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 October 14, 2010 30.Dt LIBUSB20 3 31.Os 32.Sh NAME 33.Nm libusb20 34. 35.Nd "USB access library" 36. 37. 38.Sh LIBRARY 39. 40. 41USB access library (libusb -lusb) 42. 43. 44. 45.Sh SYNOPSIS 46.In libusb20.h 47.Ft int 48.Fn libusb20_tr_close "struct libusb20_transfer *xfer" 49.Ft int 50.Fn libusb20_tr_open "struct libusb20_transfer *xfer" "uint32_t max_buf_size" "uint32_t max_frame_count" "uint8_t ep_no" 51.Ft struct libusb20_transfer* 52.Fn libusb20_tr_get_pointer "struct libusb20_device *pdev" "uint16_t tr_index" 53.Ft uint16_t 54.Fn libusb20_tr_get_time_complete "struct libusb20_transfer *xfer" 55.Ft uint32_t 56.Fn libusb20_tr_get_actual_frames "struct libusb20_transfer *xfer" 57.Ft uint32_t 58.Fn libusb20_tr_get_actual_length "struct libusb20_transfer *xfer" 59.Ft uint32_t 60.Fn libusb20_tr_get_max_frames "struct libusb20_transfer *xfer" 61.Ft uint32_t 62.Fn libusb20_tr_get_max_packet_length "struct libusb20_transfer *xfer" 63.Ft uint32_t 64.Fn libusb20_tr_get_max_total_length "struct libusb20_transfer *xfer" 65.Ft uint8_t 66.Fn libusb20_tr_get_status "struct libusb20_transfer *xfer" 67.Ft uint8_t 68.Fn libusb20_tr_pending "struct libusb20_transfer *xfer" 69.Ft void 70.Fn libusb20_tr_callback_wrapper "struct libusb20_transfer *xfer" 71.Ft void 72.Fn libusb20_tr_clear_stall_sync "struct libusb20_transfer *xfer" 73.Ft void 74.Fn libusb20_tr_drain "struct libusb20_transfer *xfer" 75.Ft void 76.Fn libusb20_tr_set_buffer "struct libusb20_transfer *xfer" "void *buffer" "uint16_t fr_index" 77.Ft void 78.Fn libusb20_tr_set_callback "struct libusb20_transfer *xfer" "libusb20_tr_callback_t *cb" 79.Ft void 80.Fn libusb20_tr_set_flags "struct libusb20_transfer *xfer" "uint8_t flags" 81.Ft uint32_t 82.Fn libusb20_tr_get_length "struct libusb20_transfer *xfer" "uint16_t fr_index" 83.Ft void 84.Fn libusb20_tr_set_length "struct libusb20_transfer *xfer" "uint32_t length" "uint16_t fr_index" 85.Ft void 86.Fn libusb20_tr_set_priv_sc0 "struct libusb20_transfer *xfer" "void *sc0" 87.Ft void 88.Fn libusb20_tr_set_priv_sc1 "struct libusb20_transfer *xfer" "void *sc1" 89.Ft void 90.Fn libusb20_tr_set_timeout "struct libusb20_transfer *xfer" "uint32_t timeout" 91.Ft void 92.Fn libusb20_tr_set_total_frames "struct libusb20_transfer *xfer" "uint32_t nframes" 93.Ft void 94.Fn libusb20_tr_setup_bulk "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t timeout" 95.Ft void 96.Fn libusb20_tr_setup_control "struct libusb20_transfer *xfer" "void *psetup" "void *pbuf" "uint32_t timeout" 97.Ft void 98.Fn libusb20_tr_setup_intr "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t timeout" 99.Ft void 100.Fn libusb20_tr_setup_isoc "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint61_t fr_index" 101.Ft uint8_t 102.Fn libusb20_tr_bulk_intr_sync "struct libusb20_transfer *xfer" "void *pbuf" "uint32_t length" "uint32_t *pactlen" "uint32_t timeout" 103.Ft void 104.Fn libusb20_tr_start "struct libusb20_transfer *xfer" 105.Ft void 106.Fn libusb20_tr_stop "struct libusb20_transfer *xfer" 107.Ft void 108.Fn libusb20_tr_submit "struct libusb20_transfer *xfer" 109.Ft void * 110.Fn libusb20_tr_get_priv_sc0 "struct libusb20_transfer *xfer" 111.Ft void * 112.Fn libusb20_tr_get_priv_sc1 "struct libusb20_transfer *xfer" 113.Ft const char * 114.Fn libusb20_dev_get_backend_name "struct libusb20_device *" 115.Ft int 116.Fn libusb20_dev_get_info "struct libusb20_device *pdev" "struct usb_device_info *pinfo" 117.Ft int 118.Fn libusb20_dev_get_iface_desc "struct libusb20_device *pdev" "uint8_t iface_index" "char *buf" "uint8_t len" 119.Ft const char * 120.Fn libusb20_dev_get_desc "struct libusb20_device *pdev" 121.Ft int 122.Fn libusb20_dev_close "struct libusb20_device *pdev" 123.Ft int 124.Fn libusb20_dev_detach_kernel_driver "struct libusb20_device *pdev" "uint8_t iface_index" 125.Ft int 126.Fn libusb20_dev_set_config_index "struct libusb20_device *pdev" "uint8_t configIndex" 127.Ft int 128.Fn libusb20_dev_get_debug "struct libusb20_device *pdev" 129.Ft int 130.Fn libusb20_dev_get_fd "struct libusb20_device *pdev" 131.Ft int 132.Fn libusb20_dev_kernel_driver_active "struct libusb20_device *pdev" "uint8_t iface_index" 133.Ft int 134.Fn libusb20_dev_open "struct libusb20_device *pdev" "uint16_t transfer_max" 135.Ft int 136.Fn libusb20_dev_process "struct libusb20_device *pdev" 137.Ft int 138.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" 139.Ft int 140.Fn libusb20_dev_req_string_sync "struct libusb20_device *pdev" "uint8_t index" "uint16_t langid" "void *ptr" "uint16_t len" 141.Ft int 142.Fn libusb20_dev_req_string_simple_sync "struct libusb20_device *pdev" "uint8_t index" "void *ptr" "uint16_t len" 143.Ft int 144.Fn libusb20_dev_reset "struct libusb20_device *pdev" 145.Ft int 146.Fn libusb20_dev_check_connected "struct libusb20_device *pdev" 147.Ft int 148.Fn libusb20_dev_set_power_mode "struct libusb20_device *pdev" "uint8_t power_mode" 149.Ft uint8_t 150.Fn libusb20_dev_get_power_mode "struct libusb20_device *pdev" 151.Ft int 152.Fn libusb20_dev_set_alt_index "struct libusb20_device *pdev" "uint8_t iface_index" "uint8_t alt_index" 153.Ft struct LIBUSB20_DEVICE_DESC_DECODED * 154.Fn libusb20_dev_get_device_desc "struct libusb20_device *pdev" 155.Ft struct libusb20_config * 156.Fn libusb20_dev_alloc_config "struct libusb20_device *pdev" "uint8_t config_index" 157.Ft struct libusb20_device * 158.Fn libusb20_dev_alloc "void" 159.Ft uint8_t 160.Fn libusb20_dev_get_address "struct libusb20_device *pdev" 161.Ft uint8_t 162.Fn libusb20_dev_get_bus_number "struct libusb20_device *pdev" 163.Ft uint8_t 164.Fn libusb20_dev_get_mode "struct libusb20_device *pdev" 165.Ft uint8_t 166.Fn libusb20_dev_get_speed "struct libusb20_device *pdev" 167.Ft uint8_t 168.Fn libusb20_dev_get_config_index "struct libusb20_device *pdev" 169.Ft void 170.Fn libusb20_dev_free "struct libusb20_device *pdev" 171.Ft void 172.Fn libusb20_dev_set_debug "struct libusb20_device *pdev" "int debug" 173.Ft void 174.Fn libusb20_dev_wait_process "struct libusb20_device *pdev" "int timeout" 175.Ft int 176.Fn libusb20_be_get_template "struct libusb20_backend *pbe" "int *ptemp" 177.Ft int 178.Fn libusb20_be_set_template "struct libusb20_backend *pbe" "int temp" 179.Ft int 180.Fn libusb20_be_get_dev_quirk "struct libusb20_backend *pber" "uint16_t index" "struct libusb20_quirk *pq" 181.Ft int 182.Fn libusb20_be_get_quirk_name "struct libusb20_backend *pbe" "uint16_t index" "struct libusb20_quirk *pq" 183.Ft int 184.Fn libusb20_be_add_dev_quirk "struct libusb20_backend *pbe" "struct libusb20_quirk *pq" 185.Ft int 186.Fn libusb20_be_remove_dev_quirk "struct libusb20_backend *pbe" "struct libusb20_quirk *pq" 187.Ft struct libusb20_backend * 188.Fn libusb20_be_alloc_default "void" 189.Ft struct libusb20_backend * 190.Fn libusb20_be_alloc_freebsd "void" 191.Ft struct libusb20_backend * 192.Fn libusb20_be_alloc_linux "void" 193.Ft struct libusb20_device * 194.Fn libusb20_be_device_foreach "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 195.Ft void 196.Fn libusb20_be_dequeue_device "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 197.Ft void 198.Fn libusb20_be_enqueue_device "struct libusb20_backend *pbe" "struct libusb20_device *pdev" 199.Ft void 200.Fn libusb20_be_free "struct libusb20_backend *pbe" 201.Ft uint8_t 202.Fn libusb20_me_get_1 "const struct libusb20_me_struct *me" "uint16_t off" 203.Ft uint16_t 204.Fn libusb20_me_get_2 "const struct libusb20_me_struct *me" "uint16_t off" 205.Ft uint16_t 206.Fn libusb20_me_encode "void *pdata" "uint16_t len" "const void *pdecoded" 207.Ft uint16_t 208.Fn libusb20_me_decode "const void *pdata" "uint16_t len" "void *pdecoded" 209.Ft "const uint8_t *" 210.Fn libusb20_desc_foreach "const struct libusb20_me_struct *me" "const uint8_t *pdesc" 211. 212. 213.Sh DESCRIPTION 214. 215The 216.Nm 217library implements functions to be able to easily access and control 218USB through the USB file system interface. 219The 220.Nm 221interfaces are specific to the 222.Fx 223usb stack and are not available on other operating systems, portable 224applications should consider using 225.Xr libusb 3 . 226. 227. 228.Sh USB TRANSFER OPERATIONS 229. 230.Pp 231. 232.Fn libusb20_tr_close 233will release all kernel resources associated with an USB 234.Fa xfer . 235. 236This function returns zero upon success. 237. 238Non-zero return values indicate a LIBUSB20_ERROR value. 239. 240.Pp 241. 242.Fn libusb20_tr_open 243will allocate kernel buffer resources according to 244.Fa max_buf_size 245and 246.Fa max_frame_count 247associated with an USB 248.Fa pxfer 249and bind the transfer to the specified 250.Fa ep_no . 251.Fa max_buf_size 252is the minimum buffer size which the data transport layer has to support. 253If 254.Fa max_buf_size 255is zero, the 256.Nm 257library will use wMaxPacketSize to compute the buffer size. 258This can be useful for isochronous transfers. 259The actual buffer size can be greater than 260.Fa max_buf_size 261and is returned by 262.Fn libusb20_tr_get_max_total_length . 263. 264If 265.Fa max_frame_count 266is OR'ed with LIBUSB20_MAX_FRAME_PRE_SCALE the remaining part of the 267argument is converted from milliseconds into the actual number of 268frames rounded up, when this function returns. 269This flag is only valid for ISOCHRONOUS transfers and has no effect 270for other transfer types. 271The actual number of frames setup is found by calling 272.Fn libusb20_tr_get_max_frames . 273. 274This function returns zero upon success. 275. 276Non-zero return values indicate a LIBUSB20_ERROR value. 277. 278.Pp 279. 280.Fn libusb20_tr_get_pointer 281will return a pointer to the allocated USB transfer according to the 282.Fa pdev 283and 284.Fa tr_index 285arguments. 286. 287This function returns NULL in case of failure. 288. 289.Pp 290. 291.Fn libusb20_tr_get_time_complete 292will return the completion time of an USB transfer in 293millisecond units. This function is most useful for isochronous USB 294transfers when doing echo cancelling. 295. 296.Pp 297. 298.Fn libusb20_tr_get_actual_frames 299will return the actual number of USB frames after an USB 300transfer completed. A value of zero means that no data was transferred. 301. 302.Pp 303. 304.Fn libusb20_tr_get_actual_length 305will return the sum of the actual length for all 306transferred USB frames for the given USB transfer. 307. 308.Pp 309. 310.Fn libusb20_tr_get_max_frames 311will return the maximum number of USB frames that were 312allocated when an USB transfer was setup for the given USB transfer. 313. 314.Pp 315. 316.Fn libusb20_tr_get_max_packet_length 317will return the maximum packet length in bytes 318associated with the given USB transfer. 