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 August 13, 2012 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.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" 52.Ft struct libusb20_transfer* 53.Fn libusb20_tr_get_pointer "struct libusb20_device *pdev" "uint16_t tr_index" 54.Ft uint16_t 55.Fn libusb20_tr_get_time_complete "struct libusb20_transfer *xfer" 56.Ft uint32_t 57.Fn libusb20_tr_get_actual_frames "struct libusb20_transfer *xfer" 58.Ft uint32_t 59.Fn libusb20_tr_get_actual_length "struct libusb20_transfer *xfer" 60.Ft uint32_t 61.Fn libusb20_tr_get_max_frames "struct libusb20_transfer *xfer" 62.Ft uint32_t 63.Fn libusb20_tr_get_max_packet_length "struct libusb20_transfer *xfer" 64.Ft uint32_t 65.Fn libusb20_tr_get_max_total_length "struct libusb20_transfer *xfer" 66.Ft uint8_t 67.Fn libusb20_tr_get_status "struct libusb20_transfer *xfer" 68.Ft uint8_t 69.Fn libusb20_tr_pending "struct libusb20_transfer *xfer" 70.Ft void 71.Fn libusb20_tr_callback_wrapper "struct libusb20_transfer *xfer" 72.Ft void 73.Fn libusb20_tr_clear_stall_sync "struct libusb20_transfer *xfer" 74.Ft void 75.Fn libusb20_tr_drain "struct libusb20_transfer *xfer" 76.Ft void 77.Fn libusb20_tr_set_buffer "struct libusb20_transfer *xfer" "void *buffer" "uint16_t fr_index" 78.Ft void 79.Fn libusb20_tr_set_callback "struct libusb20_transfer *xfer" "libusb20_tr_callback_t *cb" 80.Ft void 81.Fn libusb20_tr_set_flags "struct libusb20_transfer *xfer" "uint8_t flags" 82.Ft uint32_t 83.Fn libusb20_tr_get_length "struct libusb20_transfer *xfer" "uint16_t fr_index" 84.Ft void 85.Fn libusb20_tr_set_length "struct libusb20_transfer *xfer" "uint32_t length" "uint16_t fr_index" 86.Ft void 87.Fn libusb20_tr_set_priv_sc0 "struct libusb20_transfer *xfer" "void *sc0" 88.Ft void 89.Fn libusb20_tr_set_priv_sc1 "struct libusb20_transfer *xfer" "void *sc1" 90.Ft void 91.Fn libusb20_tr_set_timeout "struct libusb20_transfer *xfer" "uint32_t timeout" 92.Ft void 93.Fn libusb20_tr_set_total_frames "struct libusb20_transfer *xfer" "uint32_t nframes" 94.Ft void 95.Fn libusb20_tr_setup_bulk "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t timeout" 96.Ft void 97.Fn libusb20_tr_setup_control "struct libusb20_transfer *xfer" "void *psetup" "void *pbuf" "uint32_t timeout" 98.Ft void 99.Fn libusb20_tr_setup_intr "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t timeout" 100.Ft void 101.Fn libusb20_tr_setup_isoc "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint61_t fr_index" 102.Ft uint8_t 103.Fn libusb20_tr_bulk_intr_sync "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t *pactlen" "uint32_t timeout" 104.Ft void 105.Fn libusb20_tr_start "struct libusb20_transfer *xfer" 106.Ft void 107.Fn libusb20_tr_stop "struct libusb20_transfer *xfer" 108.Ft void 109.Fn libusb20_tr_submit "struct libusb20_transfer *xfer" 110.Ft void * 111.Fn libusb20_tr_get_priv_sc0 "struct libusb20_transfer *xfer" 112.Ft void * 113.Fn libusb20_tr_get_priv_sc1 "struct libusb20_transfer *xfer" 114.Ft const char * 115.Fn libusb20_dev_get_backend_name "struct libusb20_device *" 116.Ft int 117.Fn libusb20_dev_get_info "struct libusb20_device *pdev" "struct usb_device_info *pinfo" 118.Ft int 119.Fn libusb20_dev_get_iface_desc "struct libusb20_device *pdev" "uint8_t iface_index" "char *buf" "uint8_t len" 120.Ft const char * 121.Fn libusb20_dev_get_desc "struct libusb20_device *pdev" 122.Ft int 123.Fn libusb20_dev_close "struct libusb20_device *pdev" 124.Ft int 125.Fn libusb20_dev_detach_kernel_driver "struct libusb20_device *pdev" "uint8_t iface_index" 126.Ft int 127.Fn libusb20_dev_set_config_index "struct libusb20_device *pdev" "uint8_t configIndex" 128.Ft int 129.Fn libusb20_dev_get_debug "struct libusb20_device *pdev" 130.Ft int 131.Fn libusb20_dev_get_fd "struct libusb20_device *pdev" 132.Ft int 133.Fn libusb20_dev_kernel_driver_active "struct libusb20_device *pdev" "uint8_t iface_index" 134.Ft int 135.Fn libusb20_dev_open "struct libusb20_device *pdev" "uint16_t transfer_max" 136.Ft int 137.Fn libusb20_dev_process "struct libusb20_device *pdev" 138.Ft int 139.