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: head/lib/libusb/libusb20.3 276294 2014-12-27 08:31:52Z joel $ 28.\" 29.Dd January 16, 2015 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. 41.Lb libusb 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 int 52.Fn libusb20_tr_open_stream "struct libusb20_transfer *xfer" "uint32_t max_buf_size" "uint32_t max_frame_count" "uint8_t ep_no" "uint16_t stream_id" 53.Ft struct libusb20_transfer* 54.Fn libusb20_tr_get_pointer "struct libusb20_device *pdev" "uint16_t tr_index" 55.Ft uint16_t 56.Fn libusb20_tr_get_time_complete "struct libusb20_transfer *xfer" 57.Ft uint32_t 58.Fn libusb20_tr_get_actual_frames "struct libusb20_transfer *xfer" 59.Ft uint32_t 60.Fn libusb20_tr_get_actual_length "struct libusb20_transfer *xfer" 61.Ft uint32_t 62.Fn libusb20_tr_get_max_frames "struct libusb20_transfer *xfer" 63.Ft uint32_t 64.Fn libusb20_tr_get_max_packet_length "struct libusb20_transfer *xfer" 65.Ft uint32_t 66.Fn libusb20_tr_get_max_total_length "struct libusb20_transfer *xfer" 67.Ft uint8_t 68.Fn libusb20_tr_get_status "struct libusb20_transfer *xfer" 69.Ft uint8_t 70.Fn libusb20_tr_pending "struct libusb20_transfer *xfer" 71.Ft void 72.Fn libusb20_tr_callback_wrapper "struct libusb20_transfer *xfer" 73.Ft void 74.Fn libusb20_tr_clear_stall_sync "struct libusb20_transfer *xfer" 75.Ft void 76.Fn libusb20_tr_drain "struct libusb20_transfer *xfer" 77.Ft void 78.Fn libusb20_tr_set_buffer "struct libusb20_transfer *xfer" "void *buffer" "uint16_t fr_index" 79.Ft void 80.Fn libusb20_tr_set_callback "struct libusb20_transfer *xfer" "libusb20_tr_callback_t *cb" 81.Ft void 82.Fn libusb20_tr_set_flags "struct libusb20_transfer *xfer" "uint8_t flags" 83.Ft uint32_t 84.Fn libusb20_tr_get_length "struct libusb20_transfer *xfer" "uint16_t fr_index" 85.Ft void 86.Fn libusb20_tr_set_length "struct libusb20_transfer *xfer" "uint32_t length" "uint16_t fr_index" 87.Ft void 88.Fn libusb20_tr_set_priv_sc0 "struct libusb20_transfer *xfer" "void *sc0" 89.Ft void 90.Fn libusb20_tr_set_priv_sc1 "struct libusb20_transfer *xfer" "void *sc1" 91.Ft void 92.Fn libusb20_tr_set_timeout "struct libusb20_transfer *xfer" "uint32_t timeout" 93.Ft void 94.Fn libusb20_tr_set_total_frames "struct libusb20_transfer *xfer" "uint32_t nframes" 95.Ft void 96.Fn libusb20_tr_setup_bulk "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t timeout" 97.Ft void 98.Fn libusb20_tr_setup_control "struct libusb20_transfer *xfer" "void *psetup" "void *pbuf" "uint32_t timeout" 99.Ft void 100.Fn libusb20_tr_setup_intr "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t timeout" 101.Ft void 102.Fn libusb20_tr_setup_isoc "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint16_t fr_index" 103.Ft uint8_t 104.Fn libusb20_tr_bulk_intr_sync "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t *pactlen" "uint32_t timeout" 105.Ft void 106.Fn libusb20_tr_start "struct libusb20_transfer *xfer" 107.Ft void 108.Fn libusb20_tr_stop "struct libusb20_transfer *xfer" 109.Ft void 110.Fn libusb20_tr_submit "struct libusb20_transfer *xfer" 111.Ft void * 112.Fn libusb20_tr_get_priv_sc0 "struct libusb20_transfer *xfer" 113.Ft void * 114.Fn libusb20_tr_get_priv_sc1 "struct libusb20_transfer *xfer" 115.Ft const char * 116.Fn libusb20_dev_get_backend_name "struct libusb20_device *" 117.Ft int 118.Fn libusb20_dev_get_port_path "struct libusb20_device *pdev" "uint8_t *buf" "uint8_t bufsize" 119.Ft int 120.Fn libusb20_dev_get_info "struct libusb20_device *pdev" "struct usb_device_info *pinfo" 121.Ft int 122.Fn libusb20_dev_get_iface_desc "struct libusb20_device *pdev" "uint8_t iface_index" "char *buf" "uint8_t len" 123.Ft const char * 124.Fn libusb20_dev_get_desc "struct libusb20_device *pdev" 125.Ft int 126.Fn libusb20_dev_close "struct libusb20_device *pdev" 127.Ft int 128.Fn libusb20_dev_detach_kernel_driver "struct libusb20_device *pdev" "uint8_t iface_index" 129.Ft int 130.Fn libusb20_dev_set_config_index "struct libusb20_device *pdev" "uint8_t configIndex" 131.Ft int 132.Fn libusb20_dev_get_debug "struct libusb20_device *pdev" 133.Ft int 134.Fn libusb20_dev_get_fd "struct libusb20_device *pdev" 135.Ft int 136.Fn libusb20_dev_kernel_driver_active "struct libusb20_device *pdev" "uint8_t iface_index" 137.Ft int 138.Fn libusb20_dev_open "struct libusb20_device *pdev" "uint16_t transfer_max" 139.Ft int 140.Fn libusb20_dev_process "struct libusb20_device *pdev" 141.Ft int 142.