319. 320The packet length can be used round up buffer sizes so that short USB 321packets are avoided for proxy buffers. 322. 323. 324.Pp 325. 326.Fn libusb20_tr_get_max_total_length 327function will return the maximum value for the data length sum of all USB 328frames associated with an USB transfer. 329In case of control transfers the value returned does not include the 330length of the SETUP packet, 8 bytes, which is part of frame zero. 331The returned value of this function is always aligned to the maximum 332packet size, wMaxPacketSize, of the endpoint which the USB transfer is 333bound to. 334. 335.Pp 336. 337.Fn libusb20_tr_get_status 338will return the status of an USB transfer. 339. 340Status values are defined by a set of LIBUSB20_TRANSFER_XXX enums. 341. 342.Pp 343. 344.Fn libusb20_tr_pending 345will return non-zero if the given USB transfer is 346pending for completion. 347. 348Else this function returns zero. 349. 350.Pp 351. 352.Fn libusb20_tr_callback_wrapper 353This is an internal function used to wrap asynchronous USB callbacks. 354. 355.Pp 356. 357.Fn libusb20_tr_clear_stall_sync 358This is an internal function used to synchronously clear the stall on 359the given USB transfer. 360. 361Please see the USB specification for more information on stall 362clearing. 363. 364If the given USB transfer is pending when this function is called, the 365USB transfer will complete with an error after that this function has 366been called. 367. 368.Pp 369. 370.Fn libusb20_tr_drain 371will stop the given USB transfer and will not return 372until the USB transfer has been stopped in hardware. 373. 374.Pp 375. 376.Fn libusb20_tr_set_buffer 377is used to set the 378.Fa buffer 379pointer for the given USB transfer and 380.Fa fr_index . 381. 382Typically the frame index is zero. 383. 384. 385.Pp 386. 387.Fn libusb20_tr_set_callback 388is used to set the USB callback for asynchronous USB 389transfers. 390. 391The callback type is defined by libusb20_tr_callback_t. 392. 393.Pp 394. 395.Fn libusb20_tr_set_flags 396is used to set various USB flags for the given USB transfer. 397.Bl -tag 398.It LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK 399Report a short frame as error. 400.It LIBUSB20_TRANSFER_MULTI_SHORT_NOT_OK 401Multiple short frames are not allowed. 402.It LIBUSB20_TRANSFER_FORCE_SHORT 403All transmitted frames are short terminated. 404.It LIBUSB20_TRANSFER_DO_CLEAR_STALL 405Will do a clear-stall before starting the transfer. 406.El 407. 408.Pp 409. 410.Fn libusb20_tr_get_length 411returns the length of the given USB frame by index. 412After an USB transfer is complete the USB frame length will get updated to the actual transferred length. 413. 414.Pp 415. 416.Fn libusb20_tr_set_length 417sets the length of the given USB frame by index. 418. 419.Pp 420. 421.Fn libusb20_tr_set_priv_sc0 422sets private driver pointer number zero. 423. 424.Pp 425. 426.Fn libusb20_tr_set_priv_sc1 427sets private driver pointer number one. 428. 429.Pp 430. 431.Fn libusb20_tr_set_timeout 432sets the timeout for the given USB transfer. 433. 434A timeout value of zero means no timeout. 435. 436The timeout is given in milliseconds. 437. 438.Pp 439. 440.Fn libusb20_tr_set_total_frames 441sets the total number of frames that should be executed when the USB transfer is submitted. 442. 443The total number of USB frames must be less than the maximum number of USB frames associated with the given USB transfer. 444. 445.Pp 446. 