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" 140.Ft int 141.Fn libusb20_dev_req_string_sync "struct libusb20_device *pdev" "uint8_t index" "uint16_t langid" "void *ptr" "uint16_t len" 142.Ft int 143.Fn libusb20_dev_req_string_simple_sync "struct libusb20_device *pdev" "uint8_t index" "void *ptr" "uint16_t len" 144.Ft int 145.Fn libusb20_dev_reset "struct libusb20_device *pdev" 146.Ft int 147.Fn libusb20_dev_check_connected "struct libusb20_device *pdev" 148.Ft int 149.Fn libusb20_dev_set_power_mode "struct libusb20_device *pdev" "uint8_t power_mode" 150.Ft uint8_t 151.Fn libusb20_dev_get_power_mode "struct libusb20_device *pdev" 152.Ft int 153.Fn libusb20_dev_set_alt_index "struct libusb20_device *pdev" "uint8_t iface_index" "uint8_t alt_index" 154.Ft struct LIBUSB20_DEVICE_DESC_DECODED * 155.Fn libusb20_dev_get_device_desc "struct libusb20_device *pdev" 156.Ft struct libusb20_config * 157.Fn libusb20_dev_alloc_config "struct libusb20_device *pdev" "uint8_t config_index" 158.Ft struct libusb20_device * 159.Fn libusb20_dev_alloc "void" 160.Ft uint8_t 161.Fn libusb20_dev_get_address "struct libusb20_device *pdev" 162.Ft uint8_t 163.Fn libusb20_dev_get_parent_address "struct libusb20_device *pdev" 164.Ft uint8_t 165.Fn libusb20_dev_get_parent_port "struct libusb20_device *pdev" 166.Ft uint8_t 167.Fn libusb20_dev_get_bus_number "struct libusb20_device *pdev" 168.Ft uint8_t 169.Fn libusb20_dev_get_mode "struct libusb20_device *pdev" 170.Ft uint8_t 171.Fn libusb20_dev_get_speed "struct libusb20_device *pdev" 172.Ft uint8_t 173.Fn libusb20_dev_get_config_index "struct libusb20_device *pdev" 174.Ft void 175.Fn libusb20_dev_free "struct libusb20_device *pdev" 176.Ft void 177.Fn libusb20_dev_set_debug "struct libusb20_device *pdev" "int debug" 178.Ft void 179.Fn libusb20_dev_wait_process "struct libusb20_device *pdev" "int timeout" 180.Ft int 181.Fn libusb20_be_get_template "struct libusb20_backend *pbe" "int *ptemp" 182.Ft int 183.Fn libusb20_be_set_template "struct libusb20_backend *pbe" "int temp" 184.Ft int 185.Fn libusb20_be_get_dev_quirk "struct libusb20_backend *pber" "uint16_t index" "struct libusb20_quirk *pq" 186.Ft int 187.Fn libusb20_be_get_quirk_name "struct libusb20_backend *pbe" "uint16_t index" "struct libusb20_quirk *pq" 188.Ft int 189.Fn libusb20_be_add_dev_quirk "struct libusb20_backend *pbe" "struct libusb20_quirk *pq" 190.Ft int 191.Fn libusb20_be_remove_dev_quirk "struct libusb20_backend *pbe" "struct libusb20_quirk *pq" 192.Ft struct libusb20_backend * 193.Fn libusb20_be_alloc_default "void" 194.Ft struct libusb20_backend * 195.Fn libusb20_be_alloc_freebsd "void" 196.Ft struct libusb20_backend * 197.Fn libusb20_be_alloc_linux "void" 198.Ft struct libusb20_device * 199.Fn libusb20_be_device_foreach "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 200.Ft void 201.Fn libusb20_be_dequeue_device "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 202.Ft void 203.Fn libusb20_be_enqueue_device "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 204.Ft void 205.Fn libusb20_be_free "struct libusb20_backend *pbe" 206.Ft uint8_t 207.Fn libusb20_me_get_1 "const struct libusb20_me_struct *me" "uint16_t off" 208.Ft uint16_t 209.Fn libusb20_me_get_2 "const struct libusb20_me_struct *me" "uint16_t off" 210.Ft uint16_t 211.Fn libusb20_me_encode "void *pdata" "uint16_t len" "const void *pdecoded" 212.Ft uint16_t 213.Fn libusb20_me_decode "const void *pdata" "uint16_t len" "void *pdecoded" 214.Ft "const uint8_t *" 215.Fn libusb20_desc_foreach "const struct libusb20_me_struct *me" "const uint8_t *pdesc" 216.Ft "const char *" 217.Fn libusb20_strerror "int code" 218.Ft "const char *" 219.Fn libusb20_error_name "int code" 220. 