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" 143.Ft int 144.Fn libusb20_dev_req_string_sync "struct libusb20_device *pdev" "uint8_t index" "uint16_t langid" "void *ptr" "uint16_t len" 145.Ft int 146.Fn libusb20_dev_req_string_simple_sync "struct libusb20_device *pdev" "uint8_t index" "void *ptr" "uint16_t len" 147.Ft int 148.Fn libusb20_dev_reset "struct libusb20_device *pdev" 149.Ft int 150.Fn libusb20_dev_check_connected "struct libusb20_device *pdev" 151.Ft int 152.Fn libusb20_dev_set_power_mode "struct libusb20_device *pdev" "uint8_t power_mode" 153.Ft uint8_t 154.Fn libusb20_dev_get_power_mode "struct libusb20_device *pdev" 155.Ft uint16_t 156.Fn libusb20_dev_get_power_usage "struct libusb20_device *pdev" 157.Ft int 158.Fn libusb20_dev_set_alt_index "struct libusb20_device *pdev" "uint8_t iface_index" "uint8_t alt_index" 159.Ft struct LIBUSB20_DEVICE_DESC_DECODED * 160.Fn libusb20_dev_get_device_desc "struct libusb20_device *pdev" 161.Ft struct libusb20_config * 162.Fn libusb20_dev_alloc_config "struct libusb20_device *pdev" "uint8_t config_index" 163.Ft struct libusb20_device * 164.Fn libusb20_dev_alloc "void" 165.Ft uint8_t 166.Fn libusb20_dev_get_address "struct libusb20_device *pdev" 167.Ft uint8_t 168.Fn libusb20_dev_get_parent_address "struct libusb20_device *pdev" 169.Ft uint8_t 170.Fn libusb20_dev_get_parent_port "struct libusb20_device *pdev" 171.Ft uint8_t 172.Fn libusb20_dev_get_bus_number "struct libusb20_device *pdev" 173.Ft uint8_t 174.Fn libusb20_dev_get_mode "struct libusb20_device *pdev" 175.Ft uint8_t 176.Fn libusb20_dev_get_speed "struct libusb20_device *pdev" 177.Ft uint8_t 178.Fn libusb20_dev_get_config_index "struct libusb20_device *pdev" 179.Ft void 180.Fn libusb20_dev_free "struct libusb20_device *pdev" 181.Ft void 182.Fn libusb20_dev_set_debug "struct libusb20_device *pdev" "int debug" 183.Ft void 184.Fn libusb20_dev_wait_process "struct libusb20_device *pdev" "int timeout" 185.Ft int 186.Fn libusb20_be_get_template "struct libusb20_backend *pbe" "int *ptemp" 187.Ft int 188.Fn libusb20_be_set_template "struct libusb20_backend *pbe" "int temp" 189.Ft int 190.Fn libusb20_be_get_dev_quirk "struct libusb20_backend *pber" "uint16_t index" "struct libusb20_quirk *pq" 191.Ft int 192.Fn libusb20_be_get_quirk_name "struct libusb20_backend *pbe" "uint16_t index" "struct libusb20_quirk *pq" 193.Ft int 194.Fn libusb20_be_add_dev_quirk "struct libusb20_backend *pbe" "struct libusb20_quirk *pq" 195.Ft int 196.Fn libusb20_be_remove_dev_quirk "struct libusb20_backend *pbe" "struct libusb20_quirk *pq" 197.Ft struct libusb20_backend * 198.Fn libusb20_be_alloc_default "void" 199.Ft struct libusb20_backend * 200.Fn libusb20_be_alloc_freebsd "void" 201.Ft struct libusb20_backend * 202.Fn libusb20_be_alloc_linux "void" 203.Ft struct libusb20_device * 204.Fn libusb20_be_device_foreach "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 205.Ft void 206.Fn libusb20_be_dequeue_device "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 207.Ft void 208.Fn libusb20_be_enqueue_device "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 209.Ft void 210.Fn libusb20_be_free "struct libusb20_backend *pbe" 211.Ft "const char *" 212.Fn libusb20_strerror "int code" 213.Ft "const char *" 214.Fn libusb20_error_name "int code" 215.In libusb20_desc.h 216.Ft uint8_t 217.Fn libusb20_me_get_1 "const struct libusb20_me_struct *me" "uint16_t off" 218.Ft uint16_t 219.Fn libusb20_me_get_2 "const struct libusb20_me_struct *me" "uint16_t off" 220.Ft uint16_t 221.Fn libusb20_me_encode "void *pdata" "uint16_t len" "const void *pdecoded" 222.Ft uint16_t 223.Fn libusb20_me_decode "const void *pdata" "uint16_t len" "void *pdecoded" 224.Ft "const uint8_t *" 225.Fn libusb20_desc_foreach "const struct libusb20_me_struct *me" "const uint8_t *pdesc" 226. 