447.Fn libusb20_tr_setup_bulk 448is a helper function for setting up a single frame USB BULK transfer. 449. 450.Pp 451. 452.Fn libusb20_tr_setup_control 453is a helper function for setting up a single or dual 454frame USB CONTROL transfer depending on the control transfer length. 455. 456.Pp 457. 458.Fn libusb20_tr_setup_intr 459is a helper function for setting up a single frame USB INTERRUPT transfer. 460. 461.Pp 462. 463.Fn libusb20_tr_setup_isoc 464is a helper function for setting up a multi frame USB ISOCHRONOUS transfer. 465. 466.Pp 467. 468.Fn libusb20_tr_bulk_intr_sync 469will perform a synchronous BULK or INTERRUPT transfer having length given by the 470.Fa length 471argument and buffer pointer given by the 472.Fa pbuf 473argument on the USB transfer given by the 474.Fa xfer 475argument. 476. 477If the 478.Fa pactlen 479argument is non-NULL the actual transfer length will be stored at the given pointer destination. 480. 481If the 482.Fa timeout 483argument is non-zero the transfer will timeout after the given value in milliseconds. 484. 485This function does not change the transfer flags, like short packet not ok. 486. 487This function returns zero on success else a LIBUSB20_TRANSFER_XXX value is returned. 488. 489.Pp 490. 491.Fn libusb20_tr_start 492will get the USB transfer started, if not already 493started. 494. 495This function will not get the transfer queued in hardware. 496. 497This function is non-blocking. 498. 499.Pp 500. 501.Fn libusb20_tr_stop 502will get the USB transfer stopped, if not already stopped. 503. 504This function is non-blocking, which means that the actual stop can 505happen after the return of this function. 506. 507.Pp 508. 509.Fn libusb20_tr_submit 510will get the USB transfer queued in hardware. 511. 512. 513.Pp 514. 515.Fn libusb20_tr_get_priv_sc0 516returns private driver pointer number zero associated 517with an USB transfer. 518. 519. 520.Pp 521. 522.Fn libusb20_tr_get_priv_sc1 523returns private driver pointer number one associated 524with an USB transfer. 525. 526. 527.Sh USB DEVICE OPERATIONS 528. 529.Pp 530. 531.Fn libusb20_dev_get_backend_name 532returns a zero terminated string describing the backend used. 533. 534.Pp 535. 536.Fn libusb20_dev_get_info 537retrieves the BSD specific usb_device_info structure into the memory location given by 538.Fa pinfo . 539The USB device given by 540.Fa pdev 541must be opened before this function will succeed. 542This function returns zero on success else a LIBUSB20_ERROR value is returned. 543. 544.Pp 545. 546.Fn libusb20_dev_get_iface_desc 547retrieves the kernel interface description for the given USB 548.Fa iface_index . 549The format of the USB interface description is: "drivername<unit>: <description>" 550The description string is always zero terminated. 551A zero length string is written in case no driver is attached to the given interface. 552The USB device given by 553.Fa pdev 554must be opened before this function will succeed. 555This function returns zero on success else a LIBUSB20_ERROR value is returned. 556. 557.Pp 558. 559.Fn libusb20_dev_get_desc 560returns a zero terminated string describing the given USB device. 561The format of the string is: "drivername<unit>: <description>" 562. 563.Pp 564. 565.Fn libusb20_dev_close 566will close the given USB device. 567. 568This function returns zero on success else a LIBUSB20_ERROR value is 569returned. 570. 571.Pp 572. 573.Fn libusb20_dev_detach_kernel_driver 574will try to detach the kernel driver for the USB interface given by 575.Fa iface_index . 576. 