.Pp 846. 847.Fn libusb20_be_device_foreach 848is used to iterate USB devices present in a USB backend. 849. 850The starting value of 851.Fa pdev 852is NULL. 853. 854This function returns the next USB device in the list. 855. 856If NULL is returned the end of the USB device list has been reached. 857. 858.Pp 859. 860.Fn libusb20_be_dequeue_device 861will dequeue the given USB device pointer from the 862backend USB device list. 863. 864Dequeued USB devices will not be freed when the backend is freed. 865. 866.Pp 867. 868.Fn libusb20_be_enqueue_device 869This function will enqueue the given USB device pointer in the backend USB device list. 870. 871Enqueued USB devices will get freed when the backend is freed. 872. 873.Pp 874. 875.Fn libusb20_be_free 876will free the given backend and all USB devices in its device list. 877. 878. 879.Sh USB DESCRIPTOR PARSING 880. 881.Fn libusb20_me_get_1 pie offset 882This function will return a byte 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_get_2 pie offset 890This function will return a little endian 16-bit value at the given byte offset of a message 891entity. 892. 893This function is safe against invalid offsets. 894. 895.Pp 896. 897.Fn libusb20_me_encode pbuf len pdecoded 898This function will encode a so-called *DECODED structure into binary 899format. 900. 901The total encoded length that will fit in the given buffer is 902returned. 903. 904If the buffer pointer is NULL no data will be written to the buffer 905location. 906. 907.Pp 908. 909.Fn libusb20_me_decode pbuf len pdecoded 910This function will decode a binary structure into a so-called *DECODED 911structure. 912. 913The total decoded length is returned. 914. 915The buffer pointer cannot be NULL. 916. 917. 918.Sh LIBUSB VERSION 0.1 COMPATIBILITY 919. 920.Fn usb_open 921.Fn usb_close 922.Fn usb_get_string 923.Fn usb_get_string_simple 924.Fn usb_get_descriptor_by_endpoint 925.Fn usb_get_descriptor 926.Fn usb_parse_descriptor 927.Fn usb_parse_configuration 928.Fn usb_destroy_configuration 929.Fn usb_fetch_and_parse_descriptors 930.Fn usb_bulk_write 931.Fn usb_bulk_read 932.Fn usb_interrupt_write 933.Fn usb_interrupt_read 934.Fn usb_control_msg 935.Fn usb_set_configuration 936.Fn usb_claim_interface 937.Fn usb_release_interface 938.Fn usb_set_altinterface 939.Fn usb_resetep 940.Fn usb_clear_halt 941.Fn usb_reset 942.Fn usb_strerror 943.Fn usb_init 944.Fn usb_set_debug 945.Fn usb_find_busses 946.Fn usb_find_devices 947.Fn usb_device 948.Fn usb_get_busses 949These functions are compliant with LibUSB version 0.1.12. 950. 951.Sh FILES 952. 953. 954/dev/usb 955.Sh SEE ALSO 956.Xr usb 4 , 957.Xr usbconfig 8 958. 959. 960.Sh HISTORY 961. 962. 963Some parts of the 964.Nm 965API derives from the libusb project at sourceforge. 966