227. 228.Sh DESCRIPTION 229. 230The 231.Nm 232library implements functions to be able to easily access and control 233USB through the USB file system interface. 234The 235.Nm 236interfaces are specific to the 237.Fx 238usb stack and are not available on other operating systems, portable 239applications should consider using 240.Xr libusb 3 . 241. 242. 243.Sh USB TRANSFER OPERATIONS 244. 245. 246.Fn libusb20_tr_close 247will release all kernel resources associated with an USB 248.Fa xfer . 249. 250This function returns zero upon success. 251. 252Non-zero return values indicate a LIBUSB20_ERROR value. 253. 254.Pp 255. 256.Fn libusb20_tr_open 257will allocate kernel buffer resources according to 258.Fa max_buf_size 259and 260.Fa max_frame_count 261associated with an USB 262.Fa pxfer 263and bind the transfer to the specified 264.Fa ep_no . 265.Fa max_buf_size 266is the minimum buffer size which the data transport layer has to support. 267If 268.Fa max_buf_size 269is zero, the 270.Nm 271library will use wMaxPacketSize to compute the buffer size. 272This can be useful for isochronous transfers. 273The actual buffer size can be greater than 274.Fa max_buf_size 275and is returned by 276.Fn libusb20_tr_get_max_total_length . 277. 278If 279.Fa max_frame_count 280is OR'ed with LIBUSB20_MAX_FRAME_PRE_SCALE the remaining part of the 281argument is converted from milliseconds into the actual number of 282frames rounded up, when this function returns. 283This flag is only valid for ISOCHRONOUS transfers and has no effect 284for other transfer types. 285The actual number of frames setup is found by calling 286.Fn libusb20_tr_get_max_frames . 287. 288This function returns zero upon success. 289. 290Non-zero return values indicate a LIBUSB20_ERROR value. 291. 292.Pp 293. 294.Fn libusb20_tr_open_stream 295is identical to 296.Fn libusb20_tr_open 297except that a stream ID can be specified for BULK endpoints having 298such a feature. 299.Fn libusb20_tr_open 300can be used to open stream ID zero. 301. 302.Pp 303. 304.Fn libusb20_tr_get_pointer 305will return a pointer to the allocated USB transfer according to the 306.Fa pdev 307and 308.Fa tr_index 309arguments. 310. 311This function returns NULL in case of failure. 312. 313.Pp 314. 315.Fn libusb20_tr_get_time_complete 316will return the completion time of an USB transfer in 317millisecond units. 318This function is most useful for isochronous USB 319transfers when doing echo cancelling. 320. 321.Pp 322. 323.Fn libusb20_tr_get_actual_frames 324will return the actual number of USB frames after an USB 325transfer completed. 326A value of zero means that no data was transferred. 327. 328.Pp 329. 330.Fn libusb20_tr_get_actual_length 331will return the sum of the actual length for all 332transferred USB frames for the given USB transfer. 333. 334.Pp 335. 336.Fn libusb20_tr_get_max_frames 337will return the maximum number of USB frames that were 338allocated when an USB transfer was setup for the given USB transfer. 339. 340.Pp 341. 342.Fn libusb20_tr_get_max_packet_length 343will return the maximum packet length in bytes 344associated with the given USB transfer. 345. 346The packet length can be used round up buffer sizes so that short USB 347packets are avoided for proxy buffers. 348. 349. 350.Pp 351. 352.Fn libusb20_tr_get_max_total_length 353will return the maximum value for the data length sum of all USB 354frames associated with an USB transfer. 