1.\" 2.\" Copyright (c) 2008-2019 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.Dd December 27, 2019 28.Dt LIBUSB20 3 29.Os 30.Sh NAME 31.Nm libusb20 32. 33.Nd "USB access library" 34. 35. 36.Sh LIBRARY 37. 38. 39USB access library (libusb -lusb) 40. 41. 42. 43.Sh SYNOPSIS 44.In libusb20.h 45.Ft int 46.Fn libusb20_tr_close "struct libusb20_transfer *xfer" 47.Ft int 48.Fn libusb20_tr_open "struct libusb20_transfer *xfer" "uint32_t max_buf_size" "uint32_t max_frame_count" "uint8_t ep_no" 49.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" 50.Ft struct libusb20_transfer* 51.Fn libusb20_tr_get_pointer "struct libusb20_device *pdev" "uint16_t tr_index" 52.Ft uint16_t 53.Fn libusb20_tr_get_time_complete "struct libusb20_transfer *xfer" 54.Ft uint32_t 55.Fn libusb20_tr_get_actual_frames "struct libusb20_transfer *xfer" 56.Ft uint32_t 57.Fn libusb20_tr_get_actual_length "struct libusb20_transfer *xfer" 58.Ft uint32_t 59.Fn libusb20_tr_get_max_frames "struct libusb20_transfer *xfer" 60.Ft uint32_t 61.Fn libusb20_tr_get_max_packet_length "struct libusb20_transfer *xfer" 62.Ft uint32_t 63.Fn libusb20_tr_get_max_total_length "struct libusb20_transfer *xfer" 64.Ft uint8_t 65.Fn libusb20_tr_get_status "struct libusb20_transfer *xfer" 66.Ft uint8_t 67.Fn libusb20_tr_pending "struct libusb20_transfer *xfer" 68.Ft void 69.Fn libusb20_tr_callback_wrapper "struct libusb20_transfer *xfer" 70.Ft void 71.Fn libusb20_tr_clear_stall_sync "struct libusb20_transfer *xfer" 72.Ft void 73.Fn libusb20_tr_drain "struct libusb20_transfer *xfer" 74.Ft void 75.Fn libusb20_tr_set_buffer "struct libusb20_transfer *xfer" "void *buffer" "uint16_t fr_index" 76.Ft void 77.Fn libusb20_tr_set_callback "struct libusb20_transfer *xfer" "libusb20_tr_callback_t *cb" 78.Ft void 79.Fn libusb20_tr_set_flags "struct libusb20_transfer *xfer" "uint8_t flags" 80.Ft uint32_t 81.Fn libusb20_tr_get_length "struct libusb20_transfer *xfer" "uint16_t fr_index" 82.Ft void 83.Fn libusb20_tr_set_length "struct libusb20_transfer *xfer" "uint32_t length" "uint16_t fr_index" 84.Ft void 85.Fn libusb20_tr_set_priv_sc0 "struct libusb20_transfer *xfer" "void *sc0" 86.Ft void 87.Fn libusb20_tr_set_priv_sc1 "struct libusb20_transfer *xfer" "void *sc1" 88.Ft void 89.Fn libusb20_tr_set_timeout "struct libusb20_transfer *xfer" "uint32_t timeout" 90.Ft void 91.Fn libusb20_tr_set_total_frames "struct libusb20_transfer *xfer" "uint32_t nframes" 92.Ft void 93.Fn libusb20_tr_setup_bulk "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t timeout" 94.Ft void 95.Fn libusb20_tr_setup_control "struct libusb20_transfer *xfer" "void *psetup" "void *pbuf" "uint32_t timeout" 96.Ft void 97.Fn libusb20_tr_setup_intr "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t timeout" 98.Ft void 99.Fn libusb20_tr_setup_isoc "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint61_t fr_index" 100.Ft uint8_t 101.Fn libusb20_tr_bulk_intr_sync "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t *pactlen" "uint32_t timeout" 102.Ft void 103.Fn libusb20_tr_start "struct libusb20_transfer *xfer" 104.Ft void 105.Fn libusb20_tr_stop "struct libusb20_transfer *xfer" 106.Ft void 107.Fn libusb20_tr_submit "struct libusb20_transfer *xfer" 108.Ft void * 109.Fn libusb20_tr_get_priv_sc0 "struct libusb20_transfer *xfer" 110.Ft void * 111.Fn libusb20_tr_get_priv_sc1 "struct libusb20_transfer *xfer" 112.Ft const char * 113.Fn libusb20_dev_get_backend_name "struct libusb20_device *" 114.Ft int 115.Fn libusb20_dev_get_port_path "struct libusb20_device *pdev" "uint8_t *buf" "uint8_t bufsize" 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_get_stats "struct libusb20_device *pdev" "struct libusb20_device_stats *pstats" 124.Ft int 125.Fn libusb20_dev_close "struct libusb20_device *pdev" 126.Ft int 127.Fn libusb20_dev_detach_kernel_driver "struct libusb20_device *pdev" "uint8_t iface_index" 128.Ft int 129.Fn libusb20_dev_attach_kernel_driver "struct libusb20_device *pdev" "uint8_t iface_index" 130.Ft int 131.Fn libusb20_dev_set_config_index "struct libusb20_device *pdev" "uint8_t configIndex" 132.Ft int 133.Fn libusb20_dev_get_debug "struct libusb20_device *pdev" 134.Ft int 135.Fn libusb20_dev_get_fd "struct libusb20_device *pdev" 136.Ft int 137.Fn libusb20_dev_kernel_driver_active "struct libusb20_device *pdev" "uint8_t iface_index" 138.Ft int 139.Fn libusb20_dev_open "struct libusb20_device *pdev" "uint16_t transfer_max" 140.Ft int 141.Fn libusb20_dev_process "struct libusb20_device *pdev" 142.Ft int 143.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" 144.Ft int 145.Fn libusb20_dev_req_string_sync "struct libusb20_device *pdev" "uint8_t index" "uint16_t langid" "void *ptr" "uint16_t len" 146.Ft int 147.Fn libusb20_dev_req_string_simple_sync "struct libusb20_device *pdev" "uint8_t index" "void *ptr" "uint16_t len" 148.Ft int 149.Fn libusb20_dev_reset "struct libusb20_device *pdev" 150.Ft int 151.Fn libusb20_dev_check_connected "struct libusb20_device *pdev" 152.Ft int 153.Fn libusb20_dev_set_power_mode "struct libusb20_device *pdev" "uint8_t power_mode" 154.Ft uint8_t 155.Fn libusb20_dev_get_power_mode "struct libusb20_device *pdev" 156.Ft uint16_t 157.Fn libusb20_dev_get_power_usage "struct libusb20_device *pdev" 158.Ft int 159.Fn libusb20_dev_set_alt_index "struct libusb20_device *pdev" "uint8_t iface_index" "uint8_t alt_index" 160.Ft struct LIBUSB20_DEVICE_DESC_DECODED * 161.Fn libusb20_dev_get_device_desc "struct libusb20_device *pdev" 162.Ft struct libusb20_config * 163.Fn libusb20_dev_alloc_config "struct libusb20_device *pdev" "uint8_t config_index" 164.Ft struct libusb20_device * 165.Fn libusb20_dev_alloc "void" 166.Ft uint8_t 167.Fn libusb20_dev_get_address "struct libusb20_device *pdev" 168.Ft uint8_t 169.Fn libusb20_dev_get_parent_address "struct libusb20_device *pdev" 170.Ft uint8_t 171.Fn libusb20_dev_get_parent_port "struct libusb20_device *pdev" 172.Ft uint8_t 173.Fn libusb20_dev_get_bus_number "struct libusb20_device *pdev" 174.Ft uint8_t 175.Fn libusb20_dev_get_mode "struct libusb20_device *pdev" 176.Ft uint8_t 177.Fn libusb20_dev_get_speed "struct libusb20_device *pdev" 178.Ft uint8_t 179.Fn libusb20_dev_get_config_index "struct libusb20_device *pdev" 180.Ft void 181.Fn libusb20_dev_free "struct libusb20_device *pdev" 182.Ft void 183.Fn libusb20_dev_set_debug "struct libusb20_device *pdev" "int debug" 184.Ft void 185.Fn libusb20_dev_wait_process "struct libusb20_device *pdev" "int timeout" 186.Ft int 187.Fn libusb20_be_get_template "struct libusb20_backend *pbe" "int *ptemp" 188.Ft int 189.Fn libusb20_be_set_template "struct libusb20_backend *pbe" "int temp" 190.Ft int 191.Fn libusb20_be_get_dev_quirk "struct libusb20_backend *pber" "uint16_t index" "struct libusb20_quirk *pq" 192.Ft int 193.Fn libusb20_be_get_quirk_name "struct libusb20_backend *pbe" "uint16_t index" "struct libusb20_quirk *pq" 194.Ft int 195.Fn libusb20_be_add_dev_quirk "struct libusb20_backend *pbe" "struct libusb20_quirk *pq" 196.Ft int 197.Fn libusb20_be_remove_dev_quirk "struct libusb20_backend *pbe" "struct libusb20_quirk *pq" 198.Ft struct libusb20_backend * 199.Fn libusb20_be_alloc_default "void" 200.Ft struct libusb20_backend * 201.Fn libusb20_be_alloc_freebsd "void" 202.Ft struct libusb20_backend * 203.Fn libusb20_be_alloc_linux "void" 204.Ft struct libusb20_device * 