221. 222.Sh DESCRIPTION 223. 224The 225.Nm 226library implements functions to be able to easily access and control 227USB through the USB file system interface. 228The 229.Nm 230interfaces are specific to the 231.Fx 232usb stack and are not available on other operating systems, portable 233applications should consider using 234.Xr libusb 3 . 235. 236. 237.Sh USB TRANSFER OPERATIONS 238. 239. 240.Fn libusb20_tr_close 241will release all kernel resources associated with an USB 242.Fa xfer . 243. 244This function returns zero upon success. 245. 246Non-zero return values indicate a LIBUSB20_ERROR value. 247. 248.Pp 249. 250.Fn libusb20_tr_open 251will allocate kernel buffer resources according to 252.Fa max_buf_size 253and 254.Fa max_frame_count 255associated with an USB 256.Fa pxfer 257and bind the transfer to the specified 258.Fa ep_no . 259.Fa max_buf_size 260is the minimum buffer size which the data transport layer has to support. 261If 262.Fa max_buf_size 263is zero, the 264.Nm 265library will use wMaxPacketSize to compute the buffer size. 266This can be useful for isochronous transfers. 267The actual buffer size can be greater than 268.Fa max_buf_size 269and is returned by 270.Fn libusb20_tr_get_max_total_length . 271. 272If 273.Fa max_frame_count 274is OR'ed with LIBUSB20_MAX_FRAME_PRE_SCALE the remaining part of the 275argument is converted from milliseconds into the actual number of 276frames rounded up, when this function returns. 277This flag is only valid for ISOCHRONOUS transfers and has no effect 278for other transfer types. 279The actual number of frames setup is found by calling 280.Fn libusb20_tr_get_max_frames . 281. 282This function returns zero upon success. 283. 284Non-zero return values indicate a LIBUSB20_ERROR value. 285. 286.Pp 287. 288.Fn libusb20_tr_open_stream 289is identical to 290.Fn libusb20_tr_open 291except that a stream ID can be specified for BULK endpoints having 292such a feature. 293.Fn libusb20_tr_open 294can be used to open stream ID zero. 295. 296.Pp 297. 298.Fn libusb20_tr_get_pointer 299will return a pointer to the allocated USB transfer according to the 300.Fa pdev 301and 302.Fa tr_index 303arguments. 304. 305This function returns NULL in case of failure. 306. 307.Pp 308. 309.Fn libusb20_tr_get_time_complete 310will return the completion time of an USB transfer in 311millisecond units. This function is most useful for isochronous USB 312transfers when doing echo cancelling. 313. 314.Pp 315. 316.Fn libusb20_tr_get_actual_frames 317will return the actual number of USB frames after an USB 318transfer completed. A value of zero means that no data was transferred. 319. 320.Pp 321. 322.Fn libusb20_tr_get_actual_length 323will return the sum of the actual length for all 324transferred USB frames for the given USB transfer. 325. 326.Pp 327. 328.Fn libusb20_tr_get_max_frames 329will return the maximum number of USB frames that were 330allocated when an USB transfer was setup for the given USB transfer. 331. 332.Pp 333. 334.Fn libusb20_tr_get_max_packet_length 335will return the maximum packet length in bytes 336associated with the given USB transfer. 337. 338The packet length can be used round up buffer sizes so that short USB 339packets are avoided for proxy buffers. 340. 341. 342.Pp 343. 344.Fn libusb20_tr_get_max_total_length 345will return the maximum value for the data length sum of all USB 346frames associated with an USB transfer. 