355In case of control transfers the value returned does not include the 356length of the SETUP packet, 8 bytes, which is part of frame zero. 357The returned value of this function is always aligned to the maximum 358packet size, wMaxPacketSize, of the endpoint which the USB transfer is 359bound to. 360. 361.Pp 362. 363.Fn libusb20_tr_get_status 364will return the status of an USB transfer. 365. 366Status values are defined by a set of LIBUSB20_TRANSFER_XXX enums. 367. 368.Pp 369. 370.Fn libusb20_tr_pending 371will return non-zero if the given USB transfer is 372pending for completion. 373. 374Else this function returns zero. 375. 376.Pp 377. 378.Fn libusb20_tr_callback_wrapper 379This is an internal function used to wrap asynchronous USB callbacks. 380. 381.Pp 382. 383.Fn libusb20_tr_clear_stall_sync 384This is an internal function used to synchronously clear the stall on 385the given USB transfer. 386. 387Please see the USB specification for more information on stall 388clearing. 389. 390If the given USB transfer is pending when this function is called, the 391USB transfer will complete with an error after that this function has 392been called. 393. 394.Pp 395. 396.Fn libusb20_tr_drain 397will stop the given USB transfer and will not return 398until the USB transfer has been stopped in hardware. 399. 400.Pp 401. 402.Fn libusb20_tr_set_buffer 403is used to set the 404.Fa buffer 405pointer for the given USB transfer and 406.Fa fr_index . 407. 408Typically the frame index is zero. 409. 410. 411.Pp 412. 413.Fn libusb20_tr_set_callback 414is used to set the USB callback for asynchronous USB 415transfers. 416. 417The callback type is defined by libusb20_tr_callback_t. 418. 419.Pp 420. 421.Fn libusb20_tr_set_flags 422is used to set various USB flags for the given USB transfer. 423.Bl -tag -width "LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK" 424.It LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK 425Report a short frame as error. 426.It LIBUSB20_TRANSFER_MULTI_SHORT_NOT_OK 427Multiple short frames are not allowed. 428.It LIBUSB20_TRANSFER_FORCE_SHORT 429All transmitted frames are short terminated. 430.It LIBUSB20_TRANSFER_DO_CLEAR_STALL 431Will do a clear-stall before starting the transfer. 432.El 433. 434.Pp 435. 436.Fn libusb20_tr_get_length 437returns the length of the given USB frame by index. 438After an USB transfer is complete the USB frame length will get updated to the actual transferred length. 439. 440.Pp 441. 442.Fn libusb20_tr_set_length 443sets the length of the given USB frame by index. 444. 445.Pp 446. 447.Fn libusb20_tr_set_priv_sc0 448sets private driver pointer number zero. 449. 450.Pp 451. 452.Fn libusb20_tr_set_priv_sc1 453sets private driver pointer number one. 454. 455.Pp 456. 457.Fn libusb20_tr_set_timeout 458sets the timeout for the given USB transfer. 459. 460A timeout value of zero means no timeout. 461. 462The timeout is given in milliseconds. 463. 464.Pp 465. 466.Fn libusb20_tr_set_total_frames 467sets the total number of frames that should be executed when the USB transfer is submitted. 468. 469The total number of USB frames must be less than the maximum number of USB frames associated with the given USB transfer. 470. 471.Pp 472. 473.Fn libusb20_tr_setup_bulk 474is a helper function for setting up a single frame USB BULK transfer. 475. 476.Pp 477. 478.Fn libusb20_tr_setup_control 479is a helper function for setting up a single or dual 480frame USB CONTROL transfer depending on the control transfer length. 481. 482.Pp 483. 484.Fn libusb20_tr_setup_intr 485is a helper function for setting up a single frame USB INTERRUPT transfer. 486. 487.Pp 488. 489.Fn libusb20_tr_setup_isoc 490is a helper function for setting up a multi frame USB ISOCHRONOUS transfer. 491. 492.Pp 493. 494.Fn libusb20_tr_bulk_intr_sync 495will perform a synchronous BULK or INTERRUPT transfer having length given by the 496.Fa length 497argument and buffer pointer given by the 498.Fa pbuf 499argument on the USB transfer given by the 500.Fa xfer 501argument. 