205.Fn libusb20_be_device_foreach "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 206.Ft void 207.Fn libusb20_be_dequeue_device "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 208.Ft void 209.Fn libusb20_be_enqueue_device "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 210.Ft void 211.Fn libusb20_be_free "struct libusb20_backend *pbe" 212.Ft uint8_t 213.Fn libusb20_me_get_1 "const struct libusb20_me_struct *me" "uint16_t off" 214.Ft uint16_t 215.Fn libusb20_me_get_2 "const struct libusb20_me_struct *me" "uint16_t off" 216.Ft uint16_t 217.Fn libusb20_me_encode "void *pdata" "uint16_t len" "const void *pdecoded" 218.Ft uint16_t 219.Fn libusb20_me_decode "const void *pdata" "uint16_t len" "void *pdecoded" 220.Ft "const uint8_t *" 221.Fn libusb20_desc_foreach "const struct libusb20_me_struct *me" "const uint8_t *pdesc" 222.Ft "const char *" 223.Fn libusb20_strerror "int code" 224.Ft "const char *" 225.Fn libusb20_error_name "int code" 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 transfers when doing echo 319cancelling. 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.Pp 328. 329.Fn libusb20_tr_get_actual_length 330will return the sum of the actual length for all 331transferred USB frames for the given USB transfer. 332. 333.Pp 334. 335.Fn libusb20_tr_get_max_frames 336will return the maximum number of USB frames that were 337allocated when an USB transfer was setup for the given USB transfer. 338. 339.Pp 340. 341.Fn libusb20_tr_get_max_packet_length 342will return the maximum packet length in bytes 343associated with the given USB transfer. 344. 345The packet length can be used round up buffer sizes so that short USB 346packets are avoided for proxy buffers. 347. 348. 349.Pp 350. 351.Fn libusb20_tr_get_max_total_length 352will return the maximum value for the data length sum of all USB 353frames associated with an USB transfer. 354In case of control transfers the value returned does not include the 355length of the SETUP packet, 8 bytes, which is part of frame zero. 356The returned value of this function is always aligned to the maximum 357packet size, wMaxPacketSize, of the endpoint which the USB transfer is 358bound to. 359. 360.Pp 361. 362.Fn libusb20_tr_get_status 363will return the status of an USB transfer. 364. 365Status values are defined by a set of LIBUSB20_TRANSFER_XXX enums. 366. 367.Pp 368. 369.Fn libusb20_tr_pending 370will return non-zero if the given USB transfer is 371pending for completion. 372. 373Else this function returns zero. 374. 375.Pp 376. 377.Fn libusb20_tr_callback_wrapper 378This is an internal function used to wrap asynchronous USB callbacks. 379. 380.Pp 381. 382.Fn libusb20_tr_clear_stall_sync 383This is an internal function used to synchronously clear the stall on 384the given USB transfer. 385. 386Please see the USB specification for more information on stall 387clearing. 388. 389If the given USB transfer is pending when this function is called, the 390USB transfer will complete with an error after that this function has 391been called. 392. 393.Pp 394. 395.Fn libusb20_tr_drain 396will stop the given USB transfer and will not return 397until the USB transfer has been stopped in hardware. 398. 399.Pp 400. 401.Fn libusb20_tr_set_buffer 402is used to set the 403.Fa buffer 404pointer for the given USB transfer and 405.Fa fr_index . 406. 407Typically the frame index is zero. 408. 409. 410.Pp 411. 412.Fn libusb20_tr_set_callback 413is used to set the USB callback for asynchronous USB 414transfers. 415. 416The callback type is defined by libusb20_tr_callback_t. 417. 418.Pp 419. 420.Fn libusb20_tr_set_flags 421is used to set various USB flags for the given USB transfer. 