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 June 22, 2009 30.Dt LIBUSB20 3 31.Os 32.Sh NAME 33.Nm libusb20 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. 215The 216.Nm 217interfaces are specific to the 218.Fx 219usb stack and are not available on other operating systems, portable 220applications should consider using 221.Xr libusb 3 . 222. 223. 224.Sh USB TRANSFER OPERATIONS 225. 226.Pp 227. 228.Fn libusb20_tr_close 229will release all kernel resources associated with an USB 230.Fa xfer . 231. 232This function returns zero upon success. 233. 234Non-zero return values indicate a LIBUSB20_ERROR value. 235. 236.Pp 237. 238.Fn libusb20_tr_open 239will allocate kernel buffer resources according to 240.Fa max_buf_size 241and 242.Fa max_frame_count 243associated with an USB 244.Fa pxfer 245and bind the transfer to the specified 246.Fa ep_no . 247.Fa max_buf_size 248is the minimum buffer size which the data transport layer has to support. 249If 250.Fa max_buf_size 251is zero, the 252.Nm 253library will use wMaxPacketSize to compute the buffer size. 254This can be useful for isochronous transfers. 255The actual buffer size can be greater than 256.Fa max_buf_size 257and is returned by 258.Fn libusb20_tr_get_max_total_length . 259. 260This function returns zero upon success. 261. 262Non-zero return values indicate a LIBUSB20_ERROR value. 263. 264.Pp 265. 266.Fn libusb20_tr_get_pointer 267will return a pointer to the allocated USB transfer according to the 268.Fa pdev 269and 270.Fa tr_index 271arguments. 272. 273This function returns NULL in case of failure. 274. 275.Pp 276. 277.Fn libusb20_tr_get_time_complete 278will return the completion time of an USB transfer in 279millisecond units. This function is most useful for isochronous USB 280transfers when doing echo cancelling. 281. 282.Pp 283. 284.Fn libusb20_tr_get_actual_frames 285will return the actual number of USB frames after an USB 286transfer completed. A value of zero means that no data was transferred. 287. 288.Pp 289. 290.Fn libusb20_tr_get_actual_length 291will return the sum of the actual length for all 292transferred USB frames for the given USB transfer. 293. 294.Pp 295. 296.Fn libusb20_tr_get_max_frames 297will return the maximum number of USB frames that were 298allocated when an USB transfer was setup for the given USB transfer. 299. 300.Pp 301. 302.Fn libusb20_tr_get_max_packet_length 303will return the maximum packet length in bytes 304associated with the given USB transfer. 305. 306The packet length can be used round up buffer sizes so that short USB 307packets are avoided for proxy buffers. 308. 309. 310.Pp 311. 312.Fn libusb20_tr_get_max_total_length 313function will return the maximum value for the length sum of all 314USB frames associated with an USB transfer. 315. 316.Pp 317. 318.Fn libusb20_tr_get_status 319will return the status of an USB transfer. 320. 321Status values are defined by a set of LIBUSB20_TRANSFER_XXX enums. 322. 323.Pp 324. 325.Fn libusb20_tr_pending 326will return non-zero if the given USB transfer is 327pending for completion. 328. 329Else this function returns zero. 330. 331.Pp 332. 333.Fn libusb20_tr_callback_wrapper 334This is an internal function used to wrap asynchronous USB callbacks. 335. 336.Pp 337. 338.Fn libusb20_tr_clear_stall_sync 339This is an internal function used to synchronously clear the stall on 340the given USB transfer. 341. 342Please see the USB specification for more information on stall 343clearing. 344. 345If the given USB transfer is pending when this function is called, the 346USB transfer will complete with an error after that this function has 347been called. 348. 349.Pp 350. 351.Fn libusb20_tr_drain 352will stop the given USB transfer and will not return 353until the USB transfer has been stopped in hardware. 