347In case of control transfers the value returned does not include the 348length of the SETUP packet, 8 bytes, which is part of frame zero. 349The returned value of this function is always aligned to the maximum 350packet size, wMaxPacketSize, of the endpoint which the USB transfer is 351bound to. 352. 353.Pp 354. 355.Fn libusb20_tr_get_status 356will return the status of an USB transfer. 357. 358Status values are defined by a set of LIBUSB20_TRANSFER_XXX enums. 359. 360.Pp 361. 362.Fn libusb20_tr_pending 363will return non-zero if the given USB transfer is 364pending for completion. 365. 366Else this function returns zero. 367. 368.Pp 369. 370.Fn libusb20_tr_callback_wrapper 371This is an internal function used to wrap asynchronous USB callbacks. 372. 373.Pp 374. 375.Fn libusb20_tr_clear_stall_sync 376This is an internal function used to synchronously clear the stall on 377the given USB transfer. 378. 379Please see the USB specification for more information on stall 380clearing. 381. 382If the given USB transfer is pending when this function is called, the 383USB transfer will complete with an error after that this function has 384been called. 385. 386.Pp 387. 388.Fn libusb20_tr_drain 389will stop the given USB transfer and will not return 390until the USB transfer has been stopped in hardware. 391. 392.Pp 393. 394.Fn libusb20_tr_set_buffer 395is used to set the 396.Fa buffer 397pointer for the given USB transfer and 398.Fa fr_index . 399. 400Typically the frame index is zero. 401. 402. 403.Pp 404. 405.Fn libusb20_tr_set_callback 406is used to set the USB callback for asynchronous USB 407transfers. 408. 409The callback type is defined by libusb20_tr_callback_t. 410. 411.Pp 412. 413.Fn libusb20_tr_set_flags 414is used to set various USB flags for the given USB transfer. 415.Bl -tag -width "LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK" 416.It LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK 417Report a short frame as error. 418.It LIBUSB20_TRANSFER_MULTI_SHORT_NOT_OK 419Multiple short frames are not allowed. 420.It LIBUSB20_TRANSFER_FORCE_SHORT 421All transmitted frames are short terminated. 422.It LIBUSB20_TRANSFER_DO_CLEAR_STALL 423Will do a clear-stall before starting the transfer. 424.El 425. 426.Pp 427. 428.Fn libusb20_tr_get_length 429returns the length of the given USB frame by index. 430After an USB transfer is complete the USB frame length will get updated to the actual transferred length. 431. 432.Pp 433. 434.Fn libusb20_tr_set_length 435sets the length of the given USB frame by index. 436. 437.Pp 438. 439.Fn libusb20_tr_set_priv_sc0 440sets private driver pointer number zero. 441. 442.Pp 443. 444.Fn libusb20_tr_set_priv_sc1 445sets private driver pointer number one. 446. 447.Pp 448. 449.Fn libusb20_tr_set_timeout 450sets the timeout for the given USB transfer. 451. 452A timeout value of zero means no timeout. 453. 454The timeout is given in milliseconds. 455. 456.Pp 457. 458.Fn libusb20_tr_set_total_frames 459sets the total number of frames that should be executed when the USB transfer is submitted. 460. 461The total number of USB frames must be less than the maximum number of USB frames associated with the given USB transfer. 462. 463.Pp 464. 465.Fn libusb20_tr_setup_bulk 466is a helper function for setting up a single frame USB BULK transfer. 467. 468.Pp 469. 470.Fn libusb20_tr_setup_control 471is a helper function for setting up a single or dual 472frame USB CONTROL transfer depending on the control transfer length. 473. 474.Pp 475. 476.Fn libusb20_tr_setup_intr 477is a helper function for setting up a single frame USB INTERRUPT transfer. 478. 479.Pp 480. 