422.Bl -tag -width "LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK" 423.It LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK 424Report a short frame as error. 425.It LIBUSB20_TRANSFER_MULTI_SHORT_NOT_OK 426Multiple short frames are not allowed. 427.It LIBUSB20_TRANSFER_FORCE_SHORT 428All transmitted frames are short terminated. 429.It LIBUSB20_TRANSFER_DO_CLEAR_STALL 430Will do a clear-stall before starting the transfer. 431.El 432. 433.Pp 434. 435.Fn libusb20_tr_get_length 436returns the length of the given USB frame by index. 437After an USB transfer is complete the USB frame length will get updated to the actual transferred length. 438. 439.Pp 440. 441.Fn libusb20_tr_set_length 442sets the length of the given USB frame by index. 443. 444.Pp 445. 446.Fn libusb20_tr_set_priv_sc0 447sets private driver pointer number zero. 448. 449.Pp 450. 451.Fn libusb20_tr_set_priv_sc1 452sets private driver pointer number one. 453. 454.Pp 455. 456.Fn libusb20_tr_set_timeout 457sets the timeout for the given USB transfer. 458. 459A timeout value of zero means no timeout. 460. 461The timeout is given in milliseconds. 462. 463.Pp 464. 465.Fn libusb20_tr_set_total_frames 466sets the total number of frames that should be executed when the USB transfer is submitted. 467. 468The total number of USB frames must be less than the maximum number of USB frames associated with the given USB transfer. 469. 470.Pp 471. 472.Fn libusb20_tr_setup_bulk 473is a helper function for setting up a single frame USB BULK transfer. 474. 475.Pp 476. 477.Fn libusb20_tr_setup_control 478is a helper function for setting up a single or dual 479frame USB CONTROL transfer depending on the control transfer length. 480. 481.Pp 482. 483.Fn libusb20_tr_setup_intr 484is a helper function for setting up a single frame USB INTERRUPT transfer. 485. 486.Pp 487. 488.Fn libusb20_tr_setup_isoc 489is a helper function for setting up a multi frame USB ISOCHRONOUS transfer. 490. 491.Pp 492. 493.Fn libusb20_tr_bulk_intr_sync 494will perform a synchronous BULK or INTERRUPT transfer having length given by the 495.Fa length 496argument and buffer pointer given by the 497.Fa pbuf 498argument on the USB transfer given by the 499.Fa xfer 500argument. 501. 502If the 503.Fa pactlen 504argument is non-NULL the actual transfer length will be stored at the given pointer destination. 505. 506If the 507.Fa timeout 508argument is non-zero the transfer will timeout after the given value in milliseconds. 509. 510This function does not change the transfer flags, like short packet not ok. 511. 512This function returns zero on success else a LIBUSB20_TRANSFER_XXX value is returned. 513. 514.Pp 515. 516.Fn libusb20_tr_start 517will get the USB transfer started, if not already 518started. 519. 520This function will not get the transfer queued in hardware. 521. 522This function is non-blocking. 523. 524.Pp 525. 526.Fn libusb20_tr_stop 527will get the USB transfer stopped, if not already stopped. 528. 529This function is non-blocking, which means that the actual stop can 530happen after the return of this function. 531. 532.Pp 533. 534.Fn libusb20_tr_submit 535will get the USB transfer queued in hardware. 536. 537. 538.Pp 539. 540.Fn libusb20_tr_get_priv_sc0 541returns private driver pointer number zero associated 542with an USB transfer. 543. 544. 545.Pp 546. 547.Fn libusb20_tr_get_priv_sc1 548returns private driver pointer number one associated 549with an USB transfer. 550. 551. 552.Sh USB DEVICE OPERATIONS 553. 554. 555.Fn libusb20_dev_get_backend_name 556returns a zero terminated string describing the backend used. 557. 558.Pp 559. 