502. 503If the 504.Fa pactlen 505argument is non-NULL the actual transfer length will be stored at the given pointer destination. 506. 507If the 508.Fa timeout 509argument is non-zero the transfer will timeout after the given value in milliseconds. 510. 511This function does not change the transfer flags, like short packet not ok. 512. 513This function returns zero on success else a LIBUSB20_TRANSFER_XXX value is returned. 514. 515.Pp 516. 517.Fn libusb20_tr_start 518will get the USB transfer started, if not already 519started. 520. 521This function will not get the transfer queued in hardware. 522. 523This function is non-blocking. 524. 525.Pp 526. 527.Fn libusb20_tr_stop 528will get the USB transfer stopped, if not already stopped. 529. 530This function is non-blocking, which means that the actual stop can 531happen after the return of this function. 532. 533.Pp 534. 535.Fn libusb20_tr_submit 536will get the USB transfer queued in hardware. 537. 538. 539.Pp 540. 541.Fn libusb20_tr_get_priv_sc0 542returns private driver pointer number zero associated 543with an USB transfer. 544. 545. 546.Pp 547. 548.Fn libusb20_tr_get_priv_sc1 549returns private driver pointer number one associated 550with an USB transfer. 551. 552. 553.Sh USB DEVICE OPERATIONS 554. 555. 556.Fn libusb20_dev_get_backend_name 557returns a zero terminated string describing the backend used. 558. 559.Pp 560. 561.Fn libusb20_dev_get_port_path 562retrieves the list of USB port numbers which the datastream for a given USB device follows. 563The first port number is the Root HUB port number. 564Then children port numbers follow. 565The Root HUB device itself has a port path length of zero. 566Valid port numbers start at one and range until and including 255. 567Typically there should not be more than 16 levels, due to electrical and protocol limitations. 568This functions returns the number of actual port levels upon success 569else a LIBUSB20_ERROR value is returned which are always negative. 570If the actual number of port levels is greater than the maximum 571specified, a LIBUSB20_ERROR value is returned. 572. 573.Pp 574. 575.Fn libusb20_dev_get_info 576retrieves the BSD specific usb_device_info structure into the memory location given by 577.Fa pinfo . 578The USB device given by 579.Fa pdev 580must be opened before this function will succeed. 581This function returns zero on success else a LIBUSB20_ERROR value is returned. 582. 583.Pp 584. 585.Fn libusb20_dev_get_iface_desc 586retrieves the kernel interface description for the given USB 587.Fa iface_index . 588The format of the USB interface description is: "drivername<unit>: <description>" 589The description string is always zero terminated. 590A zero length string is written in case no driver is attached to the given interface. 591The USB device given by 592.Fa pdev 593must be opened before this function will succeed. 594This function returns zero on success else a LIBUSB20_ERROR value is returned. 595. 596.Pp 597. 598.Fn libusb20_dev_get_desc 599returns a zero terminated string describing the given USB device. 600The format of the string is: "drivername<unit>: <description>" 601. 602.Pp 603. 604.Fn libusb20_dev_close 605will close the given USB device. 606. 607This function returns zero on success else a LIBUSB20_ERROR value is 608returned. 609. 610.Pp 611. 612.Fn libusb20_dev_detach_kernel_driver 613will try to detach the kernel driver for the USB interface given by 614.Fa iface_index . 615. 616This function returns zero on success else a LIBUSB20_ERROR value is 617returned. 618. 619.Pp 620. 621.Fn libusb20_dev_set_config_index 622will try to set the configuration index on an USB 623device. 624. 625The first configuration index is zero. 626. 627The un-configure index is 255. 628. 629This function returns zero on success else a LIBUSB20_ERROR value is returned. 