481.Fn libusb20_tr_setup_isoc 482is a helper function for setting up a multi frame USB ISOCHRONOUS transfer. 483. 484.Pp 485. 486.Fn libusb20_tr_bulk_intr_sync 487will perform a synchronous BULK or INTERRUPT transfer having length given by the 488.Fa length 489argument and buffer pointer given by the 490.Fa pbuf 491argument on the USB transfer given by the 492.Fa xfer 493argument. 494. 495If the 496.Fa pactlen 497argument is non-NULL the actual transfer length will be stored at the given pointer destination. 498. 499If the 500.Fa timeout 501argument is non-zero the transfer will timeout after the given value in milliseconds. 502. 503This function does not change the transfer flags, like short packet not ok. 504. 505This function returns zero on success else a LIBUSB20_TRANSFER_XXX value is returned. 506. 507.Pp 508. 509.Fn libusb20_tr_start 510will get the USB transfer started, if not already 511started. 512. 513This function will not get the transfer queued in hardware. 514. 515This function is non-blocking. 516. 517.Pp 518. 519.Fn libusb20_tr_stop 520will get the USB transfer stopped, if not already stopped. 521. 522This function is non-blocking, which means that the actual stop can 523happen after the return of this function. 524. 525.Pp 526. 527.Fn libusb20_tr_submit 528will get the USB transfer queued in hardware. 529. 530. 531.Pp 532. 533.Fn libusb20_tr_get_priv_sc0 534returns private driver pointer number zero associated 535with an USB transfer. 536. 537. 538.Pp 539. 540.Fn libusb20_tr_get_priv_sc1 541returns private driver pointer number one associated 542with an USB transfer. 543. 544. 545.Sh USB DEVICE OPERATIONS 546. 547. 548.Fn libusb20_dev_get_backend_name 549returns a zero terminated string describing the backend used. 550. 551.Pp 552. 553.Fn libusb20_dev_get_info 554retrieves the BSD specific usb_device_info structure into the memory location given by 555.Fa pinfo . 556The USB device given by 557.Fa pdev 558must be opened before this function will succeed. 559This function returns zero on success else a LIBUSB20_ERROR value is returned. 560. 561.Pp 562. 563.Fn libusb20_dev_get_iface_desc 564retrieves the kernel interface description for the given USB 565.Fa iface_index . 566The format of the USB interface description is: "drivername<unit>: <description>" 567The description string is always zero terminated. 568A zero length string is written in case no driver is attached to the given interface. 569The USB device given by 570.Fa pdev 571must be opened before this function will succeed. 572This function returns zero on success else a LIBUSB20_ERROR value is returned. 573. 574.Pp 575. 576.Fn libusb20_dev_get_desc 577returns a zero terminated string describing the given USB device. 578The format of the string is: "drivername<unit>: <description>" 579. 580.Pp 581. 582.Fn libusb20_dev_close 583will close the given USB device. 584. 585This function returns zero on success else a LIBUSB20_ERROR value is 586returned. 587. 588.Pp 589. 590.Fn libusb20_dev_detach_kernel_driver 591will try to detach the kernel driver for the USB interface given by 592.Fa iface_index . 593. 594This function returns zero on success else a LIBUSB20_ERROR value is 595returned. 596. 597.Pp 598. 599.Fn libusb20_dev_set_config_index 600will try to set the configuration index on an USB 601device. 602. 603The first configuration index is zero. 604. 605The un-configure index is 255. 606. 607This function returns zero on success else a LIBUSB20_ERROR value is returned. 608. 609.Pp 610. 611.Fn libusb20_dev_get_debug 612returns the debug level of an USB device. 613. 614.Pp 615. 616.Fn libusb20_dev_get_fd 617returns the file descriptor of the given USB device. 618. 619A negative value is returned when no file descriptor is present. 