354. 355.Pp 356. 357.Fn libusb20_tr_set_buffer 358is used to set the 359.Fa buffer 360pointer for the given USB transfer and 361.Fa fr_index . 362. 363Typically the frame index is zero. 364. 365. 366.Pp 367. 368.Fn libusb20_tr_set_callback 369is used to set the USB callback for asynchronous USB 370transfers. 371. 372The callback type is defined by libusb20_tr_callback_t. 373. 374.Pp 375. 376.Fn libusb20_tr_set_flags 377is used to set various USB flags for the given USB transfer. 378.Bl -tag 379.It LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK 380Report a short frame as error. 381.It LIBUSB20_TRANSFER_MULTI_SHORT_NOT_OK 382Multiple short frames are not allowed. 383.It LIBUSB20_TRANSFER_FORCE_SHORT 384All transmitted frames are short terminated. 385.It LIBUSB20_TRANSFER_DO_CLEAR_STALL 386Will do a clear-stall before starting the transfer. 387.El 388. 389.Pp 390. 391.Fn libusb20_tr_get_length 392returns the length of the given USB frame by index. 393After an USB transfer is complete the USB frame length will get updated to the actual transferred length. 394. 395.Pp 396. 397.Fn libusb20_tr_set_length 398sets the length of the given USB frame by index. 399. 400.Pp 401. 402.Fn libusb20_tr_set_priv_sc0 403sets private driver pointer number zero. 404. 405.Pp 406. 407.Fn libusb20_tr_set_priv_sc1 408sets private driver pointer number one. 409. 410.Pp 411. 412.Fn libusb20_tr_set_timeout 413sets the timeout for the given USB transfer. 414. 415A timeout value of zero means no timeout. 416. 417The timeout is given in milliseconds. 418. 419.Pp 420. 421.Fn libusb20_tr_set_total_frames 422sets the total number of frames that should be executed when the USB transfer is submitted. 423. 424The total number of USB frames must be less than the maximum number of USB frames associated with the given USB transfer. 425. 426.Pp 427. 428.Fn libusb20_tr_setup_bulk 429is a helper function for setting up a single frame USB BULK transfer. 430. 431.Pp 432. 433.Fn libusb20_tr_setup_control 434is a helper function for setting up a single or dual 435frame USB CONTROL transfer depending on the control transfer length. 436. 437.Pp 438. 439.Fn libusb20_tr_setup_intr 440is a helper function for setting up a single frame USB INTERRUPT transfer. 441. 442.Pp 443. 444.Fn libusb20_tr_setup_isoc 445is a helper function for setting up a multi frame USB ISOCHRONOUS transfer. 446. 447.Pp 448. 449.Fn libusb20_tr_start 450will get the USB transfer started, if not already 451started. 452. 453This function will not get the transfer queued in hardware. 454. 455This function is non-blocking. 456. 457.Pp 458. 459.Fn libusb20_tr_stop 460will get the USB transfer stopped, if not already stopped. 461. 462This function is non-blocking, which means that the actual stop can 463happen after the return of this function. 464. 465.Pp 466. 467.Fn libusb20_tr_submit 468will get the USB transfer queued in hardware. 469. 470. 471.Pp 472. 473.Fn libusb20_tr_get_priv_sc0 474returns private driver pointer number zero associated 475with an USB transfer. 476. 477. 478.Pp 479. 480.Fn libusb20_tr_get_priv_sc1 481returns private driver pointer number one associated 482with an USB transfer. 483. 484. 485.Sh USB DEVICE OPERATIONS 486. 487.Pp 488. 489.Fn libusb20_dev_get_backend_name 490returns a zero terminated string describing the backend used. 491. 492.Pp 493. 494.Fn libusb20_dev_get_info 495retrives the BSD specific usb_device_info structure into the memory location given by 496.Fa pinfo . 497The USB device given by 498.Fa pdev 499must be opened before this function will succeed. 500This function returns zero on success else a LIBUSB20_ERROR value is returned. 501. 502.Pp 503. 504.Fn libusb20_dev_get_iface_desc 505retrieves the kernel interface description for the given USB 506.Fa iface_index . 