560.Fn libusb20_dev_get_port_path 561retrieves the list of USB port numbers which the datastream for a given USB device follows. 562The first port number is the Root HUB port number. 563Then children port numbers follow. 564The Root HUB device itself has a port path length of zero. 565Valid port numbers start at one and range until and including 255. 566Typically there should not be more than 16 levels, due to electrical and protocol limitations. 567This functions returns the number of actual port levels upon success 568else a LIBUSB20_ERROR value is returned which are always negative. 569If the actual number of port levels is greater than the maximum 570specified, a LIBUSB20_ERROR value is returned. 571. 572.Pp 573. 574.Fn libusb20_dev_get_info 575retrieves the BSD specific usb_device_info structure into the memory location given by 576.Fa pinfo . 577The USB device given by 578.Fa pdev 579must be opened before this function will succeed. 580This function returns zero on success else a LIBUSB20_ERROR value is returned. 581. 582.Pp 583. 584.Fn libusb20_dev_get_iface_desc 585retrieves the kernel interface description for the given USB 586.Fa iface_index . 587The format of the USB interface description is: "drivername<unit>: <description>" 588The description string is always zero terminated. 589A zero length string is written in case no driver is attached to the given interface. 590The USB device given by 591.Fa pdev 592must be opened before this function will succeed. 593This function returns zero on success else a LIBUSB20_ERROR value is returned. 594. 595.Pp 596. 597.Fn libusb20_dev_get_desc 598returns a zero terminated string describing the given USB device. 599The format of the string is: "drivername<unit>: <description>" 600. 601.Pp 602. 603.Fn libusb20_dev_get_stats 604retrieves the device statistics into the structure pointed to by the 605.Fa pstats 606argument. 607This function returns zero on success else a LIBUSB20_ERROR value is returned. 608. 609.Pp 610. 611.Fn libusb20_dev_close 612will close the given USB device. 613. 614This function returns zero on success else a LIBUSB20_ERROR value is 615returned. 616. 617.Pp 618. 619.Fn libusb20_dev_detach_kernel_driver 620will try to detach the kernel driver for the USB interface given by 621.Fa iface_index . 622. 623This function returns zero on success else a LIBUSB20_ERROR value is 624returned. 625. 626.Pp 627. 628.Fn libusb20_dev_attach_kernel_driver 629will try to attach the kernel driver for the USB interface given by 630.Fa iface_index . 631. 632This function returns zero on success else a LIBUSB20_ERROR value is 633returned. 634. 635.Pp 636. 637.Fn libusb20_dev_set_config_index 638will try to set the configuration index on an USB 639device. 640. 641The first configuration index is zero. 642. 643The un-configure index is 255. 644. 645This function returns zero on success else a LIBUSB20_ERROR value is returned. 646. 647.Pp 648. 649.Fn libusb20_dev_get_debug 650returns the debug level of an USB device. 651. 652.Pp 653. 654.Fn libusb20_dev_get_fd 655returns the file descriptor of the given USB device. 656. 657A negative value is returned when no file descriptor is present. 658. 659The file descriptor can be used for polling purposes. 660. 661.Pp 662. 663.Fn libusb20_dev_kernel_driver_active 664returns zero if a kernel driver is active on the given USB interface. 665. 666Else a LIBUSB20_ERROR value is returned. 667. 668.Pp 669. 670.Fn libusb20_dev_open 671opens an USB device so that setting up USB transfers 672becomes possible. 673. 674The number of USB transfers can be zero which means only control 675transfers are allowed. 676. 