620. 621The file descriptor can be used for polling purposes. 622. 623.Pp 624. 625.Fn libusb20_dev_kernel_driver_active 626returns zero if a kernel driver is active on the given USB interface. 627. 628Else a LIBUSB20_ERROR value is returned. 629. 630.Pp 631. 632.Fn libusb20_dev_open 633opens an USB device so that setting up USB transfers 634becomes possible. 635. 636The number of USB transfers can be zero which means only control 637transfers are allowed. 638. 639This function returns zero on success else a LIBUSB20_ERROR value is 640returned. 641. 642A return value of LIBUSB20_ERROR_BUSY means that the device is already 643opened. 644. 645.Pp 646. 647.Fn libusb20_dev_process 648is called to sync kernel USB transfers with userland USB 649transfers. 650. 651This function returns zero on success else a LIBUSB20_ERROR value is 652returned typically indicating that the given USB device has been 653detached. 654. 655.Pp 656. 657.Fn libusb20_dev_request_sync 658will perform a synchronous control request on the given 659USB device. 660. 661Before this call will succeed the USB device must be opened. 662. 663.Fa setup 664is a pointer to a decoded and host endian SETUP packet. 665.Fa data 666is a pointer to a data transfer buffer associated with the control transaction. This argument can be NULL. 667.Fa pactlen 668is a pointer to a variable that will hold the actual transfer length after the control transaction is complete. 669.Fa timeout 670is the transaction timeout given in milliseconds. 671A timeout of zero means no timeout. 672.Fa flags 673is used to specify transaction flags, for example LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK. 674. 675This function returns zero on success else a LIBUSB20_ERROR value is 676returned. 677. 678.Pp 679. 680.Fn libusb20_dev_req_string_sync 681will synchronously request an USB string by language ID 682and string index into the given buffer limited by a maximum length. 683. 684This function returns zero on success else a LIBUSB20_ERROR value is 685returned. 686. 687.Pp 688. 689.Fn libusb20_dev_req_string_simple_sync 690will synchronously request an USB string using the 691default language ID and convert the string into ASCII before storing 692the string into the given buffer limited by a maximum length which 693includes the terminating zero. 694. 695This function returns zero on success else a LIBUSB20_ERROR value is 696returned. 697. 698. 699.Pp 700. 701.Fn libusb20_dev_reset 702will try to BUS reset the given USB device and restore 703the last set USB configuration. 704. 705This function returns zero on success else a LIBUSB20_ERROR value is 706returned. 707. 708. 709.Pp 710. 711.Fn libusb20_dev_check_connected 712will check if an opened USB device is still connected. 713. 714This function returns zero if the device is still connected else a LIBUSB20_ERROR value is returned. 715. 716. 717.Pp 718. 719.Fn libusb20_dev_set_power_mode 720sets the power mode of the USB device. 721. 722Valid power modes: 723.Bl -tag -width "LIBUSB20_POWER_OFF" 724.It LIBUSB20_POWER_OFF 725.It LIBUSB20_POWER_ON 726.It LIBUSB20_POWER_SAVE 727.It LIBUSB20_POWER_SUSPEND 728.It LIBUSB20_POWER_RESUME 729.El 730.Pp 731. 732This function returns zero on success else a LIBUSB20_ERROR value is 733returned. 734. 735.Pp 736. 737.Fn libusb20_dev_get_power_mode 738returns the currently selected power mode for the given 739USB device. 740. 741.Pp 742. 743.Fn libusb20_dev_set_alt_index 744will try to set the given alternate index for the given 745USB interface index. 746. 747This function returns zero on success else a LIBUSB20_ERROR value is 748returned. 749. 750.Pp 751. 