507The format of the USB interface description is: "drivername<unit>: <description>" 508The description string is always zero terminated. 509A zero length string is written in case no driver is attached to the given interface. 510The USB device given by 511.Fa pdev 512must be opened before this function will succeed. 513This function returns zero on success else a LIBUSB20_ERROR value is returned. 514. 515.Pp 516. 517.Fn libusb20_dev_get_desc 518returns a zero terminated string describing the given USB device. 519The format of the string is: "drivername<unit>: <description>" 520. 521.Pp 522. 523.Fn libusb20_dev_close 524will close the given USB device. 525. 526This function returns zero on success else a LIBUSB20_ERROR value is 527returned. 528. 529.Pp 530. 531.Fn libusb20_dev_detach_kernel_driver 532will try to detach the kernel driver for the USB interface given by 533.Fa iface_index . 534. 535This function returns zero on success else a LIBUSB20_ERROR value is 536returned. 537. 538.Pp 539. 540.Fn libusb20_dev_set_config_index 541will try to set the configuration index on an USB 542device. 543. 544The first configuration index is zero. 545. 546The un-configure index is 255. 547. 548This function returns zero on success else a LIBUSB20_ERROR value is returned. 549. 550.Pp 551. 552.Fn libusb20_dev_get_debug 553returns the debug level of an USB device. 554. 555.Pp 556. 557.Fn libusb20_dev_get_fd 558returns the file descriptor of the given USB device. 559. 560A negative value is returned when no file descriptor is present. 561. 562The file descriptor can be used for polling purposes. 563. 564.Pp 565. 566.Fn libusb20_dev_kernel_driver_active 567returns a non-zero value if a kernel driver is active on 568the given USB interface. 569. 570Else zero is returned. 571. 572.Pp 573. 574.Fn libusb20_dev_open 575opens an USB device so that setting up USB transfers 576becomes possible. 577. 578The number of USB transfers can be zero which means only control 579transfers are allowed. 580. 581This function returns zero on success else a LIBUSB20_ERROR value is 582returned. 583. 584A return value of LIBUSB20_ERROR_BUSY means that the device is already 585opened. 586. 587.Pp 588. 589.Fn libusb20_dev_process 590is called to sync kernel USB transfers with userland USB 591transfers. 592. 593This function returns zero on success else a LIBUSB20_ERROR value is 594returned typically indicating that the given USB device has been 595detached. 596. 597.Pp 598. 599.Fn libusb20_dev_request_sync 600will perform a synchronous control request on the given 601USB device. 602. 603Before this call will succeed the USB device must be opened. 604. 605.Fa setup 606is a pointer to a decoded and host endian SETUP packet. 607.Fa data 608is a pointer to a data transfer buffer associated with the control transaction. This argument can be NULL. 609.Fa pactlen 610is a pointer to a variable that will hold the actual transfer length after the control transaction is complete. 611.Fa timeout 612is the transaction timeout given in milliseconds. 613A timeout of zero means no timeout. 614.Fa flags 615is used to specify transaction flags, for example LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK. 616. 617This function returns zero on success else a LIBUSB20_ERROR value is 618returned. 619. 620.Pp 621. 622.Fn libusb20_dev_req_string_sync 623will synchronously request an USB string by language ID 624and string index into the given buffer limited by a maximum length. 625. 626This function returns zero on success else a LIBUSB20_ERROR value is 627returned. 628. 629.Pp 630. 631.Fn libusb20_dev_req_string_simple_sync 632will synchronously request an USB string using the 633default language ID and convert the string into ASCII before storing 634the string into the given buffer limited by a maximum length which 635includes the terminating zero. 636. 