630. 631.Pp 632. 633.Fn libusb20_dev_get_debug 634returns the debug level of an USB device. 635. 636.Pp 637. 638.Fn libusb20_dev_get_fd 639returns the file descriptor of the given USB device. 640. 641A negative value is returned when no file descriptor is present. 642. 643The file descriptor can be used for polling purposes. 644. 645.Pp 646. 647.Fn libusb20_dev_kernel_driver_active 648returns zero if a kernel driver is active on the given USB interface. 649. 650Else a LIBUSB20_ERROR value is returned. 651. 652.Pp 653. 654.Fn libusb20_dev_open 655opens an USB device so that setting up USB transfers 656becomes possible. 657. 658The number of USB transfers can be zero which means only control 659transfers are allowed. 660. 661This function returns zero on success else a LIBUSB20_ERROR value is 662returned. 663. 664A return value of LIBUSB20_ERROR_BUSY means that the device is already 665opened. 666. 667.Pp 668. 669.Fn libusb20_dev_process 670is called to sync kernel USB transfers with userland USB 671transfers. 672. 673This function returns zero on success else a LIBUSB20_ERROR value is 674returned typically indicating that the given USB device has been 675detached. 676. 677.Pp 678. 679.Fn libusb20_dev_request_sync 680will perform a synchronous control request on the given 681USB device. 682. 683Before this call will succeed the USB device must be opened. 684. 685.Fa setup 686is a pointer to a decoded and host endian SETUP packet. 687.Fa data 688is a pointer to a data transfer buffer associated with the control transaction. 689This argument can be NULL. 690.Fa pactlen 691is a pointer to a variable that will hold the actual transfer length after the control transaction is complete. 692.Fa timeout 693is the transaction timeout given in milliseconds. 694A timeout of zero means no timeout. 695.Fa flags 696is used to specify transaction flags, for example LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK. 697. 698This function returns zero on success else a LIBUSB20_ERROR value is 699returned. 700. 701.Pp 702. 703.Fn libusb20_dev_req_string_sync 704will synchronously request an USB string by language ID 705and string index into the given buffer limited by a maximum length. 706. 707This function returns zero on success else a LIBUSB20_ERROR value is 708returned. 709. 710.Pp 711. 712.Fn libusb20_dev_req_string_simple_sync 713will synchronously request an USB string using the 714default language ID and convert the string into ASCII before storing 715the string into the given buffer limited by a maximum length which 716includes the terminating zero. 717. 718This function returns zero on success else a LIBUSB20_ERROR value is 719returned. 720. 721. 722.Pp 723. 724.Fn libusb20_dev_reset 725will try to BUS reset the given USB device and restore 726the last set USB configuration. 727. 728This function returns zero on success else a LIBUSB20_ERROR value is 729returned. 730. 731. 732.Pp 733. 734.Fn libusb20_dev_check_connected 735will check if an opened USB device is still connected. 736. 737This function returns zero if the device is still connected else a LIBUSB20_ERROR value is returned. 738. 739. 740.Pp 741. 742.Fn libusb20_dev_set_power_mode 743sets the power mode of the USB device. 744. 745Valid power modes: 746.Bl -tag -width "LIBUSB20_POWER_OFF" 747.It LIBUSB20_POWER_OFF 748.It LIBUSB20_POWER_ON 749.It LIBUSB20_POWER_SAVE 750.It LIBUSB20_POWER_SUSPEND 751.It LIBUSB20_POWER_RESUME 752.El 753.Pp 754. 755This function returns zero on success else a LIBUSB20_ERROR value is 756returned. 757. 758.Pp 759. 760.Fn libusb20_dev_get_power_mode 761returns the currently selected power mode for the given 762USB device. 763. 764.Pp 765. 766.Fn libusb20_dev_get_power_usage 767returns the reported power usage in milliamps for the given USB device. 768A power usage of zero typically means that the device is self powered. 