752.Fn libusb20_dev_get_device_desc 753returns a pointer to the decoded and host endian version 754of the device descriptor. 755. 756The USB device need not be opened when calling this function. 757. 758.Pp 759. 760.Fn libusb20_dev_alloc_config 761will read out and decode the USB config descriptor for 762the given USB device and config index. This function returns a pointer 763to the decoded configuration which must eventually be passed to 764free(). NULL is returned in case of failure. 765. 766.Pp 767. 768.Fn libusb20_dev_alloc 769is an internal function to allocate a new USB device. 770. 771.Pp 772. 773.Fn libusb20_dev_get_address 774returns the internal and not necessarily the real 775hardware address of the given USB device. 776Valid addresses start at one. 777. 778.Pp 779. 780.Fn libusb20_dev_get_parent_address 781returns the internal and not necessarily the real hardware address of 782the given parent USB HUB device. 783This value is zero for the root HUB which usually has a device address 784equal to one. 785Valid addresses start at one. 786. 787.Pp 788. 789.Fn libusb20_dev_get_parent_port 790returns the port number on the parent USB HUB device. 791This value is zero for the root HUB which usually has a device address 792equal to one. 793Valid port numbers start at one. 794. 795.Pp 796. 797.Fn libusb20_dev_get_bus_number 798returns the internal bus number which the given USB 799device belongs to. 800Valid bus numbers start at zero. 801. 802.Pp 803. 804.Fn libusb20_dev_get_mode 805returns the current operation mode of the USB entity. 806. 807Valid return values are: 808.Bl -tag -width "LIBUSB20_MODE_DEVICE" 809.It LIBUSB20_MODE_HOST 810.It LIBUSB20_MODE_DEVICE 811.El 812. 813.Pp 814. 815.Fn libusb20_dev_get_speed 816returns the current speed of the given USB device. 817. 818.Bl -tag -width "LIBUSB20_SPEED_VARIABLE" 819.It LIBUSB20_SPEED_UNKNOWN 820.It LIBUSB20_SPEED_LOW 821.It LIBUSB20_SPEED_FULL 822.It LIBUSB20_SPEED_HIGH 823.It LIBUSB20_SPEED_VARIABLE 824.It LIBUSB20_SPEED_SUPER 825.El 826. 827.Pp 828. 829.Fn libusb20_dev_get_config_index 830returns the currently selected config index for the given 831USB device. 832. 833.Pp 834. 835.Fn libusb20_dev_free 836will free the given USB device and all associated USB 837transfers. 838. 839.Pp 840. 841.Fn libusb20_dev_set_debug 842will set the debug level for the given USB device. 843. 844.Pp 845. 846.Fn libusb20_dev_wait_process 847will wait until a pending USB transfer has completed on 848the given USB device. 849. 850A timeout value can be specified which is passed on to the 851.Xr poll 2 852function. 853. 854.Sh USB BACKEND OPERATIONS 855. 856.Fn libusb20_be_get_template 857will return the currently selected global USB device 858side mode template into the integer pointer 859.Fa ptemp . 860This function returns zero on success else a LIBUSB20_ERROR value is 861returned. 862. 863.Pp 864. 865.Fn libusb20_be_set_template 866will set the global USB device side mode template to 867.Fa temp . 868The new template is not activated until after the next USB 869enumeration. 870The template number decides how the USB device will present itself to 871the USB Host, like Mass Storage Device, USB Ethernet Device. Also see 872the 873.Xr usb2_template 4 874module. 875This function returns zero on success else a LIBUSB20_ERROR value is 876returned. 877. 878.Pp 879. 880.Fn libusb20_be_get_dev_quirk 881will return the device quirk according to 882.Fa index 883into the libusb20_quirk structure pointed to by 884.Fa pq . 885This function returns zero on success else a LIBUSB20_ERROR value is 886returned. 887. 888If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 889returned. 890. 891.Pp 892. 893.Fn libusb20_be_get_quirk_name 894will return the quirk name according to 895.Fa index 896into the libusb20_quirk structure pointed to by 897.Fa pq . 