637This function returns zero on success else a LIBUSB20_ERROR value is 638returned. 639. 640. 641.Pp 642. 643.Fn libusb20_dev_reset 644will try to BUS reset the given USB device and restore 645the last set USB configuration. 646. 647This function returns zero on success else a LIBUSB20_ERROR value is 648returned. 649. 650.Pp 651. 652.Fn libusb20_dev_set_power_mode 653sets the power mode of the USB device. 654. 655Valid power modes: 656.Bl -tag 657.It LIBUSB20_POWER_OFF 658.It LIBUSB20_POWER_ON 659.It LIBUSB20_POWER_SAVE 660.It LIBUSB20_POWER_SUSPEND 661.It LIBUSB20_POWER_RESUME 662.El 663. 664This function returns zero on success else a LIBUSB20_ERROR value is 665returned. 666. 667.Pp 668. 669.Fn libusb20_dev_get_power_mode 670returns the currently selected power mode for the given 671USB device. 672. 673.Pp 674. 675.Fn libusb20_dev_set_alt_index 676will try to set the given alternate index for the given 677USB interface index. 678. 679This function returns zero on success else a LIBUSB20_ERROR value is 680returned. 681. 682.Pp 683. 684.Fn libusb20_dev_get_device_desc 685returns a pointer to the decoded and host endian version 686of the device descriptor. 687. 688The USB device need not be opened when calling this function. 689. 690.Pp 691. 692.Fn libusb20_dev_alloc_config 693will read out and decode the USB config descriptor for 694the given USB device and config index. This function returns a pointer 695to the decoded configuration which must eventually be passed to 696free(). NULL is returned in case of failure. 697. 698.Pp 699. 700.Fn libusb20_dev_alloc 701is an internal function to allocate a new USB device. 702. 703.Pp 704. 705.Fn libusb20_dev_get_address 706returns the internal and not necessarily the real 707hardware address of the given USB device. 708. 709.Pp 710. 711.Fn libusb20_dev_get_bus_number 712returns the internal bus number which the given USB 713device belongs to. 714. 715.Pp 716. 717.Fn libusb20_dev_get_mode 718returns the current operation mode of the USB entity. 719. 720Valid return values are: 721.Bl -tag 722.It LIBUSB20_MODE_HOST 723.It LIBUSB20_MODE_DEVICE 724.El 725. 726.Pp 727. 728.Fn libusb20_dev_get_speed 729returns the current speed of the given USB device. 730. 731.Bl -tag 732.It LIBUSB20_SPEED_UNKNOWN 733.It LIBUSB20_SPEED_LOW 734.It LIBUSB20_SPEED_FULL 735.It LIBUSB20_SPEED_HIGH 736.It LIBUSB20_SPEED_VARIABLE 737.It LIBUSB20_SPEED_SUPER 738.El 739. 740.Pp 741. 742.Fn libusb20_dev_get_config_index 743This function returns the currently select config index for the given 744USB device. 745. 746.Pp 747. 748.Fn libusb20_dev_free 749will free the given USB device and all associated USB 750transfers. 751. 752.Pp 753. 754.Fn libusb20_dev_set_debug 755will set the debug level for the given USB device. 756. 757.Pp 758. 759.Fn libusb20_dev_wait_process 760function will wait until a pending USB transfer has completed on 761the given USB device. 762. 763A timeout value can be specified which is passed on to the 764.Xr poll 2 765function. 766. 767.Sh USB BACKEND OPERATIONS 768. 769.Fn libusb20_be_get_template 770will return the currently selected global USB device 771side mode template into the integer pointer 772.Fa ptemp . 773This function returns zero on success else a LIBUSB20_ERROR value is 774returned. 775. 776.Pp 777. 778.Fn libusb20_be_set_template 779will set the global USB device side mode template to 780.Fa temp . 781The new template is not activated until after the next USB 782enumeration. 783The template number decides how the USB device will present itself to 784the USB Host, like Mass Storage Device, USB Ethernet Device. Also see 785the 786.Xr usb2_template 4 787module. 