577This function returns zero on success else a LIBUSB20_ERROR value is 578returned. 579. 580.Pp 581. 582.Fn libusb20_dev_set_config_index 583will try to set the configuration index on an USB 584device. 585. 586The first configuration index is zero. 587. 588The un-configure index is 255. 589. 590This function returns zero on success else a LIBUSB20_ERROR value is returned. 591. 592.Pp 593. 594.Fn libusb20_dev_get_debug 595returns the debug level of an USB device. 596. 597.Pp 598. 599.Fn libusb20_dev_get_fd 600returns the file descriptor of the given USB device. 601. 602A negative value is returned when no file descriptor is present. 603. 604The file descriptor can be used for polling purposes. 605. 606.Pp 607. 608.Fn libusb20_dev_kernel_driver_active 609returns a non-zero value if a kernel driver is active on 610the given USB interface. 611. 612Else zero is returned. 613. 614.Pp 615. 616.Fn libusb20_dev_open 617opens an USB device so that setting up USB transfers 618becomes possible. 619. 620The number of USB transfers can be zero which means only control 621transfers are allowed. 622. 623This function returns zero on success else a LIBUSB20_ERROR value is 624returned. 625. 626A return value of LIBUSB20_ERROR_BUSY means that the device is already 627opened. 628. 629.Pp 630. 631.Fn libusb20_dev_process 632is called to sync kernel USB transfers with userland USB 633transfers. 634. 635This function returns zero on success else a LIBUSB20_ERROR value is 636returned typically indicating that the given USB device has been 637detached. 638. 639.Pp 640. 641.Fn libusb20_dev_request_sync 642will perform a synchronous control request on the given 643USB device. 644. 645Before this call will succeed the USB device must be opened. 646. 647.Fa setup 648is a pointer to a decoded and host endian SETUP packet. 649.Fa data 650is a pointer to a data transfer buffer associated with the control transaction. This argument can be NULL. 651.Fa pactlen 652is a pointer to a variable that will hold the actual transfer length after the control transaction is complete. 653.Fa timeout 654is the transaction timeout given in milliseconds. 655A timeout of zero means no timeout. 656.Fa flags 657is used to specify transaction flags, for example LIBUSB20_TRANSFER_SINGLE_SHORT_NOT_OK. 658. 659This function returns zero on success else a LIBUSB20_ERROR value is 660returned. 661. 662.Pp 663. 664.Fn libusb20_dev_req_string_sync 665will synchronously request an USB string by language ID 666and string index into the given buffer limited by a maximum length. 667. 668This function returns zero on success else a LIBUSB20_ERROR value is 669returned. 670. 671.Pp 672. 673.Fn libusb20_dev_req_string_simple_sync 674will synchronously request an USB string using the 675default language ID and convert the string into ASCII before storing 676the string into the given buffer limited by a maximum length which 677includes the terminating zero. 678. 679This function returns zero on success else a LIBUSB20_ERROR value is 680returned. 681. 682. 683.Pp 684. 685.Fn libusb20_dev_reset 686will try to BUS reset the given USB device and restore 687the last set USB configuration. 688. 689This function returns zero on success else a LIBUSB20_ERROR value is 690returned. 691. 692. 693.Pp 694. 695.Fn libusb20_dev_check_connected 696will check if an opened USB device is still connected. 697. 698This function returns zero if the device is still connected else a LIBUSB20_ERROR value is returned. 699. 700. 701.Pp 702. 703.Fn libusb20_dev_set_power_mode 704sets the power mode of the USB device. 