898This function returns zero on success else a LIBUSB20_ERROR value is 899returned. 900. 901If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 902returned. 903. 904.Pp 905. 906.Fn libusb20_be_add_dev_quirk 907will add the libusb20_quirk structure pointed to by the 908.Fa pq 909argument into the device quirk list. 910. 911This function returns zero on success else a LIBUSB20_ERROR value is 912returned. 913. 914If the given quirk cannot be added LIBUSB20_ERROR_NO_MEM is 915returned. 916. 917.Pp 918. 919.Fn libusb20_be_remove_dev_quirk 920will remove the quirk matching the libusb20_quirk structure pointed to by the 921.Fa pq 922argument from the device quirk list. 923. 924This function returns zero on success else a LIBUSB20_ERROR value is 925returned. 926. 927If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 928returned. 929. 930.Pp 931. 932.Fn libusb20_be_alloc_default 933.Fn libusb20_be_alloc_freebsd 934.Fn libusb20_be_alloc_linux 935These functions are used to allocate a specific USB backend or the 936operating system default USB backend. Allocating a backend is a way to 937scan for currently present USB devices. 938. 939.Pp 940. 941.Fn libusb20_be_device_foreach 942is used to iterate USB devices present in a USB backend. 943. 944The starting value of 945.Fa pdev 946is NULL. 947. 948This function returns the next USB device in the list. 949. 950If NULL is returned the end of the USB device list has been reached. 951. 952.Pp 953. 954.Fn libusb20_be_dequeue_device 955will dequeue the given USB device pointer from the 956backend USB device list. 957. 958Dequeued USB devices will not be freed when the backend is freed. 959. 960.Pp 961. 962.Fn libusb20_be_enqueue_device 963will enqueue the given USB device pointer in the backend USB device list. 964. 965Enqueued USB devices will get freed when the backend is freed. 966. 967.Pp 968. 969.Fn libusb20_be_free 970will free the given backend and all USB devices in its device list. 971. 972. 973.Sh USB DESCRIPTOR PARSING 974. 975.Fn libusb20_me_get_1 pie offset 976This function will return a byte at the given byte offset of a message 977entity. 978. 979This function is safe against invalid offsets. 980. 981.Pp 982. 983.Fn libusb20_me_get_2 pie offset 984This function will return a little endian 16-bit value at the given byte offset of a message 985entity. 986. 987This function is safe against invalid offsets. 988. 989.Pp 990. 991.Fn libusb20_me_encode pbuf len pdecoded 992This function will encode a so-called *DECODED structure into binary 993format. 994. 995The total encoded length that will fit in the given buffer is 996returned. 997. 998If the buffer pointer is NULL no data will be written to the buffer 999location. 1000. 1001.Pp 1002. 1003.Fn libusb20_me_decode pbuf len pdecoded 1004This function will decode a binary structure into a so-called *DECODED 1005structure. 1006. 1007The total decoded length is returned. 1008. 1009The buffer pointer cannot be NULL. 1010. 1011. 1012.Sh USB DEBUGGING 1013.Ft const char * 1014.Fn libusb20_strerror "int code" 1015Get the ASCII representation of the error given by the 1016.Fa code 1017argument. 1018This function does not return NULL. 1019.Pp 1020.Ft const char * 1021.Fn libusb20_error_name "int code" 1022Get the ASCII representation of the error enum given by the 1023.Fa code 1024argument. 1025This function does not return NULL. 1026. 1027.Sh FILES 1028. 1029. 1030/dev/usb 1031.Sh SEE ALSO 1032.Xr usb 4 , 1033.Xr libusb 3 , 1034.Xr usbconfig 8 , 1035.Xr usbdump 8 1036. 1037. 1038.Sh HISTORY 1039. 1040. 1041Some parts of the 1042.Nm 1043API derives from the libusb project at sourceforge. 1044