788This function returns zero on success else a LIBUSB20_ERROR value is 789returned. 790. 791.Pp 792. 793.Fn libusb20_be_get_dev_quirk 794This function will return the device quirk according to 795.Fa index 796into the libusb20_quirk structure pointed to by 797.Fa pq . 798This function returns zero on success else a LIBUSB20_ERROR value is 799returned. 800. 801If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 802returned. 803. 804.Pp 805. 806.Fn libusb20_be_get_quirk_name 807will return the quirk name according to 808.Fa index 809into the libusb20_quirk structure pointed to by 810.Fa pq . 811This function returns zero on success else a LIBUSB20_ERROR value is 812returned. 813. 814If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 815returned. 816. 817.Pp 818. 819.Fn libusb20_be_add_dev_quirk 820will add the libusb20_quirk structure pointed to by the 821.Fa pq 822argument into the device quirk list. 823. 824This function returns zero on success else a LIBUSB20_ERROR value is 825returned. 826. 827If the given quirk cannot be added LIBUSB20_ERROR_NO_MEM is 828returned. 829. 830.Pp 831. 832.Fn libusb20_be_remove_dev_quirk 833will remove the quirk matching the libusb20_quirk structure pointed to by the 834.Fa pq 835argument from the device quirk list. 836. 837This function returns zero on success else a LIBUSB20_ERROR value is 838returned. 839. 840If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 841returned. 842. 843.Pp 844. 845.Fn libusb20_be_alloc_default 846.Fn libusb20_be_alloc_freebsd 847.Fn libusb20_be_alloc_linux 848These functions are used to allocate a specific USB backend or the 849operating system default USB backend. Allocating a backend is a way to 850scan for currently present USB devices. 851. 852.Pp 853. 854.Fn libusb20_be_device_foreach 855is used to iterate USB devices present in a USB backend. 856. 857The starting value of 858.Fa pdev 859is NULL. 860. 861This function returns the next USB device in the list. 862. 863If NULL is returned the end of the USB device list has been reached. 864. 865.Pp 866. 867.Fn libusb20_be_dequeue_device 868will dequeue the given USB device pointer from the 869backend USB device list. 870. 871Dequeued USB devices will not be freed when the backend is freed. 872. 873.Pp 874. 875.Fn libusb20_be_enqueue_device 876This function will enqueue the given USB device pointer in the backend USB device list. 877. 878Enqueued USB devices will get freed when the backend is freed. 879. 880.Pp 881. 882.Fn libusb20_be_free 883will free the given backend and all USB devices in its device list. 884. 885. 886.Sh USB DESCRIPTOR PARSING 887. 888.Fn libusb20_me_get_1 pie offset 889This function will return a byte at the given byte offset of a message 890entity. 891. 892This function is safe against invalid offsets. 893. 894.Pp 895. 896.Fn libusb20_me_get_2 pie offset 897This function will return a little endian 16-bit value at the given byte offset of a message 898entity. 899. 900This function is safe against invalid offsets. 901. 902.Pp 903. 904.Fn libusb20_me_encode pbuf len pdecoded 905This function will encode a so-called *DECODED structure into binary 906format. 907. 908The total encoded length that will fit in the given buffer is 909returned. 910. 911If the buffer pointer is NULL no data will be written to the buffer 912location. 913. 914.Pp 915. 916.Fn libusb20_me_decode pbuf len pdecoded 917This function will decode a binary structure into a so-called *DECODED 918structure. 919. 920The total decoded length is returned. 921. 922The buffer pointer cannot be NULL. 923. 924. 925.Sh FILES 926. 927. 928/dev/usb 929.Sh SEE ALSO 930.Xr usb 4 , 931.Xr libusb 3 , 932.Xr usbconfig 8 933. 934. 935.Sh HISTORY 936. 937. 938Some parts of the 939.Nm 940API derives from the libusb project at sourceforge. 941