677This function returns zero on success else a LIBUSB20_ERROR value is 678returned. 679. 680A return value of LIBUSB20_ERROR_BUSY means that the device is already 681opened. 682. 683.Pp 684. 685.Fn libusb20_dev_process 686is called to sync kernel USB transfers with userland USB 687transfers. 688. 689This function returns zero on success else a LIBUSB20_ERROR value is 690returned typically indicating that the given USB device has been 691detached. 692. 693.Pp 694. 695.Fn libusb20_dev_request_sync 696will perform a synchronous control request on the given 697USB device. 698. 699Before this call will succeed the USB device must be opened. 700. 701.Fa setup 702is a pointer to a decoded and host endian SETUP packet. 703.Fa data 704is a pointer to a data transfer buffer associated with the control transaction. 705This argument can be NULL. 706.Fa pactlen 707is a pointer to a variable that will hold the actual transfer length after the 708control transaction is complete. 709.Fa timeout 710is the transaction timeout given in milliseconds. 711A timeout of zero means no timeout. 712.Fa flags 713is used to specify transaction flags, for example LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK. 714. 715This function returns zero on success else a LIBUSB20_ERROR value is 716returned. 717. 718.Pp 719. 720.Fn libusb20_dev_req_string_sync 721will synchronously request an USB string by language ID 722and string index into the given buffer limited by a maximum length. 723. 724This function returns zero on success else a LIBUSB20_ERROR value is 725returned. 726. 727.Pp 728. 729.Fn libusb20_dev_req_string_simple_sync 730will synchronously request an USB string using the 731default language ID and convert the string into ASCII before storing 732the string into the given buffer limited by a maximum length which 733includes the terminating zero. 734. 735This function returns zero on success else a LIBUSB20_ERROR value is 736returned. 737. 738. 739.Pp 740. 741.Fn libusb20_dev_reset 742will try to BUS reset the given USB device and restore 743the last set USB configuration. 744. 745This function returns zero on success else a LIBUSB20_ERROR value is 746returned. 747. 748. 749.Pp 750. 751.Fn libusb20_dev_check_connected 752will check if an opened USB device is still connected. 753. 754This function returns zero if the device is still connected else a LIBUSB20_ERROR value is returned. 755. 756. 757.Pp 758. 759.Fn libusb20_dev_set_power_mode 760sets the power mode of the USB device. 761. 762Valid power modes: 763.Bl -tag -width "LIBUSB20_POWER_OFF" 764.It LIBUSB20_POWER_OFF 765.It LIBUSB20_POWER_ON 766.It LIBUSB20_POWER_SAVE 767.It LIBUSB20_POWER_SUSPEND 768.It LIBUSB20_POWER_RESUME 769.El 770.Pp 771. 772This function returns zero on success else a LIBUSB20_ERROR value is 773returned. 774. 775.Pp 776. 777.Fn libusb20_dev_get_power_mode 778returns the currently selected power mode for the given 779USB device. 780. 781.Pp 782. 783.Fn libusb20_dev_get_power_usage 784returns the reported power usage in milliamps for the given USB device. 785A power usage of zero typically means that the device is self powered. 786. 787.Pp 788. 789.Fn libusb20_dev_set_alt_index 790will try to set the given alternate index for the given 791USB interface index. 792. 793This function returns zero on success else a LIBUSB20_ERROR value is 794returned. 795. 796.Pp 797. 798.Fn libusb20_dev_get_device_desc 799returns a pointer to the decoded and host endian version 800of the device descriptor. 801. 802The USB device need not be opened when calling this function. 803. 804.Pp 805. 806.Fn libusb20_dev_alloc_config 807will read out and decode the USB config descriptor for the given USB device 808and config index. 