769. 770.Pp 771. 772.Fn libusb20_dev_set_alt_index 773will try to set the given alternate index for the given 774USB interface index. 775. 776This function returns zero on success else a LIBUSB20_ERROR value is 777returned. 778. 779.Pp 780. 781.Fn libusb20_dev_get_device_desc 782returns a pointer to the decoded and host endian version 783of the device descriptor. 784. 785The USB device need not be opened when calling this function. 786. 787.Pp 788. 789.Fn libusb20_dev_alloc_config 790will read out and decode the USB config descriptor for 791the given USB device and config index. 792This function returns a pointer 793to the decoded configuration which must eventually be passed to 794.Fn free . 795NULL is returned in case of failure. 796. 797.Pp 798. 799.Fn libusb20_dev_alloc 800is an internal function to allocate a new USB device. 801. 802.Pp 803. 804.Fn libusb20_dev_get_address 805returns the internal and not necessarily the real 806hardware address of the given USB device. 807Valid addresses start at one. 808. 809.Pp 810. 811.Fn libusb20_dev_get_parent_address 812returns the internal and not necessarily the real hardware address of 813the given parent USB HUB device. 814This value is zero for the root HUB which usually has a device address 815equal to one. 816Valid addresses start at one. 817. 818.Pp 819. 820.Fn libusb20_dev_get_parent_port 821returns the port number on the parent USB HUB device. 822This value is zero for the root HUB which usually has a device address 823equal to one. 824Valid port numbers start at one. 825. 826.Pp 827. 828.Fn libusb20_dev_get_bus_number 829returns the internal bus number which the given USB 830device belongs to. 831Valid bus numbers start at zero. 832. 833.Pp 834. 835.Fn libusb20_dev_get_mode 836returns the current operation mode of the USB entity. 837. 838Valid return values are: 839.Bl -tag -width "LIBUSB20_MODE_DEVICE" 840.It LIBUSB20_MODE_HOST 841.It LIBUSB20_MODE_DEVICE 842.El 843. 844.Pp 845. 846.Fn libusb20_dev_get_speed 847returns the current speed of the given USB device. 848. 849.Bl -tag -width "LIBUSB20_SPEED_VARIABLE" 850.It LIBUSB20_SPEED_UNKNOWN 851.It LIBUSB20_SPEED_LOW 852.It LIBUSB20_SPEED_FULL 853.It LIBUSB20_SPEED_HIGH 854.It LIBUSB20_SPEED_VARIABLE 855.It LIBUSB20_SPEED_SUPER 856.El 857. 858.Pp 859. 860.Fn libusb20_dev_get_config_index 861returns the currently selected config index for the given 862USB device. 863. 864.Pp 865. 866.Fn libusb20_dev_free 867will free the given USB device and all associated USB 868transfers. 869. 870.Pp 871. 872.Fn libusb20_dev_set_debug 873will set the debug level for the given USB device. 874. 875.Pp 876. 877.Fn libusb20_dev_wait_process 878will wait until a pending USB transfer has completed on 879the given USB device. 880. 881A timeout value can be specified which is passed on to the 882.Xr poll 2 883function. 884. 885.Sh USB BACKEND OPERATIONS 886. 887.Fn libusb20_be_get_template 888will return the currently selected global USB device 889side mode template into the integer pointer 890.Fa ptemp . 891This function returns zero on success else a LIBUSB20_ERROR value is 892returned. 893. 894.Pp 895. 896.Fn libusb20_be_set_template 897will set the global USB device side mode template to 898.Fa temp . 899The new template is not activated until after the next USB 900enumeration. 901The template number decides how the USB device will present itself to 902the USB Host, like Mass Storage Device, USB Ethernet Device. 903.\"Also see the 904.\".Xr usb2_template 4 905.\"module. 906This function returns zero on success else a LIBUSB20_ERROR value is 907returned. 908. 909.Pp 910. 911.Fn libusb20_be_get_dev_quirk 912will return the device quirk according to 913.Fa index 914into the libusb20_quirk structure pointed to by 915.Fa pq . 916This function returns zero on success else a LIBUSB20_ERROR value is 917returned. 918. 919If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 920returned. 