705. 706Valid power modes: 707.Bl -tag 708.It LIBUSB20_POWER_OFF 709.It LIBUSB20_POWER_ON 710.It LIBUSB20_POWER_SAVE 711.It LIBUSB20_POWER_SUSPEND 712.It LIBUSB20_POWER_RESUME 713.El 714. 715This function returns zero on success else a LIBUSB20_ERROR value is 716returned. 717. 718.Pp 719. 720.Fn libusb20_dev_get_power_mode 721returns the currently selected power mode for the given 722USB device. 723. 724.Pp 725. 726.Fn libusb20_dev_set_alt_index 727will try to set the given alternate index for the given 728USB interface index. 729. 730This function returns zero on success else a LIBUSB20_ERROR value is 731returned. 732. 733.Pp 734. 735.Fn libusb20_dev_get_device_desc 736returns a pointer to the decoded and host endian version 737of the device descriptor. 738. 739The USB device need not be opened when calling this function. 740. 741.Pp 742. 743.Fn libusb20_dev_alloc_config 744will read out and decode the USB config descriptor for 745the given USB device and config index. This function returns a pointer 746to the decoded configuration which must eventually be passed to 747free(). NULL is returned in case of failure. 748. 749.Pp 750. 751.Fn libusb20_dev_alloc 752is an internal function to allocate a new USB device. 753. 754.Pp 755. 756.Fn libusb20_dev_get_address 757returns the internal and not necessarily the real 758hardware address of the given USB device. 759. 760.Pp 761. 762.Fn libusb20_dev_get_bus_number 763returns the internal bus number which the given USB 764device belongs to. 765. 766.Pp 767. 768.Fn libusb20_dev_get_mode 769returns the current operation mode of the USB entity. 770. 771Valid return values are: 772.Bl -tag 773.It LIBUSB20_MODE_HOST 774.It LIBUSB20_MODE_DEVICE 775.El 776. 777.Pp 778. 779.Fn libusb20_dev_get_speed 780returns the current speed of the given USB device. 781. 782.Bl -tag 783.It LIBUSB20_SPEED_UNKNOWN 784.It LIBUSB20_SPEED_LOW 785.It LIBUSB20_SPEED_FULL 786.It LIBUSB20_SPEED_HIGH 787.It LIBUSB20_SPEED_VARIABLE 788.It LIBUSB20_SPEED_SUPER 789.El 790. 791.Pp 792. 793.Fn libusb20_dev_get_config_index 794This function returns the currently select config index for the given 795USB device. 796. 797.Pp 798. 799.Fn libusb20_dev_free 800will free the given USB device and all associated USB 801transfers. 802. 803.Pp 804. 805.Fn libusb20_dev_set_debug 806will set the debug level for the given USB device. 807. 808.Pp 809. 810.Fn libusb20_dev_wait_process 811function will wait until a pending USB transfer has completed on 812the given USB device. 813. 814A timeout value can be specified which is passed on to the 815.Xr poll 2 816function. 817. 818.Sh USB BACKEND OPERATIONS 819. 820.Fn libusb20_be_get_template 821will return the currently selected global USB device 822side mode template into the integer pointer 823.Fa ptemp . 824This function returns zero on success else a LIBUSB20_ERROR value is 825returned. 826. 827.Pp 828. 829.Fn libusb20_be_set_template 830will set the global USB device side mode template to 831.Fa temp . 832The new template is not activated until after the next USB 833enumeration. 834The template number decides how the USB device will present itself to 835the USB Host, like Mass Storage Device, USB Ethernet Device. Also see 836the 837.Xr usb2_template 4 838module. 839This function returns zero on success else a LIBUSB20_ERROR value is 840returned. 841. 842.Pp 843. 844.Fn libusb20_be_get_dev_quirk 845This function will return the device quirk according to 846.Fa index 847into the libusb20_quirk structure pointed to by 848.Fa pq . 