809This function returns a pointer to the decoded configuration which must eventually 810be passed to free(). 811NULL is returned in case of failure. 812. 813.Pp 814. 815.Fn libusb20_dev_alloc 816is an internal function to allocate a new USB device. 817. 818.Pp 819. 820.Fn libusb20_dev_get_address 821returns the internal and not necessarily the real 822hardware address of the given USB device. 823Valid addresses start at one. 824. 825.Pp 826. 827.Fn libusb20_dev_get_parent_address 828returns the internal and not necessarily the real hardware address of 829the given parent USB HUB device. 830This value is zero for the root HUB which usually has a device address 831equal to one. 832Valid addresses start at one. 833. 834.Pp 835. 836.Fn libusb20_dev_get_parent_port 837returns the port number on the parent USB HUB device. 838This value is zero for the root HUB which usually has a device address 839equal to one. 840Valid port numbers start at one. 841. 842.Pp 843. 844.Fn libusb20_dev_get_bus_number 845returns the internal bus number which the given USB 846device belongs to. 847Valid bus numbers start at zero. 848. 849.Pp 850. 851.Fn libusb20_dev_get_mode 852returns the current operation mode of the USB entity. 853. 854Valid return values are: 855.Bl -tag -width "LIBUSB20_MODE_DEVICE" 856.It LIBUSB20_MODE_HOST 857.It LIBUSB20_MODE_DEVICE 858.El 859. 860.Pp 861. 862.Fn libusb20_dev_get_speed 863returns the current speed of the given USB device. 864. 865.Bl -tag -width "LIBUSB20_SPEED_VARIABLE" 866.It LIBUSB20_SPEED_UNKNOWN 867.It LIBUSB20_SPEED_LOW 868.It LIBUSB20_SPEED_FULL 869.It LIBUSB20_SPEED_HIGH 870.It LIBUSB20_SPEED_VARIABLE 871.It LIBUSB20_SPEED_SUPER 872.It LIBUSB20_SPEED_SUPER_PLUS 873.El 874. 875.Pp 876. 877.Fn libusb20_dev_get_config_index 878returns the currently selected config index for the given 879USB device. 880. 881.Pp 882. 883.Fn libusb20_dev_free 884will free the given USB device and all associated USB 885transfers. 886. 887.Pp 888. 889.Fn libusb20_dev_set_debug 890will set the debug level for the given USB device. 891. 892.Pp 893. 894.Fn libusb20_dev_wait_process 895will wait until a pending USB transfer has completed on 896the given USB device. 897. 898A timeout value can be specified which is passed on to the 899.Xr poll 2 900function. 901. 902.Sh USB BACKEND OPERATIONS 903. 904.Fn libusb20_be_get_template 905will return the currently selected global USB device 906side mode template into the integer pointer 907.Fa ptemp . 908This function returns zero on success else a LIBUSB20_ERROR value is 909returned. 910. 911.Pp 912. 913.Fn libusb20_be_set_template 914will set the global USB device side mode template to 915.Fa temp . 916The new template is not activated until after the next USB 917enumeration. 918The template number decides how the USB device will present itself to 919the USB Host, like Mass Storage Device, USB Ethernet Device. 920Also see the 921.Xr usb2_template 4 922module. 923This function returns zero on success else a LIBUSB20_ERROR value is 924returned. 925. 926.Pp 927. 928.Fn libusb20_be_get_dev_quirk 929will return the device quirk according to 930.Fa index 931into the libusb20_quirk structure pointed to by 932.Fa pq . 933This function returns zero on success else a LIBUSB20_ERROR value is 934returned. 935. 936If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 937returned. 938. 939.Pp 940. 941.Fn libusb20_be_get_quirk_name 942will return the quirk name according to 943.Fa index 944into the libusb20_quirk structure pointed to by 945.Fa pq . 946This function returns zero on success else a LIBUSB20_ERROR value is 947returned. 