921. 922.Pp 923. 924.Fn libusb20_be_get_quirk_name 925will return the quirk name according to 926.Fa index 927into the libusb20_quirk structure pointed to by 928.Fa pq . 929This function returns zero on success else a LIBUSB20_ERROR value is 930returned. 931. 932If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 933returned. 934. 935.Pp 936. 937.Fn libusb20_be_add_dev_quirk 938will add the libusb20_quirk structure pointed to by the 939.Fa pq 940argument into the device quirk list. 941. 942This function returns zero on success else a LIBUSB20_ERROR value is 943returned. 944. 945If the given quirk cannot be added LIBUSB20_ERROR_NO_MEM is 946returned. 947. 948.Pp 949. 950.Fn libusb20_be_remove_dev_quirk 951will remove the quirk matching the libusb20_quirk structure pointed to by the 952.Fa pq 953argument from the device quirk list. 954. 955This function returns zero on success else a LIBUSB20_ERROR value is 956returned. 957. 958If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 959returned. 960. 961.Pp 962. 963.Fn libusb20_be_alloc_default 964.Fn libusb20_be_alloc_freebsd 965.Fn libusb20_be_alloc_linux 966These functions are used to allocate a specific USB backend or the 967operating system default USB backend. 968Allocating a backend is a way to scan for currently present USB devices. 969. 970.Pp 971. 972.Fn libusb20_be_device_foreach 973is used to iterate USB devices present in a USB backend. 974. 975The starting value of 976.Fa pdev 977is NULL. 978. 979This function returns the next USB device in the list. 980. 981If NULL is returned the end of the USB device list has been reached. 982. 983.Pp 984. 985.Fn libusb20_be_dequeue_device 986will dequeue the given USB device pointer from the 987backend USB device list. 988. 989Dequeued USB devices will not be freed when the backend is freed. 990. 991.Pp 992. 993.Fn libusb20_be_enqueue_device 994will enqueue the given USB device pointer in the backend USB device list. 995. 996Enqueued USB devices will get freed when the backend is freed. 997. 998.Pp 999. 1000.Fn libusb20_be_free 1001will free the given backend and all USB devices in its device list. 1002. 1003. 1004.Sh USB DESCRIPTOR PARSING 1005. 1006.Fn libusb20_me_get_1 pie offset 1007This function will return a byte at the given byte offset of a message 1008entity. 1009. 1010This function is safe against invalid offsets. 1011. 1012.Pp 1013. 1014.Fn libusb20_me_get_2 pie offset 1015This function will return a little endian 16-bit value at the given byte offset of a message 1016entity. 1017. 1018This function is safe against invalid offsets. 1019. 1020.Pp 1021. 1022.Fn libusb20_me_encode pbuf len pdecoded 1023This function will encode a so-called *DECODED structure into binary 1024format. 1025. 1026The total encoded length that will fit in the given buffer is 1027returned. 1028. 1029If the buffer pointer is NULL no data will be written to the buffer 1030location. 1031. 1032.Pp 1033. 1034.Fn libusb20_me_decode pbuf len pdecoded 1035This function will decode a binary structure into a so-called *DECODED 1036structure. 1037. 1038The total decoded length is returned. 1039. 1040The buffer pointer cannot be NULL. 1041. 1042. 1043.Sh USB DEBUGGING 1044.Ft const char * 1045.Fn libusb20_strerror "int code" 1046Get the ASCII representation of the error given by the 1047.Fa code 1048argument. 1049This function does not return NULL. 1050.Pp 1051.Ft const char * 1052.Fn libusb20_error_name "int code" 1053Get the ASCII representation of the error enum given by the 1054.Fa code 1055argument. 1056This function does not return NULL. 1057. 1058.Sh FILES 1059.Bl -tag -width Pa 1060.It Pa /dev/usb 1061.El 1062.Sh SEE ALSO 1063.Xr libusb 3 , 1064.Xr usb 4 , 1065.Xr usbconfig 8 , 1066.Xr usbdump 8 1067. 1068. 1069.Sh HISTORY 1070. 1071. 1072Some parts of the 1073.Nm 1074API derives from the libusb project at sourceforge. 1075