849This function returns zero on success else a LIBUSB20_ERROR value is 850returned. 851. 852If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 853returned. 854. 855.Pp 856. 857.Fn libusb20_be_get_quirk_name 858will return the quirk name according to 859.Fa index 860into the libusb20_quirk structure pointed to by 861.Fa pq . 862This function returns zero on success else a LIBUSB20_ERROR value is 863returned. 864. 865If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 866returned. 867. 868.Pp 869. 870.Fn libusb20_be_add_dev_quirk 871will add the libusb20_quirk structure pointed to by the 872.Fa pq 873argument into the device quirk list. 874. 875This function returns zero on success else a LIBUSB20_ERROR value is 876returned. 877. 878If the given quirk cannot be added LIBUSB20_ERROR_NO_MEM is 879returned. 880. 881.Pp 882. 883.Fn libusb20_be_remove_dev_quirk 884will remove the quirk matching the libusb20_quirk structure pointed to by the 885.Fa pq 886argument from the device quirk list. 887. 888This function returns zero on success else a LIBUSB20_ERROR value is 889returned. 890. 891If the given quirk does not exist LIBUSB20_ERROR_NOT_FOUND is 892returned. 893. 894.Pp 895. 896.Fn libusb20_be_alloc_default 897.Fn libusb20_be_alloc_freebsd 898.Fn libusb20_be_alloc_linux 899These functions are used to allocate a specific USB backend or the 900operating system default USB backend. Allocating a backend is a way to 901scan for currently present USB devices. 902. 903.Pp 904. 905.Fn libusb20_be_device_foreach 906is used to iterate USB devices present in a USB backend. 907. 908The starting value of 909.Fa pdev 910is NULL. 911. 912This function returns the next USB device in the list. 913. 914If NULL is returned the end of the USB device list has been reached. 915. 916.Pp 917. 918.Fn libusb20_be_dequeue_device 919will dequeue the given USB device pointer from the 920backend USB device list. 921. 922Dequeued USB devices will not be freed when the backend is freed. 923. 924.Pp 925. 926.Fn libusb20_be_enqueue_device 927This function will enqueue the given USB device pointer in the backend USB device list. 928. 929Enqueued USB devices will get freed when the backend is freed. 930. 931.Pp 932. 933.Fn libusb20_be_free 934will free the given backend and all USB devices in its device list. 935. 936. 937.Sh USB DESCRIPTOR PARSING 938. 939.Fn libusb20_me_get_1 pie offset 940This function will return a byte at the given byte offset of a message 941entity. 942. 943This function is safe against invalid offsets. 944. 945.Pp 946. 947.Fn libusb20_me_get_2 pie offset 948This function will return a little endian 16-bit value at the given byte offset of a message 949entity. 950. 951This function is safe against invalid offsets. 952. 953.Pp 954. 955.Fn libusb20_me_encode pbuf len pdecoded 956This function will encode a so-called *DECODED structure into binary 957format. 958. 959The total encoded length that will fit in the given buffer is 960returned. 961. 962If the buffer pointer is NULL no data will be written to the buffer 963location. 964. 965.Pp 966. 967.Fn libusb20_me_decode pbuf len pdecoded 968This function will decode a binary structure into a so-called *DECODED 969structure. 970. 971The total decoded length is returned. 972. 973The buffer pointer cannot be NULL. 974. 975. 976.Sh FILES 977. 978. 979/dev/usb 980.Sh SEE ALSO 981.Xr usb 4 , 982.Xr libusb 3 , 983.Xr usbconfig 8 984. 985. 986.Sh HISTORY 987. 988. 989Some parts of the 990.Nm 991API derives from the libusb project at sourceforge. 992