948. 949If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 950returned. 951. 952.Pp 953. 954.Fn libusb20_be_add_dev_quirk 955will add the libusb20_quirk structure pointed to by the 956.Fa pq 957argument into the device quirk list. 958. 959This function returns zero on success else a LIBUSB20_ERROR value is 960returned. 961. 962If the given quirk cannot be added LIBUSB20_ERROR_NO_MEM is 963returned. 964. 965.Pp 966. 967.Fn libusb20_be_remove_dev_quirk 968will remove the quirk matching the libusb20_quirk structure pointed to by the 969.Fa pq 970argument from the device quirk list. 971. 972This function returns zero on success else a LIBUSB20_ERROR value is 973returned. 974. 975If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 976returned. 977. 978.Pp 979. 980.Fn libusb20_be_alloc_default 981.Fn libusb20_be_alloc_freebsd 982.Fn libusb20_be_alloc_linux 983These functions are used to allocate a specific USB backend or the operating system 984default USB backend. 985Allocating a backend is a way to scan for currently present USB devices. 986.Pp 987. 988.Fn libusb20_be_device_foreach 989is used to iterate USB devices present in a USB backend. 990. 991The starting value of 992.Fa pdev 993is NULL. 994. 995This function returns the next USB device in the list. 996. 997If NULL is returned the end of the USB device list has been reached. 998. 999.Pp 1000. 1001.Fn libusb20_be_dequeue_device 1002will dequeue the given USB device pointer from the 1003backend USB device list. 1004. 1005Dequeued USB devices will not be freed when the backend is freed. 1006. 1007.Pp 1008. 1009.Fn libusb20_be_enqueue_device 1010will enqueue the given USB device pointer in the backend USB device list. 1011. 1012Enqueued USB devices will get freed when the backend is freed. 1013. 1014.Pp 1015. 1016.Fn libusb20_be_free 1017will free the given backend and all USB devices in its device list. 1018. 1019. 1020.Sh USB DESCRIPTOR PARSING 1021. 1022.Fn libusb20_me_get_1 pie offset 1023This function will return a byte at the given byte offset of a message 1024entity. 1025. 1026This function is safe against invalid offsets. 1027. 1028.Pp 1029. 1030.Fn libusb20_me_get_2 pie offset 1031This function will return a little endian 16-bit value at the given byte offset of a message 1032entity. 1033. 1034This function is safe against invalid offsets. 1035. 1036.Pp 1037. 1038.Fn libusb20_me_encode pbuf len pdecoded 1039This function will encode a so-called *DECODED structure into binary 1040format. 1041. 1042The total encoded length that will fit in the given buffer is 1043returned. 1044. 1045If the buffer pointer is NULL no data will be written to the buffer 1046location. 1047. 1048.Pp 1049. 1050.Fn libusb20_me_decode pbuf len pdecoded 1051This function will decode a binary structure into a so-called *DECODED 1052structure. 1053. 1054The total decoded length is returned. 1055. 1056The buffer pointer cannot be NULL. 1057. 1058. 1059.Sh USB DEBUGGING 1060.Ft const char * 1061.Fn libusb20_strerror "int code" 1062Get the ASCII representation of the error given by the 1063.Fa code 1064argument. 1065This function does not return NULL. 1066.Pp 1067.Ft const char * 1068.Fn libusb20_error_name "int code" 1069Get the ASCII representation of the error enum given by the 1070.Fa code 1071argument. 1072This function does not return NULL. 1073. 1074.Sh FILES 1075.Bl -tag -width Pa 1076.It Pa /dev/usb 1077.El 1078.Sh SEE ALSO 1079.Xr libusb 3 , 1080.Xr usb 4 , 1081.Xr usbconfig 8 , 1082.Xr usbdump 8 1083. 1084. 1085.Sh HISTORY 1086. 1087. 1088Some parts of the 1089.Nm 1090API derives from the libusb project at sourceforge. 1091